FARA supports research through funding competitive grants, promoting collaboration among scientists, advocating for public-private partnerships that support drug discovery, drug development and clinical research and hosting open forums for leading scientists to share their insights, ideas and challenges to advancing treatments for FA.
In addition to General Research Grants, FARA offers named awards for projects fitting specific criteria: (1) Cardiac Research; (2) Translational Research; and (3) International Collaborative Research.
The proposed research must fall within FARA's Grant Program Priorities.
A Letter of Intent (LOI) is required for all applications.
All applications will be peer-reviewed and scored as described in the Review and Decision Process.
FARA will notify applicants as to whether or not their project will be funded, usually within two months of the submission deadline.
Grant Type | LOI Deadlines | Application Deadlines | Maximum Budget (in US dollars) |
---|---|---|---|
General Research Grant | Feb 1 & July 15 | April 1 & Sept 15 | $150,000 per year for 1 or 2 years |
Keith Michael Andrus Cardiac Research Award | January 15 | March 1 | $150,000 per year for 1 or 2 years |
Kyle Bryant Translational Research Award | May 15 | July 15 | $250,000 per year for 1 or 2 years |
Bronya J. Keats International Research Collaboration Award | May 15 | July 15 | $200,000 per year for 1 or 2 years |
A Letter of Intent (LOI) is required for all grant applications and must be submitted as one PDF file containing the following information:
1) A brief description of the objectives and rationale for the project (one page);
2) Key preliminary data (up to 4 pages);
3) An estimate of the budget;
4) CV/biosketch for Principal Investigator (including contact information).
Submit this PDF file via email to grants@curefa.org. In the subject line put LOI and the grant type (e.g., LOI General Research Grant).
Each LOI is reviewed by the FARA Scientific Research Committee and, based on the outcome of this review, the applicant will be either invited to submit a full application or informed that the LOI is declined. This decision will usually be made within two weeks of receipt of the LOI.
LOIs are accepted from for-profit organizations, non-profit organizations, public or private institutions, and foreign institutions.
- Advance understanding of neuroscience / neuro systems - understanding the neurodegeneration of FA and implications for therapies
- Advance drug discovery
- Highest priority in this category will be given to genetic, epigenetic and protein approaches that target increasing frataxin levels
- Facilitate the drug development process and translational research so that the most promising discoveries are rapidly brought to treatment trials
- Highest priority in this category will be given to IND-enabling studies, biomarker discovery and validation, early phase or pilot clinical studies
- Advance clinical research - natural history, discovery and validation of clinical outcome measures and/or biomarkers, identification of early (including pre-symptomatic) quantifiable clinical features, patient reported outcomes, investigator-initiated clinical trials, or evidence-based clinical treatment guidelines
- Highest priority in this category will be given to clinical research that utilizes or expands resources of the Collaborative Clinical Research Network in FA
- Reduce the morbidity and mortality caused by cardiac disease in FA
LOIs and invited grant applications must meet the specified deadlines. Exceptions are made only for projects of high priority to FARA. With compelling justification for special consideration, investigators with high-priority projects may submit LOIs throughout the year and may also have a budget greater than $150,000 per year. Please submit all special consideration requests and LOIs via email, grants@curefa.org.
Occasionally FARA may issue Requests For Proposals (RFPs) targeting a high priority research area. Each RFP will have its own specific deadline and budget limit.
FARA funds only direct costs. Indirect costs will not be awarded.
Grant awards are made in one-year allocations. As stipulated in the contractual agreement with FARA, satisfactory progress reports (following the instructions under Reporting Requirements) must be received before FARA will provide funds for the second year of a 2-year project.
All unused funds at the end each year must be returned to FARA. In exceptional circumstances, FARA may approve a Request for a No-Cost Extension.
FARA reserves the right to terminate any grant award for inadequate progress, failure to submit reports, deviation in scope of the original research, and/or changes in FARA funding priorities. If an award is terminated, all unused funds must be returned to FARA.
Growing and developing the FA research community is a priority for FARA. As such, FARA encourages applications from junior investigators and young clinicians. FARA does not explicitly award junior investigator or training grants, but encourages early-stage researchers to apply through FARA grants appropriate for the type of research proposed. FARA reviewers take into account the investigator's career stage and will review the grant with this in mind. It is also encouraged for junior investigators to submit a personal statement describing their current position and plans for the future as it relates to FA research, and letters of support from mentors are highly encouraged. If junior investigators would like support through the application process or general advice on grant writing, they may contact jane.larkindale@curefa.org.
FARA will accept grant submissions from industry partners who have a demonstrated participation in the FA research community and are advancing therapeutic candidates for FA.
FARA requires that a Letter of Intent (LOI) be submitted prior to the submission of a grant proposal. All projects/requests should be:
- Directly related to advancing a therapeutic candidate closer to clinic, and/or
- Addressing an FA-specific issue that could be of benefit to the entire field, such as biomarker validation or mechanism of action.
FARA will also accept proposals for direct patient-related expenses for clinical studies.
All applications must be submitted using FARA's Research Portfolio Management Program - curefa.net/rpmp. All information requested on the Main Grant Page must be provided before a submission is accepted. This includes a lay summary of the project, budget and a timeline with detailed milestones. The project description, CV/biosketch of each of the key investigators, letters of support, and other relevant documents must be submitted as PDF files.
Project Description
The description of the project (excluding references to literature) should not exceed 10 pages. This includes the specific aims, background, preliminary data, and research plan.
Budget
A detailed budget must be submitted with all proposals, including a justification of all requested expenses. Allowable expenses are: personnel costs/salary with fringe benefits, laboratory reagents and supplies, equipment, animal expenses, publication costs, patient expenses directly related to study and not reimbursable by third party insurers, and patient travel. Expenses that will not be awarded include: indirect costs/overhead, investigator travel to meetings and conferences, memberships in scientific societies.
Milestones
All projects must have objective milestones that are clearly communicated. We appreciate that some projects, especially those that are more basic-science oriented, might need to have milestone adjustments based on specific experimental outcomes. If the proposal is funded, FARA will utilize the proposed milestones for scheduling progress reports and monitoring the project.
Human Subjects
If human subjects are used in the proposed study, the study must be approved by the Institutional Review Board (IRB) or equivalent. Full funding will not be provided until proof of IRB approval is demonstrated to FARA. Human subjects studied in the course of research conducted under a grant are under no circumstances a responsibility of FARA.
Animal Research
If animals are used, the proposed study must be approved by the Institutional Animal Care and Use Committee (IACUC), or equivalent, indicating that appropriate precautions have been taken to assure that proper treatment, care and humane conditions are provided.
Grant Information




Suppressing the iron/sphingolipid/PDK/Mef2 pathway implicated in FA for therapeutic evaluation

Award type: General Research Grant
Grant Title: Suppressing the iron/sphingolipid/PDK/Mef2 pathway implicated in FA for therapeutic evaluation
Lay summary: Friedreich's ataxia (FRDA), is an inherited ataxia with an incidence of 1 in 50,000 worldwide (1-2). Most FRDA patients carry trinucleotide repeat expansions in both alleles of Frataxin (FXN). FXN is evolutionarily conserved, with a similar gene version in other animal species, including yeast, plants, and fruit flies (3). My lab studies the fruit fly frataxin gene (fh) in photoreceptors (PRs) of the fruit fly eye. We identified a loss of function mutation in the fh gene that results in late-pupal lethality in a forward genetic screen designed to isolate mutations that cause neurodegeneration. We discovered that loss of fh causes a rapid functional and morphological loss of PR in mutant eye clones. Additionally, we observed an elevation of iron (i.e., Fe2+ and Fe3+) in numerous tissues in fh mutants. This accumulation of Fe activates sphingolipid synthesis—lipid molecules that serve to promote certain cellular signals within a cell. Activation of sphingolipid synthesis in turn triggered the PDK1/ Mef2 signaling pathway, a pathway that is required in muscles during development (4). Over activation of the sphingolipid activated PDK1/Mef2 pathway causes the demise of neurons and leads to the enhanced transcription of muscle genes in many tissues. When we reduce iron toxicity, suppress sphingolipid biosynthesis, or decrease PDK1 or Mef2 levels, we can delay neurodegeneration in fh mutant cells. Similarly, mice engineered to have reduced expression of FXN in the brain, have a reduced lifespan (4 months instead of 2 years), display a severe neurodegenerative phenotype, exhibit iron accumulation and show an activation of PDK1/Mef2 pathway. Interestingly, hearts of FRDA patients exhibit an iron accumulation and increased PDK1/Mef2 signaling. In the heart, activation of the Mef2 pathway may underlie the observed cardiac hypertrophy, unlike what is observed in neurons. Indeed, overexpression of Mef2 isoforms in the heart has been shown to cause a cardiac hypertrophy. These data suggest that the iron/sphingolipid/PDK1/Mef2 pathway may play an important role in the pathogenesis of FRDA and provide an avenue to attenuate or delay symptoms in patients as the pathway is evolutionarily conserved in mammals (5).
Co-Sponsor: Cure FA Foundation
Lay abstract references
- Cossee M, Schmitt M, Campuzano V, Reutenauer L, Moutou C, Mandel JL, Koenig M. (1997) "Evolution of the Friedreich's ataxia trinucleotide repeat expansion: founder effect and premutations." Proc Natl Acad Sci U S A. 94(14):7452-7.
- Delatycki MB, Corben LA. (2012) "Clinical features of Friedreich ataxia." J Child Neurol. 27(9):1133-7.
- Bencze KZ, Kondapalli KC, Cook JD, McMahon S, Millán-Pacheco C, Pastor N, Stemmler TL. (2006) "The structure and function of frataxin." Crit Rev Biochem Mol Biol. 41(5):269-91.
- Chen K, Lin G, Haelterman NA, Ho TS, Li T, Li Z, Duraine L, Graham BH, Jaiswal M, Yamamoto S, Rasband MN, Bellen HJ. (2016a) "Loss of Frataxin induces iron toxicity, sphingolipid synthesis, and Pdk1/Mef2 activation, leading to neurodegeneration." eLife 5:e16043.
- Chen K, Ho TS, Lin G, Tan KL, Rasband MN, Bellen HJ. (2016b) "Loss of Frataxin activates the iron/sphingolipid/PDK1/Mef2 pathway in mammals." eLife 5:e20732.
Development of Oligonucleotide Activators of FXN Expression

Award type: General Research Grant
Grant Title: Development of Oligonucleotide Activators of FXN Expression
Lay summary: Friedreich's ataxia (FRDA) is an incurable genetic disorder caused by reduced expression of the mitochondrial protein frataxin (FXN). Agents that increase expression of FXN would correct the disease-causing defect and are a promising approach to therapy. FRDA patients have an expanded GAA repeat region within intron one of FXN and this expanded repeat causes transcriptional silencing by a mechanism that has yet to be definitively described. We designed duplex RNAs and single stranded locked nucleic acid (LNA) oligonucleotides (short man-made strands of DNA) to recognize the repeat region and interfere with contacts that contribute to decreased transcription. We found that both duplex RNAs and LNA oligonucleotides caused increased expression of FXN protein in cells derived from FRDA patients. The increase in FXN expression was similar to the level found in normal cells. Both duplex RNAs and LNA oligonucleotides belong to classes of molecule that are being developed clinical. The combination of our promising initial results with experience using similar models in clinical trials suggests a path towards clinical translation towards treatment of FRDA. We now report extending this research to testing more compounds in more cells. Our findings extend the generality of our approach and provide a broader database for evaluating how to move forward with drug discovery.
Publications
- Liu J, Hu J, Ludlow AT, Pham JT, Shay JW, Rothstein JD, Corey DR. (2017) "c9orf72 Disease-Related Foci Are Each Composed of One Mutant Expanded Repeat RNA." Cell Chem Biol. 24: 141-148.
- Matsui M and Corey DR. (2016) "Noncoding RNAs as drug targets." Nature Rev. Drug. Discov. 16: 167-179.
Identification of FXN-increasing drug targets by CRISPR-mediated mutagenesis

Award type: General Research Grant
Grant Title: Identification of FXN-increasing drug targets by CRISPR-mediated mutagenesis
Lay summary: Currently, there is no disease-modifying treatment for Friedreich's ataxia (FRDA), a progressive neurodegenerative disease caused by low cellular levels of frataxin protein (FXN). Although a few therapeutic strategies are currently being explored, to design effective therapies for FRDA it is important to identify genes involved in the regulation of FXN levels (FXN level modifiers) since this could lead to the development of effective FXN up-regulating strategies. Identification of novel FXN level modifiers can be efficiently achieved by performing high-throughput functional screens using genome-wide mutagenesis. Here, we propose an unbiased screen to identify FXN level modifiers using the CRISPR-Cas9 technology, a recently established genome-editing tool which has gained considerable interest in the scientific community for its ability to provide specific and bi-allelic genomic disruptions at high efficiency. We will use the CRISPR-Cas9 technology to induce genome-wide mutagenesis and we will assess the effect of specific genome disruptions on FXN levels. This will be achieved by transducing two FRDA cell models with a lentiviral library of single-guide RNAs and by analysing changes in FXN protein levels, using flow cytometry. Cells with increased FXN protein expression will be isolated by Fluorescence-Activated Cell Sorting (FACS) and sequenced to identify the mutated genes responsible for the increase in FXN expression. Once we have identified novel targets, we will assess their ability to rescue the molecular hallmarks characteristic of FRDA on a series of in vitro FRDA models and assays. To the best of our knowledge this approach is novel in FRDA. Other groups are developing target identification screens for FRDA, however these are focused on the use of the RNAi technology, which presents important limitations such as off-target effects and partial target knockdown, which can ultimately decrease the efficiency of a screen. The CRISPR- Cas9 method has already shown to overcome the limitations associated with the use of RNAi. We believe that the experiments proposed in this application have the potential to identify novel therapeutic targets for FRDA as well as provide a better understanding of the regulation of FXN protein levels.
Co-sponsor: Pfizer and Ataxia UK
Publications
- Lufino MMP, Silva AM, Németh AH, Alegre-Abarrategui J, Russell AJ, Wade-Martins R. (2013) "A GAA repeat expansion reporter model of Friedreich's ataxia recapitulates the genomic context and allows rapid screening of therapeutic compounds." Human Molecular Genetics. 22: 5173-5187.
- Silva AM, Brown JM, Buckle VJ, Wade-Martins R and Lufino MMP. (2015) "Expanded GAA repeats impair FXN gene expression and reposition the FXN locus to the nuclear lamina in single cells." Human Molecular Genetics; 24:3457-71.
Drug rescue of frataxin-dependent neural and cardiac pathophysiology in FA models

PI/Investigator: Paola Giunti, MD/PhD - University College London, UK
PI/Investigator: Mark Pook, PhD - Brunel University London, UK
Award type: 2016-2017 Bronya J. Keats International Collaboration Award
Grant Title: Drug rescue of frataxin-dependent neural and cardiac pathophysiology in FA models
Lay summary: Our overall project objectives are to test seven known drugs that have been through clinical trials in humans for their ability to increase frataxin and improve mitochondrial function in the context of frataxin deficiency in vitro and in vivo, to determine the most potent as single drugs and as mixtures on a common platform. This will facilitate the identification of potent single drugs on a common platform and the identification of the most effective cocktails, both of which could speed clinical development. The hypothesis is that by using drugs that reverse multiple levels of FA pathophysiology, an additive or synergistic benefit will be obtained in terms of mitochondrial function and clinical benefit. Three functional categories of protective compounds have been identified, including those that 1) increase frataxin expression, 2) increase mitochondrial number or function or both, and 3) those that increase mitochondrial iron-sulfur cluster biogenesis. The goal of the project is to identify the most potent in each category, and to determine whether mixtures have additive effect on overall mitochondrial function and benefit in a relevant mouse model.
Co-Sponsor: FARA Ireland
A therapeutic strategy for Friedreich's ataxia: Frataxin bypass by enhancing the mitochondrial cysteine desulferase activity

Award type: General Research Grant
Grant Title: A therapeutic strategy for Friedreich's ataxia: Frataxin bypass by enhancing the mitochondrial cysteine desulferase activity
Lay summary: Friedreich's ataxia is an inherited neurodegenerative disease caused by deficiency of a mitochondrial protein, frataxin. Frataxin plays an essential role in iron-sulfur (Fe-S) cluster synthesis in mitochondria, a process critical for maintaining cellular energy generation. Frataxin acts in concert with cysteine desulfurase NFS1, scaffold protein ISCU, and accessory protein ISD11 to form a complex that enables biosynthesis of the Fe-S clusters. NFS1 removes the sulfur group from the amino acid cysteine to donate to the nascent Fe-S cluster. Frataxin is thought to contribute iron to the nascent Fe-S cluster. An additional activity of frataxin is to stimulate the cysteine desulferase activity of NFS1. Recently, our group discovered a mutation in the yeast ISCU, Isu1 M107I, that stimulates cysteine desulfurase and supports Fe-S cluster assembly in vivo in the absence of yeast frataxin. Indeed, we find that the corresponding human ISCU M106I mutant protein functions equivalently to the yeast protein, bypassing the need for frataxin to enable Fe-S cluster biosynthesis in yeast. Taken together, we predict that an ideal drug for Friedreich's ataxia could be a frataxin mimetic that can stimulate the NFS1 cysteine desulfurase in the absence of frataxin. The two specific aims of the proposal are: 1) to screen compounds and peptides that enhance substrate binding to purified NFS1 and 2) to test these compounds or peptides for their ability to stimulate Nfs1-bound persulfide formation in a yeast mitochondrial lysate. The features of the frataxin bypassing Isu1/ISCU provide proof-of-principle for the possibility of enhancing mitochondrial Fe-S cluster assembly without frataxin. If a subtly altered ISCU scaffold protein can stimulate NFS1 cysteine desulfurase and enhance Fe-S cluster assembly without frataxin being present, then a drug or therapeutic should be able to create a similar effect and serve as a substitute for frataxin. Previous drug screens and therapeutic approaches have sought to increase frataxin levels in patients (e.g. erythropoietin mimetics, tat-frataxin, histone deacetylase inhibitors) or to mitigate toxic cellular phenotypes (e.g. iron chelation, mitochondrial free radical scavengers). Both approaches make eminent sense, but they have not been successful yet, and the completely different approach of frataxin bypass could yield important dividends.
Publications
- Pandey A, Gordon DM, Pain J, Stemmler TL, Dancis A, and Pain D. (2013) "Frataxin directly stimulates mitochondrial cysteine desulfurase by exposing substrate-binding sites and a mutant Fe-S cluster scaffold protein with frataxin-bypassing ability acts similarly." J Biol Chem. 288:36773-36786.
- Yoon H, Golla R, Lesuisse E, Pain J, Donald JE, Lyver ER, Pain D, and Dancis A. (2012) "Mutation in the Fe-S scaffold protein Isu bypasses frataxin deletion." Biochem J. 441:473-480.
- Yoon H, Knight SA, Pandey A, Pain J, Zhang Y, Pain D, and Dancis A. (2014) "Frataxin -bypassing Isu1: characterization of the bypass activity in cells and mitochondria." Biochem J. 459:71-81.
Methylene Blue Derivatives Enhance Mitochondrial Function and Increase Frataxin Levels in a Cellular Model of Friedreich's Ataxia

