After spinal cord injury,impairment of the sensorimotor circuit can lead to dysfunction in the motor,sensory,proprioceptive,and autonomic nervous systems.Functional recovery is often hindered by constraints on the tim...After spinal cord injury,impairment of the sensorimotor circuit can lead to dysfunction in the motor,sensory,proprioceptive,and autonomic nervous systems.Functional recovery is often hindered by constraints on the timing of interventions,combined with the limitations of current methods.To address these challenges,various techniques have been developed to aid in the repair and reconstruction of neural circuits at different stages of injury.Notably,neuromodulation has garnered considerable attention for its potential to enhance nerve regeneration,provide neuroprotection,restore neurons,and regulate the neural reorganization of circuits within the cerebral cortex and corticospinal tract.To improve the effectiveness of these interventions,the implementation of multitarget early interventional neuromodulation strategies,such as electrical and magnetic stimulation,is recommended to enhance functional recovery across different phases of nerve injury.This review concisely outlines the challenges encountered following spinal cord injury,synthesizes existing neurostimulation techniques while emphasizing neuroprotection,repair,and regeneration of impaired connections,and advocates for multi-targeted,task-oriented,and timely interventions.展开更多
Spinal cord injury represents a severe form of central nervous system trauma for which effective treatments remain limited.Microglia is the resident immune cells of the central nervous system,play a critical role in s...Spinal cord injury represents a severe form of central nervous system trauma for which effective treatments remain limited.Microglia is the resident immune cells of the central nervous system,play a critical role in spinal cord injury.Previous studies have shown that microglia can promote neuronal survival by phagocytosing dead cells and debris and by releasing neuroprotective and anti-inflammatory factors.However,excessive activation of microglia can lead to persistent inflammation and contribute to the formation of glial scars,which hinder axonal regeneration.Despite this,the precise role and mechanisms of microglia during the acute phase of spinal cord injury remain controversial and poorly understood.To elucidate the role of microglia in spinal cord injury,we employed the colony-stimulating factor 1 receptor inhibitor PLX5622 to deplete microglia.We observed that sustained depletion of microglia resulted in an expansion of the lesion area,downregulation of brain-derived neurotrophic factor,and impaired functional recovery after spinal cord injury.Next,we generated a transgenic mouse line with conditional overexpression of brain-derived neurotrophic factor specifically in microglia.We found that brain-derived neurotrophic factor overexpression in microglia increased angiogenesis and blood flow following spinal cord injury and facilitated the recovery of hindlimb motor function.Additionally,brain-derived neurotrophic factor overexpression in microglia reduced inflammation and neuronal apoptosis during the acute phase of spinal cord injury.Furthermore,through using specific transgenic mouse lines,TMEM119,and the colony-stimulating factor 1 receptor inhibitor PLX73086,we demonstrated that the neuroprotective effects were predominantly due to brain-derived neurotrophic factor overexpression in microglia rather than macrophages.In conclusion,our findings suggest the critical role of microglia in the formation of protective glial scars.Depleting microglia is detrimental to recovery of spinal cord injury,whereas targeting brain-derived neurotrophic factor overexpression in microglia represents a promising and novel therapeutic strategy to enhance motor function recovery in patients with spinal cord injury.展开更多
Traumatic spinal cord injury result in considerable and lasting functional impairments,triggering complex inflammatory and pathological events.Spinal cord scars,often metaphorically referred to as“fire barriers,”aim...Traumatic spinal cord injury result in considerable and lasting functional impairments,triggering complex inflammatory and pathological events.Spinal cord scars,often metaphorically referred to as“fire barriers,”aim to control the spread of neuroinflammation during the acute phase but later hinder axon regeneration in later stages.Recent studies have enhanced our understanding of immunomodulation,revealing that injury-associated inflammation involves various cell types and molecules with positive and negative effects.This review employs bibliometric analysis to examine the literature on inflammatory mediators in spinal cord injury,highlighting recent research and providing a comprehensive overview of the current state of research and the latest advances in studies on neuroinflammation related to spinal cord injury.We summarize the immune and inflammatory responses at different stages of spinal cord injury,offering crucial insights for future research.Additionally,we review repair strategies based on inflammatory mediators for the injured spinal cord.Finally,this review discusses the current status and future directions of translational research focused on immune-targeting strategies,including pharmaceuticals,biomedical engineering,and gene therapy.The development of a combined,precise,and multitemporal strategy for the repair of injured spinal cords represents a promising direction for future research.展开更多
Traumatic spinal cord injury often leads to the disintegration of nerve cells and axons,resulting in a substantial accumulation of myelin debris that can persist for years.The abnormal buildup of myelin debris at site...Traumatic spinal cord injury often leads to the disintegration of nerve cells and axons,resulting in a substantial accumulation of myelin debris that can persist for years.The abnormal buildup of myelin debris at sites of injury greatly impedes nerve regeneration,making the clearance of debris within these microenvironments crucial for effective post-spinal cord injury repair.In this review,we comprehensively outline the mechanisms that promote the clearance of myelin debris and myelin metabolism and summarize their roles in spinal cord injury.First,we describe the composition and characteristics of myelin debris and explain its effects on the injury site.Next,we introduce the phagocytic cells involved in myelin debris clearance,including professional phagocytes(macrophages and microglia)and non-professional phagocytes(astrocytes and microvascular endothelial cells),as well as other cells that are also proposed to participate in phagocytosis.Finally,we focus on the pathways and associated targets that enhance myelin debris clearance by phagocytes and promote lipid metabolism following spinal cord injury.Our analysis indicates that myelin debris phagocytosis is not limited to monocyte-derived macrophages,but also involves microglia,astrocytes,and microvascular endothelial cells.By modulating the expression of genes related to phagocytosis and lipid metabolism,it is possible to modulate lipid metabolism disorders and influence inflammatory phenotypes,ultimately affecting the recovery of motor function following spinal cord injury.Additionally,therapies such as targeted mitochondrial transplantation in phagocytic cells,exosome therapy,and repeated trans-spinal magnetic stimulation can effectively enhance the removal of myelin debris,presenting promising potential for future applications.展开更多
Spinal cord injury is a neurological disorder resulting from trauma,typically affecting sensory and motor function at the injury site,even leading to paralysis and internal dysfunction.The treatment of spinal cord inj...Spinal cord injury is a neurological disorder resulting from trauma,typically affecting sensory and motor function at the injury site,even leading to paralysis and internal dysfunction.The treatment of spinal cord injury mainly relies on pharmacological and surgical interventions;however,significant challenges remain in the protection and repair of neural tissues.Autophagy,an intracellular process responsible for the degradation and recycling of macromolecular components,plays a vital role in spinal cord injury,alleviating the severity of injury by inhibiting cell apoptosis and inflammatory responses.In this review,we provide an overview of the physiological mechanisms underlying autophagy and spinal cord injury and detail the crosstalk between autophagy and other modes of cell death in spinal cord injury.In addition,we discuss the potential of targeting autophagy as a therapeutic strategy for spinal cord injury through approaches that focus on promoting or inhibiting this process,targeting specific autophagic substrates or pathways,and combining autophagy modulation with other neuroprotective or restorative interventions.In summary,this review proposes that strict regulation of autophagy may represent a viable strategy for the treatment of spinal cord injury.展开更多
