Neuroprotective effect of ischemic preconditioning in focal cerebral infarction: relationship with upregulation of vascular endothelial growth factor

Neuroprotection by ischemic preconditioning has been confirmed by many studies, but the precise mechanism remains unclear. In the present study, we performed cerebral ischemic pre- conditioning in rats by simulating a transient ischemic attack twice （each a 20-minute occlusion of the middle cerebral artery） before inducing focal cerebral infarction （2 hour occlusion-reper- fusion in the same artery）. We also explored the mechanism underlying the neuroprotective effect of ischemic preconditioning. Seven days after ocdusion-reperfusion, tetrazolium chloride staining and immunohistochemistry revealed that the infarct volume was significantly smaller in the group that underwent preconditioning than in the model group. Furthermore, vascular endothelial growth factor immunoreactivity was considerably greater in the hippocampal CA3 region of preconditioned rats than model rats. Our results suggest that the protective effects of ischemic preconditioning on focal cerebral infarction are associated with upregulation of vascu- lar endothelial growth factor.

Down-regulation of Rho-kinases induce tolerance in Ischemic preconditioning model after transient cerebral ischemia/reperfusion in rats

Background: Ischemic preconditioning (IPC) is a brief episode of ischemia/reperfusion (I/R) that protects the brain from the damage induced by subsequent prolonged ischemia. Aim: To study the neuroprotective mechanism of IPC. Methods: 30 adult male Wistar rats (150-250 g) were divided into three groups 10 rats in each;the first group was sham-operated and served as a control, I/R group of rats subjected to 30 minutes of left common carotid artery occlusion (CCAO) followed by 24-hour of reperfusion, IPC group were treated with three episodes of 5-minutes of CCAO with 10 minutes of reperfusion in between, followed by 30 minutes of CCAO and then allowed for reperfusion for 24 hours. Neurobehavioral assessments were evaluated;Rhokinases (ROCK) and nitrite were measured in affected cerebral hemisphere. Results: Rats’ neurological deficits were significantly decreased in the I/R compared with the control group (P < 0.001) whereas rats treated by precondition stimuli showed significant improvement in neurological deficit compared to I/R group (P < 0.001). Nitrite level was significantly increased in the IPC rats compared to both control and I/R groups (P contrast, the ROCK level was significantly higher in I/R group compared to control group and its level significantly decreased in IPC rats when compared to I/R group (P 0.695, P = 0.000). Conclusions: Downregulation of ROCK level following preconditioning stimuli with the potential involvement of Nitric oxide (NO) appear to be one of the neuroprotective mechanisms of IPC protection against a subsequent I/R challenge evidence by improvement in the neurological deficits.

Ischemic preconditioning partially suppresses and postpones integrin α_Vβ_3 mRNA expression following transient global cerebral ischemia in C57BL/6 mice

Previous studies of integrin αvβ3 have focused on ischemic brain damage, although the role of integrin αvβ3 in ischemic preconditioning （IP） has rarely been reported. The present study analyzed the effects of IP on integrin αvβ3 mRNA expression following cerebral ischemia through the use of hematoxylin-eosin staining and real-time quantitative polymerase chain reaction techniques. Integrin avid3 mRNA expression in the ischemia group peaked at 24 hours after ischemia-reperfusion. In the IP ＋ ischemia group, integrin αvβ3 mRNA expression increased after 24 hours, but remained significantly less than the ischemia group, and expression continued to increase until 7 days after ischemiaJreperfusion. These results demonstrate that IP effectively attenuated upregulation of integrin αvβ3 mRNA expression at 24 hours after ischemia.

Ischemic preconditioning protects against ischemic brain injury

In this study, we hypothesized that an increase in integrin αβand its co-activator vascular endothelial growth factor play important neuroprotective roles in ischemic injury. We performed ischemic preconditioning with bilateral common carotid artery occlusion for 5 minutes in C57BL/6J mice. This was followed by ischemic injury with bilateral common carotid artery occlusion for 30 minutes. The time interval between ischemic preconditioning and lethal ischemia was 48 hours. Histopathological analysis showed that ischemic preconditioning substantially diminished damage to neurons in the hippocampus 7 days after ischemia. Evans Blue dye assay showed that ischemic preconditioning reduced damage to the blood-brain barrier 24 hours after ischemia. This demonstrates the neuroprotective effect of ischemic preconditioning. Western blot assay revealed a significant reduction in protein levels of integrin αβ, vascular endothelial growth factor and its receptor in mice given ischemic preconditioning compared with mice not given ischemic preconditioning 24 hours after ischemia. These findings suggest that the neuroprotective effect of ischemic preconditioning is associated with lower integrin αβand vascular endothelial growth factor levels in the brain following ischemia.

