A hyaluronic acid granular hydrogel can promote neuronal and astrocyte colony formation and axonal extension in vitro,suggesting that the hydrogel can simulate an extracellular matrix structure to promote neural regen...A hyaluronic acid granular hydrogel can promote neuronal and astrocyte colony formation and axonal extension in vitro,suggesting that the hydrogel can simulate an extracellular matrix structure to promote neural regeneration.However,in vivo experiments have not been conducted.In this study,we transplanted a hyaluronic acid granular hydrogel nerve guidance conduit to repair a 10-mm long sciatic nerve gap.The Basso,Beattie,and Bresnahan locomotor rating scale,sciatic nerve compound muscle action potential recording,Fluoro-Gold retrograde tracing,growth related protein 43/S100 immunofluorescence staining,transmission electron microscopy,gastrocnemius muscle dry/wet weight ratio,and Masson’s trichrome staining results showed that the nerve guidance conduit exhibited similar regeneration of sciatic nerve axons and myelin sheath,and recovery of the electrophysiological function and motor function as autologous nerve transplantation.The conduit results were superior to those of a bulk hydrogel or silicone tube transplant.These findings suggest that tissue-engineered nerve conduits containing hyaluronic acid granular hydrogels effectively promote the morphological and functional recovery of the injured sciatic nerve.The nerve conduits have the potential as a material for repairing peripheral nerve defects.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
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
The sensorimotor and histological aspects of peripheral neuropathies were already studied by our team in two rat models:the sciatic nerve crush and the Charcot-Marie-Tooth-1A disease.In this study,we sought to highlig...The sensorimotor and histological aspects of peripheral neuropathies were already studied by our team in two rat models:the sciatic nerve crush and the Charcot-Marie-Tooth-1A disease.In this study,we sought to highlight and compare the protein signature of these two pathological situations.Indeed,the identification of protein profiles in diseases can play an important role in the development of pharmacological targets.In fact,Charcot-Marie-Tooth-1A rats develop motor impairments that are more severe in the hind limbs.Therefore,for the first time,protein expression in sciatic nerve of Charcot-Marie-Tooth-1A rats was examined.First,distal sciatic nerves were collected from Charcot-Marie-Tooth-1A and uninjured wild-type rats aged 3 months.After protein extraction,sequential window acquisition of all theoretical fragment ion spectra liquid chromatography and mass spectrometry was employed.445 proteins mapped to Swiss-Prot or trEMBL Uniprot databases were identified and quantified.Of these,153 proteins showed statistically significant differences between Charcot-Marie-Tooth-1A and wild-type groups.The majority of these proteins were overexpressed in Charcot-Marie-Tooth-1A.Hierarchical clustering and functional enrichment using Gene Ontology were used to group these proteins based on their biological effects concerning Charcot-Marie-Tooth-1A pathophysiology.Second,proteomic characterization of wild-type rats subjected to sciatic nerve crush was performed sequential window acquisition of all theoretical fragment ion spectra liquid chromatography and mass spectrometry.One month after injury,distal sciatic nerves were collected and analyzed as described above.Out of 459 identified proteins,92 showed significant differences between sciatic nerve crush and the uninjured wild-type rats used in the first study.The results suggest that young adult Charcot-Marie-Tooth-1A rats(3 months old)develop compensatory mechanisms at the level of redox balance,protein folding,myelination,and axonogenesis.These mechanisms seem insufficient to hurdle the progress of the disease.Notably,response to oxidative stress appears to be a significant feature of Charcot-Marie-Tooth-1A,potentially playing a role in the pathological process.In contrast to the first experiment,the majority of the proteins that differed from wild-type were downregulated in the sciatic nerve crush group.Functional enrichment suggested that neurogenesis,response to axon injury,and oxidative stress were important biological processes.Protein analysis revealed an imperfect repair at this time point after injury and identified several distinguishable proteins.In conclusion,we suggest that peripheral neuropathies,whether of a genetic or traumatic cause,share some common pathological pathways.This study may provide directions for better characterization of these models and/or identifying new specific therapeutic targets.展开更多
Hollow conduits of natural or synthetic origins have shown acceptable regeneration results in short nerve gap repair;however,results are still not comparable with the current gold standard technique“autografts”.Holl...Hollow conduits of natural or synthetic origins have shown acceptable regeneration results in short nerve gap repair;however,results are still not comparable with the current gold standard technique“autografts”.Hollow conduits do not provide a successful regeneration outcome when it comes to critical nerve gap repair.Enriching the lumen of conduits with different extracellular materials and cells could provide a better biomimicry of the natural nerve regenerating environment and is expected to ameliorate the conduit performance.In this study,we evaluated nerve regeneration in vivo using hollow chitosan conduits or conduits enriched with fibrin-collagen hydrogels alone or with the further addition of adipose-derived mesenchymal stem cells in a 15 mm rat sciatic nerve transection model.Unexpected changes in the hydrogel consistency and structural stability in vivo led to a failure of nerve regeneration after 15 weeks.Nevertheless,the molecular assessment in the early regeneration phase(7,14,and 28 days)has shown an upregulation of useful regenerative genes in hydrogel enriched conduits compared with the hollow ones.Hydrogels composed of fibrin-collagen were able to upregulate the expression of soluble NRG1,a growth factor that plays an important role in Schwann cell transdifferentiation.The further enrichment with adipose-derived mesenchymal stem cells has led to the upregulation of other important genes such as ErbB2,VEGF-A,BDNF,c-Jun,and ATF3.展开更多
Background:The underlying mechanism of sciatic nerve injury(SNI)is a common motor functional disorder,necessitates further research.Methods:A rat model of SNI was established,with the injury group subjected to compres...Background:The underlying mechanism of sciatic nerve injury(SNI)is a common motor functional disorder,necessitates further research.Methods:A rat model of SNI was established,with the injury group subjected to compressive injury of the right sciatic nerve exposed at the midpoint of the thigh and the sham surgery group undergoing the same surgical procedure.An oxygen-glucose deprivation model was employed to simulate in vitro SNI in PC12 cells.Following data acquisition and quality control,differentially expressed proteins(DEPs)in each model were identified through differential analysis,and enrichment analysis was used to explore the potential functions and pathways of the DEPs.Venn diagrams were drawn,and DEPs from both in vivo and in vitro SNI models were imported into the STRING database to construct a protein-protein interaction network and screen for hub proteins.Results:After the peptide segments obtained from rat nerve blockade and PC12 cells met quality requirements,258 DEPs were identified in rat nerve samples,and 119 DEPs were screened in PC12 cells.Enrichment analysis revealed that DEPs in the rat model were predominantly concentrated in biological functions such as myogenic cell proliferation and signaling related to lipid and energy metabolism.DEPs in the in vitro model were mainly enriched in biological processes such as phagocytosis and were associated with lipid transport and metabolism.Two hub proteins,amyloid precursor protein(APP)and fibronectin 1(FN1),were identified through MCC,MCODE,and Degree scoring.Both PC12 cells and external validation sets showed relatively higher expression of APP and FN1 in injured samples.Results of gene set enrichment analysis indicated that these two proteins were associated with metabolic pathways,such as biosynthesis of glycosaminoglycan chondroitin sulfate and biosynthesis of unsaturated fatty acids.Conclusion:APP and FN1 are potential key molecules involved in SNI and are associated with various metabolic pathways in nerve repair.These findings provide a theoretical basis for the development of therapeutic targets for SNI.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
