慢性阻塞性肺疾病大鼠转录因子KLF2对Nrf2调控γ-GCS表达的影响  

The effect of transcription factor KLF2 in expression of γ-GCS depend on regulation by Nrf2 in lung of rats with chronic obstructive pulmonary disease

作　　者：刘晓燕[1,2] 戴爱国 胡瑞成 朱黎明 谭双香 

机构地区：[1]湖南省老年医院研究所呼吸疾病研究室,长沙410016 [2]南华大学研究生院,湖南衡阳421001

出　　处：《中国应用生理学杂志》2012年第2期173-178,I0003,共7页Chinese Journal of Applied Physiology

基　　金：湖南省科技计划重点项目(2007FJ3016;2008FJ4206;2009FJ3121);湖南省医药卫生科研课题(B2005125;B2009068)

摘　　要：目的:研究肺Krüppel样转录因子(KLF2/LKLF)在慢性阻塞性肺疾病(COPD)大鼠肺组织中的表达,探讨KLF2与红系衍生因子2(Nrf2)之间的关系以及对抗氧化酶γ-谷氨酰半胱氨酸合酶(γ-GCS)表达的影响。方法:复制大鼠COPD模型,应用免疫组化、Western blot、原位杂交和RT-PCR方法检测KLF2、Nrf2、γ-GCS蛋白及mRNA的表达,并行相关分析。同时利用免疫共沉淀技术(CO-IP)研究KLF2与Nrf2蛋白之间的相互关系。结果:免疫组化及Western blot结果显示COPD组KLF2、Nrf2、γ-GCS蛋白水平较对照组明显升高(P<0.05);原位杂交及RT-PCR显示KLF2、γ-GCS mRNA水平在COPD组显著高于对照组(P<0.01),而Nrf2 mRNA在两组表达无明显差异(P>0.05);CO-IP结果显示在Nrf2抗体捕获的免疫沉淀中,KLF2抗体可杂交出明显的蛋白条带(P<0.01);直线相关分析发现KLF2蛋白与Nrf2蛋白呈正相关(P<0.05),KLF2、Nrf2蛋白与γ-GCS蛋白及mRNA均呈正相关(均P<0.05)。结论:KLF2在COPD肺组织中表达上调,可能通过活化Nrf2,促进Nrf2核积聚上调γ-GCS的基因表达,在氧化失衡中发挥作用。Objective： To study the expression of lung Krüppel-like transcription factor（KLF2/LKLF） in lung tissues of rats with chronic obstructive pulmonary disease（COPD） and the relationship between KLF2 and NF-E2-related factor 2（Nrf2）,and make further explore the effects of KLF2 on the expression of γ-glutamylcysteine synthetase（γ-GCS）.Methods： Twenty-two male SD rats were randomly divided into a COPD group（n=10） and a normal control group（n=11）.The rat model of COPD established by cigarette smoking and intratracheal instillation of lipopolysaccharide（LPS）,and lung tissues were obtained.The expressions of KLF2、Nrf2、γ-GCS mRNA and protein in lung tissues were measured by immunohistochemistry（IHC）,Western blot,in situ hybridization（ISH） and reverse transcription-polymerase chain reaction（RT-PCR）.To explore the relationship between KLF2 and Nrf2 protein,we utilize the method of co-immunoprecipitation（CO-IP）.Results： IHC and Western blot showed that protein expressions of KLF2、Nrf2、γ-GCS were higher in the lung tissues from rats with COPD than those in the control groups（all P0.05）.The levels of KLF2、γ-GCS mRNA were markedly increased in the COPD group（all P0.01） while Nrf2 mRNA expression in COPD group had no significant difference with that in control group（P0.05）.CO-IP result showed that KLF2 were obviously present in immunoprecipitates of Nrf2（P0.01）.Linear correlation analysis showed that the level of KLF2 protein was positively correlated with the level of Nrf2 protein（P0.05）,and KLF2、Nrf2 proteins were positively correlated with γ-GCS mRNA and protein（all P0.05）.Conclusion： The expression of KLF2 is significantly up-regulated in COPD,which maybe up-regulate γ-GCS mRNA expression by increasing Nrf2 expression and nuclear translocation against oxidative stress.

关 键 词：肺疾病 慢性阻塞性 肺Krüppel样转录因子 红系衍生核因子相关因子2 Γ-谷氨酰半胱氨酸合酶 

分 类 号：R563.3[医药卫生—呼吸系统]