姜黄素对血管紧张素Ⅱ刺激大鼠肾小管上皮细胞TGF-β1及smad7表达的影响

目的：观察姜黄素对血管紧张素Ⅱ(angiotensinⅡ, AngⅡ)刺激大鼠肾小管上皮细胞TGF-β1及smad7表达的影响，探讨姜黄素改善肾间质纤维化的作用机制。方法培养大鼠肾小管上皮细胞，按随机数字表法分为空白组，AngⅡ对照组，姜黄素低、中、高剂量组。除空白组外，于其余各组细胞培养液中加入10-8mol/L的AngⅡ溶液进行干预；姜黄素低、中、高剂量组分别加入2.5、5.0、10.0μmol/L姜黄素溶液进行干预。干预48 h后，采用Western blot检测各组肾小管上皮细胞TGF-β1、smad7蛋白表达，采用RT-PCR检测肾小管上皮细胞TGF-β1、smad7 mRNA表达。结果与空白组比较，AngⅡ对照组肾小管上皮细胞TGF-β1蛋白(0.23±0.03)比(0.16±0.01)]、TGF-β1 mRNA(1.89±0.20)比(1.00±0.00)]表达升高(P＜0.05)，smad7蛋白(0.19±0.03)比(0.24±0.02)]、smad7 mRNA(0.48±0.05)比(1.00±0.00)]表达降低(P＜0.05)；与 AngⅡ对照组比较，姜黄素低、中、高剂量组 TGF-β1蛋白(0.18±0.02)、(0.17±0.02)、(0.16±0.03)比(0.23±0.03)]、TGF-β1 mRNA(1.58±0.11)、(1.34±0.16)、(0.97±0.19)比(1.89±0.20)]表达下降(P＜0.05)，smad7蛋白(0.28±0.04)、(0.31±0.03)、(0.34±0.04)比(0.19±0.03)]、smad7 mRNA(0.68±0.07)、(0.80±0.06)、(0.98±0.09)比(0.48±0.05)]表达升高(P＜0.05)。结论姜黄素可对抗AngⅡ介导的肾间质纤维化从而发挥肾脏保护作用，其作用机制可能与降低TGF-β1蛋白及其mRNA表达、上调smad7蛋白及其mRNA表达有关。

Effects of curcumin on TGF-β1 and smad7 expression in rat renal tubular epithelial cells stimulated with AngⅡ

Objective To observe the effect of curcumin on the expression of smad7 and TGF-β1 in rats renal tubular cells of with Ang II, and discuss the mechanism of curcumin to improve renal interstitial fibrosis.Methods Cultured rat renal tubular epithelial cells were divided into the blank group, the Ang II control group and the low, medium and high dose curcumin group. The rest of the groups were intervened by 10-8 mol/L Ang II except the blank group; the low, medium and high dose groups of curcumin were intervened by 2.5, 5.0, 10.0μmol/L curcumin. Then Western blot was used to detect the expression of TGF-β1 and smad7 protein, RT-PCR was used to detect the TGF-β1 and smad7 mRNA expression.Results Compared with the blank group, the expression of TGF-β1 protein (0.23 ± 0.03vs. 0.16 ± 0.01), and TGF-β1 mRNA (1.89 ± 0.20vs. 1.00 ± 0.00) significantly increasedin AngⅡ control group (P<0.05), and the expression of smad7 protein (0.19 ± 0.03vs. 0.24 ± 0.02), and smad7 mRNA (0.48 ± 0.05vs. 1.00 ± 0.00) significantly reduced in AngⅡcontrol group (P<0.05). Compared with the AngⅡ control group, the expression of TGF-β1 protein in low, medium and high dose curcumingroup (0.18 ± 0.02, 0.17 ± 0.02, 0.16 ± 0.03vs. 0.23 ± 0.03) and TGF-β1 mRNA (1.58 ± 0.11, 1.34 ± 0.16, 0.97 ± 0.19vs. 1.89 ± 0.20) significantly decreased (P<0.05), and the expression of smad7 protein (0.28 ± 0.04, 0.31 ± 0.03, 0.34 ± 0.04vs. 0.19 ± 0.03) and smad7 mRNA (0.68 ± 0.07, 0.80 ± 0.06, 0.98 ± 0.09vs.0.48 ± 0.05) increased significantly (P<0.05).Conclusions Curcumin can thus play its role in renal protection by counteract the AngⅡ mediated renal interstitial fibrosis. Its mechanism may be related to the reduction of TGF-β1 protein and its mRNA expression, up regulation of smad7 protein and its mRNA expression.