Corticosteroids, heart failure, and hypertension: a role for immune cells?

Aldosterone and its receptor the mineralocorticoid receptor (MR) are best known for their regulation of fluid and electrolyte homeostasis in epithelial cells. However, it is now clear that MR are also expressed in a broad range of nonepithelial tissues including the cardiovascular system. In the heart and vascular tissues, pathological activation of MR promotes cardiovascular inflammation and remodeling for which there is increasing evidence that macrophages and other immune cells (e.g. T cells and dendritic cells) play a significant role. While the glucocorticoids and their receptors have well-described antiinflammatory actions in immune cells, a role for aldosterone and/or the MR in these cells is largely undefined. Emerging evidence, however, suggests that MR signaling may directly or indirectly promote proinflammatory responses in these immune cells. This review will discuss the current understanding of the role of corticosteroid receptors in macrophages and their effect on cardiovascular diseases involving inflammation.