A8.14 The Anti-Proliferative Function of RSK2 in Synovial Fibroblasts Protects Against TNF-α-Induced Joint Destruction in Inflammatory Arthritis

ObjectiveWe aimed to understand the role of the transcriptional co-factor Yes-associated protein (Yap) in the molecular pathway underpinning the pathogenic transformation of synovial fibroblasts (SF) in rheumatoid arthritis (RA) to become invasive and cause joint destruction.MethodsSynovium from patients with RA and mice with antigen-induced arthritis (AIA) was analysed by immunostaining and qRT-PCR. SF were targeted using Pdgfrα-CreER and Gdf5-Cre mice, crossed with fluorescent reporters for cell tracing and Yap-flox mice for conditional Yap ablation. Fibroblast phenotypes were analysed by flow cytometry, and arthritis severity was assessed by histology. Yap activation was detected using Yap–Tead reporter cells and Yap–Snail interaction by proximity ligation assay. SF invasiveness was analysed using matrigel-coated transwells.ResultsYap, its binding partner Snail and downstream target connective tissue growth factor were upregulated in hyperplastic human RA and in mouse AIA synovium, with Yap detected in SF but not macrophages. Lineage tracing showed polyclonal expansion of Pdgfrα-expressing SF during AIA, with predominant expansion of the Gdf5-lineage SF subpopulation descending from the embryonic joint interzone. Gdf5-lineage SF showed increased expression of Yap and adopted an erosive phenotype (podoplanin+Thy-1 cell surface antigen−), invading cartilage and bone. Conditional ablation of Yap in Gdf5-lineage cells or Pdgfrα-expressing fibroblasts ameliorated AIA. Interleukin (IL)-6, but not tumour necrosis factor alpha (TNF-α) or IL-1β, Jak-dependently activated Yap and induced Yap–Snail interaction. SF invasiveness induced by IL-6 stimulation or Snail overexpression was prevented by Yap knockdown, showing a critical role for Yap in SF transformation in RA.ConclusionsOur findings uncover the IL-6–Yap–Snail signalling axis in pathogenic SF in inflammatory arthritis.

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The Role of Synovial Fibroblasts in Mediating Joint Destruction in Rheumatoid Arthritis

Current Pharmaceutical Design ◽

10.2174/1381612053381945 ◽

2005 ◽

Vol 11 (5) ◽

pp. 563-568 ◽

Cited By ~ 40

Author(s):

Ingmar Meinecke ◽

Edita Rutkauskaite ◽

Steffen Gay ◽

Thomas Pap

Keyword(s):

Rheumatoid Arthritis ◽

Joint Destruction ◽

Synovial Fibroblasts

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OP0036 IL-6 ACTIVATES YES-ASSOCIATED PROTEIN (YAP) IN FIBROBLASTS AND INDUCES YAP-SNAIL COMPLEX FORMATION TO DRIVE SYNOVIAL LINING PATHOLOGY IN INFLAMMATORY ARTHRITIS

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2021-eular.2530 ◽

2021 ◽

Vol 80 (Suppl 1) ◽

pp. 19.1-19

Author(s):

R. Symons ◽

F. Colella ◽

F. Collins ◽

A. Roelofs ◽

C. De Bari

Keyword(s):

