瘦素对缺血再灌注损伤大鼠脑损伤的保护作用及机制研究  

Study on the protective effects of leptin on brain injury in rats with ischemia-reperfusion injury and its mechanism

作　　者：张艳[1] 胡诗俊 蓝翊宁 李胜昆 秦超[1] 程道宾[1] Zhang Yan;Hu Shijun;Lan Yining;Li Shengkun;Qin Chao;Cheng Daobin(Department of Neurology,The First Affiliated Hospital of Guangxi Medical University,Nanning 530021,China;Hainan Provincial People’s Hospital,Haikou 570100,China)

机构地区：[1]广西医科大学第一附属医院神经内科,南宁530021 [2]海南省人民医院,海口570100

出　　处：《广西医科大学学报》2022年第4期533-539,共7页Journal of Guangxi Medical University

基　　金：国家自然科学基金资助项目(No.81860212);海南省自然科学基金青年基金资助项目(No.819QN348)。

摘　　要：目的:探讨瘦素对大鼠脑缺血再灌注损伤后脑组织的神经保护作用及其机制。方法:将40只雄性SD大鼠随机分为假手术组、模型组、瘦素组和PI3K抑制剂组,每组10只。除假手术组外,其余3组均采用改良Longa线栓法建立大鼠大脑局灶性缺血再灌注损伤模型。对各组大鼠进行神经功能缺损评分,采用2,3,5-氯化三苯四氮唑(TTC)染色法检测脑梗死体积,苏木素—伊红(HE)染色法观察皮层组织的病理形态变化,原位末端标记(TUNEL)法检测细胞凋亡,蛋白免疫印迹法(Western blotting)检测各组磷酸化蛋白酶B(p-Akt)的表达,组织免疫荧光法比较各组内质网应激相关蛋白C/EBP同源蛋白(CHOP)和半胱氨酸蛋白酶12(Caspase 12)的表达。结果:与假手术组比较,模型组神经功能缺损评分、脑梗死体积、细胞凋亡率均升高(P<0.05),CHOP和Caspase 12的荧光强度均增强;与模型组比较,瘦素组的神经功能缺损评分、脑梗死体积、细胞凋亡率均降低(P<0.05),CHOP和Caspase 12的荧光强度均减弱,皮层组织中神经细胞形态明显改善,并且p-Akt蛋白水平升高(P<0.01);与瘦素组比较,PI3K抑制剂组的神经功能缺损评分、脑梗死体积、细胞凋亡率均升高(P<0.05);CHOP和Caspase 12的荧光强度均增强。结论:瘦素可改善大鼠脑缺血再灌注后损伤,其机制可能与激活PI3K/Akt信号通路,下调内质网应激相关的促凋亡因子CHOP和Caspase 12的表达有关。Objective:To investigate the neuroprotective effect of leptin on brain tissue after cerebral ischemiareperfusion injury in rats and its mechanism.Methods:Forty male SD rats were randomly divided into sham-operated group,model group,leptin group and PI3K inhibitor group,with 10 rats in each group.Except for the sham-operated group,the rat brain focal ischemia-reperfusion injury model was established by the modified Longa’s method in other three groups.All rats were scored for neurological deficits,and 2,3,5-triphenyltetrazolium chloride(TTC)staining was used to measure the brain infarct volume.Hematoxylin-eosin(HE)staining was used to observe the pathological and morphological changes in cortical tissues.TUNEL was used to detect apoptosis,western blotting to detect the expression of phosphatase B(p-Akt),and immunofluorescence to compare the expression of endoplasmic reticulum stress-related protein C/EBP homologous protein(CHOP)and Caspase12 in each group.Results:Compared with the sham-operated group,the neurological deficit score,brain infarct volume,and apoptosis rate were increased in the model group(P<0.05),and the fluorescence intensity of CHOP and Caspase12 were enhanced.Compared with the model group,the neurological deficit score,brain infarct volume,and apoptosis rate were decreased in the leptin group(P<0.05),the fluorescence intensity of CHOP and Caspase12 in cortical tissues was reduced,the morphology of neuronal cells in cortical tissues was significantly improved,and the level of p-Akt protein was increased(P<0.01).Compared with the leptin group,the neurological deficit score,brain infarct volume,and apoptosis rate in the PI3K inhibitor group were increased(P<0.05),and the fluorescence intensity of CHOP and Caspase12 was enhanced.Conclusion:Leptin alleviates post-ischemia-reperfusion injury in rat brain,and the mechanism may be related to the activation of PI3K/Akt signaling pathway and downregulation of the expression of endoplasmic reticulum stress-related pro-apoptotic factors CHOP and Caspase12.

关 键 词：瘦素 脑缺血/再灌注损伤 PI3K/AKT信号通路 内质网应激 

分 类 号：R743[医药卫生—神经病学与精神病学]