Despite the regenerative capabilities of peripheral nerves, severe injuries or neuronal trauma of critical size impose immense hurdles for proper restoration of neuro-muscular circuitry. Autologous nerve grafts improv...Despite the regenerative capabilities of peripheral nerves, severe injuries or neuronal trauma of critical size impose immense hurdles for proper restoration of neuro-muscular circuitry. Autologous nerve grafts improve re-establishment of connectivity, but also comprise substantial donor site morbidity. We developed a rat model which allows the testing of different cell applications, i.e., mesenchymal stem cells, to improve nerve regeneration in vivo. To mimic inaccurate alignment of autologous nerve grafts with the injured nerve, a 20 mm portion of the sciatic nerve was excised, and sutured back in place in reversed direction. To validate the feasibility of our novel model, a fibrin gel conduit containing autologous undifferentiated adipose-derived stem cells was applied around the coaptation sites and compared to autologous nerve grafts. After evaluating sciatic nerve function for 16 weeks postoperatively, animals were sacrificed, and gastrocnemius muscle weight was determined along with morphological parameters(g-ratio, axon density & diameter) of regenerating axons. Interestingly, the addition of undifferentiated adipose-derived stem cells resulted in a significantly improved re-myelination, axon ingrowth and functional outcome, when compared to animals without a cell seeded conduit. The presented model thus displays several intriguing features: it imitates a certain mismatch in size, distribution and orientation of axons within the nerve coaptation site. The fibrin conduit itself allows for an easy application of cells and, as a true critical-size defect model, any observed improvement relates directly to the performed intervention. Since fibrin and adipose-derived stem cells have been approved for human applications, the technique can theoretically be performed on humans. Thus, we suggest that the model is a powerful tool to investigate cell mediated assistance of peripheral nerve regeneration.展开更多
AIM To study the clinical findings and characteristic features in sciatic notch dumbbell tumors(SNDTs).METHODS We retrospectively reviewed the clinical outcomes and characteristic features of consecutive cases of SNDT...AIM To study the clinical findings and characteristic features in sciatic notch dumbbell tumors(SNDTs).METHODS We retrospectively reviewed the clinical outcomes and characteristic features of consecutive cases of SNDTs(n = 8). RESULTS Buttock masses occurred in three patients with SNDT(37.5%). Severe buttock tenderness and pain at rest were observed in seven patients with SNDTs(87.5%). Remarkably, none of the patients with SNDTs experienced back pain. Mean tumor size was 8.4 ± 2.0 cm(range, 3.9 to 10.6 cm) and part of the tumor mass was detected in 2 patients in the sagittal view of lumbar magnetic resonance imaging(MRI).CONCLUSION The clinical information regarding to SNDTs is scarce. The authors consider that above mentioned characteristic findings may facilitate the suspicion of pelvic pathology and a search for SNDT by MRI or computed tomography should be considered in patients presenting with sciatica without evidence of spinal diseases.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
Background: Cytokines are essential cellular modulators of various physiological and pathological activities, including peripheral nerve repair and regeneration. However, the molecular changes of these cellular mediat...Background: Cytokines are essential cellular modulators of various physiological and pathological activities, including peripheral nerve repair and regeneration. However, the molecular changes of these cellular mediators after peripheral nerve injury are still unclear. This study aimed to identify cytokines critical for the regenerative process of injured peripheral nerves.Methods: The sequencing data of the injured nerve stumps and the dorsal root ganglia(DRG) of Sprague-Dawley(SD) rats subjected to sciatic nerve(SN) crush injury were analyzed to determine the expression patterns of genes coding for cytokines. PCR was used to validate the accuracy of the sequencing data.Results: A total of 46, 52, and 54 upstream cytokines were differentially expressed in the SN at 1 day, 4 days, and 7 days after nerve injury. A total of 25, 28, and 34 upstream cytokines were differentially expressed in the DRG at these time points. The expression patterns of some essential upstream cytokines are displayed in a heatmap and were validated by PCR. Bioinformatic analysis of these differentially expressed upstream cytokines after nerve injury demonstrated that inflammatory and immune responses were significantly involved.Conclusions: In summary, these findings provide an overview of the dynamic changes in cytokines in the SN and DRG at different time points after nerve crush injury in rats, elucidate the biological processes of differentially expressed cytokines, especially the important roles in inflammatory and immune responses after peripheral nerve injury, and thus might contribute to the identification of potential treatments for peripheral nerve repair and regeneration.展开更多
Repetitive magnetic stimulation is effective for treating posttraumatic neuropathies following spinal or axonal injury.Neurotropin is a potential treatment for nerve injuries like demyelinating diseases.This study sou...Repetitive magnetic stimulation is effective for treating posttraumatic neuropathies following spinal or axonal injury.Neurotropin is a potential treatment for nerve injuries like demyelinating diseases.This study sought to observe the effects of high-frequency repetitive magnetic stimulation,neurotropin and their combined use in the treatment of peripheral nerve injury in 32 adult male Sprague-Dawley rats.To create a sciatic nerve injury model,a 10 mm-nerve segment of the left sciatic nerve was cut and rotated through 180°and each end restored continuously with interrupted sutures.The rats were randomly divided into four groups.The control group received only a reversed autograft in the left sciatic nerve with no treatment.In the high-frequency repetitive magnetic stimulation group,peripheral high-frequency repetitive magnetic stimulation treatment(20 Hz,20 min/d)was delivered for 10 consecutive days after auto-grafting.In the neurotropin group,neurotropin therapy(0.96 NU/kg per day)was administrated for 10 consecutive days after surgery.In the combined group,the combination of peripheral high-frequency repetitive magnetic stimulation(20 Hz,20 min/d)and neurotropin(0.96 NU/kg per day)was given for 10 consecutive days after the operation.The Basso-Beattie-Bresnahan locomotor rating scale was used to assess the behavioral recovery of the injured nerve.The sciatic functional index was used to evaluate the recovery of motor functions.Toluidine blue staining was performed to determine the number of myelinated fibers in the distal and proximal grafts.Immunohistochemistry staining was used to detect the length of axons marked by neurofilament 200.Our results reveal that the Basso-Beattie-Bresnahan locomotor rating scale scores,sciatic functional index,the number of myelinated fibers in distal and proximal grafts were higher and axon lengths were longer in the high-frequency repetitive magnetic stimulation,neurotropin and combined groups compared with the control group.These measures were not significantly different among the high-frequency repetitive magnetic stimulation,neurotropin and combined groups.Therefore,our results suggest that peripheral high-frequency repetitive magnetic stimulation or neurotropin can promote the repair of injured sciatic nerves,but their combined use seems to offer no significant advantage.This study was approved by the Animal Ethics Committee of the Affiliated Changzhou No.2 People’s Hospital of Nanjing Medical University,China on December 23,2014(approval No.2014keyan002-01).展开更多
