Traumatic brain injury is a global health crisis,causing significant death and disability worldwide.Neuroinflammation that follows traumatic brain injury has serious consequences for neuronal survival and cognitive im...Traumatic brain injury is a global health crisis,causing significant death and disability worldwide.Neuroinflammation that follows traumatic brain injury has serious consequences for neuronal survival and cognitive impairments,with astrocytes involved in this response.Following traumatic brain injury,astrocytes rapidly become reactive,and astrogliosis propagates from the injury core to distant brain regions.Homeostatic astroglial proteins are downregulated near the traumatic brain injury core,while pro-inflammatory astroglial genes are overexpressed.This altered gene expression is considered a pathological remodeling of astrocytes that produces serious consequences for neuronal survival and cognitive recovery.In addition,glial scar formed by reactive astrocytes is initially necessary to limit immune cell infiltration,but in the long term impedes axonal reconnection and functional recovery.Current therapeutic strategies for traumatic brain injury are focused on preventing acute complications.Statins,cannabinoids,progesterone,beta-blockers,and cerebrolysin demonstrate neuroprotective benefits but most of them have not been studied in the context of astrocytes.In this review,we discuss the cell signaling pathways activated in reactive astrocytes following traumatic brain injury and we discuss some of the potential new strategies aimed to modulate astroglial responses in traumatic brain injury,especially using cell-targeted strategies with miRNAs or lncRNA,viral vectors,and repurposed drugs.展开更多
A mathematical model has been formulated in accordance with cell chemotaxis and relevant experimental data. A three-dimensional lattice Boltzmann method was used for numerical simulation. The present study observed th...A mathematical model has been formulated in accordance with cell chemotaxis and relevant experimental data. A three-dimensional lattice Boltzmann method was used for numerical simulation. The present study observed the effects of glial scar size and inhibitor concentration on regenerative axonal growth following spinal cord transection. The simulation test comprised two parts: (1) when release rates of growth inhibitor and promoter were constant, the effects of glial scar size on axonal growth rate were analyzed, and concentrations of inhibitor and promoters located at the moving growth cones were recorded. (2) When the glial scar size was constant, the effects of inhibitor and promoter release rates on axonal growth rate were analyzed, and inhibitor and promoter concentrations at the moving growth cones were recorded. Results demonstrated that (1) a larger glial scar and a higher release rate of inhibitor resulted in a reduced axonal growth rate. (2) The axonal growth rate depended on the ratio of inhibitor to promoter concentrations at the growth cones. When the average ratio was 〈 1.5, regenerating axons were able to grow and successfully contact target cells.展开更多
The role of glial scar after intracerebral hemorrhage(ICH)remains unclear.This study aimed to investigate whether microglia-astrocyte interaction affects glial scar formation and explore the specific function of glial...The role of glial scar after intracerebral hemorrhage(ICH)remains unclear.This study aimed to investigate whether microglia-astrocyte interaction affects glial scar formation and explore the specific function of glial scar.We used a pharmacologic approach to induce microglial depletion during different ICH stages and examine how ablating microglia affects astrocytic scar formation.Spatial transcriptomics(ST)analysis was performed to explore the potential ligand-receptor pair in the modulation of microglia-astrocyte interaction and to verify the functional changes of astrocytic scars at different periods.During the early stage,sustained microglial depletion induced disorganized astrocytic scar,enhanced neutrophil infiltration,and impaired tissue repair.ST analysis indicated that microglia-derived insulin like growth factor 1(IGF1)modulated astrocytic scar formation via mechanistic target of rapamycin(mTOR)signaling activation.Moreover,repopulating microglia(RM)more strongly activated mTOR signaling,facilitating a more protective scar formation.The combination of IGF1 and osteopontin(OPN)was necessary and sufficient for RM function,rather than IGF1 or OPN alone.At the chronic stage of ICH,the overall net effect of astrocytic scar changed from protective to destructive and delayed microglial depletion could partly reverse this.The vital insight gleaned from our data is that sustained microglial depletion may not be a reasonable treatment strategy for early-stage ICH.Inversely,early-stage IGF1/OPN treatment combined with late-stage PLX3397 treatment is a promising therapeutic strategy.This prompts us to consider the complex temporal dynamics and overall net effect of microglia and astrocytes,and develop elaborate treatment strategies at precise time points after ICH.展开更多
X-irradiation has a beneficial effect in treating spinal cord injury. We supposed that X-irradiation could improve the microenvironment at the site of a spinal cord injury and inhibit glial scar formation. Thus, this ...X-irradiation has a beneficial effect in treating spinal cord injury. We supposed that X-irradiation could improve the microenvironment at the site of a spinal cord injury and inhibit glial scar formation. Thus, this study was designed to observe the effects of 8 Gy X-irradiation on the injury site at 6 hours and 2, 4, 7, and 14 days post injury, in terms of improvement in the microenvironment and hind limb motor function. Immunohistochemistry showed that the expression of macrophage marker ED-1 and the area with glial scar formation were reduced. In addition, the Basso, Beattie and Bresnahan score was higher at 7 days post injury relative to the other time points post injury. Results indicated that X-irradiation at a dose of 8 Gy can inhibit glial scar formation and alleviate the inflammatory reaction, thereby repairing spinal cord injury. X-irradiation at 7 days post spinal cord injury may be the best time window.展开更多
