On Osteoarthritis Research Articles

Jianpi qingre tongluo prescription alleviates the senescence-associated secretory phenotype with osteoarthritis by regulating STAG1/TP53/P21 signaling pathway

Ethnopharmacological relevanceJianpi Qingre Chubi prescription primarily consists of a compound formula, also known as Huangqin Qingre Chubi Capsules (HQC), which strengthens the spleen and resolves dampness, clear heat, and collaterals. Long-term clinical use has shown that HQC improves joint swelling and pain in patients with osteoarthritis. Mechanistically, we demonstrated that HQC inhibits inflammatory responses, extracellular matrix degradation, and delays chondrocyte senescence. AimTo determine the bioactivity and mechanism of action of Jianpi Qingre Tongluo prescription (HQC) on osteoarthritis (OA). Materials and methodsFirst, the chondroprotective effects of HQC were assessed using histopathology, immunohistochemical staining and protein blotting in an OA rat model. Additionally, we identified key targets for crucial targets of HQC in OA using the Network Pharmacology and Gene Expression Omnibus (GEO) dataset (GSE98918 and GSE152805). In vitro conditions, IL-1β-treated chondrocytes served to study the impact of HQC on OA development and the senescence-associated secretory phenotype (SASP). This was evaluated using a series of approaches, such as flow cytometry assays, and immunofluorescence staining, and then verified by rescue experiments. ResultsTherapy with HQC attenuated the severity of osteoarthritis (demonstrated by histopathology, OARSI grading scores, and Mankin scores) and SASP factors (as indicated by IL-1β, IL-6, IL-4, IL-37, MMP13, ADAMTS5, COL2A1, and ACAN levels, and apoptotic cell death). HQC might treat osteoarthritis via four important targets (STAG1, TP53, P21, and P16), with the p53 signalling pathway representing one of the main pathways. The HQC acts primarily on chondrocyte clusters. In vitro experiments indicated that STAG1 overexpression accelerates chondrocyte apoptosis, promotes SASP factor expression and extracellular matrix (ECM) degradation, and facilitates OA progression. HQC-containing serum suppressed the expression of the STAG1/TP53/P21 pathway, regulated SASP factors, and restored ECM balance. ConclusionJianpi Qingre Tongluo prescription modulated SASP factors by regulating the STAG1/TP53/P21 signal transduction axis and decelerating cartilage senescence and degradation in patients with OA. Jianpi Qingre Tongluo may be an effective drug candidate.

Rosmarinic acid promotes cartilage regeneration through Sox9 induction via NF-κB pathway inhibition in mouse osteoarthritis progression

BackgroundThe natural polyphenolic compound known as Rosmarinic acid (RosA) can be found in various plants. Although its potential health benefits have been extensively studied, its effect on osteoarthritis (OA) progression and cartilage regeneration function still needs to be fully elucidated in OA animal models. This study elucidated the effect of RosA on OA progression and cartilage regeneration. MethodsIn vitro assessments were conducted using RT-PCR, qRT-PCR, Western blotting, and ELISA to measure the effects of RosA. The molecular mechanisms of RosA were determined by analyzing the translocation of p65 into the nucleus using immunocytochemistry (ICC). Histological analysis of cartilage explant was performed using alcian blue staining and immunohistochemistry (IHC). For in vivo analysis, the destabilization of the medial meniscus (DMM)-induced OA mouse model was utilized to evaluate cartilage destruction through Safranin-O staining. The expression of catabolic and anabolic factors in mice knee joints was quantified by immunohistochemistry. ResultsThe expression of catabolic factors in chondrocytes was significantly impeded by RosA. It also suppressed the NF-κB signaling pathway by decreasing phosphorylation of p65 and reducing degradation of IκB protein. In ex vivo experiments, RosA protected sulfated proteoglycan erosion triggered by IL-1β and suppressed the catabolic factors in cartilage explant. RosA treatment in animal models resulted in preventing cartilage destruction and reducing catabolic factors in the cartilage. RosA was also found to promote the expression of Sox9, Col2a1, and Acan in vitro, ex vivo, and in vivo analyses. ConclusionsRosA attenuated the OA progression by suppressing the catabolic factors expression. These effects were facilitated through the suppression of the NF-κB signaling pathway. Additionally, it promotes cartilage regeneration by inducing anabolic factors. Therefore, RosA shows potential as an effective therapeutic agent for treating OA.

