Demyelination and remyelination have been major focal points in the study of peripheral nerve regeneration following peripheral nerve injury.Notably,the gene regulatory network of regenerated myelin differs from that ...Demyelination and remyelination have been major focal points in the study of peripheral nerve regeneration following peripheral nerve injury.Notably,the gene regulatory network of regenerated myelin differs from that of native myelin.Silencing of enhancer of zeste homolog 2(EZH2)hinders the differentiation,maturation,and myelination of Schwann cells in vitro.To further determine the role of EZH2 in myelination and recovery post-peripheral nerve injury,conditional knockout mice lacking Ezh2 in Schwann cells(Ezh2^(fl/fl);Dhh-Cre and Ezh2^(fl/fl);Mpz-Cre)were generated.Our results show that a significant proportion of axons in the sciatic nerve of Ezh2-depleted mice remain unmyelinated.This highlights the crucial role of Ezh2 in initiating Schwann cell myelination.Furthermore,we observed that 21 days after inducing a sciatic nerve crush injury in these mice,most axons had remyelinated at the injury site in the control nerve,while Ezh2^(fl/fl);Mpz-Cre mice had significantly fewer remyelinated axons compared with their wild-type littermates.This suggests that the absence of Ezh2 in Schwann cells impairs myelin formation and remyelination.In conclusion,EZH2 has emerged as a pivotal regulatory factor in the process of demyelination and myelin regeneration following peripheral nerve injury.Modulating EZH2 activity during these processes may offer a promising therapeutic target for the treatment of peripheral nerve injuries.展开更多
Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene g...Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene glycol(PEG),to immediately fuse closely apposed open ends of severed proximal and distal axons in rat sciatic nerves.We have previously reported that sciatic nerve axons repaired by PEG-fusion do not undergo Wallerian degeneration,and PEG-fused animals exhibit rapid(within 2–6 weeks)and extensive locomotor recovery.Furthermore,our previous report showed that PEG-fusion of severed sciatic motor axons was non-specific,i.e.,spinal motoneurons in PEG-fused animals were found to project to appropriate as well as inappropriate target muscles.In this study,we examined the consequences of PEG-fusion for sensory axons of the sciatic nerve.Young adult male and female rats(Sprague–Dawley)received either a unilateral single cut or ablation injury to the sciatic nerve and subsequent repair with or without(Negative Control)the application of PEG.Compound action potentials recorded immediately after PEG-fusion repair confirmed conduction across the injury site.The success of PEG-fusion was confirmed through Sciatic Functional Index testing with PEG-fused animals showing improvement in locomotor function beginning at 35 days postoperatively.At 2–42 days postoperatively,we anterogradely labeled sensory afferents from the dorsal aspect of the hindpaw following bilateral intradermal injection of wheat germ agglutinin conjugated horseradish peroxidase.PEG-fusion repair reestablished axonal continuity.Compared to unoperated animals,labeled sensory afferents ipsilateral to the injury in PEG-fused animals were found in the appropriate area of the dorsal horn,as well as inappropriate mediolateral and rostrocaudal areas.Unexpectedly,despite having intact peripheral nerves,similar reorganizations of labeled sensory afferents were also observed contralateral to the injury and repair.This central reorganization may contribute to the improved behavioral recovery seen after PEG-fusion repair,supporting the use of this novel repair methodology over currently available treatments.展开更多
Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the ...Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). However, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimization of the macroscopic holes silk^(+) tNGC approach containing macroscopic holes might result in improved grafting technology suitable for future clinical use.展开更多
Behavioral recovery using(viable)peripheral nerve allografts to repair ablation-type(segmental-loss)peripheral nerve injuries is delayed or poor due to slow and inaccurate axonal regeneration.Furthermore,such peripher...Behavioral recovery using(viable)peripheral nerve allografts to repair ablation-type(segmental-loss)peripheral nerve injuries is delayed or poor due to slow and inaccurate axonal regeneration.Furthermore,such peripheral nerve allografts undergo immunological rejection by the host immune system.In contrast,peripheral nerve injuries repaired by polyethylene glycol fusion of peripheral nerve allografts exhibit excellent behavioral recovery within weeks,reduced immune responses,and many axons do not undergo Wallerian degeneration.The relative contribution of neurorrhaphy and polyethylene glycol-fusion of axons versus the effects of polyethylene glycol per se was unknown prior to this study.We hypothesized that polyethylene glycol might have some immune-protective effects,but polyethylene glycol-fusion was necessary to prevent Wallerian degeneration and functional/behavioral recovery.We examined how polyethylene glycol solutions per se affect functional and behavioral recovery and peripheral nerve allograft morphological and immunological responses in the absence of polyethylene glycol-induced axonal fusion.Ablation-type sciatic nerve injuries in outbred Sprague–Dawley rats were repaired according to a modified protocol using the same solutions as polyethylene glycol-fused peripheral nerve allografts,but peripheral nerve allografts were loose-sutured(loose-sutured polyethylene glycol)with an intentional gap of 1–2 mm to prevent fusion by polyethylene glycol of peripheral nerve allograft axons with host axons.Similar to negative control peripheral nerve allografts not treated by polyethylene glycol and in contrast to polyethylene glycol-fused peripheral nerve allografts,animals with loose-sutured polyethylene glycol peripheral nerve allografts exhibited Wallerian degeneration for all axons and myelin degeneration by 7 days postoperatively and did not recover sciatic-mediated behavioral functions by 42 days postoperatively.Other morphological signs of rejection,such as collapsed Schwann cell basal lamina tubes,were absent in polyethylene glycol-fused peripheral nerve allografts but commonly observed in negative control and loose-sutured polyethylene glycol peripheral nerve allografts at 21 days postoperatively.Loose-sutured polyethylene glycol peripheral nerve allografts had more pro-inflammatory and less anti-inflammatory macrophages than negative control peripheral nerve allografts.While T cell counts were similarly high in loose-sutured-polyethylene glycol and negative control peripheral nerve allografts,loose-sutured polyethylene glycol peripheral nerve allografts expressed some cytokines/chemokines important for T cell activation at much lower levels at 14 days postoperatively.MHCI expression was elevated in loose-sutured polyethylene glycol peripheral nerve allografts,but MHCII expression was modestly lower compared to negative control at 21 days postoperatively.We conclude that,while polyethylene glycol per se reduces some immune responses of peripheral nerve allografts,successful polyethylene glycol-fusion repair of some axons is necessary to prevent Wallerian degeneration of those axons and immune rejection of peripheral nerve allografts,and produce recovery of sensory/motor functions and voluntary behaviors.Translation of polyethylene glycol-fusion technologies would produce a paradigm shift from the current clinical practice of waiting days to months to repair ablation peripheral nerve injuries.展开更多