Glial cells comprise -90% of the human brain and are divided into two subtypes: microglia and astrocytes. Astrocytes play a vital role in maintaining central nervous system (CNS) homeostasis, regulating ion concent...Glial cells comprise -90% of the human brain and are divided into two subtypes: microglia and astrocytes. Astrocytes play a vital role in maintaining central nervous system (CNS) homeostasis, regulating ion concentrations and providing metabolic support for neighboring neurons, stabilizing synapses, supporting the neurovascular system including maintenance of the blood-brain barrier (BBB) and also producing the extracellular matrix (ECM).展开更多
Objective: To observe the effect of electroacupuncture(EA) combined with oriented conductive bioprotein hydrogel(OCBH) on the recovery of nerve function in rats with complete spinal cord injury(SCI)and to explore its ...Objective: To observe the effect of electroacupuncture(EA) combined with oriented conductive bioprotein hydrogel(OCBH) on the recovery of nerve function in rats with complete spinal cord injury(SCI)and to explore its effect and mechanism on the formation and changes of glial scars.Methods: A total of 72 female Sprague-Dawley rats were randomly divided into groups according to the treatment received. A rat model of complete SCI was constructed using a spinal cord transection.Behavioral assessments, hematoxylin-eosin(H&E) staining, immunofluorescence staining, and Western blotting were performed at a fixed period after the operation.Results: The material group and the material + EA group obtained better results in the behavioral assessments(all P <.05) and the H&E staining. In the immunofluorescence staining and Western blotting,the GFAP protein was expressed more and denser in the material group and the material + EA group than in the model group, and the density of the GFAP expression in the material + EA group was lower at week 12 than in the material group(all P <.05). The expression of complement C3 in the model, material,and material + EA groups decreased in turn. Some inflammatory factors and the NF-κB signaling pathway showed similar results in the Western blotting(all P <.05). The expression of the GDNF protein in the material + EA group was significantly higher than that in the model group and the material group(both P <.01).Conclusion: EA combined with OCBH can promote the recovery of motor functions after SCI by facilitating the formation of glial scars in the early stage, preventing the further spread of an inflammatory response that would affect the activation of A1/A2 astrocytes and change the morphology of glial scars at the spinal cord-material interface in its late stage.展开更多
A rat model of spinal cord injury was established using the weight drop method. A cavity formed 14 days following spinal cord injury, and compact scar tissue formed by 56 days. Enzyme-linked immunosorbent assay and po...A rat model of spinal cord injury was established using the weight drop method. A cavity formed 14 days following spinal cord injury, and compact scar tissue formed by 56 days. Enzyme-linked immunosorbent assay and polymerase chain reaction enzyme-linked immunosorbent assay results demonstrated that glial fibrillary acidic protein and telomerase expression increased gradually after injury, peaked at 28 days, and then gradually decreased. Spearman rank correlation showed a positive correlation between glial fibrillary acidic protein expression and telomerase expression in the glial scar. These results suggest that telomerase promotes glial scar formation.展开更多
Objective:To determine if a cell cycle inhibitior, olomoucine, would decrease neuronal cell death, limit astroglial proliferation and production of inhibitory CSPGs, and eventually enhance the functional compensation ...Objective:To determine if a cell cycle inhibitior, olomoucine, would decrease neuronal cell death, limit astroglial proliferation and production of inhibitory CSPGs, and eventually enhance the functional compensation after SCI in rats. Methods: Three were used as un-operated controls and twelve as sham operated controls. Following spinal cord injury, 48 rats were randomly and blindly assigned to either olomoucine (n=24) or vehicle treatment (n=24) groups. Results: Up-regulations of cell cycle components were closely associated with neuronal cell death and astroglial proliferation as well as the production of CSPGs after SCI. Meanwhile, administration of olomoucine, a selective cell cycle kinase (CDK) inhibitor, has remarkably reduced the up-regulated cell cycle proteins and then decreased neuronal cell death, astroglial proliferation as well as accumulation of CSPGs. More importantly, the treatment with olomoucine has also increased expression of growth-associated proteins-43 (GAP-43), reduced the cavity formation, and improved functional deficits. Conclusion: Suppressing astroglial cell cycle in acute spinal cord injuries is beneficial to axonal growth. in turn, the future therapeutic strategies can be designed to achieve efficient axonal regeneration and functional compensation after traumatic CNS injury.展开更多
OBJECTIVE To explore the neuro-protective effects of saffron(Crocus satius L.) on chronic focal cerebral ischemia in rats.METHODS SD rats were randomly divided into 6 groups:sham control group,MCAO group,edaravone gro...OBJECTIVE To explore the neuro-protective effects of saffron(Crocus satius L.) on chronic focal cerebral ischemia in rats.METHODS SD rats were randomly divided into 6 groups:sham control group,MCAO group,edaravone group and saffron 30,100,300 mg·kg^(-1) groups.Focal cerebral ischemia was induced by middle cerebral artery occlusion(MCAO).Saffron was administered orally by once daily from 2 h to 42 d after ischemia.At 42 d after cerebral ischemia,neurological deficit score,spontaneous activity test,elevated plus maze test,marble burying test and novel objective recognition test were used to evaluate the effects of saffron on the behevioural change.Infarct volume,survival neuron density,activated astrocyte number,and the thickness of glial scar were also detected.GFAP expression and inflammatory cytokine contents in ischemic peripheral region were detected by Western blot and ELISA,separately.RESULTS Saffron(100,300 mg·kg^(-1)) improved the body weight decrease,neurological deficit and spontaneous activity.Saffron(30-300 mg · kg^(-1)) increased the traveled distance ratio and total time in open arm,decreased the buried marble number,which indicated that saffron could ameliorate anxiety-and depression-like behaviors.Saffron(100,300 mg·kg^(-1)) improved the learning and memory function,which manifested by increased discrimination ratio(DR) and discrim.ination index(DI) in T2 test.The results of toluidine blue found saffron treatment(100,300 mg · kg^(-1))decreased the infarct volume and increased the neuron density in cortex and hippocampal.The activated astrocyte number,the thickness of glial scar and GFAP expression in ischemic peripheral region decreased after saffron.Saffron(100,300 mg · kg^(-1)) decreased the contents of IL-6 and IL-1β,increased the content of IL-10 in ischemic peripheral region.CONCLUSION Saffron exerted neuro-protective effects on chronic focal cerebral ischemia,which could be related with inhibiting the activation of astrocyte and glial scar,following with the decrease of inflammatory reaction.展开更多
