BACKGROUND: Previous studies of cerebral ischemia have used young animals, with an ischemictime greater than 5 minutes (safe time limit). Despite an increased understanding of neuronalapoptosis, it remains uncertain w...BACKGROUND: Previous studies of cerebral ischemia have used young animals, with an ischemictime greater than 5 minutes (safe time limit). Despite an increased understanding of neuronalapoptosis, it remains uncertain whether brief cerebral ischemic events of 5 minutes or less damagebrain tissue in elderly rodents.OBJECTIVE: To investigate the effects of transient cerebral ischemia (5 minutes)/reperfusion injuryon brain cortical and hippocampal edema, aquaporin-4 (AQP-4) expression, and neuronal apoptosisin aged rats, and to compare ischemic sensitivity between cortex and hippocampus.DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at theInstitute of Cerebrovascular Disease, Qingdao University Medical School from April 2008 to March2009.MATERIALS: Rabbit anti-AQP-4 polyclonal antibody, TUNEL kit, and SABC immunohistochemistrykit were purchased from Wuhan Boster Bioengineering, China.METHODS: A total of 160 healthy, male, aged 19-21 months, Wistar rats were randomly assignedto 4 groups: sham-surgery, and ischemia 1-, 3-, and 5-minute groups, with 40 rats in each group.The global cerebral ischemia model was established using the Pusinelli four-vessel occlusion, andthe three cerebral ischemia groups were subdivided into reperfusion 12-hour, 1-, 2-, 3-, and 7-daysubgroups, with 8 rats in each subgroup. The sham-surgery group was subjected to exposure of thefirst cervical bilateral alar foramina and bilateral common carotid arteries.MAIN OUTCOME MEASURES: The dry-wet weight assay was used to measure brain water contentand histopathology of the cortex and hippocampus was observed following hematoxylin-eosinstaining. In addition, cortical and hippocampal AQP-4 expression was detected by streptavidin-biotincomplex immunohistochemistry, and neuronal apoptosis was detected by the TUNEL method.RESULTS: There was no significant difference in brain water content or AQP-4 expression in thecortex and hippocampus between ischemia 1- and 3-minute groups and the sham-surgery group orbrain water content or AQP-4 expression in the cortex between ischemia 5-minute group andsham-surgery group (P> 0.05). However, brain water content and AQP-4 expression in thehippocampus after 5 minutes of cerebral ischemia were significantly increased compared with thesham-surgery group (P < 0.05 or P < 0.01 ). Several TUNEL-positive cells were observed in thecortex and hippocampus of the sham-surgery group and ischemia 1-minute group, as well as in thecortex of the ischemia 3-minute group. In addition, the number of apoptotic neurons in thehippocampus of ischemia 3-minute group and in the cortex and hippocampus of ischemia 5-minutegroup was significantly increased (P < 0.05 or P < 0.01). Neuronal apoptosis was increased after 12hours of ischemia/reperfusion, and it reached a peak by 2 days (P < 0.01).CONCLUSION: Transient cerebral ischemia (5 minutes) resulted in increased hippocampal edema,AQP-4 expression, and neuronal apoptosis. Moreover, cerebral ischemia had a greater effect onneuronal apoptosis than brain edema or AQP-4 expression, and the hippocampus was moresensitive than the cortex.展开更多
Mitochondria play an important role in neuronal apoptosis caused by cerebral ischemia, and the role is mediated by the expression of mitochondrial proteins. This study investigated the involvement of mitochondrial pro...Mitochondria play an important role in neuronal apoptosis caused by cerebral ischemia, and the role is mediated by the expression of mitochondrial proteins. This study investigated the involvement of mitochondrial proteins in hippocampal cell apoptosis after transient cerebral ischemia-reperfusion injury in aged rats using a comparative proteomics strategy. Our experimental results show that the aged rat brain is sensitive to ischemia-reperfusion injury and that transient ischemia led to cell apoptosis in the hippocampus and changes in memory and cognition of aged rats. Differential proteomics analysis suggested that this phenomenon may be mediated by mitochondrial proteins associated with energy metabolism and apoptosis in aged rats. This study provides potential drug targets for the treatment of transient cerebral ischemia-reperfusion injury.展开更多
Proteasome activity reduction is an important pathological phenomenon, resulting in proteins aggregation and neuronal death in the injured neurons induced by transient ischemia. Our previous report showed that the tra...Proteasome activity reduction is an important pathological phenomenon, resulting in proteins aggregation and neuronal death in the injured neurons induced by transient ischemia. Our previous report showed that the trap of proteasome in the protein aggregates was a reason to lead to the reduction of proteasome activity. However, the patterns of proteasome entered into protein aggregates are not clear. In this study, we used a global ischemia model, Hematoxylin-Eosin staining, differential centrifuge, proteasome activity assay, sucrose gradient density centrifuge, and Western blot analysis to investigate this problem. Our results show that there are two aggregation patterns of proteasome after transient ischemia and reperfusion. One is that 26S proteasome is trapped by protein aggregates as a whole unit, and the other is that 19S or 20S is trapped in the protein aggregates, respectively, after 26S disassociates.展开更多
BACKGROUND:Proteasome dysfunction has been reported to induce abnormal protein aggregation and cell death. OBJECTIVE:To investigate the effect of proteasome changes on delayed neuronal death in CA1 and dentate gyrus(D...BACKGROUND:Proteasome dysfunction has been reported to induce abnormal protein aggregation and cell death. OBJECTIVE:To investigate the effect of proteasome changes on delayed neuronal death in CA1 and dentate gyrus(DG) regions of the rat hippocampus following transient cerebral ischemia. DESIGN,TIME AND SETTING:A randomized,controlled animal experiment.The study was performed at the Department of Biochemistry and Molecular Biology,Norman Bethune Medical College of Jilin University,from September 2006 to May 2008. MATERIALS:Rabbit anti-19S S10B polyclonal antibody was purchased from Bioreagents,USA; propidium iodide and fluorescently-labeled goat anti-rabbit IgG were purchased from Jackson Immunoresearch,USA;hematoxylin and eosin staining solution was purchased from Sigma,USA; LSM 510 confocal microscope was purchased from Zeiss,Germany. METHODS:A total of 40 healthy Wistar rats,male,4 months old,were randomly divided into sham surgery group(n = 8) and model group(n = 32).Ischemic models were established in the model group by transient clamping of the bilateral carotid arteries and decreased blood pressure. After 20 minutes of global ischemia,the clamp was removed to allow blood flow for 30 minutes,4,24, and 72 hours,respectively,with 8 rats at each time point.The bilateral carotid arteries were not ligated in the sham surgery group. MAIN OUTCOME MEASURES:Neuronal death in the CA1 and DG regions was observed by hematoxylin-eosin staining.Proteasome expression in CA1 and DG region neurons was detected by immunohistochemistry. RESULTS:Hematoxylin-eosin staining showed neuronal death in the CA1 region alone at 72 hours of reperfusion following ischemia.In comparison to the sham surgery group,a significant decrease in proteasome expression was observed,by immunohistochemistry,in the CA1 and DG regions in the model group,following 30 minutes,4,24,and 72 hours of reperfusion(P<0.01).After 72 hours of reperfusion following ischemia,proteasome expression had almost completely disappeared in the CA1 region.In contrast,neurons of the DG region showed minimized proteasome expression at 24 hours,with a slight increase at 72 hours(P<0.01). CONCLUSION:The alteration of proteasome following ischemia/reperfusion in the neurons of hippocampal CA1 and DG regions reduces the ability of cells to degrade abnormal protein,which may be an important factor resulting in delayed neuronal death following transient cerebral ischemia.展开更多
