Spinal cord injury is considered one of the most difficult injuries to repair and has one of the worst prognoses for injuries to the nervous system.Following surgery,the poor regenerative capacity of nerve cells and t...Spinal cord injury is considered one of the most difficult injuries to repair and has one of the worst prognoses for injuries to the nervous system.Following surgery,the poor regenerative capacity of nerve cells and the generation of new scars can make it very difficult for the impaired nervous system to restore its neural functionality.Traditional treatments can only alleviate secondary injuries but cannot fundamentally repair the spinal cord.Consequently,there is a critical need to develop new treatments to promote functional repair after spinal cord injury.Over recent years,there have been seve ral developments in the use of stem cell therapy for the treatment of spinal cord injury.Alongside significant developments in the field of tissue engineering,three-dimensional bioprinting technology has become a hot research topic due to its ability to accurately print complex structures.This led to the loading of three-dimensional bioprinting scaffolds which provided precise cell localization.These three-dimensional bioprinting scaffolds co uld repair damaged neural circuits and had the potential to repair the damaged spinal cord.In this review,we discuss the mechanisms underlying simple stem cell therapy,the application of different types of stem cells for the treatment of spinal cord injury,and the different manufa cturing methods for three-dimensional bioprinting scaffolds.In particular,we focus on the development of three-dimensional bioprinting scaffolds for the treatment of spinal cord injury.展开更多
Exosomes exhibit complex biological functions and mediate a variety of biological processes,such as promoting axonal regeneration and functional recove ry after injury.Long non-coding RNAs(IncRNAs)have been reported t...Exosomes exhibit complex biological functions and mediate a variety of biological processes,such as promoting axonal regeneration and functional recove ry after injury.Long non-coding RNAs(IncRNAs)have been reported to play a crucial role in axonal regeneration.Howeve r,the role of the IncRNA-microRNAmessenger RNA(mRNA)-competitive endogenous RNA(ceRNA)network in exosome-mediated axonal regeneration remains unclear.In this study,we performed RNA transcriptome sequencing analysis to assess mRNA expression patterns in exosomes produced by cultured fibroblasts(FC-EXOs)and Schwann cells(SCEXOs).Diffe rential gene expression analysis,Gene Ontology analysis,Kyoto Encyclopedia of Genes and Genomes analysis,and protein-protein intera ction network analysis were used to explo re the functions and related pathways of RNAs isolated from FC-EXOs and SC-EXOs.We found that the ribosome-related central gene Rps5 was enriched in FC-EXOs and SC-EXOs,which suggests that it may promote axonal regeneration.In addition,using the miRWalk and Starbase prediction databases,we constructed a regulatory network of ceRNAs targeting Rps5,including 27 microRNAs and five IncRNAs.The ceRNA regulatory network,which included Ftx and Miat,revealed that exsosome-derived Rps5 inhibits scar formation and promotes axonal regeneration and functional recovery after nerve injury.Our findings suggest that exosomes derived from fibro blast and Schwann cells could be used to treat injuries of peripheral nervous system.展开更多
CD36 is a highly glycosylated integral membrane protein that belongs to the scavenger receptor class B family and regulates the pathological progress of metabolic diseases.CD36 was recently found to be widely expresse...CD36 is a highly glycosylated integral membrane protein that belongs to the scavenger receptor class B family and regulates the pathological progress of metabolic diseases.CD36 was recently found to be widely expressed in various cell types in the nervous system,including endothelial cells,pericytes,astrocytes,and microglia.CD36 mediates a number of regulatory processes,such as endothelial dysfunction,oxidative stress,mitochondrial dysfunction,and inflammatory responses,which are involved in many central nervous system diseases,such as stroke,Alzheimer’s disease,Parkinson’s disease,and spinal cord injury.CD36 antagonists can suppress CD36 expression or prevent CD36 binding to its ligand,thereby achieving inhibition of CD36-mediated pathways or functions.Here,we reviewed the mechanisms of action of CD36 antagonists,such as Salvianolic acid B,tanshinone IIA,curcumin,sulfosuccinimidyl oleate,antioxidants,and small-molecule compounds.Moreover,we predicted the structures of binding sites between CD36 and antagonists.These sites can provide targets for more efficient and safer CD36 antagonists for the treatment of central nervous system diseases.展开更多
Injuries caused by trauma and neurodegenerative diseases can damage the peripheral nervous system and cause functional deficits.Unlike in the central nervous system,damaged axons in peripheral nerves can be induced to...Injuries caused by trauma and neurodegenerative diseases can damage the peripheral nervous system and cause functional deficits.Unlike in the central nervous system,damaged axons in peripheral nerves can be induced to regenerate in response to intrinsic cues after reprogramming or in a growth-promoting microenvironment created by Schwann cells.However,axon regeneration and repair do not automatically result in the restoration of function,which is the ultimate therapeutic goal but also a major clinical challenge.Transforming growth factor(TGF)is a multifunctional cytokine that regulates various biological processes including tissue repair,embryo development,and cell growth and differentiation.There is accumulating evidence that TGF-βfamily proteins participate in peripheral nerve repair through various factors and signaling pathways by regulating the growth and transformation of Schwann cells;recruiting specific immune cells;controlling the permeability of the blood-nerve barrier,thereby stimulating axon growth;and inhibiting remyelination of regenerated axons.TGF-βhas been applied to the treatment of peripheral nerve injury in animal models.In this context,we review the functions of TGF-βin peripheral nerve regeneration and potential clinical applications.展开更多
Rho GTPases are essential regulators of the actin cytoskeleton.They are involved in various physiological and biochemical processes such as the regulation of cytoskeleton dynamics,development,proliferation,survival,an...Rho GTPases are essential regulators of the actin cytoskeleton.They are involved in various physiological and biochemical processes such as the regulation of cytoskeleton dynamics,development,proliferation,survival,and regeneration.During the development of cochlear hair cells,Rho GTPases are activated by various extracellular signals through membrane receptors to further stimulate multiple downstream effectors.Specifically,RhoA,Cdc42,and Rac1,members of the classical subfamily of the Rho GTPase family,regulate the development and maintenance of cilia by inducing the polymerization of actin monomers and stabilizing actin filaments.In addition,they also regulate the normal morphology orientation of ciliary bundles in auditory hair cells,which is an important element of cell polarity regulation.Moreover,the actin-related pathways mediated by RhoA,Cdc42,and Rac1 also play a role in the motility of outer hair cells,indicating that the function of Rho GTPases is crucial in the highly polar auditory sensory system.In this review,we focus on the expression of RhoA,Cdc42,and Rac1 in cochlear hair cells and how these small molecules participate in ciliary bundle morphogenesis and cochlear hair cell movement.We also discuss the progress of current research investigating the use of these small molecules as drug targets for deafness treatment.展开更多
Our previous studies have shown that long noncoding RNA(lncRNA)H19 is upregulated in injured rat sciatic nerve during the process of Wallerian degeneration,and that it promotes the migration of Schwann cells and slows...Our previous studies have shown that long noncoding RNA(lncRNA)H19 is upregulated in injured rat sciatic nerve during the process of Wallerian degeneration,and that it promotes the migration of Schwann cells and slows down the growth of dorsal root ganglion axons.However,the mechanism by which lncRNA H19 regulates neural repair and regeneration after peripheral nerve injury remains unclear.In this study,we established a Sprague-Dawley rat model of sciatic nerve transection injury.We performed in situ hybridization and found that at 4–7 days after sciatic nerve injury,lncRNA H19 was highly expressed.At 14 days before injury,adeno-associated virus was intrathecally injected into the L4–L5 foramina to disrupt or overexpress lncRNA H19.After overexpression of lncRNA H19,the growth of newly formed axons from the sciatic nerve was inhibited,whereas myelination was enhanced.Then,we performed gait analysis and thermal pain analysis to evaluate rat behavior.We found that lncRNA H19 overexpression delayed the recovery of rat behavior function,whereas interfering with lncRNA H19 expression improved functional recovery.Finally,we examined the expression of lncRNA H19 downstream target SEMA6D,and found that after lncRNA H19 overexpression,the SEMA6D protein level was increased.These findings suggest that lncRNA H19 regulates peripheral nerve degeneration and regeneration through activating SEMA6D in injured nerves.This provides a new clue to understand the role of lncRNA H19 in peripheral nerve degeneration and regeneration.展开更多
