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
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
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
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
Ischemic accumulation of succinate causes cerebral damage by excess production of reactive oxygen species. However, it is unknown whether ischemic accumulation of succinate affects neural stem cell proliferation. In t...Ischemic accumulation of succinate causes cerebral damage by excess production of reactive oxygen species. However, it is unknown whether ischemic accumulation of succinate affects neural stem cell proliferation. In this study, we established a rat model of cerebral ischemia/reperfusion injury by occlusion of the middle cerebral artery. We found that succinate levels increased in serum and brain tissue(cortex and hippocampus) after ischemia/reperfusion injury. Oxygen-glucose deprivation and reoxygenation stimulated primary neural stem cells to produce abundant succinate. Succinate can be converted into diethyl succinate in cells. Exogenous diethyl succinate inhibited the proliferation of mouse-derived C17.2 neural stem cells and increased the infarct volume in the rat model of cerebral ischemia/reperfusion injury. Exogenous diethyl succinate also increased the succinylation of the Rho family GTPase Cdc42 but repressed Cdc42 GTPase activity in C17.2 cells. Increasing Cdc42 succinylation by knockdown of the desuccinylase Sirt5 also inhibited Cdc42 GTPase activity in C17.2 cells. Our findings suggest that ischemic accumulation of succinate decreases Cdc42 GTPase activity by induction of Cdc42 succinylation, which inhibits the proliferation of neural stem cells and aggravates cerebral ischemia/reperfusion injury.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
CDGSH iron sulfur domain 2 can inhibit ferroptosis,which has been associated with cerebral ischemia/reperfusion,in individuals with head and neck cancer.Therefore,CDGSH iron sulfur domain 2 may be implicated in cerebr...CDGSH iron sulfur domain 2 can inhibit ferroptosis,which has been associated with cerebral ischemia/reperfusion,in individuals with head and neck cancer.Therefore,CDGSH iron sulfur domain 2 may be implicated in cerebral ischemia/reperfusion injury.To validate this hypothesis in the present study,we established mouse models of occlusion of the middle cerebral artery and HT22 cell models of oxygen-glucose deprivation and reoxygenation to mimic cerebral ischemia/reperfusion injury in vivo and in vitro,respectively.We found remarkably decreased CDGSH iron sulfur domain 2 expression in the mouse brain tissue and HT22 cells.When we used adeno-associated virus and plasmid to up-regulate CDGSH iron sulfur domain 2 expression in the brain tissue and HT22 cell models separately,mouse neurological dysfunction was greatly improved;the cerebral infarct volume was reduced;the survival rate of HT22 cells was increased;HT22 cell injury was alleviated;the expression of ferroptosis-related glutathione peroxidase 4,cystine-glutamate antiporter,and glutathione was increased;the levels of malondialdehyde,iron ions,and the expression of transferrin receptor 1 were decreased;and the expression of nuclear-factor E2-related factor 2/heme oxygenase 1 was increased.Inhibition of CDGSH iron sulfur domain 2 upregulation via the nuclear-factor E2-related factor 2 inhibitor ML385 in oxygen-glucose deprived and reoxygenated HT22 cells blocked the neuroprotective effects of CDGSH iron sulfur domain 2 up-regulation and the activation of the nuclear-factor E2-related factor 2/heme oxygenase 1 pathway.Our data indicate that the up-regulation of CDGSH iron sulfur domain 2 can attenuate cerebral ischemia/reperfusion injury,thus providing theoretical support from the perspectives of cytology and experimental zoology for the use of this protein as a therapeutic target in patients with cerebral ischemia/reperfusion injury.展开更多
Buyanghuanwu decoction has been shown to protect against cerebral ischemia/reperfusion injury,but the underlying mechanisms remain unclear.In this study,rats were intragastrically given Buyanghuanwu decoction,15 m L/k...Buyanghuanwu decoction has been shown to protect against cerebral ischemia/reperfusion injury,but the underlying mechanisms remain unclear.In this study,rats were intragastrically given Buyanghuanwu decoction,15 m L/kg,for 3 days.A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion.In rats administered Buyanghuanwu decoction,infarct volume was reduced,serum vascular endothelial growth factor and integrin αvβ3 levels were increased,and brain tissue vascular endothelial growth factor and CD34 expression levels were increased compared with untreated animals.These effects of Buyanghuanwu decoction were partially suppressed by an angiogenesis inhibitor(administered through the lateral ventricle for 7 consecutive days).These data suggest that Buyanghuanwu decoction promotes angiogenesis,improves cerebral circulation,and enhances brain tissue repair after cerebral ischemia/reperfusion injury.展开更多
Electroacupuncture preconditioning at acupoint Baihui(GV20) can reduce focal cerebral ischemia/reperfusion injury. However, the precise protective mechanism remains unknown. Mitochondrial fission mediated by dynamin-r...Electroacupuncture preconditioning at acupoint Baihui(GV20) can reduce focal cerebral ischemia/reperfusion injury. However, the precise protective mechanism remains unknown. Mitochondrial fission mediated by dynamin-related protein 1(Drp1) can trigger neuronal apoptosis following cerebral ischemia/reperfusion injury. Herein, we examined the hypothesis that electroacupuncture pretreatment can regulate Drp1, and thus inhibit mitochondrial fission to provide cerebral protection. Rat models of focal cerebral ischemia/reperfusion injury were established by middle cerebral artery occlusion at 24 hours after 5 consecutive days of preconditioning with electroacupuncture at GV20(depth 2 mm, intensity 1 m A, frequency 2/15 Hz, for 30 minutes, once a day). Neurological function was assessed using the Longa neurological deficit score. Pathological changes in the ischemic penumbra on the injury side were assessed by hematoxylin-eosin staining. Cellular apoptosis in the ischemic penumbra on the injury side was assessed by terminal deoxyribonucleotidyl transferase-mediated d UTP-digoxigenin nick end labeling staining. Mitochondrial ultrastructure in the ischemic penumbra on the injury side was assessed by transmission electron microscopy. Drp1 and cytochrome c expression in the ischemic penumbra on the injury side were assessed by western blot assay. Results showed that electroacupuncture preconditioning decreased expression of total and mitochondrial Drp1, decreased expression of total and cytosolic cytochrome c, maintained mitochondrial morphology and reduced the proportion of apoptotic cells in the ischemic penumbra on the injury side, with associated improvements in neurological function. These data suggest that electroacupuncture preconditioning-induced neuronal protection involves inhibition of the expression and translocation of Drp1.展开更多
