Treatment with β-sitosterol ameliorates the effects of cerebral ischemia/reperfusion injury by suppressing cholesterol overload, endoplasmic reticulum stress, and apoptosis

β-Sitosterol is a type of phytosterol that occurs naturally in plants.Previous studies have shown that it has anti-oxidant,anti-hyperlipidemic,anti-inflammatory,immunomodulatory,and anti-tumor effects,but it is unknown whetherβ-sitosterol treatment reduces the effects of ischemic stroke.Here we found that,in a mouse model of ischemic stroke induced by middle cerebral artery occlusion,β-sitosterol reduced the volume of cerebral infarction and brain edema,reduced neuronal apoptosis in brain tissue,and alleviated neurological dysfunction;moreover,β-sitosterol increased the activity of oxygen-and glucose-deprived cerebral cortex neurons and reduced apoptosis.Further investigation showed that the neuroprotective effects ofβ-sitosterol may be related to inhibition of endoplasmic reticulum stress caused by intracellular cholesterol accumulation after ischemic stroke.In addition,β-sitosterol showed high affinity for NPC1L1,a key transporter of cholesterol,and antagonized its activity.In conclusion,β-sitosterol may help treat ischemic stroke by inhibiting neuronal intracellular cholesterol overload/endoplasmic reticulum stress/apoptosis signaling pathways.

The action mechanism by which C1q/tumor necrosis factor-related protein-6 alleviates cerebral ischemia/reperfusion injury in diabetic mice

Studies have shown that C1q/tumor necrosis factor-related protein-6 (CTRP6) can alleviate renal ischemia/reperfusion injury in mice. However, its role in the brain remains poorly understood. To investigate the role of CTRP6 in cerebral ischemia/reperfusion injury associated with diabetes mellitus, a diabetes mellitus mouse model of cerebral ischemia/reperfusion injury was established by occlusion of the middle cerebral artery. To overexpress CTRP6 in the brain, an adeno-associated virus carrying CTRP6 was injected into the lateral ventricle. The result was that oxygen injury and inflammation in brain tissue were clearly attenuated, and the number of neurons was greatly reduced. In vitro experiments showed that CTRP6 knockout exacerbated oxidative damage, inflammatory reaction, and apoptosis in cerebral cortical neurons in high glucose hypoxia-simulated diabetic cerebral ischemia/reperfusion injury. CTRP6 overexpression enhanced the sirtuin-1 signaling pathway in diabetic brains after ischemia/reperfusion injury. To investigate the mechanism underlying these effects, we examined mice with depletion of brain tissue-specific sirtuin-1. CTRP6-like protection was achieved by activating the sirtuin-1 signaling pathway. Taken together, these results indicate that CTRP6 likely attenuates cerebral ischemia/reperfusion injury through activation of the sirtuin-1 signaling pathway.

GPER agonist G1 suppresses neuronal apoptosis mediated by endoplasmic reticulum stress after cerebral ischemia/reperfusion injury