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 r...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.展开更多
This case report investigates the manifestation of cerebral amyloid angiopathy (CAA) through recurrent Transient Ischemic Attacks (TIAs) in an 82-year-old patient. Despite initial diagnostic complexities, cerebral ang...This case report investigates the manifestation of cerebral amyloid angiopathy (CAA) through recurrent Transient Ischemic Attacks (TIAs) in an 82-year-old patient. Despite initial diagnostic complexities, cerebral angiography-MRI revealed features indicative of CAA. Symptomatic treatment resulted in improvement, but the patient later developed a fatal hematoma. The discussion navigates the intricate therapeutic landscape of repetitive TIAs in the elderly with cardiovascular risk factors, emphasizing the pivotal role of cerebral MRI and meticulous bleeding risk management. The conclusion stresses the importance of incorporating SWI sequences, specifically when suspecting a cardioembolic TIA, as a diagnostic measure to explore and exclude CAA in the differential diagnosis. This case report provides valuable insights into these challenges, highlighting the need to consider CAA in relevant cases.展开更多
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...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.展开更多
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 unkno...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.展开更多
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 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.展开更多
The inflammato ry response plays an important role in neuroprotection and regeneration after ischemic insult.The use of non-ste roidal anti-inflammatory drugs has been a matter of debate as to whether they have benefi...The inflammato ry response plays an important role in neuroprotection and regeneration after ischemic insult.The use of non-ste roidal anti-inflammatory drugs has been a matter of debate as to whether they have beneficial or detrimental effects.In this context,the effects of the anti-inflammatory agent meloxicam have been scarcely documented after stro ke,but its ability to inhibit both cyclooxygenase isoforms(1 and 2) could be a promising strategy to modulate postischemic inflammation.This study analyzed the effect of meloxicam in a transient focal cerebral ischemia model in rats,measuring its neuroprotective effect after 48 hours and 7 days of reperfusion and the effects of the treatment on the glial scar and regenerative events such as the generation of new progenitors in the subventricular zone and axonal sprouting at the edge of the damaged area.We show that meloxicam’s neuroprotective effects remained after 7 days of reperfusion even if its administration was restricted to the two first days after ischemia.Moreover,meloxicam treatment modulated glial scar reactivity,which matched with an increase in axonal sprouting.However,this treatment decreased the formation of neuronal progenitor cells.This study discusses the dual role of anti-inflammatory treatments after stro ke and encourages the careful analysis of both the neuroprotective and the regenerative effects in preclinical studies.展开更多
Microglia,which are the resident macrophages of the central nervous system,are an important part of the inflammatory response that occurs after cerebral ischemia.Vav guanine nucleotide exchange factor 1(Vav1) is a gua...Microglia,which are the resident macrophages of the central nervous system,are an important part of the inflammatory response that occurs after cerebral ischemia.Vav guanine nucleotide exchange factor 1(Vav1) is a guanine nucleotide exchange factor that is related to microglial activation.However,how Vav1 participates in the inflammato ry response after cerebral ischemia/reperfusion inj ury remains unclea r.In this study,we subjected rats to occlusion and repe rfusion of the middle cerebral artery and subjected the BV-2 mic roglia cell line to oxygen-glucose deprivatio n/reoxygenation to mimic cerebral ischemia/repe rfusion in vivo and in vitro,respectively.We found that Vav1 levels were increased in the brain tissue of rats subjected to occlusion and reperfusion of the middle cerebral arte ry and in BV-2 cells subjected to oxygen-glucose deprivation/reoxygenation.Silencing Vav1 reduced the cerebral infarct volume and brain water content,inhibited neuronal loss and apoptosis in the ischemic penumbra,and im p roved neurological function in rats subjected to occlusion and repe rfusion of the middle cerebral artery.Further analysis showed that Vav1 was almost exclusively localized to microglia and that Vav1 downregulation inhibited microglial activation and the NOD-like receptor pyrin 3(NLRP3) inflammasome in the ischemic penumbra,as well as the expression of inflammato ry facto rs.In addition,Vov1 knoc kdown decreased the inflammatory response exhibited by BV-2 cells after oxygen-glucose deprivation/reoxyge nation.Taken together,these findings show that silencing Vav1 attenuates inflammation and neuronal apoptosis in rats subjected to cerebral ischemia/repe rfusion through inhibiting the activation of mic roglia and NLRP3 inflammasome.展开更多
Cerebral ischemia-reperfusion injury(CI/RI)remains the main cause of disability and death in stroke patients due to lack of effective therapeutic strategies.One of the main issues related to CI/RI treatment is the pre...Cerebral ischemia-reperfusion injury(CI/RI)remains the main cause of disability and death in stroke patients due to lack of effective therapeutic strategies.One of the main issues related to CI/RI treatment is the presence of the blood-brain barrier(BBB),which affects the intracerebral delivery of drugs.Ginkgolide B(GB),a major bioactive component in commercially available products of Ginkgo biloba,has been shown significance in CI/RI treatment by regulating inflammatory pathways,oxidative damage,and metabolic disturbance,and seems to be a candidate for stroke recovery.However,limited by its poor hydrophilicity and lipophilicity,the development of GB preparations with good solubility,stability,and the ability to cross the BBB remains a challenge.Herein,we propose a combinatorial strategy by conjugating GB with highly lipophilic docosahexaenoic acid(DHA)to obtain a covalent complex GB-DHA,which can not only enhance the pharmacological effect of GB,but can also be encapsulated in liposomes stably.The amount of finally constructed Lipo@GB-DHA targeting to ischemic hemisphere was validated 2.2 times that of free solution in middle cerebral artery occlusion(MCAO)rats.Compared to the marketed ginkgolide injection,Lipo@GB-DHA significantly reduced infarct volume with better neurobehavioral recovery in MCAO rats after being intravenously administered both at 2 h and 6 h post-reperfusion.Low levels of reactive oxygen species(ROS)and high neuron survival in vitro was maintained via Lipo@GB-DHA treatment,while microglia in the ischemic brain were polarized from the pro-inflammatory M1 phenotype to the tissue-repairing M2 phenotype,which modulate neuroinflammatory and angiogenesis.In addition,Lipo@GB-DHA inhibited neuronal apoptosis via regulating the apoptotic pathway and maintained homeostasis by activating the autophagy pathway.Thus,transforming GB into a lipophilic complex and loading it into liposomes provides a promising nanomedicine strategy with excellent CI/RI therapeutic efficacy and industrialization prospects.展开更多
