The Role and Mechanism of Spinal NF-κB-CXCL1/CXCR2 in Rats with Nucleus Pulposus-induced Radicular Pain.

STUDY DESIGN: Experimental study of the role and mechanism of spinal NFκB-CXCL1/CXCR2 in rats with nucleus pulposus-induced radicular pain. OBJECTIVE: This study investigated the role and mechanism of spinal NFκB-CXCL1/CXCR2 in autologous nucleus pulposus-induced pain behavior in rats and to clarify the involvement and regulation of spinal NFκB as an upstream molecule of CXCL1 in autologous nucleus pulposus-induced radicular pain in rats. SUMMARY OF BACKGROUND DATA: The inflammatory response of nerve roots is an important mechanism for the occurrence of chronic pain. NFκB-CXCL1/CXCR2 pathway plays an important role in the development of radicular pain, but its regulatory mechanism in the model of radicular pain induced by autologous nucleus pulposus is still unclear. MATERIALS AND METHODS: We established a rat model of autologous medullary nucleus transplantation. We observed and recorded the changes in 50% mechanical withdrawal threshold and thermal withdrawal latency before and after the administration of CXCL1-neutralizing antibodies, CXCR2 inhibitor, and NFκB inhibitor in each group of rats and evaluated the expression of NFκB, CXCL1, and CXCR2 in the spinal dorsal horn using immunofluorescence and Western blot. To compare differences between groups in behavioral testing, analysis of variance was employed. Dunnett's method was used to compare differences at different time points within a group and between different groups at the same time point. A comparison of the relative concentration of protein, relative concentration of mRNA, and semiquantitative data from immunofluorescence staining was conducted utilizing one-way ANOVA and Dunnett's pairwise comparison. RESULTS: Autologous nucleus pulposus transplantation can induce radicular pain in rats and upregulate the expression of CXCL1, CXCR2, and NFκB in the spinal cord. CXCL1 is co-expressed with astrocytes, CXCR2 with neurons, and NFκB with both astrocytes and neurons. The application of CXCL1 neutralizing antibodies, CXCR2 inhibitors, and NFκB inhibitors can alleviate pain hypersensitivity induced by autologous nucleus pulposus transplantation in rats. Inhibitors of NFκB could downregulate the expression of CXCL1 and CXCR2. CONCLUSIONS: We found that spinal NFκB is involved in NP-induced radicular pain in rats through the activation of CXCL1/CXCR2, enriching the mechanism of medullary-derived radicular pain and providing a possible new target and theoretical basis for the development of more effective anti-inflammatory and analgesic drugs for patients with chronic pain following LDH.

Warm Acupuncture Reduces Pain and Inflammation in Rats with Lumbar Disc Herniation Induced by Autologous Nucleus Pulposus Transplantation via Regulating p38MAPK/NF-κB Pathway.

Background: : Warm acupuncture (WA) has analgesic and anti-inflammatory effects. However, the underlying mechanism of these effects remain unclear. Objectives: : To explore the analgesic and anti-inflammatory effects of WA and the potential underlying mechanism in male Sprague-Dawley rats with non-compressive lumbar disk herniation (LDH) caused by autologous nucleus pulposus (NP) transplantation. Methods: : We used low-frequency (2 Hz) electrical stimulation and WA (40℃) to treat GB30 and BL54 acupoints in rats for 30 mins per day. We monitored the paw withdrawal threshold of rats during the experiment and measured serum cytokine levels using commercial kits. Dorsal root ganglion (DRG) tissue pathology was analyzed via H&E staining. We used qRT-PCR to measure the mRNA expression levels of IL-1ß, IL-6, and TNF-α genes in DRG. Western blot was used to analyze the expression levels of IL-1ß, IL-6, TNFα, P-p38MAPK, p38MAPK, P-IκBα, IκB α, and NF-κB p65 proteins. Results: : WA treatment significantly increased the pain threshold of rats, reduced serum IL-6, PEG2, NO, SP, NP-Y, and MMP-3 levels, and effected histopathological improvements in the DRG in rats. Moreover, WA treatment significantly downregulated the expression levels of inflammation-associated genes (Il-1ß, Il-6, and Tnf-α) and proteins (IL-1ß, IL-6, TNF-α, P-p38MAPK, P-IκBα, and NF-κB p65) in the DRG of non-compressive LDH rats. Conclusion: : WA can alleviate pain and inhibit inflammatory response in rats with non-compressive LDH caused by autologous NP transplantation, and these effects are likely associated with the inhibition of the p38MAPK/NF-κB pathway.

