[Ligusticum cycloprolactam inhibits IL-1ß-induced apoptosis and inflammation of rat chondrocytes via HMGB1/TLR4/NF-κB signaling pathway].

Chondrocytes are unique resident cells in the articular cartilage, and the pathological changes of them can lead to the occurrence of osteoarthritis(OA). Ligusticum cycloprolactam(LIGc) are derivatives of Z-ligustilide(LIG), a pharmacodynamic marker of Angelica sinensis, which has various biological functions such as anti-inflammation and inhibition of cell apoptosis. However, its protective effect on chondrocytes in the case of OA and the underlying mechanism remain unclear. This study conducted in vitro experiments to explore the molecular mechanism of LIGc in protecting chondrocytes from OA. The inflammation model of rat OA chondrocyte model was established by using interleukin-1ß(IL-1ß) to induce. LIGc alone and combined with glycyrrhizic acid(GA), a blocker of the high mobility group box-1 protein(HMGB1)/Toll-like receptor 4(TLR4)/nuclear factor-kappa B(NF-κB) signaling pathway, were used to intervene in the model, and the therapeutic effects were systematically evaluated. The viability of chondrocytes treated with different concentrations of LIGc was measured by the cell counting kit-8(CCK-8), and the optimal LIGc concentration was screened out. Annexin V-FITC/PI apoptosis detection kit was employed to examine the apoptosis of chondrocytes in each group. The enzyme-linked immunosorbent assay(ELISA) was employed to measure the expression of cyclooxygenase-2(COX-2), prostaglandin-2(PGE2), and tumor necrosis factor-alpha(TNF-α) in the supernatant of chondrocytes in each group. Western blot was employed to determine the protein levels of B-cell lymphoma-2(Bcl-2), Bcl-2-associated X protein(Bax), caspase-3, HMGB1, TLR4, and NF-κB p65. The mRNA levels of HMGB1, TLR4, NF-κB p65, and myeloid differentiation factor 88(MyD88) in chondrocytes were determined by real-time fluorescent quantitative PCR(RT-qPCR). The safe concentration range of LIGc on chondrocytes was determined by CCK-8, and then the optimal concentration of LIGc for exerting the effect was clarified. Under the intervention of IL-1ß, the rat chondrocyte model of OA was successfully established. The modeled chondrocytes showed increased apoptosis rate, promoted expression of COX-2, PGE2, and TNF-α, up-regulated protein levels of Bax, caspase-3, HMGB1, TLR4, and NF-κB p65 and mRNA levels of HMGB1, TLR4, NF-κB p65, and MyD88, and down-regulated protein level of Bcl-2. However, LIGc reversed the IL-1ß-induced changes of the above factors. Moreover, LIGc combined with GA showed more significant reversal effect than LIGc alone. These fin-dings indicate that LIGc extracted and derived from the traditional Chinese medicine A. sinensis can inhibit the inflammatory response of chondrocytes and reduce the apoptosis of chondrocytes, and this effect may be related to the HMGB1/TLR4/NF-κB signaling pathway. The pharmacological effect of LIGc on protecting chondrocytes has potential value in delaying the progression of OA and improving the clinical symptoms of patients, and deserves further study.

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-1ß 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).

Causal Factors for Osteoarthritis: A Scoping Review of Mendelian Randomization Studies.

OBJECTIVE: Mendelian randomization (MR) has increasingly been utilized as a tool for establishing causal relations between modifiable exposures and osteoarthritis (OA). The goal of this review was to summarize available MR studies of OA that evaluate the causal role of modifiable risk factors on OA. METHODS: This review was performed following the Preferred Reporting Items for Systematic Reviews and Meta-Analysis (PRISMA) Extension for Scoping Reviews model. We performed a literature search for relevant studies published before December 2021 across multiple databases using the search terms "osteoarthritis" and ("Mendelian randomization" or "polygenic risk score"). We reported the MR estimates of causal associations between exposures and OA and then assessed methodologic quality of abstracted studies according to their efforts to validate the three key MR assumptions. RESULTS: Our search identified 45 studies reporting on 141 exposure-association analyses. All studies performed a formal instrumental variable analysis to estimate the causal effect of exposure on OA. Causal associations (P < 0.05) were reported in 60 of these analyses representing 36 unique publications, and MR-Egger sensitivity analyses were performed in 45 of these analyses. MR studies provided support for causal associations of OA with increased levels of adiposity, coffee consumption, bone mineral density, and sleep disturbance, and decreased levels of serum calcium and low-density lipoprotein cholesterol. CONCLUSION: These results highlight the potential benefits of weight reduction and improvement of sleep quality to reduce the risk of OA and call for a better understanding of the relations of coffee consumption and serum calcium to OA risk.

The Causal Association between Alcohol, Smoking, Coffee Consumption, and the Risk of Arthritis: A Meta-Analysis of Mendelian Randomization Studies.

