Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and foun...Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and found that expression of platelet factor 4 was markedly up-regulated after sciatic nerve injury.Platelet factor is an important molecule in cell apoptosis,diffe rentiation,survival,and proliferation.Further,polymerase chain reaction and immunohistochemical staining confirmed the change in platelet factor 4 in the sciatic nerve at different time points after injury.Enzyme-linked immunosorbent assay confirmed that platelet factor 4 was secreted by Schwann cells.We also found that silencing platelet factor 4 decreased the proliferation and migration of primary cultured Schwann cells,while exogenously applied platelet factor 4 stimulated Schwann cell prolife ration and migration and neuronal axon growth.Furthermore,knocking out platelet factor 4 inhibited the prolife ration of Schwann cells in injured rat sciatic nerve.These findings suggest that Schwann cell-secreted platelet factor 4 may facilitate peripheral nerve repair and regeneration by regulating Schwann cell activation and axon growth.Thus,platelet factor 4 may be a potential therapeutic target for traumatic peripheral nerve injury.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
Runx2 is a major regulator of osteoblast differentiation and function;however,the role of Runx2 in peripheral nerve repair is unclea r.Here,we analyzed Runx2expression following injury and found that it was specifical...Runx2 is a major regulator of osteoblast differentiation and function;however,the role of Runx2 in peripheral nerve repair is unclea r.Here,we analyzed Runx2expression following injury and found that it was specifically up-regulated in Schwann cells.Furthermore,using Schwann cell-specific Runx2 knocko ut mice,we studied peripheral nerve development and regeneration and found that multiple steps in the regeneration process following sciatic nerve injury were Runx2-dependent.Changes observed in Runx2 knoc kout mice include increased prolife ration of Schwann cells,impaired Schwann cell migration and axonal regrowth,reduced re-myelination of axo ns,and a block in macrophage clearance in the late stage of regeneration.Taken together,our findings indicate that Runx2 is a key regulator of Schwann cell plasticity,and therefore peripheral nerve repair.Thus,our study shows that Runx2 plays a major role in Schwann cell migration,re-myelination,and peripheral nerve functional recovery following injury.展开更多
Peripheral nerves are essential components of the human body’s communication system,transmitting signals between the central nervous system and various body parts.Damage resulting from trauma or disease can result in...Peripheral nerves are essential components of the human body’s communication system,transmitting signals between the central nervous system and various body parts.Damage resulting from trauma or disease can result in debilitating sensory and motor deficits.Nerve injuries,particularly those resulting in significant gaps in the nerve tissue,pose a formidable challenge for clinicians and researchers.Despite their limitations,including limited availability and donor site morbidity,nerve autografts remain the clinical gold standard for treating nerve injuries.展开更多
Neuro regeneration is a very complex phenomenon characterized by the generation of new neurons and synapses,involving connections between adjacent cells and axonal projections.Neuroregeneration supplies additional lon...Neuro regeneration is a very complex phenomenon characterized by the generation of new neurons and synapses,involving connections between adjacent cells and axonal projections.Neuroregeneration supplies additional longterm resources to replace those altered by the injury and ensure lasting functional recovery.展开更多
Peripheral nerve injuries remain a challenging problem in need of better treatment strategies.Despite best efforts at surgical reconstruction and postoperative rehabilitation,patients are often left with persistent,de...Peripheral nerve injuries remain a challenging problem in need of better treatment strategies.Despite best efforts at surgical reconstruction and postoperative rehabilitation,patients are often left with persistent,debilitating motor and sensory deficits.There are currently no therapeutic strategies proven to enhance the regenerative process in humans.A clinical need exists for the development of technologies to promote nerve regeneration and improve functional outcomes.Recent advances in the fields of tissue engineering and nanotechnology have enabled biomaterial scaffolds to modulate the host response to tissue repair through tailored mechanical,chemical,and conductive cues.New bioengineered approaches have enabled targeted,sustained delivery of protein therapeutics with the capacity to unlock the clinical potential of a myriad of neurotrophic growth factors that have demonstrated promise in enhancing regenerative outcomes.As such,further exploration of combinatory strategies leveraging these technological advances may offer a pathway towards clinically translatable solutions to advance the care of patients with peripheral nerve injuries.This review first presents the various emerging bioengineering strategies that can be applied for the management of nerve gap injuries.We cover the rationale and limitations for their use as an alternative to autografts,focusing on the approaches to increase the number of regenerating axons crossing the repair site,and facilitating their growth towards the distal stump.We also discuss the emerging growth factor-based therapeutic strategies designed to improve functional outcomes in a multimodal fashion,by accelerating axonal growth,improving the distal regenerative environment,and preventing end-organs atrophy.展开更多
The functional properties of endogenous Schwann cells(SCs)during nerve repair are dynamic.Optimizing the functional properties of SCs at different stages of nerve repair may have therapeutic benefit in improving the r...The functional properties of endogenous Schwann cells(SCs)during nerve repair are dynamic.Optimizing the functional properties of SCs at different stages of nerve repair may have therapeutic benefit in improving the repair of damaged nerves.Previous studies showed that miR-221-3p promotes the proliferation and migration of SCs,and miR-338-3p promotes the myelination of SCs.In this study,we established rat models of sciatic nerve injury by bridging the transected sciatic nerve with a silicone tube.We injected a miR-221 lentiviral vector system together with a doxycycline-inducible Tet-On miR-338 lentiviral vector system into the cavity of nerve conduits of nerve stumps to sequentially regulate the biological function of endogenous SCs at different stages of nerve regeneration.We found that the biological function of SCs was sequentially regulated,the diameter and density of myelinated axons were increased,the expression levels of NF200 and myelin basic protein were increased,and the function of injured peripheral nerve was improved using this system.miRNA Target Prediction Database prediction,Nanopore whole transcriptome sequencing,quantitative PCR,and dual luciferase reporter gene assay results predicted and verified Cdkn1b and Nrp1 as target genes of miR-221-3p and miR-338-3p,respectively,and their regulatory effects on SCs were confirmed in vitro.In conclusion,here we established a new method to enhance nerve regeneration through sequential regulation of biological functions of endogenous SCs,which establishes a new concept and model for the treatment of peripheral nerve injury.The findings from this study will provide direct guiding significance for clinical treatment of sciatic nerve 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
