氟代柠檬酸抑制缺血后适应对树鼩脑缺血后海马HIF-1α/iNOS信号通路调控的脑损伤机制  

Fluorocitrate inhibits regulatory effect of ischemic postconditioning on HIF-1α/iNOS signaling pathway after cerebral ischemia in tree shrews with brain injury

作　　者：何亮[1] 谭树芬[2] 张富荣[1] 李树清 HE Liang;TAN Shu-fen;ZHANG Fu-rong;LI Shu-qing(Department of Anesthesiology,Yan’an Hospital Affiliated to Kunming Medical University,Kunming 650051,China;Department of Gynecologic Oncology,the Third Affiliated Hospital of Kunming Medical University,Kunming 650018,China;Department of Pathophysiology,School of Basic Medicine,Kunming Medical University,Kunming 650500,China)

机构地区：[1]昆明医科大学附属延安医院麻醉科,云南昆明650051 [2]昆明医科大学第三附属医院妇瘤科,云南昆明650018 [3]昆明医科大学基础医学院病理生理学教研室,云南昆明650500

出　　处：《中国病理生理杂志》2018年第11期2017-2024,共8页Chinese Journal of Pathophysiology

基　　金：国家自然科学基金资助项目(No.307971171)

摘　　要：目的:观察缺血后适应(PC)对树鼩脑缺血时海马HIF-1α/i NOS信号通路的调控作用,探讨抑制星形胶质细胞(AS)代谢加重脑损伤的机制。方法:光化学法建立血栓性脑缺血动物模型,氟代柠檬酸盐(FC)作为AS代谢抑制剂,于脑缺血后4 h闭/开缺血侧颈总动脉5 min,共3个循环以建立缺血PC模型。67只雄性树鼩随机分为对照组(n=9)、缺血4 h组(n=9)、缺血24 h组(n=9)、缺血PC 4 h组(n=9)、缺血PC 24 h组(n=9)、FC预处理4 h组(n=11)和FC预处理24 h组(n=11)。采用TTC染色观察树鼩脑梗死体积的变化,通过HE染色观察海马神经元病理学改变,用激光多普勒监测缺血区区域性脑血流(r CBF),免疫组化及Western blot检测海马i NOS表达,用分光光度计测定海马NO产量,用ELISA分析海马HIF-1α水平的变化。结果:脑梗死体积随缺血时间延长而增大,以缺血24 h为显著(P <0. 05);脑缺血后4 h和24 h皮层r CBF均下降(P <0. 05);而海马HIF-1α和i NOS表达增强,NO生成显著升高(P <0. 05)。缺血PC可增加皮层r CBF(P <0. 05),显著缩小脑梗死体积(P <0. 05),下调海马i NOS表达并减少NO的生成(P <0. 05)。而FC预处理组r CBF显著低于缺血组(P <0. 05),海马神经元损伤程度较缺血组加重,脑梗死体积随之增大(P <0. 05)。结论:缺血PC通过调控HIF-1α和i NOS表达而减轻缺血性脑损伤,抑制AS功能可削弱缺血PC介导的保护效应而加重脑损伤。AIM:To investigate the regulatory effect of HIF-1α/iNOS signaling pathway on the neuroprotection of ischemic postconditioning(PC)in tree shrews,and to explore the mechanisms of deteriorated cerebral injury after inhibiting astrocyte(AS)metabolism.METHODS:Thrombotic cerebral ischemia was induced by photochemical reaction in tree shrews.Fluorocitrate(FC)was used to inhibit AS metabolism and the ischemic PC was established at 4 h after ischemia followed by clipped ipsilateral common carotid artery on the ischemia side for 3 times,5 min/time.A total of 67 male tree shrews were randomly divided into 7 groups:control(n=9),ischemia(4 h and 24 h,n=9 for each group),ischemia with PC(4 h and 24 h,n=9 for each group),and FC pretreatment(4 h and 24 h,n=11 for each group).The cerebral infarction size was detected by TTC staining,and the histological changes of hippocampal neurons were observed under light microscope.The regional cerebral blood flow(rCBF)in ischemic cortex was monitored by laser Doppler brain flowmetry.The protein expression of iNOS in hippocampus was detected both by immunohistochemistry and Western blot.The production of NO detected by spectrophotometer.The level of HIF-1αin hippocampus analyzed by ELISA.RESULTS:The cerebral infarct volume was increased with prolonged duration of ischemia,and the changes of ischemia at 24 h were significant(P<0.05).The cortical rCBF was progressively decreased,and it was decreased at 4 h and 24 h after ischemia(P<0.05).The expression of HIF-1αand iNOS in hippocampus was enhanced,and the production of NO was increased significantly(P<0.05).Ischemic PC restored the cortical rCBF(P<0.05),reduced cerebral infarction volume(P<0.05),down-regulated iNOS expression and reduced NO production in the hippocampus(P<0.05).However,the cortical rCBF in FC pretreatment group was significantly lower than that in ischemic group(P<0.05),the neuronal damage was aggravated,and the infarction volume was increased after pretreatment with FC(P<0.05).CONCLUSION:Ischemic PC may reduce cerebral inj

关 键 词：脑缺血 氟代柠檬酸盐 HIF-1α/iNOS信号通路 缺血后适应 树鼩 

分 类 号：R743.3[医药卫生—神经病学与精神病学] R363.2[医药卫生—临床医学]