Some in vitro experiments have shown that erythropoietin(EPO) increases resistance to apoptosis and facilitates neuronal survival following cerebral ischemia.However,results from in vivo studies are rarely reported.Pe...Some in vitro experiments have shown that erythropoietin(EPO) increases resistance to apoptosis and facilitates neuronal survival following cerebral ischemia.However,results from in vivo studies are rarely reported.Perfusion-weighted imaging(PWI) and diffusion-weighted imaging(DWI) have been applied successfully to distinguish acute cerebral ischemic necrosis and penumbra in living animals; therefore,we hypothesized that PWI and DWI could be used to provide imaging evidence in vivo for the conclusion that EPO could reduce apoptosis in brain areas injured by cerebral ischemia/reperfusion.To validate this hypothesis,we established a rat model of focal cerebral ischemia/reperfusion injury,and treated with intra-cerebroventricular injection of EPO(5,000 U/kg) 20 minutes before injury.Brain tissue in the ischemic injury zone was sampled using MRI-guided localization.The relative area of abnormal tissue,changes in PWI and DWI in the ischemic injury zone,and the number of apoptotic cells based on Td T-mediated d UTP-biotin nick end-labeling(TUNEL) were assessed.Our findings demonstrate that EPO reduces the relative area of abnormally high signal in PWI and DWI,increases cerebral blood volume,and decreases the number of apoptotic cells positive for TUNEL in the area injured by cerebral ischemia/reperfusion.The experiment provides imaging evidence in vivo for EPO treating cerebral ischemia/reperfusion injury.展开更多
13-Methyltetradecanoic acid can stabilize cell membrane and have anti-inflammatory,antioxidant and anti-apoptotic effects.Previous studies mainly focused on peripheral nerve injury,but seldom on the central nervous sy...13-Methyltetradecanoic acid can stabilize cell membrane and have anti-inflammatory,antioxidant and anti-apoptotic effects.Previous studies mainly focused on peripheral nerve injury,but seldom on the central nervous system.We investigated whether these properties of 13-methyltetradecanoic acid have a neuroprotective effect on focal cerebral ischemia/reperfusion injury,and detected the expression of basic fibroblast growth factor and vascular endothelial growth factor.This study established rat models of middle cerebral artery occlusion/reperfusion injury by ischemia for 2 hours and reperfusion for 24 hours.At the beginning of reperfusion,13-methyltetradecanoic acid 10,40 or 80 mg/kg was injected into the tail vein.Results found that various doses of 13-methyltetradecanoic acid effectively reduced infarct volume,mitigate cerebral edema,and increased the m RNA and protein expression of basic fibroblast growth factor and vascular endothelial growth factor at 24 hours of reperfusion.The effect was most significant in the 13-methyltetradecanoic acid 40 and 80 mg/kg groups.The findings suggest that 13-methyltetradecanoic acid can relieve focal ischemia/reperfusion injury immediately after reperfusion,stimulate the upregulation of basic fibroblast growth factor and vascular endothelial growth factor to exert neuroprotective effects.展开更多
Hypoxic preconditioning can protect against cerebral ischemia/reperfusion injury. However, the underlying mechanisms that mediate this effect are not completely clear. In this study, mice were pretreated with continuo...Hypoxic preconditioning can protect against cerebral ischemia/reperfusion injury. However, the underlying mechanisms that mediate this effect are not completely clear. In this study, mice were pretreated with continuous, intermittent hypoxic preconditioning;1 hour later, cerebral ischemia/reperfusion models were generated by middle cerebral artery occlusion and reperfusion. Compared with control mice, mice with cerebral ischemia/reperfusion injury showed increased Bederson neurological function scores, significantly increased cerebral infarction volume, obvious pathological damage to the hippocampus, significantly increased apoptosis;upregulated interleukin-1β, interleukin-6, and interleukin-8 levels in brain tissue;and increased expression levels of NOD-like receptor family pyrin domain containing 3(NLRP3), NLRP inflammasome-related protein caspase-1, and gasdermin D. However, hypoxic preconditioning significantly inhibited the above phenomena. Taken together, these data suggest that hypoxic preconditioning mitigates cerebral ischemia/reperfusion injury in mice by reducing NLRP3 inflammasome expression. This study was approved by the Medical Ethics Committee of the Fourth Hospital of Baotou, China(approval No. DWLL2019001) in November 2019.展开更多
Apoptosis is an important programmed cell death process involved in ischemia/reperfusion injury.MicroRNAs are considered to play an important role in the molecular mechanism underlying the regulation of cerebral ische...Apoptosis is an important programmed cell death process involved in ischemia/reperfusion injury.MicroRNAs are considered to play an important role in the molecular mechanism underlying the regulation of cerebral ischemia and reperfusion injury.However,whether miR-670 can regulate cell growth and death in cerebral ischemia/reperfusion and the underlying mechanism are poorly understood.In this study,we established mouse models of transient middle artery occlusion and Neuro 2a cell models of oxygen-glucose deprivation and reoxygenation to investigate the potential molecular mechanism by which miR-670 exhibits its effects during cerebral ischemia/reperfusion injury both in vitro and in vivo.Our results showed that after ischemia/reperfusion injury,miR-670 expression was obviously increased.After miR-670 expression was inhibited with an miR-670 antagomir,cerebral ischemia/reperfusion injury-induced neuronal death was obviously reduced.When miR-670 overexpression was induced by an miR-670 agomir,neuronal apoptosis was increased.In addition,we also found that miR-670 could promote Yap degradation via phosphorylation and worsen neuronal apoptosis and neurological deficits.Inhibition of miR-670 reduced neurological impairments after cerebral ischemia/reperfusion injury.These results suggest that microRNA-670 aggravates cerebral ischemia/reperfusion injury through the Yap pathway,which may be a potential target for treatment of cerebral ischemia/reperfusion injury.The present study was approved by the Institutional Animal Care and Use Committee of China Medical University on February 27,2017(IRB No.2017PS035K).展开更多
