Fas ligand regulate nerve injury and repair by affecting AKT, ß-catenin, and NF-κB pathways.

Objective: To investigate the regulatory effect of Fas-L on the repair and regeneration of peripheral extension injury in rats. Methods: This study aimed to explore the effects of Fas-L on apoptosis and axonal regeneration of dorsal root ganglion (DRG) cells in rat peripheral nerve repair and regeneration by using several relevant experimental techniques from the injured nerve animal model, cell biology, and molecular biology. Results: The expression level of Fas-L in DRG tissues was significantly down-regulated after sciatic nerve injury. Interference with Fas-L can significantly promote the regeneration of DRG neuronal axons and inhibit apoptosis, while the overexpression of Fas-L is contrary to it. Moreover, Fas-L may play a role in the regulation of DRG function and the repair and regeneration of peripheral nerves in Sprague Dawley (SD) rats by affecting several signaling pathways, such as p-AKT/AKT, ß-catenin, and NF-κB. Conclusion: Fas-L may have a certain effect on the repair and regeneration of peripheral nerve injury in SD rats, which may provide an experimental basis and a new theoretical basis for the functional reconstruction of peripheral nerves. Significance statement: The expression level of Fas-L in DRG tissues was significantly down-regulated after sciatic nerve injury. Fas-L can significantly promote the regeneration of DRG neuronal axons and inhibit apoptosis. Fas-L may play a role in the regulation of DRG function and the repair and regeneration of peripheral nerves in SD rats by affecting several signaling pathways, such as p-AKT/AKT, ß-catenin, and NF-κB. Fas-L may have a certain effect on the repair and regeneration of peripheral nerve injury in SD rats, which may provide an experimental basis and a new theoretical basis for the functional reconstruction of peripheral nerves.

Role of Long Non-coding RNA in Nerve Regeneration.

Nerve injury can be caused by a variety of factors. It often takes a long time to repair a nerve injury and severe nerve injury is even difficult to heal. Therefore, increasing attention has focused on nerve injury and repair. Long non-coding RNA (lncRNA) is a newly discovered non-coding RNA with a wide range of biological activities. Numerous studies have shown that a variety of lncRNAs undergo changes in expression after nerve injury, indicating that lncRNAs may be involved in various biological processes of nerve repair and regeneration. Herein, we summarize the biological roles of lncRNAs in neurons, glial cells and other cells during nerve injury and regeneration, which will help lncRNAs to be better applied in nerve injury and regeneration in the future.

Long noncoding RNA H19 regulates degeneration and regeneration of injured peripheral nerves.

Our previous studies have shown that long noncoding RNA (lncRNA) H19 is upregulated in injured rat sciatic nerve during the process of Wallerian degeneration, and that it promotes the migration of Schwann cells and slows down the growth of dorsal root ganglion axons. However, the mechanism by which lncRNA H19 regulates neural repair and regeneration after peripheral nerve injury remains unclear. In this study, we established a Sprague-Dawley rat model of sciatic nerve transection injury. We performed in situ hybridization and found that at 4-7 days after sciatic nerve injury, lncRNA H19 was highly expressed. At 14 days before injury, adeno-associated virus was intrathecally injected into the L4-L5 foramina to disrupt or overexpress lncRNA H19. After overexpression of lncRNA H19, the growth of newly formed axons from the sciatic nerve was inhibited, whereas myelination was enhanced. Then, we performed gait analysis and thermal pain analysis to evaluate rat behavior. We found that lncRNA H19 overexpression delayed the recovery of rat behavior function, whereas interfering with lncRNA H19 expression improved functional recovery. Finally, we examined the expression of lncRNA H19 downstream target SEMA6D, and found that after lncRNA H19 overexpression, the SEMA6D protein level was increased. These findings suggest that lncRNA H19 regulates peripheral nerve degeneration and regeneration through activating SEMA6D in injured nerves. This provides a new clue to understand the role of lncRNA H19 in peripheral nerve degeneration and regeneration.

Baculoviral inhibitor of apoptosis protein repeat-containing protein 3 delays early Wallerian degeneration after sciatic nerve injury.

