Aldosterone-induced oxidative stress and inflammation in the brain are mediated by the endothelial cell mineralocorticoid receptor

•Blood pressure increase by aldosterone was unaffected by endothelial MR deficiency.•Aldosterone increased cerebrovascular superoxide production capacity.•Endothelial cell MR-deficiency inhibited aldosterone-induced increase in superoxide.•Aldosterone increased brain mRNA expression of pro-inflammatory cytokines.•CCL7 and CCL8-not IL-1β-increases were prevented by endothelial MR deficiency.

Elevated aldosterone levels, which promote cerebral vascular oxidative stress, inflammation, and endothelial dysfunction, may increase stroke risk, independent of blood pressure and other risk factors. The main target receptor of aldosterone, the mineralocorticoid receptor (MR), is expressed in many cell types, including endothelial cells. Endothelial cell dysfunction is thought to be an initiating step contributing to cardiovascular disease and stroke; however the importance of MR expressed on endothelial cells in the brain is unknown. Here we have examined whether endothelial cell MR mediates cerebral vascular oxidative stress and brain inflammation during aldosterone excess. In male mice, aldosterone (0.72 mg/kg/day, 14 days) caused a small increase (~14 mmHg) in blood pressure. The MR blocker spironolactone (25 mg/kg/d, ip) abolished this increase, whereas endothelial cell MR-deficiency had no effect. Aldosterone increased superoxide production capacity in cerebral arteries, and also mRNA expression of the pro-inflammatory cytokines chemokine (C–C motif) ligand 7 (CCL7), CCL8 and interleukin (IL)-1β in the brain. These increases were prevented by both spironolactone treatment and endothelial cell MR-deficiency; whereas IL-1β expression was blocked by spironolactone only. Endothelial cell MR mediates aldosterone-induced increases in cerebrovascular superoxide levels and chemokine expression in the brain, but not blood pressure or brain IL-1β. Endothelial cell-targeted MR antagonism may represent a novel approach to treat cerebrovascular disease and stroke, particularly during conditions of aldosterone excess.