Abnormal DNA Methylation in Thoracic Spinal Cord Tissue Following Transection Injury.

BACKGROUND Spinal cord injury (SCI) is a serious disease with high disability and mortality rates, with no effective therapeutic strategies available. In SCI, abnormal DNA methylation is considered to be associated with axonal regeneration and cell proliferation. However, the roles of key genes in potential molecular mechanisms of SCI are not clear. MATERIAL AND METHODS Subacute spinal cord injury models were established in Wistar rats. Histological observations and motor function assessments were performed separately. Whole-genome bisulfite sequencing (WGBS) was used to detect the methylation of genes. Gene ontology (GO) term enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis were performed using the DAVID database. Protein-protein interaction (PPI) networks were analyzed by Cytoscape software. RESULTS After SCI, many cavities, areas of necrotic tissue, and many inflammatory cells were observed, and motor function scores were low. After the whole-genome bisulfite sequencing, approximately 96 DMGs were screened, of which 50 were hypermethylated genes and 46 were hypomethylated genes. KEGG pathway analysis highlighted the Axon Guidance pathway, Endocytosis pathway, T cell receptor signaling pathway, and Hippo signaling pathway. Expression patterns of hypermethylated genes and hypomethylated genes detected by qRT-PCR were the opposite of WGBS data, and the difference was significant. CONCLUSIONS Abnormal methylated genes and key signaling pathways involved in spinal cord injury were identified through histological observation, behavioral assessment, and bioinformatics analysis. This research can serve as a source of additional information to expand understanding of spinal cord-induced epigenetic changes.

Analysis on the risk factors of second fracture in osteoporosis-related fractures.

OBJECTIVE: To explore the clinical characteristics and risk factors of refracture in patients suffering from osteoporosis-related fractures as well as effective interventions. METHODS: From January 2006 to January 2008, both out-patients and in-patients in our hospital who were over 50 years old and suffered from osteoporosis-related fractures were selected for this research. They were divided into fracture group and refracture group. The refracture rate was followed up for 2 years, during which 11 patients developed refracture, thus were included in the refracture group. Therefore, 273 patients, 225 first-fracture cases, aged (67.7+/-8.5) years, and 48 refracture cases, aged (72.7+/-9.5) years, were included in this study. General data including age and sex, fracture types, femoral neck bone mineral density (BMD) T-scores tested by dual-energy X-rays absorptiometry (DEXA), Charlson index, time-frame between two fractures as well as mobility skill assessment were collected and analyzed by single-factor and multivariate statistical methods. RESULTS: Females accounted for 70.2% of the fracture group and 77.1% of the refracture group. The most common refracture type was vertebral fracture for the first time and femoral neck fracture for the second time during the follow-up. The second fracture happened 3.7 years after the first one on average. The refracture rate was 2.12% within one year, and 4.66% within two years. Risk factors for a second fracture in osteoporotic fracture patients included age (larger than 75 years, HR equal to 1.23, 95%CI 1.18-1.29; larger than 85 years, HR equal to 1.68, 95% CI 1.60-1.76), female sex (HR equal to 1.36, 95%CI 1.32-1.40), prior vertebral fractures (HR equal to 1.62, 95%CI 1.01-2.07), prior hip fractures (HR equal to 1.27, 95%CI 0.89-2.42), BMD T-score less than -3.5 (HR equal to 1.38, 95%CI 1.17-1.72) and weakened motor skills (HR equal to 1.27, 95%CI 1.09-1.40). CONCLUSIONS: The risks of second fracture among patients with initial brittle fracture are substantial. There is adequate time between the first and second fractures for interventions to reduce the risks of refracture, especially for the old women with a vertebral or hip fracture. Medication, motor functional rehabilitation and fall-down prevention training are helpful.

iTRAQ-based proteomics profiling of Schwann cells before and after peripheral nerve injury.