Wallerian degeneration is a complex biological process that occurs after nerve injury, and involves nerve degeneration and regeneration. Schwann cells play a crucial role in the cellular and molecular events of Wallerian degeneration of the peripheral nervous system. However, Wallerian degeneration regulating nerve injury and repair remains largely unknown, especially the early response. We have previously reported some key regulators of Wallerian degeneration after sciatic nerve injury. Baculoviral inhibitor of apoptosis protein repeat-containing protein 3 (BIRC3) is an important factor that regulates apoptosis-inhibiting protein. In this study, we established rat models of right sciatic nerve injury. In vitro Schwann cell models were also established and subjected to gene transfection to inhibit and overexpress BIRC3. The data indicated that BIRC3 expression was significantly up-regulated after sciatic nerve injury. Both BIRC3 upregulation and downregulation affected the migration, proliferation and apoptosis of Schwan cells and affected the expression of related factors through activating c-fos and ERK signal pathway. Inhibition of BIRC3 delayed early Wallerian degeneration through inhibiting the apoptosis of Schwann cells after sciatic nerve injury. These findings suggest that BIRC3 plays an important role in peripheral nerve injury repair and regeneration. The study was approved by the Institutional Animal Care and Use Committee of Nantong University, China (approval No. 2019-nsfc004) on March 1, 2019.

Effect of lncRNA H19 on nerve degeneration and regeneration after sciatic nerve injury in rats.

Hundreds of millions of people worldwide suffer from peripheral nerve damage resulting from car accidents, falls, industrial accidents, residential accidents, and wars. The purpose of our study was to further investigate the effects of Wallerian degeneration (WD) after rat sciatic nerve injury and to screen for critical long noncoding RNAs (lncRNAs) in WD. We found H19 to be essential for nerve degeneration and regeneration and to be highly expressed in the sciatic nerves of rats with WD. lncRNA H19 potentially impaired the recovery of sciatic nerve function in rats. H19 was mainly localized in the cytoplasm of Schwann cells (SCs) and promoted their migration. H19 promoted the apoptosis of dorsal root ganglion (DRG) neurons and slowed the growth of DRG axons. The lncRNA H19 may play a role in WD through the Wnt/ß-catenin signaling pathway and is coexpressed with a variety of crucial mRNAs during WD. These data provide further insight into the molecular mechanisms of WD.

Protein kinase C theta (Prkcq) affects nerve degeneration and regeneration through the c-fos and c-jun pathways in injured rat sciatic nerves.

BACKGROUND: Previous finding using DNA microarray and bioinformatics analysis, we have reported some key factors which regulated gene expression and signaling pathways in injured sciatic nerve during Wallerian Degeneration (WD). This research is focused on protein kinase C theta (Prkcq) participates in the regulation of the WD process. METHODS: In this study, we explored the molecular mechanism by which Prkcq in Schwann cells (SCs) affects nerve degeneration and regeneration in vivo and in vitro after rat sciatic nerve injury. RESULTS: Study of the cross-sectional model showed that Prkcq expression decreased significantly during sciatic nerve repair. Functional analysis showed that upregulation and downregulation of Prkcq could affect the proliferation, migration and apoptosis of Schwann cells and lead to the expression of related factors through the activation of the ß-catenin, c-fos, and p-c-jun/c-jun pathways. CONCLUSION: The study provides insights into the role of Prkcq in early WD during peripheral nerve degeneration and/or regeneration.

Claudin 14/15 play important roles in early wallerian degeneration after rat sciatic nerve injury.

