非诺贝特对糜酶诱导的大鼠心脏成纤维细胞增殖及胶原合成的影响

目的: 探讨过氧化物酶增殖物激活受体α(PPARα)激动剂非诺贝特对心脏肥大细胞糜酶诱导的心脏成纤维细胞增殖及胶原合成的影响。方法: 分离、培养新生SD大鼠心脏的成纤维细胞，采用MTT比色法(A490值)测定细胞数目。用流式细胞仪分析细胞周期。用3H-脯氨酸掺人法测定总胶原合成，实时定量PCR检测I型和Ⅲ型胶原mRNA的表达。结果: MTT比色法的结果显示，与正常对照相比，糜酶作用后A490值升高为0.42±0.05，而给予不同浓度的非诺贝特后，A490值降低为0.35±0.06（50 mg/L）及0.28±0.05（100 mg/L），明显低于单纯糜酶组(P<0.05)。3H-脯氨酸掺入法的结果显示，与正常对照组相比，糜酶作用24 h后，心脏成纤维细胞3H-脯氨酸掺入量升高为789±67；而给予糜酶+非诺贝特后，3H-脯氨酸掺入量明显低于单纯糜酶组(P<0.05)。PCR的结果显示，与正常对照组相比，糜酶作用24 h后，心脏成纤维细胞中Ⅰ、Ⅲ型胶原mRNA表达的水平显著升高(P<0.05)；而给予糜酶+非诺贝特后，两型胶原mRNA的表达明显低于单纯糜酶组(P<0.05)。流式细胞仪分析的结果显示，单纯糜酶处理后，S期细胞的百分率和细胞的增殖指数明显增加；而非诺贝特则能显著抑制这些改变。结论: PPARα激动剂非诺贝特能够抑制糜酶诱导的心肌纤维化，可能是今后逆转心肌纤维化的另一个有效途径。

Effect of fenofibrate on chymase-induced proliferation and collagen synthesis of rat cardiac fibroblast

AIM: To investigate the effect of fenofibrate on chymase-induced proliferation and collagen synthesis of rat cardiac fibroblasts (CFs). METHODS: Cultured CFs from neonatal Sprague Dawley rats were isolated and treated with chymase or together with fenofibrate. Cellular number and cycle were evaluated by MTT colorimetry (A490 value) and flow cytometry. The total collagen synthesis by CFs was examined by 3H-proline incorporation, and the expressions of mRNAs of types I and III collagen in CFs were determined by real-time PCR. RESULTS: MTT colorimetry showed that compared with those in control group, A490 increased to 0.42±0.05, whereas the value decreased to 0.35±0.06 (50 mg/L) and 0.28±0.05 (100 mg/L) in fenofibrate+cytometry group (P<0.05). The 3H-proline incorporations increased to 789±67 after chymase treatment; however, it significantly decreased with fenofibrate (P<0.05). Real-time PCR showed that mRNA levels of types I and III collagen in CFs were markedly upregulated by chymase (P<0.05), but fenofibrate inhibited the upregulation (P<0.05). Cellular cycle analysis showed that chymase markedly decreased cellular percentage in G0/G1 stage and increased cellular percentage in S stage and proliferation index (PI), which were significantly attenuated by fenofibrate (P<0.05). CONCLUSION: PPARα agonist fenofibrate inhibits chymase-induced proliferation and collagen synthesis of rat CFs, which is probably a potential way to attenuate myocardial fibrosis.