Schwanns cell (SC) was isolated from sciatic nerve of adult rat with Wallerine degeneration. After culture, SC-serum free culture media (SCSFCM) was obtained. By ultrafiltration with PM-10 Amicon Membrane, electrophoresis with DiscPAGE,and electrical wash-out with Biotrap apparatus, D-band protein was isolated from the SC-SFCM. The D-band protein in the concentration of 25ng/ml could affect the survival of the spinal anterior horn neuron in vitro, prominently and itsactivity was not changed after being frozen. The molecular weight of the protein ranged from 43 to 67 Kd. The D-band protein might be a neurotrophic substancedifferent from the known SCderived neurotrophic factors (NTF). Its concentration with biological activity was high enough to be detected. The advantages of MTT in assessment of NTF activity were also discussed.
Objective To investigate the clinical features, treatment methods, and prognostic influence factors of patients with malignant peripheral nerve sheath tumor (MPNST). MethodsA retrospective analysis was conducted on 96 MPNST patients treated between January 1, 2015 and December 31, 2021. There were 46 males and 50 females, aged between 15 and 87 years (mean, 48.2 years). The tumors were located in the trunk in 50 cases, extremities in 39 cases, and head and neck in 7 cases. The maximum tumor diameter was <5 cm in 49 cases, ≥5 cm in 32 cases, with 15 cases missing data. Tumor depth was deep in 77 cases and superficial in 19 cases. The Fédération Nationale des Centres de Lutte Contre le Cancer (FNCLCC) histological grading was G1 in 9 cases, G2 in 12 cases, and G3 in 34 cases, with 41 cases missing data. There were 37 recurrent MPNST cases, 32 cases with neurofibromatosis type 1 (NF1), and 26 cases in stage Ⅳ. Postoperative adjuvant radiotherapy was administered to 25 patients, perioperative chemotherapy to 45 patients, and anlotinib-targeted therapy to 30 patients. R0 resection was achieved in 73 cases. Patients were divided into groups based on the presence or absence of NF1, and baseline data between the two groups were compared. Kaplan-Meier curves were generated to assess disease-free survival (DFS) and overall survival (OS) based on various factors (age, gender, presence of NF1, recurrent MPNST, stage Ⅳ MPNST, FNCLCC grade, R0 resection, tumor location, tumor size, tumor depth, perioperative chemotherapy, postoperative adjuvant radiotherapy, and anlotinib-targeted therapy), and differences between survival curves were analyzed using the Log-Rank test. Multivariate COX proportional hazards regression was used to identify independent prognostic factors for MPNST. Results Patients with NF1 had a significantly higher proportion of superficial tumors and lower FNCLCC grade compared to those without NF1 (P<0.05); no significant difference was found for other variables (P<0.05). Kaplan-Meier analysis showed that recurrent MPNST, stage Ⅳ MPNST, FNCLCC grade, R0 resection, perioperative chemotherapy, and anlotinib-targeted therapy were factors influencing 1-year DFS (P<0.05), while stage Ⅳ MPNST, FNCLCC grade, and perioperative chemotherapy were factors affecting 3-year OS (P<0.05). Multivariate COX proportional hazards regression analysis revealed that recurrent MPNST and high-grade FNCLCC (G3) were independent prognostic factors for 1-year DFS (P<0.05), while stage Ⅳ MPNST, superficial tumor depth, age over 60 years, postoperative adjuvant radiotherapy, and anlotinib-targeted therapy were independent prognostic factors for 3-year OS (P<0.05). Conclusion MPNST patients with NF1 tend to have more superficial tumors and lower FNCLCC grades. FNCLCC grade, R0 resection, and adjuvant therapies, including radiotherapy and anlotinib-targeted therapy, are closely associated with MPNST prognosis. Complete surgical resection should be prioritized in clinical management, along with adjuvant treatments such as radiotherapy and targeted therapy of anlotinib to improve patient outcomes.