Award type: General Research Grant
Grant Title: Methylene Blue Derivatives Enhance Mitochondrial Function and Increase Frataxin Levels in a Cellular Model of Friedreich's Ataxia
Lay summary: Friedreich's ataxia (FRDA) is a hereditary neurodegenerative disease for which no effective therapy is currently available. It results from reduced frataxin expression. Compounds targeting the various biochemical consequences of FRDA or aiming to increase frataxin levels may prove to be effective therapeutics. This proposal focuses on modifying and repurposing an existing FDA-approved drug, methylene blue (MB), that can act as an alternative electron carrier, thereby bypassing mitochondrial complexes I-III. This should increase mitochondrial biogenesis (by increasing the NAD+/NADH ratio) and compensate for mitochondrial dysfunction, as well as increasing the amount of frataxin in cultured FRDA ataxia lymphocytes. Methylene blue has been shown to rescue heart defects in a drosophila model of FRDA ataxia [1]. Preliminary data from our Center suggests that methylene blue analogues function as metabolic enhancers by acting as SIRT3 activators; also that they may act indirectly to increase frataxin expression, as we and others have shown in FRDA lymphocytes [2]. By the synthesis and characterization of new methylene blue analogues, we will define the Structure-Activity Relationships (SAR) in this structural class, and we will investigate the mechanisms of action in the context of published studies. Our goal is to identify 2-3 analogues with potent activity in cell- based assays, having minimal toxicity and acceptable physical and pharmacokinetic properties (e.g., solubility, blood-brain-barrier permeability, metabolic stability). These will enable testing in FRDA animal models and inform subsequent efforts to identify compounds suitable for preclinical development.
Lay abstract references
- Tricoire H, Palandri A, Bourdais A, Camadro JM and Monnier V. (2013) "Methylene blue rescues heart defects in a Drosophila model of Friedreich's ataxia." Hum. Mol. Genet. 23:968-979.
- Sahdeo S, Scott BD, McMackin MZ, Jasoliya M, Brown B, Wulff H, Perlman SL, Pook MA and Cortopassi GA. (2014) "Dyclonine rescues frataxin deficiency in animal models and buccal cells of patients with Friedreich's ataxia." Hum. Mol. Genet. 23:6848-6862.
- Roy Chowdhury S, Khdour OM, Bandyopadhyay I, and Hecht SM. (2017) "Lipophilic methylene violet analogues as modulators of mitochondrial function and dysfunction." Bioorg. Med. Chem. 25:5537-5547.
- Mastroeni D, Khdour OM, Delvaux E, Nolz J, Olsen G, Berchtold N, Cotman C, Hecht SM, and Coleman PD. (2016) "Nuclear but not mitochondrial-encoded OXPHOS genes are altered in aging, mild cognitive impairment, and Alzheimer's disease." Alzheimers Dement. S1552-5260:32932-6.
- Chevalier A, Zhang Y, Khdour OM, Kaye JB, and Hecht SM. (2016) "Mitochondrial Nitroreductase Activity Enables Selective Imaging and Therapeutic Targeting." JACS. 138:12009-12012.
Systematic Identification of Pharmacological Activators of the Repressed FXN Gene to Treat Friedreich Ataxia

Award type: General Research Grant
Grant Title: Systematic Identification of Pharmacological Activators of the Repressed FXN Gene to Treat Friedreich Ataxia
Lay summary: Friedreich ataxia (FA) is an autosomal recessive disease characterized by progressive damage to the nervous system and severe cardiac abnormalities. The disease is caused by a GAA•TTC triplet repeat expansion in the first intron of the FXN gene (hereafter called the triplet repeat expansion (TRE)-FXN gene), which represses FXN transcription. The FXN gene encodes a protein called frataxin, a ubiquitous, nuclear-encoded mitochondrial protein that plays a key role in iron metabolism. FXN repression results in reduced levels of frataxin, leading to mitochondrial dysfunction, which is the underlying basis of the disease. Currently there are no effective treatments for FA. Reactivation of the repressed TRE-FXN gene is a potential therapeutic approach for FA that would correct the root cause of the disease rather than a secondary, downstream consequence of the frataxin deficiency. We hypothesize that there are a number of epigenetic repressors whose pharmacological inhibition will lead to upregulated transcription of the TRE-FXN gene, resulting in increased frataxin levels and decreased disease symptomatology. As proof-of-concept, we performed a small-scale candidate-based RNA interference (RNAi) screen, which identified 10 epigenetic regulators of the TRE-FXN gene; for convenience we refer to these epigenetic regulators as FXN Repressing Factors (FXN-RFs). We then showed that small molecule inhibitors of these FXN-RFs can also upregulate transcription of the TRE-FXN gene. Our preliminary results strongly support the feasibility of our approach for identifying small molecule FXN-RF inhibitors that upregulate TRE-FXN transcription. Experiments in this application are focused on the discovery of new small molecule FXN-RF inhibitors, and determination of whether transcriptional upregulation of TRE-FXN can correct well-characterized mitochondrial abnormalities in FA neurons and cardiomyocytes, which are the cell types most relevant to FA. The results of the proposed cell-based experiments will identify the most efficacious, least cytotoxic compounds that in future studies can be analyzed in FA mouse models. In the long-term, the results of our study are likely to have a major impact on the field of FA therapeutics and have the potential to lead to development of a new class of drugs that can ameliorate this devastating disease.
Co-sponsor: FARA Ireland
Publications
- Gazin C, Wajapeyee N, Gobeil S, Virbasius CM, and Green MR. (2007) "An elaborate pathway required for Ras-mediated epigenetic silencing." Nature. 449:1073-7.
- Wajapeyee N, Malonia SK, Palakurthy RK, and Green MR. (2013) "Oncogenic RAS directs silencing of tumor suppressor genes through ordered recruitment of transcriptional repressors." Genes Dev. 27:2221-6.
- Serra RW, Fang M, Park SM, Hutchinson L, and Green MR. (2014) "A KRAS-directed transcriptional silencing pathway that mediates the CpG island methylator phenotype." Elife. 3:e02313.
- Fang M, Ou J, Hutchinson L, and Green MR. (2014) "The BRAF oncoprotein functions through the transcriptional repressor MAFG to mediate the CpG island methylator phenotype." Mol Cell. 55:904-15.
- Bhatnagar S, Zhu X, Ou J, Lin L, Chamberlain L, Zhu LJ, Wajapeyee N, and Green MR. (2014) "Genetic and pharmacological reactivation of the mammalian inactive X chromosome." Proc Natl Acad Sci U S A. 111:12591-8.
Chromatin structure, function and hierarchy of frataxin in FA

Award type: General Research Grant - Postdoctoral Fellowship
Grant Title: Chromatin structure, function and hierarchy of frataxin in FA
Lay summary: This postdoctoral fellowship is an extension of my graduate studies work supported by FARA, which focused on epigenetic editing of the frataxin gene as a novel therapeutic approach for FA. Frataxin (FXN) gene silencing is the result of an abnormal trinucleotide (i.e., GAA) expansion within intron 1 of the FXN gene. This has been shown to result in an abnormal epigenomic environment within the frataxin gene locus. Although several components have been implicated in the establishment of this environment—from aberrant histone and DNA methylation, heterochromatin and R-loop formation and antisense transcription—the direct causality of each of these factors and its relevance to FXN gene silencing remains elusive. Specifically, it remains to be determined the relative importance of each of these factors with respect to different frataxin gene locus elements, such as the promoter region and the regions upstream and/or downstream of the GAA repeats. With the advent of RNA guided endonuclease technology (CRISPR), I intend to interrogate these factors directly at the frataxin locus. These include studies to interrogate the lysine methyltransferases, which I studied in during my graduate tenure. I showed that one such enzyme specifically silenced the FXN gene, supporting the notion that attenuation of its activity may provide a potential therapeutic avenue to de-repress FXN silencing. Additional FXN regulatory targets I will interrogate include the histone modifications H3K9me3 and H3K27me3, which have been found to be associated with the pathologically silenced FXN in FA. I have developed histone-mutant peptides that may provide the basis for small-molecule method of alleviating both silencing histone modifications. Furthermore, I am using the CRISPR/Cas9 technology to manipulate the expression of these histone modifications to establish a hierarchy of histone post-translational modifications involved in pathologically silencing the FXN locus. These studies will not only provide insight into the mechanism of aberrant FXN silencing but might also lead to a novel and radical therapeutic approach for FRDA and potentially other epigenetically regulated disorders.
Publications
- Nageshwaran S, Festenstein R. (2015) "Epigenetics and Triplet-Repeat Neurological Diseases." Front Neurol. 6:262.
- Natisvili T, Yandim C, Silva R, Emanuelli G, Krueger F, Nageshwaran S, Festenstein R. (2016) "Transcriptional Activation of Pericentromeric Satellite Repeats and Disruption of Centromeric Clustering upon Proteasome Inhibition." PLoS One. 11:e0165873.
Identification of the mechanism of oxidant-mediated Yfh1/frataxin turnover and screen for compounds that suppress the effects of reduced Yfh1/frataxin levels

Award type: General Research Grant
Grant Title: Identification of the mechanism of oxidant-mediated Yfh1/frataxin turnover and screen for compounds that suppress the effects of reduced Yfh1/frataxin levels
Lay summary: Friedreich ataxia (FRDA) is a lethal human disorder resulting from mutations in the FXN gene, which give rise to decreased levels of the frataxin protein. The frataxin protein is targeted to the mitochondrial matrix where it plays a critical role in the synthesis of mitochondrial iron-sulfur (Fe-S) clusters. These clusters are essential prosthetic groups involved in oxygen binding and enzymatic activity. Frataxin, like many of the proteins involved in mitochondrial Fe-S cluster synthesis is highly conserved among eukaryotes. The yeast gene YFH1, encodes for the homologue of mammalian frataxin. Loss of YFH1 in yeast results in increased mitochondrial oxidants, increased mitochondrial iron accumulation and decreased Fe-S cluster synthesis. Importantly, overexpression of the human frataxin in yeast complements the loss of Yfh1 and corrects these phenotypes. As such, we utilize yeast as a model system to study FRDA and iron metabolism because of the conserved cellular function and relative ease of genetic manipulation. Using yeast, we discovered that mutation of a yeast gene ERG29 results in defective sterol synthesis, leading to increased levels of sterol intermediates. We found that these intermediates interact with iron generating mitochondrial oxidants, and that the increased mitochondrial oxidants resulted in the loss of Yfh1. Mutant ERG29-induced loss of Yfh1 led to decreased Fe-S cluster synthesis, and ultimately cell death due to decreased mitochondrial respiratory activity. The finding that mitochondrial oxidants affect Fe-S cluster activity through decreased frataxin is not restricted to yeast or to sterol intermediates (1). Together, these results support the hypothesis that conditions that increase mitochondrial oxidants will result in frataxin/Yfh1 degradation. Based on these findings, we propose to determine the mechanism of oxidant-induced loss of frataxin/Yfh1. We will also take advantage of the strong phenotype of Yfh1 and Erg29 knockdown in yeast to screen for compounds that can suppress the effects of loss of Yfh1. Determining the mechanism of how increased mitochondrial oxidants and iron affect frataxin/Yfh1 stability and identifying compounds that suppress the effects of reduced frataxin/Yfh1 levels will guide in identifying efficacious treatments for FRDA and may possibly provide novel treatments for human diseases in which mitochondrial function is compromised.
Lay abstract references
- Mouli, S., Nanayakkara, G., AlAlasmari, A., Eldoumani, H., Fu, X., Berlin, A., Lohani, M., Nie, B., Arnold, R. D., Kavazis, A., Smith, F., Beyers, R., Denney, T., Dhanasekaran, M., Zhong, J., Quindry, J. and Amin, R. (2015) "The role of frataxin in doxorubicin-mediated cardiac hypertrophy." Am J Physiol Heart Circ Physiol. 309:H844-859.
- Li, L., Kaplan, J. and Ward, D. M. (2017) "The glucose sensor Snf1 and the transcription factors Msn2 and Msn4 regulate transcription of the vacuolar iron importer gene CCC1 and iron resistance in yeast." J Biol Chem. 292:15577-15586.
- Seguin, A, Takahashi-Makise, N, Yien, YY, Huston, NC, Musso, G, Wallace, JA, Bradley, T, Bergonia, H, Matsumoto, M, Igarashi, K, Phillips, JD, Paw, BH, Kaplan, J and Ward, DM. (2017)
- "Reductions in Abcb10 affect the heme biosynthesis transcriptional profile". J. Biol. Chem. 292:16284-16299.
- Yaish, HM, Farrell, CP, Christensen, RD, MacQueen, BC, Jackson, LK, Trochez-Enciso, J, Kaplan, J, Ward, DM, Salah WK and Phillips, JD. (2017) "Two novel mutations in TMPRSS6 associated with iron-refractory iron deficiency anemia in a mother and child." Blood Cells Mol. Dis. 65:38-40. PMID: 28460265.
Evaluation of Amylyx Pharmaceutical's AM0035, a combination of tauroursodeoxycholic acid and sodium phenylbutyrate, in FRDA models

PI/Investigator: Hong Lin, PhD - in the laboratory of David Lynch, MD, PhD at Penn and CHOP
Award type: General Research Grant
Grant Title: Evaluation of Amylyx Pharmaceutical's AM0035, a combination of tauroursodeoxycholic acid and sodium phenylbutyrate, in FRDA models
Lay summary: Amylyx Pharmaceuticals has developed a novel therapeutic, AMX0035, a combination of two compounds, Sodium Phenylbutyrate (PB) and Tauroursodeoxycholic Acid (TUDCA), for the treatment of neurodegenerative disease. Amylyx discovered a synergy between these two compounds across multiple preclinical models when administered together in a specific range of doses. AMX0035 has demonstrated synergistic efficacy in models of neurodegeneration, oxidative insult, classical activation of neuro-inflammation, and bioenergetics deficits, through the combined targeting of pathways of mitochondrial dysfunction (ROS production, caspase-dependent apoptosis, mitochondrial channel formation) and ER stress. We hypothesize that reducing mitochondrial stress pathways whilst simultaneously increasing chaperone protein production could synergistically increase cellular viability in response to oxidative insults and provide an effective therapy for Friedreich's ataxia (FRDA) patients. Amylyx received FDA clearance for AMX0035's Investigational New Drug (IND) application in April 2017. Furthermore, Amylyx initiated a Phase II trial evaluating the safety and efficacy of AMX0035 in ALS patients in mid-2017 and expects to initiate a Phase II trial evaluating AMX0035 in Alzheimer's in early 2018. Taken together, Amylyx is excited and primed to explore therapeutic potential of AMX0035 in FRDA. In collaboration with Dr. Marek Napierala at the University of Alabama, Birmingham, we tested AMX0035 in FRDA patient-derived fibroblasts. We found that AMX0035 promotes cell viability, including protecting frataxin-deficient cells from metabolic stresses, potentially through a mitochondrial-targeted mechanism of action. With this FARA grant, we will continue studies to characterize the mitochondrial effects of AMX0035 in FRDA patient-derived fibroblasts. Working alongside Drs. David Lynch and Hong Lin at the Children's Hospital of Philadelphia, we will evaluate the target effects of AMX0035 in the KIKO FRDA mouse model. Here we plan to assess the early signals of mitochondrial biogenesis target engagement in vivo, as well as confirm the presence and blood-brain barrier permeability of AMX0035. Furthermore, we will evaluate the neurosensory, biochemical, and functional effects of AMX0035 in the KIKO FRDA mouse model. These industry-academia collaborations enable us to streamline the process of evaluating AMX0035 in translatable models of FA, with the potential to guide clinical drug development. These continued studies will build upon the preliminary efficacy data of AMX0035 in models of FRDA and will advance our understanding of the role of mitochondrial dysfunction in disease pathology.
Elucidating the mechanism by which synthetic molecules stimulate Frataxin in Friedreich's ataxia