The key regulators and regeneration-associated genes involved in axonal regeneration of neurons after injury have not been clarified.In high-throughput sequencing,various factors influence the final sequencing results...The key regulators and regeneration-associated genes involved in axonal regeneration of neurons after injury have not been clarified.In high-throughput sequencing,various factors influence the final sequencing results,including the number and size of cells,the depth of sequencing,and the method of cell separation.There is still a lack of research on the detailed molecular expression profile during the regeneration of dorsal root ganglion neuron axon.In this study,we performed lase r-capture microdissection coupled with RNA sequencing on dorsal root ganglion neurons at 0,3,6,and 12 hours and 1,3,and 7 days after sciatic nerve crush in rats.We identified three stages after dorsal root ganglion injury:early(3-12 hours),pre-regeneration(1 day),and regeneration(3-7 days).Gene expression patterns and related function enrichment res ults showed that one module of genes was highly related to axonal regeneration.We verified the up-regulation of activating transcription factor 3(Atf3),Kruppel like factor 6(Klf6),AT-rich inte raction domain 5A(Arid5α),CAMP responsive element modulator(Crem),and FOS like 1,AP-1 transcription factor Subunit(Fosl1) in dorsal root ganglion neurons after injury.Suppressing these transcription factors(Crem,Arid5o,Fosl1 and Klf6) reduced axonal regrowth in vitro.As the hub transcription factor,Atf3 showed higher expression and activity at the preregeneration and regeneration stages.G protein-coupled estrogen receptor 1(Gper1),inte rleukin 12a(Il12α),estrogen receptor 1(ESR1),and interleukin 6(IL6) may be upstream factors that trigger the activation of Atf3 during the repair of axon injury in the early stage.Our study presents the detailed molecular expression profile during axonal regeneration of dorsal root ganglion neurons after peripheral nerve injury.These findings may provide reference for the clinical screening of molecular targets for the treatment of peripheral nerve injury.展开更多
The low intrinsic growth capacity of neurons and an injury-induced inhibitory milieu are major contributo rs to the failure of sensory and motor functional recovery following spinal cord injury.Heat shock transcriptio...The low intrinsic growth capacity of neurons and an injury-induced inhibitory milieu are major contributo rs to the failure of sensory and motor functional recovery following spinal cord injury.Heat shock transcription factor 1(HSF1),a master regulator of the heat shock response,plays neurogenetic and neuroprotective roles in the damaged or diseased central nervous system.However,the underlying mechanism has not been fully elucidated.In the present study,we used a gecko model of spontaneous nerve regeneration to investigate the potential roles of gecko HSF1(gHSF1) in the regulation of neurite outgrowth and inflammatory inhibition of macrophages following spinal cord injury.gHSF1 expression in neurons and microglia at the lesion site increased dramatically immediately after tail amputation.gHSF1 ove rexpression in gecko primary neuro ns significantly promoted axonal growth by suppressing the expression of suppressor of cytokine signaling-3,and fa cilitated neuro nal survival via activation of the mitogen-activated extracellular signal-regulated kinase/extracellular regulated protein kinases and phosphatidylinositol 3-kinase/protein kinase B pathways.Furthermore,gHSF1 efficiently inhibited the macrophagemediated inflammatory response by inactivating 1kappa B-alpha/NF-kappaB signaling.Our findings show that HSF1 plays dual roles in promoting axonal regrowth and inhibiting leukocyte inflammation,and provide new avenues of investigation for promoting spinal co rd injury repair in mammals.展开更多
Peripheral nerve injury repair requires a certain degree of cooperation between axon regeneration and Wallerian degeneration.Therefore,investigating how axon regeneration and degeneration work together to repair perip...Peripheral nerve injury repair requires a certain degree of cooperation between axon regeneration and Wallerian degeneration.Therefore,investigating how axon regeneration and degeneration work together to repair peripheral nerve injury may uncover the molecular mechanisms and signal cascades underlying peripheral nerve repair and provide potential strategies for improving the low axon regeneration capacity of the central nervous system.In this study,we applied weighted gene co-expression network analysis to identify differentially expressed genes in proximal and distal sciatic nerve segments from rats with sciatic nerve injury.We identified 31 and 15 co-expression modules from the proximal and distal sciatic nerve segments,respectively.Functional enrichment analysis revealed that the differentially expressed genes in proximal modules promoted regeneration,while the differentially expressed genes in distal modules promoted neurodegeneration.Next,we constructed hub gene networks for selected modules and identified a key hub gene,Kif22,which was up-regulated in both nerve segments.In vitro experiments confirmed that Kif22 knockdown inhibited proliferation and migration of Schwann cells by modulating the activity of the extracellular signal-regulated kinase signaling pathway.Collectively,our findings provide a comparative framework of gene modules that are co-expressed in injured proximal and distal sciatic nerve segments,and identify Kif22 as a potential therapeutic target for promoting peripheral nerve injury repair via Schwann cell proliferation and migration.All animal experiments were approved by the Institutional Animal Ethics Committee of Nantong University,China(approval No.S20210322-008)on March 22,2021.展开更多
Astrocytes are important cellular centers of cholesterol synthesis and metabolism that help maintain normal physiological function at the organism level.Spinal cord injury results in aberrant cholesterol metabolism by...Astrocytes are important cellular centers of cholesterol synthesis and metabolism that help maintain normal physiological function at the organism level.Spinal cord injury results in aberrant cholesterol metabolism by astrocytes and excessive production of oxysterols,which have profound effects on neuropathology.25-Hydroxycholesterol(25-HC),the main product of the membrane-associated enzyme cholesterol-25-hydroxylase(CH25H),plays important roles in mediating neuroinflammation.However,whether the abnormal astrocyte cholesterol metabolism induced by spinal cord injury contributes to the production of 25-HC,as well as the resulting pathological effects,remain unclear.In the present study,spinal cord injury-induced activation of thrombin was found to increase astrocyte CH25H expression.A protease-activated receptor 1 inhibitor was able to attenuate this effect in vitro and in vivo.In cultured primary astrocytes,thrombin interacted with protease-activated receptor 1,mainly through activation of the mitogen-activated protein kinase/nuclear factor-kappa B signaling pathway.Conditioned culture medium from astrocytes in which ch25h expression had been knocked down by siRNA reduced macrophage migration.Finally,injection of the protease activated receptor 1 inhibitor SCH79797 into rat neural sheaths following spinal cord injury reduced migration of microglia/macrophages to the injured site and largely restored motor function.Our results demonstrate a novel regulatory mechanism for thrombin-regulated cholesterol metabolism in astrocytes that could be used to develop anti-inflammatory drugs to treat patients with spinal cord injury.展开更多
Spinal cord injury causes accumulation of a large number of leukocytes at the lesion site where they contribute to excessive inflammation.Overproduced chemokines are responsible for the migratory process of the leukoc...Spinal cord injury causes accumulation of a large number of leukocytes at the lesion site where they contribute to excessive inflammation.Overproduced chemokines are responsible for the migratory process of the leukocytes,but the regulatory mechanism underlying the production of chemokines from resident cells of the spinal cord has not been fully elucidated.We examined the protein levels of macrophage migration inhibitory factor and chemokine C-C motif chemokine ligand 2 in a spinal cord contusion model at different time points following spinal cord injury.The elevation of macrophage migration inhibitory factor at the lesion site coincided with the increase of chemokine C-C motif chemokine ligand 2 abundance in astrocytes.Stimulation of primary cultured astrocytes with different concentrations of macrophage migration inhibitory factor recombinant protein induced chemokine C-C motif chemokine ligand 2 production from the cells,and the macrophage migration inhibitory factor inhibitor 4-iodo-6-phenylpyrimidine attenuated the stimulatory effect.Further investigation into the underlying mechanism on macrophage migration inhibitory factor-mediated astrocytic production of chemokine C-C motif chemokine ligand 2 revealed that macrophage migration inhibitory factor activated intracellular JNK signaling through binding with CD74 receptor.Administration of the macrophage migration inhibitory factor inhibitor 4-iodo-6-phenylpyrimidine following spinal cord injury resulted in the reduction of chemokine C-C motif chemokine ligand 2-recruited microglia/macrophages at the lesion site and remarkably improved the hindlimb locomotor function of rats.Our results have provided insights into the functions of astrocyte-activated chemokines in the recruitment of leukocytes and may be beneficial to develop interventions targeting chemokine C-C motif chemokine ligand 2 for neuroinflammation after spinal cord injury.展开更多
