糖对草鱼肝脂代谢关键基因转录水平的调控研究  

Effects of Carbohydrates on Transcription of Five Key Genes Involved in Lipid Metabolism in Hepatopancreas of Grass Carp Ctenopharyngodon idella

作　　者：孙君君[1] 卢荣华[1] 常志光[1] 秦超彬 杨峰[1] 聂国兴[1] 

机构地区：[1]河南师范大学水产学院,河南新乡453007

出　　处：《水产科学》2015年第11期696-701,共6页Fisheries Science

基　　金：国家自然科学基金资助项目(31372545;31402311);河南省高校科技创新团队支持计划项目(14IRTSTHN013);河南省科技创新杰出青年支持计划项目(154100510010);河南省基础与前沿技术研究项目(142300410158);河南省教育厅科学技术研究重点项目(14A240002)

摘　　要：在目前集约化水产养殖模式下,草鱼肝脂质代谢紊乱问题比较严重,已引起人们的高度关注。为获知糖对草鱼肝脂代谢的影响及作用机理,本研究分别从活体和细胞水平上分析了糖对肝脂代谢5个关键基因转录水平变化的影响。采用实时荧光定量PCR(qRT-PCR)技术,检测了在低糖(糖含量24%)和高糖(糖含量42%)投喂条件下草鱼肝脏中固醇调节元件结合蛋白-1c、过氧化物酶体增殖物激活受体α和乙酰辅酶A羧化酶的转录水平变化,H·E染色观察肝脏组织形态学变化;并检测了在不同浓度葡萄糖作用下,草鱼肝细胞中固醇调节元件结合蛋白-1c、脂肪酸合酶和脂蛋白脂酶基因的表达变化。结果显示,肝组织中固醇调节元件结合蛋白-1c、乙酰辅酶A羧化酶在高糖组中的表达量显著高于对照组和低糖组(P<0.05),过氧化物酶体增殖物激活受体α在高糖和低糖条件下变化不明显(P>0.05);H·E染色观察发现在高糖条件下草鱼肝组织出现了大量的脂肪蓄积;在其肝细胞中固醇调节元件结合蛋白-1c、脂肪酸合酶、脂蛋白脂酶的mRNA表达量随葡萄糖浓度增加均呈先升后降趋势,分别在葡萄糖浓度为10mmol/L和20mmol/L时达到最高值(P<0.05)。研究结果表明,葡萄糖可能通过调节固醇调节元件结合蛋白-1c、乙酰辅酶A羧化酶和脂蛋白脂酶等基因的表达进而调节体内糖向脂的转化过程。研究结果为丰富鱼类糖代谢调控机理提供研究资料,并有望为提高鱼类饲料糖的利用效率提供理论依据。In current intensive aquaculture, the hepatopancreatic lipid metabolic disorderis are serious in grass carp （Ctenopharyngodon idellus）, and has caused the attention of people. The transcriptional effects of carbohydrates on the five key genes involved in lipid metabolism in hepatopancreas of grass carp were investigated in vivo and in vitro in order to get the exact regulatory mechanisms of carbohydrates on lipid metabolism in grass carp. The expression levels of sterol regulatory element-binding protein-lc （SREBP-lc）, peroxisome proliferator-activated receptor a （PPARa） and acetyl-CoA carboxylase （ACC） were analyzed in hepatopancreas of grass carp fed the diets containing low-carbohydrates （24%） and high carbohydrates （42%） using quantitative real-time fluorescent PCR technology. The histological observation was conducted in hepatopancreas of grass carp fed the diets containing low and high carbohydrates by H-E staining. The SREBP-lc, fatty acid synthase （FAS） and lipoprotein lipase （LPL） gene expression patterns in vitro hepatocytes treated with different concentrations of glucose were detected by the quantitative real-time fluorescent PCR. The results showed that there were significant higher relative expression levels of SREBP- lc and ACC in the high carbohydrate group than in the control and in low carbohydrate group （P〈0.05）, without significantly differences in relative expression level of PPARa between the high carbohydrate group and the low carbohydrate group （P 〉 0.05）. The histological observation revealed that fat accumulation was induced in the hepatopancreas, and the expression level of SREBP-lc, FAS and LPL was increased first and then decreased with the increasing concentrations of glucose in the hepatocyte cultures, with the maximal level of SREBP-lc at 10 mmol/L, and the maximal FAS and LPL at 20 mmol/L in grass carp fed the high carbohydrate diet （P〈0. 05）. The findings suggested that the expression levels of SREBP-lc, FAS, and LPL were adjusted

关 键 词：草鱼 糖类 脂代谢 基因表达 

分 类 号：Q756[生物学—分子生物学]