Protective effects of remote ischemic preconditioning in rat hindlimb on ischemia- reperfusion injury

Three cycles of remote ischemic pre-conditioning induced by temporarily occluding the bilateral femoral arteries （10 minutes） prior to 10 minutes of reperfusion were given once a day for 3 days before the animal received middle artery occlusion and reperfusion surgery. The results showed that brain infarct volume was significantly reduced after remote ischemic pre-conditioning. Scores in the forelimb placing test and the postural reflex test were significantly lower in rats having undergone remote ischemic pre-conditioning compared with those who did not receive remote ischemic pre-conditioning. Thus, neurological function was better in rats having undergone remote ischemic pre-conditioning compared with those who did not receive remote ischemic pre-conditioning. These results indicate that remote ischemic pre-conditioning in rat hindlimb exerts protective effects in ischemia-reperfusion injury.

Correlation of hypoxia-inducible factor-1 alpha and erythropoietin protein and mRNA to cerebral ischemic tolerance in a focal ischemia/reperfusion model using the twice suture method

BACKGROUND： Numerous studies have shown that transient ischemic preconditioning induces cerebral ischemic tolerance. However, the underlying mechanisms of endogenous protection following ischemic preconditioning remain unclear. OBJECTIVE： To dynamically measure erythropoietin and hypoxia-inducible factor-1α （HIF-1α） mRNA and protein expression at various times following preconditioning, and to investigate effects of erythropoietin and HIF-1α on cerebral ischemic tolerance in a model of focal ischemia/reperfusion established using the twice suture method. DESIGN, TIME AND SETTING： The randomized, controlled study was performed at the Institute of Anatomy, Medical College, Qingdao University, China from March 2006 to March 2007. MATERIALS： Rabbit anti-rat HIF-1α monoclonal antibody and biotinylated goat anti-rabbit IgG （Boster, China）, rabbit anti-rat erythropoietin monoclonal antibody （Santa Cruz Biotechnology, USA）, and one-step RT-PCR kit （Qiagen, Germany） were used in this study. METHODS： A total of 99 healthy, male, Wistar rats were randomly assigned to three groups： sham surgery （n = 9）, non-ischemic preconditioning （n = 45）, and ischemic preconditioning （n = 45）. In the ischemic preconditioning group, rat models of pre-ischemia-reperfusion-ischemia-reperfusion were established by occluding the left middle cerebral artery using the twice suture method. In the non-ischemic preconditioning group, pre-ischemia was replaced by sham surgery. Subsequently, the ischemic preconditioning and non-ischemic preconditioning groups were equally divided into five subgroups according to time of first reperfusion, including 1-, 3-, 7-, 14-, and 21-day subgroups. The sham surgery group received the sham surgery twice. MAIN OUTCOME MEASURES： HIF-la and erythropoietin protein expression was measured in the cerebral cortex, corpus striatum, and hippocampus of the ischemic hemisphere. HIF-1α and erythropoietin mRNA expression were determined in the frontal and parietal cortex of the ischemic hemisphere. RESULTS： （1） Intergroup comparison： compared with the non-ischemic preconditioning group, HIF-1α protein expression significantly increased in the rat cerebral cortex, corpus striatum, and hippocampus in the ischemic hemisphere at 1,3, and 7 days following reperfusion in the ischemic preconditioning group （P 〈 0.05 or P 〈 0.01）. Erythropoietin protein expression significantly increased in the cerebral cortex, corpus striatum, and hippocampus, as well as HIF-1α and erythropoietin mRNA expression in the frontal and parietal cortex in the ischemic hemisphere, at 3 and 7 days following reperfusion in the ischemic preconditioning group （P 〈 0.05）. （2） Temporal expression： HIF-1α protein expression in the rat cerebral cortex, corpus striatum, and hippocampus, as well as HIF-la mRNA expression in the frontal and parietal cortex, in the ischemic hemisphere increased at 3 days, and gradually decreased from 7 days following reperfusion in the ischemic preconditioning group. Temporal erythropoietin protein and mRNA expression was consistent with HIF-1α protein expression. （3） Correlation： erythropoietin mRNA expression positively correlated with HIF-1α mRNA expression （r= 0.737, P 〈 0.01）. CONCLUSION： Ischemic preconditioning induced cerebral ischemic tolerance. Pre-ischemiainduced increase in endogenous HIF-1αexpression, as well as its target gene erythropoietin, participated in the formation of cerebral ischemic tolerance.

