Oxidized mitochondrial DNA activates the cGAS-STING pathway in the neuronal intrinsic immune system after brain ischemia-reperfusion injury.

In the context of stroke and revascularization therapy, brain ischemia-reperfusion injury is a significant challenge that leads to oxidative stress and inflammation. Central to the cell's intrinsic immunity is the cGAS-STING pathway, which is typically activated by unusual DNA structures. The involvement of oxidized mitochondrial DNA (ox-mtDNA)-an oxidative stress byproduct-in this type of neurological damage has not been fully explored. This study is among the first to examine the effect of ox-mtDNA on the innate immunity of neurons following ischemia-reperfusion injury. Using a rat model of transient middle cerebral artery occlusion and a cellular model of oxygen-glucose deprivation/reoxygenation, we have discovered that ox-mtDNA activates the cGAS-STING pathway in neurons. Importantly, pharmacologically limiting the release of ox-mtDNA into the cytoplasm reduces inflammation and improves neurological functions. Our findings suggest that targeting ox-mtDNA release may be a valuable strategy to attenuate brain ischemia-reperfusion injury following revascularization therapy for acute ischemic stroke.

MircoRNA-29a in Astrocyte-derived Extracellular Vesicles Suppresses Brain Ischemia Reperfusion Injury via TP53INP1 and the NF-κB/NLRP3 Axis.

Brain ischemia reperfusion injury (BIRI) is defined as a series of brain injury accompanied by inflammation and oxidative stress. Astrocyte-derived extracellular vesicles (EVs) are importantly participated in BIRI with involvement of microRNAs (miRs). Our study aimed to discuss the functions of miR-29a from astrocyte-derived EVs in BIRI treatment. Thus, astrocyte-derived EVs were extracted. Oxygen and glucose deprivation (OGD) cell models and BIR rat models were established. Then, cell and rat activities and pyroptosis-related protein levels in these two kinds of models were detected. Functional assays were performed to verify inflammation and oxidative stress. miR-29a expression in OGD cells and BIR rats was measured, and target relation between miR-29a and tumor protein 53-induced nuclear protein 1 (TP53INP1) was certified. Rat neural function was tested. Astrocyte-derived EVs improved miR-29a expression in N9 microglia and rat brains. Astrocyte-derived EVs inhibited OGD-induced injury and inflammation in vitro, reduced brain infarction, and improved BIR rat neural functions in vivo. miR-29a in EVs protected OGD-treated cells and targeted TP53INP1, whose overexpression suppressed the protective function of EVs on OGD-treated cells. miR-29a alleviated OGD and BIRI via downregulating TP53INP1 and the NF-κB/NLRP3 pathway. Briefly, our study demonstrated that miR-29a in astrocyte-derived EVs inhibits BIRI by downregulating TP53INP1 and the NF-κB/NLRP3 axis.

Interruption of Endolysosomal Trafficking After Focal Brain Ischemia.

A typical neuron consists of a soma, a single axon with numerous nerve terminals, and multiple dendritic trunks with numerous branches. Each of the 100 billion neurons in the brain has on average 7,000 synaptic connections to other neurons. The neuronal endolysosomal compartments for the degradation of axonal and dendritic waste are located in the soma region. That means that all autophagosomal and endosomal cargos from 7,000 synaptic connections must be transported to the soma region for degradation. For that reason, neuronal endolysosomal degradation is an extraordinarily demanding and dynamic event, and thus is highly susceptible to many pathological conditions. Dysfunction in the endolysosomal trafficking pathways occurs in virtually all neurodegenerative diseases. Most lysosomal storage disorders (LSDs) with defects in the endolysosomal system preferentially affect the central nervous system (CNS). Recently, significant progress has been made in understanding the role that the endolysosomal trafficking pathways play after brain ischemia. Brain ischemia damages the membrane fusion machinery co-operated by N-ethylmaleimide sensitive factor (NSF), soluble NSF attachment protein (SNAP), and soluble NSF attachment protein receptors (SNAREs), thus interrupting the membrane-to-membrane fusion between the late endosome and terminal lysosome. This interruption obstructs all incoming traffic. Consequently, both the size and number of endolysosomal structures, autophagosomes, early endosomes, and intra-neuronal protein aggregates are increased extensively in post-ischemic neurons. This cascade of events eventually damages the endolysosomal structures to release hydrolases leading to ischemic brain injury. Gene knockout and selective inhibition of key endolysosomal cathepsins protects the brain from ischemic injury. This review aims to provide an update of the current knowledge, future research directions, and the clinical implications regarding the critical role of the neuronal endolysosomal trafficking pathways in ischemic brain injury.