Oxidative stress significantly contributes to secondary damage after spinal cord injury.Despite its importance,research on oxidative stress in spinal cord injury remains limited.Investigating the expression and regula...Oxidative stress significantly contributes to secondary damage after spinal cord injury.Despite its importance,research on oxidative stress in spinal cord injury remains limited.Investigating the expression and regulation of oxidative stress-related genes could enhance the diagnosis and treatment of spinal cord injury.In this study,we analyzed the sequencing data of human blood samples and injured mouse spinal cord tissue that were sourced from GEO databases and identified diagnostic biomarkers associated with the severity of spinal cord injury.We also explored the expression patterns of oxidative stress-related genes,potential regulatory mechanisms,and therapeutic drugs.To validate our findings,we performed immunofluorescence and quantitative polymerase chain reaction to assess gene expression in the injured spinal cord.Our results revealed biomarkers associated with oxidative stress and immune responses across different levels of spinal cord injury in humans.We identified differentially expressed oxidative stress-related genes and key hub genes in injured mouse spinal cord tissue and revealed their temporal expression patterns at both the tissue and single-cell levels.We also clarified the signaling pathways associated with oxidative stress and identified ligand-receptor pairs among various cell types at different time points after injury.Furthermore,we discovered microRNAs,long non-coding RNAs,and transcription factors that regulate these hub genes and revealed their roles in modulating gene expression at various stages after spinal cord injury.We also identified drugs targeting these hub genes.The findings from this study not only aid in identifying diagnostic biomarkers that reflect the severity of spinal cord injury,but also provide insights into the expression dynamics of oxidative stress-related genes.In addition,the study reveals potential regulatory mechanisms and identifies potential drugs to treat patients with spinal cord injury.展开更多
Ferroptosis,a type of cell death that mainly involves iron metabolism imbalance and lipid peroxidation,is strongly correlated with the phagocytic response caused by bleeding after spinal cord injury.Thus,in this study...Ferroptosis,a type of cell death that mainly involves iron metabolism imbalance and lipid peroxidation,is strongly correlated with the phagocytic response caused by bleeding after spinal cord injury.Thus,in this study,bulk RNA sequencing data(GSE47681 and GSE5296)and single-cell RNA sequencing data(GSE162610)were acquired from gene expression databases.We then conducted differential analysis and immune infiltration analysis.Atf3 and Piezo1 were identified as key ferroptosis genes through random forest and least absolute shrinkage and selection operator algorithms.Further analysis of single-cell RNA sequencing data revealed a close relationship between ferroptosis and cell types such as macrophages/microglia and their intrinsic state transition processes.Differences in transcription factor regulation and intercellular communication networks were found in ferroptosis-related cells,confirming the high expression of Atf3 and Piezo1 in these cells.Molecular docking analysis confirmed that the proteins encoded by these genes can bind cycloheximide.In a mouse model of T8 spinal cord injury,low-dose cycloheximide treatment was found to improve neurological function,decrease levels of the pro-inflammatory cytokine inducible nitric oxide synthase,and increase levels of the anti-inflammatory cytokine arginase 1.Correspondingly,the expression of the ferroptosis-related gene Gpx4 increased in macrophages/microglia,while the expression of Acsl4 decreased.Our findings reveal the important role of ferroptosis in the treatment of spinal cord injury,identify the key cell types and genes involved in ferroptosis after spinal cord injury,and validate the efficacy of potential drug therapies,pointing to new directions in the treatment of spinal cord injury.展开更多
Spinal cord ischemia-reperfusion injury,a severe form of spinal cord damage,can lead to sensory and motor dysfunction.This injury often occurs after traumatic events,spinal cord surgeries,or thoracoabdominal aortic su...Spinal cord ischemia-reperfusion injury,a severe form of spinal cord damage,can lead to sensory and motor dysfunction.This injury often occurs after traumatic events,spinal cord surgeries,or thoracoabdominal aortic surgeries.The unpredictable nature of this condition,combined with limited treatment options,poses a significant burden on patients,their families,and society.Spinal cord ischemia-reperfusion injury leads to reduced neuronal regenerative capacity and complex pathological processes.In contrast,mitophagy is crucial for degrading damaged mitochondria,thereby supporting neuronal metabolism and energy supply.However,while moderate mitophagy can be beneficial in the context of spinal cord ischemia-reperfusion injury,excessive mitophagy may be detrimental.Therefore,this review aims to investigate the potential mechanisms and regulators of mitophagy involved in the pathological processes of spinal cord ischemia-reperfusion injury.The goal is to provide a comprehensive understanding of recent advancements in mitophagy related to spinal cord ischemia-reperfusion injury and clarify its potential clinical applications.展开更多
Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance protei...Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance proteins are a diverse group of molecules that play crucial roles in axon and dendrite growth during nervous system development.Increasing evidence highlights their regulatory functions in spinal cord injury.This review provides a brief overview of the modulation patterns of key neuronal guidance proteins in neuronal axon growth during nervous system formation and subsequently focuses on their roles in neuronal regeneration and functional recovery following spinal cord injury.Neuronal guidance proteins include,but are not limited to,semaphorins and their receptors,plexins;netrins and their receptors,deleted in colorectal cancer and UNC5;Eph receptors and their ligands,ephrins;Slit and its receptor,Robo;repulsive guidance molecules and their receptor,neogenin;Wnt proteins and their receptor,Frizzled;and protocadherins.Localized Netrin-1 at the injury site inhibits motor axon regeneration after adult spinal cord injury while promoting oligodendrocyte growth.Slit2 enhances synapse formation in the injured spinal cord of rats.EphA7 regulates acute apoptosis in the early pathophysiological stages of spinal cord injury,while ephrinA1 plays a role in the nervous system’s injury response,with its reduced expression leading to impaired motor function in rats.EphA3 is upregulated following spinal cord injury,promoting an inhibitory environment for axonal regeneration.After spinal cord injury,bidirectional activation of ephrinB2 and EphB2 in astrocytes and fibroblasts results in the formation of a dense astrocyte-meningeal fibroblast scar.EphB1/ephrinB1 signaling mediates pain processing in spinal cord injury by regulating calpain-1 and caspase-3 in neurons.EphB3 expression increases in white matter after spinal cord injury,further inhibiting axon regeneration.Sema3A,expressed by neurons and fibroblasts in the scar surrounding the injury,inhibits motor neuron and sensory nerve growth after spinal cord injury.Sema4D suppresses neuronal axon myelination and axon regeneration,while its inhibition significantly enhances axon regeneration and motor recovery.Sema7A is involved in glial scar formation and may influence serotonin channel remodeling,thereby affecting motor coordination.Given these findings,the local or systemic application of neuronal guidance proteins represents a promising avenue for spinal cord injury treatment.展开更多
