Benzydamine induces apoptosis in astrocytes in vitro / Benzadamina induz apoptose em astrócitos in vitro

Objective: the present work aims to evaluate the Benzydamine (BZD) effect on cell viability in astrocyte culture and investigated the death mechanism involved with its cytotoxic effect. Methods: in order to evaluate cell viability, the 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction assay was used, while flow cytometry was used to verify cell damage. The immunofluorescence assay was used to verify the expression of the marker's caspase-8, caspase9 and p65 subunit of Factor nuclear kappa B (NFκB). A statistical analysis for MTT assay and Flow Cytometry were made using ANOVA with Dunett's post-test; Student's t-test was made for the Immunofluorescence. Significance was set at p < 0.05. Results: the MTT reduction assay showed that BZD (3.1 to 100 µg/mL) caused a decrease in astrocytes viability. The flow cytometry showed that the cytotoxic effect of BZD was caused by the activation of the apoptotic death pathway, evidenced by the externalization of phosphatidylserine. The immunofluorescence revealed an increase in caspase-8 expression and no alteration in caspase-9 expression, demonstrating that there was an activation of the extrinsic pathway of apoptosis. The mean inhibitory concentration (IC50) of BZD (26.13 µg/mL) also caused an increase in NFκB p65 expression. Conclusion: taken together, the results of the present study suggest that BZD has a cytotoxic effect on astrocyte cells, and this effect comes from its ability to activate the extrinsic apoptotic pathway

Objetivo: o presente trabalho tem como objetivo avaliar o efeito da Benzidamina (BZD) na viabilidade celular em cultura de astrócitos e investigar o mecanismo de morte envolvido com seu efeito citotóxico. Métodos: para avaliar a viabilidade celular foi utilizado o ensaio de redução do brometo de 3-(4,5-Dimetiltiazol-2-il)-2,5-difeniltetrazólio (MTT), enquanto a citometria de fluxo foi utilizada para verificar o dano celular. O ensaio de imunofluorescência foi utilizado para verificar a expressão do marcador caspase-8, caspase9 e subunidade p65 do Fator nuclear kappa B (NFκB). A análise estatística para ensaio MTT e Citometria de Fluxo foi feita utilizando ANOVA com pós-teste de Dunett; Foi feito o teste t de Student para Imunofluorescência. A significância foi estabelecida em p < 0,05. Resultados: o ensaio de redução do MTT mostrou que o BZD (3,1 a 100 µg/mL) causou diminuição na viabilidade dos astrócitos. A citometria de fluxo mostrou que o efeito citotóxico do BZD foi causado pela ativação da via de morte apoptótica, evidenciada pela externalização da fosfatidilserina. A imunofluorescência revelou aumento na expressão de caspase-8 e nenhuma alteração na expressão de caspase-9, demonstrando que houve ativação da via extrínseca de apoptose. A concentração inibitória média (CI50) de BZD (26,13 µg/mL) também causou aumento na expressão de NFκB p65. Conclusão: em conjunto, os resultados do presente estudo sugerem que o BZD tem efeito citotóxico nas células astrocitárias, e esse efeito advém de sua capacidade de ativar a via apoptótica extrínseca.

Effect of neuroglial calcium signaling on neurological impairment in ischemic stroke / 中国病理生理杂志

Stroke is one of the leading causes of disability and death in China,but its mechanism has not been thoroughly elucidated.As an important class of cells in maintaining neurological homeostasis,the intracellular calcium signaling of glial cells plays a dual role in mitigating and exacerbating neuronal damage in stroke and largely determines the progression and outcome of stroke.In this review of the literature,focusing on astrocytes,which account for the largest proportion of glial cells,we review the mechanism of glial calcium signaling after stroke and its effect on post-stroke neuro-logical function,to provide reference for post-stroke neuroprotection and repair.

Advances in research on radiation-induced brain injury / 中华放射医学与防护杂志

Radiotherapy can cause functional and morphological changes in the brain tissues of patients with primary or metastatic malignant brain tumors, leading to radiation-induced brain injury. However, the pathogenesis of radiation-induced brain injury has not yet been unanimously determined, and its research advances and treatment protocols are yet to be elucidated and improved. In this study, we explore the pathogenesis of radiation-induced brain injury from the perspective of vascular injury, inflammatory reactions, neuronal dysfunction, glial cell injury, and gut microbiota and reviewed the advances in research on its treatment and prevention. The purpose is to provide a reference and theoretical basis for the research and clinical diagnosis and treatment of radiation-induced brain injury.