Objective: To evaluate the genetic causality between alcohol intake, smoking, coffee consumption, and arthritis. Methods: Mendelian randomization (MR) studies with alcohol, smoking, and coffee consumption behaviors as exposures, and osteoarthritis (OA) and rheumatoid arthritis (RA) as outcomes were retrieved from up to July 2023. Two researchers with relevant professional backgrounds independently assessed the quality and extracted data from the included studies. Meanwhile, we applied MR analyses of four lifestyle exposures and five arthritis outcomes (two for OA and three for RA) with gene-wide association study (GWAS) data that were different from the included studies, and the results were also included in the meta-analysis. Statistical analyses were performed using Stata 16.0 and R software version 4.3.1. Results: A total of 84 studies were assessed. Of these, 11 were selected for meta-analysis. As a whole, the included studies were considered to be at a low risk of bias and were of high quality. Results of the meta-analysis showed no significant genetic causality between alcohol intake and arthritis (odds ratio (OR): 1.02 (0.94-1.11)). Smoking and arthritis had a positive genetic causal association (OR: 1.44 (1.27-1.64)) with both OA (1.44 (1.22-1.71)) and RA (1.37 (1.26-1.50)). Coffee consumption and arthritis also had a positive genetic causal association (OR: 1.02 (1.01-1.03)). Results from the subgroup analysis showed a positive genetic causality between coffee consumption and both OA (OR: 1.02 (1.00-1.03)) and RA (OR: 1.56 (1.19-2.05)). Conclusion: There is positive genetic causality between smoking and coffee consumption and arthritis (OA and RA), while there is insufficient evidence for genetic causality between alcohol intake and arthritis.

Electroacupuncture stimulating Neixiyan (EX-LE5) and Dubi (ST35) alleviates osteoarthritis in rats induced by anterior cruciate ligament transaction affecting DNA methylation regulated transcription of miR-146a and miR-140-5p.

OBJECTIVE: To explore whether electroacupuncture (EA) could alleviate osteoarthritis (OA) through affecting the DNA methylation regulated transcription of miR-146a and miR-140-5p. METHODS: Sixty male eight-week-old Sprague-Dawley rats were divided into three groups: normal group (normal healthy rats; no treatment), model group (OA rats; no treatment) and EA group (OA rats treated with EA). Safranin O staining and modified Mankin's score were performed to evaluate the histopathological alterations and degeneration of cartilage 8 weeks after 8 consecutive weeks of treatment. Quantitative real time polymerase chain reaction (qRT-PCR) assay was employed to evaluate the expression of miR-146a in the cartilage tissue and miR-140-5p in the synovium tissue, respectively. The bisulfite sequencing analysis and quantitative methylation specific PCR (qMSP) were used to analyze the status of methylation in the regulatory regions of miR-146a and miR-140-5p. Chromatin immunoprecipitation (ChIP) assay were performed to assess the binding of nuclear factor-kappa B (NF-κB) and signal transducer and activator of transcription 3 (SMAD-3) in the regulatory regions of miR-146a and miR-140-5p. Western blot analysis was performed to detect the expressions of DNA Methyltransferase 1 (DMNT1), DNA Methyltransferase 3A (DMNT3A), and DNA Methyltransferase 3A (DMNT3b), NF-κB, SMAD3 levels. RESULTS: Our results showed that EA treatment significantly upregulated miR-146a and miR-140-5p expressions. qMSP analysis showed that EA significantly decreased methylation levels of miR-140-5p regulated region and miR-146a promoter in OA cartilage and synovium. Bisulfite DNA sequencing (BDS) and ChIP analysis showed that EA significantly increased binding affinity of SMAD3 and NF-kB on the hypermethylated miR-140 regulatory region and miR-146a promoter, respectively. Western Blot analysis demonstrated that EA also significantly decreased expressions of methylation related proteins- DMNT1, DMNT3a, and DMNT3b as well as NF-κB and SMAD3. CONCLUSIONS: Electroacupuncture stimulating Neixiyan (EX-LE5) and Dubi (ST35) may alleviate OA affecting the DNA methylation regulated transcription of miR-146a and miR-140-5p.

A Study on the Potential Mechanism of Shujin Dingtong Recipe against Osteoarthritis Based on Network Pharmacology and Molecular Docking.

