Grants Awarded

PI/Investigator: Javier Santos, PhD – University of Buenos Aires, Argentina

Award type: General Research Grant

Grant Title: Trojan nanobodies to increase frataxin function

Lay summary: This project aims to find ways to increase frataxin by improving its stability and reducing its turnover in the cell.

Iron-sulfur (Fe-S) clusters are essential cofactors present in all known forms of life and required by hundreds of proteins to perform their function. In eukaryotic cells, the biogenesis of most Fe-S clusters occurs in the mitochondria and this process involves the interactions and activities of several proteins. One of them is frataxin, which is a key activator. In FA, frataxin expression is very low due to the presence of long GAA repeats in the gene and, in some rare cases, to the presence of small mutations that produce versions of frataxin that are destroyed very rapidly. Nanobodies (NBs) are smaller versions of antibodies produced in llamas that display high stability, and can be used to target and bind proteins, like frataxin. Dr. Santos and his group have selected NBs that can bind frataxin and propose that these NBs will increase the stability of unstable frataxin variants, thus increasing their level in the cell. Their hypothesis is that frataxin-specific NBs can also improve the frataxin function. They plan to create Trojan versions of NBs, by fusing them with cell penetrating peptides, to allow the NBs to enter cells, and will measure the effects of these nanobodies in rescuing the cellular dysfunction. 

PI/Investigator: Benoit D'Autréaux, PhD, CNRS-CEA-Université Paris-Saclay, France

Award type: General Research Grant

Grant Title: Discovery of frataxin substitute drug candidates for the treatment of Friedreich's ataxia

Lay summary: The D'Autreaux laboratory is looking for new drugs to treat FA by screening chemical libraries with an enzymatic assay to find small molecules that can substitute for frataxin function in the cell.
Iron-sulfur (Fe-S) clusters are small protein cofactors required for the catalytic activities of numerous enzymes, whose biosynthesis is dependent on frataxin. This project aims to find small molecules substituting frataxin in order to restore Fe-S cluster biosynthesis in FA patients. Recent advances in the elucidation of frataxin’s biochemical function make this approach feasible today. The D’Autreaux laboratory has been studying the specific step involving frataxin during Fe-S cluster biosynthesis and based on these data, developed an enzymatic assay that allows to screen chemical libraries to discover molecules replacing frataxin in Fe-S cluster biogenesis. A pilot study of 1,040 compounds from the French national chemical library was performed, validating the robustness of the assay. The investigators then performed a virtual screening, that is a computational technique to predict the ability of a molecule to replace frataxin. This virtual screening allowed them to pre-select a set of 420 molecules out of 80,000 with the highest probability to function as frataxin-substitutes. The test of these 420 promising molecules led to the identification of 8 hits that are potential frataxin-substitute drug candidates. The aims of this project are to: i) test other molecules pre-selected by virtual screening, by sets of 5,000 molecules with the highest predicted ability to replace frataxin, ii) validate the hits of these screening assays in biochemical assays more specific for frataxin activity and iii) to perform virtual screening on another library containing 230 million molecules and test these molecules. The hits of the biochemical assays will then be tested in vivo in an FA fruit fly model to test the ability of these drugs to prevent, delay or revert the phenotypes induced by frataxin deficiency. They also aim to better characterize the mode of action of the hits, to improve the efficacy of the drugs. These drug candidates can then be tested in mouse models and ultimately in clinical trials.

Co-sponsor: fara Australia

PI/Investigator: David Rufino-Ramos, PhD – Harvard Medical School

Award type: Postdoctoral Fellowship

Grant Title: Developing and delivering of novel gene editing technologies to contract GAA repeats in Friedreich's ataxia

Lay summary: One promising therapeutic approach for FA is to eliminate the root cause of the disease by contracting the expanded GAA repeat in the FXN gene using genome editing technologies. Genome editing technologies have revolutionized research by democratizing genetic changes and expanding our ability to make customizable modifications to the human genome. In this project, Dr Rufino-Ramos will explore a variety of CRISPR-based editing tools to contract the GAA repeats, which will correct the FXN defect and thereby restore frataxin expression. To minimize unwanted genetic modifications in other parts of the genome (called off-targets) by restricting the duration of expression of the genome editing tools, Dr Rufino-Ramos proposes to deliver these enzymes in a transient manner using cell derived vesicles, called extracellular vesicles (EVs). EVs encapsulate, protect, and permit targeting the CRISPR tools to the intended cells for a short period of time—long enough to contract the GAA repeats but short enough to minimize the risk of unwanted genome edits. Together, this research will explore safe and effective methods to treat FA through synergistic optimization of genome editing and delivery approaches.

Co-Sponsor: fara Australia

PI/Investigator: Hynmin Cho, PhD – Stanford University

Award type: Postdoctoral Research Award

Grant Title: Hematopoietic Stem Cell Transplantation in FRDA: Proof-of-concept studies using novel conditioning regimen and the YG8s(GAA)>800 mouse

Lay summary: This proposal seeks to explore the therapeutic potential of hematopoietic stem cell transplantation (HSCT) in a mouse model of FA and identify the mechanisms of metabolic correction by HSCT.

For many years HSCT has been used to treat severe neurodegenerative diseases in children. Recent studies in mice have shown that HSCT may also be beneficial for treating FA. The idea is that stem cells can become cells that act like microglia or macrophages (types of immune cells) in the body, which can help correct metabolic issues in cells affected by the disease by transferring healthy mitochondria. However, this idea is still controversial and needs more testing. The goal of this project is to test if HSCT can help treat FA using a mouse model of the disease and to investigate the role of the chemotherapy used before the transplant. Dr. Cho has shown that that FA mice might require less chemotherapy before the transplant compared to mice with normal levels of frataxin, that cells with low frataxin expression have better mitochondrial transfer, and that low-dose chemotherapy before HSCT can improve symptoms in FA mice. The plan is to test HSCT's potential effectiveness by looking at how it affects cells and molecules in the human FXN transgenic mouse model with more than 800 GAA trinucleotide repeats. Dr Cho will also study how cells transfer mitochondria in vitro and in vivo and identify potential mechanisms using unbiased approaches like single cell-RNA sequencing and proteomics. If successful, this study will provide more evidence to support the use of HSCT to treat FA and may offer new insights into how cells can correct metabolic issues by transferring mitochondria.

Co-Sponsor: fara Australia, made possible through the generosity of the Chant Family bequest

PI/Investigator: Shannon Boye, PhD – University of Florida

Award type: General Research Grant

Grant Title: AAV-mediated therapy for visual impairment associated with Friedreich's ataxia

Lay summary: This proposal seeks to validate a new mouse model for the eye disease in FA and develop a gene therapy to prevent vision loss.

The ocular symptoms of FA are underappreciated since they are not a major cause of mortality, despite a large proportion of FA patients being affected. The retina is the part of the eye that is affected in FA. Photoreceptor cells in the retina capture incoming light, and send signals to downstream cells and ultimately to the brain where those signals are processed as vision. In FA, the cells responsible for sending that signal to the brain, retinal ganglion cells (RGCs), are dysfunctional and can degenerate over time. The goal of this proposal is to develop a new FA mouse model with the ultimate goal of developing a gene therapy to prevent vision loss. Complete knockout of frataxin (FXN) is embryonically lethal and existing conditional knockout models do not focus on retina. Dr. Boye therefore developed a novel, conditional knockout mouse model that lacks FXN expression exclusively in RGCs. Her group has already established that this mouse ("Pou4f2-FXN KO") exhibits clear deficits in retinal structure and function. The plan now is to use those readouts to establish proof of concept that an intravitreally delivered AAV-based gene therapy can prevent vision loss in FA. Experiments are also proposed to optimize an AAV-FXN construct to allow for clinically relevant (safe and effective) levels of FXN in the target cells. To accomplish this goals, Dr. Boye will leverage her deep experience in developing AAV vectors for targeting therapies to the retina and her established track record of performing translational research.

PI/Investigator: Joseph Nabhan, PhD - Vesigen Therapeutics, Cambridge (MA)

Award type: General Research Grant

Grant Title: Evaluation of ARMMs-mediated delivery of Cas9 protein complexed with gRNAs as a non-viral disease-modifying strategy for Friedreich’s ataxia

Lay summary: Excision of the pathogenic GAA repeat expansion from at least one of the FXN alleles has the potential to be a transformative therapy for FA patients, as it does not carry the same potential for toxicity as gene therapy approaches delivering high levels of frataxin using Adeno-Associated Virus (AAV). Unfortunately, despite significant advances in gene editing technologies, like the ones using the CRISPR-Cas9 system, there are limited options for safe, transient, and targeted delivery to disease-affected cell types of these gene editing tools. ARRDC1-Mediated Microvesicles (ARMMs) are a distinct class of extracellular vesicles derived from the cell membrane that are produced through the activity of the protein ARRDC1. Vesigen Therapeutics has developed approaches to engineer their ARMMs to load a variety of cargos, including the tools necessary for genome editing of the GAA repeats. Payloads such as the gene editor Cas9 can be attached to ARRDC1, which actively recruits the cargo into engineered ARMMs. This proposal sets out to evaluate the use of ARMMs as a non-viral delivery vehicle for genome editing tools to excise the pathogenic repeat expansion in FXN. One challenge in this work will be successfully engineering ARMMs to target the tissues most affected in FA, specifically the proprioceptive system, which is responsible for the ability to sense body position and movement and whose early loss in FA leads to limited ambulatory capacity in patients.

PI/Investigator: Changfan Lin, PhD - Caltech

Award type: Postdoctoral Fellowship

Grant Title: Engineering adeno-associated viral vectors to evade immune responses

Lay summary: Gene therapy works by transferring genetic materials (cargo, the FXN gene) in a vector to FA-damaged tissues. Adeno-associated virus vectors (AAVs) are the leading vectors used in gene therapy, given their safe clinical record, robust delivery efficiency, specificity, and superior ability to enter the brain. There are also extensive studies to package regulatory elements into AAVs to make the cargo gene only active in FA-affected tissues, thus minimizing unnecessary harm to other tissues. There are two typical ways to deliver AAVs to human bodies: direct injection and intravenous (IV) injection. Direct injection involves delivering the AAVs directly into the target organ, but its downside is that it will not treat all affected tissues. IV injection on the other hand allows the AAVs to circulate in the bloodstream and reach all therapeutic targets throughout the body. However, IV injections bring the risk of immune toxicity. Up to 70% of human populations have neutralizing antibodies (NAbs) against AAVs which trigger severe immune responses and body damage. For this reason, many clinical treatments have opted to exclude patients with NAbs from AAV-based gene therapy. This proposal aims to engineer AAVs to escape from these Nabs, enabling the treatment of all FA patients. Dr. Lin aims to: (1) develop NAb-based selection assays and screen AAV variants to discover new AAVs that don't bind to NAbs and retain the desired delivery function in model animals; (2) develop novel AAVs targeting newly identified receptors important for AAVs to enter the human brain, in order to enhance brain delivery.

