Changes in plasma calcitonin gene-related peptide and serum neuron specific enolase in rats with acute cerebral ischemia after low-frequency electrical stimulation with different waveforms and intensities

Following acute cerebral ischemia in rats, plasma calcitonin gene-related peptide decreased and the level of serum neuron specific enolase and the volume of the infarction increased. Square-wave and triangular-wave electrical stimulation with low or high intensities could increase the plasma calcitonin gene-related peptide, decrease the serum neuron specific enolase and reduce the infarction volume in the brain in rats with cerebral ischemia. There was no significant difference between different wave forms and intensities. The experimental findings indicate that low-frequency electrical stimulation with varying waveforms and intensities can treat acute cerebral ischemia in rats.

An Experimental Proton Magnetic Resonance Spectroscopy Analysis on Early Stage of Acute Focal Cerebral Ischemia

U sing different m odels of focal cerebral ischemia,the temporal and spatial rules of m etabolism and energy changes in the post- ischem ia brain tissue were measured by proton m agnet- ic resonance spectroscopy(1 HMRS) to provide valuable inform ation for judging the prognosis of a- cute focal cerebral ischemia and carrying out effective therapy.Nine healthy Sprague- Dawly rats (both sexes) were randomly divided into two groups:The rats in the group A(n=4 ) were occlud- ed with self- thrombus for1h;The rats in the group B(n=5 ) were occluded with thread- em boli for1h.The 1 H MRS at30 ,4 0 ,5 0 ,6 0 min respectively was examined and the m etabolic changes of NAA,Cho and L ac in the regions of interest were sem iquantitatively analyzed. The spectrum intregral calculus area ratio of NAA,Cho,L ac to Pcr+Cr was setas the criterion.The values of NAA· Cho in the regions of interest were declined gradually within 1h after ischem ia, especially,the ratio of Cho/ (Pcr+Cr) ,NAA/ (Pcr+Cr) at6 0 m in had significant difference with that at5 0 min(P<0 .0 5 ) .The ratio of L ac/ (Pcr+Cr) began to decrease at4 0 min from initial in- crease of L ac in both A and B groups.MR proton spectrum analysis was a non- invasive,directand com prehensive tool for the study of cellular metabolism and the status of the biochemical energy in acute ischem ia stroke.

Effect of Xingnaojing injection on penumbra transformation in rats with acute cerebral ischemia

Objective:To observe the effect of Xingnaojing injection on penumbra transformation in rats with acute cerebral ischemia.Methods:The rat model of middle cerebral artery occlusion(Middle cerebral artery occlusion,MCAO)was established by suture occlusion.Except the sham operation group,the other groups were randomly divided into model group and Xingnaojing group.The rats in Xingnaojing group were intraperitoneally injected with Xingnaojing injectionaccording to 0.18ml/100g,and the sham operation group and model group were given the same amount of normal saline respectively.24 hours after the establishment of the model,the morphological changes of neurons in the penumbra of the rats were observed by Nissl staining,the ultrastructural changes of neurovascular unit(Neurovascular unit,NVU)were observed by transmission electron microscope(Transmission electron microscope,TEM),and the apoptosis of the ischemic penumbra was detected by in situ apoptosis(TdT-mediated Dutp Nick-End Labeling,TUNEL).Magnetic resonance imaging was used to observe the ischemic evolution of the penumbra of the same rat at 4.5 h and 24 h,respectively.Results:Compared with the sham operation group,the number of neurons in the model group was significantly reduced,the structure of Nissl corpuscles was destroyed,the outline was blurred or disappeared,the pathological morphology of NVU ultrastructure was obviously damaged under transmission electron microscope,a large number of apoptotic cells could be seen in the model group by TUNEL staining(P<0.01),and magnetic resonance imaging showed that there was a large area infarction in the brain tissue of the model group.Compared with the model group,the pathomorphology of neurons and NVU ultrastructure in Xingnaojing group was significantly improved,the number of apoptotic cells was significantly decreased(P<0.01),and the loss rate of penumbra was significantly lower in Xingnaojing group(P<0.05).Conclusion:Xingnaojing injection can improve the state of neurons in ischemic penumbra,reduce the injury of glial cells and microvessels,inhibit apoptosis,promote the transformation of penumbra in rats with acute cerebral ischemia,and save part of penumbra to some extent.it has a certain protective effect on the brain tissue of penumbra in the acute stage of cerebral ischemia.

Effects of cluster needling of scalp acupuncture on neurofilament protein 200 and signal transducer and activator of transcription 3 in rats with acute cerebral ischemia

Objective:Cluster needling at scalp acupoints has showed satisfying effects with acute cerebral ischemia in clinic whereas the mechanisms are not yet clear completely.This study investigated the influence of cluster needling at scalp acupoints on neurological function,as well as on neurofilament protein 200(NF200)and signal transducer and activator of transcription 3(STAT3)expression,in rats with acute cerebral ischemia.Methods:Fifty-four Sprague-Dawley rats were randomly assigned in equal numbers to the false operation(group F),model(group M),or cluster needling scalp acupuncture(group C)groups.Each group was divided into three subgroups,of six rats each,by acupuncture treatment time(24 h,7 days,and 14 days).The rat local cerebral ischemia model was prepared using a modified suture occlusion method.Group C rats were treated by cluster needling scalp acupuncture,while groups F and M did not receive acupuncture treatment.Neurological effects were evaluated using the Longa score.NF200 and STAT3 expression were measured by western blotting.Results:At 24 h,there were no statistical difference between group C and group M in nerve function(P>.05).On days 7 and 14,nerve function scores in group C were significantly lower than that in group M(respectively were P<.05 and P<.01).In addition,on days 14,expression of NF200 was significantly higher in group C compared with group M(P<.05).Compared with group M,STAT3 expression was also higher in group C on days 7 and 14,although these differences were not statistically significant(both P>.05).Conclusion:Cluster needling scalp acupuncture were efficient in improving nerve function scores in rats with cerebral ischemia,and promoting the recovery of motor function.These improvements were associated with increases in NF200 and STAT3 expression.

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.

Combination Therapy with LXW7 and Ceria Nanoparticles Protects against Acute Cerebral Ischemia/Reperfusion Injury in Rats

Ischemia/reperfusion is known to greatly increase oxidative stress in the penumbra,which results in brain damage.Integrin αvβ3 is selectively up-regulated with ischemic injury to the brain and remains elevated throughout reperfusion.We determined whether or not a new compound biotinylated-LXW7-ceria nanoparticle（Ce NP）（b LXW7-Ce NP） plays a role in brain protection in the rat model of middle cerebral artery occlusion/reperfusion and shows better effects than Ce NPs alone in improving the outcomes of focal oxidative stress and apoptosis more effectively.Male Sprague-Dawley rats were subjected to focal cerebral ischemia for 2 h followed by a 24-h reperfusion.Drug treatment was intravenously administered via the caudal vein 1 h after occlusion.Rats were randomly divided into the following 4 groups：b LXW7-Ce NP treatment group（0.5 mg/kg）;Ce NP treatment group（0.5 mg/kg）;control saline group;and sham group.Brains were harvested 24 h after reperfusion,and the neurologic deficit scores,infarction volume,blood-brain barrier（BBB） disruption,and the level of oxidative stress and apoptosis were determined.Results showed that the b LXW7-Ce NP and Ce NP treatments could improve neurologic deficit scores,infarction volume,BBB disruption,and the level of oxidative stress and apoptosis.Compound b LXW7-Ce NP treatment exhibited better effects than Ce Np treatment and showed remarkable statistical differences in the infarction volume,the degree of BBB breakdown,the apoptosis and oxidative stress,apart from neurologic deficit scores.Thus,we concluded that b LXW7-Ce NP protects against acute cerebral ischemia/reperfusion injury.BLXW7,as a ligand of integrin αvβ3,may be able to effectively localize the anti-oxidant Ce NPs to the ischemic penumbra region,which may provide more adequate opportunities for Ce NPs to exert anti-oxidative stress effects and subsequently reduce apoptosis in acute cerebral ischemia/reperfusion.

Effect of Muscone on Neuronal Glutamate Transporter EAAC1 Expression in Rats with Acute Cerebral Ischemia

Objective: To investigate muscone's neuroprotective action and it s mechanism in rats with acute cerebral ischemic injury. Methods: Rat focal ischemic model of middle cerebral artery occlusion(MCAO) was establi shed by thread inserting method. TTC staining, RT PCR and Western blot analys is were used to study the effects of muscone on infracted volume, EAAC1mRNA and protein levels.Results: Infarcted volume in the muscone treated gr oup was significantly lower than that in the model control group. Compared with normal group, EAAC1 mRNA level increased in the model control group at 6 and 24 hrs, and protein level increased at 24 hrs after modelling, muscone could reduc e the increased expression in model rats. Conclusion: Muscone po ssesses the action of neuroprotection, its mechanism may be related to reduction of EAAC1 and protein expressions.

Effects of anisodamine on altered [Ca^(2+)]i and cerebral cortex ultrastructure following acute cerebral ischemia/reperfusion injury in rabbits

BACKGROUND： Calcium ion （Ca^2＋） overload plays an important role in cerebral ischemia/reperfusion injury. Anisodamine, a type of alkaloid, can protect the myocardium from ischemia and reperfusion injury by inhibiting intracellular calcium [Ca^2＋]i overload. OBJECTIVE： To investigate effects of anisodamine on [Ca^2＋]i concentration and cortex ultrastructure following acute cerebral ischemia/reperfusion in rabbits. DESIGN, TIME AND SETTING： Randomized and controlled trial was performed at the Department of Emergency, Tongji Hospital, Tongji Medical College of Huazhong University of Science and Technology from September to December 2006. MATERIALS： Forty healthy rabbits were used to establish models of acute cerebral ischemia/reperfusion. Anisodamine was provided by Lianyungang Dongfeng Pharmaceutical Factory; Fura-2 was purchased from Nanjing Jiancheng Bioengineering Institute; dual-wave length fluorescent spectrophotometry system and DM-300 software were provided by Bio-Rad, USA; OPTON-EM10C transmission electron microscope was product of Siemens, Germany. METHODS： Forty rabbits were randomly divided into the following groups： sham operation, ischemia, ischemia/reperfusion, and anisodamine, with ten rabbits in each group. Models of complete cerebral ischemia injury were established. In addition, blood was collected from the femoral artery of rats in the ischemia/reperfusion and anisodamine groups to induce hypotension and establish repeffusion injury models. The bilateral common carotid artery clamp was removed from the anisodamine group 20 minutes after ischemia, and anisodamine （10 mg/kg body mass） was injected via the femoral vein. Rabbits in the sham operation group underwent only venous cannulation. MAIN OUTCOME MEASURES： [Ca^2＋]i concentration was determined using a dual-wave length fluorescent spectrophotometry system, and cortical ultrastructure was observed following uranyl-lead citrate staining. RESULTS： The levels of [Ca^2＋]i in the ischemia and ischemia/reperfusion groups were significantly increased, compared with the sham operation group （P 〈 0.01）, and the levels of [Ca^2＋]i in the anisodamine group were remarkably less than the ischemia and ischemia/reperfusion groups （P 〈 0.01）. Ultrastructural damage to the cortex was greatly aggravated with increasing levels of [Ca^2＋]i. In the ischemia group, cortical neuronal membranes were fragmentally damaged, including the mitochoudria and endoplasmic reticulum, as well as neufite swelling, and slight chromatin margination. In the ischemia/reperfusion group, the cellular membrane was ruptured with aggravated mitochondrial swelling, increased chromatin margination, obscure neufite structure, and the disappearance of endoplasmic reticulum. However, in the anisodamine group, cellular damage was obviously alleviated. The appearance and structure of cortical neurons was relatively normal, with intact cells. There was slight swelling of the mitochondria and endoplasmic reticulum, as well as mild chromatin margination. CONCLUSION： Cerebral tissue injury was related to increased [Ca^2＋]i levels following ischemia/ reperfusion. Anisodamine exhibited a protective role on acute cerebral ischemia/reperfusion injury by inhibiting the increase in [Ca^2＋]i levels.

Three-dimensional arterial spin labeling and diffusion kurtosis imaging in evaluating perfusion and infarct area size in acute cerebral ischemia

BACKGROUND Early thrombolytic therapy is crucial to treat acute cerebral infarction,especially since the onset of thrombolytic therapy takes 1-6 h.Therefore,early diagnosis and evaluation of cerebral infarction is important.AIM To investigate the diagnostic value of magnetic resonance multi-delay threedimensional arterial spin labeling(3DASL)and diffusion kurtosis imaging(DKI)in evaluating the perfusion and infarct area size in patients with acute cerebral ischemia.METHODS Eighty-four patients who experienced acute cerebral ischemia from March 2019 to February 2021 were included.All patients in the acute stage underwent magnetic resonance-based examination,and the data were processed by the system’s own software.The apparent diffusion coefficient(ADC),average diffusion coefficient(MD),axial diffusion(AD),radial diffusion(RD),average kurtosis(MK),radial kurtosis(fairly RK),axial kurtosis(AK),and perfusion parameters post-labeling delays(PLD)in the focal area and its corresponding area were compared.The correlation between the lesion area of cerebral infarction under MK and MD and T2-weighted imaging(T2WI)was analyzed.RESULTS The DKI parameters of focal and control areas in the study subjects were compared.The ADC,MD,AD,and RD values in the lesion area were significantly lower than those in the control area.The MK,RK,and AK values in the lesion area were significantly higher than those in the control area.The MK/MD value in the infarct lesions was used to determine the matching situation.MK/MD<5 mm was considered matching and MK/MD≥5 mm was considered mismatching.PLD1.5s and PLD2.5s perfusion parameters in the central,peripheral,and control areas of the infarct lesions in MK/MD-matched and-unmatched patients were not significantly different.PLD1.5s and PLD2.5s perfusion parameter values in the central area of the infarct lesions in MK/MD-matched and-unmatched patients were significantly lower than those in peripheral and control areas.The MK and MD maps showed a lesion area of 20.08±5.74 cm^(2) and 22.09±5.58 cm^(2),respectively.T2WI showed a lesion area of 19.76±5.02 cm^(2).There were no significant differences in the cerebral infarction lesion areas measured using the three methods.MK,MD,and T2WI showed a good correlation.CONCLUSION DKI parameters showed significant difference between the focal and control areas in patients with acute ischemic cerebral infarction.3DASL can effectively determine the changes in perfusion levels in the lesion area.There was a high correlation between the area of the infarct lesions diagnosed by DKI and T2WI.

Inhibition of NLRP3 inflammasomes reduced blood brain barrier damage by DHA during early acute cerebralischemia

The aim of this study was to explore the neuroprotective effect and mechanism of DHA on cerebral ischemia injury and blood-brain barrier(BBB)disruption.the focal cerebral I/R model was established by middle cerebral artery oclusion(MCAO).BBB permeability was assessed with the leaking amount of Evans Blue and the expression of occludin and ZO-1.The expression of pyrin domain containing(NLRP3)was checked to explore the inhibition of inflammation by DHA.The results showed that DHA could significantly reduce cortical and sub-cortical infarct volumes,neurologic de ficit scores,cerebral edema,BBB permeability after I/R injury.Leaking amount of Evans Blue was reduced by DHA,and occludin and ZO-1 were up-regulated by DHA.The expression of NLRP3 was inhibited after exposure of DHA.Our results indicated that DHA could effectively penetrate the brain of MCAO rats,aleviated the I/R injury by inhibiting NLRP3 inflammasomes and improve BBB disruption,showing a great clinical potential for stroke.

Effect of cluster needling at scalp acupoints on differential protein expression in rat brain tissue after acute focal cerebral ischemia

Objective:To explore the function of cluster needling at scalp points therapy on regulating differential protein's expression at different time points in middle cerebral artery occlusion(MCAO)model rats.Methods:Fifty-four rats were divided into three groups randomly and 18 rats in each group.The groups respectively were the model group(group M,n=18),cluster needling at scalp points group(group C,n=18),false operation group(group F,n=18).Each group was then assigned in three subgroups,including 24-h,7-day,and 14-day subgroups.Six rats in each subgroup.Acupuncture at Baihui(GV20)and 2 points beside Baihui,which was 3 e4 mm away from the midline.Longa score was used to evaluated neurological effects.Proteomics methods were used to identify differentially expression proteins with a standard of fold change greater than 1.5 and P<.05 at different times.Results:1.Nerve function scoring:The nerve function scores at 7 and 14 days decreased in group C,which showed better neural function than group M(P<.05).2.Fold change in proteins:Group M showed932 differentially expressed proteins compared with group F,and among them,414 proteins showed significant changes in expression after acupuncture.The expression levels of Cdc42 and GFAP were increased,and Mag,Shank2,and MBP levels were decreased.In the Gene Ontology analysis,the cellular component consisted of the terms cytoplasm,cytoskeleton,lysosome,and plasma membrane.The main related biological processes were cellecell signaling,protein transport,aging,and cell adhesion.Many synaptic and metabolic pathways were found by KEGG analysis.Conclusion:Cluster needling at scalp acupoints can improve the nerve function score and improve dyskinesia in MCAO model rats.Cluster needling at scalp acupoints can regulate the expression of 414 proteins,including Cdc42,GFAP,Mag,Shank2,and MBP,which are related to cerebral ischemia.The differential proteins are major concentration in cytoplasm,cytoskeleton,lysosomes,and plasma membrane,participate in cellecell signaling,protein transport,aging,and cell adhesion,and act through multiple synaptic and metabolic pathways to exert their biological functions.

Effects of L-Tetrahydropalmatine on Energy Metabolism,Endothelin-1 and NO during Acute Cerebral Ischemia-reperfusion of Rats

To investigate the effects of L-tetrahydropalmatine (L-THP) on ener-gy metabolism, endothelin-1 (ET-1 ) and NO during acute cerebral ischemia-reperfusion of rats, 24 Wistar rats were randomly divided into four groups, with 6rats in each group: sham-operation group, simple ischemia group, ischemia-reperfusion group and treatment group (L-THP group). Cerebral ATP, lactate,ET-1 and NO levels were measured in all groups. Our results showed that treat-ment with L-THP could increase cerebral ATP levels, but decrease cerebral lac-tate, ET-1 and NO concentrations during ischemia-reperfusion in the treatmentgroup. It is concluded that L-THP could improve cerebral energy metabolism and protect the injured brain tissue, the mechanism of which might be related to suppression of overproduction of ET-1 and NO.

Effects of L-Tetrahydropalmatine on Neuron Apoptosis during Acute Cerebral Ischemia-Reperfusion of Rats

To investigate the effects of L-Tetrahydropalmatine (L-THP ) on neuron apoptosis during acute cerebral ischemia-reperfusion of rats and explore the effects of heat shock protein (HSP) on neuron apoptosis, Wistar rats were randomly divided into 3 groups: normal group, ischemia- reperfusion group and treatment group. The condition of neuron apoptosis, the survival state of neuron, pathological changes under an electron microscope and the number of HSP70 positive cells were measured in all groups. Results showed that the apoptosis neuron number was increased obviously at the 24th h during reperfusion and was further increased at the 48th h, the 72th h. While the number of survival neurons was decreased gradually with the prolongation of reperfusion time. Treatment with L-THP could decrease the apoptosis neuron number but increase the survival neuron number and the HSP70 positive cell number. Our study suggested that L-THP could decrease apoptosis and necrosis of neuron, up-regulate the expression of HSP70 and protect the cerebral ischemic 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.

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.

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.

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.

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.

~1H-magnetic resonance spectroscopy of vascular endothelial growth factor-induced neuroprotection following acute cerebral ischemia and reperfusion

BACKGROUND： It has become generally accepted that measuring N-acetyl-L-aspartic acid through the use of 1H-magnetic resonance spectroscopy （1H-MRS） could be used to evaluate neuronal injury. OBJECTIVE： To study metabolic changes of N-acetyl-L-aspartic acid surrounding the acute cerebral ischemia area following vascular endothelial growth factor （VEGF） treatment using 1H-MRS imaging, and to evaluate the neuroprotective effects of VEGE DESIGN, TIME AND SETTING： Randomly controlled animal study, according to one-factor analysis of variance, was performed at the Shenzhen Hospital of Peking University and State Key Laboratory of Magnetic Resonance and Atomic and Molecular Physics, Wuhan Institute of Physics and Mathematics, Chinese Academy of Sciences from August 2003 to December 2005. MATERIALS： Twelve healthy, adult, Sprague Dawley rats were used to establish an ischemia/reperfusion model through the use of middle cerebral artery occlusion. The 4.7T superconducting nuclear magnetic resonance meter was provided by Brucker Company. VEGF164 was purchased from Shenzhen Jingmei Bioengineering Co., Ltd. Titus anesthesia machine was purchased from Draeger Medical AG ＆ Co. KG METHODS： The rats were randomly divided into model control （n = 6） and VEGF-injected （n = 6） groups. All animals received 60-minute middle cerebral artery occlusion and 24-hour reperfusion. Lateral cerebral ventricle injection was performed by stereotaxic technique at respective time points. The VEGF group received 0.1 μg/μL L VEGF （5 μ L）, and the model group received the same amount of normal saline, once daily for 3 days. MAIN OUTCOME MEASURES： Metabolic changes of N-acetyl-L-aspartic acid and lactic acid following cerebral ischemia and reperfusion were detected using 1H-MRS, and the ischemic volume was measured. RESULTS： Twelve rats were included in the final analysis.1H-MRS results revealed that the ischemic volume increased in the control group compared with prior to injection （P 〈 0.01）. In the control group, the level of N-acetyl-L-aspartic acid decreased significantly at 7 days after injection （P 〈 0.01）, while lactic acid concentrations increased （P 〈 0.05）. In the VEGF group, the level of N-acetyl-L-aspartic acid decreased slightly, as well as lactic acid concentrations （P 〈 0.05）. CONCLUSION： By means of 1H-MRS, results demonstrated that lactic acid and N-acetyl-L-aspartic acid concentrations decreased following treatment with VEGE These results suggest that VEGF can provide prompt and safe neuroprotection following ischemic stroke.

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.