Therapeutic effect of three-dimensional hanging drop cultured human umbilical cord mesenchymal stem cells on osteoarthritis in rabbits

BackgroundMesenchymal stem cells (MSCs) have shown a positive effect on Osteoarthritis (OA), but the efficacy is still not significant in clinical. Conventional two-dimensional (2D) monolayer culture method is prone to cause MSCs undergoing replication senescence, which may affect the functions of MSCs. Three-dimensional (3D) culture strategy can sustain cell proliferative capacity and multi-differentiation potential. This study aimed to investigate the therapeutic potential of human umbilical cord-derived mesenchymal stem cells (hUC-MSCs) cultured by 3D hanging drop method on OA.MethodshUC-MSCs were isolated from umbilical cord and cultured by 3D hanging drop method for 48 h. Scanning electron microscopy (SEM) was used to observe gross morphology 2D and 3D hUC-MSCs. Transcriptome comparison of gene expression differences between 2D and 3D hUC-MSCs. GO enrichment analysis, KEGG pathway enrichment analysis and GSEA enrichment analysis were used to analyze the impact of 3D hanging drop culture on the biological functions of hUC-MSCs. Female New Zealand rabbits (n = 12) were divided into 4 groups: Normal group, Model group, 2D hUC-MSCs treatment group and 3D hUC-MSCs treatment group. After 8 weeks, the gross and histological appearance of the cartilage was evaluated by safranin O-fast green staining and Mankin scoring system. The expression of type I collagen and type II collagen was detected by immunohistochemistry. The levels of IL-6, IL-7, TNFα, TGFβ1 and IL-10 in the knee joint fluid were tested by ELISA.Results3D hanging drop culture changed cell morphology but did not affect phenotype. The MSCs transcriptome profiles showed that 3D hanging drop culture method enhanced cell-cell contact, improved cell responsiveness to external stimuli and immunomodulatory function. The animal experiment results showed that hUC-MSCs could promote cartilage regeneration compared with Model group. 3D hUC-MSCs treatment group had a higher histological score and significantly increased type II collagen secretion. In addition, 3D hUC-MSCs treatment group increased the expression of anti-inflammatory factors TGFβ1 and IL-10.ConclusionThe above experimental results illustrated that 3D hanging drop culture method could enhance the therapeutic effect of hUC-MSCs, and showed a good clinical application prospect in the treatment of OA.

Effects of polysaccharide from Pueraria lobata on osteoarthritis in rats

The effects of Pueraria lobata polysaccharide (PPL-1) on osteoarthritis (OA) disease were comprehensively evaluated by using chondrocytes and synoviocytes extracted from the joints of SD rats based on in vitro cell experiments and by establishing pathological models of OA rats. The results showed that concentrations of 1.25–10 and 0.2–1.6 μg/mL, PPL-1 did not inhibit or promote chondrocytes and synoviocytes in vitro. However, at concentrations of 1.25–10 and 0.2–1.6 μg/mL, it can promote cartilage and synovial membrane cells after LPS stimulation of cell activity and inhibite LPS-induced apoptosis. The results of animal experiments showed that PPL-1 can reduce the symptoms of joint swelling in OA rats, decrease the production of serum inflammatory cytokines TNF-α, IL-1β, and IL-6, and slow down the occurrence of inflammation. Therefore, from the perspective of symptoms, inflammatory factors and pathology, PPL-1 has therapeutic effects on OA rats and alleviates the development of inflammation. It indicated that PPL-1 has the potential to be developed into an OA therapeutic drug with anti-inflammatory properties that protects and activates chondrocytes.

Genetic proxies for therapy of insulin drug targets and risk of osteoarthritis: a drug-target Mendelian randomization analysis.

