Calnexin及GRP78在大鼠非酒精性脂肪肝细胞凋亡中的作用  

Role of calnexin and GRP78 inhepatocyte apoptosis in rats with nonalcoholic fatty liver disease

作　　者：胡晓霞[1] 王艳[1] 王晋星一[1] 

机构地区：[1]贵阳医学院生理学教研室,贵州省贵阳市550004

出　　处：《世界华人消化杂志》2014年第19期2740-2745,共6页World Chinese Journal of Digestology

摘　　要：目的:观察大鼠在非酒精性脂肪肝(nonalcoholic fatty liver disease,NAFLD)形成过程中肝细胞钙联蛋白(calnexin,CNX)及葡萄糖调节蛋白78(glucose regulated protein 78,GRP78)的表达变化,旨在探讨CNX及GRP78在非酒精性脂肪肝发生发展中的作用.方法:♂SD大鼠20只,随机分为正常组和NAFLD组,每组各10只.NAFLD组大鼠采用高脂高糖饮食制备非酒精性脂肪肝动物模型,正常组大鼠则给予普通饲料喂养,造模时间为12 wk.测定各组大鼠血清甘油三酯(triglyceride,TG)、总胆固醇(total cholesterol,TC)、低密度脂蛋白(low-density lipoprotein,LDL)、高密度脂蛋白(high-density lipoprotein,HDL)及游离脂肪酸(free fatty acids,FFA)的含量;采用实时荧光定量PCR检测肝组织中CNX和GRP78 mRNA的表达变化;采用Western blot检测肝组织中CNX、GRP78、CCATT/增强子结合蛋白同源蛋白(CCATT/enhancer-binding protein homology protein,CHOP)及磷酸化JNK(p-JNK)蛋白的表达变化;同时采用TUNEL法检测肝细胞凋亡情况.结果:与正常组比较,NAFLD组大鼠血清中TG、TC、LDL、FFA含量明显增高(P<0.05或P<0.01),而HDL则明显下降(P<0.01);Western blot结果显示NAFLD组大鼠肝组织中CNX、GRP78、CHOP及p-JNK蛋白的表达显著高于正常组大鼠;实时荧光定量PCR结果显示,与正常组大鼠比较,NAFLD组大鼠肝脏中CNX及GRP78 mRNA水平明显增高(P<0.05);同时,TUNEL法检测肝细胞凋亡发现NAFLD组大鼠肝细胞凋亡数目较正常组大鼠显著增加(P<0.01).结论:钙联蛋白及GRP78表达上调可能参与了非酒精性脂肪肝的发生发展过程.AIM： To observe the changes in calnexin and GRP78 expression in nonalcoholic fatty liver disease（NAFLD） induced with a high-fat, high-sugar diet and to explore their role in hepatocyte apoptosis in rats with nonalcoholic fatty liver disease. METHODS： Twenty male SD rats were random-ly divided into either a normal control group or an NAFLD group. The rats of the NAFLD group were given a high-fat, high-sugar diet for 12 wk to induce NAFLD, while the rats of normal con-trol group were given an ordinary diet. Triglyc-eride（TG）, total cholesterol（TC）, low-density li-poprotein（LDL）, high-density lipoprotein（HDL） and free fatty acids（FFA） were evaluated. Real-time fluorescence quantitative PCR was applied to detect the mRNA expression of calnexin and GRP78 in liver tissues, and Western blot was ap-plied to detect the protein expression of calnex-in, GRP78, CHOP and p-JNK. Meanwhile, cell apoptosis in the liver was detected by TUNEL assay. RESULTS： Compared with the control group, serum levels of TG, TC, LDL and FFA signifi-cantly increased in the NAFLD group（P〈0.05 or P〈0.01）, while the level of HDL was de-creased（P〈0.01）. Western blot analysis showed that the expression of calnexin, GRP78, CHOP and p-JNK proteins in the NAFLD group was significantly higher than that in the control group. Compared with the control group, the mRNA expression of calnexin and GRP78 was also increased in the NAFLD group（P〈0.05）. TUNEL assay showed that the apoptosis of he-patocytes in the NAFLD group was significantly elevated（P〈0.01）. CONCLUSION： The up-regulation of calnexin and GRP78 may be involved in the pathogenesis of NAFLD.

关 键 词：非酒精性脂肪肝 钙联蛋白 葡萄糖调节蛋白78 细胞凋亡 

分 类 号：R575.5[医药卫生—消化系统]