Delcroix Jean-Dominique, Valletta Janice S, Wu Chengbiao, Hunt Stephen J, Kowal Anthony S, Mobley William C
Department of Neurology and Neurological Sciences, Stanford University, Stanford 94305, USA.
Neuron. 2003 Jul 3;39(1):69-84. doi: 10.1016/s0896-6273(03)00397-0.
Target-derived NGF promotes the phenotypic maintenance of mature dorsal root ganglion (DRG) nociceptive neurons. Here, we provide in vivo and in vitro evidence for the presence within DRG neurons of endosomes containing NGF, activated TrkA, and signaling proteins of the Rap1/Erk1/2, p38MAPK, and PI3K/Akt pathways. Signaling endosomes were shown to be retrogradely transported in the isolated sciatic nerve in vitro. NGF injection in the peripheral target of DRG neurons increased the retrograde transport of p-Erk1/2, p-p38, and pAkt in these membranes. Conversely, NGF antibody injections decreased the retrograde transport of p-Erk1/2 and p-p38. Our results are evidence that signaling endosomes, with the characteristics of early endosomes, convey NGF signals from the target of nociceptive neurons to their cell bodies.
靶源性神经生长因子（NGF）促进成熟背根神经节（DRG）伤害性神经元的表型维持。在此，我们提供体内和体外证据，证明DRG神经元内存在含有NGF、活化的TrkA以及Rap1/Erk1/2、p38MAPK和PI3K/Akt信号通路信号蛋白的内体。信号内体在体外分离的坐骨神经中被证明可逆行运输。向DRG神经元的外周靶标注射NGF可增加这些膜中p-Erk1/2、p-p38和pAkt的逆行运输。相反，注射NGF抗体可减少p-Erk1/2和p-p38的逆行运输。我们的结果证明，具有早期内体特征的信号内体将NGF信号从伤害性神经元的靶标传递至其细胞体。