Glial scarring following severe tissue damage and inflammation after spinal cord injury (SCI) is due to an extreme, uncontrolled form of reactive astrogliosis that typically occurs around the injury site. The scarri...Glial scarring following severe tissue damage and inflammation after spinal cord injury (SCI) is due to an extreme, uncontrolled form of reactive astrogliosis that typically occurs around the injury site. The scarring process includes the misalignment of activated astrocytes and the deposition of inhibitory chondroitin sulfate proteoglycans. Here, we first discuss recent developments in the molecular and cellular features of glial scar formation, with special focus on the potential cellular origin of scar-forming cells and the molecular mechanisms underlying glial scar formation after SCI. Second, we discuss the role of glial scar formation in the regulation of axonal regeneration and the cascades of neuro-inflammation. Last, we summarize the physical and pharmacological approaches targeting the modulation of glial scarring to better understand the role of glial scar formation in the repair of SCI.展开更多
Spinal cord injury(SCI)often leads to permanent disability,which is mainly caused by the loss of functional recovery.In this review,we aimed to investigate why the healing process is interrupted.One of the reasons for...Spinal cord injury(SCI)often leads to permanent disability,which is mainly caused by the loss of functional recovery.In this review,we aimed to investigate why the healing process is interrupted.One of the reasons for this interruption is the formation of a glial scar around the severely damaged tissue,which is usually covered by reactive glia,macrophages and fibroblasts.Aiming to clarify this issue,we summarize the latest research findings pertaining to scar formation,tissue repair,and the divergent roles of blood-derived monocytes/macrophages,ependymal cells,fibroblasts,microglia,oligodendrocyte progenitor cells(OPCs),neuron-glial antigen 2(NG2)and astrocytes during the process of scar formation,and further analyse the contribution of these cells to scar formation.In addition,we recapitulate the development of therapeutic treatments targeting glial scar components.Altogether,we aim to present a comprehensive decoding of the glial scar and explore potential therapeutic strategies for improving functional recovery after SCI.展开更多
Objective: To evaluate the effect of Buyang Huanwu Decoction(补阳还五汤,BYHWD) on glial scar after intracerebral hemorrhage(ICH) and investigate the underlying mechanism.Methods: Collagenase type Ⅶ(0.5 U) was injecte...Objective: To evaluate the effect of Buyang Huanwu Decoction(补阳还五汤,BYHWD) on glial scar after intracerebral hemorrhage(ICH) and investigate the underlying mechanism.Methods: Collagenase type Ⅶ(0.5 U) was injected stereotaxically into right globus pallidus to induce ICH model.One hundred and twenty SpragueDawley rats were randomly divided into 3 groups according to a random number table,including normal group(n=40),ICH model group(n=40) and BYHWD group(n=40),respectively.After ICH,the rats in the BYHWD group were intragastrically administered with BYHWD(4.36 g/kg) once a day for 21 days,while the rats in ICH group were administered with equal volume of distilled water for 21 days,respectively.Double immunolabeling was performed for proliferating cell nuclear antigen(PCNA)+/glial ?brillary acidic protein(GFAP)+ nuclei.The expression of GFAP and leukemia inhibitory factor(LIF) was evaluated by immunohistochemistry and quantitative real-time reverse transcription-polymerase chain reaction(RT-PCR).Results: The astrocytes with hypertrophied morphology around the hematoma was observed on day 3 after ICH.The number of GFAP positive cells and GFAP m RNA levels increased notably on day 3 and reached the peak on day 14 post-ICH(P<0.01).PCNA+/GFAP+ nuclei were observed around the hematoma and reached the peak on day 14 post-ICH(P<0.01).In addition,LIF-positive astrocytes and LIF m RNA level in the hemorrhagic region increased signi?cantly till day 14 post-ICH(P<0.01).However,BYHWD not only reduced the number of PCNA+/GFAP+ nuclei,but also decreased GFAP and LIF levels(P<0.05).Conclusion:BYHWD could attenuate ICH-induced glial scar by downregulating the expression of LIF in the rats.展开更多
The rapid formation of a glial/fibrotic scar is one of the main factors hampering axon growth after spinal cord injury. The bidirectional Eph B2/ephrin-B2 signaling of the fibroblast-astrocyte contact-dependent intera...The rapid formation of a glial/fibrotic scar is one of the main factors hampering axon growth after spinal cord injury. The bidirectional Eph B2/ephrin-B2 signaling of the fibroblast-astrocyte contact-dependent interaction is a trigger for glial/fibrotic scar formation. In the present study, a new in vitro model was produced by coculture of fibroblasts and astrocytes wounded by scratching to mimic glial/fibrotic scar-like structures using an improved slide system. After treatment with RNAi to downregulate Eph B2, changes in glial/fibrotic scar formation and the growth of VSC4.1 motoneuron axons were examined. Following RNAi treatment, fibroblasts and astrocytes dispersed without forming a glial/fibrotic scar-like structure. Furthermore, the expression levels of neurocan, NG2 and collagen I in the coculture were reduced, and the growth of VSC4.1 motoneuron axons was enhanced. These findings suggest that suppression of Eph B2 expression by RNAi attenuates the formation of a glial/fibrotic scar and promotes axon growth. This study was approved by the Laboratory Animal Ethics Committee of Jiangsu Province, China(approval No. 2019-0506-002) on May 6, 2019.展开更多