Award type: General Research Grant
Grant Title: Elucidating the mechanism by which synthetic molecules stimulate Frataxin in Friedreich's ataxia
Lay summary: Over the years, several therapeutic routes have been explored to treat Friedreich's ataxia (FA/FRDA). An ideal therapeutic strategy is to target the mechanistic root of the disease — the massive increase in number of GAA trinucleotide repeats in the frataxin gene (FXN) of FA patients. The expanded repeats block the ability of the cellular machinery to synthesize (transcribe) frataxin RNA which in turn leads to a deficiency in levels of frataxin – a protein that is essential for the optimal functioning of mitochondria, the cell's powerhouse. The extent of this trinucleotide repeat "expansion" correlates with the severity and onset of the disease. While new advances in CRISPR-based genome engineering methods have enormous potential to target the GAA repeat expansion, it remains unclear if this approach will emerge as safe treatment option in the near future.
Our lab has created novel bifunctional molecules that selectively bind GAA repeat expansions and actively enable the cellular machinery to transcribe across the repressive GAA repeats within FXN. When scrutinized with genomic approaches, our synthetic transcription elongation factors (Syn-TEFs) display the ability to specifically overcome the repressive roadblocks to transcription at FXN without perturbing the function of other cellular genes. Based on this specificity of action, we propose to utilize Syn-TEFs to examine underlying molecular mechanisms that contribute to FXN silencing in patient cells. Deeper mechanistic understanding will guide the design of next generation Syn-TEFs that are precision-tailored for individuals with the disease. We further propose to test the efficacy of Syn-TEFs in patient-derived neurons and heart cells – cell types in which frataxin deficiency results in ataxia and morbidity. Taken together, the proposed experiments will aid in the development of this class of molecules as potential individual-tailored precision therapeutics.
Publications
- Erwin GS, Grieshop MP, Ali A, Qi J, Lawlor M, Kumar D, Ahmad I, McNally A, Teider N, Worringer K, Sivasankaran R, Syed DN, Eguchi A, Ashraf M, Jeffery J, Xu M, Park PMC, Mukhtar H, Srivastava AK, Faruq M, Bradner JE, and Ansari AZ. (2017) "Synthetic transcription elongation factors license transcription across repressive chromatin." Science. 358:1617-1622
Activating frataxin expression in animals using chemically modified oligonucleotides

Award type: General Research Grant
Grant Title: Activating frataxin expression in animals using chemically modified oligonucleotides
Lay summary: Friedrich's Ataxia (FA) is an incurable genetic disease caused by insufficient expression of the mitochondrial protein frataxin. This reduced expression is primarily driven by a GAA triplet repeat expansion within the first intron of the frataxin gene, and this mutant expansion leads to formation of an "R-loop" or heterochromatin formation and transcriptional gene silencing [1]. A number of strategies are being developed for treating FA, including approaches to improve mitochondrial function, release epigenetic silencing, or modulate pathways downstream of frataxin [2]. Nevertheless, specific activation of frataxin expression is the ideal therapeutic strategy, addressing the disease at its root cause. Pioneering work by David Corey's laboratory at the University of Texas Southwestern Medical Center showed that frataxin expression could be activated by treating FA patient-derived fibroblasts with oligonucleotides complementary to the expanded repeat [3]. My group recently worked with Dr. Corey's group and others to further explore the chemistry of these repeat-targeted oligonucleotides [4]. The next key step in the development of oligonucleotide therapeutics for FA is their testing in animal models. Gene expression and regulation can differ in one tissue relative to another, and in cultured cells relative to organisms. While animal models of FA are imperfect, it is essential to test whether the frataxin activation observed in cultured cells is robust and reproducible in the more complex context of in vivo use. My laboratory has made progress on optimizing the medicinal chemistry of oligonucleotides for the central nervous system, and we are actively working on methods to improve the potency of oligonucleotides in peripheral tissues including heart. Together with our colleagues at the RNA Therapeutics Institute, we have been working on strategies including conjugation of small molecules and hydrophobic groups, use of advanced sugar-modified nucleotides, and development of multimeric oligonucleotide structures. We aim to deepen the preclinical data on lead oligonucleotide compounds, as well as lay the groundwork for clinical development of these compounds.
Grant made possible with support from the Crisp Family Fund
Lay abstract references
- Groh M, Lufino MMP, Wade-Martins R and Gromak N. (2014) "R-loops Associated with Triplet Repeat Expansions Promote Gene Silencing in Friedreich Ataxia and Fragile X Syndrome." PLOS Genetics. 10: e1004318.
- Strawser CJ, Schadt KA and Lynch DR. (2014) "Therapeutic approaches for the treatment of Friedreich's ataxia." Expert Rev. Neurotherapeutics. 14: 949-957.
- Li L, Matsui M and Corey DR. (2016). "Activating frataxin expression by repeat-targeted nucleic acids." Nat Commun. 7: 10606.
- Li L, Shen X, Liu Z, Norrbom M, Prakash TP, O'Reilly D, Sharma VK, Damha MJ, Watts JK, Rigo F and Corey DR. (2018) "Activation of Frataxin Protein Expression by Antisense Oligonucleotides Targeting the Mutant Expanded Repeat." Nucleic Acid Ther., in press.
- Pendergraff HM, Krishnamurthy PM, Debacker AJ, Moazami MP, Sharma VK, Niitsoo L, Yu Y, Tan YN, Haitchi HM, and Watts JK. (2017) "Locked Nucleic Acid Gapmers and Conjugates Potently Silence ADAM33, an Asthma-Associated Metalloprotease with Nuclear-Localized mRNA." Mol Ther Nucleic Acids. 8158-168.
- Khvorova A., Watts J.K., (2017) "The chemical evolution of oligonucleotide therapies of clinical utility." Nat. Biotechnol. 35: 238-248.

Evaluating novel capsid engineered for efficient CNS transduction, as frataxin gene delivery vehicles

Award type: General Research Grant
Grant Title: Evaluating novel capsid engineered for efficient CNS transduction, as frataxin gene delivery vehicles
Lay summary: AAV-based FXN gene therapy is a promising approach for the treatment of Friedreich's ataxia (FA), especially for the prevention and/or reversal of heart abnormalities associated with the disease. However, treating the peripheral and central nervous system aspects of FA with a gene therapy has not been possible due to the unsolved challenge of achieving widespread and efficient gene delivery throughout the young adult central and peripheral nervous systems. Using novel adeno-associated viruses (AAV) we recently evolved for enhanced noninvasive gene transfer to both the central and peripheral nervous systems (1-2), we have created Frataxin (FXN) expressing vectors that can efficiently restore FXN expression across many of the cell types thought to be most sensitive to reduced FXN levels in FA: CNS neurons and glia, peripheral sensory neurons, and cardiac muscle. We are now testing whether FXN expression by these vectors can ameliorate the neurological symptoms and pathologies in the FXN KIKO model of FA. Our objectives are in line with FARA's program priorities for advancing drug discovery with the aim of developing approaches for increasing FXN protein levels.
Co-Sponsor: fara Australia
Lay abstract references
- Deverman BE, Pravdo PL, Simpson BP, Kumar SR, Chan KY, Banerjee A, Wu W, Yang B, Huber N, Pasca SP, and Gradinaru V. (2016) "Cre-dependent selection yields AAV variants for widespread gene transfer to the adult brain." Nature Biotechnology. 34:204-209.
- Chan KY, Jang MJ, Yoo BB, Greenbaum A, Ravi N, Wu WL, Sanchez-Guardado L, Lois C, Mazmanian SK, Deverman BE*, and Gradinaru V*. (2017) "Engineered AAVs for Efficient Noninvasive Gene Delivery to the Central and Peripheral Nervous Systems." Nature Neuroscience. 20:1172-1179.
CRISPR / Cas9 mediated deletion of the human FXN intronic trinucleotide repeat as a therapeutic approach for Friedreich's Ataxia

PI/Investigator: Marek Napierala, PhD - University of Alabama at Birmingham
Award type: Kyle Bryant Translational Research Award
Grant Title: CRISPR / Cas9 mediated deletion of the human FXN intronic trinucleotide repeat as a therapeutic approach for Friedreich's Ataxia
Lay summary: Friedreich's ataxia (FA) is an incurable neurodegenerative disease caused most commonly by a pathologic expansion of a naturally occurring short DNA sequence repeat in both copies of the FXN gene. The FXN gene codes for the protein frataxin, which is needed for the proper functioning of mitochondria, the powerhouse of the cell. Having two copies of the FXN gene with expanded repeats significantly reduces the amount of frataxin protein produced and is associated with a number of serious cellular abnormalities. While frataxin protein is produced by most cells in the body, some cells are more sensitive to the degree of frataxin deficiency than others. In particular, neurons in the brain, eye, and spinal cord as well as muscle cells in the heart appear disproportionally vulnerable to damage and degeneration in the setting of reduced FXN protein. Dysfunction in these cells leads to progressive imbalance and discoordination, loss of visual acuity, and life-threatening cardiomyopathy that develops in patients diagnosed with FA. It has been shown that removing the expanded repeat sequences from FXN gene, using different DNA editing platforms (i.e. molecular scissors that can specifically excise the repeat sequences), can consistently restore the production of frataxin protein and prevent degeneration of affected cells (1-2). The CRISPR / Cas9 system, a recently discovered DNA editing strategy, is technically simpler compared to other forms of molecular scissors. In this grant, we propose to use the CRISPR / Cas9 system to remove the expanded repeat sequence from the FXN gene in FA patient-derived stem cells and in a FA mouse model. We will screen for and identify CRISPR reagents that efficiently remove the expanded repeat sequences and will optimize the delivery of these reagents to patient-derived cells and to the FA-model mouse. We will examine the restoration of frataxin protein function after repeat expansion removal. This proof of concept study will enable the generation of CRISPR-based therapeutic reagents and strategies to deliver these reagents to patient cells thereby potentially supporting the development of an effective therapy for FA.
Co-sponsor: The Cure FA Foundation
Lay abstract references
- Li Y, Polak U, Bhalla AD, Rozwadowska N, Butler JS, Lynch DR, Dent SYR, Napierala M. (2015) "Excision of Expanded GAA Repeats Alleviates the Molecular Phenotype of Friedreich's Ataxia." Mol Ther. 23:1055-1065.
- Oullet DL, Cherif K, Rousseau J, and Temblay JP. (2017) "Deletion of the GAA repeats from the human frataxin gene using CRISPR-Cas9 system in YG8R-derived cells and mouse models of Friedreich ataxia." Gene Therapy. 24: 265-274.
Epigenetic editing of the frataxin gene: a novel therapeutic approach for FA

Award type: General Research Grant – Postdoctoral Fellowship
Grant Title: Epigenetic editing of the frataxin gene: a novel therapeutic approach for FA
Lay summary: Frataxin (FXN) gene silencing is the result of an abnormal trinucleotide (i.e., GAA) expansion within intron 1 of the FXN gene. This has been shown to result in an abnormal epigenomic environment within the frataxin gene locus. Although several components have been implicated in the establishment of this environment—from aberrant histone and DNA methylation, heterochromatin and R-loop formation and antisense transcription—the direct causality of each of these factors and its relevance to FXN gene silencing remains elusive. Specifically, it remains to be determined the relative importance of each of these factors with respect to different frataxin gene locus elements, such as the promoter region and the regions upstream and/or downstream of the GAA repeats. With the advent of RNA guided endonuclease technology (CRISPR), there is now the possibility to interrogate these factors directly at the frataxin locus. Such an approach will not only provide insight into the mechanism of aberrant FXN silencing but might also lead to a novel and radical therapeutic approach for FRDA and potentially other epigenetically regulated disorders. This proposal brings together leading experts in their respective fields, including George Church, PhD; Stephan Beck, PhD; Richard Festenstein, PhD. This enables a highly collaborative effort to develop novel technology for selective engineering of the epigenome, as well as provides a controlled way to address the key hypotheses underlying pathological silencing in Friedreich's ataxia. If successful, such an approach is likely to have a huge impact in treating a variety of other diseases caused by similar mechanisms.
Co-sponsor: FARA Ireland
Publications
- Nageshwaran S, Festenstein R. (2015) "Epigenetics and Triplet-Repeat Neurological Diseases." Front Neurol. 6:262.
- Natisvili T, Yandim C, Silva R, Emanuelli G, Krueger F, Nageshwaran S, Festenstein R. (2016) "Transcriptional Activation of Pericentromeric Satellite Repeats and Disruption of Centromeric Clustering upon Proteasome Inhibition." PLoS One. 11:e0165873.
The development of gene therapy approach for the treatment of FRDA

Award type: General Research Grant
Grant Title: The development of gene therapy approach for the treatment of FRDA
Lay summary: AAV-based FXN gene therapy is a promising approach for the treatment of Friedreich's ataxia (FA), especially for the prevention and/or reversal of heart abnormalities associated with the disease. However, treating the nervous system components of FA through a gene therapy approach presents additional challenges associated with widespread gene delivery to the young adult nervous system. Using novel adeno-associated viruses (AAV) we evolved for enhanced gene transfer to the nervous system, we aim to: 1) create Frataxin (FXN) expressing vectors that can efficiently restore FXN expression across many of the cell types thought to be most sensitive to reduced FXN levels in FA (e.g., CNS neurons and glia, peripheral sensory neurons, and cardiac muscle), and 2) to test whether FXN expression by these vectors can ameliorate the neurological symptoms and pathologies in the FXN KIKO model of FA. Our objectives are in line with FARA's Program Priorities for advancing drug discovery with the aim of developing approaches for increasing FXN protein levels.
Co-sponsor: The National Ataxia Foundation
Publications
- Perdomini M, Belbellaa B, Monassier L, Reutenauer L, Messaddeq N, Cartier N, Crystal RG, Aubourg P, Puccio H. (2014) "Prevention and reversal of severe mitochondrial cardiomyopathy by gene therapy in a mouse model of Friedreich's ataxia." Nat Med. 20:542-7.
Stem Cell Gene Therapy for Friedreich’s Ataxia

Award type: General Research Grant
Grant Title: Stem Cell Gene Therapy for Friedreich’s Ataxia
Lay summary: Friedreich’s ataxia (FRDA) is a multi-systemic autosomal recessive genetic disorder caused by a mutation in the frataxin gene, which reduces the amount of frataxin made by the cell. Frataxin is a mitochondrial protein involved in iron metabolism and is critical for proper mitochondrial function and health. Consistent with the cellular role of frataxin, FRDA is characterized by ataxia, neurodegeneration, muscle weakness, and cardiomyopathy – there is no treatment for this lethal disease. Our lab is interested in the role of inflammation in disease progression, and in the ability to modulate the immune system for therapeutic gain (1-3). Specifically, we study the capacity of hematopoietic stem and progenitor cells (HSPCs) to differentiate into immune cells that can migrate to sites of inflammation in the body and halt the progression of disease. Recently, we tested this therapeutic strategy in the Y8GR mouse model of FRDA (4). This mouse model expresses exclusively the mutated human FXN transgene, thus mimicking the transcriptional deficiency and clinical phenotype seen in FRDA patients. We transplanted normal (i.e., no frataxin mutation), control HSPCs from wild-type mice into 2-month old FRDA YG8R mice and found that this therapy worked quite beyond our expectation. Control HSPCs transplanted in the YG8R mouse differentiated into macrophages that migrated to all sites of inflammation injury, such as the brain, spinal cord, dorsal root ganglia, skeletal muscle and heart of the YG8R mouse. The neurologic and muscular complications in the YG8R mouse were completely prevented as observed 7-months post-transplantation (latest time point tested) after only a single infusion of control HSPCs. As well, it appears that part of the therapeutic gain from this treatment occurs from the transfer of functional frataxin protein from the control HPSC-derived macrophages to the affected tissues in the YG8R mouse. Taken together, we hypothesize that this strategy could also treat FRDA patients. Given the high risk of morbidity and mortality associated with HSPC transplantation from a donor (i.e., allogeneic transplantation), our objective is to develop "an autologous" HSPC gene therapy approach for FRDA, whereby patient cells are extracted, corrected and returned to the patient. To accomplish our objective, we will first develop a gene-correction therapy strategy for FRDA HSPCs and determine their ability of halting disease progression in YG8R mice. Furthermore, we will treat YG8R mice in late-stage disease and determine the ability of HSPCs to reverse preexisting complications. This work represents the first autologous gene-corrected HSPC transplantation treatment strategy for FRDA and builds the foundation for a clinical application of this strategy.
Grant made possible with support from the Crisp Family Fund
Lay abstract references
- Harrison F, Yeagy BA, Rocca CJ, Kohn DB, Salomon DR, Cherqui S. (2013) "Hematopoietic stem cell gene therapy in the mouse model of cystinosis." Mol Ther. 21:433-444.
- Naphade S, Sharma J, Gaide Chevronnay HP, Shook MA, Yeagy BA, Rocca CJ, Ur SN, Lau AJ, Courtoy PJ, Cherqui S. (2015) "Lysosomal cross-correction by hematopoietic stem cell-derived macrophages via tunneling nanotubes." Stem Cells. 33:301-309.
- Gaide Chevronnay HP, Jansen V, Van Der Smissen P, Rocca CJ, Liao XH, Refetoff S, Pierreux CE, Cherqui S*, and Courtoy P*. (2016) "Hematopoietic stem cell transplantation can normalize thyroid function in a cystinosis mouse model." Endocrinology. 57:1363-1371 *co-senior author
- Rocca CJ, Goodman SM, Dulin JN, Haquang JH, Gertsman I, Blondelle J, Smith JLM, Heyser CJ, Cherqui S. (2017) "Hematopoietic stem cell transplantation prevents development of Friedreich’s Ataxia in a humanized mouse model." Sci Transl Med. 9:eeaj2347.