Objective To observe the effects of moxibustion at Huantiao(GB30)acupoint on nerve repair,regeneration,and function in rats with sciatic nerve injury(SNI),and explore the possible mechanism of SNI improvement via moxi...Objective To observe the effects of moxibustion at Huantiao(GB30)acupoint on nerve repair,regeneration,and function in rats with sciatic nerve injury(SNI),and explore the possible mechanism of SNI improvement via moxibustion.Methods A total of 70 specific pathogen-free(SPF)grade male Sprague-Dawley(SD)rats were randomly assigned to control group(n=10)and model group(n=60).Following replication of SNI to model group rats,60 SNI model rats were randomly allocated to SNI groups of 1 d,3 d,and 7 d and moxibustion groups of 1 d,3 d,and 7 d with 10 rats in each group.Moxibustion groups were given moxibustion at the Huantiao(GB30)acupoint on the affected side with a 5 cm distance from the skin under isoflurane respiratory anesthesia and treated once a day for 20 min for 1 d,3 d,and 7 d,respectively.Control and SNI groups were anesthetized with isoflurane daily for 20 min.Open field tests and thermal pain threshold tests were conducted,and the general condition of rats was observed in each group pre-modeling and on treatment day 1,3,and 7.At the end of the treatment,immunofluorescence was used to detect the axonal growth rate,axonal growth density,and Schwann cells(SCs)proliferation in the middle 1-mm cross-section of the crush injury segment in rats.The gastrocnemius muscles on both sides of the rats were taken and weighed to calculate the wet weight ratio of the gastrocnemius muscles on both sides to observe the muscle atrophy of the rats,and hematoxylin-eosin(HE)staining was used to observe the pathomorphological changes of the gastrocnemius muscles on the affected side.Quantitative real-time polymerase chain reaction(qPCR)was used to detect the expression levels of nerve growth factor(NGF),interferon(IFN),macrophage migration inhibitory factor(MIF),interleukin(IL)-4,and transforming growth factor(TGF)-βin the sciatic nerve tissue of the rats.Results After modeling,rats in both moxibustion and SNI groups showed typical signs of pain behaviors(bending and curling of the hind soles of the affected side,licking claws,and lameness)and decreased activity compared with control group.The main benefits of moxibustion were evident from day 3:compared with SNI group,rats in moxibustion group had marked relief of pain behavior,increased activity levels and movement,and a lower response to thermal pain.At the same time,moxibustion significantly promoted the repair of SNI,as evidenced by the significantly better axonal growth rate,growth density,and SCs proliferation density in the crush injury segment compared with SNI group(P<0.01).Moxibustion also regulated the local microenvironment of the injury,up-regulated the pro-nerve repair factors NGF,IL-4,and TGF-β(P<0.05),and down-regulated the pro-inflammatory factors IFN-γ(P<0.01)and MIF(P<0.05).By day 7,the histomorphology of the gastrocnemius muscle in moxibustion group was improved,as indicated by enlarged muscle fibers,elevated regular myocyte morphology and wet weight ratio of the affected and unaffected sides(P<0.05),as well as a sustained high expression levels of NGF,IL-4,and TGF-β(P<0.05,P<0.05,and P<0.01,respectively),and a maintenance of low level of IFN-γ(P<0.01).Concurrently,the MIF level was not significantly different from SNI group(P>0.05).Conclusion Moxibustion at the Huantiao(GB30)acupoint effectively improves motor function and promotes recovery of sensory function and nerve regeneration in SNI rats,which may be related to the regulation of local inflammatory response,the promotion of nerve growth factor expression,the improvement of regenerative microenvironment,and the acceleration of SCs proliferation and axonal growth rate in damaged nerves.展开更多
Stroke is the main cause of disability in the middle and old age.Hemiplegia,especially lower limb paralysis,often leads to the loss of self-care ability and a series of secondary injuries.The main method to improve he...Stroke is the main cause of disability in the middle and old age.Hemiplegia,especially lower limb paralysis,often leads to the loss of self-care ability and a series of secondary injuries.The main method to improve hemiplegic limb movement is exercise therapy,but there are still many patients with disabilities after rehabilitation treatment.As one of the non-pharmacological therapies for stroke,acupuncture has been recognized to improve motor function in patients.Here,we propose a new method,anterior sciatic nerve acupuncture,which can stimulate both the femoral nerve and the sciatic nerve.We designed this study to determine the effect of this method on lower limb motor function.Sixty participants recruited with hemiplegia after cerebral infarction will be randomly assigned to the test group or control group in a 1:1 ratio.The control group will receive Xingnao Kaiqiao acupuncture,and the test group will receive anterior sciatic nerve acupuncture on this basis.All participants will get acupuncture treatment once a day,6 times a week for 2 weeks.The primary outcome is Fugl-Meyer Assessment of Lower Extremity and the secondary outcomes are Modified Ashworth Scale and Modified Barthel Index.Data will be collected before treatment,1week after treatment,and 2 weeks after treatment,and then statistical analysis will be performed.This study can preliminarily verify the effect of anterior sciatic nerve acupuncture on improving lower limb motor function in patients with cerebral infarction,which may provide an alternative approach for clinical treatment of hemiplegia.展开更多
BACKGROUND Schwannomas are rare peripheral neural myelin sheath tumors that originate from Schwann cells.Of the different types of schwannomas,pelvic sciatic nerve schwannoma is extremely rare.Definite preoperative di...BACKGROUND Schwannomas are rare peripheral neural myelin sheath tumors that originate from Schwann cells.Of the different types of schwannomas,pelvic sciatic nerve schwannoma is extremely rare.Definite preoperative diagnosis of pelvic schwannomas is difficult,and surgical resection is the gold standard for its definite diagnosis and treatment.CASE SUMMARY We present a case of pelvic schwannoma arising from the sciatic nerve that was detected in a 40-year-old man who underwent computed tomography for intermittent right lower back pain caused exclusively by a right ureteral calculus.Subsequently,successful transperitoneal laparoscopic surgery was performed for the intact removal of the stone and en bloc resection of the schwannoma.The total operative time was 125 min,and the estimated blood loss was inconspicuous.The surgical procedure was uneventful.The patient was discharged on postoperative day 5 with the simultaneous removal of the urinary catheter.However,the patient presented with motor and sensory disorders of the right lower limb,caused by partial damage to the right sciatic nerve.No tumor recurrence was observed at the postoperative appointment.CONCLUSION Histopathological examination of the specimen confirmed the diagnosis of a schwannoma.Thus,laparoscopic surgery is safe and feasible for concomitant extirpation of pelvic schwannomas and other pelvic and abdominal diseases that require surgical treatment.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
