Transforming growth factor-β1 regulates renal α3 and β1 integrin expressions in diabetic rats: a new insight into the renoprotective effect of irbesartan / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To explore the association between renal transforming growth factor-β1 (TGF-β1) and the expressions of α3 and β1 integrins and observe the effect of irbesartan on their expressions in diabetic rats.</p><p><b>METHODS</b>Thirty 8-week-old male Wistar rats were randomly divided into normal control group (n=7), diabetic control group (n=14) and irbesartan group (n=9). Rat models of diabetes were established by a single peritoneal injection of streptozotocin (STZ), and 4 weeks later the rats received irbesartan treatment for 8 weeks. Enzyme-linked immunosorbent assay (ELISA) was used to measure the urinary albumin excretion rate, and PAS staining was utilized to observe the renal pathologies. Immunohistochemistry was performed for semi-quantitative determination of podocyte density, and real-time RT-PCR was used to detect the renal TGF-β1 and α3/β1 integrin mRNA expressions.</p><p><b>RESULTS</b>In diabetic rats, the expression of renal TGF-β1 mRNA was significantly increased, while α3 and β1 integrin mRNA expressions and podocyte density significantly decreased with increased proteinuria. Irbesartan obviously improved such changes.</p><p><b>CONCLUSION</b>In diabetic rats renal TGF-β1 can regulate α3 and β1 integrin mRNA expressions to reduce the number of podocytes, and inhibition of this pathway may be one of the mechanisms of the renal protective effect of irbesartan.</p>