OBJECTIVES: Schwann cells (SCs) have a wide range of applications as seed cells in the treatment of nerve injury during transplantation. However, there has been no report yet on kinds of proteomics changes that occur in Schwann cells before and after peripheral nerve injury. MATERIALS AND METHODS: Activated Schwann cells (ASCs) and normal Schwann cells (NSCs) were obtained from adult Wistar rat sciatic nerves. After immunofluorescence identification, we identified differentially expressed proteins in the ASCs and NSCs using isobaric tags for relative and absolute quantitation (iTRAQ) combined with high-resolution Orbitrap liquid chromatography-mass spectrometry/mass spectrometry (LC-MS/MS). In addition, all the differentially expressed proteins were analyzed by Gene ontology (GO) analysis and Kyoto encyclopedia of genes and genomes (KEGG) pathway analysis. Finally, several differentially expressed proteins were selected for Western blot verification. RESULTS: A total of 122 differentially expressed proteins in ASCs and NSCs were screened. GO analysis suggested that these different proteins are likely to accumulate in the cytoplasm and are associated with single-multicellular organism processes. The KEGG pathway analysis suggested that proteins related to purine metabolism were significantly enriched. The expression of Transmembrane glycoprotein NMB (GPNMB), Ectonucleotide pyrophosphatase/phosphodiesterase family member 3 (ENPP3), and other proteins were consistent with the proteomics data obtained by Western blot analysis. CONCLUSION: GPNMB, ENPP3, GFPT2, and other proteins may play an important role in the repair of peripheral nerve injury. This study may provide new insights into changes in SCs after peripheral nerve injury.

Comparison of DNA Methylation in Schwann Cells before and after Peripheral Nerve Injury in Rats.

This study aims to find the difference of genomewide DNA methylation in Schwann cells (SCs) before and after peripheral nerve system (PNS) injury by Methylated DNA Immunoprecipitation Sequencing (MeDIP-Seq) and seek meaningful differentially methylated genes related to repairment of injured PNS. SCs harvested from sciatic nerve were named as activated Schwann cells (ASCs), and the ones harvested from brachial plexus were named as normal Schwann cells (NSCs). Genomic DNA of ASCs and NSCs were isolated and MeDIP-Seq was conducted. Differentially methylated genes and regions were discovered and analyzed by bioinformatic methods. MeDIP-Seq analysis showed methylation differences were identified between ASCs and NSCs. The distribution of differentially methylated regions (DMRs) peaks in different components of genome was mainly located in distal intergenic regions. GO and KEGG analysis of these methylated genes were also conducted. The expression patterns of hypermethylated genes (Dgcr8, Zeb2, Dixdc1, Sox2, and Shh) and hypomethylated genes (Gpr126, Birc2) detected by qRT-PCR were opposite to the MeDIP analysis data with significance (p < 0.05), which proved MeDIP analysis data were real and believable. Our data serve as a basis for understanding the injury-induced epigenetic changes in SCs and the foundation for further studies on repair of PNS injury.

Differential expression of miRNAs in Osborne's ligament of cubital tunnel syndrome.

Cubital tunnel syndrome (CuTS) is the second most common peripheral nerve compression disease, however, the pathogenesis and pathology of CuTS remain to be fully elucidated. The aim of the present study was to compare the expression pattern of microRNAs (miRNAs) in pachyntic Osborne's ligament with that in control tendinous tissue, and select meaningful miRNAs for further investigation of the clinical pathological mechanism underlying CuTS. A microarray assay was performed to examine the expression profiles of miRNAs in the Osborne's ligament and control tendinous tissues. An online bioinformatics algorithms tool (miRWalk) was used to predict putative target genes for the deregulated miRNAs, and functional annotation was performed by Gene Ontology (GO) enrichment and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway analysis. Finally, the results of microarray were partially validated using reverse transcription­quantitative polymerase chain reaction analysis. The expression of total of 60 miRNAs were found to be significantly different between the pachyntic Osborne's ligament and control tendinous tissues. MiRWalk2.0 predicted 1,804 target genes for these miRNAs, and the GO functional analysis of the predicted genes suggested cellular mechanisms, including metabolic process, regulation of cell growth, cell cycle processes, cell division regulation, cellular metabolic process and signal transmission, were involved. Furthermore, KEGG pathway analysis revealed important pathways, including adherent junction, focal adhesion, lysine degradation, cell adhesion molecules and mitogen­activated protein kinase. Compared with the heathy tissue, Osborne's ligament tissue from patients with CuTS showed a markedly different miRNA expression profile, which suggested that miRNAs may be involved in the pathogenesis of CuTS.