Studying G-CSF as a potential treatment for Friedreich's Ataxia

Award type: General Research Grant
Grant Title: Studying G-CSF as a potential treatment for Friedreich's Ataxia
Lay summary: Despite our increased understanding of how the genetic abnormality in Friedreich ataxia (FRDA) causes disease, there are still no treatments available to reduce long term disability. There has been much excitement and hope over many years that stem cell therapies might provide an effective treatment for a variety of neurodegenerative diseases including Friedreich ataxia (FRDA). Indeed, advances in stem cell science over the last decade or more have increased the deliverability of that promise. It is now known that stem cells have multiple functions allowing them to protect against numerous disease processes. Of all the types of stem cell therapies which have been put forward, we believe that bone marrow stem cells hold the most promise, not least as they have been used extensively for many years for other conditions and thus have the best safety profile. There are many potential bone marrow stem cell therapies for FRDA, but utilizing the multiple reparative properties of ‘a patient's own' stem cells represents the simplest, safest and most readily applicable for an immediate trial. In effect, such a therapy represents a form of cellular mobilization-making stem cells travel to sites of injury in the body to repair the damage-which has been used in other conditions with effect, not least our own group's trials of autologous bone marrow transplantation for multiple sclerosis. An alternative to transplanting bone marrow cells, without the need for bone marrow harvest and infusions, would be to use bone marrow stem cell mobilizing drugs. These are drugs that are used in clinical practice that activate stem cells within the bone marrow and induce them to circulate around the body. We believe that increasing the circulation of the body's own stem cells is a promising approach for therapeutic success and we hypothesize that their potential mechanisms of actions are multiple. We have been studying stem cell-mediated neuroprotection in FRDA models for a number of years and have recently completed an exciting study of cytokine-mediated stem cell-mobilization therapy in an animal model. We have shown that a bone marrow stem cell-mobilizing cytokine called G-CSF is very effective in reversing symptoms, pathological changes and biochemical abnormalities in the model. We have therefore begun to plan for a phase 2 trial of G-CSF in FRDA. The safety profile and pharmacokinetics of G-CSF are well established, being used extensively in ‘healthy' bone marrow donors. However, prior to starting a trial we wish to establish the effect of this agent in cells derived from people with FRDA. We will conduct studies of the effect of G-CSF on frataxin levels and associated molecules in (i) lymphoblastoid cell lines derived from patients with a range of GAA trinucleotide repeat expansions, and (ii) patients with FRDA given a course of G-CSF treatment. This will allow for refinement of trial protocol and improved patient selection, with the ultimate aim of developing a novel FRDA therapy.
Co-sponsor: Ataxia UK
Publications
- Kemp KC, Cerminara N, Hares H, Redondo J, Cook AJ, Haynes HR, Burton BR, Pook M, Apps R, Scolding NJ, and Wilkins A. (2016) "Cytokine therapy-mediated neuroprotection in a Friedreich's ataxia mouse model." Annals of Neurology. 81: 212-226.
- Kemp KC, Dey R, Cook AJ, Scolding N, and Wilkins A. (2017) "Mesenchymal stem cell-derived factors restore function to human frataxin-deficient cells." The cerebellum. 16: 840-851.
A human iPSC-based cardiac model of Friedreich's Ataxia for drug discovery and patient stratification using all-optical electrophysiology

Award type: General Research Grant
Grant Title: A human iPSC-based cardiac model of Friedreich's Ataxia for drug discovery and patient stratification using all-optical electrophysiology
Lay summary: Friedreich's Ataxia (FA) is the most commonly inherited ataxia, and is caused primarily by an autosomal recessive trinucleotide GAA repeat expansion in the frataxin (FXN) gene. Low expression of FXN is associated with aberrant iron handling at the cellular level. While FA is characterized as a progressive neuromuscular disorder, it is also associated with hypertrophic cardiomyopathy and cardiac complications. It is estimated that nearly two thirds of all FA patients present with cardiac impairment or thickening of the myocardium. Cardiac dysfunction is the primary cause of death in FA patients and it appears to be unrelated to the neurological symptoms. While the neurological impact of FA has been well studied, the impact of the cardiac impairment is unexplored. Several studies suggest a correlation between GAA repeat number, risk for left ventricular hypertrophy and age of the appearance of the first clinical signs of cardiac involvement. This impairment has been evaluated through traditional analysis of cardiac function in both FA patients and mouse models. Such phenotypes, however, have not yet been recapitulated in in vitro cellular models, limiting the mechanistic understanding of FA cardiomyopathy as well as the ability to evaluate new therapeutic approaches. Recent advances in induced pluripotent stem cell (iPSC) technology have led to novel, human models of disease. iPSC based disease modeling is particularly attractive for complex conditions that are impossible to replicate in more reduced systems. Genome editing technologies are being applied to produce "disease" and "control" cell lines that are genetically identical except for the gene associated with the disease. Improved differentiation protocols are being used to produce cardiomyocytes (CMs) with properties of adult human cardiac tissue. This progress on multiple fronts is leading to significant changes in approaches to drug discovery. Precise single cell approaches will be required to forge quantitative links between the effects of pharmacological perturbations and cardiac functionality. Indeed, the establishment of such assays would allow disease-specific questions to be asked for each of the processes that constitute cardiac activity. Here we propose a collaborative study between Translate Bio and Q-State Biosciences to develop a novel human cellular model to investigate cardiac dysfunction in CMs derived from FA patient iPSC lines. Our hypothesis is that CMs with the pathological GAA repeat expansion will exhibit a measurable electrophysiological phenotype due to a decrease in FXN function. Q-State has developed a proprietary all-optical electrophysiology platform (Optopatch) that enables simultaneous readout of action potentials and calcium transients under paced conditions. These assays facilitate identification and validation of novel targets and provide a mechanism to evaluate pharmacological properties of compounds on human cardiac function. Q-State has previously demonstrated the ability to record pharmacological perturbations in a commercial source of human iPSC-CMs (1). Translate Bio has developed a novel oligonucleotide-based platform for RNA-targeted medicines that upregulate gene expression through inhibition of repressive chromatin modifiers or increased stabilization of mRNA transcripts. Using this technology, Translate Bio has demonstrated that both mRNA and protein levels of the FXN gene can be upregulated in human iPSC-CMs, providing a tractable approach to rescue FXN function.
Lay abstract references
- Dempsey GT, Chaudhary KW, Atwater N, Nguyen C, Brown BS, McNeish JD, Cohen AE, and Kralj J (2016) "Cardiotoxicity screening with simultaneous optogenetic pacing, voltage imaging and calcium imaging." Journal of Pharmacological and Toxicological Methods. 81:240-250.
Evaluation of CAT-4001 in frataxin-deficient mouse models and DRG neurons to enable its therapeutic development to treat Friedreich's Ataxia

Award type: 2015-2016 Kyle Bryant Translational Research Award
Grant Title: Evaluation of CAT-4001 in frataxin-deficient mouse models and DRG neurons to enable its therapeutic development to treat Friedreich's Ataxia
Lay summary: Neuronal dysfunction and loss occurs early on in Friedreich's ataxia (FA). As the disease progresses, different parts of the peripheral and central nervous system are affected: peripheral sensory nerves, dorsal root ganglia (DRG), spinocerebral and corticospinal tracts, and cerebellum. Therapeutic strategies established in sensory neuronal cultures will help prioritize treatments for patients, based on their effects on measurable endpoints of neuronal dysfunction. We focused our efforts on the neuroinflammation and oxidative stress observed in FA neurons, and the inactivation of protein factor nuclear factor-erythroid 2-related factor 2, or "Nrf2". Nrf2 inactivation prevents cellular signaling that protects the neuron from oxidative stress and damage that can lead to neuronal death. In our original research proposal, we aimed to test CAT-4001, a novel small-molecule Nrf2 activator and NF-KB inhibitor, in cellular and mouse models of FA to determine its functional benefits in these models. Specifically, we proposed 1) to assess the effects of CAT-4001 in frataxin-deficient primary sensory neurons and astrocytes; and 2) to determine the efficacy of CAT-4001 in modulating Nrf2 and NF-KB metabolic pathways in the nervous system of frataxin-deficient mouse models.
Is FXN DNA Methylation a determinant of response to HDAC inhibitor treatment in Friedreich's Ataxia?

Award type: General Research Grant
Grant Title: Is FXN DNA Methylation a determinant of response to HDAC inhibitor treatment in Friedreich's Ataxia?
Lay summary: Friedreich ataxia (FA) is caused by a DNA mutation that results in silencing of the FXN gene. We discovered a large amount of DNA methylation, a potent signal of gene silencing, exclusively in people with FA, in a region of the FXN gene known to control gene function. HDAC inhibitors are drugs that have the ability to reactivate the silenced FXN gene and this class of drug is presently being developed as a therapy for FA. However, individuals with FA vary widely in their response to HDAC inhibitors and the cause for this variability remains poorly understood. In a pilot study we found that the best responders to HDAC inhibitors had significantly lower levels of DNA methylation in this region of the FXN gene. This project is designed to test the possibility ("hypothesis") that methylation status of the FXN gene is a predictor of the response to HDAC inhibitor therapy in FA. This is a critical question that has important implications for the clinical development and eventual implementation of HDAC inhibitor therapy in FA.
Lay abstract references
- Chutake YK, Lam CC, Costello WN, Anderson MP, and Bidichandani SI. (2016) "Reversal of epigenetic promoter silencing in Friedreich's ataxia by a class I histone deacetylase." Nucleic Acids Research. 44: 5095-5104.

The pathogenesis of Friedreich ataxia

Award type: General Research Grant
Grant Title: The pathogenesis of Friedreich ataxia
Lay summary: Investigators of FA have established several firm observations: (1) In the vast majority of cases, FA is caused by a homozygous guanine-adenine-adenine (GAA) trinucleotide repeat expansion in intron 1 of the frataxin gene; (2) the mutation results in decreased biosynthesis of frataxin, a small mitochondrial protein; (3) frataxin is essential for the proper delivery of iron-sulfur clusters to complexes I, II, and III of the mitochondrial electron transport chain, the citric acid cycle enzyme aconitase, and to ferrochelatase; and (4) frataxin deficiency renders cultured cells sensitive to oxidative stress. It has been more difficult, however, to establish oxidative stress or defective anti-oxidant defenses in live transgenic animals or humans with FA [1-4]. It is still very uncertain how the mutation leads to the complex pathological and clinical phenotypes of FA. The key question is: how does deficiency of frataxin cause severe lesions in so many diverse locations—such as the dentate nucleus (DN) of the cerebellum, dorsal root ganglia (DRG), the Betz cells of the motor cortex, sensory peripheral nerves, heart, and the insulin-secreting ß-cells of the pancreas—while leaving other organs entirely unaffected? Most offered explanations have been speculative, and no unifying concept has emerged. We postulate that each one of the vulnerable tissues contains a unique set of proteins that undergo changes in the level of expression in response to frataxin deficiency. Therefore, the goal of this research is to identify those proteins-of-interest in FA that are up-regulated or down-regulated relative to levels in non-FA subjects, and to determine the functional consequences of these differences. Discovery and identification of FA-relevant proteins will use a combination of tissue-based proteomics with multiple antibodies (immunohistochemistry and immunofluorescence [IHC, IF]), sodium dodecylsulfate polyacrylamide gel electrophoresis (SDS-PAGE), Western blotting (WB), and reverse-phase protein array or reverse-phase protein lysate microarray (RPA). While FA is still incurable, the investigation seeks to establish a firm understanding of the pathogenesis of the disease by a combination of techniques. The results are expected to fine-tune how we understand and classify the presentation of disease in FA. For example, these findings may replace words like "atrophy" and "degeneration" typically used to describe pathologic changes to the DRG, with the words "hypoplasia" and "hyperplasia". This distinction is important, because therapy for hypoplasia and hyperplasia in any "degenerative" condition is generally unsuccessful. Additionally, our research strategy includes an effort to "discover" proteins that are relevant to FA. Lastly, the described methods will also contribute to an understanding of the emerging maladaptive mitochondriogenesis and possible toxic effects of frataxin replacement therapy.
Lay abstract references
- Hayashi G and Cortopassi G. (2015) "Oxidative stress in inherited mitochondrial diseases." Free Radic Biol Med. 88:10-7.
- Hayashi G, Shen Y, Pedersen TL, Newman JW, Pook M, and Cortopassi G. (2014) "Frataxin deficiency increases cyclooxygenase 2 and prostaglandins in cell and animal models of Friedreich's ataxia." Hum Mol Genet. 23: 6838-47.
- Schulz JB, Dehmer T, Schols L, Mende H, Hardt C, Vorgerd M, Bürk K, Matson W, Dichgans J, Beal MF, and Bogdanov MB. (2000) "Oxidative stress in patients with Friedreich ataxia." Neurology 55:1719-21.
- Shan Y, Schoenfeld RA, Hayashi G, Napoli E, Akiyama T, Iodi Carstens M, Carstens EE, Pook MA, and Cortopassi GA. (2013) "Frataxin deficiency leads to defects in expression of antioxidants and Nrf2 expression in dorsal root ganglia of the Friedreich's ataxia YG8R mouse model." Antiox Redox Signal. 19:1481-93.
Publications
- Koeppen AH, Becker AB, Qian J, Gelman BB, Mazurkiewicz and JE. (2017) "Friedreich Ataxia: developmental failure of the dorsal root ganglion." J Neuropathol Exp Neurol. 76: 969-977.
- B. Koeppen AH, Becker AB, Qian J, and Feustel PJ. (2017) "Friedreich ataxia: hypoplasia of spinal cord and dorsal root ganglia." J Neuropathol Exp Neuorol. 76:101-108.
- C. Koeppen AH, Becker AB, Feustel PJ, Gelman BB, and Mazurkiewicz JE. (2017) "The significance of intercalated discs in the pathogenesis of Friedreich cardiomyopathy." J Neurol Sci. 367:171-176.
Endurance and resistance mitigate Friedreich's ataxia

Award type: General Research Grant
Grant Title: Endurance and resistance mitigate Friedreich's ataxia
Lay summary: The most common clinical symptoms of Friedreich's ataxia (FRDA) are ataxia, muscle weakness, diabetes and heart failure; the latter three conditions are directly related to loss of mitochondrial function and progressive oxidative damage in skeletal muscle and heart. Exercise is a potent means to promote mitochondrial function in various tissue types. This includes endurance (aerobic) exercise of the heart and skeletal muscle, which involves lower-body strength training such as running, jogging, or swimming. The role of endurance exercise in FRDA, however, has not been studied. Over the last decade, my lab has focused on the impact of endurance exercise on mitochondrial remodeling. We have recently obtained exciting new data to show that a single bout of treadmill running induces mitophagy [i.e., self-eating (autophagy) of mitochondria] in the muscles of mice, supporting a model of exercise-mediated improvement of mitochondrial quality. This improvement is achieved by simultaneous processes of the addition of new mitochondria through biogenesis, and the removal of damaged mitochondria through mitophagy. We propose that every bout of exercise acts as a "stress test" for all mitochondria, promoting the removal of suboptimal mitochondria and signaling for the making of new mitochondria. This dynamic process underscores the improvement of mitochondrial function with endurance exercise training. More recently, we have also developed a novel mouse model of resistance (strength) training involving voluntary weightlifting. Our resistance exercise paradigm shows evidence of enhanced contractile and metabolic adaptations in skeletal muscle following training. Altogether, the objective of this proposal is to elucidate how exercise affects mitochondria in skeletal muscle and heart in a mouse model of FRDA. I propose the following two specific aims to thoroughly examine the impacts of two major types of exercise on the FRDA mice: 1) to determine if resistance training and endurance exercise are equally effective in preventing symptomatic FRDA in these mice; and 2) to elucidate the mechanism by which endurance exercise improves exercise capacity and metabolic functions in the FRDA mouse. The findings will likely lead to paradigm shifting practice for FRDA prevention and treatment and pave the way for the development of effective therapeutics for this detrimental disease.
Publications
- Yan Z, Lira VA, and Greene NP. (2012) "Exercise training-induced regulation of mitochondrial quality." Exerc Sport Sci Rev. 40:159-64.
- Lira VA, Okutsu M, Zhang M, Greene NP, Laker RC, Breen DS, Hoehn KL, and Yan Z. (2013) "Autophagy is required for exercise training-induced skeletal muscle adaptation and improvement of physical performance." FASEB J. 27:4184-93.
- Drake JC, Wilson RJ, and Yan Z. (2016) "Molecular mechanisms for mitochondrial adaptation to exercise training in skeletal muscle." FASEB J. 30:13-22.
- Laker RC, Drake JC, Wilson RJ, Lira VA, Lewellen BM, Ryall KA, Zhang M, Saucerman JJ, Goodyear LJ, Kundu M, and Yan Z. (2017) "AMPK phosphorylation of Ulk1 is required for lysosome targeting of mitochondria in mitophagy induced by exercise." Nat Commun. 8:548.
Identification of genetic factors involved on FXN transcriptional silencing mediated by the GAA repeat expansion

