C1q/肿瘤坏死因子相关蛋白3对高尿酸大鼠血管内皮的保护作用研究

Protective effect of C1q/tumor necrosis factor-related protein 3 on vascu⁃lar endothelium in rats with hyperuricemia

目的:探讨C1q/肿瘤坏死因子相关蛋白3(CTRP3)对高尿酸大鼠血管内皮的保护作用及机制。方法:雄性SD大鼠饮用10%果糖水构建高尿酸大鼠模型,对照组饮用普通纯净水,每组10只。12周后,两组大鼠分别予以尾静脉一次性注射Ad-CTRP3或Ad-GFP,转染2周后结束实验。取血清,检测血尿酸和血清一氧化氮(NO)的水平,ELISA法检测血清肿瘤坏死因子α(TNF-α)和白细胞介素6(IL-6)浓度。取胸主动脉,HE染色观察内膜形态改变,TUNEL法检测内皮细胞凋亡情况,RT-qPCR法检测内皮型一氧化氮合酶(eNOS)、TNF-α和IL-6的mRNA水平,Western blot法检测CTRP3和Toll样受体4(TLR4)蛋白表达的变化。结果:与正常对照组比较,高尿酸大鼠主动脉CTRP3蛋白表达显著减少,TLR4蛋白表达显著升高(P<0.05)。与正常对照组比较,高尿酸大鼠血尿酸水平和血清TNF-α及IL-6水平显著升高(P<0.05),胸主动脉内膜结构紊乱,内皮细胞凋亡率显著增加(P<0.05),TNF-α和IL-6 mRNA表达显著升高(P<0.05),eNOS mRNA表达显著降低(P<0.05)。相反,高尿酸大鼠过表达CTRP3后,TLR4蛋白表达显著降低,炎症因子表达减少,主动脉形态及功能得到显著改善。结论:CTRP3可以保护高尿酸大鼠血管内皮功能,其机制可能与下调TLR4炎症信号通路相关。

AIM:To study whether C1q/tumor necrosis factor(TNF)-related protein 3(CTRP3)protect vascular endothelium in rats with hyperuricemia and its potential mechanisms.METHODS:An animal model of hyperuricemia was established by using male SD rats drinking 10%fructose water(n=10).The rats drinking normal water served as normal controls(n=10).After 12 weeks,the rats were given a single injection with Ad-CTRP3 or Ad-GFP.The experiment was ended at 14th day after transfection.The serum levels of uric acid and nitric oxide(NO)were evaluated.The serum contents of TNF-α and interleukin-6(IL-6)were measured by ELISA.HE staining and TUNEL assay were used to assess the morphological changes of intima and apoptosis of endothelial cells in thoracic aorta,respectively.The mRNA levels of endothelial nitric oxide synthase(eNOS),TNF-αand IL-6 were detected by RT-qPCR.The protein levels of CTRP3 and Toll-like receptor 4(TLR4)were determined by Western blot.RESULTS:Compared with normal control group,the rats with hyperuricemia showed lower CTRP3 and higher TLR4 protein levels in the thoracic aorta(P<0.05).Hyperuricemic rats had higher serum contents of uric acid,TNF-α and IL-6(P<0.05).Also,the intima structure disturbance of thoracic aorta,increased apoptotic rate,higher mRNA levels of TNF-α and IL-6 as well as lower mRNA levels of eNOS were observed(P<0.05).By contrast,CTRP3 over-expression decreased TLR4 protein levels,reduced inflammatory cytokines,and obviously improved the morphology and function of thoracic aorta in the rats with hyperuricemia.CONCLUSION:CTRP3 protect vascular endothelium in rats with hyperuricemia maybe via down-regulation of TLR4-mediated inflammatory signaling pathway.