类线粒体内膜肽酶2(IMMP2L)基因突变激活线粒体凋亡途径加重小鼠脑缺血性损伤  

IMMP2L gene mutation activates mitochondrial apoptotic pathway to aggravate cerebral ischemic injury in mice

作　　者：程钲益 米晓娟 张紫晶 马轶[1] CHENG Zhengyi;MI Xiaojuan;ZHANG Zijing;MA Yi(Department of Pathology,Basic Medical College,Ningxia Medical University;Department of Anesthesiology,Ningxia Chinese Medicine Research Center,Yinchuan 750004,China)

机构地区：[1]宁夏医科大学基础医学院病理系,宁夏银川750004 [2]宁夏回族自治区中医医院暨中医研究院麻醉科(宁夏中医医院),宁夏银川750004

出　　处：《细胞与分子免疫学杂志》2021年第7期616-622,共7页Chinese Journal of Cellular and Molecular Immunology

基　　金：国家自然科学基金(81760240,81360196);宁夏医科大学科学研究基金(XM2011002)。

摘　　要：目的探讨类线粒体内膜肽酶2(IMMP2L)基因突变对脑缺血性损伤的影响及其机制。方法采用野生型(WT)小鼠及IMMP2L基因突变(IMMP2L^(+/-))小鼠,通过大脑中动脉栓塞法(MCAO)建立脑缺血再灌注(I/R)模型,于再灌注0、1、5、24 h收集皮质区脑组织。通过激光散斑血流成像技术(LSCI)监测脑血流(CBF)变化、Longa行为学评分评价神经功能、三苯基氯化四氮唑(TTC)染色评估脑梗死范围、HE染色观察神经元损伤;用原位末端转移酶标记技术(TUNEL)染色分析神经元凋亡的变化情况,Western blot法检测裂解型胱天蛋白酶3(c-caspase-3)及凋亡诱导因子(AIF)的蛋白表达。结果与WT脑缺血组相比,IMMP2L^(+/-)脑缺血组神经行为学评分增加;再灌注5、24 h,梗死灶体积扩大、变性神经元数量增多、脑水肿程度加重;再灌注0、1、5、24 h,凋亡细胞增加;c-caspase-3和AIF的蛋白水平在I/R 5、24 h出现上调。结论IMMP2L突变加重脑缺血性损伤,并可能通过激活线粒体凋亡途径加重脑缺血性损伤。Objective To investigate the effect of inner mitochondrial membrane peptidase 2-like(IMMP2L)gene mutation on cerebral ischemic injury and its mechanism.Methods The cerebral ischemia/reperfusion(I/R)model was established in wild-type(WT)mice and mice with IMMP2L gene mutation(IMMP2L^(+/-))by middle cerebral artery occlusion(MCAO),and cortical tissues were collected at 0,1,5 and 24 hours after reperfusion.Laser speckle contrast imaging(LSCI)was used to monitor the change in cerebral blood flow(CBF).Longa behavioral score was used to evaluate neurological function.triphenyltetrazolium chloride(TTC),HE staining was used to evaluate cerebral infarction and neuron injury,TUNEL was used to evaluate the neuronal apoptosis.The protein expression of cleaved caspase-3 and apoptosis-inducing factor(AIF)was analyzed by Western blotting.The changes of cerebral blood flow(CBF)were monitored by laser speckle contrast imaging(LSCI),neurological function was evaluated by longa behavioral score,and cerebral infarction area and neuronal injury were observed by TTC staining and HE staining respectively;the changes of neuronal apoptosis were analyzed by TUNEL,and the protein expressions of cleaved caspase-3(c-caspase-3)and apoptosis inducing factor(AIF)were detected by Western blotting.Results The neurobehavioral score was significantly higher in the IMMP2L^(+/-) versus WT mice.The volume of the infarcted region,the number of degenerated neurons,and the degree of cerebral edema all increased at 5 and 24 hours after reperfusion.The apoptotic neurons increased at 0,1,5 and 24 hours after reperfusion and the protein levels of c-caspase-3 and AIF were up-regulated at 5 and 24 hours after I/R.Conclusion IMMP2L mutation aggravates cerebral ischemic injury by activating the mitochondrial apoptosis pathway.

关 键 词：脑缺血再灌注损伤 脑血流量 细胞凋亡 胱天蛋白酶3(caspase-3) 凋亡诱导因子(AIF) 类线粒体内膜肽酶2(IMMP2L) 

分 类 号：R743.31[医药卫生—神经病学与精神病学] R392-33[医药卫生—临床医学]