PURPOSE: Wallerian degeneration (WD) is an antegrade degenerative process distal to peripheral nerve injury. Numerous genes are differentially regulated in response to the process. However, the underlying mechanism is unclear, especially the early response. We aimed at investigating the effects of sciatic nerve injury on WD via CLDN 14/15 interactions in vivo and in vitro. METHODS: Using the methods of molecular biology and bioinformatics analysis, we investigated the molecular mechanism by which claudin 14/15 participate in WD. Our previous study showed that claudins 14 and 15 trigger the early signal flow and pathway in damaged sciatic nerves. Here, we report the effects of the interaction between claudin 14 and claudin 15 on nerve degeneration and regeneration during early WD. RESULTS: It was found that claudin 14/15 were upregulated in the sciatic nerve in WD. Claudin 14/15 promoted Schwann cell proliferation, migration and anti-apoptosis in vitro. PKCα, NT3, NF2, and bFGF were significantly upregulated in transfected Schwann cells. Moreover, the expression levels of the ß-catenin, p-AKT/AKT, p-c-jun/c-jun, and p-ERK/ERK signaling pathways were also significantly altered. CONCLUSION: Claudin 14/15 affect Schwann cell proliferation, migration, and anti-apoptosis via the ß-catenin, p-AKT/AKT, p-c-jun/c-jun, and p-ERK/ERK pathways in vitro and in vivo. The results of this study may help elucidate the molecular mechanisms of the tight junction signaling pathway underlying peripheral nerve degeneration.

Protein Kinase Cα Promotes Proliferation and Migration of Schwann Cells by Activating ERK Signaling Pathway.

Wallerian degeneration (WD) and axon regeneration generally take place following peripheral nerve injury (PNI). Schwann cells (SCs) and macrophages play major role in WD. SCs, acting as repair cells and primary signal mediators, dedifferentiate and proliferate to remove the debris, form Büngner's bands and secrete trophic factors during these processes. However, the underlying mechanisms remain poorly understood. Here, we found that protein kinase Cα (PKCα), a serine/threonine kinase, expressed in SCs was significantly up-regulated after PNI. Activating PKCα with phorbol 12-myristate 13-acetate (PMA), a phorbol ester binds and activates PKCα) promoted SCs proliferation and migration. While, silence of PKCα by siRNAs inhibited these processes. PD184352, an inhibitor of MEK1, reversed the effect induced by PMA on SCs. Mechanism studies revealed that PKCα functioned through activating the ERK signaling pathway. Furthermore, PKCα also exhibited a neuroprotective role by upregulating the expression of neurotrophic factors in SCs. To sum up, this study offers novel insights for clarifying our understanding of the involvement of PKCα in the mechanism of peripheral nerve degeneration as well as regeneration.

Claudin-15 overexpression inhibits proliferation and promotes apoptosis of Schwann cells in vitro.

Our previous experiments have discovered that Claudin-15 was up-regulated in Schwann cells of the distal nerve stumps of rat models of sciatic nerve injury. However, how Claudin-15 affects Schwann cell function is still unknown. This study aimed to identify the effects of Claudin-15 on proliferation and apoptosis of Schwann cells cultured in vitro and explore the underlying mechanisms. Primary Schwann cells were obtained from rats. Claudin-15 in Schwann cells was knocked down using siRNA (siRNA-1 group) compared with the negative control siRNA transfection group (negative control group). Claudin-15 in Schwann cells was overexpressed using pGV230-Claudin-15 plasmid (pGV230-Claudin-15 group). The pGV230 transfection group (pGV230 group) acted as the control of the pGV230-Claudin-15 group. Cell proliferation was analyzed with EdU assay. Cell apoptosis was analyzed with flow cytometric analysis. Cell migration was analyzed with Transwell inserts. The mRNA and protein expressions were analyzed with quantitative polymerase chain reaction assay and western blot assay. The results showed that compared with the negative control group, cell proliferation rate was up-regulated; p-AKT/AKT ratio, apoptotic rate, p-c-Jun/c-Jun ratio, mRNA expression of protein kinase C alpha, Bcl-2 and Bax were down-regulated; and mRNA expression of neurotrophins basic fibroblast growth factor and neurotrophin-3 were increased in the siRNA-1 group. No significant difference was found in cell migration between the negative control and siRNA-1 groups. Compared with the pGV230 group, the cell proliferation rate was down-regulated; apoptotic rate, p-c-Jun/c-Jun ratio and c-Fos protein expression increased; mRNA expression of protein kinase C alpha and Bax decreased; and mRNA expressions of neurotrophins basic fibroblast growth factor and neurotrophin-3 were up-regulated in the pGV230-Claudin-15 group. The above results demonstrated that overexpression of Claudin-15 inhibited Schwann cell proliferation and promoted Schwann cell apoptosis in vitro. Silencing of Claudin-15 had the reverse effect and provided neuroprotective effect. This study was approved by the Experimental Animal Ethics Committee of Jilin University of China (approval No. 2016-nsfc001) on March 5, 2016.