Peripheral nerve injuries with a poor prognosis are common.Evening primrose oil（EPO） has beneficial biological effects and immunomodulatory properties.Since electrical activity plays a major role in neural regenerat...Peripheral nerve injuries with a poor prognosis are common.Evening primrose oil（EPO） has beneficial biological effects and immunomodulatory properties.Since electrical activity plays a major role in neural regeneration,the present study investigated the effects of electrical stimulation（ES）,combined with evening primrose oil（EPO）,on sciatic nerve function after a crush injury in rats.In anesthetized rats,the sciatic nerve was crushed using small haemostatic forceps followed by ES and/or EPO treatment for 4 weeks.Functional recovery of the sciatic nerve was assessed using the sciatic functional index.Histopathological changes of gastrocnemius muscle atrophy were investigated by light microscopy.Electrophysiological changes were assessed by the nerve conduction velocity of sciatic nerves.Immunohistochemistry was used to determine the remyelination of the sciatic nerve following the interventions.EPO ＋ ES,EPO,and ES obviously improved sciatic nerve function assessed by the sciatic functional index and nerve conduction velocity of the sciatic nerve at 28 days after operation.Expression of the peripheral nerve remyelination marker,protein zero（P0）,was increased in the treatment groups at 28 days after operation.Muscle atrophy severity was decreased significantly while the nerve conduction velocity was increased significantly in rats with sciatic nerve injury in the injury ＋ EPO ＋ ES group than in the EPO or ES group.Totally speaking,the combined use of EPO and ES may produce an improving effect on the function of sciatic nerves injured by a crush.The increased expression of P0 may have contributed to improving the functional effects of combination therapy with EPO and ES as well as the electrophysiological and histopathological features of the injured peripheral nerve.展开更多
Platelet-rich plasma containing various growth factors can promote nerve regeneration. An inside-out vein graft can substitute nerve autograft to repair short nerve defects. It is hypothesized that an inside-out vein ...Platelet-rich plasma containing various growth factors can promote nerve regeneration. An inside-out vein graft can substitute nerve autograft to repair short nerve defects. It is hypothesized that an inside-out vein graft filled with platelet-rich plasma shows better effects in the repair of short sciatic nerve defects. In this study, an inside-out vein autograft filled with platelet-rich plasma was used to bridge a 10 mm-long sciatic nerve defect in rats. The sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better improved than that of rats with a simple inside-out vein autograft. At 6 and 8 weeks, the sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better than that of rats undergoing nerve autografting. Compared with the sciatic nerve repaired with a simple inside-out vein autograft, the number of myelinated axons was higher, axon diameter and myelin sheath were greater in the sciatic nerve repaired with an inside-out vein autograft filled with plateletrich plasma and they were similar to those in the sciatic nerve repaired with nerve autograft. These findings suggest that an inside-out vein graft filled with platelet-rich plasma can substitute nerve autograft to repair short sciatic nerve defects.展开更多
Nerve scarring after peripheral nerve injury can severely hamper nerve regeneration and functional recovery.Further,the anti-inflammatory cytokine,interleukin-10,can inhibit nerve scar formation.Saikosaponin a（SSa） ...Nerve scarring after peripheral nerve injury can severely hamper nerve regeneration and functional recovery.Further,the anti-inflammatory cytokine,interleukin-10,can inhibit nerve scar formation.Saikosaponin a（SSa） is a monomer molecule extracted from the Chinese medicine,Bupleurum.SSa can exert anti-inflammatory effects in spinal cord injury and traumatic brain injury.However,it has not been shown whether SSa can play a role in peripheral nerve injury.In this study,rats were randomly assigned to three groups.In the sham group,the left sciatic nerve was directly sutured after exposure.In the sciatic nerve injury（SNI） ＋ SSa and SNI groups,the left sciatic nerve was sutured and continuously injected daily with SSa（10 mg/kg） or an equivalent volume of saline for 7 days.Enzyme linked immunosorbent assay results demonstrated that at 7 days after injury,interleukin-10 level was considerably higher in the SNI ＋ SSa group than in the SNI group.Masson staining and western blot assay demonstrated that at 8 weeks after injury,type I and III collagen content was lower and nerve scar formation was visibly less in the SNI ＋ SSa group compared with the SNI group.Simultaneously,sciatic functional index and nerve conduction velocity were improved in the SNI ＋ SSa group compared with the SNI group.These results confirm that SSa can increase the expression of the anti-inflammatory factor,interleukin-10,and reduce nerve scar formation to promote functional recovery of injured sciatic nerve.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
Objective To investigate the mechanisms of acupuncture in accelerating regeneration of injured sciatic nerve, the effect of electroacupuncture （EA） at ＂Huantiao （环跳 GB 30）＂ and ＂Zusanli （足三里 ST 36）＂ on ...Objective To investigate the mechanisms of acupuncture in accelerating regeneration of injured sciatic nerve, the effect of electroacupuncture （EA） at ＂Huantiao （环跳 GB 30）＂ and ＂Zusanli （足三里 ST 36）＂ on conduction velocity and mRNA expression of receptors of advanced glycation end products （RAGE） of the sciatic nerve were observed in experimental diabetic rats. Methods Streptozotocin was injected into the left abdomen in 30 male rats to establish diabetes mellitus （DM） models with hyperglycemia （〉16.7 mmol/L）. Thirty rats with DM were divided into a diabetes model group （group DM）, a Methycobal group （group MET） and an EA group （group EA）. Another 8 rats comparable in body weight and age were used as a normal control group （group NC）. General situation and blood sugar levels of all the rats were recorded, and the conduction velocities of the sciatic nerves were measured. RAGE mRNA expression of the sciatic nerve was detected by means of reverse transcription polymerase chain reaction（RT-PCR）16 weeks after treatment. Results After 16 weeks, the conduction velocities of the sciatic nerves were lowered in group DM, compared with those in group NC, indicating lesion of peripheral nerves. Compared with group DM, the conduction velocities of the sciatic nerves were significantly elevated in both group EA and group MET （P〈0.01 ）, and there was a significant difference between the two groups, showing superiority of EA to Methycobal （P〈0.01）. The RAGE mRNA levels of the sciatic nerves in group DM were significantly higher than those in group NC （P〈0.01）. The RAGE mRNA levels of the sciatic nerves in both group EA and group MET were remarkably lowered than those in group DM （P〈0.01）, and the decrease in group EA was more obviously than that in group MET （P〈0.01）. Conclusion EA may exert its therapeutic effects on diabetic perineuropathy （DPN） by way of regulating abnormal expression of RAGE mRNA in the sciatic nerve and alleviating its injury caused by advanced glycation end products （AGEs） accumulation and diminishing oxidative stress to enhance its conduction velocity.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
Using electroacupuncture and moxibustion to treat peripheral nerve injury is highly efficient with low side effects. However, the electroacupuncture-and moxibustion-based mechanisms underlying nerve repair are still u...Using electroacupuncture and moxibustion to treat peripheral nerve injury is highly efficient with low side effects. However, the electroacupuncture-and moxibustion-based mechanisms underlying nerve repair are still unclear. Here, in vivo and in vitro experiments uncovered one mechanism through which electroacupuncture and moxibustion affect regeneration after peripheral nerve injury. We first established rat models of sciatic nerve injury using neurotomy. Rats were treated with electroacupuncture or moxibustion at acupoints Huantiao （GB30） and Zusanli （ST36）. Each treatment lasted 15 minutes, and treatments were given six times a week for 4 consecutive weeks. Behavioral testing was used to determine the sciatic functional index. We used electrophysiological detection to measure sciatic nerve conduction velocity and performed hematoxylin-eosin staining to determine any changes in the gastrocnemius muscle. We used immunohistochemistry to observe changes in the expression of S100—a specific marker for Schwann cells—and an enzyme-linked immunosorbent assay to detect serum level of nerve growth factor. Results showed that compared with the model-only group, sciatic functional index, recovery rate of conduction velocity, diameter recovery of the gastrocnemius muscle fibers, number of S100-immunoreactive cells,and level of nerve growth factor were greater in the electroacupuncture and moxibustion groups. The efficacy did not differ between treatment groups. The serum from treated rats was collected and used to stimulate Schwann cells cultured in vitro. Results showed that the viability of Schwann cells was much higher in the treatment groups than in the model group at 3 and 5 days after treatment. These findings indicate that electroacupuncture and moxibustion promoted nerve regeneration and functional recovery; its mechanism might be associated with the enhancement of Schwann cell proliferation and upregulation of nerve growth factor.展开更多