Effect of pre-ischemia on hypoxia-inducible factor expression in the brain tissue of rats with cerebral ischemia/reperfusion injury

Hypoxia-inducible factor 1 （HIF-1） can lead to the adaptative reaction of body for hypoxia and ischemia. HIF-1 plays an important role in the response of ischemia-hypoxia. At present, there has been no overall report on the significance for the expression of HIF-1 following experimental cerebral ischemia. OBJECTIVE： To observe the expression of HIF-1 after middle cerebral artery occlusion （MCAO） by immunohistochemical method. DESIGN： Completely randomly grouped controlled animal experiment. SETTING： Second Hospital, Xi＇an Jiaotong University. MATERIALS： Thirty-six Sprague-Dawley healthy male rats, with body mass of 250 - 330 g, were used in this study. Thirty-six rats were randomized into 3 groups： preischemia group, sham-operation group and control group, with 12 rats in each. METHODS： This study was carried out in the clinical laboratory, People＇s Hospital of Ningjin County of Shandong Province from March 2006 to January 2007. Rats in the pre-ischemia group were created into preischemia models by two embolisms twice. Three days after ischemic preconditioning, middle cerebral artery （MCA） was occluded for 2 hours with the same method. After being perfused for 22 hours, the rats were euthanized. In the sham-operation group, rats were not given the treatment of preischemia. In the first operation, only common carotid artery （CCA） and its crotch were exposed in the first operation, and MCA was not blocked by inserting embolism. At postoperative 3 days, rats were euthanized after being subjected to MCAO for 2 hours and reperfusion 22 hours by the same procedure as that in the preischemia group. As for each rat in the control group, only CCA and its crotch were exposed, and no any other treatment was carried out on them. MAIN OUTCOME MEASURES： Brain tissue of each rat was performed immunohistochemical staining at reperfusion 22 hours after preischemia, HIF-1 expression and brain infarct volume were detected. RESULTS： Thirty-six Sprague-Dawley rats were involved in the experiment. During the experiment, 8 rats dropped out, and another 8 rats were supplemented. The infarct volume of rats in the preischemia group was significantly smaller than that in the sham-operation group （t=3.22, P 〈 0.01 ） . HIF-1 expression was not found in the control group, but many HIF-I positive cells were found in the other two groups. Absorbance in the preischemia group was significantly higher than that in the sham-operation group （t=4.31, P 〈 0.01）. CONCLUSION： Slight ischemia caused preconditioning can increase HIF-1 content, and it is one of protective mechanisms for nerve cells.

远端缺血预适应在脑梗死中的脑保护机制及临床应用研究进展

脑梗死是全球范围内致残率和致死率较高的疾病之一,大量研究表明,远端缺血预适应(remote ischemic preconditioning,RIPC)能够显著提高靶器官对缺血的耐受程度,减小梗死面积,改善患者预后,但目前对其在脑梗死发生发展中的作用机制研究较少。本文将从神经、体液和免疫3个方面,结合相关信号通路对RIPC在脑梗死中的作用及作用机制进行总结,并综述RIPC目前在临床缺血性脑疾病中的应用进展,以期为后续研究提供参考依据。

Pretreatment with repeated electroacupuncture attenuates transient focal cerebral ischemic injury in rats

Objective To investigate whether pretreatment with repeated electroacupuncture (EA)at the Baihui acupoint could induce ischemic tolerance against transient focal cerebral ischemic injury in rats. Methods Thirty male Sprague-Dawley (SD) rats were randomly divided into 3 groups (n=10 for each): the control group consisted of animals receiving no treatment, the isoflurane (ISO) group had animals that inhaled 1.5% isoflurane for 30 min a day for 5 days, and animals in the EA group received electroacupuncture at the Baihui acupoint for 30 min a day for 5 days under 1.5% isoflurane anesthesia. Twenty-four hours after the last treatment, the middle cerebral artery was occluded with No. 3 nylon monofilament for 120 min. The neurological outcomes were evaluated 24 h after reperfusion. The infarct volumes were then assessed using 2% triphenyltetrazolium chloride staining after the neurological outcome evaluation. Results The neurological deficit score (NDS) of the EA group was lower than that of the ISO group and the control group , P<0.05. The infarct volume of the EA group (38.3±25.4 mm 3) was significantly smaller than that of the control group (220.5±66.0 mm 3) and the ISO group (168.6±57.6 mm 3) 24 h after reperfusion. Conclusion Electroacupuncture at the Baihui acupoint 30 min a day for 5 days significantly reduces neurological injury induced by transient middle cerebral artery occlusion.

