Abstract P2111: Hutchinson Gilford Progeria Patient-specific Induced Cardiomyocyte Model Carrying Lamin A Gene Variant C.1824 C > T

Abstract

Background: Hutchinson-Gilford progeria (HGP) is a rare genetic disorder in which children age rapidly. They suffer from atherosclerosis, cardiovascular diseases, and strokes. The LMNA variant c.1824C>T accounts for ~90% of HGP cases. This variant causes an abnormal Lamin A protein called progerin. The detailed molecular mechanisms of Lamin A in the heart remain elusive due to the lack of appropriate in vitro models. Hypothesis: We hypothesize that HGP patient’s induced pluripotent stem cell (iPSC)-derived cardiomyocytes (iCMCs) will provide a model platform to study the cardio-pathologic mechanisms associated with progeria. Methods and Results: We performed in silico analysis of LMNA variant c.1824C>T to determine its effects on Lamin A structure and stability. For validation , skin fibroblasts (SFs) from a de-identified HGP patient (hPGP1, proband) and parents were obtained from the Progeria Foundation. Through Sanger sequencing (Fig 1A) and restriction fragment length polymorphism, with enzyme EciI , targeting Lamin A, we characterized hPGP1-SFs as heterozygous mutants for variant c.1824 C>T. Then, we reprogrammed the three SFs into iPSCs (Fig 1B) using a safe mRNA-based reprogramming method , and differentiated them into iCMCs, which gained beating on day 7. We found that hPGP1-iCMCs (Fig 1C) had an irregular contractile function by Particle Image Velocimetry Analysis and decreased cardiac-specific gene and protein expressions by qRT-PCR and Western Blot. Conclusions: We successfully generated iCMCs from a progeria patient carrying LMNA variant c.1824C>T. These iCMCs were found to be functionally and structurally defective when compared to normal iCMCs. Our in vitro model will help elucidate the role of Lamin A and the cardio-pathologic mechanisms associated with progeria.