A matrix metalloproteinase-responsive hydrogel system controls angiogenic peptide release for repair of cerebral ischemia/reperfusion injury

Vascular endothelial growth factor and its mimic peptide KLTWQELYQLKYKGI(QK)are widely used as the most potent angiogenic factors for the treatment of multiple ischemic diseases.However,conventional topical drug delivery often results in a burst release of the drug,leading to transient retention(inefficacy)and undesirable diffusion(toxicity)in vivo.Therefore,a drug delivery system that responds to changes in the microenvironment of tissue regeneration and controls vascular endothelial growth factor release is crucial to improve the treatment of ischemic stroke.Matrix metalloproteinase-2(MMP-2)is gradually upregulated after cerebral ischemia.Herein,vascular endothelial growth factor mimic peptide QK was self-assembled with MMP-2-cleaved peptide PLGLAG(TIMP)and customizable peptide amphiphilic(PA)molecules to construct nanofiber hydrogel PA-TIMP-QK.PA-TIMP-QK was found to control the delivery of QK by MMP-2 upregulation after cerebral ischemia/reperfusion and had a similar biological activity with vascular endothelial growth factor in vitro.The results indicated that PA-TIMP-QK promoted neuronal survival,restored local blood circulation,reduced blood-brain barrier permeability,and restored motor function.These findings suggest that the self-assembling nanofiber hydrogel PA-TIMP-QK may provide an intelligent drug delivery system that responds to the microenvironment and promotes regeneration and repair after cerebral ischemia/reperfusion injury.

Endoplasmic reticulum stress and autophagy in cerebral ischemia/reperfusion injury:PERK as a potential target for intervention

Several studies have shown that activation of unfolded protein response and endoplasmic reticulum(ER)stress plays a crucial role in severe cerebral ischemia/reperfusion injury.Autophagy occurs within hours after cerebral ischemia,but the relationship between ER stress and autophagy remains unclear.In this study,we established experimental models using oxygen-glucose deprivation/reoxygenation in PC12 cells and primary neurons to simulate cerebral ischemia/reperfusion injury.We found that prolongation of oxygen-glucose deprivation activated the ER stress pathway protein kinase-like endoplasmic reticulum kinase(PERK)/eukaryotic translation initiation factor 2 subunit alpha(e IF2α)-activating transcription factor 4(ATF4)-C/EBP homologous protein(CHOP),increased neuronal apoptosis,and induced autophagy.Furthermore,inhibition of ER stress using inhibitors or by si RNA knockdown of the PERK gene significantly attenuated excessive autophagy and neuronal apoptosis,indicating an interaction between autophagy and ER stress and suggesting PERK as an essential target for regulating autophagy.Blocking autophagy with chloroquine exacerbated ER stress-induced apoptosis,indicating that normal levels of autophagy play a protective role in neuronal injury following cerebral ischemia/reperfusion injury.Findings from this study indicate that cerebral ischemia/reperfusion injury can trigger neuronal ER stress and promote autophagy,and suggest that PERK is a possible target for inhibiting excessive autophagy in cerebral ischemia/reperfusion injury.

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.

Cav3.2 channel regulates cerebral ischemia/reperfusion injury:a promising target for intervention

Calcium influx into neurons triggers neuronal death during cerebral ischemia/reperfusion injury.Various calcium channels are involved in cerebral ischemia/reperfusion injury.Cav3.2 channel is a main subtype of T-type calcium channels.T-type calcium channel blockers,such as pimozide and mibefradil,have been shown to prevent cerebral ischemia/reperfusion injury-induced brain injury.However,the role of Cav3.2 channels in cerebral ischemia/reperfusion injury remains unclear.Here,in vitro and in vivo models of cerebral ischemia/reperfusion injury were established using middle cerebral artery occlusion in mice and high glucose hypoxia/reoxygenation exposure in primary hippocampal neurons.The results showed that Cav3.2 expression was significantly upregulated in injured hippocampal tissue and primary hippocampal neurons.We further established a Cav3.2 gene-knockout mouse model of cerebral ischemia/reperfusion injury.Cav3.2 knockout markedly reduced infarct volume and brain water content,and alleviated neurological dysfunction after cerebral ischemia/reperfusion injury.Additionally,Cav3.2 knockout attenuated cerebral ischemia/reperfusion injury-induced oxidative stress,inflammatory response,and neuronal apoptosis.In the hippocampus of Cav3.2-knockout mice,calcineurin overexpression offset the beneficial effect of Cav3.2 knockout after cerebral ischemia/reperfusion injury.These findings suggest that the neuroprotective function of Cav3.2 knockout is mediated by calcineurin/nuclear factor of activated T cells 3 signaling.Findings from this study suggest that Cav3.2 could be a promising target for treatment of cerebral ischemia/reperfusion injury.

