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Osteoarthritis (OA) pain originates in the joint by sensitization of articular nociceptors. While behavioural assessments provide valuable information regarding pain symptoms, the techniques are subjective and open to interpretation by the experimenter. This study used in vivo electrophysiological approaches to measure objectively joint nociceptor properties in three rodent models of OA. Single unit extracellular recordings of joint mechanosensitive afferents were carried out in male and female rats following either (1) transection of the medial meniscus (MMT: post-traumatic OA), (2) intra-articular injection of sodium monoiodoacetate (MIA: chemically-induced OA), or (3) intra-articular injection of lysophosphatidic acid (LPA: neuropathic OA). In naïve male control rats, the mechanical threshold of joint mechanonociceptors (23.5 ± 1.8 mNm) was significantly reduced with MMT (9.4 ± 1.1 mNm) and MIA (15.1 ± 1.6 mNm). In females, the mechanical threshold of naïve rats (23.2 ± 3.1 mNm) was reduced following induction of MMT (8.3 ± 1.0 mNm) and LPA (10.6 ± 2.2 mNm). Afferent firing frequency increased in male MMT (∼275 %), LPA (∼175 %), MIA (225 %), and female MMT (∼146 %), LPA (∼200 %), and MIA (∼192 %). Mechanical threshold and evoked firing were negatively correlated in all models for both sexes except LPA rats (male + female) and female MMT. These data indicate that MMT, MIA, and LPA induce peripheral sensitization of joint afferents thereby validating their use in OA pain studies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)

Osteoarthritis (OA) is a joint disease caused by inflammation of cartilage and synovial tissue. Suppressing the process of inflammatory reaction and the generation of oxidative stress is an effective strategy to alleviate the progression of OA. Liensinine is one of the main components of lotus seeds, which has anti-hypertensive and anti-arrhythmia activities. In this study, we aimed to determine the anti-inflammatory effect of liensinine in an OA. Here, we found that liensinine significantly inhibited the inflammatory response of SW1353 cells and primary chondrocytes by inhibiting the release of inflammatory cytokines and oxidative stress. Moreover, we showed that liensinine was able to inhibit the activation of the NF-κB signaling pathway in IL-1β-induced SW1353 cells. Lastly, we found that liensinine significantly ameliorated cartilage damage and inflammatory response in papain-induced rats. Our study demonstrated a significant protective effect of liensinine against OA, which might be by inhibiting the activation of the NF-κB signaling pathway, and provide a new insight for the treatment of OA using liensinine., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)

Osteoarthritis (OA) is an age-related disease characterized by inflammation, pain, articular cartilage damage, synovitis, and irreversible disability. Gynostemma pentaphyllum (Thunb.) Makino (GP), a herbal medicine traditionally used in East Asia for its anti-inflammatory properties, was investigated for its potential to modulate OA pathology and symptoms. This study evaluated GP's efficacy in inhibiting pain, functional decline, and cartilage destruction in monosodium iodoacetate-induced OA and acetic acid-induced writhing models. Additionally, the effects of GP on OA-related inflammatory targets were assessed via mRNA and protein expression in rat knee cartilage and lipopolysaccharide-induced RAW 264.7 cells. The GP group demonstrated significant pain relief, functional improvement, and cartilage protection. Notably, GP inhibited key inflammatory mediators, including interleukin (IL)-1β, IL-6, matrix metalloproteinases (MMP)-3 and MMP-13, cyclooxygenase-2, and prostaglandin E receptor 2, surpassing the effects of active controls. These findings suggest that GP is a promising candidate for disease-modifying OA drugs and warrants further comprehensive studies.

The objective of the present study was to review the molecular mechanisms of the adverse effects of environmental pollutants on chondrocytes and extracellular matrix (ECM). Existing data demonstrate that both heavy metals, including cadmium (Cd), lead (Pb), and arsenic (As), as well as organic pollutants, including polychlorinated dioxins and furans (PCDD/Fs) and polychlorinated biphenyls (PCB), bisphenol A, phthalates, polycyclic aromatic hydrocarbons (PAH), pesticides, and certain other organic pollutants that target cartilage ontogeny and functioning. Overall, environmental pollutants reduce chondrocyte viability through the induction apoptosis, senescence, and inflammatory response, resulting in cell death and impaired ECM production. The effects of organic pollutants on chondrocyte development and viability were shown to be mediated by binding to the aryl hydrocarbon receptor (AhR) signaling and modulation of non-coding RNA expression. Adverse effects of pollutant exposures were observed in articular and growth plate chondrocytes. These mechanisms also damage chondrocyte precursors and subsequently hinder cartilage development. In addition, pollutant exposure was shown to impair chondrogenesis by inhibiting the expression of Sox9 and other regulators. Along with altered Runx2 signaling, these effects also contribute to impaired chondrocyte hypertrophy and chondrocyte-to-osteoblast trans-differentiation, resulting in altered endochondral ossification. Several organic pollutants including PCDD/Fs, PCBs and PAHs, were shown to induce transgenerational adverse effects on cartilage development and the resulting skeletal deformities. Despite of epidemiological evidence linking human environmental pollutant exposure to osteoarthritis or other cartilage pathologies, the data on the molecular mechanisms of adverse effects of environmental pollutant exposure on cartilage tissue were obtained from studies in laboratory rodents, fish, or cell cultures and should be carefully extrapolated to humans, although they clearly demonstrate that cartilage should be considered a putative target for environmental pollutant toxicity., (© 2024. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Pain is a common public health problem and remains as an unmet medical need. Currently available analgesics usually have limited efficacy or are accompanied by many adverse side effects. To achieve satisfactory pain relief by multimodal analgesia, new combinations of nefopam and gabapentinoids (pregabalin/gabapentin) were designed and assessed in inflammatory, osteoarthritis and neuropathic pain. Isobolographic analysis was performed to analyze the interactions between nefopam and gabapentinoids in carrageenan-induced inflammatory pain, mono-iodoacetate-induced osteoarthritis pain and paclitaxel-induced peripheral neuropathic pain in mice. The anti-inflammatory effect and motor performance of monotherapy or their combinations were evaluated in the carrageenan-induced inflammatory responses and rotarod test, respectively. Nefopam (1, 3, 5, 10, 30 mg/kg, p.o.), pregabalin (3, 6, 12, 24 mg/kg, p.o.) or gabapentin (25, 50, 75, 100 mg/kg, p.o.) dose-dependently reversed mechanical allodynia in three pain models. Isobolographic analysis indicated that the combinations of nefopam and gabapentinoids exerted synergistic anti-nociceptive effects in inflammatory, osteoarthritis, and neuropathic pain mouse models, as evidenced by the experimental ED 50 (median effective dose) falling below the predicted additive line. Moreover, the combination of nefopam-pregabalin/gabapentin alleviated carrageenan-induced inflammation and edema, and also prevented gabapentinoids-related sedation or ataxia by lowering their effective doses. Collectively, the co-administration of nefopam and gabapentinoids showed synergistic analgesic effects and may result in improved therapeutic benefits for treating pain., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Background: Ferroptosis is caused by iron-dependent peroxidation of membrane phospholipids and chondrocyte ferroptosis contributes to osteoarthritis (OA) progression. Glutathione peroxidase 4 (GPX4) plays a master role in blocking ferroptosis. N6-methyladenosine (m6A) is an epigenetic modification among mRNA post-transcriptional modifications. This study investigated the effect of methyltransferase-like 14 (METTL14), the key component of the m6A methyltransferase, on chondrocyte ferroptosis via m6A modification., Methods: An OA rat model was established through an intra-articular injection of monosodium iodoacetate in the right knee. OA cartilages in rat models were used for gene expression analysis. Primary mouse chondrocytes or ADTC5 cells were stimulated with IL-1β or erastin. The m6A RNA methylation quantification kit was used to measure m6A level. The effect of METTL14 and GPX4 on ECM degradation and ferroptosis was investigated through western blotting, fluorescence immunostaining, propidium iodide staining, and commercially available kits. The mechanism of METTL14 action was explored through MeRIP-qPCR assays., Results: METTL14 and m6A expression was upregulated in osteoarthritic cartilages and IL-1β-induced chondrocytes. METTL14 depletion repressed the IL-1β or erastin-stimulated ECM degradation and ferroptosis in mouse chondrocytes. METTL14 inhibited GPX4 gene through m6A methylation modification. GPX4 knockdown reversed the si-METTL14-mediated protection in IL-1β-induced chondrocytes., Conclusion: METTL14 depletion inhibits ferroptosis and ECM degradation by suppressing GPX4 mRNA m6A modification in injured chondrocytes., (© 2024 Asia Pacific League of Associations for Rheumatology and John Wiley & Sons Australia, Ltd.)

Stigmasterol, a plant-derived sterol, sharing structural similarity with cholesterol, has demonstrated anti-osteoarthritis (OA) properties, attributed to its antioxidant and anti-inflammatory capabilities. Given that OA often arises in weight bearing or overused joints, prolonged localized treatment effectively targets inflammatory aspects of the disease. This research explored the impact of stigmasterol-loaded nanoparticles delivered via intra-articular injections in an OA rat model. Employing mesoporous silica nanomaterials (MSNs) combined with β-cyclodextrin (β-CD) as a vehicle, stigmasterol was loaded in conjunction with tannic acid, forming stigmasterol/β-CD-MSNs to facilitate a sustained stigmasterol release. The study employed RAW 264.7 cells to examine the in vitro cytotoxicity and anti-inflammatory effect of stigmasterol/β-CD-MSNs. For in vivo experimentation, we used healthy control rats and monosodium iodoacetate (MIA)-induced OA rats, separated into five groups, varying the injection substances. In vitro findings indicated that stigmasterol/β-CD-MSNs suppressed the mRNA expression of key pro-inflammatory mediators such as interleukin-6, tumor necrosis factor-α, and matrix metalloproteinase-3 in a dose-dependent manner. In vivo experiments revealed a substantial decrease in the mRNA levels of pro-inflammatory factors in the stigmasterol(50 µg)/β-CD-MSN group compared to the others. Macroscopic, radiographic, and histological evaluations established that intra-articular injections of stigmasterol/β-CD-MSNs inhibited cartilage degeneration and subchondral bone deterioration. Therefore, in a chemically induced OA rat model, intra-articular stigmasterol delivery was associated with reduction in both local and systemic inflammatory responses, alongside a slowdown in joint degradation and arthritic progression., (© 2024. Controlled Release Society.)

