Department of Medicine, Graduate School of Medicine, Shiga University of Medical Science, Seta Tukinowa, Otsu, Japan.
Int J Mol Med. 2011 Feb;27(2):263-8. doi: 10.3892/ijmm.2010.575. Epub 2010 Dec 6.
Interleukin (IL)-32 is a recently described proinflammatory cytokine, characterized by induction of nuclear factor (NF)-κB activation. We studied IL-32α expression in human colonic subepithelial myofibroblasts (SEMFs). Colonic SEMFs were isolated from normal human colon tissue. IL-32α protein expression was evaluated by Western blot analyses, and IL-32α mRNA expression was analyzed by real-time PCR. IL-32α mRNA was weakly expressed without a stimulus, and its expression was markedly enhanced by IL-1ß and TNF-α. IL-1ß and TNF-α enhanced intracellular accumulation of IL-32α protein, but IL-32α was not detected in supernatants. Each cytokine dose- and time-dependently induced IL-32α mRNA expression. An inhibitor of phosphatidylinositol 3-kinase (LY294002) significantly suppressed IL-1ß- and TNF-α-induced IL-32α mRNA expression, although MAPK inhibitors had no effect. Akt activation in response to these cytokines was confirmed by Western blotting. Blockade of NF-κB activation by an adenovirus expressing a stable mutant form of IκBα markedly suppressed IL-1ß- and TNF-α-induced IL-32α mRNA expression. Human colonic SEMFs expressed IL-32α in response to IL-1ß and TNF-α. IL-32α mRNA expression depends on the phosphatidylinositol 3-kinase and the NF-κB system.
白细胞介素 (IL)-32 是一种新发现的促炎细胞因子，其特征在于诱导核因子 (NF)-κB 激活。我们研究了人结肠黏膜下肌成纤维细胞 (SEMFs) 中的 IL-32α 表达。从正常人类结肠组织中分离出结肠 SEMFs。通过 Western blot 分析评估 IL-32α 蛋白表达，通过实时 PCR 分析 IL-32α mRNA 表达。在没有刺激的情况下，IL-32α mRNA 表达较弱，而在 IL-1β 和 TNF-α 的作用下，其表达明显增强。IL-1β 和 TNF-α 增强了细胞内 IL-32α 蛋白的积累，但在上清液中未检测到 IL-32α。每种细胞因子均呈剂量和时间依赖性诱导 IL-32α mRNA 表达。PI3K 抑制剂 (LY294002) 显著抑制了 IL-1β 和 TNF-α 诱导的 IL-32α mRNA 表达，尽管 MAPK 抑制剂没有影响。通过 Western blot 证实了这些细胞因子对 Akt 的激活。通过表达稳定的 IκBα 突变形式的腺病毒阻断 NF-κB 激活，显著抑制了 IL-1β 和 TNF-α 诱导的 IL-32α mRNA 表达。人结肠 SEMFs 对 IL-1β 和 TNF-α 反应表达 IL-32α。IL-32α mRNA 表达依赖于 PI3K 和 NF-κB 系统。