ObjectiveTo investigate the effects of exosomes from adipose-derived stem cells (ADSCs) on peripheral nerve regeneration, and to find a new treatment for peripheral nerve injury. MethodsThirty-six adult Sprague Dawley (SD) rats (male or female, weighing 220-240 g) were randomly divided into 3 groups (n=12). Group A was the control group; group B was sciatic nerve injury group; group C was sciatic nerve injury combined with exosomes from ADSCs treatment group. The sciatic nerve was only exposed without injury in group A, and the sciatic nerve crush injury model was prepared in groups B and C. The SD rats in groups A and B were injected with PBS solution of 200 μL via tail veins; the SD rats in group C were injected with pure PBS solution of 200 μL containing 100 μg exosomes from ADSCs, once a week and injected for 12 weeks. At 1 week after the end of the injection, the rats were killed and the sciatic nerves were taken at the part of injury. The sciatic nerve fiber bundles were observed by HE staining; the SCs apoptosis of the sciatic nerve tissue were detected by TUNEL staining; the ultrastructure and SCs autophagy of the sciatic nerve were observed by transmission electron microscope. ResultsGross observation showed that there was no obvious abnormality in the injured limbs of group A, but there were the injured limbs paralysis and muscle atrophy in groups B and C, and the degree of paralysis and muscle atrophy in group C were lighter than those in group B. HE staining showed that the perineurium of group A was regular; the perineurium of group B was irregular, and there were a lot of cell-free structures and tissue fragments in group B; the perineurium of group C was more complete, and significantly well than that of group B. TUNEL staining showed that the SCs apoptosis was significantly increased in groups B and C than in group A, in group B than in group C (P<0.01). Transmission electron microscope observation showed that the SCs autophagosomes in groups B and C were significantly increased than those in group A, but the autophagosomes in group C were significantly lower than those in group B. ConclusionThe exosomes from ADSCs can promote the peripheral nerve regeneration. The mechanism may be related to reducing SCs apoptosis, inhibiting SCs autophagy, and reducing nerve Wallerian degeneration.
ObjectiveTo investigate the effect of folic acid coated-crosslinked urethane-doped polyester elastomer (fCUPE) nerve conduit in repairing long distance peripheral nerve injury. MethodsThirty-six 3-month-old male Sprague Dawley rats weighing 180-220 g were randomly assigned to 3 groups, each consisting of 12 rats: CUPE nerve conduit transplantation group (group A), fCUPE nerve conduit transplantation group (group B), and autologous nerve transplantation group (group C), the contralateral healthy limb of group C served as the control group (group D). A 20-mm-long sciatic nerve defect model was established in rats, and corresponding materials were used to repair the nerve defect according to the group. The sciatic function index (SFI) of groups A-C was calculated using the Bain formula at 1, 2, and 3 months after operation. The nerve conduction velocity (NCV) of the affected side in groups A-D was assessed using neuroelectrophysiological techniques. At 3 months after operation, the regenerated nerve tissue was collected from groups A-C for S-100 immunohistochemical staining and Schwann cell count in groups A and B to compare the level of nerve repair and regeneration in each group. ResultsAt 3 months after operation, the nerve conduits in all groups partially degraded. There was no significant adhesion between the nerve and the conduit and the surrounding tissues, the conduit was well connected with the distal and proximal nerves, and the nerve-like tissues in the conduit could be observed when the nerve conduit stents were cut off. SFI in group A was significantly higher than that in group C at each time point after operation and was significantly higher than that in group B at 2 and 3 months after operation (P<0.05). There was no significant difference in SFI between groups B and C at each time point after operation (P>0.05). NCV in group A was significantly slower than that in the other 3 groups at each time point after operation (P<0.05). The NCV of groups B and C were slower than that of group D, but the difference was significant only at 1 month after operation (P<0.05). There was no significant difference between groups B and C at each time point after operation (P>0.05). Immunohistochemical staining showed that the nerve tissue of group A had an abnormal cavo-like structure, light tissue staining, and many non-Schwann cells. In group B, a large quantity of normal neural structures was observed, the staining was deeper than that in group A, and the distribution of dedifferentiated Schwann cells was obvious. In group C, the nerve bundles were arranged neatly, and the tissue staining was the deepest. The number of Schwann cells in group B was (727.50±57.60) cells/mm2, which was significantly more than that in group A [(298.33±153.12) cells/mm2] (t=6.139, P<0.001). ConclusionThe fCUPE nerve conduit is effective in repairing long-distance sciatic nerve defects and is comparable to autologous nerve grafts. It has the potential to be used as a substitute material for peripheral nerve defect transplantation.