Ethnopharmacological Relevance: The increasing incidence of osteoarthritis (OA), especially among the elderly population, highlights the need for more efficacious treatments that go beyond mere symptomatic relief. Tinospora crispa (L.) Hook. f. & Thomson (TC) boasts a rich traditional heritage, widespread use in Ayurveda, traditional Chinese medicine (TCM), and diverse indigenous healing practices throughout Southeast Asia for treating arthritis, rheumatism, fever, and inflammation., Aim of the Study: This study investigates the anti-inflammatory and chondroprotective potential of TC stem extracts, including ethanolic TC extract (ETCE) and aqueous TC extract (ATCE), in modulating OA pathogenesis through in vitro and in vivo approaches., Materials and Methods: The study utilized LC-MS/MS to identify key compounds in TC stem extracts. In vitro experiments assessed the antioxidative and anti-inflammatory properties of ETCE and ATCE in activated macrophages, while an in vivo monoiodoacetate (MIA)-induced OA rat model evaluated the efficacy of ETCE treatment. Key markers of oxidative stress, such as superoxide dismutase (SOD) and catalase (CAT), were assessed alongside pro-inflammatory cytokines TNF-α and IL-1β, and matrix-degrading enzymes, matrix metalloproteinase (MMP 13 and MMP 3), to evaluate the therapeutic effects of TC stem extracts on OA., Results: Chemical profiling of the extracts was conducted using LC-MS/MS in positive ionization, identifying seven compounds, including pseudolaric acid B, stylopine, and reticuline, which were reported for the first time in this species. The study utilized varying concentrations of TC stem extracts, specifically 6.25-25 μg/mL for in vitro assays and 500 mg/kg for in vivo studies. Our findings also revealed that both ETCE and ATCE exhibit dose-dependent reduction in reactive oxygen species (41%-52%) and nitric oxide (NO) levels (50% and 72%), with ETCE displaying superior antioxidative efficacy and marked anti-inflammatory properties, significantly reducing TNF-α and IL-6 at concentrations above 12.5 μg/mL. In the MIA-induced OA rat model, ETCE treatment notably outperformed ATCE, markedly lowering TNF-α (1.91 ± 0.37 pg/mL) and IL-1β (26.30 ± 3.68 pg/mL) levels and effectively inhibiting MMP 13 and MMP 3 enzymes. Furthermore, macroscopic and histopathological assessments, including ICRS scoring and OARSI grading, indicate that TC stem extracts reduce articular damage and proteoglycan loss in rat knee cartilage. These results suggest that TC stem extracts may play a role in preventing cartilage degradation and potentially alleviating inflammation and pain associated with OA, though further studies are needed to confirm these effects., Conclusion: This study highlights the potential of TC stem extracts as a novel, chondroprotective therapeutic avenue for OA management. By targeting oxidative stress, pro-inflammatory cytokines, and cartilage-degrading enzymes, TC stem extracts promise to prevent cartilage degradation and alleviate inflammation and pain associated with OA., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Osteoarthritis (OA) is a chronic degenerative joint disease that causes chronic pain, swelling, stiffness, disability, and significantly reduces the quality of life. Typically, OA is treated using painkillers and non-steroidal anti-inflammatory drugs (NSAIDs). While current pharmacologic treatments are common, their potential side effects have prompted exploration into functional dietary supplements. Recently, eggshell membrane (ESM) has emerged as a potential functional ingredient for joint and connective tissue disorders due to its clinical efficacy in relieving joint pain and stiffness. Despite promising clinical evidence, the effects of ESM on OA progression and its mechanism of action remain poorly understood. This study evaluated the efficacy of Ovomet ® , a powdered natural ESM, against joint pain and disease progression in a monosodium iodoacetate (MIA)-induced rodent model of OA in mice and rats. The results demonstrate that ESM significantly alleviates joint pain and attenuates articular cartilage destruction in both mice and rats that received oral supplementation for 5 days prior to OA induction and for 28 days thereafter. Interestingly, ESM significantly inhibited mRNA expression levels of pro-inflammatory cytokines including tumor necrosis factor alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-6 (IL-6), as well as inflammatory mediators, cyclooxygenase-2 (COX-2), and inducible nitric oxide synthase in the knee joint cartilage at the early stage of OA, within 7 days after OA induction. However, this effect was not observed in the late stage at 28 days after OA induction. ESM further attenuates the induction of protein expression for cartilage-degrading enzymes like matrix metalloproteinase (MMPs) 3 and 13, and a disintegrin and metalloproteinase with thrombospondin motifs 5 (ADAMTS-5), in the late-stage. In addition, MIA-induced reduction of the protein expression levels of cartilage components, cartilage oligomeric matrix protein (COMP), aggrecan (ACAN) and collagen type II α-1 chain (COL2α1), and cartilage extracellular matrix (ECM) synthesis promoting transcriptional factor SRY-Box 9 (SOX-9) were increased via ESM treatment in the cartilage tissue. Our findings suggest that Ovomet ® , a natural ESM powder, is a promising dietary functional ingredient that can alleviate pain, inflammatory response, and cartilage degradation associated with the progression of OA., Competing Interests: The authors declare no conflicts of interest.

Osteoarthritis (OA) is a common degenerative joint disease in the elderly, while oxidative stress-induced chondrocyte degeneration plays a key role in the pathologic progression of OA. One possible reason is that the expression of nuclear factor erythroid 2-related factor 2 (Nrf2), which acts as the intracellular defense factor against oxidative stress, is significantly inhibited in chondrocytes. Spinosin (SPI) is a potent Nrf2 agonist, but its effect on OA is still unknown. In this study, we found that SPI can alleviate tert-Butyl hydroperoxide (TBHP)-induced extracellular matrix degradation of chondrocytes. Additionally, SPI can effectively activate Nrf2, heme oxygenase-1 (HO-1), and NADPH quinone oxidoreductase 1 (NQO1) in chondrocytes under the TBHP environment. When Nrf2 was silenced by siRNA, the cartilage protective effect of SPI was also weakened. Finally, SPI showed good alleviative effects on OA in mice. Thus, SPI can ameliorate oxidative stress-induced chondrocyte dysfunction and exhibit a chondroprotective effect through activating the Nrf2/HO-1 pathway, which may provide a novel and promising option for the treatment of OA.

Osteoarthritis (OA) is a challenging degenerative joint disease to manage. Previous research has indicated that cell-free fat extract (CEFFE) may hold potential for OA treatment. This study investigated the role of Annexin A5 (AnxA5) within CEFFE in regulating macrophage polarization and protecting chondrocytes. In vitro experiments demonstrated that AnxA5 effectively inhibited M1 macrophage polarization by facilitating toll-like receptor (TLR) 4 internalization and lysosomal degradation through calcium-dependent endocytosis. This process decreased TLR4 expression, suppressed pro-inflammatory mediator release, and reduced the production of reactive oxygen species. Furthermore, AnxA5 displayed protective effects against chondrocyte necrosis and apoptosis. In vivo, studies revealed that intra-articular administration of AnxA5 ameliorated pain symptoms in a monosodium iodoacetate-induced osteoarthritis rat model. Histological analyses indicated a decrease in synovial inflammation and mitigation of cartilage damage following AnxA5 treatment. These results underscored the potential of AnxA5 as a therapeutic option for OA due to its capacity to regulate macrophage polarization and maintain chondrocyte viability. Further investigation into the specific mechanisms and clinical applications of AnxA5 may help improve the management of OA., Competing Interests: Competing Interests: The authors have declared that no competing interest exists., (© The author(s).)

Purpose: This study seeks to identify potential clinical biomarkers for osteoarthritis (OA) using bioinformatics and investigate OA mechanisms through cellular assays., Methods: Differentially Expressed Genes (DEGs) from GSE52042 (four OA samples, four control samples) were screened and analyzed with protein-protein interaction (PPI) analysis. Overlapping genes in GSE52042 and GSE206848 (seven OA samples, and seven control samples) were identified and evaluated using Gene Set Enrichment Analysis (GSEA) and clinical diagnostic value analysis to determine the hub gene. Finally, whether and how the hub gene impacts LPS-induced OA progression was explored by in vitro experiments, including Western blotting (WB), co-immunoprecipitation (Co-IP), flow cytometry, etc ., Result: Bioinformatics analysis of DEGs (142 up-regulated and 171 down-regulated) in GSE52042 identified two overlapping genes (U2AF2, TPX2) that exhibit significant clinical diagnostic value. These genes are up-regulated in OA samples from both GSE52042 and GSE206848 datasets. Notably, TPX2, which AUC = 0.873 was identified as the hub gene. In vitro experiments have demonstrated that silencing TPX2 can alleviate damage to chondrocytes induced by lipopolysaccharide (LPS). Furthermore, there is a protein interaction between TPX2 and MMP13 in OA. Excessive MMP13 can attenuate the effects of TPX2 knockdown on LPS-induced changes in OA protein expression, cell growth, and apoptosis., Conclusion: In conclusion, our findings shed light on the molecular mechanisms of OA and suggested TPX2 as a potential therapeutic target. TPX2 could promote the progression of LPS-induced OA by up-regulating the expression of MMP13, which provides some implications for clinical research., Competing Interests: The authors declare that they have no competing interests., (© 2024 Yu et al.)