Lactiplantibacillus plantarum AR113 alleviates microbiota dysbiosis of tongue coating and cerebral ischemia/reperfusion injury in rat

Stroke is one of the leading causes of death and disability worldwide.However,information on stroke-related tongue coating microbiome(TCM)is limited,and whether TCM modulation could benefit for stroke prevention and rehabilitation is unknown.Here,TCM from stroke patients(SP)was characterized using molecular techniques.The occurrence of stroke resulted in TCM dysbiosis with significantly reduced species richness and diversity.The abundance of Prevotella,Leptotrichia,Actinomyces,Alloprevotella,Haemophilus,and TM7_[G-1]were greatly reduced,but common infection Streptococcus and Pseudomonas were remarkably increased.Furthermore,an antioxidative probiotic Lactiplantibacillus plantarum AR113 was used for TCM intervention in stroke rats with cerebral ischemia/reperfusion(I/R).AR113 partly restored I/R induced change of TCM and gut microbiota with significantly improved neurological deficit,relieved histopathologic change,increased activities of antioxidant enzymes,and decreased contents of oxidative stress biomarkers.Moreover,the gene expression of antioxidant-related proteins and apoptosis-related factors heme oxygenase-1(HO-1),superoxide dismutase(SOD),glutathione peroxidase(GSH-Px),nuclear factor erythroid 2-related factor 2(Nrf2),NAD(P)H:quinone oxidoreductase-1(NQO-1),and Bcl-2 was significantly increased,but cytochrome C,cleaved caspase-3,and Bax were markedly decreased in the brain by AR113 treatment.The results suggested that AR113 could ameliorate cerebral I/R injury through antioxidation and anti-apoptosis pathways,and AR113 intervention of TCM may have the application potential for stroke prevention and control.

Investigation multi-target synergistic mechanism of Choerospondias axillaris in the treat of cerebral ischemia based on systems pharmacology and experimental verification

Background:Choerospondias axillaris(CA)is a traditional Mongolian medicine that has been proven to have a good therapeutic effect on cerebrovascular disease.Cerebral Ischemia(CI)is a severe and life-threatening cerebrovascular disease.However,the specific mechanism of action of CA in the treatment of CI is still unclear.Methods:In this study,the related targets and pathways of CA in the treatment of CI were first predicted by system pharmacology and then verified by relevant experiments.Results:The results showed that 12 active ingredients and 208 targets were selected.Further validation through protein-protein interaction(PPI)network analysis and active ingredients-target-pathway(A-T-P)network analysis has confirmed the pivotal roles of the main bioactive constituents,including quercetin,kaempferol,naringin,β-sitosterol,and gallic acid.These components exert their anti-ischemic effects by modulating key targets such as IL6,TNF,MAPK3,and CASP3,thereby regulating the PI3K-Akt,HIF-1,and MAPK signaling pathways,which are integral to processes like inflammation,apoptosis,and oxidative stress.More importantly,through experimental verification,this study confirmed our prediction that CAE significantly reduced neurological function scores,infarct volume,and the percentage of apoptosis neurons.Conclusion:This indicates that CA acts on CI through multi-target synergistic mechanism,and this study provides theoretical basis for the clinical application of CA.

Pinacidil reduces neuronal apoptosis following cerebral ischemia-reperfusion in rats through both mitochondrial and death-receptor signal pathways