Dexmedetomidine is a selective α2-adrenoceptor agonist that is used because of its sedative,anxiolytic,and analgesic effects.Dexketoprofen,which is used as an analgesic,is a nonselective nonsteroidal anti-inflammator...Dexmedetomidine is a selective α2-adrenoceptor agonist that is used because of its sedative,anxiolytic,and analgesic effects.Dexketoprofen,which is used as an analgesic,is a nonselective nonsteroidal anti-inflammatory drug (NSAID).The use of dexmedetomidine and dexketoprofen as adjuvants to local anesthetics for the peripheral nerve is gradually increasing.In this study,we aimed to investigate the effects of different doses of dexmedetomidine and dexketoprofen on conduction block of rat sciatic nerve.The isolated sciatic nerve from adult rats was transferred to a nerve chamber.The compound action potentials (CAPs) were recorded from stimulated nerve with electrophysiological methods.Dexmedetomidine (n = 8) and dexketoprofen (n = 8) were administered in the chamber with cumulative concentrations of 10–9 to 10–5 M,and the CAPs were recorded for 5 and 10 minutes.The CAP parameters were calculated.Both dexmedetomidine and dexketoprofen significantly depressed all CAP parameters in a dose-dependent manner compared with the control group,i.e.,the group in which rats did not receive treatment.CAP parameters showed there was no significant difference in nerve conduction inhibition between dexmedetomidine and dexketoprofen.Higher doses of dexmedetomidine suppressed the conduction in the fast-conducting fibers;however,dexketoprofen was found to suppress the conduction in the slow-conducting fibers in a time-dependent manner and suppress the conduction in the medium- and slow-conducting fibers in a dose-dependent manner.These findings suggest that dexmedetomidine and dexketoprofen exhibit better anesthetic effects on peripheral nerve through different ways of action.The experimental procedures were approved by the Necmettin Erbakan University on January 30,2013 (approval No.2013-024).展开更多
Various studies have reported that galanin can promote axonal regeneration of dorsal root ganglion neurons in vitro and inhibit neuropathic pain.However,little is known about its effects on diabetic peripheral neuropa...Various studies have reported that galanin can promote axonal regeneration of dorsal root ganglion neurons in vitro and inhibit neuropathic pain.However,little is known about its effects on diabetic peripheral neuropathy,and in vivo experimental data are lacking.We hypothesized that repeated applications of exogenous galanin over an extended time frame may also repair nerve damage in diabetic peripheral neuropathy,and relieve pain in vivo.We found that neuropathic pain occurred in streptozotocin-induced diabetic rats and was more severe after sciatic nerve pinch injury at 14 and 28 days than in diabetic sham-operated rats.Treatment with exogenous galanin alleviated the neuropathic pain and promoted sciatic nerve regeneration more effectively in diabetic rats than in non-diabetic rats after sciatic nerve pinch injury.This was accompanied by changes in the levels of endogenous galanin,and its receptors galanin receptor 1 and galanin receptor 2 in the dorsal root ganglia and the spinal dorsal horn when compared with nerve pinch normal rats.Our results show that application of exogenous galanin daily for 28 days can promote the regeneration of injured sciatic nerves,and alleviate neuropathic pain in diabetic rats.展开更多
Studies have shown that acellular nerve xenografts do not require immunosuppression and use of acellular nerve xenografts for repair of peripheral nerve injury is safe and effective.However,there is currently no widel...Studies have shown that acellular nerve xenografts do not require immunosuppression and use of acellular nerve xenografts for repair of peripheral nerve injury is safe and effective.However,there is currently no widely accepted standard chemical decellularization method.The purpose of this study is to investigate the efficiency of bovine-derived nerves decellularized by the modified Hudson’s protocol in the repair of rat sciatic nerve injury.In the modified Hudson’s protocol,Triton X-200 was replaced by Triton X-100,and DNase and RNase were used to prepare accelular nerve xenografts.The efficiency of bovine-derived nerves decellularized by the modified Hudson’s protocol was tested in vitro by hematoxylin&eosin,Alcian blue,Masson’s trichrome,and Luxol fast blue staining,immunohistochemistry,and biochemical assays.The decellularization approach excluded cells,myelin,and axons of nerve xenografts,without affecting the organization of nerve xenografts.The decellularized nerve xenograft was used to bridge a 7 mm-long sciatic nerve defect to evaluate its efficiency in the repair of peripheral nerve injury.At 8 weeks after transplantation,sciatic function index in rats subjected to transplantation of acellular nerve xenograft was similar to that in rats undergoing transplantation of nerve allograft.Morphological analysis revealed that there were a large amount of regenerated myelinated axons in acellular nerve xenograft;the number of Schwann cells in the acellular nerve xenograft was similar to that in the nerve allograft.These findings suggest that acellular nerve xenografts prepared by the modified Hudson’s protocol can be used for repair of peripheral nerve injury.This study was approved by the Research Ethics Committee,Research and Technology Chancellor of Guilan University of Medical Sciences,Iran(approval No.IR.GUMS.REC.1395.332)on February 11,2017.展开更多
BACKGROUND:Previous tissue-engineered nerve studies have focused on artificial nerve and nerve cell cultures.The effects of regeneration chambers with autologous nerve bridging for the repair of nerve defects remain u...BACKGROUND:Previous tissue-engineered nerve studies have focused on artificial nerve and nerve cell cultures.The effects of regeneration chambers with autologous nerve bridging for the repair of nerve defects remain unclear.OBJECTIVE:To explore the feasibility and advantages of chitosan tube bridging autologous nerve segments for repairing 12-mm sciatic nerve defects in rats.DESIGN,TIME AND SETTING:A randomized,controlled,animal study using nerve tissue engineering was performed at the Animal Laboratory and Laboratory of Histology and Embryology,Liaoning Medical University from June 2008 to March 2009.MATERIALS:Chitosan powder was purchased from Jinan Haidebei Marine Bioengineering,China.METHODS:A sciatic nerve segment of approximately 8 mm was excised from the posterior margin of the piriformis muscle of Sprague Dawley rats.The two nerve ends shrank to form a 12-mm defect,and the nerve defect was repaired using a chitosan tube bridging autologous nerve segment (bridge group),a chitosan tube-encapsulated autologous nerve segment (encapsulation group),and a chitosan tube alone (chitosan tube alone group),respectively.MAIN OUTCOME MEASURES:Histological and ultrastructural changes of the injured sciatic nerve;number of regenerated myelinated nerve fibers;nerve conduction velocity;leg muscle atrophy;and sciatic nerve functional index.RESULTS:At 4 months after implantation,the chitosan tube was absorbed.The tube was thin,but maintained the original shape,and vascular proliferation was observed around the tube.In the bridge group,regenerative myelinated nerve fibers were thick and orderly,with a thick myelin sheath and intact axonal structure.The number of myelinated nerve fibers and nerve conduction velocity were significantly greater compared with the other groups (P < 0.01).Moreover,nerve and muscle function was significantly improved following chitosan tube bridging autologous nerve segment treatment compared with the other groups (P < 0.05 or P < 0.01).CONCLUSION:Chitosan tube bridging autologous nerve segments exhibited better repair effects on nerve defects compared with chitosan tubeencapsulated autologous nerve segments and a chitosan tube alone.This method provided a simple and effective treatment for long-segmental nerve defects.展开更多
