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Osteoarthritis (OA) is generally considered to be characterized by progressive articular cartilage destruction. Increasing evidence demonstrates that CDK9, which is a member of cyclin-dependent kinase family, plays a significant role in the regulation of acute and chronic inflammatory diseases. IL-1β, a major proinflammatory cytokine, was used to establish a model of OA in vitro after stimulating chondrocytes. We found that CDK9 was highly expressed in in vitro and in vivo models of inflammation. The role of LDC000067 (abbreviated as LDC067), a specific inhibitor of CDK9, in protecting articular cartilage from immune response has not been fully clarified. Intriguingly, in this study, we demonstrated that LDC067 prevented IL-1β-induced production of metalloproteinases (MMPs) and inflammatory cytokines, including MMP3, MMP9, MMP13, IL-6, IL-8 and TNF-ɑ. Furthermore, we revealed that LDC067 inhibited IL-1β-induced NF-κB signaling pathway activation in chondrocytes. The inhibition of CDK9 could also delay cartilage degeneration in an anterior cruciate ligament transection (ACLT) mouse model in vivo. Taken together, these results highlighted the significance of this CDK9 inhibitor in preventing cartilage destruction and indicated that LDC067 might serve as a potential therapeutic agent for OA. • CDK9 is upregulated in osteoarthritis cartilage and is correlated with the severity of OA. • The specific inhibitor of CDK9, LDC067 attenuates the catabolism and hypertrophic changes of chondrocytes in vitro. • LDC067 suppresses the activation of the NF-κB signaling pathway. • LDC067 ameliorates OA cartilage destruction in vivo and may be a novel therapeutic agent. [ABSTRACT FROM AUTHOR]

Osteoarthritis (OA) has traditionally been defined as a non-inflammatory disease. Recently, many studies have demonstrated that OA also has an inflammatory component. BRD4, a member of the Bromodomain and Extra-Terminal Domain family, has emerged as an important regulator of some chronic inflammatory diseases. JQ1, an antagonist of BRD4, modulates transcription of several genes. Our study demonstrated that BRD4 is up-regulated in articular cartilage of OA. BRD4 inhibition attenuated the inflammation and catabolism of chondrocytes and suppressed NF-κB signalling pathway activation. In addition, BRD4 inhibition abolished the transcriptional activity of High Mobility Group Protein B1 (HMGB1). We identified HMGB1 as a direct target of BRD4. Genetic and pharmacological inhibition of BRD4 suppressed IL-1β-induced expression and translocation of HMGB1. Chromatin immunoprecipitation (ChIP) showed the enrichment of BRD4 around the HMGB1 upstream non-promoter region, which diminished with JQ1 treatment. Finally, haematoxylin & eosin and Safranin o/Fast Green staining demonstrated that JQ1 attenuates cartilage destruction in mice with anterior cruciate ligament transection without significant toxic effects. These studies highlighted the importance of BRD4 in the chronic inflammatory reactions of OA, which, as far as we know, was the first report of this finding, and suggested that BRD4 might be a novel potential therapeutic target for the treatment of OA. [ABSTRACT FROM AUTHOR]

The purinergic receptor P2X ligand-gated ion channel 3 (P2X3) is crucially involved in peripheral nociceptive processes of somatic and visceral pain. Endometriosis pain is considered as a kind of inflammatory and neuropathic pain. However, whether P2X3 is involved in endometriosis pain has not been reported up to date. Here, we aimed to determine whether P2X3 expression in endometriotic lesions is involved in endometriosis pain, which is regulated by inflammatory mediators through extracellular regulated protein kinases (ERK) signalling pathway. We found that P2X3 expressions in endometriosis endometrium and endometriotic lesions were both significantly higher as compared with control endometrium (P<0.05), and both positively correlated with pain (P<0.05). The expression levels of phosphorylated –ERK (p-ERK), phosphorylated-cAMP-response element binding protein (p-CREB), and P2X3 in endometriotic stromal cells (ESCs) were all significantly increased in comparison to the initial levels after treated with interleukin (IL)-1β (P<0.05) or adenosine triphosphate (ATP) (P<0.05), respectively, and did not increase after the ESCs were pre-treated with ERK1/2 inhibitor. Additionally, P2X3 and calcitonin gene related peptide (CGRP) were co-expressed in endometriotic lesions. These obtained results suggest that P2X3 might be involved in endometriosis pain signal transduction via ERK signal pathway. [ABSTRACT FROM AUTHOR]

Background: Osteoarthritis (OA) is widely recognized as the most common chronic joint disease accompanied by progressive cartilage and subchondral bone damage. Toddalolactone (TOD), a natural compound extracted from Toddalia asiatica (L.) Lam., has been widely used in the treatment of stroke, rheumatoid arthritis, and oedema. Nevertheless, what TOD acts as in the pathogenesis and progression of OA hasn't been reported. In this investigation, we have aimed to determine how TOD affects OA in vitro and in vivo. Methods: LPS (10 µg/ml) and IL-1β (10 ng/ml) were employed to induce chondrocyte inflammation or RANKL to induce osteoclast differentiation in bone marrow derived macrophages (BMMs). The effects of TOD on chondrocyte inflammation and osteoclast differentiation were evaluated. Anterior cruciate ligament transection (ACLT) was performed to develop an OA animal model and study the effects of TOD. Results: We found that TOD inhibited the expression of inflammatory and catabolic mediators (IL-6, IL-8, TNF-α, MMP2, MMP9, and MMP13) in inflammatory chondrocytes in vitro. Furthermore, TOD was proven to inhibit RANKL-induced-osteoclastogenesis and inhibit the expression of osteoclast marker genes. Our data also confirmed that TOD suppressed the destruction of articular cartilage and osteoclastogenesis via inhibiting the activation of NF-κB and MAPK signalling pathways. In the ACLT mouse model, we found that TOD attenuated cartilage erosion and inhibited bone resorption. Conclusions: These results showed that TOD can be adopted as a potential therapeutic agent for OA. [ABSTRACT FROM AUTHOR]

