Assessing Sarcomere Structure and Twitch Stress in Fabry-derived iPSC Cardiomyocytes

Student’s Name: Mia Dolan Home Institution: Vanderbilt University NNCI Site: CNS @ Harvard University REU Principal Investigator: Dr. Kit Parker – Disease Biophysics Group, Harvard University REU Mentor: Dr. Julia Deinsberger, Visiting Scholar Abstract: Fabry disease (FD), an X-linked lysosomal storage disorder, affects between 1 in 40,000 and 1 in 117,000 individuals (Pieroni et al., 2021). This condition results from a mutation or absence of the GLA gene, leading to decreased activity of α-galactosidase A, an enzyme that breaks down globotriaosylceramide (lyso-Gb3) in the lysosome. (Choi et al., 2015). The buildup of lyso-Gb3 impairs the function of cardiomyocytes and stimulates secondary pathways that can lead to left ventricular hypertrophy (Pieroni et al., 2021), and in some patients, heart failure (Weissman et. al, 2024). We hypothesize that human induced pluripotent stem cell derived cardiomyocytes (hiPSC-CMs) expressing Fabry disease phenotypes exhibit decreased twitch stress and abnormal calcium propagation (Bray et al., 2007). Using patient derived hiPSC-CMs, we will model Fabry disease conductive and contractile phenotypes using the heart-on-a-chip platform. Wild-type (wt) hiPSC-CMs were seeded onto MTFs and G-Nodes and analyzed to establish baseline measurements for twitch stress and longitudinal conduction velocity. The recordings of twitch stress and calcium propagation in cardiomyocytes derived from healthy human-induced pluripotent stem cells will be analyzed and compared to those from FD patients. Additionally, confocal microscopy was used to assess the structural integrity of the wt cells. Structural data of wt and hiPSC-CMs will also be compared to establish an accurate disease model to better understand the molecular basis of FD.