Schwann cell transplantation is considered one of the most promising cell-based therapy to repair injured spinal cord due to its unique growth-promoting and myelin-forming properties.A the Food and Drug Administration...Schwann cell transplantation is considered one of the most promising cell-based therapy to repair injured spinal cord due to its unique growth-promoting and myelin-forming properties.A the Food and Drug Administration-approved Phase I clinical trial has been conducted to evaluate the safety of transplanted human autologous Schwann cells to treat patients with spinal cord injury.A major challenge for Schwann cell transplantation is that grafted Schwann cells are confined within the lesion cavity,and they do not migrate into the host environment due to the inhibitory barrier formed by injury-induced glial scar,thus limiting axonal reentry into the host spinal cord.Here we introduce a combinatorial strategy by suppressing the inhibitory extracellular environment with injection of lentivirus-mediated transfection of chondroitinase ABC gene at the rostral and caudal borders of the lesion site and simultaneously leveraging the repair capacity of transplanted Schwann cells in adult rats following a mid-thoracic contusive spinal cord injury.We report that when the glial scar was degraded by chondroitinase ABC at the rostral and caudal lesion borders,Schwann cells migrated for considerable distances in both rostral and caudal directions.Such Schwann cell migration led to enhanced axonal regrowth,including the serotonergic and dopaminergic axons originating from supraspinal regions,and promoted recovery of locomotor and urinary bladder functions.Importantly,the Schwann cell survival and axonal regrowth persisted up to 6 months after the injury,even when treatment was delayed for 3 months to mimic chronic spinal cord injury.These findings collectively show promising evidence for a combinatorial strategy with chondroitinase ABC and Schwann cells in promoting remodeling and recovery of function following spinal cord injury.展开更多
Remyelination plays a key role in functional recovery of axons after spinal cord injury.Glial cells are the most abundant cells in the central nervous system.When spinal cord injury occurs,many glial cells at the lesi...Remyelination plays a key role in functional recovery of axons after spinal cord injury.Glial cells are the most abundant cells in the central nervous system.When spinal cord injury occurs,many glial cells at the lesion site are immediately activated,and different cells differentially affect inflammatory reactions after injury.In this review,we aim to discuss the core role of oligodendrocyte precursor cells and crosstalk with the rest of glia and their subcategories in the remyelination process.Activated astrocytes influence proliferation,differentiation,and maturation of oligodendrocyte precursor cells,while activated microglia alter remyelination by regulating the inflammatory reaction after spinal cord injury.Understanding the interaction between oligodendrocyte precursor cells and the rest of glia is necessary when designing a therapeutic plan of remyelination after spinal cord injury.展开更多
In the last few decades,intracerebral transplantation has grown from a dubious neuroscientific topic to a plausible modality for treatment of neurological disorders.The possibility for cell replacement opens a new fie...In the last few decades,intracerebral transplantation has grown from a dubious neuroscientific topic to a plausible modality for treatment of neurological disorders.The possibility for cell replacement opens a new field of perspectives in the therapy of neurodegenerative disorders,ischemia,and neurotrauma,with the most lessons learned from intracerebral transplantation in Parkinson's disease.Multiple animal studies and a few small-scale clinical trials have proven the concept of intracerebral grafting,but still have to provide a uniform and highly efficient approach to the procedure,suitable for clinical application.The success of intracerebral transplantation is highly dependent on the integration of the grafted cells with the host brain.In this process,glial cells are clearly more than passive bystanders.They provide transplanted cells with mechanical support,trophics,mediate synapse formation,and participate in graft vascularization.At the same time,glial cells mediate scarring,graft rejection,and neuroinflammation,which can be detrimental.We can use this information to try to understand the mechanisms behind the glial reaction to intracerebral transplantation.Recognizing and utilizing glial reactivity can move translational research forward and provide an insight not only to post-transplantation events but also to mechanisms of neuronal death and degeneration.Knowledge about glial reactivity to transplanted cells could also be a key for optimization of transplantation protocols,which ultimately should contribute to greater patient benefit.展开更多
Traumatic brain injury results in neuronal loss and glial scar formation.Replenishing neurons and eliminating the consequences of glial scar formation are essential for treating traumatic brain injury.Neuronal reprogr...Traumatic brain injury results in neuronal loss and glial scar formation.Replenishing neurons and eliminating the consequences of glial scar formation are essential for treating traumatic brain injury.Neuronal reprogramming is a promising strategy to convert glial scars to neural tissue.However,previous studies have reported inconsistent results.In this study,an AAV9P1 vector incorporating an astrocyte-targeting P1 peptide and glial fibrillary acidic protein promoter was used to achieve dual-targeting of astrocytes and the glial scar while minimizing off-target effects.The results demonstrate that AAV9P1 provides high selectivity of astrocytes and reactive astrocytes.Moreover,neuronal reprogramming was induced by downregulating the polypyrimidine tract-binding protein 1 gene via systemic administration of AAV9P1 in a mouse model of traumatic brain injury.In summary,this approach provides an improved gene delivery vehicle to study neuronal programming and evidence of its applications for traumatic brain injury.展开更多
基金supported by grants PICT 2019-08512017-2203,UBACYT and PIP CONICET(to AJR).