Spinal cord injury is a severe neurological condition characterized by the permanent loss of nerve cell function and a failure in neural circuit reconstruction-key factors contributing to disability.Therefore,explorin...Spinal cord injury is a severe neurological condition characterized by the permanent loss of nerve cell function and a failure in neural circuit reconstruction-key factors contributing to disability.Therefore,exploring effective strategies to promote the repair and regeneration of nerve cells after spinal cord injury is crucial for optimizing patient prognosis.The purpose of this paper is to conduct an in-depth review of the pathological changes in nerve cells after spinal cord injury and to present the state of research on the role of exercise training in promoting the repair and regeneration of nerve cells after spinal cord injury.In terms of the intrinsic growth capacity of neurons,disruptions in the dynamic balance between growth cones and the cytoskeleton,the dysregulation of transcription factors,abnormal protein signaling transduction,and altered epigenetic modifications collectively hinder axonal regeneration.Additionally,the microenvironment of neurons undergoes a series of complex changes,initially manifesting as edema,which may be exacerbated by spinal cord ischemia-reperfusion injury,further increasing the extent of nerve cell damage.The abnormal proliferation of astrocytes leads to the formation of glial scars,creating a physical barrier to nerve regeneration.The inflammatory response triggered by the excessive activation of microglia negatively impacts the process of nerve repair.Non-invasive interventions involving exercise training have shown significant potential in promoting nerve repair as part of a comprehensive treatment strategy for spinal cord injury.Specifically,exercise training can reshape the growth cone and cytoskeletal structures of neurons,regulate transcription factor activity,modulate protein signaling pathways,and influence epigenetic modifications,thereby activating the intrinsic repair mechanisms of neurons.Moreover,exercise training can regulate the activation state of astrocytes,optimize the inflammatory response and metabolic processes,promote astrocyte polarization,enhance angiogenesis,reduce glial scar formation,and modulate the expression levels of nerve growth factors.It also effectively helps regulate microglial activation,promotes axonal regeneration,and improves phagocytic function,thereby optimizing the microenvironment for nerve repair.In terms of clinical translation,we summarize the preliminary results of new drug research and development efforts,the development of innovative devices,and the use of exercise training in promoting clinical advancements in nerve repair following spinal cord injury,while considering their limitations and future application prospects.In summary,this review systematically analyzes findings relating to the pathological changes occurring in nerve cells after spinal cord injury and emphasizes the critical role of exercise training in facilitating the repair and regeneration of nerve cells.This work is expected to provide new ideas and methods for the rehabilitation of patients with spinal cord injury.展开更多
In the early stages of traumatic spinal cord injury,extensive accumulation of autophagosomes creates a neurotoxic microenvironment,exacerbating neuronal cell death and worsening tissue damage,ultimately hindering neur...In the early stages of traumatic spinal cord injury,extensive accumulation of autophagosomes creates a neurotoxic microenvironment,exacerbating neuronal cell death and worsening tissue damage,ultimately hindering neurofunctional recovery.Activin A is a critical growth factor necessary for the development of the embryonic nervous system and for maintaining neuronal function in the adult cerebral cortex.It can inhibit excessive autophagy in ischemic stroke to reduce neuronal damage.However,the specific mechanism through which Activin A functions in the spinal cord remains poorly understood.In this study,we administered different concentrations of Activin A to neural stem cells from the spinal cord and found that Activin A stimulated the proliferation and neuronal differentiation of neural stem cells.Then,we established an in vitro oxidative stress model by using hydrogen peroxide to stimulate the neural stem cells-induced neurons.We found that Activin A could reduce apoptosis caused by oxidative stress.Subsequently,we treated a mouse model of spinal cord contusion with intrathecal injection of Activin A.Behavioral and electrophysiological results showed that Activin A promoted recovery of motor function and reconstruction of neural circuits in the model mice.Finally,RNA sequencing indicated that Activin A inhibited autophagy by activating the PI3K/AKT/mTOR pathway and upregulating the expression of synaptogenesis-related factor Sema3A in the spinal cord.These results suggest that Activin A may mediate the excessive autophagic response after spinal cord injury,promote the reconstruction of damaged neural circuits,and restore neurological function in the injured spinal cord.展开更多
Mitophagy is closely associated with the pathogenesis of secondary spinal cord injury.Abnormal mitophagy may contribute significantly to secondary spinal cord injury,leading to the impaired production of adenosine tri...Mitophagy is closely associated with the pathogenesis of secondary spinal cord injury.Abnormal mitophagy may contribute significantly to secondary spinal cord injury,leading to the impaired production of adenosine triphosphate,ion imbalance,the excessive production of reactive oxygen species,neuroinflammation,and neuronal cell death.Therefore,maintaining an appropriate balance of mitophagy is crucial when treating spinal cord injury,as both excessive and insufficient mitophagy can impede recovery.In this review,we summarize the pathological changes associated with spinal cord injury,the mechanisms of mitophagy,and the direct and indirect relationships between mitophagy and spinal cord injury.We also consider therapeutic approaches that target mitophagy for the treatment of spinal cord injury,including ongoing clinical trials and other innovative therapies,such as use of stem cells,nanomaterials,and small molecule polymers.Finally,we highlight the current challenges facing this field and suggest potential directions for future research.The aim of our review is to provide a theoretical reference for future studies targeting mitophagy in the treatment of spinal cord injury.展开更多
Few studies have investigated alterations in the immune cell microenvironment of the dorsal root ganglia following spinal cord injury and whether these modifications facilitate axonal regeneration.In this study,we use...Few studies have investigated alterations in the immune cell microenvironment of the dorsal root ganglia following spinal cord injury and whether these modifications facilitate axonal regeneration.In this study,we used a single-cell RNA sequencing dataset to create a comprehensive profile of the diverse cell types in the dorsal root ganglia and spinal cord of a mid-thoracic contusion injury model in cynomolgus monkeys.Cell communication analysis indicated that specific signaling events among various dorsal root ganglia cell types occur in response to spinal cord injury.Single-cell analysis using dimensionality reduction clustering identified distinct molecular signatures for nine cell types,including macrophage subpopulations,and differential gene expression profiles between dorsal root ganglia cells and spinal cord cells following spinal cord injury.The macrophage subpopulations were categorized into 11 clusters(MC0-MC10)based on differentially expressed genes,with the top 10 genes being ABCA6,RBMS3,EBF1,LAMA4,ANTXR2,LAMA2,SOX5,FOXP2,GHR,and APOD.MC0,MC1,and MC2 constituted the predominant macrophage populations.MC4,MC6,and MC9 were nearly absent in the spinal cord,but exhibited significant increases in the dorsal root ganglia post-spinal cord injury.Notably,these subpopulations possess a strong capacity for regulating axonal regeneration.The developmental progression of dorsal root ganglia macrophages after spinal cord injury was elucidated using cell trajectory and pseudo-time analyses.Genes such as EBF1(MC6 and MC9 marker),RBMS3(MC6 and MC9 marker),and ABCA6(MC6 marker)showed high expression levels in the critical pathways of macrophage function.Through ligand-receptor pair analysis,we determined that the effects of macrophages on microglia are predominantly mediated through interaction pairs(e.g.,SPP1-CD44,LAMC1-CD44,and FN1-CD44),potentially facilitating specific cellular communications within the immune microenvironment.The single-cell RNA sequencing dataset used in this study represents the first comprehensive transcriptional analysis of the dorsal root ganglia after spinal cord injury in cynomolgus monkeys,encompassing nearly all cell types within the dorsal root ganglia region.Using this dataset,we evaluated diverse subtypes of macrophages in the post-spinal cord injury dorsal root ganglia area and examined the signaling pathways that facilitate interactions among immune response-related macrophages in the dorsal root ganglia.Findings from this study provide a theoretical basis for understanding how the immune microenvironment influences the regenerative capacity of dorsal root ganglia neurons after spinal cord injury and offer novel insights into the complex processes underlying the pathobiology of spinal cord injury.展开更多
