The aryl hydrocarbon receptor (AHR), which is a ligand-activated transcription factor, controls complex transcription programs in a ligand-specific, cell type-specific, and context-specific manner by integrating signals from the environment, diet, microorganisms, and metabolism. Emerging evidence indicates that AHR participates in the regulation of multiple cell death pathways, including apoptosis, necroptosis, autophagy, pyroptosis, and ferroptosis, playing a crucial role in influencing the pathogenesis of diseases. Originally identified as a sensor for environmental toxins, AHR is now recognized for its interactions with both endogenous and microbial ligands, allowing it to orchestrate complex biological processes. This review synthesizes current knowledge on the structural dynamics, ligand diversity, and activation mechanisms of AHR, while highlighting its dual roles in programmed cell death (PCD). Additionally, we discuss the significance of AHR-regulated cell death in inflammatory diseases, neurological disorders, respiratory diseases, and cancer, highlighting its potential as a therapeutic target for various human conditions.

Objectives Dysregulated mitophagy coupled with osteoclast activation orchestrates the development and progression of osteoporosis.Although albiflorin (ALB) exhibits bone-protective effects through anti-inflammatory and antioxidant activities, its precise mechanism—particularly regarding mitochondrial regulation—remains unknown. This study therefore investigates ALB as a novel osteoclast inhibitor by examining its molecular mechanism in regulating mitophagy via the Rap1a/ERK signaling pathway. Materials and Methods ALB was evaluated using murine models of postmenopausal osteoporosis. Key methodologies included RNA sequencing (RNA-seq) for gene expression pathway analysis, transmission electron microscopy (TEM) for visualization of mitochondrial and autophagic structures, MitoTracker/LysoTracker co-staining for assessment of mitophagy, and Western blotting for protein signaling validation. The impact of ALB on osteoclast differentiation and the prevention of bone loss was evaluated in both laboratory and live animal studies.. Results ALB significantly inhibited osteoclastogenesis and osteoclast differentiation, thereby effectively reducing osteoporosis in murine models. RNA-seq analysis revealed that ALB modulated mitophagy by regulating the expression of Rap1a and components of the ERK signaling pathway. Validation through TEM demonstrated suppressed mitochondrial autophagy, while MitoTracker/LysoTracker co-staining confirmed a reduction in mitophagy. Furthermore, Western blot analysis showed that ALB inhibited osteoclast activation via the Rap1a/ERK signaling axis. Conclusion ALB mitigates postmenopausal osteoporosis by suppressing osteoclast activation through Rap1a/ERK-dependent inhibition of mitophagy. These findings identify ALB as a promising therapeutic strategy for osteoporosis, addressing the need for safer long-term treatment options.

Postmenopausal osteoporosis and depression often occur together, but a single treatment that improves both conditions is currently lacking. The loss of estrogen can trigger oxidative stress, damage mitochondria, and drive dysregulated autophagy with impaired flux, simultaneously harming bone and the brain. We evaluated whether total flavonoids from Drynaria fortunei (TFDF) could counter these problems by activating sirtuin-1 (SIRT1), a protein that supports autophagy and mitochondrial health. In menopausal and chronic stress model mice and in cultured bone-forming cells and hippocampal neurons exposed to oxidative injury, we measured bone structure and strength indicators, mood-related behaviors, mitochondrial function, and gene activity patterns. The flavonoids preserved bone density and fine bone structure, shifted bone turnover toward formation, and improved depression-like behaviors (greater exploration and sucrose preference, less immobility). Across bone and the brain, TFDF modulated SIRT1-FOXO3-DEPP1 signaling and FOXO-linked oxidative stress and autophagy programs, thereby normalizing autophagic recycling and mitochondrial function. In cellular models, TFDF preserved mitochondrial function and restored autophagic recycling, and the loss or gain of SIRT1 function abolished or enhanced these benefits, respectively, indicating that SIRT1 activity is necessary for the effects of TFDF. These findings identify TFDF as a single, mechanism-based strategy that addresses both skeletal deterioration and depressive symptoms after menopause by engaging SIRT1-dependent stress autophagy pathways to restore cellular recycling and energy control.

