芍药苷通过调节前列腺素E_2受体抑制大鼠成纤维滑膜细胞增殖

Inhibitory effect of paeoniflorin on rat fibroblast-like synoviocytes hyperplasia induced by PGE2 via β-arrestin 2 regulating EP2 receptor

目的从前列腺素E2(PGE2)受体EP2和β-arrestin 2的表达分布变化特点,探讨PGE2诱导大鼠成纤维样滑膜细胞(FLS)异常增殖的分子机制以及芍药苷(Pae)的作用。方法组织块培养法培养大鼠FLS,3H-TdR参入法检测FLS增殖情况,放免法测定细胞内环磷酸腺苷(cAMP)浓度,流式细胞术检测FLS胞膜EP2受体水平,Western blot法检测FLS EP2和β-arrestin 2总蛋白和胞膜蛋白的表达。结果PGE2(125μg.L-1)刺激24 h,诱导FLS的异常增殖,降低细胞内cAMP浓度和胞膜EP2受体水平,但上调胞膜β-ar-restin 2表达和FLS中EP2、β-arrestin 2的总表达,Pae可抑制FLS过度增殖,恢复cAMP水平和胞膜EP2表达,下调胞膜β-arrestin 2和总EP2、β-arrestin 2水平。结论 Pae可能通过抑制β-arrestin 2的表达和转膜,减少EP2受体内吞而升高cAMP,抑制FLS在PGE2作用下的异常增殖。

Aim To investigate the potential molecular mechanism of paeoniflorin（Pae） in inhibiting PGE2 induced rat fibroblast-like synoviocytes（FLSs） hyperplasy.Methods Rat FLSs were cultured in the presence of prostaglandin E2（PGE2） with or without different concentrations of Pae.FLSs proliferations were determined by 3H-TdR incorporation assay.Cyclic adenosine monophosphate（cAMP） levels in synoviocytes were assessed by radioimmunoassay（RIA）.The expressions of EP2 and β-arrestin 2 in whole FLSs or on membrane were measured by Western blot or flow cytometry.Results Pae significantly inhibited rat FLS proliferation induced by PGE2 via increasing cAMP levels.High levels of total EP2,β-arrestin 2 and membrane β-arrestin 2 expression in FLSs induced by PGE2 were decreased by different concentrations of Pae administration.EP2 was downregulated on FLSs membrane after PGE2 stimulation;however,was restored by Pae in various degrees.Conclusions Our findings suggest that Pae inhibits rat FLSs proliferation induced by PGE2 via arresting EP2 receptor internalization by inhibiting β-arrestin 2 recruit to cell membrane.