CKLF1 interference alleviates IL‑1β‑induced inflammation, apoptosis and degradation of the extracellular matrix in chondrocytes via CCR5

Elucidating the molecular mechanisms of CCR5-containing extracellular vesicles in vitro and in a rat model of experimental Rheumatoid arthritis

Extracellular vesicles from Rheumatoid arthritis (RA) derived synovial fibroblasts (EVsRASF) have been implicated in the pathogenesis of RA, acting as mediators of cell-to-cell communication. This study aimed to elucidate the role of the chemokine receptor CCR5 and EVs positive for CCR5 (EVsRASF) in RA, focusing on their impact on cartilage destruction and bone erosion in a rat model of Adjuvant-induced arthritis (AIA). In vivo experiments were conducted using AIA rats, treated with either EVsRASF, EVsRASF without CCR5 (EVsRASF-CCR5), or EVsM which encapsulated the CCR5 antagonist Maraviroc. The results demonstrated that EVsRASF-CCR5 reversed the catabolic effect of EVsRASF on hRA-CHs. EVsRASF accelerated cartilage destruction and bone erosion in the AIA rats, as evidenced by increased arthritis scores, joint damage, and NF-κB activation. In contrast, EVsRASF-CCR5 and EVsM treatment mitigated these effects, suggesting a detrimental role of CCR5 in EVsRASF-mediated RA pathogenesis. These findings highlight the critical role of CCR5 in mediating the pro-inflammatory and destructive effects of EVsRASF in RA, suggesting that targeting CCR5 may represent a novel therapeutic strategy for RA management. In conclusion, this study provides valuable insights into one of the molecular mechanisms underlying RA pathogenesis, emphasizing the importance of EVsRASF and CCR5 in mediating synovial inflammation and joint destruction. The results underscore the potential of CCR5 as a therapeutic target, opening avenues for the development of targeted interventions in RA treatment with synovial fibroblast derived EVs serving as a convenient, stabilizing vehicle for delivering Maraviroc into the RA affected joint tissues.

Isoliquiritigenin inhibits apoptosis and ameliorates oxidative stress in rheumatoid arthritis chondrocytes through the Nrf2/HO-1-mediated pathway

Rheumatoid arthritis (RA) is a chronic inflammatory condition known for its irreversible destructive impact on the joints. Chondrocytes play a pivotal role in the production and maintenance of the cartilage matrix. However, the presence of inflammatory cytokines can hinder chondrocyte proliferation and promote apoptosis. Isoliquiritigenin (ISL), a flavonoid, potentially exerts protective effects against various inflammatory diseases. However, its specific role in regulating the nuclear factor E2-associated factor 2 (Nrf2)/heme oxygenase-1 (HO-1) pathway in chondrocytes in RA remains unclear. To investigate this, this study used human chondrocytes and Sprague-Dawley rats to construct in vitro and in vivo RA models, respectively. The study findings reveal that cytokines markedly induced oxidative stress, the activation of matrix metalloproteinases, and apoptosis both in vitro and in vivo. Notably, ISL treatment significantly mitigated these effects. Moreover, Nrf2 or HO-1 inhibitors reversed the protective effects of ISL, attenuated the expression of Nrf2/HO-1 and peroxisome proliferator-activated receptor gamma-coactivator-1α, and promoted chondrocyte apoptosis. This finding indicates that ISL primarily targets the Nrf2/HO-1 pathway in RA chondrocytes. Moreover, ISL treatment led to improved behavior scores, reduced paw thickness, and mitigated joint damage as well as ameliorated oxidative stress in skeletal muscles in an RA rat model. In conclusion, this study highlights the pivotal role of the Nrf2/HO-1 pathway in the protective effects of ISL and demonstrates the potential of ISL as a treatment option for RA.