Ginsenoside Rb1 protects brain through Cav-1 for mice with cerebral ischemia-reperfusion injury / 中国临床药理学与治疗学

AIM: To investigate the protective effect of ginsenoside Rb1 on brain through Cav-1 in mice with cerebral ischemia-reperfusion injury. METHODS: One hundred and twenty C57/B6 mice were randomly divided into sham operation group, model group, model + ginsenoside Rb1 group, ginsenoside Rb1+ Cav-1 siRNA group, ginsenoside Rb1+siNC group, 24 in each group. The model of cerebral ischemia-reperfusion injury in mice was established by middle cerebral artery occlusion (MCAO). The ginsenoside Rb1 group received intraperitoneally injection of ginsenoside Rb1 (40 mg/kg); the sham operation group and model group were intraperitoneally injected with an equal amount of physiological saline immediately after modeling. For the ginsenoside Rb1+ cav-1 siRNA group and the ginsenoside Rb1+siNC group, cav-1 siRNA and siNC were injected into the lateral ventricle 24 h before molding, respectively, and the other operations were the same as the ginsenoside Rb1 group. The neurobehavioral scores of the mice in each group were measured at 24 h after reperfusion, and the water content of brain tissue, cerebral infarction volume, Cav-1 mRNA and Cav-1, Bcl-2 and Bax protein expressions in the cerebral cortex penumbra were measured in each group. RESULTS:Compared with the sham operation group, the neurobehavioral scores, cerebral infarction volume and brain tissue water content in the model group were significantly increased (P<0.05), and the expressions of Cav-1 mRNA and Cav-1 protein, and the Bcl-2 /Bax ratio were significantly decreased (P<0.05). Compared with the model group, the neurobehavioral scores, cerebral infarction volume and brain tissue water content in the ginsenoside Rb1 group were significantly decreased, and the expressions of Cav-1 mRNA and Cav-1 protein, and the Bcl-2 /Bax ratio were significantly increased (P<0.05). Compared with the ginsenoside Rb1 group, the neurobehavioral scores, cerebral infarction volume and brain tissue water content in the ginsenoside Rb1 + cav-1 siRNA group were significantly increased, and the expressions of Cav-1 mRNA and Cav-1 protein, and the Bcl-2 /Bax ratio were significantly decreased (P<0.05). CONCLUSION: Ginsenoside Rb1 can protects brain for mice with cerebral ischemia-reperfusion injury. After Cav-1 siRNA decreased the expression of Cav-1 protein in the brain tissue of mice, it significantly reverses the cerebral protective effect of ginsenoside Rb1, indicating that Cav-1 protein mediated the cerebral protective effect of ginsenoside Rb1 on cerebral ischemia reperfusion injury mice.

Combined Ischemic Preconditioning and Resveratrol Improved Bloodbrain Barrier Breakdown via Hippo/YAP/TAZ Signaling Pathway.

BACKGROUND: Transient Ischemia/Reperfusion (I/R) is the main reason for brain injury and results in disruption of the Blood-Brain Barrier (BBB). It had been reported that BBB injury is one of the main risk factors for early death in patients with cerebral ischemia. Numerous investigations focus on the study of BBB injury which have been carried out. OBJECTIVE: The objective of this study was to investigate the treatment function of the activation of the Hippo/Yes-Associated Protein (YAP) signaling pathway by combined Ischemic Preconditioning (IPC) and resveratrol (RES) before brain Ischemia/Reperfusion (BI/R) improves Blood-Brain Barrier (BBB) disruption in rats. METHODS: Sprague-Dawley (SD) rats were pretreated with 20 mg/kg RES and IPC and then subjected to 2 h of ischemia and 22 h of reperfusion. The cerebral tissues were collected; the cerebral infarct volume was determined; the Evans Blue (EB) level, the brain Water Content (BWC), and apoptosis were assessed; and the expressions of YAP and TAZ were investigated in cerebral tissues. RESULTS: Both IPC and RES preconditioning reduced the cerebral infarct size, improved BBB permeability, lessened apoptosis, and upregulated expressions of YAP and transcriptional co-activator with PDZ-binding motif (TAZ) compared to the Ischemia/Reperfusion (I/R) group, while combined IPC and RES significantly enhanced this action. CONCLUSION: combined ischemic preconditioning and resveratrol improved blood-brain barrier breakdown via Hippo/YAP/TAZ signaling pathway.