Objective
To review the mechanism and effects of cell autophagy in the pathophysiology changes of peripheral nerve injury.
Methods
The recent literature about cell autophagy in peripheral nerve injury and regeneration was extensively reviewed and summarized.
Results
The researches through drugs intervention and gene knockout techniques have confirmed that the Schwann cell autophagy influences the myelin degeneration, debris clearance, inflammatory cells infiltration, and axon regeneration through JNK/c-Jun pathway. To adjust autophagy process could slow down the Wallerian degeneration, maintain the integrity of injured nerve, while the effect on axon regeneration is still controversial.
Conclusion
The Schwann cell autophagy plays a key role in the pathophysiology changes of peripheral nerve injury, the further study of its mechanism could provide new methods for the therapy of peripheral nerve injury.
ObjectiveTo review recent research progress in the use of auxiliary components of nerve conduits for the treatment of peripheral nerve injuries. MethodsAn extensive review of recent domestic and international literature was conducted to evaluate the role of auxiliary components in nerve conduits for peripheral nerve repair, with a focus on their effects and underlying mechanisms. ResultsBy incorporating auxiliary components such as bioactive molecules, therapeutic cells, and their derivatives, nerve conduits can create a more biomimetic regenerative microenvironment. This is achieved by providing neurotrophic support, modulating the immune microenvironment, improving blood and oxygen supply, and offering directional guidance for nerve regeneration. Consequently, the nerve conduit is transformed from a simple physical scaffold into an active, bio-functional repair system, which enhances the effectiveness for PNI. ConclusionWhile nerve conduits augmented with auxiliary components demonstrate improved effectiveness, further advancements are required in drug delivery systems and the integration of cellular components. Moreover, most current studies are based on animal or in vitro experiments. Randomized controlled clinical trials are necessary to validate their clinical effectiveness.
Objective To explore the effect of short-term low-frequency electrical stimulation (SLES) during operation on nerve regeneration in delayed peripheral nerve injury with long gap. Methods Thirty female adult Sprague Dawley rats, weighing 160-180 g, were used to prepare 13-mm defect model by trimming the nerve stumps. Then all rats were randomly divided into 2 groups, 15 rats in each group. After nerve defect was bridged by the contralateral normal sciatic nerve, SLES was applied in the experimental group, but was not in the control group. The spinal cords and dorsal root ganglions (DRGs) were harvested to carry out immunofluorescence histochemistry double staining for growth-associated proteins 43 (GAP-43) and brain-derived neurotrophic factor (BDNF) at 1, 2, and 7 days after repair. Fluorogold (FG) retrograde tracing was performed at 3 months after repair. The mid-portion regenerated segments were harvested to perform Meyer’s trichrome staining, immunofluorescence double staining for neurofilament (NF) and soluble protein 100 (S-100) on the transversely or longitudinal sections at 3 months after repair. The segment of the distal sciatic nerve trunk was harvested for electron microscopy and morphometric analyses to measure the diameter of the myelinated axons, thickness of myelin sheaths, the G ratio, and the density of the myelinated nerve fibers. The gastrocnemius muscles of the operated sides were harvested to measure the relative wet weight ratios. Karnovsky-Root cholinesterase staining of the motor endplate was carried out. Results In the experimental group, the expressions of GAP-43 and BDNF were higher than those in the control group at 1 and 2 days after repair. The number of labeled neurons in the anterior horn of gray matter in the spinal cord and DRGs at the operated side from the experimental group was more than that from the control group. Meyer’s trichrome staining, immunofluorescence double staining, and the electron microscopy observation showed that the regenerated nerves were observed to develop better in the experimental group than the control group. The relative wet weight ratio of experimental group was significantly higher than that of the control group (t=4.633,P=0.000). The size and the shape of the motor endplates in the experimental group were better than those in the control group. Conclusion SLES can promote the regeneration ability of the short-term (1 month) delayed nerve injury with long gap to a certain extent.
