SAT0065 Alpha-enolase facilitates migration of fibroblast-like synoviocytes in rheumatoid arthritis. (23rd January 2014)

• Record Type: Journal Article
• Authors: Shin, K.; Park, J.A.; Bae, S.; Kang, J.S.; Song, Y.W.
• Is Part Of: Annals of the rheumatic diseases. Volume 71(2012)Supplement 3
• Page Start: 492
• Page End: 492
• Publication Date: 2014-01-23
• Subjects: Rheumatism -- Periodicals; 616.723005
• DOI: 10.1136/annrheumdis-2012-eular.3012
• Languages: English
• ISSNs: 0003-4967

Abstract

Abstract : Background: Alpha-enolase (ENO1) is a multifunctional glycolytic enzyme ubiquitously expressed in the cytoplasm. Citrullinated ENO1 is reported to be a candidate autoantigen in rheumatoid arthritis (RA), yet its specific biologic function remains unknown. Histologic analysis indicates that ENO1 is expressed in fibroblast-like synoviocytes (FLS), monocytes, and endothelial cells in the synovium. In pro-inflammatory conditions, ENO1 is translocated to the cell surface where it activates plasminogen. Its expression in monocytes mediates migration of the cells into inflamed lung tissues in animal models. Objectives: Our aim was to investigate the role of surface-expressed ENO1 in RA FLS, the key constituent of pannus in RA synovium. Methods: FLS from RA synovial tissues were isolated and cultured in vitro . ENO1 expression on the cell surface was assessed by confocal microscopy. Cell surface-expressed ENO1 was treated with a mouse anti-human ENO1-stimulating monoclonal antibodyas well as an isotype control. Scratch test of cultured FLS and transwell experiments under platelet-derived growth factor (PDGF) were performed to assess FLS migration. Cytoskeletal rearrangement was analyzed after staining FLS with an anti-fillagrin antibody. Fluo-4 fluorophore was used for calcium-flux assays directly on discs plated with FLS. Results: Cell surface ENO1 expression was low in (5∼6 passages) cultured FLSunder normal condtions. However, overnight TNF-alpha (as low as 0.1ng/ml)treatment induced ENO1 translocation to the cell surface, which peaked at 24 hours (figure ). Stimulation of cell surface-expressed ENO1 induced faster repopulation of FLS in the scratch test assay, and increased PDGF-induced transwell migration. Cytoplasmic actin filament rearrangement in FLS was markedly enhanced with ENO1 stimulation. Moreover, ENO1 stimulation induced a positive calcium flux response in FLS under intravital confocal microscopy. Conclusions: Translocation of cytoplasmic ENO1 to the cell surface in RA FLS is potentiated by TNF-alpha. Our results indicate that ENO1 can contribute to migration of RA FLS, especially under the pro-inflammatory milieu as in the RA synovium. Disclosure of Interest: None Declared