Exploring the causal relationship between inflammatory cytokines and inflammatory arthritis: A Mendelian randomization study

Oral Administration of Lactiplantibacillus plantarum CCFM8661 Alleviates Dichlorvos-Induced Toxicity in Mice

Dichlorvos (DDVP) is an organophosphorus pesticide commonly used in agriculture for pest control, which may enter the organism from the food chain and cause harm. This study aimed to investigate the mitigation effect of Lactiplantibacillus plantarum CCFM8661 (a strain of the bacteria) on DDVP toxicity. Sixty male mice were randomly divided into five groups including control (saline), model (DDVP), low-dose, medium-dose, and high-dose groups, and alleviating effect was evaluated by determining body weight, pesticide residues, oxidative stress, and inflammation, and by histological analysis. The results showed that compared with the model group, body weight and acetylcholinesterase activity, and SOD, CAT, T-AOC, and GSH levels significantly increased, and serum DDVP content, MDA level, IL-1β, and TNF-α significantly decreased after administration of the L. plantarum CCFM8661. The study demonstrated that L. plantarum CCFM8661 exhibited a significant detoxification effect on pesticide toxicity in mice, providing a theoretical basis for the application of probiotics in mitigating pesticide-induced damage.

Mechanistic Exploration of Smilax glabra Roxb. in Osteoarthritis: Insights from Network Pharmacology, Molecular Docking, and In Vitro Validation

Background: Arthritis, a debilitating joint disease, remains a significant global health burden. This study uncovers the therapeutic potential of the medicinal plant Smilax glabra Roxb. (SGR) in attenuating progression of disease by modulating immune responses. Methods: Through computational approaches, key bioactive compounds in SGR were identified by using freely available databases: TCMSP, TCMID, HIT2.0, HERB, and INPUT in order to elucidate their underlying mechanisms of action. Therapeutic targets for the disease have been retrieved by TTD, GeneCard, and OMIM databases. The STRING database was used to analyze the protein-protein interactions (PPI) of intersecting genes. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses were performed to reveal the functional roles of genes. Mcule was used for molecular docking and binding affinity of compounds and targets were evaluated by DeepPurpose model. ALP activity, cell viability assay, TRAP staining were also performed. Results: A total of 14 active SGR compounds with 59 common targets for arthritis have been identified. These targets have a major role in controlling biological processes such as wound healing, oxygen responses, and chemical stimuli. Molecular docking by Mcule platform demonstrated that quercetin and β-sitosterol showed higher binding energy affinities with TNF, TP53, PTGS2, and JUN as compared to other targets. To explore the complex relationship between compounds and targets, pre-trained Davis and KIBA models were used to predict the affinity values of selected compounds. In MC3T3-E1 cells, ALP activity was significantly increased and bone marrow macrophages (BMM) showed a low number of TRAP-positive cells in SGR-treated cells. Conclusions: Our findings demonstrate that SGR effectively inhibits/regulates inflammatory responses, prevents cartilage degradation, promotes bone regeneration, and can be used as a promising candidate for the development of novel arthritis treatment.

The causal association between type 2 diabetes and spinal stenosis: A Mendelian randomization analysis

Spinal stenosis is a prevalent degenerative spinal disease and one of the main causes of pain and dysfunction in older adults. Substantial evidence indicates a potentially relevant association between type 2 diabetes mellitus (T2DM) and spinal stenosis. However, the causality between these 2 disorders remains unclear. Therefore, we intended to elucidate this relationship using Mendelian Randomization (MR) analysis in this study. Based on genome-wide association study (GWAS) data on T2DM and spinal stenosis, we performed a bidirectional 2-sample MR analysis to evaluate the causality of T2DM and spinal stenosis. We assessed heterogeneity using Cochran's Q statistic and horizontal pleiotropy using the MR-Egger-intercept. "Leave-one-out" analysis was performed to determine the reliability of causal relationships. In addition, we conducted multivariate MR to clarify the direct influence of T2DM on spinal stenosis after accounting for the effect of body mass index (BMI) on spinal stenosis. Our results indicated that Individuals with T2DM had a heightened risk of spinal stenosis (odds ratio [OR]: 1.050; 95% CI: 1.004-1.098, P = .031). Moreover, no reverse causality existed between T2DM and spinal stenosis. The results of the sensitivity analysis suggest that causality is steady and robust. Multivariate MR results demonstrated that the causality of T2DM on spinal stenosis was not related to BMI (OR, 1.047; 95% CI: 1.003-1.093; P = .032). MR analyses demonstrated a possible positive causal relationship between T2DM and spinal stenosis and that this causality was unrelated to BMI.

The Contribution of Macrophage Plasticity to Inflammatory Arthritis and Their Potential as Therapeutic Targets

Inflammatory arthritis are common chronic inflammatory autoimmune diseases characterised by progressive, destructive inflammation of the joints leading to a loss of function and significant comorbidities; importantly, there are no cures and only 20% of patients achieve drug-free remission for over 2 years. Macrophages play a vital role in maintaining homeostasis, however, under the wrong environmental cues, become drivers of chronic synovial inflammation. Based on the current "dogma", M1 macrophages secrete pro-inflammatory cytokines and chemokines, promoting tissue degradation and joint and bone erosion which over time lead to accelerated disease progression. On the other hand, M2 macrophages secrete anti-inflammatory mediators associated with wound healing, tissue remodelling and the resolution of inflammation. Currently, four subtypes of M2 macrophages have been identified, namely M2a, M2b, M2c and M2d. However, more subtypes may exist due to macrophage plasticity and the ability for repolarisation. Macrophages are highly plastic, and polarisation exists as a continuum with diverse intermediate phenotypes. This plasticity is achieved by a highly amenable epigenome in response to environmental stimuli and shifts in metabolism. Initiating treatment during the early stages of disease is important for improved prognosis and patient outcomes. Currently, no treatment targeting macrophages specifically is available. Such therapeutics are being investigated in ongoing clinical trials. The repolarisation of pro-inflammatory macrophages towards the anti-inflammatory phenotype has been proposed as an effective approach in targeting the M1/M2 imbalance, and in turn is a potential therapeutic strategy for IA diseases. Therefore, elucidating the mechanisms that govern macrophage plasticity is fundamental for the success of novel macrophage targeting therapeutics.