Qian-Zheng-San, a traditional Chinese prescription consisting of Typhonii Rhizoma, Bombyx Batryticatus, Scorpio, has been found to play an active therapeutic role in central nervous system diseases. However, it is unc...Qian-Zheng-San, a traditional Chinese prescription consisting of Typhonii Rhizoma, Bombyx Batryticatus, Scorpio, has been found to play an active therapeutic role in central nervous system diseases. However, it is unclear whether Qian-Zheng-San has therapeutic value for peripheral nerve injury. Therefore, we used Sprague-Dawley rats to investigate this. A sciatic nerve crush injury model was induced by clamping the right sciatic nerve. Subsequently, rats in the treatment group were administered 2 mL Qian-Zheng-San(1.75 g/mL) daily as systemic therapy for 1, 2, 4, or 8 weeks. Rats in the control group were not administered Qian-Zheng-San. Rats in sham group did not undergo surgery and systemic therapy. Footprint analysis was used to assess nerve motor function. Electrophysiological experiments were used to detect nerve conduction function. Immunofluorescence staining was used to assess axon counts and morphological analysis. Immunohistochemical staining was used to observe myelin regeneration of the sciatic nerve and the number of motoneurons in the anterior horn of the spinal cord. At 2 and 4 weeks postoperatively, the sciatic nerve function index, nerve conduction velocity, the number of distant regenerated axons and the axon diameter of the sciatic nerve increased in the Qian-Zheng-San treatment group compared with the control group. At 2 weeks postoperatively, nerve fiber diameter, myelin thickness, and the number of motor neurons in the lumbar spinal cord anterior horn increased in the Qian-Zheng-San treatment group compared with the control group. These results indicate that QianZheng-San has a positive effect on peripheral nerve regeneration.展开更多
Peripheral nerves have a limited capacity for self-repair and those that are severely damaged or have significant defects are challenging to repair. Investigating the pathophysiology of peripheral nerve repair is impo...Peripheral nerves have a limited capacity for self-repair and those that are severely damaged or have significant defects are challenging to repair. Investigating the pathophysiology of peripheral nerve repair is important for the clinical treatment of peripheral nerve repair and regeneration. In this study, rat models of right sciatic nerve injury were established by a clamping method. Protein chip assay was performed to quantify the levels of neurotrophic, inflammation-related, chemotaxis-related and cell generation-related factors in the sciatic nerve within 7 days after injury. The results revealed that the expression levels of neurotrophic factors(ciliary neurotrophic factor) and inflammationrelated factors(intercellular cell adhesion molecule-1, interferon γ, interleukin-1α, interleukin-2, interleukin-4, interleukin-6, monocyte chemoattractant protein-1, prolactin R, receptor of advanced glycation end products and tumor necrosis factor-α), chemotaxis-related factors(cytokine-induced neutrophil chemoattractant-1, L-selectin and platelet-derived growth factor-AA) and cell generation-related factors(granulocyte-macrophage colony-stimulating factor) followed different trajectories. These findings will help clarify the pathophysiology of sciatic nerve injury repair and develop clinical treatments of peripheral nerve injury. This study was approved by the Ethics Committee of Peking University People's Hospital of China(approval No. 2015-50) on December 9, 2015.展开更多
Although autogenous nerve transplantation is the gold standard for treating peripheral nerve defects of considerable length,it still has some shortcomings,such as insufficient donors and secondary injury.Composite chi...Although autogenous nerve transplantation is the gold standard for treating peripheral nerve defects of considerable length,it still has some shortcomings,such as insufficient donors and secondary injury.Composite chitosan scaffolds loaded with controlled release of nerve growth factor can promote neuronal survival and axonal regeneration after short-segment sciatic nerve defects.However,the effects on extended nerve defects remain poorly understood.In this study,we used chitosan scaffolds loaded with nerve growth factor for 8 weeks to repair long-segment(20 mm)sciatic nerve defects in adult rats.The results showed that treatment markedly promoted the recovery of motor and sensory functions.The regenerated sciatic nerve not only reconnected with neurons but neural circuits with the central nervous system were also reconstructed.In addition,the regenerated sciatic nerve reconnected the motor endplate with the target muscle.Therefore,this novel biomimetic scaffold can promote the regeneration of extended sciatic nerve defects and reconstruct functional circuits.This provides a promising method for the clinical treatment of extended peripheral nerve injury.This study was approved by the Animal Ethics Committee of Capital Medical University,China(approval No.AEEI-2017-033)on March 21,2017.展开更多
The spatial arrangement of the cell is important and considered as underlying mechanism for mathematical modeling of cell to cell interaction.The ability of cells to take on the characteristics of other cells in an or...The spatial arrangement of the cell is important and considered as underlying mechanism for mathematical modeling of cell to cell interaction.The ability of cells to take on the characteristics of other cells in an organism,it is important to understand the dynamical behavior of the cells.This method implements experimental parameters of the cell-cell interaction into the mathematical simulation of cell arrangement.The purpose of this research was to explore the three-dimensional spatial distribution of anterior horn cells in the rat spinal cord to examine differences after sciatic nerve injury.Sixteen Sprague-Dawley male rats were assigned to control and axotomy groups.Twelve weeks after surgery,the anterior horn was removed for first-and second-order stereological studies.Second-order stereological techniques were applied to estimate the pair correlation and cross-correlation functions using a dipole probe superimposed onto the spinal cord sections.The findings revealed 7% and 36% reductions in the mean volume and total number of motoneurons,respectively,and a25% increase in the neuroglial cell number in the axotomized rats compared to the control rats.In contrast,the anterior horn volume remained unchanged.The results also indicated a broader gap in the pair correlation curve for the motoneurons and neuroglial cells in the axotomized rats compared to the control rats.This finding shows a negative correlation for the distribution of motoneurons and neuroglial cells in the axotomized rats.The cross-correlation curve shows a negative correlation between the motoneurons and neuroglial cells in the axotomized rats.These findings suggest that cellular structural and functional changes after sciatic nerve injury lead to the alterations in the spatial arrangement of motoneurons and neuroglial cells,finally affecting the normal function of the central nervous system.The experimental protocol was reviewed and approved by the Animal Ethics Committee of Shahid Beheshti University of Medical Sciences(approval No.IR.SBMU.MSP.REC1395.375) on October 17,2016.展开更多
基金supported by the National Natural Science Foundation of China,Nos.81620108008(to YQL),31971112(to YQL),82071373(to JC)Innovation Capability Support Program of Shaanxi,No.2021TD-57(to YQL)。
文摘A hyaluronic acid granular hydrogel can promote neuronal and astrocyte colony formation and axonal extension in vitro,suggesting that the hydrogel can simulate an extracellular matrix structure to promote neural regeneration.However,in vivo experiments have not been conducted.In this study,we transplanted a hyaluronic acid granular hydrogel nerve guidance conduit to repair a 10-mm long sciatic nerve gap.The Basso,Beattie,and Bresnahan locomotor rating scale,sciatic nerve compound muscle action potential recording,Fluoro-Gold retrograde tracing,growth related protein 43/S100 immunofluorescence staining,transmission electron microscopy,gastrocnemius muscle dry/wet weight ratio,and Masson’s trichrome staining results showed that the nerve guidance conduit exhibited similar regeneration of sciatic nerve axons and myelin sheath,and recovery of the electrophysiological function and motor function as autologous nerve transplantation.The conduit results were superior to those of a bulk hydrogel or silicone tube transplant.These findings suggest that tissue-engineered nerve conduits containing hyaluronic acid granular hydrogels effectively promote the morphological and functional recovery of the injured sciatic nerve.The nerve conduits have the potential as a material for repairing peripheral nerve defects.