Recently,we have reported that Oenanthe javanica extract(OJE)displays strong neuroprotective effect against ischemic damage after transient global cerebral ischemia.However,neuroprotective mechanisms of OJE have not b...Recently,we have reported that Oenanthe javanica extract(OJE)displays strong neuroprotective effect against ischemic damage after transient global cerebral ischemia.However,neuroprotective mechanisms of OJE have not been fully identified.Thus,this study investigated the neuroprotection of OJE in the hippocampal CA1 area and its anti-inflammatory activity in gerbils subjected to 5 minutes of transient global cerebral ischemia.We treated the animals by intragastrical injection of OJE(100 and 200 mg/kg)once daily for 1 week prior to transient global cerebral ischemia.Neuroprotection of OJE was observed by immunohistochemistry for neuronal nuclear antigen and histofluorescence staining for Fluoro-Jade B.Immunohistochemistry of glial fibrillary acidic protein and ionized calcium-binding adapter molecule 1 was done for astrocytosis and microgliosis,respectively.To investigate the neuroprotective mechanisms of OJE,we performed immunohistochemistry of tumor necrosis factor-alpha and interleukin-2 for pro-inflammatory function and interleukin-4 and interleukin-13 for anti-inflammatory function.When we treated the animals by intragastrical administration of 200 mg/kg of OJE,hippocampal CA1 pyramidal neurons were protected from transient global cerebral ischemia and cerebral ischemia-induced gliosis was inhibited in the ischemic hippocampal CA1 area.We also found that interleukin-4 and-13 immunoreactivities were significantly increased in pyramidal neurons of the ischemic CA1 area after OJE pretreatment,and the increased immunoreactivities were sustained in the CA1 pyramidal neurons after transient global cerebral ischemia.However,OJE pretreatment did not increase interleukin-2 and tumor necrosis factor-alpha immunoreactivities in the CA1 pyramidal neurons.Our findings suggest that pretreatment with OJE can protect neurons and attenuate gliosis from transient global cerebral ischemia via increasing expressions of interleukin-4 and-13.The experimental plan of this study was reviewed and approved by the Institutional Animal Care and Use Committee(IACUC)in Kangwon National University(approval No.KW-160802-1)on August 10,2016.展开更多
Ilexonin A is a compound isolated from the root of Ilex pubescens,a traditional Chinese medicine.Ilexonin A has been shown to play a neuroprotective role by regulating the activation of astrocytes and microglia in the...Ilexonin A is a compound isolated from the root of Ilex pubescens,a traditional Chinese medicine.Ilexonin A has been shown to play a neuroprotective role by regulating the activation of astrocytes and microglia in the peri-infarct area after ischemia.However,the effects of ilexonin A on astrocytes and microglia in the infarct-free region of the hippocampal CA1 region remain unclear.Focal cerebral ischemia models were established by 2-hour occlusion of the middle cerebral artery in rats.Ilexonin A(20,40 or 80 mg/kg)was administered immediately after ischemia/reperfusion.The astrocyte marker glial fibrillary acidic protein,microglia marker Iba-1,neural stem cell marker nestin and inflammation markers were detected by immunohistochemistry and western blot assay.Expression levels of tumor necrosis factor-αand interleukin 1βwere determined by enzyme linked immunosorbent assay in the hippocampal CA1 tissue.Astrocytes were activated immediately in progressively increasing numbers from 1,3,to 7 days post-ischemia/reperfusion.The number of activated astrocytes further increased in the hippocampal CA1 region after treatment with ilexonin A.Microglial cells remained quiescent after ischemia/reperfusion,but became activated after treatment with ilexonin A.Ilexonin A enhanced nestin expression and reduced the expression of tumor necrosis factor-αand interleukin 1βin the hippocampus post-ischemia/reperfusion.The results of the present study suggest that ilexonin A has a neuroprotective effect in the hippocampus after ischemia/reperfusion,probably through regulating astrocytes and microglia activation,promoting neuronal stem cell proliferation and reducing the levels of pro-inflammatory factors.This study was approved by the Animal Ethics Committee of the Fujian Medical University Union Hospital,China.展开更多
Transient ischemia in the whole brain leads to neuronal loss/death in vulnerable brain regions. The striatum, neocortex and hippocampus selectively loose specific neurons after transient ischemia. Just 5 minutes of tr...Transient ischemia in the whole brain leads to neuronal loss/death in vulnerable brain regions. The striatum, neocortex and hippocampus selectively loose specific neurons after transient ischemia. Just 5 minutes of transient ischemia can cause pyramidal neuronal death in the hippocampal cornu ammonis (CA) 1 field at 4 days after transient ischemia. In this study, we investigated the effects of 5-minute (mild), 15-minute (severe), and 20-minute (lethal) transient ischemia by bilateral common carotid artery occlusion (BCCAO) on behavioral change and neuronal death and gliosis (astrocytosis and microgliosis) in gerbil hippocampal subregions (CA1-3 region and dentate gyrus). We performed spontaneous motor activity test to evaluate gerbil locomotor activity, cresyl violet staining to detect cellular distribution, neuronal nuclei immunohistochemistry to detect neuronal distribution, and Fluoro-Jade B histofluorescence to evaluate neuronal death. We also conducted immunohistochemical staining for glial fibrillary acidic protein and ionized calcium-binding adapter molecule 1 (Ibal) to evaluate astrocytosis and microgliosis, respectively. Animals subjected to 20-minute BCCAO died in at least 2 days. BCCAO for 15 minutes led to pyramidal cell death in hippocampal CA1-3 region 2 days later and granule cell death in hippocampal de匚tate gyrus 5 days later. Similar results were not found in animals subjected to 5-minute BCCAO. Gliosis was much more rapidly and severely progressed in animals subjected to 15-minute BCCAO than in those subjected to 5- minute BCCAO. Our results indicate that neuronal loss in the hippocampal formation following transient ischemia is significantly different according to regions and severity of transient ischemia. The experimental protocol was approved by Institutional Animal Care and Use Committee (AICUC) of Kangwon National University (approval No. KW-180124-1) on May 22, 2018.展开更多
