Meyerson G, Parrow V, Gestblom C, Johansson I, Påhlman S
Department of Pathology, University of Uppsala, University Hospital, Sweden.
J Neurosci Res. 1994 Feb 15;37(3):303-12. doi: 10.1002/jnr.490370303.
The human neuroblastoma cell line, SH-SY5Y, differentiates into a neuronal, sympathetic phenotype in the presence of phorbol ester and serum. Growth cones prepared from differentiating SH-SY5Y cells have characteristics similar to those of growth cones from embryonic rat brain. In addition, SH-SY5Y growth cones contain ribosomes. In this study we show, by metabolic labeling of isolated growth cones, that local protein synthesis occurred in these structures. The pattern of labeled proteins was very similar to that of the corresponding cell body fraction. RNA was shown to be transported to the growth cone compartment, and by in situ hybridization. beta-actin mRNA could be visualized in intact neuritic growth cones. Comparison by Northern blot hybridizations of RNA prepared from growth cones and cell bodies, respectively, showed that mRNAs coding for growth-associated protein 43, microtubule-associated protein 2, actin, neuropeptide tyrosine, and glyceraldehyde-3-phosphate dehydrogenase were present in both fractions. In contrast, mRNAs coding for the nuclear proteins c-jun and N-myc were virtually absent in the growth cone, but readily detectable in the cell body preparation. The selective distribution of mRNAs to the growth cones was not restricted to stable, abundant mRNA species, since mRNA coding for the insulin-like growth factor I receptor was stable, but not present in growth cones. Thus, differentiating SH-SY5Y cells can sort and transport RNA to the growth cone compartment, suggesting that this system of clonal cells could be useful to unravel mechanisms involved in the compartmentalization of mRNA.
人神经母细胞瘤细胞系SH-SY5Y在佛波酯和血清存在的情况下可分化为具有神经元、交感神经表型的细胞。从分化的SH-SY5Y细胞制备的生长锥具有与胚胎大鼠脑生长锥相似的特征。此外，SH-SY5Y生长锥含有核糖体。在本研究中，我们通过对分离的生长锥进行代谢标记表明，这些结构中发生了局部蛋白质合成。标记蛋白质的模式与相应细胞体部分的模式非常相似。通过原位杂交显示RNA被转运到生长锥区室。在完整的神经突生长锥中可以观察到β-肌动蛋白mRNA。分别对从生长锥和细胞体制备的RNA进行Northern印迹杂交比较，结果表明生长相关蛋白43、微管相关蛋白2、肌动蛋白、神经肽酪氨酸和甘油醛-3-磷酸脱氢酶的编码mRNA在这两个部分中均存在。相比之下，核蛋白c-jun和N-myc的编码mRNA在生长锥中几乎不存在，但在细胞体制备物中很容易检测到。mRNA向生长锥的选择性分布并不局限于稳定、丰富的mRNA种类，因为胰岛素样生长因子I受体的编码mRNA是稳定的，但不存在于生长锥中。因此，分化的SH-SY5Y细胞可以对RNA进行分选并转运到生长锥区室，这表明这种克隆细胞系统可能有助于揭示mRNA区室化所涉及的机制。