Objective To investigate effect of pinacidil, an ATP sensitive potassium channel （KATP） opener, on the neuronal apoptosis and its signaling transduction mechanism following focal cerebral ischemia-reperfusion in rats. Methods One hundred male Wistar rats were randomly divided into four groups： A, sham-operated group; B, ischemia-reperfusion group; C, KATe opener treatment group; and D, KATe opener and blocker treatment group. The middle cerebral artery occlusion （MCAO） model was established by using the intraluminal suture occlusion method, neuronal apoptosis was determined by TUNEL staining, and expressions of caspase-8, caspase-9 and caspase-3 mRNA were detected by in situ hybridization. Results （1） The numbers of apoptotic neurons at 12 h, 24 h, 48 h, and 72 h were significantly less in group C than in groups B and D （P 〈 0.01 or P 〈 0.05）; and there was no difference between groups B and D at all time points （P 〉 0.05）. （2） The expressions of caspase-3 mRNA and caspase-8 mRNA at all times and the expressions of caspase-9 mRNA at 12 h, 24 h, 48 h, 72 h were significantly lower in group C than in groups B and D （P 〈 0.01 or P 〈 0.05）; and there were no differences between groups B and D at all time points （P 〉 0.05）. Conclusions KATP opener can significantly decrease the neuronal apoptosis and the expressions of caspase-3, caspase-8 and caspase-9 mRNAs following cerebral ischemiareperfusion. The neuronal apoptosis may be decreased by the inhibition of both mitochondrial and death-receptor signal pathways.

N-methyl-D-aspartate receptors mediate diphosphorylation of extracellular signal-regulated kinases through Src family tyrosine kinases and Ca^2＋/calmodulin-dependent protein kinase Ⅱ in rat hippocampus after cerebral ischemia

Objective： Extracellular signal-regulated kinases （ERKs） can be activated by calcium signals. In this study, we investigated whether calcium-dependent kinases were involved in ERKs cascade activation after global cerebral ischemia. Methods Cerebral ischemia was induced by four-vessel occlusion, and the calcium-dependent proteins were detected by immunoblot. Results Lethal-simulated ischemia significantly resulted in ERKs activation in N-methyl-D-aspartate （NMDA） receptor-dependent manner, accompanying with differential upregulation of Src kinase and Ca^2＋/calmodulin-dependent protein kinase Ⅱ （CaMKⅡ） activities. With the inhibition of Src family tyrosine kinases or CaMKⅡ by administration of PP2 or KN62, the phosphorylation of ERKs was impaired dramatically during post-ischemia recovery. However, ischemic challenge also repressed ERKs activity when Src kinase was excessively activated. Conclusions Src family tyrosine kinases and CaMKⅡ might be involved in the activation of ERKs mediated by NMDA receptor in response to acute ischemic stimuli in vivo, but the intense activation of Src kinase resulted from ischemia may play a reverse role in the ERKs cascade.

EFFECTS OF ELECTROACUPUNCTURE ON EXPRESSION OF INTERCELLULAR ADHESION MOLECULE-1 IN THE RAT OF LOCAL CEREBRAL ISCHEMIA-REPERFUSION

Objective To investigate effects of electroacupuncture （EA） on expression of intercellular adhesion molecule-1 （ICAM-1） in the rat of local cerebral ischemia-reperfusion. Methods Eighty SD rats were randomly divided into a normal control group, a sham operation group, a model group and an EA treatment group, 20 rats in each group. The thread-obstruction method was used for preparation of ischemia-reperfusion model. Zea-Longa rating criteria were used for evaluation of nervous function disorder; Immunohistochemical SABC method was used for detection of ICAM-1 expression in the microvascular endothelial cell of the ischemic brain region, and ELISA method for the soluble ICAM-1 （slCAM-1） content in peripheral blood. Re. suits After cerebral ischemia-reperfusion, both ICAM-1 expression level in the microvascular endethelium cell of the ischemic brain region and slCAM-1 content in the peripheral blood significantly increased in the model group as compared with the normal group and the sham operation group （P〈0.01）; After EA treatment, the ICAM-1 expression level in the microvascular endothelial cell of the ischemic brain region and slCAM-1 content in the peripheral blood were significantly down-regulated in the EA treatment group as com- pared with the model group （P〈 0.05）. Conclusion After cerebral ischemia-reperfusion, the microvascular endothelial cell of the ischemic brain region releases ICAM-1, which induces inflammatory injury of cerebral tissues; EA treatment can decease the expression of ICAM-1, so as to prevent the brain from the injury.