Background: With the aging of the social population, Osteoarthritis (OA) has already become a vital health and economic problem globally. Shujin Dingtong recipe (SJDTR) is an effective formula to treat OA in China. Although studies have shown that SJDTR can significantly alleviate OA symptoms, its mechanism still remains unclear. Purpose: This study is aimed at investigating the potential mechanism of SJDTR for the treatment of OA based on network pharmacology and molecular docking. Methods: Main ingredients of SJDTR were retrieved from the Traditional Chinese Medicine Systems Pharmacology (TCMSP) database. OA disease targets were obtained from the Gene Expression Omnibus (GEO) database. The overlapped targets and signaling pathways were explored using Protein-Protein Interaction (PPI) network, Gene Ontology (GO), and Kyoto Encyclopedia of Genes and Genomes (KEGG). Following this, the core targets were employed to dock with corresponding components via molecular docking in order to further explore the mechanism of SJDTR in the treatment of OA. Results: From network pharmacology, we found 100 active components of SJDTR, 31 drug and OA-related targets, 1161 GO items, and 91 signaling pathways. Based on the analysis with PPI network and molecular docking, TP53, CCNB1, and MMP-2 were selected for the core targets of SJDTR against OA. Molecular docking demonstrated that Quercetin, Baicalein, and Luteolin, had good binding with the TP53, CCNB1, and MMP-2 protein, respectively. Conclusion: To conclude, our study suggested the main ingredients of SJDTR might alleviate the progression of OA through multiple targets and pathways. Additionally, network pharmacology and molecular docking, as new approaches, were adopted for systematically exploring the potential mechanism of SJDTR for the treatment of OA.

[Study on mechanism of Rehmanniae Radix Praeparata for treatment of osteoarthritis based on network pharmacology and molecular docking].

The mechanism of Rehmanniae Radix Praeparata against osteoarthritis was investigated based on network pharmacology, molecular docking, and in vitro experiments in the present study. Osteoclast models were established via receptor activator of nuclear factor-κB ligand(RANKL) and macrophage colony-stimulating factor(M-CSF) inducing RAW264.7 cells. Further, the influence of Rehmanniae Radix Praeparata on the activity of tartrate-resistant acid phosphatase(TRAP) was evaluated and the efficacy of Rehmanniae Radix Praeparata in the treatment of osteoarthritis was verified. The active components of Rehmanniae Radix Praeparata were obtained from Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform(TCMSP) and literature, and the potential targets of the components were collected from SwissTargetPrediction. Osteoarthritis disease targets were searched in Online Mendelian Inheritance in Man(OMIM), Therapeutic Target Database(TTD), GeneCards, and DisGeNET. The intersection targets of Rehmanniae Radix Praeparata and osteoarthritis were obtained by Venny platform. The protein-protein interaction(PPI) network was constructed by Cytoscape 3.8.2, and key targets were obtained based on topology algorithm. The Database for Annotation, Visualization and Integrated Discovery(DAVID) was used to perform Gene Ontology(GO) and Kyoto Encyclopedia of Genes and Genomes(KEGG) pathway enrichment analysis. Finally, the mRNA expression of the key targets was determined by RT-qPCR and the binding activity between the components and key targets was validated by molecular docking. The results showed that Rehmanniae Radix Prae-parata inhibited the TRAP activity, thus inhibiting bone resorption by osteoclasts and treating osteoarthritis. By network pharmacology, 14 active components of Rehmanniae Radix Praeparata and 126 intersection targets were obtained. The network pharmacology enrichment results revealed 432 biological processes and 139 signaling pathways. Key targets such as proto-oncogene tyrosine-protein kinase Src(SRC), signal transducer and activator of transcription 3(STAT3) and transcription factor p65(RELA) were obtained according to the degree in topological analysis. SRC was highly expressed in osteoclasts, which accelerated the development of osteoarthritis. Therefore, SRC was selected for subsequent verification, and Rehmanniae Radix Praeparata decreased the gene expression level of SRC. The molecular docking showed that acteoside, isoacteoside, raffinose had good bonding activity with SRC, suggesting that they might be the critical components in treating osteoarthritis. In conclusion, Rehmanniae Radix Praeparata can inhibit bone resorption by osteoclasts and balance the metabolism of articular cartilage and subchondral bone via acting on SRC, thus playing a therapeutic role in osteoarthritis. In addition, Rehmanniae Radix Praeparata may exert overall efficacy on osteoarthritis through other targets such as STAT3 and RELA, and other related pathways such as PI3 K-AKT and IL-17 signaling pathways.

Analyzing network pharmacology and molecular docking to clarify Duhuo Jisheng decoction potential mechanism of osteoarthritis mitigation.