Neurotrophic factors,particularly nerve growth factor,enhance neuronal regeneration.However,the in vivo applications of nerve growth factor are largely limited by its intrinsic disadvantages,such as its short biologic...Neurotrophic factors,particularly nerve growth factor,enhance neuronal regeneration.However,the in vivo applications of nerve growth factor are largely limited by its intrinsic disadvantages,such as its short biological half-life,its contribution to pain response,and its inability to cross the blood-brain barrier.Considering that let-7(human miRNA)targets and regulates nerve growth factor,and that let-7 is a core regulator in peripheral nerve regeneration,we evaluated the possibilities of let-7 application in nerve repair.In this study,anti-let-7a was identified as the most suitable let-7 family molecule by analyses of endogenous expression and regulatory relationship,and functional screening.Let-7a antagomir demonstrated biosafety based on the results of in vivo safety assessments and it entered into the main cell types of the sciatic nerve,including Schwann cells,fibroblasts and macrophages.Use of hydrogel effectively achieved controlled,localized,and sustained delivery of let-7a antagomir.Finally,let-7a antagomir was integrated into chitosan conduit to construct a chitosan-hydrogel scaffold tissue-engineered nerve graft,which promoted nerve regeneration and functional recovery in a rat model of sciatic nerve transection.Our study provides an experimental basis for potential in vivo application of let-7a.展开更多
MicroRNAs(miRNAs) can regulate the modulation of the phenotype of Schwann cells. Numerous novel miRNAs have been discovered and identified in rat sciatic nerve segments, including miR-3099. In the current study, miR-3...MicroRNAs(miRNAs) can regulate the modulation of the phenotype of Schwann cells. Numerous novel miRNAs have been discovered and identified in rat sciatic nerve segments, including miR-3099. In the current study, miR-3099 expression levels following peripheral nerve injury were measured in the proximal stumps of rat sciatic nerves after surgical crush. Real-time reverse transcription-polymerase chain reaction was used to determine miR-3099 expression in the crushed nerve segment at 0, 1, 4, 7, and 14 days post sciatic nerve injury, which was consistent with Solexa sequencing outcomes. Expression of miR-3099 was up-regulated following peripheral nerve injury. EdU and transwell chamber assays were used to observe the effect of miR-3099 on Schwann cell proliferation and migration. The results showed that increased miR-3099 expression promoted the proliferation and migration of Schwann cells. However, reduced miR-3099 expression suppressed the proliferation and migration of Schwann cells. The potential target genes of miR-3099 were also investigated by bioinformatic tools and high-throughput outcomes. miR-3099 targets genes Aqp4, St8 sia2, Tnfsf15, and Zbtb16 and affects the proliferation and migration of Schwann cells. This study examined the levels of miR-3099 at different time points following peripheral nerve injury. Our results confirmed that increased miR-3099 level induced by peripheral nerve injury can promote the proliferation and migration of Schwann cells.展开更多
High mobility group box 1(HMGB1) interacts with pattern-recognition receptors of immune cells to activate the inflammatory response. Astrocytes play a positive role in the inflammatory response of the central nervous ...High mobility group box 1(HMGB1) interacts with pattern-recognition receptors of immune cells to activate the inflammatory response. Astrocytes play a positive role in the inflammatory response of the central nervous system by expressing a broad range of patternrecognition receptors. However, the underlying relationship between HMGB1 and the inflammatory reaction of astrocytes remains unclear. In this study, we established rat models of spinal cord injury via laminectomy at the T8–10 level, and the injured spinal cord was subjected to transcriptome sequencing. Our results showed that the HMGB1/Toll-like receptor 4(TLR4) axis was involved in the activation of astrocyte inflammatory response through regulation of cyclooxygenase 2(COX2)/prostaglandin E2(PGE2) signaling. Both TLR4 and COX2 were distributed in astrocytes and showed elevated protein levels following spinal cord injury. Stimulation of primary astrocytes with recombinant HMGB1 showed that COX2 and microsomal PGE synthase(mPGES)-1, rather than COX1, mPGES-2, or cytosolic PGE synthase, were significantly upregulated. Accordingly, PGE2 production in astrocytes was remarkably increased in response to recombinant HMGB1 challenges. Pharmacologic blockade of TLR2/4 attenuated HMGB1-mediated activation of the COX2/PGE2 pathway. Interestingly, HMGB1 did not impact the production of tumor necrosis factor-α or interleukin-1β in astrocytes. Our results suggest that HMGB1 mediates the astrocyte inflammatory response through regulating the COX2/PGE2 signaling pathway. The study was approved by the Laboratory Animal Ethics Committee of Nantong University, China(approval No. 20181204-001) on December 4, 2018.展开更多
Schwann cell proliferation,migration and remyelination of regenerating axons contribute to regeneration after peripheral nervous system injury.Lithium promotes remyelination by Schwann cells and improves peripheral ne...Schwann cell proliferation,migration and remyelination of regenerating axons contribute to regeneration after peripheral nervous system injury.Lithium promotes remyelination by Schwann cells and improves peripheral nerve regeneration.However,whether lithium modulates other phenotypes of Schwann cells,especially their proliferation and migration remains elusive.In the current study,primary Schwann cells from rat sciatic nerve stumps were cultured and exposed to 0,5,10,15,or 30 mM lithium chloride(LiCl)for 24 hours.The effects of LiCl on Schwann cell proliferation and migration were examined using the Cell Counting Kit-8,5-ethynyl-2′-deoxyuridine,Transwell and wound healing assays.Cell Counting Kit-8 and 5-ethynyl-2′-deoxyuridine assays showed that 5,10,15,and 30 mM LiCl significantly increased the viability and proliferation rate of Schwann cells.Transwell-based migration assays and wound healing assays showed that 10,15,and 30 mM LiCl suppressed the migratory ability of Schwann cells.Furthermore,the effects of LiCl on the proliferation and migration phenotypes of Schwann cells were mostly dose-dependent.These data indicate that lithium treatment significantly promotes the proliferation and inhibits the migratory ability of Schwann cells.This conclusion will inform strategies to promote the repair and regeneration of peripheral nerves.All of the animal experiments in this study were ethically approved by the Administration Committee of Experimental Animal Center of Nantong University,China(approval No.20170320-017)on March 2,2017.展开更多
Glial cells play an important role in signal transduction,energy metabolism,extracellular ion homeostasis and neuroprotection of the central nervous system.However,few studies have explained the potential effects of e...Glial cells play an important role in signal transduction,energy metabolism,extracellular ion homeostasis and neuroprotection of the central nervous system.However,few studies have explained the potential effects of exosomes from glial cells on central nervous system health and disease.In this study,the genes expressed in exosomes from astrocytes and microglia were identified by deep RNA sequencing.Kyoto Encyclopedia of Genes and Genomes analysis indicated that several pathways in these exosomes are responsible for promoting neurodegenerative diseases,including Alzheimer's disease,Parkinson's disease and Huntington's disease.Gene ontology analysis showed that extracellular exosome,mitochondrion and growth factor activity were enriched in exosomes from the unique astrocyte group,while extracellular exosome and mitochondrion were enriched in exosomes from the unique microglia group.Next,combined with the screening of hub genes,the protein-protein interaction network analysis showed that exosomes from astrocytes influence neurodegenerative diseases through metabolic balance and ubiquitin-dependent protein balance,whereas exosomes from microglia influence neurodegenerative diseases through immune inflammation and oxidative stress.Although there were differences in RNA expression between exosomes from astrocytes and microglia,the groups were related by the hub genes,ubiquitin B and heat shock protein family A(Hsp70) member 8.Ubiquitin B appeared to be involved in pleiotropic regulatory functions,including immune regulation,inflammation inhibition,protein catabolism,intracellular protein transport,exosomes and oxidative stress.The results revealed the clinical significance of exosomes from glia in neurodegenerative diseases.This study was approved by the Animal Ethics Committee of Nantong University,China(approval No.S20180102-152) on January 2,2018.展开更多