Toll-Like Receptor 4 (TLR4) Expression Affects Schwann Cell Behavior in vitro.

Peripheral nerve injury can result in the decreased quality of life and bring us economic burden on society and individuals. Wallerian degeneration (WD) is critical for nerve degeneration and regeneration, but the mechanisms of WD are still elusive. Here, we report the effect of Toll-like receptor 4 (TLR4) on cultured Schwann cells (SCs) in vitro. The data showed that TLR4 expression was up-regulated after sciatic nerve injury of rat. TLR4 was expressed in cultured SCs. Enhanced or silenced expression of TLR4 affected SC proliferation, migration, apoptosis and relative gene expression. Furthermore, altered expression of TLR4 resulted in expression changes in c-Jun, ERK and catenin but not AKT and c-Fos pathways in SCs. These results suggested that TLR4 may be an important effective target in peripheral nerve degeneration and/or regeneration during WD in future investigations.

Fas Ligand Gene (Faslg) Plays an Important Role in Nerve Degeneration and Regeneration After Rat Sciatic Nerve Injury.

Wallerian degeneration (WD) is associated with changes in the expression levels of a large number of genes. However, the effects of these up- or down-regulated genes are poorly understood. We have reported some key factors that are differentially regulated during WD in our previous research. Here, we explored the roles of Fas ligand gene (Faslg) in WD after rat sciatic nerve injury. The data showed that Faslg was up-regulated in injured nerves. Expression changed of Faslg in Schwann cells (SCs) resulted in alterations in the release of related factors. Silencing or overexpression of Faslg affected SC proliferation, migration, and apoptosis through ß-catenin, nuclear factor-κB (NF-κB), and caspase-3 pathways in vivo and in vitro. Our data suggest that Faslg is a key regulatory gene that affects nerve repair and regeneration in peripheral nerve injury. This study sheds new light on the effects of Faslg on peripheral nerve degeneration and/or regeneration.

Effect of Spp1 on nerve degeneration and regeneration after rat sciatic nerve injury.

BACKGROUND: Wallerian degeneration (WD) in injured peripheral nerves is associated with a large number of up- or down-regulated genes, but the effects of these changes are poorly understood. In our previous studies, we reported some key factors that are differentially expressed to activate nerve degeneration and regeneration during WD. Here, we determined the effects of secreted phosphoprotein 1 (Spp1) on WD after rat sciatic nerve injury. RESULTS: Spp1 was upregulated from 6 h to 14 days after sciatic nerve injury. Altered expression of Spp1 in Schwann cells (SC) resulted in altered mRNA and protein expression levels for cytokines, c-Fos, PKCα and phospho-ERK/ERK and affected SC apoptosis in vitro. Silencing of Spp1 expression in SCs using siRNA technology reduced proliferation and promoted migration of SCs in vitro. By contrast, overexpression of Spp1 promoted proliferation and reduced migration in SCs in vitro. Differential expression of Spp1 after sciatic nerve injury in vivo altered the expression of cytokines, c-Fos, PKCα, and the p-ERK/ERK pathway. CONCLUSIONS: Spp1 is a key regulatory factor that affects nerve degeneration and regeneration through c-Fos, PKCα and p-ERK/ERK pathways after rat sciatic nerve injury. These results shed new light on the role of Spp1 in nerve degeneration and regeneration during WD.

Mitochondrial carnitine palmitoyl transferase-II inactivity aggravates lipid accumulation in rat hepatocarcinogenesis.