As a classic remedy for treating Osteoarthritis (OA), Duhuo Jisheng decoction has successfully treated countless patients. Nevertheless, its specific mechanism is unknown. This study explored the active constituents of Duhuo Jisheng decoction and the potential molecular mechanisms for treating OA using a Network Pharmacology approaches. Screening active components and corresponding targets of Duhuo parasite decoction by traditional Chinese medicine systems pharmacology database and analysis platform database. Combining the following databases yielded OA disease targets: GeneCards, DrugBank, PharmGkb, Online Mendelian Inheritance in Man, and therapeutic target database. The interaction analysis of the herb-active ingredient-core target network and protein-protein interaction protein network was constructed by STRING platform and Cytoscape software. Gene ontology functional enrichment analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment analysis were carried out. PyMOL and other software were used to verify the molecular docking between the essential active components and the core target. 262 active ingredients were screened, and their main components were quercetin, kaempferol, wogonin, baicalein, and beta-carotene. 108 intersection targets of disease and drug were identified, and their main components were RELA, FOS, STAT3, MAPK14, MAPK1, JUN, and ESR1. Gene ontology analysis showed that the key targets were mainly involved in biological processes such as response to lipopolysaccharide, response to xenobiotic stimulus, and response to nutrient levels. The results of Kyoto Encyclopedia of Genes and Genomes analysis show that the signal pathways include the AGE - RAGE signaling pathway, IL - 17 signaling pathway, TNF signaling pathway, and Toll - like receptor signaling pathway. Molecular docking showed that the main active components of Duhuo parasitic decoction had a good bonding activity with the key targets in treating OA. Duhuo Jisheng decoction can reduce the immune-inflammatory reaction, inhibit apoptosis of chondrocytes, strengthen proliferation and repair of chondrocytes and reduce the inflammatory response in a multi-component-multi-target-multi-pathway way to play a role in the treatment of OA.

[Progress of researches on acupuncture-moxibustion treatment of cartilage damage of osteoarthritis].

Cartilage damage is the key pathological mechanism in the progressive development of osteoarthritis(OA). Slowing down cartilage damage and accelerating cartilage repair are strategies for effective treatment of OA. Acupuncture and moxibustion therapies are widely used in relieving symptoms of OA and have a protective effect on cartilage. In this paper, we reviewed the mechanisms of acupuncture and moxibustion underlying relieving cartilage damage from three aspects: 1) promoting chondrocyte homeostasis by inhibiting apoptosis and improving cellular autophagy, 2) regulating extracellular matrix (ECM) metabolism (inhibiting decomposition and promoting synthesis) by suppressing the release of inflammatory factors and the activity of proteolytic enzymes, and 3) improving OA microenvironment by reducing the number of macrophagocyte 1 (M1) and increasing the ratio of M2/M1 in the local inflammatory locus. In addition, most studies on the mechanisms of acupuncture and moxibustion underlying remission of OA focus on the improvement of pathological changes, such as joint histopathology, cartilage morphology, synovial inflammatory reaction and infiltration, subchondral bone remodeling, etc., thus, the exact functions of acupuncture and moxibustion in ameliorating cartilage injury remain unknown. In view of the important role of mitochondrial dysfunction in promoting OA development and cartilage damage and the current use of tissue engineering methods of chondrocytes and mesenchymal stem cells to repair articular cartilage injury, it is highly recommended that future studies should pay more attention to these aspects.

Potential role of nutraceuticals via targeting a Wnt/ß-catenin and NF-κB pathway in treatment of osteoarthritis.

Osteoarthritis (OA) is a disease due to the aging of the articular cartilage, a post-mitotic tissue that stays functioning until primary homeostatic processes fail. Because of pain and disability, OA significantly influences national healthcare expenses and patient quality of life. It is a whole-joint illness characterized by inflammatory and oxidative signaling pathways and significant epigenetic alterations that cause cartilage extracellular matrix degradation. The canonical Wnt pathway (Wnt/ß-catenin pathway) and nuclear factor kappa B (NF-κB) signaling pathways may function in joint tissues by modulating the activity of synovial cells, osteoblasts, and chondrocytes. However, finding innovative ways to treat osteoarthritis and get the joint back to average balance is still a struggle. Nutraceuticals are dietary supplements that promote joint health by balancing anabolic and catabolic signals. New therapeutic methods for OA treatment have been developed based on many research findings that show nutraceuticals have strong anti-inflammation, antioxidant, anti-bone resorption, and anabolic properties. For the treatment of osteoarthritis, we explore the possible involvement of nutraceuticals that target the Wnt/ß-catenin and NF-κB pathways. PRACTICAL APPLICATIONS: In keeping with the aging population, osteoarthritis is becoming more widespread. In this extensive research, we studied the role of the Wnt/ß-catenin and NF-κB pathway in OA formation and progression. Nutraceuticals that target these OA-related signaling pathways are a viable therapy option. Wnt/ß-catenin and NF-κB signaling pathway are inhibited by polyphenols, flavonoids, alkaloids, and vitamins from the nutraceutical category, making them possible therapeutic drugs for OA therapy.

Drugging the circadian clock feedback cycle to ameliorate cartilage degeneration.

