高脂饮食诱导的肥胖大鼠下丘脑及肝脏组织中Toll样受体4的表达

摘要

目的 探讨在高脂饮食诱导下Toll样受体4(Toll-like receptor4,TLR4)在肥胖大鼠下丘脑及肝脏组织中的表达.方法 建立高脂饮食诱导的肥胖(DIO)大鼠模型,应用免疫组化染色和Real Time PCR方法检测下丘脑及肝脏组织中TLR4的蛋白及mRNA的表达.结果 喂养8周后,DIO组平均体重为(456.38±19.20)g,高于正常饮食对照组平均体重(372.10±22.47)g,两组间比较差异有显著性意义(P＜0.01)；DIO组饮食量为(1229.23±57.29)g,高于正常饮食对照组饮食量(905.50±52.17)g,两组大鼠饮食量比较差异有显著性意义(P＜0.01).Real Time PCR方法显示,DIO组大鼠下丘脑组织TLR4 mRNA含量(0.56±0.16),高于正常饮食对照组TLR4 mRNA (0.39±0.10),P＜0.05; DIO组大鼠肝脏组织TLR4 mRNA含量(0.87±0.24),高于正常饮食对照组TLR4 mRNA(0.54±0.16),两组间差异也有显著性意义(P＜0.01).免疫组化染色肥胖组大鼠下丘脑及肝脏TLR4表达呈强阳性.结论 Toll样受体4在肥胖大鼠下丘脑及肝脏中的表达增多,提示下丘脑及肝脏的炎症反应参与了高脂饮食诱导肥胖的发生.%Objective To investigate the expression of Toll -like receptor 4 in hypothalamus and liver of obese rats fed by high - fat diet. Methods To duplicate the obese rat model fed with high - fat diet (diet - induced - obesity rats, DIO group) , and detect the expression of TLR4 in hypothalamus and liver by immunohistochemical staining and Real Time PCR. Results After 8 weeks, the average weight of DIO group (456.38 ± 19.20) g washigher than that of normal diet control group (372. 10 ± 22. 47) g, the difference between two groups was significant (P < 0. 01). The amount of diet of DIO group (1229.23 ±57.29)g was higher than that of control (905. 50 ±52. 17) g, the difference between two groups was significant ( P < 0.01). Real - Time PCR showed the fold of hypothalamus TLR4 mRNA ( 0. 56 ± 0. 16) in DIO group was higher than that in control (0.39 ±0.10), The difference was significant between the two groups (P <0. 05) .The fold of liver TLR4 mRNA (0. 87 ±0.24) in DIO group was higher than that in control group(0. 54 ±0. 16) , The difference was significant between the two groups (P<0.01).The immunohistochemistry result showed that there were TLR4 strong expressions in hypothalamus and liver of obese rats. Conclusion The increased TLR4 expressions in hypothalamus and liver of obese rat indicated that inflammatory response in the organs involved in the mechanism of high - fat - diet - induced obesity.