[Effect of Triptolide on TNFalpha-induced activation of NF-kappaB and expression of COX-2 and iNOS in human rheumatoid arthritis synovial fibroblasts].
To explore the effects of Triptolide (TP) on TNFalpha-induced cell proliferation and expressions of cyclooxygenase-2 (COX-2), inducible nitric oxide synthase (iNOS) and their inducing products PGE2, NO in human rheumatoid arthritis synovial fibroblasts (RASF).



Fibroblasts (RASF) were obtained from synovial tissue of patients with RA and were cultured in vitro. RASF were stimulated with TNFalpha(20 microg/L) in the presence or absence of TP(0 - 100 microg/L) for 20 h. The RASF proliferation was determined by (3)H-TdR incorporation, and the productions of PGE2 and NO in culture supernatants of RASF were detected with competitive ELISA and enzyme reduction of nitrate. Expressions of COX-2 and iNOS mRNA in RASF were analyzed by semi-quantitative RT-PCR. Expressions of COX-2 and iNOS protein were estimated by Western-blot method and cellular enzyme immunoassay in synovial fibroblasts. NF-kappaB activity in whole-cell extract of RASF was also measured by an ELISA-based method.



TP (>20 microg/L) down-regulated markedly TNFalpha-induced COX-2 and iNOS mRNA and protein expression, and their inducing products PGE2 and NO of synovial fibroblasts. This effect was positively correlated with TP concentrations. NF-kappaB activity in TNFalpha-stimulated synovial cells was suppressed profoundly by TP treatment (IC(50) approximately 35microg/L). The activity of NF-kappaB was correlated with the levels of COX-2 and iNOS expression in TNFalpha-stimulated RASF. No change was observed in proliferation of synovial cells after treatment of TP.



TP could significantly down-regulate TNFalpha-induced COX-2, iNOS expression and production of PGE2, NO in human RASF, which is associated with the suppression of NF-kappaB activity.
Shao
Xue-ting
XT
The First Hospital, College of Medicine, Zhejiang University, Hangzhou 310003, China. shaoxt@126.com
Feng
Lei
L
Yao
Hang-ping
HP
Sun
Wen-ji
WJ
Zhang
Li-huang
LH
D001172:Arthritis, Rheumatoid / Q000188:drug therapy* / Q000378:metabolism; D051546:Cyclooxygenase 2; D004224:Diterpenes / Q000494:pharmacology*; D004852:Epoxy Compounds; D005347:Fibroblasts / Q000378:metabolism; D005786:Gene Expression Regulation / Q000187:drug effects; D006801:Humans; D007527:Isoenzymes / Q000032:analysis / Q000235:genetics*; D008565:Membrane Proteins; D016328:NF-kappa B / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000032:analysis / Q000235:genetics*; D052247:Nitric Oxide Synthase Type II; D010616:Phenanthrenes / Q000494:pharmacology*; D011451:Prostaglandin-Endoperoxide Synthases / Q000032:analysis / Q000235:genetics*; D012333:RNA, Messenger / Q000032:analysis; D013583:Synovial Membrane / Q000166:cytology / Q000378:metabolism; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
D004224:Diterpenes; D004852:Epoxy Compounds; D007527:Isoenzymes; D008565:Membrane Proteins; D016328:NF-kappa B; D010616:Phenanthrenes; D012333:RNA, Messenger; D014409:Tumor Necrosis Factor-alpha; C001899:triptolide; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases