Aldosterone mediates glomerular inflammation in experimental mesangial proliferative glomerulonephritis

BACKGROUND: The renoprotection of the mineralocorticoid receptor antagonist (MRA) is considered to be mainly via its antifibrotic activity, and the possibility that it may also have antiinflammatory effects has not been studied. We tested the hypothesis that MRA might influence the inflammatory changes that accompany experimental glomerular injury. METHODS: Administration of vehicle (control) or a selective MRA, eplerenone (50 mg/kg x 2 times/day) was started 7 days (-7d) before induction of anti-Thy-1.1 glomerulonephritis. Kidney samples were evaluated serially over a 12-day period for the presence of cell proliferation, macrophage infiltration, mesangial cell phenotypic activation and expression of the chemokine monocyte chemoattractant protein-1 (MCP-1). RESULTS: MRA did not prevent the mesangiolysis associated with anti-Thy-1 antibody. However, MRA significantly inhibited MCP-1 expression, glomerular macrophage infiltration and mesangial phenotypic activation (alpha-smooth muscle actin expression). CONCLUSION: MRA alters glomerular inflammation and mesangial cell activation in experimental glomerular injury. MRA may be a novel way to treat acute glomerular diseases.