前列腺素E2受体激动剂对转化生长因子β1诱导的小鼠系膜细胞损伤的保护作用

Protective effect of EP2 agonists on mesangial cell lesion induced by TGF-β1 in mice

目的探讨前列腺素E2受体2亚型（EP2）激动剂（Butaprost）对转化生长因子B1（TGF—B1）诱导的小鼠肾小球系膜细胞增殖、细胞周期、细胞外基质的影响及可能机制。方法实验分组：（1）对照组；（2）TGF-β1（10rig／m1）组；（3）～（5）Butaprost干预组：不同浓度Butaprost（10、1、0．1μmol／L）＋TGF-β1。CCK-8法检测细胞增殖；流式细胞术测定细胞周期；ELISA法检测细胞上清中环磷酸腺苷（cAMP）及前列腺激素E2（PGE2）的水平；实时定量PCR法检测细胞层黏连蛋白（LN）、纤连蛋白（FN）、结缔组织生长因子（CTGF）、环氧化酶1、2（COX1、COX2）、周期素激酶抑制剂p27KiplmRNA的表达。Western印迹法检测LN、FN、CTGF、COX2、p27Kipl蛋白及p38丝裂素活化蛋白激酶（MAPK）活性变化。结果与对照组相比，TGF—B1组系膜细胞增殖及c2＋s期细胞比例明显增加；cAMP、PGE2表达增加；p27KiplmRNA及蛋白表达降低；FN、LN、CTGF、COX2mRNA及蛋白表达升高；p38MAPK活性增加（均P〈0．05）。Butaprost干预后呈剂量依赖性抑制系膜细胞增殖，下调G2＋S期细胞比例，上调cAMP及p27KiplmRNA及蛋白的表达，抑制FN、LN、CTGF、COX2mRNA及蛋白表达及上清中PGE2的表达，抑制p38MAPK活性（均P〈0．05）。结论Butaprost可能通过增加cAMP的表达，抑制p38MAPK活性，反馈抑制COX2及PGE2的表达，从而下调FN、LN、CTGF的表达，减轻TGF-β1导致的系膜细胞损伤。

Objective To explore the effects and mechanism of Butaprost （PGE2 receptor 2 agonist） on proliferation and secretion of extraeellular matrix （ECM） accumulation induced by TGF-β1 in mouse mesangial cell. Methods Mouse golmerular mesangial cell （GMC） were divided into 5 groups： control group; TGF- β1 group; TGF- β1 plus Butaprost group （10, 1, 0.1 μmol/L）. The proliferation of GMCs was measured by CCK-8, the proportion of G2 ＋ S phase in the cell cycle was measured by flow eytometry and cAMP, PGE2 secreted into media by ELISA assay. The expression of LN, FN, CTGF, COX1, COX2, p27 protein and mRNA was measured by Western blot and real time quantitative reverse PCR, phosphorylation of p38 MAPK was measured by Western blot as well. Results TGF β1 induced the proliferation of GMCs and increased the secretion of cAMP and PGE2 as well as the proportion of G2 ＋ S phase. Besides, TGFβ1 significantly upregulated the expression of FN, LN, CTGF, COX2 and phosphorylated p38 MAPK mRNA and protein while the expression of p27Kipl mRNA and protein was reduced （all P 〈 0.05）. Butaprost effectively reversed above changes and their activities （all P 〈0.05）. All the effects of Butaprost were dose- dependent. Conclusions Butaprost may inhibit TGF-β1-induced cell proliferation and ECM accumulation by upregulate the expression of cAMP and repress the activity of p38 MAP kinase thus decreased the expression of COX2, PGE2, FN, LN and CTGF.