26 SYNOVIAL FLUID FROM PATIENTS WITH OSTEOARTHRITIS AND MENISCAL INJURY MODULATES THE RESPONSE OF FIBROBLAST-LIKE SYNOVIOCYTES TO TLR-2 AND TLR-4 LIGANDS VIA SOLUBLE CD14

Abstract Background: Abnormal proliferation of fibroblast-like synoviocytes (FLSs) in the synovial lining layer is the primary cause of synovial hyperplasia and joint destruction in rheumatoid arthritis (RA). Currently, the relationship between metabolic abnormalities and FLS proliferation is a new focus of investigation. However, little is known regarding the relationship between amino acid metabolism and RA. Methods: The concentrations of amino acids and cytokines in the synovial fluid of RA (n=9) and osteoarthritis (OA,n=9) were detected by LC-MS/MS and CBA assay, respectively. The mRNA and protein expression of CAT-1 were determined in FLSs isolated from RA and OA patients by real-time PCR and western blotting. MTT assay, cell cycle, apoptosis, invasion and cytokine secretion were determined in FLSs knocked down of CAT-1 using siRNA or treated with D-arginine under normoxic and hypoxic culture conditions. A mouse collagen-induced arthritis (CIA) model was applied to test the therapeutic potential of blocking the uptake of L-arginine in vivo.Results: L-arginine was upregulated in the synovial fluid of RA patients and was positively correlated with elevation of the cytokines IL-1β, IL-6 and IL-8. Further examination demonstrated that cationic amino acid transporter-1 (CAT-1) was the primary transporter for L-arginine and was overexpressed on RA FLSs compared to OA FLSs. Moreover, knockdown of CAT-1 using siRNA or inhibition of L-arginine uptake using D-arginine significantly suppressed L-arginine metabolism, cell proliferation, migration and cytokine secretion in RA FLSs under normoxic and hypoxic culture conditions in vitro but increased cell apoptosis in a dose-dependent manner. Meanwhile, in vivo assays revealed that an L-arginine-free diet or blocking the uptake of L-arginine using D-arginine suppressed arthritis progression in CIA mice. Conclusion: CAT-1 is upregulated and promotes FLS proliferation by taking up L-arginine, thereby promoting RA progression.

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Commentary on an article by Gaetano J. Scuderi, MD, et al.: “Identification of a Novel Fibronectin-Aggrecan Complex in the Synovial Fluid of Knees with Painful Meniscal Injury”

The Journal of Bone and Joint Surgery (American) ◽

10.2106/jbjs.j.01774 ◽

2011 ◽

Vol 93 (4) ◽

pp. e13(1)

Author(s):

Armando F Vidal

Keyword(s):

Synovial Fluid ◽

Meniscal Injury

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P058 Chemokine CCL18 enriched in synovial fluid is involved in joint destruction through promoting migration of fibroblast-like synoviocytes in rheumatoid arthritis

10.1136/annrheumdis-2018-ewrr2019.50 ◽

2019 ◽

Author(s):

Y-Q Mo ◽

G-C Zhang ◽

J Jing ◽

J-D Ma ◽

L Dai

Keyword(s):

Rheumatoid Arthritis ◽

Synovial Fluid ◽

Joint Destruction ◽

Fibroblast Like Synoviocytes

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Soluble CD14 Levels in the Serum, Synovial Fluid, and Cerebrospinal Fluid of Patients with Various Stages of Lyme Disease

The Journal of Infectious Diseases ◽

10.1086/315357 ◽

2000 ◽

Vol 181 (3) ◽

pp. 1185-1188 ◽

Cited By ~ 24

Author(s):

Bo Lin ◽

Richard Noring ◽

Allen C. Steere ◽

Mark S. Klempner ◽

Linden T. Hu

Keyword(s):

Cerebrospinal Fluid ◽

Lyme Disease ◽

Synovial Fluid ◽

Soluble Cd14

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Phenotypic and functional characterization of synovial fluid-derived fibroblast-like synoviocytes in rheumatoid arthritis

Scientific Reports ◽

10.1038/s41598-021-01692-7 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Ditte Køster ◽

Johanne Hovgaard Egedal ◽

Søren Lomholt ◽

Malene Hvid ◽

Martin R. Jakobsen ◽

...