Studies have confirmed a strong association between activation of the endoplasmic reticulum stress pathway and cerebral ischemia/reperfusion(I/R) injury.In this study,three key proteins in the endoplasmic reticulum stress pathway(glucose-regulated protein 78,caspase-12,and C/EBP homologous protein) were selected to examine the potential mechanism of endoplasmic reticulum stress in the neuroprotective effect of G protein-coupled estrogen receptor.Female Sprague-Dawley rats received ovariectomy(OVX),and then cerebral I/R rat models(OVX+ I/R) were established by middle cerebral artery occlusion.Immediately after I/R,rat models were injected with 100 μg/kg E2(OVX + I/R +E2),or 100 μg/kg G protein-coupled estrogen receptor agonist G1(OVX + I/R + G1) in the lateral ventricle.Longa scoring was used to detect neurobehavioral changes in each group.Infarct volumes were measured by 2,3,5-triphenyltetrazolium chloride staining.Morphological changes in neurons were observed by Nissl staining.Terminal dexynucleotidyl transferase-mediated nick end-labeling staining revealed that compared with the OVX + I/R group,neurological function was remarkably improved,infarct volume was reduced,number of normal Nissl bodies was dramatically increased,and number of apoptotic neurons in the hippocampus was decreased after E2 and G1 intervention.To detect the expression and distribution of endoplasmic reticulum stress-related proteins in the endoplasmic reticulum,caspase-12 distribution and expression were detected by immunofluorescence,and mRNA and protein levels of glucose-regulated protein 78,caspase-12,and C/EBP homologous protein were determined by polymerase chain reaction and western blot assay.The results showed that compared with the OVX+ I/R group,E2 and G1 treatment obviously decreased mRNA and protein expression levels of glucose-regulated protein 78,C/EBP homologous protein,and caspase-12.However,the G protein-coupled estrogen receptor antagonist G15(OVX + I/R + E2 + G15) could eliminate the effect of E2 on cerebral I/R injury.These results confirm that E2 and G protein-coupled estrogen receptor can inhibit the expression of endoplasmic reticulum stress-related proteins and neuronal apoptosis in the hippocampus,thereby improving dysfunction caused by cerebral I/R injury.Every experimental protocol was approved by the Institutional Ethics Review Board at the First Affiliated Hospital of Shihezi University School of Medicine,China(approval No.SHZ A2017-171) on February 27,2017.

Inosine inhibits apoptosis and cytochrome C mRNA expression in rat neurons after cerebral ischemia/reperfusion

BACKGROUND: It has been demonstrated that adenosine can induce glial cell to release cytochrome C,enhance expression of apoptotic gene bax,inhibit anti-apoptotic gene bcl-2,and activate caspase-3 to apoptosis;Whereas inosine can inhibit neuronal apoptosis which is similar to bil-2.OBJECTIVE: To observe the affects of inosine on neuronal apoptosis and expression of cytochrome C mRNA in rats after focal cerebral ischemia/reperfusion,and analyze the pathway of its neuroprotective effect.DESIGN: A randomised controlled animal trial.SETTINGS: Department of Neurology,Rongcheng Second People's Hospital;Department of Neruology,Affiliated Union Hospital,Tongji Medical College,Huazhong University of Science and Technology.MATERIALS: Sixty-eight rats,weighing 230-280 g and clean grade,were used.TdT-mediated dUTP-biotin nick end labeling(TUNEL)and cytochrome C mRNA in situ hybridization kits and DAB staining kit were purchased from Wuhan Boster Biological Co.,Ltd;Inosine injection[200mg(2ml)each] from Qingdao First Pharmaceutical Factory.METHODS:The experiment was accomplished in the animal experimental center in Tongji Medical College of Huazhong University of Science and Technology from December 2003 to June 2005.①Sixty-four rats were made into focal ischemia by middle cerebral artery occlusion(MCAO)with a nylon monofilament suture.The successfully induced rats were assigned to inosine group(n=32)and model group(n=32)at random.Rats in the inosine group were intraperitoneally administrated with inosine in dose of 100mg/kg preoperatively.twice a day,7 days in all.The rats in the control group were injected with the same dose of saline solution by the similar way preoperatively.Each group was randomized into ischemia/reperfusion 2,6,12,24 hours,2,3,7 and 14 days subgroups consisted of 4 rats.The other 4 rats were taken as the sham-operated group,the rats were given the same treatment except for not introduced the filament into the external carotid artery stump.and brain tissue was removed at 2 hours of reperfusion. ②In situ hybridization was performed to examine the expression of cytochrome C mRNA while TUNEL staining was made to characterize apoptosis.③The t test was used to compare the difference of measurement data.MAIN OUTCOME MEASURES:①Neuronal apoptosis in the different regions of the ischemic brain tissue;②Expression of cytochrome C mRNA in the different regions at different time points after MCAO.RESULTS:All the 68 rats were involved in the analysis of results.①Neuronal apoptosis:A small number of TUNEL-positive cells were detected in the sham-operated brain and non-ischemic brain.The number of apoptotic cells in the ischemic cortex peaked at 24 hours of reperfusion[(72.00±1.98)cells]and that in the striatum peaked at 2 days[(94.75±3.57)cells],then decreased to the level of sham-operated group at 14 days.Inosine could reduce apoptotic cells from 12 hours to 7 days of reperfusion as compared with the model group (t:6.19-26.67,P＜0.01).②Cytochrome C mRNA expression:There was weak expression of cytochrome C mRNA in both sham-operated brain and contralateral brain. Cytochrome C was detected at 2 hours of reperfusion in ischemic brain[(25.75±3.50),(39.75±2.49)cells],and strongly increased to a peak at 12 hours and 24 hours of reperfusion in cortex and striatum[(122.50±6.69), (119.25±5.12)cells], respectively.Furthermore,inosine could significantly decrease cytochrome C expression in cortex at 12 hours to 14 days of reperfusion after ischemic reperfusion and that in striatum at 12 hours to 3 days(t=8.67-43.26,P＜0.01).CONCLUSION:Inosine can exert a neuroprotective effect by inhibiting apoptosis and cytochrome C mRNA expression.