Wallerian degeneration （WD） remains an important research topic. Many genes are differentially expressed during the process of WD, but the precise mechanisms responsible for these differentiations are not completely...Wallerian degeneration （WD） remains an important research topic. Many genes are differentially expressed during the process of WD, but the precise mechanisms responsible for these differentiations are not completely understood. In this study, we used microarrays to analyze the expression changes of the distal nerve stump at 0, 1, 4, 7, 14, 21 and 28 days after sciatic nerve injury in rats. The data revealed 6 076 differentiatly-expressed genes, with 23 types of expression, specifically enriched in genes associated with nerve development and axonogenesis, cytokine biosynthesis, cell differentiation, cytokine/chemokine production, neuron differentiation, cytokinesis, phosphorylation and axon regeneration. Kyoto Encyclopedia of Genes and Genomes pathway analysis gave findings related mainly to the MAPK signaling pathway, the Jak-STAT signaling pathway, the cell cycle, cytokine-cytokine receptor interaction, the p53 signaling pathway and the Wnt signaling pathway. Some key factors were NGF, MAG, CNTF, CTNNA2, p53, JAK2, PLCB1, STAT3, BDNF, PRKC, collagen II, FGF, THBS4, TNC and c-Src, which were further validated by real-time quantitative PCR, Western blot, and immunohistochemistry. Our findings contribute to a better understanding of the functional analysis of differentially-expressed genes in WD and may shed light on the molecular mechanisms of nerve degeneration and regeneration.展开更多
The transplantation of polylactic glycolic acid conduits combining bone marrow mesenchymal stem cells and extracellular matrix gel for the repair of sciatic nerve injury is effective in some respects, but few data com...The transplantation of polylactic glycolic acid conduits combining bone marrow mesenchymal stem cells and extracellular matrix gel for the repair of sciatic nerve injury is effective in some respects, but few data comparing the biomechanical factors related to the sciatic nerve are available. In the present study, rabbit models of 10-mm sciatic nerve defects were prepared. The rabbit models were repaired with autologous nerve, a polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells, or a polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel. After 24 weeks, mechanical testing was performed to determine the stress relaxation and creep parameters. Following sciatic nerve injury, the magnitudes of the stress decrease and strain increase at 7,200 seconds were largest in the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel group, followed by the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells group, and then the autologous nerve group. Hematoxylin-eosin staining demonstrated that compared with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells group and the autologous nerve group, a more complete sciatic nerve regeneration was found, including good myelination, regularly arranged nerve fibers, and a completely degraded and resorbed conduit, in the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel group. These results indicate that bridging 10-mm conduit ＋ bone marrow mesenchymal stem sciatic nerve defects with a polylactic glycolic acid cells ＋ extracellular matrix gel construct increases the stress relaxation under a constant strain, reducing anastomotic tension. Large elongations under a constant physiological load can limit the anastomotic opening and shift, which is beneficial for the regeneration and functional reconstruction of sciatic nerve. Better regeneration was found with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel grafts than with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells grafts and the autologous nerve grafts.展开更多
3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-cycloastragenol （astragaloside IV）, the main active component of the traditional Chinese medicine astragalus membranaceus, has been shown to be neuroprotective. Thi...3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-cycloastragenol （astragaloside IV）, the main active component of the traditional Chinese medicine astragalus membranaceus, has been shown to be neuroprotective. This study investigated whether astragaloside IV could promote the repair of injured sciatic nerve. Denervated sciatic nerve of mice was subjected to anastomosis. The mice were intraperitoneally injected with 10, 5, 2.5 mg/kg astragaloside IV per day for 8 consecutive days Western blot assay and real-time PCR results demonstrated that growth-associated protein-43 ex- pression was upregulated in mouse spinal cord segments L4-6 after intervention with 10, 5, 2.5 mg/kg astragaloside IV per day in a dose-dependent manner. Luxol fast blue staining and elec- trophysiological detection suggested that astragaloside IV elevated the number and diameter of myelinated nerve fibers, and simultaneously increased motor nerve conduction velocity and action potential amplitude in the sciatic nerve of mice. These results indicated that astragaloside IV con- tributed to sciatic nerve regeneration and functional recovery in mice. The mechanism underlying this effect may be associated with the upregulation of growth-associated protein-43 expression.展开更多
基金financially supported by the National Natural Science Foundation of China,Nos.82172104(to CX),81873767(to HZ)a grant from Jiangsu Provincial Research Hospital,Nos.YJXYY202204(to HZ),YJXYY202204-ZD04(to HZ)+5 种基金a grant from Jiangsu Provincial Key Medical CenterJiangsu Provincial Medical Innovation Center,No.CXZX202212Jiangsu Provincial Medical Key Discipline,No.ZDXK202240the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)Technology Project of Nantong,No.MS22022008(to HZ)Postgraduate Research&Practice Innovation Program of Jiangsu Province,No.SJCX21_1457(to WW)。
文摘Demyelination and remyelination have been major focal points in the study of peripheral nerve regeneration following peripheral nerve injury.Notably,the gene regulatory network of regenerated myelin differs from that of native myelin.Silencing of enhancer of zeste homolog 2(EZH2)hinders the differentiation,maturation,and myelination of Schwann cells in vitro.To further determine the role of EZH2 in myelination and recovery post-peripheral nerve injury,conditional knockout mice lacking Ezh2 in Schwann cells(Ezh2^(fl/fl);Dhh-Cre and Ezh2^(fl/fl);Mpz-Cre)were generated.Our results show that a significant proportion of axons in the sciatic nerve of Ezh2-depleted mice remain unmyelinated.This highlights the crucial role of Ezh2 in initiating Schwann cell myelination.Furthermore,we observed that 21 days after inducing a sciatic nerve crush injury in these mice,most axons had remyelinated at the injury site in the control nerve,while Ezh2^(fl/fl);Mpz-Cre mice had significantly fewer remyelinated axons compared with their wild-type littermates.This suggests that the absence of Ezh2 in Schwann cells impairs myelin formation and remyelination.In conclusion,EZH2 has emerged as a pivotal regulatory factor in the process of demyelination and myelin regeneration following peripheral nerve injury.Modulating EZH2 activity during these processes may offer a promising therapeutic target for the treatment of peripheral nerve injuries.
