Aldosterone-Induced Transformation of Vascular Smooth Muscle Cells into Macrophage-like Cells Participates in Inflammatory Vascular Lesions

Vascular smooth muscle cells (VSMCs) are the most abundant cell type in blood vessels, participating in cardiovascular diseases in various ways, among which their transformation into macrophage-like cells has become a research hotspot. In this study, rats were infused with aldosterone for 12 weeks, and VSMCs stimulated with aldosterone in vitro were used to observe aortic injury and the role of VSMC transformation. Vascular changes were detected via small animal ultrasound and H&E staining. Moreover, immunohistochemistry, immunofluorescence, Western blot, and flow cytometry were used to verify that the transformation of VSMCs into macrophage-like cells is regulated by mineralocorticoid receptor (MR) activation and macrophage colony-stimulating factor (M-CSF) and its receptor. Rat vasculature and in vitro cellular experiments revealed that VSMCs transformed into macrophage-like cells and secreted inflammatory factors such as interleukin-1β (IL-1β) and monocyte chemoattractant protein-1 (MCP-1), thereby exacerbating inflammatory vascular lesions, which was inhibited by the MR antagonist esaxerenone. These results reveal that increased levels of aldosterone activate MR, leading to the secretion of M-CSF by VSMCs. This further promotes the transformation of VSMCs into macrophage-like cells, which participate in inflammatory vascular lesions. Therefore, inhibiting the formation of macrophage-like cells can effectively reduce inflammatory vascular lesions.