Differential effects of APOE polymorphism in neurotoxicity-responsive astrocytes induced by inflammatory factor / 吉林大学学报(医学版)

Objective:To discuss the differential effects of apolipoprotein E(APOE)gene polymorphism in the neurotoxicity-reactive astrocytes,and to provide the theoretical basis for the study of the pathogenesis of Alzheimer's disease(AD).Methods:The primary cortical astrocytes from the APOE-knockout mice(APOE-/-)were isolated and cultured in vitro,and the purity of the cells was identified by immunofluorescence staining.The human APOE3 and APOE4 recombinant over-expression plasmids were constructed and separately transfected into the primary APOE-/-astrocytes,and the APOE-/-primary cells were regarded as control.Western blotting method was used to detect the expression levels of APOE and glial fibrillary acidic protein(GFAP)proteins in the cells;enzyme-linked immunosorbent assay(ELISA)method was used to detect the APOE level in the cellular culture supernatant.The inflammatory models were prepared with the primary astrocytes transfected with APOE3 and APOE4 and co-stimulated with interleukin-1α(IL-1α),tumor necrosis factor(TNF),and complement C1q.The cells were divided into APOE3+PBS group,APOE4+PBS group,APOE3+IL-1α+TNF+ C1q group,and APOE4+IL-1α+TNF+C1q group.Cell immunofluorescence staining method was used to observe the morphology of the cells in various groups;real-time fluorescence quantitative PCR(RT-qPCR)method was used to detect the expression levels of glypican 4(Gpc4),glypican 6(Gpc6),thrombospondin 1(Thbs1),thrombospondin 2(Thbs2),SPARC-like protein 1(Sparcl1)and glial cell line derived neurotrophic factor(GDNF),C3,and S100 calcium binding protein B(S100B)mRNA in the cells in various groups;microsphere phagocytosis assay was used to detect the phagocytic capacities of the cells in various groups;Western blotting was used to detect the protein expression levels of B-cell lymphoma 2(Bcl-2),and cysteinyl aspartate specific protease-3(Caspase-3)proteins in the cells in various groups.Results:Compared with APOE-/-group,the expression levels of APOE and GFAP proteins in the cells and the APOE level in the cellular culture supernatant in transfected APOE3 and transfected APOE4 groups were increased(P<0.01).The fluorescence microscope observation results showed that compared with APOE3+PBS and APOE4+PBS groups,the astrocytic processes in APOE3+IL-1α +TNF+Cq1 group and APOE4+IL-1α+TNF+Cq1 group became shorter and the cell bodies became larger;compared with APOE3+IL-1α +TNF+Cq1 group,the astrocytic processes in APOE4+IL-1α +TNF+Cq1 group were even shorter.Compared with APOE3+PBS and APOE4+PBS groups,the expression levels of Gpc4,Gpc6,Thbs1,Thbs2,and Sparcl1 mRNA in the cells in APOE3+IL-1α +TNF+Cq1 group and APOE4+IL-1α +TNF+Cq1 group were significantly decreased(P<0.01);compared with APOE3+IL-1α +TNF+Cq1 group,the expression levels of Gpc4,Gpc6,Thbs1,Thbs2,and Sparcl1 mRNA in the cells in APOE4+IL-1α +TNF+Cq1 group were significantly decreased(P<0.05 or P<0.01).Compared with APOE3+PBS and APOE4+PBS groups,the expression levels of GDNF mRNA in the cells in APOE3+IL-1α+TNF+Cq1 group and APOE4+ IL-1α +TNF+Cq1 group were decreased(P<0.01),and the expression levels of C3 and S100B mRNA were increased(P<0.01);compared with APOE3+IL-1α +TNF+Cq1 group,the expression level of GDNF mRNA in the cells in APOE4+IL-1α+TNF+Cq1 group was decreased(P<0.05),and the expression levels of C3 and S100B mRNA were increased(P<0.05).Compared with APOE3+ PBS group and APOE4+PBS group,the numbers of hagocytosis of microspheres in the cells in APOE3+ IL-1α +TNF+Cq1 group and APOE4+IL-1α +TNF+Cq1 group were significantly decreased;compared with APOE3+IL-1α+TNF+Cq1 group,the number of hagocytosis of microspheres in the cells in APOE4+IL-1α+TNF+Cq1 group was significantly decreased.Compared with APOE3+PBS group and APOE4+PBS group,the expression levels of Bcl-2 protein in the cells in APOE3+IL-1α+TNF+ Cq1 group and APOE4+IL-1α +TNF+Cq1 group were decreased(P<0.05 or P<0.01)and the expression levels of Caspase-3 protein were significantly increased(P<0.01);compared with APOE3+ IL-1α+TNF+Cq1 group,the expression level of Bcl-2 protein in the cells in APOE4+IL-1α+TNF+ Cq1 group was decreased(P<0.01),and the expression level of Caspase-3 protein was increased(P<0.05).Conclusion:The APOE4 genotype has a stronger ability to induce the inflammatory factors compared with APOE3;it can lead to a neurotoxicity-reactive astrocyte phenotype,increase the neurotoxicity,affect the astrocyte apoptosis,and aggravate the neuron damage.