Interleukin-4(IL-4) has a protective effect against cerebral ischemia/reperfusion injury. Animal experiments have shown that IL-4 improves the short-and long-term prognosis of neurological function. The Akt(also calle...Interleukin-4(IL-4) has a protective effect against cerebral ischemia/reperfusion injury. Animal experiments have shown that IL-4 improves the short-and long-term prognosis of neurological function. The Akt(also called protein kinase B, PKB)/glycogen synthase kinase-3β(Akt/GSK-3β) signaling pathway is involved in oxidative stress, the inflammatory response, apoptosis, and autophagy. However, it is not yet clear whether the Akt/GSK-3β pathway participates in the neuroprotective effect of IL-4 against cerebral ischemia/reperfusion injury. In the present study, we established a cerebral ischemia/reperfusion mouse model by middle cerebral artery occlusion for 60 minutes followed by a 24-hour reperfusion. An IL-4/anti-IL-4 complex(10 μg) was intraperitoneally administered 30 minutes before surgery. We found that administration of IL-4 significantly alleviated the neurological deficits, oxidative stress, cell apoptosis, and autophagy and reduced infarct volume of the mice with cerebral ischemia/reperfusion injury 24 hours after reperfusion. Simultaneously, IL-4 activated Akt/GSK-3β signaling pathway. However, an Akt inhibitor LY294002, which was injected at 15 nmol/kg via the tail vein, attenuated the protective effects of IL-4. These findings indicate that IL-4 has a protective effect on cerebral ischemia/reperfusion injury by mitigating oxidative stress, reducing apoptosis, and inhibiting excessive autophagy, and that this mechanism may be related to activation of the Akt/GSK-3β pathway. This animal study was approved by the Animal Ethics Committee of Renmin Hospital of Wuhan University, China(approval No. WDRY2017-K037) on March 9, 2017.展开更多
Severe cerebral ischemia/reperfusion injury has been shown to induce high-level autophagy and neuronal death.Therefore,it is extremely important to search for a target that inhibits autophagy activation.Long non-codin...Severe cerebral ischemia/reperfusion injury has been shown to induce high-level autophagy and neuronal death.Therefore,it is extremely important to search for a target that inhibits autophagy activation.Long non-coding RNA MEG3 participates in autophagy.However,it remains unclear whether it can be targeted to regulate cerebral ischemia/reperfusion injury.Our results revealed that in oxygen and glucose deprivation/reoxygenation-treated HT22 cells,MEG3 expression was obviously upregulated,and autophagy was increased,while knockdown of MEG3 expression greatly reduced autophagy.Furthermore,MEG3 bound mi R-181 c-5 p and inhibited its expression,while mi R-181 c-5 p bound to autophagy-related gene ATG7 and inhibited its expression.Further experiments revealed that mir-181 c-5 p overexpression reversed the effect of MEG3 on autophagy and ATG7 expression in HT22 cells subjected to oxygen and glucose deprivation/reoxygenation.In vivo experiments revealed that MEG3 knockdown suppressed autophagy,infarct volume and behavioral deficits in cerebral ischemia/reperfusion mice.These findings suggest that MEG3 knockdown inhibited autophagy and alleviated cerebral ischemia/reperfusion injury through the mi R-181 c-5 p/ATG7 signaling pathway.Therefore,MEG3 can be considered as an intervention target for the treatment of cerebral ischemia/reperfusion injury.This study was approved by the Animal Ethics Committee of the First Affiliated Hospital of Zhengzhou University,China(approval No.XF20190538)on January 4,2019.展开更多
BACKGROUND:Aquaporin-4 (AQP-4) over-expression following cerebral ischemia results in cerebral edema. Picroside Ⅱ has been shown to exhibit a neuroprotective effect on neuronal apoptosis. However,few reports have add...BACKGROUND:Aquaporin-4 (AQP-4) over-expression following cerebral ischemia results in cerebral edema. Picroside Ⅱ has been shown to exhibit a neuroprotective effect on neuronal apoptosis. However,few reports have addressed the neuroprotective mechanisms and therapeutic times following cerebral ischemic reperfusion injury. OBJECTIVE:To explore the neuroprotective effects and ideal treatment window for picroside II treatment of middle cerebral artery occlusion and reperfusion injury in rats. DESIGN,TIME AND SETTING:A randomized,controlled,animal experiment was performed at Institute of Cerebrovascular Diseases,Qingdao University Medical College from September 2008 to May 2009. MATERIALS:Picroside Ⅱ was purchased from Tianjin Kuiqing Medical Technology,China. METHODS:A total of 165 adult,healthy,male,Wistar rats were randomly assigned to sham-surgery (n = 15),model (n = 75),and treatment groups (n = 75). Rats in the model and treatment groups underwent middle cerebral artery occlusion and reperfusion through the use of an intraluminal monofilament suture on the left external-internal carotid artery. The treatment group was injected with 1.0% picroside Ⅱ (10 mg/kg) into the tail vein,and the model and sham-surgery groups were injected with 0.1 mol/L phosphate buffered saline (250 μL). MAIN OUTCOME MEASURES:Neurological functional scores were evaluated using the Longa's method; cerebral infarction volume was detected through the use of tetrazolium chloride staining; cellular apoptosis was determined through the use of the in situ end-labeling method; aquaporin-4 expression was measured using fluorescence labeling analysis and reverse transcription polymerase chain reaction technique. RESULTS:At 0.5 hour following cerebral ischemic injury,neurological functional scores were low,and a small infarction focus was detected in the ischemic cortex of the model group. Along with prolonged ischemia and an increased number of apoptosis-positive cells,AQP-4 mRNA and protein expression was increased. At 1-2 hours after ischemia,neurological scores and infarction sizes were significantly increased in the model group. Apoptotic-positive cells were widespread in the ipsilateral cortex and striatum. In addition,AQP-4 mRNA and protein expression levels were increased. Picroside Ⅱ treatment significantly decreased neurological scores and infarction volume,and reduced AQP-4 mRNA and protein expression levels compared with the model group (P < 0.05 or P < 0.01). At 1 hour after ischemia,the therapeutic effect of picroside Ⅱ was notable (P < 0.01). CONCLUSION:Picroside Ⅱ played a protective role in cerebral ischemic reperfusion injury by inhibiting apoptosis and regulating AQP-4 expression. The best therapeutic time window was 1 hour after cerebral ischemic reperfusion.展开更多
