核苷酸结合寡聚化结构域样受体蛋白3炎性小体在心肺转流大鼠围术期神经认知障碍中的作用

Effect of nucleotide-binding oligomerization domain-like receptor protein 3 inflammasome on perioperative neurocognitive disorders in rats after cardiopulmonary bypass

目的探讨核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎性小体在心肺转流(CPB)大鼠围术期神经认知障碍(PND)中的作用。方法成年雄性SD大鼠30只,体重350~450 g,进行Morris水迷宫训练5 d后随机分为三组,每组10只:假手术组(S组)、CPB组(C组)和CPB+NLRP3炎性小体抑制剂Ac-YVAD-cmk组(Y组)。S组进行双侧隐动脉、右大隐静脉和右颈内静脉穿刺置管,但不进行CPB;C组穿刺置管后行CPB 60 min;Y组在CPB前30 min给予Ac-YVAD-cmk 8 mg/kg腹腔注射,穿刺置管后行CPB 60 min。术后第3天采用Morris水迷宫实验评估大鼠认知功能,ELISA法检测血浆和海马组织IL-1β和IL-18浓度,Western blot法检测海马组织NLRP3、凋亡相关点样蛋白(ASC)和半胱氨酸蛋白水解酶-1前体(pro-caspase-1)蛋白含量,TUNEL法检测海马组织凋亡情况,计算凋亡指数。结果与S组比较,C组和Y组逃避潜伏期明显延长(P<0.05),120 s穿越原平台次数明显减少(P<0.05),血浆和海马组织IL-1β和IL-18浓度、NLRP3、ASC和pro-caspase-1蛋白含量以及凋亡指数明显升高(P<0.05)。与C组比较,Y组逃避潜伏期明显缩短(P<0.05),120 s穿越原平台次数明显增多(P<0.05),血浆和海马组织IL-1β和IL-18浓度、NLRP3、ASC和pro-caspase-1蛋白含量以及凋亡指数明显降低(P<0.05)。结论 CPB后大鼠PND可能与NLRP3炎性小体的激活有关,使用NLRP3炎性小体抑制剂可减轻大鼠PND的发生。

Objective To investigate the effect of nucleotide-binding oligomerization domain-like receptor protein 3(NLRP3) inflammasome on perioperative neurocognitive disorders(PND) in rats after cardiopulmonary bypass(CPB). Methods Thirty adult male SD rats(350-450 g) were randomly divided into three groups after 5 days of Morris water maze training: sham-operated group(group S), CPB group(group C), and CPB+NLRP3 inflammasome inhibitor Ac-YVAD-cmk group(group Y). Rats in group S received puncturation and catheterization of bilateral saphenous arteries, right great saphenous vein and right internal jugular vein, without CPB. Rats in group C received CPB for 60 min after puncturation and catheterization. Rats in group Y received intraperitoneal injection of Ac-YVAD-cmk 8 mg/kg 30 min before CPB, and then the same as group C. Three days after operation, Morris water maze test was performed to evaluate the cognitive function of rats. The levels of IL-1β and IL-18 in plasma and hippocampus were detected by ELISA. The expression of NLRP3, ASC, and pro-caspase-1 in hippocampus were detected by Western blot. Apoptotic index in hippocampus was detected by TUNEL. Results Compared with group S, the escape latency was prolonged, the number of crossing the original platform was decreased, the apoptotic index in hippocampus was increased, the levels of IL-1β and IL-18 in plasma and hippocampus were increased, as well as the expression of NLRP3, ASC, and pro-caspase-1 in hippocampus were increased in group C and group Y(P < 0.05). Compared with group C, escape latency was shortened, number of crossing the original platform was increased, the apoptotic index in hippocampus was decreased, the levels of IL-1β and IL-18 in plasma and hippocampus were decreased, as well as the expression of NLRP3, ASC, and pro-caspase-1 in hippocampus were decreased in group Y(P < 0.05). Conclusion PND in rats after CPB may be associa￣ted with activation of NLRP3 inflammasome.