Live and Dead Clostridium butyricum GKB7 Diminish Osteoarthritis Pain and Progression in Preclinical Animal Model.

Osteoarthritis (OA) is a degenerative joint disease primarily affecting the elderly. It is characterized by the progressive decline of joint cartilage and alterations in the underlying bone. Several probiotic strains have exhibited immunomodulatory and anti-inflammatory properties. Here, we examined the functions of live and dead Clostridium butyricum GKB7 (GKB7-L and GKB7-D) in a preclinical anterior cruciate ligament transection (ACLT)-enhanced OA procedure. Oral administration of GKB7-L and GKB7-D ameliorated ACLT-induced bone pain as assessed by weight-bearing behavioral testing but did not affect body weight. Micro-computed tomography (CT) results showed that GKB7-L and GKB7-D diminished ACLT-induced bone destruction and loss. GKB7-L and GKB7-D-enriched therapies also reduced ACLT-induced production of the pro-inflammatory cytokines interleukin (IL)-1ß and tumor necrosis factor (TNF)-α, as well as the chondrolytic factor matrix metalloproteinase (MMP)-3, leading to inhibition of aggrecan and collagen type II degradation and thereby blocking cartilage breakdown. We therefore suggest that oral supplementation with GKB7-L or GKB7-D can be beneficial in the prevention and treatment of OA.

FGF23 facilitates IL-1ß synthesis in rheumatoid arthritis through activating PI3K, Akt, and NF-κB pathways.

Rheumatoid arthritis (RA) is a well-known autoimmune disorder related with joint pain, joint swelling, cartilage and bone degradation as well as deformity. Fibroblast growth factor 23 (FGF23) is an endocrine factor of the FGF family primarily produced by osteocytes and osteoblasts, involves an essential effect in pathogenesis of RA. IL-1ß is a vital proinflammatory factor in the development of RA. However, the role of FGF23 on IL-1ß synthesis in RA has not been fully explored. Our analysis of database revealed higher levels of FGF23 and IL-1ß in RA samples compared with healthy controls. High-throughput screening demonstrated that IL-1ß is a potential candidate factor after FGF23 treatment in RA synovial fibroblasts (RASFs). FGF23 concentration dependently promotes IL-1ß synthesis in RASFs. FGF23 enhances IL-1ß expression by activating the PI3K, Akt, and NF-κB pathways. Our findings support the notion that FGF23 is a promising target in the remedy of RA.

Visfatin Polymorphisms, Lifestyle Risk Factors and Risk of Oral Squamous Cell Carcinoma in a Cohort of Taiwanese Males.

Oral cancer is the eighth greatest generally diagnosed cancer amongst males worldwide and the fourth most generally malignancy amongst Taiwanese males. The pro-inflammatory adipocytokine visfatin promotes tumor growth. Elevated plasma visfatin levels have been identified in patients with oral squamous cell carcinoma (OSCC), although the biological mechanisms underlying the involvement of visfatin in the pathogenesis of OSCC are not well understood. Moreover, no information is available regarding associations between visfatin polymorphisms and carcinogenic lifestyle factors with OSCC. This study, therefore, investigated the effects of four visfatin gene polymorphisms (rs11977021, rs61330082, rs2110385, and rs4730153) and carcinogenic lifestyle factors (betel nut chewing, alcohol consumption and cigarette smoking) on the risk of developing OSCC in 1,275 Taiwanese males with OSCC, and 1,195 healthy males (controls). We also examined the associations between these visfatin genotypes and OSCC histopathological prognostic factors (pathological stage, tumor status, lymph node status, and metastasis). We found that compared with subjects with the CC genotype of SNP rs11977021, those with the CT+TT genotype were less likely to progress OSCC. In addition, an association was found between the rs4730153 variant and lymph node metastasis in the OSCC cohort.

miR-144-3p ameliorates the progression of osteoarthritis by targeting IL-1ß: Potential therapeutic implications.