Cerebral ischemia/reperfusion injury impairs learning and memory in patients.Studies have shown that synaptic function is involved in the formation and development of memory,and that DNA methylation plays a key role i...Cerebral ischemia/reperfusion injury impairs learning and memory in patients.Studies have shown that synaptic function is involved in the formation and development of memory,and that DNA methylation plays a key role in the regulation of learning and memory.To investigate the role of DNA hypomethylation in cerebral ischemia/reperfusion injury,in this study,we established a rat model of cerebral ischemia/reperfusion injury by occlusion of the middle cerebral artery and then treated the rats with intraperitoneal 5-aza-2′-deoxycytidine,an inhibitor of DNA methylation.Our results showed that 5-aza-2′-deoxycytidine markedly improved the neurological function,and cognitive,social and spatial memory abilities,and dose-dependently increased the synaptic density and the expression of SYP and SHANK2 proteins in the hippocampus in a dose-dependent manner in rats with cerebral ischemia/reperfusion injury.The effects of 5-aza-2′-deoxycytidine were closely related to its reduction of genomic DNA methylation and DNA methylation at specific sites of the Syp and Shank2 genes in rats with cerebral ischemia/reperfusion injury.These findings suggest that inhibition of DNA methylation by 5-aza-2′-deoxycytidine promotes the recovery of learning and memory impairment in a rat model of cerebral ischemia/reperfusion injury.These results provide theoretical evidence for stroke treatment using epigenetic methods.展开更多
Although stroke is a major global health problem, a pharmacological treatment to inhibit ongoing neuronal death in patients is still lacking. In cerebral ischemia, the prevailing form of stroke, severely reduced blood...Although stroke is a major global health problem, a pharmacological treatment to inhibit ongoing neuronal death in patients is still lacking. In cerebral ischemia, the prevailing form of stroke, severely reduced blood supply by obstruction of blood vessels deprives neurons from oxygen and glucose, eventually leading to metabolic derailment and death of neurons in the affected brain area.展开更多
BACKGROUND: Immediate early gene (IEG) c-jun is a sensitive marker for functional status of nerve cells. Caspase-3 is a cysteine protease, which is a critical regulator of apoptosis. The effect of exogenous nerve grow...BACKGROUND: Immediate early gene (IEG) c-jun is a sensitive marker for functional status of nerve cells. Caspase-3 is a cysteine protease, which is a critical regulator of apoptosis. The effect of exogenous nerve growth factor (NGF) on the expression of c-jun mRNA and Caspase-3 protein in striate cortex of rats with transient global cerebral ischemia/reperfusion (IR) is unclear. OBJECTIVE: To study the protective effect of exogenous NGF on the brain of rats with transient global cerebral IR and its effecting pathway by observing the expression of c-jun mRNA and Caspase-3 protein. DESIGN: Randomized controlled animal trial. SETTING: Department of Neural Anatomy, Institute of Brain, China Medical University.MATERIALS:Eighteen healthy male SD rats of clean grade, aged 1 to 3 months, with body mass of 250 to 300 g, were involved in this study. NGF was provided by Dalian Svate Pharmaceutical Co.,Ltd. c-jun in situ hybridization detection kit, Caspase-3 antibody and SABC kit were purchased from Boster Biotechnology Co.,Ltd.METHODS: This trial was carried out in the Department of Neural Anatomy, Institute of Brain, China Medical University during September 2003 to April 2005. ① Experimental animals were randomized into three groups with 6 in each: sham-operation group, IR group and NGF group.②After the rats were anesthetized, the bilateral common carotid arteries and right external carotid arteries of rats were bluntly dissected and bilateral common carotid arteries were clamped for 30 minutes with bulldog clamps. Reperfusion began after buldog clamps were removed. Normal saline of 1mL and NGF (1×106 U/L) of 1 mL was injected into the common carotid artery of rats via right external carotid arteries in the IR group and NGF group respectively. The injection was conducted within 30 minutes, and then the right external carotid arteries were ligated. In the sham-operation group, occlusion of bilateral common carotid arteries and administration of drugs were omitted.③All the rats were executed by decollation at 3 hours after modeling. The animals were fixed with phosphate buffer solution (PBS, 0.1 mol/L) containing 40 g/L polyformaldehyde, their brains were quickly removed. The coronal section tissue mass containing striate cortex about 3 mm before line between two ears was taken and made into successive frozen sections.④The expression of c-jun mRNA and Caspase-3 protein in striate cortex of global cerebral ischemia rats were detected with in situ hybridization, immunohistochemistry and microscope image analysis. ⑤t test was used for comparing the difference of the measurement data.MAIN OUTCOME MEASURES:Comparison of the expression of IEG c-jun mRNA and Caspase-3 protein in striate cortex of brain of rats in each group.RESULTS:All the 18 SD rats were involved in the analysis of results. The c-jun mRNA and Caspase-3 protein positive reaction cells were found brown yellow in the striate cortex of rats, and most of them were in lamellas Ⅱ and Ⅲ, mainly presenting round or oval. The expression of c-jun mRNA and Caspase-3 protein in sham-operation group was weak or negative. The average gray value of c-jun mRNA and Caspase-3 protein in the IR group was significantly lower than that in the sham-operation group (49.52±4.13 vs. 95.48±5.28; 74.73±4.29 vs. 162.38±9.16,P < 0.01). The average gray value of c-jun mRNA and Caspase-3 protein in the NGF group was significantly higher than that in the IR group (63.96±4.25 vs.49.52±4.13; 83.98±4.13 vs. 74.73±4.29, P < 0.05). CONCLUSION: NGF can protect ischemic neurons by down-regulating the expression of c-jun mRNA and Caspase-3 protein in striate cortex of global cerebral ischemia rats.展开更多
In vivo imaging of cerebral ischemia/reperfusion injury remains an important challenge.We injected porous Ag/Au@SiO_(2) bimetallic hollow nanoshells carrying anti-tropomyosin 4 as a molecular probe into mice with cere...In vivo imaging of cerebral ischemia/reperfusion injury remains an important challenge.We injected porous Ag/Au@SiO_(2) bimetallic hollow nanoshells carrying anti-tropomyosin 4 as a molecular probe into mice with cerebral ischemia/reperfusion injury and observed microvascular changes in the brain using photoacoustic imaging with ultrasonography.At each measured time point,the total photoacoustic signal was significantly higher on the affected side than on the healthy side.Twelve hours after reperfusion,cerebral perfusion on the affected side increased,cerebrovascular injury worsened,and anti-tropomyosin 4 expression increased.Twenty-four hours after reperfusion and later,perfusion on the affected side declined slowly and stabilized after 1 week;brain injury was also alleviated.Histopathological and immunohistochemical examinations confirmed the brain injury tissue changes.The nanoshell molecular probe carrying anti-tropomyosin 4 has potential for use in early diagnosis of cerebral ischemia/reperfusion injury and evaluating its progression.展开更多
基金Supported by: the Foundation Program of Shandong Heatth Department, No. 2001CAICKAF