Dampened peripheral clocks have been linked to osteoarthritis (OA), yet it is unclear whether drugging the clock can ameliorate OA. Given that RORs and REV-ERBs mediate respectively, positive and negative transcriptional feedback of the master clock gene BMAL1, we investigate whether RORs agonist Nobiletin (NOB) and SR1078, and REV-ERBs antagonist SR8278 can enhance BMAL1 expression and attenuate cartilage degeneration. NOB and SR8278 promoted BMAL1 expression and elicited mitigating effects against IL-1ß-induced degeneration of cartilage explants, as evidenced by increased cellular density and collagen synthesis along with alleviated catabolism and collagen denaturation. Despite promoted BMAL1 expression, SR1078 concomitantly suppressed chondrocyte anabolism and catabolism. Consistent with these findings, NOB and SR8278 treatment, but not SR1078, effectively attenuated structural destruction of articular cartilage in surgery-induced OA mouse models. Notably, the beneficial effects of NOB and SR8278 were evidently observed in IL-1ß-induced degeneration of human cartilage explants and immortalized human chondrocytes. Moreover, BMAL1 knockdown assays indicated that NOB and SR8278 enhanced clock function and concordantly rendered protection against altered anabolism and catabolism in a BMAL1-dependent regime. Collectively, our study suggests that targeting RORs and REV-ERBs to promote the dampened peripheral clocks could be a route taken to apply chronotherapy within the context of OA.

Molecular mechanism analysis of Miao medicine Jinwujiangu decoction in treating osteoarthritis based on a network pharmacology approach.

OBJECTIVE: To investigate molecular mechanisms of Jinwujiangu decoction (, JWJG) in treating osteoarthritis (OA) using network pharmacology analysis. METHODS: Principal active compounds of JWJG were screened out via the Traditional Chinese Medicine Systems Pharmacology Database and Analysis Platform (TCMSP) and BATMAN-TCM, and potential targets for OA treatment were identified through Online Mendelian Inheritance in Man (OMIM) and GeneCards databases. The JWJG network diagrams of both principal chemical compound-action targets and OA treatment target-OA disease were constructed applying the Cytoscape 3.7.2 software. The diagram of protein-protein interaction network was plotted for core analysis. Meanwhile, the common targets and relevant signaling pathways involved in both networks were analyzed using the Gene Ontology function analysis and Kyoto Encyclopedia of Genes and Genomes pathway enrichment. The predicted results were ultimately verified through animal experiments. RESULTS: Effects of JWJG were indicated in acting on key targets interleukin-6, insulin, protein kinase B, glyceraldehyde-3-phosphate dehydrogenase, and mitosis-specific MRE11-RAD50-NBS1 associated protein by regulating signaling pathways of phosphoinositide 3-kinase- protein kinase B, mitogen-activated protein kinases, tumor necrosis factor, and colorectal cancer. Meanwhile, it inhibited the over-activation of signaling pathways and the release of inflammatory factors in OA treatment. Following a signaling pathway analysis utilizing network pharmacology technique, it was demonstrated that JWJG could treat OA through the Wnt/ß-catenin signaling pathway verified by animal experiments. CONCLUSIONS: The present study preliminarily analyzed the pharmacological mechanism of JWJG in treating OA on a network pharmacology approach and provided a great theoretical significance for clinical application.

Safranal Treatment Induces Sirt1 Expression and Inhibits Endoplasmic Reticulum Stress in Mouse Chondrocytes and Alleviates Osteoarthritis Progression in a Mouse Model.

Osteoarthritis (OA) is an age-related degenerative disease. Oxidative stress (OS) modulates OA pathogenesis by enhancing chondrocyte apoptosis and extracellular matrix (ECM) degeneration via activation of the endoplasmic reticulum (ER) stress. Prior studies revealed that safranal plays a critical role in multiple diseases treatments, but there are no reports on its effect on OA. Therefore, investigating the effect of safranal on OA is needed. As a compound that can lead excessive reactive oxygen species (ROS) accumulation, tert-butyl hydroperoxide (TBHP) was used to induce OS and OS-mediated endoplasmic reticulum (ER) stress for imitating OA in vitro. Besides, the bilateral medial meniscus was removed to induce joint instability and excessive friction of the joint surface to establish destabilization of medial meniscus for imitating the initiation and progression of OA in vivo. We, next, conducted Western blot and RT-PCR analyses to identify biomarkers of the underlying signaling pathway. Our results demonstrated that 30 µM safranal strongly upregulated Sirt1 expression, suppressed TBHP-mediated ER stress, and, in turn, prevented chondrocyte apoptosis and ECM degeneration. Furthermore, compared with the other two classic signaling pathways of ER stress, safranal can inhibit the PERK-eIF2α-CHOP axis at the lower concentration (5 and 15 µM). In vivo, using Safranin O staining, X-ray, immunofluorescence (IF), and immunohistochemical (IHC) staining, we demonstrated that OA progression can be postponed with intraperitoneal injection of 90 and 180 mg/kg safranal in an OA mouse model. Taken together, our analyses revealed that safranal can potentially prevent OA development.