Activation of A1 reactive astrocytes in the medullary dorsal horn of rats participates in the chronification of trigeminal neuralgia / 中南大学学报(医学版)

Objective:The activation of astrocytes is an important process in the formation of chronic pain.This study aims to observe the activation of A1 reactive astrocytes in the medullary dorsal horn in the rat model of trigeminal neuralgia,and to explore the mechanism of central sensitization caused by A1 reactive astrocyte. Methods:The adult male rats were randomly divided into a sham group and a chronic constriction injury of infraorbital nerve(ION-CCI)group.The facial mechanical pain threshold and thermal withdrawal latency were measured before the operation and on the 1st,3rd,7th,10th,and 14th day after the operation.After pain behavior observation,the expression of glial fibrillary acidic protein(GFAP)in the medullary dorsal horn was observed by immunohistochemistry and immunofluorescence colocalization of GFAP,complement 3(C3)/S100A10,and 4',6-diamidino-2-phenylindole(DAPI)was analyzed.Primary astrocytes were cultured and randomly divided into a naive group and a DHK group.The DHK group was treated with 1 mmol/L of astrocyte activation inhibitor dihydrokainic acid(DHK).Fura-2/AM was used to stain the astrocytes and the calcium wave of the 2 groups under the stimulation of high potassium was recorded and compared.The expression of C3 was detected by Western blotting. Results:The facial mechanical pain threshold and thermal withdrawal latency of the ION-CCI group were significantly lower than those of the sham group(both P<0.05).There were a large number of GFAP positive astrocytes in the medullary dorsal horn of the ION-CCI group.The fluorescence intensity of GFAP in the ION-CCI group was higher than that in the sham group(P<0.05).GFAP and C3/S100A10 were co-expressed in astrocytes.Compared with the sham group,the fluorescence intensity of C3 and the protein expression of C3 in the ION-CCI group were increased(both P<0.05).The expression of C3 in ION-CCI group was significantly increased(P<0.05).Compared with the naive group,the C3 protein expression was significantly decreased in the DHK group(P<0.05).The intensity of calcium fluorescence was increased after high potassium stimulation in both groups.Furthermore,the peak and increase amplitude of calcium fluorescence in the naive group were much higher than those in the DHK group(both P<0.05). Conclusion:A1 reactive astrocytes in the medullary dorsal horn of trigeminal neuralgia model rats are increased significantly,which may participate in central sensitization of trigeminal neuralgia by impacting astrocyte calcium wave.

