TNF-alpha and neuropathic pain--a review

Molecular Subtypes and Immune Microenvironment Characterization of the Annulus Fibrosus in Intervertebral Disc Degeneration: Insights From Translation Factor-Related Gene Analysis

Objective

This study aims to examine the role of translation factors (TF) in intervertebral disc degeneration (IVDD) and to evaluate their clinical relevance through unsupervised clustering methods.

Methods

Gene expression data were retrieved from the GEO database, and the expression levels of translation factor-related genes (TFGs) were extracted for analysis.

Results

Two distinct molecular clusters were identified based on the differential expression of nine significantly altered TFGs. Immune infiltration was notably higher in Cluster C2 compared to Cluster C1. Subsequently, two gene clusters were identified based on the differentially expressed genes between the clusters. A Sankey diagram illustrated a high degree of consistency between the molecular clusters and the gene clusters. Additionally, four machine learning models were developed and evaluated, with the SVM model being utilized to construct a nomogram for predicting the incidence of IVDD. Validation using external datasets and clinical samples confirmed the low expression of EEF2K, which was further analyzed in a pan-cancer context.

Conclusion

The identification and comprehensive assessment of the two molecular clusters offer significant insights for the classification and treatment of individuals with IVDD.

A Nomogram Model Integrating Inflammation Markers for Predicting the Risk of Recurrent Sciatica After Selective Nerve Root Blocks

Background

Lumbar disc herniation (LDH) usually c auses sciatica. Although selective nerve root block (SNRB) is an effective, highly target-oriented interventional procedure for patients with LDH, accurately predicting the risk of sciatica recurrence in such patients after SNRB remains a major challenge.

Objective

We aimed to construct a nomogram model by integrating clinical data, imaging features and inflammation markers that could predict recurrent sciatica following SNRB in LDH patients, which fill the inflammation data gaps during model construction.

Methods

In total, 121 sciatica patients were enrolled and assigned to the recurrence group (n = 41) and non-recurrence group (n = 80). By performing the logistic regression analyses, we identified risk factors serving as independent predictors and constructed the nomogram prediction model. Then, the performance and clinical practicality of the nomogram model were validated by performing the receiver operating characteristic curve (ROC) analysis, calibration curve analysis, and decision curve analysis (DCA). The bootstrap method was applied for the internal validation of the nomogram model.

Results

Preoperative sensory symptoms (odds ratio [OR] [95% confidence interval (CI)]: 2.933 [1.211-7.353]), type of herniation (OR [95% CI]: 2.712 [1.261-6.109]), and systemic inflammation response index (OR [95% CI]: 2.447 [1.065-6.271]) were included in the nomogram for predicting unfavorable outcomes following sciatica. The nomogram AUC was 0.764, and the prognostic precision, validated using the bootstrap method, reached 0.756. The ROC and calibration curve analyses, and DCA also produced excellent results, exhibiting favorable predictive performance and clinical benefit.

Conclusion

This study thus identified risk factors that predict unfavorable outcomes after sciatica and developed a risk prediction model based on clinical, radiologic, and inflammatory factors, thereby facilitating early predictions by clinicians and offering an individualized medical interventions for patients with recurrent sciatica in early stages.

Neuronal p38 MAPK Signaling Contributes to Cisplatin-Induced Peripheral Neuropathy

This study investigates the role of p38 mitogen-activated protein kinase (MAPK) activation in dorsal root ganglion (DRG) neurons in the development and progression of chemotherapy-induced peripheral neuropathy (CIPN). This research evaluates whether inhibiting activation of p38 MAPK could reduce neuropathic outcomes in a transgenic breast cancer mouse model (C3TAg) and wild-type mice (FVB/N) treated with cisplatin. Cisplatin treatment stimulated p38 MAPK phosphorylation and nuclear translocation in DRG neurons. Neflamapimod, a specific inhibitor of p38 MAPK alpha (p38α), proven to be safe in clinical trials, inhibited neuronal cisplatin-induced p38 MAPK phosphorylation in vitro and in vivo. Neflamapimod also reduced cisplatin-induced oxidative stress, mitochondrial dysfunction, and cleaved caspase-3 expression in DRG neurons in vitro, protecting neuronal integrity and preventing axonal damage. Functionally, neflamapimod improved mechanical and musculoskeletal hyperalgesia, and cold sensitivity in cisplatin-treated mice, reversing neuropathic pain and neurotoxicity. This study identifies p38 MAPK activation as a critical driver of CIPN and highlights its potential as a therapeutic target for CIPN. Targeting p38 MAPK activation with neflamapimod offers a promising strategy to mitigate neurotoxicity and hyperalgesia without exacerbating cancer progression, positioning it as a novel intervention for CIPN.

Ornidazole Regulates Inflammatory Response and Odontogenic Differentiation of Human Dental Pulp Cells

AIM

This study aimed to explore the potential of ornidazole as an alternative treatment for pulpitis, focusing on its effects on human dental pulp cells (hDPCs) and macrophages. We assessed the cytotoxicity of various concentrations of ornidazole, its safety and efficacy in treating inflamed hDPCs, and its regulatory impact on inflammatory markers during inflammation.

MATERIALS AND METHODS

Inflammation in hDPCs was induced using lipopolysaccharides (LPS), and varying doses of ornidazole were introduced. Cell proliferation, migration, inflammation regulation, and dentinogenesis under inflammatory conditions were evaluated. Additionally, macrophages were cultured with different doses of ornidazole to analyse the expression of inflammatory genes. If statistically significant differences were observed between the control and treatment groups, this was considered evidence of ornidazole's effects on hDPCs. Statistical analysis was performed using SPSS 26.0, with one-way analysis of variance and Tukey's test for comparisons. A P-value of < 0.05 was considered statistically significant.

RESULTS

Ornidazole influenced cell proliferation, inflammation regulation, and dentinogenesis. Concentrations below 10 µg/mL did not exhibit significant cytotoxic effects on hDPCs over a 7-day period, and the cytotoxicity of ornidazole was both concentration- and time-dependent. Ornidazole decreased the expression of proinflammatory markers (IL-6 and TNF-α) while enhancing the expression of anti-inflammatory markers (IL-1Ra and IL-8). It also suppressed alkaline phosphatase (ALP) activity but increased the expression of odontogenic differentiation markers at both mRNA and protein levels in the presence of inflammatory stimuli. Furthermore, ornidazole demonstrated immunomodulatory effects on macrophages.

CONCLUSIONS

Low concentrations of ornidazole were found to be safe for hDPCs. Ornidazole modulated the expression of inflammatory markers (IL-6, TNF-α, IL-8, IL-1Ra) in inflamed hDPCs and regulated odontogenesis-related markers. Furthermore, low concentrations of ornidazole enhanced the immune regulation in macrophages, highlighting its potential as a therapeutic agent for pulpitis.

CLINICAL RELEVANCE

This study aimed to understand the interactions of ornidazole with hDPCs, its anti-inflammatory properties, and its regulatory effects on odontogenic processes. By examining the impact of different concentrations of ornidazole on cells associated with pulp inflammation, this study provides valuable insights into its therapeutic potential for pulpitis and tends to support its clinical application.

A transcriptional atlas of gut-innervating neurons reveals activation of interferon signaling and ferroptosis during intestinal inflammation

Enteric infections often cause long-term sequelae, including persistent gastrointestinal symptoms, such as pain, discomfort, or irritable bowel syndrome. The plethora of sensory symptoms indicates that gut-innervating neurons might be directly affected by inflammation. However, sequencing studies of neurons in the gastrointestinal tract are hampered by difficulties in purifying neurons, especially during inflammation. Activating a nuclear GFP tag selectively in neurons enabled sort purification of intrinsic and extrinsic neurons of the gastrointestinal tract in models of intestinal inflammation. Using bulk and single-nucleus RNA sequencing, we mapped the whole transcriptomic landscape and identified a conserved neuronal response to inflammation, which included the interferon signaling and ferroptosis pathway. Deletion of the interferon receptor 1 in neurons regulated ferroptosis, neuronal loss, and consequently gut-transit time. Collectively, this study offers a resource documenting neuronal adaptation to inflammatory conditions and exposes the interferon and ferroptosis pathways as signaling cascades activated in neurons during inflammation.

Exploring the therapeutic potential of α-(Phenylselanyl) acetophenone in tumor necrosis Factor-α-Induced depressive-like and hyperalgesic behavior in mice

Chronic pain and depression exhibit a high comorbidity, are challenging to manage, and their pathophysiology mechanisms are intricated and closely related to the up-regulation of pro-inflammatory response and oxidative stress. Chronic pain and depression often coexist and present significant management challenges. Their underlying pathophysiological mechanisms are complex and closely linked to the up-regulation of pro-inflammatory responses and oxidative stress. α-(Phenylselanyl) acetophenone (PSAP), an organoselenium compound, has shown antioxidant, antidepressant-like and antinociceptive effects in animal models. This study aimed to evaluate the effects of acute PSAP administration in a comorbid pain-depression model induced by intracerebroventricular (i.c.v.) injection of the pro-inflammatory cytokine tumor necrosis factor-α (TNF-α) in male Swiss mice. TNF-α (0.1 ƒg/5 µL, i.c.v.) was injected 1 h before the behavioral tests, followed by acute PSAP treatment (10 mg/kg, intragastrically [i.g.]) 30 min post-TNF-α injection. TNF-α decreased the latency time to first immobility episode and increased the total immobility time of mice in the forced swimming test (FST), effects prevented by PSAP treatment. PSAP also reversed TNF-α-induced nociceptive responses in mice, assessed by the hot plate test. These behavioral improvements may be attributed, at least in part, to the capacity of PSAP treatment reverse the TNF-α-induced increase on reactive species and lipoperoxidation levels, as well as modulate altered activities of antioxidant enzymes catalase and superoxide dismutase in the cerebral cortex and hippocampus. Furthermore, PSAP decreased circulating corticosterone levels elevated by TNF-α injection. In conclusion, PSAP emerges as a promising candidate for the development of innovative therapeutic strategies to address the comorbidity of pain and depression.