Ginsenoside Rb1 from Panax ginseng attenuates monoiodoacetate-induced osteoarthritis by inhibiting miR-21-5p/FGF18-mediated inflammation.

Ginsenoside Rb1 (Rb1) is a major active compound in Panax ginseng and has shown considerable anti-inflammation effects. Osteoarthritis (OA) is one of the major degenerative disorders affecting the knee. MiR-21-5p is a potential therapeutic target for OA treatment. This study explored the anti-OA effects of Rb1 by focusing on its interaction with the miR-21-5p/FGF18 axis. OA was induced in rats using monoiodoacetate (MIA) and managed with Rb1. Then, changes in the histological structure and miR-21-5p-mediated signaling pathway were measured in joint tissues. The role of miR-21-5p/FGF18 in the anti-OA effects of Rb1 was confirmed by inducing its levels in rats and chondrocytes. Rb1 improved the histological structure and suppressed the production of cytokines in joint tissues. At the molecular level, Rb1 down-regulated miR-12-5p levels and up-regulated FGF18 levels. In chondrocytes, Rb1 increased cell viability, suppressed inflammation, down-regulated miR-21-5p levels, and up-regulated FGF18 levels. The restored level of miR-21-5p compromised the anti-OA effects of Rb1. In a nutshell, our study reported that the anti-OA effects of Rb1 relied on the inhibited expression of miR-21-5p. PRACTICAL APPLICATIONS: Ginsenoside Rb1 (Rb1) is a major active compound in Panax ginseng and has shown considerable anti-osteoarthritis (OA) effects. The current study not only relates the anti-OA function of ginsenoside Rb1 with microRNA but also provides valuable information for exploring novel targets for the development the anti-OA strategies.

Integrating Network Pharmacology and Experimental Validation to Explore the Key Mechanism of Gubitong Recipe in the Treatment of Osteoarthritis.

Background: Gubitong Recipe (GBT) is a prescription based on the Traditional Chinese Medicine (TCM) theory of tonifying the kidney yang and strengthening the bone. A previous multicentral randomized clinical trial has shown that GBT can effectively relieve joint pain and improve quality of life with a high safety in treating osteoarthritis (OA). This study is aimed at elucidating the active compounds, potential targets, and mechanisms of GBT for treating OA. Method: The network pharmacology method was used to predict the key active compounds, targets, and mechanisms of GBT in treating OA. An OA rat model was established with Hulth surgery, and the pathological changes of articular cartilage were observed to evaluate the effects of GBT. Chondrocytes were stimulated with LPS to establish in vitro models, and key targets and mechanisms predicted by network pharmacology were verified via qRT-PCR, ELISA, western blot, and immunofluorescence. The Contribution Index Model and molecular docking were used to determine the key active compounds of GBT and the major nodes affecting predicted pathways. Result: A total of 500 compounds were acquired from related databases, where 87 active compounds and their 254 corresponding targets were identified. 2979 OA-related genes were collected from three databases, 150 of which were GBT-regulating OA genes. The compound-target network weight analysis and PPI results showed that IL-6 and PGE2 are key targets of GBT in treating OA. KEGG results showed that PI3K/AKT, Toll-like receptor, NFκB, TNF, and HIF-1 are the key signaling pathways. An in vivo experiment showed that GBT could effectively suppress cartilage degradation of OA rats. In vitro experiments demonstrated that GBT can inhibit the key targets of KEGG-related pathways. Molecular-docking results suggested that luteolin, licochalcone A, and ß-carotene were key targets of GBT, and the mechanisms may be associated with the NFκB signaling pathway. Blockage experiments showed that the NFκB pathway is the key pathway of GBT in treating OA. Conclusion: This study verified that GBT can effectively protect articular cartilage through multitarget and multipathway, and its inhibitory effect on the NFκB pathway is the most key mechanism in treating OA.

4cRNA NEAT1 Sponge Adsorption of miR-378 Modulates Activity of Lipopolysaccharide-treated Articular Chondrocytes and Influences the Pathological Development of Osteoarthritis.