Activation of astrocytes in distal segments of the spinal cord mediating widespread pain induced by peripheral nerve injury / 解剖学报

Objective To discuss the relationship between activated glia cells in distal segment of the spinal cord and widespread pain.Methods Fifty female rats were randomly divided into sham group,the chronic constriction injury of the infraorbital nerve(CCI-ION)group,CCI-ION+minocycline(Mino)group,CCI-ION+L-2-aminoadipic acid(LAA)group,and CCI-ION+normal saline(NS)group,n=10 for each group.CCI-ION model was established and Mino,LAA,and normal saline were delivered intrathecally to CCI-ION rats.Immunofluorescence staining was used to detect activated astrocytes and microglia in the medulla oblongata,cervical,thoracic,and lumbar spinal cord segments.On the 7th,14th,21st,28th day,von Frey filaments were used to evaluate the mechanical withdrawal threshold of vibrissa pad,and electronic von Frey tactile pain meter was used to measure the mechanical withdrawal threshold of front paw,chest and hind paw.The radiant thermal stimulator was used to measure the thermal withdrawal threshold of hind paw.Results After intrathecal injection of Mino to inhibit microglia,the activated microglia in each spinal cord segment decreased.Moreover,inhibiting astrocytes by using LAA significantly reduced activated astrocytes in spinal dorsal horn from distal segments.Behavioral assay showed that after intrathecal injection of Mino and LAA,the mechanical allodynia of vibrissa pad in CCI-ION rats was relieved.However,there was no significant difference(P>0.05)in the thermal and mechanical withdrawal thresholds in the hind paw of CCI-ION rats after intrathecal injection of Mino,while intrathecal injection of LAA significantly increased the thermal and mechanical withdrawal thresholds in the hind paw,indicating the relief of widespread pain induced by CCI-ION.Conclusion The activated astrocytes in distal segments of the spinal cord mediated CCI-ION-induced widespread pain.

Panax notoginseng saponin relieving the inflammatory pain caused by complete Freund’s adjuvant by inhibiting the activation of astrocytes in mice / 解剖学报

Objective To analyse the analgesic effect and possible mechanism of panax notoginseng saponin (PNS) on mouse models of chronic inflammatory pain caused by complete Freund’s adjuvant (CFA). Methods A total of 48 male C57BL/ 6J mice were divided randomly into four groups: normal saline control group (Ctrl), CFA group (CFA), CFA + PNS group (CFA+PNS), CFA + dexamethasone (DEX) group (CFA+DEX). Von Frey filaments were used to detect mechanical pain in mice. Immunohistochemistry was used to detect the number and morphological changes of glial fibrillary acidic protein (GFAP) positive astrocytes. Western blotting was used to detect the expressions of GFAP, nucleotide-binding and oligomerization domain(NOD)-like receptor thermal protein domain associated protein 3 (NLRP3), apoptosis-associated speck-like protein containing a CARD (ASC), Caspase-1, interleukin (IL)-1β, and IL-18 in mice’s spinal cord segments in each group. Results Compared with the Ctrl group, mice in the CFA group showed a significant decrease in mechanical pain thresholds at day 1, day 3, day 5, day 7, and day 14. Additionally, there was a significant decrease in NLRP3, ASC, Caspase-1, IL-1β and IL-18 in the spinal cord of the mice. PNS intervention could relieve mechanical pain and down-regulate the expressions of NLRP3, ASC, Caspase-1, IL-1β and IL-18 in the spinal cord of mice, with no significant difference compared with the CFA+DEX group. CFA group mice had significantly more GFAP positive cells in their posterior horns than Ctrl group mice, as measured by immunohistochemistry; PNS intervention decreased the number of GFAP positive cells in the posterior horn of the spinal cord in model mice;DEX had no effect on the number of GFAP positive cells in the dorsal horn of spinal cord. According to Western blotting results, GFAP expression in the spinal cord of the CFA group was significantly more than that of the Ctrl group; PNS intervention significantly reduced GFAP expression in the spinal cord of CFA group mice;DEX had no effect on the expression of GFAP in the posterior horn of spinal cord. Conclusion PNS has a good alleviating effect on inflammatory pain, and its mechanism may be related to inhibition of astrocyte activation and NLRP3 inflammasome activation.