The effect of platelet-rich plasma on nerve regeneration remains controversial.In this study,we established a rabbit model of sciatic nerve small-gap defects with preserved epineurium and then filled the gaps with pla...The effect of platelet-rich plasma on nerve regeneration remains controversial.In this study,we established a rabbit model of sciatic nerve small-gap defects with preserved epineurium and then filled the gaps with platelet-rich plasma.Twenty-eight rabbits were divided into the following groups(7 rabbits/group):model,low-concentrati on PRP(2.5-3.5-fold concentration of whole blood platelets),medium-concentration PRP(4.5-6.5-fold concentration of whole blood platelets),and high-concentration PRP(7.5-8.5-fold concentration of whole blood platelets).Electrophysiological and histomorphometrical assessments and proteomics analysis we re used to evaluate regeneration of the sciatic nerve.Our results showed that platelet-rich plasma containing 4.5-6.5-and 7.5-8.5-fold concentrations of whole blood platelets promoted repair of sciatic nerve injury.Proteomics analysis was performed to investigate the possible mechanism by which platelet-rich plasma promoted nerve regeneration.Proteomics analysis showed that after sciatic nerve injury,platelet-rich plasma increased the expression of integrin subunitβ-8(ITGB8),which participates in angiogenesis,and differentially expressed proteins were mainly enriched in focal adhesion pathways.Additionally,two key proteins,ribosomal protein S27 a(RSP27 a)and ubiquilin 1(UBQLN1),which were selected after protein-protein interaction analysis,are involved in the regulation of ubiquitin levels in vivo.These data suggest that platelet-rich plasma promotes peripheral nerve regeneration after sciatic nerve injury by affecting angiogenesis and intracellular ubiquitin levels.展开更多
Recent results emphasize the supportive effects of adipose-derived multipotent stem/progenitor cells(ADSPCs)in peripheral nerve recovery.Cultivation under hypoxia is considered to enhance the release of the regenerati...Recent results emphasize the supportive effects of adipose-derived multipotent stem/progenitor cells(ADSPCs)in peripheral nerve recovery.Cultivation under hypoxia is considered to enhance the release of the regenerative potential of ADSPCs.This study aimed to examine whether peripheral nerve regeneration in a rat model of autologous sciatic nerve graft benefits from an additional custom-made fibrin conduit seeded with hypoxic pre-conditioned(2%oxygen for 72 hours)autologous ADSPCs(n=9).This treatment mode was compared with three others:fibrin conduit seeded with ADSPCs cultivated under normoxic conditions(n=9);non-cell-carrying conduit(n=9);and nerve autograft only(n=9).A 16-week follow-up included functional testing(sciatic functional index and static sciatic index)as well as postmortem muscle mass analyses and morphometric nerve evaluations(histology,g-ratio,axon density,and diameter).At 8 weeks,the hypoxic pre-conditioned group achieved significantly higher sciatic functional index/static sciatic index scores than the other three groups,indicating faster functional regeneration.Furthermore,histologic evaluation showed significantly increased axon outgrowth/branching,axon density,remyelination,and a reduced relative connective tissue area.Hypoxic pre-conditioned ADSPCs seeded in fibrin conduits are a promising adjunct to current nerve autografts.Further studies are needed to understand the underlying cellular mechanism and to investigate a potential application in clinical practice.展开更多
Currently available commercial nerve guidance conduits have been applied in the repair of peripheral nerve defects.However,a conduit exhibiting good biocompatibility remains to be developed.In this work,a series of ch...Currently available commercial nerve guidance conduits have been applied in the repair of peripheral nerve defects.However,a conduit exhibiting good biocompatibility remains to be developed.In this work,a series of chitosan/graphene oxide(GO)films with concentrations of GO varying from 0-1 wt%(collectively referred to as CHGF-n)were prepared by an electrodeposition technique.The effects of CHGF-n on proliferation and adhesion abilities of Schwann cells were evaluated.The results showed that Schwann cells exhibited elongated spindle shapes and upregulated expression of nerve regeneration-related factors such as Krox20(a key myelination factor),Zeb2(essential for Schwann cell differentiation,myelination,and nerve repair),and transforming growth factorβ(a cytokine with regenerative functions).In addition,a nerve guidance conduit with a GO content of 0.25%(CHGFC-0.25)was implanted to repair a 10-mm sciatic nerve defect in rats.The results indicated improvements in sciatic functional index,electrophysiology,and sciatic nerve and gastrocnemius muscle histology compared with the CHGFC-0 group,and similar outcomes to the autograft group.In conclusion,we provide a candidate method for the repair of peripheral nerve defects using free-standing chitosan/GO nerve conduits produced by electrodeposition.展开更多
Growth-associated protein 43 plays a key role in neurite outgrowth through cytoskeleton remodeling.We have previously demonstrated that structural damage of peripheral nerves induces growth-associated protein 43 upreg...Growth-associated protein 43 plays a key role in neurite outgrowth through cytoskeleton remodeling.We have previously demonstrated that structural damage of peripheral nerves induces growth-associated protein 43 upregulation to promote growth cone formation.Conversely,the limited regenerative capacity of the central nervous system due to an inhibitory environment prevents major changes in neurite outgrowth and should be presumably associated with low levels of growth-associated protein 43 expression.However,central alterations due to peripheral nerve damage have never been assessed using the growthassociated protein 43 marker.In this study,we used the tubulization technique to repair 1 cm-long nerve gaps in the rat nerve injury/repair model and detected growth-associated protein 43 expression in the peripheral and central nervous systems.First,histological analysis of the regeneration process confirmed an active regeneration process of the nerve gaps through the conduit from 10 days onwards.The growth-associated protein 43 expression profile varied across regions and follow-up times,from a localized expression to an abundant and consistent expression throughout the regeneration tissue,confirming the presence of an active nerve regeneration process.Second,spinal cord changes were also histologically assessed,and no apparent changes in the structural and cellular organization were observed using routine staining methods.Surprisingly,remarkable differences and local changes appeared in growth-associated protein 43 expression at the spinal cord level,in particular at 20 days post-repair and beyond.Growth-associated protein 43 protein was first localized in the gracile fasciculus and was homogeneously distributed in the left posterior cord.These findings differed from the growth-associated protein 43 pattern observed in the healthy control,which did not express growth-associated protein 43 at these levels.Our results revealed a differential expression in growth-associated protein 43 protein not only in the regenerating nerve tissue but also in the spinal cord after peripheral nerve transection.These findings open the possibility of using this marker to monitor changes in the central nervous system after peripheral nerve injury.展开更多