自由基在肢体缺血预处理诱导的大鼠脑缺血耐受中的作用

目的:我们前期的研究证实,肢体缺血预处理(limb ischemic preconditioning,LIP)能够诱导大鼠的脑缺血耐受,并且p38 MAPK和ERK在其中发挥了重要的神经保护作用。本研究旨在探讨自由基是否参与LIP诱导的大鼠脑缺血耐受和p38 MAPK和ERK表达的上调。方法:128只永久凝闭双侧椎动脉的Wistar大鼠,随机分为假手术(sham)组(n=16)、全脑缺血(cerebral ischemia,CI)组(n=16)、LIP+CI组(n=16)、DMTU(自由基清除剂)+LIP+CI组(n=64)和DMTU+sham组(n=16)。各组6只大鼠于末次手术后7 d取材,硫堇染色观察海马CA1区锥体神经元迟发性死亡(delayed neuronal death,DND)情况;另外10只大鼠应用免疫组织化学和Western blot观察海马CA1区p38 MAPK和ERK的表达。结果:致死性全脑缺血引起大鼠海马CA1区出现明显的DND。然而,LIP明显逆转了上述损伤性变化:与CI组比较,CA1区组织学分级降低、神经元密度增加(P<0.01);此外,与CI组比较,海马CA1区p38 MAPK和ERK的表达明显上调(P<0.01)。与LIP+CI组相比,LIP前经股静脉给予自由基清除剂DMTU,可部分逆转LIP的脑保护作用,也可部分阻断LIP对脑缺血大鼠海马CA1区p38 MAPK和ERK表达的上调作用(P<0.01)。结论:自由基参与了LIP诱导的大鼠脑保护作用和p38 MAPK和ERK表达的上调。

基于网络药理学研究化浊行血汤产生缺血耐受的作用机制及实验验证

目的:基于网络药理学及动物实验分析化浊行血汤治疗脑缺血耐受(CIT)的机制。方法:通过中药系统药理学数据库与分析平台(TCMSP)、中医药百科全书数据库(ETCM)、中药分子机制的生物信息学分析工具(BATMAN-TCM)数据库及文献筛选化浊行血汤的有效成分及其靶点;通过基因数据库(GeneCards)、在线人类孟德尔遗传病数据库(OMIM)获取CIT靶点,绘制韦恩图获得化浊行血汤调治CIT的作用靶点;利用STRING平台构建靶点相互作用网络。利用Metascape对关键靶点进行基因本体(GO)通路富集分析与京都基因与基因组百科全书(KEGG)通路富集分析。通过大鼠实验进行验证,将SD大鼠用线栓法行脑缺血造模,灌服中药化浊行血汤及缺血预适应干预,横木行走试验(BWT)评价运动功能恢复情况、TTC染色法计算脑梗死体积、酶联免疫吸附试验法检测一氧化氮合酶不同亚型(内皮型一氧化氮合酶、神经元型一氧化氮合酶、诱生型一氧化氮合酶)的浓度观测缺血耐受程度。结果:网络药理学发现化浊行血汤中槲皮素、山柰酚、植物甾醇、木犀草素等化合物协同发挥产生缺血耐受的作用,涉及磷脂酰肌醇-3-激酶-蛋白激酶B(PI3K-AKT)、缺氧诱导因子1(HIF-1)、环腺苷酸(cAMP)、核因子κB(NF-κB)等信号通路及蛋白激酶B(AKT1)、肿瘤坏死因子(TNF)、白细胞介素-6(IL-6)、抑癌基因53(TP53)等靶点蛋白。动物实验预缺血+缺血组与中药+缺血组内皮型一氧化氮合酶、神经元型一氧化氮合酶、诱生型一氧化氮合酶的浓度以及脑梗死体积差异无统计学意义(P>0.05),预缺血+缺血组、中药+缺血组脑梗死体积小于缺血组(P<0.05),内皮型一氧化氮合酶的浓度明显高于缺血组(P<0.05)。结论:研究阐述了化浊行血汤多靶点、多通路产生缺血耐受的机制,证实了化浊行血汤能够影响内皮型一氧化氮合酶的表达,验证了网络药理学结果,为深入研究化浊行血汤产生缺血耐受提供了依据。