AIM: To investigate the dynamic alteration of mitochondrial carnitine palmitoyl transferase II (CPT-II) expression during malignant transformation of rat hepatocytes. METHODS: Sprague-Dawley male rats were fed with normal, high fat (HF), and HF containing 2-fluorenylacetamide (2-FAA) diet, respectively. According to the Hematoxylin and Eosin staining of livers, rats were divided into control, fatty liver, degeneration, precancerous, and cancerous groups. Liver lipids were dyed with Oil Red O, CPT-II alterations were analyzed by immunohistochemistry, and compared with CPT-II specific concentration (µg/mg protein). Levels of total cholesterol (Tch), triglyceride (TG), and amino-transferases [alanine aminotransferase (ALT), aspartate aminotransferase (AST)] were determined by the routine methods. RESULTS: After intake of HF and/or HF+2-FAA diets, the rat livers showed mass lipid accumulation. The lipid level in the control group was significantly lower than that in other groups. The changes of serum TG and Tch levels were abnormally increasing, 2-3 times more than those in the controls (P < 0.05). During the rat liver morphological changes from normal to cancer development process with hepatocyte injury, serum AST and ALT levels were significantly higher (4-8 times, P < 0.05) than those in the control group. The specific concentration of CPT-II in liver tissues progressively decreased during hepatocyte malignant transformation, with the lowest CPT-II levels in the cancer group than in any of the other groups (P < 0.05). CONCLUSION: Low CPT-II expression might lead to abnormal hepatic lipid accumulation, which should promote the malignant transformation of hepatocytes.

Nonalcoholic Lipid Accumulation and Hepatocyte Malignant Transformation.

Worldwide incidence of hepatocellular carcinoma (HCC) is steadily increasing, highlighting its status as a public health concern, particularly due to its significant association with other comorbidities, such as diabetes. However, nonalcoholic fatty liver disease (NAFLD) has emerged as a primary risk factor, with its own prevalence increasing in recent years, and it has gradually caught up with the historical primary etiological factors of infection with hepatitis B virus and hepatitis C virus, exposure to aflatoxin, or alcohol liver disease. The deeply worrisome aspects of all of these high risk factors, however, are their remarkable presence within populations. Systemic and genetic mechanisms involved in the malignant transformation of liver cells, as well as useful biomarkers of early stage HCC are being investigated. However, the exact mechanisms underlying the interrelation of NAFLD and HCC remain largely unknown. In this review, some of the recent advances in our understanding of liver lipid accumulation are summarized and discussed to provide insights into the relationship between NAFLD and hepatocyte malignant transformation.

Abnormal expressions of inflammatory-related mediators and inhibition of fat metabolism in mice infected with influenza a virus.

The pathophysiological role of influenza infection is poorly understood. In this study, one non-neurovirulent virus (IAV/Aichi/2/68/H3N2) strain was used to infect intra-nasally mice at different age to investigate the mechanism of cerebral edema formation and lower activities of mitochondria enzymes after influenza A virus (IAV) infection. Mice suffered 46.4% mortality in newborn compared with 96.0% in weanling, 100% in adult on day 7, respectively. IAV-RNA was easily detected in the brain of newborn mice. Significant production of endothelin-1 and inducible nitric oxide syntheses were increased on the 3rd and 5th day after IAV infection, associated with increasing blood-brain barrier permeability, brain edema formation and the higher mortality of animals. Production of tumor necrosis factor-α was related to inhibition of mitochondrial enzyme activities, suggesting that over expression of inflammatory cytokines and lower enzyme activities in mitochondria after IAV infection.

Abbreviated half-lives and impaired fuel utilization in carnitine palmitoyltransferase II variant fibroblasts.

Carnitine palmitoyltransferase II (CPT II) deficiency is one of the most common causes of fatty acid oxidation metabolism disorders. However, the molecular mechanism between CPT2 gene polymorphisms and metabolic stress has not been fully clarified. We previously reported that a number of patients show a thermal instable phenotype of compound hetero/homozygous variants of CPT II. To understand the mechanism of the metabolic disorder resulting from CPT II deficiency, the present study investigated CPT II variants in patient fibroblasts, [c.1102 G>A (p.V368I)] (heterozygous), [c.1102 G>A (p.V368I)] (homozygous), and [c.1055 T>G (p.F352C)] (heterozygous) + [c.1102 G>A (p.V368I)] (homozygous) compared with fibroblasts from healthy controls. CPT II variants exerted an effect of dominant negative on the homotetrameric proteins that showed thermal instability, reduced residual enzyme activities and a short half-life. Moreover, CPT II variant fibroblasts showed a significant decrease in fatty acid ß-oxidation and adenosine triphosphate generation, combined with a reduced mitochondrial membrane potential, resulting in cellular apoptosis. Collectively, our data indicate that the CPT II deficiency induces an energy crisis of the fatty acid metabolic pathway. These findings may contribute to the elucidation of the genetic factors involved in metabolic disorder encephalopathy caused by the CPT II deficiency.