Keyword(s):

Rheumatoid Arthritis ◽

Synovial Fluid ◽

Mononuclear Cells ◽

Functional Characterization ◽

Surface Protein ◽

Tissue Destruction ◽

Peripheral Blood Mononuclear ◽

Surface Protein Expression ◽

Fibroblast Like Synoviocytes

AbstractFibroblast-like synoviocytes (FLS) play an important pathological role in persistent inflammatory joint diseases such as rheumatoid arthritis (RA). These cells have primarily been characterized in the RA synovial membrane. Here we aim to phenotypically and functionally characterize cultured synovial fluid-derived FLS (sfRA-FLS). Paired peripheral blood mononuclear cells (PBMC) and sfRA-FLS from patients with RA were obtained and monocultures of sfRA-FLS and autologous co-cultures of sfRA-FLS and PBMC were established. The in situ activated sfRA-FLS were CD34-, CD45-, Podoplanin+, Thymocyte differentiation antigen-1+. SfRA-FLS expressed uniform levels of NFкB-related pathway proteins and secreted several pro-inflammatory cytokines dominated by IL-6 and MCP-1. In a co-culture model with autologous PBMC, the ICAM-1 and HLA-DR expression on sfRA-FLS and secretion of IL-1β, IL-6, and MCP-1 increased. In vivo, human sfRA-FLS were cartilage invasive both at ipsilateral and contralateral implantation site. We conclude that, sfRA-FLS closely resemble the pathological sublining layer FLS subset in terms of surface protein expression, cytokine production and leukocyte cross-talk potential. Further, sfRA-FLS are comparable to tissue-derived FLS in their capabilities to invade cartilage at implantation sites but also spread tissue destruction to a distant site. Collectively, sfRA-FLS can serve as a an easy-to-obtain source of pathological sublining FLS in RA.

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T helper cells in synovial fluid of patients with rheumatoid arthritis primarily have a Th1 and a CXCR3+Th2 phenotype

Arthritis Research & Therapy ◽

10.1186/s13075-020-02349-y ◽

2020 ◽

Vol 22 (1) ◽

Author(s):

Jonathan Aldridge ◽

Anna-Karin H. Ekwall ◽

Linda Mark ◽

Beatrice Bergström ◽

Kerstin Andersson ◽

...

Keyword(s):

Rheumatoid Arthritis ◽

Synovial Fluid ◽

Receptor Expression ◽

Th2 Cells ◽

T Helper ◽

Tfh Cells ◽

Follicular Helper ◽

Culture Supernatants ◽

Bead Arrays ◽

Fibroblast Like Synoviocytes

Abstract Background The majority of CD4+ T helper (Th) cells found in the synovial fluid (SF) of patients with rheumatoid arthritis (RA) express CXCR3, a receptor associated with Th1 cells. In blood, subsets of Th2 and Th17 cells also express CXCR3, but it is unknown if these cells are present in RA SF or how cytokines from these subsets affect cytokine/chemokine secretion by fibroblast-like synoviocytes (FLS) from patients with RA. Methods We examined the proportions of Th1, Th2, CXCR3+Th2, Th17, CXCR3+Th17, Th1Th17, peripheral T helper (TPh) and T follicular helper (TFh) cells in paired SF and blood, as well as the phenotype of TPh and TFh cells in RA SF (n = 8), by the use of flow cytometry. We also examined the cytokine/chemokine profile in paired SF and plasma (n = 8) and in culture supernatants of FLS from patients with chronic RA (n = 7) stimulated with Th-associated cytokines, by the use of cytometric bead arrays and ELISA. Cytokine receptor expression in FLS (n = 3) were assessed by the use of RNA sequencing and qPCR. Results The proportions of Th1 and CXCR3+Th2 cells were higher in SF than in blood (P < 0.05). TPh and PD-1highTFh in RA SF were primarily of a Th1 and a CXCR3+Th2 phenotype. Moreover, the levels of CXCL9, CXCL10, CCL20, CCL2, CXCL8, IL-6 and IL-10 were higher in SF than in plasma (P < 0.05). Lastly, IL-4, IL-13 and IL-17A induced RA FLS to secrete proinflammatory IL-6, CCL2, CXCL1 and CXCL8, while IFNγ mainly induced CXCL10. Conclusion These findings indicate that not only Th1 but also CXCR3+Th2 cells may have a pathogenic role in RA synovial inflammation.

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