Cellular senescence and proliferation are essential for wound healing and tissue remodeling.However,senescence-proliferation cell fate after peripheral nerve injury has not been clearly revealed.Here,post-injury gene ...Cellular senescence and proliferation are essential for wound healing and tissue remodeling.However,senescence-proliferation cell fate after peripheral nerve injury has not been clearly revealed.Here,post-injury gene expression patterns in rat sciatic nerve stumps(SRP113121)and L4–5 dorsal root ganglia(SRP200823)obtained from the National Center for Biotechnology Information were analyzed to decipher cellular senescence and proliferation-associated genetic changes.We first constructed a rat sciatic nerve crush model.Then,β-galactosidase activities were determined to indicate the existence of cellular senescence in the injured sciatic nerve.Ki67 and EdU immunostaining was performed to indicate cellular proliferation in the injured sciatic nerve.Both cellular senescence and proliferation were less vigorous in the dorsal root ganglia than in sciatic nerve stumps.These results reveal the dynamic changes of injury-induced cellular senescence and proliferation from both genetic and morphological aspects,and thus extend our understanding of the biological processes following peripheral nerve injury.The study was approved by the Animal Ethics Committee of Nantong University,China(approval No.20190226-001)on February 26,2019.展开更多
Long noncoding RNAs(lncRNAs)participate in a variety of biological processes and diseases.However,the expression and function of lncRNAs after spinal cord injury has not been extensively analyzed.In this study of righ...Long noncoding RNAs(lncRNAs)participate in a variety of biological processes and diseases.However,the expression and function of lncRNAs after spinal cord injury has not been extensively analyzed.In this study of right side hemisection of the spinal cord at T10,we detected the expression of lncRNAs in the proximal tissue of T10 lamina at different time points and found 445 lncRNAs and 6522 mRNA were differentially expressed.We divided the differentially expressed lncRNAs into 26 expression trends and analyzed Profile 25 and Profile 2,the two expression trends with the most significant difference.Our results showed that the expression of 68 lncRNAs in Profile 25 rose first and remained high 3 days post-injury.There were 387 mRNAs co-expressed with the 68 lncRNAs in Profile 25.The co-expression network showed that the co-expressed genes were mainly enriched in cell division,inflammatory response,FcγR-mediated cell phagocytosis signaling pathway,cell cycle and apoptosis.The expression of 56 lncRNAs in Profile2 first declined and remained low after 3 days post-injury.There were 387 mRNAs co-expressed with the 56 lncRNAs in Profile 2.The co-expression network showed that the co-expressed genes were mainly enriched in the chemical synaptic transmission process and in the signaling pathway of neuroactive ligand-receptor interaction.The results provided the expression and regulatory network of the main lncRNAs after spinal cord injury and clarified their co-expressed gene enriched biological processes and signaling pathways.These findings provide a new direction for the clinical treatment of spinal cord injury.展开更多
BACKGROUND Serum small extracellular vesicles(sEVs)and their small RNA(sRNA)cargoes could be promising biomarkers for the diagnosis of liver injury.However,the dynamic changes in serum sEVs and their sRNA components d...BACKGROUND Serum small extracellular vesicles(sEVs)and their small RNA(sRNA)cargoes could be promising biomarkers for the diagnosis of liver injury.However,the dynamic changes in serum sEVs and their sRNA components during liver injury have not been well characterized.Given that hepatic macrophages can quickly clear intravenously injected sEVs,the effect of liver injury-related serum sEVs on hepatic macrophages deserves to be explored.AIM To identify the characteristics of serum sEVs and the sRNAs during liver injury and explore their effects on hepatic macrophages.METHODS To identify serum sEV biomarkers for liver injury,we established a CCL4-induced mouse liver injury model in C57BL/6 mice to simulate acute liver injury(ALI),chronic liver injury(CLI)and recovery.Serum sEVs were obtained and characterized by transmission electron microscopy and nanoparticle tracking analysis.Serum sEV sRNAs were profiled by sRNA sequencing.Differentially expressed microRNAs(miRNAs)were compared to mouse liver-enriched miRNAs and previously reported circulating miRNAs related to human liver diseases.The biological significance was evaluated by Ingenuity Pathway Analysis of altered sEV miRNAs and conditioned cultures of ALI serum sEVs with primary hepatic macrophages.RESULTS We found that both ALI and CLI changed the concentration and morphology of serum sEVs.The proportion of serum sEV miRNAs increased upon liver injury,with the liver as the primary contributor.The altered serum sEV miRNAs based on mouse studies were consistent with human liver disease-related circulating miRNAs.We established serum sEV miRNA signatures for ALI and CLI and a panel of miRNAs(miR-122-5p,miR-192-5p,and miR-22-3p)as a common marker for liver injury.The differential serum sEV miRNAs in ALI contributed mainly to liver steatosis and inflammation,while those in CLI contributed primarily to hepatocellular carcinoma and hyperplasia.ALI serum sEVs decreased both CD86 and CD206 expression in monocyte-derived macrophages but increased CD206 expression in resident macrophages in vitro.CONCLUSION Serum sEVs acquired different concentrations,sizes,morphologies and sRNA contents upon liver injury and could change the phenotype of liver macrophages.Serum sEVs therefore have good diagnostic and therapeutic potential for liver injury.展开更多
The initial mechanical damage of a spinal cord injury(SCI)triggers a progressive secondary injury cascade,which is a complicated process integrating multiple systems and cells.It is crucial to explore the molecular an...The initial mechanical damage of a spinal cord injury(SCI)triggers a progressive secondary injury cascade,which is a complicated process integrating multiple systems and cells.It is crucial to explore the molecular and biological process alterations that occur after SCI for therapy development.The differences between the rostral and caudal regions around an SCI lesion have received little attention.Here,we analyzed the differentially expressed genes between rostral and caudal sites after injury to determine the biological processes in these two segments after SCI.We identified a set of differentially expressed genes,including Col3a1,Col1a1,Dcn,Fn1,Kcnk3,and Nrg1,between rostral and caudal regions at different time points following SCI.Functional enrichment analysis indicated that these genes were involved in response to mechanical stimulus,blood vessel development,and brain development.We then chose Col3a1,Col1a1,Dcn,Fn1,Kcnk3,and Nrg1 for quantitative real-time PCR and Fn1 for immunostaining validation.Our results indicate alterations in different biological events enriched in the rostral and caudal lesion areas,providing new insights into the pathology of SCI.展开更多
基金supported by the National Natural Science Foundation of China,No.82171380(to CD)Jiangsu Students’Platform for Innovation and Entrepreneurship Training Program,No.202110304098Y(to DJ)。
文摘Spinal cord injury is considered one of the most difficult injuries to repair and has one of the worst prognoses for injuries to the nervous system.Following surgery,the poor regenerative capacity of nerve cells and the generation of new scars can make it very difficult for the impaired nervous system to restore its neural functionality.Traditional treatments can only alleviate secondary injuries but cannot fundamentally repair the spinal cord.Consequently,there is a critical need to develop new treatments to promote functional repair after spinal cord injury.Over recent years,there have been seve ral developments in the use of stem cell therapy for the treatment of spinal cord injury.Alongside significant developments in the field of tissue engineering,three-dimensional bioprinting technology has become a hot research topic due to its ability to accurately print complex structures.This led to the loading of three-dimensional bioprinting scaffolds which provided precise cell localization.These three-dimensional bioprinting scaffolds co uld repair damaged neural circuits and had the potential to repair the damaged spinal cord.In this review,we discuss the mechanisms underlying simple stem cell therapy,the application of different types of stem cells for the treatment of spinal cord injury,and the different manufa cturing methods for three-dimensional bioprinting scaffolds.In particular,we focus on the development of three-dimensional bioprinting scaffolds for the treatment of spinal cord injury.
