Curcumin ameliorates Podocytic adhesive capacity damage under mechanical stress by inhibiting miR-124 expression.

BACKGROUND/AIMS Curcumin, a kind of plant polyphenolic compound, has been recently discovered to have renoprotective effects on diabetic nephropathy (DN). Podocyte can respond to various injuries including mechanical stress secondary to DN. Our previous study showed that podocyte miR-124 expression was up-regulated accompanied with podocytic adhesive capacity damage in vitro and in vivo. We hypothesized, in the present research that curcumin would ameliorate podocyte adhesion damage under mechanical stress by inhibiting miR-124 expression. METHODS Gene expression of miR-124 was measured by real-time PCR and protein expression of integrin α3 was measured by Western blotting in STZ-induced uninephrectomized diabetic rats and cultured podocytes under mechanical stress treated with curcumin respectively. Western blot and luciferase reporter assays were used to detect the effects of miR-124 overexpression on the Itga3 expression in podocytes. RESULTS Gene expression of miR-124 was upregulated and α3 was downregulated in renal cortex of diabetic rats and cultured podocytes under mechanical stress which were ameliorated by curcumin treatment significantly. Transient co-transfection of miR-124 mimics with luciferase expression plasmids resulted in a significant repression of luciferase activity in podocytes. Mechanistically, Itga3 may be a regulation target of miR-124. CONCLUSIONS These results provide a novel idea that curcumin prevents against podocytic adhesive capacity damage under mechanical stress by inhibitting miR-124