Biomarkers in orofacial pain conditions: A narrative review

Orofacial pain conditions, including temporomandibular disorder, migraine, dental pain, and trigeminal neuralgia, are complex, multifactorial disorders with significant impacts on patients' quality of life. As understanding of the pathophysiology of these conditions has deepened, the role of molecular and genetic biomarkers in diagnosing, monitoring, and potentially treating orofacial pain has garnered increasing interest. This scoping review provides a comprehensive overview of the current state of research on biomarkers associated with orofacial pain conditions. By analyzing existing literature, we identify key biomarkers linked to inflammation, neural activity, and tissue degradation that are common across multiple conditions, as well as those specific to particular disorders. Our findings underscore the potential of these biomarkers to guide the development of personalized therapeutic strategies. However, the review also highlights the challenges faced by current biomarker research, including heterogeneity in study designs, small sample sizes, and a lack of longitudinal data. Addressing these challenges is critical for translating biomarker research into clinical practice and improving outcomes for patients with orofacial pain.

Cytokine Signaling in Diabetic Neuropathy: A Key Player in Peripheral Nerve Damage

Diabetic peripheral neuropathy (DPN) is a debilitating complication of diabetes mellitus, characterized by progressive nerve damage driven by chronic hyperglycemia and systemic inflammation. The pathophysiology of DPN is significantly influenced by pro-inflammatory cytokines, such as IL-1β, IL-6, and TNF-α. These cytokines promote oxidative stress, vascular dysfunction, and neuronal degeneration by activating important signaling pathways including NF-κB and MAPK. While IL-6 promotes a pro-inflammatory microenvironment, increasing neuronal damage and neuropathic pain, TNF-α and IL-1β worsen Schwann cell failure by compromising axonal support and causing demyelination. Immune cell infiltration and TLR activation increase the inflammatory cascade in DPN, resulting in a persistent neuroinflammatory state that sustains peripheral nerve injury. The main characteristics of DPN are axonal degeneration, decreased neurotrophic support, and Schwann cell dysfunction, which weaken nerve transmission and increase susceptibility to damage. Advanced glycation end-products, TNF-α, and CXCL10 are examples of biomarkers that may be used for early diagnosis and disease progression monitoring. Additionally, crucial molecular targets have been found using proteomic and transcriptome techniques, enabling precision medicine for the treatment of DPN. This review emphasizes the importance of cytokine signaling in the pathogenesis of DPN and how cytokine-targeted treatments might reduce inflammation, restore nerve function, and improve clinical outcomes for diabetic patients.

Design, Synthesis, and Anti-Prostate Cancer Potential of 2-(4-Nitrobenzyl) Malonates In Vitro and DAL Acute Oral Toxicity Assessment In Vivo

New 4-nitrobenzyl derivatives were designed and synthesised by nucleophilic substitution reactions of 4-nitrobenzyl bromide with malonic acid and its derivatives. The synthesised molecules were characterised using mass analysis and spectroscopic techniques and tested for their antioxidant properties using various methods, such as nitric oxide, DPPH, and hydrogen peroxide radical scavenging methods. The anti-inflammatory activities of the molecules were assessed using RBC membrane stabilisation and albumin denaturation methods. We evaluated the compounds' potential anti-prostate cancer activity using the DU145 cell line. The MTT assay determined the cell viability, indicating good anti-proliferative activity. The molecule 3 c exhibited the highest potency, with a CTC50 of 11.83 μg/mL. Molecular dynamics simulations were performed to study the stability of the ligand within the protein after docking and the resulting protein-ligand complex. The in vivo analysis of molecule 3 c in the DAL xenograft model demonstrated promising results. The increase in life span, reduction in tumor volume, and comparable effects to standard drugs are encouraging features that suggest that molecule 3 c may possess significant potential as an anti-cancer agent. The research also implies that these molecules might be potential lead compounds for developing new prostate cancer drugs.

The Role of Extracellular Vesicles in Aging and Age-Related Disorders

A variety of molecular and cellular changes distinguish the multifaceted biological process of aging. Recent studies in this decade have demonstrated the essential role of extracellular vesicles (EVs) in the aging process. Mitochondrial malfunction and increased oxidative stress are major contributors for the aging process. This review investigates the role of EVs in intercellular communication, tissue regeneration, and inflammation in the context of aging. We also discuss the exosome and its utility to reduce oxidative stress, which is a key part of aging, as well as the possibility of using the exosomes (EVs) as anti-aging drugs. Changes in cargo composition can influence the aging phenotype and impact the functionality of cells and tissues. Additionally, the role of EVs in oxidative stress during the aging process addresses potential treatment strategies and the development of biomarkers for age-associated disorders. The review also highlighted the role of exosomes in providing antioxidant properties, which help reduce excessive reactive oxygen species (ROS) and strengthen cellular defenses against oxidative stress. Additionally, it emphasized the role of extracellular vesicles (EVs) in age-related pathologies, such as neurodegenerative diseases, cardiovascular disorders, and immunosenescence, offering insights into targeted interventions for promoting healthy aging. This article provides a comprehensive analysis of the current body of knowledge regarding the therapeutic effects of EVs on aging, with a particular emphasis on the implications of this emerging field of research and its relationship to oxidative stress.

Cannabis sativa L. Extract Increases COX-1, COX-2 and TNF-α in the Hippocampus of Rats with Neuropathic Pain

Inflammation is the critical component of neuropathic pain; therefore, this study aimed to assess the potential anti-inflammatory effects of Cannabis sativa L. extracts in a vincristine-induced model of neuropathic pain. The effects of different doses (5.0-40.0 mg/kg) of two Cannabis sativa L. extracts (B and D) on COX-1, COX-2, TNF-α, and NF-κB mRNA and protein levels were examined in the rat hippocampus, cerebral cortex, and blood lymphocytes. There were statistically significant differences in COX-1, COX-2, and TNF-α mRNA and protein expression in the hippocampus and cerebral cortex, with significant differences in COX-2 and TNF-α in the lymphocytes. Extract D dose-dependently increased COX-1 mRNA and protein in the hippocampus and cortex. In contrast, Extract B dose-dependently increased COX-1 mRNA and decreased COX-2 mRNA (in a dose of 7.5 mg/kg) and TNF-α protein levels in the cortex. Cannabis sativa L. extracts significantly influenced the expression of inflammatory genes and proteins, with effects varying based on dose and tissue type. The increased expression of COX-1, COX-2, and TNF-α (in comparison to groups receiving NaCl, vincristine, and gabapentin) in the rat hippocampus and COX-1 in the cerebral cortex suggests that Cannabis may have a pro-inflammatory effect. Due to species specificity, the results of our research based on rats require confirmation in humans. However, Cannabis sativa should be recommended with caution for treating pain with an inflammatory component.

Static Magnetic Stimulation and Magnetic Microwires Synergistically Enhance and Guide Neurite Outgrowth

Axonal growth is heavily influenced by topography and biophysical stimuli including magnetic and electrical fields. Despite extensive investigation, the degree of influence and the underlying genetic mechanisms remain poorly understood. Here, a novel approach to guide neurite growth is undertaken using an innovative ferromagnetic composite material - glass-coated magnetic microwire - to furnish a synergistic combination of magnetic and topographical cues. Whole rat dorsal root ganglia (DRG) are cultured under five different conditions: control, static magnetic field, magnetic microwire, static magnetic field + glass fiber, and static magnetic field + magnetic microwire. DRG outgrowth responses under each condition, including total neurite outgrowth and directionality, are compared. The combination of both magnetic stimulation and topography significantly increases total neurite outgrowth compared to the controls. The combination of magnetic stimulation and magnetic microwire lead to a strong directional bias of growth along the microwire, double what is observed with the glass fiber. Next generation RNA sequencing of DRG exposed to static magnetic field + magnetic microwire reveals the downregulation of genes relating to the immune response, interleukin signaling, and signal transduction. These results set the stage for contemplating future biophysical stimulation for axonal guidance and improved understanding of material-tissue interactions.

Unraveling the role of oligodendrocytes and myelin in pain

Oligodendrocytes, the myelin-producing cells in the central nervous system (CNS), are crucial for rapid action potential conduction and neuronal communication. While extensively studied for their roles in neuronal support and axonal insulation, their involvement in pain modulation is an emerging research area. This review explores the interplay between oligodendrocytes, myelination, and pain, focusing on neuropathic pain following peripheral nerve injury, spinal cord injury (SCI), chemotherapy, and HIV infection. Studies indicate that a decrease in oligodendrocytes and increased cytokine production by oligodendroglia in response to injury can induce or exacerbate pain. An increase in endogenous oligodendrocyte precursor cells (OPCs) may be a compensatory response to repair damaged oligodendrocytes. Exogenous OPC transplantation shows promise in alleviating SCI-induced neuropathic pain and enhancing remyelination. Additionally, oligodendrocyte apoptosis in brain regions such as the medial prefrontal cortex is linked to opioid-induced hyperalgesia, highlighting their role in central pain mechanisms. Chemotherapeutic agents disrupt oligodendrocyte differentiation, leading to persistent pain, while HIV-associated neuropathy involves up-regulation of oligodendrocyte lineage cell markers. These findings underscore the multifaceted roles of oligodendrocytes in pain pathways, suggesting that targeting myelination processes could offer new therapeutic strategies for chronic pain management. Further research should elucidate the underlying molecular mechanisms to develop effective pain treatments.