Oxidative stress mediated decrement of spinal endomorphin-2 contributes to lumbar disc herniation sciatica in rats.

Increasing evidence supported that oxidative stress induced by herniated lumbar disc played important role in the formation of lumbar disc herniation sciatica (LDHS), however, the neural mechanisms underlying LDHS need further clarification. Endomorphin-2 (EM2) is the endogenous ligand for mu-opioid receptor (MOR), and there is increasing evidence implicating the involvement of spinal EM2 in neuropathic pain. In this study, using an nucleus pulposus implantation induced LDHS rat model that displayed obvious mechanical allodynia, it was found that the expression of EM2 in dorsal root ganglion (DRG) and spinal cord was significantly decreased. It was further found that oxidative stress in DRG and spinal cord was significantly increased in LDHS rats, and the reduction of EM2 in DRG and spinal cord was determined by oxidative stress dominated increment of dipeptidylpeptidase IV activity. A systemic treatment with antioxidant could prevent the forming of mechanical allodynia in LDHS rats. In addition, MOR expression in DRG and spinal cord remained unchanged in LDHS rats. Intrathecal injection of MOR antagonist promoted pain behavior in LDHS rats, and the analgesic effect of intrathecal injection of EM2 was stronger than that of endomorphin-1 and morphine. Taken together, our findings suggest that oxidative stress mediated decrement of EM2 in DRG and spinal cord causes the loss of endogenous analgesic effects and enhances the pain sensation of LDHS.

Association between vertebral endplate defects and patient-reported symptoms: an immunohistochemical study investigating the COX-2/PGE-2/EP-4 axis.