Differential gene expression in proximal and distal nerve segments of rats with sciatic nerve injury during Wallerian degeneration.

Wallerian degeneration is a subject of major interest in neuroscience. A large number of genes are differentially regulated during the distinct stages of Wallerian degeneration: transcription factor activation, immune response, myelin cell differentiation and dedifferentiation. Although gene expression responses in the distal segment of the sciatic nerve after peripheral nerve injury are known, differences in gene expression between the proximal and distal segments remain unclear. In the present study in rats, we used microarrays to analyze changes in gene expression, biological processes and signaling pathways in the proximal and distal segments of sciatic nerves undergoing Wallerian degeneration. More than 6,000 genes were differentially expressed and 20 types of expression tendencies were identified, mainly between proximal and distal segments at 7-14 days after injury. The differentially expressed genes were those involved in cell differentiation, cytokinesis, neuron differentiation, nerve development and axon regeneration. Furthermore, 11 biological processes were represented, related to responses to stimuli, cell apoptosis, inflammatory response, immune response, signal transduction, protein kinase activity, and cell proliferation. Using real-time quantitative PCR, western blot analysis and immunohistochemistry, microarray data were verified for four genes: aquaporin-4, interleukin 1 receptor-like 1, matrix metalloproteinase-12 and periaxin. Our study identifies differential gene expression in the proximal and distal segments of a nerve during Wallerian degeneration, analyzes dynamic biological changes of these genes, and provides a useful platform for the detailed study of nerve injury and repair during Wallerian degeneration.

The effects of claudin 14 during early Wallerian degeneration after sciatic nerve injury.

Claudin 14 has been shown to promote nerve repair and regeneration in the early stages of Wallerian degeneration (0-4 days) in rats with sciatic nerve injury, but the mechanism underlying this process remains poorly understood. This study reported the effects of claudin 14 on nerve degeneration and regeneration during early Wallerian degeneration. Claudin 14 expression was up-regulated in sciatic nerve 4 days after Wallerian degeneration. The altered expression of claudin 14 in Schwann cells resulted in expression changes of cytokines in vitro. Expression of claudin 14 affected c-Jun, but not Akt and ERK1/2 pathways. Further studies revealed that enhanced expression of claudin 14 could promote Schwann cell proliferation and migration. Silencing of claudin 14 expression resulted in Schwann cell apoptosis and reduction in Schwann cell proliferation. Our data revealed the role of claudin 14 in early Wallerian degeneration, which may provide new insights into the molecular mechanisms of Wallerian degeneration.

Protein expression profiling during wallerian degeneration after rat sciatic nerve injury.

INTRODUCTION: Wallerian degeneration (WD) is an important area of research in modern neuroscience. Many protein expressions are regulated by differentially expressed genes in WD, but the precise mechanisms are elusive. METHODS: In this study, we profiled differentially expressed proteins in WD after rat sciatic nerve injury using an antibody array. RESULTS: Functional analysis positively identified cell proliferation, regulation of cell proliferation, and immune system processes. Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis revealed molecular networks related mainly to cytokine-cytokine receptor interaction, the mitogen-activated proteinkinase (MAPK) signaling pathway, apoptosis, the toll-like receptor (TLR) signaling pathway, and the Janus kinase (Jak) - signal transducer and activator of transcription (STAT) signaling pathway. Interactions between these differential proteins were well established and regulated by the key factors transforming growth factor beta 1 (TGF-ß1), toll-like receptor 4 (TLR4), Fas ligand (FasL), and 5'-AMP-activated protein kinase catalytic subunit alpha-1 (PRKAA1). CONCLUSIONS: These results provide information related to functional analysis of differentially expressed genes during WD.

Expression changes and bioinformatic analysis of Wallerian degeneration after sciatic nerve injury in rat.

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 differentially-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.