BACKGROUND:Cerebral ischemic stroke is one of the main fatal and disabling diseases in the clinic,but only a few patients benefit from vascular recanalization in time,so it is urgent to explore new and effective therapy.As one of the critical pathological changes of ischemic stroke,the glial scar formed mainly by astrocytes is one major cause that hinders axonal regeneration and neurological recovery at the late stage of stroke. OBJECTIVE:To elucidate the pathological process and crucial signal regulatory mechanism of astrocytes in the formation of glial scar after ischemic stroke,as well as the potential therapeutic targets,to provide a theoretical reference for intervening astrocytic scar formation against ischemic stroke effectively,and novel strategies for promoting post-stroke rehabilitation. METHODS:The relevant articles published in CNKI,PubMed and Web of Science databases from 2010 to 2022 were retrieved.The search terms were"Ischemic stroke,Brain ischemi*,Cerebral ischemi*,Astrocyt*,Astroglia*,Glial scar,Gliosis,Astrogliosis"in Chinese and English.Finally,78 articles were included after screening and summarized. RESULTS AND CONCLUSION:(1)Astrocytes play an important role in the maintenance of central nervous system homeostasis.After ischemic stroke,astrocytes change from a resting state to an active state.According to the different severities of cerebral ischemic injury,astrocyte activation changes dynamically from swelling and proliferation to glial scar formation.(2)Mature astrocytes are stimulated to restart the cell cycle,then proliferate and migrate to lesions,which is the main source of the glial scar.Neural stem cells in the subventricular zone,neuron-glial antigen 2 precursor cells and ependymal precursor cells in the brain parenchyma can also differentiate into astrocytes.Endothelin-1,aquaporin 4,ciliary neurotrophic factor and connexins are involved in this process.In addition,chondroitin sulfate proteoglycan,as the main component of the extracellular matrix,forms the dense glial scar barrier with proliferated astrocytes,which hinders the polarization and extension of axons.(3)Activation or inhibition of crucial signal molecules involved in astrocyte activation,proliferation,migration and pro-inflammation functions regulate the glial scar formation.Transforming growth factor beta 1/Smad and Janus kinase/signal transducer and activator of transcription 3 are classical pathways related to astrogliosis,while receptor-interacting protein 1 kinase and glycogen synthase kinase 3β are significant molecules regulating the inflammatory response.However,there are relatively few studies on Smad ubiquitination regulatory factor 2 and Interleukin-17 and their downstream signaling pathways in glial scar formation,which are worthy of further exploration.(4)Drugs targeting astrogliosis-related signaling pathways,cell proliferation regulatory proteins and inflammatory factors effectively inhibit the formation of glial scar after cerebral ischemic stroke.Among them,the role of commonly used clinical drugs such as melatonin and valproic acid in regulating glial scar formation has been verified,which makes it possible to use drugs that inhibit glial scar formation to promote the recovery of neurological function in patients with stroke.(5)Considering the protective effects of glial scar in the acute phase,how to choose the appropriate intervention chance of drugs to maintain the protective effect of the glial scar while promoting nerve regeneration and repair in the local microenvironment is the direction of future efforts.