The pro-inflammatory cytokine interleukin 1 beta (IL-1ß) plays a critical role in osteoarthritis (OA) disease pathogenesis. MicroRNA (miRNA) activity is related to inflammation in OA and some miRNAs specifically regulate IL-mediated degradation of cartilage type II collagen. Previous studies have indicated that miR-144-3p is a useful target in the regulation of pro-inflammatory cytokines in different diseases. However, the role of miR-144-3p in OA is unclear. In this study, we observed a negative correlation between miR-144-3p and IL-1ß expression in OA. miR-144-3p mimic transfection of OA synovial fibroblasts downregulated levels of IL-1ß expression, while blocking the MAPK, PI3K/Akt, and NF-κB signaling pathways relating to IL-1ß production, and effectively increased miR-144-3p expression in OASFs. Findings from an anterior cruciate ligament transection rat model revealed that administration of miR-144-3p mimic effectively ameliorated OA progression and reduced the numbers of IL-1ß-positive cells in synovial tissue. This study suggests that miR-144-3p is a useful therapeutic target in OA disease.

Targeting CCN Proteins in Rheumatoid Arthritis and Osteoarthritis.

The CCN family of matricellular proteins (CYR61/CCN1, CTGF/CCN2, NOV/CCN3 and WISP1-2-3/CCN4-5-6) are essential players in the key pathophysiological processes of angiogenesis, wound healing and inflammation. These proteins are well recognized for their important roles in many cellular processes, including cell proliferation, adhesion, migration and differentiation, as well as the regulation of extracellular matrix differentiation. Substantial evidence implicates four of the proteins (CCN1, CCN2, CCN3 and CCN4) in the inflammatory pathologies of rheumatoid arthritis (RA) and osteoarthritis (OA). A smaller evidence base supports the involvement of CCN5 and CCN6 in the development of these diseases. This review focuses on evidence providing insights into the involvement of the CCN family in RA and OA, as well as the potential of the CCN proteins as therapeutic targets in these diseases.

Chondroprotective Effects of a Histone Deacetylase Inhibitor, Panobinostat, on Pain Behavior and Cartilage Degradation in Anterior Cruciate Ligament Transection-Induced Experimental Osteoarthritic Rats.

Osteoarthritis (OA) is the most common articular degenerative disease characterized by chronic pain, joint inflammation, and movement limitations, which are significantly influenced by aberrant epigenetic modifications of numerous OA-susceptible genes. Recent studies revealed that both the abnormal activation and differential expression of histone deacetylases (HDACs) might contribute to OA pathogenesis. In this study, we investigated the chondroprotective effects of a marine-derived HDAC inhibitor, panobinostat, on anterior cruciate ligament transection (ACLT)-induced experimental OA rats. The intra-articular administration of 2 or 10 µg of panobinostat (each group, n = 7) per week from the 6th to 17th week attenuates ACLT-induced nociceptive behaviors, including secondary mechanical allodynia and weight-bearing distribution. Histopathological and microcomputed tomography analysis showed that panobinostat significantly prevents cartilage degeneration after ACLT. Moreover, intra-articular panobinostat exerts hypertrophic effects in the chondrocytes of articular cartilage by regulating the protein expressions of HDAC4, HDAC6, HDAC7, runt-domain transcription factor-2, and matrix metalloproteinase-13. The study indicated that HDACs might have different modulations on the chondrocyte phenotype in the early stages of OA development. These results provide new evidence that panobinostat may be a potential therapeutic drug for OA.

Rhodoptilometrin, a Crinoid-Derived Anthraquinone, Induces Cell Regeneration by Promoting Wound Healing and Oxidative Phosphorylation in Human Gingival Fibroblast Cells.

Gingival recession (GR) potentially leads to the exposure of tooth root to the oral cavity microenvironment and increases susceptibility to dental caries, dentin hypersensitivity, and other dental diseases. Even though many etiological factors were reported, the specific mechanism of GR is yet to be elucidated. Given the species richness concerning marine biodiversity, it could be a treasure trove for drug discovery. In this study, we demonstrate the effects of a marine compound, (+)-rhodoptilometrin from crinoid, on gingival cell migration, wound healing, and oxidative phosphorylation (OXPHOS). Experimental results showed that (+)-rhodoptilometrin can significantly increase wound healing, migration, and proliferation of human gingival fibroblast cells, and it does not have effects on oral mucosa fibroblast cells. In addition, (+)-rhodoptilometrin increases the gene and protein expression levels of focal adhesion kinase (FAK), fibronectin, and type I collagen, changes the intracellular distribution of FAK and F-actin, and increases OXPHOS and the expression levels of complexes I~V in the mitochondria. Based on our results, we believe that (+)-rhodoptilometrin might increase FAK expression and promote mitochondrial function to affect cell migration and promote gingival regeneration. Therefore, (+)-rhodoptilometrin may be a promising therapeutic agent for GR.