肢体缺血预适应训练对脑梗死患者脑血流灌注及再发的影响

目的探讨肢体缺血预适应训练对脑梗死患者脑血流灌注及再发的影响。方法采用便利抽样法选取2021年3月至2022年3月唐山市人民医院收治的96例脑梗死患者为研究对象,根据治疗方法不同分为对照组和观察组,各48例。对照组给予基础治疗及药物治疗(硫酸氢氯吡格雷片每次75 mg、每日1次,阿司匹林每次100 mg、每日1次),共治疗1个月;观察组在对照组基础上进行肢体缺血预适应训练,共治疗1个月。于治疗前、治疗1个月后,比较两组患者脑血流灌注指标(脑血容量、脑血流量),神经功能缺损情况[美国国立卫生研究院卒中量表(NIHSS)评分]、认知功能[蒙特利尔认知评估量表(MoCA)评分],以及两组患者6个月内脑梗死再发情况。结果治疗前后脑血容量、脑血流量的主效应差异有统计学意义(P<0.01);不考虑测量时间,各指标组间的主效应差异有统计学意义(P<0.01);组间和时点间存在交互作用(P<0.01)。与治疗前相比,治疗后两组脑血容量、脑血流量均升高,且观察组高于对照组[(2.37±0.27)ml/100 g比(1.97±0.28)ml/100 g、(22.9±1.9)ml/(100 g·min)比(19.5±1.8)ml/(100 g·min)](P<0.05)。治疗前后NIHSS、MoCA评分的主效应差异有统计学意义(P<0.01);不考虑测量时间,NIHSS、MoCA评分组间的主效应差异有统计学意义(P<0.05或P<0.01);组间和时点间存在交互作用(P<0.01)。与治疗前相比,治疗后两组NIHSS评分均降低,且观察组低于对照组[(10.21±2.9)分比(14.56±3.2)分](P<0.05);治疗后两组MoCA评分均升高,且观察组高于对照组[(27.1±2.3)分比(23.9±3.6)分](P<0.05)。随访6个月后,观察组再发率低于对照组[10.42%(5/48)比27.08%(13/48)](χ^(2)=4.376,P=0.036)。结论肢体缺血预适应训练可改善脑梗死患者脑血流灌注、神经功能缺损情况及认知功能,且可预防脑梗死再发。

远端缺血预处理对皮质下缺血性血管性痴呆患者认知能力的改善作用

目的:评价远端缺血预处理(RIPC)对皮质下缺血性血管性痴呆(SIVD)患者认知能力的改善作用。方法:选取2019年1月—2021年1月佳木斯市中心医院诊治的74例SIVD患者,按随机数字表法分为治疗组36例,对照组38例,治疗组进行RIPC治疗,对照组给予安慰剂治疗,为期3个月,比较两组治疗前后认知能力评分、血清炎症因子和磁共振成像参数。结果:治疗前两组认知能力评分、血清炎症因子和影像学参数比较差异均无统计学意义(P>0.05)。治疗后,治疗组霍普金斯词语学习测验修订版(HVLT-R)、受控口头词语联想测试(COWAT)、连线试验A和B(TMT-A、TMT-B)及线方向判断(JLO)评分优于治疗前(P<0.05);治疗组所有炎症因子均低于治疗前和对照组(P<0.05);对照组仅HVLT-R和TMT-B评分优于治疗前,差异均有统计学意义(P<0.05)。磁共振成像参数组间及组内治疗前后比较差异均无统计学意义(P>0.05)。所有患者均顺利完成治疗,无明显不良反应。结论:RIPC可在一定程度上改善SIVD患者的认知功能,且无明显不良反应。