PI/Investigator: Arturo Sala, PhD - Brunel University, London

Award type: Kyle Bryant Translational Research Award

Grant Title: Therapeutic activity of a haematopoietic stem cell delivered tissue penetrating peptide in a Friedreich's ataxia mouse model

Lay summary: The idea behind this proposal is to restore the expression of the Frataxin protein in Friedreich's patients by engineering a secreted, cell penetrating version of the molecule that will be delivered by haematopoietic stem cells (HSCs). Patient's blood stem cells will be modified to carry a virus that produces the cell-penetrating Frataxin. The Frataxin-producing stem cells will be reinfused into patients where they will be retained into the bone marrow. Modified haematopoietic cells circulating in the blood stream will differentiate into macrophages, oligodendrocytes and other terminally differentiated cells which will deliver the therapeutic protein to the damaged tissues, hopefully resulting in a permanent treatment. The main goal of the study is to validate this concept using a mouse model of Friedrich's ataxia, called YG8XLR. YG8XLR mice show reduced expression of FXN and symptoms similar to those of patients. Dr. Sala and his collaborators will use this mouse model to investigate whether intravenous injections of HSCs modified to express Frataxin fused to a cell penetrating peptide ameliorate symptoms and restore normal organ systems functions. In parallel, they will carry out safety studies to gain proof of principle that expression of the therapeutic gene and lentivirus infections are well tolerated and do not result in genotoxicity in mice. If completed, this study should lead to the first cell and gene therapy trial for Friedrich's ataxia.

PI/Investigator: Hélène Puccio, PhD - Institute NeuroMyoGène, Lyon, France

Award type: General Research Grant

Grant Title: Defining the therapeutic window and threshold for neuronal gene therapy in Friedreich Ataxia

Lay summary: Gene replacement therapy is an experimental technique that uses genetic material to treat or prevent a disease. One promising gene replacement therapeutic approach for Friedreich ataxia (FA) is to deliver the frataxin gene to affected cells, using viral vectors. Several groups have recently shown that this type of approach could prevent and treat the disease in relevant mouse models. However, there are a number of questions that need to be addressed to optimize the development of a safe therapeutic protocol. In particular, it is now accepted in the field that too much frataxin expression can be detrimental to the normal function of the cell. It is therefore essential to develop a therapeutic vector that will mimic the normal endogenous expression of frataxin. Furthermore, it is important to estimate the number of neurons that need to be corrected to produce a clinical benefit. Recent studies have shown that the sensory ataxia in FA might be partly related to problems during the development, and it is therefore important to determine if gene replacement can correct this very early damage to the tissue. Dr. Puccio and her team will address these questions with a particular focus on the neurological aspects, using two relevant mouse models of the disease, and a novel viral vector that expresses frataxin at near physiological levels.

PI/Investigator: Jill Napierala, PhD - University of Alabama at Birmingham

Award type: General Research Grant

Grant Title: Regulation of frataxin expression - implications for Friedreich's ataxia therapy

Lay summary: Friedreich's ataxia (FRDA), a severe progressive neurodegenerative disorder, is caused by an increasing number of specific DNA sequences, termed GAA repeats, that are present in the Friedreich's ataxia gene (FXN). This error in DNA causes a block in the flow of information from DNA to RNA, and ultimately leads to a deficiency of the final FXN product, a protein called frataxin. One of the major types of therapeutic approaches for FRDA currently being developed tries to counteract this frataxin deficiency. In order for the therapy to be successful, we need to determine what is the minimum amount of frataxin increase that will be beneficial for patients as well as what is the maximum possible increase of frataxin that will not cause any negative consequences. This is called a therapeutic window and is an essential parameter for therapy development for FRDA. Also, to better understand dosing of potential drugs that could increase frataxin levels, results of the proposed work will determine the ways that frataxin production, maintenance and removal are controlled. In summary, this work is contributing to the development of critical therapeutic guidelines for treatment of frataxin deficiency in Friedreich's ataxia.

PI/Investigator: Natalia Gomez-Ospina, MD, PhD - Stanford University

Award type: General Research Grant

Grant Title: Development of autologous transplantation of genetically corrected hematopoietic stem cells for Friedreich Ataxia

Lay summary: Previous studies have suggested that bone marrow transplantation can improve symptoms in a mouse model of Friedreich's ataxia. A conclusive demonstration of the efficacy and feasibility of such an approach for this disease would enable a one-time treatment for this otherwise devastating disease. If such benefit were to be firmly established, as it has in other neurological diseases, donor-blood stem cell transplantation could quickly become a treatment alternative for individuals with Friedreich's ataxia, while launching the development of patient-derived stem cell transplantation approaches in which the patient's own stem cells have been genetically corrected. Dr. Gomez-Ospina proposes to investigate the application of blood stem cell transplantation to treat Friedreich's ataxia by: 1) performing stem cell transplantation experiments into a new model of Friedreich's ataxia and assessing the molecular and functional outcomes, 2) using genetic engineering to investigate whether expression of the protein Frataxin is required in specific blood cell types for the therapeutic benefit of stem cell transplant, and 3) establishing an in vitro model to assess if cellular bodies called mitochondria undergo inter-cellular transfer to confer function to neighboring cells. These studies will provide support for further development of a blood stem cell-based therapy for Friedreich's ataxia.
Co-funding: FARA Ireland

PI/Investigator: Brent R. Stockwell, PhD – Columbia University

Award type: General Research Grant

Grant Title: Treatment of Friedreich’s ataxia using novel ferroptosis inhibitors

Lay summary: Ferroptosis, a form of cell death driven by excess iron, was discovered in the Stockwell Lab in 2012. Since this discovery, ferroptosis has been implicated in a variety of diseases, including Friedreich’s Ataxia (FA). The pathology of FA involves iron dysregulation and therapies that inhibit ferroptosis could counteract damage to the body in FA. Previous work demonstrated that the ferroptosis inhibitor Ferrostatin-1 (Fer-1) is protective in a variety of disease models. However, fer-1 is unstable, necessitating development of better drug candidates. Dr Stockwell and his group thus have created analogs of fer-1 with improved drug-like properties, including better stability and brain penetration. These compounds have been further evaluated in mice, demonstrating good tolerability. To evaluate the effectiveness of these compounds for FA, various assays will be performed both in FA cell models and in tissues of FA mice. These studies will both advance our understanding of ferroptosis in FA and potentially yield a drug candidate that treats the heart and the nervous system through a new mechanism.

PI/Investigator: Daniele Lettieri-Barbato, PhD - University of Rome Tor Vergata, Italy

Award type: General Research Grant

Grant Title: Testing the efficacy of dietary butyrate in ameliorating ataxic symptoms in Friedreich's ataxia mouse models

Lay summary: Together with degeneration in the brain and spinal cord, FRDA patients frequently develop metabolic complications that culminate in heart disease and type 2 diabetes, which significantly aggravate FRDA progression. A direct link has been discovered in recent years between the gut and the brain and alteration of the composition of the microbial gut population is associated with several neurodegenerative diseases. In this project, by using mouse models of FRDA, Dr. Lettieri-Barbato and his team will investigate whether the gut microbiome is altered in FRDA with a particular focus on bacteria producing short chain fatty acids, including butyrate, as these molecules possess both a neuroprotective and anti-diabetic function. FRDA mice will be treated with a diet rich in butyrate and the effect on motor function and molecular hallmarks of the disease will be analyzed in the cerebellum at single cell level. If butyrate will demonstrate efficacy in mitigating the neuromotor symptoms and molecular deregulation identified in the cerebellum of FRDA mouse models, translation from bench to bedside could be highly feasible as this physiologically produced molecule has been shown to be safe in humans.

Co-sponsor: AFAF

PI/Investigator: Elena Dedkova, PhD - University of California, Davis

Award type: General Research Grant

Grant Title: Cardiac benefit of drugs that stimulate Nrf2 and HCA2 pathways in Friedreich's ataxia

Lay summary: The most common cause of death in Friedriech's ataxia (FA) is cardiomyopathy, thus a therapeutic drug that increases frataxin, iron-sulfur and mitochondrial functions has the potential to ameliorate the most lethal consequence of FA. Ixchel Pharma, a UC Davis spinout company, has developed a novel chemical entity, IMF, that increases frataxin, iron-sulfur and mitochondrial functions in the FXNKD mouse model of FA, that closely resembles the human FA condition. IMF dosing in these FXNKD mice rescues their cardiac pathology. Furthermore, IMF dosing increases survival in the frataxin MCK-Cre mouse, which only lacks frataxin in the heart, and dies because of this loss. Thus, IMF is potentially a novel therapeutic with greater efficacy than the related DMF, and operating through other mechanisms. This group proposes that IMF works by increasing frataxin expression and mitochondrial gene expression, which appears to be upstream from the target of RTA408, Omaveloxolone, which does not increase frataxin and works to benefit oxidative status downstream of frataxin deficiency. Thus, this group proposes to compare efficacy of IMF and RTA408 in mice, and if IMF has higher efficacy, then to carry out pharmacokinetics, metabolism and toxicity studies of IMF. If successful this would take IMF to the next level of preclinical development.

PI/Investigator: Misa Nishiyama, PhD – Burke Neurological Institute

Award type: Postdoctoral Fellowship

Grant Title: Anatomical and functional analysis of corticospinal tract in FRDA mouse model

Lay summary: This proposal aims at advancing our understanding of the pathophysiology of corticospinal tracts (CST) in FRDA and examines the potential of targeted CST stimulation as a novel therapy.

Mouse models are an important tool for investigating the pathogenesis of FRDA and testing the effectiveness of new treatment methods. The main affected neuronal tissues in FRDA are cerebellum, dorsal root ganglia, spinal cord, and CST. Few studies have focused on CST in FRDA mice, and this proposal aims to fill this knowledge gap. In previous research using a novel mouse model, Dr Nishiyama showed CST atrophy and impaired motor skills. In this mouse model, frataxin is reduced throughout the body. This does not allow to tease out the specific contribution of the CST in the pathology, as cerebellar and spinal cord damage may be affecting motor function, as well as CST. Therefore, Dr Nishiyama will investigate what changes occur when frataxin is reduced in the CST selectively. She will also investigate whether CST can be a therapeutic target. Brain stimulation through magnetic field generation has been shown to be effective in treating some FRDA symptoms. Dr Nishiyama hypothesizes that CST activation could also improve symptoms and will use methods to selectively stimulate the CST in FRDA mice and monitor if this treatment is beneficial.