BACKGROUND CONTEXT: Vertebral endplate defects are often implicated in degenerative disc disorders, yet their connection to patient-reported symptoms remains unclear. COX-2 and PGE-2 are known for their roles in inflammation and pain, with EP-4 receptor involvement in pain signaling. Examining their expression in vertebral endplate tissues may provide insights into pathomechanism of low back pain. PURPOSE: To investigate the association between endplate defects and patient-reported symptoms and to further clarify the role of the COX-2/PGE-2/EP-4 axis in the pathogenesis of chronic low back pain. STUDY DESIGN/SETTING: Retrospective study. PATIENT SAMPLE: A total of 71 patients who had undergone single-level L4/5 or L5/S1 modified laminectomy decompression preserving proximal upper laminae and transforaminal lumbar interbody fusion surgery were included in this study, including 18 patients diagnosed with lumbar disc herniation, 19 with lumbar disc herniation accompanied by degenerative lumbar spinal stenosis, and 34 with degenerative spondylolisthesis. OUTCOME MEASURES: Demographic data, Pfirrmann grade, Modic changes, endplate defect score, visual analog scale (VAS) for back and leg pain, and Oswestry Disability Index (ODI) before surgery, 3-month and 6-month follow-up, and the percentage of immune-positive cells (COX-2, PGE-2, and EP-4) in endplate tissue sections. METHODS: Patients were divided into defect and nondefect groups according to endplate morphology on lumbar MR. All intraoperative endplate specimens were immediately fixed in 10% formaldehyde, and then embedded in paraffin 3 days later for tissue sections. The outcome measures were compared between the defect group and nondefect group. Data were analyzed using independent t-tests and χ² tests. Pearson's rank correlation test was used to assess correlations between patient-reported symptoms and the percentage of immune-positive cells in the groups. Multivariable logistic regression models using the forward stepwise likelihood ratio method were used to identify the factors that were independently associated with endplate defects. RESULTS: The age of Defect group was significantly higher than that of nondefect group (52.5±7.7 vs 57.2±9.1. p=.024). There were no significant differences in gender, diagnosis, BMI, comorbidities, or surgical level between the two groups. Modic changes (Type Ⅱ/Type Ⅲ) were more common in patients of Defect group than nondefect group (38.5% vs 11.1%, p<.001), and so was disc degeneration (Pfirrmann grade Ⅳ/Ⅴ) (69.2% vs 33.3%, p<.001). Defect group had significantly higher VAS-Back (6.5±2.0 vs 4.9±1.6, p<.001) and ODI scores (62.9±10.7 vs 45.2±14.8, p<.001) than nondefect group, while there was no significant differences between the two groups during the 3 and 6-month follow-up after surgery. Histologically, Defect group was characterized by upregulation of COX-2, PGE-2, and EP-4 in endplate tissue sections. Both in defect and nondefect groups, VAS-Back showed moderate positive correlations with the expressions of COX-2 (r=0.643; r=0.558, p both<.001), PGE-2 (r=0.611; r=0.640, p both<.001), and EP-4 (r=0.643; r=0.563, p both<.001). Multivariate regression analyses reveled that percentage of COX-2-positive cells was associated with endplate defects (OR=1.509, 95%CI [1.048-2.171], p=.027), as well as percentage of PGE-2-positive (OR=1.291, 95%CI [1.106-1.508], p=.001) and EP-4-positive cells (OR=1.284, 95%CI [1.048∼2.171], p=.003). CONCLUSIONS: Patients with endplate defects had worse quality of life, more severe disc degeneration and Modic changes, and up-regulated COX-2/PGE-2/EP-4 axis expression in cartilage endplates in patients with defected endplates. Inflammatory factors may significantly contribute to the onset and progression of chronic low back pain in patients with endplate defects, consequently impacting patient-reported symptoms.

NF-kB mediated CX3CL1 activation in the dorsal root ganglion contributes to the maintenance of neuropathic pain induced in adult male Sprague Dawley rats

Abstract Purpose: To evaluate the role of CX3CL1 and NF-κB in the lumbar disc herniation induced neuropathic pain. Methods: After LDH induced by implantation of autologous nucleus pulposus (NP) on the left L5 nerve root was established, mechanical thresholds and thermal hyperalgesia were tested at relevant time points during an observation period of 28 days. Expression of CX3CL1 and NF-κBin the dorsal root ganglion (DRG) were performed by using Western blotting and RT-PCR. Results: Implantation of autologous nucleus pulposus (NP) induced neuropathic pain, associated with increased mRNA and protein expression of CX3CL1 in the DRG. Moreover, intrathecal injection of neutralizing antibody against CX3CL1 could attenuates LDH-induced persistent pain hypersensitivity. Interestingly, NF-κB activation in the DRGs were found in LDH-induced neuropathic pain. Furthermore, NF-κB downregulation by p65 inhibitor PDTC markedly alleviated LDH-induced mechanical allodynia and thermal hyperalgesia in rat. Importantly, CX3CL1 neutralizing antibody (10 μg/10 μl, i.t.) reduces p-p65 protein level in DRG Conclusions: CX3XL1 could regulate LDH-induced neuropathic pain through NF-κB pathway. Targeting CX3CL1 and NF-κB may represent a potential treatment for neuropathic pain caused by LDH.

Valoración pormenorizada de las capacidades residuales de una pinche de cocina para adaptación de su puesto de trabajo / Detailed evaluation of residuals capacities of a sculler to create an adaptation of her work placement