Senile osteoporosis progression is closely related to the decreased osteogenic differentiation capacity of senescent bone marrow stromal stem cells (BMSCs). This study demonstrated that the Traf6-mediated Nrf2/Nlrp3 signaling axis significantly influences inflammatory senescence progression in BMSCs, and targeting Traf6 can effectively alleviate bone loss caused by inflammatory senescence. High-throughput sequencing revealed that primary BMSCs from 18Ms mice were differentially enriched in anti-inflammatory, antioxidant, and immune-related biological processes compared to those from young mice, with significant differences in the protein expression of Traf6, Nrf2, and Nlrp3-related pathways, indicating potential crosstalk. In vitro experiments using western blotting and immunofluorescence confirmed high levels of intracellular inflammation, oxidative stress, and elevated expression of Traf6, Nrf2, and Nlrp3 inflammatory vesicles in senescent BMSCs. We used lentiviral transfection to knockdown Traf6 and intervention with Nrf2 agonists and inhibitors, and we verified the regulation of the expression of Nrf2/Nlrp3 inflammatory vesicles by Traf6 and its effect on inflammatory senescence progression in BMSCs. We performed in vivo experiments involving targeted Traf6 knockdown in bone tissue, morphological analysis of the femur by micro-computed tomography and immunohistochemistry, measurement of serum MDA and bone metabolism-related indices using ELISA, and calcein labeling to observe the calcium salt deposition rate. These experiments confirmed that the Traf6-mediated Nrf2/Nlrp3 signaling axis significantly influences the inflammatory senescence of BMSCs. Targeting Traf6 effectively alleviates bone loss caused by inflammatory senescence, presenting a potential method for preventing and controlling senile osteoporosis.

A growing number of studies have highlighted the significance of human gut microbiota (GM) as a potential target for osteoporosis. In this review, we discuss the effect of GM to bone metabolism focusing on two aspects: the local alterations of the human gut permeability that modify how the GM interact with the gut–bone axis (e.g., intestinal leakage, nutrient absorption), and the alterations of the GM itself (e.g., changes in microbiota metabolites, immune secretion, hormones) that modify the events of the gut–bone axis. We then classify these changes as possible therapeutic targets of bone metabolism and highlight some associated promising microbiome-based therapies. We also extend our discussions into combinatorial treatments that incorporate conservative treatments, such as exercise. We anticipate our review can provide an overview of the current pathophysiological and therapeutic paradigms of the gut–bone axis, as well as the prospects of ongoing clinical trials for readers to gain further insights into better microbiome-based treatments to osteoporosis and other bone-degenerative diseases.The translational potential of this article: This paper reviewed the potential links between gut microbiota and osteoporosis, as well as the prospective therapeutic avenues targeting gut microbiota for osteoporosis management, presenting a thorough and comprehensive literature review.

Osteoporosis (OP) represents a significant global health burden, characterized by reduced bone density and an increased risk of fractures due to imbalances in bone remodeling processes. Traditional therapeutic strategies, while mitigating symptoms, often lack the precision to address the multifactorial nature of OP effectively. In recent years, functionalized nanoparticles have emerged as a versatile platform, offering enhanced drug delivery, targeted therapy, and the potential for theranostic applications in OP treatment. This review examines the various types and architectures of functionalized nanoparticles, emphasizing their unique capabilities in targeting bone tissue and modulating bone metabolism. By focusing on their roles in inflammation modulation, oxidative stress reduction, and promoting bone regeneration, we discuss the mechanisms by which these nanoparticles offer multifunctional, synergistic effects. Additionally, we address the challenges in achieving controlled drug release, biocompatibility, and effective bone tissue penetration, proposing future directions that integrate emerging nanotechnologies, biomechanics, and regenerative medicine approaches to optimize therapeutic outcomes. This comprehensive review provides a foundation for the future development of functionalized nanoparticle therapies, positioning them as promising tools for advanced, personalized OP treatment.

NOD-like receptor (NLR) family pyrin domain-containing 3 (NLRP3) is a vital sensor of the innate immune system, capable of responding to various exogenous invading pathogens and endogenous cell injury. Once the danger signal is detected, NLRP3 recruits downstream molecules to assemble into inflammasomes, which induce inflammatory cell death and trigger an inflammatory response. PANoptosis is a specific mode of inflammatory cell death that integrates the processes of pyroptosis, apoptosis, and necrosis. It is primarily driven by a multiprotein complex termed the PANoptosome. The NLRP3 inflammasome, an essential component of the PANoptosome, is implicated in the pathogenesis of several human disorders. Targeted inhibition of NLRP3 activation specifically has a notable impact on mitigating a variety of disease conditions. This review briefly describes how the NLRP3 inflammasome forms and is activated, outlines its multifaceted roles in disorders, and emphasizes the vital role of NLRP3 in PANoptosis. Additionally, we discuss the potential of NLRP3 as a target for the clinical management of associated diseases. Improved understanding of the NLRP3 inflammasome and its involvement in PANoptosis is crucial for guiding new treatment strategies.

