scholarly journals Spontaneously Resolving Joint Inflammation Is Characterised by Metabolic Agility of Fibroblast-Like Synoviocytes

2021 ◽  
Vol 12 ◽  
Author(s):  
Jane Falconer ◽  
Valentina Pucino ◽  
Sally A. Clayton ◽  
Jennifer L. Marshall ◽  
Sabrina Raizada ◽  
...  

Fibroblast-like synoviocytes (FLS) play an important role in maintaining joint homeostasis and orchestrating local inflammatory processes. When activated during injury or inflammation, FLS undergo transiently increased bioenergetic and biosynthetic demand. We aimed to identify metabolic changes which occur early in inflammatory disease pathogenesis which might support sustained cellular activation in persistent inflammation. We took primary human FLS from synovial biopsies of patients with very early rheumatoid arthritis (veRA) or resolving synovitis, and compared them with uninflamed control samples from the synovium of people without arthritis. Metabotypes were compared using NMR spectroscopy-based metabolomics and correlated with serum C-reactive protein levels. We measured glycolysis and oxidative phosphorylation by Seahorse analysis and assessed mitochondrial morphology by immunofluorescence. We demonstrate differences in FLS metabolism measurable after ex vivo culture, suggesting that disease-associated metabolic changes are long-lasting. We term this phenomenon ‘metabolic memory’. We identify changes in cell metabolism after acute TNFα stimulation across disease groups. When compared to FLS from patients with early rheumatoid arthritis, FLS from patients with resolving synovitis have significantly elevated mitochondrial respiratory capacity in the resting state, and less fragmented mitochondrial morphology after TNFα treatment. Our findings indicate the potential to restore cell metabotypes by modulating mitochondrial function at sites of inflammation, with implications for treatment of RA and related inflammatory conditions in which fibroblasts play a role.

2021 ◽  
Vol 23 (1) ◽  
Author(s):  
Marit Stockfelt ◽  
Anna-Carin Lundell ◽  
Merete Lund Hetland ◽  
Mikkel Østergaard ◽  
Till Uhlig ◽  
...  

Abstract Background The type I interferon (IFN) gene signature is present in a subgroup of patients with early rheumatoid arthritis (RA). Protein levels of IFNα have not been measured in RA and it is unknown whether they associate with clinical characteristics or treatment effect. Methods Patients with early untreated RA (n = 347) were randomized to methotrexate combined with prednisone, certolizumab-pegol, abatacept, or tocilizumab. Plasma IFNα protein levels were determined by single molecular array (Simoa) before and 24 weeks after treatment initiation and were related to demographic and clinical factors including clinical disease activity index, disease activity score in 28 joints, swollen and tender joint counts, and patient global assessment. Results IFNα protein positivity was found in 26% of the patients, and of these, 92% were double-positive for rheumatoid factor (RF) and anti-citrullinated protein antibodies (ACPA). IFNα protein levels were reduced 24 weeks after treatment initiation, and the absolute change was similar irrespective of treatment. IFNα protein positivity was associated neither with disease activity nor with achievement of CDAI remission 24 weeks after randomization. Conclusion IFNα protein positivity is present in a subgroup of patients with early RA and associates with double-positivity for autoantibodies but not with disease activity. Pre-treatment IFNα positivity did not predict remission in any of the treatment arms, suggesting that the IFNα system is distinct from the pathways of TNF, IL-6, and T-cell activation in early RA. A spin-off study of the NORD-STAR randomized clinical trial, NCT01491815 (ClinicalTrials), registered 12/08/2011, https://clinicaltrials.gov/ct2/show/NCT01491815.


Author(s):  
Yuji Joyo ◽  
Yohei Kawaguchi ◽  
Hiroki Yonezu ◽  
Hiroya Senda ◽  
Sanshiro Yasuma ◽  
...  