基金supported by the National Natural Science Foundation of China,No.81870975(to SZ)。
文摘Exosomes exhibit complex biological functions and mediate a variety of biological processes,such as promoting axonal regeneration and functional recove ry after injury.Long non-coding RNAs(IncRNAs)have been reported to play a crucial role in axonal regeneration.Howeve r,the role of the IncRNA-microRNAmessenger RNA(mRNA)-competitive endogenous RNA(ceRNA)network in exosome-mediated axonal regeneration remains unclear.In this study,we performed RNA transcriptome sequencing analysis to assess mRNA expression patterns in exosomes produced by cultured fibroblasts(FC-EXOs)and Schwann cells(SCEXOs).Diffe rential gene expression analysis,Gene Ontology analysis,Kyoto Encyclopedia of Genes and Genomes analysis,and protein-protein intera ction network analysis were used to explo re the functions and related pathways of RNAs isolated from FC-EXOs and SC-EXOs.We found that the ribosome-related central gene Rps5 was enriched in FC-EXOs and SC-EXOs,which suggests that it may promote axonal regeneration.In addition,using the miRWalk and Starbase prediction databases,we constructed a regulatory network of ceRNAs targeting Rps5,including 27 microRNAs and five IncRNAs.The ceRNA regulatory network,which included Ftx and Miat,revealed that exsosome-derived Rps5 inhibits scar formation and promotes axonal regeneration and functional recovery after nerve injury.Our findings suggest that exosomes derived from fibro blast and Schwann cells could be used to treat injuries of peripheral nervous system.
基金supported by the National Major Project of Research and Development,No.2022YFA1105500(to SZ)the National Natural Science Foundation of China,No.81870975(to SZ)Innovation Program for Graduate Students in Jiangsu Province of China,No.KYCX223335(to MZ)。
文摘CD36 is a highly glycosylated integral membrane protein that belongs to the scavenger receptor class B family and regulates the pathological progress of metabolic diseases.CD36 was recently found to be widely expressed in various cell types in the nervous system,including endothelial cells,pericytes,astrocytes,and microglia.CD36 mediates a number of regulatory processes,such as endothelial dysfunction,oxidative stress,mitochondrial dysfunction,and inflammatory responses,which are involved in many central nervous system diseases,such as stroke,Alzheimer’s disease,Parkinson’s disease,and spinal cord injury.CD36 antagonists can suppress CD36 expression or prevent CD36 binding to its ligand,thereby achieving inhibition of CD36-mediated pathways or functions.Here,we reviewed the mechanisms of action of CD36 antagonists,such as Salvianolic acid B,tanshinone IIA,curcumin,sulfosuccinimidyl oleate,antioxidants,and small-molecule compounds.Moreover,we predicted the structures of binding sites between CD36 and antagonists.These sites can provide targets for more efficient and safer CD36 antagonists for the treatment of central nervous system diseases.
基金supported by the National Natural Science Foundation of China,Nos.31971277 and 31950410551(both to DY)。
文摘Injuries caused by trauma and neurodegenerative diseases can damage the peripheral nervous system and cause functional deficits.Unlike in the central nervous system,damaged axons in peripheral nerves can be induced to regenerate in response to intrinsic cues after reprogramming or in a growth-promoting microenvironment created by Schwann cells.However,axon regeneration and repair do not automatically result in the restoration of function,which is the ultimate therapeutic goal but also a major clinical challenge.Transforming growth factor(TGF)is a multifunctional cytokine that regulates various biological processes including tissue repair,embryo development,and cell growth and differentiation.There is accumulating evidence that TGF-βfamily proteins participate in peripheral nerve repair through various factors and signaling pathways by regulating the growth and transformation of Schwann cells;recruiting specific immune cells;controlling the permeability of the blood-nerve barrier,thereby stimulating axon growth;and inhibiting remyelination of regenerated axons.TGF-βhas been applied to the treatment of peripheral nerve injury in animal models.In this context,we review the functions of TGF-βin peripheral nerve regeneration and potential clinical applications.
基金supported by the Natural Science Foundation of Jiangsu Province,No.BK20221377(to JG)the Natural Science Foundation of the Jiangsu Higher Education Institutions of China,No.22KJB180023(to JG)。
文摘Rho GTPases are essential regulators of the actin cytoskeleton.They are involved in various physiological and biochemical processes such as the regulation of cytoskeleton dynamics,development,proliferation,survival,and regeneration.During the development of cochlear hair cells,Rho GTPases are activated by various extracellular signals through membrane receptors to further stimulate multiple downstream effectors.Specifically,RhoA,Cdc42,and Rac1,members of the classical subfamily of the Rho GTPase family,regulate the development and maintenance of cilia by inducing the polymerization of actin monomers and stabilizing actin filaments.In addition,they also regulate the normal morphology orientation of ciliary bundles in auditory hair cells,which is an important element of cell polarity regulation.Moreover,the actin-related pathways mediated by RhoA,Cdc42,and Rac1 also play a role in the motility of outer hair cells,indicating that the function of Rho GTPases is crucial in the highly polar auditory sensory system.In this review,we focus on the expression of RhoA,Cdc42,and Rac1 in cochlear hair cells and how these small molecules participate in ciliary bundle morphogenesis and cochlear hair cell movement.We also discuss the progress of current research investigating the use of these small molecules as drug targets for deafness treatment.
基金supported by the National Natural Science Foundation of China,Nos.31971277(to DBY),31950410551(to DBY)Scientific Research Foundation for Returned Scholars,Ministry of Education of China(to DBY)+2 种基金a project funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)(to DBY)the Postgraduate Research&Practice Innovation Program of Jiangsu Province of China,No.KYCX 19-2050(to JS)Jiangsu College Students’Innovation and Entrepreneurship Training Program,No.202213993005Y(to YY)。
文摘Our previous studies have shown that long noncoding RNA(lncRNA)H19 is upregulated in injured rat sciatic nerve during the process of Wallerian degeneration,and that it promotes the migration of Schwann cells and slows down the growth of dorsal root ganglion axons.However,the mechanism by which lncRNA H19 regulates neural repair and regeneration after peripheral nerve injury remains unclear.In this study,we established a Sprague-Dawley rat model of sciatic nerve transection injury.We performed in situ hybridization and found that at 4–7 days after sciatic nerve injury,lncRNA H19 was highly expressed.At 14 days before injury,adeno-associated virus was intrathecally injected into the L4–L5 foramina to disrupt or overexpress lncRNA H19.After overexpression of lncRNA H19,the growth of newly formed axons from the sciatic nerve was inhibited,whereas myelination was enhanced.Then,we performed gait analysis and thermal pain analysis to evaluate rat behavior.We found that lncRNA H19 overexpression delayed the recovery of rat behavior function,whereas interfering with lncRNA H19 expression improved functional recovery.Finally,we examined the expression of lncRNA H19 downstream target SEMA6D,and found that after lncRNA H19 overexpression,the SEMA6D protein level was increased.These findings suggest that lncRNA H19 regulates peripheral nerve degeneration and regeneration through activating SEMA6D in injured nerves.This provides a new clue to understand the role of lncRNA H19 in peripheral nerve degeneration and regeneration.
