细胞外基质对气道平滑肌细胞增殖活性的促进作用及其机制

目的 观察纤维粘连蛋白（FN），层粘连蛋白（LN），及胶原蛋白I（ColI)等主要细胞外基质成分，对气道平滑肌细胞（ASMCs)增殖活性的影响，并探讨其作用机制。方法 将原代培养的大鼠ASMCs，接种于不同细胞外基质蛋白包被的培养板，观察各时间点细胞的贴壁数量。在培养的ASMCs中分别加入两种浓度（20和60mg/L)的不同细胞外基质蛋白溶液，即FN组，LN组和Col I组，采用^3H-TdR掺入法，检测作用8，12和24h后各组ASMCs增殖活性的变化。间接免疫荧光染色法检测RAS蛋白在各组ASMCs中的表达。结果 与无包被组相比较，FN，ColI包被组及LN包被组ASMCs的贴壁数量明显高（P＜0．01或P＜0．05）。与正常对照组相比较，FN和Col I各浓度组ASMCs的增殖活性增高显著（P＜0．01），且与浓度和作用时间成正比；而LN组ASMCs的活性无明显差异。同时，FN和Col I组ASMCs的RAS染色呈强阳性；对照组及LN组ASMCs的染色则为弱阳性。结论 ASMCs对FN，LN和Col I均有良好的粘附性，但只有FN的ColI 能明显提高ASMCs的增殖活性，其作用是通过RAS信号转导途径而实现的。表明细胞外基质是哮喘气道重塑的重要刺激因子之一。

The effects of extracellular matrixes on proliferation of airway smooth muscle cells and their mechanism

Aim To investigate the effects of extracellular matrixes, including fibronectin(FN), laminin(LN) and collagen I(Col I), on the proliferation of murine airway smooth muscle cells(ASMCs), and to explore their mechanism. Methods Primarily cultured ASMCs were inoculated on the plates coated with difference matrix proteins, namely FN, LN or Col I coated groups. Then the numbers of adherent cells were counted at various time points. Two concentrations (20 and 60 mg/L) of different matrix solutions were added respectively to cultured ASMCs, namely FN, LN or Col I group. The proliferation of ASMCs was detected by 3H TdR incorporation method at 8, 12 and 24 hours after addition of different matrixes. RAS expression in ASMCs of three groups was examined by indirect immunofluorescent staining. Results The numbers of adherent cells in FN, Col I or LN coated groups were much higher than that of non coated group( P <0.01 or P <0.05). The proliferative activities of ASMCs in FN group and Col I group increased significantly, but there was no difference between LN group and control group. At the same time, RAS expressions in FN and Col I groups was strongly positive, but it was weakly positive in LN group. Conclusion ASMCs can adhere to FN, LN or Col I effectively, but only FN and Col I increase the ASMCs proliferation mediated through RAS signal transduction. These data strongly implicates that extracellular matrix is an important stimulating factor in airway remodeling of asthma patients.