低氧预处理人牙髓干细胞移植对缺氧缺血性脑损伤新生大鼠脑白质损伤的影响

目的探讨低氧预处理人牙髓干细胞移植(H-hDPSCs)对缺氧缺血性脑损伤(HIBD)新生大鼠脑白质损伤及内源性神经干细胞的影响。方法将健康7 d龄Sprague-Dawley新生大鼠随机分为假手术组、HIBD组、常氧培养hDPSC移植组(N-hDPSCs组)及低氧预处理hDPSC移植组(H-hDPSCs组),每组11只。采用经典的Rice-Vannucci法复制HIBD模型。模型复制后7 d采用增殖细胞核抗原(PCNA)/巢蛋白(Nestin)免疫荧光双标法检测大鼠侧脑室室管膜下区内源性神经干细胞(NSCs)的增殖;模型复制后3周,滑竿实验、Y迷宫实验及模型复制后4周Morris水迷宫实验检测大鼠的运动及空间记忆能力;行为学实验后采用神经元特异性核蛋白(NeuN)免疫荧光法检测大鼠脑组织皮层和海马CA1区神经元的表达;采用髓鞘碱性蛋白(MBP)及神经纤维丝蛋白重链(NF200)免疫荧光双标法检测纹状体及胼胝体区髓鞘及神经纤维的表达。结果HIBD组模型复制后7 d的侧脑室室管膜下区增殖NSCs数较假手术组少(P<0.05),N-hDPSCs组、H-hDPSCs组较HIBD组多,但较假手术组少(P<0.05),N-hDPSCs组较H-hDPSCs组少(P<0.05)。N-hDPSCs组、H-hDPSCs组模型复制后3周爬杆时间较假手术组长(P<0.05),但较HIBD组短(P<0.05),H-hDPSCs组较N-hDPSCs组短(P<0.05)。HIBD组新异臂停留时间较假手术组短(P<0.05),N-hDPSCs组、H-hDPSCs组较HIBD组长(P<0.05),但较假手术组短(P<0.05),而N-hDPSCs组较H-hDPSCs组短(P<0.05)。各组大鼠第1天、第2天、第3天、第4天逃避潜伏期比较,经重复测量设计的方差分析,结果:(1)不同时间点逃避潜伏期有差异(F=662.825,P=0.000);(2)各组逃避潜伏期有差异(F=109.286,P=0.000),N-hDPSCs组、H-hDPSCs组大鼠较假手术组长(P<0.05),但均较HIBD组短(P<0.05),H-hDPSCs组较N-hDPSCs组短(P<0.05);(3)各组逃避潜伏期变化趋势有差异(F=20.543,P=0.000)。N-hDPSCs组、H-hDPSCs组大鼠在第5天的空间探索实验中穿台次数较假手术组少(P<0.05),但较HIBD组多(P<0.05),H-hDPSCs组较N-hDPSCs组多(P<0.05)。N-hDPSCs组、H-hDPSCs组大鼠在目标象逗留时间百分比较假手术组小(P<0.05),但较HIBD组多(P<0.05),H-hDPSCs组较N-hDPSCs组多(P<0.05)。NhDPSCs组、H-hDPSCs组NeuN阳性细胞数较HIBD组多(P<0.05),但较假手术组少(P<0.05),N-hDPSCs组较H-hDPSCs组少(P<0.05)。N-hDPSCs组、H-hDPSCs组纹状体、胼胝体区MBP、NF200蛋白平均荧光强度高于HIBD组(P<0.05),但低于假手术组(P<0.05),H-hDPSCs组高于N-hDPSCs组(P<0.05)。结论HhDPSCs与N-hDPSCs移植可有效改善HIBD新生大鼠远期行为学,并促进HIBD新生大鼠内源性NSCs的增殖,减轻脑白质损伤进而促进HIBD神经修复,且H-hDPSCs移植的疗效优于N-hDPSCs。

远隔缺血预适应通过激活HIF-1α/VEGF通路保护大鼠缺血性脑卒中

目的:研究远隔缺血预适应(RIPC)对大鼠脑缺血模型的保护作用及分子机制。方法:30只成年雄性SD大鼠随机分为4组:假手术组(sham)、RIPC组、缺血再灌注组(MCAO/R)组、RIPC+MCAO/R组;术前通过夹闭双侧股动脉给予相应组RIPC处理,利用大脑中动脉栓塞再灌注法(MCAO/R)制备大鼠缺血性脑卒中模型,神经功能评分检测大鼠的神经功能,用2,3,5-三苯四唑氯(TTC)对脑切片进行染色以评估脑梗死的程度。利用real time RT-PCR检测大脑皮质中低氧诱导因子-1α(HIF-1α)和血管内皮生长因子(VEGF) mRNA的表达。结果:与MCAO/R组大鼠相比,RIPC处理组大鼠神经功能缺损症状较轻(P<0.05),脑梗死体积缩小(P<0.01),皮质中HIF-1α和VEGF mRNA的表达表达明显升高(P<0.05)。结论:RIPC处理对减轻缺血性脑卒中大鼠具有保护作用,其分子机制可能与激活HIF-1α/VEGF通路有关。

