胆固醇诱导未折叠蛋白反应及其调节酰基辅酶A胆固醇酰基转移酶2基因的表达  

The Study on Cholesterol Induced Unfolded Protein Response and Acyl-CoA Cholesterol Acyltransferase-2 Expression

作　　者：王琼[1] 刘志国[1] 田俊[1] 宗义强[1] 屈伸[1] 

机构地区：[1]华中科技大学同济医学院生物化学与分子生物学系,湖北省武汉市430030

出　　处：《中国动脉硬化杂志》2007年第4期253-255,共3页Chinese Journal of Arteriosclerosis

基　　金：国家自然科学基金(30300134)

摘　　要：目的探讨胆固醇对肝细胞和小肠粘膜上皮细胞中未折叠蛋白反应及其调节酰基辅酶A胆固醇酰基转移酶2基因表达的影响。方法以不同浓度(10mg/L和20mg/L)的游离胆固醇和氧化胆固醇温育肝癌细胞系HepG2细胞和小肠粘膜上皮细胞系Caco2细胞,应用半定量逆转录聚合酶链反应法检测两种细胞中X盒结合蛋白1和酰基辅酶A胆固醇酰基转移酶2mRNA的表达水平。结果随着游离胆固醇和氧化胆固醇温育浓度的升高,HepG2细胞和Caco2细胞中的X盒结合蛋白1和酰基辅酶A胆固醇酰基转移酶2mRNA表达均上调,呈现浓度依赖性。结论胆固醇和氧化胆固醇均可诱导未折叠蛋白反应中标记分子X盒结合蛋白1的表达,并上调酰基辅酶A胆固醇酰基转移酶2的表达,提示酰基辅酶A胆固醇酰基转移酶2的表达可能受未折叠蛋白反应的调控;鉴于酰基辅酶A胆固醇酰基转移酶2在胆固醇吸收的酯化过程中具有重要作用,未折叠蛋白反应可能在胆固醇吸收调控中具有重要意义。Aim To investigate the regulation of X-box binding protein-1 （XBP-1 ） and acyl-CoA cbolesterol acyltransferase-2 （ACAT-2） expression by cholesterol in hepatic cell and enterocyte. Methods HepG2 cell and Caco2 cell were incubated with different concentration of free cbolesterol and oxidative cholesterol. The mRNA level of XBP-1 and ACAT-2 in cells were detected by semi-quantitative RT-PCR. Results In cells incubated with free cholesterol and oxidative cholesterol, XBP-1 and ACAT-2 mRNA levels in HepG2 cell and Caco2 cell were up-regulated, and were dependent on the concentration increase. Conclusions Both of cholesterol and oxidative cholesterol can induce UPR, and ACAT-2 mRNA level can be upregulated, the results imply the possibility that ACAT-2 may be regulated by UPR; in view of ACAT-2 playing an important role in the cholesterol esterificafion and absorption, UPR may have important significance in cholesterol absorption.

关 键 词：分子生物学 胆固醇 未折叠蛋白反应 酰基辅酶A胆固醇酰基转移酶2 X盒结合蛋白1 氧化胆固醇 

分 类 号：Q7[生物学—分子生物学]