亚低温治疗对缺血-再灌注损伤大鼠脑组织中NLRP3炎性小体表达的影响  

Effect of mild hypothermia therapy on expression of NLRP3 inflammasome in brain tissues of rats with ischemia-reperfusion injury

作　　者：李波 应勇[1] 洪伟力 李永宁[2] LI Bo;YING Yong;HONG Weili(Department of Neurosurgery,Taizhou First People’s Hospital,Taizhou318020,CHINA)

机构地区：[1]台州市第一人民医院神经外科,浙江318020 [2]辽宁大连医科大学附属第一医院急诊科

出　　处：《江苏医药》2021年第4期329-332,F0003,共5页Jiangsu Medical Journal

基　　金：大连市医学科学研究计划项目(1812007);台州市科技计划项目(1901ky60)。

摘　　要：目的探讨亚低温治疗对缺血-再灌注(I-R)损伤大鼠脑组织中核苷酸结合寡聚化结构域样受体蛋白3(NLRP3)炎性小体表达的影响及其作用机制。方法24只雄性SD大鼠随机均分为假手术组(S组)、NT组和MT组。NT组和MT组采用窒息法建立大鼠心脏骤停模型,在自主循环恢复后分别采用常温和亚低温治疗(目标温度32℃)。24 h后各组大鼠进行神经功能缺损评分(NDS),处死大鼠后取大脑皮层行HE染色观察病理损伤,TUNEL法检测大脑皮层神经细胞凋亡,Western blot法检测NLRP3炎性小体、裂解的Caspase-1和IL-1β蛋白表达,透射电镜下观察大脑皮层神经细胞内部结构变化。结果24 h后,MT组NDS高于NT组(P<0.05)。HE染色可见S组神经细胞结构正常,排列有序,NT组神经细胞水肿、破裂和坏死明显,而MT组仅见部分细胞水肿和坏死。TUNEL检测发现MT组神经细胞凋亡率低于NT组,高于S组(P<0.05)。Western blot法结果显示MT组NLRP3炎性小体、裂解的Caspase-1、IL-1β蛋白表达低于NT组,高于S组(P<0.05)。透射电镜下S组细胞核膜完整,核染色质分布均匀;NT组细胞核染色质边集、体积固缩,线粒体嵴断裂、空化明显;MT组细胞核染色质部分边集,线粒体轻度水肿扩张,形态基本完整。结论亚低温治疗脑I-R损伤抑制NLRP3炎性小体介导的炎症反应,促进大鼠神经功能恢复。其机制可能与下调裂解的Caspase-1和IL-1β蛋白表达引起的细胞死亡有关。Objective To investigate the effect of mild hypothermia therapy on the expression of nucleotide-binding oligomerization domain-like receptor 3(NLRP3)inflammasome in brain tissues of the rats with ischemia-reperfusion(I-R)injury and its mechanism.Methods Twenty-four male S-D rats were equally randomized into 3 groups.The cardiac arrest rat model was established by asphyxia in groups of NT and MT.After the recovery of spontaneous circulation,the rats were treated with normothermia in group NT and mild hypothermia(target temperature 32℃)in group MT.Group S accepted sham operation as the control.After 24 hours,the neurological deficit score(NDS)was evaluated in each group.The rats were killed and the cerebral cortex tissues were collected for HE staining to observe the pathological injury.TUNEL method was used to detect the apoptosis of cortical neurons.The protein expressions of NLRP3 inflammasome,cleaved Caspase-1 and IL-1βwere detected by Western blot.The changes of inner structure of neurons in the cerebral cortex were observed by transmission electron microscope.Results The NDS of group MT was higher than that of group NT after 24 hours(P<0.05).HE staining showed that the structure of neurons in group S was normal and the neurons were arranged orderly.Edema,rupture and necrosis of neurons were obvious in group NT,while only partial neurons presented edema and necrosis in group MT.TUNEL revealed that the apoptotic rate of neurons in group MT was lower than that in group NT,which was higher than that in group S(P<0.05).Western blot demonstrated that the expressions of NLRP3 inflammasome,cleaved Caspase-1 and IL-1βprotein in group MT were lower than those in group NT,which were higher than those in group S(P<0.05).Transmission electron microscopy showed that the nuclear membrane was intact and the distribution of nuclear chromatin was uniform in group S.The nuclear chromatin presented margination and pyknosis,and the mitochondrial cristae showed obvious disruption and cavitation in group NT.The nuclear chromati

关 键 词：亚低温治疗 缺血-再灌注损伤 核苷酸结合寡聚化结构域样受体蛋白3 细胞焦亡 

分 类 号：R743[医药卫生—神经病学与精神病学]