Mesenchymal stromal cell transplantation is an effective and promising approach for treating various systemic and diffuse diseases.However,the biological characteristics of transplanted mesenchymal stromal cells in hu...Mesenchymal stromal cell transplantation is an effective and promising approach for treating various systemic and diffuse diseases.However,the biological characteristics of transplanted mesenchymal stromal cells in humans remain unclear,including cell viability,distribution,migration,and fate.Conventional cell tracing methods cannot be used in the clinic.The use of superparamagnetic iron oxide nanoparticles as contrast agents allows for the observation of transplanted cells using magnetic resonance imaging.In 2016,the National Medical Products Administration of China approved a new superparamagnetic iron oxide nanoparticle,Ruicun,for use as a contrast agent in clinical trials.In the present study,an acute hemi-transection spinal cord injury model was established in beagle dogs.The injury was then treated by transplantation of Ruicun-labeled mesenchymal stromal cells.The results indicated that Ruicunlabeled mesenchymal stromal cells repaired damaged spinal cord fibers and partially restored neurological function in animals with acute spinal cord injury.T2*-weighted imaging revealed low signal areas on both sides of the injured spinal cord.The results of quantitative susceptibility mapping with ultrashort echo time sequences indicated that Ruicun-labeled mesenchymal stromal cells persisted stably within the injured spinal cord for over 4 weeks.These findings suggest that magnetic resonance imaging has the potential to effectively track the migration of Ruicun-labeled mesenchymal stromal cells and assess their ability to repair spinal cord injury.展开更多
Unlike mammals,zebrafish possess a remarkable ability to regenerate their spinal cord after injury,making them an ideal vertebrate model for studying regeneration.While previous research has identified key cell types ...Unlike mammals,zebrafish possess a remarkable ability to regenerate their spinal cord after injury,making them an ideal vertebrate model for studying regeneration.While previous research has identified key cell types involved in this process,the underlying molecular and cellular mechanisms remain largely unexplored.In this study,we used single-cell RNA sequencing to profile distinct cell populations at different stages of spinal cord injury in zebrafish.Our analysis revealed that multiple subpopulations of neurons showed persistent activation of genes associated with axonal regeneration post injury,while molecular signals promoting growth cone collapse were inhibited.Radial glial cells exhibited significant proliferation and differentiation potential post injury,indicating their intrinsic roles in promoting neurogenesis and axonal regeneration,respectively.Additionally,we found that inflammatory factors rapidly decreased in the early stages following spinal cord injury,creating a microenvironment permissive for tissue repair and regeneration.Furthermore,oligodendrocytes lost maturity markers while exhibiting increased proliferation following injury.These findings demonstrated that the rapid and orderly regulation of inflammation,as well as the efficient proliferation and redifferentiation of new neurons and glial cells,enabled zebrafish to reconstruct the spinal cord.This research provides new insights into the cellular transitions and molecular programs that drive spinal cord regeneration,offering promising avenues for future research and therapeutic strategies.展开更多
Spinal cord injuries have overwhelming physical and occupational implications for patients.Moreover,the extensive and long-term medical care required for spinal cord injury significantly increases healthcare costs and...Spinal cord injuries have overwhelming physical and occupational implications for patients.Moreover,the extensive and long-term medical care required for spinal cord injury significantly increases healthcare costs and resources,adding a substantial burden to the healthcare system and patients'families.In this context,chondroitinase ABC,a bacterial enzyme isolated from Proteus vulgaris that is modified to facilitate expression and secretion in mammals,has emerged as a promising therapeutic agent.It works by degrading chondroitin sulfate proteoglycans,cleaving the glycosaminoglycanchains of chondroitin sulfate proteoglycans into soluble disaccharides or tetrasaccharides.Chondroitin sulfate proteoglycans are potent axon growth inhibitors and principal constituents of the extracellular matrix surrounding glial and neuronal cells attached to glycosaminoglycan chains.Chondroitinase ABC has been shown to play an effective role in promoting recovery from acute and chronic spinal cord injury by improving axonal regeneration and sprouting,enhancing the plasticity of perineuronal nets,inhibiting neuronal apoptosis,and modulating immune responses in various animal models.In this review,we introduce the classification and pathological mechanisms of spinal cord injury and discuss the pathophysiological role of chondroitin sulfate proteoglycans in spinal cord injury.We also highlight research advancements in spinal cord injury treatment strategies,with a focus on chondroitinase ABC,and illustrate how improvements in chondroitinase ABC stability,enzymatic activity,and delivery methods have enhanced injured spinal cord repair.Furthermore,we emphasize that combination treatment with chondroitinase ABC further enhances therapeutic efficacy.This review aimed to provide a comprehensive understanding of the current trends and future directions of chondroitinase ABC-based spinal cord injury therapies,with an emphasis on how modern technologies are accelerating the optimization of chondroitinase ABC development.展开更多
Spinal cord injury is a critical event characterized by intricate pathogenic mechanisms.Although recent studies have highlighted tissue exosomes as key mediators of inflammatory responses in diverse organs and tissues...Spinal cord injury is a critical event characterized by intricate pathogenic mechanisms.Although recent studies have highlighted tissue exosomes as key mediators of inflammatory responses in diverse organs and tissues,their role in spinal cord injury has yet to be determined.In this study,we investigated the role and mechanisms of spinal cord tissue exosomes in the inflammatory response following spinal cord injury.We found morphological,concentration,and functional differences between exosomes extracted from injured and normal spinal cord tissues,and identified proinflammatory effects associated with spinal cord injury-generated tissue exosomes but not with exosomes derived from normal spinal cord tissue.Our in vivo and in vitro analyses showed that spinal cord injury-generated tissue exosomes promoted microglial M1 polarization and inflammatory cytokine expression,thereby exacerbating tissue and neuronal injury in the spinal cord.In addition,the combination of exosomal miRNA sequencing and experimental verification showed that the miR-155-5p level was higher in spinal cord injury-generated tissue exosomes than in spinal cord tissue.We further found that spinal cord injury-generated tissue exosomes-derived miR-155-5p induced a significant inhibition of forkhead box O3a phosphorylation and activated the nuclear factor-kappa B pathway,thereby promoting microglial M1 polarization and inflammatory cytokine expression.These findings suggest that injury-induced miR-155-5p-containing exosomes exacerbate spinal cord injury via the promotion of microglial M1 polarization and inflammatory responses.Thus,targeting miR-155-5p expression or exosome secretion could be a novel strategy for attenuating inflammation and reducing secondary injury post-spinal cord injury.展开更多
基金supported by the National Key Research and Development Program of China,No.2023YFC3603705(to DX)the National Natural Science Foundation of China,No.82302866(to YZ).
文摘After spinal cord injury,impairment of the sensorimotor circuit can lead to dysfunction in the motor,sensory,proprioceptive,and autonomic nervous systems.Functional recovery is often hindered by constraints on the timing of interventions,combined with the limitations of current methods.To address these challenges,various techniques have been developed to aid in the repair and reconstruction of neural circuits at different stages of injury.Notably,neuromodulation has garnered considerable attention for its potential to enhance nerve regeneration,provide neuroprotection,restore neurons,and regulate the neural reorganization of circuits within the cerebral cortex and corticospinal tract.To improve the effectiveness of these interventions,the implementation of multitarget early interventional neuromodulation strategies,such as electrical and magnetic stimulation,is recommended to enhance functional recovery across different phases of nerve injury.This review concisely outlines the challenges encountered following spinal cord injury,synthesizes existing neurostimulation techniques while emphasizing neuroprotection,repair,and regeneration of impaired connections,and advocates for multi-targeted,task-oriented,and timely interventions.