Proteomic and bioinformatic analyses of spinal cord injury­induced skeletal muscle atrophy in rats.

Spinal cord injury (SCI) may result in skeletal muscle atrophy. Identifying diagnostic biomarkers and effective targets for treatment is an important challenge in clinical work. The aim of the present study is to elucidate potential biomarkers and therapeutic targets for SCI­induced muscle atrophy (SIMA) using proteomic and bioinformatic analyses. The protein samples from rat soleus muscle were collected at different time points following SCI injury and separated by two­dimensional gel electrophoresis and compared with the sham group. The identities of these protein spots were analyzed by mass spectrometry (MS). MS demonstrated that 20 proteins associated with muscle atrophy were differentially expressed. Bioinformatic analyses indicated that SIMA changed the expression of proteins associated with cellular, developmental, immune system and metabolic processes, biological adhesion and localization. The results of the present study may be beneficial in understanding the molecular mechanisms of SIMA and elucidating potential biomarkers and targets for the treatment of muscle atrophy.

Open versus endoscopic in situ decompression in cubital tunnel syndrome: A systematic review and meta-analysis.

OBJECTIVE: We conducted this systematic review and meta-analysis to compare the clinical efficacy and safety between open and endoscopic in situ decompression surgery methods for cubital tunnel syndrome (CuTS). METHODS: PubMed, Medline, Embase, Cochrane Library and CNKI were searched for eligible studies. The data were extracted by two of the coauthors (WL, BYF) independently and were analyzed using RevMan statistical software, version 5.1. Relative risks (RRs) and 95% confidence intervals (CIs) were calculated. Cochrane Collaboration's Risk of Bias Tool and the Newcastle-Ottawa Scale were used to assess the risk of bias. RESULTS: Seven studies were included for systematic review, and six studies were included for meta-analysis. The CuTS patients received open in situ decompression (OISD) or endoscopic in situ decompression (EISD). A pooled analysis of postoperative Bishop score showed that the difference was not statistically significant between the EISD group and the OISD group (RR = 0.99, 95% CI = 0.88-1.12, P = 0.88). The overall estimate of postoperative satisfaction between the EISD group and the OISD group was not found to be significant (RR = 0.98, 95% CI = 0.89-1.08, P = 0.70). The overall estimate of complications (RR = 0.88, 95% CI = 0.24-3.29, P = 0.85) suggested that the difference was not statistically significant. CONCLUSIONS: EISD and OISD for treating CuTS have equivalent efficacy for postoperative clinical improvement, whereas the incidences of complications of endoscopic surgical procedure were also same as those with the open surgical procedure. In situ decompression (especially EISD, with minor intraoperative trauma) could be treated as a valuable alternative to treat CuTS.

Does local lavage influence functional recovery during lumber discectomy of disc herniation?: One year's systematic follow-up of 410 patients.

Lumbar disc herniation (LDH) is a common disease and lumbar discectomy is the most common surgical procedure carried out for patients with low back pain and leg symptoms. Although most researchers are focusing on the surgical techniques during operation, the aim of this study is to evaluate the effect of local intervertebral lavage during microdiscectomy.In this retrospective study, 410 patients were operated on by microdiscectomy for LDH during 2011 to 2014. Retrospectively, 213 of them (group A) accepted local intervertebral irrigation with saline water before wound closure and 197 patients (group B) only had their operative field irrigated with saline water. Systematic records of visual analog scores (VAS), Oswestry disability Index (ODI) questionnaire scale scores, use of analgesia, and hospital length of stay were done after hospitalization.The majority (80.49%) of the cases were diagnosed with lumber herniation at the levels of L4/5 and L5/S1. Fifty-one patients had herniations at 2 levels. There were significant decreases of VAS scores and ODI in both groups between preoperation and postoperation of different time points. VAS scores decreased more in group A than group B at early stage of postoperation follow-up. However, there were no statistically significant differences between 2 groups in using analgesia, VAS and ODI up to 1 month of follow-up.Microdiscectomy for LDH offers a marked improvement in back and radicular pain. Local irrigation of herniated lumber disc area could relief dick herniation-derived low back pain and leg radicular pain at early stage of post-operation. However, the pain relief of this intervention was not noticeable for a long period.