Protective Effects of Sodium Magnesium Fructose Diphosphate on Brain Damage of Rats Subjected to Focal Cerebral Ischemia and Reperfusion

Objective: To study the effects of sodium magnesiusm fructose diphosphate(FDPM) on brain damage of rats after ischemia-reperfusion. Methods: Rats were subjected to cerebral ischemia-reperfusion induced by inserting a nylon thread into internal carotid artery to block the origin of middle cerebral artery and removing the thread later. FDPM (400 mg·kg -1), fructose-1,6-diphosphate (FDP, 400 mg·kg -1)and magnesium sulfate (MgSO 4, 30 mg·kg -1) were administrated 10 min after the onset of ischemia. Neurological scale, brain infarct area, Malondialdehyde(MDA) content and histopathological changes of brain tissue were studied. Results: FDPM decreased neurological scale, diminished brain infarct area, reduced MDA content and relieved histopathological change of rat brain tissue subjected to ischemia-reperfusion. These effects were more powerful than that of FDP or MgSO 4. Conclusions: It is suggested that FDPM markedly prevented rats against brain damage after cerebral ischemia-reperfusion, and its effect was better than that of FDP or MgSO 4.

Effects of Berberine on TXB 2 and 6 Keto PGF 1α Plasma Levels in Rabbits with Uncomplete Cerebral Ischemia

Effects of berberine (Ber) on platelet aggregation and TXB2 and 6 keto PGF1a plasma levels were studied in rabbits with uncomplete cerebral ischemia. Ber inhibited uncomplete cerebral ischemic rabbit platelet aggregation triggered by collagen, ADP, and arachidonic acid (AA) with the IC 50 of 0.15, 0.46, and 0.51 mg·ml 1 , respectively. In rabbits, Ber 25, or 50 mg·kg 1 iv 30 min after uncomplete cerebral ischemia, restrained the collagen ADP and AA induced platelet aggregation determined 90 min later. With radioimmunoassay, we measured the thromboxane B2 (TXB 2) and 6 ketoprostaglandin F 1α (6 keto PGF 1α ) contents in rabbit plasma. The results indicated that the TXB 2 level in rabbit 120 min after uncomplete cerebral ischemia (921±539 pg·ml 1 ) was higher than that (230±71 pg·ml 1 ) in normal rabbits ( P < 0.01), but 6 keto PGF 1α level after ischemia (73±23pg·ml 1 ) was lower than that (262±988pg·ml 1 ) in normal rabbit. Ber (5, 25 or 50 mg·kg 1 ) reduced obviously the plasma TXB 2 level in rabbit with uncomplete cerebral ischemia (504±196, 386±174, or 272±183 vs 921±539 pg·ml 1 , respectively, P < 0.01). We conclude that the decrease of TXB 2 content is one of the possible mechanisms of Ber anti cerebral ischemic effect.

Effects of Pravastatin on neuroprotection and neurogenesis after cerebral ischemia in rats

Objective Statins inhibit hydroxymethylglutaryl coenzyme A （HMG-CoA） reductase activity and lower total serum cholesterol levels. We investigated the effects of Pravastatin on neuroprotection and neurogenesis in the dentate gyrus （DG）, subventricular zone （SVZ） and striatum after cerebral ischemia in rats. Methods The filament method was used for temporary middle cerebral artery occlusion （tMCAO）. Pravastatin or saline post-ischemically were administered at subsequent time points： 6 h after tMCAO, and then on every subsequent day up to day 14 after tMCAO. Neurological outcome was investigated by using a neuroscore, the beam balance test and the rotarod test. Cholesterol and triglycerides levels were determined by blood sample analysis prior to sacrifice. Infarct area was calculated by microtubule-associated protein 2 （MAP2） staining. Neurogenesis was evaluated by triple staining with bromodeoxyuridine （BrdU）, doublecortin （DCX）, and neuronal nuclei （NeuN）. Results Compared with the control groups, Pravastatin treated animals were significantly improved in neurological outcome in rotarod test, with smaller infarct size. Pravastatin increased BrdU- positive cells number in the DG （P = 0.0029） and the SVZ （P = 0.0280） but not in the striatum （P = 0.3929）. Furthermore, Pravastatin increased BrdU-labeled DCX positive cells number in the DG （P = 0.0031）, SVZ （P = 0.0316） and striatum （P = 0.0073）. We also observed a DCX-positive cells stream from the SVZ to the striatum, suggesting a migration route of those immature neurons. No significant differences of total serum cholesterol and triglycerides were observed between groups. Conclusion The Pravastatin administration strategy is safe and could promote neurological recovery in ischemic stroke. Pravastatin induces neurogenesis in the DG and SVZ, and increases the number of migration cells in the striatum. These effects are independent of the cholesterol-lowering property of Pravastatin.