Ethnopharmacological Relevance: Ginkgo biloba, as the most widely available medicinal plant worldwide, has been frequently utilized for treat cardiovascular, cerebrovascular, diabetic and other diseases. Due to its distinct pharmacological effects, it has been broadly applications in pharmaceuticals, health products, dietary supplements, and so on. Ginkgolide C (GC), a prominent extract of Ginkgo biloba, possesses potential in anti-inflammatory and anti-oxidant efficacy., Aims of the Study: To determine whether GC mitigated the progressive degeneration of articular cartilage in a Monosodium Iodoacetate (MIA)-induced osteoarthritis (OA) rat model by inhibiting the activation of the NLRP3 inflammasome, and the specific underlying mechanisms., Materials and Methods: In vivo, an OA rat model was established by intra-articular injection of MIA. The protective effect of GC (10 mg/kg) on articular cartilage was evaluated. Application of ATDC5 cells to elucidate the mechanism of the protective effect of GC on articular cartilage. Specifically, the expression levels of molecules associated with cartilage ECM degrading enzymes, OS, ERS, and NLRP3 inflammasome activation were analyzed., Results: In vivo, GC ameliorated MIA-induced OA rat joint pain, and exhibited remarkable anti-inflammatory and anti- ECM degradation effects via inhibition of the activation of NLRP3 inflammasome, the release of inflammatory factors, and the expression of matrix-degrading enzymes in cartilage. Mechanically, GC inhibited the activation of NLRP3 inflammasome by restraining ROS-mediated p-IRE1α and activating Nrf2/NQO1 signal path, thereby alleviating OA. The ROS scavenger NAC was as effective as GC in reducing ROS production and inhibiting the activation of NLRP3 inflammasome., Conclusions: GC have exerted chondroprotective effects by inhibiting the activation of NLRP3 inflammasome., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Osteoarthritis (OA) is a debilitating joint disorder characterized by cartilage degradation and chronic inflammation, accompanied by high oxidative stress. In this study, we utilized the monosodium iodoacetate (MIA)-induced OA model to investigate the efficacy of oligo-fucoidan-based formula (FF) intervention in mitigating OA progression. Through its capacity to alleviate joint bearing function and inflammation, improvements in cartilage integrity following oligo-fucoidan-based formula intervention were observed, highlighting its protective effects against cartilage degeneration and structural damage. Furthermore, the oligo-fucoidan-based formula modulated the p38 signaling pathway, along with downregulating cyclooxygenase-2 (COX-2) and inducible nitric oxide synthase (iNOS) expression, contributing to its beneficial effects. Our study provides valuable insights into targeted interventions for OA management and calls for further clinical investigations to validate these preclinical findings and to explore the translational potential of an oligo-fucoidan-based formula in human OA patients.

Chondrodysplasia is closely associated with low birth weight and increased susceptibility to osteoarthritis in adulthood. Prenatal prednisone exposure (PPE) can cause low birth weight; however, its effect on offspring cartilage development remains unexplored. Herein, rats are administered clinical doses of prednisone intragastrically on gestational days (GDs) 0-20 and underwent long-distance running during postnatal weeks (PWs) 24-28. Knee cartilage is assayed for quality and related index changes on GD20, PW12, and PW28. In vitro experiments are performed to elucidate the mechanism. PPE decreased cartilage proliferation and matrix synthesis, causing offspring chondrodysplasia. Following long-distance running, the PPE group exhibited more typical osteoarthritis-like changes. Molecular analysis revealed that PPE caused cartilage circRNomics imbalance in which circGtdc1 decreased most significantly and persisted postnatally. Mechanistically, prednisolone reduced circGtdc1 expression and binding with Srsf1 to promote degradation of Srsf1 via K48-linked polyubiquitination. This further inhibited the formation of EDA/B + Fn1 and activation of PI3K/AKT and TGFβ pathways, reducing chondrocyte proliferation and matrix synthesis. Finally, intra-articular injection of offspring with AAV-circGtdc1 ameliorated PPE-induced chondrodysplasia, but this effect is reversed by Srsf1 knockout. Altogether, this study confirms that PPE causes chondrodysplasia and susceptibility to osteoarthritis by altering the circGtdc1-Srsf1-Fn1 axis; in vivo, overexpression of circGtdc1 can represent an effective intervention target for ameliorating PPE-induced chondrodysplasia., (© 2024 The Authors. Advanced Science published by Wiley‐VCH GmbH.)

Background: This study aimed to investigate the analgesic impact of S(+)-ketamine on pain behavior and synovial inflammation in an osteoarthritis (OA) model., Methods: Animals were grouped as follows: OA-Saline (n = 24) and OA-Ketamine (n = 24), OA induced via intra-articular sodium monoiodoacetate (MIA); a Non-OA group (n = 24) served as the control. On the 7 th day post OA induction, animals received either saline or S(+)-ketamine (0.5 mg.kg -1 ). Behavioral and histopathological assessments were conducted up to day 28., Results: S(+)-ketamine reduced allodynia from day 7 to 28 and hyperalgesia from day 10 to 28. It notably alleviated weight distribution deficits from day 10 until the end of the study. Significant walking improvement was observed on day 14 in S(+)-ketamine-treated rats. Starting on day 14, OA groups showed grip force decline, which was countered by S(+)-ketamine on day 21. However, S(+)-ketamine did not diminish synovial inflammation., Conclusion: Low Intra-articular (IA) doses of S(+)-ketamine reduced MIA-induced OA pain but did not reverse synovial histopathological changes., Irb Approval Number: 23115 012030/2009-05., Competing Interests: Declaration of competing interest The authors declare no conflicts of interest., (Copyright © 2024 Sociedade Brasileira de Anestesiologia. Published by Elsevier España S.L.U. All rights reserved.)

Inflammation is crucial to osteoarthritis (OA) pathogenesis. The aim of this study was to evaluate Siraitia grosvenorii residue extract (NHGRE) obtained by extracting S. grosvenorii fruits with water as a potential food supplement for treating arthritis based on its analgesic, anti-inflammatory, and chondroprotective effects and the remaining residue with 70% ethanol. We observed the analgesic activity of NHGRE based on the acetic acid-induced writhing response in mice, examined its anti-inflammatory efficacy against carrageenan-induced paw oedema in mice, and investigated its effect on inflammatory cytokine expression in interleukin (IL)-1β-induced SW1353 cells. Furthermore, we determined its effects on cartilage protection in interleukin-1β (IL-1β)-treated SW1353 cells. NHGRE at 200 mg/kg significantly reduced the acetic acid-induced writhing response and prevented oedema formation in the carrageenan-induced paw oedema model. In IL-1β-induced SW1353 cells, NHGRE at 400 µg/mL reduced the expression of inflammation mediators such as tumour necrosis factor (TNF)-α (55.3%), IL-6 (35.4%), and prostaglandin E2 (PGE2) (36.9%) and down-regulated the expression of matrix metalloproteinase (MMP)-1 (38.6%), MMP-3 (29.3%), and MMP-13 (44.8%). Additionally, it restored degraded collagen II levels in chondrocytes. NHGRE plays a protective role in chondrocytes by regulating Nuclear factor kappa B (NF-κB) activation. Overall, NHGRE may be a useful therapeutic agent for OA by controlling pain, oedema formation, and inflammation-related mechanisms.

Osteoarthritis (OA) is a degenerative bone disease characterized by inflammation as a primary pathology and currently lacks therapeutic interventions to impede its progression. Erigeron breviscapus (Vant.) Hand.-Mazz. (EB) is an east Asian herbal medicine with a long history of use and a wide range of confirmed efficacy against cardiovascular and central nervous system diseases. The purpose of this study is to evaluate whether EB is worthy of further investigation as a treatment for OA based on anti-inflammatory activity. This study aims to assess the potential of EB as a treatment for OA, focusing on its anti-inflammatory properties. Analgesic effects, functional improvements, and inhibition of cartilage destruction induced by EB were evaluated in acetic acid-induced peripheral pain mice and monosodium iodoacetate-induced OA rat models. Additionally, the anti-inflammatory effect of EB was assessed in serum and cartilage tissue in vivo, as well as in lipopolysaccharide-induced RAW 264.7 cells. EB demonstrated a significant alleviation of pain, functional impairment, and cartilage degradation in OA along with a notable inhibition of pro-inflammatory cytokines, including interleukin-1β, interleukin-6, matrix metalloproteinases 13, and nitric oxide synthase 2, both in vitro and in vivo, in a dose-dependent manner compared to the active control. Accordingly, EB merits further exploration as a potential disease-modifying drug for OA, capable of mitigating the multifaceted pathology of osteoarthritis through its anti-inflammatory properties. Nonetheless, additional validation through a broader experimental design is essential to substantiate the findings of this study.

The aim of this study is to conduct a thorough evaluation of the association between Benzophenone-3 (BP-3) exposure and OA, offering critical insights into the underlying mechanisms involved. The National Health and Nutrition Examination Survey (NHANES) database was utilized to investigate the correlation between BP-3 and osteoarthritis. Proteomic sequencing from clinical sample and the PharmMapper online tool were employed to predict the biological target of BP-3. Cellular molecular assays and transfection studies were performed to verify the prediction from bioinformatics analyses. Through cross-sectional analysis of the NHANES database, we identified BP-3 as a risk factor for OA development. The results of proteomic sequencing showed that Secreted Protein Acidic and Rich in Cysteine (SPARC) was significantly elevated in the area of damage compared to the undamaged area. SPARC was also among the potential biological targets of BP-3 predicted by the online program. Through in vitro cell experiments, we further determined that the toxicological effects of BP-3 may be due to SPARC, which elevates intracellular GPX4 levels, activates the glutathione system, and promotes lipid peroxidation to mitigate ferroptosis. Inhibiting SPARC expression has been shown to reduce inflammation and ferroptosis in OA contexts. This research provides an expansive understanding of BP-3's influence on osteoarthritis development. We have identified SPARC as a potent target for combating chondrocyte ferroptosis in BP-3-associated osteoarthritis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)

Background: Osteoarthritis (OA) patients taking prescription opioids for pain are at increased risk of fall or fracture, and the concomitant use of interacting drugs may further increase the risk of these events., Aims: To identify prescription opioid-related medication combinations associated with fall or fracture., Materials & Methods: We conducted a case-crossover-based screening of two administrative claims databases spanning 2003 through 2021. OA patients were aged 40 years or older with at least 365 days of continuous enrollment and 90 days of continuous prescription opioid use before their first eligible fall or fracture event. The primary analysis quantified the odds ratio (OR) between fall and non-opioid medications dispensed in the 90 days before the fall date after adjustment for prescription opioid dosage and confounding using a case-time-control design. A secondary analogous analysis evaluated medications associated with fracture. The false discovery rate (FDR) was used to account for multiple testing., Results: We identified 41 693 OA patients who experienced a fall and 24 891 OA patients who experienced a fracture after at least 90 days of continuous opioid therapy. Top non-opioid medications by ascending p-value with OR > 1 for fall were meloxicam (OR 1.22, FDR = 0.08), metoprolol (OR 1.06, FDR >0.99), and celecoxib (OR 1.13, FDR > 0.99). Top non-opioid medications for fracture were losartan (OR 1.20, FDR = 0.80), alprazolam (OR 1.14, FDR > 0.99), and duloxetine (OR 1.12, FDR = 0.97)., Conclusion: Clinicians may seek to monitor patients who are co-prescribed drugs that act on the central nervous system, especially in individuals with OA., (© 2024 John Wiley & Sons Ltd.)