基金supported by the Department of Defense AFIRMⅢW81XWH-20-2-0029 grant subcontractLone Star Paralysis gift,UT POC19-1774-13 grant+1 种基金Neuraptive Therapeutics Inc.26-7724-56 grantNational Institutes of Health R01-NS128086(all to GDB)。
文摘Peripheral nerve injuries result in the rapid degeneration of distal nerve segments and immediate loss of motor and sensory functions;behavioral recovery is typically poor.We used a plasmalemmal fusogen,polyethylene glycol(PEG),to immediately fuse closely apposed open ends of severed proximal and distal axons in rat sciatic nerves.We have previously reported that sciatic nerve axons repaired by PEG-fusion do not undergo Wallerian degeneration,and PEG-fused animals exhibit rapid(within 2–6 weeks)and extensive locomotor recovery.Furthermore,our previous report showed that PEG-fusion of severed sciatic motor axons was non-specific,i.e.,spinal motoneurons in PEG-fused animals were found to project to appropriate as well as inappropriate target muscles.In this study,we examined the consequences of PEG-fusion for sensory axons of the sciatic nerve.Young adult male and female rats(Sprague–Dawley)received either a unilateral single cut or ablation injury to the sciatic nerve and subsequent repair with or without(Negative Control)the application of PEG.Compound action potentials recorded immediately after PEG-fusion repair confirmed conduction across the injury site.The success of PEG-fusion was confirmed through Sciatic Functional Index testing with PEG-fused animals showing improvement in locomotor function beginning at 35 days postoperatively.At 2–42 days postoperatively,we anterogradely labeled sensory afferents from the dorsal aspect of the hindpaw following bilateral intradermal injection of wheat germ agglutinin conjugated horseradish peroxidase.PEG-fusion repair reestablished axonal continuity.Compared to unoperated animals,labeled sensory afferents ipsilateral to the injury in PEG-fused animals were found in the appropriate area of the dorsal horn,as well as inappropriate mediolateral and rostrocaudal areas.Unexpectedly,despite having intact peripheral nerves,similar reorganizations of labeled sensory afferents were also observed contralateral to the injury and repair.This central reorganization may contribute to the improved behavioral recovery seen after PEG-fusion repair,supporting the use of this novel repair methodology over currently available treatments.
基金supported by the Lorenz B?hler Fonds,#2/19 (obtained by the Neuroregeneration Group,Ludwig Boltzmann Institute for Traumatology)the City of Vienna project ImmunTissue,MA23#30-11 (obtained by the Department Life Science Engineering,University of Applied Sciences Technikum Wien)。
文摘Peripheral nerve injuries induce a severe motor and sensory deficit. Since the availability of autologous nerve transplants for nerve repair is very limited, alternative treatment strategies are sought, including the use of tubular nerve guidance conduits(tNGCs). However, the use of tNGCs results in poor functional recovery and central necrosis of the regenerating tissue, which limits their application to short nerve lesion defects(typically shorter than 3 cm). Given the importance of vascularization in nerve regeneration, we hypothesized that enabling the growth of blood vessels from the surrounding tissue into the regenerating nerve within the tNGC would help eliminate necrotic processes and lead to improved regeneration. In this study, we reported the application of macroscopic holes into the tubular walls of silk-based tNGCs and compared the various features of these improved silk^(+) tNGCs with the tubes without holes(silk^(–) tNGCs) and autologous nerve transplants in an 8-mm sciatic nerve defect in rats. Using a combination of micro-computed tomography and histological analyses, we were able to prove that the use of silk^(+) tNGCs induced the growth of blood vessels from the adjacent tissue to the intraluminal neovascular formation. A significantly higher number of blood vessels in the silk^(+) group was found compared with autologous nerve transplants and silk^(–), accompanied by improved axon regeneration at the distal coaptation point compared with the silk^(–) tNGCs at 7 weeks postoperatively. In the 15-mm(critical size) sciatic nerve defect model, we again observed a distinct ingrowth of blood vessels through the tubular walls of silk^(+) tNGCs, but without improved functional recovery at 12 weeks postoperatively. Our data proves that macroporous tNGCs increase the vascular supply of regenerating nerves and facilitate improved axonal regeneration in a short-defect model but not in a critical-size defect model. This study suggests that further optimization of the macroscopic holes silk^(+) tNGC approach containing macroscopic holes might result in improved grafting technology suitable for future clinical use.
基金supported by grants from the Lone Star Paralysis Foundation,NIH R01NS081063Department of Defense award W81XWH-19-2-0054 to GDB+2 种基金supported by University of Wyoming Startup funds,Department of Defense grant W81XWH-17-1-0402the University of Wyoming Sensory Biology COBRE under National Institutes of Health(NIH)award number 5P20GM121310-02the National Institute of General Medical Sciences of the NIH under award number P20GM103432 to JSB。
文摘Behavioral recovery using(viable)peripheral nerve allografts to repair ablation-type(segmental-loss)peripheral nerve injuries is delayed or poor due to slow and inaccurate axonal regeneration.Furthermore,such peripheral nerve allografts undergo immunological rejection by the host immune system.In contrast,peripheral nerve injuries repaired by polyethylene glycol fusion of peripheral nerve allografts exhibit excellent behavioral recovery within weeks,reduced immune responses,and many axons do not undergo Wallerian degeneration.The relative contribution of neurorrhaphy and polyethylene glycol-fusion of axons versus the effects of polyethylene glycol per se was unknown prior to this study.We hypothesized that polyethylene glycol might have some immune-protective effects,but polyethylene glycol-fusion was necessary to prevent Wallerian degeneration and functional/behavioral recovery.We examined how polyethylene glycol solutions per se affect functional and behavioral recovery and peripheral nerve allograft morphological and immunological responses in the absence of polyethylene glycol-induced axonal fusion.Ablation-type sciatic nerve injuries in outbred Sprague–Dawley rats were repaired according to a modified protocol using the same solutions as polyethylene glycol-fused peripheral nerve allografts,but peripheral nerve allografts were loose-sutured(loose-sutured polyethylene glycol)with an intentional gap of 1–2 mm to prevent fusion by polyethylene glycol of peripheral nerve allograft axons with host axons.Similar to negative control peripheral nerve allografts not treated by polyethylene glycol and in contrast to polyethylene glycol-fused peripheral nerve allografts,animals with loose-sutured polyethylene glycol peripheral nerve allografts exhibited Wallerian degeneration for all axons and myelin degeneration by 7 days postoperatively and did not recover sciatic-mediated behavioral functions by 42 days postoperatively.Other morphological signs of rejection,such as collapsed Schwann cell basal lamina tubes,were absent in polyethylene glycol-fused peripheral nerve allografts but commonly observed in negative control and loose-sutured polyethylene glycol peripheral nerve allografts at 21 days postoperatively.Loose-sutured polyethylene glycol peripheral nerve allografts had more pro-inflammatory and less anti-inflammatory macrophages than negative control peripheral nerve allografts.While T cell counts were similarly high in loose-sutured-polyethylene glycol and negative control peripheral nerve allografts,loose-sutured polyethylene glycol peripheral nerve allografts expressed some cytokines/chemokines important for T cell activation at much lower levels at 14 days postoperatively.MHCI expression was elevated in loose-sutured polyethylene glycol peripheral nerve allografts,but MHCII expression was modestly lower compared to negative control at 21 days postoperatively.We conclude that,while polyethylene glycol per se reduces some immune responses of peripheral nerve allografts,successful polyethylene glycol-fusion repair of some axons is necessary to prevent Wallerian degeneration of those axons and immune rejection of peripheral nerve allografts,and produce recovery of sensory/motor functions and voluntary behaviors.Translation of polyethylene glycol-fusion technologies would produce a paradigm shift from the current clinical practice of waiting days to months to repair ablation peripheral nerve injuries.