BACKGROUND:In the initial stage of multiple sclerosis,central immune cells activate and release a large number of inflammatory factors,causing white matter demyelination and even involving gray matter neurons.The equilibrium of differentiation between different subsets of CD4+ T cells plays an important role in the progression of experimental autoimmune encephalomyelitis.The previous results of the research group showed that the active ingredient astragalus glycoprotein in astragalus can regulate the immune response in experimental autoimmune encephalomyelitis mice,and whether it has a regulatory effect on the differentiation of T cell subsets has not been determined. OBJECTIVE:To explore the therapeutic effects and immune regulatory mechanisms of astragaloside IV on experimental autoimmune encephalomyelitis mice. METHODS:Female C57BL/6 mice were divided into the normal control group,experimental autoimmune encephalomyelitis disease model group,and astragaloside IV treatment group(n=8 per group).Myelin oligodendrocyte glycoprotein peptides 35-55 were used for experimental autoimmune encephalomyelitis model induction in the last two groups.On day 10 to 28 after immunization,the astragaloside IV treatment group was treated with 40 mg/kg per day astragaloside IV intragastrically.Body weight and clinical scores of mice in each group were recorded from the immunization day to the 28th day.On the 28th day after immunization,the mouse spinal cord was taken and made into frozen sections for hematoxylin-eosin staining and Lux fast blue staining to observe pathological changes in the spinal cord.Percentage of splenic T cell subsets was detected using flow cytometry.Western blot assay was used to determine the protein expression of interferon-γ,interleukin-17 and interleukin-6 in the spinal cord.Levels of interferon-γ,interleukin-17,interleukin-6 and interleukin-4 in supernatants of cultured splenocytes were determined by ELISA. RESULTS AND CONCLUSION:(1)Compared with the experimental autoimmune encephalomyelitis disease model group,astragaloside IV could reduce the degree of weight loss in experimental autoimmune encephalomyelitis mice(P<0.05),ameliorate clinical symptoms(P<0.05),inhibit the infiltration of inflammatory cells and alleviate myelin loss(P<0.01,P<0.05).(2)Compared with the experimental autoimmune encephalomyelitis disease model group,astragaloside IV could inhibit the proportion of CD4+T cell subsets expressing interferon-γ(P<0.001)and interleukin-17(P<0.001),but increase percentages of CD4+ interleukin-10+(P<0.001)and CD4+ transforming growth factor-β+(P<0.01)T cell subsets.(3)Astragaloside IV could inhibit the expression of interferon-γ(P<0.05,P<0.01),interleukin-17(P<0.05,P<0.05),and interleukin-6(P<0.05,P<0.05)in the spinal cord and spleen,and up-regulate the expression of interleukin-4(P<0.01)in spleen.(4)These findings confirm that astragaloside IV alleviates clinical symptoms in experimental autoimmune encephalomyelitis mice,which may be related to regulating the splenic T cell subsets,therefore,inhibiting the infiltration of inflammatory cells into the center and reducing the demyelination.

BACKGROUND:Ischemic stroke is a serious threat to human health.After ischemia and hypoxia,astrocyte expresses lipocalin-2 in large amounts to aggravate brain injury,but the specific mechanism is not clear.Hydroxysafflor yellow A has anti-ischemia,anti-oxidation,anti-thrombosis and anti-inflammatory effects.However,whether hydroxysafflor yellow A affects the expression of lipocalin-2 in astrocytes after cerebral ischemia and hypoxia and its mechanism are not clear. OBJECTIVE:To investigate the effect and mechanism of hydroxysafflor yellow A on the expression of lipocalin-2 in astrocytes after cerebral ischemia and reperfusion. METHODS:(1)Thirty adult SD rats were randomly divided into three groups:sham operation group,middle cerebral artery occlusion and reperfusion group,and hydroxysafflor yellow A group.The middle cerebral artery occlusion and reperfusion model was established in the latter two groups,and hydroxysafflor yellow A group was intraperitoneally injected with 12 mg/kg hydroxysafflor yellow A after reperfusion.Longa score was used to evaluate the degree of neurological impairment.Infarct volume was determined by TTC staining.JAK2/STAT3 pathway and lipocalin-2 expression were detected by western blot assay and immunofluorescence.Levels of interleukin 1β,interleukin 6 and tumor necrosis factor α were detected by ELISA.(2)Astrocytes were divided into four groups:Normal group,glucose-oxygen deprivation group,hydroxysafflor yellow A group and AG490 group.In the latter three groups,glucose-oxygen deprivation and glucose-oxygen recovery models were established.Astrocytes were treated with 75 μmol/L hydroxysafflor yellow A and 10 μmol/L tyrosine phosphorylation inhibitor AG490 for 8 hours during glucose-oxygen deprivation,respectively.The mechanism of hydroxysafflor yellow A on lipocalin-2 was further verified. RESULTS AND CONCLUSION:(1)Compared with the sham operation group,cerebral infarction was significantly increased in the middle cerebral artery occlusion and reperfusion group,accompanied by aggravated neurological impairment(P<0.01).Hydroxysafflor yellow A treatment could reduce cerebral infarction volume and improve neurological function(P<0.01).(2)The expressions of p-JAK2,p-STAT3 and lipocalin-2 in the middle cerebral artery occlusion and reperfusion group were higher than those in the sham operation group(P<0.01).Hydroxysafflor yellow A treatment reduced the expressions of JAK2,STAT3 and lipocalin-2(P<0.01).(3)The expression levels of interleukin 1β,interleukin-6 and tumor necrosis factor α in the middle cerebral artery occlusion and reperfusion group were higher than those in the sham operation group(P<0.01).Hydroxysafflor yellow A inhibited the expressions of interleukin 1β,interleukin-6 and tumor necrosis factor α(P<0.01).(4)In vitro,the expressions of p-JAK2,p-STAT3 and lipocalin-2 in the glucose-oxygen deprivation group were significantly higher than those in the normal group(P<0.01).After adding AG490,the phosphorylation of JAK2 and STAT3 decreased,and the expression of lipocalin-2 was inhibited(P<0.01).The results suggest that hydroxysafflor yellow A may inhibit the expression of lipocalin-2 in astrocytes after ischemia and hypoxia by regulating the JAK2/STAT3 signaling pathway,thereby reducing brain injury.