Effect of Cholecystokinin Octapeptide on Expression of GLT-1 in Glutamate-induced Hippocampal Astrocytes / 华中科技大学学报(医学版)

Objective To investigate the effect of cholecystokinin octapeptide(CCK-8)on glutamate transporter 1(GLT-1)expression in hippocampal astrocytes induced by glutamate(Glu).Methods The mouse hippocampal astrocytes were isolated and the toxicity of CCK-8 at different concentrations on the mouse hippocampal astrocytes was detected.The cells were divided into control group,Glu group,Glu+0.1 μmol/L CCK-8 group,Glu+0.5 μmol/L CCK-8 group and Glu+1.0 μmol/L CCK-8 group.MTT assay was used to detect cell proliferation.Flow cytometry was used to detect cell apoptosis.Biochemical kit was used to detect Glu content in the extracellular supernatant,and qRT-PCR was used to detect the mRNA expression of GLT-1 and glutamate/aspartate transporter(GLAST).The protein expressions of Caspase-3,Bcl-2,GLT-1 and GLAST were detected by Western blotting,and the expression of TNF-α in the cell supernatant was detected by ELISA.Results CCK-8 at different concentrations had no significant effect on the proliferation of mouse hippocampal astrocytes.Compared with the control group,the cell proliferation ability and the expression levels of Bcl-2 protein,GLT-1 and GLAST mRNA and protein in Glu group were significantly decreased(all P＜0.01),the apoptosis rate,extracellular Glu content,Caspase-3 protein expression level in cells and TNF-α level in cell supernatant were significantly increased(all P＜0.01);Compared with the Glu group,the cell proliferation a-bility and the expression levels of Bcl-2 protein,GLT-1 and GLAST mRNA and protein in the Glu+0.5 μmol/L CCK-8 group and Glu+1.0 μmol/L CCK-8 group were significantly increased(all P＜0.05),the apoptosis rate,extracellular Glu content,Caspase-3 protein expression level in cells and TNF-α level in cell supernatant were significantly decreased(all P＜0.01).Con-clusion CCK-8 can inhibit Glu-induced inflammatory response of astrocytes,promote the expression of GLT-1,reduce the con-centration of extracellular Glu,promote cell proliferation and inhibit apoptosis.

Astrocytes regulate glial scar formation in cerebral ischemic stroke / 中国组织工程研究

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.

Single-cell RNA sequencing reveals the heterogeneity of astrocytes / 中国组织工程研究

BACKGROUND:Astrocytes are the most abundant cells in the central nervous system,and various subsets of astrocytes are heterogeneous,performing a variety of special functions.Single-cell RNA sequencing(scRNA-seq)technology developed in recent years has extended our understanding of astrocyte heterogeneity from the perspective of transcriptome profiling. OBJECTIVE:To summarize the heterogeneity of scRNA-seq technology in different time and space,and pathological states and expand our knowledge of astrocyte heterogeneity on both molecular and functional levels. METHODS:The relevant articles on astrocyte heterogeneity and scRNA-seq were searched on PubMed,Elsevier,and CNKI databases.The search terms were"astrocytes,scRNA-seq,heterogeneity,Alzheimer disease,spinal cord injury,multiple sclerosis"in Chinese and English.Finally,74 articles were selected for viewing after screening according to inclusion criteria. RESULTS AND CONCLUSION:scRNA-seq studies related to the heterogeneity of astrocytes have shown that astrocyte is significantly heterogeneous across four aspects:species,developmental stage,central nervous system region,and pathological state.(1)Unique expression of certain genes occurs in astrocytes of different species,and the discovery of species-specific genes is beneficial for the translation of clinical studies.(2)During astrocyte development,differential gene expression emerged in the cellular subtypes identified at each stage,which further refined the cellular lineage of astrocytes and laid the foundation for the study of astrocyte developmental trajectories and mechanisms.(3)The discovery of differential gene expression allows regional localization of different astrocyte subpopulations and assists in the diagnosis and treatment of neurological diseases.(4)Astrocyte heterogeneity revealed by scRNA-seq can provide specific markers at the time of disease diagnosis and identify potential therapeutic targets.(5)The heterogeneity of astrocytes exists in many aspects,interacts with each other and is complex.The mechanisms of its generation,maintenance and transformation remain unclear.At present,molecular research on the single-cell level is still lacking.Linking transcriptionally defined astrocyte subpopulations to cellular activity,behavior and disease markers in real time remains one of the great challenges in the field.

Hydroxysafflor yellow A intervenes astrocyte lipocalin 2 expression after cerebral ischemia/reperfusion injury / 中国组织工程研究

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.