Context: Osteoarthritis (OA) is a chronic joint disease that can eventually lead to degeneration, fibrosis, fractures, and defects of the articular cartilage. Long non-coding RNA (lncRNA) is a key substance in many processes, such as epigenetic regulation and cell-cycle and cell-differentiation modulation, and its relationship with OA has been repeatedly verified. Objective: The study intended to clarify the influence of lncRNA nuclear enriched abundant transcript 1 (NEAT1), lncRNA NEAT1, on lipopolysaccharide (LPS)-induced OA chondrocytes through sponge adsorption of microRNA-378 (miR-378) and to provide novel insights into future diagnosis and treatment of OA. Design: The research team performed an animal study. Setting: The study took place in the Department of Rehabilitation Medicine at Linyi People's Hospital in Linyi, Shangdong, China. Animals: The study's animals were 10 Sprague Dawley (SD) rats, 3-5 days old and 10-15 g in weight, of the specific-pathogen-free (SPF) grade. Intervention: The rat chondrocytes for the positive control group (the model group) were treated with 500 ng/mL of LPS to induce OA. Chondrocytes treated with the same amount of normal saline were used as the negative control group. The chondrocytes of the LPS-induced rats were into six groups: (1) a positive control group transfected with NEAT1-interfering RNA, the sh-NEAT1 group; (2) a negative control group not transfected with NEAT1-interfering RNA, the NEAT1 empty vector (NC-NEAT1) group; (3) an intervention group co-transfected with NEAT1 interfering RNA and the miR-378 inhibitor sequence (Inh-miR-378 the sh-NEAT1+ Inh-miR-378 group; (4) a negative control group transfected with NEAT1 interfering RNA but not transfected with the miR-378 inhibitor sequence, the sh-NEAT1+ miR-378 negative control (NC-miR-378) group; (5) a negative control group transfected with the miR-378 inhibitor sequence but not transfected with NEAT1 interfering RNA, the NEAT1 empty vector (NC-NEAT1) + Inh-miR-378 group; (6) a negative control group not transfected with either NEAT1 interfering RNA or the miR-378 inhibitor sequence, the NC-NEAT1 + NC-miR-378 group. Outcome Measures: An OA-chondrocyte model was induced by LPS and measurements of NEAT1 and miR-378 expression were made by real-time quantitative reverse transcription (qRT)- polymerase chain reaction (PCR). Then, small NEAT1-interfering RNA (sh-NEAT1), empty vector NEAT1 (NC-NEAT1), inhibitor-sequence-miR-378 (Inh-miR-378), and negative-control-miR-378 (NC-miR-378) were transfected into cells, and cell viability and apoptosis rate were measured. Finally, the study verified the relationship between NEAT1 and miR-378. Results: Compared to the control group, NEAT1 was significantly elevated in the model group, and its miR-378 was significantly decreased. Silencing NEAT1 can enhance OA-chondrocyte activity and decrease apoptosis. When NEAT1 and miR-378 were inhibited together, as shown fort the NC-NEAT1 + NC-miR-378 group, NEAT1 expression, as well as the multiplication and apoptosis ability of the OA-model cells, were the same as those of cells transfected with an empty vector, the NC-NEAT1 group. Also, the NEAT1 + NC-miR-378 group's cell activity was lower than that of the sh-NEAT1+NC-miR-378 group but higher than that of the NC-NEAT1 + Inh-miR-378 group. Finally, higher fluorescence activity occurred for NEAT1-mutant type (MUT) transfected with Inh-miR-378. Conclusions: NEAT1, which is highly expressed in OA, mediates LPS-induced OA-chondrocyte activity through sponge adsorption of miR-378.

Fibrin deposition associates with cartilage degeneration in arthritis.

BACKGROUND: Cartilage damage in inflammatory arthritis is attributed to inflammatory cytokines and pannus infiltration. Activation of the coagulation system is a well known feature of arthritis, especially in rheumatoid arthritis (RA). Here we describe mechanisms by which fibrin directly mediates cartilage degeneration. METHODS: Fibrin deposits were stained on cartilage and synovial tissue of RA and osteoarthritis (OA) patients and in murine adjuvant-induced arthritis (AIA) in wild-type or fibrinogen deficient mice. Fibrinogen expression and procoagulant activity in chondrocytes were evaluated using qRT-PCR analysis and turbidimetry. Chondro-synovial adhesion was studied in co-cultures of human RA cartilage and synoviocytes, and in the AIA model. Calcific deposits were stained in human RA and OA cartilage and in vitro in fibrinogen-stimulated chondrocytes. FINDINGS: Fibrin deposits on cartilage correlated with the severity of cartilage damage in human RA explants and in AIA in wild-type mice, whilst fibrinogen deficient mice were protected. Fibrin upregulated Adamts5 and Mmp13 in chondrocytes. Chondro-synovial adhesion only occurred in fibrin-rich cartilage areas and correlated with cartilage damage. In vitro, autologous human synoviocytes, cultured on RA cartilage explants, adhered exclusively to fibrin-rich areas. Fibrin co-localized with calcification in human RA cartilage and triggered chondrocyte mineralization by inducing pro-calcification genes (Anx5, Pit1, Pc1) and the IL-6 cytokine. Similar fibrin-mediated mechanisms were observed in OA models, but to a lesser extent and without pseudo-membranes formation. INTERPRETATION: In arthritis, fibrin plaques directly impair cartilage integrity via a triad of catabolism, adhesion, and calcification. FUNDING: None.