Leptin deficiency leads to nerve degeneration and impairs axon remyelination by inducing Schwann cell apoptosis and demyelination in type 2 diabetic peripheral neuropathy in rats

Diabetic peripheral neuropathy, characterized by symptoms such as paresthesia, neuropathic pain, and potential lower limb amputation, poses significant clinical management challenges. Recent studies suggest that chronic hyperglycemia-induced Schwann cells (SCs) apoptosis contributes to neurodegeneration and impaired nerve regeneration, but the detailed mechanisms are still unknown. Our study investigated a mixed-sex type 2 diabetes mellitus (T2DM) rat model using leptin knockout (KO) to simulate obesity and diabetes-related conditions. Through extensive assessments, including mechanical allodynia, electrophysiology, and microcirculation analyses, along with myelin degradation studies in KO versus wild-type rats, we focused on apoptosis, autophagy, and SCs dedifferentiation in the sciatic nerve and examined nerve regeneration in KO rats. KO rats exhibited notable reductions in mechanical withdrawal force, prolonged latency, decreased compound muscle action potential (CMAP) amplitude, reduced microcirculation, myelin sheath damage, and increases in apoptosis, autophagy, and SCs dedifferentiation. Moreover, leptin KO was found to impair peripheral nerve regeneration postinjury, as indicated by reduced muscle weight, lower CMAP amplitude, extended latency, and decreased remyelination and SCs density. These findings underscore the effectiveness of the T2DM rat model in clarifying the impact of leptin KO on SCs apoptosis, dedifferentiation, and demyelination, providing valuable insights into new therapeutic avenues for treating T2DM-induced peripheral neuropathy.

Potential use of salivary TNF-α as a vaccine-induced pain biomarker in people with cerebral palsy and communication disorders

BACKGROUND

Pain in people with cerebral palsy (CP) has been classically underestimated and poorly treated, particularly in individuals with impaired communication skills.

OBJECTIVE

To analyze changes in different salivary metabolites and pain behavior scales after a painful procedure in adults with CP and adults with typical development.

METHODS

Salivary levels of sTNF-α, sIgA, Cortisol, FRAP, ADA and Alpha Amylase, as well as 3 observational pain scales (Wong-Baker, Non-Communicating Adults Pain Checklist and Facial Action Coding System) were assessed before and after an intramuscular injection in 30 Individuals with CP and 30 healthy controls. Video recording of face expression was performed during the procedure for offline analysis.

RESULTS

Pain in subjects with CP was higher than in healthy controls after the intramuscular injection as displayed by observational scales. sTNF-α experienced a significant post-stimulus increase in both groups and that increase shows a tendency to correlate with the observational scales scores. Other biomarkers classically associated with stress (cortisol, Alpha Amylase) remain stable.

CONCLUSION

sTNF-α might be a promising pain indicator. Further research using controlled painful stimuli of greater intensity and pain self-reports, would be necessary to better understand its use as a pain biomarker.

Pulsed radiofrequency alleviates neuropathic pain by upregulating MG53 to inhibit microglial activation

BACKGROUND

Patients with neuropathic pain (NP) have significantly lower quality of life. Because the pathophysiology of NP is not fully understood, there is a lack of effective treatment for it in clinic. This study set out to investigate the precise mechanism by which pulsed radiofrequency (PRF) alleviated NP.

METHOD

The rat models of chronic constriction injury of the sciatic nerve (CCI) were established to simulate the occurrence of NP, following with measuring MWT and TWL to evaluate the pain of the rats. HE staining was utilized to observe the rat spinal cord tissue pathology. The expression of MG53, ATF4 and CHOP was evaluated by qRT-PCR and WB, while the expression of inflammatory factors was measured by ELISA. In addition, immunofluorescence assay was used to detect the expression of MG53 and Iba-1.

RESULT

PRF treatment alleviated NP in CCI rats, as well as upregulating the expression of MG53 and inhibiting microglial activation. After MG53 knockdown, the remission of NP by PRF was significantly weakened, but microglial activation and endoplasmic reticulum stress (ERS) exhibited enhancement. Therefore, PRF inhibited microglial activation by upregulating MG53. After injection of ERS inducer in CCI rats, the inhibition effect of overexpressed MG53 on microglial activation and its alleviation effect on NP were reversed. Consequently, MG53 played a role in suppressing microglial activation by mediating the inhibition of ERS.

CONCLUSION

PRF attenuated microglial activation by upregulating MG53 to inhibit ERS, resulting in the alleviation of NP in CCI rats.

Effects of PEMF and LIPUS Therapy on the Expression of Genes Related to Peripheral Nerve Regeneration in Schwann Cells

Peripheral nerve regeneration remains a major challenge in neuroscience, despite advancements in understanding its mechanisms. Current treatments, including nerve transplantation and drug therapies, face limitations such as invasiveness and incomplete recovery of nerve function. Physical therapies, like pulsed electromagnetic fields (PEMF) and low-intensity ultrasound (LIPUS), are gaining attention for their potential to enhance regeneration. This study analyzes the effects of PEMF and LIPUS on gene expression in human primary Schwann cells, which are crucial for nerve myelination and repair. Key genes involved in neurotrophin signaling (NGF, BDNF), inflammation (IL-1β, IL-6, IL-10, TNF-α, TGF-β), and regeneration (CRYAB, CSPG, Ki67) were assessed. The results of this study reveal that combined PEMF and LIPUS therapies promote Schwann cell proliferation, reduce inflammation, and improve the regenerative environment, offering potential for optimizing these therapies for clinical use in regenerative medicine.

Evidence from Mendelian randomization analysis combined with meta-analysis for the causal validation of the relationship between 91 inflammatory factors and lumbar disc herniation

Lumbar disc herniation (LDH) is a common spinal disease. In recent years, an increasing number of observational studies have reported the impact of inflammatory factors on LDH. By conducting Mendelian randomization (MR) analysis on 91 inflammatory factors, it is possible to reveal their causal relationship with LDH, providing new insights for prevention and treatment strategies. In this study, a two-sample MR analysis was performed, using 91 inflammatory factors as exposure data, and LDH data from 2 different sources as outcome data. Subsequently, the most significant results from the inverse-variance weighted analysis were subjected to meta-analysis, with multiple corrections applied to the thresholds to ensure result accuracy. Finally, reverse causality MR analysis was conducted to validate the causal relationship between the identified positive inflammatory factors and LDH. Ninety-one cytokines were analyzed in relation to LDH using MR with data from the Finngen and UK Biobank databases. The inverse-variance weighted results from both analyses were then meta-analyzed, and multiple corrections were applied to the significance threshold of the meta-analysis results. Ultimately, only 1 cytokine, tumor necrosis factor-beta levels (genome-wide association study ID: GCST90274840), showed a significant association after the combined MR analysis and multiple corrections, with an odds ratio of 1.073 (95% confidence interval: 1.034-1.113, P = .0154). Furthermore, this positive cytokine did not display any reverse causality with LDH from either data source. Tumor necrosis factor-beta levels are a risk factor for LDH, potentially increasing the risk of developing the condition and exacerbating its symptoms.

Spinal pain processing in arthritis: Neuron and glia (inter)actions

Diseases of joints are among the most frequent causes of chronic pain. In the course of joint diseases, the peripheral and the central nociceptive system develop persistent hyperexcitability (peripheral and central sensitization). This review addresses the mechanisms of spinal sensitization evoked by arthritis. Electrophysiological recordings in anesthetized rats from spinal cord neurons with knee input in a model of acute arthritis showed that acute spinal sensitization is dependent on spinal glutamate receptors (AMPA, NMDA, and metabotropic glutamate receptors) and supported by spinal actions of neuropeptides such as neurokinins and CGRP, by prostaglandins, and by proinflammatory cytokines. In several chronic arthritis models (including immune-mediated arthritis and osteoarthritis) spinal glia activation was observed to be coincident with behavioral mechanical hyperalgesia which was attenuated or prevented by intrathecal application of minocycline, fluorocitrate, and pentoxyfylline. Some studies identified specific pathways of micro- and astroglia activation such as the purinoceptor- (P2X7-) cathepsin S/CX3CR1 pathway, the mobility group box-1 protein (HMGB1), and toll-like receptor 4 (TLR4) activation, spinal NFκB/p65 activation and others. The spinal cytokines TNF, interleukin-6, interleukin-1β, and others form a functional spinal network characterized by an interaction between neurons and glia cells which is required for spinal sensitization. Neutralization of spinal cytokines by intrathecal interventions attenuates mechanical hyperalgesia. This effect may in part result from local suppression of spinal sensitization and in part from efferent effects which attenuate the inflammatory process in the joint. In summary, arthritis evokes significant spinal hyperexcitability which is likely to contribute to the phenotype of arthritis pain in patients.

Identification of Cytisine Derivatives as Agonists of the Human Delta Opioid Receptor by Supercomputer-Based Virtual Drug Screening and Transcriptomics

Delta opioid receptors (DORs) are rising as therapeutic targets, not only for the treatment of pain but also other neurological disorders (e.g., Parkinson's disease). The advantage of DOR agonists compared to μ-opioid receptor agonists is that they have fewer side effects and a lower potential to induce tolerance. However, although multiple candidates have been tested in the past few decades, none have been approved for clinical use. The current study focused on searching for new DOR agonists by screening a chemical library containing 40,000 natural and natural-derived products. The functional activity of the top molecules was evaluated in vitro through the cyclic adenosine monophosphate accumulation assay. Compound 3 showed promising results, and its activity was further investigated through transcriptomic methods. Compound 3 inhibited the expression of TNF-α, prevented NF-κB translocation to the nucleus, and activated the G-protein-mediated ERK1/2 pathway. Additionally, compound 3 is structurally different from known DOR agonists, making it a valuable candidate for further investigation for its anti-inflammatory and analgesic potential.