Osteoporosis-induced implant loosening can lead to surgical failure and impede patient recovery. Various approaches, including anti-osteoporosis drugs, have been explored to improve implant stability, however, they fail to improve bone formation or restore bone balance, underscoring the need for novel therapeutic strategies. Certain natural products, such as Chikusetsusaponin IVa (CHSs IVa) exhibit strong antioxidant and bone-protective properties, making them viable options for improving implant stability. This study aims to investigate the inhibitory effect of CHS IVa on ferroptosis and its potential to restore bone formation in bone marrow mesenchymal stem cells (BMSCs) and mouse embryonic osteoblast precursor cells (MC3T3-E1). By mitigating ferroptosis, CHS IVa increases bone mass and promotes bone integration, improving implant stability. Using a rat model of implant loosening under osteoporosis, we conducted morphological analysis, bone microstructure assessment, on tissue surrounding the implants. In vitro experiments and phosphorylated antibody chip experiments combined with molecular docking were employed to investigate the inhibitory mechanism of CHS IVa. Our findings reveal that ferroptosis occurs around internal implants under osteoporotic conditions. CHS IVa inhibits ferroptosis in osteoblasts by intervening in the GSK3β/NRF2/GPX4 pathway, saving osteoblasts osteogenic ability and increasing bone mass at the implant bone interface, further enhancing implant stability.

Objectives: To analyze and describe the spatiotemporal trends of Low back pain (LBP) burdens from 1990 to 2019 and anticipate the following decade’s incidence.Methods: Using data from the Global Burden of Disease (GBD) 2019 Study, we described net drifts, local drifts, age effects, and period cohort effects in incidence and forecasted incidence rates and cases by sex from 2020 to 2029 using the Nordpred R package.Results: LBP remained the leading cause of the musculoskeletal disease burden globally and across all socio-demographic index (SDI) regions. China is the top country. For recent periods, high-SDI countries faced unfavorable or worsening risks. The relative risk of incidence showed improving trends over time and in successively younger birth cohorts amongst low-middle-, middle- and high-middle-SDI countries. Additionally, the age-standardized incidence rates (ASIR) of LBP in both sexes globally showed a decreasing trend, but the incident cases would increase from 223 to 253 million overall in the next decade.Conclusion: As the population ages, incident cases will rise but ASIR will fall. To minimise LBP, public awareness and disease prevention and control are needed.

Injectable hydrogels are gaining prominence as a biocompatible, minimally invasive, and adaptable platform for cartilage tissue engineering. Commencing with their synthesis, this review accentuates the tailored matrix formulations and cross-linking techniques essential for fostering three-dimensional cell culture and melding with complex tissue structures. Subsequently, it spotlights the hydrogels' enhanced properties, highlighting their augmented functionalities and broadened scope in cartilage tissue repair applications. Furthermore, future perspectives are advocated, urging continuous innovation and exploration to surmount existing challenges and harness the full clinical potential of hydrogels in regenerative medicine. Such advancements are crucial for validating the long-term efficacy and safety of hydrogels, positioning them as a promising direction in regenerative medicine to address cartilage-related ailments.

Fibrosis, an excessive self-repair response, is an age-related pathological process that universally affects various major organs such as the heart, liver, kidney, and lungs. Continuous accumulation of pathological tissue fibrosis destroys structural integrity and causes loss of function, with consequent organ failure and increased mortality. Although some differences exist in the triggering mechanisms and pathophysiologic manifestations of organ-specific fibrosis, they usually share similar cascading responses and features, including chronic inflammatory stimulation, parenchymal cell injury, and macrophage recruitment. Macrophages, due to their high plasticity, can polarize into different phenotypes in response to varied microenvironments and play a crucial role in the development of organ fibrosis. This review examined the relationship between macrophages and the pathogenesis of organ fibrosis. Moreover, it analyzed how fibrosis can be modulated by targeting macrophages, which may become a novel and promising therapeutic strategy for fibrosis.

