Nishida Atsushi, Andoh Akira, Shioya Makoto, Kim-Mitsuyama Shokei, Takayanagi Atsushi, Fujiyama Yoshihide
Department of Medicine, Shiga University of Medical Science, Seta-Tukinowa, Otsu 520-2192, Japan.
Am J Physiol Gastrointest Liver Physiol. 2008 Mar;294(3):G831-8. doi: 10.1152/ajpgi.00535.2007. Epub 2008 Jan 31.
Interleukin (IL)-32 is a recently described proinflammatory cytokine, characterized by the induction of nuclear factor (NF)-kappaB activation. We studied IL-32alpha expression in human pancreatic periacinar myofibroblasts, which play important roles in the regulation of extracellular matrix metabolism and inflammatory responses in the pancreas. IL-32alpha protein expression was evaluated by Western blot analyses, and IL-32alpha mRNA expression was analyzed by Northern blot and real-time PCR analyses. IL-32alpha mRNA was weakly expressed without a stimulus, and its expression was markedly enhanced by IL-1beta, IFN-gamma, and TNF-alpha. IL-1beta, IFN-gamma, and TNF-alpha enhanced intracellular accumulation of IL-32alpha protein, but IL-32alpha was not detected in supernatants. Each cytokine dose and time dependently induced IL-32alpha mRNA expression. An inhibitor of phosphatidylinositol 3-kinase (LY294002) significantly suppressed IL-1beta-, IFN-gamma-, and TNF-alpha-induced IL-32alpha mRNA expression, although MAPK inhibitors had no effect. Akt activation in response to these cytokines was confirmed by Western blot. Furthermore, LY294002 suppressed both IL-1beta- and TNF-alpha-induced NF-kappaB activation and IL-1beta-, TNF-alpha-, and IFN-gamma-induced activated protein-1 (AP-1) activation. Blockade of NF-kappaB and AP-1 activation by an adenovirus expressing a stable mutant form of IkappaBalpha and a dominant negative mutant of c-Jun markedly suppressed IL-1beta-, IFN-gamma-, and/or TNF-alpha-induced IL-32alpha mRNA expression. Human pancreatic periacinar myofibroblasts expressed IL-32alpha in response to IL-1beta, TNF-alpha, and IFN-gamma. IL-32alpha mRNA expression is dependent on interactions between the phosphatidylinositol 3-kinase/Akt-pathway and the NF-kappaB/AP-1 system.
白细胞介素（IL）-32是一种最近被描述的促炎细胞因子，其特征在于诱导核因子（NF）-κB活化。我们研究了人胰腺腺泡周围肌成纤维细胞中IL-32α的表达，这些细胞在胰腺细胞外基质代谢和炎症反应的调节中起重要作用。通过蛋白质印迹分析评估IL-32α蛋白表达，并通过Northern印迹和实时PCR分析来分析IL-32αmRNA表达。在没有刺激的情况下，IL-32αmRNA表达较弱，而白细胞介素-1β（IL-1β）、干扰素-γ（IFN-γ）和肿瘤坏死因子-α（TNF-α）可显著增强其表达。IL-1β、IFN-γ和TNF-α可增强IL-32α蛋白在细胞内的积累，但在上清液中未检测到IL-32α。每种细胞因子的剂量和时间均呈依赖性地诱导IL-32αmRNA表达。磷脂酰肌醇3-激酶抑制剂（LY294002）可显著抑制IL-1β、IFN-γ和TNF-α诱导的IL-32αmRNA表达，而丝裂原活化蛋白激酶（MAPK）抑制剂则无此作用。通过蛋白质印迹证实了这些细胞因子诱导的Akt活化。此外，LY294002可抑制IL-1β和TNF-α诱导的NF-κB活化以及IL-1β、TNF-α和IFN-γ诱导的活化蛋白-1（AP-1）活化。通过表达稳定突变形式的IkappaBalpha的腺病毒和c-Jun的显性负突变体对NF-κB和AP-1活化的阻断，可显著抑制IL-1β、IFN-γ和/或TNF-α诱导的IL-32αmRNA表达。人胰腺腺泡周围肌成纤维细胞在IL-1β、TNF-α和IFN-γ刺激下表达IL-32α。IL-32αmRNA表达依赖于磷脂酰肌醇3-激酶/Akt信号通路与NF-κB/AP-1系统之间的相互作用。