PI/Investigator: Lucie Hermet – Institut NeuroMyoGène, Lyon

Award type: Graduate Research Fellowship

Grant Title: Deciphering the neurodevelopmental component in Friedreich ataxia

Lay summary: This project aims at understanding the defects in the development of the nervous system in FA

In FA, both developmental deficits and progressive degeneration of the nervous system are believed to contribute to the pathology. The loss of proprioception, the perception of the position of the body in space, is the consequence of the loss of neurons within the dorsal root ganglia (DRG), the root of nerves that carry information from the periphery of the body to the central nervous system. The aim of this PhD project is to investigate if frataxin deficiency affects the formation of the DRG and spinal cord during the development of the nervous system. To address this question, Ms Hermet will use a mouse model of FA that expresses a mutation in frataxin called G127V. This mutation decreases frataxin levels dramatically throughout the life of the mouse, including during development, which is similar to what is seen in FA patients. Ms Hermet will investigate DRG and spinal cord formation and maturation during embryonic and post-natal development and will analyze the impact of embryonic defects on the appearance of sensory and motor phenotypes in the mouse. Knowledge of the onset and type of neurological damage will allow to better understand FA pathophysiology and design better treatments.

PI/Investigators: Stephanie Cherqui, PhD and Nicole Coufal, MD, PhD – University of California San Diego

Award type: General Research Grant

Grant Title: Mechanism of neuronal rescue by microglia expressing frataxin and characterization of neuronal defects in Friedreich’s ataxia

Lay summary: The overall goal of this project is to investigate the role and contribution of microglia (resident immune cells in the brain) to FA pathology.

Dr Cherqui and her collaborators have previously showed in a mouse model of FA that transplantation of wild-type hematopoietic stem and progenitor cell (HSPC) completely corrected the neurologic, muscular and cardiac complications. It is believed that transplanted HSPCs differentiate into microglia/macrophages, type of resident immune cells in the brain and other tissues. They have previously showed that tissue rescue was at least partly mediated by transfer of frataxin from HSPC-derived microglia-like cells to diseased neurons, but the exact mechanism of rescue including how microglial replacement and frataxin transfer from microglia-like cells to neurons contributes to this rescue are still unknown. These investigators believe that the impressive response of the FXN-expressing HSPC transplant is due to, not only the transfer of frataxin to neurons, but also to rescuing function of microglia. They will utilize novel in vitro and in vivo methods including patient-derived organoids (mini-brains) and a mouse model of human microglia to ascertain the microglial contribution to FA pathogenesis and the potential for gene editing to correct this phenotype. This project will provide supporting evidence that CRISPR-edited HPSC transplantation can be used to treat FA and will advance the understanding of microglia-neuron interactions.

PI/Investigator: Angela Xiong – Boston College

Award type: Graduate Research Fellowship

Grant Title: Investigating the effects of frataxin deficiency on the human proteome

Lay summary: This proposal seeks to identify the proteins that are affected by frataxin loss.

Frataxin contributes to the assembly of iron-sulfur clusters, which are fundamental molecular ensembles necessary for all domains of life. Proteins containing iron-sulfur clusters, iron-sulfur proteins, are important for cellular energy production, cell division and the maintenance of general cellular health. To better understand the molecular mechanism behind FA pathogenesis, Ms Xiong will study the consequences of frataxin deficiency in cells. To do so, she will use a human cell line where the FXN gene is deleted and a new technique that allows for the identification of those iron-sulfur proteins affected by the loss of frataxin. The goal is to pinpoint the group of proteins that lose their iron-sulfur clusters when frataxin is deficient. The activity of these impaired iron-sulfur proteins will then be further analyzed in FA patient cells to confirm their relevance to the molecular mechanism of FA pathogenesis. The identified iron-sulfur proteins represent new potential therapeutic targets for FA.

PI/Investigator: Morgan Tackett – University of Oklahoma Health Sciences Center

Award type: Graduate Research Fellowship

Grant Title: Population and cellular heterogeneity in Friedreich ataxia

Lay summary: The goal of this project is to understand how the length of the GAA repeat affects the silencing of the FXN gene and to identify the precise distribution of FA throughout the world.

While the majority of people with FA inherit very long GAA repeat expansions (>500 repeats) from each parent, about 20% inherit at least one gene with a relatively shorter expansion (<500 repeats). Those with the shorter expansion have a milder disease presentation, with later onset of symptoms, slower progression, lesser prevalence of heart disease and longer lifespan. One of the goals of this study is to understand why these individuals fare so much better. Preliminary findings suggest that these individuals do better because they have a proportion of cells in their body that have normally functioning FXN genes, and Ms. Tackett and her mentor Dr. Bidichandani propose that the shorter GAA expansion is the reason why some cells are able to escape from the gene shutdown mechanism that is otherwise very robust in the typical presentation of FA when both FXN genes have >500 repeats. Ms. Tackett will confirm this finding by evaluating multiple FA individuals with <500 repeats using a novel technique that allows simultaneous analysis of thousands of single human cells. This has important implications for the development of therapies for FA, because it suggests that correction of even a small proportion of cells (i.e., not necessarily all or most cells) could produce considerable clinical benefit. Another goal of this study is to understand why individuals respond variably to therapies designed to reactivate the FXN genes that are shutdown in FA. The hypothesis is that this is because FA individuals have variable numbers of cells that are amenable to reactivation, and Ms. Tackett will use the same novel single cell assay to test this hypothesis. Finally, it has been recognized for a long time that FA is not seen in every population in the world. FA is seen in people from Europe, North Africa, the Middle East, and South Asia, and is not seen in people from Sub-Saharan Africa and East Asia. This broad description of FA distribution likely misses small and isolated populations that may have FA but are not presently recognized. The final goal of this project is to determine the true distribution of FA by searching for DNA markers of FA susceptibility in publicly available genomic sequence databases that include these small and underrepresented populations.

PI/Investigator: Amy Hulme, PhD – University of Wollongong

Award type: Postdoctoral Fellowship

Grant Title: Investigating the Mechanosensory System in Friedreich’s Ataxia using Stem Cell Models

Lay summary: This project will use induced pluripotent stem cells to generate the specialized nerve cells that are defective in FA and investigate how they respond to mechanical stimuli to understand how they contribute to the pathology in FA. 

Mechanosensation plays a crucial role in regulating daily functions such as balance, mobility, bladder control, and digestion. The mechanosensory system is comprised of different nerve cells that are located within the spinal cord, which include (1) proprioceptor cells, which detect movement, balance, muscle pressure and tension and (2) low threshold mechanoreceptors (LTMRs), which detect touch, vibration, and internal organ sensation. The degeneration of this mechanosensory system is a characteristic hallmark of Friedreich’s Ataxia (FA), with the degeneration of proprioceptor cells leading to impaired proprioception causing difficulties in maintaining balance and coordinating movements. Additionally, FA patients may experience sensory abnormalities related to the degeneration of LTMR cells such as altered touch perception and reduced ability to sense vibrations and impaired bladder and bowel function, however, the role of LTMR cells in the progression of FA remains uncharacterized. Additionally, it is not clear why these mechanosensory nerve cells are specifically affected by the low frataxin levels in FA compared to other cell types. To better understand what is happening to the mechanosensory system in FA, Dr. Hulme will use patient derived-induced pluripotent stem cells (iPSCs) (which can be transformed into any cell type in the body) to generate the proprioceptor and LTMR nerve cells. By studying these iPSC-derived nerve cells, Dr. Hulme will investigate the molecular and functional aspects of these mechanosensory nerve cells and examine how these cells respond to types of mechanical stimuli such as touch and stretch. Providing a platform to unravel the connection between FA symptoms and the malfunctioning mechanosensory system. Additionally, this project also aims to test compounds on these cells and assess their effectiveness in restoring normal mechanosensory function or protecting against degeneration. This research will further discover the contribution and roles of mechanosensory nerves in FA and will ultimately assist in the development of FA therapies that target specific cell types and will provide a novel platform to screen candidate FA therapies. This research hopes to be used to develop potential interventions to alleviate symptoms and improve the quality of life for individuals affected by FA. 

Co-sponsor: fara Australia

PI/Investigator: Donald Joseph, PhD – Children’s Hospital of Philadelphia

Award type: General Research Grant

Grant Title: Identification of concordant electrophysiological biomarkers in Friedreich Ataxia

Lay summary: This project aims to understand the dysfunction in the neuronal circuits of the cerebellum in FA 

The anatomy of the cerebellum in FA is relatively normal, except for some deterioration in a subregion of the cerebellum called the dentate nuclei. This suggests that the sensation and balance problems in FA are probably due to malfunction of the cells in the cerebellum instead of their excessive deterioration. At this moment, it is not clear what those cellular malfunctions are and how they change over time to make the disease worse. This application seeks to address these knowledge gaps through the use of standard and advanced techniques to test the hypothesis that functional circuit deficits in the cerebellum are early and relatively concordant with phenotypes of FA and that early FXN reexpression will rescue these deficits with more efficacy than late intervention. Preliminary data in two FA mouse models revealed that global electrical communication between granule (GrC) and Purkinje (PC) cells of the cerebellum was similarly. Further testing showed that the ability of the PCs and nerve cells in a region of the cerebellum called the dentate nuclei to respond to current stimulation was similarly reduced. The impact of FXN loss on electrical communication globally and at the individual cells will be correlated with changes in the shape these cells and their mitochondria. The investigator will determine whether gene therapy approaches to increase frataxin in all cerebellar cells or selectively in PCs will result in better and longer-lasting reversal of the malfunction. Data from this proposal could lead to the identification of factors that can better predict the start of the disease, expand the possible factors to target for a treatment, and allow for monitoring how well a clinical trial is going.

PI/Investigator: Jordi Tamarit, PhD – Universitat de Lleida, Spain

Award type: Award for Innovative Mindset

Grant Title: Uncovering the function of a conserved site in eukaryotic frataxins

Lay summary: This project aims at identifying all functions of frataxin 

Dr. Tamarit and his group identified the presence of a group of amino-acids highly conserved in frataxins from different organisms.  This group of amino acids, called cluster 3, is however not conserved in bacteria. This led to the hypothesis that these amino acids in eukaryotes could be performing a crucial role, gained during evolution, in frataxin function. The working hypothesis is that these residues may be involved in frataxin antioxidant properties or in ferroxidase activity, activities not observed in bacterial frataxins. To test this hypothesis, the investigators will generate mutant frataxins in which amino acids from cluster 3 will be substituted by the residues found in bacteria and test their function. The results from the proposed project may open new perspectives for treatment, as drugs mimicking the function of complex 3 could be developed. They may also contribute to understand the mechanism by which frataxin overexpression is toxic and to design strategies to attenuate such toxicity. 