Ethnopharmacological Relevance: Dauricine (DA) is a natural plant-derived alkaloid extracted from Menispermum dauricum. Menispermum dauricum has been used in traditional Chinese medicine as a classic remedy for rheumatoid arthropathy and is believed to be effective in alleviating swelling and pain in the limbs., Aim of the Study: Osteoarthritis (OA) is a classic degenerative disease involving chondrocyte death, and there is still a lack of effective therapeutic agents that can reverse the progression of the disease. Here we explored the therapeutic effects of DA against OA and further explored the mechanism., Materials and Methods: The effect of DA on cell viability was assessed by CCK-8. IL-1β-treated mouse chondrocytes were used as an in vitro model of OA, and apoptosis was detected by flow cytometry. QRT-PCR, western blotting, cell staining, and immunofluorescence were used to detect relevant inflammatory factors and cartilage-specific expression. RNA sequencing was used to identify pertinent signaling pathways. The therapeutic effect of DA was verified by micro-CT, histological analysis and immunohistochemical analysis in a mouse OA model., Results: DA demonstrated a high safety profile on chondrocytes, significantly reversing the inflammatory response induced by IL-1β, and promoting factors associated with cartilage regeneration. Moreover, DA exhibited a significant protective effect on the knee joints of mice undergoing ACLT-DMM, effectively preventing cartilage degeneration and subchondral bone tissue destruction. These positive therapeutic effects were achieved through the modulation of the NF-κB pathway and the Ca 2+ signaling pathway by DA., Conclusion: Being derived from a traditional herb, DA exhibits remarkable therapeutic potential and safety in OA treatment, presenting a promising option for patients dealing with osteoarthritis., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Osteoarthritis (OA) is a progressive age-related disease characterised by pathological changes in the synovium, articular cartilage, and subchondral bone, significantly reducing the patients' quality of life. This study investigated the role of glucocorticoids, specifically dexamethasone, in OA progression, with a particular focus on their effects on chondrocytes. Although glucocorticoids are commonly used for OA pain relief, our research demonstrated that high concentrations of dexamethasone may accelerate OA progression by enhancing the ability of reactive oxygen species to inhibit chondrocyte autophagy, resulting in cell death and accelerated cartilage degeneration. Despite reports on the acceleration of pathogenesis and cartilage damage in some patients of OA taking corticosteroids, the mechanism behind the same has not been investigated. This necessitates an investigation of the concentration-dependent changes in the cartilage cells upon dexamethasone administration. In addition, the protective effect of PPAR γ on chondrocytes can prevent the decrease in chondrocyte autophagy and delay cartilage degeneration. Therefore, our study suggests that the therapeutic use of glucocorticoids in OA treatment should be more nuanced considering their potential detrimental effects. Future investigations should focus on the mechanisms underlying the glucocorticoid-mediated modulation of cell death processes, which could provide insights into new therapeutic strategies for OA treatment., Competing Interests: Declaration of competing interest The authors declare that they have no known financial, professional, or personal relationships with other people or organizations that could inappropriately influence or bias the content of the paper. All authors have contributed significantly to the research and the preparation of the manuscript, have read and approved the final version submitted for publication, and have agreed to be accountable for all aspects of the work. No external funding was received for this study. Any affiliations, financial holdings, or other potential conflicts of interest related to the subject matter or materials discussed in the manuscript are disclosed., (Copyright © 2024. Published by Elsevier B.V.)

Because inflammation in chondrocytes contributes to the induction of osteoarthritis (OA), regulation of their activity is essential. A previous study showed that stimulation of the reverse erythroblastosis virus (REV-ERB) nuclear receptors in spinal glial cells elicits anti-inflammatory and antinociception effects in animal models of chronic pain. However, the involvement of REV-ERBs in chondrocyte functions and OA pathologies remains to be elucidated. In the current study, we found that pretreatment with the REV-ERB agonist SR9009 significantly blocked the increases in inflammatory molecules [(matrix metalloproteinase (MMP) 3, MMP9, and MMP13] and cytokines (interleukin-1β and tumor necrosis factor) in primary cultured chondrocytes following treatment with lipopolysaccharide. Furthermore, repeated intra-articular treatment with SR9009 significantly prevented monosodium iodoacetate-induced mechanical hypersensitivity and tended to partially reduce knee joint damage in mice. In conclusion, our findings suggest that REV-ERBs have a critical role in alleviating nociceptive hypersensitivity in OA pathologies by negatively regulating inflammation in chondrocytes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Heavy metals found in the environment, including arsenic (As) pose significant risks to human health and present a risk factor for osteoarthritis (OA). This study researched the impact of As on cartilage degeneration by focusing on the role of As in causing OA in mice. We employed chemical inhibition and inductively coupled plasma mass spectrometry analyses to identify the effect of As on chondrocytes as well as studying its accumulation in organs after oral administration in mice. Additionally, the study examined the effect of intra-articular As treatment on the levels of crucial catabolic factors, namely Hif-2α (Epas1) and Zip8 (Slc39a8), during OA progression. Mice that were administered As orally in conjunction with surgically induced joint instability, had heightened cartilage destruction compared to wild-type mice. Quantitative analysis revealed a significant increase in Hif-2α and Zip8 mRNA expression (p = 0.0352,0.0004 respectively) and protein expression (p = 0.0101,0.008 respectively) post oral administration. Our findings illustrated the role of As in influencing crucial cellular functions that are triggered by reactive oxygen species. These events consequently activate the Akt/Hif-2α/NF-κB pathways, leading to disruptions in articular cartilage homeostasis. This study provides a comprehensive understanding of the impact of As on the development of osteoarthritis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Osteoarthritis (OA) is common and affected by several factors, such as age, weight, sex, and genetics. The pathogenesis of OA remains unclear. Therefore, using a rat model of monosodium iodoacetate (MIA)-induced OA, we examined genomic-wide DNA methylation using methyl-seq and characterized the transcriptome using RNA-seq in the articular cartilage tissue from a negative control (NC) and MIA-induced rats. We identified 170 genes (100 hypomethylated and upregulated genes and 70 hypermethylated and downregulated genes) regulated by DNA methylation in OA. DNA methylation-regulated genes were enriched in functions related to focal adhesion, extracellular matrix (ECM)-receptor interaction and the PI3K-Akt and Hippo signaling pathways. Functions related to extracellular matrix organization, extracellular matrix proteoglycans, and collagen formation were involved in OA. A molecular and protein-protein network was constructed using methylated expression-correlated genes. Erk1/2 was a downstream target of OA-induced changes in DNA methylation and RNA expression. We found that the integrin subunit alpha 2 (ITGA2) gene is important in focal adhesion, alpha6-beta4 integrin signaling, and the inflammatory response pathway in OA. Overall, gene expression changes because DNA methylation influences OA pathogenesis. ITGA2, whose gene expression changes are regulated by DNA methylation during OA onset, is a candidate gene. Our findings provide insights into the epigenetic targets of OA processes in rats.

Osteoarthritis (OA) is characterized by the gradual deterioration and worsening of the knee joint, leading to both pain and deformity. The current research exhibited the anti-osteoarthritis effect of lusianthridin against monosodium iodoacetate (MIA) induced OA in rats. RAW cells were used for the cell viability. The inflammatory cytokines and mediators were estimated in the cell lines after the lipopolysaccharide (LPS) treatment. For the in vivo study, the rats were received the intraperitoneal administration of MIA (3 mg/kg) for the induction of OA. The rats were received the oral administration of lusianthridin (5, 10 and 20 mg/kg) and the body and organ weight estimated. Antioxidant, cytokines, inflammatory and matrix metalloproteinases (MMP) level were also estimated. The mRNA expression of MMP were also estimated. The lusianthridin treatment remarkably suppressed the cell viability. LPS induced RAW cell suppressed the level of nitrate, tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), interleukin-6 (IL-6), cyclooxygenase-2 (COX-2), prostaglandin (PGE2), MMP-2 and MMP-9 level. Lusianthridin remarkably altered the level of body weight and organ weight (liver, spleen, renal and heart weight). lusianthridin suppressed the oxidative stress via altered the level of antioxidant parameters. Lusianthridin significantly (p < 0.001) decreased the level of cartilage oligometrix matrix protein (COMP) and c-reactive protein (CRP); cytokines such as TNF-α, IL-1β, IL-6, IL-10; inflammatory parameters include 5- Lipoxygenase (5-LOX), COX-2, leukotriene B4 (LTB4), PGE2; transforming growth factor beta (TGF-β); MMP level like MMP-1, 3, 9, 13, respectively. Lusianthridin significantly suppressed the mRNA expression of MMP. Collectively, the result of the study showed that antiosteoarthritis effect of lusianthridin via suppression of inflammatory parameters.

