IL-6 is an independent predictive factor of drug survival after dose escalation of infliximab in patients with rheumatoid arthritis

Mitochondria transfer restores fibroblasts-like synoviocytes (FLS) plasticity in LPS-induced, in vitro synovitis model

Background

Synovitis (SI) is one of the most common and serious orthopedic diseases in horses of different age, breed and sex, which contributes to the development of osteoarthritis. The burden of SI includes economic loss and represents a real challenge for current veterinary health care. At the molecular level, fibroblasts-like synoviocytes (FLS) are recognized as major cell populations involved in SI pathogenesis. In the course of SI, FLSs are losing their protective and pro-regenerative cytological features, become highly proliferative and initiate various stress signaling pathways.

Methods

Fibroblast-like synoviocytes were treated with LPS in order to generate SI in vitro model. Mitochondria were isolated from peripheral blood derived mononuclear cells and co-cultured with FLS. After 24 h of culture, cells were subjected to RT-qPCR, western blot, cytometric and confocal microscopy analysis.

Results

Mitochondrial transfer (MT) was observed in vitro studies using confocal microscopy. Further studies revealed, that MT to LPS-treated FLS reduced cell proliferation, modulated apoptosis and decreased inflammatory response. Overall, MT Resulted in the considerable recovery of recipient cells cytophysiological properties.

Conclusions

Presented data provides evidence that mitochondria transfersignificantly modulate FLS proliferative and metabolic activity through improved mitochondrial biogenesis and dynamics in activated FLS. Obtained results for the first time demonstrate that horizontal MT might be considered as a therapeutic tool for synovitis treatment; however, further clinical studies are strongly required.

Factors affecting persistence with biologic treatments in patients with rheumatoid arthritis: a systematic literature review

Introduction: Biologic treatments are a milestone in the management of rheumatoid arthritis (RA) patients with an inadequate response to conventional synthetic treatments. With the increase in the number of biologic treatments, predictor factors of discontinuation are needed to choose the right treatment for the right patient.Areas covered: In this article, the factors affecting persistence with biologic treatments will be covered: factors associated with the demographic characteristics and comordidities of the patients, those with the characteristics of the disease, the biomarkers, and the adherence.Expert opinion: Seeking factors affecting persistence with biologic treatments is an important field of clinical research to offer the best management to the RA patients. Personalized medicine is the ultimate goal in this field to choose the biological therapy with the highest persistence for every patient. To achieve this goal, biomarkers could be a milestone.

IL‑1β increases the expression of inflammatory factors in synovial fluid‑derived fibroblast‑like synoviocytes via activation of the NF‑κB‑mediated ERK‑STAT1 signaling pathway

Interleukin (IL)-1β serves a crucial role in the progression of rheumatoid arthritis. Previous studies have indicated that the ERK/STAT1 signaling pathway may be involved in the inflammatory response in synovial fluid-derived fibroblast-like synoviocytes (sfd-FLSs). However, the molecular mechanisms underlying the pathological effects of the inflammatory factors induced by IL-1β in sfd-FLSs remain unclear. The aim of the present study was to investigate the IL-1β-mediated signaling pathways involved in the expression of inflammatory factors in sfd-FLSs and in a rat model of rheumatoid arthritis. Reverse transcription-quantitative PCR, western blotting, and immunohistochemistry were used to analyze the role of IL-1β in the rat model of rheumatoid arthritis. The results suggested that IL-1β administration exacerbated rheumatoid arthritis, bone injury and increased the expression levels of inflammatory factors, such as IL-17 and tumor necrosis factor α (TNF-α), whereas treatment with anti-IL-1β exhibited opposite effects. In vitro experiments in sfd-FLSs further suggested that treatment with IL-1β influenced the expression levels of various inflammatory factors. In specific, IL-1β increased the expression of IL-17 and TNF-α, and decreased the expression of IL-6 and IL-10 in sfd-FLSs. Additionally, treatment with IL-1β increased the mRNA expression and protein phosphorylation of NF-κB, ERK and STAT1 in sfd-FLSs. Treatment with anti-IL-1β exhibited opposite effects on the expression levels of inflammatory factors and suppressed the NF-κB-mediated ERK-STAT1 signaling pathway activation in sfd-FLSs. Finally, treatment with a NF-κB inhibitor suppressed the effects of IL-1β, and NF-κB overexpression reversed the effects of anti-IL-1β on the expression levels of IL-17, TNF-α, NF-κB, ERK and STAT1. In conclusion, the present results demonstrated that treatment with IL-1β increased the expression levels of inflammatory factors in sfd-FLSs via the regulation of the NF-κB-mediated ERK/STAT1 signaling pathway in a rat model of rheumatoid arthritis. Therefore, the NF-κB/ERK/STAT1 signaling pathway may represent a potential target for the development of novel treatments for rheumatoid arthritis.

The Role of IL-6RA in UHMWPE Promotes Proliferation in Fibro-Like Synovial Cells

UHMWPE granule could induce macrophages and inflammatory responses in interfacial tissues, which eliminated the wear debris of UHMWPE component and further induced dissolution of the surrounding bone, leading aseptic loosening. However, the mechanism of synovial cells, especially fibroblast-like synovial (FLS) cells response to UHMWPE, remains unknown. Herein we choose FLS cells as research object. Vimentin (+) CD68 (-) was identified by flow cytometry and immunofluorescent staining assay, and the cells were identified as FLS cells, which was consistent with the experimental requirements. The inhibitory evaluation showed that UHMWPE could significantly promote the proliferation and inhibit apoptosis of FLS cells in dose- and time-dependent manners and increase the levels of proinflammatory cytokines, including IL-6, IL-1β, TNF-α, PGE2, MMP2, and LOX. UHMWPE also can induce the expression of mIL-6R protein in FLS cells and further investigate the relationship between apoptosis and inflammation. Interestingly enough, when we added the interleukin-6 receptor antagonist (IL-6RA), the expression levels of proapoptosis-related proteins increased; in other words, UHMWPE-induced antiapoptosis diminished by IL-6RA (50 μg/ml). Taken together, these findings clearly demonstrated that UHMWPE promote growth in FLS cells through upregulating inflammatory factors to produce antiapoptotic effect.