氧化苦参碱对糖尿病大鼠肾组织TLR4及炎症因子表达的影响

Effect of oxymatrine on expressions of TLR4 and inflammatory factors in kidney tissue of diabetic rats

摘要:

目的 通过观察氧化苦参碱（OM）对糖尿病（DM）大鼠肾组织Toll 样受体4（TLR4）及炎症因子表达的影响，探讨OM 抗炎、抗纤维化的可能机制。方法 采用链脲佐菌素复制大鼠DM 模型，随机分为糖尿病组（DM 组）和氧化苦参碱干预组（OM 组），每组8 只大鼠。OM 组大鼠从模型复制成功次日起给予OM 75 mg/（kg·d）灌胃，同时设正常对照组（NC 组）（8 只大鼠）。16 周后处死大鼠，观察肾组织病理学改变，采用免疫组织化学法和Western blot 检测各组大鼠肾组织TLR4、蛋白激酶Cα（PKCα）及胶原蛋白Ⅳ的表达，酶联免疫吸附法检测各组大鼠肾组织匀浆中炎症因子白细胞介素6（IL-6）和肿瘤坏死因子（TNF-α）的表达。结果 与NC 组相比，DM 组大鼠体重减轻，血糖和24 h 尿蛋白升高（P <0.05）；肾组织TLR4、PKCα 及胶原蛋白Ⅳ表达增多（P <0.05）；炎症因子IL-6 和TNF-α 表达增多（P <0.05）。与DM 组相比，OM 组大鼠体重逐渐增加，血糖和24 h 尿蛋白降低（P <0.05）；TLR4、PKCα 及胶原蛋白Ⅳ表达下调（P <0.05）；炎症因子IL-6 和TNF-α 表达下调（P <0.05）。结论 OM 可下调DM 大鼠肾组织TLR4 的表达，减少炎症因子的表达和细胞外基质的沉积，从而缓解DN 纤维化病变的发生、发展，其机制可能与抑制PKCα 蛋白的表达有关。

Abstract:

Objective To investigate the effect of oxymatrine on expressions of Toll-like receptor 4 (TLR4) and inflammatory factors in the kidney tissue of rats with diabetes mellitus (DM) and to explore the possible mechanisms of oxymatrine involved in anti-inflammation and anti-fibrosis. Methods The DM rat model was established by tail-vein injection of Streptozotocin. The rats were randomly divided into two groups: diabetic group (DM) and oxymatrine treatment group (OM) (8 in each group). Meanwhile, 8 rats were grouped into normal control group (NC group). The rats in the OM group were given oxymatrine solution (75 mg/kg) by gastric gavage once a day for 16 w after the DM rat model was established. After 16 w, the rats were sacrificed to detect relevant biochemical parameters, and observe the pathological changes of the kidneys and pancreas as well. In addition,immunohistochemical staining and Western blot were employed to detect the protein expressions of TLR4, protein kinase Cα (PKCα) and collagen IV. And the expressions of interleukin 6 (IL-6) and tumor necrosis factor α (TNF-α) were detected by ELISA. Results Compared with the NC group, the levels of blood glucose and 24-h urine protein were remarkably increased in the DM group (P < 0.05). The protein expressions of TLR4, PKCα and collagen IV in the kidneys were increased in the DM group (P < 0.05), and the expressions of IL-6 and TNF-α were significantly increased in the DM group (P < 0.05). Compared with the DM group, the levels of blood glucose and 24-h urine protein were remarkably reduced in the OM group, and the protein expressions of TLR4, PKCα and collagen IV in the kidneys were reduced and the expressions of IL-6 and TNF-α were significantly reduced in the OM group (P < 0.05). Conclusions Oxymatrine may down-regulate the expression of TLR4 in the kidneys of diabetic rats,reduce the expressions of inflammatory factors and the accumulation of extracellular matrix via inhibiting the expression of PKCα.