Effects of propofol on amino acid neurotransmitter levels and neuronal apoptosis in the hippocampus in a rat model of ischemia/reperfusion injury

BACKGROUND: Excitatory amino acids including glutamic acid and aspartic acid play a neurotrophic role during early development of the central nervous system but go on to promote toxic effects. Inhibitory amino acids include γ-aminobutyric acid and glycine. Changes in their concentration can reflect the degree of injury to brain tissue after cerebral infarction. OBJECTIVE: To investigate the effects of propofol on amino acid neurotransmitter levels and neuronal apoptosis in the hippocampus in a rat model of ischemia/reperfusion injury. DESIGN: Randomized controlled animal study. MATERIALS: Sixty male Wistar rats were randomly divided into a sham operation group, model group and propofol (50, 100 and 150 mg/kg) groups (n = 12). METHODS: Global brain models of ischemia/reperfusion injury were established in the model group and the propofol groups. The vertebral artery and common carotid artery were merely isolated in the sham operation group. Ten minutes before ischemia, rats in the propofol groups were induced with an intraperitoneal injection of propofol (50, 100 or 150 mg/kg); rats in the model and sham operation groups were induced with an intraperitoneal injection of saline (5 mL). MAIN OUTCOME MEASURES: Content of amino acids, neuronal apoptotic index and density of apoptotic neurons in the hippocampal CA1 region. RESULTS: After a 10-minute ischemia / 60-minute reperfusion, the content of glutamic acid and aspartic acid was significantly decreased in the propofol (50, 100 and 150 mg/kg) groups compared with the model group (P < 0.05 or P < 0.01); but the content of γ-aminobutyric acid was significantly increased in the propofol (100 and 150 mg/kg) groups (P < 0.05). After a 72-hour reperfusion, the neuronal apoptotic index was significantly decreased in the propofol (50, 100 and 150 mg/kg) groups compared with the model group (P < 0.05 or P < 0.01), and the decrease was remarkable in the propofol (100 and 150 mg/kg) groups. After a 72-hour reperfusion, neuronal apoptosis was not observed in the hippocampal CA1 region in the sham operation group, and the density of apoptotic neurons in the propofol (50, 100 and 150 mg/kg) groups showed a significantly dose-dependent decrease in the hippocampal CA1 region compared with the model group (P < 0.01). CONCLUSION: Propofol can protect from brain ischemia/reperfusion injury. This is possibly related to inhibition of excitatory amino acid release, reduction in inhibitory amino acid consumption and decreasing neuronal apoptosis.