文摘Traumatic brain injury is a global health crisis,causing significant death and disability worldwide.Neuroinflammation that follows traumatic brain injury has serious consequences for neuronal survival and cognitive impairments,with astrocytes involved in this response.Following traumatic brain injury,astrocytes rapidly become reactive,and astrogliosis propagates from the injury core to distant brain regions.Homeostatic astroglial proteins are downregulated near the traumatic brain injury core,while pro-inflammatory astroglial genes are overexpressed.This altered gene expression is considered a pathological remodeling of astrocytes that produces serious consequences for neuronal survival and cognitive recovery.In addition,glial scar formed by reactive astrocytes is initially necessary to limit immune cell infiltration,but in the long term impedes axonal reconnection and functional recovery.Current therapeutic strategies for traumatic brain injury are focused on preventing acute complications.Statins,cannabinoids,progesterone,beta-blockers,and cerebrolysin demonstrate neuroprotective benefits but most of them have not been studied in the context of astrocytes.In this review,we discuss the cell signaling pathways activated in reactive astrocytes following traumatic brain injury and we discuss some of the potential new strategies aimed to modulate astroglial responses in traumatic brain injury,especially using cell-targeted strategies with miRNAs or lncRNA,viral vectors,and repurposed drugs.
基金supported by the National Natural Science Foundation of China,No. 10572085Shanghai Leading Academic Discipline Projects,No. S30106
文摘A mathematical model has been formulated in accordance with cell chemotaxis and relevant experimental data. A three-dimensional lattice Boltzmann method was used for numerical simulation. The present study observed the effects of glial scar size and inhibitor concentration on regenerative axonal growth following spinal cord transection. The simulation test comprised two parts: (1) when release rates of growth inhibitor and promoter were constant, the effects of glial scar size on axonal growth rate were analyzed, and concentrations of inhibitor and promoters located at the moving growth cones were recorded. (2) When the glial scar size was constant, the effects of inhibitor and promoter release rates on axonal growth rate were analyzed, and inhibitor and promoter concentrations at the moving growth cones were recorded. Results demonstrated that (1) a larger glial scar and a higher release rate of inhibitor resulted in a reduced axonal growth rate. (2) The axonal growth rate depended on the ratio of inhibitor to promoter concentrations at the growth cones. When the average ratio was 〈 1.5, regenerating axons were able to grow and successfully contact target cells.
基金supported by the National Natural Science Foundation of China(Grant Nos.:82071287,81870916)the National Natural Science Foundation of China(Grant No.:81971097)+3 种基金the Basic Public Interests Research Plan of Zhejiang Province,China(Grant No.:GF18H090006)the National Natural Science Foundation of China(Grant No.:81701214)the National Natural Science Foundation of China(Grant No.:82001299)the Natural Science Foundation of Zhejiang Province,China(Grant No.:TGD23C040017).
文摘The role of glial scar after intracerebral hemorrhage(ICH)remains unclear.This study aimed to investigate whether microglia-astrocyte interaction affects glial scar formation and explore the specific function of glial scar.We used a pharmacologic approach to induce microglial depletion during different ICH stages and examine how ablating microglia affects astrocytic scar formation.Spatial transcriptomics(ST)analysis was performed to explore the potential ligand-receptor pair in the modulation of microglia-astrocyte interaction and to verify the functional changes of astrocytic scars at different periods.During the early stage,sustained microglial depletion induced disorganized astrocytic scar,enhanced neutrophil infiltration,and impaired tissue repair.ST analysis indicated that microglia-derived insulin like growth factor 1(IGF1)modulated astrocytic scar formation via mechanistic target of rapamycin(mTOR)signaling activation.Moreover,repopulating microglia(RM)more strongly activated mTOR signaling,facilitating a more protective scar formation.The combination of IGF1 and osteopontin(OPN)was necessary and sufficient for RM function,rather than IGF1 or OPN alone.At the chronic stage of ICH,the overall net effect of astrocytic scar changed from protective to destructive and delayed microglial depletion could partly reverse this.The vital insight gleaned from our data is that sustained microglial depletion may not be a reasonable treatment strategy for early-stage ICH.Inversely,early-stage IGF1/OPN treatment combined with late-stage PLX3397 treatment is a promising therapeutic strategy.This prompts us to consider the complex temporal dynamics and overall net effect of microglia and astrocytes,and develop elaborate treatment strategies at precise time points after ICH.
基金supported by the National Natural Science Foundation of China, No. 81070982, 81201400Tianjin Research Program of Application Foundation and Advanced Technology, No. 10JCZDJC18800, 13JCQNJC11100the Research Foundation of Tianjin Health Bureau, No. 09kz104
文摘X-irradiation has a beneficial effect in treating spinal cord injury. We supposed that X-irradiation could improve the microenvironment at the site of a spinal cord injury and inhibit glial scar formation. Thus, this study was designed to observe the effects of 8 Gy X-irradiation on the injury site at 6 hours and 2, 4, 7, and 14 days post injury, in terms of improvement in the microenvironment and hind limb motor function. Immunohistochemistry showed that the expression of macrophage marker ED-1 and the area with glial scar formation were reduced. In addition, the Basso, Beattie and Bresnahan score was higher at 7 days post injury relative to the other time points post injury. Results indicated that X-irradiation at a dose of 8 Gy can inhibit glial scar formation and alleviate the inflammatory reaction, thereby repairing spinal cord injury. X-irradiation at 7 days post spinal cord injury may be the best time window.