Objective To provide useful information for selecting the most appropriate peripheral nerve injury model for different research purposes in nerve injury and repair studies,and to compare nerve regeneration capacity an...Objective To provide useful information for selecting the most appropriate peripheral nerve injury model for different research purposes in nerve injury and repair studies,and to compare nerve regeneration capacity and characteristics between them.Methods Sixty adult SD rats were randomly divided into two groups and underwent crush injury alone(group A,n=30)or transection injury followed by surgical repair(group B,n=30)of the right hind paw.Each group was subjected to the CatWalk test,gastrocnemius muscle evaluation,pain threshold measurement,electrophysiological examination,retrograde neuronal labeling,and quantification of nerve regeneration before and 7,14,21,and 28 days after injury.Results Gait analysis showed that the recovery speed in group A was significantly faster than that in group B at 14 days.At 21 days,the compound muscle action potential of the gastrocnemius muscle in group A was significantly higher than that in group B,and the number of labeled motor neurons in group B was lower than that in group A.The number of new myelin sheaths and the g-ratio were higher in group A than in group B.There was a 7-day time difference in the regeneration rate between the two injury groups.Conclusion The regeneration of nerve fibers was rapid after crush nerve injury,whereas the transection injury was relatively slow,which provides some ideas for the selection of clinical research models.展开更多
Vision depends on accurate signal conduction from the retina to the brain through the optic nerve,an important part of the central nervous system that consists of bundles of axons originating from retinal ganglion cel...Vision depends on accurate signal conduction from the retina to the brain through the optic nerve,an important part of the central nervous system that consists of bundles of axons originating from retinal ganglion cells.The mammalian optic nerve,an important part of the central nervous system,cannot regenerate once it is injured,leading to permanent vision loss.To date,there is no clinical treatment that can regenerate the optic nerve and restore vision.Our previous study found that the mobile zinc(Zn^(2+))level increased rapidly after optic nerve injury in the retina,specifically in the vesicles of the inner plexiform layer.Furthermore,chelating Zn^(2+)significantly promoted axonal regeneration with a long-term effect.In this study,we conditionally knocked out zinc transporter 3(ZnT3)in amacrine cells or retinal ganglion cells to construct two transgenic mouse lines(VGAT^(Cre)ZnT3^(fl/fl)and VGLUT2^(Cre)ZnT3^(fl/fl),respectively).We obtained direct evidence that the rapidly increased mobile Zn^(2+)in response to injury was from amacrine cells.We also found that selective deletion of ZnT3 in amacrine cells promoted retinal ganglion cell survival and axonal regeneration after optic nerve crush injury,improved retinal ganglion cell function,and promoted vision recovery.Sequencing analysis of reginal ganglion cells revealed that inhibiting the release of presynaptic Zn^(2+)affected the transcription of key genes related to the survival of retinal ganglion cells in postsynaptic neurons,regulated the synaptic connection between amacrine cells and retinal ganglion cells,and affected the fate of retinal ganglion cells.These results suggest that amacrine cells release Zn^(2+)to trigger transcriptomic changes related to neuronal growth and survival in reginal ganglion cells,thereby influencing the synaptic plasticity of retinal networks.These results make the theory of zinc-dependent retinal ganglion cell death more accurate and complete and provide new insights into the complex interactions between retinal cell networks.展开更多
Peripheral nerve injury(PNI)seriously affects people’s quality of life.Stem cell therapy is considered a promising new option for the clinical treatment of PNI.Dental stem cells,particularly dental pulp stem cells(DP...Peripheral nerve injury(PNI)seriously affects people’s quality of life.Stem cell therapy is considered a promising new option for the clinical treatment of PNI.Dental stem cells,particularly dental pulp stem cells(DPSCs),are adult pluripotent stem cells derived from the neuroectoderm.DPSCs have significant potential in the field of neural tissue engineering due to their numerous advantages,such as easy isolation,multidifferentiation potential,low immunogenicity,and low transplant rejection rate.DPSCs are extensively used in tissue engineering and regenerative medicine,including for the treatment of sciatic nerve injury,facial nerve injury,spinal cord injury,and other neurodegenerative diseases.This article reviews research related to DPSCs and their advantages in treating PNI,aiming to summarize the therapeutic potential of DPSCs for PNI and the underlying mechanisms and providing valuable guidance and a foundation for future research.展开更多
We previously combined reduced graphene oxide(rGO)with gelatin-methacryloyl(GelMA)and polycaprolactone(PCL)to create an rGO-GelMA-PCL nerve conduit and found that the conductivity and biocompatibility were improved.Ho...We previously combined reduced graphene oxide(rGO)with gelatin-methacryloyl(GelMA)and polycaprolactone(PCL)to create an rGO-GelMA-PCL nerve conduit and found that the conductivity and biocompatibility were improved.However,the rGO-GelMA-PCL nerve conduits differed greatly from autologous nerve transplants in their ability to promote the regeneration of injured peripheral nerves and axonal sprouting.Extracellular vesicles derived from bone marrow mesenchymal stem cells(BMSCs)can be loaded into rGO-GelMA-PCL nerve conduits for repair of rat sciatic nerve injury because they can promote angiogenesis at the injured site.In this study,12 weeks after surgery,sciatic nerve function was measured by electrophysiology and sciatic nerve function index,and myelin sheath and axon regeneration were observed by electron microscopy,immunohistochemistry,and immunofluorescence.The regeneration of microvessel was observed by immunofluorescence.Our results showed that rGO-GelMA-PCL nerve conduits loaded with BMSC-derived extracellular vesicles were superior to rGO-GelMA-PCL conduits alone in their ability to increase the number of newly formed vessels and axonal sprouts at the injury site as well as the recovery of neurological function.These findings indicate that rGO-GelMA-PCL nerve conduits loaded with BMSC-derived extracellular vesicles can promote peripheral nerve regeneration and neurological function recovery,and provide a new direction for the curation of peripheral nerve defect in the clinic.展开更多
Olfactory ensheathing cells(OECs)are promising seed cells for nerve regeneration.However,their application is limited by the hypoxic environment usually present at the site of injury.Exosomes derived from human umbili...Olfactory ensheathing cells(OECs)are promising seed cells for nerve regeneration.However,their application is limited by the hypoxic environment usually present at the site of injury.Exosomes derived from human umbilical cord mesenchymal stem cells have the potential to regulate the pathological processes that occur in response to hypoxia.The ability of OECs to migrate is unknown,especially in hypoxic conditions,and the effect of OECs combined with exosomes on peripheral nerve repair is not clear.Better understanding of these issues will enable the potential of OECs for the treatment of nerve injury to be addressed.In this study,OECs were acquired from the olfactory bulb of Sprague Dawley rats.Human umbilical cord mesenchymal stem cell-derived exosomes(0–400μg/mL)were cultured with OECs for 12–48 hours.After culture with 400μg/mL exosomes for 24 hours,the viability and proliferation of OECs were significantly increased.We observed changes to OECs subjected to hypoxia for 24 hours and treatment with exosomes.Exosomes significantly promoted the survival and migration of OECs in hypoxic conditions,and effectively increased brain-derived neurotrophic factor gene expression,protein levels and secretion.Finally,using a 12 mm left sciatic nerve defect rat model,we confirmed that OECs and exosomes can synergistically promote motor and sensory function of the injured sciatic nerve.These findings show that application of OECs and exosomes can promote nerve regeneration and functional recovery.This study was approved by the Institutional Ethical Committee of the Air Force Medical University,China(approval No.IACUC-20181004)on October 7,2018;and collection and use of human umbilical cord specimens was approved by the Ethics Committee of the Linyi People’s Hospital,China(approval No.30054)on May 20,2019.展开更多
