Calcium communication among intracellular compartments in FA patient-derived cells

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 types 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.