Efficacy, safety, and cost of surgical versus nonsurgical treatment for carpal tunnel syndrome: A systematic review and meta-analysis.

BACKGROUND: Carpal tunnel syndrome (CTS) is a common peripheral nerve entrapment disease. Either surgical or conservative intervention for CTS patients is needed to choose. We conducted this systematic review and meta-analysis to compare the clinical efficacy, safety, and cost of surgical versus nonsurgical intervention. METHODS: The eligible studies were acquired from PubMed, Medline, Embase, Web of Science, Google, and Cochrane Library. The data were extracted by 2 of the coauthors independently and were analyzed by RevMan5.3. Standardized mean differences (SMDs), odds ratios (ORs), and 95% confidence intervals (CIs) were calculated. Cochrane Collaboration Risk of Bias Tool and Newcastle-Ottawa Scale were used to assess risk of bias. RESULTS: Thirteen studies including 9 randomized controlled trials (RCTs) and 4 observational studies were assessed. The methodological quality of the trials ranged from moderate to high. The difference of clinical efficacy was statistically significant between surgical and nonsurgical intervention, and nonsurgical treatment was more effective (OR = 2.35, 95%CI = 1.18-4.67, P = 0.01). Meanwhile, different results were discovered by subgroup analysis. The pooled results of function improvement, symptom improvement, neurophysiological parameters improvement, and cost of care at different follow-up times showed that the differences were not statistically significant between the 2 interventions. The difference of complications and side-effects was statistically significant and conservative treatment achieved better result than surgery (OR = 2.03, 95%CI = 1.28-3.22, P = 0.003). Sensitivity analysis proved the stability of the pooled results. CONCLUSION: Both surgical and conservative interventions had benefits in CTS. Nonsurgical treatment was more effective and safety than surgical treatment, but there were no significant differences in function improvement, symptom improvement, neurophysiological parameters improvement, and cost of care. Nonsurgical treatment is recommended as the optical choice for CTS. If conservative treatment fails, surgical release can be taken.

Efficacy and safety of tension band wiring versus plate fixation in olecranon fractures: a systematic review and meta-analysis.

BACKGROUND: Olecranon fracture (OF) is a common upper limb fracture, and the most commonly used techniques are still tension band wiring (TBW) and plate fixation (PF). The aim of the current study is to discuss whether TBW or PF technique of internal fixation is better in the treatment of OFs, using the method of meta-analysis. METHODS: The eligible studies were acquired from PubMed, CNKI, Embase, Cochrane Library, and other sources. The data were extracted by two of the coauthors independently and were analyzed by RevMan5.3. Standardized mean differences (SMDs), odds ratios (ORs), and 95% confidence intervals (CIs) were calculated. Cochrane Collaboration's Risk of Bias Tool and Newcastle-Ottawa Scale were used to assess risk of bias. RESULTS: Thirteen studies including 1 RCT and 12 observational studies were assessed. Our meta-analysis results showed that both in RCT and observational studies, there were no significant differences between the two groups in disabilities of the arm, shoulder and hand (DASH) (SMD = 0.07, 95% CI = -0.32 to 0.46, p = 0.73), improvement rate (OR = 0.76, 95% CI = 0.48-1.22, p = 0.26), range of motion (ROM), operation time (SMD = -0.51, 95% CI = -1.17 to 0.14, p = 0.12) and blood loss (SMD = -0.97, 95% CI = -2.06 to 0.11, p = 0.08). The overall estimate of complications indicated that the pooled OR was 2.61 (95% CI = 1.65-4.14, p < 0.0001), suggesting that the difference was statistically significant. We also compared the outcomes of patients with mayo type IIA OFs treated by TBW and PF in DASH and ROM and found no differences. CONCLUSIONS: Both TBW and PF interventions had treatment benefit in OFs. The current study reveals that there are no significant differences in DASH, improvement rate, ROM, operation time, and blood loss between TBW and PF for OFs. Due to the less complications, we recommend the PF approach as the optical choice for OFs. More high-quality studies are required to further confirm our results.