PI/Investigator: Lisa Romano, PhD - University of Florida

Award type: Postdoctoral Research Award

Grant Title: Repeat associated non-AUG (RAN) proteins in FA: contribution to disease and therapeutic opportunities

Lay summary: This project aims to understand if repeat-associated non-AUG (RAN) translation, a process in which repeat expansions produce unexpected toxic repetitive proteins, contributes to FA, thus opening new avenues for therapeutic intervention.

In 2011, the Ranum lab made the surprising discovery that repeat expansions produce unexpected toxic repetitive proteins without the canonical AUG start codon in a process called repeat-associated non-AUG (RAN ) translation. RAN proteins have been shown to be toxic to cells and to contribute to disease in other repeat expansion disorders like myotonic dystrophy type 2 and C9-ALS/FTD. Given that RAN proteins are found in a growing number of repeat expansion diseases, this raises the possibility that RAN proteins may be expressed from the FXN GAA•TTC expansion mutation and potentially contribute to FA. The Ranum lab recently developed antibodies that specifically recognize the repetitive sequences in RAN proteins and found that RAN aggregates accumulate in cerebellum and spinal cord from FA (n>5) but not control (n>4) autopsy cases. This discovery creates an urgent need to understand how these proteins are produced and if they contribute to disease. The current project aims at addressing gaps in knowledge about the GAA•TTC expansion mutation, RAN translation, and if toxic RAN proteins contribute to FA. The aims are structured to provide a comprehensive analysis of RAN proteins in human autopsy tissue and patient-derived models and examine the association between frataxin levels and FA RAN protein accumulation. Since the Ranum lab has successfully found a way to inhibit RAN translation, Dr, Romano will use genetic and pharmacological approaches to reduce RAN proteins in FA models to determinate if lowering RAN proteins improves cellular FA phenotypes. The long-term goal of this project is to understand if and how RAN proteins contribute to FA and ultimately to generate a new therapeutic treatment strategies for FA patients.

Co-sponsor: fara Australia

PI/Investigators: Massimo Pandolfo, MD and Stefano Stifani, PhD - McGill University, Canada

Award type: General Research Grant

Grant Title: An induced pluripotent stem cell model to investigate microglia in Friedreich ataxia

Lay summary: This project aims to use induced pluripotent stem cells to investigate the mechanisms causing malfunction and death of vulnerable cells in the nervous system in FA and to study the potential toxic or protective effect of microglia - cells that remove cellular debris and foreign invaders from the brain and spinal cord- on frataxin-deficient neurons.

This project will use an induced pluripotent stem cell (iPSC)-based neuronal model for Friedreich ataxia (FA) to investigate the mechanisms causing malfunction and death of vulnerable cells in the nervous system, with implications for therapies. iPSCs are derived from skin or blood cells and “reprogrammed” to become undifferentiated cells that resemble those in the embryo. iPSCs can be differentiated into different cell types by using appropriate techniques. The Pandolfo laboratory has experience in turning FA iPSCs into neurons and the Stifani lab has set up methods to turn them into these other cells found in the nervous system called microglia. Microglial cells are not neurons, they are related to a type of white blood cells (macrophages) and “keep the brain clean” by removing cellular debris. Microglia may be protective for the brain but can also be deleterious by promoting inflammation. This proposal aims at characterizing microglia obtained from FA iPSCs and compare with that obtained from healthy controls iPSCs. Drs Pandolfo and Stifani hypothesize that microglial cells in FA will show a signature of inflammation that would point at their involvement in the disease pathology. They will assess the functional properties of FA microglia and explore if its interaction with neurons promotes neurodegeneration or is protective. For this purpose, they will investigate how FA and control microglia interact with FA and control neurons. These findings will define a role for this cell type and for inflammation in FA, indicating potential therapeutic targets.

PI/Investigator: Andre Nussenzweig, PhD - National Cancer Institute, NIH

Award type: General Research Grant

Grant Title: Mechanism of repeat expansion in Friedreich's ataxia

Lay summary: The group of Dr. Andre Nussenzweig will investigate the molecular mechanisms causing GAA expansion and FXN gene silencing in Friedreich ataxia (FA) by examining the role of transcription in repeat expansion and formation of alternative DNA structures, and testing whether molecules that reverse these structures will also block repeat expansion.

Although the genetic cause of FA has been known for more than two decades, the molecular mechanisms causing (GAA)n expansion and FXN gene silencing remain unclear. One prevailing model to explain the FXN downregulation in FA cells is that alternative DNA secondary structures accumulate at this locus which become a barrier to productive elongation of FXN transcripts. Recently, the group of Dr. Andre Nussenzweig, in collaboration with Dr. Karen Usdin and Dr. Marek Napierala, developed methods that detected alternative DNA structures (DNA triplexes) in cells derived from Friedreich’s ataxia patients. Here, Dr. Nussenzweig joins forces with the Usdin and Napierala groups to determine the molecular basis for (GAA)n repeat instability and FXN gene silencing. The investigators will examine the role of transcription in repeat expansion. They will boost or reduce transcription of the FXN gene and determine how this affects the length of the GAA tract. They will also ask whether transcription is required for formation of alternative DNA structures, by boosting or reducing transcription of FXN and testing for triplex formation. Finally, the investigators plan to test whether molecules that reverse alternative DNA structure formation will also block repeat expansion. The hope is to identify efficient ways to prevent expansion or promote contraction in order to restore FXN gene expression.

PI/Investigator: Pei-Yu Chen, PhD - Yale University

Award type: Award for Innovative Mindset

Grant Title: TGFβ signaling activity as disease biomarkers and therapeutic targets in Friedreich’s Ataxia

Lay summary: Friedreich’s ataxia (FA) is associated with fibrosis in the heart, a process by which the heart becomes thicker and stiffer and has a harder time pumping blood. Recently, the development of cardiac fibrosis has been linked to changes in the cells that make up the inner surface of blood vessels, called endothelial cells (ECs). The process involving these changes is called endothelial to mesenchymal transition or EndMT, and is a poorly understood phenomenon in which ECs become different cells. These cellular changes have been observed in heart samples obtained from FA patients, suggesting that EndMT in blood vessels may contribute to the pathogenesis of cardiac fibrosis in FA. Dr. Chen plans to study the molecular processes that characterize EndMT and its contribution to cardiac fibrosis in FA. The aims of these studies are to determine whether these molecular changes can be used to track the heart disease in FA and whether therapeutic interventions that disrupt this process could be beneficial.

PI/Investigator: Sarah Robinson-Thiewes, PhD - St. Jude Children’s Research Hospital

Award type: Postdoctoral Fellowship

Grant Title: Illuminating how SynGRs liberate gene expression from heterochromatin

Lay summary: The Ansari lab developed a new class of small molecule therapeutics called synthetic gene regulators (SynGRs), one of which, SynTEF1, binds to the FA GAA genetic mutation and specifically increases FXN expression. While the lab has a working model for how SynTEF1 works, the data also indicate that SynTEF1 pushes the boundaries of our knowledge of gene expression. Namely, that SynTEF1 improves FXN expression while the gene is considered “off”. Dr Robinson-Thiewes’s proposal is tailored to investigate the scientific quandaries SynTEF1 has illuminated and lay the groundwork to show that SyTEF1 is a viable treatment option for patients. To this end, this investigator has divided her proposal into three questions. First, how does SynTEF1 alleviate FXN's transcriptional dysregulation? To answer this question, Dr Robinson-Thiewes will use CRISPR/Cas9 genome editing to visualize FXN expression and predicted SynTEF1 protein partners in live cells. Second, does SynTEF1 restore mitochondrial function? To answer this question, she will treat FA patient cells with SynTEF1 and analyze mitochondrial health as well as markers of cellular damage. Third, how does long term exposure to SynTEF1 affect gene expression? To answer this question, she will use two complementary approaches to assess gene expression: RNA sequencing and sequencing that identifies area of the genome that could be “on”. Answering these questions will advance basic science investigations into gene expression that will be beneficial to not only FA patients, but to countless others who have diseases caused by faulty gene expression.

PI/Investigator: Anna Stepanova, PhD - Weill Cornell Medical College

Award type: Postdoctoral Research Award

Grant Title: Calcium communication among intracellular compartments in FA patient-derived cells

Lay summary: Calcium communication among intracellular compartments in FA patient-derived cells

Lay summary: Cells interact with each other and within themselves using small molecules - words of the language of life. Calcium (Ca) is the most common means of communication within the cell, between its different compartments such as cytosol, mitochondria and endoplasmic reticulum (ER) - the main Ca storage inside the cell. Healthy cells keep cytosolic Ca levels at four orders of magnitude lower than extracellular ones. Ca is vital for the heart cells' well-being; however, keeping appropriate Ca levels requires a lot of energy, thus the good quality of mitochondria. This study aims to uncover the elusive link between mitochondria, Ca communication, and heart cells' well-being in patients with FA. Dr Stepanova and her collaborators will use a state-of-the-art technique to monitor Ca levels in specific locations inside the cell (cytosol, mitochondria, or ER). They will convert stem cells from FA patients into two heart cell types. 1) Cardiac muscle cells, or cardiomyocytes, are the most abundant cell type in the heart and are responsible for heart contraction. Each heartbeat relies on quick changes in Ca levels. 2) Myofibroblasts (MyoFB) are minor cell type in healthy hearts. However, they increase in number after an injury because of their role in wound healing. The overabundance of MyoFB can lead to cardiac fibrosis - a common heart condition found in FA. Ca plays a crucial role in various functions of MyoFB, and the knowledge of these cells in FA is limited. This study will answer whether heart cells suffer from miscommunication of Ca messages between different cell compartments and may lead to novel therapies for cardiomyopathy in FA.