At present,predicting the severity of brain injury caused by global cerebral ischemia/reperfusion injury(GCI/RI)is a clinical problem.After such an injury,clinical indicators that can directly reflect neurological dys...At present,predicting the severity of brain injury caused by global cerebral ischemia/reperfusion injury(GCI/RI)is a clinical problem.After such an injury,clinical indicators that can directly reflect neurological dysfunction are lacking.The change in hippocampal microstructure is the key to memory formation and consolidation.Diffusion tensor imaging is a highly sensitive tool for visualizing injury to hippocampal microstructure.Although hippocampal microstructure,brain-derived neurotrophic factor(BDNF),and tropomyosin-related kinase B(Trk B)levels are closely related to nerve injury and the repair process after GCI/RI,whether these indicators can reflect the severity of such hippocampal injury remains unknown.To address this issue,we established rat models of GCI/RI using the four-vessel occlusion method.Diffusion tensor imaging parameters,BDNF,and Trk B levels were correlated with modified neurological severity scores.The results revealed that after GCI/RI,while neurological function was not related to BDNF and Trk B levels,it was related to hippocampal fractional anisotropy.These findings suggest that hippocampal fractional anisotropy can reflect the severity of hippocampal injury after global GCI/RI.The study was approved by the Institutional Animal Care and Use Committee of Capital Medical University,China(approval No.AEEI-2015-139)on November 9,2015.展开更多
Ischemic stroke leads to high potentiality of mortality and disability. The current treatment for ischemic stroke is mainly focused on intravenous thrombolytic therapy. However, ischemia/reperfusion induces neuronal d...Ischemic stroke leads to high potentiality of mortality and disability. The current treatment for ischemic stroke is mainly focused on intravenous thrombolytic therapy. However, ischemia/reperfusion induces neuronal damage, which significantly influences the outcome of patients with ischemic stroke, and the exact mechanism implicated in ischemia/reperfusion injury remains unclear, although evidence shows that oxidative stress is likely to be involved. Betulinic acid is mainly known for its anti-tumor and anti-inflammatory activities. Our previous study showed that betulinic acid could decrease the reactive oxygen species(ROS) production by regulating the expression of NADPH oxidase. Thus, we hypothesized that betulinic acid may protect against brain ischemic injury in the animal model of stroke. Focal cerebral ischemia was achieved by using the standard intraluminal occlusion method and reperfusion enabled after 2 h ischemia. Neurological deficits were scored. Infarct size was determined with 2,3,5-triphenyltetrazolium chloride monohydrate(TTC) staining and the mRNA expression of NADPH oxidase 4(NOX4) was determined by RT-PCR in infarct tissue. ROS generation and apoptosis in ischemic tissue were analyzed by measuring the oxidative conversion of cell permeable 2',7'-dichloro-fluorescein diacetate(DCF-DA) to fluorescent dichlorofluorescein(DCF) in fluorescence microplate reader and TUNEL assay, respectively. In Kunming mice, 2 h of middle cerebral artery(MCA) occlusion followed by 24 or 72 h of reperfusion led to an enhanced NOX4 expression in the ischemic hemisphere. This was associated with elevated levels of ROS generation and neuronal apoptosis. Pre-treatment with betulinic acid(50 mg/kg/day for 7 days via gavage) prior to MCA occlusion prevented the ischemia/reperfusion-induced up-regulation of NOX4 and ROS production. In addition, treatment with betulinic acid could markedly blunt the ischemia/reperfusion-induced neuronal apoptosis. Finally, betulinic acid reduced infarct volume and ameliorated the neurological deficit in this stroke mouse model. Our results suggest that betulinic acid protects against cerebral ischemia/reperfusion injury in mice and the down-regulation of NOX4 may represent a mechanism contributing to this effect.展开更多
BACKGROUND: Endoplasmic reticulum (ER) stress impairs ER functions and leads to the accumulation of unfolded or misfolded proteins in the ER lumen. ER stress-induced cell death plays an important role in cerebral isch...BACKGROUND: Endoplasmic reticulum (ER) stress impairs ER functions and leads to the accumulation of unfolded or misfolded proteins in the ER lumen. ER stress-induced cell death plays an important role in cerebral ischemia. Edaravon (3-methyl-1-phenyl-2-pyrazolin-5-one) is a potent and novel scavenger of free radicals that inhibit delayed neuronal death, as demonstrated by in vitro and animal studies. However, its effect on ER stress and induced neuronal apoptosis in a rat model of brief middle cerebral artery occlusion remains unclear. OBJECTIVE: To explore the effects of edaravone on the expression of ER stress-related factors and neuronal apoptosis, based on the hypothesis that edaravone influences ER stress in a rat model of cerebral ischemia/reperfusion. DESIGN, TIME AND SETTING: A randomized, controlled, animal study was performed at the Laboratory of Department of Neurology, Xiangya Hospital and the Department of Laboratory Animals, Xiangya Medical College, Central South University in China from June 2005 to May 2006. MATERIALS: Edaravone was purchased from Simcere Pharmaceutical Group, China. METHODS: A total of 216 adult, male, Sprague Dawley rats were randomly assigned to sham-surgery, model and edaravone groups, with 72 rats in each group. Brief middle cerebral artery occlusion was established in the model and edaravone groups. In addition, the edaravone group rats were injected with 3 mg/kg edaravone through the tail vein. MAIN OUTCOME MEASURES: RNA-dependent protein kinase-like endoplasmic reticulum eukaryotic translation initiation factor 2α kinase (PERK) and C/EBP homology protein (CHOP) mRNA expression in the ischemic parietal cortex was determined by reverse transcription- polymerase chain reaction; phosphorylated PERK and CHOP protein expression was detected by immunohistochemistry; neuronal apoptosis was detected by TdT-mediated-dUTP nick end labeling. RESULTS: Neurological deficit scores were significantly reduced in the edaravone group compared to the model group at 12, 24, and 72 hours following reperfusion (P < 0.05). In addition, PERK and CHOP mRNA as well as phosphorylated PERK and CHOP protein expression were significantly reduced in the edaravone group compared to the model group at 1, 3, and 6 hours following reperfusion (P < 0.05, P < 0.01). CHOP mRNA expression was decreased in the edaravone group compared to the model group at 3, 6, 12, and 24 hours following reperfusion (P < 0.01), while CHOP protein expression was less than the model group at 6, 12, and 24 hours following reperfusion (P < 0.05). CONCLUSION: Edaravone treatment resulted in decreased PERK and CHOP expression following ischemia/reperfusion, as well as reduced neuronal apoptosis. Edaravone exhibited a neuroprotective role by inhibiting endoplasmic reticulum stress.展开更多
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 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.
