TGF-β1诱导的大鼠ASM细胞增殖的信号转导途径

目的　探求转化生长因子 β1(TGF β1)诱导的大鼠气道平滑肌 (ASM )细胞增殖的可能的分子信号转导途径。 方法　将体外培养的大鼠ASM细胞分为 3组 :对照组 (2 0mL·L-1FCS/DMEM) ,10 μg·L-1TGF β1组和 10 μg·L-1TGF β1/U 0 12 6 (1μmol·L-1)组 (U 0 12 6是特异性ERK1/ 2抑制剂 ) ,通过MTT法观察 3组ASM细胞增殖变化。免疫组化染色法观察 3组细胞磷酸化p4 4 / p4 2MAPK(pERK1/pERK2 )表达情况 ,并进行图像分析检测免疫组化染色灰度值。结果　细胞培养第 2天起 ,MTT法检测的 10 μg·L-1TGF β1组A值 (0 .36± 0 .0 4 3)明显高于对照组 (0 .12 6± 0 .0 5 2 ,t=5 .4 4 ,P <0 .0 5 )和 10 μg·L-1TGF β1/U 0 12 6组 (0 .175± 0 .0 5 0 ,t=6 .38,P <0 .0 5 )。免疫组化染色法观察 3组pERK1/ 2表达情况 ,10 μg·L-1TGF β1组灰度值 (6 6 .12± 6 .86 2 )明显高于对照组 (112 .4±11.82 ,t=3.89,P <0 .0 2 )和 10 μg·L-1TGF β1/U 0 12 6组 (14 8.4± 16 .97,t=10 .76 ,P <0 .0 0 1)。结论　特异性ERK1/2抑制剂U 0 12 6明显抑制TGF β1诱导的大鼠ASM细胞的增殖 ,TGF β1可能是通过MAPK信号转导途径促使大鼠ASM细胞的增殖 ,ERK1/ 2是这一过程中重要的信号分子。

Signal transduction in TGF-β1-induced airway smooth muscle cell proliferation in rats

Objective To investigate possible intracellular s ignal molecules involved in TGF-β-induced airway smooth muscle cell proli feration in rats. Methods The cultured airway smooth muscle cells were divide d into 3 groups: control group (20 mL·L -1FCS/DMEM), 10 μg·L -1 TGF-β1 group and 10μg·L -1 TGF-β1 /U-0126 (1 μ mol·L -1) group. The proliferation of ASMCs was detected by MTT. Exp ression of phospho-p42/p44 extracellular signal-regulated kinase (ERKs) with i mmunocytochemistry were examined in different groups. A values were detected by image analysis. Results By MTT, A values of 10μg·L -1 TGF- β1 group (0.36±0.043) were significantly higher than those of control grou p (0.126±0.052, t=5.44,7.62, P<0.05) and 10μg·L -1 TGF-β1/ U-0126 group (0.175±0.050, t=6.38, P<0.05) from day 2. The immunost aining for phospho- ERK1/2 with immunocytochemistry in 10μg·L -1 TGF -β1 group was significantly denser than that in control group and 10μ g·L -1 TGF-β1 /U-0126 group, with A values being 66.12±6.862 ( TGF-β1 group), 112.4±11.82(control group, t=3.89, P<0.02) and 148.4±16.97 (10μg·L -1 TGF-β1/U-0126 group, t=10.76, P<0.001). Conclusion The proliferation of ASMCs induced by TGF-β may be due to its ability to activate p44/42 MAP kinase (ERK1/ERK2).