文摘Glial cells comprise -90% of the human brain and are divided into two subtypes: microglia and astrocytes. Astrocytes play a vital role in maintaining central nervous system (CNS) homeostasis, regulating ion concentrations and providing metabolic support for neighboring neurons, stabilizing synapses, supporting the neurovascular system including maintenance of the blood-brain barrier (BBB) and also producing the extracellular matrix (ECM).
基金financially supported by the National Natural Science Foundation of China (81973882 and 81804119)
文摘Objective: To observe the effect of electroacupuncture(EA) combined with oriented conductive bioprotein hydrogel(OCBH) on the recovery of nerve function in rats with complete spinal cord injury(SCI)and to explore its effect and mechanism on the formation and changes of glial scars.Methods: A total of 72 female Sprague-Dawley rats were randomly divided into groups according to the treatment received. A rat model of complete SCI was constructed using a spinal cord transection.Behavioral assessments, hematoxylin-eosin(H&E) staining, immunofluorescence staining, and Western blotting were performed at a fixed period after the operation.Results: The material group and the material + EA group obtained better results in the behavioral assessments(all P <.05) and the H&E staining. In the immunofluorescence staining and Western blotting,the GFAP protein was expressed more and denser in the material group and the material + EA group than in the model group, and the density of the GFAP expression in the material + EA group was lower at week 12 than in the material group(all P <.05). The expression of complement C3 in the model, material,and material + EA groups decreased in turn. Some inflammatory factors and the NF-κB signaling pathway showed similar results in the Western blotting(all P <.05). The expression of the GDNF protein in the material + EA group was significantly higher than that in the model group and the material group(both P <.01).Conclusion: EA combined with OCBH can promote the recovery of motor functions after SCI by facilitating the formation of glial scars in the early stage, preventing the further spread of an inflammatory response that would affect the activation of A1/A2 astrocytes and change the morphology of glial scars at the spinal cord-material interface in its late stage.
基金funded by the National Natural Science Foundation of China, No. 81060106
文摘A rat model of spinal cord injury was established using the weight drop method. A cavity formed 14 days following spinal cord injury, and compact scar tissue formed by 56 days. Enzyme-linked immunosorbent assay and polymerase chain reaction enzyme-linked immunosorbent assay results demonstrated that glial fibrillary acidic protein and telomerase expression increased gradually after injury, peaked at 28 days, and then gradually decreased. Spearman rank correlation showed a positive correlation between glial fibrillary acidic protein expression and telomerase expression in the glial scar. These results suggest that telomerase promotes glial scar formation.
基金the National Science Foundation of China(C30230140,C30400142)
文摘Objective:To determine if a cell cycle inhibitior, olomoucine, would decrease neuronal cell death, limit astroglial proliferation and production of inhibitory CSPGs, and eventually enhance the functional compensation after SCI in rats. Methods: Three were used as un-operated controls and twelve as sham operated controls. Following spinal cord injury, 48 rats were randomly and blindly assigned to either olomoucine (n=24) or vehicle treatment (n=24) groups. Results: Up-regulations of cell cycle components were closely associated with neuronal cell death and astroglial proliferation as well as the production of CSPGs after SCI. Meanwhile, administration of olomoucine, a selective cell cycle kinase (CDK) inhibitor, has remarkably reduced the up-regulated cell cycle proteins and then decreased neuronal cell death, astroglial proliferation as well as accumulation of CSPGs. More importantly, the treatment with olomoucine has also increased expression of growth-associated proteins-43 (GAP-43), reduced the cavity formation, and improved functional deficits. Conclusion: Suppressing astroglial cell cycle in acute spinal cord injuries is beneficial to axonal growth. in turn, the future therapeutic strategies can be designed to achieve efficient axonal regeneration and functional compensation after traumatic CNS injury.
基金supported by the Foundation of Science Technology Department of Zhejiang Province(2016C37099)
文摘OBJECTIVE To explore the neuro-protective effects of saffron(Crocus satius L.) on chronic focal cerebral ischemia in rats.METHODS SD rats were randomly divided into 6 groups:sham control group,MCAO group,edaravone group and saffron 30,100,300 mg·kg^(-1) groups.Focal cerebral ischemia was induced by middle cerebral artery occlusion(MCAO).Saffron was administered orally by once daily from 2 h to 42 d after ischemia.At 42 d after cerebral ischemia,neurological deficit score,spontaneous activity test,elevated plus maze test,marble burying test and novel objective recognition test were used to evaluate the effects of saffron on the behevioural change.Infarct volume,survival neuron density,activated astrocyte number,and the thickness of glial scar were also detected.GFAP expression and inflammatory cytokine contents in ischemic peripheral region were detected by Western blot and ELISA,separately.RESULTS Saffron(100,300 mg·kg^(-1)) improved the body weight decrease,neurological deficit and spontaneous activity.Saffron(30-300 mg · kg^(-1)) increased the traveled distance ratio and total time in open arm,decreased the buried marble number,which indicated that saffron could ameliorate anxiety-and depression-like behaviors.Saffron(100,300 mg·kg^(-1)) improved the learning and memory function,which manifested by increased discrimination ratio(DR) and discrim.ination index(DI) in T2 test.The results of toluidine blue found saffron treatment(100,300 mg · kg^(-1))decreased the infarct volume and increased the neuron density in cortex and hippocampal.The activated astrocyte number,the thickness of glial scar and GFAP expression in ischemic peripheral region decreased after saffron.Saffron(100,300 mg · kg^(-1)) decreased the contents of IL-6 and IL-1β,increased the content of IL-10 in ischemic peripheral region.CONCLUSION Saffron exerted neuro-protective effects on chronic focal cerebral ischemia,which could be related with inhibiting the activation of astrocyte and glial scar,following with the decrease of inflammatory reaction.
