Heart tissue extracellular vesicles reprogram smooth muscle cell proteome

Dysregulation of ERalpha has been linked with increased metabolic and cardiovascular disease risk. Uncovering the impact of ERα deficiency in specific tissues has implications for understanding the role of ERα in normal physiology and disease, the increased disease risk in postmenopausal women, and the design of tissue-specific ERα-based therapies for a range of pathologies including cardiac disease and cancer. Cardiac myocyte-specific ER knockout mice (ERalphaHKO) were generated to assess the role of ERα in the heart. Female ERHKO mice displayed a mild cardiac phenotype, but unexpectedly, the most striking phenotype was obesity in female ERHKO but not male ERHKO mice. We identified mild cardiac dysfunction, metabolic and lipid dysregulation in hearts of female ERHKO mice. We also show that extracellular vesicles (EVs) collected from the perfusate from Langendorff-isolated hearts from female ERHKO mice have a distinct proteome compared to male ERHKO; enriched for functions associated with muscle, metabolic and fatty acid dysregulation.