RNAi介导的SOCS3基因沉默对高脂肥胖大鼠瘦素抵抗的影响

目的研究RNA干扰(RNAi)介导的细胞因子信号转导抑制因子3(SOCS3)基因沉默对高脂肥胖大鼠瘦素抵抗的影响。方法选用5周的SD大鼠60只,随机分为3组,实验组:下丘脑注射SOCS3基因RNA干扰慢病毒(LV-shSOCS3),高脂饲料喂养;阴性组:下丘脑注射阴性序列慢病毒(LV-negtive),高脂饲料喂养;对照组:下丘脑注射生理盐水,高脂饲料喂养。饲养8周末,检测血总胆固醇、三酰甘油、高密度脂蛋白胆固醇、低密度脂蛋白胆固醇,放射免疫法检测血清瘦素,利用荧光实时定量PCR(real-time PCR)技术检测各组下丘脑内SOCS3和瘦素受体(OB-Rb)的mRNA表达水平。结果实验组体重、瘦素、三酰甘油、总胆固醇、低密度脂蛋白胆固醇低于阴性组和对照组(P<0.05)。实验组下丘脑的SOCS3mRNA水平低于阴性组和对照组(P<0.05)。实验组下丘脑的OB-RbmRNA水平高于阴性组和对照组(P<0.05)。而阴性组和对照组比较无差异(P>0.05)。结论下调SOCS3基因可以减轻高脂肥胖大鼠瘦素抵抗,对肥胖症可能有预防和治疗作用。

Effects of RNAi-mediated SOCS3 Gene Silence on Leptin Resistance in Obese Rats Fed with High-fat Diet

Objective To study the effects of RNAi-mediated SOCS3 gene silence on leptin resistance in obese rats fed with high-fat diet.Methods Sixty five-week-old healthy male SD rats were divided into three groups randomly.In experiment group,the lentiviral vector expressing a short-hairpin RNA targeting SOCS3 gene(LV-shSOCS3)were stereotaxically injected into the hypothalamus of rats which then fed with high-fat diet.In the negative group,the lentiviral vector expressing a short-hairpin RNA targeting an unrelated sequence(LV-negtive)were stereotaxically injected into the hypothalamus of rats which then fed with high-fat diet;In the control group,the normal sodium were stereotaxically injected into the hypothalamus of rats which then fed with high-fat diet.At the end of 8 weeks,serum lipid levels including total cholesterol,triglyceride,high density lipoprotein cholesterol and low density lipoprotein cholesterol were determined.Serum leptinlevels were measured by radioimmunoassay.Real-time PCR were used to evaluate the level of SOCS3mRNA and OB-Rb mRNA in the hypothalamus.Results The body weight of rats was decreased significantly in experiment group(P<0.05).The concentrations of serum leptin,triglyceride,total cholesterol and low density lipoprotein cholesterol in experiment group were decreased obviously compared with control group and negative group(P<0.05).The expression of SOCS3 mRNA in experiment group were decreased markedly compared with control group and negative group(P<0.05).The expression of OB-Rb mRNA in experiment group were increased markedly compared with control group and negative group(P<0.05).There were no significant differences in control group and negative group(P>0.05).Conclusion The down-regulated expression of SOCS3 gene reduces leptin resistance in obese rats fed high-fat diet.