Imperative and effective reversion of synovial hyperplasia and cartilage destruction in rheumatoid arthritis through multiple synergistic effects of O2 and Ca2

HSP90 Exacerbates Bone Destruction in Rheumatoid Arthritis by Activating TRAF6/NFATc1 Signaling

Rheumatoid arthritis (RA) is an autoimmune disease characterized by a notably high disability rate, primarily attributed to cartilage and bone degradation. The involvement of heat shock protein 90 (HSP90) as a molecular chaperone in the inflammatory response of RA has been established, but its role in bone destruction remains uncertain. In the present study, the expression of HSP90 was augmented in osteoclasts induced by the receptor activator of nuclear factor-κB ligand. Additionaly, it was observed that the outcomes revealed a noteworthy inhibition of osteoclast formation and differentation when triptolide was utilized to hinder the expression of HSP90. Furthermore, the positive influence of HSP90 in osteoclast differentiation was substantiated by overexpressing HSP90 in osteoclast precursor cells. Mechanically, HSP90 significantly activated the TNF receptor-associated factor 6 (TRAF6)/Nuclear factor of activated T cells 1 (NFATc1) signaling axis, accompanied by markedly promoting osteoclast differentiation. This effect was consistently observed in the destructive joint of rats with collagen-induced arthritis, where HSP90 effectively activated osteoclasts and contributed to arthritic bone destruction by activating the TRAF6/NFATc1 signaling. Overall, the findings of this study provide compelling evidence that HSP90 exacerbates bone destruction in RA by promoting osteoclast differentiation through the activation of TRAF6/NFATc1 signaling, and interference with HSP90 may be a promising strategy for the discovery of anti-arthritic bone destruction agents.

Nano-Based Co-Delivery System for Treatment of Rheumatoid Arthritis

A systemic autoimmune condition known as rheumatoid arthritis (RA) has a significant impact on patients’ quality of life. Given the complexity of RA’s biology, no single treatment can totally block the disease’s progression. The combined use of co-delivery regimens integrating various diverse mechanisms has been widely acknowledged as a way to make up for the drawbacks of single therapy. These days, co-delivery systems have been frequently utilized for co-treatment, getting over drug limitations, imaging of inflammatory areas, and inducing reactions. Various small molecules, nucleic acid drugs, and enzyme-like agents intended for co-delivery are frequently capable of producing the ability to require positive outcomes. In addition, the excellent response effect of phototherapeutic agents has led to their frequent use for delivery together with chemotherapeutics. In this review, we discuss different types of nano-based co-delivery systems and their advantages, limitations, and future directions. In addition, we review the prospects and predicted challenges for the combining of phototherapeutic agents with conventional drugs, hoping to provide some theoretical support for future in-depth studies of nano-based co-delivery systems and phototherapeutic agents.

Secretory phosphoprotein 1 secreted by fibroblast-like synoviocytes promotes osteoclasts formation via PI3K/AKT signaling in collagen-induced arthritis

Synovial tissue hyperplasia is a major cause of bone damage in rheumatoid arthritis (RA). Over-proliferation and secretion of cytokines of fibroblast-like synoviocytes (FLSs) are key contributors to bone damage in the joint microenvironment. Therefore, inhibition of FLSs-mediated bone damage is of great significance in RA patients. The aim of this study was to investigate the molecular mechanisms by which FLSs-mediated bone damage in the joint microenvironment. The results of whole transcriptome sequencing showed that Spp1 gene expression was significantly upregulated in collagen-induced arthritis FLSs compared to Normal FLSs. KEGG enrichment analysis revealed up-regulated Spp1 gene expression, associated with PI3K/AKT signaling. Animal and cellular experiments were designed to validate and explore the results of sequencing. Briefly, the data demonstrated secretory phosphoprotein 1 (SPP1) (encoded by Spp1 gene) secreted by FLSs promotes osteoclasts differentiation in vivo and in vitro and exacerbates articular bone damage in collagen-induced arthritis mice. Interestingly, SPP1 secreted by FLSs does not affect its own proliferation and apoptosis. The results of co-culture of FLSs with bone marrow-derived monocytes indicated the level of SPP1 secreted by FLSs positively correlates with the frequency of p-PI3K⁺PI3K⁺ osteoclasts, whereas not with the frequency of p-AKT⁺AKT⁺ osteoclasts. This may suggest that SPP1 secreted by FLSs acts directly on PI3K while indirectly on AKT. Together, the results revealed SPP1 secreted by FLSs promotes osteoclasts formation via PI3K/AKT signaling in collagen-induced arthritis. Regulation of Spp1 gene expression in FLSs may be a potential approach to treat RA bone damage in the joint microenvironment.

Apoptosis, Autophagy, NETosis, Necroptosis, and Pyroptosis Mediated Programmed Cell Death as Targets for Innovative Therapy in Rheumatoid Arthritis

Rheumatoid arthritis (RA) is a chronic inflammatory joint disease that can lead to clinical manifestations of systemic diseases. Its leading features include chronic synovial inflammation and degeneration of the bones and joints. In the past decades, multiple susceptibilities for rheumatoid arthritis have been identified along with the development of a remarkable variety of drugs for its treatment; which include analgesics, glucocorticoids, nonsteroidal anti-inflammatory medications (NSAIDs), disease-modifying anti-rheumatic drugs (DMARDs), and biologic response modifiers (bDMARDs). Despite the existence of many clinical treatment options, the prognosis of some patients remains poor due to complex mechanism of the disease. Programmed cell death (PCD) has been extensively studied and ascertained to be one of the essential pathological mechanisms of RA. Its dysregulation in various associated cell types contributes to the development of RA. In this review, we summarize the role of apoptosis, cell death-associated neutrophil extracellular trap formation, necroptosis, pyroptosis, and autophagy in the pathophysiology of RA to provide a theoretical reference and insightful direction to the discovery and development of novel therapeutic targets for RA.

Treatment of rheumatoid arthritis by phototherapy: advances and perspectives

Rheumatoid arthritis (RA) is an inflammatory disease that is prevalent worldwide and seriously threatens human health. Though traditional drug therapy can alleviate RA symptoms and slow progression, high dosage and frequent administration would cause unfavorable side effects. Phototherapy including photodynamic therapy (PDT) and photothermal therapy (PTT) has demonstrated distinctive potential in RA treatment. Under light irradiation, phototherapy can convert light into heat, or generate ROS, to promote necrosis or apoptosis of RA inflammatory cells, thus reducing the concentration of related inflammatory factors and relieving the symptoms of RA. In this review, we will summarize the development in the application of phototherapy in the treatment of rheumatoid arthritis.