MicroRNA-670 aggravates cerebral ischemia/reperfusion injury via the Yap pathway

Apoptosis is an important programmed cell death process involved in ischemia/reperfusion injury.MicroRNAs are considered to play an important role in the molecular mechanism underlying the regulation of cerebral ischemia and reperfusion injury.However,whether miR-670 can regulate cell growth and death in cerebral ischemia/reperfusion and the underlying mechanism are poorly understood.In this study,we established mouse models of transient middle artery occlusion and Neuro 2a cell models of oxygen-glucose deprivation and reoxygenation to investigate the potential molecular mechanism by which miR-670 exhibits its effects during cerebral ischemia/reperfusion injury both in vitro and in vivo.Our results showed that after ischemia/reperfusion injury,miR-670 expression was obviously increased.After miR-670 expression was inhibited with an miR-670 antagomir,cerebral ischemia/reperfusion injury-induced neuronal death was obviously reduced.When miR-670 overexpression was induced by an miR-670 agomir,neuronal apoptosis was increased.In addition,we also found that miR-670 could promote Yap degradation via phosphorylation and worsen neuronal apoptosis and neurological deficits.Inhibition of miR-670 reduced neurological impairments after cerebral ischemia/reperfusion injury.These results suggest that microRNA-670 aggravates cerebral ischemia/reperfusion injury through the Yap pathway,which may be a potential target for treatment of cerebral ischemia/reperfusion injury.The present study was approved by the Institutional Animal Care and Use Committee of China Medical University on February 27,2017(IRB No.2017PS035K).

Effects of L-Tetrahydropalmatine on the Expressions of bcl-2 and bax in Rat after Acute Global Cerebral Ischemia and Reperfusion

To investigate the effects of L-Tetrahydropalmatine (L-THP) on the expressions of bcl-2, bax and neuronal apoptosis after cerebral ischemia and reperfusion, 60 Wistars rats were randomly divided into 3 groups: sham-operation group (group S, n = 20), ischemic-reperfusion group treated with saline (group I, n=20) and ischemia-reperfusion group treated with L-THP (group T, n=20) .The rat model of global cerebral ischemia and reperfusion was induced by Pulsinelli’s four-vessel occlusion method. The expression of bcl-2 and bax mRNA was detected by in situ hybridization and reverse transcriptional polymerase chain reaction (RT-PCR). The number of apoptotic neurons was examined by terminal deoxynucleotidyl-transferase (TdT)-mediated dUTP nick end-labeling (TUNEL) method. Compared with group S, the expression of bcl-2 and bax mRNA in group I was increased significantly (P<0.01), and the number of apoptotic neurons increased either (P< 0.01). After L-THP treatment, the expression of bcl-2 mRNA was up-regulated (P<0.01) and that of bax mRNA was down-regulated (P<0.01); the number of apoptotic neurons was decreased (P<0.01). Our results indicated that bcl-2 may suppress apoptosis and bax promote apoptosis after cerebral ischemia and reperfusion. L-THP could ameliorate cerebral ischemia and reperfusion damage by reducing the apoptosis through regulating bcl-2 and bax.

Let-7a gene knockdown protects against cerebral ischemia/reperfusion injury

The micro RNA(mi RNA) let-7 was one of the first mi RNAs to be discovered, and is highly conserved and widely expressed among species. let-7 expression increases in brain tissue after cerebral ischemia/reperfusion injury; however, no studies have reported let-7 effects on nerve injury after cerebral ischemia/reperfusion injury. To investigate the effects of let-7 gene knockdown on cerebral ischemia/reperfusion injury, we established a rat model of cerebral ischemia/reperfusion injury. Quantitative reverse transcription-polymerase chain reaction demonstrated that 12 hours after cerebral ischemia/reperfusion injury, let-7 expression was up-regulated, peaked at 24 hours, and was still higher than that in control rats after 72 hours. Let-7 gene knockdown in rats suppressed microglial activation and inflammatory factor release, reduced neuronal apoptosis and infarct volume in brain tissue after cerebral ischemia/reperfusion injury. Western blot assays and luciferase assays revealed that mitogen-activated protein kinase phosphatase-1(MKP1) is a direct target of let-7. Let-7 enhanced phosphorylated p38 mitogen-activated protein kinase(MAPK) and c-Jun N-terminal kinase(JNK) expression by down-regulating MKP1. These findings suggest that knockdown of let-7 inhibited the activation of p38 MAPK and JNK signaling pathways by up-regulating MKP1 expression, reduced apoptosis and the inflammatory reaction, and exerted a neuroprotective effect following cerebral ischemia/reperfusion injury.