The inflammation causes the destroyed osseointegration at the implant-bone interface, significantly increasing the probability of implant loosening in osteoporotic patients. Currently, inhibiting the differentiation of M1 macrophages and the inflammatory response could be a solution to stabilize the microenvironment of implants. Interestingly, some natural products have anti-inflammatory and anti-polarization effects, which could be a promising candidate for stabilizing the implants’ microenvironment in osteoporotic patients. This research aims to explore the inhibitory effect of Urolithin B(UB) on macrophage M1 polarization, which ameliorates inflammation, thus alleviating implant instability. We established an osteoporosis mouse model of implant loosening. The mouse tissues were taken out for morphological analysis, staining analysis, and bone metabolic index analysis. In in vitro experiments, RAW264.7 cells were polarized to M1 macrophages using lipopolysaccharide (LPS) and analyzed by immunofluorescence (IF) staining, Western blot (WB), and flow cytometry. The CSP100 plus chip experiments were used to explore the potential mechanisms behind the inhibiting effects of UB. Through observation of these experiments, UB can improve the osseointegration between the implants and femurs in osteoporotic mice and enhance the stability of implants. The UB can inhibit the differentiation of M1 macrophages and local inflammation via inhibiting the phosphorylation of VEGFR2, which can be further proved by the weakened inhibited effects of UB in macrophages with lentivirus-induced overexpression of VEGFR2. Overall, UB can specifically inhibit the activation of VEGFR2, alleviate local inflammation, and improve the stability of implants in osteoporotic mice.

Osteoporosis is the result of osteoclast formation exceeding osteoblast production, and current osteoporosis treatments targeting excessive osteoclast bone resorption have serious adverse effects. There is a need to fully understand the mechanisms of osteoclast-mediated bone resorption, identify new drug targets, and find better drugs to treat osteoporosis. Gar C (Gar C) is a major naturally occurring phytochemical isolated from mangosteen, and is a derivative of the naturally occurring phenolic antioxidant lutein. We used an OP mouse model established by ovariectomy (OVX). We found that treatment with Gar C significantly increased bone mineral density and significantly decreased the expression of TRAP, NFATC1 and CTSK relative to untreated OP mice. We found that Garcinone C could disrupt osteoclast activation and resorption functions by inhibiting RANKL-induced osteoclast differentiation as well as inhibiting the formation of multinucleated osteoclasts. Immunoblotting showed that Gar C downregulated the expression of osteoclast-related proteins. In addition, Gar C significantly inhibited RANKL-induced ROS production and affected NF-κB activity by inhibiting phosphorylation Formylation of P65 and phosphorylation and degradation of ikba. These data suggest that Gar C significantly reduced OVX-induced osteoporosis by inhibiting osteoclastogenesis and oxidative stress in bone tissue. Mechanistically, this effect was associated with inhibition of the ROS-mediated NF-κB pathway.

Currently, the failure rate for internal fixation in patients with osteoporosis can be reduced by antiosteoporosis therapy alone. However, the administration of anti-osteoporotic drugs is not a complete solution. Therefore, it is necessary to investigate other causes of surgical failure, such as inflammation. In recent years, the inflammation caused by macrophage M1 polarization has garnered wide attention. The purpose of this research is to explore the inhibitory effect of avicularin (AL) on macrophage M1 polarization, by which it ameliorates inflammation, thus alleviating implant instability. We established an osteoporosis mouse model of implant loosening. The mouse tissues were taken out for morphological analysis, staining analysis and bone metabolic index analysis. In in vitro experiments, bone marrow derived macrophages (BMDM) and RAW264.7 cells were polarized to M1 macrophages using lipopolysaccharide (LPS), and analyzed by immunofluorescence (IF) staining, Western blot (WB) and flow cytometry. WB was also used to analyze the nuclear factor kappa-B (NF-κB) pathway. In addition, the expression levels of inflammatory cytokines were detected in cell supernatant using ELISA kits. Through observation of this experiments, we found that AL can inhibit M1 polarization of macrophages. Moreover, it can significantly inhibit the release of inflammatory factors to improve multiple mouse femur parameters. Furthermore, AL inhibited the phosphorylation of IKBα and P65 in the NF-κB pathway. The above data indicate that AL ameliorates inflammatory responses by inhibiting macrophage M1 polarization via its inhibitory effect on the NF-κB pathway, thus alleviating the instability of implants in mice with osteoporosis.