Inactivation of NSF ATPase Leads to Cathepsin B Release After Transient Cerebral Ischemia.

Neurons have extraordinary large cell membrane surface area, thus requiring extremely high levels of intracellular membrane-trafficking activities. Consequently, defects in the membrane-trafficking activities preferentially affect neurons. A critical molecule for controlling the membrane-trafficking activities is the N-ethylmaleimide-sensitive factor (NSF) ATPase. This study is to investigate the cascade of events of NSF ATPase inactivation, resulting in a massive buildup of late endosomes (LEs) and fatal release of cathepsin B (CTSB) after transient cerebral ischemia using the 2-vessel occlusion with hypotension (2VO+Hypotension) global brain ischemia model. Rats were subjected to 20 min of transient cerebral ischemia followed by 0.5, 4, 24, and 72 h of reperfusion. Neuronal histopathology and ultrastructure were examined by the light and electron microscopy, respectively. Western blotting and confocal microscopy were utilized for analyzing the levels, redistribution, and co-localization of Golgi apparatus and endosome or lysosome markers. Transient cerebral ischemia leads to delayed neuronal death that occurs at 48-72 h of reperfusion mainly in hippocampal CA1 and neocortical (Cx) layers 3 and 5 pyramidal neurons. During the delayed period, NSF ATPase is irreversibly trapped into inactive protein aggregates selectively in post-ischemic neurons destined to die. NSF inactivation leads to a massive buildup of Golgi fragments, transport vesicles (TVs) and late endosomes (LEs), and release of the 33 kDa LE type of CTSB, which is followed by delayed neuronal death after transient cerebral ischemia. The results support a novel hypothesis that transient cerebral ischemia leads to NSF inactivation, resulting in a cascade of events of fatal release of CTSB and delayed neuronal death after transient cerebral ischemia.

Dysfunction of Membrane Trafficking Leads to Ischemia-Reperfusion Injury After Transient Cerebral Ischemia.

Neurons require an extraordinarily high level of membrane trafficking activities because of enriched axonal terminals and dendritic branches. For that reason, defects in the membrane trafficking pathway are a hallmark of most, and may be all, neurodegenerative disorders. A major cellular membrane trafficking pathway is the Golgi apparatus (Golgi hereafter)-late endosome-lysosome axis for supplying lysosomal enzymes. This pathway is regulated by N-ethylmaleimide-sensitive factor (NSF) ATPase. This review article is to discuss a novel hypothesis that brain ischemia inactivates NSF ATPase, resulting in a cascade of events of disruption of the Golgi-endosome-lysosome pathway, release of cathepsin B (CTSB), and induction of mitochondrial outer membrane permeabilization (MOMP) during the postischemic phase. This hypothesis is supported by recent studies demonstrating that NSF is trapped into inactive protein aggregates in neurons destined to die after brain ischemia. Consequently, Golgi, transport vesicles (TVs), and late endosomes (LEs) are accumulated and damaged, which is followed by CTSB release from these damaged structures. Moderate release of CTSB cleaves Bax-like BH3 protein (Bid) to become active truncated Bid (tBid). Active tBid is then translocated to the mitochondrial outer membrane, resulting in oligomerization of BCL2-associated X protein (Bax) forming the mitochondrial outer membrane pores, and releasing mitochondrial intramembranous proteins. Extensive CTSB release, however, can digest cellular proteins indiscriminately to induce cell death. Based on these new observations, we propose a novel hypothesis, i.e., brain ischemia leads to NSF inactivation, resulting in a massive buildup of damaged Golgi, TVs and LEs, fatal release of CTSB, induction of MOMP, and eventually brain ischemia-reperfusion injury.