A protease-activated receptor 1 antagonist protects against global cerebral ischemia/reperfusion injury after asphyxial cardiac arrest in rabbits

Cerebral ischemia/reperfusion injury is partially mediated by thrombin, which causes brain damage through protease-activated receptor 1(PAR1). However, the role and mechanisms underlying the effects of PAR1 activation require further elucidation. Therefore, the present study investigated the effects of the PAR1 antagonist SCH79797 in a rabbit model of global cerebral ischemia induced by cardiac arrest. SCH79797 was intravenously administered 10 minutes after the model was established. Forty-eight hours later, compared with those administered saline, rabbits receiving SCH79797 showed markedly decreased neuronal damage as assessed by serum neuron specific enolase levels and less neurological dysfunction as determined using cerebral performance category scores. Additionally, in the hippocampus, cell apoptosis, polymorphonuclear cell infiltration, and c-Jun levels were decreased, whereas extracellular signal-regulated kinase phosphorylation levels were increased. All of these changes were inhibited by the intravenous administration of the phosphoinositide 3-kinase/Akt pathway inhibitor LY29004(3 mg/kg) 10 minutes before the SCH79797 intervention. These findings suggest that SCH79797 mitigates brain injury via anti-inflammatory and anti-apoptotic effects, possibly by modulating the extracellular signal-regulated kinase, c-Jun N-terminal kinase/c-Jun and phosphoinositide 3-kinase/Akt pathways.

Does closure of acid-sensing ion channels reduce ischemia/reperfusion injury in the rat brain?

Acidosis is a common characteristic of brain damage. Because studies have shown that permeable Ca2+-acid-sensing ion channels can mediate the toxic effects of calcium ions, they have become new targets against pain and various intracranial diseases. However, the mechanism associated with expression of these channels remains unclear. This study sought to observe the expression characteristics of permeable Ca2+-acid-sensing ion channels during different reperfusion inflows in rats after cerebral ischemia. The rat models were randomly divided into three groups: adaptive ischemia/reperfusion group, one-time ischemia/reperfusion group, and severe cerebral ischemic injury group. Western blot assays and immunofluorescence staining results exhibited that when compared with the one-time ischemia/reperfusion group, acid-sensing ion channel 3 and Bcl-x/l expression decreased in the adaptive ischemia/reperfusion group. Calmodulin expression was lowest in the adaptive ischemia/reperfusion group. Following adaptive reperfusion, common carotid artery flow was close to normal, and the pH value improved. Results verified that adaptive reperfusion following cerebral ischemia can suppress acid-sensing ion channel 3 expression, significantly reduce Ca 2+ influx, inhibit calcium overload, and diminish Ca 2+ toxicity. The effects of adaptive ischemia/reperfusion on suppressing cell apoptosis and relieving brain damage were better than that of one-time ischemia/reperfusion.

Effects of Electroacupuncture on Hippocampal and Cortical Apoptosis in A Mouse Model of Cerebral Ischemia-reperfusion Injury

Objective: To observe the effects of electroacupuncture on hippocampal and cortical apoptosis in a mouse model of cerebral ischemia-reperfusion injury. Methods: Mouse models established by repeated cerebral ischemia-reperfusion, followed by electroacupuncture at Shenshu, Geshu, and Baihui points. The control group mice were intragastrically administered Hydergine. On day 1 and 7 post-treatment, hippocampal and cortical apoptosis was detected by terminal-deoxynucleotidyl transferase mediated dUTP nick-end labeling (TUNEL), and apoptosis images in the hippocampal CA1 zone and cortical area were analyzed. Results: In the model group, apoptotic cells were detected one day after treatment and some cellular fibers were disarrayed. By day 7 post-treatment, there was an increase in the number of apoptotic cells in the hippocampal CA1 region. In addition, there were apoptotic cells in the cortical area, the cortical layers were thinner with localized neuronal loss and sieve-like lymphocyte infiltration, as well as glial cell proliferation and visible infarct lesions. However, in the Hydergine and electroacupuncture groups, there was a small number of apoptotic cells. At 7 days post-treatment in the model group, field number, numerical density on area, and surface density were increased. However, in the Hydergine and electroacupuncture groups these parameters were decreased (P<0.01), with a significant difference between the two treatment groups (P<0.01). Conclusion: Electroacupuncture treatment inhibited apoptosis and provided neuroprotection.