Postmenopausal women are susceptible to osteoporosis and osteoarthritis. Tocotrienol, a bone-protective nutraceutical, is reported to prevent osteoarthritis in male rats. However, its efficacy on joint health in oestrogen deficiency has not been validated. Besides, data on the use of emulsification systems in enhancing bioavailability and protective effects of tocotrienol are limited. Ovariectomised adult female Sprague-Dawley rats (3 months old) were treated with refined olive oil, emulsified (EPT, 100 mg/kg/day with 25% vitamin E content), non-emulsified palm tocotrienol (NEPT, 100 mg/kg/day with 50% vitamin E content) and calcium carbonate (1% w/v in drinking water) plus glucosamine sulphate (250 mg/kg/day) for 10 weeks. Osteoarthritis was induced with monosodium iodoacetate four weeks after ovariectomy. Baseline control was sacrificed upon receipt, while the sham group was not ovariectomised and treated with refined olive oil. EPT and NEPT prevented femoral metaphyseal and subchondral bone volume decline caused by ovariectomy. EPT decreased subchondral trabecular separation compared to the negative control. EPT preserved stiffness and Young's Modulus at the femoral mid-shaft of the rats. Circulating RANKL was reduced post-treatment in the EPT group. Joint width was reduced in all the treatment groups vs the negative control. The EPT group's grip strength was significantly improved over the negative control and NEPT group. EPT also preserved cartilage histology based on several Mankin's subscores. EPT performed as effectively as NEPT in preventing osteoporosis and osteoarthritis in ovariectomised rats despite containing less vitamin E content. This study justifies clinical trials for the use of EPT in postmenopausal women with both conditions., Competing Interests: Declaration of Competing Interest The authors declare that they have no competing interests., (Copyright © 2023 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Osteoarthritis (OA) is characterized by gradual articular cartilage degradation, accompanied by persistent low-grade joint inflammation, correlating with radiographic and pain-related progression. The latent therapeutic potential of DZ2002, a reversible inhibitor of S-adenosyl-L-homocysteine hydrolase (SAHH), holds promise for OA intervention. This study endeavored to examine the therapeutic efficacy of DZ2002 within the milieu of OA. The cytotoxicity of DZ2002 was evaluated using the MTT assay on bone marrow-derived macrophages. The inhibitory impact of DZ2002 during the process of osteoclastogenesis was assessed using TRAP staining, analysis of bone resorption pits, and F-actin ring formation. Mechanistic insights were derived from qPCR and Western blot analyses. Through the intra-articular injection of monosodium iodoacetate (MIA), an experimental rat model of OA was successfully instituted. This was subsequently accompanied by a series of assessments including Von Frey filament testing, analysis of weight-bearing behaviors, and micro-CT imaging, all aimed at assessing the effectiveness of DZ2002. The findings emphasized the effectiveness of DZ2002 in mitigating osteoclastogenesis induced by M-CSF/RANKL, evident through a reduction in TRAP-positive OCs and bone resorption. Moreover, DZ2002 modulated bone resorption-associated gene and protein expression (CTSK, CTR, Integrin β3) via the MEK/ERK pathway. Encouragingly, DZ2002 also alleviates MIA-induced pain, cartilage degradation, and bone loss. In conclusion, DZ2002 emerges as a potential therapeutic contender for OA, as evidenced by its capacity to hinder in vitro M-CSF/RANKL-induced osteoclastogenesis and mitigate in vivo osteoarthritis progression. This newfound perspective provides substantial support for considering DZ2002 as a compelling agent for osteoarthritis intervention., Competing Interests: Declaration of Competing Interest The authors have no conflicts of interest., (Copyright © 2023 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Background and Objective: NXT15906F6 (TamaFlex TM ) is a proprietary herbal composition containing Tamarindus indica seeds and Curcuma longa rhizome extracts. NXT15906F6 supplementation has been shown clinically effective in reducing knee joint pain and improving musculoskeletal functions in healthy and knee osteoarthritis (OA) subjects. The objective of the present study was to assess the possible molecular basis of the anti-OA efficacy of NXT15906F6 in a monosodium iodoacetate (MIA)-induced model of OA in rats., Methods: Healthy male Sprague Dawley rats (age: 8-9 wk body weight, B.W.: 225-308 g ( n  = 12) were randomly assigned to one of the six groups, (a) vehicle control, (b) MIA control, (c) Celecoxib (10 mg/kg B.W.), (d) TF-30 (30 mg/kg B.W.), (e) TF-60 (60 mg/kg B.W.), and (f) TF-100 (100 mg/kg B.W.). OA was induced by an intra-articular injection of 3 mg MIA into the right hind knee joint. The animals received either Celecoxib or TF through oral gavage over 28 days. The vehicle control animals received intra-articular sterile normal saline., Results: Post-treatment, NXT15906F6 groups showed significant ( p  < 0.05) dose-dependent pain relief as evidenced by improved body weight-bearing capacity on the right hind limb. NXT15906F6 treatment also significantly reduced the serum tumor necrosis factor-α (TNF-α, p  < 0.05) and nitrite ( p  < 0.05) levels in a dose-dependent manner. mRNA expression analyses revealed the up-regulation of collagen type-II (COL2A1) and down-regulation of matrix metalloproteinases (MMP-3, MMP-9 and MMP-13) in the cartilage tissues of NXT15906F6-supplemented rats. Cyclooxygenase-2 and inducible nitric oxide synthase (iNOS) protein expressions were down-regulated. Decreased immunolocalization of NF-κβ (p65) was observed in the joint tissues of NXT15906F6-supplemented rats. Furthermore, microscopic observations revealed that NXT15906F6 preserved MIA-induced rats' joint architecture and integrity., Conclusion: NXT15906F6 reduces MIA-induced joint pain, inflammation, and cartilage degradation in rats.

Osteoarthritis, the most common joint disease worldwide, is a degenerative disease characterized by cartilage degeneration and inflammation. The active ingredients in the traditional Chinese medicinal plant Achyranthes bidentate can be used to treat waist, leg, and joint pain caused by rheumatism arthralgia. In this study, we identified the optimal microwave extraction protocol for saponins from A. bidentate, evaluated their protective effects against IL-1β-induced inflammation in SW1353 human chondrocytes, and explored their protective pathway. The microwave-extraction parameters required to obtain the maximum yield of A. bidentate saponins using 80% ethanol were identified using response surface methodology. The parameters were solid-liquid ratio, 1:10; extraction time, 20 min; power, 721 W; temperature, 65 °C. The actual yield of saponins extracted was to be 194.01 μg/mg extract. The SW1353 cells were pretreated with A. bidentate extract (ABE) at a concentration of 50 or 100 μg/mL for 3 h, after which an inflammatory response was stimulated using IL-1β. The ABE significantly reduced the expression of proinflammatory factors IL-6, TNF-α, COX-2, iNOS, PGE2, and NO, and inhibited NF-κB activity, effectively attenuating the inflammatory response. ABE also inhibited MMP13 and ADAMTS-5 expression, reducing IL-1β-induced degradation of the extrachondral matrix. This confirmed that ABE effectively inhibits NF-κB activity and reduces IL-1β-induced inflammation, extracellular matrix degradation, and expression of apoptotic proteins Bax and caspase-3. Therefore, ABE has potential as a new botanical drug for preventing osteoarthritis., (Copyright © 2023 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.)

Background and Purpose: Osteoarthritis (OA) pain remains a major clinical problem. It is urgent to identify novel therapeutic approaches for OA pain states. Bromodomain and extra-terminal (BET) protein inhibitors have robust anti-inflammatory effects in several pain models. However, the underlying mechanisms of these inhibitors in OA pain have not been determined. We, therefore, investigated the effects and the underlying mechanism(s) of BET inhibition on pain-related behaviours in a rat model of OA., Experimental Approach: The OA model was established by intra-articular injection of monosodium iodoacetate (MIA) in rat knees. Pain behaviours were assessed in rats by hindlimb weight-bearing asymmetry, mechanical allodynia and thermal hyperalgesia. Possible mechanisms underlying BET inhibition were explored in the MIA-induced OA pain model in the spinal cord and dorsal root ganglia (DRG)., Key Results: Inhibiting bromodomain-containing protein 4 (Brd4) with either JQ1 or MS417, or using AAV2/9-shRNA-Brd4-EGFP-mediated knockdown of Brd4 genes, significantly attenuated MIA-induced pain behaviours. Brd4 inhibition suppressed NF-κB and NF-κB-mediated inflammatory cytokines in both the spinal cord and DRG in rats with MIA-induced OA pain. Brd4 inhibition also attenuated the oxidative stress and promoted nuclear factor erythroid-2-related factor 2 (Nrf2)-dependent antioxidant genes in both the spinal cord and DRG in our odel of MIA-induced OA pain., Conclusions and Implications: In conclusion, Brd4 inhibition alleviated MIA-induced OA pain in rats, via suppression of neuroinflammation and activation of Nrf2-mediated antioxidant signalling. Although our model does not perfectly represent how OA develops in humans, inhibition of Brd4 may provide novel insights into possible treatments for OA pain., (© 2023 British Pharmacological Society.)

Osteoarthritis (OA) is a pathology that is characterized by progressive erosion of articular cartilage. In this context, medicinal plants have become relevant tools regarding their potential role in the prevention and treatment of OA, being safe and effective. The aim of this work was investigate the therapeutic efficacy of the ethyl acetate fraction of Bixa orellana leaves (BoEA) and ellagic acid (ElAc) for the therapeutic treatment of OA induced by monosodium iodoacetate (MIA) in rats. The plant material was extracted via maceration with 70 % hydroalcoholic solvent (BoHE). The ethyl acetate (BoEA) fraction was by solvents in increasing order of polarity. The ElAc was identified and isolated in BoEA using high performance liquid chromatography (HPLC-DAD) and analytical curve. The OA was induced using MIA in the right knee at the knee joint. Doses of BoEA and ElAc were administered daily (every 24 h, orally) at concentrations of 50, 100 and 50 mg/kg, respectively, for 28 days after induced OA. We evaluated the animals through clinical and radiological examinations every 7 days and, on the 29th day, the animals were euthanized, the joints being removed for histopathological analysis and the serum for cytokine analysis. BoEA and ElAc compounds reduced inflammation and nociception in OA and were as effective as indomethacin in clinical parameters of joint discomfort and allodynia in rats, in addition to showing improvements in radiological and histopathological images, acting on the progress of cartilage deterioration, proving properties related to anti-inflammatory and analgesic processes, being important allies for new therapeutic interventions for the treatment of OA., Competing Interests: Declaration of Competing Interest We wish to confirm that there are no known conflicts of interest associated with this publication and there has been no significant financial support for this work that could have influenced its outcome., (Copyright © 2023 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Background: Osteoarthritis (OA) is a prevalent degenerative joint disease [1]. It has come to light that AZD8330 can suppress the generation of proinflammatory factors and deter the inflammatory response [2]. Given that inflammation is a primary causative factor in OA, it is posited that AZD8330 might exhibit superior efficacy in OA management., Methods: In this study, we investigated the potential of intraperitoneal injection of AZD8330 to retard the progression of osteoarthritis in a murine model with surgically induced medial meniscus destruction (DMM). Concurrently, we employed ATDC5 cartilage cells to dissect the mechanism through which AZD8330 inhibits the TNF-α-induced NF-κB signaling pathway via modulation of RIP1. The findings revealed that AZD8330 mitigated cartilage degradation and the inflammatory response, leading to a substantial reduction in OARSI scores among DMM mice treated with AZD8330. Mechanistically, AZD8330 functioned as a suppressor of the TNF-α-induced NF-κB/p65 signaling pathway by facilitating the phosphorylation activation of cIAP1-mediated RIP1. The combination of data from both in vivo and in vitro experiments supports the conclusion that AZD8330 can attenuate chondrocyte degradation, thereby alleviating OA, by regulating the NF-κB/P65 signaling pathway through modulation of RIP1 activity. Consequently, the utilization of AZD8330 may hold potential in the prophylaxis of osteoarthritis., Results: Our investigation delineates the role of AZD8330 in the regulation of inflammation in the context of OA treatment. Furthermore, we have unveiled that the inhibitory impact of AZD8330 on OA may hinge upon the activation of cIAP1, which in turn downregulates RIP1, thereby restraining the NF-κB/P65 signaling pathway. This study lends credence to the notion that AZD8330 may be a promising contender for osteoarthritis therapy., Conclusions: Our study provides compelling evidence attesting to the capacity of AZD8330 in managing inflammation within the realm of OA treatment. Likewise, our study has elucidated that the attenuation of OA by AZD8330 relies on the activation of cIAP1 to inhibit RIP1, consequently suppressing the NF-κB signaling pathway. On the strength of our present study, we may have identified a viable drug candidate for OA treatment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier B.V.)