Endothelial Cell-Derived von Willebrand Factor Is the Major Determinant That Mediates von Willebrand Factor-Dependent Acute Ischemic Stroke by Promoting Postischemic Thrombo-Inflammation.

OBJECTIVE: von Willebrand factor (VWF), which is synthesized in endothelial cells and megakaryocytes, is known to worsen stroke outcome. In vitro studies suggest that platelet-derived VWF (Plt-VWF) is biochemically different from the endothelial cell-derived VWF (EC-VWF). However, little is known about relative contribution of different pools of VWF in stroke. APPROACH AND RESULTS: Using bone marrow transplantation, we generated chimeric Plt-VWF mice, Plt-VWF mice that lack ADAMTS13 in platelets and plasma (Plt-VWF/Adamts13(-/-)), and EC-VWF mice to determine relative contribution of different pools of VWF in stroke. In brain ischemia/reperfusion injury model, we found that infarct size and postischemic intracerebral thrombo-inflammation (fibrin(ogen) deposition, neutrophil infiltration, interleukin-1ß, and tumor necrosis factor-α levels) within lesions were comparable between EC-VWF and wild-type mice. Infarct size and postischemic thrombo-inflammation were comparable between Plt-VWF and Plt-VWF/Adamts13(-/-) mice, but decreased compared with EC-VWF and wild-type mice (P<0.05) and increased compared with Vwf(-/-) mice (P<0.05). Susceptibility to FeCl3 injury-induced carotid artery thrombosis was comparable between wild-type and EC-VWF mice, whereas Plt-VWF and Plt-VWF/Adamts13(-/-) mice exhibited defective thrombosis. Although most of the injured vessels did not occlude, slope over time showed that thrombus growth rate was increased in both Plt-VWF and Plt-VWF/Adamts13(-/-) mice compared with Vwf(-/-) mice (P<0.05), but decreased compared with wild-type or EC-VWF mice. CONCLUSIONS: Plt-VWF, either in presence or absence of ADAMTS13, partially contributes to VWF-dependent injury and postischemic thrombo-inflammation after stroke. EC-VWF is the major determinant that mediates VWF-dependent ischemic stroke by promoting postischemic thrombo-inflammation.

Look into brain energy crisis and membrane pathophysiology in ischemia and reperfusion.

In an ischemic environment, brain tissue responds to oxygen deprivation with the initiation of rapid changes in bioenergetic metabolism to ensure ion and metabolic homeostasis. At the same time, the accelerated cleavage of membrane phospholipids changes membrane composition and increases free fatty acid concentration. Phospholipid breakdown also generates specific messengers that participate in signaling cascades that can either promote neuronal protection or cause injury. The net impact of signaling events affects the final outcome of the stroke. While reoxygenation is a life-saving intervention, it can exacerbate brain damage. Although compromised energy metabolism is restored shortly after reperfusion, alterations in membrane phospholipid composition with subsequent accumulation of lipid oxoderivates are neurotoxic, causing oxidative stress and ischemia-reperfusion (IR) injury. Thus, plasma and mitochondrial membranes are the first responders as well as mediators of IR-induced stress signals. In this review, we focus on ischemia-induced changes in brain energy metabolism and membrane functions as the causal agents of cell stress responses upon reoxygenation. The first part of the review deals with the specificities of neuronal bioenergetics during IR and their impact on metabolic processes. The second part is concentrated on involvement of both plasma and mitochondrial membranes in the production of messengers which can modulate neuroprotective pathways or participate in oxidative/electrophilic stress responses. Although the etiology of IR injury is multifactorial, deciphering the role of membrane and membrane-associated processes in brain damage will uncover new therapeutic agents with the ability to stabilize neuronal membranes and modulate their responses in favor of prosurvival pathways.

Co-ultramicronized Palmitoylethanolamide/Luteolin in the Treatment of Cerebral Ischemia: from Rodent to Man.