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supported by a doctoral fellowship from the European Union(European Regional Development Fund).
文摘The sensorimotor and histological aspects of peripheral neuropathies were already studied by our team in two rat models:the sciatic nerve crush and the Charcot-Marie-Tooth-1A disease.In this study,we sought to highlight and compare the protein signature of these two pathological situations.Indeed,the identification of protein profiles in diseases can play an important role in the development of pharmacological targets.In fact,Charcot-Marie-Tooth-1A rats develop motor impairments that are more severe in the hind limbs.Therefore,for the first time,protein expression in sciatic nerve of Charcot-Marie-Tooth-1A rats was examined.First,distal sciatic nerves were collected from Charcot-Marie-Tooth-1A and uninjured wild-type rats aged 3 months.After protein extraction,sequential window acquisition of all theoretical fragment ion spectra liquid chromatography and mass spectrometry was employed.445 proteins mapped to Swiss-Prot or trEMBL Uniprot databases were identified and quantified.Of these,153 proteins showed statistically significant differences between Charcot-Marie-Tooth-1A and wild-type groups.The majority of these proteins were overexpressed in Charcot-Marie-Tooth-1A.Hierarchical clustering and functional enrichment using Gene Ontology were used to group these proteins based on their biological effects concerning Charcot-Marie-Tooth-1A pathophysiology.Second,proteomic characterization of wild-type rats subjected to sciatic nerve crush was performed sequential window acquisition of all theoretical fragment ion spectra liquid chromatography and mass spectrometry.One month after injury,distal sciatic nerves were collected and analyzed as described above.Out of 459 identified proteins,92 showed significant differences between sciatic nerve crush and the uninjured wild-type rats used in the first study.The results suggest that young adult Charcot-Marie-Tooth-1A rats(3 months old)develop compensatory mechanisms at the level of redox balance,protein folding,myelination,and axonogenesis.These mechanisms seem insufficient to hurdle the progress of the disease.Notably,response to oxidative stress appears to be a significant feature of Charcot-Marie-Tooth-1A,potentially playing a role in the pathological process.In contrast to the first experiment,the majority of the proteins that differed from wild-type were downregulated in the sciatic nerve crush group.Functional enrichment suggested that neurogenesis,response to axon injury,and oxidative stress were important biological processes.Protein analysis revealed an imperfect repair at this time point after injury and identified several distinguishable proteins.In conclusion,we suggest that peripheral neuropathies,whether of a genetic or traumatic cause,share some common pathological pathways.This study may provide directions for better characterization of these models and/or identifying new specific therapeutic targets.
基金funded by the Spanish “Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica, Ministerio de Economía y Competitividad (Instituto de Salud Carlos Ⅲ),grants Nos. FIS PI14-1343, FIS PI17-0393, and FIS PI20-0318 co-financed by the “Fondo Europeo de Desarrollo Regional ERDF-FEDER European Union”grant No. P18-RT-5059 by “Plan Andaluz de Investigación, Desarrollo e Innovación (PAIDI 2020),Consejería de Transformación Económica, Industria, Conocimiento y Universidades, Junta de Andalucía, España”grant No. A-CTS-498-UGR18 by “Programa Operativo FEDER Andalucía 2014–2020, Universidad de Granada, Junta de Andalucía, España”, co-funded by ERDF-FEDER, the European Union (all to VC)
文摘Hollow conduits of natural or synthetic origins have shown acceptable regeneration results in short nerve gap repair;however,results are still not comparable with the current gold standard technique“autografts”.Hollow conduits do not provide a successful regeneration outcome when it comes to critical nerve gap repair.Enriching the lumen of conduits with different extracellular materials and cells could provide a better biomimicry of the natural nerve regenerating environment and is expected to ameliorate the conduit performance.In this study,we evaluated nerve regeneration in vivo using hollow chitosan conduits or conduits enriched with fibrin-collagen hydrogels alone or with the further addition of adipose-derived mesenchymal stem cells in a 15 mm rat sciatic nerve transection model.Unexpected changes in the hydrogel consistency and structural stability in vivo led to a failure of nerve regeneration after 15 weeks.Nevertheless,the molecular assessment in the early regeneration phase(7,14,and 28 days)has shown an upregulation of useful regenerative genes in hydrogel enriched conduits compared with the hollow ones.Hydrogels composed of fibrin-collagen were able to upregulate the expression of soluble NRG1,a growth factor that plays an important role in Schwann cell transdifferentiation.The further enrichment with adipose-derived mesenchymal stem cells has led to the upregulation of other important genes such as ErbB2,VEGF-A,BDNF,c-Jun,and ATF3.
基金funded by the Project of 2022 Health Commission Technology Plan of Zhejiang Province(Project Number:2022KY1169)the 2022 Ningbo Natural Science Foundation Young Doctoral Project(Project Number:2022J027).
文摘Background:The underlying mechanism of sciatic nerve injury(SNI)is a common motor functional disorder,necessitates further research.Methods:A rat model of SNI was established,with the injury group subjected to compressive injury of the right sciatic nerve exposed at the midpoint of the thigh and the sham surgery group undergoing the same surgical procedure.An oxygen-glucose deprivation model was employed to simulate in vitro SNI in PC12 cells.Following data acquisition and quality control,differentially expressed proteins(DEPs)in each model were identified through differential analysis,and enrichment analysis was used to explore the potential functions and pathways of the DEPs.Venn diagrams were drawn,and DEPs from both in vivo and in vitro SNI models were imported into the STRING database to construct a protein-protein interaction network and screen for hub proteins.Results:After the peptide segments obtained from rat nerve blockade and PC12 cells met quality requirements,258 DEPs were identified in rat nerve samples,and 119 DEPs were screened in PC12 cells.Enrichment analysis revealed that DEPs in the rat model were predominantly concentrated in biological functions such as myogenic cell proliferation and signaling related to lipid and energy metabolism.DEPs in the in vitro model were mainly enriched in biological processes such as phagocytosis and were associated with lipid transport and metabolism.Two hub proteins,amyloid precursor protein(APP)and fibronectin 1(FN1),were identified through MCC,MCODE,and Degree scoring.Both PC12 cells and external validation sets showed relatively higher expression of APP and FN1 in injured samples.Results of gene set enrichment analysis indicated that these two proteins were associated with metabolic pathways,such as biosynthesis of glycosaminoglycan chondroitin sulfate and biosynthesis of unsaturated fatty acids.Conclusion:APP and FN1 are potential key molecules involved in SNI and are associated with various metabolic pathways in nerve repair.These findings provide a theoretical basis for the development of therapeutic targets for SNI.