基金supported by the National Natural Science Foundation of China,Nos. 31730031 and 32130060the National Major Project of Research and Development,No. 2017YFA0104700the Natural Science Foundation of Jiangsu Province,No. BK20202013 (all to XSG)。
文摘The key regulators and regeneration-associated genes involved in axonal regeneration of neurons after injury have not been clarified.In high-throughput sequencing,various factors influence the final sequencing results,including the number and size of cells,the depth of sequencing,and the method of cell separation.There is still a lack of research on the detailed molecular expression profile during the regeneration of dorsal root ganglion neuron axon.In this study,we performed lase r-capture microdissection coupled with RNA sequencing on dorsal root ganglion neurons at 0,3,6,and 12 hours and 1,3,and 7 days after sciatic nerve crush in rats.We identified three stages after dorsal root ganglion injury:early(3-12 hours),pre-regeneration(1 day),and regeneration(3-7 days).Gene expression patterns and related function enrichment res ults showed that one module of genes was highly related to axonal regeneration.We verified the up-regulation of activating transcription factor 3(Atf3),Kruppel like factor 6(Klf6),AT-rich inte raction domain 5A(Arid5α),CAMP responsive element modulator(Crem),and FOS like 1,AP-1 transcription factor Subunit(Fosl1) in dorsal root ganglion neurons after injury.Suppressing these transcription factors(Crem,Arid5o,Fosl1 and Klf6) reduced axonal regrowth in vitro.As the hub transcription factor,Atf3 showed higher expression and activity at the preregeneration and regeneration stages.G protein-coupled estrogen receptor 1(Gper1),inte rleukin 12a(Il12α),estrogen receptor 1(ESR1),and interleukin 6(IL6) may be upstream factors that trigger the activation of Atf3 during the repair of axon injury in the early stage.Our study presents the detailed molecular expression profile during axonal regeneration of dorsal root ganglion neurons after peripheral nerve injury.These findings may provide reference for the clinical screening of molecular targets for the treatment of peripheral nerve injury.
基金supported by the National Natural Science Foundation of China,No.31871211 (to YJunW)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)。
文摘The low intrinsic growth capacity of neurons and an injury-induced inhibitory milieu are major contributo rs to the failure of sensory and motor functional recovery following spinal cord injury.Heat shock transcription factor 1(HSF1),a master regulator of the heat shock response,plays neurogenetic and neuroprotective roles in the damaged or diseased central nervous system.However,the underlying mechanism has not been fully elucidated.In the present study,we used a gecko model of spontaneous nerve regeneration to investigate the potential roles of gecko HSF1(gHSF1) in the regulation of neurite outgrowth and inflammatory inhibition of macrophages following spinal cord injury.gHSF1 expression in neurons and microglia at the lesion site increased dramatically immediately after tail amputation.gHSF1 ove rexpression in gecko primary neuro ns significantly promoted axonal growth by suppressing the expression of suppressor of cytokine signaling-3,and fa cilitated neuro nal survival via activation of the mitogen-activated extracellular signal-regulated kinase/extracellular regulated protein kinases and phosphatidylinositol 3-kinase/protein kinase B pathways.Furthermore,gHSF1 efficiently inhibited the macrophagemediated inflammatory response by inactivating 1kappa B-alpha/NF-kappaB signaling.Our findings show that HSF1 plays dual roles in promoting axonal regrowth and inhibiting leukocyte inflammation,and provide new avenues of investigation for promoting spinal co rd injury repair in mammals.
基金supported by the National Major Project of Research and Development of China,No.2017YFA0104701(to BY)the National Natural Science Foundation of China,No.32000725(to QQC)+1 种基金the Natural Science Foundation of Jiangsu Province of China,No.BK20200973(to QQC)the Jiangsu Provincial University Innovation Training Key Project of China,No.202010304021Z(to ML)。
文摘Peripheral nerve injury repair requires a certain degree of cooperation between axon regeneration and Wallerian degeneration.Therefore,investigating how axon regeneration and degeneration work together to repair peripheral nerve injury may uncover the molecular mechanisms and signal cascades underlying peripheral nerve repair and provide potential strategies for improving the low axon regeneration capacity of the central nervous system.In this study,we applied weighted gene co-expression network analysis to identify differentially expressed genes in proximal and distal sciatic nerve segments from rats with sciatic nerve injury.We identified 31 and 15 co-expression modules from the proximal and distal sciatic nerve segments,respectively.Functional enrichment analysis revealed that the differentially expressed genes in proximal modules promoted regeneration,while the differentially expressed genes in distal modules promoted neurodegeneration.Next,we constructed hub gene networks for selected modules and identified a key hub gene,Kif22,which was up-regulated in both nerve segments.In vitro experiments confirmed that Kif22 knockdown inhibited proliferation and migration of Schwann cells by modulating the activity of the extracellular signal-regulated kinase signaling pathway.Collectively,our findings provide a comparative framework of gene modules that are co-expressed in injured proximal and distal sciatic nerve segments,and identify Kif22 as a potential therapeutic target for promoting peripheral nerve injury repair via Schwann cell proliferation and migration.All animal experiments were approved by the Institutional Animal Ethics Committee of Nantong University,China(approval No.S20210322-008)on March 22,2021.
基金supported by the National Natural Science Foundation of ChinaNo.81971826 (to AG)+5 种基金the China Postdoctoral Science FoundationNo.2020M681 689 (to YH)the Scientific Research Project of The Health Commission of Jiangsu ProvinceNo.ZDB2020003 (to AG)the Basic Scientific Research Projects of NantongNo.JC2020041 (to YH)
文摘Astrocytes are important cellular centers of cholesterol synthesis and metabolism that help maintain normal physiological function at the organism level.Spinal cord injury results in aberrant cholesterol metabolism by astrocytes and excessive production of oxysterols,which have profound effects on neuropathology.25-Hydroxycholesterol(25-HC),the main product of the membrane-associated enzyme cholesterol-25-hydroxylase(CH25H),plays important roles in mediating neuroinflammation.However,whether the abnormal astrocyte cholesterol metabolism induced by spinal cord injury contributes to the production of 25-HC,as well as the resulting pathological effects,remain unclear.In the present study,spinal cord injury-induced activation of thrombin was found to increase astrocyte CH25H expression.A protease-activated receptor 1 inhibitor was able to attenuate this effect in vitro and in vivo.In cultured primary astrocytes,thrombin interacted with protease-activated receptor 1,mainly through activation of the mitogen-activated protein kinase/nuclear factor-kappa B signaling pathway.Conditioned culture medium from astrocytes in which ch25h expression had been knocked down by siRNA reduced macrophage migration.Finally,injection of the protease activated receptor 1 inhibitor SCH79797 into rat neural sheaths following spinal cord injury reduced migration of microglia/macrophages to the injured site and largely restored motor function.Our results demonstrate a novel regulatory mechanism for thrombin-regulated cholesterol metabolism in astrocytes that could be used to develop anti-inflammatory drugs to treat patients with spinal cord injury.