Osteoporosis (OP) is mainly manifested by bone loss and bone degeneration. OP is considered a risk factor for pathological fractures, as well as impacts the health of middle-aged and elderly individuals. Drug therapy remains the main treatment scheme for OP; however, its efficacy is limited and has been associated with serious side effects. Therefore, it is important to develop new, effective, and safe treatment methods for OP. Avicularin (AL) is a flavonoid and quercetin derivative from various plants. Our study showed that AL disrupts osteoclast activation and resorptive function via inhibition of the RANKL-induced osteoclast differentiation together with the resorption capacity of bone marrow-derived macrophages (BMMs). Hence, AL prevents the activation and resorptive activity of osteoclasts. The results of qPCR showed that genes related to osteoclasts exhibited downregulated expression after AL treatment. Furthermore, AL inhibited RANKL-induced phosphorylation as well as degradation of the inhibitor IκBα of the NF-κB pathway, together with P65 phosphorylation in BMMs. We used an OP mouse model that was established by ovariectomy (OVX). Relative to untreated OP mice, mice that received AL treatment showed a significant increase in bone mineral density; however, the expression of TRAP, NFATC1, mmp9, and CTX-1 was significantly reduced. These results indicate that AL disrupts osteoclastogenesis via inhibition of the NF-κB pathway, which in turn improves OVX-induced OP.

Periprosthetic osteolysis (PPO), caused by wear particles, has become a major cause of joint replacement failure. Secondary surgery after joint replacement poses a serious threat to public health worldwide. Therefore, determining how to effectively inhibit wear particle-induced PPO has become an urgent issue. Recently, the interaction between osteogenic inhibition and wear particles at the biological interface of the implant has been found to be an important factor in the pathological process. Previous studies have found that the central nervous system plays an important role in the regulation of bone formation and bone remodeling. Dopamine (DA), an important catecholamine neurotransmitter, plays an integral role in the physiological and pathological processes of various tissues through its corresponding receptors. Our current study found that upregulation of dopamine first receptors could be achieved by activating the Wnt/β-catenin pathway, improving osteogenesis in vivo and in vitro, and significantly reducing the inhibition of titanium particle-induced osteogenesis. Overall, these findings suggest that dopamine first receptor (D1R) may be a plausible target to promote osteoblast function and resist wear particle-induced PPO.

Abnormal bone metabolism and subsequence osteoporotic fractures are common complications of chronic inflammatory diseases. No effective treatment for these bone-related complications is available at present. The chronic inflammatory state in these diseases has been considered as a key factor of bone loss. Therefore, the combination of inflammation inhibition and bone loss suppression may be an important strategy for reducing bone damage associated with inflammatory diseases. Bushen Huoxue Decoction (BSHXD) is a traditional Chinese herbal compound that has demonstrated the ability to improve bone quality and increase bone density. However, the efficacy of BSHXD on inflammatory bone loss and its underlying mechanisms remain unclear. This study aimed to investigate whether BSHXD inhibits inflammatory bone loss in mice and its potential molecular mechanisms. In the present study, the effect of BSHXD on lipopolysaccharide (LPS)-induced M1 polarization of RAW264.7 macrophage and on local inflammatory bone loss model of mouse skull was determined. The results showed that after treating RAW264.7 cells with LPS for 24 h, the expression levels of IL-1β (39.42 ± 3.076 ng/L, p < 0.05), IL-6 (49.24 ± 1.766 mg/L, p < 0.05) and TNF-α (286.3 ± 27.12 ng/L, p < 0.05) were significantly increased. The addition of BSHXD decreased the expression levels of IL-1β, IL-6, and TNF-α to 31.55 ± 1.296 ng/L, 37.94 ± 0.8869 mg/L, and 196.4 ± 25.25 ng/L, respectively (p < 0.05). The results of immunofluorescence staining, Western blotting (WB) and flow cytometry indicated that the proportion of M1 macrophages in RAW264.7 cells treated with BSHXD for 24 h was significantly lower than that in the LPS group (13.36% ± 0.9829% VS 24.80% ± 4.619%, p < 0.05). The evidence from in-vitro experiments showed that the immunomodulatory ability of BSHXD may be associated with the activation of AMP-dependent protein kinase (AMPK) pathway in LPS-treated macrophages. In addition, the results of micro-CT, H&E staining, immunohistochemical staining and immunofluorescence staining of mouse skull further demonstrated that BSHXD treatment significantly alleviated LPS-induced local bone loss and inflammatory damage in mouse skull model. All results indicated that BSHXD significantly inhibited inflammatory factors release and M1 polarization of macrophage through AMPK signaling pathway. Therefore, BSHXD may be a promising drug for the treatment of inflammatory bone loss.

