摘要目的:评价NOD样受体相关蛋白3(NLRP3)炎症小体介导小胶质细胞激活在小鼠心肌缺血再灌注致脑损伤中的作用。方法:SPF级健康雄性野生型C57BL/6小鼠及NLRP3 -/-小鼠各52只，8~10周龄，采用随机数字表法分为4组( n＝26)：野生型假手术组(W-S组)、野生型心肌缺血再灌注组(W-IR组)、NLRP3 -/-假手术组(NLRP3 -/--S组)和NLRP3 -/-心肌缺血再灌注组(NLRP3 -/--IR组)。采用结扎左冠状动脉前降支45 min、再灌注24 h的方法建立小鼠心肌缺血再灌注致脑损伤模型。于再灌注24 h时采用改良Morris水迷宫实验评估小鼠认知功能，取血后处死取脑组织，测定血脑屏障通透性和含水量，光镜下观察脑组织病理学结果，计算神经元凋亡率和树突棘密度，采用ELISA法测定血清S-100β蛋白和神经元特异性烯醇化酶(NSE)浓度以及海马组织IL-1β、IL-6和TNF-α含量，采用免疫荧光法和(或)蛋白质印迹法测定海马NLRP3、凋亡相关斑点样蛋白(ASC)、裂解的半胱氨酸天冬氨酸蛋白酶-1(cleaved-caspase-1)、消皮素D(GSDMD)、离子化钙结合衔接分子(Iba-1)和闭合蛋白(occludin)表达。 结果:与假手术组比较，缺血再灌注组逃避潜伏期延长，穿越原平台位置次数减少，目标象限停留时间缩短，血清S-100β蛋白和NSE浓度升高，血脑屏障通透性及脑组织含水量增加，海马CA1区树突棘密度降低，海马IL-1β、IL-6、TNF-α含量增加，NLRP3、ASC、cleaved-caspase-1、GSDMD和Iba-1表达上调，occludin表达下调( P<0.05)，脑组织发生病理学损伤；与W-IR组比较，NLRP3 -/--IR组逃避潜伏期缩短，穿越原平台位置次数增加，目标象限停留时间延长，血清S-100β蛋白和NSE浓度降低，血脑屏障通透性及脑组织含水量降低，海马CA1区树突棘密度增加，海马IL-1β、IL-6、TNF-α含量降低，NLRP3、ASC、cleaved-caspase-1、GSDMD和Iba-1表达下调，occludin表达上调( P<0.05)，脑组织病理损伤减轻。 结论:NLRP3炎症小体介导小胶质细胞激活参与了小鼠心肌缺血再灌注致脑损伤的过程。

abstractsObjective:To evaluate the role of NOD-like receptor protein 3 (NLRP3) inflammasome-mediated microglia activation in myocardial ischaemia-reperfusion-induced brain injury in mice.Methods:Fifty-two SPF healthy male wild-type C57BL/6 mice and 52 NLRP3 -/- mice, aged 8-10 weeks, were divided into 4 groups ( n=26 each) using a random number table method: wild type sham operation group (W-S group), wild type myocardial ischemia-reperfusion group (W-IR group), NLRP3 -/- sham operation group (NLRP3 -/--S group), and NLRP3 -/- myocardial ischemia-reperfusion group (NLRP3 -/--IR group). The myocardial ischemia-reperfusion-induced brain injury model was established by ligating the left anterior descending coronary artery for 45 min followed by 24 h of reperfusion in anesthetized mice. The cognitive function was evaluated using the modified Morris water maze test at 24 h of reperfusion. The mice were sacrificed after blood specimens were collected, and brain tissues were obtained for measurement of the blood-brain barrier permeability and water content, for microscopic examination of the pathological changes of brain tissues, and for determination of serum S-100β protein and neuron-specific enolase (NSE) concentrations, contents of interleukin-1 beta (IL-1β), IL-6 and tumor necrosis factor-alpha (TNF-α) in hippocampal tissues (by enzyme-linked immunosorbent assay), expression of NLRP3, apoptosis-associated speck-like protein (ASC), cleaved cysteine aspartate protease 1 (cleaved-caspase-1), gasdermin D (GSDMD), ionized calcium-binding adapter molecule 1 (Iba-1), and occludin in hippocampal tissues (by immunofluorescence and/or Western blot). The apoptosis rate of neurons and density of dendritic spine were calculated. Results:Compared with sham operation group, the escape latency was significantly prolonged, the number of crossing the original platform was decreased, and the time spent in the target quadrant was shortened, the concentrations of serum S-100β protein and NSE were increased, the blood-brain barrier permeability and brain water content were increased, the dendritic spine density in the hippocampal CA1 area was decreased, the contents of IL-1β, IL-6 and TNF-α were increased, the expression of NLRP3, ASC, cleaved-caspase-1, GSDMD and Iba-1 was up-regulated, and the expression of occludin was down-regulated ( P<0.05), and the pathological injury to brain tissues was found in ischemia-reperfusion group. Compared with W-IR group, the escape latency was significantly shortened, the number of crossing the original platform was increased, and the time spent in the target quadrant was prolonged, the concentrations of serum S-100β protein and NSE were decreased, the blood-brain barrier permeability and brain water content were decreased, the dendritic spine density in the hippocampal CA1 area was increased, the contents of IL-1β, IL-6 and TNF-α were decreased, the expression of NLRP3, ASC, cleaved-caspase-1, GSDMD and Iba-1 was down-regulated, and the expression of occludin was up-regulated ( P<0.05), and the pathological injury to brain tissues was alleviated in NLRP3 -/--IR group. Conclusions:NLRP3 inflammasome-mediated microglia activation is involved in myocardial ischaemia-reperfusion-induced brain injury in mice.