NUC1 (Nutraceutical compound 1) is an ethanol extract composed of a formulation based on medicinal herbs traditionally used for the treatment of arthritis in Korea and China. This study investigated the therapeutic effects of NUC1 on osteoarthritis (OA). The protective effect of NUC1 on OA was tested in a rabbit model of collagenase-induced arthritis (CIA) for 4 weeks. Results were compared among four groups ( n = 9 per group): the normal group (untreated), the CIA group (vehicle control), the NUC1 group (CIA rabbits treated with 200 mg/kg NUC1), and the JOINS group (positive control, CIA rabbits treated with 200 mg/kg JOINS tablet). NUC1 significantly inhibited NO production ( p < 0.05 at 125 μg/ml, p < 0.01 at 250 μg/ml, and p < 0.001 at 500 μg/ml) and iNOS expression in macrophages, in a concentration-dependent manner. NUC1 also inhibited the release and protein expression of MMP-1, 3, and 13, in TNF-α-induced chondrosarcoma cells in a concentration-dependent manner. In vivo, the MMP-1 and MMP-3 levels in synovial fluids were significantly ( p < 0.05) lower in NUC1 group (77.50 ± 20.56 and 22.50 ± 7.39 pg/ml, respectively) than in the CIA group (148.33 ± 68.58 and 77.50 ± 20.46 pg/ml, respectively). Also, in histopathological, NUC1 ameliorated articular cartilage damage in OA by increasing the abundance of chondrocytes and proteoglycan in the articular cartilage. Thus, NUC1 showed promise as a potential therapeutic agent, and it can be generalized to a broader study population in different OA animal models.

The objective of this study was to investigate the effect of low-molecular-weight fish collagen (valine-glycine-proline-hydroxyproline-glycine-proline-alanine-glycine; LMWCP) on H 2 O 2 - or LPS-treated primary chondrocytes and monoiodoacetate (MIA)-induced osteoarthritis rat models. Our findings indicated that LMWCP treatment exhibited protective effects by preventing chondrocyte death and reducing matrix degradation in both H 2 O 2 -treated primary chondrocytes and cartilage tissue from MIA-induced osteoarthritis rats. This was achieved by increasing the levels of aggrecan, collagen type I, collagen type II, TIMP-1, and TIMP-3, while simultaneously decreasing catabolic factors such as phosphorylation of Smad, MMP-3, and MMP-13. Additionally, LMWCP treatment effectively suppressed the activation of inflammation and apoptosis pathways in both LPS-treated primary chondrocytes and cartilage tissue from MIA-induced osteoarthritis rats. These results suggest that LMWCP supplementation ameliorates the progression of osteoarthritis through its direct impact on inflammation and apoptosis in chondrocytes.

Objectives: Polycyclic aromatic hydrocarbons (PAHs) are environmental endocrine-disrupting compounds, which have been widely recognised as a risk factor for human health. However, the relationship between PAHs exposure and the risk of osteoarthritis has rarely been reported. This study aimed to investigate the association between individual and mixed exposure to PAHs and osteoarthritis., Methods: In this cross-sectional study, participants aged ≥20 years with data on urinary PAHs and osteoarthritis were extracted from the National Health and Nutrition Examination Survey (NHANES) between 2001 and 2016. Logistic regression analysis was utilised to assess the relationship between individual PAHs exposure and osteoarthritis. The quantile-based g computation (qgcomp) analysis and Bayesian kernel machine regression (BKMR) analysis were performed to assess the effect of mixed exposure to PAHs on osteoarthritis, respectively., Results: A total of 10,613 participants were enrolled, 980 (9.23%) of whom had osteoarthritis. Exposure to high levels of 1-hydroxynaphthalene (1-NAP) [odds ratio (OR)=1.06, 95% confidence interval (CI): 1.01-1.10], 3-hydroxyfluorene (3-FLU) (OR=1.09, 95%CI: 1.02-1.17), and 2-hydroxyfluorene (2-FLU) (OR=1.06, 95%CI: 1.01-1.13) were all associated with greater odds of osteoarthritis after adjusting for age, sex, body mass index, drinking alcohol, and hypertension. The qgcomp analysis showed that the joint weighted value of mixed PAHs exposure (OR=1.11, 95%CI: 1.02-1.22; p=0.017) was significantly related to higher odds of osteoarthritis. The BKMR analysis demonstrated that mixed exposure to PAHs was positively correlated with the risk of osteoarthritis., Conclusions: Both individual and mixed exposure to PAHs were positively correlated with the risk of osteoarthritis.

Osteoarthritis (OA) is a common debilitating degenerative disease of the elderly. We aimed to study the therapeutic effects of combining curcumin and swimming in monosodium iodoacetate (MIA)-induced OA in a rat model. The rats were divided into 5 groups (n = 9). Group 1 received saline and served as a control group. Groups 2-5 were injected intra-articularly in the right knee with 100 μL MIA. One week later, groups 3 and 5 were started on daily swimming sessions that gradually increased to 20-mins per session, and for groups 4 and 5, oral curcumin was administered at a dose of 200 mg/kg for 4 weeks. The combination therapy (curcumin + swimming) showed the most effective results in alleviating pain and joint stiffness as well as improving histological and radiological osteoarthritis manifestations in the knee joints. The combination modality also reduced serum C-reactive protein and tissue cartilage oligomeric matrix protein levels. Mechanistically, rats received dual treatment exhibited restoration of miR-130a and HDAC3 expression. The dual treatment also upregulated PPAR-γ alongside downregulation of NF-κB and its inflammatory cytokine targets TNF-α and IL-1β. Additionally, there was downregulation of MMP1 and MMP13 in the treated rats. In conclusion, our data showed that there is a therapeutic potential for combining curcumin with swimming in OA, which is attributed, at least in part, to the modulation of miR-130a/HDAC3/PPAR-γ signaling axis., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)

Rationale: Asteoarthritis (OA) is a leading cause of chronic pain in the elderly population and is often associated with emotional comorbidities such as anxiety and depression. Despite age is a risk factor for both OA and mood disorders, preclinical studies are mainly conducted in young adult animals., Objectives: Here, using young adult (11-week-old) and older adult (20-month-old) mice, we evaluate in a monosodium-iodoacetate-(MIA)-induced OA model the development of anxio-depressive-like behaviors and whether brain neuroinflammation may underlie the observed changes. We also test whether an effective pain treatment may prevent behavioral and biochemical alterations., Methods: Mechanical allodynia was monitored throughout the experimental protocol, while at the end of protocol (14 days), anxio-depressive-like behaviors and cognitive dysfunction were assessed. Neuroinflammatory condition was evaluated in prefrontal cortex, hippocampus and hypothalamus. Serum IFNγ levels were also measured. Moreover, we test the efficacy of a 1-week treatment with morphine (2.5 mg/kg) on pain, mood alterations and neuroinflammation., Results: We observed that young adult and older adult controls (CTRs) mice had comparable allodynic thresholds and developed similar allodynia after MIA injection. Older adult CTRs were characterized by altered behavior in the tests used to assess the presence of depression and cognitive impairment and by elevated neuroinflammatory markers in brain areas compared to younger ones. The presence of pain induced depressive-like behavior and neuroinflammation in adult young mice, anxiety-like behavior in both age groups and worsened neuroinflammation in older adult mice. Morphine treatment counteracted pain, anxio-depressive behaviors and neuroinflammatory activation in both young adult and older adult mice., Conclusions: Here, we demonstrated that the presence of chronic pain in young adult mice induces mood alterations and supraspinal biochemical changes and aggravates the alterations already evident in older adult animals. A treatment with morphine, counteracting the pain, prevents the development of anxio-depressive disorders and reduces neuroinflammation., (© 2023. The Author(s).)