文摘BACKGROUND: Previous studies of cerebral ischemia have used young animals, with an ischemictime greater than 5 minutes (safe time limit). Despite an increased understanding of neuronalapoptosis, it remains uncertain whether brief cerebral ischemic events of 5 minutes or less damagebrain tissue in elderly rodents.OBJECTIVE: To investigate the effects of transient cerebral ischemia (5 minutes)/reperfusion injuryon brain cortical and hippocampal edema, aquaporin-4 (AQP-4) expression, and neuronal apoptosisin aged rats, and to compare ischemic sensitivity between cortex and hippocampus.DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at theInstitute of Cerebrovascular Disease, Qingdao University Medical School from April 2008 to March2009.MATERIALS: Rabbit anti-AQP-4 polyclonal antibody, TUNEL kit, and SABC immunohistochemistrykit were purchased from Wuhan Boster Bioengineering, China.METHODS: A total of 160 healthy, male, aged 19-21 months, Wistar rats were randomly assignedto 4 groups: sham-surgery, and ischemia 1-, 3-, and 5-minute groups, with 40 rats in each group.The global cerebral ischemia model was established using the Pusinelli four-vessel occlusion, andthe three cerebral ischemia groups were subdivided into reperfusion 12-hour, 1-, 2-, 3-, and 7-daysubgroups, with 8 rats in each subgroup. The sham-surgery group was subjected to exposure of thefirst cervical bilateral alar foramina and bilateral common carotid arteries.MAIN OUTCOME MEASURES: The dry-wet weight assay was used to measure brain water contentand histopathology of the cortex and hippocampus was observed following hematoxylin-eosinstaining. In addition, cortical and hippocampal AQP-4 expression was detected by streptavidin-biotincomplex immunohistochemistry, and neuronal apoptosis was detected by the TUNEL method.RESULTS: There was no significant difference in brain water content or AQP-4 expression in thecortex and hippocampus between ischemia 1- and 3-minute groups and the sham-surgery group orbrain water content or AQP-4 expression in the cortex between ischemia 5-minute group andsham-surgery group (P> 0.05). However, brain water content and AQP-4 expression in thehippocampus after 5 minutes of cerebral ischemia were significantly increased compared with thesham-surgery group (P < 0.05 or P < 0.01 ). Several TUNEL-positive cells were observed in thecortex and hippocampus of the sham-surgery group and ischemia 1-minute group, as well as in thecortex of the ischemia 3-minute group. In addition, the number of apoptotic neurons in thehippocampus of ischemia 3-minute group and in the cortex and hippocampus of ischemia 5-minutegroup was significantly increased (P < 0.05 or P < 0.01). Neuronal apoptosis was increased after 12hours of ischemia/reperfusion, and it reached a peak by 2 days (P < 0.01).CONCLUSION: Transient cerebral ischemia (5 minutes) resulted in increased hippocampal edema,AQP-4 expression, and neuronal apoptosis. Moreover, cerebral ischemia had a greater effect onneuronal apoptosis than brain edema or AQP-4 expression, and the hippocampus was moresensitive than the cortex.
基金supported by a grant from Ministry of Science and Technology of Qingdao City,No.10-3-4-7-8-JCH
文摘Mitochondria play an important role in neuronal apoptosis caused by cerebral ischemia, and the role is mediated by the expression of mitochondrial proteins. This study investigated the involvement of mitochondrial proteins in hippocampal cell apoptosis after transient cerebral ischemia-reperfusion injury in aged rats using a comparative proteomics strategy. Our experimental results show that the aged rat brain is sensitive to ischemia-reperfusion injury and that transient ischemia led to cell apoptosis in the hippocampus and changes in memory and cognition of aged rats. Differential proteomics analysis suggested that this phenomenon may be mediated by mitochondrial proteins associated with energy metabolism and apoptosis in aged rats. This study provides potential drug targets for the treatment of transient cerebral ischemia-reperfusion injury.
基金Supported by the National Natural Science Foundation of China(Nos.30973110 81072071)+2 种基金the International Cooperation Grant(No.20070721)the Outstanding Youth Grant from the Science and Technology Department of Jilin ProvinceChina (No.20080139)
文摘Proteasome activity reduction is an important pathological phenomenon, resulting in proteins aggregation and neuronal death in the injured neurons induced by transient ischemia. Our previous report showed that the trap of proteasome in the protein aggregates was a reason to lead to the reduction of proteasome activity. However, the patterns of proteasome entered into protein aggregates are not clear. In this study, we used a global ischemia model, Hematoxylin-Eosin staining, differential centrifuge, proteasome activity assay, sucrose gradient density centrifuge, and Western blot analysis to investigate this problem. Our results show that there are two aggregation patterns of proteasome after transient ischemia and reperfusion. One is that 26S proteasome is trapped by protein aggregates as a whole unit, and the other is that 19S or 20S is trapped in the protein aggregates, respectively, after 26S disassociates.
基金Supported by:the Postdoctoral Foundation of China,No.20080440422International Cooperation G rant,No.20070721+1 种基金Outstanding Youth Grant of the Science and Technology Department of Jilin Province, No.20080139a grant from the Science and Technology Department of Changchun City,No.2007128
文摘BACKGROUND:Proteasome dysfunction has been reported to induce abnormal protein aggregation and cell death. OBJECTIVE:To investigate the effect of proteasome changes on delayed neuronal death in CA1 and dentate gyrus(DG) regions of the rat hippocampus following transient cerebral ischemia. DESIGN,TIME AND SETTING:A randomized,controlled animal experiment.The study was performed at the Department of Biochemistry and Molecular Biology,Norman Bethune Medical College of Jilin University,from September 2006 to May 2008. MATERIALS:Rabbit anti-19S S10B polyclonal antibody was purchased from Bioreagents,USA; propidium iodide and fluorescently-labeled goat anti-rabbit IgG were purchased from Jackson Immunoresearch,USA;hematoxylin and eosin staining solution was purchased from Sigma,USA; LSM 510 confocal microscope was purchased from Zeiss,Germany. METHODS:A total of 40 healthy Wistar rats,male,4 months old,were randomly divided into sham surgery group(n = 8) and model group(n = 32).Ischemic models were established in the model group by transient clamping of the bilateral carotid arteries and decreased blood pressure. After 20 minutes of global ischemia,the clamp was removed to allow blood flow for 30 minutes,4,24, and 72 hours,respectively,with 8 rats at each time point.The bilateral carotid arteries were not ligated in the sham surgery group. MAIN OUTCOME MEASURES:Neuronal death in the CA1 and DG regions was observed by hematoxylin-eosin staining.Proteasome expression in CA1 and DG region neurons was detected by immunohistochemistry. RESULTS:Hematoxylin-eosin staining showed neuronal death in the CA1 region alone at 72 hours of reperfusion following ischemia.In comparison to the sham surgery group,a significant decrease in proteasome expression was observed,by immunohistochemistry,in the CA1 and DG regions in the model group,following 30 minutes,4,24,and 72 hours of reperfusion(P<0.01).After 72 hours of reperfusion following ischemia,proteasome expression had almost completely disappeared in the CA1 region.In contrast,neurons of the DG region showed minimized proteasome expression at 24 hours,with a slight increase at 72 hours(P<0.01). CONCLUSION:The alteration of proteasome following ischemia/reperfusion in the neurons of hippocampal CA1 and DG regions reduces the ability of cells to degrade abnormal protein,which may be an important factor resulting in delayed neuronal death following transient cerebral ischemia.