Acute ischemic stroke, the most frequent cause of permanent disability in adults worldwide, results from transient or permanent reduction in regional cerebral blood flow and involves oxidative stress and inflammation. Despite the success of experimental animal models of stroke in identifying anti-inflammatory/neuroprotective compounds, translation of these putative neuroprotectants to human clinical trials has failed to produce a positive outcome. Tissue injury and stress activate endogenous mechanisms which function to restore homeostatic balance and prevent further damage by upregulating the synthesis of lipid signaling molecules, including N-palmitoylethanolamine (PEA or palmitoylethanolamide). PEA exerts neuroprotection and reduces inflammatory secondary events associated with brain ischemia reperfusion injury (middle cerebral artery occlusion (MCAo)). Here, we examined the neuroprotective potential of a co-ultramicronized composite containing PEA and the antioxidant flavonoid luteolin (10:1 by mass), nominated co-ultraPEALut. The study consisted of two arms. In the first, rats subjected to MCAo and treated with co-ultraPEALut post-ischemia showed reduced edema and brain infract volume, improved neurobehavioral functions, and reduced expression of pro-inflammatory markers and astrocyte markers. In the second arm, a cohort of 250 stroke patients undergoing neurorehabilitation on either an inpatient or outpatient basis were treated for 60 days with a pharmaceutical preparation of co-ultraPEALut (Glialia). At baseline and after 30 days of treatment, all patients underwent a battery of evaluations to assess neurological status, impairment of cognitive abilities, the degree of spasticity, pain, and independence in daily living activities. All indices showed statistically significant gains at study end. Despite its observational nature, this represents the first description of co-ultraPEALut administration to human stroke patients and clinical improvement not otherwise expected from spontaneous recovery. Further, controlled trials are warranted to confirm the utility of co-ultraPEALut to improve clinical outcome in human stroke.

The role of high mobility group protein 1 mediated the endoplasmic reticulum stress in cerebral ischemia/reperfusion injury / 中华危重病急救医学

Objective To explore the mechanism of high mobility group protein 1 (HMGB1) involved in endoplasmic reticulum stress (ERS) induced by brain ischemia/reperfusion (I/R),based on I/R-HMGB1-ERS as the breakthrough point.Methods The brain of rats birthed 1-3 days was harvested,and the brain cells were cultured in vitro,which were used in the experiment when the cells were in the third passage.The cells were divided into two groups:cells in blank control group were cultured under the normal conditions without any treatment,and the cells in hypoxia/reoxygenation group were cultured with 99.9％ nitrogen for 60 minutes (hypoxia) followed by opening the bottle neck for reoxygenation 120 minutes to simulate I/R model.The HMGB1 gene was silenced by using small interfering RNA (siRNA,siRNA and transfection reagent Lipofectamine 2000 mixture gradient was transfected into the cultured cells) as HMGB1-siRNA transfection group,and blank control (without any treatment) and negative control group (transfected with control siRNA) served as controls.The mRNA and protein expressions of HMGB1 and ERS related molecules were determined by real-time reverse transcription-polymerase chain reaction (RT-PCR) and Western Blot.Results ① In cells of hypoxia/reoxygenation group,the mRNA and protein expressions of HMGB1 and ESR related proteins,including glucose regulating protein 78 (GRP78),C/EBP homologous protein (CHOP) and caspase-12,were significantly higher than those of blank control group with statistical difference (the value in blank control group was served as baseline 1,HMGB1 mRNA:3.19±0.48 vs.1,t =2.183,P =0.008;GRP78 mRNA:2.07±0.33 vs.1,t =3.292,P =0.016;CHOP mRNA:1.93±0.28 vs.1,t =2.573,P =0.021;caspase-12 mRNA:2.42±0.42 vs.1,t =2.261,P =0.027:HMGB1 protein:2.28±0.36 vs.1,t =2.042,P =0.009;GRP78 protein:1.33±0.24 vs.1,t =2.781,P =0.016;CHOP protein:1.67±0.34 vs.1,t =2.174,P =0.021;easpase-12 protein:1.36±0.44 vs.1,t =3.192,P =0.008).It was indicated that ERS related molecules involved in cell hypoxia/reoxygenation process.2② After HMGB1 gene was silenced by siRNA,the cells after hypoxia/reoxygenation showed a decrease in the mRNA and protein expressions of HMGB1 and ERS related moleculars as compared with those of blank control group and negative control group (served the value in blank control group as baseline 1,HMGB1 mRNA:0.27±0.12 vs.1,1.02 ± 0.04;GRP78 mRNA:0.16 ± 0.13 vs.1,0.96 ± 0.04;CHOP mRNA:0.47 ± 0.09 vs.1,0.98 ± 0.07;caspase-12 mRNA:0.31 ±0.11 vs.1,1.05±0.02;HMGBI protein:0.23±0.04 vs.1,1.08±0.01;GRP78 protein:0.14±0.09 vs.1,1.35±0.03;CHOP protein:0.32±0.10 vs.1,0.93±0.06;caspase-12 protein:0.27±0.09 vs.1,0.97±0.08;P ＜ 0.05 or P ＜ 0.01).It was indicated that HMGB1 involved in ERS related with GPR7,CHOP,caspase-12.Conclusion Hypoxia/reoxygenation brain intracellular HMGB1 and ERS related molecules expression levels were significantly up-regulated,and silencing HMGB1 gene can significantly inhibit the expression levels of these molecules,and I/R-HMGB 1-ERS pathway may participate in the mechanism of brain I/R injury.