Background: Endometriosis is defined as a chronic inflammatory disease. Recent studies have shown that increased coagulation parameters including fibrinogen and platelets are associated with endometriosis. The objective of this study was to determine the levels of inflammatory markers and coagulation parameters and their correlations in women with endometriomas compared to those with benign ovarian cysts or normal pelvic anatomy.Methods: Between June 2015 and June 2017, a total of 548 women who underwent laparoscopic/laparotomic surgery for ovarian endometriomas (OMA group, n = 226), non-endometriosis benign ovarian cysts (Cyst group, n = 210) and tubal reanastomosis (Control group, n = 112) were recruited in this study. Inflammatory markers including c-reactive protein (CRP), neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR) and coagulation parameters including platelet count, thrombin time (TT), prothrombin time (PT), activated partial thromboplastin time, and plasma fibrinogen as well as CA-125 were determined.Results: Compared with Cyst group and Control group, TT and PT in OMA group were significantly shorter and plasma fibrinogen levels were significantly higher (P < 0.05). Moreover, the levels of plasma fibrinogen were positively correlated with CRP, NLR and PLR (P < 0.05). In addition, the confidence intervals for the area under the curve (AUC) for CA-125 × fibrinogen were significantly higher than those for CA-125 (0.904-0.952 vs. 0.899-0.949) in the diagnosis of endometrioma.Conclusions: These results indicate that women with endometriomas demonstrate a hypercoagulable status due to the inflammatory nature of endometriosis. The combined determination for CA-125 and fibrinogen demonstrate a higher area under the curve than the single detection of CA-125 in those with endometriomas compared to these with benign ovarian cysts.Trial Registration: This study was approved by the Human Ethics Committee of the Women's Hospital, School of Medicine, Zhejiang University (No.20170174) and all women provided written informed consent. [ABSTRACT FROM AUTHOR]

We aimed to identify RNA N6-methyladenosine methylation associated genes in osteoarthritis (OA), and to explore possible regulatory mechanisms of these RNA methylation associated genes. Bioinformatics analyses, including differential expression analysis, functional enrichment analysis, verification analysis, and box plot analysis, were conducted based on different datasets from OA and non-OA patients. Gene expression at mRNA and protein levels was determined by quantitative reverse transcription PCR, western blot and immunofluorescence. Interleukin 1β (IL-1β)-treated SW1353 cells was used as cell model. Lentiviral vector was used for over-expression METTL3 in vitro. CCK-8 assay kit was used to determine cell viability and inflammatory cytokines (IL-1α, IL-6, IL-8, IL-10 and TNF-α) was detected using ELISA kits. Bioinformatics analysis showed that METTL3 expression was decreased in OA group, which was confirmed in clinical samples. Expression of METTL3 was also reduced in IL-1β-treated cells. Levels of inflammatory cytokines were obviously reduced in the METTL3 overexpression group, while IL-1β treatment reversed such decrease caused by METTL3 overexpression (p < 0.05). Both METTL3 overexpression and IL-1β treatment promoted expression of p65 protein and p-ERK (p < 0.01). Additionally, increased expression of MMP1 and MMP3 , and decreased expression of MMP13 , TIMP-1 , and TIMP-2 at both mRNA and protein levels were observed in the METTL3 overexpression group when compared with the control group (p < 0.01). Expression of m6A methylation gene METTL3 was reduced in OA. METTL3 is involved in OA probably by regulating the inflammatory response. METTL 3 overexpression may affect extracellular matrix degradation in OA by adjusting the balance between TIMPs and MMPs. • METTL3 and YTHDC2 were identified as m6A methylation-related genes in OA. • METTL3 may be involved in OA by regulating the inflammatory response. • METTL3 overexpression may affect ECM degradation in OA. [ABSTRACT FROM AUTHOR]

• EsA attenuates inflammation and catabolism of chondrocytes. • EsA restrains RANKL-induced osteoclast formation. • Treatment with EsA suppresses NF-κB and MAPK signalling pathway activation in vitro. • EsA protects OA cartilage in vivo and may be a novel therapeutic target. Osteoarthritis is a relatively common disorder of articular deterioration related to cartilage damage, subchondral bone remodelling, inflammation and metabolism. Agents that can inhibit cartilage degradation and osteoclastogenesis are required for the prevention and treatment of osteoarthritis. Esculentoside A, the highest concentration triterpene saponin isolated from the root of Phytolacca esculenta, has commonly been used for the treatment of chronic bronchitis. However, the role esculentoside A plays in ameliorating osteoarthritis has not been reported. We found that esculentoside A suppresses the expression of IL-1β-induced inflammatory and metabolic factors (IL-6, IL-8, TNF-α, MMP2, MMP3 and MMP13). In addition, esculentoside A restrains osteoclast formation by inhibiting the marker gene expression of NFATc1 and c-Fos. Our results indicate that esculentoside A markedly suppresses IL-1β-induced NF-κB and MAPK signalling pathway activation in chondrocytes, and inhibits RANKL-induced osteoclast precursor generation. Finally, treatment with esculentoside A inhibits the progressive cartilage degeneration and osteoclastogenesis in osteoarthritis mouse models. In summary, these results demonstrate that esculentoside A could be a latent therapeutic reagent for the treatment of osteoarthritis. [ABSTRACT FROM AUTHOR]