Sophoridine exerts anti-arthritic effects on fibroblast-like synoviocytes and collagen-induced arthritis in rats

The discovery of alternative medicines with fewer adverse effects is urgently needed for rheumatoid arthritis (RA). Sophoridine (SR), the naturally occurring quinolizidine alkaloid isolated from the leguminous sophora species, has been demonstrated to possess a wide range of pharmacological activities. However, the effect of SR on RA remains unknown. In this study, the collagen-induced arthritis (CIA) rat model and tumor necrosis factor alpha (TNFα)-induced fibroblast-like synoviocytes (FLSs) were utilized to investigate the inhibitory effect of SR on RA. The anti-arthritic effect of SR was evaluated using the CIA rat model in vivo and TNFα-stimulated FLSs in vitro. Mechanistically, potential therapeutic targets and pathways of SR in RA were analyzed through drug target databases and disease databases, and validation was carried out through immunofluorescence, immunohistochemistry, and Western blot. The in vivo results revealed that SR treatment effectively ameliorated synovial inflammation and bone erosion in rats with CIA. The in vitro studies showed that SR could significantly suppress the proliferation and migration in TNFα-induced arthritic FLSs. Mechanistically, SR treatment efficiently inhibited the activation of MAPKs (JNK and p38) and NF-κB pathways in TNFα-induced arthritic FLSs. These findings were further substantiated by Immunohistochemistry results in the CIA rat. SR exerts an anti-arthritic effect in CIA rats through inhibition of the pathogenic characteristic of arthritic FLSs via suppressing NF-κB and MAPKs (JNK and p38) signaling pathways. SR may have a great potential for development as a novel therapeutic agent for RA treatment.

Target Role of Monocytes as Key Cells of Innate Immunity in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic, systemic, and inflammatory autoimmune condition characterized by synovitis, pannus formation (with adjacent bone erosion), and joint destruction. In the perpetuation of RA, fibroblast-like synoviocytes (FLSs), macrophages, B cells, and CD4+ T-cells-specifically Th1 and Th17 cells-play crucial roles. Additionally, dendritic cells, neutrophils, mast cells, and monocytes contribute to the disease progression. Monocytes, circulating cells primarily derived from the bone marrow, participate in RA pathogenesis. Notably, CCR2 interacts with CCL2, and CX3CR1 (expressed by monocytes) cooperates with CX3CL1 (produced by FLSs), facilitating the migration involved in RA. Canonical "classical" monocytes predominantly acquire the phenotype of an "intermediate" subset, which differentially expresses proinflammatory cytokines (IL-1β, IL-6, and TNF) and surface markers (CD14, CD16, HLA-DR, TLRs, and β1- and β2-integrins). However, classical monocytes have greater potential to differentiate into osteoclasts, which contribute to bone resorption in the inflammatory milieu; in RA, Th17 cells stimulate FLSs to produce RANKL, triggering osteoclastogenesis. This review aims to explore the monocyte heterogeneity, plasticity, antigenic expression, and their differentiation into macrophages and osteoclasts. Additionally, we investigate the monocyte migration into the synovium and the role of their cytokines in RA.

Genetically predicted circulating levels of cytokines and the risk of oral cavity and pharyngeal cancer: a bidirectional mendelian-randomization study

Background: Epidemiological research has established associations between various inflammatory cytokines and the occurrence of oral cancer and oropharyngeal cancer (OCPC). We performed a Mendelian randomization (MR) analysis to systematically investigate the causal relationship between inflammatory cytokines and OCPC. Methods: We performed a bidirectional two-sample MR analysis using OCPC from 12 studies (6,034 cases and 6,585 controls) and genome-wide association study (GWAS) results for 41 serum cytokines from 8,293 Finns, respectively. Inverse variance weighting was used as the primary MR method and four additional MR methods (MR Egger, Weighted median, Simple mode, Weighted mode) were used to examine genetic associations between inflammatory traits and OCPC, and Cochran's Q test, MR-Egger intercept, leave-one-out analysis, funnel plot, and multivariate MR (MVMR) analysis were used to assess the MR results. Results: The results suggested a potential association between high gene expression of Macrophage inflammatory protein-1α (MIP1α/CCL3) and an increased risk of OCPC (Odds Ratio (OR): 1.71, 95% Confidence Interval (CI): 1.09-2.68, p = 0.019). Increasing the expression levels of the interleukin-7 (IL-7) gene by 1 standard deviation reduced the risk of OCPC (OR: 0.64, 95%CI: 0.48-0.86, p = 0.003). In addition, multivariate Mendelian randomization analysis also showed the same results (MIP1α/CCL3, OR: 1.002, 95% CI: 0.919-1.092, p = 0.044; IL-7, OR: 0.997, 95% CI: 0.994-0.999, p = 0.011). Conversely, there was a positive correlation between genetic susceptibility to OCPC and an increase in Interleukin-4 (IL-4) (OR: 1.04, 95%CI: 1.00-1.08, p = 0.027). Conclusion: Our study systematically assessed the association between inflammatory cytokines and the risk of OCPC. We identified two upstream regulatory factors (IL-7 and CCL3) and one downstream effector factor (IL-4) that were associated with OCPC, offering potential avenues for the development of novel treatments.