Shexiang Huangqi compound dripping pills-containing serum promotes proliferation and differentiation of bone marrow mesenchymal stem cells / 中国组织工程研究

BACKGROUND:Bone marrow mesenchymal stem cells have been widely used to treat neurological diseases.However,due to limitations of the blood-brain barrier,low survival rate and differentiation rate of stem cells at damaged sites,the therapeutic effect is limited. OBJECTIVE:To investigate the effects of Shexiang Huangqi compound dripping pills on proliferation,migration and astrocyte differentiation of bone marrow mesenchymal stem cells. METHODS:Male SD rats were treated with Shexiang Huangqi compound dripping pills for 5 days after continuous gavage.Blood was collected from the abdominal aorta and serum was separated for later use.The effect of 5%,10%and 20%drug-containing serum on the proliferation of bone marrow mesenchymal stem cells was detected by CCK-8 assay.The effect of 10%drug-containing serum on lateral migration of bone marrow mesenchymal stem cells was observed by scratch test.Bone marrow mesenchymal stem cells were cultured in Transwell cells.The effects of 10%drug-containing serum on longitudinal migration of bone marrow mesenchymal stem cells were observed by crystal violet staining and DAPI nuclear staining.Differentiation of bone marrow mesenchymal stem cells into astrocytes was observed by inducing solution with 10%drug-containing serum or co-culture with astrocytes. RESULTS AND CONCLUSION:(1)10%and 20%drug-containing serum promoted cell proliferation more significantly on days 2 and 3,and there was no statistical difference between the two concentrations.(2)At 30 and 48 hours,bone marrow mesenchymal stem cell migration in 10%drug-containing serum group was significantly higher than that in the control group.(3)The number of bone marrow mesenchymal stem cells filtered through Transwell cells in 10%drug-containing serum group was higher than that in the control group.(4)10%drug-containing serum might promote the differentiation of bone marrow mesenchymal stem cells to astrocytes,but the differentiation effect was weak,and astrocytes might further promote the differentiation of bone marrow mesenchymal stem cells into astrocytes induced by drug-containing serum.(5)The results exhibited that the 10%drug-containing serum could promote the proliferation and migration of bone marrow mesenchymal stem cells in vitro.Co-culture with astrocytes may promote the differentiation of bone marrow mesenchymal stem cells towards astrocytes.

Neuron-derived extracellular vesicles promote neurogenesis of neural stem cells / 中国组织工程研究

BACKGROUND:It has been shown that neural stem cells can differentiate into neurons,astrocytes,and oligodendrocytes.Mesenchymal stem cells-derived extracellular vesicles have also been shown to cross the blood-brain barrier to reach sites of central nervous injury and promote neural repair.However,it is not clear whether neuron-derived extracellular vesicles promote the differentiation of neural stem cells in a direction that is beneficial for neurogenesis. OBJECTIVE:To investigate whether neuron-derived extracellular vesicles facilitate neural stem cell differentiation towards neurogenesis. METHODS:Neurons and neural stem cells were extracted from neonatal SD rat cerebral cortex by trypsin digestion.Cell supernatants of neurons were collected.Neuron-derived extracellular vesicles were extracted.Neural stem cells cultured for 10 days were co-cultured with neuron-derived extracellular vesicles or PBS for 7 days.Immunoblotting,immunofluorescence,and RT-qPCR were used to detect proteins specifically expressed by neurons,neural stem cells,oligodendrocytes,and astrocytes. RESULTS AND CONCLUSION:The neural stem cells co-cultured with neuron-derived extracellular vesicles showed high expression of neuron-specific proteins and oligodendrocyte-specific proteins including β3-tubulin,neurofilament 200 and myelin basic protein,and low expression of astrocyte-specific protein glial fibrillary acidic protein.These results suggest that neuron-derived extracellular vesicles can promote the differentiation of neural stem cells into neurons and oligodendrocytes and prevent the differentiation of neural stem cells into astrocytes.

miR-146a-3p regulates astrocyte proliferation,migration and apoptosis by inhibiting insulin-like growth factor 1 expression / 中国组织工程研究