BACKGROUND:Although traditional therapies,including drugs and surgery,cannot repair the damaged myocardial tissue,the mortality rate of myocardial infarction remains high.Stem cells provide the possibility to solve this problem due to their self-renewal and multi-directional differentiation potential. OBJECTIVE:To analyze the research progress of stem cell therapy for myocardial infarction in recent ten years by bibliometric analysis. METHODS:The related articles on stem cells and myocardial infarction published in SCI-E and SSCI from January 1,2012 to December 1,2022 in the Web of Science database were searched.EXCEL,CiteSpace and VOSviewer software were used to make statistical and visualization analyses of the data such as the number of publications,authors,institutions,journals,countries and keywords. RESULTS AND CONCLUSION:A total of 3 210 core articles were published,and the total number increased year by year.hausenloy,derek j.is the author with the largest number of publications,China is the country with the largest number of publications,and the Fourth Military Medical University is the institution with the largest number of publications.The research hotspots in this field are changing from cell experiments and animal experiments to clinical trials.In the past ten years,research in this field has been highly popular and still has great development prospects.It is necessary to promote international and inter-agency exchange and learning,and further explore the role of stem cells in the treatment of myocardial infarction.

BACKGROUND:Vascular regeneration,as one of the crucial repair processes after its onset,necessitates visual analysis between the two. OBJECTIVE:To analyze the literature on ischemic stroke and vascular regeneration in the past decade using bibliometrics and sort out the current status,hotspots,and future research trends in this field. METHODS:We used a bibliometric approach to search the Web of Science database for literature on ischemic stroke and vascular regeneration published between January 2011 and May 2023.The obtained data were systematically analyzed using the VOSviewer visualization software to identify the number of articles,countries,keywords,institutions,authors,citations,and trends. RESULTS AND CONCLUSION:We searched and selected 1 484 articles and found that the relationship between ischemic stroke and vascular regeneration has emerged as a research hotspot in the cerebrovascular field,with the number of published articles continuing to rise.Most of these articles were authored by institutions from China and the United States.Shanghai Jiao Tong University was the most cited institution.The most influential author was Hermann DM,whose article had been cited 1 003 times.The current hot research topics in the field include extracellular vesicles,microRNAs and mesenchymal stem cells,which are being studied for their correlations with relevant diseases.To conclude,the bibliometric analysis provides a visual analysis of ischemic stroke and vascular regeneration,which is found to be an emerging focus as well as a valuable reference for future trends and highlights in ischemic stroke and vascular regeneration.

