骨髓间充质干细胞抗肺泡上皮细胞凋亡作用研究

Anti-apoptosis Effects of Bone Marrow Mesenchymal Stem Cells on Alveolar Epithelial Cells

目的研究骨髓间充质干细胞对LPS诱导的肺泡上皮细胞凋亡的影响及作用.方法用人肺泡上皮细胞株(A549细胞株)与人骨髓间充质干细胞株(第3代h BMMSC株)建立Transwell非接触分层共培养体系,分4组:(1)空白对照组;PBS+A549;(2)LPS诱导组;LPS+A549;(3)BMMSC对照组:BS+A549+BMMSC;(4)BMMSC干预组:LPS+A549+BMMSC.采用Annexin V/PI双染色流式细胞仪检测A549细胞凋亡率;Western blotting检测caspase 3、bcl-2和bax蛋白表达.结果 10μg/m L LPS可体外诱导A549细胞凋亡;BMMSC干预组A549细胞凋亡率、caspase-3与bax蛋白表达水平明显低于LPS诱导组、空白对照组和BMMSC对照组(P<0.01);bcl-2蛋白表达水平显著高于LPS诱导组、空白对照组和BMMSC对照组(P<0.01).结论与LPS诱导的A549细胞共培养,BMMSC能促进A549细胞表达抗凋亡蛋白bcl-2和抑制促凋亡蛋白caspase-3和bax的表达,具有抗细胞凋亡作用.

Objective To investigate the effects of bone marrow mesenchymal stem cells on LPS-induced apoptosis of alveolar epithelial cells.Methods Human alveolar type Ⅱ epithelial cell （A549） and human bone marrow mesenchymal stem cells （BMMSC） were cocultured on cell-cell noncontact transwell system in vitro.there are 4 cell experiments groups：（1） negative control group,PBS＋A549; （2） LPS-induced group,LPS＋A549; （3） BMMSC control group,PBS＋A549＋BMMSC; （4） BMMSC interference group,LPS＋A549＋BMMSC.The apoptotic percentage of A549 was quantified by flow cytometry staining with annexin V/PI.Caspase 3,Bcl-2 and Bax protein expression in A549 was assayed by Western blotting.Results 10 μg/mL LPS can induce A549 apoptosis in vitro appropriately.A549 in BMMSC interference group had a significantly increased bcl-2 expression,a decreased level of caspase 3 and bax,compared with the other groups （P＜0.01） Conclusions Cocultured with A549,BMMSC can increase expression of anti-apoptosis protein bcl-2 in A549,decrease the level of pro-apoptosis protein caspase 3 and bax expression.BMMSC can inhibit apoptosis of alveolar type Ⅱ epithelial cell