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supported by the National Natural Science Foundation of China,No. 81671164 (to SHQ)the Natural Science Foundation of Jiangsu Province of China,No. BK20211348 (to SHQ)Xuzhou Basic Research Program,No. KC21030 (to LYH)。
文摘Ischemic accumulation of succinate causes cerebral damage by excess production of reactive oxygen species. However, it is unknown whether ischemic accumulation of succinate affects neural stem cell proliferation. In this study, we established a rat model of cerebral ischemia/reperfusion injury by occlusion of the middle cerebral artery. We found that succinate levels increased in serum and brain tissue(cortex and hippocampus) after ischemia/reperfusion injury. Oxygen-glucose deprivation and reoxygenation stimulated primary neural stem cells to produce abundant succinate. Succinate can be converted into diethyl succinate in cells. Exogenous diethyl succinate inhibited the proliferation of mouse-derived C17.2 neural stem cells and increased the infarct volume in the rat model of cerebral ischemia/reperfusion injury. Exogenous diethyl succinate also increased the succinylation of the Rho family GTPase Cdc42 but repressed Cdc42 GTPase activity in C17.2 cells. Increasing Cdc42 succinylation by knockdown of the desuccinylase Sirt5 also inhibited Cdc42 GTPase activity in C17.2 cells. Our findings suggest that ischemic accumulation of succinate decreases Cdc42 GTPase activity by induction of Cdc42 succinylation, which inhibits the proliferation of neural stem cells and aggravates cerebral ischemia/reperfusion injury.
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.
基金supported by the National Natural Science Foundation of China,No.81402930Natural Science Foundation of Universities in Anhui Province,No.KJ2021A0688+2 种基金National College Students Innovation and Entrepreneurship Program,No.202110367071Key projects of science and technology projects of Bengbu Medical College,No.2020byzd017512 Talents Training Program of Bengbu Medical College,No.BY51201104(all to SYD).
文摘CDGSH iron sulfur domain 2 can inhibit ferroptosis,which has been associated with cerebral ischemia/reperfusion,in individuals with head and neck cancer.Therefore,CDGSH iron sulfur domain 2 may be implicated in cerebral ischemia/reperfusion injury.To validate this hypothesis in the present study,we established mouse models of occlusion of the middle cerebral artery and HT22 cell models of oxygen-glucose deprivation and reoxygenation to mimic cerebral ischemia/reperfusion injury in vivo and in vitro,respectively.We found remarkably decreased CDGSH iron sulfur domain 2 expression in the mouse brain tissue and HT22 cells.When we used adeno-associated virus and plasmid to up-regulate CDGSH iron sulfur domain 2 expression in the brain tissue and HT22 cell models separately,mouse neurological dysfunction was greatly improved;the cerebral infarct volume was reduced;the survival rate of HT22 cells was increased;HT22 cell injury was alleviated;the expression of ferroptosis-related glutathione peroxidase 4,cystine-glutamate antiporter,and glutathione was increased;the levels of malondialdehyde,iron ions,and the expression of transferrin receptor 1 were decreased;and the expression of nuclear-factor E2-related factor 2/heme oxygenase 1 was increased.Inhibition of CDGSH iron sulfur domain 2 upregulation via the nuclear-factor E2-related factor 2 inhibitor ML385 in oxygen-glucose deprived and reoxygenated HT22 cells blocked the neuroprotective effects of CDGSH iron sulfur domain 2 up-regulation and the activation of the nuclear-factor E2-related factor 2/heme oxygenase 1 pathway.Our data indicate that the up-regulation of CDGSH iron sulfur domain 2 can attenuate cerebral ischemia/reperfusion injury,thus providing theoretical support from the perspectives of cytology and experimental zoology for the use of this protein as a therapeutic target in patients with cerebral ischemia/reperfusion injury.
基金financially supported by the National Natural Science Foundation of China,No.81072799
文摘Buyanghuanwu decoction has been shown to protect against cerebral ischemia/reperfusion injury,but the underlying mechanisms remain unclear.In this study,rats were intragastrically given Buyanghuanwu decoction,15 m L/kg,for 3 days.A rat model of cerebral ischemia/reperfusion injury was established by middle cerebral artery occlusion.In rats administered Buyanghuanwu decoction,infarct volume was reduced,serum vascular endothelial growth factor and integrin αvβ3 levels were increased,and brain tissue vascular endothelial growth factor and CD34 expression levels were increased compared with untreated animals.These effects of Buyanghuanwu decoction were partially suppressed by an angiogenesis inhibitor(administered through the lateral ventricle for 7 consecutive days).These data suggest that Buyanghuanwu decoction promotes angiogenesis,improves cerebral circulation,and enhances brain tissue repair after cerebral ischemia/reperfusion injury.
基金supported by the Natural Science Foundation of Shandong Province of China,No.ZR2015HM023a grant from the Science and Technology Plan Project of Shinan District of Qingdao City of China,No.2016-3-029-YY
文摘Electroacupuncture preconditioning at acupoint Baihui(GV20) can reduce focal cerebral ischemia/reperfusion injury. However, the precise protective mechanism remains unknown. Mitochondrial fission mediated by dynamin-related protein 1(Drp1) can trigger neuronal apoptosis following cerebral ischemia/reperfusion injury. Herein, we examined the hypothesis that electroacupuncture pretreatment can regulate Drp1, and thus inhibit mitochondrial fission to provide cerebral protection. Rat models of focal cerebral ischemia/reperfusion injury were established by middle cerebral artery occlusion at 24 hours after 5 consecutive days of preconditioning with electroacupuncture at GV20(depth 2 mm, intensity 1 m A, frequency 2/15 Hz, for 30 minutes, once a day). Neurological function was assessed using the Longa neurological deficit score. Pathological changes in the ischemic penumbra on the injury side were assessed by hematoxylin-eosin staining. Cellular apoptosis in the ischemic penumbra on the injury side was assessed by terminal deoxyribonucleotidyl transferase-mediated d UTP-digoxigenin nick end labeling staining. Mitochondrial ultrastructure in the ischemic penumbra on the injury side was assessed by transmission electron microscopy. Drp1 and cytochrome c expression in the ischemic penumbra on the injury side were assessed by western blot assay. Results showed that electroacupuncture preconditioning decreased expression of total and mitochondrial Drp1, decreased expression of total and cytosolic cytochrome c, maintained mitochondrial morphology and reduced the proportion of apoptotic cells in the ischemic penumbra on the injury side, with associated improvements in neurological function. These data suggest that electroacupuncture preconditioning-induced neuronal protection involves inhibition of the expression and translocation of Drp1.