BACKGROUND:Current studies have confirmed that Ganoderma lucidum polysaccharides can promote nerve regeneration in neurodegeneration-related diseases.The occurrence of neurodegenerative diseases is closely related to mitochondrial dysfunction,but the role of Ganoderma lucidum polysaccharides on the regulation of apoptosis and mitochondrial function in neurodegenerative diseases is not yet clarified. OBJECTIVE:To explore the regulatory effects and mechanisms of Ganoderma lucidum polysaccharides on apoptosis and mitochondrial dysfunction in H2O2-induced SH-SY5Y cells. METHODS:SH-SY5Y cells were divided into three groups:control group,H2O2 group,and Ganoderma lucidum polysaccharides group.Cells in the control group were normally cultured.Cells in the H2O2 group were treated with 300 μmol/L H2O2 for 24 hours.In the Ganoderma lucidum polysaccharides group,the intervention with 300 μg/L Ganoderma lucidum polysaccharides was conducted first for 1-2 hours,followed by the addition of 300 μmol/L H2O2 for 24 hours.The mitochondrial membrane potential was detected by JC-1 kit.Apoptosis was detected by TUNEL staining kit.The activities of malondialdehyde and superoxide dismutase were detected by malondialdehyde test kit and superoxide dismutase test kit,respectively.The apoptosis and expression of mitochondrial dynamics-related proteins were detected by immunofluorescence staining and western blot assay. RESULTS AND CONCLUSION:(1)Compared with the control group,the mitochondrial membrane potential and superoxide dismutase activity were significantly reduced,as well as apoptotic rate and malondialdehyde levels were significantly increased in the H2O2 group(P<0.05).After treatment with Ganoderma lucidum polysaccharides,the membrane potential and superoxide dismutase activities were significantly increased,and apoptotic rate and malondialdehyde levels were significantly reduced compared with the H2O2 group(P<0.05).(2)The expression levels of pro-apoptotic proteins Bax and Caspase-3 were significantly increased,but the expression of anti-apoptotic protein Bcl-2 was significantly decreased in the H2O2 group compared with the control group(P<0.05).Compared with the H2O2 group,the levels of Bax and Caspase-3 were significantly decreased,but the expression of anti-apoptotic protein Bcl-2 was significantly increased in the Ganoderma lucidum polysaccharides group(P<0.05).(3)Compared with the control group,the expression of mitochondrial splitting proteins Fis1 and p-Drp1 was significantly increased,but the expression of mitochondrial fusion proteins OPA1,Mfn1,and Mfn2 was decreased in the H2O2 group(P<0.05).Compared with the H2O2 group,Fis1 and p-Drp1 expression was significantly reduced,but the expression levels of OPA1,Mfn1,and Mfn2 were significantly increased in the Ganoderma lucidum polysaccharides group(P<0.05).(4)The above results confirm that Ganoderma lucidum polysaccharides can attenuate H2O2-induced oxidative stress damage and apoptosis in SH-SY5Y cells by ameliorating mitochondrial dysfunction.

BACKGROUND:Ischemic stroke is a highly prevalent disease associated with apoptosis.Neuronal death occurs after cerebral ischemia,including necrosis and apoptosis.The ischemic core region is dominated by necrosis,while delayed neuronal death in the penumbra is dominated by apoptosis.The penumbra has become a target for the treatment of ischemic stroke.This bibliometric analysis was used to identify the characteristics,hotspots,and frontiers of global scientific output related to apoptosis in ischemic stroke over the past 5 years. OBJECTIVE:To analyze the role of apoptosis and its mechanisms in the pathological process of ischemic stroke through a bibliometric approach. METHODS:A total of 927 relevant literature records from 2018 to 2022 were retrieved from Science Citation Index Expanded(SCI-Expanded)and Social Science Citation Index Expanded(SSCI-Expanded)of the Web of Science Core Collection.Research trends and hotspots of apoptosis in ischemic stroke were visualized using Citespace,VOSviewer and Bibliometrix. RESULTS AND CONCLUSION:From 2018 to 2020,the number of papers on the role of apoptosis in ischemic stroke showed an upward trend,but in 2020,the number of papers began to reduce.China had the largest number of publications,and the United States ranked the second.Capital Medical University and BRAIN RESEARCH BULLETIN were the institutions and journals with the most articles,respectively.In recent years,the two keywords"expression"and"oxidative stress"have appeared more frequently.The bibliometric study showed that in the past 5 years,most of the studies focused on basic research,in which research on the role of apoptosis in ischemic stroke has gradually decreased in the last 3 years,showing a downward trend.On the contrary,nerve regeneration has gradually become a research hotspot,especially the regulation of neurotrophic factors under the influence of different mechanisms,and the research on angiogenesis and glial cell repair is on the rise.At the same time,apoptosis in nerve regeneration is a potential point of discovery.