Excavatolide B Attenuates Rheumatoid Arthritis through the Inhibition of Osteoclastogenesis.

Osteoclasts are multinucleated giant cells of macrophage/monocyte lineage, and cell differentiation with the upregulation of osteoclast-related proteins is believed to play a major role in the destruction of the joints in the course of rheumatoid arthritis (RA). Pro-inflammatory cytokines, such as interleukin-17A (IL-17A) and macrophage colony-stimulating factor (M-CSF), can be overexpressed in RA and lead to osteoclastogenesis. In a previous study, we found that cultured-type soft coral-derived excavatolide B (Exc-B) exhibited anti-inflammatory properties. In the present study, we thus aimed to evaluate the anti-arthritic activity of Exc-B in in vitro and in vivo models. The results demonstrated that Exc-B inhibits LPS-induced multinucleated cell and actin ring formation, as well as TRAP, MMP-9, and cathepsin K expression. Additionally, Exc-B significantly attenuated the characteristics of RA in adjuvant (AIA) and type II collagen-induced arthritis (CIA) in rats. Moreover, Exc-B improved histopathological features, and reduced the number of TRAP-positive multinucleated cells in the in vivo AIA and CIA models. Immunohistochemical analysis showed that Exc-B attenuated the protein expression of cathepsin K, MMP-2, MMP-9, CD11b, and NFATc1 in ankle tissues of AIA and CIA rats. Level of interleukin-17A and macrophage colony-stimulating factor were also decreased by Exc-B. These findings strongly suggest that Exc-B could be of potential use as a therapeutic agent by inhibiting osteoclast differentiation in arthritis. Moreover, this study also illustrates the use of the anti-inflammatory marine compound, Exc-B, as a potential therapeutic strategy for RA.

Anti-Inflammatory and Analgesic Effects of the Marine-Derived Compound Excavatolide B Isolated from the Culture-Type Formosan Gorgonian Briareum excavatum.

In recent years, several marine-derived compounds have been clinically evaluated. Diterpenes are secondary metabolites from soft coral that exhibit anti-inflammatory, anti-tumor and cytotoxic activities. In the present study, we isolated a natural diterpene product, excavatolide B, from cultured Formosan gorgonian Briareum excavatum and investigated its anti-inflammatory activities. We found that excavatolide B significantly inhibited the mRNA expression of the proinflammatory mediators, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2), in lipopolysaccharide (LPS)-challenged murine macrophages (RAW 264.7). We also examined the anti-inflammatory and anti-nociceptive effects of excavatolide B on intraplantar carrageenan-induced inflammatory responses. Excavatolide B was found to significantly attenuate carrageenan-induced nociceptive behaviors, mechanical allodynia, thermal hyperalgesia, weight bearing deficits and paw edema. In addition, excavatolide B inhibited iNOS, as well as the infiltration of immune cells in carrageenan-induced inflammatory paw tissue.

Dihydroaustrasulfone Alcohol (WA-25) Impedes Macrophage Foam Cell Formation by Regulating the Transforming Growth Factor-ß1 Pathway.

Atherosclerosis is considered an inflammatory disease. However, clinically used anti-atherosclerotic drugs, such as simvastatin, have many side effects. Recently, several unique marine compounds have been isolated that possess a variety of bioactivities. In a previous study, we found a synthetic precursor of the marine compound (austrasulfone), which is dihydroaustrasulfone alcohol (WA-25), has anti-atherosclerotic effects in vivo. However, the detailed mechanisms remain unclear. Therefore, to clarify the mechanisms through which WA-25 exerts anti-atherosclerotic activity, we used RAW 264.7 macrophages as an in vitro model to evaluate the effects of WA-25. In lipopolysaccharide (LPS)-stimulated RAW 264.7 cells, WA-25 significantly inhibited expression of the pro-inflammatory proteins, inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2). In contrast, simvastatin increased the COX-2 expression compared to WA-25. In addition, WA-25 impedes foam cell formation and up-regulated the lysosomal and cyclic adenosine monophosphate (cAMP) signaling pathway. We also observed that transforming growth factor ß1 (TGF-ß1) was up-regulated by WA-25 and simvastatin in LPS-induced RAW 264.7 cells, and the promising anti-atherosclerosis effects of WA-25 were disrupted by blockade of TGF-ß1 signaling. Besides, WA-25 might act through increasing lipolysis than through alteration of lipid export. Taken together, these data demonstrate that WA-25 may have potential as an anti-atherosclerotic drug with anti-inflammatory effects.