Studies have confirmed that bone marrow-derived mesenchymal stem cells(MSCs) can be used for treatment of several nervous system diseases. However, isolation of bone marrow-derived MSCs(BMSCs) is an invasive and painf...Studies have confirmed that bone marrow-derived mesenchymal stem cells(MSCs) can be used for treatment of several nervous system diseases. However, isolation of bone marrow-derived MSCs(BMSCs) is an invasive and painful process and the yield is very low. Therefore, there is a need to search for other alterative stem cell sources. Adipose-derived MSCs(ADSCs) have phenotypic and gene expression profiles similar to those of BMSCs. The production of ADSCs is greater than that of BMSCs, and ADSCs proliferate faster than BMSCs. To compare the effects of venous grafts containing BMSCs or ADSCs on sciatic nerve injury, in this study, rats were randomly divided into four groups: sham(only sciatic nerve exposed), Matrigel(MG; sciatic nerve injury + intravenous transplantation of MG vehicle), ADSCs(sciatic nerve injury + intravenous MG containing ADSCs), and BMSCs(sciatic nerve injury + intravenous MG containing BMSCs) groups. Sciatic functional index was calculated to evaluate the function of injured sciatic nerve. Morphologic characteristics of nerves distal to the lesion were observed by toluidine blue staining. Spinal motor neurons labeled with Fluoro-Gold were quantitatively assessed. Compared with sham-operated rats, sciatic functional index was lower, the density of small-diameter fibers was significantly increased, and the number of motor neurons significantly decreased in rats with sciatic nerve injury. Neither ADSCs nor BMSCs significantly improved the sciatic nerve function of rats with sciatic nerve injury, increased fiber density, fiber diameters, axonal diameters, myelin sheath thickness, and G ratios(axonal diameter/fiber diameter ratios) in the sciatic nerve distal to the lesion site. There was no significant difference in the number of spinal motor neurons among ADSCs, BMSCs and MG groups. These results suggest that neither BMSCs nor ADSCs provide satisfactory results for peripheral nerve repair when using MG as the conductor for engraftment.展开更多
The aim of this study was to investigate the effect of platelet-rich plasma(PRP)on cavernous nerve(CN)regeneration and functional status in a nerve-crush rat model.Twenty-four Sprague-Dawley male rats were randomly di...The aim of this study was to investigate the effect of platelet-rich plasma(PRP)on cavernous nerve(CN)regeneration and functional status in a nerve-crush rat model.Twenty-four Sprague-Dawley male rats were randomly divided into three equal groups:eight had a sham operation,eight underwent bilateral nerve crushing with no further intervention and eight underwent bilateral nerve crushing with an immediate application of PRP on the site of injury.Erectile function was assessed by CN electrostimulation at 3 months and nerve regeneration was assessed by toluidine blue staining of CN and nicotinamide adenine dinucleotide phosphate(NADPH)-diaphorase staining of penile tissue.Three months after surgery,in the group that underwent bilateral nerve crushing with no further intervention,the functional evaluation showed a lower mean maximal intracavernous pressure(ICP)and maximal ICP per mean arterial pressure(MAP)with CN stimulation than those in the sham group.In the group with an immediate application of PRP,the mean maximal ICP and maximal ICP/MAP were significantly higher than those in the injured control group.Histologically,the group with the application of PRP had more myelinated axons of CNs and more NADPH-diaphorase-positive nerve fibres than the injured control group but fewer than the sham group.These results show that the application of PRP to the site of CN-crush injury facilitates nerve regeneration and recovery of erectile function.Our research indicates that clinical application of PRP has potential repairing effect on CN and peripheral nerves.展开更多
Treatment of peripheral nerve injuries remains a challenge to modern medicine due to the complexity of the neurobiological nerve regenerating process. There is a greater challenge when the transected nerve ends are no...Treatment of peripheral nerve injuries remains a challenge to modern medicine due to the complexity of the neurobiological nerve regenerating process. There is a greater challenge when the transected nerve ends are not amenable to primary end-to-end tensionless neurorraphy. When facing a segmental nerve defect, great effort has been made to develop an alternative to the autologous nerve graft in order to circumvent morbidity at donor site, such as neuroma formation, scarring and permanent loss of function. Tubolization techniques have been developed to bridge nerve gaps and have been extensively studied in numerous experimental and clinical trials. The use of a conduit intends to act as a vehicle for moderation and modulation of the cellular and molecular ambience for nerve regeneration. Among several conduits, vein tubes were validated for clinical application with improving outcomes over the years. This article aims to address the investigation and treatment of segmental nerve injury and draw the current panorama on the use of vein tubes as an autogenous nerve conduit.展开更多
基金supported by the National Natural Science Foundation of China,Nos.31730031,32130060the National Natural Science Foundation of China,No.31971276(to JH)+1 种基金the Natural Science Foundation of Jiangsu Province,No.BK20202013(to XG)the Natural Science Foundation of Jiangsu Higher Education Institutions of China(Major Program),No.19KJA320005(to JH)。
文摘Schwann cells in peripheral nerves react to traumatic nerve injury by attempting to grow and regenerate.Howeve r,it is unclear what factors play a role in this process.In this study,we searched a GEO database and found that expression of platelet factor 4 was markedly up-regulated after sciatic nerve injury.Platelet factor is an important molecule in cell apoptosis,diffe rentiation,survival,and proliferation.Further,polymerase chain reaction and immunohistochemical staining confirmed the change in platelet factor 4 in the sciatic nerve at different time points after injury.Enzyme-linked immunosorbent assay confirmed that platelet factor 4 was secreted by Schwann cells.We also found that silencing platelet factor 4 decreased the proliferation and migration of primary cultured Schwann cells,while exogenously applied platelet factor 4 stimulated Schwann cell prolife ration and migration and neuronal axon growth.Furthermore,knocking out platelet factor 4 inhibited the prolife ration of Schwann cells in injured rat sciatic nerve.These findings suggest that Schwann cell-secreted platelet factor 4 may facilitate peripheral nerve repair and regeneration by regulating Schwann cell activation and axon growth.Thus,platelet factor 4 may be a potential therapeutic target for traumatic peripheral nerve injury.