The potential effects of insulin therapy on osteoarthritis (OA) risk are poorly understood. This study aimed to explore the causal relationship between insulin therapy and OA. Mendelian randomization (MR) analysis was performed to examine the association between genetically proxied inhibition of insulin targets and the risk of overall, hip (HOA) and knee OA (KOA). We then performed univariable MR using summary statistics regarding insulin target genes derived from the DrugBank database. Data related to blood glucose reduction levels were used as a proxy for insulin levels. Two phenotypes, type 2 diabetes, and glycosylated hemoglobin levels, were selected as positive controls to confirm the direction and validity of the proxies. The OA datasets were derived from the UK Biobank cohort. Multivariable MR was adjusted for body mass index, sedentary behavior, cigarette smoking, frequency of alcohol intake, age, and genetic sex. Genetically proxied insulin therapy was associated with an increased risk of overall OA [odds ratio (OR):1.2595; 95% confidence interval (CI):1.0810-1.4675] and HOA (OR:1.4218; 95%CI:1.1240-1.7985), which remained consistent across multiple MR methods. After adjusting for confounders, we found evidence supporting a significant causal link with a higher risk of overall OA and HOA. A further two-step MR analysis revealed no significant mediation effects from the six mediators in the associations. There was a causal association between genetically proxied insulin therapy and a higher risk of OA, especially HOA.

Tisochrysis lutea Fucoxanthin Suppresses NF-κB, JNK, and p38-Associated MMP Expression in Arthritis Pathogenesis via Antioxidant Activity.

Tisochrysis lutea is a highly nutritious marine microalga that has various applications in aquaculture and biotechnology. However, the effects of T. lutea extract (TLE) on osteoarthritis (OA) pathogenesis remain unexplored. In this study, we aimed to determine the effects of TLE on OA development. We found that TLE inhibits the expression of matrix metalloproteinases (MMPs) and reactive oxygen species (ROS) activity in an OA mouse model generated by the destabilization of the medial meniscus (DMM) surgery. In vivo assays of the OA model mice demonstrated that TLE has a protective effect against cartilage destruction by inhibiting MMP3 and MMP13 expression. To enable the medical use of TLE, the components of TLE were characterized using high-performance liquid chromatography (HPLC) analysis. Interestingly, we found that Fucoxanthin accounts for 41.2% of TLE and showed anti-catabolic and antioxidant effects under IL-1β-treated in vitro conditions. RNA sequencing analysis showed that fucoxanthin decreased p38, NF-κB, and JNK signaling pathway gene expression, all of which are activated by IL-1β. Furthermore, in vivo analysis showed that fucoxanthin inhibited the IL-1β-stimulated phosphorylation of p65, JNK, and p38. These results highlight new possibilities for the use of TLE as a source of fucoxanthin, an antioxidant, for OA treatment.

Polygonatum sibiricum polysaccharides protect against knee osteoarthritis by inhibiting the TLR2/NF-κB signaling pathway in vivo and in vitro

Polygonatum sibiricum polysaccharides (PSP), the primary constituent of Polygonatum sibiricum, have been shown to exhibit a wide range of pharmacological effects, but their impact on osteoarthritis (OA) remains unclear. The objective of this study was to investigate the protective effects of PSP against OA and to elucidate its underlying molecular mechanism. In our in vitro experiments, PSP not only inhibited the IL-1β-induced inflammatory responses and the nuclear factor kappa-B (NF-κB) signaling pathway in chondrocytes but also regulated the cartilage matrix metabolism. In addition, we detected 394 significantly differentially expressed genes through RNA-seq analysis on PSP-intervened chondrocytes, and the toll-like receptor 2 (TLR2) was identified as the most important feature by functional network analysis and qRT-PCR. It was also revealed that PSP treatment significantly reversed the IL-1-induced up-regulation of TLR2 expression in chondrocytes, while TLR2 overexpression partially inhibited the regulatory effects of PSP on inflammation, NF-κB signaling pathway and matrix metabolism. In our in vivo experiments, PSP treatment alleviated the development of destabilization of medial meniscus (DMM)-induced OA in mouse knee joints, inhibited the DMM-induced activation of the TLR2/NF-κB signaling pathway in mouse knee joint cartilage, and reduced the serum levels of inflammatory cytokines. In conclusion, PSP exerts its anti-inflammatory, matrix synthesis-promoting and matrix catabolism-suppressing effects in knee OA by inhibiting the TLR2/NF-κB signaling pathway, suggesting that PSP may be potentially targeted as a novel all-natural, low-toxicity drug for OA prevention and treatment.

