Huttunen H J, Fages C, Rauvala H
Laboratory of Molecular Neurobiology, Institute of Biotechnology, and Department of Biosciences, Division of Biochemistry, University of Helsinki, Finland.
J Biol Chem. 1999 Jul 9;274(28):19919-24. doi: 10.1074/jbc.274.28.19919.
Receptor for advanced glycation end products (RAGE) mediates neurite outgrowth in vitro on amphoterin-coated substrates. Ligation of RAGE by two other ligands, advanced glycation end products or amyloid beta-peptide, is suggested to play a role in cell injury mechanisms involving cellular oxidant stress and activation of the transcription factor NF-kappaB. However, the RAGE signaling pathways in neurite outgrowth and cell injury are largely unknown. Here we show that transfection of RAGE to neuroblastoma cells induces extension of filopodia and neurites on amphoterin-coated substrates. Furthermore, ligation of RAGE in transfected cells enhances NF-kappaB-dependent transcription. Both the RAGE-mediated neurite outgrowth and activation of NF-kappaB are blocked by deletion of the cytoplasmic domain of RAGE. Moreover, dominant negative Rac and Cdc42 but not dominant negative Ras inhibit the extension of neurites induced by RAGE-amphoterin interaction. In contrast, the activation of NF-kappaB is inhibited by dominant negative Ras but not Rac or Cdc42. These data suggest that distinct signaling pathways are used by RAGE to induce neurite outgrowth and regulate gene expression through NF-kappaB.
晚期糖基化终末产物受体(RAGE)在体外介导了神经突在两性霉素包被底物上的生长。另外两种配体,即晚期糖基化终末产物或β淀粉样肽与RAGE的结合,被认为在涉及细胞氧化应激和转录因子NF-κB激活的细胞损伤机制中发挥作用。然而,RAGE在神经突生长和细胞损伤中的信号通路在很大程度上尚不清楚。在此我们表明,将RAGE转染至神经母细胞瘤细胞可诱导丝状伪足和神经突在两性霉素包被底物上的延伸。此外,转染细胞中RAGE的结合增强了NF-κB依赖性转录。RAGE介导的神经突生长和NF-κB的激活均因RAGE胞质结构域的缺失而被阻断。而且,显性负性Rac和Cdc42而非显性负性Ras抑制了由RAGE-两性霉素相互作用诱导的神经突延伸。相反,显性负性Ras而非Rac或Cdc42抑制了NF-κB的激活。这些数据表明,RAGE利用不同的信号通路来诱导神经突生长并通过NF-κB调节基因表达。