Mujer de 52 años con puesto de pinche de cocina del hospital, con artrodesis de columna lumbo-sacra L4-S1 y resección de hernias discales C5-C7 que requiere dos años de baja. Tras su reincorporación, se realiza una valoración médica en el Servicio de Prevención de Riesgos Laborales, donde posterior a la aplicación de los protocolos de manipulación manual de cargas, movimientos repetitivos y microtraumas repetidos, se sugiere como No Apta para realizar las funciones de pinche. Se propone una adaptación del puesto de imposible cumplimiento por su mando intermedio. Posteriormente se reclama un cargo que pueda ejercer según sus limitaciones, sin respuesta positiva. La trabajadora denuncia su caso ante la Inspección de Trabajo y solicita una minusvalía al Instituto de Mayores y Servicios Sociales (IMSERSO) de Ceuta. La Inspección de Trabajo emite una resolución exhortando a la empresa a realizar una adaptación del puesto de trabajo ya que se debe garantizar la reinserción de los trabajadores con minusvalías por condiciones médicas. Se replantea la adaptación del puesto de trabajo con una nueva valoración de los riesgos por parte del Técnico de Prevención en conjunto con la gobernanta, haciéndolo de forma minuciosa, se logra un acuerdo para su incorporación laboral a dicha área. Sin embargo la trabajadora sufre múltiples conflictos con sus compañeros de trabajo por la adaptación del puesto. Se toman medidas pertinentes y mejoran las situaciones del entorno laboral. La adaptación del puesto de trabajo a las personas con discapacidad es un objetivo deseable por las empresas. La primera tarea es analizar cuál es la adaptación Necesaria identificando los problemas y planteando soluciones. Así mismo mejorar las relaciones interpersonales en Los equipos de trabajo aumenta la productividad y disminuye los riesgos psicosociales (AU)

A 52 years old woman, who is kitchens cullion’s in a hospital, with arthrodesis of lumbo-sacra spine L4-S1 and resection of dial hernias C5-C7 who needs two years of temporary disability. After this time, a medical valuation is realized by the Service of Prevention of Occupational Risks, where it does not approve the protocols of manipulation of loads, repetitive movements, repeated microtraumas, declaring herself with non capacity to realize the scullion’s functions. It is suggested an adjustment of the work place, which is refused by the head chef. Later is claimed a place where she could exercise according to her limitations, without positive response. A disability is requested to the Institute of Adults and Social Services (IMSERSO), where the medical inspector forces to realize an adjustment of the working place since it is necessary to guarantee the rehabilitation of the workers with certain medical conditions. An adjustment of the working place is reconsidered with a new valuation of the risks by the technician of prevention as a whole with the head chef, doing it in meticulous form and finally obtaining an agreement to work in that area. Nevertheless the worker is victim of multiple conflicts with her co-workers after the adjustment of the working place. Some measurements are taken to improve her job environment. The adaptation of the working place to the persons with disability is an imperfectly asumible. The first task is to analyze which is the necessary adjustment, identifying the problems and raising solutions. Likewise, improving the interpersonal relations in teams of workincreases the productivity and diminishes the psychosocial risks (AU)

Analysis of crucial molecules involved in herniated discs and degenerative disc disease

OBJECTIVES: Herniated discs and degenerative disc disease are major health problems worldwide. However, their pathogenesis remains obscure. This study aimed to explore the molecular mechanisms of these ailments and to identify underlying therapeutic targets. MATERIAL AND METHODS: Using the GSE23130 microarray datasets downloaded from the Gene Expression Omnibus database, differentially co-expressed genes and links were identified using the differentially co-expressed gene and link method with a false discovery rate ,0.25 as a significant threshold. Subsequently, the underlying molecular mechanisms of the differential co-expression of these genes were investigated using Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis. In addition, the transcriptional regulatory relationship was also investigated. RESULTS: Through the analysis of the gene expression profiles of different specimens from patients with these diseases, 539 differentially co-expressed genes were identified for these ailments. The ten most significant signaling pathways involving the differentially co-expressed genes were identified by enrichment analysis. Among these pathways, apoptosis and extracellular matrix-receptor interaction pathways have been reported to be related to these diseases. A total of 62 pairs of regulatory relationships between transcription factors and their target genes were identified as critical for the pathogenesis of these diseases. CONCLUSION: The results of our study will help to identify the mechanisms responsible for herniated discs and degenerative disc disease and provides a theoretical basis for further therapeutic study.