Role of Brain Derived Neurotrophic Factor and Related Therapeutic Strategies in Central Post-Stroke Pain

Brain-derived neurotrophic factor (BDNF) is vital for synaptic plasticity, cell persistence, and neuronal development in peripheral and central nervous systems (CNS). Numerous intracellular signalling pathways involving BDNF are well recognized to affect neurogenesis, synaptic function, cell viability, and cognitive function, which in turn affects pathological and physiological aspects of neurons. Stroke has a significant psycho-socioeconomic impact globally. Central post-stroke pain (CPSP), also known as a type of chronic neuropathic pain, is caused by injury to the CNS following a stroke, specifically damage to the somatosensory system. BDNF regulates a broad range of functions directly or via its biologically active isoforms, regulating multiple signalling pathways through interactions with different types of receptors. BDNF has been shown to play a major role in facilitating neuroplasticity during post-stroke recovery and a pro-nociceptive role in pain development in the nervous system. BDNF-tyrosine kinase receptors B (TrkB) pathway promotes neurite outgrowth, neurogenesis, and the prevention of apoptosis, which helps in stroke recovery. Meanwhile, BDNF overexpression plays a role in CPSP via the activation of purinergic receptors P2X4R and P2X7R. The neuronal hyperexcitability that causes CPSP is linked with BDNF-TrkB interactions, changes in ion channels and inflammatory reactions. This review provides an overview of BDNF synthesis, interactions with certain receptors, and potential functions in regulating signalling pathways associated with stroke and CPSP. The pathophysiological mechanisms underlying CPSP, the role of BDNF in CPSP, and the challenges and current treatment strategies targeting BDNF are also discussed.

Comparison of the efficacy of auricular vagus nerve stimulation and conventional low back rehabilitation in patients with chronic low back pain

BACKGROUND

In recent years, human and animal studies have provided increasing evidence that vagus nerve stimulation (VNS) can produce analgesic effects as well as alleviating resistant epilepsy and depression. Our study was designed to compare the efficacy of transcutaneous auricular vagus nerve stimulation with conventional low back rehabilitation in patients with chronic low back pain (CLBP).

METHODS

Sixty patients with LBP were randomly divided into two groups. Group 1 received conventional rehabilitation and home exercise, and Group 2 received transcutaneous auricular VNS and home exercise. Both groups received treatment five days a week for three weeks. Trunk mobility (Modified Schober test, fingertip-to-floor test), muscle strength (CSMI-Cybex Humac-Norm isokinetic dynamometer and Lafayette manual muscle strength measuring device), trunk endurance, balance tests, Visual Analog Scale, Beck Depression Scale, Pittsburgh Sleep Quality Index, Oswestry Disability Index were evaluated.

RESULTS

At the end of three weeks, within-group assessment results showed positive effects on mobility, functional status, depression and sleep in all groups (p < 0.05). Pain level, endurance time and flexion trunk muscle strength results showed more improvement in Group 2 (p < 0.05). Some parameters of isokinetic lower extremity quadriceps muscle strength and fall risk scores showed a significant improvement in Group 1 (p < 0.05).

DISCUSSION

VNS has been observed to be more effective on pain, trunk muscle strength and endurance duration and sleep status. Auricular VNS may be included in the treatment of patients with CLBP in whom conventional physical therapy is inadequate or not applicable.

Ginkgolide B effectively mitigates neuropathic pain by suppressing the activation of the NLRP3 inflammasome through the induction of mitophagy in rats

Neuropathic pain is a pathological state induced by the aberrant generation of pain signals within the nervous system. Ginkgolide B(GB), an active component found of Ginkgo. biloba leaves, has neuroprotective properties. This study aimed to explore the effects of GB on neuropathic pain and its underlying mechanisms. In the in vivo study, we adopted the rat chronic constriction injury model, and the results showed that GB(4 mg/kg) treatment effectively reduced pain sensation in rats and decreased the expressions of Iba-1 (a microglia marker), NLRP3 inflammasome, and inflammatory factors, such as interleukin (IL)-1β, in the spinal cord 7 days post-surgery. In the in vitro study, we induced microglial inflammation using lipopolysaccharide (500 ng/mL) / adenosine triphosphate (5 mM) and treated it with GB (10, 20, and 40 μM). GB upregulated the expression of mitophagy proteins, such as PINK1, Parkin, LC3 II/I, Tom20, and Beclin1, and decreased the cellular production of reactive oxygen species. Moreover, it lowered the expression of inflammation-related proteins, such as Caspase-1, IL-1β, and NLRP3 in microglia. However, this effect was reversed by Parkin shRNA/siRNA or the autophagy inhibitor 3-methyladenine (5 mM). These findings reveal that GB alleviates neuropathic pain by mitigating neuroinflammation through the activation of PINK1-Parkin-mediated mitophagy.

Rat Model of Neuropathic Pain Induced by Spinal Nerve Ligation: A New Approach via an Oblique Lateral Incision

Purpose

The spinal nerve ligation (SNL) model is a typical peripheral neuropathic pain model. During its construction, the removal of paraspinal muscles and transverse processes typically occurs, resulting in additional trauma that may potentially affect the pathophysiologic process of neuropathic pain. This study aimed to investigate the feasibility of establishing a more reliable SNL model using an oblique lateral approach.

Methods

36 adult male Sprague-Dawley rats were randomly divided into three groups: the traditional SNL (T-SNL) group, the new SNL (N-SNL) group (where the left L5 spinal nerve was ligated with a titanium clip via an oblique lateral approach), and the sham-operated (Sham) group. The operation time, Intraoperative bleeding, the number of rats that died, gait behavior, mechanical and cold pain threshold were recorded and measured. Stereology technology was used to calculate the number of microglia in spinal dorsal horn, and the Enzyme-linked immunosorbent assay (ELISA) technology was used to detect the expression of TNF-α and IL-1β in spinal cord as well as C-reactive protein (CRP) in serum in order to assess the effect of surgery on animal inflammation.

Results

Compared with the T-SNL group, operative time and intraoperative bleeding were significantly decreased in the N-SNL group. Within 14 days postoperation, one rat in the N-SNL group was died, two rats in the T-SNL group were died. Compared with the Sham group, the N-SNL group showed obvious spontaneous pain behavior, decreased the pain thresholds, the number of microglia and the expression of TNF-α and IL-1β were significantly increased, and there was no significant difference in these indexes compared with T-SNL group. There was no significant difference in serum CRP levels among the three groups.

Conclusion

This study suggests that the oblique lateral approach SNL model is a reliable NP model with the advantages of good reproducibility, accessibility, and low trauma.

Neurogenic and angiogenic poly(N-acryloylglycine)-co-(acrylamide)-co-(N-acryloyl-glutamate) hydrogel: preconditioning effect under oxidative stress and use in neuroregeneration

Traumatic injuries, neurodegenerative diseases and oxidative stress serve as the early biomarkers for neuronal damage and impede angiogenesis and subsequently neuronal growth. Considering this, the present work aimed to develop a poly(N-acryloylglycine)-co-(acrylamide)-co-(N-acryloylglutamate) hydrogel [p(NAG-Ac-NAE)] with angiogenesis/neurogenesis properties. As constituents of this polymer modulate their vital role in biological functions, inhibitory neurotransmitter glycine regulates neuronal homeostasis, and glutamatergic signalling regulates angiogenesis. The p(NAG-Ac-NAE) hydrogel is a highly branched, biodegradable and pH-responsive polymer with a very high swelling behavior of 6188%. The mechanical stability (G', 2.3-2.7 kPa) of this polymeric hydrogel is commendable in the differentiation of mature neurons. This hydrogel is biocompatible (as tested in HUVEC cells) and helps to proliferate PC12 cells (152.7 ± 13.7%), whereas it is cytotoxic towards aggressive cancers such as glioblastoma (LN229 cells) and triple negative breast cancer (TNBC; MDA-MB-231 cells) and helps to maintain the healthy cytoskeleton framework structure of primary cortical neurons by facilitating the elongation of the axonal pathway. Furthermore, FACS results revealed that the synthesized hydrogel potentiates neurogenesis by inducing the cell cycle (G0/G1) and arresting the sub-G1 phase by limiting apoptosis. Additionally, RT-PCR results revealed that this hydrogel induced an increased level of HIF-1α expression, providing preconditioning effects towards neuronal cells under oxidative stress by scavenging ROS and initiating neurogenic and angiogenic signalling. This hydrogel further exhibits more pro-angiogenic activities by increasing the expression of VEGF isoforms compared to previously reported hydrogels. In conclusion, the newly synthesized p(NAG-Ac-NAE) hydrogel can be one of the potential neuroregenerative materials for vasculogenesis-assisted neurogenic applications and paramount for the management of neurodegenerative diseases.

