Department of Medicine and Clinical Science, Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Okayama University, 2-5-1 Shikata-cho, Okayama 700-8558, Japan.
Cell Immunol. 2012;272(2):293-8. doi: 10.1016/j.cellimm.2011.09.004. Epub 2011 Sep 22.
TNF-like weak inducer of apoptosis (TWEAK), a member of the TNF superfamily, has been shown to increase cytokine production by rheumatoid arthritis (RA) fibroblast-like synoviocytes (FLS). In this study, we determined the effect of interaction between TWEAK and its receptor fibroblast growth factor-inducible-14 (Fn14) on cytokine expression in RAFLS.
RAFLS were obtained from surgical synovial specimens and used at passage 5-10. Cytokine protein and mRNA expression were measured with ELISA and real time-PCR, respectively. Apoptotic cells were detected by TUNEL assay. RelB activation was detected by Western blot analysis.
TWEAK inhibited IL-6 production from total synovial cells from RA. TWEAK weakly induced FLS IL-6 and IL-8, but in contrast TWEAK dose-dependently inhibited IL-6 and IL-8 production by TNFα-activated FLS. TWEAK did not induce apoptosis in FLS but inhibited proliferation of TNFα-activated FLS. TWEAK induced RelB activation and suppressed IL-6 mRNA expression in TNFα-activated FLS and both of these phenomenon were abolished by inhibition of new protein synthesis with cycloheximide.
TWEAK has a previously unsuspected inhibitory effect on cytokine production by TNFα-activated RAFLS. This observation suggests that the effects of TWEAK on cytokine expression varies with the pro-inflammatory context, and that in TNFα-activated states such as RA TWEAK may have a net inhibitory effect.
TNF 样凋亡弱诱导物（TWEAK）是 TNF 超家族的一员，已被证明可增加类风湿关节炎（RA）成纤维细胞样滑膜细胞（FLS）的细胞因子产生。在这项研究中，我们确定了 TWEAK 与其受体成纤维细胞生长因子诱导 14（Fn14）之间相互作用对 RAFLS 细胞因子表达的影响。
从手术滑膜标本中获得 RAFLS，并在第 5-10 代使用。通过 ELISA 和实时 PCR 分别测量细胞因子蛋白和 mRNA 的表达。通过 TUNEL 测定检测凋亡细胞。通过 Western blot 分析检测 RelB 激活。
TWEAK 抑制 RA 总滑膜细胞中 IL-6 的产生。TWEAK 弱诱导 FLS 的 IL-6 和 IL-8，但相反，TWEAK 浓度依赖性地抑制 TNFα 激活的 FLS 中 IL-6 和 IL-8 的产生。TWEAK 不会诱导 FLS 凋亡，但抑制 TNFα 激活的 FLS 的增殖。TWEAK 诱导 RelB 激活并抑制 TNFα 激活的 FLS 中的 IL-6 mRNA 表达，而这两种现象均被环已酰亚胺抑制新蛋白合成所消除。
TWEAK 对 TNFα 激活的 RAFLS 细胞因子产生具有先前未被怀疑的抑制作用。这一观察表明，TWEAK 对细胞因子表达的影响随促炎状态而变化，在 TNFα 激活状态下，如 RA 中，TWEAK 可能具有净抑制作用。