Mechanisms of lysosomal proteases participating in cerebral ischemia-induced neuronal death

There are three different types of cell death, including apoptosis （Type I）, autophagic cell death （Type II）, and necrosis （Type III）. Ischemic neuronal death influences stroke development and progression. Lysosomes are important organelles having an acidic milieu to maintain cellular metabolism by degrading unneeded extra- and intracellular substances. Lysosomal enzymes, including cathepsins and some lipid hydrolases, when secreted following rupture of the lysosomal membrane, can be very harmful to their environment, which results in pathological destruction of cellular structures. Since lysosomes contain catalytic enzymes for degrading proteins, carbohydrates and lipids, it seems natural that they should participate in cellular death and dismantling. In this review, we discuss the recent developments in ischemic neuronal death, and present the possible molecular mechanisms that the lysosomal enzymes participate in the three different types of cell death in ischemic brain damage. Moreover, the research related to the selective cathepsin inhibitors may provide a novel therapeutic target for treating stroke and promoting recovery.

Autophagy: a double-edged sword for neuronal survival after cerebral ischemia

Evidence suggests that autophagy may be a new therapeutic target for stroke, but whether acti- vation of autophagy increases or decreases the rate of neuronal death is still under debate. This review summarizes the potential role and possible signaling pathway of autophagy in neuronal survival after cerebral ischemia and proposes that autophagy has dual effects.

Ligustrazine monomer against cerebral ischemia/reperfusion injury

Ligustrazine （2,3,5,6-tetramethylpyrazine） is a major active ingredient of the Szechwan lovage rhizome and is extensively used in treatment of ischemic cerebrovascular disease. The mecha- nism of action of ligustrazine use against ischemic cerebrovascular diseases remains unclear at present. This study summarizes its protective effect, the optimum time window of administra- tion, and the most effective mode of administration for clinical treatment of cerebral ischemia/ reperfusion injury. We examine the effects of ligustrazine on suppressing excitatory amino acid release, promoting migration, differentiation and proliferation of endogenous neural stem cells. We also looked at its effects on angiogenesis and how it inhibits thrombosis, the inflammatory response, and apoptosis after cerebral ischemia. We consider that ligustrazine gives noticeable protection from cerebral ischemia/reperfusion injury. The time window of ligustrazine admin- istration is limited. The protective effect and time window of a series of derivative monomers of ligustrazine such as 2-[（1,1-dimethylethyl）oxidoimino]methyl]-3,5,6-trimethylpyrazine, CXC137 and CXC 195 after cerebral ischemia were better than ligustrazine.

Atorvastatin protects against cerebral ischemia/ reperfusion injury through anti-inflammatory and antioxidant effects

In addition to its lipid-lowering effect, atorvastatin exerts anti-inflammatory and antioxidant effects as well. In this study, we hypothesized that atorvastatin could protect against cerebral isch-emia/reperfusion injury. The middle cerebral artery ischemia/reperfusion model was established, and atorvastatin, 6.5 mg/kg, was administered by gavage. We found that, after cerebral ischemia/ reperfusion injury, levels of the inflammation-related factors E-selectin and myeloperoxidase were upregulated, the oxidative stress-related marker malondialdehyde was increased, and super- oxide dismutase activity was decreased in the ischemic cerebral cortex. Atorvastatin pretreatment significantly inhibited these changes. Our findings indicate that atorvastatin protects against ce-rebral ischemia/reperfusion injury through anti-inflammatory and antioxidant effects.

Neuroprotective effects of Buyang Huanwu decoction on cerebral ischemia-induced neuronal damage

Among the various treatment methods for stroke, increasing attention has been paid to tradi- tional Chinese medicines. Buyang Huanwu decoction is a commonly used traditional Chinese medicine for the treatment of stroke. This paper summarizes the active components of the Chinese herb, which is composed of Huangqi （Radix Astragali seu Hedysari）, Danggui （Radix Angelica sinensis）, Chishao （Radix Paeoniae Rubra）, Chuanxiong （Rhizoma Ligustici Chuanx- iong）, Honghua （Flos Carthami）, Taoren （Semen Persicae） and Dilong （Pheretima）, and identifies the therapeutic targets and underlying mechanisms that contribute to the neuroprotective prop- erties of Buyang Huanwu decoction.