Tumor Necrosis Factor and Interleukin Modulators for Pathologic Pain States: A Narrative Review

Chronic pain, a complex and debilitating condition, involves intricate interactions between central and peripheral inflammatory processes. Cytokines, specifically tumor necrosis factor (TNF) and interleukins (IL), are key mediators in the initiation and maintenance of chronic pain states. Sensory neurons expressing receptors for cytokines like TNF, IL-1, and IL-6 are implicated in peripheral sensitization, contributing to increased signaling of painful sensations. The potential of targeting TNF and IL for therapeutic intervention in chronic pain states is the focus of this review, with preclinical and clinical evidence supporting the use of TNF and IL modulators for pain management. The physiological and pathological roles of TNF in neuropathic pain is complex. Experimental evidence highlights the effectiveness of TNF modulation in mitigating pain symptoms in animal models and displays promising outcomes of clinical trials with TNF inhibitors, such as infliximab and etanercept. ILs, a diverse group of cytokines, including IL-1, IL-6, and IL-17, are discussed for their contributions to chronic pain through inflammation and peripheral sensitization. Specific IL modulators, such as secukinumab and tocilizumab, have shown potential in managing chronic neuropathic pain, as demonstrated in various studies and clinical trials. The pharmacokinetics, safety profiles, and challenges associated with TNF and IL modulators highlight the need for cautious medication monitoring in clinical practice. Comparative evaluations have revealed distinct efficacy and safety profiles among different cytokine modulators, emphasizing the need for personalized approaches based on the specific underlying causes of pain. Further research is necessary to elucidate the intricate mechanisms by which cytokines contribute to chronic pain, as well as to understand why they may affect pain differently in various contexts. Additionally, long-term safety profiles of cytokine modulators require more thorough investigation. This continued exploration holds the promise of enhancing our comprehension of cytokine modulation in chronic pain and shaping more potent therapeutic strategies for the future.

Exploring the Effects of Ixekizumab on Pain in Patients with Ankylosing Spondylitis Based on Objective Measures of Inflammation: Post Hoc Analysis from a Large Randomized Clinical Trial

INTRODUCTION

The objective of this analysis is to evaluate the improvement in spinal pain with ixekizumab, placebo, and adalimumab based on objective measures of inflammation response in patients with ankylosing spondylitis (AS).

METHODS

The COAST-V 52-week, double-blind, placebo-controlled, randomized phase III trial examined the efficacy of ixekizumab in patients with active AS; adalimumab was used as an active reference arm. Treatment effects on reduction in pain were assessed by objective measures of controlled and persisting inflammation (defined by magnetic resonance imaging [MRI], C-reactive protein [CRP], or MRI + CRP status). Pathway analysis was used to analyze treatment effect that was not attributable to reduction in inflammation biomarkers.

RESULTS

In patients with AS, when inflammation was controlled as assessed by MRI, patients treated with ixekizumab experienced a reduction in spinal pain at night (SP-N, numeric rating scale, ixekizumab mean = - 3.9, p < 0.001, adalimumab mean = - 2.6, p < 0.05) compared to placebo (mean =  - 1.6) at week 16. When inflammation was controlled as assessed by MRI + CRP, ixekizumab and adalimumab had numerically greater reductions at week 16 in SP-N versus placebo. All ixekizumab groups had further improvements at week 52. When inflammation was persisting as assessed by MRI + CRP, ixekizumab-treated patients had significant reduction in SP-N (mean = - 3.7, p < 0.001) versus placebo (mean = - 1.7), improvement with adalimumab did not reach significance (mean = - 2.6, p = 0.06). In the pathway analysis at week 16, ixekizumab had a greater effect on pain outcomes compared to adalimumab.

CONCLUSION

This post hoc analysis is supportive of the hypothesis that ixekizumab reduces pain in AS by additional mechanisms other than the reduction of measurable inflammation.

TRIAL REGISTRATION NUMBER

NCT02696785.

Concomitant Treatment with Doxycycline and Rifampicin in Balb/c Mice Infected with Brucella abortus 2308 Fails to Reduce Inflammation and Motor Disability

Brucellosis is an infection widely distributed around the world, and in some countries it is considered a public health problem. Brucellosis causes insidious symptoms that make it difficult to diagnose. Infection can also trigger chronic pain and neuropsychiatric complications. Antibiotics are not always effective to eradicate infection, contributing to chronicity. We aimed to investigate the effects of antibiotic treatment on proinflammatory cytokines, neurotransmitters, corticosterone, and behavior in a murine model of infecrion of B. abortus strain 2308. Four study groups were created: (a) control; (b) antibiotic control; (c) infected with B. abortus 2308; and (d) infected and treated with rifampicin and doxycycline. We determined B. abortus 2308 colony-forming units (CFUs), the count of dendritic cells, and macrophages in the spleen; serum levels of cytokines and corticosterone; levels of serotonin, dopamine, epinephrine, and norepinephrine in the brain; and equilibrium, physical strength, anxiety, and hopelessness tests. The infected and treated mice group was compared with the control and infected mice to assess whether treatment is sufficient to recover neuroimmunoendocrine parameters. Our results showed that despite the treatment of brucellosis with rifampicin and doxycycline, antibiotic-treated mice showed a persistence of B. abortus 2308 CFUs, an increased count in macrophage number, and higher circulating levels of corticosterone. Furthermore, the levels of IL-12, IL-6, and TNF-α remained higher. We found a decrease in muscular strength and equilibrium concomitant to changes in neurotransmitters in the hippocampus, cerebellum, and frontal cortex. Our data suggest that the remaining bacterial load after antibiotic administration favors inflammatory, neurochemical, and behavioral alterations, partly explaining the widespread and paradoxical symptomatology experienced by patients with chronic brucellosis.

Sacral Bioneuromodulation: The Role of Bone Marrow Aspirate in Spinal Cord Injuries

Spinal cord injury (SCI) represents a severe trauma to the nervous system, leading to significant neurological damage, chronic inflammation, and persistent neuropathic pain. Current treatments, including pharmacotherapy, immobilization, physical therapy, and surgical interventions, often fall short in fully addressing the underlying pathophysiology and resultant disabilities. Emerging research in the field of regenerative medicine has introduced innovative approaches such as autologous orthobiologic therapies, with bone marrow aspirate (BMA) being particularly notable for its regenerative and anti-inflammatory properties. This review focuses on the potential of BMA to modulate inflammatory pathways, enhance tissue regeneration, and restore neurological function disrupted by SCI. We hypothesize that BMA's bioactive components may stimulate reparative processes at the cellular level, particularly when applied at strategic sites like the sacral hiatus to influence lumbar centers and higher neurological structures. By exploring the mechanisms through which BMA influences spinal repair, this review aims to establish a foundation for its application in clinical settings, potentially offering a transformative approach to SCI management that extends beyond symptomatic relief to promoting functional recovery.

CXCL1-CXCR2 axis mediates inflammatory response after sciatic nerve injury by regulating macrophage infiltration

Macrophages play a crucial role in the inflammatory response following sciatic nerve injury. Studies have demonstrated that C-X-C motif chemokine (CXCL) 1 recruit macrophages by binding to C-X-C chemokine receptor (CXCR) 2 and participates in the inflammatory response of various diseases. Based on these findings, we aimed to explore the role of the CXCL1-CXCR2 axis in the repair process after peripheral nerve injury. Initially, we simulated sciatic nerve injury and observed an increased expression of CXCL1 and CXCR2 in the nerves of the injury group. Both in vivo and in vitro experiments confirmed that the heightened CXCL1 expression occurs in Schwann cells and is secreted, while the elevated CXCR2 is expressed by recruited macrophages. In addition, in vitro experiments demonstrated that the binding of CXCL1 to CXCR2 can activate the NLRP3 inflammasome and promote the production of interleukin-1 beta (IL-1β) in macrophages. However, after mice were subjected to sciatic nerve injury, the number of macrophages and the expression of inflammatory factors in the sciatic nerve were reduced following treatment with the CXCR2 inhibitor SB225002. Simultaneously, we evaluated the sciatic nerve function index, the expression of p75 neurotrophic factor receptor (p75NTR), and myelin proteins, and all of these results were improved with the use of SB225002. Thus, our results suggest that after sciatic nerve injury, the CXCL1-CXCR2 axis mediates the inflammatory response by promoting the recruitment and activation of macrophages, which is detrimental to the repair of the injured nerves. In contrast, treatment with SB225002 promotes the repair of injured sciatic nerves.

Recent Advances in Management of Neuropathic, Nociceptive, and Chronic Pain: A Narrative Review with Focus on Nanomedicine, Gene Therapy, Stem Cell Therapy, and Newer Therapeutic Options

PURPOSE OF REVIEW

This manuscript summarizes novel clinical and interventional approaches in the management of chronic, nociceptive, and neuropathic pain.

RECENT FINDINGS

Pain can be defined as a feeling of physical or emotional distress caused by an external stimulus. Pain can be grouped into distinct types according to characteristics including neuropathic pain, which is a pain caused by disease or lesion in the sensory nervous system; nociceptive pain, which is pain that can be sharp, aching, or throbbing and is caused by injury to bodily tissues; and chronic pain, which is long lasting or persisting beyond 6 months. With improved understanding of different signaling systems for pain in recent years, there has been an upscale of methods of analgesia to counteract these pathological processes. Novel treatment methods such as use of cannabinoids, stem cells, gene therapy, nanoparticles, monoclonal antibodies, and platelet-rich plasma have played a significant role in improved strategies for therapeutic interventions. Although many management options appear to be promising, extensive additional clinical research is warranted to determine best practice strategies in the future for clinicians.

Efficacy of acupuncture on cancer pain: A systematic review and meta-analysis

BACKGROUND

Pain associated with cancer is one of the greatest causes of reduced quality of life in patients. Acupuncture is one of the treatments used to address this issue, with the great advantage of having little or no side effects, especially when compared with pharmacological pain-killers.

OBJECTIVE

The aim of this systematic review and meta-analysis was to evaluate the current evidence regarding the efficacy of acupuncture for cancer pain.