BACKGROUND:Multiple sclerosis is a chronic inflammatory demyelinating disease of the central nervous system mediated by T cells.The Toll-like receptors(TLRs)/myeloid differentiation factor 88(MyD88)/nuclear factor kappa-B(NF-κB)signaling pathway plays an important role in the development of the disease.Exploring the specific mechanism of the signaling pathway is essential for further treatment of the disease and improving the prognosis of patients. OBJECTIVE:To review the TLRs/MyD88/NF-κB signaling pathway and its role in multiple sclerosis/experimental autoimmune encephalomyelitis models,which provides new ideas and strategies for the treatment of multiple sclerosis by inhibiting the TLRs/MyD88/NF-κB signaling pathway. METHODS:The literature related to the topic from January 2002 to December 2022 was searched in CNKI,WanFang and PubMed databases.A total of 61 articles were finally included for analysis. RESULTS AND CONCLUSION:The TLRs/MyD88/NF-κB signaling pathway is an important pathway that triggers a pro-inflammatory immune response.The TLRs/MyD88/NF-κB signaling pathway plays an important role in the development of multiple sclerosis by regulating the antigen presentation of dendritic cells,destroying the integrity of the blood-brain barrier,and promoting the activation of T cells,B cells and microglia.By targeting TLRs,MyD88 and NF-κB molecules,inhibiting the activation or signal transduction of TLRs,MyD88 and NF-κB,and reducing the secretion of pro-inflammatory factors,multiple sclerosis can be treated.Animal studies have shown that active ingredients of traditional Chinese medicines,such as flavonoids and glycosides,and traditional Chinese medicine compound formulas,such as Buyang Huanwu Tang,can also treat experimental autoimmune encephalomyelitis by regulating the TLRs/MyD88/NF-κB signaling pathway,which points to the direction of searching for medicines targeting the TLRs/MyD88/NF-κB signaling pathway for the treatment of multiple sclerosis.

BACKGROUND:Astrocytes play an important role in the pathology of central nervous system diseases.The phenotypic and functional changes in astrocytes suggest that it may be an effective therapeutic target for central nervous system diseases.Our previous studies have confirmed that astragaloside can inhibit the lipopolysaccharide-induced astrocyte inflammatory response.Whether astragaloside can regulate the phenotype and function of astrocytes through Notch-1 and its downstream signaling pathway remains unclear. OBJECTIVE:To explore the effect of astragaloside on astrocyte activation and inflammatory response induced by inflammation and its possible mechanism. METHODS:Cerebral cortex astrocytes derived from neonatal C57BL/6 mouse were cultured in vitro.CCK-8 assay was used to determine the optimum concentration of astragaloside and Notch active inhibitor DAPT.The astrocytes were divided into five groups:PBS group,lipopolysaccharide group,lipopolysaccharide + astragaloside group,lipopolysaccharide + DAPT group and lipopolysaccharide + DAPT + astragaloside group.The secretion level of inflammatory factors was detected by ELISA,and the level of nitric oxide was detected by Griess method.The astrocytes and splenic mononuclear cells were co-cultured in Transwell chamber to observe the migration of CD4T cells.The expression of astrocyte activation marker GFAP,A1 marker C3 and A2 marker S100A10 as well as Notch 1 and Jag-1 was detected by immunofluorescence staining.The expressions of CFB,C3,S100A10,PTX3,Notch-1,Jag-1,and Hes were detected by western blot assay. RESULTS AND CONCLUSION:(1)According to the results of CCK8 assay,the final concentration of astragaloside was selected as 25 μmol/L and the final concentration of DAPT was 50 μmol/L for follow-up experiments.