文摘Some in vitro experiments have shown that erythropoietin(EPO) increases resistance to apoptosis and facilitates neuronal survival following cerebral ischemia.However,results from in vivo studies are rarely reported.Perfusion-weighted imaging(PWI) and diffusion-weighted imaging(DWI) have been applied successfully to distinguish acute cerebral ischemic necrosis and penumbra in living animals; therefore,we hypothesized that PWI and DWI could be used to provide imaging evidence in vivo for the conclusion that EPO could reduce apoptosis in brain areas injured by cerebral ischemia/reperfusion.To validate this hypothesis,we established a rat model of focal cerebral ischemia/reperfusion injury,and treated with intra-cerebroventricular injection of EPO(5,000 U/kg) 20 minutes before injury.Brain tissue in the ischemic injury zone was sampled using MRI-guided localization.The relative area of abnormal tissue,changes in PWI and DWI in the ischemic injury zone,and the number of apoptotic cells based on Td T-mediated d UTP-biotin nick end-labeling(TUNEL) were assessed.Our findings demonstrate that EPO reduces the relative area of abnormally high signal in PWI and DWI,increases cerebral blood volume,and decreases the number of apoptotic cells positive for TUNEL in the area injured by cerebral ischemia/reperfusion.The experiment provides imaging evidence in vivo for EPO treating cerebral ischemia/reperfusion injury.
基金supported by grants from of the Science and Technology Project of Fujian Province of China,No.2010Y0027the Professor Development Fund of Fujian Medical University of China,No.JS12001
文摘13-Methyltetradecanoic acid can stabilize cell membrane and have anti-inflammatory,antioxidant and anti-apoptotic effects.Previous studies mainly focused on peripheral nerve injury,but seldom on the central nervous system.We investigated whether these properties of 13-methyltetradecanoic acid have a neuroprotective effect on focal cerebral ischemia/reperfusion injury,and detected the expression of basic fibroblast growth factor and vascular endothelial growth factor.This study established rat models of middle cerebral artery occlusion/reperfusion injury by ischemia for 2 hours and reperfusion for 24 hours.At the beginning of reperfusion,13-methyltetradecanoic acid 10,40 or 80 mg/kg was injected into the tail vein.Results found that various doses of 13-methyltetradecanoic acid effectively reduced infarct volume,mitigate cerebral edema,and increased the m RNA and protein expression of basic fibroblast growth factor and vascular endothelial growth factor at 24 hours of reperfusion.The effect was most significant in the 13-methyltetradecanoic acid 40 and 80 mg/kg groups.The findings suggest that 13-methyltetradecanoic acid can relieve focal ischemia/reperfusion injury immediately after reperfusion,stimulate the upregulation of basic fibroblast growth factor and vascular endothelial growth factor to exert neuroprotective effects.
基金supported by National Natural Science Foundation of China,No.81771270(to QP)Inner Mongolia Science Foundation of China,No.2020MS08063(to YQP)+3 种基金Health and Family Planning Scientific Research Plan Project of Inner Mongolia Autonomous Region of China,No.201702138(to YQP)Baotou Science and Technology Plan Project of China,No.2018C2007-4-10(to YQP)Baotou Medical and Health Science and Technology Project of China,No.wsjj2019036(to JY)Baotou Medical College Foundation of China,No.BSJJ201904(to JY)。
文摘Hypoxic preconditioning can protect against cerebral ischemia/reperfusion injury. However, the underlying mechanisms that mediate this effect are not completely clear. In this study, mice were pretreated with continuous, intermittent hypoxic preconditioning;1 hour later, cerebral ischemia/reperfusion models were generated by middle cerebral artery occlusion and reperfusion. Compared with control mice, mice with cerebral ischemia/reperfusion injury showed increased Bederson neurological function scores, significantly increased cerebral infarction volume, obvious pathological damage to the hippocampus, significantly increased apoptosis;upregulated interleukin-1β, interleukin-6, and interleukin-8 levels in brain tissue;and increased expression levels of NOD-like receptor family pyrin domain containing 3(NLRP3), NLRP inflammasome-related protein caspase-1, and gasdermin D. However, hypoxic preconditioning significantly inhibited the above phenomena. Taken together, these data suggest that hypoxic preconditioning mitigates cerebral ischemia/reperfusion injury in mice by reducing NLRP3 inflammasome expression. This study was approved by the Medical Ethics Committee of the Fourth Hospital of Baotou, China(approval No. DWLL2019001) in November 2019.
基金supported by the National Natural Science Foundation of China,Nos.81771271(to JF),81902537(to MJY),82001475(to SJY)a Scientific Fund of Shengjing Hospital of China Medical University,No.M0124(to SJY)+1 种基金the“345 Talent Project”from Shengjing Hospital of China Medical University(to SJY)the Natural Science Foundation of Liaoning Province of China,No.20180550913(to MJY).
文摘Apoptosis is an important programmed cell death process involved in ischemia/reperfusion injury.MicroRNAs are considered to play an important role in the molecular mechanism underlying the regulation of cerebral ischemia and reperfusion injury.However,whether miR-670 can regulate cell growth and death in cerebral ischemia/reperfusion and the underlying mechanism are poorly understood.In this study,we established mouse models of transient middle artery occlusion and Neuro 2a cell models of oxygen-glucose deprivation and reoxygenation to investigate the potential molecular mechanism by which miR-670 exhibits its effects during cerebral ischemia/reperfusion injury both in vitro and in vivo.Our results showed that after ischemia/reperfusion injury,miR-670 expression was obviously increased.After miR-670 expression was inhibited with an miR-670 antagomir,cerebral ischemia/reperfusion injury-induced neuronal death was obviously reduced.When miR-670 overexpression was induced by an miR-670 agomir,neuronal apoptosis was increased.In addition,we also found that miR-670 could promote Yap degradation via phosphorylation and worsen neuronal apoptosis and neurological deficits.Inhibition of miR-670 reduced neurological impairments after cerebral ischemia/reperfusion injury.These results suggest that microRNA-670 aggravates cerebral ischemia/reperfusion injury through the Yap pathway,which may be a potential target for treatment of cerebral ischemia/reperfusion injury.The present study was approved by the Institutional Animal Care and Use Committee of China Medical University on February 27,2017(IRB No.2017PS035K).