七氟醚预处理和后处理对局灶性脑缺血再灌注损伤大鼠神经元坏死性凋亡的影响

目的参照改良Zea-longa线栓法建立局灶性脑缺血再灌注损伤的大鼠模型,观察七氟醚处理对局灶性脑缺血再灌注损伤大鼠神经元的影响,并探讨其作用机制。方法选取成年雄性SD大鼠进行实验,按随机分组原则分为4组:假手术(Sham)组、缺血再灌注(IR)组、七氟醚预处理(Spre)组、七氟醚后处理(Spo)组,每组各10只。造模结束后,采用Longa评分法评测神经行为学;酶联免疫吸附测定(ELISA)法检测大鼠脑组织中超氧化物歧化酶(SOD)活性及丙二醛(MDA)水平;采用Western blotting检测蛋白还原型烟酰胺腺嘌呤二核苷酸磷酸氧化酶4(NOX4)、Caspase3的表达情况;流式细胞术检测细胞凋亡情况。结果相对于Sham组,IR组的神经行为学评分、MDA水平、NOX4、Caspase3的表达、神经元凋亡数明显升高,SOD活性降低,差异有统计学意义(P<0.05);与IR组相比,Spre组和Spo组的神经行为学评分、MDA水平、NOX4、Caspase3的表达、神经元凋亡数明显降低,SOD活性升高,差异均有统计学意义(P<0.05)。结论在局灶性脑缺血再灌注损伤模型大鼠中,七氟醚预处理和后处理对缺血再灌注大鼠脑组织均有一定的保护作用,其保护作用可能通过抑制氧化应激损伤导致的神经元坏死性凋亡来实现的。

巴豆霜干预脑缺血再灌注损伤大鼠皮质区JNK/p38 MAPK及神经元凋亡的机制

背景:巴豆霜能够激活ERK通路、对神经元细胞具有抗凋亡作用,是否具有抑制JNK、p38通路的激活而发挥抗凋亡的协同效应尚不清楚。目的:探讨巴豆霜对脑缺血再灌注损伤大鼠缺血侧皮质区神经元损伤和凋亡的影响及机制。方法:①将90只SD大鼠随机分为假手术组,模型组,巴豆霜低、中、高剂量组,尼莫地平组,每组15只,除假手术组外,剩余各组均采取线栓法制备大脑中动脉栓塞大鼠模型,巴豆霜各组大鼠分别按剂量20,40,60 mg/kg灌胃;假手术组和模型组大鼠给予等量生理盐水,1次/d,连续给药7 d。运用神经功能缺损评分、TTC染色、脑组织含水量、苏木精-伊红染色及尼氏染色筛选出最佳浓度即巴豆霜高剂量。②将120只SD大鼠随机分为假手术组、模型组、巴豆霜组、JNK抑制剂组、巴豆霜+JNK抑制剂组、p38 MAPK抑制剂组、巴豆霜+p38 MAPK抑制剂组和尼莫地平组,每组15只,除假手术组外,剩余各组大鼠均制备大脑中动脉栓塞大鼠模型,在造模之前30 min,将10μL JNK抑制剂SP600125或10μL p38 MAPK抑制剂SB203580分别注射到大鼠侧脑室,巴豆霜各组大鼠灌胃60 mg/kg巴豆霜,7 d后,采用Western Blot、TUNEL染色及流式细胞术检测各组大鼠脑组织JNK/p38 MAPK信号通路及凋亡相关蛋白水平及细胞凋亡情况。结果与结论:①与假手术组相比,模型组神经功能缺损评分、脑含水量、脑梗死体积、细胞凋亡率显著升高(P<0.05),神经细胞呈散乱分布;与模型组相比,巴豆霜中、高剂量组和尼莫地平组大鼠神经功能缺损评分、脑组织含水量、脑梗死体积显著降低(P<0.05),神经细胞病理形态明显改善;②与JNK抑制剂组相比,巴豆霜+抑制剂组大鼠脑组织p-JNK/JNK、p-p38/p38、Bax表达显著降低(P<0.05),细胞凋亡率显著降低(P<0.05),而Bcl-2表达显著升高(P<0.05);③结果提示,巴豆霜可能通过抑制JNK/p38 MAPK信号通路的激活、减少神经元凋亡等途径,达到对脑缺血再灌注损伤大鼠的神经保护作用。