Cerebral ischemia and neuroregeneration

Cerebral ischemia is one of the leading causes of morbidity and mortality worldwide. Although stroke （a form of cerebral ischemia）-related costs are expected to reach 240.67 billion dollars by 2030, options for treatment against cerebral ischemia/stroke are limited. All therapies except anti-thrombolytics （i.e., tissue plasminogen activator） and hypothermia have failed to reduce neuronal injury, neurological deficits, and mortality rates following cerebral ischemia, which suggests that development of novel therapies again st stroke/cerebral ischemia are urgently needed. Here, we discuss the possible mechanism（s） underlying cerebral ischemia-induced brain injury, as well as current and future novel therapies （i.e., growth factors, nicotinamide adenine dinucleotide, melatonin, resveratrol, protein kinase C isozymes, pifithrin, hypothermia, fatty acids, sympathoplegic drugs, and stem cells） as it relates to cerebral ischemia.

Inhibition of Excitatory Amino Acid Efflux Contributes to Protective Effects of Puerarin Against Cerebral Ischemia in Rats

To investigate whether the protective effects of puerarine （Pur） against cerebral ischemia is associated with depressing the extracellular levels of amino acid transmitters in brain of rats. Methods Male Sprague-Dawley rats were subjected to transient middle cerebral artery occlusion （MCAO） for 60 min followed by 24 h reperfusion. Put （50, 100 mg/kg, i.p.） was administered at the onset of MCAO. The infarct rate and edema rate were detected on TTC （2,3,5-triphenyltetrazolium chloride）-stained coronal sections. The extracellular levels of amino acid transmitters were monitored in striatum of rats with ischemic/reperfusion injury using in vivo microdialysis technique. Furthermore, the protective effects of Pur against glutamate-induced neurotoxicity were detected. Glutamate-induced apoptotic and necrotic cells in hippocampus were estimated by flow cytometric analysis of Annexin-V and PI labeling cells. Results Pur （100 mg/kg） significantly decreased infarct size by 31.6% （P〈0.05）, reduced edema volume （P〈0.05）, and improved neurological functions （P〈0.05） following MCAO. In these rats, the ischemia-induced extracellular levels of aspartate （Asp）, glutamate （Glu）, γ-aminobutyric acid （GABA）, and taurine （Tau） were significantly reduced in striatum of vehicle-treated animals by 54.7%, 56.7%, 75.8%, and 68.1% （P〈0.01 and P〈0.05）. Pur reduced the peak values of Glu and Asp more obviously than those of GABA and Tau, and the rate of Glu/GABA during MCAO markedly decreased in Pur-treated MCAO rats, compared with the vehicle-treated MCAO rats. Meanwhile, apoptosis and necrosis induced by Glu in cultured hippocampal neurons were significantly reduced after Pur treatment. Conclusion Acute treatment with Put at the onset of occlusion significantly depresses ischemia-induced efflux of amino acids, especially, excitotoxicity in the striatum, a mechanism underlying the neuroprotective effect on cellular survival.

Neuronal apoptosis in cerebral ischemia/reperfusion area following electrical stimulation of fastigial nucleus

Previous studies have indicated that electrical stimulation of the cerebellar fastigial nucleus in rats may reduce brain infarct size, increase the expression of Ku70 in cerebral ischemia/ reperfusion area, and decrease the number of apoptotic neurons. However, the anti-apoptotic mechanism of Ku70 remains unclear. In this study, fastigial nucleus stimulation was given to rats 24, 48, and 72 hours before cerebral ischemia/reperfusion injury. Results from the electrical stim- ulation group revealed that rats exhibited a reduction in brain infarct size, a significant increase in the expression of KuT0 in cerebral ischemia/reperfusion regions, and a decreased number of terminal deoxynucleotidyl transferase dUTP nick end labeling （TUNEL）-positive cells. Double immunofluorescence staining revealed no co-localization of Ku70 with TUNEL-positive cells. However, Ku70 partly co-localized with Bax protein in the cytoplasm of rats with cerebral ischemia/reperfusion injury. These findings suggest an involvement of Ku70 with Bax in the cy- toplasm of rats exposed to electrical stimulation of the cerebellar fastigial nucleus, and may thus provide an understanding into the anti-apoptotic activity of KuT0 in cerebral ischemia/reperfu- sion injury.