远隔缺血预适应联合盐酸多奈哌齐片治疗脑小血管病患者的临床观察

目的探讨远隔缺血预适应联合盐酸多奈哌齐片治疗脑小血管病(cerebral small vessel disease,CSVD)患者的临床效果。方法选取78例CSVD患者作为研究对象,观察组(盐酸多奈哌齐片联合远隔缺血预适应治疗)39例,对照组(盐酸多奈哌齐片治疗)39例。治疗结束后比较2组的疗效,并比较2组治疗前后蒙特利尔认知量表(Montreal cognitive scale,MoCA)、简化36医疗结局研究量表(36-item short form survey instrument,SF-36)生活质量评分、脑血管灌注参数[平均通过时间(mean transit time,MTT)、脑血流量(cerebral blood flow,CVB)、血流速度(blood flow velocity,CBF)]、血清肿瘤坏死因子-α(tumor necrosis factor-α,TNF-α)、白细胞介素-8(interleukin-8,IL-8)、中枢神经特异性蛋白(central nervous system specific protein,S100β)、脑源性神经营养因子(brain-derived neurotrophic factor,BDNF)、血管内皮生长因子(vascular endothelial growth factor,VEGF)水平。结果治疗前2组各参数比较差异均无统计学意义(P>0.05),治疗后2组MoCA、SF-36量表、CVB、CBF、BDNF、VEGF上升,MTT、TNF-α、IL-8、S100β水平下降(P<0.05);与对照组比较,观察组MoCA、SF-36量表、CVB、CBF、BDNF、VEGF及总有效率更高,MTT、TNF-α、IL-8、S100β更低(P<0.05)。治疗后观察组及对照组的总有效率分别为89.74%、71.79%,2组比较差异有统计学意义(P<0.05)。结论远隔缺血预适应联合盐酸多奈哌齐片可显著改善CSVD患者的认知功能障碍、脑血流灌注及炎性反应,并能提高患者的生活质量。

远隔缺血预适应通过上调miR⁃21⁃5p减轻脑缺血模型大鼠细胞凋亡

目的:研究远隔缺血预适应(RIPC)对脑缺血模型大鼠的保护作用及分子机制。方法:18只成年雄性SD大鼠随机分为3组:假手术组(sham)、缺血再灌注组(MCAO/R)组、RIPC+MCAO/R组;术前利用间断夹闭双侧股动脉的方法给予大鼠RIPC处理,利用大脑中动脉栓塞法(MCAO)制备大鼠缺血性脑卒中模型,利用转棒实验检测大鼠运动功能,利用TUNEL染色检测缺血区细胞凋亡,利用real time RT⁃PCR检测大脑缺血区皮质中miR⁃21⁃5p及SPRY1和程序性细胞死亡因子4(PDCD4)mRNA的表达。结果:与MCAO/R组大鼠相比,RIPC处理组大鼠运动功能有所改善,皮质细胞凋亡减少。miR⁃21⁃5p表达增加,而SPRY1和PDCD4 mRNA表达下调(P<0.05)。结论:RIPC处理对减轻缺血性脑卒中大鼠miR⁃21⁃5p表达上调,后者通过抑制靶分子SPRY1和PDCD4的表达抑制细胞凋亡。