基金supported by the National Natural Science Foundation of China,Nos.82072165 and 82272256(both to XM)the Key Project of Xiangyang Central Hospital,No.2023YZ03(to RM)。
文摘Spinal cord injury represents a severe form of central nervous system trauma for which effective treatments remain limited.Microglia is the resident immune cells of the central nervous system,play a critical role in spinal cord injury.Previous studies have shown that microglia can promote neuronal survival by phagocytosing dead cells and debris and by releasing neuroprotective and anti-inflammatory factors.However,excessive activation of microglia can lead to persistent inflammation and contribute to the formation of glial scars,which hinder axonal regeneration.Despite this,the precise role and mechanisms of microglia during the acute phase of spinal cord injury remain controversial and poorly understood.To elucidate the role of microglia in spinal cord injury,we employed the colony-stimulating factor 1 receptor inhibitor PLX5622 to deplete microglia.We observed that sustained depletion of microglia resulted in an expansion of the lesion area,downregulation of brain-derived neurotrophic factor,and impaired functional recovery after spinal cord injury.Next,we generated a transgenic mouse line with conditional overexpression of brain-derived neurotrophic factor specifically in microglia.We found that brain-derived neurotrophic factor overexpression in microglia increased angiogenesis and blood flow following spinal cord injury and facilitated the recovery of hindlimb motor function.Additionally,brain-derived neurotrophic factor overexpression in microglia reduced inflammation and neuronal apoptosis during the acute phase of spinal cord injury.Furthermore,through using specific transgenic mouse lines,TMEM119,and the colony-stimulating factor 1 receptor inhibitor PLX73086,we demonstrated that the neuroprotective effects were predominantly due to brain-derived neurotrophic factor overexpression in microglia rather than macrophages.In conclusion,our findings suggest the critical role of microglia in the formation of protective glial scars.Depleting microglia is detrimental to recovery of spinal cord injury,whereas targeting brain-derived neurotrophic factor overexpression in microglia represents a promising and novel therapeutic strategy to enhance motor function recovery in patients with spinal cord injury.
基金supported by the National Natural Science Foundation of China,Nos.82272470 (to GN),82072439 (to GN),81930070 (to SF)the Tianjin Health Key Discipline Special Project,No.TJWJ2022XK011 (to GN)+2 种基金the Outstanding Youth Foundation of Tianjin Medical University General Hospital,No.22ZYYJQ01 (to GN)Tianjin Key Medical Disciplines,No.TJYXZDXK-027A (to SF)National Key Research and Development Program-Stem Cells and Transformation Research,No.2019YFA0112100 (to SF)
文摘Traumatic spinal cord injury result in considerable and lasting functional impairments,triggering complex inflammatory and pathological events.Spinal cord scars,often metaphorically referred to as“fire barriers,”aim to control the spread of neuroinflammation during the acute phase but later hinder axon regeneration in later stages.Recent studies have enhanced our understanding of immunomodulation,revealing that injury-associated inflammation involves various cell types and molecules with positive and negative effects.This review employs bibliometric analysis to examine the literature on inflammatory mediators in spinal cord injury,highlighting recent research and providing a comprehensive overview of the current state of research and the latest advances in studies on neuroinflammation related to spinal cord injury.We summarize the immune and inflammatory responses at different stages of spinal cord injury,offering crucial insights for future research.Additionally,we review repair strategies based on inflammatory mediators for the injured spinal cord.Finally,this review discusses the current status and future directions of translational research focused on immune-targeting strategies,including pharmaceuticals,biomedical engineering,and gene therapy.The development of a combined,precise,and multitemporal strategy for the repair of injured spinal cords represents a promising direction for future research.
基金supported by the National Natural Science Foundation of China,Nos.82271411(to RG),51803072(to WL)the International Cooperative Project of Talent Cultivation“Xinghai Project”at the China-Japan Union Hospital of Jilin University,No.XHLH202404(to WL)+1 种基金the Science and Technology Development Plan of Jilin Province,No.YDZJ202201ZYTS038(to WL)Jilin Provincial Finance Program,No.2022SCZ10(to WL)。
文摘Traumatic spinal cord injury often leads to the disintegration of nerve cells and axons,resulting in a substantial accumulation of myelin debris that can persist for years.The abnormal buildup of myelin debris at sites of injury greatly impedes nerve regeneration,making the clearance of debris within these microenvironments crucial for effective post-spinal cord injury repair.In this review,we comprehensively outline the mechanisms that promote the clearance of myelin debris and myelin metabolism and summarize their roles in spinal cord injury.First,we describe the composition and characteristics of myelin debris and explain its effects on the injury site.Next,we introduce the phagocytic cells involved in myelin debris clearance,including professional phagocytes(macrophages and microglia)and non-professional phagocytes(astrocytes and microvascular endothelial cells),as well as other cells that are also proposed to participate in phagocytosis.Finally,we focus on the pathways and associated targets that enhance myelin debris clearance by phagocytes and promote lipid metabolism following spinal cord injury.Our analysis indicates that myelin debris phagocytosis is not limited to monocyte-derived macrophages,but also involves microglia,astrocytes,and microvascular endothelial cells.By modulating the expression of genes related to phagocytosis and lipid metabolism,it is possible to modulate lipid metabolism disorders and influence inflammatory phenotypes,ultimately affecting the recovery of motor function following spinal cord injury.Additionally,therapies such as targeted mitochondrial transplantation in phagocytic cells,exosome therapy,and repeated trans-spinal magnetic stimulation can effectively enhance the removal of myelin debris,presenting promising potential for future applications.
基金funded by the National Natural Science Foundation of China,No.82271395(to GL),the Guangdong Basic and Applied Basic Research Foundation,No.2023A1515030073(to GL)the grants from University of Macao Research Committee,China,No.MYRG2022-00074-ICMS(to CTV)Guangzhou Science and Technology Program Project,No.2025A04J4740(to GL).
文摘Spinal cord injury is a neurological disorder resulting from trauma,typically affecting sensory and motor function at the injury site,even leading to paralysis and internal dysfunction.The treatment of spinal cord injury mainly relies on pharmacological and surgical interventions;however,significant challenges remain in the protection and repair of neural tissues.Autophagy,an intracellular process responsible for the degradation and recycling of macromolecular components,plays a vital role in spinal cord injury,alleviating the severity of injury by inhibiting cell apoptosis and inflammatory responses.In this review,we provide an overview of the physiological mechanisms underlying autophagy and spinal cord injury and detail the crosstalk between autophagy and other modes of cell death in spinal cord injury.In addition,we discuss the potential of targeting autophagy as a therapeutic strategy for spinal cord injury through approaches that focus on promoting or inhibiting this process,targeting specific autophagic substrates or pathways,and combining autophagy modulation with other neuroprotective or restorative interventions.In summary,this review proposes that strict regulation of autophagy may represent a viable strategy for the treatment of spinal cord injury.