Research of the mechanism of spatholobi caulis for immune-inflammatory of osteoarthritis based on clinical data mining,network pharmacology and cell experiment verification

BackgroundTraditional Chinese medicine is widely used in the treatment of osteoarthritis. This study explores the therapeutic effect of Traditional Chinese Medicine (TCM) on osteoarthritis (OA), as well as the mechanism by which Spatholobi Caulis (SPC) improves the immune-Inflammatory response of OA. MethodsThe clinical data mining techniques to evaluate the efficacy of Caulis spatholobi in treating OA, and elucidated its mechanism of action using network pharmacology, molecular docking, and cell experiments. The random walk model was applied to systematically evaluate the therapeutic efficacy of Chinese herbal medicine on OA. ResultsThe evaluation based on the clinical data mining showed that TCM is effective in improving ESR, CRP, C3, C4, and PLT. Data mining results showed significant OA treatment. Network analysis results showed that it may fight OA by targeting JUN, ESR1 and PPARG; molecular docking results showed good JUN, ESR1, PPARG and active component formononetin. Finally, in vitro experiments conducted the preliminary validation of formononetin for the core target of FLS. Cell proliferation was measured by CCK-8, and JUN, ESR1, PPARG protein, and mRNA expression was measured by quantitative real-time RCR at 48 h after drug intervention. ConclusionThe present study demonstrated that the SPC effectively relieved immune inflammation indicators in OA patients. Formononetin, the main active component of the chicken blood vine, acts to reduce the immune validation response in OA patients by reducing the expression of ESR1, JUN, and PPARG.

Genistein promotes cartilage repair and inhibits synovial inflammatory response after anterior cruciate ligament transection in rats by regulating the Wnt/β-catenin axis.

To confirm the protective mechanism of genistein on osteoarthritis (OA). Firstly, we constructed an anterior cruciate ligament transection (ACLT) rat model and administered two doses of genistein via gavage. The effects of the drug on cartilage damage repair and synovitis in OA rats were evaluated through pain-related behavioral assessments, pathological staining, detection of inflammatory factors, and western blot analysis. Secondly, we constructed IL-1-induced chondrocytes and synovial fibroblast models, co-incubated them with genistein, and evaluated the protective effects of genistein on both types of cells through cell apoptosis and cytoskeleton staining. To verify the role of this pathway, we applied the GSK3β inhibitor TWS119 and the Wnt/β-catenin inhibitor XAV939 to ACLT rats and two types of cells to analyze the potential mechanism of genistein's action on OA. Our results confirmed the protective effect of genistein on joint cartilage injury in ACLT rats and its alleviating effect on synovitis. The results of cell experiments showed that genistein can protect IL-1β-induced chondrocytes and synovial fibroblasts, inhibit IL-1β-induced cell apoptosis, increase the fluorescence intensity of F-actin, and inhibit inflammatory response. The results of in vivo and in vitro mechanism studies indicated that TWS119 and XAV939 can attenuate the protective effects of genistein on OA rats and IL-1-induced cell damage. Our research confirmed that genistein may be an effective drug for treating osteoarthritis. Furthermore, we discussed and confirmed that the GSK3β/Wnt/β-catenin axis serves as a downstream signaling pathway of genistein, providing theoretical support for its application.

Alleviating Effect of a Flower Extract of Styphnolobium japonicum L. on Symptoms of Experimentally Induced Osteoarthritis in Rats

In the present study, we prepared an ethanol extract from the flowers of Styphnolobium japonicum L. (SJFE) and found that it contains rutin as a major constituent as well as quercetin kaempferol and isorhamnetin as minor components. In lipopolysaccharide-stimulated RAW 264.7 macrophages, we observed that SJFE significantly inhibited the production of nitric oxide and the expression of major inflammatory biomarkers such as inducible NO synthase, cyclooxygenase-2, interleukin (IL)-6, and IL-1β significantly. Based on these in vitro results, we investigated the anti-inflammatory properties of SJFE on osteoarthritis (OA) of the left hind knee joints induced by monosodium iodoacetate in rats. SJFE was orally administered to the rats with arthritis for 4 weeks, and the following results were obtained. The rats treated with SJFE exhibited a 24% improvement in the weight-bearing index of their affected legs, as well as reductions of 31.5% and 23.2% in serum levels of cartilage oligomeric matrix protein and C-terminal telopeptide 2, respectively. Additionally, Mankin’s score, an indicator used to assess the severity of joint cartilage damage, decreased by 2.75 points compared to the control with no treatment. These findings suggest that SJFE possesses anti-inflammatory properties and can alleviate symptoms of OA, indicating its potential to offer relief to individuals suffering from arthritis.

Potential Benefits of Statin Therapy in Reducing Osteoarthritis Risk: A Mendelian Randomization Study.

