Inhibition of integrin-linked kinase by angiotensin II receptor antagonist, irbesartan attenuates podocyte injury in diabetic rats.

Background: Integrin-linked kinase (ILK) dysregulation is involved in the progression of diabetic nephropathy (DN). The aim of this study was to investigate the effects of angiotensin II receptor blocker (ARB), irbesartan, on ILK expression and podocyte injury in DN.

Methods: DN was induced by the combined feeding of high-sucrose, high-fat diet and intra-peritoneal injection of low dose of streptozotocin (35 mg/kg) in spontaneously hypertensive rats. Diabetic rats were treated with irbesartan (50 mg×kg(-1)×d(-1)) by gavage for 8 weeks. The renal morphologic changes and podocyte injury were investigated by light and electron microscopy, and the ILK expression was evaluated by real-time RT-PCR and Western blotting analysis.

Results: Diabetic rats exhibited with the similar clinical feature of type 2 DN. Morphologically, they were characterized by expansion of mesangial matrix, loss of podocyte and podocyte injury. Impressively, compared to controls, the ILK expression in diabetic rats were upregulated, which were positively correlated with both podocyte injury and albuminuria. Irbesartan significantly prevented ILK overexpression, along with the amelioration of podocyte injury and albuminuria.

Conclusions: ILK plays an important role in mediating podocyte injury in DN; irbesartan inhibits ILK upregulation and attenuates podocyte injury, which might offer a new insight into the role of ARB in preventing DN progression.