基金supported by grants from the National Basic Research Development Program of China (2011CB504401)the National Natural Science Foundation of China (31130024,31070922 and 81261130313)
文摘Glial scarring following severe tissue damage and inflammation after spinal cord injury (SCI) is due to an extreme, uncontrolled form of reactive astrogliosis that typically occurs around the injury site. The scarring process includes the misalignment of activated astrocytes and the deposition of inhibitory chondroitin sulfate proteoglycans. Here, we first discuss recent developments in the molecular and cellular features of glial scar formation, with special focus on the potential cellular origin of scar-forming cells and the molecular mechanisms underlying glial scar formation after SCI. Second, we discuss the role of glial scar formation in the regulation of axonal regeneration and the cascades of neuro-inflammation. Last, we summarize the physical and pharmacological approaches targeting the modulation of glial scarring to better understand the role of glial scar formation in the repair of SCI.
基金supported by the National Key Basic Research Program of China,No.2017YFA0104701The National Natural Science Foundation of China,No.81801281,81870975,81671230The Natural Science Foundation of Jiangsu Province(BK20202013).
文摘Spinal cord injury(SCI)often leads to permanent disability,which is mainly caused by the loss of functional recovery.In this review,we aimed to investigate why the healing process is interrupted.One of the reasons for this interruption is the formation of a glial scar around the severely damaged tissue,which is usually covered by reactive glia,macrophages and fibroblasts.Aiming to clarify this issue,we summarize the latest research findings pertaining to scar formation,tissue repair,and the divergent roles of blood-derived monocytes/macrophages,ependymal cells,fibroblasts,microglia,oligodendrocyte progenitor cells(OPCs),neuron-glial antigen 2(NG2)and astrocytes during the process of scar formation,and further analyse the contribution of these cells to scar formation.In addition,we recapitulate the development of therapeutic treatments targeting glial scar components.Altogether,we aim to present a comprehensive decoding of the glial scar and explore potential therapeutic strategies for improving functional recovery after SCI.
基金the National Natural Science Foundation of China(No.81202625,30400581,30873221 and 81173175)the Project for New Century Excellent Talents(NCET-11-0522)+2 种基金the Hunan Provincial Natural Science Foundation(No.07JJ5007 and 10JJ2023)the Hubei Provincial Natural Science Foundation(No.2017CFB468)the Key Laboratory of Cardiovascular and Cerebrovascular Diseases Translational Medicine(Three Gorges University,No.2016KXN06)
文摘Objective: To evaluate the effect of Buyang Huanwu Decoction(补阳还五汤,BYHWD) on glial scar after intracerebral hemorrhage(ICH) and investigate the underlying mechanism.Methods: Collagenase type Ⅶ(0.5 U) was injected stereotaxically into right globus pallidus to induce ICH model.One hundred and twenty SpragueDawley rats were randomly divided into 3 groups according to a random number table,including normal group(n=40),ICH model group(n=40) and BYHWD group(n=40),respectively.After ICH,the rats in the BYHWD group were intragastrically administered with BYHWD(4.36 g/kg) once a day for 21 days,while the rats in ICH group were administered with equal volume of distilled water for 21 days,respectively.Double immunolabeling was performed for proliferating cell nuclear antigen(PCNA)+/glial ?brillary acidic protein(GFAP)+ nuclei.The expression of GFAP and leukemia inhibitory factor(LIF) was evaluated by immunohistochemistry and quantitative real-time reverse transcription-polymerase chain reaction(RT-PCR).Results: The astrocytes with hypertrophied morphology around the hematoma was observed on day 3 after ICH.The number of GFAP positive cells and GFAP m RNA levels increased notably on day 3 and reached the peak on day 14 post-ICH(P<0.01).PCNA+/GFAP+ nuclei were observed around the hematoma and reached the peak on day 14 post-ICH(P<0.01).In addition,LIF-positive astrocytes and LIF m RNA level in the hemorrhagic region increased signi?cantly till day 14 post-ICH(P<0.01).However,BYHWD not only reduced the number of PCNA+/GFAP+ nuclei,but also decreased GFAP and LIF levels(P<0.05).Conclusion:BYHWD could attenuate ICH-induced glial scar by downregulating the expression of LIF in the rats.
基金supported by the Priority Academic Program Development of Jiangsu Higher Education Institutes of China(PAPD)the Science and Technology Plan Project of Nantong of China,No.JC2020026(to JW)the National Science Research of Jiangsu Higher Education Institutions of China,No.19KJB310012(to RYY)。
文摘The rapid formation of a glial/fibrotic scar is one of the main factors hampering axon growth after spinal cord injury. The bidirectional Eph B2/ephrin-B2 signaling of the fibroblast-astrocyte contact-dependent interaction is a trigger for glial/fibrotic scar formation. In the present study, a new in vitro model was produced by coculture of fibroblasts and astrocytes wounded by scratching to mimic glial/fibrotic scar-like structures using an improved slide system. After treatment with RNAi to downregulate Eph B2, changes in glial/fibrotic scar formation and the growth of VSC4.1 motoneuron axons were examined. Following RNAi treatment, fibroblasts and astrocytes dispersed without forming a glial/fibrotic scar-like structure. Furthermore, the expression levels of neurocan, NG2 and collagen I in the coculture were reduced, and the growth of VSC4.1 motoneuron axons was enhanced. These findings suggest that suppression of Eph B2 expression by RNAi attenuates the formation of a glial/fibrotic scar and promotes axon growth. This study was approved by the Laboratory Animal Ethics Committee of Jiangsu Province, China(approval No. 2019-0506-002) on May 6, 2019.