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 National Natural Science Foundation of China,No.82104795 (to RH)。
文摘Runx2 is a major regulator of osteoblast differentiation and function;however,the role of Runx2 in peripheral nerve repair is unclea r.Here,we analyzed Runx2expression following injury and found that it was specifically up-regulated in Schwann cells.Furthermore,using Schwann cell-specific Runx2 knocko ut mice,we studied peripheral nerve development and regeneration and found that multiple steps in the regeneration process following sciatic nerve injury were Runx2-dependent.Changes observed in Runx2 knoc kout mice include increased prolife ration of Schwann cells,impaired Schwann cell migration and axonal regrowth,reduced re-myelination of axo ns,and a block in macrophage clearance in the late stage of regeneration.Taken together,our findings indicate that Runx2 is a key regulator of Schwann cell plasticity,and therefore peripheral nerve repair.Thus,our study shows that Runx2 plays a major role in Schwann cell migration,re-myelination,and peripheral nerve functional recovery following injury.
基金supported by the Royal Thai Government Scholarship(to PM).
文摘Peripheral nerves are essential components of the human body’s communication system,transmitting signals between the central nervous system and various body parts.Damage resulting from trauma or disease can result in debilitating sensory and motor deficits.Nerve injuries,particularly those resulting in significant gaps in the nerve tissue,pose a formidable challenge for clinicians and researchers.Despite their limitations,including limited availability and donor site morbidity,nerve autografts remain the clinical gold standard for treating nerve injuries.
基金supported by PIAno di inCEntivi per la Rlcerca di Ateneo 2020/2022 Linea di In tervento3"Starting Grant""REPAIR"(to GM)。
文摘Neuro regeneration is a very complex phenomenon characterized by the generation of new neurons and synapses,involving connections between adjacent cells and axonal projections.Neuroregeneration supplies additional longterm resources to replace those altered by the injury and ensure lasting functional recovery.
基金supported by The Plastic Surgery Foundation Research Pilot Grant,No.627383(to KAS).
文摘Peripheral nerve injuries remain a challenging problem in need of better treatment strategies.Despite best efforts at surgical reconstruction and postoperative rehabilitation,patients are often left with persistent,debilitating motor and sensory deficits.There are currently no therapeutic strategies proven to enhance the regenerative process in humans.A clinical need exists for the development of technologies to promote nerve regeneration and improve functional outcomes.Recent advances in the fields of tissue engineering and nanotechnology have enabled biomaterial scaffolds to modulate the host response to tissue repair through tailored mechanical,chemical,and conductive cues.New bioengineered approaches have enabled targeted,sustained delivery of protein therapeutics with the capacity to unlock the clinical potential of a myriad of neurotrophic growth factors that have demonstrated promise in enhancing regenerative outcomes.As such,further exploration of combinatory strategies leveraging these technological advances may offer a pathway towards clinically translatable solutions to advance the care of patients with peripheral nerve injuries.This review first presents the various emerging bioengineering strategies that can be applied for the management of nerve gap injuries.We cover the rationale and limitations for their use as an alternative to autografts,focusing on the approaches to increase the number of regenerating axons crossing the repair site,and facilitating their growth towards the distal stump.We also discuss the emerging growth factor-based therapeutic strategies designed to improve functional outcomes in a multimodal fashion,by accelerating axonal growth,improving the distal regenerative environment,and preventing end-organs atrophy.
基金supported by the National Natural Science Foundation of China,No.81771351the National Key R&D Program of China,No.2017YFA0105802+1 种基金the Joint Research Fund Liaoning-Shenyang National Laboratory for Materials Science,No.2019JH3/30100022the National Science Foundation for Post-doctoral Scientists of China,No.2018M641732(all to QA and LLW)。
文摘The functional properties of endogenous Schwann cells(SCs)during nerve repair are dynamic.Optimizing the functional properties of SCs at different stages of nerve repair may have therapeutic benefit in improving the repair of damaged nerves.Previous studies showed that miR-221-3p promotes the proliferation and migration of SCs,and miR-338-3p promotes the myelination of SCs.In this study,we established rat models of sciatic nerve injury by bridging the transected sciatic nerve with a silicone tube.We injected a miR-221 lentiviral vector system together with a doxycycline-inducible Tet-On miR-338 lentiviral vector system into the cavity of nerve conduits of nerve stumps to sequentially regulate the biological function of endogenous SCs at different stages of nerve regeneration.We found that the biological function of SCs was sequentially regulated,the diameter and density of myelinated axons were increased,the expression levels of NF200 and myelin basic protein were increased,and the function of injured peripheral nerve was improved using this system.miRNA Target Prediction Database prediction,Nanopore whole transcriptome sequencing,quantitative PCR,and dual luciferase reporter gene assay results predicted and verified Cdkn1b and Nrp1 as target genes of miR-221-3p and miR-338-3p,respectively,and their regulatory effects on SCs were confirmed in vitro.In conclusion,here we established a new method to enhance nerve regeneration through sequential regulation of biological functions of endogenous SCs,which establishes a new concept and model for the treatment of peripheral nerve injury.The findings from this study will provide direct guiding significance for clinical treatment of sciatic nerve 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 grants from the Department of Technology of Jilin Province,Nos.3D5195941430(to YSW),20190201087(to ZCK)the Department of Finance of Jilin Province,No.3D517DV93429(to ZCK)。
文摘The effect of platelet-rich plasma on nerve regeneration remains controversial.In this study,we established a rabbit model of sciatic nerve small-gap defects with preserved epineurium and then filled the gaps with platelet-rich plasma.Twenty-eight rabbits were divided into the following groups(7 rabbits/group):model,low-concentrati on PRP(2.5-3.5-fold concentration of whole blood platelets),medium-concentration PRP(4.5-6.5-fold concentration of whole blood platelets),and high-concentration PRP(7.5-8.5-fold concentration of whole blood platelets).Electrophysiological and histomorphometrical assessments and proteomics analysis we re used to evaluate regeneration of the sciatic nerve.Our results showed that platelet-rich plasma containing 4.5-6.5-and 7.5-8.5-fold concentrations of whole blood platelets promoted repair of sciatic nerve injury.Proteomics analysis was performed to investigate the possible mechanism by which platelet-rich plasma promoted nerve regeneration.Proteomics analysis showed that after sciatic nerve injury,platelet-rich plasma increased the expression of integrin subunitβ-8(ITGB8),which participates in angiogenesis,and differentially expressed proteins were mainly enriched in focal adhesion pathways.Additionally,two key proteins,ribosomal protein S27 a(RSP27 a)and ubiquilin 1(UBQLN1),which were selected after protein-protein interaction analysis,are involved in the regulation of ubiquitin levels in vivo.These data suggest that platelet-rich plasma promotes peripheral nerve regeneration after sciatic nerve injury by affecting angiogenesis and intracellular ubiquitin levels.