SEARCH STRATEGY

Six electronic databases (PubMed, EBSCO, Cochrane Library, Scielo, b-On and Scopus) were searched for relevant articles about pain relief in cancer patients from their beginning until 2022 using MeSH terms such as "acupuncture," "electroacupuncture," "ear acupuncture," "acupuncture analgesia," ''oncological pain," and "cancer pain."

INCLUSION CRITERIA

Studies included were randomized controlled trials (RCTs) where acupuncture was compared with no treatment, placebo acupuncture or usual care.

DATA EXTRACTION AND ANALYSIS

Three independent reviewers participated in data extraction and evaluation of risk of bias, and a meta-analysis was conducted. The primary outcome was pain intensity, measured with the visual analog scale, numeric rating scale, or brief pain inventory. Secondary outcomes also assessed were quality of life, functionality, xerostomia, pain interference, and analgesic consumption. Results were expressed as standardized mean difference (SMD) with 95% confidence interval (CI).

RESULTS

Sixteen RCTs with a total of 1124 participants were included in the meta-analysis, with the majority of the studies presenting a low or unclear risk of bias. Acupuncture was more effective in reducing pain than no treatment (SMD = -0.90, 95 % CI [-1.68, -0.12]), sham acupuncture (SMD = -1.10, 95 % CI [-1.59, -0.61]) or usual care (SMD = -1.16, 95 % CI [-1.38, -0.93]).

CONCLUSION

The results of this study suggest that acupuncture may be an effective intervention to reduce pain associated with cancer. Despite some limitations due to the low quality and small sample size of some included studies, as well as the different types and stages of cancer, acupuncture might provide an effective and safe treatment to reduce cancer pain. Please cite this article as: Faria M, Teixeira M, Pinto MJ, Sargento P. Efficacy of acupuncture on cancer pain: A systematic review and meta-analysis. J Integr Med. 2024; 22(3): 235-244.

BDNF in Neuropathic Pain; the Culprit that Cannot be Apprehended

In males but not in females, brain derived neurotrophic factor (BDNF) plays an obligatory role in the onset and maintenance of neuropathic pain. Afferent terminals of injured peripheral nerves release colony stimulating factor (CSF-1) and other mediators into the dorsal horn. These transform the phenotype of dorsal horn microglia such that they express P2X4 purinoceptors. Activation of these receptors by neuron-derived ATP promotes BDNF release. This microglial-derived BDNF increases synaptic activation of excitatory dorsal horn neurons and decreases that of inhibitory neurons. It also alters the neuronal chloride gradient such the normal inhibitory effect of GABA is converted to excitation. By as yet undefined processes, this attenuated inhibition increases NMDA receptor function. BDNF also promotes the release of pro-inflammatory cytokines from astrocytes. All of these actions culminate in the increase dorsal horn excitability that underlies many forms of neuropathic pain. Peripheral nerve injury also alters excitability of structures in the thalamus, cortex and mesolimbic system that are responsible for pain perception and for the generation of co-morbidities such as anxiety and depression. The weight of evidence from male rodents suggests that this preferential modulation of excitably of supra-spinal pain processing structures also involves the action of microglial-derived BDNF. Possible mechanisms promoting the preferential release of BDNF in pain signaling structures are discussed. In females, invading T-lymphocytes increase dorsal horn excitability but it remains to be determined whether similar processes operate in supra-spinal structures. Despite its ubiquitous role in pain aetiology neither BDNF nor TrkB receptors represent potential therapeutic targets.

Potassium channel modulation in macrophages sensitizes dorsal root ganglion neurons after nerve injury

Macrophages and satellite glial cells are found between injured and uninjured neurons in the lumbar dorsal root ganglia (DRG). We explored the mechanism of neuro-immune and neuron-glia crosstalk leading to hyperexcitability of DRG neurons. After spared nerve injury (SNI), CX3CR1+ resident macrophages became activated, proliferated, and increased inward-rectifying potassium channel Kir 2.1 currents. Conditioned medium (CM) by macrophages, obtained from DRG of SNI mice, sensitized small DRG neurons from naïve mice. However, treatment with CM from GFAP+ glial cells did not affect neuronal excitability. When subjected to this macrophage-derived CM, DRG neurons had increased spontaneous activity, current-evoked responses and voltage-gated NaV 1.7 and NaV 1.8 currents. Silencing Kir 2.1 in macrophages after SNI prevented the induction of neuronal hyperexcitability from their CM. Blocking vesicular exocytosis or soluble tumor necrosis factor in CM or interfering with the downstream intracellular p38 pathway in neurons, also prevented neuronal hyperexcitability. Blocking protein trafficking in neurons reduced the effect of CM, suggesting that the hyperexcitable state resulted from changes in NaV channel trafficking. These results suggest that DRG macrophages, primed by peripheral nerve injury, contribute to neuron-glia crosstalk, NaV channel dysregulation and neuronal hyperexcitability implicated in the development of neuropathic pain.

How inflammation dictates diabetic peripheral neuropathy: An enlightening review

BACKGROUND

Diabetic peripheral neuropathy (DPN) constitutes a debilitating complication associated with diabetes. Although, the past decade has seen rapid developments in understanding the complex etiology of DPN, there are no approved therapies that can halt the development of DPN, or target the damaged nerve. Therefore, clarifying the pathogenesis of DPN and finding effective treatment are the crucial issues for the clinical management of DPN.

AIMS

This review is aiming to summary the current knowledge on the pathogenesis of DPN, especially the mechanism and application of inflammatory response.

METHODS

We systematically summarized the latest studies on the pathogenesis and therapeutic strategies of diabetic neuropathy in PubMed.

RESULTS

In this seminal review, the underappreciated role of immune activation in the progression of DPN is scrutinized. Novel insights into the inflammatory regulatory mechanisms of DPN have been unearthed, illuminating potential therapeutic strategies of notable clinical significance. Additionally, a nuanced examination of DPN's complex etiology, including aberrations in glycemic control and insulin signaling pathways, is presented. Crucially, an emphasis has been placed on translating these novel understandings into tangible clinical interventions to ameliorate patient outcomes.

CONCLUSIONS

This review is distinguished by synthesizing cutting-edge mechanisms linking inflammation to DPN and identifying innovative, inflammation-targeted therapeutic approaches.

Scoping Review: The Role of Psychedelics in the Management of Chronic Pain

Introduction

Amid a lack of effective chronic pain treatments, psychedelics have gained attention as a potential solution, although their Schedule 1 classification poses challenges. Psychedelics, such as lysergic acid diethylamide (LSD) and psilocybin, have gained popularity as alternatives and adjuncts for chronic pain treatment. Studies suggest that they may modulate pain processing through agonism primarily at the serotonin receptor, 5-HT2A. One of the first of its nature, we present an artificial intelligence (AI)-powered scoping review primarily focusing on evaluating psychedelics for chronic pain conditions such as cluster headache, phantom limb pain, and fibromyalgia.

Methods

In accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) guidelines, we used an AI-powered comprehensive search strategy utilizing the ChatGPT4.0 Bing chat to search Medline, Embase, Cochrane, and Google Scholar for articles addressing chronic pain. The query was performed on June 1, 2023, focusing on psychedelics for chronic, non-cancer pain including headache disorders. Inclusion criteria were English-only, peer-reviewed articles involving human participants >18 years, focusing on chronic pain conditions (eg, phantom limb pain and cluster headache), using LSD, 2.5-dimethoxy-4-bromophenethylamine (2C-B), N, N-dimethyltryptamine (DMT), psilocybin, or mescaline. Exclusion criteria were reviews, editorials, and opinion articles and studies focusing on tetrahydrocannabinol/cannabis and/or ketamine.

Results

A total of 186 unique database entries were retrieved, of which nine studies were included in the scoping review. These included four case reports/series, an open-label study, a cohort study, two online surveys, and a randomized, double-blind, placebo-controlled trial. They comprised three studies addressing phantom limb pain, four addressing cluster headaches, and two addressing fibromyalgia, spinal cord injury, complex regional pain syndrome, and lumbar radiculopathy.

Conclusion

Psychedelics may have potential in alleviating pain symptoms secondary to a multitude of chronic pain conditions. However, further randomized, double-blind, placebo-controlled trials are needed to further explore and evaluate the role of psychedelics in chronic, non-cancer pain.

Vertebral Subluxation and Systems Biology: An Integrative Review Exploring the Salutogenic Influence of Chiropractic Care on the Neuroendocrine-Immune System

In this paper we synthesize an expansive body of literature examining the multifaceted influence of chiropractic care on processes within and modulators of the neuroendocrine-immune (NEI) system, for the purpose of generating an inductive hypothesis regarding the potential impacts of chiropractic care on integrated physiology. Taking a broad, interdisciplinary, and integrative view of two decades of research-documented outcomes of chiropractic care, inclusive of reports ranging from systematic and meta-analysis and randomized and observational trials to case and cohort studies, this review encapsulates a rigorous analysis of research and suggests the appropriateness of a more integrative perspective on the impact of chiropractic care on systemic physiology. A novel perspective on the salutogenic, health-promoting effects of chiropractic adjustment is presented, focused on the improvement of physical indicators of well-being and adaptability such as blood pressure, heart rate variability, and sleep, potential benefits that may be facilitated through multiple neurologically mediated pathways. Our findings support the biological plausibility of complex benefits from chiropractic intervention that is not limited to simple neuromusculoskeletal outcomes and open new avenues for future research, specifically the exploration and mapping of the precise neural pathways and networks influenced by chiropractic adjustment.

