慢性阻塞性肺疾病大鼠肺组织中Mdig表达及调控

The expression and regulation of Mdig in the lung of COPD model rats

目的探讨矿物粉尘诱导基因(mineral dust induced gene,Mdig)在慢性阻塞性肺疾病(COPD)模型大鼠肺组织中的表达及其调控机制。方法12只Wistar雄性大鼠随机分为2组,正常对照组和COPD模型组,利用单纯吸入香烟烟雾的方法,每日2h,连续烟熏16周制造COPD模型大鼠;HE染色观察大鼠肺组织形态学改变;利用Western blot和Real time PCR技术检测COPD模型大鼠肺组织Mdig蛋白和基因的表达情况;利用免疫沉淀技术分析COPD模型大鼠肺组织Mdig蛋白是否存在泛素化修饰及泛素化修饰水平。结果单纯吸入香烟烟雾法连续烟熏16周后,大鼠肺组织出现典型的COPD病理改变;与对照组相比COPD模型大鼠肺组织中Mdig蛋白及基因表达水平均显著升高。免疫沉淀结果显示Mdig蛋白存在泛素化修饰作用,且COPD模型大鼠肺组织中Mdig蛋白泛素化修饰水平高于对照组,通过基因转录调控和翻译后泛素化修饰作用调控COPD病理状态下Mdig表达,导致Mdig蛋白表达增多。结论Mdig可能是COPD引起肺癌发生的重要机制之一。

Objective To investigate the expression and regulation of mineral dust induced gene(mdig)in chronic obstruction pulmonary disease(COPD)model Wistar rat.Methods 12 male Wistar rats were divided into the control group and COPD model group.The COPD model was established by respiration in cigarette smoking for 16 weeks,2h/day;the morphological changes of lungs was analysed by HE staining;the expression of Mdig protein and gene was detected by Western blot and qPCR respectively;immunoprecipitation was employed to identify whether Mdig was ubiquitinated and the ubiquitin level.Results COPD pathologic change was found in lung 16-week after cigarette smoking.The expression level of Mdig protein and mRNA in lungs was significantly upregulated in COPD model rats than in control group.Immunoprecipitation showed that Mdig was ubiquitinated and the ubiquitination level in lung was higher in COPD rats than in control.The expression level of Mdig in lung of COPD rats was regulated in transcriptional and posttranslational(ubiquintation)level,resulting in the elevation of Mdig expression level.Conclusion Mdig protein might be involved in the process of transfering COPD to lung cancer.