基金supported by the National Natural Science Foundation of China,Nos.81901994(to BZ)and 81571147(to XXX)the Natural Science Foundation of Hubei Province,China,No.2019CFC847(to WWG)the Fundamental Research Funds for the Central Universities,China,No.2042018kf0149(to ML)
文摘Interleukin-4(IL-4) has a protective effect against cerebral ischemia/reperfusion injury. Animal experiments have shown that IL-4 improves the short-and long-term prognosis of neurological function. The Akt(also called protein kinase B, PKB)/glycogen synthase kinase-3β(Akt/GSK-3β) signaling pathway is involved in oxidative stress, the inflammatory response, apoptosis, and autophagy. However, it is not yet clear whether the Akt/GSK-3β pathway participates in the neuroprotective effect of IL-4 against cerebral ischemia/reperfusion injury. In the present study, we established a cerebral ischemia/reperfusion mouse model by middle cerebral artery occlusion for 60 minutes followed by a 24-hour reperfusion. An IL-4/anti-IL-4 complex(10 μg) was intraperitoneally administered 30 minutes before surgery. We found that administration of IL-4 significantly alleviated the neurological deficits, oxidative stress, cell apoptosis, and autophagy and reduced infarct volume of the mice with cerebral ischemia/reperfusion injury 24 hours after reperfusion. Simultaneously, IL-4 activated Akt/GSK-3β signaling pathway. However, an Akt inhibitor LY294002, which was injected at 15 nmol/kg via the tail vein, attenuated the protective effects of IL-4. These findings indicate that IL-4 has a protective effect on cerebral ischemia/reperfusion injury by mitigating oxidative stress, reducing apoptosis, and inhibiting excessive autophagy, and that this mechanism may be related to activation of the Akt/GSK-3β pathway. This animal study was approved by the Animal Ethics Committee of Renmin Hospital of Wuhan University, China(approval No. WDRY2017-K037) on March 9, 2017.
文摘Severe cerebral ischemia/reperfusion injury has been shown to induce high-level autophagy and neuronal death.Therefore,it is extremely important to search for a target that inhibits autophagy activation.Long non-coding RNA MEG3 participates in autophagy.However,it remains unclear whether it can be targeted to regulate cerebral ischemia/reperfusion injury.Our results revealed that in oxygen and glucose deprivation/reoxygenation-treated HT22 cells,MEG3 expression was obviously upregulated,and autophagy was increased,while knockdown of MEG3 expression greatly reduced autophagy.Furthermore,MEG3 bound mi R-181 c-5 p and inhibited its expression,while mi R-181 c-5 p bound to autophagy-related gene ATG7 and inhibited its expression.Further experiments revealed that mir-181 c-5 p overexpression reversed the effect of MEG3 on autophagy and ATG7 expression in HT22 cells subjected to oxygen and glucose deprivation/reoxygenation.In vivo experiments revealed that MEG3 knockdown suppressed autophagy,infarct volume and behavioral deficits in cerebral ischemia/reperfusion mice.These findings suggest that MEG3 knockdown inhibited autophagy and alleviated cerebral ischemia/reperfusion injury through the mi R-181 c-5 p/ATG7 signaling pathway.Therefore,MEG3 can be considered as an intervention target for the treatment of cerebral ischemia/reperfusion injury.This study was approved by the Animal Ethics Committee of the First Affiliated Hospital of Zhengzhou University,China(approval No.XF20190538)on January 4,2019.
基金the National Natural Science Foundation of China,No. 30873391
文摘BACKGROUND:Aquaporin-4 (AQP-4) over-expression following cerebral ischemia results in cerebral edema. Picroside Ⅱ has been shown to exhibit a neuroprotective effect on neuronal apoptosis. However,few reports have addressed the neuroprotective mechanisms and therapeutic times following cerebral ischemic reperfusion injury. OBJECTIVE:To explore the neuroprotective effects and ideal treatment window for picroside II treatment of middle cerebral artery occlusion and reperfusion injury in rats. DESIGN,TIME AND SETTING:A randomized,controlled,animal experiment was performed at Institute of Cerebrovascular Diseases,Qingdao University Medical College from September 2008 to May 2009. MATERIALS:Picroside Ⅱ was purchased from Tianjin Kuiqing Medical Technology,China. METHODS:A total of 165 adult,healthy,male,Wistar rats were randomly assigned to sham-surgery (n = 15),model (n = 75),and treatment groups (n = 75). Rats in the model and treatment groups underwent middle cerebral artery occlusion and reperfusion through the use of an intraluminal monofilament suture on the left external-internal carotid artery. The treatment group was injected with 1.0% picroside Ⅱ (10 mg/kg) into the tail vein,and the model and sham-surgery groups were injected with 0.1 mol/L phosphate buffered saline (250 μL). MAIN OUTCOME MEASURES:Neurological functional scores were evaluated using the Longa's method; cerebral infarction volume was detected through the use of tetrazolium chloride staining; cellular apoptosis was determined through the use of the in situ end-labeling method; aquaporin-4 expression was measured using fluorescence labeling analysis and reverse transcription polymerase chain reaction technique. RESULTS:At 0.5 hour following cerebral ischemic injury,neurological functional scores were low,and a small infarction focus was detected in the ischemic cortex of the model group. Along with prolonged ischemia and an increased number of apoptosis-positive cells,AQP-4 mRNA and protein expression was increased. At 1-2 hours after ischemia,neurological scores and infarction sizes were significantly increased in the model group. Apoptotic-positive cells were widespread in the ipsilateral cortex and striatum. In addition,AQP-4 mRNA and protein expression levels were increased. Picroside Ⅱ treatment significantly decreased neurological scores and infarction volume,and reduced AQP-4 mRNA and protein expression levels compared with the model group (P < 0.05 or P < 0.01). At 1 hour after ischemia,the therapeutic effect of picroside Ⅱ was notable (P < 0.01). CONCLUSION:Picroside Ⅱ played a protective role in cerebral ischemic reperfusion injury by inhibiting apoptosis and regulating AQP-4 expression. The best therapeutic time window was 1 hour after cerebral ischemic reperfusion.
