Reza J N, Gavazzi I, Cohen J
Department of Developmental Neurobiology, King's College, London Bridge, United Kingdom.
Mol Cell Neurosci. 1999 Oct-Nov;14(4-5):317-26. doi: 10.1006/mcne.1999.0786.
Neuropilin-1 on the growth cones of NGF-dependent embryonic dorsal root ganglion (DRG) neurons mediates the repulsive effects of secreted semaphorin3a, but its role in adult neurons is unknown. Here we show that most adult rat DRG neurons, regardless of cell diameter/afferent phenotype, express neuropilin-1 protein in vitro. However, the response of growth cones belonging to these neurons (induced by recombinant collapsin-1/semaphorin3a and blocked by the anti-neuropilin-1 antibody) was restricted to those of small cell body diameter (<30 microm), corresponding primarily to nociceptive sensory afferents. Neurotrophic factors had a differential effect on neuropilin-1 expression in vitro, with DRG neurons cultured in either NGF or GDNF expressing the highest levels on their neurites. These findings suggest that neuropilin-1-mediated repellent effects of semaphorins may regulate the behavior of nociceptive sensory axons in the adult as well as the embryonic peripheral nervous system.
神经营养因子依赖的胚胎背根神经节（DRG）神经元生长锥上的神经纤毛蛋白-1介导分泌型信号素3a的排斥作用，但其在成年神经元中的作用尚不清楚。在此我们表明，大多数成年大鼠DRG神经元，无论细胞直径/传入表型如何，在体外均表达神经纤毛蛋白-1。然而，这些神经元的生长锥对重组塌陷蛋白-1/信号素3a的反应（并被抗神经纤毛蛋白-1抗体阻断）仅限于小细胞体直径（<30微米）的神经元，主要对应于伤害性感觉传入神经。神经营养因子在体外对神经纤毛蛋白-1的表达有不同影响，在NGF或GDNF中培养的DRG神经元在其神经突上表达水平最高。这些发现表明，信号素通过神经纤毛蛋白-1介导的排斥作用可能在成年以及胚胎外周神经系统中调节伤害性感觉轴突的行为。