Award type: 2016-2017 Bronya J. Keats International Research Collaboration Award
Grant Title: Identification of genetic factors involved on FXN transcriptional silencing mediated by the GAA repeat expansion
Lay summary: Friedreich's ataxia (FA) is a multi-systemic disease caused by the expansion of GAA repeats within the first intron of the frataxin gene (FXN). This expansion leads to a transcriptional partial silencing of FXN which results in the deficiency of the frataxin protein function. Frataxin is a nuclear-encoded mitochondrial protein necessary for life. One major model suggests that long GAA expansions induce silencing of FXN expression by heterochromatin-mediated repression. To better understand the mechanisms of FXN silencing in vivo, and identify genetic factors that could be involved in the transcriptional silencing of FXN mediated by the GAA repeat expansion, we have developed a Drosophila or fruit fly model containing FXN intron 1 and flanking exons with a pathological number of the GAA repeats. In our model flies, the expression of a reporter gene (firefly luciferase) is under the effect of the expansion of ˜300 GAA repeats. Our hypothesis is that the GAA repeats with disrupt expression of the firefly luciferase gene, such that the readout—bioluminescence or light production-will be lessened due to changes induced by the repeats. As a control, we have a model with only 9 GAA repeats, which we hypothesize is insufficient to cause repress FXN promoter function of the firefly luciferase gene. We validated this model, comparing the effects of 300 GAA repeats and 9 GAA repeats on the mRNA levels of the firefly luciferase gene and the luciferase activity, or light production. We found that the pathological expansion provokes a significant reduction (about 25%) in these parameters. Moreover, when monitor the genomic changes to this repeat region, we find higher levels of chromatin compaction in the vicinity of the GAA repeats of the 300 GAA line compared with the 9 GAA line. Finally, as a proof of concept, we evaluated whether our model in the fruit fly is useful to identify genes that might be involved in the transcriptional repression caused by the GAA expansion. We found that mutations of Su(var)2-1, Su(var)2-5, and Su(var)3-9 increase significantly the firefly luciferase expression in the 300 GAA strain to levels similar to those showed by the 9 GAA strain. All these results encouraged us to use this new fruit fly model to identify genetic factors involved in FXN silencing and therefore potential therapeutic targets for the treatment of FA, the goal of research grant.
Co-sponsor: FARA Ireland
Publications
- Soriano S, Calap-Quintana P, Llorens JV, Al-Ramahi I, Gutierrez L, Martinez-Sebastian MJ, Botas J, and Molto MD. (2016) "Metal Homeostasis Regulators Suppress FRDA Phenotypes in a Drosophila Model of the Disease." PLoS ONE. 11:e0159209.
- Calap-Quintana P, Soriano S, Llorens JV, Al-Ramahi I, Botas J, Molto MD, Martinez-Sebastian MJ. (2015) "TORC1 Inhibition by Rapamycin Promotes Antioxidant Defences in a Drosophila Model of Friedreich's Ataxia." PLoS ONE. 10:e0132376
- Soriano S, Llorens JV, Blanco-Sobero L, Gutierrez L, Calap-Quintana P, Morales MP, Molto MD, and Martínez-Sebastian MJ. (2013) "Deferiprone and idebenone rescue frataxin depletion phenotypes in a Drosophila model of Friedreich's ataxia." Gene. 521:274-281.
- Navarro JA, Llorens JV, Soriano S, Botella JA, Schneuwly S, Martinez-Sebastian MJ, Molto MD (2011). "Overexpression of human and fly frataxins in Drosophila provokes deleterious effects at biochemical, physiological and developmental levels." PLoS ONE. 6:e21017.
Functional analysis of primary sensory neurons and (proprio) sensory pathology in Friedreich's ataxia

Award type: General Research Grant
Grant Title: Functional analysis of primary sensory neurons and (proprio) sensory pathology in Friedreich's ataxia
Lay summary: Friedreich's ataxia (FA) is a physiologically complex disorder that affects several tissues over the course of the disease. Early clinical symptoms in FA patients include areflexia, sensory loss, progressive limb and gait ataxia, and weakness. Impairments in patient's sensory systems consist of a loss of large dorsal root ganglion (DRG) neurons, atrophy of sensory neuron (SN) axons in the dorsal columns, atrophy in the dorsal nucleus of Clarke. Additionally, the patient sensory system exhibits degeneration of the dorsal spinocerebellar tract, corticospinal tract, primary sensory nuclei (cochlear nucleus, lateral geniculate nucleus), and dentate nucleus of the cerebellum. Functionally, defects in conduction velocity along sensory fibers of FA patients have also described. These observations raise the question whether the neuronal pathology in FA results from abnormalities in sensory circuitry. We initially focused on several aspects of mitochondria morphology and dynamics in in vitro and in vivo models of FA, and studied the peripheral nervous system and spinal cords of adult FA mouse models. This proposal aims to study whether reduced frataxin (Fxn) levels have an early impact on DRG SNs, with ambitions to shed light into the progression of sensory loss in FA. Our objectives are: 1) To explore the mechanisms of mitochondrial and neuronal dysfunction in embryonic SNs derived from a FA mouse model; and 2) to investigate early abnormalities in the sensory circuitry by using in vivo and ex vivo imaging.
Publications
- Bolea I, Gan WB, Manfredi G, Magrane J (2014) "Imaging of mitochondrial dynamics in motor and sensory axons of living mice." Methods Enzymol, 547:97-110.
- Lin H, Magrane J, Rattelle A, Stepanova A, Galkin A, Clark EM, Dong Y, Halawani SM, and Lynch DR. (2017) "Early cerebellar deficits in mitochondrial biogenesis and respiratory chain complexes in the KIKO mouse model of Friedreich ataxia." Disease Models & Mechanisms. 10:1343-1352.
Studying the role of brown fat in Friedreich's ataxia

Award type: General Research Grant
Grant Title: Studying the role of brown fat in Friedreich's ataxia
Lay summary: Friedreich's ataxia (FRDA) is characterized by a variable phenotype, which includes pervasive neurological and cardiomyopathy symptoms (1), as well as diabetes mellitus (2). To date, the major cause of diabetes mellitus occurrence in FRDA patients seems to be related to impairment of mitochondria in pancreatic ß-cells (3)— that are fundamental in generating signals that trigger and amplify insulin secretion and regulate body adiposity (i.e., body fat). Defective pancreatic ß-cells cause insulin resistance and increased body adiposity in FRDA patients (2). The increased fat storage is due to the accumulation of triglycerides (TGs), the main constituent of body fat in humans. Typically, the expansion of TG fat depots is commonly found in overweight and obese individuals and occurs in what is called "white adipose tissue" (WAT) and "brown adipose tissue" [BAT; (4)]. BAT is a metabolically active, specialized tissue that can break down TGs (i.e., lipolysis) through a process called thermogenesis. For many years, the conventional belief was that BAT existed only in infants but not in adults, thus little research was performed on this tissue in adult humans. Recently, it has been discovered that metabolically active BAT is present also in adult humans and its activity contributes in maintaining glycaemia (5). Given the accumulation of intracellular TGs found in many cells and tissues of FRDA patients, we predict that the activity of BAT in these patients is defective. Therefore, we want to characterize BAT function in a FRDA mouse model of FXN deficiency. We aim to address whether BAT is dysfunctional in this model and if dysfunction contributes to the progression towards diabetes. We intend to unravel whether thermogenic function is impaired in mouse FRDA BAT in terms of defective mitochondrial, TG lipolytic activity, lipogenesis (i.e., fat production) and adipogenesis (i.e. adipose cell generation). After evaluation of body metabolic parameters by metabolic chambers and blood biochemical tests (e.g. glycaemia, lipid profile, OGTT), we will determine BAT morphology and activity (e.g. by assaying uncoupling respiration, thermogenic and lipolytic proteins). Adipogenesis will be also studied in mouse-derived brown adipocytes precursors. Increased thermogenesis via BAT has beneficial effects on overall body metabolism. Thus, we will induce lipolysis and thermogenesis in adipocytes via treatment of the FRDA mouse with butyrate (6). Butyrate is a metabolite with significant anti-diabetic effects including enhancing the thermogenic cascade in WAT and BAT (7). The goal of this butyrate supplementation strategy is to test if butyrate might restore BAT function and halt disease progression in the FRDA mouse model. The results obtained will provide insights into whether BAT is a prospective therapeutic target to combat metabolic disturbances observed in the FRDA mouse. Lastly, our work will explore butyrate as a valuable and safe molecule to be employed for future clinical research.
Lay abstract references
- Koeppen AH, Ramirez RL, Becker AB, Bjork ST, Levi S, Santambrogio P, Parsons PJ, Kruger PC, Yang KX, Feustel PJ, and Mazurkiewicz JE. (2015) "The pathogenesis of cardiomyopathy in Friedreich ataxia." PLoS One. 10:e0116396.
- Cnop M, Mulder H and Igoillo-Esteve M. (2013) "Diabetes in Friedreich ataxia." J Neurochem. 126:94-102.
- Cnop M, Igoillo-Esteve M, Rai M, Begu A, Serroukh Y, Depondt C, Musuaya AE, Marhfour I, Ladriere L, Moles Lopez X, Lefkaditis D, Moore F, Brion JP, Cooper JM, Schapira AH, Clark A, Koeppen AH, Marchetti P, Pandolfo M, Eizirik DL, and Fery F. (2012) "Central role and mechanisms of beta-cell dysfunction and death in friedreich ataxia-associated diabetes." Ann Neurol. 72:971-982.
- Tseng YH, Cypess AM, and Kahn CR. (2010) "Cellular bioenergetics as a target for obesity therapy." Nat Rev Drug Discov. 9:465-482.
Structural Dynamics and the Consolidation of Protein Function in Protein Complexes Involved in the Biosynthesis of Iron-Sulfur Clusters: Quaternary Addition of Small Trojan Tutor Proteins

Award type: General Research Grant
Grant Title: Structural Dynamics and the Consolidation of Protein Function in Protein Complexes Involved in the Biosynthesis of Iron-Sulfur Clusters: Quaternary Addition of Small Trojan Tutor Proteins
Lay summary: Iron-sulfur (Fe-S) clusters are essential cofactors present in all known forms of life, and hundreds of proteins require such cofactors to work. In eukaryotes, the biogenesis of most Fe-S clusters takes place in the mitochondria. The process involves the interactions and activities of several key proteins, namely frataxin (FXN), NFS1, ISCU, and ISD11. Mutations in these proteins lead to very serious human diseases, among them mutations in FXN results in Friedreich's Ataxia (FRDA). The Fe-S biosynthesis process can be summarized in three main steps: The first step is critical and involves the activity of cysteine desulfurase NFS1/ISD11, ISCU and FXN as a protein complex. Iron, sulfur, and electrons are transferred to a protein scaffold (ISCU); the second step is the assembly of Fe-S cluster itself; and the third step is the transfer of the Fe-S cluster from the scaffold to a receiving Fe-S protein. NFS1 is stabilized by its interactions with the ISD11 protein. FXN upregulates the transfer process of the sulfur group from NSF1 to the nascent Fe-S cluster and, given that FXN maintains iron soluble, it is thought that this protein assists in iron transfer. Our lab studies the stability, internal motions, and functionality of FXN variants. We study human FXN mutants to better understand the root cause of FXN instability in pathogenic variants. Inspired by the stabilizing interactions of NFS1 and ISD11, we propose delivering a small anchoring protein—or "Trojan" tutor protein—to the cell to modulate and stabilize FXN. In stabilizing FXN, we aim to improve FXN structural dynamics and its activity in the Fe-S cluster biosynthesis protein complex. We have selected the protein Sac7d to prepare Trojan tutor proteins with high affinity for FXN. Moreover, we will prepare TAT-signal peptide-Sac7d variants, which will enable the Sac7d protein to enter the mitochondrial matrix, where Fe-S biosynthesis occurs. To guide our study toward a feasible protein therapy, we will test the immunogenicity of the Sac7d variants. Furthermore, we will search for other Trojan tutor or scaffolding proteins to aid FXN. In this way, we will increase our chances of successfully stabilizing FXN and improving Fe-S cluster biosynthesis.
Lay abstract references
- Faraj SE, Gonzalez-Lebrero RM, Roman EA, and Santos J. (2016) "Human frataxin folds via an intermediate state. Role of the C-terminal region." Nature Scientific Reports. 6: 20782.
- Faraj SE, Roman EA, Aran M, Gallo M, Santos J. (2014) "The Alteration of the C-terminal Region of Human Frataxin Distorts its Structural Dynamics and Function." FEBS J. 281: 3397-3419.
Analysis of mitochondrial dynamics in cultured neurons and in in vivo mouse models of Friedreich's ataxia.

Award type: General Research Grant
Grant Title: Analysis of mitochondrial dynamics in cultured neurons and in in vivo mouse models of Friedreich's ataxia.
Lay summary: Mitochondria are often involved in the pathogenesis of neurodegenerative diseases. Appropriate distribution and supply of mitochondria along axons are necessary for the maintenance of neuronal function. Friedreich's ataxia (FA) is a primary mitochondrial disorder which causes degeneration of different neuronal types, with a preference for large sensory neurons, cerebellar neurons, and corticospinal tracts. Very few studies, none of which in mammalian systems, have addressed the involvement of mitochondrial dynamics, such as axonal transport, fusion and fission, in FA neurons. Since work from us and others suggest that alterations of mitochondrial dynamics compromise neuronal function, synaptic activity, and the architecture of the cell, we hypothesize that abnormal dynamics may participate to the specificity of neuronal cell loss in FA. The main goal of this proposal then is to determine whether abnormalities in mitochondrial dynamics and distribution occur in FA mice. We will use live imaging fluorescent microscopy in isolated neurons and in living mice to examine mitochondrial morphology, distribution along axons, transport, and fusion and fission events in mouse models of FA. Mitochondria will be labeled with mitoDendra, a mitochondrially-targeted photo-convertible fluorescent protein both in culture (by transfection) and in vivo (mitoDendra transgenic mouse). The existence of mitochondrial dynamics abnormalities: 1) will provide a novel readout of FA pathology; 2) may help to explain the specificity of the neuronal populations affected in FA; 3) may help to open a new avenue of investigation to determine the molecular determinants of defective mitochondrial dynamics as a pathogenic factor.
Publications
- Bolea I, Gan WB, Manfredi G, Magrane J (2014) Imaging of mitochondrial dynamics in motor and sensory axons of living mice. Methods Enzymol. 547:97-110
- Lin H, Magrane J, Rattelle A, Stepanova A, Galkin A, Clark EM, Dong Y, Halawani SM, Lynch DR (2017) "Early cerebellar deficits in mitochondrial biogenesis and respiratory chain complexes in the KIKO mouse model of Friedreich ataxia." Disease Models & Mechanisms. 10:1343-1352

Standardization and characterization of mouse models for the study of FA

Award type: General Research Grant
Grant Title: Standardization and characterization of mouse models for the study of FA
Lay summary: Friedreich's Ataxia (FRDA) is an autosomal recessive ataxia caused by a mutation in the frataxin gene. This mutation is characterized by an expanded tri-nucleotide (GAA) repeat within the first intron of the gene. This expansion leads to reduced expression of frataxin, a ubiquitously expressed protein that acts in iron sulfur cluster and heme biosynthesis. Insufficiency in frataxin causes decreased activity of iron-sulfur cluster enzymes, such as enzymes critical to maintaining mitochondrial function like aconitase in the TCA cycle and the respiratory complexes of the electron transport chain. A current cutting-edge approach to modeling FRDA in the laboratory mouse model entails knocking out the mouse Fxn gene and adding in a mouse or human FRDA Fxn that contains a large amount of GAA repeats. The Rare and Orphan Disease Center at The Jackson Laboratory (JAX) currently manages a repository of ~15 of these FRDA mouse models for distribution to the scientific community. However, these current models fall short at recapitulating many of the pathological and physiological features of the disease in humans. Therefore, with our grant we prioritize genetic standardization of these models, comprehensive phenotyping to compare these models to one another, and continued development and optimization of Fxn silencing in these models. Newly available genome editing technologies enable us to evolve this current FRDA collection and make new models at an efficiency never seen before. Advanced models include new BAC transgenic models that carry the human Fxn gene with greater repeat number and lower FXN levels, conditional allele models that do not require licenses, knock-in models with larger repeat size, and siRNA silencing approaches to generating relevant alleles. Overall, our aim is to provide better models to the FRDA community to aid in the advancement of therapeutic discovery.
Publications
- O'Rourke JG, Bogdanik L, Muhammad AK, Gendron TF, Kim KJ, Austin A, Cady J, Liu EY, Zarrow J, Grant S, Ho R, Bell S, Carmona S, Simpkinson M, Lall D, Wu K, Daughrity L, Dickson DW, Harms MB, Petrucelli L, Lee EB, Lutz CM, and Baloh RH. (2015) "C9orf72 BAC Transgenic Mice Display Typical Pathologic Features of ALS/FTD." Neuron. 88:892-901.
- Osborne MA, Gomez D, Feng Z, Cirillo K, El-Khodor, Ling, K, McKemy DD, Bogdanik L, Davis C, Doty R, Ghavami A, Kobayashi D, Ko CP, Ramboz S, and Lutz CM. (2012) "Characterization of behavioral and neuromuscular junction phenotypes in a novel allelic series of SMA mouse models." Hum Mol Genet. 21:4431-47.
Development of a novel iPSC-derived neuronal cell model for Friedreich's ataxia: generation of stable doxycycline-inducible expression of progerin in FRDA neuronal cells (Post-doctoral fellowship: Baohu Ji, PhD)

