食源性肥胖大鼠下丘脑Tsc1启动子区甲基化率、mTOR表达变化  

Tsc1Promoter Methylation Rate,mTOR Expression in Food-induced Obese Rat Hypothalamus

作　　者：张林[1] 李珂[2] 何虹[2] 胡茂清[1] 

机构地区：[1]成都中医药大学第三附属医院四川省糖尿病防治中心,成都610041 [2]成都中医药大学针灸推拿学院,成都610041

出　　处：《四川大学学报（医学版）》2015年第1期47-50,共4页Journal of Sichuan University(Medical Sciences)

基　　金：国家自然科学基金(No.81202844);成都中医药大学校基金(No.ZRYY201113)资助

摘　　要：目的观察食源性肥胖大鼠下丘脑结节性硬化症基因1(tuberous sclerosis complex 1,Tsc1)启动子区甲基化率及哺乳动物雷帕霉素靶蛋白(mammalian target of rapamycin,mTOR)的表达。方法 16只雄性SD大鼠分为高脂喂养组和基础饲料喂养组(对照组),每组8只,共喂养12周。测定两组大鼠体质量、腹腔脂肪量、腹腔脂肪/体质量比值,采用重亚硫酸盐的测序法检测Tsc1启动子甲基化,RT-PCR、Western blot分别检测mTOR mRNA和蛋白表达。结果高脂组大鼠体质量、腹腔脂肪量、腹腔脂肪/体质量比均高于对照组(P<0.05)。两组大鼠下丘脑Tsc1启动子区均有11个位点可被甲基化,食源性肥胖组甲基化率(94.50%±4.66%)高于对照组(86.60%±3.49%,P<0.002),mTOR mRNA和蛋白表达均高于对照组(P<0.05)。结论食源性肥胖大鼠下丘脑Tsc1基因启动子甲基化率增加,其下游基因mTOR表达上调,可能参与了肥胖的发生。Objective To investigate the methylation rate of tuberous sclerosis complex 1 （Tsc1） promoter and expression of mammalian target of rapamycin （roTOR） in food-induced rat hypothalamus. Methods 16 male SD rats were divided into high fat diet induced group （8 rats） and normal control group （8 rats） feeding for 12 weeks. Body mass, mass of celiac fat, celiac fat/body mass were measured. Methylation of Tsc1 promoter, mRNA and protein expression of roTOR were detected by bisulfite sequencing method, RT-PCR and Western blot, respectively. Results Mass of celiac fat, celiac fat/body mass were higher in food-induced rat than that in control group. There were 11 methylation sites in SD rat hypothalamus. Obese group has significantly higher methylation rates （94.50% ±4.66%） than that of control group （86.60% ±3.49%） （P〈0. 002）. The mRNA and protein expression of roTOR were noted lower in control group than in obese group （P〈0.05）. Conclusion The increased methylation rate of Tsc1 promoter in food-induced rat bypothalamus and up-regulated expression of roTOR, downstream gene of Tscl may promote the obesity.

关 键 词：食源性肥胖 结节性硬化症基因1 哺乳动物雷帕霉素靶蛋白 甲基化 

分 类 号：R589.2[医药卫生—内分泌]