PI/Investigators: Shawn Liu, PhD & Joriene de Nooij PhD - Columbia University

Award type: General Research Grant

Grant Title: Rescue of Friedreich’s Ataxia cells by DNA methylation editing of the FXN gene

Lay summary: Rescue of Friedreich’s Ataxia cells by DNA methylation editing of the FXN gene

Lay summary: Reactivation of the silenced FXN gene represents an attractive therapeutic strategy because the FXN coding sequence remains intact in the vast majority of FRDA patients. However, the molecular mechanisms underlying the silencing of FXN are under active investigation. One of these mechanisms is DNA hypermethylation, a code that is written onto genes, but goes beyond the genetic code - thereby called epigenetic - and consist of chemically changing the structure of one of the 4 DNA building blocks, by adding methyl groups. DNA hypermethylation of the FXN gene has been documented in FRDA patients and has been correlated with FXN transcriptional deficiency and age of disease onset. However, the functional significance of this DNA methylation event to the pathogenesis of FRDA remains unclear due to the lack of a precise molecular tool to manipulate this methylation event in the disease-affected cells. Dr. Liu has developed a CRISPR-based molecular tool to precisely edit DNA methylation. With this new tool, his group will test whether demethylation of the FXN gene may reactivate its expression and rescue FRDA-associated cellular defects. In collaboration with Dr. Joriene De Nooij’s laboratory (co-principal investigator) at Columbia University Medical Center, Dr. Liu will apply the DNA methylation editing tool to demethylate FXN in sensory neurons derived from FRDA-patient induced pluripotent stem cells (iPSCs), and in Dorsal Root Ganglia sensory neurons obtained from a mouse model of FRDA. They will then phenotypically characterize the in vitro and in vivo DNA methylation-edited neurons. Precise editing of FXN methylation will permit an evaluation of the functional significance of this epigenetic event in the pathogenesis of FRDA. Moreover, these studies may demonstrate the therapeutic potential of DNA methylation editing for FRDA.

PI/Investigator: Xinnan Wang, MD, PhD - Stanford University

Award type: General Research Grant

Grant Title: Novel Mitochondrial Targets for Friedreich’s Ataxia

Lay summary: In this grant proposal, Dr. Wang seeks to target the oxidative stress in FA cells in a new way. ROS - reactive oxygen species - are highly reactive molecules normally produced in the cells by many reactions, but when allowed to accumulate, as is the case for FA, they can induce damage and eventually cell death. Dr. Wang proposes a new therapeutic strategy for FA that instead of reducing ROS, targets the consequences of elevated ROS inside the cell, that cause cell damage. Dr. Wang and her group discovered that high ROS levels cause impairment of a mechanism that is important to recycle mitochondria and found molecules that can target this mechanism and restore mitochondrial recycling. Dr. Wang provided evidence that targeting this pathway rescues the phenotype of a fruit fly model of FA and improves survival of FA cells. With this work she aims to validate novel therapeutic targets and test small molecules that could be translated into disease-modifying therapies.

PI/Investigator: David Lynch, MD, PhD - Children’s Hospital of Philadelphia

Award type: General Research Grant

Grant Title: Understanding ketogenesis in FRDA: Pathophysiology, biomarkers and nutritional therapies

Lay summary: Understanding ketogenesis in FRDA: Pathophysiology, biomarkers and nutritional therapies

Lay summary: The role of mitochondria in metabolism may mediate some components of FRDA, either in overall progression or in components such as diabetes. For example, platelets from patients with FRDA utilize fats in preference to sugars, suggestive of generalized metabolic dysfunction. Moreover, FRDA patients develop exercise intolerance, again suggesting that altered metabolism might play a role in the symptoms of FRDA. Understanding these events is important not only for creating new therapies for FRDA, but also for the development of new markers. The relative inaccessibility of affected tissue in FRDA and the difficulty of measuring frataxin levels in vivo require the development of novel biomarkers “close” to the events caused by frataxin loss. Metabolic and chemical imaging measurement of the markers in ketone utilization offer the possibility of providing such markers. Recent evidence from Dr. Lynch’s laboratory suggests a crucial role of metabolism of compounds called ketone bodies in the cause of FRDA. Frataxin controls ketone body metabolism through regulation of a specific enzyme, 3-Oxoacid CoA-Transferase 1 (OXCT1). This enzyme leads to use of ketone bodies as energy. Dr. Lynch and his group found that frataxin physically interacts with OXCT1 and blocks its degradation leading to failed ketone utilization when frataxin is not present. In this proposal, they will first define the diversity and significance of disruptions in ketone utilization in frataxin deficient cells. In addition, they will define the contribution of OXCT1 decreases to FRDA pathophysiology in animal models of FRDA. Finally, they will attempt to understand the role of abnormalities of ketone utilization in patients with FRDA. Collectively, these aims will determine the role of failed ketone utilization in features of FRDA.

PI/Investigator: Rucha Sarwade, PhD - Monash University, Australia

Award type: Postdoctoral fellowship

Grant Title: Investigating epigenetic silencing in Friedreich's Ataxia

Lay summary: Several models have been proposed to explain FXN gene silencing. Two eminent amongst them are; 1. Formation of unusual triplex DNA structures and R-loops that interferes with the RNA pol II processivity leading to transcriptional blockage, 2. Formation of heterochromatin. While research findings are consistent with both possibilities, neither of them adequately explains transcriptional silencing of FXN gene. This project aims to fill this critical knowledge gap and uncover sequential epigenetic events that are crucial to design effective treatment strategies for Friedreich's Ataxia (FRDA). In a parallel universe, studies on plants that have a peculiar growth defect due to an intronic triplet repeat expansion led to interesting observations. This plant model shares striking parallels at the molecular level with FRDA, suggestive of potential common underlying biology. In the plant model, repeat expansion causes accumulation of specific non-coding RNA species called siRNAs. These siRNAs lead to gene silencing by RdDM (RNA dependent DNA methylation) -dependent epigenetic modifications. Interestingly, repeat expansion-associated plant phenotype was rescued by mutations in enzymes that can cause post-translational modification of proteins. Excitingly, HETEROCHROMATIN PROTEIN 1 (HP1) that has been shown to be associated with epigenetic silencing in FRDA is known to be affected by such post-translational modifications. Dr. Sarwade hypothesizes that RNA -mediated epigenetic changes occurring at the FXN locus are maintained by protein modifications of chromatin modifiers such as, HP1. Through this fellowship, Dr. Sarwade intends to test whether the learnings from the plant research also translate to FRDA, using cell lines derived from patients.

Co-sponsor: fara Australia

PI/Investigator: Chen Liang, PhD - University of Rochester

Award type: Postdoctoral Fellowship

Grant Title: Pathophysiology of Muscle Dysfunction in Friedreich's Ataxia

Lay summary: FRDA is a deadly neurodegenerative disorder that is associated with significant muscle wasting and weakness. However, the reasons for this have not been extensively examined. Given that skeletal muscle plays a critical role in movement and daily activity, there is a pressing need to enhance our understanding of how altered skeletal muscle function contributes to the development and progression of FRDA. A major barrier to achieving this goal has been the lack of an animal model that accurately reflect the clinical features of FRDA in skeletal muscle. To overcome this barrier, Dr. Liang will generate two new pre-clinical mouse models, constitutive and inducible muscle-specific Fxn knockout mice. These mouse models will enable detailed analyses of the role of Fxn in muscle development and function, as well as the acute effect on muscle function of Fxn deficiency in adulthood. These mouse models will also be used to identify and test the efficacy of new interventions designed to counteract the deficits that result from Fxn deficiency during development and adulthood. This investigator and her mentors hypothesize that reduced Fxn expression in skeletal muscle results in muscle dysfunction and that restoration of Fxn expression ameliorates muscle dysfunction and prolongs survival. They further hypothesize that Fxn deficiency in skeletal muscle arises from mitochondrial damage due to mitochondrial Ca2+ overload and that muscle function is improved by blocking the activity of mitochondrial permeability transition pore (mPTP) through ablation of cyclophilin D. These hypotheses will be comprehensively evaluated using a multidisciplinary approach that includes muscle physiology, molecular biology, biochemistry, and Ca2+ imaging. The outcome of this study will provide new insights into the pathogenic mechanisms and treatment of the debilitating muscle dysfunction experienced by FRDA patients.

PI/Investigator: Sara Anjomani-Virmouni, PhD - Brunel University, London

Award type: General research grant

Grant Title: Sphingolipid rheostat as a potential target for Friedreich's Ataxia

Lay summary: Evidence indicates that defective sphingolipid metabolism may contribute to different neurodegenerative conditions, including Alzheimer’s disease, Huntington’s disease and Parkinson’s disease. Sphingolipid is a group of lipids important for the activity of the brain and therefore, disturbances in their metabolism can have a huge impact on brain function. Dr Anjomani Virmouni and her group have recently found that the sphingolipid levels and their related genes are altered in FRDA mouse and human samples, which may play a critical role in the disease progression. The aim of this project is to have a clear picture of the sphingolipid changes in FRDA and to identify potential and novel targets for the development of therapeutic strategies in the disease. This may involve the design of novel drugs or repurposing of currently licensed drugs.

PI/Investigator: Jordi Magrane, PhD - Weill Cornell Medicine

Award type: General research grant

Grant Title: Assessment of early somatosensory impairment in the KIKO mouse model of Friedreich's ataxia

Lay summary: Alterations in the normal development of the nervous system may explain some of the earliest pathology in Friedreich's ataxia (FRDA). Clinical and histological evidence suggest that FRDA patients may suffer from an impaired neurodevelopmental process that may occur during embryonic development or during early years after birth. No research studies have directly examined the consequences of frataxin reduction on the maturation of the nervous system during perinatal and early postnatal stages in mouse models of the disease. Dr. Magrane and his group have obtained experimental evidence using a well-characterized FRDA mouse model that frataxin deficiency causes a delay in the appearance of sensory and motor functions in neonates. Based on these novel observations, they aim to further investigate pathology in FRDA mouse pups affecting the nervous system structure and function, and to study the molecular mechanisms involved, with a focus on mitochondria. Successful completion of these studies will not only be important for our understanding of the pathogenesis of FRDA but will also validate the use of this model to evaluate the impact of early therapeutic approaches targeting the sensorimotor system.