基金supported by the Fundamental Research Funds for Central Public Welfare Research Institute of China,Nos.2015CZ-36(to HTL)and 2019CZ-7(to WZW)。
文摘At present,predicting the severity of brain injury caused by global cerebral ischemia/reperfusion injury(GCI/RI)is a clinical problem.After such an injury,clinical indicators that can directly reflect neurological dysfunction are lacking.The change in hippocampal microstructure is the key to memory formation and consolidation.Diffusion tensor imaging is a highly sensitive tool for visualizing injury to hippocampal microstructure.Although hippocampal microstructure,brain-derived neurotrophic factor(BDNF),and tropomyosin-related kinase B(Trk B)levels are closely related to nerve injury and the repair process after GCI/RI,whether these indicators can reflect the severity of such hippocampal injury remains unknown.To address this issue,we established rat models of GCI/RI using the four-vessel occlusion method.Diffusion tensor imaging parameters,BDNF,and Trk B levels were correlated with modified neurological severity scores.The results revealed that after GCI/RI,while neurological function was not related to BDNF and Trk B levels,it was related to hippocampal fractional anisotropy.These findings suggest that hippocampal fractional anisotropy can reflect the severity of hippocampal injury after global GCI/RI.The study was approved by the Institutional Animal Care and Use Committee of Capital Medical University,China(approval No.AEEI-2015-139)on November 9,2015.
基金supported by the National Natural Science Foundation of China(No.30800445 and No.81341034)
文摘Ischemic stroke leads to high potentiality of mortality and disability. The current treatment for ischemic stroke is mainly focused on intravenous thrombolytic therapy. However, ischemia/reperfusion induces neuronal damage, which significantly influences the outcome of patients with ischemic stroke, and the exact mechanism implicated in ischemia/reperfusion injury remains unclear, although evidence shows that oxidative stress is likely to be involved. Betulinic acid is mainly known for its anti-tumor and anti-inflammatory activities. Our previous study showed that betulinic acid could decrease the reactive oxygen species(ROS) production by regulating the expression of NADPH oxidase. Thus, we hypothesized that betulinic acid may protect against brain ischemic injury in the animal model of stroke. Focal cerebral ischemia was achieved by using the standard intraluminal occlusion method and reperfusion enabled after 2 h ischemia. Neurological deficits were scored. Infarct size was determined with 2,3,5-triphenyltetrazolium chloride monohydrate(TTC) staining and the mRNA expression of NADPH oxidase 4(NOX4) was determined by RT-PCR in infarct tissue. ROS generation and apoptosis in ischemic tissue were analyzed by measuring the oxidative conversion of cell permeable 2',7'-dichloro-fluorescein diacetate(DCF-DA) to fluorescent dichlorofluorescein(DCF) in fluorescence microplate reader and TUNEL assay, respectively. In Kunming mice, 2 h of middle cerebral artery(MCA) occlusion followed by 24 or 72 h of reperfusion led to an enhanced NOX4 expression in the ischemic hemisphere. This was associated with elevated levels of ROS generation and neuronal apoptosis. Pre-treatment with betulinic acid(50 mg/kg/day for 7 days via gavage) prior to MCA occlusion prevented the ischemia/reperfusion-induced up-regulation of NOX4 and ROS production. In addition, treatment with betulinic acid could markedly blunt the ischemia/reperfusion-induced neuronal apoptosis. Finally, betulinic acid reduced infarct volume and ameliorated the neurological deficit in this stroke mouse model. Our results suggest that betulinic acid protects against cerebral ischemia/reperfusion injury in mice and the down-regulation of NOX4 may represent a mechanism contributing to this effect.
文摘BACKGROUND: Endoplasmic reticulum (ER) stress impairs ER functions and leads to the accumulation of unfolded or misfolded proteins in the ER lumen. ER stress-induced cell death plays an important role in cerebral ischemia. Edaravon (3-methyl-1-phenyl-2-pyrazolin-5-one) is a potent and novel scavenger of free radicals that inhibit delayed neuronal death, as demonstrated by in vitro and animal studies. However, its effect on ER stress and induced neuronal apoptosis in a rat model of brief middle cerebral artery occlusion remains unclear. OBJECTIVE: To explore the effects of edaravone on the expression of ER stress-related factors and neuronal apoptosis, based on the hypothesis that edaravone influences ER stress in a rat model of cerebral ischemia/reperfusion. DESIGN, TIME AND SETTING: A randomized, controlled, animal study was performed at the Laboratory of Department of Neurology, Xiangya Hospital and the Department of Laboratory Animals, Xiangya Medical College, Central South University in China from June 2005 to May 2006. MATERIALS: Edaravone was purchased from Simcere Pharmaceutical Group, China. METHODS: A total of 216 adult, male, Sprague Dawley rats were randomly assigned to sham-surgery, model and edaravone groups, with 72 rats in each group. Brief middle cerebral artery occlusion was established in the model and edaravone groups. In addition, the edaravone group rats were injected with 3 mg/kg edaravone through the tail vein. MAIN OUTCOME MEASURES: RNA-dependent protein kinase-like endoplasmic reticulum eukaryotic translation initiation factor 2α kinase (PERK) and C/EBP homology protein (CHOP) mRNA expression in the ischemic parietal cortex was determined by reverse transcription- polymerase chain reaction; phosphorylated PERK and CHOP protein expression was detected by immunohistochemistry; neuronal apoptosis was detected by TdT-mediated-dUTP nick end labeling. RESULTS: Neurological deficit scores were significantly reduced in the edaravone group compared to the model group at 12, 24, and 72 hours following reperfusion (P < 0.05). In addition, PERK and CHOP mRNA as well as phosphorylated PERK and CHOP protein expression were significantly reduced in the edaravone group compared to the model group at 1, 3, and 6 hours following reperfusion (P < 0.05, P < 0.01). CHOP mRNA expression was decreased in the edaravone group compared to the model group at 3, 6, 12, and 24 hours following reperfusion (P < 0.01), while CHOP protein expression was less than the model group at 6, 12, and 24 hours following reperfusion (P < 0.05). CONCLUSION: Edaravone treatment resulted in decreased PERK and CHOP expression following ischemia/reperfusion, as well as reduced neuronal apoptosis. Edaravone exhibited a neuroprotective role by inhibiting endoplasmic reticulum stress.
