芍药苷对胶原性关节炎大鼠滑膜细胞G蛋白偶联信号的调节作用

目的研究芍药苷(paeoniflorin,Pae)对胶原诱导性关节炎(collagen-induced arthritis,CIA)大鼠滑膜细胞G蛋白偶联信号转导的调节作用。方法用鸡Ⅱ型胶原诱导胶原性关节炎。在免疫后d16~23,胶原性关节炎大鼠灌胃给予Pae(25、50、100mg·kg-1)。通过足爪肿胀和关节炎指数评价关节炎。采用Western blot技术检测滑膜细胞中抑制性G蛋白(Gi)表达。用放免法检测滑膜细胞中cAMP水平,用激酶发光分析法测定滑膜细胞中蛋白激酶A(PKA)的活性。结果胶原性关节炎大鼠出现明显的继发性炎症反应。滑膜细胞中Gi蛋白表达增加,而cAMP水平和PKA活性明显降低。Pae抑制胶原性关节炎大鼠的炎症应答。在100mg·kg-1,Pae抑制Gi的表达。在50mg·kg-1和100mg·kg-1剂量,Pae提高cAMP水平和PKA活性。体外研究发现,Pae(2·5、12·5、62·5mg·L-1)降低滑膜细胞中Gi的表达,而提高降低的cAMP水平和PKA活性。结论胶原性关节炎大鼠滑膜细胞中G蛋白偶联的信号转导与滑膜炎病理机制密切相关;Pae对胶原性关节炎大鼠的抗炎作用是通过调节G蛋白偶联的信号转导实现的。

Regulatory effects of Paeoniflorin on G protein-coupled signaling of synoviocytes in collagen-induced arthritis rats

Aim To investigate the regulatory effects of Paeoniflorin on G protein-coupled signaling by synoviocytes of collagen-induced arthritis (CIA) rats. Methods CIA was induced by chicken type Ⅱcollagen. Pae (25, 50, 100 mg·kg-1) was administered to CIA rats from d 16 to d 23 after immunization. Arthritis was evaluated by hind paw swelling and arthritis index. Expression of inhibitory G protein (Gi) was detected by Western blotting technique. The level of cAMP in synoviocytes was measured by radioimmunoassay. Protein kinase A (PKA) activity was assessed by Kinase-Glo Luminescent Kinase Assay. Results There was remarkably secondary inflammation in CIA rats. The expression of Gi in synoviocytes increased. While cAMP level and PKA activity of synoviocytes decreased. The inflammatory responses of CIA rats were inhibited after administration of Pae. At the dose of 100 mg·kg-1, Pae reduced Gi expression. cAMP level and PKA activity were enhanced by Pae at the doses of 50 and 100 mg·kg-1 respectively. In ivtro, Pae (2.5, 12.5, 62.5 mg·L-1) reduced Gi expression, but enhanced the level of cAMP and PKA activity. Conclusion G protein-coupled signaling was associated with the pathogenesis of synovitis in CIA rats. Pae has anti-inflammatory effects on CIA rats by modulating G protein -coupled signaling.