Interleukin-18 in chronic pain: Focus on pathogenic mechanisms and potential therapeutic targets

Chronic pain has been proven to be an independent disease, other than an accompanying symptom of certain diseases. Interleukin-18 (IL-18), a pro-inflammatory cytokine with pleiotropic biological effects, participates in immune modulation, inflammatory response, tumor growth, as well as the process of chronic pain. Compelling evidence suggests that IL-18 is upregulated in the occurrence of chronic pain. Antagonism or inhibition of IL-18 expression can alleviate the occurrence and development of chronic pain. And IL-18 is located in microglia, while IL-18R is mostly located in astrocytes in the spinal cord. This indicates that the interaction between microglia and astrocytes mediated by the IL-18/IL-18R axis is involved in the occurrence of chronic pain. In this review, we described the role and mechanism of IL-18 in different types of chronic pain. This review provides strong evidence that IL-18 is a potential therapeutic target in pain management.

Arterial hypertension in the chronic evolution of migraine: bystander or risk factor? An overview

BACKGROUND

Several risk factors are associated with the chronic evolution of migraine. Clinical and preclinical studies have provided data about the role of hypertension (HT) as one of the potential modifiable risk factors of chronic migraine (CM). This review is focused on the biological and clinical evidence supporting common mechanisms underlying HT and migraine and the potential role of HT in the transition from episodic to chronic migraine.

METHODS

We conducted a narrative review from a literature search covering the available evidence from studies investigating: i) the role of HT in the transition to CM in clinical practice; ii) the biological mechanisms potentially underpinning the association between HT and evolution to CM; iii) the role of antihypertensive medications in migraine prophylaxis.

RESULTS

HT proved to be at the base of multiple mechanisms underlying migraine and migraine chronicization. Endothelial dysfunction, blood-brain barrier alterations, calcitonin gene-related peptide signaling, and renin-angiotensin-aldosterone system dysregulation are involved in the worsening effect of HT on migraine frequency, and the role of HT in the transition to CM is supported by clinical observations.

CONCLUSIONS

The observed evidence supports HT contribution to CM evolution due to shared pathophysiologic mechanisms. While a bidirectional influence appears to be ascertained, data are still lacking about the one-way role of HT as direct risk factor for CM transition. Further research is needed to confirm a causal role of HT in this process.

The role of purinergic signaling in acupuncture-mediated relief of neuropathic and inflammatory pain

Acupuncture is a traditional medicinal practice in China that has been increasingly recognized in other countries in recent decades. Notably, several reports have demonstrated that acupuncture can effectively aid in pain management. However, the analgesic mechanisms through which acupuncture provides such benefits remain poorly understood. Purinergic signaling, which is mediated by purine nucleotides and purinergic receptors, has been proposed to play a central role in acupuncture analgesia. On the one hand, acupuncture affects the transmission of nociception by increasing adenosine triphosphate dephosphorylation and thereby decreasing downstream P2X3, P2X4, and P2X7 receptors signaling activity, regulating the levels of inflammatory factors, neurotrophic factors, and synapsin I. On the other hand, acupuncture exerts analgesic effects by promoting the production of adenosine, enhancing the expression of downstream adenosine A1 and A2A receptors, and regulating downstream inflammatory factors or synaptic plasticity. Together, this systematic overview of the field provides a sound, evidence-based foundation for future research focused on the application of acupuncture as a means of relieving pain.

The Known Biology of Neuropathic Pain and Its Relevance to Pain Management

Patients with neuropathic pain are heterogeneous in pathophysiology, etiology, and clinical presentation. Signs and symptoms are determined by the nature of the injury and factors such as genetics, sex, prior injury, age, culture, and environment. Basic science has provided general information about pain etiology by studying the consequences of peripheral injury in rodent models. This is associated with the release of inflammatory cytokines, chemokines, and growth factors that sensitize sensory nerve endings, alter gene expression, promote post-translational modification of proteins, and alter ion channel function. This leads to spontaneous activity in primary afferent neurons that is crucial for the onset and persistence of pain and the release of secondary mediators such as colony-stimulating factor 1 from primary afferent terminals. These promote the release of tertiary mediators such as brain-derived neurotrophic factor and interleukin-1β from microglia and astrocytes. Tertiary mediators facilitate the transmission of nociceptive information at the spinal, thalamic, and cortical levels. For the most part, these findings have failed to identify new therapeutic approaches. More recent basic science has better mirrored the clinical situation by addressing the pathophysiology associated with specific types of injury, refinement of methodology, and attention to various contributory factors such as sex. Improved quantification of sensory profiles in each patient and their distribution into defined clusters may improve translation between basic science and clinical practice. If such quantification can be traced back to cellular and molecular aspects of pathophysiology, this may lead to personalized medicine approaches that dictate a rational therapeutic approach for each individual.

Acupuncture Relieves Cervical Spondylosis Radiculopathy by Regulating Spinal Microglia Activation Through MAPK Signaling Pathway in Rats

Purpose

Local acupuncture has been found to have a good analgesic effect in rats with cervical spondylosis radiculopathy (CSR), but it lacks a regulatory effect on traditional Chinese medicine syndrome types of CSR. We proposed "Invigorating Qi and activating Blood" (IQAB) acupuncture, compared with Fenbid, and local electroacupuncture (LEA), to observe whether it has advantages in the protection of the CSR rat model and to elucidate its mechanism through the MAPK (mitogen-activated protein kinase) signaling pathway.

Materials and Methods

Male Sprague-Dawley rats were randomly divided into six groups: control, sham, model, Fenbid, LEA, and IQAB. The CSR model was induced by inserting nylon sutures to compress the C4-T1 nerve root. The Fenbid group was treated with ibuprofen sustained-release capsules (15 mg/kg·d, ig). The LEA group received electroacupuncture at both C5 and C7 EX-B2 once a day. The IQAB group received acupuncture at both ST36 and BL17 based on the LEA group's intervention. Mechanical allodynia and gait, morphological changes in the spinal cord, IL-6 and TNF-α levels, MAPKs phosphorylation ratio, monocyte chemoattractant protein-1 (MCP-1) levels in the spinal cord, and the expression of p-p38 in the spinal cord and its colocalization with neurons and glial cell activation markers were detected.

Results

Mechanical allodynia, gait disorder, edema, reduced Nissl-positive cell numbers, and increased IL-6 and TNF-α levels in the spinal cord were observed in CSR rats. IQAB significantly alleviated these changes, and the effects were generally comparable to those of Fenbid. Meanwhile, the phosphorylation ratios of p38 and extracellular regulated protein kinase (ERK), co-expression of p-p38 with neuron/microglia, and MCP-1 levels in the spinal cord were markedly down-regulated by IQAB compared with those in CSR model rats.

Conclusion

IQAB reduced p38-activation-related microglia activation and MCP-1 levels, thus alleviating pathological changes, inflammation levels in the local spinal cord, and pain behavior of CSR.

Deciphering the Molecular Mechanism of Escin against Neuropathic Pain: A Network Pharmacology Study

Background

Escin is the main active component in Aesculus hippocastanum. It has been demonstrated that escin has anti-inflammatory properties. This study combined the methods of network pharmacology, molecular docking, and molecular dynamics to explore the molecular mechanism of escin against neuropathic pain (NP).

Methods

The Swiss Target Prediction and the Pharm Mapper database were employed for predicting the targets of escin. Also, the candidate targets of NP were gathered via the databases including Therapeutic Targets, DisGeNet, GeneCards, DrugBank, and OMIM. Subsequently, the network of protein-protein interaction was screened for the key targets by the software Cytoscape 3.8.0. Then, the intersection of these targets was analysed by Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment. Additionally, we further investigated the ligand-target interactions by molecular docking and molecular dynamics simulations.

Results

In total, 94 escin targets were predicted by network pharmacology. Among them, SRC, MMP9, PTGS2, and MAPK1 were the core candidate targets. Subsequently, the analysis of GO and KEGG enrichment revealed that escin affected NP by regulating protein kinase C, MAP kinase, TRP channels, the T-cell receptors signaling pathway, and the TNF signaling pathway. The results of molecular docking and molecular dynamics simulation confirmed that escin not only had a strong binding activity with the four core target proteins but also stably combined in 50 ns.

Conclusions

Our study revealed that escin acts on the core targets SRC, MMP9, PTGS2, MAPK1, and associated enrichment pathways to alleviate neuronal inflammation and regulate the immune response, thus exerting anti-NP efficacy. This study provided innovative ideas and methods for the promising treatment of escin in relieving NP.

The effect of risperidone on behavioral reactions and gene expression of pro- and anti-inflammatory cytokines in neuropathic pain model induced by chronic constriction injury of the sciatic nerve in rat

BACKGROUND

Neuropathic pain results from lesions or diseases affecting the somatosensory system. The management of a patient with chronic neuropathic pain remains a challenge several studies report the analgesic effect of serotonin receptor antagonists in different models of experimental pain. The present study was designed to study the effect of systemic administration of risperidone, on behavioral scores of neuropathic pains in chronic constriction (CCI) model in rats.

METHODS

Inducing neuropathic pain with the CCI model which causes heat hyperalgesia, heat, and mechanical allodynia was performed on rats, and then, in two phases, risperidone effect was determined. In the acute phase, risperidone 1, 2, 4 mg was administered for three groups half an hour before behavioral tests on the 7th, 14th, and 21st day after surgery, and in the chronic phase, risperidone 1, 2, and 4 mg was administered for three different groups from the 1st to 14th days after surgery than on 14th-day behavioral scores were performed. For gene expression analysis, samples are taken from spinal cord tissues in lumbar segments.

RESULTS

This study shows chronic administration of risperidone as an antipsychotic drug was effective on heat hyperalgesia and allodynia. However, only the max dosage (4 mg) of risperidone showed meaningful improvement in increasing mechanical allodynia. However, acute administering of risperidone did not show any meaningful changes in behavioral tests on neuropathic pain induced by chronic constriction injury of the sciatic nerve in rats. In addition, gene expression results showed an increase in IL-4 and IL-10 gene expression in the risperidone group compared to the sham group.

