TY - JOUR T1 - Tumor necrosis factor-alpha protects synovial cells from nitric oxide induced apoptosis through phosphoinositide 3-kinase Akt signal transduction. JF - The Journal of Rheumatology JO - J Rheumatol SP - 1061 LP - 1068 VL - 33 IS - 6 AU - Qingquan Chen AU - Bruno Casali AU - Laura Pattacini AU - Luigi Boiardi AU - Carlo Salvarani Y1 - 2006/06/01 UR - http://www.jrheum.org/content/33/6/1061.abstract N2 - OBJECTIVE: To investigate the anti-apoptotic role of tumor necrosis factor-a (TNF-a) and its signaling pathways in cultured human fibroblast-like synoviocytes (FLS) from patients with rheumatoid arthritis. METHODS: FLS were cultured in Dulbecco's modified Eagle's medium. Apoptotic cells were identified by TUNEL assay and Hoechst staining. Cell viability was determined by the MTT method. Expression of phospho-Akt and phospho-BAD was measured by Western blotting. RESULTS: A 24-h TNF-a treatment prevented FLS apoptosis induced by nitric oxide (NO) donor sodium nitroprusside dihydrate (SNP), achieving 70% protection. At 1-10 ng x ml-1 concentrations, TNF-a induced phosphorylation of Akt and BAD in a time and concentration-dependent manner. This effect was blocked by treatment with both LY294002 and nuclear factor-kB inhibitor pyrrolidine-dithiocarbamate. CONCLUSION: TNF-a has an anti-apoptotic effect in human FLS. Activation of Akt and BAD may have an important role in this process. ER -