基金Hunan Provincial Natural Science Foundation Youth Fund Project (2023JJ40480)Hunan Province Key Research and Development Program Project (2024JK2130)Outstanding Youth Project of Hunan University of Chinese Medicine (2022XJB003)。
文摘Objective To observe the effects of moxibustion at Huantiao(GB30)acupoint on nerve repair,regeneration,and function in rats with sciatic nerve injury(SNI),and explore the possible mechanism of SNI improvement via moxibustion.Methods A total of 70 specific pathogen-free(SPF)grade male Sprague-Dawley(SD)rats were randomly assigned to control group(n=10)and model group(n=60).Following replication of SNI to model group rats,60 SNI model rats were randomly allocated to SNI groups of 1 d,3 d,and 7 d and moxibustion groups of 1 d,3 d,and 7 d with 10 rats in each group.Moxibustion groups were given moxibustion at the Huantiao(GB30)acupoint on the affected side with a 5 cm distance from the skin under isoflurane respiratory anesthesia and treated once a day for 20 min for 1 d,3 d,and 7 d,respectively.Control and SNI groups were anesthetized with isoflurane daily for 20 min.Open field tests and thermal pain threshold tests were conducted,and the general condition of rats was observed in each group pre-modeling and on treatment day 1,3,and 7.At the end of the treatment,immunofluorescence was used to detect the axonal growth rate,axonal growth density,and Schwann cells(SCs)proliferation in the middle 1-mm cross-section of the crush injury segment in rats.The gastrocnemius muscles on both sides of the rats were taken and weighed to calculate the wet weight ratio of the gastrocnemius muscles on both sides to observe the muscle atrophy of the rats,and hematoxylin-eosin(HE)staining was used to observe the pathomorphological changes of the gastrocnemius muscles on the affected side.Quantitative real-time polymerase chain reaction(qPCR)was used to detect the expression levels of nerve growth factor(NGF),interferon(IFN),macrophage migration inhibitory factor(MIF),interleukin(IL)-4,and transforming growth factor(TGF)-βin the sciatic nerve tissue of the rats.Results After modeling,rats in both moxibustion and SNI groups showed typical signs of pain behaviors(bending and curling of the hind soles of the affected side,licking claws,and lameness)and decreased activity compared with control group.The main benefits of moxibustion were evident from day 3:compared with SNI group,rats in moxibustion group had marked relief of pain behavior,increased activity levels and movement,and a lower response to thermal pain.At the same time,moxibustion significantly promoted the repair of SNI,as evidenced by the significantly better axonal growth rate,growth density,and SCs proliferation density in the crush injury segment compared with SNI group(P<0.01).Moxibustion also regulated the local microenvironment of the injury,up-regulated the pro-nerve repair factors NGF,IL-4,and TGF-β(P<0.05),and down-regulated the pro-inflammatory factors IFN-γ(P<0.01)and MIF(P<0.05).By day 7,the histomorphology of the gastrocnemius muscle in moxibustion group was improved,as indicated by enlarged muscle fibers,elevated regular myocyte morphology and wet weight ratio of the affected and unaffected sides(P<0.05),as well as a sustained high expression levels of NGF,IL-4,and TGF-β(P<0.05,P<0.05,and P<0.01,respectively),and a maintenance of low level of IFN-γ(P<0.01).Concurrently,the MIF level was not significantly different from SNI group(P>0.05).Conclusion Moxibustion at the Huantiao(GB30)acupoint effectively improves motor function and promotes recovery of sensory function and nerve regeneration in SNI rats,which may be related to the regulation of local inflammatory response,the promotion of nerve growth factor expression,the improvement of regenerative microenvironment,and the acceleration of SCs proliferation and axonal growth rate in damaged nerves.
基金Supported by the National Key Research and Development Program of China:Evidence Based Study on the Treatment of Post Stroke Motor Aphasia with the Rehabilitation Plan of“Xing Nao Kai Qiao”(No.2018YFC1706001)。
文摘Stroke is the main cause of disability in the middle and old age.Hemiplegia,especially lower limb paralysis,often leads to the loss of self-care ability and a series of secondary injuries.The main method to improve hemiplegic limb movement is exercise therapy,but there are still many patients with disabilities after rehabilitation treatment.As one of the non-pharmacological therapies for stroke,acupuncture has been recognized to improve motor function in patients.Here,we propose a new method,anterior sciatic nerve acupuncture,which can stimulate both the femoral nerve and the sciatic nerve.We designed this study to determine the effect of this method on lower limb motor function.Sixty participants recruited with hemiplegia after cerebral infarction will be randomly assigned to the test group or control group in a 1:1 ratio.The control group will receive Xingnao Kaiqiao acupuncture,and the test group will receive anterior sciatic nerve acupuncture on this basis.All participants will get acupuncture treatment once a day,6 times a week for 2 weeks.The primary outcome is Fugl-Meyer Assessment of Lower Extremity and the secondary outcomes are Modified Ashworth Scale and Modified Barthel Index.Data will be collected before treatment,1week after treatment,and 2 weeks after treatment,and then statistical analysis will be performed.This study can preliminarily verify the effect of anterior sciatic nerve acupuncture on improving lower limb motor function in patients with cerebral infarction,which may provide an alternative approach for clinical treatment of hemiplegia.