Award type: General Research Grant
Grant Title: Development of a novel iPSC-derived neuronal cell model for Friedreich's ataxia: generation of stable doxycycline-inducible expression of progerin in FRDA neuronal cells (Post-doctoral fellowship: Baohu Ji, PhD)
Lay summary: The invention of induced pluripotent stem cells (iPSCs) technology allows patient-specific, mature somatic cells to be converted into pluripotent stem cells. As such, iPSCs provide a powerful tool for in vitro modeling of neurodegenerative diseases and an unlimited source for cell therapy. These iPSCs can then in turn be differentiated into any cell type, including the cell types affected in Friedreich's ataxia (FRDA), namely neurons and cardiomyocytes. However, studies in our lab and other groups have failed to uncover a clear pathological phenotype in neuronal cells derived from FRDA patient iPSCs. While recent work reported that the abundance of various iron-sulfur cluster proteins is reduced in such cells [1], mitochondrial dysfunction has not been observed despite several years of effort. We hypothesize that this failure could be due to the immature nature of the neuronal cells, and the fact that most FRDA patients present with symptoms between the ages of 8 to 15 years, with no symptoms at birth. Numerous studies have indicated that reprogramming of patient fibroblasts to iPSCs resets their identity back to an embryonic, immature age, and this presents a significant hurdle for modeling late-onset disorders (see, for example [3]). Since iPSC-derived neuronal cells are generally quite immature, it is not that surprising that these cells fail to recapitulate the degenerative hallmarks of FRDA, such as mitochondrial dysfunction and oxidative stress. To circumvent these limitations of iPSC-derived neurons, we have generated stable doxycycline-dependent inducible expression of progerin in FRDA patient iPSC-derived cells. Progerin is a truncated form of the nuclear protein Lamin A and is responsible for the early onset aging disease Huntchinson Gilford Progeria. Based on previous studies in the literature, forced expression of progerin in neuronal cells has been demonstrated to successfully model late-onset diseases, taking into account age progression properties [2]. We hypothesize that similar expression of progerin in FRDA neurons will allow us to establish reproducible phenotypes of FRDA, such as mitochondrial dysfunction, oxidative stress, etc. Additionally, previous studies have been performed with unspecified neuronal cells, rather than peripheral sensory neurons, which are the cell types primarily affected in FRDA. Such neuronal cells will be beneficial to both study the underlying molecular mechanisms in FRDA and to screen for therapeutic compounds that can reverse hallmarks of disease, including FXN expression, epigenetic modifications and mitochondrial function.
Co-sponsor: FARA Ireland
Lay abstract references
- Codazzi F, Hu A, Rai M, Donatello S, Salerno Scarzella F, Mangiameli E, Pelizzoni I, Grohovaz F, and Pandolfo M. (2016) "Friedreich ataxia-induced pluripotent stem cell-derived neurons show a cellular phenotype that is corrected by a benzamide HDAC inhibitor." Hum Mol Genet. 25:4847-4855.
- Mertens J, Paquola AC, Ku M, Hatch E, Bohnke L, Ladjevardi S, McGrath S, Campbell B, Lee H, Herdy JR, Goncalves JT, Toda T, Kim Y, Winkler J, Yao J, Hetzer MW, and Gage FH. (2015) "Directly Reprogrammed Human Neurons Retain Aging-Associated Transcriptomic Signatures and Reveal Age-Related Nucleocytoplasmic Defects." Cell Stem Cell. 17:705-718.
- Miller JD, Ganat YM, Kishinevsky S, Bowman RL, Liu B, Tu EY, Mandal PK, Vera E, Shim JW, Kriks S, Taldone T, Fusaki N, Tomishima MJ, Krainc D, Milner TA, Rossi DJ, and Studer L. (2013) "Human iPSC-based modeling of late-onset disease via progerin-induced aging." Cell Stem Cell 13:691-705.
- Soragni E and Gottesfeld JM. (2016) "Translating HDAC inhibitors in Friedreich's ataxia." Expert Opin. Orphan Drugs. 4:961-970.
- Soragni E, Chou CJ, Rusche JR and Gottesfeld JM. (2015) "Mechanism of action of 2-aminobenzamide HDAC inhibitors in reversing gene silencing in Friedreich's ataxia." Front. Neurol. 6:44.
Longitudinal MR Imaging and Spectroscopy at 9.4T in a Conditional Mouse Model of FA

Award type: General Research Grant
Grant Title: Longitudinal MR Imaging and Spectroscopy at 9.4T in a Conditional Mouse Model of FA
Lay summary: This proposal stems from our ongoing human FRDA imaging study at the Center for Magnetic Resonance Research (CMRR) in the Department of Radiology at the University of Minnesota. Our study thus far has revealed large differences between controls and individuals with FRDA using spinal cord MRS, diffusion MRI, and morphometry (cross-sectional area). Additionally, larges differences were found throughout the cerebrum/cerebellum using diffusion MRI and morphometry. Significant longitudinal changes were also observed in all these measures over 12 and 24 months. While we can detect these abnormalities in FRDA patients, the extent to which such changes could be reversed upon restoration of frataxin in the CNS is unknown. A recently developed conditional mouse model of FRDA by Dr. Vijay Chandran at the University of California Los Angeles serves as an ideal candidate model to investigate if there are parallels to the mouse with frataxin suppression, and, importantly, to test the hypothesis that neurochemical, volumetric and microstructural changes observed in the CNS may be reversed upon treatment. A similar proof-of-concept study [1] showed that neurochemical changes are reversible in the cerebellum in a conditional mouse model of SCA1. While the study used only MRS, our study of the FRDA mouse model will benefit from adding the other modalities from our human study (i.e., diffusion MRI and morphometry), since we have demonstrated even greater changes in diffusion MRI data over 24 months in humans (+26% in mean diffusivity, p<0.0005) in the spinal cord (compared to -18% cross-sectional area, p<0.0001 and -17% in tNAA/mIns, p=0.02). It is important at this stage to determine which modalities may be more sensitive and informative in the mouse model, especially at early stage. Therefore, we propose to acquire data using the same imaging modalities (adapted for the mouse at 9.4T) used in the human FARA study, namely: spine MRS, spine and brain diffusion MRI, as well as spine and brain volumetry. We also propose to add one modality: cerebellum MRS. To summarize, the main goal of our study is to compare the biochemical, microstructural and volumetric changes observed in patients with early-stage FRDA with the same imaging modalities acquired in a conditional mouse model of FRDA. This will enable validation of our MR biomarkers in a preclinical mouse model. Furthermore, these studies will enable us to determine whether these maladaptive changes are reversible upon restoration of frataxin in this FRDA model.
Co-sponsor: Cure FA Foundation
Lay abstract references
- Oz G, Vollmers ML, Nelson CD, Shanley R, Eberly LE, Orr HT, and Clark HB. (2011) "In vivo monitoring of recovery from neurodegeneration in conditional transgenic SCA1 mice." Experimental Neurology. 232:290-298.
- Valette J, Park JY, Grohn O, Ugurbil K, Garwood M, and Henry PG. (2007) "Spectroscopic imaging with volume selection by unpaired adiabatic pi pulses: theory and application." J Magn Reson. 189:1-12.
- Farooq H, Xu J, Nam JW, Keefe DF, Yacoub E, Georgiou T, and Lenglet C. (2016) "Microstructure Imaging of Crossing (MIX) White Matter Fibers from diffusion MRI." Sci Rep. 6:38927.
Transplantation studies of sensory neurons derived from Friedreich Ataxia induced pluripotent stem cells into the dorsal root ganglia

PI/Investigator: Lachlan Thompson, PhD - University of Melbourne, Australia
Award type: General Research Grant
Grant Title: Transplantation studies of sensory neurons derived from Friedreich Ataxia induced pluripotent stem cells into the dorsal root ganglia
Lay summary: The peripheral sensory nervous system is one of the primary and most significant sites of degeneration occurring in Friedreich ataxia (FRDA), which significantly contributes to the ataxia, dysarthia and areflexia of the lower limbs. Whilst drug therapies are being developed to treat neurodegeneration occurring in FRDA, cell replacement therapies still remain an 'ideal' approach in terms of replacing mutated FXN cells for certain tissues. We have previously reported transplantation of neural progenitors derived from FRDA induced pluripotent stem cells (iPSCs) into the cerebellar regions of adult rodents [1]. These studies show proof-of-concept for the capacity of donor FRDA iPS-derived neural progenitors to differentiate, survive and integrate into the adult nervous system. We have since developed an efficient system to differentiate human pluripotent stem cells to peripheral sensory neurons of the dorsal root ganglia (DRG) [2]. The major aim of this project is to transplant sensory neurons derived from FRDA and control stem cells into the DRG region of adult rodents and examine their capacity to survive and establish functional connections. To date we have transplanted FRDA and control stem cells either directly into the DRG or within the surrounding DRG region, including the sciatic nerve. Our analyses of transplanted tissues demonstrate that the FRDA and control stem cells are able to generate peripheral neurons within the DRG and the surrounding DRG region. For the latter, donor neurons extended their processes a significant distance along the sciatic nerve. We are currently determining how long post-transplantation donor neurons survive and whether they are also functional. The outcome of these studies will address the possibility of developing cell replacement therapies to treat neurodegeneration occurring within the peripheral sensory nervous system in FRDA.
Co-sponsors: FARA Ireland & fara Australia
Lay abstract references
- Bird MJ, Needham K, Frazier AE, van Rooijen J, Leung J, Hough S, Denham M, Thornton ME, Parish CL, Nayagam BA, Pera M, Thorburn DR, Thompson LH, and Dottori M. (2014) "Functional characterization of Friedreich ataxia iPS-derived neural progenitors and their integration in the adult brain." Plos One 9:e101718.
- Denham M, Hasegawa K, Menheniott T, Rollo B, Zhang D, Hough S, Alshawaf A, Febbraro F, Ighaniyan S, Leung J, Elliott D, Newgreen DF, Pera MF and Dottori M. (2015) "Multipotent caudal neural progenitors derived from human pluripotent stem cells that give rise to lineages of the central and peripheral nervous system." Stem Cells 33:1759-1770.
- Crombie DE, Curl CL, Raaijmakers AJ, Sivakumaran P, Kulkarni T, Wong RC, Minami I, Evans-Galea MV, Lim SY, Delbridge L, Corben LA, Dottori M, Nakatsuji N, Trounce IA, Hewitt AW, Delatycki MB, Pera MF, and Pebay A. (2017) "Friedreich's ataxia induced pluripotent stem cell-derived cardiomyocytes display electrophysiological abnormalities and calcium handling deficiency." Aging (Albany NY). 9:1440-1452.
- Evans-Galea MV, Pebay A, Dottori M, Corben LA, Ong SH, Lockhart PJ, and Delatycki MB. (2014) "Cell and gene therapy for Friedreich ataxia: progress to date." Human Gene Ther. 25:684-693.
Effect of early and late intervention of frataxin restoration in frataxin knockdown mouse model

Award type: General Research Grant
Grant Title: Effect of early and late intervention of frataxin restoration in frataxin knockdown mouse model
Lay summary: Friedreich's ataxia (FRDA) the most commonly inherited ataxia is caused by severely reduced levels of frataxin (Fxn). The generation of mouse models for FRDA is vital for understanding and designing better therapeutic strategies. Existing fxn knockout FRDA animal models are either mildly symptomatic or restricted in their ability to recapitulate and evaluate the spatial and temporal aspects of FRDA pathology, as they are engineered to be tissue-specific conditional knockouts. We have developed an inducible mouse model for FRDA that permits reversible frataxin knockdown and detailed studies of the temporal progression or recovery following restoration of frataxin expression. We targeted a single copy shRNA against the Fxn transgene (doxycycline- inducible) under the control of H1 promoter gene into the rosa26 genomic locus. Fxn knockdown was achieved to control the onset and progression of the disease depending on the dose of doxycycline (dox). We observed behavioral deficits including ataxia, early mortality, defect in muscle strength, as well as degeneration of dorsal root ganglia, cardiomyopathy, and iron deposition, parallel to what is observed in FRDA patients. It is important to note that this is the first FRDA animal model that exhibits several symptoms parallel to FRDA, which can be rescued. Rescue experiments were carried out by withdrawal of dox to reverse the acceleration of disease progression even after significant motor dysfunction was observed. In this proposed project, we plan to characterize and identify molecular mechanism due to the effect of early and late frataxin restoration after Fxn knockdown in our mouse model. We plan to ask three critical questions: (1) What are the early molecular changes due to Fxn knockdown and restoration? (2) Which behavioral, physiological and pathological deficits can be rescued when Fxn levels are restored at the end stage of the disease? (3) What are the structural, molecular and functional architectural changes in intact biological tissues due to Fxn knockdown and rescue? These questions and this mouse model will enable us to better understand the Fxn function and will be essential for establishing various therapeutic strategies for FRDA.
Publications
- Chandran V, Gao K, Swarup V, Versano R, Dong H, Jordan MC, and Geschwind DH. (2017) "Inducible and reversible phenotypes in a novel mouse model of Friedreich's Ataxia." Elife. 6:e30054.

For more informational about grants awarded for Natural history,
please visit our Clinical Network and Trials page.
Additionally, please visit the Research resources page to learn more about FA models
and patient sample collection and sharing within the FA research community.

Protein biomarkers in FRDA cardiomyopathy to monitor disease progression and therapeutic efficacy

Award type: General Research Grant
Grant Title: Protein biomarkers in FRDA cardiomyopathy to monitor disease progression and therapeutic efficacy
Lay summary: Monitoring disease progression and therapeutic efficacy of possible treatments represents a major challenge in FRDA. In this proposal, we describe preliminary data and an established research pipeline centered around the role of protein acetylation in heart failure. Acetylation is a small chemical modification present on several cardiac proteins, whose abundance increases in hearts and on serum proteins from humans with FRDA. Therefore, we propose a comprehensive experimental design to monitor changes in circulating proteins and changes in cardiac proteins or their acetylation state. Based on these findings, we will test an innovative idea that existing or novel protein biomarkers when analyzed in their acetylated form(s) could successfully stratify patients in early stages of heart failure in FRDA. We will leverage our expertise in proteomic technologies and our collaborations with the FRDA community to identify protein biomarkers in FRDA cardiomyopathy to monitor disease progression. Future development of this proposal would be inexpensive and have multiple, early benchmarks, and could be applied to on-going pre-clinical studies. If successful, this new tool could be quickly implemented and have significant impact on the diagnosis and treatment of heart failure in FRDA.
Publications
- Martin AS, Abraham DM, Hershberger KA, Bhatt DP, Mao L, Cui H, Liu J, Liu X, Muehlbauer MJ, Grimsrud PA, Locasale JW, Payne RM, and Hirschey MD. (2017) "Nicotinamide mononucleotide requires SIRT3 to improve cardiac function and bioenergetics in a Friedreich's ataxia cardiomyopathy model." JCI Insight. 2:93885.
- Stram AR, Wagner GR, Fogler BD, Pride PM, Hirschey MD, and Payne RM. (2017) "Progressive mitochondrial protein lysine acetylation and heart failure in a model of Friedreich's ataxia cardiomyopathy." PLoS ONE. 12:e0178354.
Clinical outcome measures of efficacy in the treatment of Friedreich's ataxia

Award type: General Research Grant
Grant Title: Clinical outcome measures of efficacy in the treatment of Friedreich's ataxia
Lay summary: The purpose of this multi-year longitudinal study is to identify the natural progression of Friedreich's Ataxia (FA), including disease phenotypes and their correlation with disease severity, current standard of care and adverse events. A key goal of this study is to develop and validate outcome measures that can be used in the development of future clinical trials for definitive treatment of FA. The development of a successful treatment is dependent not only on the understanding of the pathophysiological mechanisms of the disease and the attributes of the proposed therapeutic product, but also on the identification of sensitive and non-invasive, or minimally invasive outcome measures to demonstrate the potential effect of treatment. The identification of sensitive outcome measures evaluating both the cardiac, metabolic, and neuromuscular function in FA will be crucial to: 1) Evaluate the naturally-occurring changes in neural function as the result of growth, maturation, disease progression, or secondary consequences of the disease; and 2) Detect the effectiveness of potential therapeutic strategies. In this study, we will characterize measures of cardiac performance, neuromuscular physiology, speech and swallowing, as well as frataxin protein quantification in children and adults with FA. To achieve these objectives, we will use cutting edge techniques, including echocardiography and magnetic resonance imaging (MRI), metabolic exercise testing, neurophysiological and mass spectrometry measures. We are planning a 5-year, bi-annual, longitudinal study of 50 individuals with a confirmed diagnosis of Friedreich's Ataxia. Completion of this project will be an important milestone to advance the study of the natural history, discovery and validation of clinical outcome measures and biomarkers in FA. In addition, results of this study might be implemented in potential clinical trials to evaluate the effect of treatment.
Publications
- Smith BK, Renno MS, Green MM, Sexton TM, Lawson LA, Martin AD, Corti M, and Byrne BJ. (2016) "Respiratory motor function in individuals with centronuclear myopathies." Muscle Nerve. 53:214-21.
- Doerfler P, Nayak S, Corti M, Morel L, Herzog R, and Byrne BJ. (2016) "Targeted Approaches to Induce Immune Tolerance for Pompe Disease Therapy." Molecular therapy. Methods & clinical development. 3:15053.
- Corti M, Cleaver B, Clément N, Conlon TJ, Faris KJ, Wang G, Benson J, Tarantal AF, Fuller D, Herzog RW, and Byrne BJ. (2015) "Evaluation of Readministration of a Recombinant Adeno-Associated Virus Vector Expressing Acid Alpha-Glucosidase in Pompe Disease: Preclinical to Clinical Planning. Hum Gene Ther Clin Dev. 26:185-93.
- Corti M, Elder M, Falk D, Lawson L, Smith B, Nayak S, Conlon T, Clement N, Erger K, Lavassani E, Green M, Doerfler P, Herzog R, and Byrne B. (2014) "B-Cell Depletion is Protective Against Anti-AAV Capsid Immune Response: A Human Subject Case Study." Mol Ther Methods Clin Dev. 1. pii: 14033.
Early and longitudinal assessment of neurodegeneration in the brain and spinal cord in Friedreich's ataxia