Bioinformatics analysis combined with experimental validation to explore the mechanism of XianLing GuBao capsule against osteoarthritis.

ETHNOPHARMACOLOGICAL RELEVANCE: XianLing GuBao Capsule (XLGB) is often used to treat osteoarthritis (OA), osteoporosis, fractures, and other musculoskeleton disorders. However, the molecular mechanism of XLGB for treating OA is still unclear. AIM OF THE STUDY: This study set out to uncover the molecular mechanism underlying the treatment of osteoarthritis with XLGB. MATERIALS AND METHODS: Disease genes were obtained from CTD, DisGeNET, and GeneCards databases, and XLGB drug targets were obtained from ETCM and target genes predicted by XLGB metabolic components reported in the literature. Then we used the Venn diagram viewer to extract disease and drug intersection genes as potential therapeutic genes for Protein-protein interaction (PPI), GO terminology, and KEGG pathway analysis. Subsequently, we performed qRT-PCR, Western blot and histological analysis to validate the therapeutic effect of XLGB against OA and its molecular mechanism. RESULTS: A total of 1039 OA genes and 949 XLGB target genes were collected, and finally 188 potential therapeutic target genes were obtained. PPI network analysis indicated that the main target genes for XLGB to treat OA include Akt1, Mapk3, Il-6, Il-1ß, Ptgs2, Mmp9, etc. The results of KEGG and GO enrichment analysis suggested that XLGB may treat OA by anti-inflammatory and reducing extracellular matrix degradation. In vitro, XLGB down-regulated the expressions of Mmp3, Mmp9, Mmp12, Mmp13, Cox-2, Il-6, increased the expression of Collagen II and Sox9. Mechanistically, XLGB inhibits the activation of PI3K/AKT/NF-κB and MAPK pathways. Moreover, the results of animal experiments indicated that XLGB reduced cartilage destruction, bone resorption, and synovitis in osteoarthritic rats. CONCLUSIONS: XLGB has a protective effect against OA by suppressing PI3K/AKT/NF-κB and MAPK signaling. Our study provides a theoretical basis for XLGB in the treatment of osteoarthritis.

Interdisciplinary management of FGF23-related phosphate wasting syndromes: a Consensus Statement on the evaluation, diagnosis and care of patients with X-linked hypophosphataemia.

X-linked hypophosphataemia (XLH) is the most frequent cause of hypophosphataemia-associated rickets of genetic origin and is associated with high levels of the phosphaturic hormone fibroblast growth factor 23 (FGF23). In addition to rickets and osteomalacia, patients with XLH have a heavy disease burden with enthesopathies, osteoarthritis, pseudofractures and dental complications, all of which contribute to reduced quality of life. This Consensus Statement presents the outcomes of a working group of the European Society for Clinical and Economic Aspects of Osteoporosis, Osteoarthritis and Musculoskeletal Diseases, and provides robust clinical evidence on management in XLH, with an emphasis on patients' experiences and needs. During growth, conventional treatment with phosphate supplements and active vitamin D metabolites (such as calcitriol) improves growth, ameliorates leg deformities and dental manifestations, and reduces pain. The continuation of conventional treatment in symptom-free adults is still debated. A novel therapeutic approach is the monoclonal anti-FGF23 antibody burosumab. Although promising, further studies are required to clarify its long-term efficacy, particularly in adults. Given the diversity of symptoms and complications, an interdisciplinary approach to management is of paramount importance. The focus of treatment should be not only on the physical manifestations and challenges associated with XLH and other FGF23-mediated hypophosphataemia syndromes, but also on the major psychological and social impact of the disease.

Selenophosphate synthetase 1 deficiency exacerbates osteoarthritis by dysregulating redox homeostasis.

Aging and mechanical overload are prominent risk factors for osteoarthritis (OA), which lead to an imbalance in redox homeostasis. The resulting state of oxidative stress drives the pathological transition of chondrocytes during OA development. However, the specific molecular pathways involved in disrupting chondrocyte redox homeostasis remain unclear. Here, we show that selenophosphate synthetase 1 (SEPHS1) expression is downregulated in human and mouse OA cartilage. SEPHS1 downregulation impairs the cellular capacity to synthesize a class of selenoproteins with oxidoreductase functions in chondrocytes, thereby elevating the level of reactive oxygen species (ROS) and facilitating chondrocyte senescence. Cartilage-specific Sephs1 knockout in adult mice causes aging-associated OA, and augments post-traumatic OA, which is rescued by supplementation of N-acetylcysteine (NAC). Selenium-deficient feeding and Sephs1 knockout have synergistic effects in exacerbating OA pathogenesis in mice. Therefore, we propose that SEPHS1 is an essential regulator of selenium metabolism and redox homeostasis, and its dysregulation governs the progression of OA.