基金supported by National Science Fund for Distinguished Young Scholars(grant No.32025029)Shanghai Education Committee Scientific Research Innovation Project(grant No.2101070007800120)+1 种基金Clinical research project in health industry of Shanghai Municipal Health Commission(202240379)the Development Fund for Shanghai Talents(grant No.2021077).
文摘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.
文摘This case report investigates the manifestation of cerebral amyloid angiopathy (CAA) through recurrent Transient Ischemic Attacks (TIAs) in an 82-year-old patient. Despite initial diagnostic complexities, cerebral angiography-MRI revealed features indicative of CAA. Symptomatic treatment resulted in improvement, but the patient later developed a fatal hematoma. The discussion navigates the intricate therapeutic landscape of repetitive TIAs in the elderly with cardiovascular risk factors, emphasizing the pivotal role of cerebral MRI and meticulous bleeding risk management. The conclusion stresses the importance of incorporating SWI sequences, specifically when suspecting a cardioembolic TIA, as a diagnostic measure to explore and exclude CAA in the differential diagnosis. This case report provides valuable insights into these challenges, highlighting the need to consider CAA in relevant cases.
基金supported by the National Natural Science Foundation of China,Nos.82102295(to WG),82071339(to LG),82001119(to JH),and 81901994(to BZ).
文摘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.
基金supported by the National Natural Science Foundation of China,Nos.82104158(to XT),31800887(to LY),31972902(to LY),82001422(to YL)China Postdoctoral Science Foundation,No.2020M683750(to LY)partially by Young Talent Fund of University Association for Science and Technology in Shaanxi Province of China,No.20200307(to LY).
文摘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.
基金supported by the Natural Science Foundation of Anhui Province of China,No.2208085Y32Scientific Research Plan Project of Anhui Province of China,No.2022AH020076the Chen Xiao-Ping Foundation for the Development of Science and Technology of Hubei Province,No.CXPJJH12000005-07-115(all to CT).
文摘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.
基金supported by MINECO and FEDER funds:ref CPP2021-008855 and RTC-2015-4094-1,Junta de Castilla y León ref.LE025P1 7Neural Therapies SLref.NTDev-01 (all to AFL and JMGO)。
文摘The inflammato ry response plays an important role in neuroprotection and regeneration after ischemic insult.The use of non-ste roidal anti-inflammatory drugs has been a matter of debate as to whether they have beneficial or detrimental effects.In this context,the effects of the anti-inflammatory agent meloxicam have been scarcely documented after stro ke,but its ability to inhibit both cyclooxygenase isoforms(1 and 2) could be a promising strategy to modulate postischemic inflammation.This study analyzed the effect of meloxicam in a transient focal cerebral ischemia model in rats,measuring its neuroprotective effect after 48 hours and 7 days of reperfusion and the effects of the treatment on the glial scar and regenerative events such as the generation of new progenitors in the subventricular zone and axonal sprouting at the edge of the damaged area.We show that meloxicam’s neuroprotective effects remained after 7 days of reperfusion even if its administration was restricted to the two first days after ischemia.Moreover,meloxicam treatment modulated glial scar reactivity,which matched with an increase in axonal sprouting.However,this treatment decreased the formation of neuronal progenitor cells.This study discusses the dual role of anti-inflammatory treatments after stro ke and encourages the careful analysis of both the neuroprotective and the regenerative effects in preclinical studies.
基金Natural Science Foundation of Liaoning Province (General Program),No.2017010825 (to JQ)。
文摘Microglia,which are the resident macrophages of the central nervous system,are an important part of the inflammatory response that occurs after cerebral ischemia.Vav guanine nucleotide exchange factor 1(Vav1) is a guanine nucleotide exchange factor that is related to microglial activation.However,how Vav1 participates in the inflammato ry response after cerebral ischemia/reperfusion inj ury remains unclea r.In this study,we subjected rats to occlusion and repe rfusion of the middle cerebral artery and subjected the BV-2 mic roglia cell line to oxygen-glucose deprivatio n/reoxygenation to mimic cerebral ischemia/repe rfusion in vivo and in vitro,respectively.We found that Vav1 levels were increased in the brain tissue of rats subjected to occlusion and reperfusion of the middle cerebral arte ry and in BV-2 cells subjected to oxygen-glucose deprivation/reoxygenation.Silencing Vav1 reduced the cerebral infarct volume and brain water content,inhibited neuronal loss and apoptosis in the ischemic penumbra,and im p roved neurological function in rats subjected to occlusion and repe rfusion of the middle cerebral artery.Further analysis showed that Vav1 was almost exclusively localized to microglia and that Vav1 downregulation inhibited microglial activation and the NOD-like receptor pyrin 3(NLRP3) inflammasome in the ischemic penumbra,as well as the expression of inflammato ry facto rs.In addition,Vov1 knoc kdown decreased the inflammatory response exhibited by BV-2 cells after oxygen-glucose deprivation/reoxyge nation.Taken together,these findings show that silencing Vav1 attenuates inflammation and neuronal apoptosis in rats subjected to cerebral ischemia/repe rfusion through inhibiting the activation of mic roglia and NLRP3 inflammasome.
基金This research was funded by the National Natural Science Foundation of China(No.81773911,81690263 and 81573616)the Development Project of Shanghai Peak Disciplines-Integrated Medicine(No.20180101).