文摘BACKGROUND Schwannomas are rare peripheral neural myelin sheath tumors that originate from Schwann cells.Of the different types of schwannomas,pelvic sciatic nerve schwannoma is extremely rare.Definite preoperative diagnosis of pelvic schwannomas is difficult,and surgical resection is the gold standard for its definite diagnosis and treatment.CASE SUMMARY We present a case of pelvic schwannoma arising from the sciatic nerve that was detected in a 40-year-old man who underwent computed tomography for intermittent right lower back pain caused exclusively by a right ureteral calculus.Subsequently,successful transperitoneal laparoscopic surgery was performed for the intact removal of the stone and en bloc resection of the schwannoma.The total operative time was 125 min,and the estimated blood loss was inconspicuous.The surgical procedure was uneventful.The patient was discharged on postoperative day 5 with the simultaneous removal of the urinary catheter.However,the patient presented with motor and sensory disorders of the right lower limb,caused by partial damage to the right sciatic nerve.No tumor recurrence was observed at the postoperative appointment.CONCLUSION Histopathological examination of the specimen confirmed the diagnosis of a schwannoma.Thus,laparoscopic surgery is safe and feasible for concomitant extirpation of pelvic schwannomas and other pelvic and abdominal diseases that require surgical treatment.
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 Neuroscience Research Center of the Tabriz University of Medical Sciences,Tabriz,Iran
文摘Peripheral nerve injuries with a poor prognosis are common.Evening primrose oil（EPO） has beneficial biological effects and immunomodulatory properties.Since electrical activity plays a major role in neural regeneration,the present study investigated the effects of electrical stimulation（ES）,combined with evening primrose oil（EPO）,on sciatic nerve function after a crush injury in rats.In anesthetized rats,the sciatic nerve was crushed using small haemostatic forceps followed by ES and/or EPO treatment for 4 weeks.Functional recovery of the sciatic nerve was assessed using the sciatic functional index.Histopathological changes of gastrocnemius muscle atrophy were investigated by light microscopy.Electrophysiological changes were assessed by the nerve conduction velocity of sciatic nerves.Immunohistochemistry was used to determine the remyelination of the sciatic nerve following the interventions.EPO ＋ ES,EPO,and ES obviously improved sciatic nerve function assessed by the sciatic functional index and nerve conduction velocity of the sciatic nerve at 28 days after operation.Expression of the peripheral nerve remyelination marker,protein zero（P0）,was increased in the treatment groups at 28 days after operation.Muscle atrophy severity was decreased significantly while the nerve conduction velocity was increased significantly in rats with sciatic nerve injury in the injury ＋ EPO ＋ ES group than in the EPO or ES group.Totally speaking,the combined use of EPO and ES may produce an improving effect on the function of sciatic nerves injured by a crush.The increased expression of P0 may have contributed to improving the functional effects of combination therapy with EPO and ES as well as the electrophysiological and histopathological features of the injured peripheral nerve.
基金supported by Basic Science Research Program through the National Research Foundation of Korea(NRF)funded by the Ministry of Education,Science and Technology,No.2011-0010429
文摘Platelet-rich plasma containing various growth factors can promote nerve regeneration. An inside-out vein graft can substitute nerve autograft to repair short nerve defects. It is hypothesized that an inside-out vein graft filled with platelet-rich plasma shows better effects in the repair of short sciatic nerve defects. In this study, an inside-out vein autograft filled with platelet-rich plasma was used to bridge a 10 mm-long sciatic nerve defect in rats. The sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better improved than that of rats with a simple inside-out vein autograft. At 6 and 8 weeks, the sciatic nerve function of rats with an inside-out vein autograft filled with platelet-rich plasma was better than that of rats undergoing nerve autografting. Compared with the sciatic nerve repaired with a simple inside-out vein autograft, the number of myelinated axons was higher, axon diameter and myelin sheath were greater in the sciatic nerve repaired with an inside-out vein autograft filled with plateletrich plasma and they were similar to those in the sciatic nerve repaired with nerve autograft. These findings suggest that an inside-out vein graft filled with platelet-rich plasma can substitute nerve autograft to repair short sciatic nerve defects.
基金financially supported by the National Natural Science Foundation of China,No.11672332,11102235,8167050417the National Key Research and Development Plan of China,No.2016YFC1101500+1 种基金the Key Science and Technology Support Foundation of Tianjin City of China,No.17YFZCSY00620the Natural Science Foundation of Tianjin City of China,No.15JCYBJC28600,17JCZDJC35400
文摘Nerve scarring after peripheral nerve injury can severely hamper nerve regeneration and functional recovery.Further,the anti-inflammatory cytokine,interleukin-10,can inhibit nerve scar formation.Saikosaponin a（SSa） is a monomer molecule extracted from the Chinese medicine,Bupleurum.SSa can exert anti-inflammatory effects in spinal cord injury and traumatic brain injury.However,it has not been shown whether SSa can play a role in peripheral nerve injury.In this study,rats were randomly assigned to three groups.In the sham group,the left sciatic nerve was directly sutured after exposure.In the sciatic nerve injury（SNI） ＋ SSa and SNI groups,the left sciatic nerve was sutured and continuously injected daily with SSa（10 mg/kg） or an equivalent volume of saline for 7 days.Enzyme linked immunosorbent assay results demonstrated that at 7 days after injury,interleukin-10 level was considerably higher in the SNI ＋ SSa group than in the SNI group.Masson staining and western blot assay demonstrated that at 8 weeks after injury,type I and III collagen content was lower and nerve scar formation was visibly less in the SNI ＋ SSa group compared with the SNI group.Simultaneously,sciatic functional index and nerve conduction velocity were improved in the SNI ＋ SSa group compared with the SNI group.These results confirm that SSa can increase the expression of the anti-inflammatory factor,interleukin-10,and reduce nerve scar formation to promote functional recovery of injured sciatic nerve.
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.
文摘Objective To investigate the mechanisms of acupuncture in accelerating regeneration of injured sciatic nerve, the effect of electroacupuncture （EA） at ＂Huantiao （环跳 GB 30）＂ and ＂Zusanli （足三里 ST 36）＂ on conduction velocity and mRNA expression of receptors of advanced glycation end products （RAGE） of the sciatic nerve were observed in experimental diabetic rats. Methods Streptozotocin was injected into the left abdomen in 30 male rats to establish diabetes mellitus （DM） models with hyperglycemia （〉16.7 mmol/L）. Thirty rats with DM were divided into a diabetes model group （group DM）, a Methycobal group （group MET） and an EA group （group EA）. Another 8 rats comparable in body weight and age were used as a normal control group （group NC）. General situation and blood sugar levels of all the rats were recorded, and the conduction velocities of the sciatic nerves were measured. RAGE mRNA expression of the sciatic nerve was detected by means of reverse transcription polymerase chain reaction（RT-PCR）16 weeks after treatment. Results After 16 weeks, the conduction velocities of the sciatic nerves were lowered in group DM, compared with those in group NC, indicating lesion of peripheral nerves. Compared with group DM, the conduction velocities of the sciatic nerves were significantly elevated in both group EA and group MET （P〈0.01 ）, and there was a significant difference between the two groups, showing superiority of EA to Methycobal （P〈0.01）. The RAGE mRNA levels of the sciatic nerves in group DM were significantly higher than those in group NC （P〈0.01）. The RAGE mRNA levels of the sciatic nerves in both group EA and group MET were remarkably lowered than those in group DM （P〈0.01）, and the decrease in group EA was more obviously than that in group MET （P〈0.01）. Conclusion EA may exert its therapeutic effects on diabetic perineuropathy （DPN） by way of regulating abnormal expression of RAGE mRNA in the sciatic nerve and alleviating its injury caused by advanced glycation end products （AGEs） accumulation and diminishing oxidative stress to enhance its conduction velocity.
