17β-Estradiol Counteracts Pathological Microtubule Remodeling To Enhance Cardiac Function

The female-predominate sex hormone 17β-estradiol exerts cardioprotective effects via multiple mechanisms. Available data demonstrate 17β-estradiol modulates microtubule dynamics in vitro, but its effects on pathogenic microtubule remodeling in pressure-overloaded cardiomyocytes are unexplored. Here, we show 17β-estradiol directly blunts microtubule polymerization in vitro, counteracts endothelin-mediated microtubule remodeling in iPSC-cardiomyocytes, and mitigates microtubule stabilization in pulmonary artery banded right ventricular cardiomyocytes. 17β-estradiol treatment blunts cardiomyocyte and nuclear hypertrophy, restores t-tubule architecture, and prevents mislocalization of connexin-43 in RV cardiomyocytes of pulmonary artery banded rats. These cellular phenotypes are paired with significant improvements in RV function. Thus, we propose 17β-estradiol exerts cardioprotective effects via direct modulation of microtubules in addition to its well ascribed signaling functions.