文摘Cerebral ischemia-reperfusion injury(CI/RI)remains the main cause of disability and death in stroke patients due to lack of effective therapeutic strategies.One of the main issues related to CI/RI treatment is the presence of the blood-brain barrier(BBB),which affects the intracerebral delivery of drugs.Ginkgolide B(GB),a major bioactive component in commercially available products of Ginkgo biloba,has been shown significance in CI/RI treatment by regulating inflammatory pathways,oxidative damage,and metabolic disturbance,and seems to be a candidate for stroke recovery.However,limited by its poor hydrophilicity and lipophilicity,the development of GB preparations with good solubility,stability,and the ability to cross the BBB remains a challenge.Herein,we propose a combinatorial strategy by conjugating GB with highly lipophilic docosahexaenoic acid(DHA)to obtain a covalent complex GB-DHA,which can not only enhance the pharmacological effect of GB,but can also be encapsulated in liposomes stably.The amount of finally constructed Lipo@GB-DHA targeting to ischemic hemisphere was validated 2.2 times that of free solution in middle cerebral artery occlusion(MCAO)rats.Compared to the marketed ginkgolide injection,Lipo@GB-DHA significantly reduced infarct volume with better neurobehavioral recovery in MCAO rats after being intravenously administered both at 2 h and 6 h post-reperfusion.Low levels of reactive oxygen species(ROS)and high neuron survival in vitro was maintained via Lipo@GB-DHA treatment,while microglia in the ischemic brain were polarized from the pro-inflammatory M1 phenotype to the tissue-repairing M2 phenotype,which modulate neuroinflammatory and angiogenesis.In addition,Lipo@GB-DHA inhibited neuronal apoptosis via regulating the apoptotic pathway and maintained homeostasis by activating the autophagy pathway.Thus,transforming GB into a lipophilic complex and loading it into liposomes provides a promising nanomedicine strategy with excellent CI/RI therapeutic efficacy and industrialization prospects.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2017R1D1A1B03033271,to JDK)the Bio-Synergy Research Project(NRF-2018M3A9C4076478,to IJK)of the Ministry of Science,ICT and Future Planning through the National Research Foundation
文摘Recently,we have reported that Oenanthe javanica extract(OJE)displays strong neuroprotective effect against ischemic damage after transient global cerebral ischemia.However,neuroprotective mechanisms of OJE have not been fully identified.Thus,this study investigated the neuroprotection of OJE in the hippocampal CA1 area and its anti-inflammatory activity in gerbils subjected to 5 minutes of transient global cerebral ischemia.We treated the animals by intragastrical injection of OJE(100 and 200 mg/kg)once daily for 1 week prior to transient global cerebral ischemia.Neuroprotection of OJE was observed by immunohistochemistry for neuronal nuclear antigen and histofluorescence staining for Fluoro-Jade B.Immunohistochemistry of glial fibrillary acidic protein and ionized calcium-binding adapter molecule 1 was done for astrocytosis and microgliosis,respectively.To investigate the neuroprotective mechanisms of OJE,we performed immunohistochemistry of tumor necrosis factor-alpha and interleukin-2 for pro-inflammatory function and interleukin-4 and interleukin-13 for anti-inflammatory function.When we treated the animals by intragastrical administration of 200 mg/kg of OJE,hippocampal CA1 pyramidal neurons were protected from transient global cerebral ischemia and cerebral ischemia-induced gliosis was inhibited in the ischemic hippocampal CA1 area.We also found that interleukin-4 and-13 immunoreactivities were significantly increased in pyramidal neurons of the ischemic CA1 area after OJE pretreatment,and the increased immunoreactivities were sustained in the CA1 pyramidal neurons after transient global cerebral ischemia.However,OJE pretreatment did not increase interleukin-2 and tumor necrosis factor-alpha immunoreactivities in the CA1 pyramidal neurons.Our findings suggest that pretreatment with OJE can protect neurons and attenuate gliosis from transient global cerebral ischemia via increasing expressions of interleukin-4 and-13.The experimental plan of this study was reviewed and approved by the Institutional Animal Care and Use Committee(IACUC)in Kangwon National University(approval No.KW-160802-1)on August 10,2016.
基金supported by the Natural Science Foundation of Fujian Province of China,No.2014J01327the Program for New Century Excellent Talents in Colleges and Universities of Fujian Province of China,No.NCETFJ-0704the Professorial Academic Development Foundation of Fujian Medical University of China,No.JS09014(all to GYZ)
文摘Ilexonin A is a compound isolated from the root of Ilex pubescens,a traditional Chinese medicine.Ilexonin A has been shown to play a neuroprotective role by regulating the activation of astrocytes and microglia in the peri-infarct area after ischemia.However,the effects of ilexonin A on astrocytes and microglia in the infarct-free region of the hippocampal CA1 region remain unclear.Focal cerebral ischemia models were established by 2-hour occlusion of the middle cerebral artery in rats.Ilexonin A(20,40 or 80 mg/kg)was administered immediately after ischemia/reperfusion.The astrocyte marker glial fibrillary acidic protein,microglia marker Iba-1,neural stem cell marker nestin and inflammation markers were detected by immunohistochemistry and western blot assay.Expression levels of tumor necrosis factor-αand interleukin 1βwere determined by enzyme linked immunosorbent assay in the hippocampal CA1 tissue.Astrocytes were activated immediately in progressively increasing numbers from 1,3,to 7 days post-ischemia/reperfusion.The number of activated astrocytes further increased in the hippocampal CA1 region after treatment with ilexonin A.Microglial cells remained quiescent after ischemia/reperfusion,but became activated after treatment with ilexonin A.Ilexonin A enhanced nestin expression and reduced the expression of tumor necrosis factor-αand interleukin 1βin the hippocampus post-ischemia/reperfusion.The results of the present study suggest that ilexonin A has a neuroprotective effect in the hippocampus after ischemia/reperfusion,probably through regulating astrocytes and microglia activation,promoting neuronal stem cell proliferation and reducing the levels of pro-inflammatory factors.This study was approved by the Animal Ethics Committee of the Fujian Medical University Union Hospital,China.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education(NRF-2016R1D1A1B01011790 to JHC)+3 种基金Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Science,ICT&Future Planning(NRF-2017R1A2B4009079 to MHW)Cooperative Research Program for Agriculture Science and Technology Development(Project No.PJ01329401to MHW) Rural Development Administration,Republic of Korea
文摘Transient ischemia in the whole brain leads to neuronal loss/death in vulnerable brain regions. The striatum, neocortex and hippocampus selectively loose specific neurons after transient ischemia. Just 5 minutes of transient ischemia can cause pyramidal neuronal death in the hippocampal cornu ammonis (CA) 1 field at 4 days after transient ischemia. In this study, we investigated the effects of 5-minute (mild), 15-minute (severe), and 20-minute (lethal) transient ischemia by bilateral common carotid artery occlusion (BCCAO) on behavioral change and neuronal death and gliosis (astrocytosis and microgliosis) in gerbil hippocampal subregions (CA1-3 region and dentate gyrus). We performed spontaneous motor activity test to evaluate gerbil locomotor activity, cresyl violet staining to detect cellular distribution, neuronal nuclei immunohistochemistry to detect neuronal distribution, and Fluoro-Jade B histofluorescence to evaluate neuronal death. We also conducted immunohistochemical staining for glial fibrillary acidic protein and ionized calcium-binding adapter molecule 1 (Ibal) to evaluate astrocytosis and microgliosis, respectively. Animals subjected to 20-minute BCCAO died in at least 2 days. BCCAO for 15 minutes led to pyramidal cell death in hippocampal CA1-3 region 2 days later and granule cell death in hippocampal de匚tate gyrus 5 days later. Similar results were not found in animals subjected to 5-minute BCCAO. Gliosis was much more rapidly and severely progressed in animals subjected to 15-minute BCCAO than in those subjected to 5- minute BCCAO. Our results indicate that neuronal loss in the hippocampal formation following transient ischemia is significantly different according to regions and severity of transient ischemia. The experimental protocol was approved by Institutional Animal Care and Use Committee (AICUC) of Kangwon National University (approval No. KW-180124-1) on May 22, 2018.