PI/Investigator: Elisabetta Indelicato, MD, PhD - Medical University of Innsbruck, Austria

Award type: Postdoctoral Research Award

Grant Title: Hepcidin-Ferroportin axis in Friedreich's ataxia

Lay summary: One of the open questions in Friedreich´s ataxia (FRDA) is elucidating the role of iron in the development of the disease. In heart and brain of FRDA abnormal iron deposits are found in the mitochondria, the cell organelles mostly affected by the disease. Abnormal iron deposition is believed to trigger damage of mitochondria and contribute to disease manifestations. Over the past years, research in other fields identified the protein hepdicin (HAMP) as the main regulator of iron metabolism in the human body. HAMP is produced by the liver and in conditions of iron excess binds to ferroportin (FPN), an iron-exporting protein located in the cell membrane. This binding triggers FPN destruction and thus prevent the outflow of the ingested iron from the intestinal cells in the blood. Few studies in autopsies and in mouse models suggested that HAMP pathway may be altered in FRDA. To explore HAMP involvement in FRDA, Dr. Indelicato designed a pilot study in which she will measure levels of HAMP, iron and copper parameters, erythropoietin and erythroferrone (another human hormones with iron-regulating properties), as well as frataxin and FPN expression in blood cells of FRDA patients, carriers and control subjects. Moreover, Dr. Indelicato will study if iron accumulates in organs other than the nervous system and the heart by means of an MRI examination of the abdomen, which can visualize iron content in liver, pancreas and spleen. The aim of this proposal is to elucidate if the whole-body regulation of iron through the key factors HAMP and FNP is impaired in FRDA. These findings will help to guide therapeutic interventions on iron metabolism in FRDA and will help to understand if levels of HAMP may provide indirect information on disease state in FRDA.

Co-sponsors: fara Australia and FARA Ireland

PI/Investigator: Erin Seifert, PhD - Thomas Jefferson University

Award type: General research grant

Grant Title: Metabolic (mal)adaptation of heart and skeletal muscle to frataxin depletion

Lay summary: Dr. Seifert's lab has previously shown that in an animal model of FA (“UCLA” mice), heart function can be normal despite >98% loss of Frataxin (Fxn) and evidence of iron overload; normal function likely relies on preservation of fat oxidation and activation of processes that protect the heart. Interestingly, the hearts of Fxn-depleted mice show perturbations in 3 major signaling pathways, indicating that the Fxn-depleted heart is not normal. Some of these pathways may help to preserve heart function in the face of Fxn depletion, while others may lead to poor heart function if left unchecked. To understand how each pathway impacts the Fxn-depleted heart, the team will take advantage of existing small molecules: rapamycin (inhibits mTORC1 pathway), AICAR (activates AMPK pathway), and ISRIB (blocks the Integrated Stress Response pathway). The goal of this project is to test these small molecules in the UCLA mice, which have normal/compensated heart function, and in “MCK” mice that have complete Fxn loss in muscle soon after birth and show dramatic cardiac pathology. This group of investigators will determine if each of the 3 small molecules has a beneficial or harmful effect on heart function, size and metabolism in both mouse models. They will also determine if these molecules can protect skeletal muscle in these animals from declining in mass and strength. This study will fundamentally address whether the observed changes in signaling pathways are beneficial or maladaptive, and whether these pathways can be useful therapeutic targets.

PI/Investigator: Arnulf H. Koeppen, MD - VA Medical Center, Albany

Award type: General research grant

Grant Title: The pathogenesis of the major neural lesions in Friedreich ataxia: dorsal root ganglion and dentate nucleus

Lay summary: The mutation in Friedreich ataxia (FA) was established in 1996, but the mechanisms by which brain, spinal cord, dorsal root ganglia (DRG), and sensory peripheral nerves are damaged have remained elusive. The principal investigator hypothesizes 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 in FA. 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 is accomplished by a combination of antibody microarrays with tissue lysates; slide technology (immunohistochemistry and immunofluorescence), gel electrophoresis and Western blotting. Antibody microarrays offer enough sensitivity to detect structural and signaling proteins relative to total protein. The success of proteomic methods depends on validation of antibodies and their reactivity with identifiable proteins. The investigator uses tissue samples obtained at the time of autopsy that were generously donated by the families of patients who succumbed to FA. The project has already yielded several important conclusions among which are: (1) Frataxin deficiency causes developmental hypoplasia of DRG; and (2) further destruction is due to proliferation of satellite cells that normally surround and nourish the nerve cells of DRG.

PI/Investigators: Yutaka Yoshida, PhD - Burke Neurological Institute & Joriene de Nooij, PhD - Columbia University

Award type: General research grant

Grant Title: Constancy of FRDA phenotypes across neuronal types and development

Lay summary: Despite remarkable progress, there remain considerable gaps in our knowledge of FRDA pathology in neuronal tissues. This lack of knowledge limits our ability to predict which new types of medication may be more effective in treating the disease and deserve a higher priority. This proposal is focused on three such areas that remain understudied. First, is the mechanism of disease the same in all neuronal tissues? Second, is the effect of the loss of FXN the same in a developing neuron as in a mature neuron? Lastly, does the loss of FXN in the developing neuron lead to permanent (genomic) alterations that cause or exacerbate disease in later life? Based on expertise in the development of two FRDA-affected neuronal tissues: proprioceptive sensory neurons (PSNs) and corticospinal neurons (CSNs), these investigators propose to perform a detailed comparative phenotypic and molecular analysis to examine the similarities or dissimilarities between the FRDA pathology in these two different tissues, and during their development. The result of these studies will inform design strategies for new therapeutics, or guide the evaluation of existing experimental treatments, particularly for those that pertain to neurological FRDA phenotypes.

Co-funding: CureFA Foundation

PI/Investigator: Henry Houlden, MD, PhD - University College London, UK

Award type: Bronya J. Keats International Research Collaboration Award

Grant Title: Identification of genetic modifiers of Friedreich's ataxia

Lay summary: The GAA expansion length associated with Friedreich ataxia (FRDA) correlates with severity of symptoms and inversely with age of onset, particularly for the shorter allele (GAA1), with a prediction of 2.3 years earlier onset for every 100 GAA repeats added to GAA1. However, the GAA repeat size only accounts for between 36% to 56% of the variation in age of onset and the GAA expansion content has only been investigated for large scale interruptions. This suggests that other contributory factors such as non-coding or coding modifying genetic variation, environmental factors or small repeat sequence interruptions, may influence age of onset and severity. Identifying these factors in FRDA will be important in a number of ways, such as: 1. To define the individual genetic profile of each patient to help determine disease progression, predict clinical problems and understand allele lengths and age at onset, 2. To stratify patients more effectively for treatment trials and 3. The modifying molecular pathways identified will certainly improve our understanding of FRDA and may in themselves be potential therapeutic targets.

This international group collected a large series of FRDA from Europe/South America with DNA and core clinical features. To identify genetic modifying factors in FRDA, the following aims will be carried out:

A. A genome wide association study (GWAS) to identify genetic variants associated with (a) FRDA age at onset (AAO), (b) disease progression in FRDA and (c) investigate the overlap of modifiers associated with other repeat disorders (such as HD and SCAs). This part of project will be funded by Vertex Pharmaceuticals in a joint project with FARA. Vertex will fund genotyping of FRDA in each FRDA patient at University College London, to enable the collaboration with colleagues in the United States (Prof David Lynch and colleagues), where Vertex is currently funding SNP genotyping of their FRDA cases (to be completed in 2020) and enable comparison of data.

B. Identify biological pathways and gene networks influencing FRDA age at onset and severity.

C. Long-read sequencing of the FRDA GAA expansion to assess variation/and repeat changes in the FRDA expansion tract and the 5' and 3' flanking regions of the expansion, we will also carry out PacBio long-read sequencing of 400 FRDA patients.

The group is keen to be in contact with other research groups and clinical teams that are interested to be part of this study: email This email address is being protected from spambots. You need JavaScript enabled to view it.

PI/Investigator: Esther Becker, PhD – University of Oxford

Award type: General Research Grant

Grant Title: Modelling Friedreich Ataxia in human iPSC-derived cerebellar organoids

Lay summary: This project will establish three-dimensional models of the human cerebellum in a dish from stem cells derived from FA patients.

This project aims to create three-dimensional models of the human cerebellum called ‘organoids’, using induced pluripotent stem cells from patients with FA. This innovative method will allow to better understand why nerve cells in the cerebellum are particularly vulnerable to FA and use this insight to test potential therapeutic treatments for FA. Human induced pluripotent stem cells (iPSCs) are obtained from individuals’ skin cells by a process known as reprogramming and resemble stem cells present in the developing human embryo that are capable of turning into any cell type in the body. Coaxing iPSCs obtained from patients into brain cells allows studying living human nerve cells from affected patients in the laboratory and to recapitulate early events that lead to disease in the relevant, vulnerable cell types. The Becker group is one of the few worldwide that has set up a protocol to use human iPSCs to produce nerve cells of the cerebellum and grow tissue-like cerebellar organoids. Dr Becker proposes to produce cerebellar organoids from FA patient iPSCs and compare these to organoids generated from healthy controls. This will shed light on the molecular and cellular processes that go awry in the FA cerebellum and that might be amenable to therapeutic correction. Overall, this study will provide valuable insights into how FA affects the cerebellum and could help develop better treatments for this disease.

PI/Investigator: Robert Wilson, MD, PhD – Children’s Hospital of Philadelphia

Award type: General Research Grant

Grant Title: A tractable vertebrate model that recapitulates key aspects of Friedreich ataxia

Lay summary: This proposal seeks to validate a new animal model of FA, a freshwater fish, called zebrafish, that has been genetically modified to express low levels of frataxin. This model addresses some of the shortcomings of FA mouse models and can be used for drug testing.

Dr Wilson and his collaborators used gene editing technology to develop an FA zebrafish model by mutating zebrafish frataxin (zFXN). The zFXN-mutant zebrafish constitute a vertebrate, whole-organism model that recapitulates key aspects of FA in humans that mouse models do not. GAA-repeat-expansion mouse models have no significant cardiac phenotype, and the neurological phenotypes take many months to develop and are very mild. zFXN-mutant zebrafish show a decrease in survival especially when stressed by starvation. Compared to control fish, adults are significantly smaller, have an increased heart size compared to their body size, blood-vessel abnormalities and stress-response-pathway activation. zFXN-mutant phenotypes develop rapidly and are pronounced, which simplifies drug testing. Finally, zebrafish are much cheaper to work with than mice and allow rapid testing of multiple drugs, as well as screening of compound libraries. Importantly, this organism has human-length telomeres (the ends of chromosomes). Telomeres protect the ends of chromosomes and there is evidence that telomere damage and shortening contributes to FA pathophysiology. This aspect of FA cannot be recapitulated in mouse models – mouse telomeres are 5-10x longer than human telomeres – but can be modeled in zebrafish. This proposal focuses on two important validations that would enhance the utility of the FA zebrafish model: Aim 1. To validate additional adult phenotypes, such as ataxia. Aim 2. To determine drug effects predictive of efficacy in humans by testing responses to drugs already evaluated in clinical trials for FA, in particular omaveloxolone, which is now FDA-approved. This model will provide a valuable tool for therapeutic development, especially for testing small molecules.