BACKGROUND:The alteration of miR-146a-3p level is a common event in the pathogenesis of most neurological diseases,and the specific mechanism of miR-146a-3p regulation of astrocytes has not been studied. OBJECTIVE:To verify that miR-146a-3p regulates astrocyte proliferation,migration and apoptosis through insulin-like growth factor 1. METHODS:12 SD rats were divided into a sham operation group and a spinal cord injury group,with six rats in each group.RNA sequencing analysis was performed on the spinal cord tissues of all groups 2 weeks after surgery to screen out the differential genes(log2FC>2),and to select spinal cord injury-related genes(Score>20)in the Genecards database,and then to predict the target genes of miR-146a-3p by Targetscan.The intersection of three gene sets was obtained to screen out insulin-like growth factor 1 as one of the important target genes.qPCR,western blot assay and immunohistochemistry were performed to analyze the expression level of insulin-like growth factor 1 in spinal cord tissues.The primary astrocytes were divided into NC group,NC-mimics group and miR-146a-3p mimics group.Annexin-V/PI staining was used to detect cell apoptosis.CCK-8 assay was used to detect cell proliferation.Transwell assay was used to detect cell migration ability. RESULTS AND CONCLUSION:The expression of miR-146a-3p in the spinal cord tissue of the spinal cord injury group was lower than that of the sham operation group(P<0.05).The expression of insulin-like growth factor 1 in the spinal cord tissue of the spinal cord injury group was higher than that of the sham operation group(P<0.05).Compared with the NC group and NC-mimics group,the apoptotic rate of astrocytes was increased(P<0.01);the proliferation of astrocytes was decreased(P<0.01)and the number of migration was decreased(P<0.01)in the miR-146a-3p mimics group.To conclude,the expression of miR-146a-3p decreased and the expression of insulin-like growth factor 1 increased in spinal cord tissue after spinal cord injury.miR-146a-3p targeted regulation of insulin-like growth factor 1 in astrocytes,inhibited the proliferation and migration of astrocytes and promoted their apoptosis.

Astragaloside inhibits astrocyte activation and inflammatory response induced by inflammation / 中国组织工程研究

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.

Optimization and methods of culture in vitro of astrocytes from cerebral cortical mice / 安徽医科大学学报

Objective @#To explore and optimize the in vitro primary culture method of astrocytes in neonatal mouse cerebral cortex , which provides a better solution for the in vitro culture of astrocytes.@*Methods @#In order to optimize the in vitro culture method of mouse cerebral cortex astrocytes , 3 ⁃day⁃old C57BL/6J mouse cerebral cortex tissues were taken , meninges and blood vessels were removed , digested by pancreatic enzymes and centrifuged , andhigh⁃glucose dulbecco ′s modified eagle medium (DMEM) was added to form cell suspension , which was purified by differential adhesion method , cross hand method and constant temperature shaking method.The cells were inoculated in poly⁃D ⁃lysine⁃coated culture bottles with different culture densities , and the purity of astrocytes was determined by morphological ob servation and immunofluorescence staining.@*Results @#The cells were inoculated at a density of 5 × 106 cells per bottle with good effect and high activity. The purity of astrocytes reached 99% by using high sugar DMEM medium combined with differential adhesion method , cross hand method and constant temperature shaking method.@*Conclusion @#The primary culture method of astrocytes in mouse cerebral cortex is successfully established and optimized.

Temporal-spatial Generation of Astrocytes in the Developing Diencephalon / 神经科学通报·英文版

Astrocytes are the largest glial population in the mammalian brain. However, we have a minimal understanding of astrocyte development, especially fate specification in different regions of the brain. Through lineage tracing of the progenitors of the third ventricle (3V) wall via in-utero electroporation in the embryonic mouse brain, we show the fate specification and migration pattern of astrocytes derived from radial glia along the 3V wall. Unexpectedly, radial glia located in different regions along the 3V wall of the diencephalon produce distinct cell types: radial glia in the upper region produce astrocytes and those in the lower region produce neurons in the diencephalon. With genetic fate mapping analysis, we reveal that the first population of astrocytes appears along the zona incerta in the diencephalon. Astrogenesis occurs at an early time point in the dorsal region relative to that in the ventral region of the developing diencephalon. With transcriptomic analysis of the region-specific 3V wall and lateral ventricle (LV) wall, we identified cohorts of differentially-expressed genes in the dorsal 3V wall compared to the ventral 3V wall and LV wall that may regulate astrogenesis in the dorsal diencephalon. Together, these results demonstrate that the generation of astrocytes shows a spatiotemporal pattern in the developing mouse diencephalon.