基金supported by Shenzhen Science and Technology Program, No. JCYJ20230807110259002 (to JL)The Seventh Affiliated Hospital of Sun Yat-sen University, No. ZSQYRSFPD0050 (to JL)The Postdoctoral Fellowship Program of CPSF, No. GZC20242074 (to KT)
文摘Oxidative stress significantly contributes to secondary damage after spinal cord injury.Despite its importance,research on oxidative stress in spinal cord injury remains limited.Investigating the expression and regulation of oxidative stress-related genes could enhance the diagnosis and treatment of spinal cord injury.In this study,we analyzed the sequencing data of human blood samples and injured mouse spinal cord tissue that were sourced from GEO databases and identified diagnostic biomarkers associated with the severity of spinal cord injury.We also explored the expression patterns of oxidative stress-related genes,potential regulatory mechanisms,and therapeutic drugs.To validate our findings,we performed immunofluorescence and quantitative polymerase chain reaction to assess gene expression in the injured spinal cord.Our results revealed biomarkers associated with oxidative stress and immune responses across different levels of spinal cord injury in humans.We identified differentially expressed oxidative stress-related genes and key hub genes in injured mouse spinal cord tissue and revealed their temporal expression patterns at both the tissue and single-cell levels.We also clarified the signaling pathways associated with oxidative stress and identified ligand-receptor pairs among various cell types at different time points after injury.Furthermore,we discovered microRNAs,long non-coding RNAs,and transcription factors that regulate these hub genes and revealed their roles in modulating gene expression at various stages after spinal cord injury.We also identified drugs targeting these hub genes.The findings from this study not only aid in identifying diagnostic biomarkers that reflect the severity of spinal cord injury,but also provide insights into the expression dynamics of oxidative stress-related genes.In addition,the study reveals potential regulatory mechanisms and identifies potential drugs to treat patients with spinal cord injury.
基金supported by the National Natural Science Foundation of China,No.81972073(to HZ)a grant from the Taishan Scholars Program ofShandong Province-Young Taishan Scholars,No.tsqn201909197(to HZ)+1 种基金a grant from Tianjin Key Medical Discipline(Specialty)Construct Project,No.TJYXZDXK-027A(to SF)a grant from Academic Expert International Innovation Summit,No.22JRRCRC00010(to SF).
文摘Ferroptosis,a type of cell death that mainly involves iron metabolism imbalance and lipid peroxidation,is strongly correlated with the phagocytic response caused by bleeding after spinal cord injury.Thus,in this study,bulk RNA sequencing data(GSE47681 and GSE5296)and single-cell RNA sequencing data(GSE162610)were acquired from gene expression databases.We then conducted differential analysis and immune infiltration analysis.Atf3 and Piezo1 were identified as key ferroptosis genes through random forest and least absolute shrinkage and selection operator algorithms.Further analysis of single-cell RNA sequencing data revealed a close relationship between ferroptosis and cell types such as macrophages/microglia and their intrinsic state transition processes.Differences in transcription factor regulation and intercellular communication networks were found in ferroptosis-related cells,confirming the high expression of Atf3 and Piezo1 in these cells.Molecular docking analysis confirmed that the proteins encoded by these genes can bind cycloheximide.In a mouse model of T8 spinal cord injury,low-dose cycloheximide treatment was found to improve neurological function,decrease levels of the pro-inflammatory cytokine inducible nitric oxide synthase,and increase levels of the anti-inflammatory cytokine arginase 1.Correspondingly,the expression of the ferroptosis-related gene Gpx4 increased in macrophages/microglia,while the expression of Acsl4 decreased.Our findings reveal the important role of ferroptosis in the treatment of spinal cord injury,identify the key cell types and genes involved in ferroptosis after spinal cord injury,and validate the efficacy of potential drug therapies,pointing to new directions in the treatment of spinal cord injury.
基金supported by Cuiying Scientific and Technological Innovation Program of Second Hospital of Lanzhou University,Nos.CY2023-QN-B18(to YD),2020QN-16(to YZ)the Natural Science Foundation of Gansu Province,No.22JR11RA082(to YZ)Key R&D Plan of Gansu Provincial Department of Science and Technology-Social Development Projects,No.23YFFA0043(to XK).
文摘Spinal cord ischemia-reperfusion injury,a severe form of spinal cord damage,can lead to sensory and motor dysfunction.This injury often occurs after traumatic events,spinal cord surgeries,or thoracoabdominal aortic surgeries.The unpredictable nature of this condition,combined with limited treatment options,poses a significant burden on patients,their families,and society.Spinal cord ischemia-reperfusion injury leads to reduced neuronal regenerative capacity and complex pathological processes.In contrast,mitophagy is crucial for degrading damaged mitochondria,thereby supporting neuronal metabolism and energy supply.However,while moderate mitophagy can be beneficial in the context of spinal cord ischemia-reperfusion injury,excessive mitophagy may be detrimental.Therefore,this review aims to investigate the potential mechanisms and regulators of mitophagy involved in the pathological processes of spinal cord ischemia-reperfusion injury.The goal is to provide a comprehensive understanding of recent advancements in mitophagy related to spinal cord ischemia-reperfusion injury and clarify its potential clinical applications.
基金supported by Shenzhen University General Hospital Scientific Research Project,No.SUGH2019QD002Shenzhen Science and Technology Development Foundation,No.20220810173216001(both to ZS).
文摘Spinal cord injury is a severe neurological condition with limited neuronal regeneration and functional recovery.Currently,no effective treatments exist to improve spinal cord injury prognosis.Neuronal guidance proteins are a diverse group of molecules that play crucial roles in axon and dendrite growth during nervous system development.Increasing evidence highlights their regulatory functions in spinal cord injury.This review provides a brief overview of the modulation patterns of key neuronal guidance proteins in neuronal axon growth during nervous system formation and subsequently focuses on their roles in neuronal regeneration and functional recovery following spinal cord injury.Neuronal guidance proteins include,but are not limited to,semaphorins and their receptors,plexins;netrins and their receptors,deleted in colorectal cancer and UNC5;Eph receptors and their ligands,ephrins;Slit and its receptor,Robo;repulsive guidance molecules and their receptor,neogenin;Wnt proteins and their receptor,Frizzled;and protocadherins.Localized Netrin-1 at the injury site inhibits motor axon regeneration after adult spinal cord injury while promoting oligodendrocyte growth.Slit2 enhances synapse formation in the injured spinal cord of rats.EphA7 regulates acute apoptosis in the early pathophysiological stages of spinal cord injury,while ephrinA1 plays a role in the nervous system’s injury response,with its reduced expression leading to impaired motor function in rats.EphA3 is upregulated following spinal cord injury,promoting an inhibitory environment for axonal regeneration.After spinal cord injury,bidirectional activation of ephrinB2 and EphB2 in astrocytes and fibroblasts results in the formation of a dense astrocyte-meningeal fibroblast scar.EphB1/ephrinB1 signaling mediates pain processing in spinal cord injury by regulating calpain-1 and caspase-3 in neurons.EphB3 expression increases in white matter after spinal cord injury,further inhibiting axon regeneration.Sema3A,expressed by neurons and fibroblasts in the scar surrounding the injury,inhibits motor neuron and sensory nerve growth after spinal cord injury.Sema4D suppresses neuronal axon myelination and axon regeneration,while its inhibition significantly enhances axon regeneration and motor recovery.Sema7A is involved in glial scar formation and may influence serotonin channel remodeling,thereby affecting motor coordination.Given these findings,the local or systemic application of neuronal guidance proteins represents a promising avenue for spinal cord injury treatment.
基金supported by the National Natural Science Foundation of China,No.81641048Research Project of Yan’an University,No.2023JBZR-011(both to LZ).