Transcription Factor ◽

Complex Formation ◽

Inflammatory Arthritis ◽

Normal Mouse ◽

Joint Destruction ◽

Proximity Ligation Assay ◽

Synovial Lining ◽

Arthritis Severity ◽

Marginal Erosions

Background:In rheumatoid arthritis (RA), the fibroblast-like synoviocytes (FLS) in synovial lining become invasive and cause joint destruction. The molecular mechanisms underpinning this pathogenic FLS phenotype are incompletely understood. The FLS descend from Growth differentiation factor 5 (Gdf5)-expressing joint interzone cells in the embryo, and we showed that conditional ablation of the transcriptional co-activator Yes associated protein (Yap) in Gdf5-lineage cells prevents synovial lining hyperplasia after traumatic cartilage injury in mice [1].Objectives:Here, we investigated a potential role for Yap in pathogenic FLS in immune-mediated inflammatory arthritis.Methods:Immunohistochemistry was used to detect Yap in human RA synovium and Yap, Snail and Ctgf in mouse synovium following antigen-induced arthritis (AIA). To determine the effect of Yap knockout (KO) in synovial stromal cells, AIA was induced in Gdf5-Cre;tdTomato;Yapfl/fl (Yap cKO) and Gdf5-Cre;tdTomato;Yapwt/wt (control) mice, or in Pdgfrα-CreER;Yapfl/fl (Yap ciKO, targeting Pdgfrα-expressing fibroblasts) and Yapfl/fl or YapWT/fl (control) mice after adult tamoxifen induction. Yap KO in both models was confirmed by immunohistochemistry. After nine days, arthritis severity was determined by histological scoring of synovial lining hyperplasia, immune infiltrates, cellular exudate, and marginal erosions. TdTomato+ Gdf5-lineage cells in synovium were quantified. In vitro, Yap reporter cells were treated with inflammatory cytokines to evaluate their ability to stimulate Yap-induced GFP expression by flow cytometry. Snail overexpression, siRNA-mediated Yap knockdown, and IL-6/sIL-6R stimulation were performed on normal mouse FLS, AIA-FLS or human RA-FLS, and cell invasion through a matrigel-coated transwell was quantified. A proximity ligation assay was utilised to detect Yap/Snail complex formation.Results:Average expression levels of Yap (p<0.0001), its transcription factor partner Snail (p=0.002), and their downstream target Ctgf (p=0.0003), were increased in mouse synovium after AIA (n=5), and Yap was highly expressed by FLS in human RA synovium. Yap cKO mice (n=24) showed a significantly decreased arthritis severity (p=0.002) after AIA compared to controls (n=22), with significant reductions in synovial lining hyperplasia (p<0.001), synovial immune cell infiltrates (p=0.026) and marginal erosions (p=0.002). Similarly, Yap ciKO mice (n=6) showed a significant decrease in arthritis score (p=0.039) after AIA compared to controls (n=9). However, both control mice (p<0.001) and Yap cKO mice (p<0.001) showed an extensive expansion of tdTomato+ Gdf5-lineage synovial cells after AIA, with no significant difference between control and Yap cKO mice. In vitro, Yap knockdown prevented IL-6/sIL-6R-induced invasion of normal mouse FLS (p=0.037) and decreased the invasiveness of AIA-FLS (p=0.0057). Using Yap reporter cells, we found that Yap was activated by IL-6/sIL-6R (p=0.016), but not TNFα or IL-1β. Finally, IL-6/sIL-6R treatment of normal mouse FLS (p=0.033) or human RA-FLS (p=0.036) induced Yap-Snail complex formation, and Yap knockdown prevented FLS invasion induced by Snail overexpression (p=0.027).Conclusion:These data demonstrate that via activation by IL-6, and co-operation with the transcription factor Snail, Yap acts as a key modulator of the invasive and destructive phenotype of FLS in inflammatory arthritis. Therapeutic targeting of Yap could reduce joint destruction in RA.References:[1]A. J. Roelofs et al., “Joint morphogenetic cells in the adult mammalian synovium,” Nat. Commun., vol. 8, no. May, p. 15040, 2017. DOI: 10.1136/annrheumdis-2018-213799Acknowledgements:This work was funded by the Medical Research Council (MR/L020211/1 and MR/L022893/1) and Versus Arthritis (20775 and 21156).Disclosure of Interests:None declared

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TNF-α inhibitor persistence less costly in inflammatory arthritis

PharmacoEconomics & Outcomes News ◽

10.1007/s40274-021-08219-z ◽

2021 ◽

Vol 892 (1) ◽

pp. 24-24

Keyword(s):

Inflammatory Arthritis ◽

Tnf Α

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SAT0246 Proteomic analysis of synovial tissue: A unique tool to predict response to anti-TNF-α therapy in patients with inflammatory arthritis

Annals of the Rheumatic Diseases ◽

10.1136/annrheumdis-2012-eular.3193 ◽

2013 ◽

Vol 71 (Suppl 3) ◽

pp. 555.1-555

Author(s):

O.S. Ademowo ◽

E. Collins ◽

C. Rooney ◽

A. van Kuijk ◽

D. Gerlag ◽

...