Co-sponsor: FARA Ireland

PI/Investigator: Mirella Dottori, PhD - University of Wollongong, Australia

Award type: General Research Grant

Grant Title: Investigating Proprioceptor Development and Function in Friedreich’s Ataxia

Lay summary: A deficiency in proprioception, the perception of the body position and movement, is one of the earliest symptoms observed in Friedreich ataxia (FA). The loss of proprioception is associated with prominent neurodegeneration in proprioceptor sensory neurons and within the cerebellum. A major question in FA research is ‘when’ does the proprioceptor impairment start and what is the mechanism underlying this in terms of having reduced Frataxin expression. There is some evidence to suggest that the defect in proprioceptor function is genetically determined rather than progressive post symptom onset. Other studies have reported that increased Frataxin levels is associated with proprioceptor/sensory neuronal differentiation, suggesting that low frataxin levels may impact proprioceptor development. This project aims to understand the neurodevelopment and neurodegenerative changes of FA and their implications for pathogenesis and therapies. Specifically, Dr. Dottori will use stem cells generated from FA patients to produce proprioceptor neurons as a model to investigate the mechanisms underlying proprioceptor dysfunction in FA. This is a necessary first step to determine ‘when’ and ‘how’ FA proprioception deterioration begins and when and how this can be halted and/or rescued by increasing Frataxin expression, and determine the appropriate timing of treatment.

Co-sponsor: fara Australia

PI/Investigator: Paola Costantini, PhD - University of Padova, Italy

Award type: General Research Grant

Grant Title: Three-dimensional mature cardiac microtissues from human induced pluripotent stem cells to explore mitochondrial dynamics, cardiac function and therapeutic options in Friedreich Ataxia

Lay summary: Myocardial energy production in significantly impaired in Friedreich ataxia patients and this reduction may even precede the development of tissue damage in the heart. These investigators have recently found that the shape of mitochondria, which is crucial for their function, is altered in isolated Friedreich ataxia patient cells and can be restored by genetically increasing the levels of the mitochondria shaping protein OPA1. In this project they will use an innovative tool, cardiac microtissues or “mini-hearts”, obtained from patient stem cells to investigate 1) if remodeling of the mitochondrial shape can correct cardiac dysfunction and 2) if increasing the levels of frataxin can correct the mitochondrial and cardiac defects. Modeling cardiac dysfunctions in Friedreich ataxia is a crucial and challenging task and cardiac microtissue is an advanced cellular model that will allow to mimic more closely the human myocardium. Defining the molecular features of the disease, in an appropriate cellular context, will facilitate the development of novel therapeutic strategies for Friedreich ataxia.

PI/Investigators: Shweta Sahni – All India Institute of Medical Sciences (AIIMS), New Delhi

Award type: Graduate Research Fellowship

Grant Title: Elucidation of the peripheral immune axis in FRDA and identification of blood-based biomarkers of inflammation

Lay summary:This proposal aims at identifying blood-based biomarkers of FA

The development and inclusion of different types of biomarkers can advance the process of drug development and clinical trials through determining target engagement of a drug, predicting disease progression rate, drug responsiveness and/or occurrence of adverse events. An ideal biomarker for FA should, among other characteristics, show correlation with disease processes in the nervous system or track disease progression and is conveniently obtained in peripheral tissue such as blood. Emerging evidence reveals the presence of inflammation in various tissues in FA, but little is known about its significance and extent. This proposal is aimed at elucidating the role of the peripheral inflammatory process in FA and its cross-talk with inflammation in the central nervous system. The goal is to identify blood-based non-invasive biomarkers to monitor disease progression. In combination with imaging techniques and other assays of neuronal degeneration, a noninvasive blood based prognostic biomarker would provide a better sense of the disease progression rate and will open a new window of therapeutic opportunity. The study will define and optimize an inflammatory biomarker panel using gene expression profiles of peripheral blood from 100 FA patients and 50 control subjects.

PI/Investigators: Eric Wang, PhD & S. H. Subramony, MD, - University of Florida

Award type: Award for Innovative Mindset

Grant Title: Measurement of Frataxin mRNA in NHP and human biofluids

Lay summary: This project aims to develop biomarkers to detect early efficacy in clinical trials, by measuring frataxin in small vesicles present in the fluid that surrounds the brain and the spinal cord

Biomarkers play an important role to help determine optimal doses and provide early signs of potential efficacy in clinical trials testing gene therapy products. The investigators plan to measure the content of small vesicles found in the fluid surrounding the brain and spinal cord (cerebrospinal fluid or CSF), called exosomes. These vesicles are surrounded by membrane and contain protein, lipids and different types of RNA and that reflect the content of the cells in the brain that secrete them. The aim of the study is to develop methods to measure FXN mRNA in these vesicles found in CSF and blood of FA patients.

Co-sponsor: fara Australia

PI/Investigators: Thiago Rezende, PhD – University of Campinas, Brazil & Ian Harding, PhD – Monash University, Australia

Award type: General Research Grant

Grant Title: An optimized deep learning-based method for cerebellum segmentation

Lay summary:This project aims to develop a tool that will help standardize and automate the analysis of images of the cerebellum obtained in MRI studies in FA patients.

A critical gap for FRDA therapeutic development is the lack of sensitive clinical or biological outcome measures for treatment monitoring, pharmacodynamic tracking, and patient stratification. In this sense, neuroimaging-based parameters have emerged as potential candidates, although further studies are necessary to validate them. In particular, the cerebellum is a major site of neurodegeneration in FRDA with recognize progressive pattern of damage in the cerebellar cortex and pathways. Unfortunately, the segmentation of cerebellum and its structures is a challenging task due to the intricately folded cerebellar cortical tissue and its proximity with the cerebral cortex. Efforts towards creating accurate tools to address these challenges are underway. Nevertheless, these tools suffer from accuracy, reproducibility, and generalizability limitations, particularly when applied to patients with FRDA. The investigators therefore propose to leverage the availability and maximize the utility of the high-quality data resources that are being collected and aggregated through significant funding investments in TRACK-FA, ENIGMA-Ataxia, and other in-house projects to deliver updated and optimized analytical tools. In particular, they will develop a comprehensive deep learning-based model for cerebellum segmentation to achieve automated and standardized tools that can be readily deployed for use in observational, natural history, and treatment trials. An accurate and sensitive quantitative assessment of cerebellum structure is essential to maximize the likelihood of successful neuroimaging biomarker discovery.

PI/Investigators: David Lynch, MD, PhD, William Gaetz, PhD & Timothy Roberts, PhD - Children’s Hospital of Philadelphia

Award type: General Research Grant

Grant Title: Imaging of glutathione and GABA in the brain as biomarkers of Friedreich Ataxia

Lay summary: Frataxin deficiency in FA leads to changes in iron handling by the body as well as changes in metabolic pathways, the way chemicals are broken down in the body. Clinical research in FA has advanced rapidly in recent years, with the development of clinical measures and successful execution of clinical trials such as MOXIe (omaveloxolone). Still, future clinical trials need novel ways based on biology to assess outcomes in clinical studies, and to understand better how new drugs alter the causes of disease in patients with FA. At present, Spectroscopy (a type of MRI scan) can provide utility in some situations, but ongoing studies of brain structure and chemicals reflect the late pathophysiology of FA, and thus are unlikely to be early markers of disease or early effects of treatment. In this proposal, Dr. Lynch, Dr Gaetz and Dr Roberts will use advanced, edited magnetic resonance spectroscopy to assess brain levels of glutathione (a molecule that is an indicator of the presence of free radicals and oxidative stress) and the neurotransmitter γ-aminobutyric acid (GABA) (a compound involved in nerve communication in the brain), two potential markers of the proximal pathophysiology of FRDA. The hypothesis of this proposal is that assessment of brain glutathione and GABA levels provides accurate biomarkers of disease status in FA. In this pilot proposal, using advanced edited magnetic resonance spectroscopy, the investigators will assess GABA and glutathione in the brain motor cortex of 10 FA subjects and 10 age-matched controls. They will also assess the relationship of glutathione and GABA motor cortex levels to markers of FA disease severity. Finally, 5 FA subjects will be tested after initiation of omaveloxolone therapy (as it becomes clinically available). This will allow to determine whether glutathione spectroscopy responds to the new drug omaveloxolone and whether imaging of glutathione and/or GABA will advance monitoring of FA.

PI/Investigator: Louise Corben, PhD - Murdoch Children’s Research Institute

Award type: General Research Grant

Grant Title: Measuring ataxia in children with Friedreich ataxia

Lay summary: Friedreich ataxia (FA) impacts many aspects of daily life including walking, speech, arm function and vision. The common element underscoring this impact is ataxia or incoordination. Ataxia in FA is measured by clinical rating scales such as the modified Friedreich’s Ataxia Rating Scale (mFARS). In children under the age of 12 years measurement of ataxia may be difficult as the system that controls movement is still maturing, making it difficult to discern by a rating scale, what movements are ataxic and what is related to normal maturation. It is important to develop valid measurements of ataxia in younger children so we can potentially monitor their response to new treatments. Dr. Corben has developed devices that use movement analysis technology to measure ataxia. She and her collaborators plan to evaluate the capacity of these devices called the Ataxia Instrumented Measure -Cup (AIM-C) and Ataxia Instrumented Measure - Pendant (AIM-P) to measure arm movement and balance in 12 children with, and 12 children without FA. If they are able to demonstrate that the AIM-C and AIM-P can detect and measure ataxia in young children with FA, they will then conduct a longitudinal trial to evaluate if these devices are useful as outcome measures for young children with FA participating in clinical trials.

PI/Investigators: Joseph Baur, PhD - University of Pennsylvania & Shana McCormack, MD - Children’s Hospital of Philadelphia

Award type: Kyle Bryant Translational Research Award

Grant Title: Detection and enhancement of tissue NAD+ levels in Friedreich’s Ataxia

Lay summary: Nicotinamide adenine dinucleotide (NAD+) is a critical co-factor for cellular metabolism and signaling. It is especially important for energy generation by mitochondria, the “powerhouse of the cell.” Recently, it has been shown that NAD+ is lower in failing hearts, and that boosting NAD+ improves heart function in animal models. In mice with heart-specific loss of frataxin, supplementing NAD+ with nicotinamide mononucleotide (NMN) improved heart function. Dr Baur and his group were able to enhance mitochondrial function with NAD+ supplementation in mice that have reduced frataxin levels in their whole bodies, which is thought to better reflect the human disease. In collaboration with Dr McCormack and other scientists at the University of Pennsylvania and the Children’s Hospital of Philadelphia, he plans to extend these findings in mice and evaluate tissue NAD+ levels in human subjects with FA. Mice with low levels of frataxin will be treated with nicotinamide riboside (NR) or NMN to increase NAD+ levels. Heart function will be evaluated by echocardiography and mitochondria will be tested for the capacity to generate energy. In addition, they will measure the levels of metabolites in the brain, heart tissue and mitochondria under each condition. In human subjects, these investigators will take advantage of a recently developed method for detection of NAD+ in living tissue by proton magnetic resonance spectroscopy (MRS). This method will be used to measure NAD+ in both the brain and skeletal muscle of subjects with FA and healthy controls. Together, these studies have the potential to uncover novel biomarkers and will guide decisions concerning the suitability and therapeutic potential of NAD+ precursors in individuals with FA.