Purpose: To evaluate the effectiveness and safety of intra-arterial imipenem/cilastatin sodium (IPM/CS) infusion for painful interphalangeal joint osteoarthritis (OA)., Materials and Methods: Fifty-eight patients with interphalangeal joint OA who underwent intra-arterial IPM/CS infusion were retrospectively evaluated. Intra-arterial infusions were performed via percutaneous wrist arterial access. The Numerical Rating Scale (NRS), Functional Index for Hand Osteoarthritis (FIHOA), and Patient Global Impression of Change (PGIC) scale scores were assessed at intervals of 1, 3, 6, 12, and 18 months. Clinical success was evaluated based on PGIC., Results: All patients were followed up for at least 6 months after treatment. Of them, 30 and 6 patients were followed up for 12 and 18 months, respectively. No severe or life-threatening adverse events were encountered. The mean NRS score was 6.0 ± 1.4 at baseline, which significantly decreased to 2.8 ± 1.4, 2.2 ± 1.9, and 2.4 ± 1.9 at 1, 3, and 6 months after treatment, respectively (all P < .001). The mean NRS scores were 2.8 ± 1.7 and 2.9 ± 1.9 at 12 and 18 months, respectively, in the remaining patients. The mean FIHOA score significantly decreased from 9.8 ± 5.0 at the baseline to 4.1 ± 3.5 at 3 months (P < .001). The mean FIHOA score was 4.5 ± 3.3 at 12 months in the remaining 30 patients. The clinical success rates based on PGIC at 1, 3, 6, 12, and 18 months were 62.1%, 77.6%, 70.7%, 63.4%, and 50.0%, respectively., Conclusions: Intra-arterial IPM/CS infusion is a potential treatment option for interphalangeal joint OA refractory to medical management., (Copyright © 2023. Published by Elsevier Inc.)

Osteoarthritis (OA) contributes to significant medical and socioeconomic burden in many populations. Its prevalence is expected to rise continuously owing to the combined effects of aging and increase in risk factors, including obesity, physical inactivity, and joint injuries. Pain is a hallmark presentation of OA. Topical nonsteroidal anti-inflammatory drugs (NSAIDs) are recommended by many international guidelines as an early treatment option of the management of osteoarthritic pain. However, the use of topical NSAIDs remains low in Malaysia and appears not to be a preferred agent in managing OA pain by prescribers. There is also limited guidance from local medical bodies on the use of topical NSAIDs to manage OA pain. This consensus recommendation is intended to serve as a practical guide for healthcare practitioners on the use of topical NSAIDs in the management of OA pain. Eight statements and recommendations were finalized covering the areas of OA burden, topical NSAIDs formulations, safety and efficacy of topical NSAIDs, and patient education. Robust evidence is available to support the efficacy and safety of topical NSAIDs, with its benefits further strengthened by ease of use and access. Taking these into consideration, we recommend that healthcare practitioners advocate for the early use of topical NSAIDs over oral NSAIDs for mild-to-moderate OA pain, while engaging in a shared decision-making process with patients for optimal clinical outcomes., (© 2023 The Authors. Journal of Orthopaedic Research® published by Wiley Periodicals LLC on behalf of Orthopaedic Research Society.)

Osteoporotic osteoarthritis is primarily associated with low subchondral bone mass. However, the mechanisms and therapeutic targets of osteoporotic osteoarthritis caused by prenatal dexamethasone exposure (PDE) in offspring remain unclear. In this study, pregnant Wistar rats were injected with dexamethasone to obtain bone tissue from fetal and postnatal rat offspring for analysis. Bone marrow mesenchymal stem cells (BMSCs) were isolated in vitro to elucidate the underlying molecular mechanisms. We determined in vivo that PDE reduced subchondral bone mass in adult female rat offspring, which originated from dysplasia of the subchondral bone. PDE led to a continuous increase in miR-6215 expression, accompanied by a decrease in FERM domain-containing protein 6 (FRMD6) expression. In vitro, dexamethasone upregulated miR-6215 expression through the glucocorticoid receptor, thereby inhibiting FRMD6 expression, promoting the translocation of yes-associated protein 1 (YAP1) into the nucleus of BMSCs, and downregulating downstream osteogenic marker genes. Finally, the rAAV-miR-6215 inhibitor rescued the low subchondral bone mass and osteoarthritis susceptibility caused by PDE in rat offspring. In conclusion, increased expression of miR-6215 mediates low subchondral bone mass caused by PDE through FRMD6/YAP1 signaling. Therefore, miR-6215 is a promising therapeutic target for PDE-induced low subchondral bone mass in offspring., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023. Published by Elsevier Inc.)

Membrane-type I metalloproteinase (MT1-MMP/MMP14) plays a key role in various pathophysiological processes, indicating an unaddressed need for a targeted therapeutic approach. However, mice genetically deficient in Mmp14 show severe defects in development and growth. To investigate the possibility of MT1-MMP inhibition as a safe treatment in adults, we generated global Mmp14 tamoxifen-induced conditional knockout (Mmp14 kd ) mice and found that MT1-MMP deficiency in adult mice resulted in severe inflammatory arthritis. Mmp14 kd mice started to show noticeably swollen joints two weeks after tamoxifen administration, which progressed rapidly. Mmp14 kd mice reached a humane endpoint 6 to 8 weeks after tamoxifen administration due to severe arthritis. Plasma TNF-α levels were also significantly increased in Mmp14 kd mice. Detailed analysis revealed chondrocyte hypertrophy, synovial fibrosis, and subchondral bone remodeling in the joints of Mmp14 kd mice. However, global conditional knockout of MT1-MMP in adult mice did not affect body weight, blood glucose, or plasma cholesterol and triglyceride levels. Furthermore, we observed substantial expression of MT1-MMP in the articular cartilage of patients with osteoarthritis. We then developed chondrocyte-specific Mmp14 tamoxifen-induced conditional knockout (Mmp14 chkd ) mice. Chondrocyte MT1-MMP deficiency in adult mice also caused apparent chondrocyte hypertrophy. However, Mmp14 chkd mice did not exhibit synovial hyperplasia or noticeable arthritis, suggesting that chondrocyte MT1-MMP is not solely responsible for the onset of severe arthritis observed in Mmp14 kd mice. Our findings also suggest that highly cell-type specific inhibition of MT1-MMP is required for its potential therapeutic use., Competing Interests: Declaration of Competing Interest The authors have declared no conflict of interest., (Copyright © 2023. Published by Elsevier B.V.)

An animal model of osteoarthritis (OA) induced by monosodium iodoacetate (MIA) can be effectively adjusted based on the concentration of MIA to control the onset, progression, and severity of OA as required. The rat temporomandibular joint osteoarthritis (TMJOA) model using MIA is a useful tool for studying the effectiveness of disease-modifying OA drugs in TMJOA research. However, the intricate and complex anatomy of the rat TMJ often poses challenges in achieving consistent TMJOA induction during experiments. In the previous article, a reference point was established by drawing parallel lines based on the line connecting the external ear and the zygomatic arch. However, this is not suitable for the anatomical characteristics of the rat. We used the zygomatic arch as a reference, which is a technical protocol that considers it. In our protocol, we designated a point ∼1 mm away from the point where the zygomatic arch bends toward the ear as the injection site. To ensure precise injection of MIA and increase the likelihood of inducing OA, it is recommended to insert the needle at a 45° angle so that the needle tip contacts the joint projection. To confirm TMJOA induction, we identified changes in the condyle using in vivo microcomputed tomography (CT) in a rat model of MIA-induced OA and measured the degree of pain-related inflammation using head withdrawal threshold (HWT) measurements. Micro-CT scanning revealed typical OA-like lesions, including degenerative changes and subchondral bone remodeling induced by MIA in the TMJ. Pain, a major clinical feature of OA, showed an appropriate response corresponding to the structural changes shown in micro-CT scanning. In addition, the MIA concentration suitable for long-term observation of lesions was determined through ex vivo micro-CT imaging and HWT measurements. The 8 mg concentration exhibited a significant difference compared with others, confirming the sustained presence of lesions, particularly through changes in subchondral bone over an extended period. Consequently, we have successfully established a reliable rat TMJOA induction model and identified the MIA concentration suitable for long-term observation of subchondral bone research, which will greatly contribute to the study of TMJOA-an incurable disease lacking specific treatment options. The Clinical Trial Registration number is 2021-12-208.

Osteoarthritis (OA) is a widespread joint disease that affects millions of people worldwide. Conventional treatments for OA, including non-steroidal anti-inflammatory drugs (NSAIDs) and steroids, have a risk of various adverse events, including liver, gastrointestinal, cardiovascular, and kidney disease, which are unsatisfactory in their effectiveness. In this study, Sorbus commixta Hedl. Stem extracts (SCE) were evaluated in animal models as potential inhibitors for the progression of OA. Sorbus commixta Hedl., which was found to have substantial anti-inflammatory and antioxidant activities in earlier investigations, has shown potential as a candidate for OA treatment. To mimic human OA symptoms, male rats were injected using sodium iodoacetate (MIA) in their knee joints. SCE significantly reduced MIA-induced weight-bearing loss in rats after the MIA injection and alleviated cartilage degradation and subchondral bone injury caused by MIA. In addition, SCE administration reduced levels of TNF-α and IL-1β such as pro-inflammatory cytokines in serum, as well as the levels of matrix metalloproteinases (MMPs) such as MMP-1, -3, -8 and -13 in the joint cartilage. SCE significantly inhibited the writhing responses in acetic acid-administered mice and was used to quantify pain. In lipopolysaccharide (LPS)-activated RAW264.7, SCE suppressed NO production and reduced the expression of TNF-α, PGE2, IL-6, IL-1β, MMP1, MMP3, MMP8, and MMP-13. Our study showed that SCE alleviated inflammation and cartilage degradation in arthritis through its anti-inflammatory activities on multiple targets.

Background: With the restriction of organophosphorus and other insecticides, pyrethroids are currently the second most-used group of insecticides worldwide due to their advantages such as effectiveness and low toxicity for mammalian. Animal studies and clinical case reports have documented associations between adverse health outcomesand exposure to pyrethroids. At present, the association between chronic pyrethroid exposure and osteoarthritis (OA) remains elusive., Methods: Cross-sectional data from the National Health and Nutrition Examination Survey 1999-2002 and 2007-2014 were used to explore the associations of pyrethroid exposure and OA. Urinary level of 3-phenoxybenzoic acid (3-PBA) in urine samples was used to evaluate the exposure of pyrethroid, and OA was determined on the basis of self-reported physician diagnoses. Multivariable logistic regression models were used to investigate the association between pyrethroid exposure and OA., Results: Among the 6528 participants, 650 had OA. The weighted geometric mean of urinary volume-based 3-PBA concentration were 0.45 µg/L. With adjustments for major confounders, compared to participants in the lowest quartile of urinary volume-based 3-PBA, those in the highest quartilehad higher odds of OA (odds ratio, 1.39; 95% confidence interval: 1.01, 1.92). There was no nonlinear relationship between urinary volume-based 3-PBA and OA (P for non-linearity = 0.89)., Conclusion: High urinary 3-PBA concentration was associated with increased OA odds in the US adults. Pyrethroid exposure in the population should be monitored regularly., (© 2023. BioMed Central Ltd., part of Springer Nature.)