基金supported by the China Postdoctoral Science Foundation,No.2020M681689(to YMH)the Basic Scientific Research Projects of Nantong,Nos.JC2020015(to HX)and JC2020041(to YMH)。
文摘Spinal cord injury causes accumulation of a large number of leukocytes at the lesion site where they contribute to excessive inflammation.Overproduced chemokines are responsible for the migratory process of the leukocytes,but the regulatory mechanism underlying the production of chemokines from resident cells of the spinal cord has not been fully elucidated.We examined the protein levels of macrophage migration inhibitory factor and chemokine C-C motif chemokine ligand 2 in a spinal cord contusion model at different time points following spinal cord injury.The elevation of macrophage migration inhibitory factor at the lesion site coincided with the increase of chemokine C-C motif chemokine ligand 2 abundance in astrocytes.Stimulation of primary cultured astrocytes with different concentrations of macrophage migration inhibitory factor recombinant protein induced chemokine C-C motif chemokine ligand 2 production from the cells,and the macrophage migration inhibitory factor inhibitor 4-iodo-6-phenylpyrimidine attenuated the stimulatory effect.Further investigation into the underlying mechanism on macrophage migration inhibitory factor-mediated astrocytic production of chemokine C-C motif chemokine ligand 2 revealed that macrophage migration inhibitory factor activated intracellular JNK signaling through binding with CD74 receptor.Administration of the macrophage migration inhibitory factor inhibitor 4-iodo-6-phenylpyrimidine following spinal cord injury resulted in the reduction of chemokine C-C motif chemokine ligand 2-recruited microglia/macrophages at the lesion site and remarkably improved the hindlimb locomotor function of rats.Our results have provided insights into the functions of astrocyte-activated chemokines in the recruitment of leukocytes and may be beneficial to develop interventions targeting chemokine C-C motif chemokine ligand 2 for neuroinflammation after spinal cord injury.
基金supported by the National Natural Science Foundation of China,No.31970968(to SYL)the Collegiate Natural Science Foundation of Jiangsu Province,No.16KJA310005(to SYL)+1 种基金Priority Academic Program Development of Jiangsu Higher Education Institutions[PAPD]the Natural Science Foundation of Jiangsu Province,No.BK20200976(to XHW).
文摘Neurotrophic factors,particularly nerve growth factor,enhance neuronal regeneration.However,the in vivo applications of nerve growth factor are largely limited by its intrinsic disadvantages,such as its short biological half-life,its contribution to pain response,and its inability to cross the blood-brain barrier.Considering that let-7(human miRNA)targets and regulates nerve growth factor,and that let-7 is a core regulator in peripheral nerve regeneration,we evaluated the possibilities of let-7 application in nerve repair.In this study,anti-let-7a was identified as the most suitable let-7 family molecule by analyses of endogenous expression and regulatory relationship,and functional screening.Let-7a antagomir demonstrated biosafety based on the results of in vivo safety assessments and it entered into the main cell types of the sciatic nerve,including Schwann cells,fibroblasts and macrophages.Use of hydrogel effectively achieved controlled,localized,and sustained delivery of let-7a antagomir.Finally,let-7a antagomir was integrated into chitosan conduit to construct a chitosan-hydrogel scaffold tissue-engineered nerve graft,which promoted nerve regeneration and functional recovery in a rat model of sciatic nerve transection.Our study provides an experimental basis for potential in vivo application of let-7a.
基金supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province of China,No.KYCX17-1910(to QYL)a Project Funded by the Priority Academic Program Development of Jiangsu Higher Education Institutions of China(PAPD)
文摘MicroRNAs(miRNAs) can regulate the modulation of the phenotype of Schwann cells. Numerous novel miRNAs have been discovered and identified in rat sciatic nerve segments, including miR-3099. In the current study, miR-3099 expression levels following peripheral nerve injury were measured in the proximal stumps of rat sciatic nerves after surgical crush. Real-time reverse transcription-polymerase chain reaction was used to determine miR-3099 expression in the crushed nerve segment at 0, 1, 4, 7, and 14 days post sciatic nerve injury, which was consistent with Solexa sequencing outcomes. Expression of miR-3099 was up-regulated following peripheral nerve injury. EdU and transwell chamber assays were used to observe the effect of miR-3099 on Schwann cell proliferation and migration. The results showed that increased miR-3099 expression promoted the proliferation and migration of Schwann cells. However, reduced miR-3099 expression suppressed the proliferation and migration of Schwann cells. The potential target genes of miR-3099 were also investigated by bioinformatic tools and high-throughput outcomes. miR-3099 targets genes Aqp4, St8 sia2, Tnfsf15, and Zbtb16 and affects the proliferation and migration of Schwann cells. This study examined the levels of miR-3099 at different time points following peripheral nerve injury. Our results confirmed that increased miR-3099 level induced by peripheral nerve injury can promote the proliferation and migration of Schwann cells.
基金supported by the National Key Research and Development Program of China,No.2018YFC1105603(to YJunW)the National Natural Science Foundation of China,No.31871211(to YJunW)+2 种基金the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)(to YJunW)the China Postdoctoral Science Foundation,No.2020M681689(to YMH)the Basic Scientific Research Projects of Nantong of China,No.JC2018065(to HHS)。
文摘High mobility group box 1(HMGB1) interacts with pattern-recognition receptors of immune cells to activate the inflammatory response. Astrocytes play a positive role in the inflammatory response of the central nervous system by expressing a broad range of patternrecognition receptors. However, the underlying relationship between HMGB1 and the inflammatory reaction of astrocytes remains unclear. In this study, we established rat models of spinal cord injury via laminectomy at the T8–10 level, and the injured spinal cord was subjected to transcriptome sequencing. Our results showed that the HMGB1/Toll-like receptor 4(TLR4) axis was involved in the activation of astrocyte inflammatory response through regulation of cyclooxygenase 2(COX2)/prostaglandin E2(PGE2) signaling. Both TLR4 and COX2 were distributed in astrocytes and showed elevated protein levels following spinal cord injury. Stimulation of primary astrocytes with recombinant HMGB1 showed that COX2 and microsomal PGE synthase(mPGES)-1, rather than COX1, mPGES-2, or cytosolic PGE synthase, were significantly upregulated. Accordingly, PGE2 production in astrocytes was remarkably increased in response to recombinant HMGB1 challenges. Pharmacologic blockade of TLR2/4 attenuated HMGB1-mediated activation of the COX2/PGE2 pathway. Interestingly, HMGB1 did not impact the production of tumor necrosis factor-α or interleukin-1β in astrocytes. Our results suggest that HMGB1 mediates the astrocyte inflammatory response through regulating the COX2/PGE2 signaling pathway. The study was approved by the Laboratory Animal Ethics Committee of Nantong University, China(approval No. 20181204-001) on December 4, 2018.
基金supported by the National Natural Science Foundation of China,No.81970820(to HX)
文摘Schwann cell proliferation,migration and remyelination of regenerating axons contribute to regeneration after peripheral nervous system injury.Lithium promotes remyelination by Schwann cells and improves peripheral nerve regeneration.However,whether lithium modulates other phenotypes of Schwann cells,especially their proliferation and migration remains elusive.In the current study,primary Schwann cells from rat sciatic nerve stumps were cultured and exposed to 0,5,10,15,or 30 mM lithium chloride(LiCl)for 24 hours.The effects of LiCl on Schwann cell proliferation and migration were examined using the Cell Counting Kit-8,5-ethynyl-2′-deoxyuridine,Transwell and wound healing assays.Cell Counting Kit-8 and 5-ethynyl-2′-deoxyuridine assays showed that 5,10,15,and 30 mM LiCl significantly increased the viability and proliferation rate of Schwann cells.Transwell-based migration assays and wound healing assays showed that 10,15,and 30 mM LiCl suppressed the migratory ability of Schwann cells.Furthermore,the effects of LiCl on the proliferation and migration phenotypes of Schwann cells were mostly dose-dependent.These data indicate that lithium treatment significantly promotes the proliferation and inhibits the migratory ability of Schwann cells.This conclusion will inform strategies to promote the repair and regeneration of peripheral nerves.All of the animal experiments in this study were ethically approved by the Administration Committee of Experimental Animal Center of Nantong University,China(approval No.20170320-017)on March 2,2017.
