New Perspectives on Sex Steroid and Mineralocorticoid Receptor Signaling in Cardiac Ischemic Injury.

The global burden of ischemic heart disease is burgeoning for both men and women. Although advances have been made, the need for new sex-specific therapies targeting key differences in cardiovascular disease outcomes in men and women remains. Mineralocorticoid receptor directed treatments have been successfully used for blood pressure control and heart failure management and represent a potentially valuable therapeutic option for ischemic cardiac events. Clinical and experimental data indicate that mineralocorticoid excess or inappropriate mineralocorticoid receptor (MR) activation exacerbates ischemic damage, and many of the intracellular response pathways activated in ischemia and subsequent reperfusion are regulated by MR. In experimental contexts, where MR are abrogated genetically or mineralocorticoid signaling is suppressed pharmacologically, ischemic injury is alleviated, and reperfusion recovery is enhanced. In the chronic setting, mineralocorticoid signaling induces fibrosis, oxidative stress, and inflammation, which can predispose to ischemic events and exacerbate post-myocardial infarct pathologies. Whilst a range of cardiac cell types are involved in mineralocorticoid-mediated regulation of cardiac function, cardiomyocyte-specific MR signaling pathways are key. Selective inhibition of cardiomyocyte MR signaling improves electromechanical resilience during ischemia and enhances contractile recovery in reperfusion. Emerging evidence suggests that the MR also contribute to sex-specific aspects of ischemic vulnerability. Indeed, MR interactions with sex steroid receptors may differentially regulate myocardial nitric oxide bioavailability in males and females, potentially determining sex-specific post-ischemic outcomes. There is hence considerable impetus for exploration of MR directed, cell specific therapies for both women and men in order to improve ischemic heart disease outcomes.