文摘Spinal cord injury is a severe neurological condition characterized by the permanent loss of nerve cell function and a failure in neural circuit reconstruction-key factors contributing to disability.Therefore,exploring effective strategies to promote the repair and regeneration of nerve cells after spinal cord injury is crucial for optimizing patient prognosis.The purpose of this paper is to conduct an in-depth review of the pathological changes in nerve cells after spinal cord injury and to present the state of research on the role of exercise training in promoting the repair and regeneration of nerve cells after spinal cord injury.In terms of the intrinsic growth capacity of neurons,disruptions in the dynamic balance between growth cones and the cytoskeleton,the dysregulation of transcription factors,abnormal protein signaling transduction,and altered epigenetic modifications collectively hinder axonal regeneration.Additionally,the microenvironment of neurons undergoes a series of complex changes,initially manifesting as edema,which may be exacerbated by spinal cord ischemia-reperfusion injury,further increasing the extent of nerve cell damage.The abnormal proliferation of astrocytes leads to the formation of glial scars,creating a physical barrier to nerve regeneration.The inflammatory response triggered by the excessive activation of microglia negatively impacts the process of nerve repair.Non-invasive interventions involving exercise training have shown significant potential in promoting nerve repair as part of a comprehensive treatment strategy for spinal cord injury.Specifically,exercise training can reshape the growth cone and cytoskeletal structures of neurons,regulate transcription factor activity,modulate protein signaling pathways,and influence epigenetic modifications,thereby activating the intrinsic repair mechanisms of neurons.Moreover,exercise training can regulate the activation state of astrocytes,optimize the inflammatory response and metabolic processes,promote astrocyte polarization,enhance angiogenesis,reduce glial scar formation,and modulate the expression levels of nerve growth factors.It also effectively helps regulate microglial activation,promotes axonal regeneration,and improves phagocytic function,thereby optimizing the microenvironment for nerve repair.In terms of clinical translation,we summarize the preliminary results of new drug research and development efforts,the development of innovative devices,and the use of exercise training in promoting clinical advancements in nerve repair following spinal cord injury,while considering their limitations and future application prospects.In summary,this review systematically analyzes findings relating to the pathological changes occurring in nerve cells after spinal cord injury and emphasizes the critical role of exercise training in facilitating the repair and regeneration of nerve cells.This work is expected to provide new ideas and methods for the rehabilitation of patients with spinal cord injury.
基金supported by the National Natural Science Foundation of China,Nos.82271419,81901902(to YZ),82202702(to ZW),82202351(to XH),82301550(to LYang),82271418(to XX)the Shanghai Rising-Star Program,No.22QA1408200(to YZ)the Fundamental Research Fundsfor the Central Universities,No.22120220555(to YZ).
文摘In the early stages of traumatic spinal cord injury,extensive accumulation of autophagosomes creates a neurotoxic microenvironment,exacerbating neuronal cell death and worsening tissue damage,ultimately hindering neurofunctional recovery.Activin A is a critical growth factor necessary for the development of the embryonic nervous system and for maintaining neuronal function in the adult cerebral cortex.It can inhibit excessive autophagy in ischemic stroke to reduce neuronal damage.However,the specific mechanism through which Activin A functions in the spinal cord remains poorly understood.In this study,we administered different concentrations of Activin A to neural stem cells from the spinal cord and found that Activin A stimulated the proliferation and neuronal differentiation of neural stem cells.Then,we established an in vitro oxidative stress model by using hydrogen peroxide to stimulate the neural stem cells-induced neurons.We found that Activin A could reduce apoptosis caused by oxidative stress.Subsequently,we treated a mouse model of spinal cord contusion with intrathecal injection of Activin A.Behavioral and electrophysiological results showed that Activin A promoted recovery of motor function and reconstruction of neural circuits in the model mice.Finally,RNA sequencing indicated that Activin A inhibited autophagy by activating the PI3K/AKT/mTOR pathway and upregulating the expression of synaptogenesis-related factor Sema3A in the spinal cord.These results suggest that Activin A may mediate the excessive autophagic response after spinal cord injury,promote the reconstruction of damaged neural circuits,and restore neurological function in the injured spinal cord.
基金supported by the National Natural Science Foundation of China,Nos.82371389,82071382(to MZ)the Priority Academic Program Development of Jiangsu Higher Education Institutions,PAPD(to MZ)+4 种基金Jiangsu Maternal and Child Health Research Key Project,No.F202013(to HS)Jiangsu 333 High Level Talent Training Project,2022(to HS)Gusu District Health Talent Training Project,No.2024145(to HS)Suzhou BenQ Medical Center Project,No.H220918(to MZ)Undergraduate Training Program for Innovation and Entrepreneurship,Soochow University,No.202410285091Z(to MZ)。
文摘Mitophagy is closely associated with the pathogenesis of secondary spinal cord injury.Abnormal mitophagy may contribute significantly to secondary spinal cord injury,leading to the impaired production of adenosine triphosphate,ion imbalance,the excessive production of reactive oxygen species,neuroinflammation,and neuronal cell death.Therefore,maintaining an appropriate balance of mitophagy is crucial when treating spinal cord injury,as both excessive and insufficient mitophagy can impede recovery.In this review,we summarize the pathological changes associated with spinal cord injury,the mechanisms of mitophagy,and the direct and indirect relationships between mitophagy and spinal cord injury.We also consider therapeutic approaches that target mitophagy for the treatment of spinal cord injury,including ongoing clinical trials and other innovative therapies,such as use of stem cells,nanomaterials,and small molecule polymers.Finally,we highlight the current challenges facing this field and suggest potential directions for future research.The aim of our review is to provide a theoretical reference for future studies targeting mitophagy in the treatment of spinal cord injury.
基金supported by the Tianjin Key Medical Discipline(Specialty)Construct Project,No.TJYXZDXK-027A(to SF)the National Key Research andDevelopment Project of Stem Cell and Transformation Research,No.2019YFA0112100(to SF)+2 种基金Tianjin Natural Science Foundation’s Youth Project for DiverseInvestments,No.21JCQNJC01300(to BF)the National Natural Science Foundation of China(Youth Program),No.82102563(to BF)Tianjin Major Science andTechnology Special Projects and Engineering Projects,No.21ZXJBSY00080(to YR).
文摘Few studies have investigated alterations in the immune cell microenvironment of the dorsal root ganglia following spinal cord injury and whether these modifications facilitate axonal regeneration.In this study,we used a single-cell RNA sequencing dataset to create a comprehensive profile of the diverse cell types in the dorsal root ganglia and spinal cord of a mid-thoracic contusion injury model in cynomolgus monkeys.Cell communication analysis indicated that specific signaling events among various dorsal root ganglia cell types occur in response to spinal cord injury.Single-cell analysis using dimensionality reduction clustering identified distinct molecular signatures for nine cell types,including macrophage subpopulations,and differential gene expression profiles between dorsal root ganglia cells and spinal cord cells following spinal cord injury.The macrophage subpopulations were categorized into 11 clusters(MC0-MC10)based on differentially expressed genes,with the top 10 genes being ABCA6,RBMS3,EBF1,LAMA4,ANTXR2,LAMA2,SOX5,FOXP2,GHR,and APOD.MC0,MC1,and MC2 constituted the predominant macrophage populations.MC4,MC6,and MC9 were nearly absent in the spinal cord,but exhibited significant increases in the dorsal root ganglia post-spinal cord injury.Notably,these subpopulations possess a strong capacity for regulating axonal regeneration.The developmental progression of dorsal root ganglia macrophages after spinal cord injury was elucidated using cell trajectory and pseudo-time analyses.Genes such as EBF1(MC6 and MC9 marker),RBMS3(MC6 and MC9 marker),and ABCA6(MC6 marker)showed high expression levels in the critical pathways of macrophage function.Through ligand-receptor pair analysis,we determined that the effects of macrophages on microglia are predominantly mediated through interaction pairs(e.g.,SPP1-CD44,LAMC1-CD44,and FN1-CD44),potentially facilitating specific cellular communications within the immune microenvironment.The single-cell RNA sequencing dataset used in this study represents the first comprehensive transcriptional analysis of the dorsal root ganglia after spinal cord injury in cynomolgus monkeys,encompassing nearly all cell types within the dorsal root ganglia region.Using this dataset,we evaluated diverse subtypes of macrophages in the post-spinal cord injury dorsal root ganglia area and examined the signaling pathways that facilitate interactions among immune response-related macrophages in the dorsal root ganglia.Findings from this study provide a theoretical basis for understanding how the immune microenvironment influences the regenerative capacity of dorsal root ganglia neurons after spinal cord injury and offer novel insights into the complex processes underlying the pathobiology of spinal cord injury.
