Exacerbation of albuminuria and renal fibrosis in subtotal renal ablation model of adiponectin-knockout mice

Objective - Obesity is recognized increasingly as a major risk factor for kidney disease. We reported previously that plasma adiponectin levels were decreased in obesity, and that adiponectin had defensive properties against type 2 diabetes and hypertension. In this study, we investigated the role of adiponectin for kidney disease in a subtotal nephrectomized mouse model. Methods and Results - Subtotal (5/6) nephrectomy was performed in adiponectin-knockout (APN-KO) and wild-type (WT) mice. The procedure resulted in significant accumulation of adiponectin in glomeruli and interstitium in the remnant kidney. Urinary albumin excretion, glomerular hypertrophy, and tubulointerstitial fibrosis were significantly worse in APN-KO mice compared with WT mice. Intraglomerular macrophage infiltration and mRNA levels of vascular cell adhesion molecule (VCAM)-1, MCP-1, tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta 1, collagen type I/III, and NADPH oxidase components were significantly increased in KO mice compared with WT mice. Treatment of APN-KO mice with adenovirus-mediated adiponectin resulted in amelioration of albuminuria, glomerular hypertrophy, and tubulointerstitial fibrosis and reduced the elevated levels of VCAM-1, MCP-1, TNF-alpha, TGF-beta 1, collagen type I/III, and NADPH oxidase components mRNAs to the same levels as those in WT mice. Conclusions - Adiponectin accumulates to the injured kidney, and prevents glomerular and tubulointerstitial injury through modulating inflammation and oxidative stress.