PI/Investigators: Ankur Jain, PhD - Whitehead Institute for Biomedical Research & Ricardo Mouro Pinto, PhD - Harvard Medical School and Massachusetts General Hospital

Award type: Award for Innovative Mindset

Grant Title: A New Ultrasensitive Single-Molecule Assay for Frataxin Measurement

Lay summary: These investigators propose to develop a sensitive and quantitative assay for measuring frataxin levels that could help drug development in FA as well as advance our understanding of disease mechanism. Direct measurement of frataxin remains challenging owing to its low abundance and the inherent detection noise of commonly used assays. Dr Jain and Dr Mouro Pinto propose to overcome this hurdle by implementing a technology that allows detection of very small amounts of molecules directly from serum, blood, or tissue extracts. This method, called SiMPull, combines immuno pull-down (isolating a molecule with antibodies) with single-molecule microscopy, allowing to visualize single protein molecules with a microscope. This assay was recently utilized to measure a variety of biomarkers in blood present at very low concentrations. The investigators hypothesize that the increased sensitivity, quantitative readout, and dynamic range afforded by SiMPull will allow to accurately quantify frataxin levels, including measurements of subtle changes that are undetectable by conventional methods. SiMPull may provide opportunities to use frataxin in accessible biospecimen such as blood, serum, and cerebrospinal fluid as a biomarker for disease progression and for assessing the effectiveness of therapies in clinical trials.

PI/Investigators: Mark Payne, MD - Indiana University School of Medicine & Thomas O’Connell, PhD - Indiana University School of Medicine

Award type: General Research Grant

Grant Title: Diagnostic and Mechanistic Validation of a Metabolic Biomarker Panel to Guide Therapeutic Interventions in Friedreich’s Ataxia

Lay summary: A key roadblock for all therapies has been a lack of biomarkers which can rapidly report on the efficacy and/or toxicity of a therapeutic intervention, and the biochemistry of the disease. In Friedreich Ataxia, affected tissues, such as heart or brain, cannot be assayed to quantify frataxin levels in response to therapies. The goal of this project is to conduct pre-clinical studies on a new set of biomarkers that Dr. Payne and Dr. O’Connell have discovered that reveals a distinct and highly specific metabolic profile in FA patients. Dr. Payne and Dr. O’Connell will test the hypothesis that a metabolic panel can be used as biomarkers for loss or recovery of FXN expression. They will first refine and optimize the biomarker panel using blood samples from 40 FA and 40 control subjects and then validate the performance of the defined biomarker panel using a larger, separate cohort of 60 FA and 60 control subjects. The investigators will subsequently evaluate the response of the biomarker panel to therapeutic intervention using TAT-FXN in a mouse model of FA. The short-term goal is to develop a biomarker panel for FA that quickly reports on disease state and efficacy of therapeutic intervention. The long-term goal of these studies is to understand the metabolic derangements in FA that determine patient outcomes.

PI/Investigator: Chad Heatwole, MD - University of Rochester Medical Center, NY

Award type: General Research Grant

Grant Title: LEOPARD-FA: Longitudinal Endpoint Optimization to Provide an Assessment of Relevant Drugs in Friedreich’s Ataxia

Lay summary: Patients with Friedreich’s Ataxia (FA) experience a variety of life-altering symptoms. As new therapies and clinical trials are planned for FA, it is important for researchers, clinicians, patients, and regulatory agencies to have clinical trial tools that are capable of detecting meaningful changes in the symptoms and issues that are most important to patients. Dr. Heatwole previously developed two state-of-the-art outcome measures for patients with FA (The FA Health Indices). The first instrument, the Friedreich’s Ataxia Health Index (FA-HI), measures symptomatic burden using the perspective of the patient. The second instrument, the Friedreich’s Ataxia Caregiver Reported Health Index (FACR-HI), measures symptomatic burden in younger children with FA and is completed by caregivers. Together, these instruments provide a mechanism for a patient’s or caregiver’s perception of the effectiveness of a therapy to be recorded and utilized during a clinical trial. While these instruments are highly reliable, versatile, multifaceted, and relevant to FA patients, they have not yet been evaluated in longitudinal studies. Such assessments are necessary to complete the validation process for the instruments, satisfy FDA guidance criteria for their use in drug-labeling claims, optimize the responsiveness of the instruments, and prepare them for global use as relevant markers of symptomatic disease burden. This research will satisfy existing needs by developing, validating, assessing, and optimizing the responsiveness, relevance, performance, and usability of the FA-Health Indices. Dr. Heatwole’s group will accomplish this using accepted methodology and the parallel utilization of the FA-Health Indices in: 1) An 18-month longitudinal validation study utilizing the FA Global Patient Registry; and, 2) The ongoing Friedreich’s Ataxia Clinical Outcome Measures Study (FACOMS). In addition, natural history data in FA will be collected and analyzed. These data will: 1) demonstrate how disease progresses over time in FA, 2) identify which areas of FA symptomatic burden progress the fastest, and, 3) determine which demographic features are associated with a faster or slower progression of disease. Through this research, these investigators will also generate responsiveness data and performance metrics for the FA-Heath Indices and their subscales to assist in the design of future clinical studies. At the completion of this work, the FA research community will have two fully-validated and patient-centered outcome measures to promote the development of meaningful therapies in FA.

Co-sponsor: fara Australia

PI/Investigator: Mark Payne, MD – Indiana University School of Medicine

Award type: General Research Grant

Grant Title: Role of the Thromboxane-Prostanoid Receptor in FRDA Cardiomyopathy

Lay summary: This project will test if the drug ifetroban, currently in clinical trials for other diseases that affect the heart, improves the survival of a mouse model of FA.

The long-term goal of this project is to improve the heart function in people who have Friedreich ataxia. It is known that the heart in this disease develops significant thickening and has extensive fibrosis that develops over time. This markedly decreases the function of the heart and leads to early death. This project will determine if a drug called ifetroban will stop or decrease fibrosis in the heart of the Friedreich ataxia mouse thus extending its life. This drug is targeted to a specific receptor called the thromboxane-prostanoid receptor which, in heart, stimulates production of fibrosis. By studying the effect of ifetroban in the FA mouse model, Dr Payne hopes to generate enough data to apply for a grant from NIH or FDA to support a clinical trial of ifetroban in FA patients.

Co-sponsor: fara Australia

PI/Investigator: Laura Kropp, PhD, MPH - Stealth BioTherapeutics

Award type: Keith Michael Andrus Cardiac Research Award

Grant Title: Advancing novel mitochondrial therapies for FA cardiomyopathy: a pragmatic collaboration to move new therapies forward

Lay summary: In Friedreich’s ataxia, frataxin deficiency causes mitochondria dysregulation and impaired cellular energy production. Stealth BioTherapeutics has recently developed a series of new compounds that were designed to address dysregulated mitochondria in FA cardiomyopathy. These compounds have been developed to correct the impairments in bioenergetics of the cell and to prevent iron-mediated cell death (known as ferroptosis). Three compounds have been identified with the potential to mitigate mitochondrial dysfunction in FA cardiomyopathy: the first compound helps with improving energy production in mitochondria, the second prevents ferroptosis in cellular assays, and the third demonstrates potential “dual pharmacology” by improving both pathways. In this study, Dr. Kropp will test whether this series of compounds can ameliorate signs and disease biomarkers of cardiomyopathy in a mouse model of FA. She will also characterize the mechanism of these drugs by measuring their effect on energy production and ferroptosis in the FA mouse heart. These studies may provide new scientific insight as to whether inhibiting both pathways will be superior, or equipotent, to mechanistic approaches that inhibit either pathway alone. Successful completion of these studies will help to advance the development of a drug candidate for FA cardiomyopathy.

PI/Investigators: Marcondes França Jr, MD, PhD & Thiago de Rezende, MSc - University of Campinas, Brazil

Award type: Postdoctoral Research Award

Grant Title: Cardiac Imaging Biomarkers in Friedreich's Ataxia

Lay summary: Biomarkers are urgently needed to assist in the clinical care and the design of clinical trials for Friedreich´s ataxia (FRDA). Neuroimaging-based parameters have emerged as potential candidates, although further studies are necessary to validate them. In particular, cardiac magnetic resonance imaging (cMRI) has emerged as a promising diagnostic technique. In FRDA, cardiac studies have not received as much research interest as the neurological manifestations, despite heart failure being the main cause of death in such patients. For this reason, further studies in this area are needed to provide relevant information on the natural history and pathophysiology of the disease, in order to identify useful and sensitive biomarkers for clinical trial and follow-up. Therefore, this research proposal centers on the following objectives: 1. To characterize and quantify cardiac damage in pediatric patients with FRDA, patients with long standing FRDA and patients with late-onset FRDA (LOFA); 2. To characterize longitudinal progression of such damage in each of these groups; 3. To investigate whether image parameters correlate with clinical measures, mainly ataxia severity.

PI/Investigators: Manuela Corti, PhD & Tanja Taivassalo, PhD - University of Florida

Award type: Award for Innovative Mindset

Grant Title: Functional electrical stimulation (FES) cycling training to improve motor and cardiac functions in patients with Friedreich’s Ataxia: a feasibility and efficacy study

Lay summary: The purpose of this exploratory study is to assess the feasibility and potential efficacy of a novel therapeutic strategy involving Functional Electrical Stimulation (FES) cycle exercise training in patients with Friedreich’s Ataxia (FA). This pilot study will take advantage of innovative FES technology paired with isokinetic cycling provided by the MyoCycle Home FES Cycling Therapy System (Myolyn, LLC, Gainesville, Florida) and use a home-based, remotely supervised training strategy to encourage feasibility and compliance to the protocol. This study will recruit six non-ambulatory FA patients to assess the effect of training with cycling plus FES versus cycling alone. The investigators will test feasibility, motor function and exercise capacity using integrative, non-invasive approaches, including novel magnetic resonance imaging techniques to assess functional and morphological changes in the heart and skeletal muscle.

Co-sponsor: AFAF