基金support by the Faculty of Medicine,Ludwig-Maximilians-University(FöFoLe,Project 843 and 955,to TH and MMS).
文摘Recent results emphasize the supportive effects of adipose-derived multipotent stem/progenitor cells(ADSPCs)in peripheral nerve recovery.Cultivation under hypoxia is considered to enhance the release of the regenerative potential of ADSPCs.This study aimed to examine whether peripheral nerve regeneration in a rat model of autologous sciatic nerve graft benefits from an additional custom-made fibrin conduit seeded with hypoxic pre-conditioned(2%oxygen for 72 hours)autologous ADSPCs(n=9).This treatment mode was compared with three others:fibrin conduit seeded with ADSPCs cultivated under normoxic conditions(n=9);non-cell-carrying conduit(n=9);and nerve autograft only(n=9).A 16-week follow-up included functional testing(sciatic functional index and static sciatic index)as well as postmortem muscle mass analyses and morphometric nerve evaluations(histology,g-ratio,axon density,and diameter).At 8 weeks,the hypoxic pre-conditioned group achieved significantly higher sciatic functional index/static sciatic index scores than the other three groups,indicating faster functional regeneration.Furthermore,histologic evaluation showed significantly increased axon outgrowth/branching,axon density,remyelination,and a reduced relative connective tissue area.Hypoxic pre-conditioned ADSPCs seeded in fibrin conduits are a promising adjunct to current nerve autografts.Further studies are needed to understand the underlying cellular mechanism and to investigate a potential application in clinical practice.
基金supported by the National Natural Science Foundation of China, No. 81871493 (to YC)the Medical Science Advancement Program (Clinical Medicine) of Wuhan University, No. TFLC2018003 (to YC)
文摘Currently available commercial nerve guidance conduits have been applied in the repair of peripheral nerve defects.However,a conduit exhibiting good biocompatibility remains to be developed.In this work,a series of chitosan/graphene oxide(GO)films with concentrations of GO varying from 0-1 wt%(collectively referred to as CHGF-n)were prepared by an electrodeposition technique.The effects of CHGF-n on proliferation and adhesion abilities of Schwann cells were evaluated.The results showed that Schwann cells exhibited elongated spindle shapes and upregulated expression of nerve regeneration-related factors such as Krox20(a key myelination factor),Zeb2(essential for Schwann cell differentiation,myelination,and nerve repair),and transforming growth factorβ(a cytokine with regenerative functions).In addition,a nerve guidance conduit with a GO content of 0.25%(CHGFC-0.25)was implanted to repair a 10-mm sciatic nerve defect in rats.The results indicated improvements in sciatic functional index,electrophysiology,and sciatic nerve and gastrocnemius muscle histology compared with the CHGFC-0 group,and similar outcomes to the autograft group.In conclusion,we provide a candidate method for the repair of peripheral nerve defects using free-standing chitosan/GO nerve conduits produced by electrodeposition.
基金financed by the Spanish"Plan Nacional de Investigación Cientifica,Desorrollo e Innovación Tecnológica,Ministerio de Economíay Competitividod(Instituto de Solud CarlosⅢ)",grant Nos:FIS PI17-0393,FIS PI20-0318co-financed by the"Fondo Europeo de Desorrollo Regional ERDF-FEDER European Union",grant No.P18-RT-5059+2 种基金by"Plan Andaluz de Investigación,Desarrollo e Innovación(PAIDI 2020)Consejerio de Transformoción Económico,Industria,Conocimiento y Universidades,Junta de Andolucío,Espa?a",and grant No.A-CTS-498-UGR18by"Programa Operotivo FEDER Andalucía 2014-2020,Universidod de Granada,Junta de Andalucía,Espa?a",ca-funded by ERDF-FEDER,the European Union(all to VC)。
文摘Growth-associated protein 43 plays a key role in neurite outgrowth through cytoskeleton remodeling.We have previously demonstrated that structural damage of peripheral nerves induces growth-associated protein 43 upregulation to promote growth cone formation.Conversely,the limited regenerative capacity of the central nervous system due to an inhibitory environment prevents major changes in neurite outgrowth and should be presumably associated with low levels of growth-associated protein 43 expression.However,central alterations due to peripheral nerve damage have never been assessed using the growthassociated protein 43 marker.In this study,we used the tubulization technique to repair 1 cm-long nerve gaps in the rat nerve injury/repair model and detected growth-associated protein 43 expression in the peripheral and central nervous systems.First,histological analysis of the regeneration process confirmed an active regeneration process of the nerve gaps through the conduit from 10 days onwards.The growth-associated protein 43 expression profile varied across regions and follow-up times,from a localized expression to an abundant and consistent expression throughout the regeneration tissue,confirming the presence of an active nerve regeneration process.Second,spinal cord changes were also histologically assessed,and no apparent changes in the structural and cellular organization were observed using routine staining methods.Surprisingly,remarkable differences and local changes appeared in growth-associated protein 43 expression at the spinal cord level,in particular at 20 days post-repair and beyond.Growth-associated protein 43 protein was first localized in the gracile fasciculus and was homogeneously distributed in the left posterior cord.These findings differed from the growth-associated protein 43 pattern observed in the healthy control,which did not express growth-associated protein 43 at these levels.Our results revealed a differential expression in growth-associated protein 43 protein not only in the regenerating nerve tissue but also in the spinal cord after peripheral nerve transection.These findings open the possibility of using this marker to monitor changes in the central nervous system after peripheral nerve injury.
