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目的:探讨过氧化物酶增殖物激活受体α(PPARα)激动剂非诺贝特(fenofibrate)对糜酶介导的大鼠心脏成纤维细胞(CFs)增殖的影响及作用机制。方法:用胰酶消化法分离、培养新生SD大鼠的CFs。采用3H-脱氧胸腺嘧啶核苷(3H-TdR)掺入法测定CFs的DNA合成,用流式细胞术分析细胞周期,用RT-PCR检测PPARα及转化生长因子β1(TGF-β1)mRNA的表达。结果:①以不同浓度的非诺贝特预处理后,CFs的3H-TdR掺入量呈浓度依赖性减少,其中50和100μmol/L组均较糜酶组明显减少(分别为P<0.05和P<0.01)。②随着非诺贝特浓度的增加,CFs在G0/G1期的百分率逐渐增加,S期的百分率和增殖指数逐渐减少,其中50和100μmol/L组与糜酶组比较,上述各项指标均有显著性差异(分别为P<0.05和P<0.01)。③以25、50和100μmol/L非诺贝特预处理后,PPARαmRNA表达的水平呈浓度依赖性增加,其中50和100μmol/L组均较糜酶组显著增加(分别为P<0.05和P<0.01)。④随着非诺贝特浓度的增加,TGF-β1 mRNA表达水平呈递减趋势,其中50和100μmol/L组均较糜酶组明显减少(P<0.01)。结论:PPARα激动剂非诺贝特以浓度依赖的方式抑制糜酶诱导的大鼠CFs增殖的作用,其机制与PPARα基因表达的上调和TGF-β1基因表达的下调有关,提示PPARα和TGF-β1这两条信号通路可能存在信息交流。
Objective: To investigate the effects of fenofibrate, a peroxisome proliferator-activated receptor α (PPARα) agonist, on the chymase-induced proliferation of rat cardiac fibroblasts (CFs) and its possible mechanism. Methods: The CFs of newborn SD rats were isolated and cultured by trypsin digestion. The DNA synthesis of CFs was determined by the incorporation of 3H-thymidine (3H-TdR). The cell cycle was analyzed by flow cytometry. The mRNA expression of PPARα and TGF-β1 was detected by RT-PCR . Results: ① After pre-treatment with fenofibrate at different concentrations, 3H-TdR incorporation in CFs decreased in a concentration-dependent manner, with 50 and 100 μmol / L decreased significantly P <0.01). ② With the increase of fenofibrate concentration, the percentage of CFs in G0 / G1 phase gradually increased, the percentage of S phase and proliferation index gradually decreased, among which 50 and 100μmol / L groups compared with chymase group, the above indexes There were significant differences (P <0.05 and P <0.01, respectively). ③ After pretreatment with fenofibrate at 25, 50 and 100 μmol / L, PPARαmRNA expression increased in a concentration-dependent manner, and the levels of PPARαmRNA in 50 and 100 μmol / L groups were significantly increased compared with those of chymase (P <0.05 and P < 0.01). ④ With the increase of fenofibrate concentration, the expression of TGF-β1 mRNA showed a decreasing trend, in which 50 and 100 μmol / L groups were significantly lower than those of chymase group (P <0.01). Conclusion: PPARα agonist fenofibrate inhibits the chymase-induced CFs proliferation in a concentration-dependent manner. The mechanism is related to the up-regulation of PPARα gene expression and the down-regulation of TGF-β1 gene expression, suggesting that PPARα and TGF-β1 There may be information exchange between these two signaling pathways.