Ethnopharmacological Relevance: Shang-Ke-Huang-Shui (SKHS) is a classic traditional Chinese medicine formula originally from the southern China city of Foshan. It has been widely used in the treatment of osteoarthritis (OA) but underlying molecular mechanisms remain unclear., Aim of Study: Recently, activation of C-X-C chemokine receptor type 4 (CXCR4) signaling has been reported to induce cartilage degradation in OA patients; therefore, inhibition of CXCR4 signaling has becoming a promising approach for OA treatment. The aim of this study was to validate the cartilage protective effect of SKHS and test whether the anti-OA effects of SKHS depend on its inhibition on CXCR4 signaling. Additionally, CXCR4 antagonist in SKHS should be identified and its anti-OA activity should also be tested in vitro and in vivo., Methods: The anti-OA effects of SKHS and the newly identified CXCR4 antagonist was evaluated by monosodium iodoacetate (MIA)-induced rats. The articular cartilage surface was examined by hematoxylin and eosin (H&E) staining and Safranin O-Fast Green (S-F) staining whereas the subchondral bone was examined by micro-CT. CXCR4 antagonist screenings were conducted by molecular docking and calcium response assay. The CXCR4 antagonist was characterized by UPLC/MS/MS. The bulk RNA-Seq was conducted to identify CXCR4-mediated signaling pathway. The expression of ADAMTS4,5 was tested by qPCR and Western blot., Results: SKHS protected rats from MIA-induced cartilage degradation and subchondral bone damage. SKHS also inhibited CXCL12-indcued ADAMTS4,5 overexpression in chondrocytes through inhibiting Akt pathway. Coptisine has been identified as the most potent CXCR4 antagonist in SKHS. Coptisine reduced CXCL12-induced ADAMTS4,5 overexpression in chondrocytes. Furthermore, in MIA-induced OA model, the repaired cartilage and subchondral bone were observed in the coptisine-treated rats., Conclusion: We first report here that the traditional Chinese medicine formula SKHS and its predominate phytochemical coptisine significantly alleviated cartilage degradation as well as subchondral bone damage through inhibiting CXCR4-mediated ADAMTS4,5 overexpression. Together, our work has provided an important insight of the molecular mechanism of SKHS and coptisine for their treatment of OA., Competing Interests: Declaration of competing interest Authors declare that they have no competing interest., (Copyright © 2023 Elsevier B.V. All rights reserved.)

Autophagy inhibition is known to be involved in the development of adult osteoarthritis. Dexamethasone, as a synthetic glucocorticoid, is widely used for premature delivery and related pregnancy diseases in clinics. We have previously shown that prenatal dexamethasone exposure (PDE) was associated with increased susceptibility to postnatal osteoarthritis in offspring. However, whether the occurrence of fetal-originated adult osteoarthritis induced by PDE is related to autophagy remains unclear. In this study, we first found that PDE could increase the mRNA and protein expression of cartilage matrix-degrading enzymes (MMP3, MMP13, and ADAMTS5) and decrease the cartilage matrix contents in adult offspring, and the in vitro results suggested that this might be related to the autophagy inhibition of chondrocytes. Further, we demonstrated a persistent autophagy inhibition with autolysosome accumulation, low expression of cathepsin D (CTSD), increased H3K9ac level, and expression of miR-1912-3p in the cartilage of PDE offspring from fetus to adulthood. In vitro experiments showed that dexamethasone inhibited autophagy flux and CTSD expression in fetal chondrocytes, while overexpression of CTSD could alleviate the inhibition of autophagic flux induced by dexamethasone. Finally, we confirmed that dexamethasone increased the H3K9ac level and expression of miR-1912-3p through activation of the glucocorticoid receptor (GR), resulting in the decreased expression of CTSD and inhibition of autophagy flux in fetal chondrocytes. In conclusion, intrauterine miR-1912-3p/CTSD programming-mediated autophagy inhibition promoted the susceptibility to osteoarthritis in PDE adult offspring rats. This study provides new ideas for exploring early prevention and therapeutic targets in fetal-originated osteoarthritis., (© 2023 Federation of American Societies for Experimental Biology.)

Introduction: The association between metabolic syndrome (MetS) and osteoarthritis (OA) development has become increasingly recognized. In this context, the exact role of cholesterol and cholesterol-lowering therapies in OA development has remained elusive. Recently, we did not observe beneficial effects of intensive cholesterol-lowering treatments on spontaneous OA development in E3L.CETP mice. We postulated that in the presence of local inflammation caused by a joint lesion, cholesterol-lowering therapies may ameliorate OA pathology., Materials and Methods: Female ApoE3∗Leiden.CETP mice were fed a cholesterol-supplemented Western type diet. After 3 weeks, half of the mice received intensive cholesterol-lowering treatment consisting of atorvastatin and the anti-PCSK9 antibody alirocumab. Three weeks after the start of the treatment, OA was induced via intra-articular injections of collagenase. Serum levels of cholesterol and triglycerides were monitored throughout the study. Knee joints were analyzed for synovial inflammation, cartilage degeneration, subchondral bone sclerosis and ectopic bone formation using histology. Inflammatory cytokines were determined in serum and synovial washouts., Results: Cholesterol-lowering treatment strongly reduced serum cholesterol and triglyceride levels. Mice receiving cholesterol-lowering treatment showed a significant reduction in synovial inflammation (P = 0.008, WTD: 95% CI: 1.4- 2.3; WTD + AA: 95% CI: 0.8- 1.5) and synovial lining thickness (WTD: 95% CI: 3.0-4.6, WTD + AA: 95% CI: 2.1-3.2) during early-stage collagenase-induced OA. Serum levels of S100A8/A9, MCP-1 and KC were significantly reduced after cholesterol-lowering treatment (P = 0.0005, 95% CI: -46.0 to -12.0; P = 2.8 × 10 -10 , 95% CI: -398.3 to -152.1; P = 2.1 × 10 -9 , -66.8 to -30.4, respectively). However, this reduction did not reduce OA pathology, determined by ectopic bone formation, subchondral bone sclerosis and cartilage damage at end-stage disease., Conclusion: This study shows that intensive cholesterol-lowering treatment reduces joint inflammation after induction of collagenase-induced OA, but this did not reduce end stage pathology in female mice., (Copyright © 2023 The Author(s). Published by Elsevier Ltd.. All rights reserved.)

Introduction: Understanding what the most effective and safe non-steroidal anti-inflammatory drug (NSAID) is for managing osteoarthritis (OA) is complicated. OA is prevalent worldwide and people living with OA commonly have multiple comorbidities. The efficacy and safety of NSAIDs in a patient are influenced by their intrinsic and extrinsic factors. Current guidelines recommend the lowest dose for the shortest duration, monitoring patients for risk factors and comorbidities but generally do not specify, which NSAID is most suitable for a patient with specific comorbidities., Areas Covered: This paper looks at the mechanism of action of all NSAIDs and reviews the current literature concerning their safety in patients with and without comorbidities. Relevant publications were identified by searching PubMed and Cochrane Library using key terms. The search was conducted from inception to 18 July 2023 and included results published before 18 July 2023. The search results and their references were then manually reviewed., Expert Opinion: In the paper, we determine whether the current practice of 'lowest dose for shortest duration' is in fact the best approach for prescribing NSAIDs and identify which NSAIDs are most suitable given a patient's risk factors and comorbidities. Our aim is to help guide health professionals in recommending the most suitable NSAID for each patient.

Background: The activation of P2Y 14 receptor (P2Y 14 R) promotes osteoclast formation and causes neuropathic pain, exhibiting possible link to osteoarthritis (OA). Given lack of P2Y 14 R antagonist, the present study aims to search a novel P2Y 14 R antagonist with low toxicity and high activity from natural products as a possible drug candidate in treatment of OA., Methods: The role of P2Y 14 R on OA was verified using P2Y 14 R knockout (KO) rats. Molecular docking virtual screening strategy and activity test in P2Y 14 R stably-expressed HEK293 cells were used to screen target compound from natural product library. The MM/GBSA free energy calculation/decomposition technique was used to determine the principal interaction mechanism. Next, the binding of target compound to P2Y 14 R was examined using cellular thermal shift assay and drug affinity responsive target stability test. Finally, the therapeutic effect of target compound was performed in monosodium iodoacetate (MIA)-induced OA mouse model. To verify whether the effect of target compound was attributed to P2Y 14 R, we establish the osteoarthritis model in P2Y 14 R KO mice to perform pharmacodynamic evaluation. Importantly, to investigate the potential mechanism by which target compound attenuate OA, expressions of the major transcription factors involved in osteoclast differentiation were detected by western blot, while markers of nerve damage in dorsal root ganglion (DRG) were evaluated by RT-qPCR and immunofluorescence techniques., Results: Deficiency of P2Y 14 R alleviated pain behavior and cartilage destruction in MIA-induced OA rats. 14 natural compounds were screened by Glide docking-based virtual screening, among which paederosidic acid exhibited the highest antagonistic activity to P2Y 14 R with IC 50 of 8.287 μM. As a bioactive component extracted from Paederia scandens, paederosidic acid directly interacted with P2Y 14 R to enhance the thermostability and decrease the protease sensitivity of target protein, which significantly inhibited receptor activator for nuclear factor-κB ligand (RANKL)-mediated osteoclastogenesis. More importantly, paederosidic acid suppressed osteoclast formation by downregulating expressions of NFAT2 and ATP6V0D2, as well as relieved neuropathic pain by decreasing expressions of CGRP, CSF1 and galanin in DRG., Conclusions: Paederosidic acid targeted P2Y 14 R to improve OA through alleviating osteoclast formation and neuropathic pain, which provided an available strategy for developing novel drug leads for treatment of OA., Competing Interests: Declaration of Competing Interest All the authors state that they have no interest conflicts for this work., (Copyright © 2023 Elsevier GmbH. All rights reserved.)