Resveratrol ameliorates renal myofibroblastic phenotype and fibrosis by inhibiting protein kinase B phosphorylation / 中国药理学与毒理学杂志

ABSTRACT

OBJECTIVE To investigate the effect of resveratrol on renal myofibroblastic phenotype and fibrosis. METHODS A rat model of unilateral ureteral obstruction (UUO) was established. From the day of surgery, resveratrol 20 mg.kg" was given daily and for 7 d. The pathological changes and fibrosis of renal tissues were observed by HE and Masson staining. The expression of myofibroblasticmarker a-smooth muscle actin (a-SMA) in renal tissues was detected by immunohistochemical staining. Renal tubular epithelial cells (NRK-52E) and fibroblasts (NRK-49F) were cultured in vitro, and divided into four groups Normal cell control group, TGF-p, 5 pg-L"' group, TGF-(3, 5 pg-L" +resveratrol 10 or 100 mmol-L"' group. In vitro, the expressions of a-SMA, E-cadherin and extracellular matrix component (collagen III) were detected by immunofluorescence staining. The expressions of protein kinase B (AKT) and phospholated AKT (ρ-AKT) in cells or renal tissues were determined by Western blotting. RESULTS Compared with normal control group, HE staining showed an enlarged interstitial area in the UUO model group (ρ<0.01), Masson staining showed significant accumulation of collagen in the UUO model group (P<0.05). but these changes were inhibited in the resveratrol intervention group (F< 0.05). At the same time, the formation of a-SMA positive myofibroblasts was also inhibited (F<0.05). After TGF-p, stimulation in vitro, a-SMA was significantly increased (ρ<0.05). All this suggested that the number of myofibroblasts transformed from renal cells was significantly increased, accompanied by excessive accumulation of collagen (F<0.01), but these changes were inhibited in the resveratrol intervention group. Western boltting results showed that AKT phosphorylation was increased during myofibroblast production (P<0.01). After intervention with resveratrol, AKT phosphorylation was inhibited not only in UUO model group (ρ<0.05) but also in vitro (ρ<0.05). CONCLUSION Resveratrol may inhibit myofibroblastic phenotype by antagonizing the activation of AKT, thereby reducing the accumulation of extracellular matrix and alleviating renal fibrosis.