Division of Gastroenterology and Hepatology, Department of Internal Medicine, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan.
Division of Gastroenterology and Hepatology, Department of Internal Medicine, Shuang-Ho Hospital, New Taipei, Taiwan.
Front Immunol. 2019 Feb 26;10:109. doi: 10.3389/fimmu.2019.00109. eCollection 2019.
The receptor for advanced glycation end products (RAGE) interacts with various molecules in the cell membrane to induce an inflammatory response. The cytolethal distending toxin (CDT) produced by contains three subunits: CdtA, CdtB, and CdtC. Amongst, CdtA and CdtC interact with membrane lipid rafts, by which CdtB enters the nucleus to induce pathogenesis. In this study, we first explored the relationships between RAGE, lipid rafts, and inflammation in gastrointestinal epithelial cells exposed to CDT. Our results showed that CDT activated the expression of RAGE and high mobility group box 1 (HMGB1), followed by the recruitment of RAGE into lipid rafts. In contrast, RAGE antagonist inhibited CDT-induced inflammation via the RAGE-HMGB1 axis. Disruption of lipid rafts decreased CDT-induced downstream signaling, which in turn attenuated the inflammatory response. Furthermore, studies revealed severe inflammation and upregulation of RAGE and IL-1β in the intestinal tissues of CDT-treated mice. These results demonstrate that mobilization of RAGE to lipid rafts plays a crucial role in CDT-induced inflammation.
晚期糖基化终产物受体(RAGE)与细胞膜中的各种分子相互作用,引发炎症反应。 产生的细胞致死性扩张毒素(CDT)包含三个亚基:CdtA、CdtB 和 CdtC。其中,CdtA 和 CdtC 与膜脂筏相互作用,CdtB 进入细胞核诱导发病机制。在这项研究中,我们首先探讨了胃肠道上皮细胞暴露于 CDT 时 RAGE、脂筏和炎症之间的关系。结果表明,CDT 激活了 RAGE 和高迁移率族蛋白 B1(HMGB1)的表达,随后 RAGE 被募集到脂筏中。相反,RAGE 拮抗剂通过 RAGE-HMGB1 轴抑制 CDT 诱导的炎症。破坏脂筏会降低 CDT 诱导的下游信号转导,从而减轻炎症反应。此外,研究还揭示了 CDT 处理小鼠的肠道组织中严重的炎症和 RAGE 及 IL-1β 的上调。这些结果表明,RAGE 向脂筏的募集在 CDT 诱导的炎症中起着关键作用。