Flexibilide obtained from cultured soft coral has anti-neuroinflammatory and analgesic effects through the upregulation of spinal transforming growth factor-ß1 in neuropathic rats.

Chronic neuroinflammation plays an important role in the development and maintenance of neuropathic pain. The compound flexibilide, which can be obtained from cultured soft coral, possesses anti-inflammatory and analgesic effects in the rat carrageenan peripheral inflammation model. In the present study, we investigated the antinociceptive properties of flexibilide in the rat chronic constriction injury (CCI) model of neuropathic pain. First, we found that a single intrathecal (i.t.) administration of flexibilide significantly attenuated CCI-induced thermal hyperalgesia at 14 days after surgery. Second, i.t. administration of 10-µg flexibilide twice daily was able to prevent the development of thermal hyperalgesia and weight-bearing deficits in CCI rats. Third, i.t. flexibilide significantly inhibited CCI-induced activation of microglia and astrocytes, as well as the upregulated proinflammatory enzyme, inducible nitric oxide synthase, in the ipsilateral spinal dorsal horn. Furthermore, flexibilide attenuated the CCI-induced downregulation of spinal transforming growth factor-ß1 (TGF-ß1) at 14 days after surgery. Finally, i.t. SB431542, a selective inhibitor of TGF-ß type I receptor, blocked the analgesic effects of flexibilide in CCI rats. Our results suggest that flexibilide may serve as a therapeutic agent for neuropathic pain. In addition, spinal TGF-ß1 may be involved in the anti-neuroinflammatory and analgesic effects of flexibilide.

Anti-inflammatory and analgesic effects of the marine-derived compound comaparvin isolated from the crinoid Comanthus bennetti.

To date, no study has been conducted to explore the bioactivity of the crinoid Comanthus bennetti. Here we report the anti-inflammatory properties of comaparvin (5,8-dihydroxy-10-methoxy-2-propylbenzo[h]chromen-4-one) based on in vivo experiments. Our preliminary screening for anti-inflammatory activity revealed that the crude extract of Comanthus bennetti significantly inhibited the expression of pro-inflammatory proteins in lipopolysaccharide (LPS)-stimulated murine RAW 264.7 macrophage cells. Comaparvin isolated from crinoids significantly decreased the expression of inducible nitric oxide synthase (iNOS) protein and mRNA in LPS-stimulated macrophage cells. Moreover, our results showed that post-treatment with comaparvin significantly inhibited mechanical allodynia, thermal hyperalgesia and weight-bearing deficits in rats with carrageenan-induced inflammation. Comaparvin also attenuated leukocyte infiltration and iNOS protein expression in carrageenan-induced inflamed paws. These results suggest that comaparvin is a potential anti-inflammatory therapeutic agent against inflammatory pain.

Effects of Etanercept on Experimental Osteoarthritis in Rats: Role of Histone Deacetylases.

OBJECTIVE: Mounting evidence suggests that histone deacetylases (HDAC) inhibitors reduce cartilage destruction in animal models of osteoarthritis (OA). Tumor necrosis factor (TNF)-α-blocking treatment for OA may provide effective joint protection by slowing joint damage. To investigate the effects of intraperitoneal administration of etanercept (a TNF-α inhibitor) on OA development in rats and changes in the nociceptive behavior of rats and expression of HDACs, RUNX2, and MMP13 in cartilage. METHODS: Induction of OA in Wistar rats was accomplished through anterior cruciate ligament transection (ACLT). One or five milligrams (mg) of etanercept was administered intraperitoneally for 5 consecutive weeks after ACLT to the ACLT + etanercept (1 and 5 mg/kg) groups. Nociceptive behavior and changes in knee joint width were analyzed. Cartilage was evaluated histologically and immunohistochemically. RESULTS: ACLT + etanercept significantly improved mechanical allodynia and weight-bearing distribution compared to ACLT alone. In OA rats treated with etanercept, cartilage degeneration and synovitis were significantly less pronounced than those in ACLT rats. OA-affected cartilage also showed reduced expression of HDAC 6, 7, RUNX-2, and MMP-13 in response to etanercept but increased expression of HDAC4. CONCLUSION: Our study demonstrated that etanercept therapy (1) attenuated the development of OA and synovitis in rats, (2) reduced nociception, and (3) regulated chondrocyte metabolism, possibly by inhibiting cell HDAC6 and HDAC7, RUNX2, and MMP13 and increasing HDAC4 expression. Based on new evidence, etanercept may have therapeutic potential in OA.