缺血预适应训练治疗老年脑梗死的疗效观察

目的观察缺血预适应训练治疗老年脑梗死的临床效果。方法择取104例老年脑梗死患者为研究对象,依照计算机随机分组模式分为对照组和实验组,每组52例。对照组给予常规治疗,实验组在对照组基础上给予缺血预适应训练。对比两组治疗效果、治疗前后脑氧代谢指标[颈静脉球血氧饱和度(SjvO2)、桡动脉与颈内静脉球氧含量差(Da-jvO2)、动脉血氧含量(CaO2)、氧摄取率(ERO2)]及血清学指标[色素上皮衍生因子(PEDF)、脑源性神经营养因子(BDNF)、基质金属蛋白酶9(MMP-9)及血清和肽素]。结果实验组总有效率为94.23%,明显高于对照组的80.77%,差异有统计学意义(P<0.05)。治疗后,两组SjvO2、Da-jvO2、ERO2、CaO2均明显优于本组治疗前,且实验组SjvO2(61.02±4.25)%明显高于对照组的(57.68±3.89)%,Da-jvO2、ERO2、CaO2分别为(50.22±2.15)ml/L、(15.14±1.36)%、(150.36±8.52)ml/L,明显低于对照组的(53.28±2.58)ml/L、(21.69±1.89)%、(160.96±9.63)ml/L,差异有统计学意义(P<0.05)。治疗后,两组BDNF、PEDF、MMP-9及血清和肽素均明显优于本组治疗前,且实验组BDNF、PEDF分别为(41.36±5.28)μg/L、(32.52±2.18)ng/ml,均明显高于对照组的(35.68±5.10)μg/L、(26.12±2.20)ng/ml,MMP-9、血清和肽素分别为(223.63±33.58)μg/L、(3.25±1.30)pmol/L,均明显低于对照组的(276.58±34.56)μg/L、(6.36±1.89)pmol/L,差异有统计学意义(P<0.05)。结论对老年脑梗死患者给予缺血预适应训练简便有效,能够明显改善患者脑氧代谢指标水平,缩小梗死面积,提高神经功能与PEDF、BDNF表达水平,具有较高的推广价值。

远隔缺血预适应训练对缺血性脑卒中患者的脑保护作用

目的探讨远隔缺血预适应训练(RIPC)对缺血性脑卒中(IS)患者的脑保护作用。方法将86例IS患者随机分为对照组和RIPC组,每组43例。对照组采用常规治疗,RIPC组在对照组的基础上加用RIPC,两组均治疗6个月。比较两组疗效、神经功能缺损程度、脑梗死体积、上肢功能、血清脑源性神经营养因子(BDNF)水平和血清神经生长因子(NGF)水平。结果治疗6个月后,RIPC组的总有效率高于对照组(P<0.05)。治疗前,两组美国国立卫生研究院卒中量表(NIHSS)评分、脑梗死体积、Fuel-Meyer上肢运动功能评定量表(FMA-UE)评分、Wolf运动功能评价量表(WMFT)评分、血清NGF水平、血清BDNF水平差异均无统计学意义(均P>0.05);治疗3个月后和治疗6个月后,RIPC组的NIHSS评分、脑梗死体积均低/小于对照组,FMA-UE评分、WMFT评分、血清BDNF水平、血清NGF水平均高于对照组;NIHSS评分、脑梗死体积、FMA-UE评分、WMFT评分、血清BDNF水平、血清NGF水平的分组与时间均有交互效应(均P<0.05)。结论RIPC可上调IS患者血清BDNF和NGF的表达,减轻神经功能缺损,减小脑梗死体积,改善上肢功能,是一种有效的脑保护方案。

肢体缺血预处理减少大鼠全脑缺血再灌注诱导的海马CA1区锥体神经元凋亡(英文)

探探讨肢体缺血预处理(limb ischemic preconditioning,LIP)对大鼠全脑缺血再灌注后海马CA1区锥体细胞凋亡的影响。46只大鼠椎动脉凝闭后分为假手术组、肢体缺血组、脑缺血组、LIP组。重复夹闭大鼠双侧股动脉3次(每次10min,间隔10min)作为LIP,之后立即夹闭双侧颈总动脉进行全脑缺血8min后再灌注。DNA凝胶电泳、TUNEL和吖啶橙/溴乙锭(AO/EB)双染技术从生化和形态学方面观察海马神经元凋亡的情况。凝胶电泳显示,脑缺血组出现了凋亡特征性DNA梯状条带,而LIP组无上述条带出现。与脑缺血组比较,LIP可明显减少海马CAI区TUNEL阳性神经元数(17.8±5.8vs 69.8±12,P<0.01)。AO/EB染色也显示LIP可明显减少脑缺血再灌注引起的神经元凋亡。以上结果提示,LIP可抑制脑缺血再灌注后海马神经元的凋亡,进而减轻脑缺血再灌注损伤,提供脑保护作用。