脑缺血再灌注后神经细胞凋亡及针灸干预机制的研究进展

脑缺血再灌注损伤(CIRI)是指在梗死区缺血脑组织的血管重新恢复血流灌注后所产生的一系列级联反应而造成的损害,其症状可较前期加重,表现为脑神经细胞凋亡、坏死或者组织形态学改变等。神经细胞凋亡在CIRI病理过程中发挥关键作用。现通过国内外文献总结了脑缺血再灌注后神经细胞凋亡的相关因素,主要包括兴奋性氨基酸/氧自由基、钙超载、线粒体损伤、凋亡基因、内质网应激、炎症反应。溶栓治疗是目前缺血性脑血管病(IVCD)最有效、最常用的治疗方式,但存在过程复杂化、操作不便利等缺点,而针灸疗法对于IVCD治疗具有操作方便、不良反应少等优点,能很好地弥补溶栓疗法操作复杂、易受时间地点等客观因素限制的不足,有较佳的辅助治疗效果。目前经大量基础研究发现,针灸疗法可介导包括兴奋性氨基酸毒性、钙超载、炎症反应、凋亡基因等方面对神经细胞凋亡进行治疗,但目前在内质网应激、线粒体损伤的针灸疗法研究较少,故加强对于这2个方向的研究可为针灸治疗IVCD取得新的突破。

葛根素对局灶性脑缺血/再灌流大鼠神经细胞凋亡的作用

目的 研究葛根素在局灶性脑缺血 /再灌流过程中对神经细胞凋亡的作用。方法 测定葛根素干预后局灶性脑缺血鼠脑组织中神经细胞凋亡和突触体钙浓度。结果 葛根素有减少突触体钙超载和神经元阳性凋亡细胞出现率的作用。结论 葛根素有一定的抗神经细胞凋亡的作用 。

中药三七对缺血/再灌注损伤的保护作用及应用前景

心肌缺血/再灌注损伤是缺血心肌获得最佳疗效的主要障碍,目前临床中还无有效药物进行预防和治疗。三七是传统的化瘀止痛药物,临床中常用于治疗心绞痛、冠心病等,随着研究的深入,发现三七及其提取物能够调控多种信号通路,对心肌缺血/再灌注损伤产生保护作用,具有较广阔的应用前景。该文综述了近年来三七及其活性成分对心肌缺血/再灌注损伤的治疗作用及作用机制,以期为后期药物开发提供参考。

神经调节素对大鼠脑缺血再灌注损伤细胞凋亡和STAT3及GFAP表达的影响

目的探讨神经调节素-1β(NRG-1β)对大鼠脑缺血再灌注损伤细胞凋亡、信号转导和转录激活因子3(STAT3)及胶质纤维酸性蛋白(GFAP)表达的影响。方法成年雄性Wistar大鼠,用线拴法经颈外-颈内动脉插线建立大脑中动脉闭塞再灌注(MCAO/R)动物模型,经颈内动脉单剂量注射1.5NRG-1β5μl干预治疗。荧光DendEndTUNEL法检测神经细胞凋亡;免疫组织化学和免疫荧光染色检测脑组织STAT3和GFAP表达。结果脑缺血再灌注损伤可诱导脑组织细胞凋亡和STAT3及GFAP表达。对照组随缺血时间延长,皮质、纹状体和海马区细胞凋亡逐渐增多,STAT3和GFAP表达逐渐增强。治疗组在缺血不同时间点细胞凋亡较对照组相应脑区显著减少(P<0.05),STAT3和GFAP表达水平较对照组相应脑区显著增强(P<0.05)。结论NRG-1β可能通过激活细胞JAK/STAT信号传导途径,促进星形细胞胶质化,启动神经细胞抗凋亡机制,对缺血性脑损伤起保护作用。