NGF facilitates ICAM-1-dependent monocyte adhesion and M1 macrophage polarization in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a chronic autoimmune inflammatory disorder in which monocytes adhering to synovial tissue differentiate into the pro-inflammatory M1 macrophage phenotype. Nerve growth factors (NGF) referred to as neurotrophins have been associated with inflammatory events; however, researchers have yet to elucidate the role of NGF in RA. Our examination of clinical tissue samples and analysis of data sourced from the Gene Expression Omnibus dataset unveiled elevated expression levels of M1 macrophage markers in human RA synovial tissue samples compared to normal tissue, with no such distinction observed for M2 markers. Furthermore, immunofluorescence data depicted increased expression levels of NGF and M1 macrophages in RA mice in contrast to normal mice. It appears that NGF stimulation facilitates macrophage polarization from the M0 to the M1 phenotype. It also appears that NGF promotes ICAM-1 production in human RA synovial fibroblasts, which enhances monocyte adhesion through the TrkA, MEK/ERK, and AP-1 signaling cascades. Our findings indicate NGF/TrkA axis as a novel target for the treatment of RA.

The joint protective function of live- and dead-Lactobacillus plantarum GKD7 on anterior cruciate ligament transection induces osteoarthritis.

Osteoarthritis (OA) is a chronic inflammatory disease accompanied by joint pain, bone degradation, and synovial inflammation. Tumor necrosis factor (TNF)-α and interleukin (IL)-1ß play key roles in chronic inflammation, and matrix metalloproteinase (MMP)3 is the first enzyme released by chondrocytes and synovial cells that promotes MMPs' degrading cartilage matrix (including collage II and aggrecan) function. Using an anterior cruciate ligament transection (ACLT) rat model, Lactobacillus plantarum GKD7 has shown anti-inflammatory and analgesic properties. The present investigation examined the chondroprotective effects of several dosages and formulas of GKD7 on rats in an ACLT-induced OA model. The findings indicate that oral treatment with both live-GKD7 (GKD7-L) and dead-GKD7 (GKD7-D), along with celecoxib (positive control), all reduce post-ACLT pain and inflammation in OA joints. Subsequently, the immunohistochemical staining results demonstrate that following GKD7-L and GKD7-D treatment, there was a reversal of the degradation of collagen II and aggrecan, as well as a decrease in the expression of IL-1ß and TNF-α on the synovial tissue and MMP3 on the cartilage. Accordingly, our findings imply that the treatment of both GKD7-L and GKD7-D has chondroprotective and analgesic effects on the OA rat model, and that celecoxib and GKD7-L at dosages (100 mg/kg) have comparable therapeutic benefits. As a result, we propose that both GKD7-L and GKD7-D are helpful supplements for OA management.

CXCL13 promotes TNF-α synthesis in rheumatoid arthritis through activating ERK/p38 pathway and inhibiting miR-330-3p generation.

Rheumatoid arthritis (RA) is a well-known autoimmune disorder associated with joint pain, joint swelling, cartilage and bone degradation as well as deformity. The chemokine (C-X-C motif) ligand 13 (CXCL13) plays a crucial role in multiple cellular pathogenesis processes, including RA. TNF-α is a vital proinflammatory factor in the progression of RA. However, the role of CXCL13 in TNF-α production in RA has not been fully explored. Our analysis of both database and clinical samples revealed higher levels of CXCL13 and TNF-α in RA samples compared to healthy controls. CXCL13 concentration-dependently induces TNF-α synthesis in RA synovial fibroblasts. CXCL13 enhances TNF-α expression by interacting with the CXCR5 receptor, activating the ERK/p38 pathways, and inhibiting miR-330-3p generation. Importantly, treatment with CXCL13 shRNA counteracted the upregulation of TNF-α production induced by collagen-induced arthritis. Our findings support the notion that CXCL13 is a promising target in the treatment of RA.