基金supported by the National Key R&D Program of China,Nos.2017YFA0104302(to NG and XM)and 2017YFA0104304(to BW and ZZ)
文摘Mesenchymal stromal cell transplantation is an effective and promising approach for treating various systemic and diffuse diseases.However,the biological characteristics of transplanted mesenchymal stromal cells in humans remain unclear,including cell viability,distribution,migration,and fate.Conventional cell tracing methods cannot be used in the clinic.The use of superparamagnetic iron oxide nanoparticles as contrast agents allows for the observation of transplanted cells using magnetic resonance imaging.In 2016,the National Medical Products Administration of China approved a new superparamagnetic iron oxide nanoparticle,Ruicun,for use as a contrast agent in clinical trials.In the present study,an acute hemi-transection spinal cord injury model was established in beagle dogs.The injury was then treated by transplantation of Ruicun-labeled mesenchymal stromal cells.The results indicated that Ruicunlabeled mesenchymal stromal cells repaired damaged spinal cord fibers and partially restored neurological function in animals with acute spinal cord injury.T2*-weighted imaging revealed low signal areas on both sides of the injured spinal cord.The results of quantitative susceptibility mapping with ultrashort echo time sequences indicated that Ruicun-labeled mesenchymal stromal cells persisted stably within the injured spinal cord for over 4 weeks.These findings suggest that magnetic resonance imaging has the potential to effectively track the migration of Ruicun-labeled mesenchymal stromal cells and assess their ability to repair spinal cord injury.
基金supported by the Jiangsu Province Traditional Chinese Medicine Technology Development Plan Project,Nos.MS2023113(to JC),MS2022090Young and Middle-aged Academic Leaders of Jiangsu Qing-Lan Project(to GL).
文摘Unlike mammals,zebrafish possess a remarkable ability to regenerate their spinal cord after injury,making them an ideal vertebrate model for studying regeneration.While previous research has identified key cell types involved in this process,the underlying molecular and cellular mechanisms remain largely unexplored.In this study,we used single-cell RNA sequencing to profile distinct cell populations at different stages of spinal cord injury in zebrafish.Our analysis revealed that multiple subpopulations of neurons showed persistent activation of genes associated with axonal regeneration post injury,while molecular signals promoting growth cone collapse were inhibited.Radial glial cells exhibited significant proliferation and differentiation potential post injury,indicating their intrinsic roles in promoting neurogenesis and axonal regeneration,respectively.Additionally,we found that inflammatory factors rapidly decreased in the early stages following spinal cord injury,creating a microenvironment permissive for tissue repair and regeneration.Furthermore,oligodendrocytes lost maturity markers while exhibiting increased proliferation following injury.These findings demonstrated that the rapid and orderly regulation of inflammation,as well as the efficient proliferation and redifferentiation of new neurons and glial cells,enabled zebrafish to reconstruct the spinal cord.This research provides new insights into the cellular transitions and molecular programs that drive spinal cord regeneration,offering promising avenues for future research and therapeutic strategies.
基金supported by the National Natural Science Foundation of China,No.82002645China Postdoctoral Science Foundation,No.2022M722321Jiangsu Funding Program for Excellent Postdoctoral Talent,No.2022ZB552(all to YH)。
文摘Spinal cord injuries have overwhelming physical and occupational implications for patients.Moreover,the extensive and long-term medical care required for spinal cord injury significantly increases healthcare costs and resources,adding a substantial burden to the healthcare system and patients'families.In this context,chondroitinase ABC,a bacterial enzyme isolated from Proteus vulgaris that is modified to facilitate expression and secretion in mammals,has emerged as a promising therapeutic agent.It works by degrading chondroitin sulfate proteoglycans,cleaving the glycosaminoglycanchains of chondroitin sulfate proteoglycans into soluble disaccharides or tetrasaccharides.Chondroitin sulfate proteoglycans are potent axon growth inhibitors and principal constituents of the extracellular matrix surrounding glial and neuronal cells attached to glycosaminoglycan chains.Chondroitinase ABC has been shown to play an effective role in promoting recovery from acute and chronic spinal cord injury by improving axonal regeneration and sprouting,enhancing the plasticity of perineuronal nets,inhibiting neuronal apoptosis,and modulating immune responses in various animal models.In this review,we introduce the classification and pathological mechanisms of spinal cord injury and discuss the pathophysiological role of chondroitin sulfate proteoglycans in spinal cord injury.We also highlight research advancements in spinal cord injury treatment strategies,with a focus on chondroitinase ABC,and illustrate how improvements in chondroitinase ABC stability,enzymatic activity,and delivery methods have enhanced injured spinal cord repair.Furthermore,we emphasize that combination treatment with chondroitinase ABC further enhances therapeutic efficacy.This review aimed to provide a comprehensive understanding of the current trends and future directions of chondroitinase ABC-based spinal cord injury therapies,with an emphasis on how modern technologies are accelerating the optimization of chondroitinase ABC development.
基金supported by the Joint Funds for the Innovation of Science and Technology,Fujian Province,No.2023Y9233(to HH)the QuanzhouScience and Technology Project,No.2022C036R(to HH)+1 种基金the Science and Technology Bureau of Quanzhou,No.2020CT003(to SL)the Quanzhou MunicipalMedical and Health Guiding Science and Technology Project,No.2023N066S(to YZhou).
文摘Spinal cord injury is a critical event characterized by intricate pathogenic mechanisms.Although recent studies have highlighted tissue exosomes as key mediators of inflammatory responses in diverse organs and tissues,their role in spinal cord injury has yet to be determined.In this study,we investigated the role and mechanisms of spinal cord tissue exosomes in the inflammatory response following spinal cord injury.We found morphological,concentration,and functional differences between exosomes extracted from injured and normal spinal cord tissues,and identified proinflammatory effects associated with spinal cord injury-generated tissue exosomes but not with exosomes derived from normal spinal cord tissue.Our in vivo and in vitro analyses showed that spinal cord injury-generated tissue exosomes promoted microglial M1 polarization and inflammatory cytokine expression,thereby exacerbating tissue and neuronal injury in the spinal cord.In addition,the combination of exosomal miRNA sequencing and experimental verification showed that the miR-155-5p level was higher in spinal cord injury-generated tissue exosomes than in spinal cord tissue.We further found that spinal cord injury-generated tissue exosomes-derived miR-155-5p induced a significant inhibition of forkhead box O3a phosphorylation and activated the nuclear factor-kappa B pathway,thereby promoting microglial M1 polarization and inflammatory cytokine expression.These findings suggest that injury-induced miR-155-5p-containing exosomes exacerbate spinal cord injury via the promotion of microglial M1 polarization and inflammatory responses.Thus,targeting miR-155-5p expression or exosome secretion could be a novel strategy for attenuating inflammation and reducing secondary injury post-spinal cord injury.
