Hypertrophic cardiomyopathy-associated mutations drive stromal activation via EGFR-mediated paracrine signaling

Summary

Hypertrophic cardiomyopathy (HCM) is characterized by thickening of the left ventricular wall, diastolic dysfunction, and fibrosis, and is associated with mutations in genes encoding sarcomere proteins. While in vitro studies have used human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) to study HCM, these models have not examined the multicellular interactions involved in fibrosis. Using engineered cardiac microtissues (CMTs) composed of HCM-causing MYH7-variant hiPSC-CMs and wild-type fibroblasts, we observed cell-cell cross-talk leading to increased collagen deposition, tissue stiffening, and decreased contractility dependent on fibroblast proliferation. hiPSC-CM conditioned media and single-nucleus RNA sequencing data suggested that fibroblast proliferation is mediated by paracrine signals from MYH7-variant cardiomyocytes. Furthermore, inhibiting epidermal growth factor receptor tyrosine kinase with erlotinib hydrochloride attenuated stromal activation. Last, HCM-causing MYBPC3-variant CMTs also demonstrated increased stromal activation and reduced contractility, but with distinct characteristics. Together, these findings establish a paracrine-mediated cross-talk potentially responsible for fibrotic changes observed in HCM.

Authors Ewoldt JK, Wang MC, McLellan MA, Cloonan PE, Chopra A, Gorham J, Li L, DeLaughter DM, Gao X, Lee JH, Willcox JAL, Layton O, Luu RJ, Toepfer CN, Eyckmans J, Seidman CE, Seidman JG, Chen CS
Journal Science advances
Publication Date 2024 Oct 18;10(42):eadi6927
PubMed 39413182
PubMed Central PMC11482324
DOI 10.1126/sciadv.adi6927

Research Projects

Cell Lines