Protection and mechanism of effective fraction from Buyang Huanwu Decoction on focal cerebral ischemia-reperfusion injury in rats / 中草药

Objective: To study the protection and mechanisms of effective fraction from Buyang Huanwu Decoction (EFBHD) on rat brain after cerebral ischemia-reperfusion injury. Methods: Rat model of cerebral ischemia-reperfusion injury was created by the middle cerebral artery occlusion (MCAO) by modified suture method. Healthy male SD rats were randomly divided into six groups: Sham-operated group, model group, high-, middle-, and low-dose (200, 100, and 50 mg/kg) of EFBHD groups, and positive control group (treated with EGB 100 mg/kg). The neurological deficit symptom scores were observed and the infarct volume was measured by triphenyltetrazolium chloride (TTC) staining in 24 h after the cerebral ischemia. The contents of TNF-α, IL-1β, and IL-6 in serum were measured by enzyme-linked immunosorbent assay (ELISA) methods. In addition, the activity of LDH and MDA content in serum were determined by abdominal arterial blood and centrifuged. Results: Compared with the model group, EFBHD could significantly improve the neruological dysfuction, decrease the cerebral infarct volume, and inhibit the activity of LDH, and reduce the contents of MDA, TNF-α, IL-1β, and IL-6 in serum (P<0.01, 0.05). Conclusion: EFBHD has significant protection on cerebral ischemia-reperfusion injury in rats, which may be related to the inhibition of inflammatory cytokine secretion and expression and inducing the inflammation in brain tissue.

Involvement of Glutamate transporter-1 in neuroprotection against global brain ischemia-reperfusion injury induced by postconditioning in rats.

Ischemic postconditioning refers to several transient reperfusion and ischemia cycles after an ischemic event and before a long duration of reperfusion. The procedure produces neuroprotective effects. The mechanisms underlying these neuroprotective effects are poorly understood. In this study, we found that most neurons in the CA1 region died after 10 minutes of ischemia and is followed by 72 hours of reperfusion. However, brain ischemic postconditioning (six cycles of 10 s/10 s reperfusion/re-occlusion) significantly reduced neuronal death. Significant up-regulation of Glutamate transporter-1 was found after 3, 6, 24, 72 hours of reperfusion. The present study showed that ischemic postconditioning decreases cell death and that upregulation of GLT-1 expression may play an important role on this effect.