基金supported by the National Natural Science Foundation of China,No.81870975 (to SLZ)Innovation and Entrepreneurship Training Program for College Students in Jiangsu Province of China,No.202010304034Z (to FYZ)。
文摘Glial cells play an important role in signal transduction,energy metabolism,extracellular ion homeostasis and neuroprotection of the central nervous system.However,few studies have explained the potential effects of exosomes from glial cells on central nervous system health and disease.In this study,the genes expressed in exosomes from astrocytes and microglia were identified by deep RNA sequencing.Kyoto Encyclopedia of Genes and Genomes analysis indicated that several pathways in these exosomes are responsible for promoting neurodegenerative diseases,including Alzheimer's disease,Parkinson's disease and Huntington's disease.Gene ontology analysis showed that extracellular exosome,mitochondrion and growth factor activity were enriched in exosomes from the unique astrocyte group,while extracellular exosome and mitochondrion were enriched in exosomes from the unique microglia group.Next,combined with the screening of hub genes,the protein-protein interaction network analysis showed that exosomes from astrocytes influence neurodegenerative diseases through metabolic balance and ubiquitin-dependent protein balance,whereas exosomes from microglia influence neurodegenerative diseases through immune inflammation and oxidative stress.Although there were differences in RNA expression between exosomes from astrocytes and microglia,the groups were related by the hub genes,ubiquitin B and heat shock protein family A(Hsp70) member 8.Ubiquitin B appeared to be involved in pleiotropic regulatory functions,including immune regulation,inflammation inhibition,protein catabolism,intracellular protein transport,exosomes and oxidative stress.The results revealed the clinical significance of exosomes from glia in neurodegenerative diseases.This study was approved by the Animal Ethics Committee of Nantong University,China(approval No.S20180102-152) on January 2,2018.
基金supported by the National Natural Science Foundation of China,No.31970968(to SYL)Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)。
文摘Cellular senescence and proliferation are essential for wound healing and tissue remodeling.However,senescence-proliferation cell fate after peripheral nerve injury has not been clearly revealed.Here,post-injury gene expression patterns in rat sciatic nerve stumps(SRP113121)and L4–5 dorsal root ganglia(SRP200823)obtained from the National Center for Biotechnology Information were analyzed to decipher cellular senescence and proliferation-associated genetic changes.We first constructed a rat sciatic nerve crush model.Then,β-galactosidase activities were determined to indicate the existence of cellular senescence in the injured sciatic nerve.Ki67 and EdU immunostaining was performed to indicate cellular proliferation in the injured sciatic nerve.Both cellular senescence and proliferation were less vigorous in the dorsal root ganglia than in sciatic nerve stumps.These results reveal the dynamic changes of injury-induced cellular senescence and proliferation from both genetic and morphological aspects,and thus extend our understanding of the biological processes following peripheral nerve injury.The study was approved by the Animal Ethics Committee of Nantong University,China(approval No.20190226-001)on February 26,2019.
文摘Long noncoding RNAs(lncRNAs)participate in a variety of biological processes and diseases.However,the expression and function of lncRNAs after spinal cord injury has not been extensively analyzed.In this study of right side hemisection of the spinal cord at T10,we detected the expression of lncRNAs in the proximal tissue of T10 lamina at different time points and found 445 lncRNAs and 6522 mRNA were differentially expressed.We divided the differentially expressed lncRNAs into 26 expression trends and analyzed Profile 25 and Profile 2,the two expression trends with the most significant difference.Our results showed that the expression of 68 lncRNAs in Profile 25 rose first and remained high 3 days post-injury.There were 387 mRNAs co-expressed with the 68 lncRNAs in Profile 25.The co-expression network showed that the co-expressed genes were mainly enriched in cell division,inflammatory response,FcγR-mediated cell phagocytosis signaling pathway,cell cycle and apoptosis.The expression of 56 lncRNAs in Profile2 first declined and remained low after 3 days post-injury.There were 387 mRNAs co-expressed with the 56 lncRNAs in Profile 2.The co-expression network showed that the co-expressed genes were mainly enriched in the chemical synaptic transmission process and in the signaling pathway of neuroactive ligand-receptor interaction.The results provided the expression and regulatory network of the main lncRNAs after spinal cord injury and clarified their co-expressed gene enriched biological processes and signaling pathways.These findings provide a new direction for the clinical treatment of spinal cord injury.
文摘BACKGROUND Serum small extracellular vesicles(sEVs)and their small RNA(sRNA)cargoes could be promising biomarkers for the diagnosis of liver injury.However,the dynamic changes in serum sEVs and their sRNA components during liver injury have not been well characterized.Given that hepatic macrophages can quickly clear intravenously injected sEVs,the effect of liver injury-related serum sEVs on hepatic macrophages deserves to be explored.AIM To identify the characteristics of serum sEVs and the sRNAs during liver injury and explore their effects on hepatic macrophages.METHODS To identify serum sEV biomarkers for liver injury,we established a CCL4-induced mouse liver injury model in C57BL/6 mice to simulate acute liver injury(ALI),chronic liver injury(CLI)and recovery.Serum sEVs were obtained and characterized by transmission electron microscopy and nanoparticle tracking analysis.Serum sEV sRNAs were profiled by sRNA sequencing.Differentially expressed microRNAs(miRNAs)were compared to mouse liver-enriched miRNAs and previously reported circulating miRNAs related to human liver diseases.The biological significance was evaluated by Ingenuity Pathway Analysis of altered sEV miRNAs and conditioned cultures of ALI serum sEVs with primary hepatic macrophages.RESULTS We found that both ALI and CLI changed the concentration and morphology of serum sEVs.The proportion of serum sEV miRNAs increased upon liver injury,with the liver as the primary contributor.The altered serum sEV miRNAs based on mouse studies were consistent with human liver disease-related circulating miRNAs.We established serum sEV miRNA signatures for ALI and CLI and a panel of miRNAs(miR-122-5p,miR-192-5p,and miR-22-3p)as a common marker for liver injury.The differential serum sEV miRNAs in ALI contributed mainly to liver steatosis and inflammation,while those in CLI contributed primarily to hepatocellular carcinoma and hyperplasia.ALI serum sEVs decreased both CD86 and CD206 expression in monocyte-derived macrophages but increased CD206 expression in resident macrophages in vitro.CONCLUSION Serum sEVs acquired different concentrations,sizes,morphologies and sRNA contents upon liver injury and could change the phenotype of liver macrophages.Serum sEVs therefore have good diagnostic and therapeutic potential for liver injury.
基金supported by Postgraduate Research&Practice Innovation Program of Jiangsu Province,No.KYCX-2065(to XMC).
文摘The initial mechanical damage of a spinal cord injury(SCI)triggers a progressive secondary injury cascade,which is a complicated process integrating multiple systems and cells.It is crucial to explore the molecular and biological process alterations that occur after SCI for therapy development.The differences between the rostral and caudal regions around an SCI lesion have received little attention.Here,we analyzed the differentially expressed genes between rostral and caudal sites after injury to determine the biological processes in these two segments after SCI.We identified a set of differentially expressed genes,including Col3a1,Col1a1,Dcn,Fn1,Kcnk3,and Nrg1,between rostral and caudal regions at different time points following SCI.Functional enrichment analysis indicated that these genes were involved in response to mechanical stimulus,blood vessel development,and brain development.We then chose Col3a1,Col1a1,Dcn,Fn1,Kcnk3,and Nrg1 for quantitative real-time PCR and Fn1 for immunostaining validation.Our results indicate alterations in different biological events enriched in the rostral and caudal lesion areas,providing new insights into the pathology of SCI.