The purpose of this study was to determine the causal effect of statins on osteoarthritis (OA) risk using Mendelian randomization (MR). Single nucleotide polymorphism-based genome-wide association analyses of statins were collected from the UK Biobank and FinnGen dataset, and OA data were collected from the UK Biobank and Arthritis Research UK Osteoarthritis Genetics (arcOGEN) study. Two-sample MR analyses were performed using the inverse-variance weighted (IVW) technique. MR-Egger, weighted median, and weighted mode served as supplementary analyses. MR-Egger regression, Cochran's Q test, and Mendelian Randomization Pleiotropy Residual Sum and Outlier analysis were performed as sensitivity analyses. Hydroxymethylglutaryl-coenzyme A reductase (HMGCR) expression and OA risk were evaluated using summary data-based MR (SMR). MR analyses consistently supported a causal connection between statin use and OA risk. A causal effect was observed for atorvastatin (IVW: β = -2.989, P = 0.003) and rosuvastatin (IVW: β = -14.141, P = 0.006) treatment on hip OA. Meta-analysis showed the association between atorvastatin and knee OA was statistically significant (odds ratio 0.15; P = 0.004). Simvastatin use exhibited a protective effect against knee (IVW: β = -1.056, P = 0.004) and hip OA (IVW: β = -1.405, P = 0.001). Statin medication showed a protective effect on hip OA (IVW: β = -0.054, P = 0.013). HMGCR correlated significantly with a reduced risk of knee OA (β = -0.193, PSMR = 0.017), rather than hip OA (β = 0.067, PSMR = 0.502), which suggested that statins' protective effect on OA may not be related to its lipid-lowering effect. This MR study provides compelling evidence that statin treatment may be a protective factor for OA. Further research is required to clarify its underlying mechanism.

Osteoarthritis Development Following Meniscectomy vs. Meniscal Repair for Posterior Medial Meniscus Injuries: A Systematic Review.

This systematic review aims to evaluate critically and synthesize the existing literature on the outcomes of meniscectomy versus meniscal repair for posterior medial meniscus injuries, with a focus on osteoarthritis (OA) development. We sought to assess the incidence of OA following both treatment modalities, compare functional outcomes post-treatment, and identify factors influencing treatment choice, providing evidence-based recommendations for clinical decision-making. A comprehensive search strategy was employed across PubMed, Scopus, and Embase up until December 2023, adhering to PRISMA guidelines. The primary outcomes included OA development, functional knee outcomes, and quality of life measures. Six studies met the inclusion criteria, encompassing 298 patients. The systematic review revealed a significant association between meniscal repair and decreased progression of OA compared to meniscectomy. Meniscectomy patients demonstrated a 51.42% progression rate towards OA, significantly higher than the 21.28% observed in meniscal repair patients. Functional outcomes, as measured by the International Knee Documentation Committee (IKDC) and Lysholm scores, were notably better in the repair group, with average scores of 74.68 (IKDC) and 83.78 (Lysholm) compared to 67.55 (IKDC) and 74.56 (Lysholm) in the meniscectomy group. Furthermore, the rate of complete healing in the repair group was reported at 71.4%, as one study reported, indicating a favorable prognosis for meniscal preservation. However, these pooled data should be interpreted with consideration to the heterogeneity of the analyzed studies. Meniscal repair for posterior medial meniscus injuries is superior to meniscectomy in preventing OA development and achieving better functional outcomes and quality of life post-treatment. These findings strongly suggest the adoption of meniscal repair as the preferred treatment modality for such injuries, emphasizing the need for a paradigm shift in clinical practice towards preserving meniscal integrity to optimize patient outcomes.

Association between glyphosate exposure and osteoarthritis in US adults: Especially in people who are obese and inactive in leisure time physical activity