Cx43 hemichannels and panx1 channels contribute to ethanol-induced astrocyte dysfunction and damage

Background Alcohol, a widely abused drug, significantly diminishes life quality, causing chronic diseases and psychiatric issues, with severe health, societal, and economic repercussions. Previously, we demonstrated that non-voluntary alcohol consumption increases the opening of Cx43 hemichannels and Panx1 channels in astrocytes from adolescent rats. However, whether ethanol directly affects astroglial hemichannels and, if so, how this impacts the function and survival of astrocytes remains to be elucidated. Results Clinically relevant concentrations of ethanol boost the opening of Cx43 hemichannels and Panx1 channels in mouse cortical astrocytes, resulting in the release of ATP and glutamate. The activation of these large-pore channels is dependent on Toll-like receptor 4, P2X7 receptors, IL-1β and TNF-α signaling, p38 mitogen-activated protein kinase, and inducible nitric oxide (NO) synthase. Notably, the ethanol-induced opening of Cx43 hemichannels and Panx1 channels leads to alterations in cytokine secretion, NO production, gliotransmitter release, and astrocyte reactivity, ultimately impacting survival. Conclusion Our study reveals a new mechanism by which ethanol impairs astrocyte function, involving the sequential stimulation of inflammatory pathways that further increase the opening of Cx43 hemichannels and Panx1 channels. We hypothesize that targeting astroglial hemichannels could be a promising pharmacological approach to preserve astrocyte function and synaptic plasticity during the progression of various alcohol use disorders.

Effect of Astrocyte-neuron Coupling Imbalance in Development of Alzheimer's Disease and Intervention Mechanism of Kidney-tonifying and Marrow-filling TCM Prescriptions / 中国实验方剂学杂志

Astrocytes are important nerve cells in the central nervous system （CNS）， which mainly play a key role in nutrition and support. Astrocytes and neurons undergo close energy coupling and substance coupling， which are closely related and interact with each other. In recent years， many studies have shown that the astrocyte-neuron coupling imbalance plays a central role in the occurrence and progression of Alzheimer's disease （AD） and serves as an important therapeutic target receiving increasing attention. According to traditional Chinese medicine （TCM） theory， the main pathogenesis of AD is kidney deficiency and marrow inadequacy， and in clinical medication， kidney-tonifying and marrow-filling TCM prescriptions are often employed with satisfactory results achieved. As reported， many kidney-tonifying and marrow-filling prescriptions exhibit regulatory and protective effects on the imbalance of astrocyte-neuron coupling， suggesting that the effect of kidney-tonifying and marrow-filling prescriptions in treating AD may have some internal relationship with its regulation of the imbalance of astrocyte-neuron coupling. This article reviewed the underlying internal relationship between the imbalance of astrocyte-neuron coupling and the pathogenesis of kidney deficiency and marrow inadequacy in AD and the research progress in the intervention mechanism of TCM for tonifying the kidney and filling the marrow.

Association of Glial Activation and α-Synuclein Pathology in Parkinson's Disease / 神经科学通报·英文版

The accumulation of pathological α-synuclein (α-syn) in the central nervous system and the progressive loss of dopaminergic neurons in the substantia nigra pars compacta are the neuropathological features of Parkinson's disease (PD). Recently, the findings of prion-like transmission of α-syn pathology have expanded our understanding of the region-specific distribution of α-syn in PD patients. Accumulating evidence suggests that α-syn aggregates are released from neurons and endocytosed by glial cells, which contributes to the clearance of α-syn. However, the activation of glial cells by α-syn species produces pro-inflammatory factors that decrease the uptake of α-syn aggregates by glial cells and promote the transmission of α-syn between neurons, which promotes the spread of α-syn pathology. In this article, we provide an overview of current knowledge on the role of glia and α-syn pathology in PD pathogenesis, highlighting the relationships between glial responses and the spread of α-syn pathology.