Keyword(s):

Synovial Tissue ◽

Proteomic Analysis ◽

Inflammatory Arthritis ◽

Tnf Α

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TNF-α Activating Osteoclasts in Patients with Psoriatic Arthritis Enhances the Recruitment of Osteoclast Precursors: A Plausible Role of WNT5A-MCP-1 in Osteoclast Engagement in Psoriatic Arthritis

International Journal of Molecular Sciences ◽

10.3390/ijms23020921 ◽

2022 ◽

Vol 23 (2) ◽

pp. 921

Author(s):

Shang-Hung Lin ◽

Ji-Chen Ho ◽

Sung-Chou Li ◽

Yu-Wen Cheng ◽

Chung-Yuan Hsu ◽

...

Keyword(s):

Psoriatic Arthritis ◽

Rna Interference ◽

Joint Destruction ◽

Neutralizing Antibody ◽

Healthy Controls ◽

Osteoclast Precursors ◽

Tnf Α ◽

Wnt Ligands

Psoriatic arthritis (PsA) results from joint destruction by osteoclasts. The promising efficacy of TNF-α blockage indicates its important role in osteoclastogenesis of PsA. WNT ligands actively regulate osteoclastogenesis. We investigated how WNT ligands activate osteoclasts amid the TNF-α milieu in PsA. We first profiled the expression of WNT ligands in CD14+ monocyte-derived osteoclasts (MDOC) from five PsA patients and five healthy controls (HC) and then validated the candidate WNT ligands in 32 PsA patients and 16 HC. Through RNA interference against WNT ligands in MDOC, we determined the mechanisms by which TNF-α exerts its effects on osteclastogenesis or chemotaxis. WNT5A was selectively upregulated by TNF-α in MDOC from PsA patients. The number of CD68+WNT5A+ osteoclasts increased in PsA joints. CXCL1, CXCL16, and MCP-1 was selectively increased in supernatants of MDOC from PsA patients. RNA interference against WNT5A abolished the increased MCP-1 from MDOC and THP-1-cell-derived osteoclasts. The increased migration of osteoclast precursors (OCP) induced by supernatant from PsA MDOC was abolished by the MCP-1 neutralizing antibody. WNT5A and MCP-1 expressions were decreased in MDOC from PsA patients treated by biologics against TNF-α but not IL-17. We conclude that TNF-α recruits OCP by increased MCP-1 production but does not directly activate osteoclastogenesis in PsA.

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Loss of α2-6 sialylation promotes the transformation of synovial fibroblasts into a pro-inflammatory phenotype in Rheumatoid Arthritis

10.1101/2020.03.08.970046 ◽

2020 ◽

Author(s):

Yilin Wang ◽

Aneesah Khan ◽

Aristotelis Antonopoulos ◽

Laura Bouché ◽

Christopher D Buckley ◽

...

Keyword(s):