Context With the development of society, the number of patients with osteoporosis is increasing. The prevention and control of osteoporosis has become a serious and urgent issue. With the continuous progress of biomedical research, ferroptosis has attracted increased attention. However, the pathophysiology and mechanisms of ferroptosis and osteoporosis still need further study. Natural products are widely used in East Asian countries for osteoporosis prevention and treatment. Objective In this paper, we will discuss the basic mechanisms of ferroptosis, the relationship between ferroptosis and osteoclasts and osteoblasts, and in vitro and in vivo studies of natural products to prevent osteoporosis by interfering with ferroptosis. Methods This article takes ferroptosis, natural products, osteoporosis, osteoblasts and osteoclast as key words. Retrieve literature from 2012 to 2023 indexed in databases such as PubMed Central, PubMed, Web of Science, Scopus and ISI. Results Ferroptosis has many regulatory mechanisms, including the system XC -/GSH/GPX4, p62/Keap1/Nrf2, FSP1/NAD (P) H/CoQ10, P53/SAT1/ALOX15 axes etc. Interestingly, we found that natural products, such as Artemisinin, Biochanin A and Quercetin, can play a role in treating osteoporosis by promoting ferroptosis of osteoclast and inhibiting ferroptosis of osteoblasts. Conclusions Natural products have great potential to regulate OBs and OCs by mediating ferroptosis to prevent and treat osteoporosis, and it is worthwhile to explore and discover more natural products that can prevent and treat osteoporosis.

Inflammatory arthritis, primarily including rheumatoid arthritis, osteoarthritis and ankylosing spondylitis, is a group of chronic inflammatory diseases, whose general feature is joint dysfunction with chronic pain and eventually causes disability in older people. To date, both Western medicine and traditional Chinese medicine (TCM) have developed a variety of therapeutic methods for inflammatory arthritis and achieved excellent results. But there is still a long way to totally cure these diseases. TCM has been used to treat various joint diseases for thousands of years in Asia. In this review, we summarize clinical efficacies of TCM in inflammatory arthritis treatment after reviewing the results demonstrated in meta-analyses, systematic reviews, and clinical trials. We pioneered taking inflammatory arthritis-related cell targets of TCM as the entry point and further elaborated the molecular targets inside the cells of TCM, especially the signaling pathways. In addition, we also briefly discussed the relationship between gut microbiota and TCM and described the role of drug delivery systems for using TCM more accurately and safely. We provide updated and comprehensive insights into the clinical application of TCM for inflammatory arthritis treatment. We hope this review can guide and inspire researchers to further explore mechanisms of the anti-arthritis activity of TCM and make a great leap forward in comprehending the science of TCM.

Background: Osteoarthritis is a common chronic degenerative disease, and recently, an increasing number of studies have shown that immunity plays an important role in the progression of osteoarthritis, which is exacerbated by local inflammation. The role of N6-methyladenine (m6A) modification in immunity is being explored. However, the role of m6A modification in regulating the immune microenvironment of osteoarthritis remains unknown. In this study, we sought to discuss the association between the N6-methyladenine (m6A) modification and the immune microenvironment of osteoarthritis.Methods: First, the data and gene expression profiles of 139 samples, including 33 healthy samples and 106 osteoarthritis samples, were obtained from the Genetics osteoARthritis and Progression (GARP) study. Then the differences in m6A regulators between healthy individuals and osteoarthritis patients were analyzed. The correlation between m6A regulators and immune characteristics was also investigated by single-sample gene set enrichment analysis (ssGSEA). Principal component analysis (PCA), Gene Set Variation Analysis (GSVA) enrichment analysis, weighted gene coexpression network analysis (WGCNA), and Associated R packages were used to identify the m6A phenotype and its biological functions.Results: A total of 23 m6A regulators were involved in this study. We found a close correlation between most m6A regulators in all samples as well as in osteoarthritis samples. VIRMA and LRPPRC were the most highly correlated m6A regulators and showed a positive correlation, whereas VIRMA and RBM15B were the most negatively correlated. M6A regulators are associated with osteoarthritis immune characteristics. For example, MDSC cell abundance was strongly correlated with RBM15B and HNRNPC. Meanwhile, RBM15B and HNRNPC were important effectors of natural killer cell immune responses. IGFBP3 is an important regulator of cytolytic activity immune function. We performed an unsupervised consensus cluster analysis of the osteoarthritis samples based on the expression of 23 m6A regulators. Three different m6A subtypes of osteoarthritis were identified, including 27 samples in subtype C1, 21 samples in subtype C2, and 58 samples in subtype C3. Different m6A subtypes have unique biological pathways and play different roles in the immune microenvironment of osteoarthritis.Conclusion: The m6A modification plays a crucial role in the diversity and complexity of the immune microenvironment in osteoarthritis.