ObjectiveLittle has been known on the effect of chronic glyphosate exposure on osteoarthritis (OA). The aim of this study was to investigate the association between glyphosate exposure and OA and to further investigate the different moderating effects of leisure time physical activity (LTPA) and body mass index (BMI) types on the association between glyphosate exposure and OA. MethodsCross-sectional data from 2540 participants in the 2015–2018 National Health and Nutrition Examination Survey (NHANES) were used to explore the association between glyphosate exposure and OA. Multivariate logistic regression models and restricted cubic spline models were used to investigate the association between glyphosate exposure and OA, and further analyses were conducted to determine the association between glyphosate exposure and OA under different LTPA and BMI types. ResultsOf the 2540 participants, 346 had OA. Participants with the highest glyphosate concentration (Q4) had a higher incidence of OA compared to participants with the lowest glyphosate concentration (Q1) (OR, 1.88; 95 % confidence interval [CI]: 1.13, 3.13), there was no nonlinear association between glyphosate and OA (non-linear P = 0.343). In the no LTPA group, glyphosate concentration in the Q4 group was correlated with OA (OR, 2.65; 95%CI: 1.27, 5.51). In the obese group, glyphosate concentration in the Q4 group was correlated with OA (OR, 2.74; 95 % CI: 1.48, 5.07). Among people with high BMI and inactive in LTPA, glyphosate concentrations in Q4 were associated with OA (OR, 2.19; 95 % CI: 1.07, 4.48). ConclusionsGlyphosate is associated with OA odd, and physical activity and moderate weight loss can mitigate this association to some degree. This study provides a scientific basis for rational prevention of OA by regulation of LTPA and BMI under glyphosate exposure.

Geniposidic acid alleviates osteoarthritis progression through inhibiting inflammation and chondrocytes ferroptosis.

Osteoarthritis is one of the common diseases that seriously affects the quality of life of middle-aged and elderly people worldwide. Geniposidic acid (GPA) is extracted from Eucommia ulmoides that exhibits various pharmacological effects. This study investigated the function of GPA on osteoarthritis (OA) in IL-1β-stimulated mouse chondrocytes and mouse OA model. Mouse OA model was established by destabilization of the medial meniscus (DMM) and GPA was given intraperitoneal injection. The results demonstrated that GPA could alleviate DMM-induced OA in mice. Invitro, IL-1β-induced PGE2, NO, MMP1 and MMP3 were suppressed by GPA. Furthermore, IL-1β-induced ferroptosis was inhibited by GPA, as confirmed by the inhibition of MDA, iron, and ROS, as well as the upregulation of GSH, GPX4, and Ferritin. In addition, GPA was found to increase the expression of Nrf2 and HO-1. And the inhibition of GPA on IL-1β-induced inflammation and ferroptosis were prevented by Nrf2 inhibitor. In conclusion, GPA alleviates OA progression through inhibiting inflammation and chondrocytes ferroptosis via Nrf2 signalling pathway.

Comprehensive in vitro and in vivo investigations of the therapeutic potential of Jeju lava seawater salt in osteoarthritis

Salts play a crucial role in maintaining human health by regulating fluid levels and supporting various physiological processes. However, conventional seawater-derived salts are associated with microplastic pollution and pose potential health risks. Jeju lava seawater (JLS), sourced exclusively from Jeju Island, has emerged as a unique alternative, free of microplastics and enriched with essential minerals such as magnesium, calcium, zinc, and iron. In this study, we investigated the effects of JLS on osteoarthritis (OA) pathogenesis, focusing on chondrocyte metabolism and OA development. We performed surgical destabilization of the medial meniscus to establish a murine model of OA. We examined the expression of catabolic and anabolic factors in JLS-treated chondrocytes. Our cell viability assay revealed that JLS treatment was not cytotoxic to chondrocytes at concentrations ≤ 0.5%. Additionally, JLS treatment resulted in a concentration-dependent increase in the expression of anabolic factors like aggrecan, SOX9, and COL2A1 while decreasing the expression of catabolic factors such as MMP3, MMP13, ADAMTS4, and ADAMTS5 in the chondrocytes stimulated with pro-inflammatory cytokines. Although not statistically significant compared to the control group, JLS intake slightly attenuated the OARSI score, osteophyte score, synovitis score, subchondral bone thickness, and osteophyte size in the mouse model of OA. Conclusively, these results suggest that JLS ameliorates OA by positively influencing chondrocyte metabolism, making it a promising therapeutic candidate for OA management.

Baicalin Maintains Articular Cartilage Homeostasis and Alleviates Osteoarthritis by Activating FOXO1.

