Introduction: Cardiovascular disease (CVD) is the leading cause of death among women. Epidemiologic studies indicate that pre-menopausal women are protected against the development of CVD when compared to age-matched men. Women show less cardiac remodeling, with downregulation in fibrosis and inflammation pathways. Remodeling is manifested by morphology and electrophysiological changes including hypertrophy, apoptosis, fibroblast proliferation, fibrosis and accumulation of fibrillar collagens. Hypothesis: We hypothesize that female protection against CVD is associated with estrogen levels as the incidence and severity of CVD increases after menopause. Methods: Induced pluripotent stem cells (IPSC) from male (M) and female (F) controls were differentiated to cardiomyocytes (IPSC-CMs) and cardiac fibroblasts (IPSC-CFs). Samples were cultured for 30 days and collected for analysis before and after 48 hs incubation with 1uM of 17-b-estradiol (EST). In IPSC-CMs we analyzed gene expression, morphology and beating frequency. Gene expression, morphology and wound healing were analyzed in IPSC-CFs. Results: Expression of ESR1 , and MYH7 was higher in female IPSC-CMs with upregulation after EST treatment in females but not males. Male IPSC-CMs showed higher expression of COL1A1 , CX43 , MYH6 and RYR2 ; MYH6 , RYR2 and COL1A1 were downregulated after EST treatment. No differences were observed in morphology or beating frequency before or after EST treatment (F:27.5±4.5 bpm vs M:22±2.5 bpm). In IPSC-CFs, males showed higher expression of the fibrotic markers COL1A1 , POSTN, SMAD2 and CCL2 ; EST treatment decreased the expression of POSTN and SMAD2 . Wound healing assays showed a decrease of the wound healing % in women after EST treatment (CT F:86.4±19.7% vs EST F:57.43±10.1%, at 8 hs, *p<0.05). Male wound healing rate was slower than women in control and treated groups, with no changes after EST treatment (CT F: 86.4±19.7% vs CT M: 51.65±18.4%, at 8 hs, *p<0.05). Conclusions: Estrogen treatment exerts an effect on gene expression in female and male IPSC-CMs and IPSC-CFs with men showing higher expression of fibrotic markers, which are down-regulated by EST. Further functional studies will shed light on the phenotypic effects of gene expression changes.
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