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

2020 ◽  
Author(s):  
Yilin Wang ◽  
Aneesah Khan ◽  
Aristotelis Antonopoulos ◽  
Laura Bouché ◽  
Christopher D Buckley ◽  
...  

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.

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Yilin Wang ◽  
Aneesah Khan ◽  
Aristotelis Antonopoulos ◽  
Laura Bouché ◽  
Christopher D. Buckley ◽  
...  

AbstractIn healthy joints, synovial fibroblasts (SFs) provide the microenvironment required to mediate homeostasis, but these cells adopt a pathological function in rheumatoid arthritis (RA). Carbohydrates (glycans) on cell surfaces are fundamental regulators of the interactions between stromal and immune cells, but little is known about the role of the SF glycome in joint inflammation. Here we study stromal guided pathophysiology by mapping SFs glycosylation pathways. Combining transcriptomic and glycomic analysis, we show that transformation of fibroblasts into pro-inflammatory cells is associated with glycan remodeling, a process that involves TNF-dependent inhibition of the glycosyltransferase ST6Gal1 and α2-6 sialylation. SF sialylation correlates with distinct functional subsets in murine experimental arthritis and remission stages in human RA. We propose that pro-inflammatory cytokines remodel the SF-glycome, converting the synovium into an under-sialylated and highly pro-inflammatory microenvironment. These results highlight the importance of glycosylation in stromal immunology and joint inflammation.


2005 ◽  
Vol 11 (5) ◽  
pp. 563-568 ◽  
Author(s):  
Ingmar Meinecke ◽  
Edita Rutkauskaite ◽  
Steffen Gay ◽  
Thomas Pap

Author(s):  
Andrew Filer ◽  
Maria Juarez ◽  
Christopher Buckley

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.


Cells ◽  
2019 ◽  
Vol 8 (9) ◽  
pp. 953 ◽  
Author(s):  
Marzena Ciechomska ◽  
Leszek Roszkowski ◽  
Wlodzimierz Maslinski

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.


Arthritis ◽  
2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Misato Hashizume ◽  
Masahiko Mihara

Several clinical studies have demonstrated that the humanized anti-interleukin-6 (IL-6) receptor antibody tocilizumab (TCZ) improves clinical symptoms and prevents progression of joint destruction in rheumatoid arthritis (RA). However, the precise mechanism by which IL-6 blockade leads to the improvement of RA is not well understood. IL-6 promotes synovitis by inducing neovascularization, infiltration of inflammatory cells, and synovial hyperplasia. IL-6 causes bone resorption by inducing osteoclast formation via the induction of RANKL in synovial cells, and cartilage degeneration by producing matrix metalloproteinases (MMPs) in synovial cells and chondrocytes. Moreover, IL-6 is involved in autoimmunity by altering the balance between Th17 cells and Treg. IL-6 also acts on changing lipid concentrations in blood and on inducing the production of hepcidin which causes iron-deficient anemia. In conclusion, IL-6 is a major player in the pathogenesis of RA, and current evidence indicates that the blockade of IL-6 is a beneficial therapy for RA patients.


2020 ◽  
Author(s):  
Marlene Corbet ◽  
Miguel A Pineda ◽  
Kun Yang ◽  
Anuradha Tarafdar ◽  
Sarah McGrath ◽  
...  

AbstractThe parasitic worm product, ES-62 protects against collagen-induced arthritis, a mouse model of rheumatoid arthritis (RA) by suppressing the synovial fibroblast (SF) responses perpetuating inflammation and driving joint destruction. Such SF responses are shaped during disease progression by the inflammatory microenvironment of the joint that promotes remodelling of their epigenetic landscape, inducing an “aggressive” pathogenic SF phenotype. Critically, exposure to ES-62 in vivo induces a stably imprinted “safe” phenotype that exhibits responses more typical of healthy SFs. Surprisingly however, DNA methylome analysis reveals that rather than simply preventing the pathogenic rewiring of SFs, ES-62 induces further epigenetic remodelling, including targeting genes associated with ciliogenesis and differentiation, to program a distinct “protective” phenotype. Such unique behaviour signposts potential DNA methylation signatures predictive of pathogenesis and its resolution and hence, candidate mechanisms by which novel therapeutic interventions could prevent SFs from perpetuating joint inflammation and destruction in RA.


Bone Research ◽  
2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Eugenie Macfarlane ◽  
Markus J. Seibel ◽  
Hong Zhou

Abstract Rheumatoid arthritis and osteoarthritis, the most common forms of arthritis, are chronic, painful, and disabling conditions. Although both diseases differ in etiology, they manifest in progressive joint destruction characterized by pathological changes in the articular cartilage, bone, and synovium. While the potent anti-inflammatory properties of therapeutic (i.e., exogenous) glucocorticoids have been heavily researched and are widely used in clinical practice, the role of endogenous glucocorticoids in arthritis susceptibility and disease progression remains poorly understood. Current evidence from mouse models suggests that local endogenous glucocorticoid signaling is upregulated by the pro-inflammatory microenvironment in rheumatoid arthritis and by aging-related mechanisms in osteoarthritis. Furthermore, these models indicate that endogenous glucocorticoid signaling in macrophages, mast cells, and chondrocytes has anti-inflammatory effects, while signaling in fibroblast-like synoviocytes, myocytes, osteoblasts, and osteocytes has pro-inflammatory actions in rheumatoid arthritis. Conversely, in osteoarthritis, endogenous glucocorticoid signaling in both osteoblasts and chondrocytes has destructive actions. Together these studies provide insights into the role of endogenous glucocorticoids in the pathogenesis of both inflammatory and degenerative joint disease.


2005 ◽  
Vol 2 (3) ◽  
pp. 359-365 ◽  
Author(s):  
Christian A. Seemayer ◽  
Michel Neidhart ◽  
Astrid Jüngel ◽  
Renate E. Gay ◽  
Steffen Gay

2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Stefan Teufel ◽  
Petra Köckemann ◽  
Christine Fabritius ◽  
Lena I. Wolff ◽  
Jessica Bertrand ◽  
...  

AbstractAgonists and antagonists of the canonical Wnt signaling pathway are modulators of pathological aspects of rheumatoid arthritis (RA). Their activity is primarily modifying bone loss and bone formation, as shown in animal models of RA. More recently, modulation of Wnt signaling by the antagonist Sclerostin has also been shown to influence soft-tissue-associated inflammatory aspects of the disease pointing towards a role of Wnt signaling in soft-tissue inflammation as well. Yet, nothing is known experimentally about the role of Wnt ligands in RA. Here we provide evidence that altering Wnt signaling at the level of a ligand affects all aspects of the rheumatoid arthritic disease. WNT9a levels are increased in the pannus tissue of RA patients, and stimulation of synovial fibroblasts (SFB) with tumor necrosis factor (TNF) leads to increased transcription of Wnt9a. Loss of Wnt9a in a chronic TNF-dependent RA mouse model results in an aggravation of disease progression with enhanced pannus formation and joint destruction. Yet, loss of its activity in the acute K/BxN serum-transfer induced arthritis (STIA) mouse model, which is independent of TNF signaling, has no effect on disease severity or progression. Thus, suggesting a specific role for WNT9a in TNF-triggered RA. In synovial fibroblasts, WNT9a can activate the canonical Wnt/β-catenin pathway, but it can also activate P38- and downregulate NFκB signaling. Based on in vitro data, we propose that loss of Wnt9a creates a slight proinflammatory and procatabolic environment that boosts the TNF-mediated inflammatory response.


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