亚硫酸钠对HL-7702细胞极低密度脂蛋白组装分泌和内质网应激的影响  

Effects of sodium sulfite on very low density lipoprotein assembly and secretion,and endoplasmic reticulum stress in HL-7702 liver cells

作　　者：张艳[1] 白剑英[1] 雷佩玉[1] 王幼萍[1] 赵春燕[1] 梁瑞峰[1] 

机构地区：[1]山西医科大学公共卫生学院环境卫生学教研室,山西太原030001

出　　处：《癌变．畸变．突变》2016年第3期169-173,178,共6页Carcinogenesis,Teratogenesis & Mutagenesis

基　　金：国家自然科学基金(30972445);山西省回国留学人员科研资助项目(2014-034)

摘　　要：目的:研究亚硫酸钠(Na_2SO_3)是否通过抑制极低密度脂蛋白(VLDL)组装分泌和诱导内质网应激引起肝细胞脂肪变性。方法:分别经不同浓度(0.1、0.5、2.5、10 mmol/L)Na_2SO_3染毒人正常HL-7702肝细胞24和48 h后,采用酶联免疫吸附法(ELISA)和Western blot测定细胞外VLDL水平;采用荧光定量PCR法(qPCR)检测VLDL组装相关因子微粒体载脂蛋白B100(apoB100)、甘油三酯转移蛋白(MTP)、二脂酰甘油酰基转移酶2(DGAT2)、甘油三酯水解酶(TGH)的mRNA表达水平;采用Western blot法检测内质网应激相关重链结合蛋白(BiP)和钙连蛋白(Calnexin)的表达水平。结果:ELISA和Western blot结果显示染毒24 h后,与阴性对照组相比,各Na_2SO_3处理组VLDL含量均明显增加,差异均有统计学意义(P均<0.05);而作用48 h后,各Na_2SO_3处理组VLDL含量与阴性对照组相比均无明显变化(P均>0.05)。qPCR检测结果显示,与阴性对照组相比,染毒24 h,10mmol/L Na_2SO_3组肝细胞内apoB100mRNA表达升高(P<0.05);2.5和10 mmol/L Na_2SO_3可使肝细胞内TGH mRNA表达升高(P<0.05);染毒48 h,0.5和2.5 mmol/L Na_2SO_3引起肝细胞内TGH mRNA表达量明显升高(P<0.05)。Western blot结果显示染毒24 h和48h后,不同浓度Na_2SO_3对细胞内BiP蛋白表达水平均无明显影响,但可以明显增加Calnexin蛋白表达(P<0.05)。结论:Na_2SO_3不能抑制VLDL组装分泌,但可能对肝细胞糖蛋白的正确折叠有一定干扰作用。OBJECTIVE：To investigate whether sodium sulfite（Na_2SO_3） induces lipid accumulation by inhibition of very low density lipoprotein（VLDL） assembly and activation of endoplasmic reticulum stress.METHODS：Human diploid liver cells（HL-7702） were cultured in DMEM medium containing 10%fetal bovine serum.Cells were exposed to different concentrations（0.1,0.5,2.5,10 mmol/L） of Na_2SO_3 for 24 h and 48 h,and positive controls were used.VLDL secretion was detected by ELISA and Western blot,mRNA levels of VLDL assembly related factors were detected by quantitative real-time PCR（qPCR） and protein expressions of endoplasmic reticulum stress were detected by Western blot.RESULTS：ELISA and Western blot results showed that after exposure to Na_2SO_3 for 24 h,VLDL contents were significantly increased compared to the controls（P〈0.05）.After 48 hours,the difference became non-significant（P〉0.05）.QPCR test results showed that,compared with the negative control group,exposure to 10 mmol/L Na_2SO_3 for 24 h increased the expression of apoB100 mRNA significantly（P〈0.05）.In addition,the mRNA level of TGH in 10 mmol/L Na_2SO_3 and 2.5 mmol/L Na_2SO_3 groups were significantly increased（P〈0.05）.After exposure for 48 h,the mRNA levels of TGH in 2.5 mmol/L Na_2SO_3 and 0.5 mmol/L Na_2SO_3groups were increased significantly（P〈0.05）.Protein expression of Calnexin was significantly increased（P0.05） after Na_2SO_3 exposure.CONCLUSION：Na_2SO_3 may increase VLDL assembly and interfere with the correct folding of glycoprotein in hepatocytes.

关 键 词：亚硫酸钠 极低密度脂蛋白组装 内质网应激 肝细胞 

分 类 号：R994.41[医药卫生—毒理学]