Transplantation of autologous activated Schwann cells in the treatment of spinal cord injury: six cases, more than five years of follow-up.

Schwann cells (SCs) are the main glial cells of the peripheral nervous system, which can promote neural regeneration. Grafting of autologous SCs is one of the well-established and commonly performed procedures for peripheral nerve repair. With the aim to improve the clinical condition of patients with spinal cord injury (SCI), a program of grafting autologous activated Schwann cells (AASCs), as well as a series of appropriate neurorehabilitation programs, was employed to achieve the best therapeutic effects. We selected six patients who had a history of SCI before transplantation. At first, AASCs were obtained by prior ligation of sural nerve and subsequently isolated, cultured, and purified in vitro. Then the patients accepted an operation of laminectomy and cell transplantation, and no severe adverse event was observed in any of these patients. Motor and sensitive improvements were evaluated by means of American Spinal Injury Association (ASIA) grading and Functional Independence Measure (FIM); bladder and urethral function were determined by clinical and urodynamic examination; somatosensory evoked potentials (SSEPs) and motor evoked potentials (MEPs) were used to further confirm the functional recovery following transplantation. The patients were followed up for more than 5 years. All of the patients showed some signs of improvement in autonomic, motor, and sensory function. So we concluded that AASC transplantation might be feasible, safe, and effective to promote neurorestoration of SCI patients.

Combination of activated Schwann cells with bone mesenchymal stem cells: the best cell strategy for repair after spinal cord injury in rats.

AIM: We aim to explore the repair effect of combined cell therapy using activated Schwann cells (ASCs) and bone mesenchymal stem cells (BMSCs) in traumatic spinal cord injury (SCI) in rats. MATERIALS & METHODS: ASCs and BMSCs were used for combined transplantation to treat acute SCI in rats, both of which can be obtained from SCI patients. ASCs were obtained by prior ligation of saphenous nerve and BMSCs by flush of the marrow cavity with Dulbecco's modified Eagle's medium solution. Our experiment in vitro confirmed that ASCs promoted BMSCs to differentiate into mature neural cells. It also indicates that BMSCs hold the potential to repair CNS injury. ASCs and BMSCs were co-transplanted into the injured epicenter of spinal cord made by the New York University (NYU) impactor machine using a 10 g × 50 mm drop weight. Complete ASCs, BMSCs and Dulbecco's modified Eagle's medium were also transplanted in rats with SCI as a control. Recovery of rat's hindlimb function was serially evaluated by Basso, Beattie, Bresnahan locomotor rating scale and footprint analysis. Changes of neurological potential were recorded by nerve electrophysiologic test. Improvement in the microenvironment of the injured spinal cord was evaluated by hematoxylin and eosin staining, glial fibrillary acidic protein staining, biotinylated dextran amine anterograde tracing and electron microscopy. RESULTS: Using biotinylated dextran amine anterograde tracing, we demonstrated that there were more regenerative axons of corticospinal tract surrounding and passing through the injured cavity to the caudal cord in the ASC-BMSC co-graft group than those in the other three groups, and we also confirmed this further by quantitative analysis. Immunostaining for glial fibrillary acidic protein showed the smallest population of astrocytes in the injury epicenter in the ASC-BMSC group compared with the other three groups. Relatively complete myelin sheaths and organelles were found in the ASC-BMSC group compared with the other three groups under electron microscopy. CONCLUSION: Effective co-transplantation of ASCs and BMSCs promotes functional recovery in rats' hindlimbs and reduces the formation of glial scar, and remyelinates the injured axons as compared with the other three groups. This conclusion was also supported by the observation of immunohistochemistry staining and electron microscopy, suggesting the possible clinical application for the treatment of spinal injury.