ObjectiveTo describe the research progress of silk-based biomaterials in peripheral nerve repair and provide useful ideals to accelerate the regeneration of large-size peripheral nerve injury. Methods The relative documents about silk-based biomaterials used in peripheral nerve regeneration were reviewed and the different strategies that could accelerate peripheral nerve regeneration through building bioactive microenvironment with silk fibroin were discussed. Results Many silk fibroin tissue engineered nerve conduits have been developed to provide multiple biomimetic microstructures, and different microstructures have different mechanisms of promoting nerve repair. Biomimetic porous structures favor the nutrient exchange at wound sites and inhibit the invasion of scar tissue. The aligned structures can induce the directional growth of nerve tissue, while the multiple channels promote the axon elongation. When the fillers are introduced to the conduits, better growth, migration, and differentiation of nerve cells can be achieved. Besides biomimetic structures, different nerve growth factors and bioactive drugs can be loaded on silk carriers and released slowly at nerve wounds, providing suitable biochemical cues. Both the biomimetic structures and the loaded bioactive ingredients optimize the niches of peripheral nerves, resulting in quicker and better nerve repair. With silk biomaterials as a platform, fusing multiple ways to achieve the multidimensional regulation of nerve microenvironments is becoming a critical strategy in repairing large-size peripheral nerve injury. Conclusion Silk-based biomaterials are useful platforms to achieve the design of biomimetic hierarchical microstructures and the co-loading of various bioactive ingredients. Silk fibroin nerve conduits provide suitable microenvironment to accelerate functional recovery of peripheral nerves. Different optimizing strategies are available for silk fibroin biomaterials to favor the nerve regeneration, which would satisfy the needs of various nerve tissue repair. Bioactive silk conduits have promising future in large-size peripheral nerve regeneration.
Objective To investigate the differences in biomechanical properties between fresh and chemically extracted acellular peri pheral nerve. Methods Thirty-six sciatic nerves were harvested from 18 adult male Wistar rats of 3 months old and randomly assigned into 3 groups (n=12 per group): normal control group (group A), the nerve segments received no treatment; Sondell method group (group B), the nerve segments were chemically extracted with the detergents of Triton X-100 and sodium deoxycholate; and improved method group (group C), chemically extracted acellular treatment of nerve was done with the detergents of Triton X-200, Sulfobetaine-10 (SB-10), and SB-16. After the acellularization, the structural changes of nerves in each group were observed by HE staining and field emission scanning electron microscope,then the biomechanical properties of nerves were tested using mechanical apparatus (Endura TEC ELF 3200). Results HE staining and field emission scanning electron microscope showed that the effect of acellularization of group C was similar to that of group B, but the effects of demyel ination and integrity of nerve fiber tube of group C were better than those of group B; the structure of broken nerves was more chaotic than before biomechanical test. The biomechanical test showed that the ultimate load, ultimate stress, ultimate strain, mechanical work to fracture in group A were the largest, the next was group C, the least was group B; the tenacity and elastic modulus in group C were the largest, the next was group B, the least was group A; but the differences were not significant (P gt; 0.05). Conclusion Compared with Sondell method, the nerve treated by improved method is more appropriate for use in vivo.
ObjectiveTo summarize the research status of mandibular sensory dysfunction after transoral endoscopic thyroidectomy vestibular approach (TOETVA), and explore its potential treatment methods and existing problems, and provide ideas and methods for future clinical treatments or research. MethodThe domestic and foreign literatures about peripheral nerve injury and its treatment after TOETVA were searched and reviewed. ResultsMental nerve injury was considered to be the main cause of mandibular sensory dysfunction after TOETVA. Due to the lack of unified definitions and assessment standards, the true incidence remained unclear. In order to reduce the risk of mental nerve injury, methods such as exposing the mental nerve and combining vestibular approaches during surgery had certain advantages. In terms of treatment, several methods promoting nerve repair were noteworthy, including B vitamins, nerve growth factors, physical therapy and so on. In addition, some auxiliary treatments of Traditional Chinese Medicine also showed effectiveness in promoting nerve regeneration. ConclusionsIt is essential to avoid damage to the mental nerve and mandibular tissues during surgery. For patients with significant complaints postoperatively, active treatment should be pursued. Establishing objective and quantifiable standards for evaluating mandibular sensory dysfunction and seeking effective clinical plans through a multidisciplinary approach may be the direction for future research.
