高盐饮食加重脑缺血损伤机制

Mechanism of high salt diet exacerbating cerebral ischemia injury

目的探讨高盐饮食加重脑缺血损伤机制。方法 (1)体内实验:高盐饮食14 d小鼠建立永久性大脑中动脉结扎(pMCAL)模型;2,3,5-三苯基氯化四氮唑(TTC)染色检测小鼠脑组织损伤面积;伊文思蓝染色检测血脑屏障破坏程度;Western blot方法检测小鼠脑组织中微血管内皮细胞紧密连接蛋白claudin-5表达情况。(2)体外实验:Western blot方法检测高盐环境(80 mmol/L)及氧糖剥夺(OGD)+高盐(80 mmol/L)条件下b End.3小鼠脑微血管内皮细胞claudin-5表达情况。结果 (1)TTC染色显示高盐饮食组小鼠脑缺血面积明显高于正常饮食组(P<0.05);伊文思蓝染色显示高盐饮食组小鼠脑内伊文思蓝含量显著高于正常饮食组(P<0.01);Western blot结果显示高盐饮食组小鼠脑组织中claudin-5表达明显低于正常饮食组(P<0.05)。(2)体外实验Western blot结果显示,与正常培养组相比,高盐组脑内微血管内皮细胞claudin-5表达显著降低(P<0.01);与OGD组相比,OGD+高盐组,小鼠脑微血管内皮细胞claudin-5蛋白表达显著降低(P<0.01)。结论高盐饮食加重脑缺血损伤;高盐饮食可下调脑血管内皮细胞紧密连接蛋白claudin-5的表达,破坏血脑屏障,加重脑损伤。

Objective To study the mechanism of high salt diet exacerbating cerebral ischemic injury. Methods （1）Experiments in vivo： the permanent middle cerebral artery ligature （pMCAL） modes of C57BL/6 male mice fed with high salt diet for 14 days were established; The brain tissue damage area of mice were stained by 2,3,5-triphenyl tetrazolium chloride （T-FC） ; The blood brain barrier damage was detected by Evans blue injeetion ; The expression of protein claudin-5 （mouse brain microvascular endothelial cells） was analysed by Western blot; （2）Experiments in vitro ： the expression of protein claudin-5 was analysed in the condition of high salt diet （80 mmol/L） and the condition of oxygen glucose deprivation and high salt diet （80 mmol/L） by Western blot. Results （1）The ischemic area of mice brain with high salt diet were obviously larger than the ones with normal diet by TTC staining （ P 〈 0. 05 ） ; The Evans blue leakage in the brain of mice with high salt diet were more than the ones with normal diet in Evans blue staining （P 〈 0.01 ） ; The expression of claudin-5 protein of mice with high salt diet were lower than the ones with normal diet by Western blot （P 〈 0. 05 ） ; （2）Compared with normal culturing group, the expression of claudin-5 protein in brain microvascular endothelial cells with high salt was lower （P 〈0.01 ） ; Compared with the OGD group, the brain microvascular endothelial cell protein claudin-5 of high salt group decreased in the condition of OGD and high salt together （P 〈 0. 01 ）. Conclusion High salt diet exacerbated cerebral ischemia injury; High salt diet may lead to further destruction of blood-brain barrier by reducing the expression of tight junction protein claudin-5 in brain microvascular endothelial cells.