基金supported by the National Natural Science Foundation of China,No.82101567Doctoral Start-up Foundation of Liaoning Province,No.2021-BS-111345 Talent Project of Shengjing Hospital of China Medical University,No.M0673(all to XYF)。
文摘Cerebral ischemia/reperfusion injury impairs learning and memory in patients.Studies have shown that synaptic function is involved in the formation and development of memory,and that DNA methylation plays a key role in the regulation of learning and memory.To investigate the role of DNA hypomethylation in cerebral ischemia/reperfusion injury,in this study,we established a rat model of cerebral ischemia/reperfusion injury by occlusion of the middle cerebral artery and then treated the rats with intraperitoneal 5-aza-2′-deoxycytidine,an inhibitor of DNA methylation.Our results showed that 5-aza-2′-deoxycytidine markedly improved the neurological function,and cognitive,social and spatial memory abilities,and dose-dependently increased the synaptic density and the expression of SYP and SHANK2 proteins in the hippocampus in a dose-dependent manner in rats with cerebral ischemia/reperfusion injury.The effects of 5-aza-2′-deoxycytidine were closely related to its reduction of genomic DNA methylation and DNA methylation at specific sites of the Syp and Shank2 genes in rats with cerebral ischemia/reperfusion injury.These findings suggest that inhibition of DNA methylation by 5-aza-2′-deoxycytidine promotes the recovery of learning and memory impairment in a rat model of cerebral ischemia/reperfusion injury.These results provide theoretical evidence for stroke treatment using epigenetic methods.
基金the Swiss National Science Foundation (grants 31003A_156648 and 31003A_182325 to DB)the Foundation for Research in Science and the Humanities at the University of Zurich (grant STWF-18-005 to DB)。
文摘Although stroke is a major global health problem, a pharmacological treatment to inhibit ongoing neuronal death in patients is still lacking. In cerebral ischemia, the prevailing form of stroke, severely reduced blood supply by obstruction of blood vessels deprives neurons from oxygen and glucose, eventually leading to metabolic derailment and death of neurons in the affected brain area.
基金the Natural Science Foundation of LiaoningProvince, No. 619019
文摘BACKGROUND: Immediate early gene (IEG) c-jun is a sensitive marker for functional status of nerve cells. Caspase-3 is a cysteine protease, which is a critical regulator of apoptosis. The effect of exogenous nerve growth factor (NGF) on the expression of c-jun mRNA and Caspase-3 protein in striate cortex of rats with transient global cerebral ischemia/reperfusion (IR) is unclear. OBJECTIVE: To study the protective effect of exogenous NGF on the brain of rats with transient global cerebral IR and its effecting pathway by observing the expression of c-jun mRNA and Caspase-3 protein. DESIGN: Randomized controlled animal trial. SETTING: Department of Neural Anatomy, Institute of Brain, China Medical University.MATERIALS:Eighteen healthy male SD rats of clean grade, aged 1 to 3 months, with body mass of 250 to 300 g, were involved in this study. NGF was provided by Dalian Svate Pharmaceutical Co.,Ltd. c-jun in situ hybridization detection kit, Caspase-3 antibody and SABC kit were purchased from Boster Biotechnology Co.,Ltd.METHODS: This trial was carried out in the Department of Neural Anatomy, Institute of Brain, China Medical University during September 2003 to April 2005. ① Experimental animals were randomized into three groups with 6 in each: sham-operation group, IR group and NGF group.②After the rats were anesthetized, the bilateral common carotid arteries and right external carotid arteries of rats were bluntly dissected and bilateral common carotid arteries were clamped for 30 minutes with bulldog clamps. Reperfusion began after buldog clamps were removed. Normal saline of 1mL and NGF (1×106 U/L) of 1 mL was injected into the common carotid artery of rats via right external carotid arteries in the IR group and NGF group respectively. The injection was conducted within 30 minutes, and then the right external carotid arteries were ligated. In the sham-operation group, occlusion of bilateral common carotid arteries and administration of drugs were omitted.③All the rats were executed by decollation at 3 hours after modeling. The animals were fixed with phosphate buffer solution (PBS, 0.1 mol/L) containing 40 g/L polyformaldehyde, their brains were quickly removed. The coronal section tissue mass containing striate cortex about 3 mm before line between two ears was taken and made into successive frozen sections.④The expression of c-jun mRNA and Caspase-3 protein in striate cortex of global cerebral ischemia rats were detected with in situ hybridization, immunohistochemistry and microscope image analysis. ⑤t test was used for comparing the difference of the measurement data.MAIN OUTCOME MEASURES:Comparison of the expression of IEG c-jun mRNA and Caspase-3 protein in striate cortex of brain of rats in each group.RESULTS:All the 18 SD rats were involved in the analysis of results. The c-jun mRNA and Caspase-3 protein positive reaction cells were found brown yellow in the striate cortex of rats, and most of them were in lamellas Ⅱ and Ⅲ, mainly presenting round or oval. The expression of c-jun mRNA and Caspase-3 protein in sham-operation group was weak or negative. The average gray value of c-jun mRNA and Caspase-3 protein in the IR group was significantly lower than that in the sham-operation group (49.52±4.13 vs. 95.48±5.28; 74.73±4.29 vs. 162.38±9.16,P < 0.01). The average gray value of c-jun mRNA and Caspase-3 protein in the NGF group was significantly higher than that in the IR group (63.96±4.25 vs.49.52±4.13; 83.98±4.13 vs. 74.73±4.29, P < 0.05). CONCLUSION: NGF can protect ischemic neurons by down-regulating the expression of c-jun mRNA and Caspase-3 protein in striate cortex of global cerebral ischemia rats.
基金supported by the National Natural Science Foundation of China,No.81730050(to WH).
文摘In vivo imaging of cerebral ischemia/reperfusion injury remains an important challenge.We injected porous Ag/Au@SiO_(2) bimetallic hollow nanoshells carrying anti-tropomyosin 4 as a molecular probe into mice with cerebral ischemia/reperfusion injury and observed microvascular changes in the brain using photoacoustic imaging with ultrasonography.At each measured time point,the total photoacoustic signal was significantly higher on the affected side than on the healthy side.Twelve hours after reperfusion,cerebral perfusion on the affected side increased,cerebrovascular injury worsened,and anti-tropomyosin 4 expression increased.Twenty-four hours after reperfusion and later,perfusion on the affected side declined slowly and stabilized after 1 week;brain injury was also alleviated.Histopathological and immunohistochemical examinations confirmed the brain injury tissue changes.The nanoshell molecular probe carrying anti-tropomyosin 4 has potential for use in early diagnosis of cerebral ischemia/reperfusion injury and evaluating its progression.