(2)Compared with PBS group,interleukin-6,interleukin-12 and nitric oxide secretion levels in the lipopolysaccharide group were significantly increased(P<0.05,P<0.05,P<0.01).Compared with the lipopolysaccharide group,interleukin-6(all P<0.05),interleukin-12(P>0.05,P<0.05,P<0.05)and nitric oxide(P<0.05,P<0.01,P<0.01)secretion significantly reduced in the lipopolysaccharide + astragaloside group,lipopolysaccharide +DAPT group,lipopolysaccharide + DAPT + astragaloside group.(3)Compared with the PBS group,the expression of GFAP that is the marker of activated astrocytes and the migration of CD4 T cells were significantly increased in the lipopolysaccharide group(P<0.01).Compared with the lipopolysaccharide group,astrocyte activation was significantly inhibited and CD4 T cell migration was significantly reduced in the lipopolysaccharide + astragaloside,lipopolysaccharide +DAPT,lipopolysaccharide + DAPT + astragaloside group(P<0.05,P<0.05,P<0.01).(4)Compared with the PBS group,the expressions of A1 markers C3 and CFB in the lipopolysaccharide group were increased(P<0.01,P<0.05),and the expressions of A2 markers S100A10 and PTX3 were decreased(P<0.01,P<0.05).Compared with the lipopolysaccharide group,C3(all P<0.01)and CFB(both P<0.05)were significantly reduced and S100A10(all P<0.01)and PTX3(P<0.05,P<0.05 and P>0.05)were increased in the lipopolysaccharide + astragaloside,lipopolysaccharide +DAPT,lipopolysaccharide + DAPT + astragaloside group.(5)Compared with the PBS group,the expressions of Jag-1,Notch-1 and Hes in the lipopolysaccharide group were significantly increased(all P<0.01).Compared with the lipopolysaccharide group,the expressions of Jag-1(all P<0.01),Notch-1(all P<0.01)and Hes(P<0.05,P<0.01 and P<0.01)were significantly reduced in the lipopolysaccharide + astragaloside,lipopolysaccharide +DAPT,lipopolysaccharide + DAPT + astragaloside group.(6)The results indicate that astragaloside can promote the transformation of astrocytes from A1 to A2 by regulating Notch-1 signaling pathway,reduce the secretion of inflammatory factors and the migration of CD4 T cells,and thus inhibit astrocyte activation and inflammatory response.

OBJECTIVE To investigate the protective effect proanthocyanidin B2(PC-B2) on oxidative damage and apoptosis of mouse astrocytes(AS) induced by hydrogen peroxide(H2O2) and its mechanism. METHODS AS were isolated and cultured from neonatal C57BL/6 mice(1−3 d). The optimal concentration of H2O2 and PC-B2 was divided into four groups: normal group, normal+PC-B2 group(100 μg·mL‒1 PC-B2 treated for 24 h), H2O2 model group(200 μmol·L‒1 H2O2 treated for 24 h), PC-B2 group(200 μmol·L‒1 H2O2 and 100 μg·mL‒1 PC-B2 treated for 24 h). The cell viability of each group was detected by CCK-8 method. Cytotoxicity was detected by LDH method. The antioxidant capacity was detected by ABTS and DPPH. The content of MDA and the activity of SOD, CAT and GSH-Px were detected by ELISA kit. Detection of apoptosis in each group was done by TUNEL staining. The mRNA and protein expression levels of Bax, Bcl-2, Caspase-3, Akt/Stat3, p-Akt, p-Stat3 and Nrf2/HO-1 in AS were detected by RT-PCR and Western blotting, respectively. RESULTS PC-B2 could significantly enhance cell viability and inhibit AS apoptosis. Compared with the H2O2 model group, PC-B2 intervention could significantly reduce the content of LDH and MDA in AS, and increase the activity of SOD, CAT and GSH-Px. PC-B2 intervention could inhibit the mRNA and protein expression of Bax and Caspase-3, and up-regulate the mRNA and protein expression of Akt/Stat3, Bcl-2, Nrf2/HO-1. CONCLUSION PC-B2 can enhance the antioxidant capacity of AS through Akt/Stat3 and Nrf2/HO-1 pathways, therefore reduce H2O2-induced AS oxidative damage and apoptosis.