瘦素对小鼠局灶性脑缺血再灌注损伤的保护作用及表达Cx43的影响  

The Effect of Leptin on Cx43 Expression in Protecting Rat Cerebral Ischemia/Reperfusion Injury

作　　者：吴其艳[1] 张金英[1] 邓子辉[1] 颜光涛[1] 

机构地区：[1]解放军总医院基础医学研究所、生物化学研究室,北京100853

出　　处：《四川大学学报（医学版）》2012年第3期314-318,共5页Journal of Sichuan University(Medical Sciences)

基　　金：国家自然科学基金(批准号30670821)资助

摘　　要：目的探讨瘦素对局灶性脑缺血再灌注损伤大脑缝隙连接蛋白43(Cx43)表达的影响及瘦素的脑保护作用机制。方法将45只健康雄性昆明小鼠随机分为假手术组、模型组和瘦素组。模型组和瘦素组制备小鼠大脑中动脉局灶性脑栓塞模型,瘦素组于缺血0min时腹腔注射1mg/kg瘦素,缺血2h再灌注24h后评价神经功能状态,脑组织TTC染色测定脑梗死体积,HE染色观察组织病理学改变;原代培养SD乳鼠的大脑皮层星形胶质细胞(Ast),将纯化后的Ast分为对照组、模型组、瘦素100μg/L组和瘦素500μg/L组,制作大鼠大脑皮质星形胶质细胞缺氧复氧模型,MTT法检测星形胶质细胞存活率,Western blot方法检测脑组织及星形胶质细胞中Cx43的表达变化。结果与模型组相比,瘦素组神经功能损伤状态得到改善(P<0.05),脑缺血再灌注后脑梗死体积缩小(P<0.05),脑组织病理学损伤程度减轻,Cx43的表达明显降低(P<0.01);与模型组比较,瘦素100μg/L组Ast存活率提高,Cx43表达减少,但差异均无统计学意义(P>0.05),瘦素500μg/L组Ast存活率显著提高(P<0.01),Cx43表达明显减少(P<0.01)。结论体内和体外实验均提示,瘦素可能通过降低损伤后脑组织中Cx43的表达,减轻脑缺血再灌注损伤。Objective To explore the effect of leptin on expression of Cx43 after rat cerebral ischemia/reperfusion injury and its related mechanism.Methods Forty-five male kunming mice were randomly divided into 3 groups： sham group,model group and leptin group.Mouse models of transient focal cerebral ischemia were established by occlusion of the right middle cerebral artery for 2 h followed by 24 h reperfusion in model and leptin group.Mice of leptin group were intraperitoneally injected with 1 mg/kg leptin at 0 minute after ischemia.The infarct volume and neurological deficit scores following leptin treatment were determined using TTC staining and the Longa＇s score,respectively,to evaluate the protective effect of leptin against ischemic cerebral injury.The histopathological changes in the brain were observed with HE staining.The astrocytes of SD rat cerebral cotex were cultured primaryly and purified,and then divided them into four groups： control,model,leptin 100 μg/L,and leptin 500 μg/L.The cerebral astrocytes with hypoxia/reoxygenation injury were induced.The cellular viability of injury was detected by MTT assay.The effect of leptin on Cx43 expression was detected by Western blot in brain tissues and astrocytes.Results Compared with the model group,the neurological deficits and cerebral infarct volume of leptin group were reduced（P0.05）,the histopathological injury in the brain tissues was alleviated and the expression of Cx43 was decreased markedly（P0.01）.The survival rate of astrocytes was increased significantly in leptin 500 μg/L group（P0.01）,whereas the Cx43 expression of astrocytes decreased（P0.01）.But the difference of leptin 100 μg/L was not significant（P0.05）.Conclusion Leptin can ameliorate cerebral pathological changes in the event of IR injury by suppressing the expression of Cx43 both in vivo and vitro experiments.

关 键 词：瘦素 星形胶质细胞 脑缺血再灌注损伤 缝隙连接蛋白43 

分 类 号：R743[医药卫生—神经病学与精神病学]