Baicalin has been acknowledged for its anti-inflammatory properties. However, its potential impact on osteoarthritis (OA) has not yet been explored. Therefore, our study aimed to examine the effects of Baicalin on OA, both in laboratory and animal models. To evaluate its efficacy, human chondrocytes affected by OA were treated with interleukin-1β and/or Baicalin. The effects were then assessed through viability tests using the cell counting kit-8 (CCK-8) method and flow cytometry. In addition, we analyzed the expressions of various factors such as FOXO1, autophagy, apoptosis, and cartilage synthesis and breakdown to corroborate the effects of Baicalin. We also assessed the severity of OA through analysis of tissue samples. Our findings demonstrate that Baicalin effectively suppresses inflammatory cytokines and MMP-13 levels caused by collagenase-induced osteoarthritis, while simultaneously preserving the levels of Aggrecan and Col2. Furthermore, Baicalin has been shown to enhance autophagy. Through the use of FOXO1 inhibitors, lentivirus-mediated knockdown, and chromatin immunoprecipitation, we verified that Baicalin exerts its protective effects by activating FOXO1, which binds to the Beclin-1 promoter, thereby promoting autophagy. In conclusion, our results show that Baicalin has potential as a therapeutic agent for treating OA (Clinical Trial Registration number: 2023-61).

Melatonin is a potential novel analgesic agent for osteoarthritis: Evidence from cohort studies in humans and preclinical research in rats.

Melatonin exhibits potential for pain relief and long-term safety profile. We examined the analgesic effects of oral melatonin on osteoarthritis (OA) and investigated the underlying mechanism. Using data from a UK primary care database, we conducted a cohort study in individuals with OA to compare the number of oral analgesic prescriptions and the risk of knee/hip replacement between melatonin initiators and hypnotic benzodiazepines (i.e., active comparator) initiators using quantile regression models and Cox-proportional hazard models, respectively. To elucidate causation, we examined the effects of melatonin on pain behaviors and explored several metabolites that may serve as potential regulatory agents of melatonin in the monoiodoacetate rat model of OA. Using data from another community-based cohort study,that is, the Xiangya OA Study, we verified the association between the key serum metabolite and incident symptomatic knee OA. Compared with the hypnotic benzodiazepines cohort (n = 8135), the melatonin cohort (n = 813) had significantly fewer subsequent prescriptions of oral analgesics (50th percentile: 5 vs. 7, 75th percentile: 19 vs. 29, and 99th percentile: 140 vs. 162) and experienced a lower risk of knee/hip replacement (hazard ratio = 0.47, 95% Cl: 0.30-0.73) during the follow-up period. In rats, oral melatonin alleviated pain behaviors and increased serum levels of glycine. There was an inverse association between baseline serum glycine levels and the risk of incident symptomatic knee OA in humans (n = 760). In conclusion, our findings indicate that oral melatonin shows significant potential to be a novel treatment for OA pain. The potential role of glycine in its analgesic mechanism warrants further investigation.

Bisdemethoxycurcumin, a curcumin, protects chondrocytes, and reduces cartilage inflammation via the NRF2/HO-1/NLRP3 pathway.

The objective of this thesis is to evaluate the effect of bisdemethoxycurcumin (BDMC) on osteoarthritis (OA) and comprehensively evaluate the role of the Nuclear Factor erythroid 2-Related Factor 2 (Nrf2) signalling pathway in chondrocytes. In our study, we treated chondrocytes with BDMC in an in vitro chondrocyte assay and measured its influence on extracellular matrix (ECM) expression, downstream heme oxygenase-1 (HO-1) and NOD-like receptor thermal protein domain associated protein 3 (NLRP3) levels. Our study indicates that BDMC significantly activates the Nrf2 signaling pathway in chondrocytes in vitro. Furthermore, the expression of matrix metalloproteinase 3, interleukin 1β, recombinant a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)4 and (ADAMTS)5 was significantly suppressed by BDMC. This study confirms the potential for BDMC to activate the Nrf2/HO-1/NLRP3 signalling pathway and alleviate OA symptoms. Therefore, BDMC is a promising therapeutic agent for OA that offers new insights and treatment methods.