基金supported by the National Natural Science Foundation of China:Investigation on central cortical functional compensation and re-organization after hypoglossal-facial neurorrhaphy for facial nerve injury using repetitive transcranial magnetic stimulation combined with biofeedback peripheral electrical stimulation[Grant No.82171364]the Beijing Municipal Health Commission:Study on repair mechanism of nervous system injury[Grant No.PXM2020_026280_000002].
文摘Objective To provide useful information for selecting the most appropriate peripheral nerve injury model for different research purposes in nerve injury and repair studies,and to compare nerve regeneration capacity and characteristics between them.Methods Sixty adult SD rats were randomly divided into two groups and underwent crush injury alone(group A,n=30)or transection injury followed by surgical repair(group B,n=30)of the right hind paw.Each group was subjected to the CatWalk test,gastrocnemius muscle evaluation,pain threshold measurement,electrophysiological examination,retrograde neuronal labeling,and quantification of nerve regeneration before and 7,14,21,and 28 days after injury.Results Gait analysis showed that the recovery speed in group A was significantly faster than that in group B at 14 days.At 21 days,the compound muscle action potential of the gastrocnemius muscle in group A was significantly higher than that in group B,and the number of labeled motor neurons in group B was lower than that in group A.The number of new myelin sheaths and the g-ratio were higher in group A than in group B.There was a 7-day time difference in the regeneration rate between the two injury groups.Conclusion The regeneration of nerve fibers was rapid after crush nerve injury,whereas the transection injury was relatively slow,which provides some ideas for the selection of clinical research models.
基金the National Key R&D Project of China,No.2020YFA0112701(to YZ)the National Natural Science Foundation of China,Nos.82171057(to YZ),81870657(to YL)+1 种基金Science and Technology Program of Guangzhou of China,No.202206080005(to YZ)the Natural Science Foundation of Guangdong Province of China,No.2022A1515012168(to YL)。
文摘Vision depends on accurate signal conduction from the retina to the brain through the optic nerve,an important part of the central nervous system that consists of bundles of axons originating from retinal ganglion cells.The mammalian optic nerve,an important part of the central nervous system,cannot regenerate once it is injured,leading to permanent vision loss.To date,there is no clinical treatment that can regenerate the optic nerve and restore vision.Our previous study found that the mobile zinc(Zn^(2+))level increased rapidly after optic nerve injury in the retina,specifically in the vesicles of the inner plexiform layer.Furthermore,chelating Zn^(2+)significantly promoted axonal regeneration with a long-term effect.In this study,we conditionally knocked out zinc transporter 3(ZnT3)in amacrine cells or retinal ganglion cells to construct two transgenic mouse lines(VGAT^(Cre)ZnT3^(fl/fl)and VGLUT2^(Cre)ZnT3^(fl/fl),respectively).We obtained direct evidence that the rapidly increased mobile Zn^(2+)in response to injury was from amacrine cells.We also found that selective deletion of ZnT3 in amacrine cells promoted retinal ganglion cell survival and axonal regeneration after optic nerve crush injury,improved retinal ganglion cell function,and promoted vision recovery.Sequencing analysis of reginal ganglion cells revealed that inhibiting the release of presynaptic Zn^(2+)affected the transcription of key genes related to the survival of retinal ganglion cells in postsynaptic neurons,regulated the synaptic connection between amacrine cells and retinal ganglion cells,and affected the fate of retinal ganglion cells.These results suggest that amacrine cells release Zn^(2+)to trigger transcriptomic changes related to neuronal growth and survival in reginal ganglion cells,thereby influencing the synaptic plasticity of retinal networks.These results make the theory of zinc-dependent retinal ganglion cell death more accurate and complete and provide new insights into the complex interactions between retinal cell networks.
基金Supported by Wuhan University of Science and Technology Startup Fund(Chu Tian Scholars Program),No.XZ2020024Open Laboratory Fund from Hubei Province Key Laboratory of Oral and Maxillofacial Development and Regeneration,No.2022kqhm005Hubei Provincial Health and Health Commission Research Project,No.WJ2023M121。
文摘Peripheral nerve injury(PNI)seriously affects people’s quality of life.Stem cell therapy is considered a promising new option for the clinical treatment of PNI.Dental stem cells,particularly dental pulp stem cells(DPSCs),are adult pluripotent stem cells derived from the neuroectoderm.DPSCs have significant potential in the field of neural tissue engineering due to their numerous advantages,such as easy isolation,multidifferentiation potential,low immunogenicity,and low transplant rejection rate.DPSCs are extensively used in tissue engineering and regenerative medicine,including for the treatment of sciatic nerve injury,facial nerve injury,spinal cord injury,and other neurodegenerative diseases.This article reviews research related to DPSCs and their advantages in treating PNI,aiming to summarize the therapeutic potential of DPSCs for PNI and the underlying mechanisms and providing valuable guidance and a foundation for future research.
基金supported by the National Natural Science Foundation of China, No. 31671248the Natural Science Foundation of Beijing, No. 7222198 (both to NH)
文摘We previously combined reduced graphene oxide(rGO)with gelatin-methacryloyl(GelMA)and polycaprolactone(PCL)to create an rGO-GelMA-PCL nerve conduit and found that the conductivity and biocompatibility were improved.However,the rGO-GelMA-PCL nerve conduits differed greatly from autologous nerve transplants in their ability to promote the regeneration of injured peripheral nerves and axonal sprouting.Extracellular vesicles derived from bone marrow mesenchymal stem cells(BMSCs)can be loaded into rGO-GelMA-PCL nerve conduits for repair of rat sciatic nerve injury because they can promote angiogenesis at the injured site.In this study,12 weeks after surgery,sciatic nerve function was measured by electrophysiology and sciatic nerve function index,and myelin sheath and axon regeneration were observed by electron microscopy,immunohistochemistry,and immunofluorescence.The regeneration of microvessel was observed by immunofluorescence.Our results showed that rGO-GelMA-PCL nerve conduits loaded with BMSC-derived extracellular vesicles were superior to rGO-GelMA-PCL conduits alone in their ability to increase the number of newly formed vessels and axonal sprouts at the injury site as well as the recovery of neurological function.These findings indicate that rGO-GelMA-PCL nerve conduits loaded with BMSC-derived extracellular vesicles can promote peripheral nerve regeneration and neurological function recovery,and provide a new direction for the curation of peripheral nerve defect in the clinic.