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financially supported by the Faculty of Medicine,LMU(to TH and MMSFöFole,Project 843 and 955)
文摘Despite the regenerative capabilities of peripheral nerves, severe injuries or neuronal trauma of critical size impose immense hurdles for proper restoration of neuro-muscular circuitry. Autologous nerve grafts improve re-establishment of connectivity, but also comprise substantial donor site morbidity. We developed a rat model which allows the testing of different cell applications, i.e., mesenchymal stem cells, to improve nerve regeneration in vivo. To mimic inaccurate alignment of autologous nerve grafts with the injured nerve, a 20 mm portion of the sciatic nerve was excised, and sutured back in place in reversed direction. To validate the feasibility of our novel model, a fibrin gel conduit containing autologous undifferentiated adipose-derived stem cells was applied around the coaptation sites and compared to autologous nerve grafts. After evaluating sciatic nerve function for 16 weeks postoperatively, animals were sacrificed, and gastrocnemius muscle weight was determined along with morphological parameters(g-ratio, axon density & diameter) of regenerating axons. Interestingly, the addition of undifferentiated adipose-derived stem cells resulted in a significantly improved re-myelination, axon ingrowth and functional outcome, when compared to animals without a cell seeded conduit. The presented model thus displays several intriguing features: it imitates a certain mismatch in size, distribution and orientation of axons within the nerve coaptation site. The fibrin conduit itself allows for an easy application of cells and, as a true critical-size defect model, any observed improvement relates directly to the performed intervention. Since fibrin and adipose-derived stem cells have been approved for human applications, the technique can theoretically be performed on humans. Thus, we suggest that the model is a powerful tool to investigate cell mediated assistance of peripheral nerve regeneration.
文摘AIM To study the clinical findings and characteristic features in sciatic notch dumbbell tumors(SNDTs).METHODS We retrospectively reviewed the clinical outcomes and characteristic features of consecutive cases of SNDTs(n = 8). RESULTS Buttock masses occurred in three patients with SNDT(37.5%). Severe buttock tenderness and pain at rest were observed in seven patients with SNDTs(87.5%). Remarkably, none of the patients with SNDTs experienced back pain. Mean tumor size was 8.4 ± 2.0 cm(range, 3.9 to 10.6 cm) and part of the tumor mass was detected in 2 patients in the sagittal view of lumbar magnetic resonance imaging(MRI).CONCLUSION The clinical information regarding to SNDTs is scarce. The authors consider that above mentioned characteristic findings may facilitate the suspicion of pelvic pathology and a search for SNDT by MRI or computed tomography should be considered in patients presenting with sciatica without evidence of spinal diseases.
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.
基金supported by the Postgraduate Research&Practice Innovation Program of Jiangsu Province (KYCX19_2064)the Nantong University Undergraduate Innovation Program (201910304032Z)the Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)。
文摘Background: Cytokines are essential cellular modulators of various physiological and pathological activities, including peripheral nerve repair and regeneration. However, the molecular changes of these cellular mediators after peripheral nerve injury are still unclear. This study aimed to identify cytokines critical for the regenerative process of injured peripheral nerves.Methods: The sequencing data of the injured nerve stumps and the dorsal root ganglia(DRG) of Sprague-Dawley(SD) rats subjected to sciatic nerve(SN) crush injury were analyzed to determine the expression patterns of genes coding for cytokines. PCR was used to validate the accuracy of the sequencing data.Results: A total of 46, 52, and 54 upstream cytokines were differentially expressed in the SN at 1 day, 4 days, and 7 days after nerve injury. A total of 25, 28, and 34 upstream cytokines were differentially expressed in the DRG at these time points. The expression patterns of some essential upstream cytokines are displayed in a heatmap and were validated by PCR. Bioinformatic analysis of these differentially expressed upstream cytokines after nerve injury demonstrated that inflammatory and immune responses were significantly involved.Conclusions: In summary, these findings provide an overview of the dynamic changes in cytokines in the SN and DRG at different time points after nerve crush injury in rats, elucidate the biological processes of differentially expressed cytokines, especially the important roles in inflammatory and immune responses after peripheral nerve injury, and thus might contribute to the identification of potential treatments for peripheral nerve repair and regeneration.
基金funded by the National Natural Science Foundation of China,No.81471338 and No.81671284(to XJZ)the Changzhou Science&Technology Program of China,No.CE20145045(to XJZ)the Changzhou High-Level Medical Talents Training Project of China,No.2016CZLJ018(to XJZ)
文摘Repetitive magnetic stimulation is effective for treating posttraumatic neuropathies following spinal or axonal injury.Neurotropin is a potential treatment for nerve injuries like demyelinating diseases.This study sought to observe the effects of high-frequency repetitive magnetic stimulation,neurotropin and their combined use in the treatment of peripheral nerve injury in 32 adult male Sprague-Dawley rats.To create a sciatic nerve injury model,a 10 mm-nerve segment of the left sciatic nerve was cut and rotated through 180°and each end restored continuously with interrupted sutures.The rats were randomly divided into four groups.The control group received only a reversed autograft in the left sciatic nerve with no treatment.In the high-frequency repetitive magnetic stimulation group,peripheral high-frequency repetitive magnetic stimulation treatment(20 Hz,20 min/d)was delivered for 10 consecutive days after auto-grafting.In the neurotropin group,neurotropin therapy(0.96 NU/kg per day)was administrated for 10 consecutive days after surgery.In the combined group,the combination of peripheral high-frequency repetitive magnetic stimulation(20 Hz,20 min/d)and neurotropin(0.96 NU/kg per day)was given for 10 consecutive days after the operation.The Basso-Beattie-Bresnahan locomotor rating scale was used to assess the behavioral recovery of the injured nerve.The sciatic functional index was used to evaluate the recovery of motor functions.Toluidine blue staining was performed to determine the number of myelinated fibers in the distal and proximal grafts.Immunohistochemistry staining was used to detect the length of axons marked by neurofilament 200.Our results reveal that the Basso-Beattie-Bresnahan locomotor rating scale scores,sciatic functional index,the number of myelinated fibers in distal and proximal grafts were higher and axon lengths were longer in the high-frequency repetitive magnetic stimulation,neurotropin and combined groups compared with the control group.These measures were not significantly different among the high-frequency repetitive magnetic stimulation,neurotropin and combined groups.Therefore,our results suggest that peripheral high-frequency repetitive magnetic stimulation or neurotropin can promote the repair of injured sciatic nerves,but their combined use seems to offer no significant advantage.This study was approved by the Animal Ethics Committee of the Affiliated Changzhou No.2 People’s Hospital of Nanjing Medical University,China on December 23,2014(approval No.2014keyan002-01).