Award type: General Research Grant
Grant Title: Early and longitudinal assessment of neurodegeneration in the brain and spinal cord in Friedreich's ataxia
Lay summary: This project is a continuation of our Kyle Bryant Translational Research Award (2013-2014). Our main goal is to identify neuroimaging biomarkers of Friedreich's ataxia (FRDA) using Magnetic Resonance Spectroscopy (MRS) and diffusion Magnetic Resonance Imaging (diffusion MRI) in the central nervous system of individuals with FRDA. This work is conducted at the Center for Magnetic Resonance Research (CMRR) at the University of Minnesota. This year, a number of participants (N=11) from the initial cohort came back for one-year follow-up scans, so that we could investigate how the measured MR parameters vary over time. MRS imaging showed a statistically significant decrease (-19%, p = 0.004) in a metabolite called N-acetyl-aspartate (tNAA) in the spine over one year. tNAA is a validated biomarker of brain activity and is localized in neurons. As such, the loss of tNAA directly reflects neurodegeneration. Similarly, dMRI scans showed a decrease in fractional anisotropy (-5.5%) in the spine, at the C4-C5 level, over one year, which was close to statistical significance (p = 0.057). This is consistent with loss of fiber tracts in the spine, again indicative of neurodegeneration. In the brain, we observed trending longitudinal changes in certain white matter pathways, such as the corticospinal tracts or cerebellar peduncles. However, these data did not reach statistical significance, though we are still analyzing some datasets. For the current funding period of our grant, we recruited eight new individuals with early stage FRDA and five new controls to match the distributions of age/gender of newly enrolled participants. We have two specific aims: 1) a longitudinal follow-up of patients with FRDA already scanned at the CMRR to assess the year-to-year evolution of observed microstructural and neurochemical alterations; and 2) an assessment of biochemical and microstructural changes in pre-symptomatic/early stage individuals. To summarize our findings thus far, both MRS and DWI measurements appear to be sensitive to disease progression in the spine in a relatively small number of subjects, and are therefore promising candidate biomarkers.
Publications
- Farooq H, Xu J, Nam JW, Keefe DF, Yacoub E, Georgiou T, and Lenglet C. (2016) "Microstructure Imaging of Crossing (MIX) White Matter Fibers from diffusion MRI." Sci Rep. 6:38927.
- Valette J, Park JY, Gröhn O, Ugurbil K, Garwood M, and Henry PG. (2007) "Spectroscopic imaging with volume selection by unpaired adiabatic pi pulses: theory and application." J Magn Reson. 189:1-12.
Measurement of the TCA cycle rate in the dentate nucleus in Friedreich's Ataxia

Award type: General Research Grant
Grant Title: Measurement of the TCA cycle rate in the dentate nucleus in Friedreich's Ataxia
Lay summary: In vivo carbon-13 magnetic resonance spectroscopy (13C MRS) allows for non-invasive measurement of metabolic rates in living tissues. Imaging is achieved following systemic administration of a nontoxic 13C- labeled substrate. In particular, the TCA cycle rate can be measured non-invasively in the human brain as an indicator of neuronal damage from impairments in mitochondrial energy production, such as those observed in Friedreich's ataxia (FRDA). As glucose can cross the blood-brain barrier and is readily taken up by neurons, one can monitor the conversion of 13C- labeled glucose—[1-13C]glucose—to 13C-glutamate, which occurs in the TCA cycle (1). Incorporation of the 13C-label from [1-13C]glucose into [3-13C]-glutamate or [4-13C]-glutamate occurs in functional mitochondria with an active TCA cycle. Measurements of this incorporation are fitted with a mathematical model to determine the TCA cycle rate. In a previous study in the rat brain at 3 Tesla using this methodology, treatment with an inhibitor of succinate dehydrogenase in the TCA cycle, 3-nitroproprionate, resulted in a statistically significant 18% decrease in the TCA cycle rate (2). This demonstrated that impairment of the TCA cycle can be measured in vivo. We propose to conduct these measurements in FRDA patients here at the Center for Magnetic Resonance Research (CMRR) at the University of Minnesota with the team of Dr. Elizabeth Seaquist, who is Director of the Division of Endocrinology and Diabetes at the University of Minnesota. Dr. Seaquist and the CMRR have been conducting numerous studies of brain energy metabolism using glucose infusion 13C-glucose infusion in the past 20 years. Examples of studies include measurement of the TCA cycle rate in the visual cortex during visual stimulation (3) and measurement of the TCA cycle rate in the visual cortex in diabetic patients (4). For our study, we aim to perform similar measurements of the TCA cycle rate in the cerebellar white matter, in a relatively small volume (5 ml) encompassing the dentate nucleus in one hemisphere. These would be the first measurements of the TCA cycle in the human cerebellum using 13C MRS, and the first such measurements in FRDA patients.
Co-sponsor: CureFA Foundation
Lay abstract references
- Henry PG, Adriany G, Deelchand D, Gruetter R, Marjanska M, Oz G, Seaquist ER, Shestov A, Ugurbil K. (2006) "In vivo 13C NMR spectroscopy and metabolic modeling in the brain: a practical perspective." Magn Reson Imaging. 24:527-39.
- Henry PG, Lebon V, Vaufrey F, Brouillet E, Hantraye P, and Bloch G. (2002) "Decreased TCA cycle rate in the rat brain after acute 3-NP treatment measured by in vivo 1H-[13C] NMR spectroscopy." Journal of Neurochemistry. 82:857-866.
- Chen W, Zhu XH, Gruetter R, Seaquist ER, Adriany G, and Ugurbil K. (2001) "Study of tricarboxylic acid cycle flux changes in human visual cortex during hemifield visual stimulation using 1H-{13C} MRS and fMRI." Magnetic Resonance in Medicine. 45:349-355.
- Henry PG, Criego AB, Kumar A, and Seaquist ER. (2010) "Measurement of cerebral oxidative glucose consumption in patients with type 1 diabetes mellitus and hypoglycemia unawareness using (13)C nuclear magnetic resonance spectroscopy." Metabolism: clinical and experimental. 59:100-106.
Defining the molecular signature of FA to identify novel biomarkers

Award type: General Research Grant
Grant Title: Defining the molecular signature of FA to identify novel biomarkers
Lay summary: Friedreich's ataxia (FRDA) is a severe progressive neurodegenerative disorder caused by lower production of the frataxin protein. Its deficiency leads to complex changes in multiple organs of FRDA patients. Neurons and heart cells are the most sensitive to reduced frataxin. As all functions of a living being are interconnected, the deficiency of a single, critical protein has severe consequences to other genes and proteins in cells. Identifying these changes that occur in FRDA requires sensitive analyses of many samples. Uncovering the consequences of frataxin deficiency can define new therapeutic targets, and help identify new molecular hallmarks of the disease called biomarkers. The National Institutes of Health define a biomarker as any characteristic that can be objectively measured and evaluated as an indicator of normal functions, disease, or response to treatment. Identifying reliable biomarkers is important for consistent assessment of disease progression, treatment effectiveness, or prediction of symptom development. We conducted a detailed analysis of all genes active in FRDA fibroblast cells and compared them to unaffected fibroblast cells. We also conducted a similar comparative screen of small regulatory molecules called miRNAs. For these experiments, we used state of the art next generation RNA sequencing and miRNA sequencing techniques and many patient and control samples that have been collected over the past four years. In the proposed project we will: (i) define novel FRDA biomarkers identified by RNA and miRNA analyses (ii) validate these biomarkers in neuronal and cardiac cells; (iii) validate and adapt the analysis of selected biomarkers for routine testing in a clinical setting. The primary goal of these studies is to uncover and validate novel biomarkers that can be used in clinical practice, as well as define new targets for therapy. This work will also result in a well- characterized Friedreich's ataxia cell bank available to the entire FRDA research community.
Co-sponsor: FARA Ireland
Publications
- Li Y, Lu Y, Polak U, Lin K, Shen J, Farmer J, Seyer L, Bhalla AD, Rozwadowska N, Lynch DR, Butler JS, Napierala M. (2015) "Expanded GAA repeats impede transcription elongation through the FXN gene and induce transcriptional silencing that is restricted to the FXN locus." Human molecular genetics. 24:6932-43.
- Li Y, Polak U, Bhalla AD, Rozwadowska N, Butler JS, Lynch DR, Dent SYR, Napierala M. (2015) "Excision of Expanded GAA Repeats Alleviates the Molecular Phenotype of Friedreich's Ataxia." Molecular therapy: the journal of the American Society of Gene Therapy. 23:1055-1065.
Identification of FRDA gene expression biomarkers for Phase II/III efficacy trials in FA

Award type: General Research Grant
Grant Title: Identification of FRDA gene expression biomarkers for Phase II/III efficacy trials in FA
Lay summary: The focus of our research is to conduct gene expression studies using the cutting-edge technology RNA-sequencing with two broad aims. For the first aim, we seek to identify FRDA gene expression biomarkers that can be used for Phase II/III efficacy trials in FRDA patients. While frataxin (mRNA or protein) provides a valid biomarker for such studies, increases in frataxin do not necessarily indicate reversal of mitochondrial dysfunction. Thus, we wish to identify gene expression signatures that are common to both cells that are affected in FRDA (i.e., neurons and cardiomyocytes, derived from patient induced pluripotent stem cells or iPSCs) and circulating lymphocytes (i.e., PBMCs from FRDA patients) that reflect correction of mitochondrial dysfunction in FRDA. Patient PBMCs will be obtained by local patient donation at Scripps Clinic and through on-going collaborative efforts with FARA and Dr. Susan Perlman at University of California Los Angles (UCLA). For our second aim, we seek to determine the genome-wide effects of a protective single nucleotide polymorphism (SNP) - serine to asparagine mutation at amino acid 46 (Ser/Asn46) - in the gene encoding the protein deacetylase Sirt6. Preliminary data obtained in collaboration with Dr. David Lynch at the Children's Hospital of Philadelphia (CHOP) has suggested that individuals who are heterozygous for the Sirt6 gene have a better disease outcome than expected, when considering their GAA repeat status. We wish to identify genes and pathways that are differentially affected in neuronal cells expressing the most common Sirt6 variant (i.e, Asn/Asn46) versus the SNP Asn/Ser46 Sirt6. This will be accomplished using RNA-sequencing methods and isogenic iPSC-derived neurons.
Publications
- Soragni E, Gottesfeld JM. (2016) "Translating HDAC inhibitors in Friedreich's ataxia." Expert Opin Orphan Drugs. 4:961-970.
- Soragni E, Chou CJ, Rusche JR, Gottesfeld JM. (2015) Mechanism of Action of 2-Aminobenzamide HDAC Inhibitors in Reversing Gene Silencing in Friedreich's Ataxia. Front Neurol. 6:44.

Impact of Frataxin deficiency on cardiac substrate metabolism

Award type: Keith Michael Andrus Cardiac Research Award
Grant Title: Impact of Frataxin deficiency on cardiac substrate metabolism
Lay summary: Hypertrophic cardiomyopathy occurs in many individuals diagnosed with Friedreich's Ataxia (FA), and can progress to heart failure; approximately 60% of deaths from FA are due to heart failure. How deficiency in Frataxin (Fxn) causes hypertrophic cardiomyopathy and heart failure remains unknown. Cardiomyopathy from other causes is often associated with changes in cardiac metabolism that can worsen the cardiac dysfunction. Because Fxn deficiency is associated with a decrease in the activity of key enzymes of the Krebs cycle and the electron transport chain, it seems reasonable to predict that Fxn deficiency will be associated with disturbances in mitochondrial ATP production and substrate metabolism, and that these disturbance cause or worsen heart function. As such, the goal of our proposal is to investigate shifts in cardiac and skeletal muscle substrate metabolism in the UCLA inducible Friedreich's ataxia mouse model. The first aim of our proposal focuses on cardiac fatty acid metabolism, as fatty acids are the main oxidized substrate in the heart. As deficiency of Krebs cycle and electron transport chain activities worsens due to Fxn depletion, we hypothesize that lipid overload will develop in cardiac mitochondria, with a subsequent accumulation of acyl-CoA and acetyl-CoA species, a decreased ability to switch to glucose oxidation, and hyperacetylation of mitochondrial proteins. Overall, this is predicted to further decrease the ATP-synthesizing capacity of cardiac mitochondria beyond the primary effects of Fxn depletion. A second area of interest for our group is the skeletal muscle, which, like the heart, relies heavily on mitochondrial fatty acid oxidation to synthesize ATP, even at rest. Thus, we hypothesize that skeletal muscle deficient in Fxn will also exhibit metabolic abnormalities, and that these will correlate with the progression of cardiac dysfunction. Furthermore, we suspect that, like the heart, these abnormalities will stem from lipid overload in mitochondria due to progressive dysfunction of the Krebs cycle and the electron transport chain. Proteins that mediate substrate uptake and metabolism in heart mitochondria are currently being targeted for treating cardiomyopathy of various origins, with the goal of preventing the progression to heart failure. Understanding how Fxn deficiency alters cardiac metabolism would tell us if drugs that are efficacious for treating other forms of cardiomyopathy could be useful for FA patients.
Publications
- Moffat C, Bhatia L, Nguyen T, Lynch P, Wang M, Wang D, Ilkayeva OR, Han X, Hirschey MD, Claypool SM, Seifert EL. (2014) "Acyl-CoA thioesterase-2 facilitates fatty acid oxidation in the liver". J Lipid Res. 55:2458-70.
- Antony AN*, Paillard M*, Moffat C*, Juskeviciute E, Correnti J, Bolon B, Rubin E, Csordas G, Seifert EL#, Hoek JB# and Hajnoczky G#. (2016) "MICU1 regulation of mitochondrial Ca2+ uptake dictates survival and tissue regeneration". Nature Communications. 7:10955. *co-first authors. #Co-corresponding authors.
Screening of phenotypic abnormalities in Friedreich's ataxia-induced pluripotent stem cell-derived CMs

Award type: Keith Michael Andrus Cardiac Research Award
Grant Title: Screening of phenotypic abnormalities in Friedreich's ataxia-induced pluripotent stem cell-derived CMs
Lay summary: Stem cells derived from patients are ideal for therapies as they are not rejected following transplantation. Until recently, this could only be achieved by deriving human embryonic stem cells (hESCs) from fertilized embryos. A novel technology has been developed to generate induced pluripotent stem cells (iPSCs), whereby 4-6 genes are introduced into an adult somatic cell, like skin fibroblast, resulting in its reprogramming to become 'embryonic-like' or pluripotent. These iPSCs are similar to hESCs in that they are able to differentiate into all cell types of the body. iPSCs can be generated from sufferers of genetically inherited diseases such as Friedreich's ataxia (FRDA), and would not be rejected following transplantation back to the patient. Therefore, iPSCs provide an excellent alternative to therapeutic cloning with hESCs. Furthermore, iPSCs derived from patients can be used as human cellular disease modeling and as a platform for personalized medicine. We have developed efficient protocols to generate high numbers of iPSC-derived cardiomyocytes (CMs), which can be used to assess disease-specific phenotypes and as a drug-screening platform for rescue of identified pathogenic signatures. Using iPSCs-CMs generated from FRDA patients, we have identified the following cellular phenotypes in the FRDA-CMs: reduced oxidative phosphorylation activity and abnormal electrophysiology. Using these cell lines, we will test for other cellular phenotypes (e.g., calcium cycling) to assess whether the phenotypes contribute to the pathogenesis of the FRDA cardiac dysfunction. As well, we aim to correct these phenotypes using an oligonucleotide approach to augment frataxin (Fxn) levels, reversing the genetic deficiency of Fxn in FRDA. This project will identify cardiac phenotypes in human FRDA-CMs and lead to the generation of a drug-screening platform, enabling the identification of potential new treatments as well as the assessment of efficacy (and toxicity) of current potential treatments. Taken together, iPSC technology holds great potential for developing novel therapeutic approaches in FRDA.
Publications
- Crombie DE, Curl CL, Raaijmakers AJ, Sivakumaran P, Kulkarni T, Wong RC, Minami I, Evans-Galea MV, Lim SY, Delbridge L, Corben LA, Dottori M, Nakatsuji N, Trounce IA, Hewitt AW, Delatycki MB, Pera MF, Pebay A. (2017) "Friedreich's ataxia induced pluripotent stem cell-derived cardiomyocytes display electrophysiological abnormalities and calcium handling deficiency." Aging (Albany NY). 9:1440-1452.
- Crombie DE, Daniszewski M, Liang HH, Kulkarni T, Li F, Lidgerwood GE, Conquest A, Hernandez D, Hung SS, Gill KP, De Smit E, Kearns LS, Clarke L, Sluch VM, Chamling X, Zack DJ, Wong RCB, Hewitt AW, Pebay A. (2017) "Development of a Modular Automated System for Maintenance and Differentiation of Adherent Human Pluripotent Stem Cells." SLAS Discov. 22:1016-1025.
Mitochondrial Protein Acetylation and Heart Failure in FA

PI/Investigator: Matthew Hirschey, PhD - Duke University, NC, USA
Award type: General Research Grant
Grant Title: Mitochondrial Protein Acetylation and Heart Failure in FA
Lay summary: Friedreich's Ataxia (FRDA) is a progressive and fatal disease of the heart and brain with no definite treatment modality. Patients die at a young age with severe hypertrophic cardiomyopathy due to mitochondrial proliferation and heart failure, and are at increased risk of poor cardiovascular outcome and death with surgical stress. There is an urgent and unmet need to understand the mechanism(s) of heart failure in FRDA to guide the rational development of effective treatments and identify patients at greatest risk of death. This project is a collaborative effort between Dr. Mark Payne, MD, at the Indiana University School of Medicine, and Dr. Matt Hirschey, PhD, at Duke University School of Medicine, to understand the biochemical basis of heart failure in FRDA. Both of our labs have independently made recent novel findings that may represent critical events in the mitochondrial dysfunction that underlies the fatal cardiomyopathy of FRDA: The Hirschey lab has made the fundamental finding that mitochondrial proteins can be modified ('acetylated') and become less active, and that a specific enzyme ('SIRT3') is responsible for restoring their activity to normal. The Payne lab has made the disease-related finding that mitochondrial proteins from the heart in FRDA are heavily modified ('acetylated'), and this may reduce their ability to use normal fuels (fat) for energy, thus causing heart failure. We propose to combine the strengths of both labs to explore and determine the mechanism of mitochondrial dysfunction underlying heart failure in FRDA. If correct, these findings would identify an important mechanism underlying mitochondrial dysfunction in FRDA, and would explain why FRDA patients develop a fatal hypertrophic cardiomyopathy. Furthermore, these findings would identify a new treatment strategy for FRDA patients by pharmacologically targeting protein acetylation, resulting in new and innovative approaches for FRDA treatment.
Co-sponsor: FARA Ireland
Publications
- Stram AR, Wagner GR, Fogler BD, Pride PM, Hirschey MD, Payne RM. (2017) "Progressive mitochondrial protein lysine acetylation and heart failure in a model of Friedreich's ataxia cardiomyopathy." PLoS One. 12:e0178354.
- Martin AS, Abraham DM, Hershberger KA, Bhatt DP, Mao L, Cui H, Liu J, Liu X, Muehlbauer MJ, Grimsrud PA, Locasale JW, Payne RM, Hirschey MD. (2017) "Nicotinamide mononucleotide requires SIRT3 to improve cardiac function and bioenergetics in a Friedreich's ataxia cardiomyopathy model." JCI Insight. 2:93885.
Investigation of cardiac pathophysiological mechanism and relevant biomarker in the context of FXN deficiency and FXN overexpression induced toxicity