Soft coral-derived lemnalol alleviates monosodium urate-induced gouty arthritis in rats by inhibiting leukocyte infiltration and iNOS, COX-2 and c-Fos protein expression.

An acute gout attack manifests in the joint as dramatic inflammation. To date, the clinical use of medicinal agents has typically led to undesirable side effects. Numerous efforts have failed to create an effective and safe agent for the treatment of gout. Lemnalol-an extract from Formosan soft coral-has documented anti-inflammatory and anti-nociceptive properties. In the present study, we attempt to examine the therapeutic effects of lemnalol on intra-articular monosodium urate (MSU)-induced gouty arthritis in rats. In the present study, we found that treatment with lemnalol (intramuscular [im]), but not colchicine (oral [po]), significantly attenuated MUS-induced mechanical allodynia, paw edema and knee swelling. Histomorphometric and immunohistochemistry analysis revealed that MSU-induced inflammatory cell infiltration, as well as the elevated expression of c-Fos and pro-inflammatory proteins (inducible nitric oxide synthase and cyclooxygenase-2) observed in synovial tissue, were significantly inhibited by treatment with lemnalol. We conclude that lemnalol may be a promising candidate for the development of a new treatment for gout and other acute neutrophil-driven inflammatory diseases.

Flexibilisquinone, a new anti-inflammatory quinone from the cultured soft coral Sinularia flexibilis.

A new quinone derivative, flexibilisquinone (1), was isolated from the cultured soft coral Sinularia flexibilis, originally distributed in the waters of Taiwan. The structure of quinone 1 was established by extensive spectroscopic methods, particularly 1D and 2D NMR experiments. In the in vitro anti-inflammatory effects test, quinone 1 was found to significantly inhibit the accumulation of the pro-inflammatory iNOS and COX-2 proteins of the LPS-stimulated RAW264.7 macrophage cells.

Oral Administration of Protease-Soluble Chicken Type II Collagen Ameliorates Anterior Cruciate Ligament Transection-Induced Osteoarthritis in Rats.

This study investigated whether oral supplementation with protease-soluble chicken type II collagen (PSCC-II) mitigates the progression of anterior cruciate ligament transection (ACLT)-induced osteoarthritis (OA) in rats. Eight-week-old male Wistar rats were randomly assigned to the following groups: control, sham, ACLT, group A (ACLT + pepsin-soluble collagen type II collagen (C-II) with type I collagen), group B (ACLT + Amano M-soluble C-II with type I collagen), group C (ACLT + high-dose Amano M-soluble C-II with type I collagen), and group D (ACLT + unproteolyzed C-II). Various methods were employed to analyze the knee joint: nociceptive tests, microcomputed tomography, histopathology, and immunohistochemistry. Rats treated with any form of C-II had significant reductions in pain sensitivity and cartilage degradation. Groups that received PSCC-II treatment effectively mitigated the ACLT-induced effects of OA concerning cancellous bone volume, trabecular number, and trabecular separation compared with the ACLT alone group. Furthermore, PSCC-II and unproteolyzed C-II suppressed ACLT-induced effects, such as the downregulation of C-II and upregulation of matrix metalloproteinase-13, tumor necrosis factor-α, and interleukin-1ß. These results indicate that PSCC-II treatment retains the protective effects of traditional undenatured C-II and provide superior benefits for OA management. These benefits encompass pain relief, anti-inflammatory effects, and the protection of cartilage and cancellous bone.

Nesfatin-1 stimulates BMP5 expression and osteoclastogenesis in rheumatoid arthritis.

Rheumatoid arthritis (RA) is a common autoimmune disease marked by immune cell activation and chronic inflammation in the synovium accompanied by osteoclast activation and local joint destruction. Increased levels of the adipokine nesfatin-1 in RA synovium are associated with proinflammatory cytokines. Our analysis of datasets from the Gene Expression Omnibus (GEO) database and synovial tissue samples from RA patients revealed that these had higher levels of nesfatin-1 and osteoclast markers compared with normal synovium. These findings were the same in tissue samples from mice with collagen-induced arthritis (CIA) and normal healthy controls. RNA sequencing analysis revealed that nesfatin-1 increased levels of bone morphogenetic protein-5 (BMP5) expression via JAK/STAT signaling in RA synovial fibroblasts. Finally, we found that nesfatin-1 short hairpin RNA reduced BMP5 and osteoclast formation in CIA mice. These findings provide new insights into the pathogenesis of RA.