胞外基质蛋白与血小板生长因子对气道平滑肌细胞的影响

Influence of extracellular matrix proteins and PDGF-BB on airway smooth muscle cells

目的研究层黏蛋白(laminin,LN)、纤维连接蛋白(fibronectin,FN)、I型胶原(collagen I,Col I)3种不同细胞外基质(extracelluar matrix,ECM)蛋白对血小板生长因子(platelet derived growth factor-BB,PDGF-BB)诱导的气道平滑肌细胞(airway smooth muscle cells,ASMCs)形态及收缩变化的影响。方法将ASMCs分别附着在LN、ColI、FN表衬的细胞培养皿中,并分成2组,分别在有或无PDGF-BB(10 mg/L)的无血清培养基中培养0～5 d。然后采用显微图像方法观测细胞形态和宽长比,光学磁微粒扭转细胞测量方法测量细胞受KCl或组胺(histamine)刺激时的收缩反应。结果在有PDGF-BB的培养条件下,ASMCs形态总体上变细变长,即细胞宽长比减小,但附着在LN上的ASMCs比附着在Col I或FN上的细胞宽长比相对要大。在无PDGF-BB的培养条件下,ASMCs对KCl刺激的收缩响应随培养时间增加而增加,但不受ECM蛋白成分的影响。而在有PDGF-BB的培养条件下,ASMCs对KCl或Histamine刺激的收缩响应总体上随培养时间呈下降趋势,但附着在LN上的ASMCs收缩响应下降程度相对较小。结论 ASMCs受PDGF-BB作用时,其形态和收缩性的变化与不同ECM蛋白成分有关,相对于Col I和FN,附着在LN的细胞形态和收缩性的变化较小。ECM蛋白成分对PDGF-BB诱导的ASMCs形态和收缩性变化的差异性影响,对于深入认识基质蛋白、炎症因子与气道平滑肌细胞的相互作用及其与哮喘病理生理机制的关系具有重要意义。

Objective To investigate the influence of three extracellular matrix（ECM） proteins,namely,laminin（LN）,collagen type I（Col I）,fibronectin（FN） on the morphology and contractility changes in airway smooth muscle cells（ASMCs） induced by platelet-derived growth factor-BB（PDGF-BB）.Methods ASMCs were seeded on the culture dish coated with LN,Col I,or FN,respectively,and divided into two groups to be cultured either in the absence or presence of PDGF-BB（10 mg/L） for 0~5 d.Subsequently,cell morphology was examined by the optical microscopy and quantified as the ratio of cell width to length,and the KCl/histamine-induced contractile responses of the cell were measured by optical magnetic twisting cytometry（OMTC）.Results ASMCs cultured in the presence of PDGF-BB generally appeared in longer and thinner cell shapes,namely,a smaller ratio of cell width to length,but the cell width/length ratio for ASMCs adhered on LN was relatively bigger than that on Col I or FN.In the absence of PDGF-BB,contractility of ASMCs to KCl increased with the duration of culture,which was independent of the ECM proteins.In contrast,in the presence of PDGF-BB,contractility of ASMCs to KCl or histamine decreased in all situations,but degree of the decrease was smaller for ASMCs adhered on LN than those on Col I or FN.Conclusions The morphology and contractility changes in ASMCs induced by PDGF-BB are influenced by ECM proteins on which cells are grown.For ASMCs adhered on LN,the morphology and contractility changes are relatively smaller than those on Col I and FN.The differential effect of ECM proteins on PDGF-BB-induced changes in morphology and contractility of ASMCs is important to fully understand the interactions between ECM proteins,inflammatory factors,ASMCs,and their relation to the pathophysiological mechanism of asthma.