AbstractGliostatin/thymidine phosphorylase (GLS/TP) is known to have angiogenic and arthritogenic activities in the pathogenesis of rheumatoid arthritis (RA). The novel oral Janus kinase (JAK) inhibitor baricitinib has demonstrated high efficacy in RA. However, the effect of baricitinib on fibroblast-like synoviocytes (FLSs), a key component of invasive synovitis, has not been still elucidated. This study investigated whether GLS/TP production could be regulated by JAK/signal transducers and activators of transcription (STAT) signaling in FLSs derived from patients with RA. FLSs were cultured and stimulated by interferon (IFN)γ in the presence of baricitinib. Expression levels of GLS/TP were determined using reverse transcription-polymerase chain reaction (RT-PCR), enzyme-linked immunosorbent assay (ELISA), and immunocytochemistry. Phosphorylation of STAT proteins was investigated by Western blot. In cultured FLSs, GLS/TP mRNA and protein levels were significantly induced by treatment with IFNγ and these inductions were suppressed by baricitinib treatment. Baricitinib inhibited IFNγ-induced STAT1 phosphorylation, while JAK/STAT activation played a pivotal role in IFNγ-mediated GLS/TP upregulation in RA. These results suggested that baricitinib suppressed IFNγ-induced GLS/TP expression by inhibiting JAK/STAT signaling, resulting in the attenuation of neovascularization, synovial inflammation, and cartilage destruction.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ying-Jie Chen ◽  
Yu-Xi Liu ◽  
Jia-Ying Wu ◽  
Chun-Yu Li ◽  
Min-Min Tang ◽  
...  

AbstractFibroblast-like synoviocytes (FLS) play a pathogenic role in rheumatoid arthritis (RA). STAT3 signaling is activated in FLS of RA patients (RA-FLS), which in turn causes RA-FLS hyperproliferation. RL is a traditional remedy for treating inflammatory diseases in China. It comprises Rosae Multiflorae Fructus and Lonicerae Japonicae Flos. A standardized ethanolic extract of RL (RLE) has been shown to exert anti-arthritic effects in collagen-induced arthritis (CIA) rats. Some constituents of RLE were reported to inhibit JAK2/STAT3 signaling in rat FLS. Here, we determined whether RLE inhibits FLS hyperproliferation, and explored the involvement of STAT3 signaling in this inhibition. In joints of CIA rats, RLE increased apoptotic FLS. In IL-6/sIL-6R-stimulated RA-FLS, RLE reduced cell viability and evoked cell apoptosis. In synovial tissues of CIA rats, RLE lowered the protein level of phospho-STAT3. In IL-6/sIL-6R-stimulated RA-FLS, RLE inhibited activation/phosphorylation of STAT3 and JAK2, decreased the nuclear localization of STAT3, and downregulated protein levels of Bcl-2 and Mcl-1. Over-activation of STAT3 diminished RLE’s anti-proliferative effects in IL-6/sIL-6R-stimulated RA-FLS. In summary, RLE inhibits hyperproliferation of FLS in rat and cell models, and suppression of STAT3 signaling contributes to the underlying mechanisms. This study provides further pharmacological groundwork for developing RLE as a modern anti-arthritic drug.


2022 ◽  
Vol 17 (1) ◽  
Author(s):  
Peilong Dong ◽  
Xiaobo Tang ◽  
Jian Wang ◽  
Botao Zhu ◽  
Zhiyun Li

Abstract Background Rheumatoid arthritis (RA) is a chronic systemic autoimmune disease. Several studies reported that fibroblast-like synoviocytes (FLSs) and miRNAs are associated with RA pathogenesis. This study explored the function of miR-653-5p in the regulation of human fibroblast-like synoviocytes-rheumatoid arthritis (HFLS-RA) cells. Methods The mRNA and protein levels of genes were measured by RT-qPCR and western blot, respectively. MTT, wound healing, and invasion assays were used to evaluate the viability and metastasis of FLSs. Luciferase reporter and RNA pull-down assays were employed to determine the interaction between miR-653-5p and FGF2. Results RT-qPCR results demonstrated that miR-653-5p expression was decreased and FGF2 level was increased in synovial tissues and FLSs of RA. Moreover, the viability and metastasis of FLSs were accelerated by miR-653-5p addition, which was restrained by miR-653-5p suppression. Furthermore, we demonstrated that levels of Rac1, Cdc42, and RhoA were decreased after miR-653-5p addition. Besides, luciferase reporter and RNA pull-down assays implied that miR-653-5p targeted the 3′-UTR of FGF2. Functional assays showed that FGF2 overexpression neutralized the suppressive effects of miR-653-5p addition on HFLS-RA cell viability, metastasis, and the levels of Rho family proteins. Meanwhile, the levels of β-catenin, cyclin D1, and c-myc were declined by miR-653-5p supplementation, but enhanced by FGF2 addition. Conclusion In sum, we manifested that miR-653-5p restrained HFLS-RA cell viability and metastasis via targeting FGF2 and repressing the Wnt/beta-Catenin pathway.


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