赤芍801可能通过下调nNOS及iNOS的表达抑制缺血性神经元凋亡

目的研究赤芍801(PG)对大鼠脑缺血/再灌注模型缺血区周边组织神经元凋亡的抑制作用及其可能机制。方法线栓左侧大脑中动脉(MCAO)建立大鼠短暂局灶性脑缺血模型,腹腔内注射PG(23.5,47,94μmol·kg-1)干预,分别于缺血2h再灌注1、2、4、6、12、24h收集脑组织标本,通过Nissl、TUNEL染色法观察模型鼠缺血区周边组织阳性神经元数量;蛋白免疫印迹、免疫组织化学方法检测活化型Caspase3、神经元型一氧化氮合酶(nNOS)、诱导型一氧化氮合酶(iNOS)的表达情况。结果再灌注1、2h时段nNOS表达明显增强;自1h起iNOS开始表达并逐渐增强,以12h较明显;再灌注6h活化型Caspase3开始表达,于12h达到高峰,24h表达减弱;于12h开始出现TUNEL阳性神经元,24h其数量明显增多,自4h起Nissl染色阳性神经元逐渐减少,以24h为著,神经元凋亡率亦于同期达到高峰。PG干预各剂量组,nNOS(1h)、iNOS(12h)及活化型Caspase3(12h)表达均有不同程度减弱,TUNEL阳性神经元数量明显减少(24h),Nissl阳性神经元增多(24h),神经元凋亡率明显降低,以94μmol·kg-1作用为著。结论PG可能通过下调nNOS及iNOS的表达而抑制缺血性神经元凋亡。

黄芪注射液对脑缺血/再灌注大鼠海马神经元Caspase-3表达的影响

目的观察黄芪注射液对脑缺血/再灌注大鼠海马神经元Caspase-3表达的影响。方法将132只♂SD大鼠随机分为4组:假手术组、模型组、黄芪注射液溶剂对照组及黄芪注射液组。采用四血管阻断法建立大鼠脑缺血/再灌注模型[1],于再灌注后0、0.5、2、6、24、72和120 h断头取脑。采用免疫组织化学法、Western blot法检测大鼠海马组织Caspase-3蛋白的表达,实时荧光PCR法检测Caspase-3 mR-NA的表达。结果模型组除0和0.5 h外,其余各个时间点Caspase-3蛋白及mRNA表达均较假手术组增加(P<0.05);与模型组相比,黄芪注射液组除0和0.5 h外其余各个时间点Caspase-3蛋白及mRNA表达均减少(P<0.05),而黄芪注射液溶剂对照组则无明显变化(P>0.05)。结论黄芪注射液能抑制大鼠海马神经元Caspase-3的表达,从而抑制海马神经元的凋亡,保护神经元。

人参皂苷Rg1对大鼠海马神经元缺糖氧／复糖氧后钙内流的影响

目的观察人参皂苷Rg1对大鼠海马神经元缺糖氧／复糖氧后钙内流的影响，并探讨其可能的脑保护机制。方法建立大鼠海马神经元缺糖影复糖氧模型，随机分为正常对照组、模型组和人参皂苷Rg1干预组（5、20、60μmol／L）。复糖氧后24h以Fluo-3 AM荧光染色法观察各组海马神经元细胞内钙离子浓度变化，以Hoechst染色法检测细胞凋亡，并检测细胞四甲基偶氮唑盐（MTT）代谢率。结果与模型组比较，人参皂苷Rg1中、高剂量组海马神经元细胞内钙离子浓度降低，凋亡细胞减少，MTT代谢率升高，人参皂苷Rg1低剂量组变化不明显。结论脑缺血后神经元细胞内钙超载与脑损伤关系密切，人参皂苷Rg1可通过减少缺糖氧神经元细胞内钙内流，发挥脑保护作用。