Effects of VX765 on osteoarthritis and chondrocyte inflammation in rats

To investigate the effects and underlying mechanisms of VX765 on osteoarthritis (OA) and chondrocytes inflammation in rats. Chondrocytes were isolated from the knee joints of 4-week-old Sprague Dawley (SD) rats. The third-generation cells were subjected to cell counting kit 8 (CCK-8) analysis to assess the impact of various concentrations (0, 1, 5, 10, 20, 50, 100 μmol/L) of VX765 on rat chondrocyte activity. An in vitro lipopolysaccharide (LPS) induced cell inflammation model was employed, dividing cells into control group, LPS group, VX765 concentration 1 group and VX765 concentration 2 group without obvious cytotoxicity. Western blot, real-time fluorescence quantitative PCR, and ELISA were conducted to measure the expression levels of inflammatory factors-transforming growth factor β 1 (TGF-β 1), interleukin 6 (IL-6), and tumor necrosis factor α (TNF-α). Additionally, Western blot and immunofluorescence staining were employed to assess the expressions of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase 1 (HO-1). Thirty-two SD rats were randomly assigned to sham surgery group (group A), OA group (group B), OA+VX765 (50 mg/kg) group (group C), and OA+VX765 (100 mg/kg) group (group D), with 8 rats in each group. Group A underwent a sham operation with a medial incision, while groups B to D underwent additional transverse incisions to the medial collateral ligament and anterior cruciate ligament, with removal of the medial meniscus. One week post-surgery, groups C and D were orally administered 50 mg/kg and 100 mg/kg VX765, respectively, while groups A and B received an equivalent volume of saline. Histopathological examination using HE and safranin-fast green staining was performed, and Mankin scoring was utilized for evaluation. Immunohistochemical staining technique was employed to analyze the expressions of matrix metalloproteinase 13 (MMP-13) and collagen type Ⅱ. The CCK-8 assay indicated a significant decrease in cell viability at VX765 concentrations exceeding 10 μmol/L ( P<0.05), so 4 μmol/L and 8 μmol/L VX765 without obvious cytotoxicity were selected for subsequent experiments. Following LPS induction, the expressions of TGF-β 1, IL-6, and TNF-α in cells significantly increased when compared with the control group ( P<0.05). However, intervention with 4 μmol/L and 8 μmol/L VX765 led to a significant decrease in expression compared to the LPS group ( P<0.05). Western blot and immunofluorescence staining demonstrated a significant upregulation of Nrf2 pathway-related molecules Nrf2 and HO-1 protein expressions by VX765 ( P<0.05), indicating Nrf2 pathway activation. Histopathological examination of rat knee joint tissues and immunohistochemical staining revealed that, compared to group B, treatment with VX765 in groups C and D improved joint structural damage in rat OA, alleviated inflammatory reactions, downregulated MMP-13 expression, and increased collagen type Ⅱ expression. VX765 can improve rat OA and reduce chondrocyte inflammation, possibly through the activation of the Nrf2 pathway.

General Control Non-derepressible 2 Alleviates Cartilage Degeneration and Inhibits NLRP3 Inflammasome Activation in Osteoarthritis.

This study aimed to evaluate the effects of general control non-derepressible 2 (GCN2) on osteoarthritis (OA) in vivo and in vitro. First, anterior cruciate ligament transection (ACLT)-induced rat model and interleukin (IL)-1β-induced ATDC5 chondrocyte were established. Hematoxylin and eosin staining and safranin O/fast green staining were employed for analyzing the histological changes in the rat cartilage. In addition, immunohistochemistry, quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, western blot, and immunofluorescence staining were employed for examining cartilage degeneration-, inflammation-, autophagy-, and NLR family pyrin domain containing 3 (NLRP3) inflammasome-associated genes expression. Moreover, 2,7-dichlorodihydrofluorescein acetoacetic acid probe was utilized for examining the intracellular reactive oxygen species. In addition, 5-ethynyl-2'-deoxyuridine assay and flow cytometry were applied for detecting chondrocyte proliferation and apoptosis IL-1β-treated ATDC5 chondrocytes. GCN2 overexpression ameliorated articular cartilage degeneration and inflammation but promoted chondrocyte autophagy in ACLT-induced OA rats. Similarly, we demonstrated that the upregulation of GCN2 could promote chondrocyte proliferation, suppress chondrocyte apoptosis, attenuate chondrocyte inflammation and extracellular matrix degradation, and promote chondrocyte autophagy. Moreover, GCN2 overexpression could inhibit the activation of NLRP3 inflammasome in IL-1β-induced ATDC5 chondrocyte. Furthermore, 3-methyladenine neutralized the protective and autophagy-promoting effects of GCN2 overexpression on ATDC5 chondrocytes. GCN2 could attenuate inflammation and cartilage degeneration, promote chondrocyte autophagy, and inhibit NLRP3 inflammasome activation in OA.