摘要目的 观察纤溶酶原激活物抑制剂-1(PAI-1)在罗格列酮抑制大鼠胚肺成纤维细胞转化及胶原合成中的作用及信号机制.方法 大鼠胚肺成纤维细胞分为3组:罗格列酮组加入罗格列酮30 mmol/L,PAI-1组加入罗格列酮30 mmol/L及PAI-1 20 mmol/L,对照组加入等量的培养基,分别于24、48和72 h收取细胞,离心后-80℃冻存备用.采用RT-PCR法检测成纤维细胞24hⅠ型胶原、Ⅲ型胶原mRNA的表达;Western blot技术分析3个时间点PAI-1,α-平滑肌肌动蛋白(α-SMA)、p-AKT和p-ERK的表达.结果 24、48和72 h罗格列酮组成纤维细胞PAI-1的蛋白表达(0.732±0.015、0.583±0.005、0.762±0.032)较对照组(1.116 ±0.046)明显减低,PAI-1组(0.923 ±0.042、1.024±0.009、1.070±0.011)较罗格列酮组明显增加,差异均有明显统计学意义(F=78.609,均P＜0.01).24、48和72 h罗格列酮组α-SMA的蛋白表达(0.209±0.012、0.280±0.140、0.254±0.025)较对照组(0.340 ±0.026)明显降低,PAI-1组(0.386 ±0.042、0.400±0.037、0.385±0.026)均较罗格列酮组明显增加(F=35.009,均P＜0.01).罗格列酮组肺成纤维细胞Ⅰ型胶原(1.065±0.004)和Ⅲ型胶原(1.282±0.001)的mRNA含量较对照组(1.279 ±0.013、1.690±0.005)明显减低,而PAI-1组(1.390 ±0.029、1.350 ±0.044)较罗格列酮组明显增加(F=12.429、127.456,均P＜0.01).24、48和72 h p-AKT的蛋白含量在3组间无明显改变(F=2.736,P＞0.05),p-ERK的表达在PAI-1组(0.561 ±0.101、0.448±0.022、0.406 ±0.003)、罗格列酮组(0.288±0.010、0.311±0.034、0.336±0.038)和对照组(0.506±0.032)间差异有统计学意义(F=153.548,P＜0.01).结论 罗格列酮可以抑制大鼠胚肺成纤维细胞PAI-1的表达,活化纤溶系统.上调PAI-1表达后,罗格列酮抑制大鼠胚肺成纤维细胞向肌成纤维细胞转化及胶原合成的能力减弱.罗格列酮对成纤维细胞的调节作用可能是通过PAI-1与ERK信号途径之间的相互作用实现的.

abstractsObjective To investigate the role of plasminogen activator inhibitor-1 (PAI-1) in the inhibition of rosiglitazone on the transformation and collagen synthesis of rats' embryo lung fibroblasts and to examine the signal pathways in the process.Methods Fibroblasts from rats' embryo lung tissues were divided into 3 groups:Control,Rosiglitazone (Rosiglitazone 30 mmol/L) and PAI-1 (Rosiglitazone 30 mmol/L and PAI-1 20 mmol/L) groups.The fibroblasts were collected at 24,48 and 72 h,and stored at -80 ℃.RT-PCR was used to determine the expressions of collagen type-1 and type-3 at 24 h.Western blot analysis was used to determine the expressions of PAI-1,a-smooth muscle actin (α-SMA),p-AKT and p-ERK at 24,48 and 72 h.Results There was a significant decrease in the protein expression of PAI-1 in the Rosiglitazone group(0.732 ±0.015,0.583 ±0.005,0.762 ±0.032) at 24,48 and 72 h compared with the Control group(1.116 ±0.046).There was a significant increase in the protein expression in the PAI-1 group(0.923 ± 0.042,1.024 ± 0.009,1.070 ± 0.011) compared with the Rosiglitazone group(F =78.609,P ＜ 0.01).The α-SMA protein expressions were significantly reduced in the Rosiglitazone group (0.209 ± 0.012,0.280 ± 0.140,0.254 ± 0.025) compared with the Control group (0.340 ± 0.026),while the expressions were significantly increased in the PAI-1 group(0.386 ±0.042,0.400 ±0.037,0.385 ±0.026)compared with the Rosiglitazone group (F =35.009,P ＜ 0.01).The collagen type-1 (1.065 ± 0.004) and type-3(1.282 ±0.001) mRNA expressions were significantly reduced in the Rosiglitazone group compared with the Control group(1.279 ± 0.013,1.690 ± 0.005),while the expressions were significantly increased in the PAI-1 groups(1.390 ±0.029,1.350 ±0.044) compared with the Rosiglitazone group (type-1:F =12.429,P ＜ 0.01;type-3:F =127.456,P ＜ 0.01).The expressions of p-AKT showed no differences among the 3 groups,but there were significant differences in the expressions of p-ERK in the Rosiglitazone group(0.288 ± 0.010,0.311 ± 0.034,0.336 ± 0.038) compared with the Control group (0.506 ± 0.032),and in PAI-1 groups(0.561 ±0.101,0.448 ±0.022,0.406 ±0.003) compared with the Rosiglitazone group (F =153.548,P ＜ 0.01).Conclusions Rosiglitazone inhibits PAI-1 expression in fibroblasts from rats' embryo lung tissues and activates the fibrinolytic system.The up-regulation of PAI-1 expression alleviates the inhibition effect of rosiglitazone on the transformation and collagen synthesis of fibroblasts.The cross-talk between PAI-1 and ERK signal pathway may play an important role in the regulation of rosiglitazone on fibrosis.