基金Scientific Committee Foundation(No.13102007) of Selcuk University,Konya,Turkey(to HB)
文摘Dexmedetomidine is a selective α2-adrenoceptor agonist that is used because of its sedative,anxiolytic,and analgesic effects.Dexketoprofen,which is used as an analgesic,is a nonselective nonsteroidal anti-inflammatory drug (NSAID).The use of dexmedetomidine and dexketoprofen as adjuvants to local anesthetics for the peripheral nerve is gradually increasing.In this study,we aimed to investigate the effects of different doses of dexmedetomidine and dexketoprofen on conduction block of rat sciatic nerve.The isolated sciatic nerve from adult rats was transferred to a nerve chamber.The compound action potentials (CAPs) were recorded from stimulated nerve with electrophysiological methods.Dexmedetomidine (n = 8) and dexketoprofen (n = 8) were administered in the chamber with cumulative concentrations of 10–9 to 10–5 M,and the CAPs were recorded for 5 and 10 minutes.The CAP parameters were calculated.Both dexmedetomidine and dexketoprofen significantly depressed all CAP parameters in a dose-dependent manner compared with the control group,i.e.,the group in which rats did not receive treatment.CAP parameters showed there was no significant difference in nerve conduction inhibition between dexmedetomidine and dexketoprofen.Higher doses of dexmedetomidine suppressed the conduction in the fast-conducting fibers;however,dexketoprofen was found to suppress the conduction in the slow-conducting fibers in a time-dependent manner and suppress the conduction in the medium- and slow-conducting fibers in a dose-dependent manner.These findings suggest that dexmedetomidine and dexketoprofen exhibit better anesthetic effects on peripheral nerve through different ways of action.The experimental procedures were approved by the Necmettin Erbakan University on January 30,2013 (approval No.2013-024).
基金supported by the National Natural Science Foundation of China,No.31440047the Natural Science Foundation of Guangdong Province in China,No.2015A030310152
文摘Various studies have reported that galanin can promote axonal regeneration of dorsal root ganglion neurons in vitro and inhibit neuropathic pain.However,little is known about its effects on diabetic peripheral neuropathy,and in vivo experimental data are lacking.We hypothesized that repeated applications of exogenous galanin over an extended time frame may also repair nerve damage in diabetic peripheral neuropathy,and relieve pain in vivo.We found that neuropathic pain occurred in streptozotocin-induced diabetic rats and was more severe after sciatic nerve pinch injury at 14 and 28 days than in diabetic sham-operated rats.Treatment with exogenous galanin alleviated the neuropathic pain and promoted sciatic nerve regeneration more effectively in diabetic rats than in non-diabetic rats after sciatic nerve pinch injury.This was accompanied by changes in the levels of endogenous galanin,and its receptors galanin receptor 1 and galanin receptor 2 in the dorsal root ganglia and the spinal dorsal horn when compared with nerve pinch normal rats.Our results show that application of exogenous galanin daily for 28 days can promote the regeneration of injured sciatic nerves,and alleviate neuropathic pain in diabetic rats.
基金supported by the Research and Technology Chancellor of Guilan University of Medical Sciences(No.95110202to AZa).
文摘Studies have shown that acellular nerve xenografts do not require immunosuppression and use of acellular nerve xenografts for repair of peripheral nerve injury is safe and effective.However,there is currently no widely accepted standard chemical decellularization method.The purpose of this study is to investigate the efficiency of bovine-derived nerves decellularized by the modified Hudson’s protocol in the repair of rat sciatic nerve injury.In the modified Hudson’s protocol,Triton X-200 was replaced by Triton X-100,and DNase and RNase were used to prepare accelular nerve xenografts.The efficiency of bovine-derived nerves decellularized by the modified Hudson’s protocol was tested in vitro by hematoxylin&eosin,Alcian blue,Masson’s trichrome,and Luxol fast blue staining,immunohistochemistry,and biochemical assays.The decellularization approach excluded cells,myelin,and axons of nerve xenografts,without affecting the organization of nerve xenografts.The decellularized nerve xenograft was used to bridge a 7 mm-long sciatic nerve defect to evaluate its efficiency in the repair of peripheral nerve injury.At 8 weeks after transplantation,sciatic function index in rats subjected to transplantation of acellular nerve xenograft was similar to that in rats undergoing transplantation of nerve allograft.Morphological analysis revealed that there were a large amount of regenerated myelinated axons in acellular nerve xenograft;the number of Schwann cells in the acellular nerve xenograft was similar to that in the nerve allograft.These findings suggest that acellular nerve xenografts prepared by the modified Hudson’s protocol can be used for repair of peripheral nerve injury.This study was approved by the Research Ethics Committee,Research and Technology Chancellor of Guilan University of Medical Sciences,Iran(approval No.IR.GUMS.REC.1395.332)on February 11,2017.
文摘BACKGROUND:Previous tissue-engineered nerve studies have focused on artificial nerve and nerve cell cultures.The effects of regeneration chambers with autologous nerve bridging for the repair of nerve defects remain unclear.OBJECTIVE:To explore the feasibility and advantages of chitosan tube bridging autologous nerve segments for repairing 12-mm sciatic nerve defects in rats.DESIGN,TIME AND SETTING:A randomized,controlled,animal study using nerve tissue engineering was performed at the Animal Laboratory and Laboratory of Histology and Embryology,Liaoning Medical University from June 2008 to March 2009.MATERIALS:Chitosan powder was purchased from Jinan Haidebei Marine Bioengineering,China.METHODS:A sciatic nerve segment of approximately 8 mm was excised from the posterior margin of the piriformis muscle of Sprague Dawley rats.The two nerve ends shrank to form a 12-mm defect,and the nerve defect was repaired using a chitosan tube bridging autologous nerve segment (bridge group),a chitosan tube-encapsulated autologous nerve segment (encapsulation group),and a chitosan tube alone (chitosan tube alone group),respectively.MAIN OUTCOME MEASURES:Histological and ultrastructural changes of the injured sciatic nerve;number of regenerated myelinated nerve fibers;nerve conduction velocity;leg muscle atrophy;and sciatic nerve functional index.RESULTS:At 4 months after implantation,the chitosan tube was absorbed.The tube was thin,but maintained the original shape,and vascular proliferation was observed around the tube.In the bridge group,regenerative myelinated nerve fibers were thick and orderly,with a thick myelin sheath and intact axonal structure.The number of myelinated nerve fibers and nerve conduction velocity were significantly greater compared with the other groups (P < 0.01).Moreover,nerve and muscle function was significantly improved following chitosan tube bridging autologous nerve segment treatment compared with the other groups (P < 0.05 or P < 0.01).CONCLUSION:Chitosan tube bridging autologous nerve segments exhibited better repair effects on nerve defects compared with chitosan tubeencapsulated autologous nerve segments and a chitosan tube alone.This method provided a simple and effective treatment for long-segmental nerve defects.
