Esaxerenone Attenuates Aldosterone-Induced Renal Fibrosis by Suppressing Fibroblast-to-Lymphatic Endothelial-like Cell Transdifferentiation

Fibroblasts and lymphangiogenesis promote renal fibrosis. However, whether fibroblasts promote renal fibrosis via lymphangiogenesis has not yet been fully elucidated. This study set out to clarify whether aldosterone induces fibroblast transdifferentiation into lymphatic endothelial-like cells, thus promoting lymphangiogenesis and renal fibrosis. In vivo, twenty-four male Wistar rats were randomized into Sham, ALD (6-week aldosterone infusion), and ALD + ESA (aldosterone infusion with esaxerenone co-treatment) groups. In vitro, primary rat renal interstitial fibroblasts (RKFs) were used. Immunohistochemistry and Western blot were used to detect lymphatic endothelial and fibroblast marker expression in kidneys from aldosterone-infused rats and RKFs. Their co-expression was determined by flow cytometry and immunofluorescence co-staining. Mineralocorticoid receptor (MR) activation and related signaling pathways were also analyzed by Western blot, immunohistochemistry, and flow cytometry. Additionally, RKF migration and tube formation were examined to investigate the role of aldosterone-induced fibroblast-to-lymphatic endothelial-like transdifferentiation in renal fibrosis. Our data suggest that aldosterone activates the MR and induces the transdifferentiation of fibroblasts into lymphatic endothelial-like cells via the MR/VEGFC/VEGFR-3 pathway, thereby promoting lymphangiogenesis. In addition, the administration of esaxerenone (a mineralocorticoid receptor blocker, MRB) to rats significantly suppresses this transdifferentiation and alleviates fibrosis.