论文部分内容阅读
目的探讨解偶联蛋白3(uncoupling protein 3,UCP3)敲除对高盐介导的血管内皮功能损害的影响及机制。方法雄性UCP3敲除(UCP3KO,C57BL/6J背景)及相应的野生型小鼠(wild type,WT)各20只,分普盐饮食组(normalsalt,NS:饮食中含0.5%食盐)和高盐饮食干预组(High Salt,HS:饮食中含8%食盐),每组10只小鼠;饮食干预24周后:①二氢乙锭(dihydroethidium,DHE)染色荧光显微镜观察各组小鼠肠系膜动脉中超氧阴离子水平;②微血管张力检测仪观察肠系膜动脉血管功能,包括内皮依赖性舒张功能和非内皮依赖性舒张功能;③测定鼠尾血压观察各组小鼠干预前后的收缩压与舒张压水平。④取小鼠的胸主动脉,蛋白印迹法(Western blot)观察UCP3蛋白和p-eNOS的表达。结果与普盐饮食WT小鼠比较,高盐饮食WT小鼠的血管超氧阴离子水平显著升高(P<0.01);而UCP3敲除则显著增加高盐环境下超氧阴离子的水平(P<0.05),与高盐WT小鼠比较;高盐环境使血管内皮依赖性舒张功能受损,而高盐干预的UCP3敲除小鼠与WT小鼠比较,内皮功能的损害更为显著(P<0.05);Western blot结果提示,高盐饮食显著增加WT小鼠胸主动脉组织中的UCP3表达水平,降低p-eNOS水平。结论 UCP3敲除后使小鼠抗氧化应激能力下降,在高盐状态下,使血管功能的损害加重,血压升高。
Objective To investigate the effect and mechanism of uncoupling protein 3 (UCP3) knockout on salt-induced vascular endothelial dysfunction. Methods Twenty male UCP3 knock-out (UCP3KO, C57BL / 6J background) and corresponding wild type (WT) mice were divided into normal salt (NS: 0.5% salt diet) and high salt Diet intervention group (High Salt, HS: diet containing 8% salt), each group of 10 mice; diet intervention after 24 weeks: ① dihydroethidium (DHE) staining by fluorescence microscope to observe the mesenteric artery ; (2) Microvascular tension tester was used to observe the function of mesenteric artery, including endothelium-dependent relaxation and non-endothelium-dependent relaxation; (3) Measurement of rat tail blood pressure (SBP) was performed to observe the systolic and diastolic blood pressure before and after the intervention. The thoracic aorta of mice was taken and the expression of UCP3 protein and p-eNOS were observed by Western blot. Results Compared with normal saline diet WT mice, the level of superoxide anion in WT mice increased significantly (P <0.01), while UCP3 knockdown significantly increased the levels of superoxide anion in high salt diet (P < 0.05). Compared with high-salt WT mice, high-salt environment impaired endothelium-dependent vasodilatation. Compared with WT mice, UCP3 knockout mice exposed to high salt showed more significant endothelial dysfunction (P < 0.05). Western blot results suggested that high-salt diet significantly increased UCP3 expression in thoracic aorta and decreased p-eNOS level in WT mice. Conclusion After UCP3 knockout, the ability of anti-oxidative stress in mice decreased. Under the condition of high salt, the damage of vascular function aggravated and the blood pressure increased.