基金supported by grants from the National Natural Science Foundation of China,No.81872699(to MS)Key project of Shaanxi Province,China,No.2017ZDXM-SF-043(to MS)the Military Medical Science and Technology Youth Development Program,China,No.19QNP061(to CL)
文摘Olfactory ensheathing cells(OECs)are promising seed cells for nerve regeneration.However,their application is limited by the hypoxic environment usually present at the site of injury.Exosomes derived from human umbilical cord mesenchymal stem cells have the potential to regulate the pathological processes that occur in response to hypoxia.The ability of OECs to migrate is unknown,especially in hypoxic conditions,and the effect of OECs combined with exosomes on peripheral nerve repair is not clear.Better understanding of these issues will enable the potential of OECs for the treatment of nerve injury to be addressed.In this study,OECs were acquired from the olfactory bulb of Sprague Dawley rats.Human umbilical cord mesenchymal stem cell-derived exosomes(0–400μg/mL)were cultured with OECs for 12–48 hours.After culture with 400μg/mL exosomes for 24 hours,the viability and proliferation of OECs were significantly increased.We observed changes to OECs subjected to hypoxia for 24 hours and treatment with exosomes.Exosomes significantly promoted the survival and migration of OECs in hypoxic conditions,and effectively increased brain-derived neurotrophic factor gene expression,protein levels and secretion.Finally,using a 12 mm left sciatic nerve defect rat model,we confirmed that OECs and exosomes can synergistically promote motor and sensory function of the injured sciatic nerve.These findings show that application of OECs and exosomes can promote nerve regeneration and functional recovery.This study was approved by the Institutional Ethical Committee of the Air Force Medical University,China(approval No.IACUC-20181004)on October 7,2018;and collection and use of human umbilical cord specimens was approved by the Ethics Committee of the Linyi People’s Hospital,China(approval No.30054)on May 20,2019.
基金supported by Brazilian grants from Fundacao de Amparo à Pesquisa do Estado de Sao Paulo(FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico(CNPq)CAPES
文摘Studies have confirmed that bone marrow-derived mesenchymal stem cells(MSCs) can be used for treatment of several nervous system diseases. However, isolation of bone marrow-derived MSCs(BMSCs) is an invasive and painful process and the yield is very low. Therefore, there is a need to search for other alterative stem cell sources. Adipose-derived MSCs(ADSCs) have phenotypic and gene expression profiles similar to those of BMSCs. The production of ADSCs is greater than that of BMSCs, and ADSCs proliferate faster than BMSCs. To compare the effects of venous grafts containing BMSCs or ADSCs on sciatic nerve injury, in this study, rats were randomly divided into four groups: sham(only sciatic nerve exposed), Matrigel(MG; sciatic nerve injury + intravenous transplantation of MG vehicle), ADSCs(sciatic nerve injury + intravenous MG containing ADSCs), and BMSCs(sciatic nerve injury + intravenous MG containing BMSCs) groups. Sciatic functional index was calculated to evaluate the function of injured sciatic nerve. Morphologic characteristics of nerves distal to the lesion were observed by toluidine blue staining. Spinal motor neurons labeled with Fluoro-Gold were quantitatively assessed. Compared with sham-operated rats, sciatic functional index was lower, the density of small-diameter fibers was significantly increased, and the number of motor neurons significantly decreased in rats with sciatic nerve injury. Neither ADSCs nor BMSCs significantly improved the sciatic nerve function of rats with sciatic nerve injury, increased fiber density, fiber diameters, axonal diameters, myelin sheath thickness, and G ratios(axonal diameter/fiber diameter ratios) in the sciatic nerve distal to the lesion site. There was no significant difference in the number of spinal motor neurons among ADSCs, BMSCs and MG groups. These results suggest that neither BMSCs nor ADSCs provide satisfactory results for peripheral nerve repair when using MG as the conductor for engraftment.
基金the National Natural Science Foundation of China(No.30600616).
文摘The aim of this study was to investigate the effect of platelet-rich plasma(PRP)on cavernous nerve(CN)regeneration and functional status in a nerve-crush rat model.Twenty-four Sprague-Dawley male rats were randomly divided into three equal groups:eight had a sham operation,eight underwent bilateral nerve crushing with no further intervention and eight underwent bilateral nerve crushing with an immediate application of PRP on the site of injury.Erectile function was assessed by CN electrostimulation at 3 months and nerve regeneration was assessed by toluidine blue staining of CN and nicotinamide adenine dinucleotide phosphate(NADPH)-diaphorase staining of penile tissue.Three months after surgery,in the group that underwent bilateral nerve crushing with no further intervention,the functional evaluation showed a lower mean maximal intracavernous pressure(ICP)and maximal ICP per mean arterial pressure(MAP)with CN stimulation than those in the sham group.In the group with an immediate application of PRP,the mean maximal ICP and maximal ICP/MAP were significantly higher than those in the injured control group.Histologically,the group with the application of PRP had more myelinated axons of CNs and more NADPH-diaphorase-positive nerve fibres than the injured control group but fewer than the sham group.These results show that the application of PRP to the site of CN-crush injury facilitates nerve regeneration and recovery of erectile function.Our research indicates that clinical application of PRP has potential repairing effect on CN and peripheral nerves.
文摘Treatment of peripheral nerve injuries remains a challenge to modern medicine due to the complexity of the neurobiological nerve regenerating process. There is a greater challenge when the transected nerve ends are not amenable to primary end-to-end tensionless neurorraphy. When facing a segmental nerve defect, great effort has been made to develop an alternative to the autologous nerve graft in order to circumvent morbidity at donor site, such as neuroma formation, scarring and permanent loss of function. Tubolization techniques have been developed to bridge nerve gaps and have been extensively studied in numerous experimental and clinical trials. The use of a conduit intends to act as a vehicle for moderation and modulation of the cellular and molecular ambience for nerve regeneration. Among several conduits, vein tubes were validated for clinical application with improving outcomes over the years. This article aims to address the investigation and treatment of segmental nerve injury and draw the current panorama on the use of vein tubes as an autogenous nerve conduit.