基金supported in part by NIH R01 NS100531,R01 NS103481NIH R21NS130241(to LD)+3 种基金Merit Review Award I01 BX002356,I01 BX003705 from the U.S.Department of Veterans AffairsIndiana Spinal Cord and Brain Injury Research Foundation(No.19919)Mari Hulman George Endowment Funds(to XMX)Indiana Spinal Cord&Brain Injury Research Fund from ISDH(to NKL and LD)。
文摘Schwann cell transplantation is considered one of the most promising cell-based therapy to repair injured spinal cord due to its unique growth-promoting and myelin-forming properties.A the Food and Drug Administration-approved Phase I clinical trial has been conducted to evaluate the safety of transplanted human autologous Schwann cells to treat patients with spinal cord injury.A major challenge for Schwann cell transplantation is that grafted Schwann cells are confined within the lesion cavity,and they do not migrate into the host environment due to the inhibitory barrier formed by injury-induced glial scar,thus limiting axonal reentry into the host spinal cord.Here we introduce a combinatorial strategy by suppressing the inhibitory extracellular environment with injection of lentivirus-mediated transfection of chondroitinase ABC gene at the rostral and caudal borders of the lesion site and simultaneously leveraging the repair capacity of transplanted Schwann cells in adult rats following a mid-thoracic contusive spinal cord injury.We report that when the glial scar was degraded by chondroitinase ABC at the rostral and caudal lesion borders,Schwann cells migrated for considerable distances in both rostral and caudal directions.Such Schwann cell migration led to enhanced axonal regrowth,including the serotonergic and dopaminergic axons originating from supraspinal regions,and promoted recovery of locomotor and urinary bladder functions.Importantly,the Schwann cell survival and axonal regrowth persisted up to 6 months after the injury,even when treatment was delayed for 3 months to mimic chronic spinal cord injury.These findings collectively show promising evidence for a combinatorial strategy with chondroitinase ABC and Schwann cells in promoting remodeling and recovery of function following spinal cord injury.
基金supported by the National Natural Science Foundation of China,No.81601957
文摘Remyelination plays a key role in functional recovery of axons after spinal cord injury.Glial cells are the most abundant cells in the central nervous system.When spinal cord injury occurs,many glial cells at the lesion site are immediately activated,and different cells differentially affect inflammatory reactions after injury.In this review,we aim to discuss the core role of oligodendrocyte precursor cells and crosstalk with the rest of glia and their subcategories in the remyelination process.Activated astrocytes influence proliferation,differentiation,and maturation of oligodendrocyte precursor cells,while activated microglia alter remyelination by regulating the inflammatory reaction after spinal cord injury.Understanding the interaction between oligodendrocyte precursor cells and the rest of glia is necessary when designing a therapeutic plan of remyelination after spinal cord injury.
文摘In the last few decades,intracerebral transplantation has grown from a dubious neuroscientific topic to a plausible modality for treatment of neurological disorders.The possibility for cell replacement opens a new field of perspectives in the therapy of neurodegenerative disorders,ischemia,and neurotrauma,with the most lessons learned from intracerebral transplantation in Parkinson's disease.Multiple animal studies and a few small-scale clinical trials have proven the concept of intracerebral grafting,but still have to provide a uniform and highly efficient approach to the procedure,suitable for clinical application.The success of intracerebral transplantation is highly dependent on the integration of the grafted cells with the host brain.In this process,glial cells are clearly more than passive bystanders.They provide transplanted cells with mechanical support,trophics,mediate synapse formation,and participate in graft vascularization.At the same time,glial cells mediate scarring,graft rejection,and neuroinflammation,which can be detrimental.We can use this information to try to understand the mechanisms behind the glial reaction to intracerebral transplantation.Recognizing and utilizing glial reactivity can move translational research forward and provide an insight not only to post-transplantation events but also to mechanisms of neuronal death and degeneration.Knowledge about glial reactivity to transplanted cells could also be a key for optimization of transplantation protocols,which ultimately should contribute to greater patient benefit.
基金supported by the National Natural Science Foundation of China,No.82073783(to YY)the Natural Science Foundation of Beijing,No.7212160(to YY).
文摘Traumatic brain injury results in neuronal loss and glial scar formation.Replenishing neurons and eliminating the consequences of glial scar formation are essential for treating traumatic brain injury.Neuronal reprogramming is a promising strategy to convert glial scars to neural tissue.However,previous studies have reported inconsistent results.In this study,an AAV9P1 vector incorporating an astrocyte-targeting P1 peptide and glial fibrillary acidic protein promoter was used to achieve dual-targeting of astrocytes and the glial scar while minimizing off-target effects.The results demonstrate that AAV9P1 provides high selectivity of astrocytes and reactive astrocytes.Moreover,neuronal reprogramming was induced by downregulating the polypyrimidine tract-binding protein 1 gene via systemic administration of AAV9P1 in a mouse model of traumatic brain injury.In summary,this approach provides an improved gene delivery vehicle to study neuronal programming and evidence of its applications for traumatic brain injury.