Combination of taurine and diazepam has neuroprotective effect on focal cerebral ischemia-reperfusion in rats / 中国病理生理杂志

AIM: To observe the neuroprotective effect of combined treatment with taurine and diazepam against focal cerebral ischemia-reperfusion in rats. METHODS: Sixty male Sprague-Dawley rats were randomly divided into five groups: sham-operation group, vehicle group, taurine group (200 mg/kg, ip), diazepam group (10 mg/kg, ip) and combined treatment group (taurine 100 mg/kg+diazepam 5 mg/kg). Focal cerebral ischemia was induced by the method of middle cerebral artery occlusion (MCAO) in rats, and reperfusion was emerged by removing the thread 2 h later. The drugs were administered respectively at the time of reperfusion, and subsequently repeated once 12 h later. The animals in vehicle group were intraperitoneally injected with isodose normal saline. The neurological deficit score, the brain water content and cerebral infarction were measured 48 h after MCAO. Other 5 group animals of focal cerebral ischemia-reperfusion (n=16 in each group) were set up as mentioned above and accepted treatments 10 h after reperfusion, likewise repeated once 12 h later. Twelve animals in each group were adopted the same management as the previous 5 groups at 48 h after MCAO. The remained 4 animals in each group were sacrificed until two weeks after MCAO to observe the histopathological changes by nissl staining. RESULTS: Compared to vehicle group, the animals in combined treatment group at 2 h or 12 h after MCAO both decreased the neurological deficit score, reduced the brain water content and infarct volume (P<0.01 or P<0.05). The combined treatment significantly alleviated the neurological necrosis as well. The neuroprotective effect of the combined treatment was superior to that of using taurine or diazepam alone. CONCLUSION: These results suggest that combination of taurine and diazepam treatment has a coordinate neuroprotective effect on both the acute and chronic brain damage of focal cerebral ischemia-reperfusion.

Effects of Angelica sinensis on the expression of vascular endothelial growth factor after the brain ischemia-reperfusion injury in rats / 中国康复理论与实践

@#ObjectiveTo investigate the effects of Angelica sinensis on the expression of vascular endothelial growth factor (VEGF) Flt-1, Flk-1 mRNA after the brain ischemia-reperfusion injury in rats.MethodsWistar rats were randomly divided into the group A, group B and normal control group. The group A underwent middle cerebral artery occlusion (MCAO) for 2h by suture, group B underwent MCAO for 2h meanwhile received treatment with Angelica sinensis (5 g/kg). Immunohistochemistry and quantitative reverse transcription and polymerase chain reaction (RT-PCR) technique were used to examine the gene expression of VEGF.ResultsThe result of immunohistry revealed that VEGF in the group A and group B reached its peak at 24 h after reperfusion then declined gradually. The result of RT-PCR manifested that the gene expression of VEGF in the group A increased from 3 h after reperfusion and reached its peak at 6 h; in the group B reached its peak on the 3rd day. The expression of VEGF in the group B was significantly increased than group A at the same time point.ConclusionAngelica sinensis can enhance the expression of Flt-1, Flk-1 after transient interruption of cerebral blood flow in rats.

Effects of amitriptyline on monoamines of brain tissue in rats with focal cerebral ischemia-reperfusion injury / 中国药理学通报

Aim To study the effects of amitriptyline(Ami)on focal cerebral ischemia-reperfusion injury in rats.Methods An animal model of focal cerebral ischemia-reperfusion injury was induced by the middle cerebral artery occlusion(MCAO) by reversibly inserting a nylon thread method.The rats were decapitated after ischemia for 1 hour and reperfusion for 2 hours.The infarct volumes were determined using a 2,3,5-tri-phenyl tetrazolium chloride(TTC) staining and assessed by image analysis system.The neurologic deficit status were evaluated on 0~5 grade scale.The levels of dopamine(DA),norepinephrine(NE),serotonin(5-HT) and its metabolic product~hydroxyindole acetic acid(5-HIAA) in cortex and striatum were measured by fluoro-spectrophotometry.Results Ami treatment exhibited a remarkable reduction in infarct volume and neurologic deficit scores.The monoamines content of cortex and striatum had a significant increase compared with ischemia-reperfusion group.Conclusion Amitriptyline has protective effect on cerebral ischemia-reperfusion injury in rats.The mechanism might be related to reducing the release of NE,DA and 5-HT during cerebral ischemia-reperfusion,attenuating or inhibiting of the neurotoxic effects of monoamine neurotransmitters.