基金supported by the National Natural Science Foundation of China,No.31571235(to PXZ),31771322(to PXZ),81401007(to ZYW)National Key Basic Research Program of China(973 Program),No.2014CB542201(to PXZ)+2 种基金Beijing Science and Technology New Star Cross Program of China,No.2018019(to PXZ)Natural Science Foundation of Beijing of China,No.7162098(to WGZ)Fostering Young Scholars of Peking University Health Science Center of China,No.BMU2017PY013(to PXZ)
文摘Qian-Zheng-San, a traditional Chinese prescription consisting of Typhonii Rhizoma, Bombyx Batryticatus, Scorpio, has been found to play an active therapeutic role in central nervous system diseases. However, it is unclear whether Qian-Zheng-San has therapeutic value for peripheral nerve injury. Therefore, we used Sprague-Dawley rats to investigate this. A sciatic nerve crush injury model was induced by clamping the right sciatic nerve. Subsequently, rats in the treatment group were administered 2 mL Qian-Zheng-San(1.75 g/mL) daily as systemic therapy for 1, 2, 4, or 8 weeks. Rats in the control group were not administered Qian-Zheng-San. Rats in sham group did not undergo surgery and systemic therapy. Footprint analysis was used to assess nerve motor function. Electrophysiological experiments were used to detect nerve conduction function. Immunofluorescence staining was used to assess axon counts and morphological analysis. Immunohistochemical staining was used to observe myelin regeneration of the sciatic nerve and the number of motoneurons in the anterior horn of the spinal cord. At 2 and 4 weeks postoperatively, the sciatic nerve function index, nerve conduction velocity, the number of distant regenerated axons and the axon diameter of the sciatic nerve increased in the Qian-Zheng-San treatment group compared with the control group. At 2 weeks postoperatively, nerve fiber diameter, myelin thickness, and the number of motor neurons in the lumbar spinal cord anterior horn increased in the Qian-Zheng-San treatment group compared with the control group. These results indicate that QianZheng-San has a positive effect on peripheral nerve regeneration.
基金supported by the National Key Research and Development Program of China,No. 2016YFC1101604 (to YHK)the Fundamental Research Funds for the Central Universities,Clinical Medicine Plus X-Young Scholars Project of Peking University,No. PKU2020LCXQ020 (to YHK)+2 种基金the Key Laboratory of Trauma and Neural Regeneration (Peking University),Ministry of Education of China,No. BMU2019XY007-01 (to YHK)Guangdong Basic and Applied Basic Research Foundation of China,Nos. 2019A1515110983 (to FY) and 2019A1515011290 (to FY)Shenzhen “San-Ming” Project of Medicine of China,No. SZSM201612092 (to FY)。
文摘Peripheral nerves have a limited capacity for self-repair and those that are severely damaged or have significant defects are challenging to repair. Investigating the pathophysiology of peripheral nerve repair is important for the clinical treatment of peripheral nerve repair and regeneration. In this study, rat models of right sciatic nerve injury were established by a clamping method. Protein chip assay was performed to quantify the levels of neurotrophic, inflammation-related, chemotaxis-related and cell generation-related factors in the sciatic nerve within 7 days after injury. The results revealed that the expression levels of neurotrophic factors(ciliary neurotrophic factor) and inflammationrelated factors(intercellular cell adhesion molecule-1, interferon γ, interleukin-1α, interleukin-2, interleukin-4, interleukin-6, monocyte chemoattractant protein-1, prolactin R, receptor of advanced glycation end products and tumor necrosis factor-α), chemotaxis-related factors(cytokine-induced neutrophil chemoattractant-1, L-selectin and platelet-derived growth factor-AA) and cell generation-related factors(granulocyte-macrophage colony-stimulating factor) followed different trajectories. These findings will help clarify the pathophysiology of sciatic nerve injury repair and develop clinical treatments of peripheral nerve injury. This study was approved by the Ethics Committee of Peking University People's Hospital of China(approval No. 2015-50) on December 9, 2015.
基金supported by the National Natural Science Foundation of China,Nos.31900749(to PH),31730030(to XGL),81941011(to XGL),31971279(to ZYY),31771053(to HMD)the Natural Science Foundation of Beijing of China,No.7214301(to FH)。
文摘Although autogenous nerve transplantation is the gold standard for treating peripheral nerve defects of considerable length,it still has some shortcomings,such as insufficient donors and secondary injury.Composite chitosan scaffolds loaded with controlled release of nerve growth factor can promote neuronal survival and axonal regeneration after short-segment sciatic nerve defects.However,the effects on extended nerve defects remain poorly understood.In this study,we used chitosan scaffolds loaded with nerve growth factor for 8 weeks to repair long-segment(20 mm)sciatic nerve defects in adult rats.The results showed that treatment markedly promoted the recovery of motor and sensory functions.The regenerated sciatic nerve not only reconnected with neurons but neural circuits with the central nervous system were also reconstructed.In addition,the regenerated sciatic nerve reconnected the motor endplate with the target muscle.Therefore,this novel biomimetic scaffold can promote the regeneration of extended sciatic nerve defects and reconstruct functional circuits.This provides a promising method for the clinical treatment of extended peripheral nerve injury.This study was approved by the Animal Ethics Committee of Capital Medical University,China(approval No.AEEI-2017-033)on March 21,2017.
基金supported by the Research Vice-chancellor of Shahid Beheshti University of Medical Sciences,Tehran,Iran(No.1394-373 to RMF)
文摘The spatial arrangement of the cell is important and considered as underlying mechanism for mathematical modeling of cell to cell interaction.The ability of cells to take on the characteristics of other cells in an organism,it is important to understand the dynamical behavior of the cells.This method implements experimental parameters of the cell-cell interaction into the mathematical simulation of cell arrangement.The purpose of this research was to explore the three-dimensional spatial distribution of anterior horn cells in the rat spinal cord to examine differences after sciatic nerve injury.Sixteen Sprague-Dawley male rats were assigned to control and axotomy groups.Twelve weeks after surgery,the anterior horn was removed for first-and second-order stereological studies.Second-order stereological techniques were applied to estimate the pair correlation and cross-correlation functions using a dipole probe superimposed onto the spinal cord sections.The findings revealed 7% and 36% reductions in the mean volume and total number of motoneurons,respectively,and a25% increase in the neuroglial cell number in the axotomized rats compared to the control rats.In contrast,the anterior horn volume remained unchanged.The results also indicated a broader gap in the pair correlation curve for the motoneurons and neuroglial cells in the axotomized rats compared to the control rats.This finding shows a negative correlation for the distribution of motoneurons and neuroglial cells in the axotomized rats.The cross-correlation curve shows a negative correlation between the motoneurons and neuroglial cells in the axotomized rats.These findings suggest that cellular structural and functional changes after sciatic nerve injury lead to the alterations in the spatial arrangement of motoneurons and neuroglial cells,finally affecting the normal function of the central nervous system.The experimental protocol was reviewed and approved by the Animal Ethics Committee of Shahid Beheshti University of Medical Sciences(approval No.IR.SBMU.MSP.REC1395.375) on October 17,2016.
