Averill S, Delcroix J D, Michael G J, Tomlinson D R, Fernyhough P, Priestley J V
Department of Neuroscience, St. Bartholomew's School of Medicine and Dentistry, Queen Mary University of London, London, UK.
Mol Cell Neurosci. 2001 Aug;18(2):183-96. doi: 10.1006/mcne.2001.1015.
Mature dorsal root ganglion cells respond to neurotrophins, and the intracellular signalling pathways activated by neurotrophins have been characterized in vitro. We have now used immunocytochemistry and Western blots to examine the expression and activation of extracellular signal-regulated protein kinase-1/2 (ERK) in rat dorsal root ganglion cells in vivo, using antisera to total (tERK) and phosphorylated (pERK) forms. This has revealed a number of novel findings. tERK immunoreactivity is present in most dorsal root ganglion cells but is expressed most strongly in small (nociceptive) cells and, surprisingly, is absent in a population of large cells that expressed trkB or trkC but mainly lack p75(NTR) immunoreactivity. In contrast pERK is prominent in a few trkA cells and in satellite glial cells, and is further increased by NGF treatment. tERK and pERK both undergo fast anterograde and retrograde axonal transport, indicated by accumulation at a sciatic nerve ligature, and NGF reduces the level of retrograde pERK transport.
成熟的背根神经节细胞对神经营养因子有反应，并且神经营养因子激活的细胞内信号通路已在体外得到表征。我们现在使用免疫细胞化学和蛋白质印迹法，利用针对总（tERK）和磷酸化（pERK）形式的抗血清，来检测大鼠背根神经节细胞中细胞外信号调节蛋白激酶1/2（ERK）的表达和激活情况。这揭示了许多新发现。tERK免疫反应性存在于大多数背根神经节细胞中，但在小（伤害性感受）细胞中表达最强，令人惊讶的是，在一群表达trkB或trkC但主要缺乏p75（NTR）免疫反应性的大细胞中不存在。相比之下，pERK在一些trkA细胞和卫星胶质细胞中很突出，并且通过NGF处理会进一步增加。tERK和pERK都经历快速的顺行和逆行轴突运输，坐骨神经结扎处的积累表明了这一点，并且NGF会降低逆行pERK运输的水平。