CONCLUSION

This study suggests the helpful preventive effects of risperidone in developing and increasing neuropathic pain, but it does not have any instant effect.

Periodontitis promotes bacterial extracellular vesicle-induced neuroinflammation in the brain and trigeminal ganglion

Gram-negative bacteria derived extracellular vesicles (EVs), also known as outer membrane vesicles, have attracted significant attention due to their pathogenic roles in various inflammatory diseases. We recently demonstrated that EVs secreted by the periodontopathogen Aggregatibacter actinomycetemcomitans (Aa) can cross the blood-brain barrier (BBB) and that their extracellular RNA cargo can promote the secretion of proinflammatory cytokines, such as IL-6 and TNF-α, in the brain. To gain more insight into the relationship between periodontal disease (PD) and neuroinflammatory diseases, we investigated the effect of Aa EVs in a mouse model of ligature-induced PD. When EVs were administered through intragingival injection or EV-soaked gel, proinflammatory cytokines were strongly induced in the brains of PD mice. The use of TLR (Toll-like receptor)-reporter cell lines and MyD88 knockout mice confirmed that the increased release of cytokines was triggered by Aa EVs via TLR4 and TLR8 signaling pathways and their downstream MyD88 pathway. Furthermore, the injection of EVs through the epidermis and gingiva resulted in the direct retrograde transfer of Aa EVs from axon terminals to the cell bodies of trigeminal ganglion (TG) neurons and the subsequent activation of TG neurons. We also found that the Aa EVs changed the action potential of TG neurons. These findings suggest that EVs derived from periodontopathogens such as Aa might be involved in pathogenic pathways for neuroinflammatory diseases, neuropathic pain, and other systemic inflammatory symptoms as a comorbidity of periodontitis.

Single-cell analysis of dorsal root ganglia reveals metalloproteinase signaling in satellite glial cells and pain

Satellite glial cells (SGCs) are among the most abundant non-neuronal cells in dorsal root ganglia (DRGs) and closely envelop sensory neurons that detect painful stimuli. However, little is still known about their homeostatic activities and their contribution to pain. Using single-cell RNA sequencing (scRNA-seq), we were able to obtain a unique transcriptional profile for SGCs. We found enriched expression of the tissue inhibitor metalloproteinase 3 (TIMP3) and other metalloproteinases in SGCs. Small interfering RNA and neutralizing antibody experiments revealed that TIMP3 modulates somatosensory stimuli. TIMP3 expression decreased after paclitaxel treatment, and its rescue by delivery of a recombinant TIMP3 protein reversed and prevented paclitaxel-induced pain. We also established that paclitaxel directly impacts metalloproteinase signaling in cultured SGCs, which may be used to identify potential new treatments for pain. Therefore, our results reveal a metalloproteinase signaling pathway in SGCs for proper processing of somatosensory stimuli and potential discovery of novel pain treatments.

Autocrine positive feedback of tumor necrosis factor from activated microglia proposed to be of widespread relevance in chronic neurological disease

Over a decade's experience of post-stroke rehabilitation by administering the specific anti-TNF biological, etanercept, by the novel perispinal route, is consistent with a wide range of chronically diminished neurological function having been caused by persistent excessive cerebral levels of TNF. We propose that this TNF persistence, and cerebral disease chronicity, largely arises from a positive autocrine feedback loop of this cytokine, allowing the persistence of microglial activation caused by the excess TNF that these cells produce. It appears that many of these observations have never been exploited to construct a broad understanding and treatment of certain chronic, yet reversible, neurological illnesses. We propose that this treatment allows these chronically activated microglia to revert to their normal quiescent state, rather than simply neutralizing the direct harmful effects of this cytokine after its release from microglia. Logically, this also applies to the chronic cerebral aspects of various other neurological conditions characterized by activated microglia. These include long COVID, Lyme disease, post-stroke syndromes, traumatic brain injury, chronic traumatic encephalopathy, post-chemotherapy, post-irradiation cerebral dysfunction, cerebral palsy, fetal alcohol syndrome, hepatic encephalopathy, the antinociceptive state of morphine tolerance, and neurogenic pain. In addition, certain psychiatric states, in isolation or as sequelae of infectious diseases such as Lyme disease and long COVID, are candidates for being understood through this approach and treated accordingly. Perispinal etanercept provides the prospect of being able to treat various chronic central nervous system illnesses, whether they are of infectious or non-infectious origin, through reversing excess TNF generation by microglia.

Neuropathic pain; what we know and what we should do about it

Neuropathic pain can result from injury to, or disease of the nervous system. It is notoriously difficult to treat. Peripheral nerve injury promotes Schwann cell activation and invasion of immunocompetent cells into the site of injury, spinal cord and higher sensory structures such as thalamus and cingulate and sensory cortices. Various cytokines, chemokines, growth factors, monoamines and neuropeptides effect two-way signalling between neurons, glia and immune cells. This promotes sustained hyperexcitability and spontaneous activity in primary afferents that is crucial for onset and persistence of pain as well as misprocessing of sensory information in the spinal cord and supraspinal structures. Much of the current understanding of pain aetiology and identification of drug targets derives from studies of the consequences of peripheral nerve injury in rodent models. Although a vast amount of information has been forthcoming, the translation of this information into the clinical arena has been minimal. Few, if any, major therapeutic approaches have appeared since the mid 1990's. This may reflect failure to recognise differences in pain processing in males vs. females, differences in cellular responses to different types of injury and differences in pain processing in humans vs. animals. Basic science and clinical approaches which seek to bridge this knowledge gap include better assessment of pain in animal models, use of pain models which better emulate human disease, and stratification of human pain phenotypes according to quantitative assessment of signs and symptoms of disease. This can lead to more personalized and effective treatments for individual patients. Significance statement: There is an urgent need to find new treatments for neuropathic pain. Although classical animal models have revealed essential features of pain aetiology such as peripheral and central sensitization and some of the molecular and cellular mechanisms involved, they do not adequately model the multiplicity of disease states or injuries that may bring forth neuropathic pain in the clinic. This review seeks to integrate information from the multiplicity of disciplines that seek to understand neuropathic pain; including immunology, cell biology, electrophysiology and biophysics, anatomy, cell biology, neurology, molecular biology, pharmacology and behavioral science. Beyond this, it underlines ongoing refinements in basic science and clinical practice that will engender improved approaches to pain management.

Pathogenic mechanisms of human immunodeficiency virus (HIV)-associated pain

Chronic pain is a prevalent neurological complication among individuals living with human immunodeficiency virus (PLHIV) in the post-combination antiretroviral therapy (cART) era. These individuals experience malfunction in various cellular and molecular pathways involved in pain transmission and modulation, including the neuropathology of the peripheral sensory neurons and neurodegeneration and neuroinflammation in the spinal dorsal horn. However, the underlying etiologies and mechanisms leading to pain pathogenesis are complex and not fully understood. In this review, we aim to summarize recent progress in this field. Specifically, we will begin by examining neuropathology in the pain pathways identified in PLHIV and discussing potential causes, including those directly related to HIV-1 infection and comorbidities, such as antiretroviral drug use. We will also explore findings from animal models that may provide insights into the molecular and cellular processes contributing to neuropathology and chronic pain associated with HIV infection. Emerging evidence suggests that viral proteins and/or antiretroviral drugs trigger a complex pathological cascade involving neurons, glia, and potentially non-neural cells, and that interactions between these cells play a critical role in the pathogenesis of HIV-associated pain.

DEAD-box helicase 54 regulates microglial inflammatory response in rats with chronic constriction injuries through NF-κB/NLRP3 signaling axis

Neuropathic pain (NP) is caused by damage to or disease of the somatosensory nervous system, but its mechanism is still not fully understood. In this study, DEAD-box helicase 54 (DDX54) was targeted, and its regulatory role was explored in a chronic constriction injury (CCI) rat model. Microglia and HMC3 cells were stimulated with LPS. The interaction between DDX54 and myeloid differentiation factor-88 adapter protein (MYD88) was verified. A CCI of sciatic nerve model in rats was established. Behavioral testing was performed before and after the CCI. The expressions of IL-1β, TNF-α, and IL-6 were upregulated, and those of DDX54, MYD88, NF-κB, and NOD-like receptor 3 (NLRP3) were upregulated in microglia and HMC3 cells after LPS induction. DDX54 knockdown in microglia and HMC3 cells inhibited IL-1β, TNF-α, and IL-6 expressions and downregulated the protein levels of MYD88, p-NF-κB p65 (p-p65), and NLRP3. DDX54 overexpression promoted the stability of MYD88 mRNA. DDX54 binds to the MYD88-3'-untranslated region (UTR). DDX54 interference in rats could alleviate the decrease of paw withdrawal mechanical threshold (PWMT) and paw withdrawal thermal latency (PWTL) induced by CCI, inhibit Iba1 expression, and reduce inflammatory factors as well as MYD88 and NF-κB expressions. DDX54 promotes the activation of NF-κB/NLRP3 signaling by regulating MYD88 mRNA stability, thereby affecting inflammatory response and NP progression in CCI rats.NEW & NOTEWORTHY The role of DDX54 protein in LPS-induced microglia and a chronic constriction injury (CCI) rat model was investigated for the first time. DDX54 interference can inhibit microglial activation and reduce the secretion of inflammatory factors. The interaction between DDX54 protein and MYD88 mRNA was explored for the first time. DDX54 promotes NF-κB/NLRP3 signaling activation by regulating MYD88 transcription in a CCI rat model.