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supported by the National Natural Science Foundation of China,No.81373754,81102670
文摘Using electroacupuncture and moxibustion to treat peripheral nerve injury is highly efficient with low side effects. However, the electroacupuncture-and moxibustion-based mechanisms underlying nerve repair are still unclear. Here, in vivo and in vitro experiments uncovered one mechanism through which electroacupuncture and moxibustion affect regeneration after peripheral nerve injury. We first established rat models of sciatic nerve injury using neurotomy. Rats were treated with electroacupuncture or moxibustion at acupoints Huantiao （GB30） and Zusanli （ST36）. Each treatment lasted 15 minutes, and treatments were given six times a week for 4 consecutive weeks. Behavioral testing was used to determine the sciatic functional index. We used electrophysiological detection to measure sciatic nerve conduction velocity and performed hematoxylin-eosin staining to determine any changes in the gastrocnemius muscle. We used immunohistochemistry to observe changes in the expression of S100—a specific marker for Schwann cells—and an enzyme-linked immunosorbent assay to detect serum level of nerve growth factor. Results showed that compared with the model-only group, sciatic functional index, recovery rate of conduction velocity, diameter recovery of the gastrocnemius muscle fibers, number of S100-immunoreactive cells,and level of nerve growth factor were greater in the electroacupuncture and moxibustion groups. The efficacy did not differ between treatment groups. The serum from treated rats was collected and used to stimulate Schwann cells cultured in vitro. Results showed that the viability of Schwann cells was much higher in the treatment groups than in the model group at 3 and 5 days after treatment. These findings indicate that electroacupuncture and moxibustion promoted nerve regeneration and functional recovery; its mechanism might be associated with the enhancement of Schwann cell proliferation and upregulation of nerve growth factor.
基金supported by grants from the National Natural Science Foundation of China (81130080, 30870811)the Scientific Research Foundation for Returned Overseas Chinese Scholars, Ministry of Education of China+1 种基金the Natural Science Foundation of Jiangsu Province, China (BK2010282)the Priority Academic Program Development of Higher Education Institutions of Jiangsu Province, China
文摘Wallerian degeneration （WD） remains an important research topic. Many genes are differentially expressed during the process of WD, but the precise mechanisms responsible for these differentiations are not completely understood. In this study, we used microarrays to analyze the expression changes of the distal nerve stump at 0, 1, 4, 7, 14, 21 and 28 days after sciatic nerve injury in rats. The data revealed 6 076 differentiatly-expressed genes, with 23 types of expression, specifically enriched in genes associated with nerve development and axonogenesis, cytokine biosynthesis, cell differentiation, cytokine/chemokine production, neuron differentiation, cytokinesis, phosphorylation and axon regeneration. Kyoto Encyclopedia of Genes and Genomes pathway analysis gave findings related mainly to the MAPK signaling pathway, the Jak-STAT signaling pathway, the cell cycle, cytokine-cytokine receptor interaction, the p53 signaling pathway and the Wnt signaling pathway. Some key factors were NGF, MAG, CNTF, CTNNA2, p53, JAK2, PLCB1, STAT3, BDNF, PRKC, collagen II, FGF, THBS4, TNC and c-Src, which were further validated by real-time quantitative PCR, Western blot, and immunohistochemistry. Our findings contribute to a better understanding of the functional analysis of differentially-expressed genes in WD and may shed light on the molecular mechanisms of nerve degeneration and regeneration.
基金supported by the Science and Technology Development Program of Jilin Province in China,No.20110492
文摘The transplantation of polylactic glycolic acid conduits combining bone marrow mesenchymal stem cells and extracellular matrix gel for the repair of sciatic nerve injury is effective in some respects, but few data comparing the biomechanical factors related to the sciatic nerve are available. In the present study, rabbit models of 10-mm sciatic nerve defects were prepared. The rabbit models were repaired with autologous nerve, a polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells, or a polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel. After 24 weeks, mechanical testing was performed to determine the stress relaxation and creep parameters. Following sciatic nerve injury, the magnitudes of the stress decrease and strain increase at 7,200 seconds were largest in the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel group, followed by the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells group, and then the autologous nerve group. Hematoxylin-eosin staining demonstrated that compared with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells group and the autologous nerve group, a more complete sciatic nerve regeneration was found, including good myelination, regularly arranged nerve fibers, and a completely degraded and resorbed conduit, in the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel group. These results indicate that bridging 10-mm conduit ＋ bone marrow mesenchymal stem sciatic nerve defects with a polylactic glycolic acid cells ＋ extracellular matrix gel construct increases the stress relaxation under a constant strain, reducing anastomotic tension. Large elongations under a constant physiological load can limit the anastomotic opening and shift, which is beneficial for the regeneration and functional reconstruction of sciatic nerve. Better regeneration was found with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells ＋ extracellular matrix gel grafts than with the polylactic glycolic acid conduit ＋ bone marrow mesenchymal stem cells grafts and the autologous nerve grafts.
文摘3-O-beta-D-xylopyranosyl-6-O-beta-D-glucopyranosyl-cycloastragenol （astragaloside IV）, the main active component of the traditional Chinese medicine astragalus membranaceus, has been shown to be neuroprotective. This study investigated whether astragaloside IV could promote the repair of injured sciatic nerve. Denervated sciatic nerve of mice was subjected to anastomosis. The mice were intraperitoneally injected with 10, 5, 2.5 mg/kg astragaloside IV per day for 8 consecutive days Western blot assay and real-time PCR results demonstrated that growth-associated protein-43 ex- pression was upregulated in mouse spinal cord segments L4-6 after intervention with 10, 5, 2.5 mg/kg astragaloside IV per day in a dose-dependent manner. Luxol fast blue staining and elec- trophysiological detection suggested that astragaloside IV elevated the number and diameter of myelinated nerve fibers, and simultaneously increased motor nerve conduction velocity and action potential amplitude in the sciatic nerve of mice. These results indicated that astragaloside IV con- tributed to sciatic nerve regeneration and functional recovery in mice. The mechanism underlying this effect may be associated with the upregulation of growth-associated protein-43 expression.
