Beclin-1 restrains aldosterone signaling via autophagic degradation of the mineralocorticoid receptor to protect against cardiovascular injury
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Cells deploy adaptive programs to maintain homeostasis under stress, yet mechanisms counteracting damage triggered by transmembrane signaling remain poorly defined. Using a hyperaldosteronism model, we examined how autophagy regulates aldosterone-mediated mineralocorticoid receptor (MR) activation. In human umbilical vein endothelial cells (HUVECs), aldosterone induced autophagy, as evidenced by elevated Beclin-1, an increased LC3-II/LC3-I ratio, and reduced SQSTM1/p62. Aldosterone also promoted MR translocation from the cytosol to the nucleus. Co-immunoprecipitation and immunofluorescence revealed direct interaction and colocalization between MR and Beclin-1, as well as enhanced MR-lysosome association. Domain mapping showed that the Beclin-1 middle domain (161–241 AA) binds the MR C-terminal region (601–984 AA). Bioinformatic prediction and ChIP-qPCR confirmed that MR occupies the promoters of IL-1β , IL-6 , and TNF-α upon aldosterone stimulation. Beclin-1 overexpression attenuated MR nuclear translocation, promoter binding, and inflammatory cytokine expression, whereas Beclin-1 knockdown reversed these effects. In vivo, aldosterone-infused Beclin-1 transgenic ( Becn1-tg ) mice exhibited lower blood pressure, reduced aortic medial thickening, and attenuated cardiac hypertrophy relative to wild-type controls, with no difference in body weight. Our findings identify Beclin-1 as a critical negative regulator of aldosterone signaling through an autophagy-dependent negative feedback loop. By interacting with MR and directing it toward lysosomal sequestration, Beclin-1 limits MR nuclear translocation and transcriptional activity, thereby mitigating aldosterone-induced vascular inflammation and cardiovascular injury.
Highlights
Aldosterone activates autophagy and promotes MR–Beclin-1 interaction in HUVECs
Beclin-1 binds the C-terminal MR domain and directs MR to lysosomal degradation
Beclin-1 overexpression suppresses MR nuclear translocation and cytokine gene activation
Beclin-1 transgenic mice are protected from aldosterone-induced cardiovascular injury