Rheumatoid Arthritis ◽

Immune Cells ◽

Joint Destruction ◽

Inflammatory Cells ◽

Synovial Fibroblasts ◽

Surface Proteins ◽

Cellular Interactions ◽

Inflammatory Microenvironment ◽

Distinct Disease ◽

Inflammatory Phenotype

AbstractIn healthy joints, synovial fibroblasts (SFs) provide the microenvironment required to mediate homeostasis but are recognized to adopt a pathological role in rheumatoid arthritis (RA), promoting the infiltration and activation of immune cells to perpetuate local inflammation, pain and joint destruction. Carbohydrates (glycans) attached to cell surface proteins are fundamental regulators of cellular interactions between stromal and immune cells, but very little is known about the glycome of SFs or how glycosylation regulates their biology. Here we fill these gaps in our understanding of stromal guided pathophysiology by systematically mapping glycosylation pathways in healthy and arthritic SFs. We used a combination of transcriptomic and glycomic analysis to show that transformation of fibroblasts into pro-inflammatory cells in RA is associated with profound glycan remodeling, a process that involves reduction of α2-6 terminal sialylation that is mostly mediated by TNFα-dependent inhibition of the glycosyltransferase ST6Gal1. We also show that sialylation of SFs correlates with distinct disease stages and SFs functional subsets in both human RA and models of mouse arthritis. We propose that pro-inflammatory cytokines in the joint remodel the SF-glycome, transforming a regulatory tissue intended to preserve local homeostasis, into an under-sialylated and highly pro-inflammatory microenvironment that contributes to an amplificatory inflammatory network that perpetuates chronic inflammation. These results highlight the importance of cell glycosylation in stromal immunology.

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Fibroblasts and mesenchymal cells

Oxford Textbook of Rheumatology ◽

10.1093/med/9780199642489.003.0051 ◽

2013 ◽

pp. 379-385

Author(s):

Andrew Filer ◽

Maria Juarez ◽

Christopher Buckley

Keyword(s):

Rheumatoid Arthritis ◽

Wound Healing ◽

Joint Destruction ◽

Joint Inflammation ◽

Synovial Fibroblasts ◽

Mesenchymal Cells ◽

Structure And Function ◽

Epigenetic Programming ◽

Disease Initiation ◽

And Function

In order to understand and explore the function and roles of fibroblasts, it is necessary to understand their lineage relationships to other mesenchymal cells. Fibroblasts are ubiquitous non-epithelial, non-endothelial, and non-haematopoietic adherent cells that have the capacity to produce and remodel extracellular matrix. In addition to their well-known ’landscaping’ function which determines the unique structure and function of different organs, they play an important role in wound healing, immune tolerance, and disease. In cancer, epithelial-stromal interactions have been implicated in disease initiation and progression. In rheumatoid arthritis, synovial fibroblasts at diseased sites become persistently activated and behave abnormally, orchestrating joint inflammation and contributing to joint destruction. Recent evidence suggests that the activated phenotype of fibroblasts in pathology may result from epigenetic programming, which is becoming a major focus for development of new therapeutics.

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DNA Methylation as a Future Therapeutic and Diagnostic Target in Rheumatoid Arthritis

Cells ◽

10.3390/cells8090953 ◽

2019 ◽

Vol 8 (9) ◽

pp. 953 ◽

Cited By ~ 4

Author(s):

Marzena Ciechomska ◽

Leszek Roszkowski ◽

Wlodzimierz Maslinski

Keyword(s):

Rheumatoid Arthritis ◽

Dna Methylation ◽

Joint Destruction ◽

Synovial Fibroblasts ◽

Genetic Mutation ◽

Unknown Etiology ◽

Non Invasive ◽

Fibroblast Like Synoviocytes

Rheumatoid arthritis (RA) is a long-term autoimmune disease of unknown etiology that leads to progressive joint destruction and ultimately to disability. RA affects as much as 1% of the population worldwide. To date, RA is not a curable disease, and the mechanisms responsible for RA development have not yet been well understood. The development of more effective treatments and improvements in the early diagnosis of RA is direly needed to increase patients’ functional capacity and their quality of life. As opposed to genetic mutation, epigenetic changes, such as DNA methylation, are reversible, making them good therapeutic candidates, modulating the immune response or aggressive synovial fibroblasts (FLS—fibroblast-like synoviocytes) activity when it is necessary. It has been suggested that DNA methylation might contribute to RA development, however, with insufficient and conflicting results. Besides, recent studies have shown that circulating cell-free methylated DNA (ccfDNA) in blood offers a very convenient, non-invasive, and repeatable “liquid biopsy”, thus providing a reliable template for assessing molecular markers of various diseases, including RA. Thus, epigenetic therapies controlling autoimmunity and systemic inflammation may find wider implications for the diagnosis and management of RA. In this review, we highlight current challenges associated with the treatment of RA and other autoimmune diseases and discuss how targeting DNA methylation may improve diagnostic, prognostic, and therapeutic approaches.

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