OBJECTIVE: To investigate the expression of the transcription factor Ets-1 in synovial tissue and cultured synovial fibroblasts from patients with rheumatoid arthritis (RA) and osteoarthritis (OA) and to study the regulation of Ets-1 expression and activation in synovial fibroblasts by proinflammatory cytokines. METHODS: In situ expression of Ets-1 in synovial tissue from RA and OA patients was examined by double immunohistochemistry. The effects of interleukin-1 (IL-1) or tumor necrosis factor alpha (TNFalpha) on Ets-1 expression and activation (DNA binding) in cultured synovial fibroblasts were analyzed by Western blotting and DNA gel shift assay, respectively. In addition, the intracellular location of Ets-1 in synovial fibroblasts was determined by immunofluorescence. RESULTS: Pronounced expression of Ets-1 was detected in synovial tissues from all RA patients evaluated, particularly in the synovial lining layer and the sublining areas. Ets-1 was expressed by both fibroblasts and macrophages as well as by endothelial cells, while only a few T cells stained positive for Ets-1. In synovial specimens from OA patients, Ets-1 expression was much less frequently observed and was largely restricted to vascular cells. Ets-1 was expressed to a similar degree in cultured synovial fibroblasts from RA and OA patients, as demonstrated by reverse transcriptase-polymerase chain reaction and Western blotting. Both IL-1 and TNFalpha induced pronounced up-regulation of Ets-1 in synovial fibroblasts. Moreover, binding of Ets-1 to its specific DNA binding site was induced by both cytokines, although with different time courses. Immunofluorescence staining revealed a dominant nuclear localization of Ets-1 in IL-1- or TNFalpha-stimulated synovial fibroblasts. CONCLUSION: The overexpression of Ets-1 observed in RA synovial tissue appears to be caused by TNFalpha and IL-1, suggesting that Ets-1 may be an important factor in the cytokine-mediated inflammatory and destructive cascade characteristic of RA.
OBJECTIVE: To investigate the expression of the transcription factor Ets-1 in synovial tissue and cultured synovial fibroblasts from patients with rheumatoid arthritis (RA) and osteoarthritis (OA) and to study the regulation of Ets-1 expression and activation in synovial fibroblasts by proinflammatory cytokines. METHODS: In situ expression of Ets-1 in synovial tissue from RA and OA patients was examined by double immunohistochemistry. The effects of interleukin-1 (IL-1) or tumor necrosis factor alpha (TNFalpha) on Ets-1 expression and activation (DNA binding) in cultured synovial fibroblasts were analyzed by Western blotting and DNA gel shift assay, respectively. In addition, the intracellular location of Ets-1 in synovial fibroblasts was determined by immunofluorescence. RESULTS: Pronounced expression of Ets-1 was detected in synovial tissues from all RApatients evaluated, particularly in the synovial lining layer and the sublining areas. Ets-1 was expressed by both fibroblasts and macrophages as well as by endothelial cells, while only a few T cells stained positive for Ets-1. In synovial specimens from OA patients, Ets-1 expression was much less frequently observed and was largely restricted to vascular cells. Ets-1 was expressed to a similar degree in cultured synovial fibroblasts from RA and OA patients, as demonstrated by reverse transcriptase-polymerase chain reaction and Western blotting. Both IL-1 and TNFalpha induced pronounced up-regulation of Ets-1 in synovial fibroblasts. Moreover, binding of Ets-1 to its specific DNA binding site was induced by both cytokines, although with different time courses. Immunofluorescence staining revealed a dominant nuclear localization of Ets-1 in IL-1- or TNFalpha-stimulated synovial fibroblasts. CONCLUSION: The overexpression of Ets-1 observed in RA synovial tissue appears to be caused by TNFalpha and IL-1, suggesting that Ets-1 may be an important factor in the cytokine-mediated inflammatory and destructive cascade characteristic of RA.
Authors: Wenguang Feng; Phillip Chumley; Minolfa C Prieto; Kayoko Miyada; Dale M Seth; Huma Fatima; Ping Hua; Gabriel Rezonzew; Paul W Sanders; Edgar A Jaimes Journal: Hypertension Date: 2015-01-26 Impact factor: 10.190
Authors: Johannes Grisar; Daniel Aletaha; Carl W Steiner; Theresa Kapral; Sabine Steiner; Marcus Säemann; Ilse Schwarzinger; Barbara Buranyi; Günter Steiner; Josef S Smolen Journal: Ann Rheum Dis Date: 2007-02-09 Impact factor: 19.103
Authors: Nicola H Dryden; Andrea Sperone; Silvia Martin-Almedina; Rebecca L Hannah; Graeme M Birdsey; Samia Taufiq Khan; Janice A Layhadi; Justin C Mason; Dorian O Haskard; Berthold Göttgens; Anna M Randi Journal: J Biol Chem Date: 2012-02-15 Impact factor: 5.157