慢性阻塞性肺疾病膈肌细胞凋亡的实验研究

Apoptosis of diaphragmatic muscle cell in Chronic obstructive pulmonary disease

目的观察烟雾和内毒素对大鼠膈肌细胞凋亡的影响,为探索COPD发生机制提供新的思路。方法 30只Wistar大鼠随机分为COPD组和对照组,采用烟雾暴露和气管内注入内毒素法建立COPD大鼠模型。第1、14、28天分别采集大鼠膈肌和肺组织标本,HE染色评估肺部病理改变,原位缺口末端标记法检测膈肌细胞凋亡,免疫组化法检测膈肌细胞Fas蛋白和半胱氨酸蛋白酶表达,RT-PCR测定Fas基因表达水平,第28天检测大鼠肺功能。结果第28天,COPD组大鼠的肺组织病理符合慢性支气管炎、肺气肿改变,肺功能均较对照组明显下降;第14、28天,COPD大鼠膈肌细胞凋亡率[(23.40±1.72)%和(34.60±1.25)%]明显高于对照大鼠[(1.04±0.10)%和(1.07±0.11)%],膈肌细胞Caspase-3表达、Fas蛋白及Fas基因表达COPD组也显著增高(P<0.01)。结论在COPD的发生过程中存在膈肌细胞过度凋亡,Caspase-3和Fas/FasL途径参与了膈肌细胞凋亡的调控。

Objective To investigate the influence of lipopolysaccharide and cigarette on apoptosis of diaphgramatic muscle cell in rats with COPD.Methods 30 Wistar rats were randomly divided into control group and COPD group.The rat model of COPD was established by exposure to cigarette smoke for 28 days,and lipopolysaccharide was injected intratracheally on the fisrt and 14 th day.On the 1 st,14 th and 28 th day,5 rats of each group were sacrificed. The rate of apoptosis,Caspase-3,Fas protein and Fas gene expression of diaphgramatic muscle cell were detected.The pulmonary function of rats was measured on the 28th day before they were sacrificed.Results On the 28th day,destruction of alveolar walls and enlargement of alveolar space were observed on COPD group.Pulmonary function of COPD group was less than contorl group.They were the same as pathological changes of lung tissues in COPD.On the 14th and 28th day,rate of apoptosis in COPD group [（23.40±1.72）% and （34.60±1.25）%] was increased than control group [（1.04±0.10）% and （1.07±0.11）%]. Caspase-3,Fas gene and protein expression in COPD group were also significantly increased （P0.01）.Conclusion Abnormal apoptosis of diaphgramatic muscle cell was present in rats with COPD,which was related to the changes of lung function or pathological changes of lung tissues.Fas/FasL mediated apoptosis way was involved in diaphragm apoptosis.