Trichostatin A cooperates with Fas-mediated signal to induce apoptosis in rheumatoid arthritis synovial fibroblasts.
OBJECTIVE
To clarify the effects of trichostatin A (TSA), a histone deacetylase inhibitor, on the growth and survival of rheumatoid arthritis synovial fibroblasts (RA-SF).


METHODS
Cell viability was assessed using a WST-8 assay and direct cell counting. Apoptosis was detected by annexin V staining on a flow cytometer. Protein and mRNA expression was determined by Western blotting, flow cytometry, and RT-PCR.


RESULTS
TSA suppressed cell growth of RA-SF in a dose-dependent manner, as determined by WST-8 assay and direct cell counting. Other histone deacetylase inhibitors also showed inhibitory effects on RA-SF proliferation. TSA upregulated p21(WAF1/CIP1) cell cycle inhibitor, suggesting that cell cycle arrest is involved in the reduction of cell numbers. In addition, TSA cooperated with Fas-induced pathway to induce cell death, determined by WST-8 assay and annexin V staining. TSA reduced FLICE inhibitory protein (FLIP) expression but not Bcl-2, Bcl-XL, and Fas expression, indicating that the synergistic effect may be through downregulation of FLIP.


CONCLUSIONS
TSA has antirheumatic effects on RA-SF and might be a potential therapeutic tool for the treatment of RA.
Morinobu
Akio
A
Department of Clinical Pathology and Immunology, Kobe University Graduate Schoool of Medicine, Kobe 650-0017, Japan. morinobu@med.kobe-u.ac.jp
Wang
Biao
B
Liu
Jun
J
Yoshiya
Shinichi
S
Kurosaka
Masahiro
M
Kumagai
Shunichi
S
D017209:Apoptosis / Q000187:drug effects*; D001172:Arthritis, Rheumatoid; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D050759:Cyclin-Dependent Kinase Inhibitor p21 / Q000235:genetics / Q000378:metabolism; D004305:Dose-Response Relationship, Drug; D004338:Drug Combinations; D004357:Drug Synergism; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005347:Fibroblasts / Q000187:drug effects / Q000378:metabolism / Q000473:pathology; D005434:Flow Cytometry; D019084:Fluorescent Antibody Technique, Indirect; D006801:Humans; D006877:Hydroxamic Acids / Q000494:pharmacology*; D012333:RNA, Messenger / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015398:Signal Transduction; D013583:Synovial Membrane / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D019014:fas Receptor / Q000494:pharmacology*
C493956:CDKN1A protein, human; D050759:Cyclin-Dependent Kinase Inhibitor p21; D004338:Drug Combinations; D004791:Enzyme Inhibitors; D006877:Hydroxamic Acids; D012333:RNA, Messenger; D019014:fas Receptor; C012589:trichostatin A