Award type: Keith Michael Andrus Cardiac Research Award
Grant Title: Investigation of cardiac pathophysiological mechanism and relevant biomarker in the context of FXN deficiency and FXN overexpression induced toxicity
Lay summary: Many therapeutic strategies for FA aim at increasing the cellular level of FXN or alleviating the secondary pathological events which are both impairing mitochondria function and bioenergetics. However, most of the clinical trials have relied on peripheral cells (blood or buccal cells) to validate the short-term bio-availability and the biological effect of the investigational drug. In the present proposal, we aim at developing a comprehensive framework for facilitating the preclinical development and validation of therapeutic strategies for FA cardiomyopathy, with a particular focus on the cardiac gene therapy protocol that we have developed. We have previously shown the proof of concept for the prevention and the correction of FA cardiomyopathy by in vivo gene therapy [1]. More recently, we have conducted a series of dose response studies, which have defined the therapeutic thresholds (histological and molecular) conditioning the stabilization or the correction of the cardiac function in the MCK mouse model (funded by FARA and AAVLife/Annapurna Therapeutics). On the basis of these results, AAVlife/Annapurna is optimizing the administration paradigm in large animal model. The vector that has currently been used in proof of concept studies in the MCK model is under the control of a ubiquitous promoter that expresses levels of frataxin that are 10 to 50 fold higher than the endogenous level. Although no toxicity has been seen with this level of frataxin in the MCK mouse model over 1 year, it is difficult to predict the potential of toxicity of such high amounts of frataxin over several years, as it would be the case in FA patients. Therefore, to finalize the preclinical development of this gene therapy protocol, we have started to investigate the effect of high level of FXN overexpression in order to identify the upper threshold limit. In parallel, we are trying to identify potential biomarkers reflecting the physiological state of the cardiomyocytes in the context of FXN deficiency or FXN overexpression. In preliminary experiments, we have shown in the MCK mouse model that cardiac overexpression of FXN at a level over 100 fold the endogenous level is associated with severe mitochondria and cardiomyocytes dysfunction, which is eventually deleterious for cardiac function. The first objective of this project is to study the pathological mechanisms associated with these toxic events and to identify clinical relevant biomarkers reflecting the mitochondria function and metabolic state of cardiomyocytes in order to provide biosafety guidelines in FA clinical trials (gene or pharmacological therapies). The second objective is to generate with a minimum time and resources, a specific cardiac conditional KO mouse model recapitulating the FA cardiac phenotype similarly to the MCK mouse model, but without the artefactual peripheral myopathy observed at 15 weeks of age in the MCK mice model [1]. This new mouse model will be available to the FA community and should facilitate greatly the therapeutic evaluation of new drug and the investigation of specific plasmatic biomarker. The third objective is to identify potential biomarkers relevant for FXN deficiency and FA cardiomyopathy, either plasmatic or by in vivo imaging, which could be used as secondary endpoints in clinical trial, the clinical management of FA patients, as a diagnostic and if possible a predictive tool of the cardiac phenotype.
Lay abstract references
- Perdomini M, Belbellaa B, Monassier L, Reutenauer L, Messaddeq N, Cartier N, Crystal RG, Aubourg P, Puccio H. (2014) "Prevention and reversal of severe mitochondrial cardiomyopathy by gene therapy in a mouse model of Friedreich's ataxia." Nat Med. 20:542-7.

Speech treatment in Friedreich ataxia

PI/Investigator: Matthis Synofzik, PhD - University of Tubingen, Germany
Award type: Bronya J. Keats International Research Collaboration Award
Grant Title: Speech treatment in Friedreich ataxia
Lay summary: Disordered speech is a devastating and inevitable consequence of many hereditary ataxias, particularly in Friedreich ataxia (FRDA). There are no known therapies that halt the natural progression of the overall disease or the speech disorder (dysarthria) in any neurodegenerative ataxia; however, therapy that improves speech is within reach. Our research in speech and ataxia has described the insidious functional decline, loss of ability to carry out basic tasks and diminished quality of life in FRDA. Our successful pilot trial of a speech treatment in hereditary ataxias using principles of motor learning (PML), neuroplasticity, and biofeedback, as well as interventions by Synofzik/Schöls delivered via physiotherapy or highly motivating exercise video-gaming have now paved the way for first evidence-based therapies in FRDA. The clinical space for FRDA now urgently warrants an evidence based speech rehabilitation program that caters to the physical, sensory and motor limitations of people with FRDA. To that end, we have designed a home-based, intensive four-week speech exercise program designed to improve speech in people with FRDA. The treatment protocol is based on PML and neuroplasticity with a focus on improving speech intelligibility and vocal control. Exercises and feedback were created to enhance self-monitoring and include computer based aural, visual and results feedback and self-management. We will measure speech objectively using methods designed for clinical trials by Vogel and Maruff, and perceptual gains in speech intelligibility and quality of life at baseline, directly after intervention, and 3- and 6-months post intervention. Neither the Ataxia UK nor FARA Clinical Guidelines could provide evidence based speech rehabilitation options for clinicians. We will now establish the world-first evidence-based speech therapy for FRDA. Specifically, our aim is to evaluate the hypothesis that intensive speech rehabilitation using biofeedback will lead to improved speech intelligibility (i.e., ability to be understood) in FRDA compared to existing care. If this hypothesis is supported, our research will change the landscape of clinical care for FRDA globally by influencing health policy and improving patient outcomes in this disease group and likely also other degenerative ataxias.
Co-sponsor: fara Australia and FARA Ireland
Publications
- Folker JE, Murdoch BE, Cahill LM, Delatycki MB, Corben LA, and Vogel AP. (2010) "Dysarthria in Friedreich's ataxia: a perceptual analysis." Folia Phoniatrica et Logopaedia. 62:97-103.
- Ilg W, Schatton C, Schicks J, Giese MA, Schols L, and Synofzik M. (2012) "Video game-based coordinative training improves ataxia in children with degenerative ataxia." Neurology. 79:2056-60.
- Brendel B, Ackermann H, Berg D, Lindig T, Schölderle T, Schöls L, Synofzik M, and Ziegler W. (2013) "Friedreich Ataxia: Dysarthria Profile and Clinical Data." Cerebellum. 12:475-84.
- Gibilisco P, and Vogel AP. (2013) "Friedreich ataxia." BMJ. 347: f7062.
- Synofzik M and Ilg W. (2014) "Motor Training in Degenerative Spinocerebellar Disease: Ataxia- Specific Improvements by Intensive Physiotherapy and Exergames." BioMed Research International. 2014: 583507.
- Schatton C, Synofzik M, Fleszar Z, Giese MA, Schöls L, and Ilg W. (2017) "Individualized exergame training improves postural control in advanced degenerative spinocerebellar ataxia: A rater- blinded, intra-individually controlled trial." Parkinsonism & Related Disorders. 39:80-4.
- Vogel AP, Wardrop M, Folker J, Synofzik M, Corben L, Delatycki M, and Awan S. (2017) "Voice in Friedreich Ataxia." Journal of Voice. 31:e9–243.


Specific guidelines for each grant type
FARA accepts LOIs from qualified investigators for projects that target FARA's research priorities twice per year (due February 1 and July 15).
For those invited to submit a full application, the deadlines for submission are April 1 and September 15, respectively.
On the Main Grant Page, put "General Research" in the "Grant Type" field.
The applicant may request a budget of up to $150,000 per year for one or two years.
General Research Grant Subtype:
Postdoctoral Trainees and Ph.D. Students
Salaries for all those contributing to the research project (PI, postdocs, graduate students, research associates, etc.) can be requested under personnel costs in the budget of a General Research Grant application.
Additionally, FARA has an application subtype specifically for PIs requesting only salary (plus applicable benefits) to support postdoctoral trainees and Ph.D. students in their laboratory. The PI is encouraged to involve the trainee/student in the preparation of the research plan to be submitted with the application. The name and CV of the postdoctoral trainee or Ph.D. student must be included in the application.
The guidelines for General Research Grants should be followed, but the only allowable budget item is salary for the postdoctoral trainee or Ph.D. student (plus applicable benefits and tuition support) and the requested amount must not exceed the appropriate NIH stipend level.
FARA accepts LOIs focusing on FA research that relies on international collaboration among investigators in at least two different countries. Special consideration will be given to proposals that bring new scientists to the FA community. The rationale for the collaboration needs to be convincing and must clearly demonstrate that the research goals could not be achieved by just one of the participating groups and that the synergy among the groups is essential for the success of the project.
The deadline for the LOI is May 15. For those invited to submit a full application, the deadline for submission is July 15.
On the Main Grant Page, put "Keats Award" in the "Grant Type" field. The applicants may request a combined budget of up to $200,000 per year for one or two years.
FARA accepts LOIs focusing on advancing understanding and/or treatment of the cardiac involvement in FA.
The deadline for the LOI is January 15. For those invited to submit a full application, the deadline for submission is March 1. On the Main Grant Page, put "KMA Award" in the "Grant Type" field. The applicant may request a budget of up to $150,000 per year for one or two years.
Learn more about Keith Michael Andrus and past award recipients
FARA accepts LOIs focusing on pre-clinical and clinical investigations that will advance treatments for FA. The specific aims must target one or more of the following:
- Identification of biomarkers for FA that will elucidate disease variability, severity, and prognosis; facilitate drug screening, and/or optimize selection of patients and clinical endpoints for clinical trials;
- Development of tools and technologies that can (a) be directly used for therapy development; (b) overcome existing obstacles to treatment and (c) be directly applied to, or adapted for, delivery of potential therapeutics;
- Pre-clinical development and testing of potential therapeutics, biologics, and devices in cells and animals;
- Clinical studies of patient outcome measures, potential interventions, or devices.
The deadline for the LOI is May 15. For those invited to submit a full application, the deadline for submission is July 15. On the Main Grant Page, put "KB Translational Award" in the "Grant Type" field. The applicant may request a budget of up to $250,000 per year for one or two years.
FARA fosters collaboration and supports the research community through sponsorship and organization of scientific workshops or meetings. We feel strongly that sharing insights, ideas, and expertise is essential for accelerating progress towards treatments for FA and for helping scientists advance their work effectively. Workshops that bring together FA researchers and researchers in related disease and specialty areas will generate new hypotheses, discoveries and collaborations. These workshops are of two types:
- International Scientific Conferences that provide the opportunity for the full scientific community involved in all aspects of research related to FA to come together to share findings and insights. The conferences are usually a minimum of three days in length. When necessary, FARA will seek financial support from other organizations to help support the conferences. FARA is also willing to receive requests for grant support from other organizations hosting similar workshops.
- Focused Workshops for small groups of scientists that enable in-depth discussions of specific research topics and facilitate ongoing communication and cooperation among the participants. Such workshops should optimize collaboration and minimize costs, and must align with FARA's scientific priorities and mission.
Summaries of scientific meetings that have been hosted by FARA are available at:
http://www.curefa.org/conference.html
FARA will fund direct costs only. Individuals or organizations with a specific interest in organizing a scientific meeting should contact FARA's Executive Director directly (jen.farmer@curefa.org). An executive summary outlining the goals and objectives of the meeting, intended participants, explanation of relevance to the FARA mission, timeline and budget will be required. All requests will be reviewed by FARA's scientific review committee and a recommendation will be submitted to FARA's Board of Directors. The final funding decision will be made by the Board.
FARA will issue RFPs on an ad-hoc basis. These RFPs will be targeted to areas of special interest or to solicit proposals to address a question, issue or resource that has priority. All RFPs will be announced through this website and through our e-bulletin list. If you are not a subscriber please sign-up by selecting "Join Mailing List" at the top of this page and follow the prompts.
All grant applications submitted to FARA undergo a rigorous and confidential review procedure that is overseen by the FARA Scientific Review Committee (SRC) and involves the following steps:
- The SRC makes a preliminary review and if the application is considered acceptable, it undergoes external peer-review by established researchers with the appropriate expertise. The reviewers are assigned by the SRC, often based on suggestions provided by the applicant. Usually one of the reviewers is a member of the FARA Scientific Advisory Board (SAB).
- Each reviewer provides comments and scores based on significance of proposal, approach/methods of the research plan, innovation, investigator/experience, and environment/resources. If funding is recommended, comments are also provided on the appropriateness of the requested budget.
- Following thorough discussion of the reviews, as well as the significance and relevance of the proposed research to FARA's mission and strategic research priorities, the SRC submits those applications for which funding is recommended to the FARA Board of Directors (BOD).
- In making a final funding decision, the FARA BOD takes into account the reviewer comments, the SRC comments and recommendation, the importance and priority level of the proposed research to FARA's goals, and the availability of funds in the FARA treasury (including an assessment of future commitments and requirements).
- Only applications that are recommended for funding by the SRC will be considered for funding by the FARA BOD. The funding decision made by the FARA BOD is final.
All FARA grantees must submit, at a minimum, annual scientific and financial reports.
The required frequency of reports will be stated in the formal funding agreement with FARA. Each report must be submitted as a pdf file by email to grants@curefa.org.Continuation funding will not be provided until all required progress reports are received and reviewed by the FARA SRC, and approved for funding by the FARA BOD.
Instructions and format for Progress and Final Project Reports are as follows:
This report is due two weeks before the end of the annual project period (unless more frequent reports are requested.) It must include the following sections:
- Lay summary of progress towards achieving goals and research plans for the next year, including significance of work to the development of therapies for FA (Maximum of 500 words)
- Scientific report of research results and progress against milestones and research objectives for upcoming term of grant (Maximum of four pages)
- List of publications and presentations that have resulted from FARA funding for this project (Provide a pdf of each publication)
- Patents received/pending and products developed as a result of FARA funding for this project
- Other grants received by the FARA grantee for FA research projects over the past year (agency, title, funding period, overlap with this FARA project)
- Budget status:
- Financial report documenting allocation/use of funds expended from grant during term of award
- Amount and justification of request for the next project period
This report is due no later than one month after the end of the grant. It must include:
- Lay summary of research results including significance of work to the development of therapies for FA (Maximum of 500 words)
- Scientific report of research results and progress against milestones (Maximum of four pages)
- List of publications and presentations that have resulted from FARA funding for this project (Provide a pdf of each publication)
- Patents received/pending and products developed as a result of FARA funding for this project
- Other grants received by the FARA grantee for FA research projects over the past year (agency, title, overlap with this project)
- Budget status:
- Financial report documenting allocation/use of funds expended from grant (Unused funds are to be returned to FARA)
- As stipulated in the contractual agreement with FARA, an official financial statement from the recipient institution must be received no later than two months after the end of the grant
In general, FARA does not allow no-cost extensions. However, a request for a no-cost extension of up to one year will be considered if it is made at least one month before the end of the grant and the reason for the request is compelling. The funds to be carried forward cannot exceed 25% of the amount awarded in the final year. The investigator must explain why the funds were not spent, why the extension is needed and how the requested carry-over will be used to advance the research project.
For a two-year grant, FARA will consider a request for a carry-over of funds at the end of the first year. The amount cannot be greater than 25% of the first year award, the request must be made at least one month before the end of the first year, and a detailed explanation must be provided.
FARA can usually be flexible with the start date for a grant award and will work with the investigator to determine a suitable date, which may be up to three months after the award is approved. If circumstances arise during the funding period that interfere with the progress of the funded research and make it likely that a request will be made for a no-cost extension and/or a carry-over of funds, the investigator is strongly advised to inform FARA immediately.
Additional Grant-Making Organizations
Non-Profit Organizations
US Government Agencies
National Institutes of Health
A principal concern of the NIH is to invest wisely the tax dollars entrusted to it for the support and conduct of biomedical research. This link provides grants and funding opportunities offered by NIH.
NIH is comprised of about 25 separate Institutes and Centers. The Institutes listed below cover one or more symptoms associated with Friedreich's ataxia. You can click on a link to a selected institute to learn more about grant funding and areas of program interest.
Neurological Disorders: National Institute for Neurological Disorders and Stroke (NINDS). The NIH Institute with primary oversight of biomedical research on FRDA.
Diabetes: National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Hypertrophic Cardiomyopathy: National Heart, Lung and Blood Institute (NHLBI)
Genetics: National Human Genome Research Institute (NHGRI)
Antioxidation: National Institute on Aging
Orthopedics: National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Child Development: National Institute of Child and Human Development (NICHD)
Hearing Impairment: National Institute on Deafness & Other Communication Disorders (NIDCD)
NIH RePORTER: (Research Portfolio Online Reporting Tools) A searchable repository of NIH-funded biomedical research projects, as well as publications and patents resulting from NIH funding.