Stocker K M, Baizer L, Coston T, Sherman L, Ciment G
Department of Cell Biology & Anatomy, Oregon Health Sciences University, Portland 97201-3098, USA.
J Neurobiol. 1995 Aug;27(4):535-52. doi: 10.1002/neu.480270408.
Neurofibromatosis type 1 (NF1) is a common human genetic disease involving various neural crest (NC)-derived cell types, in particular, Schwann cells and melanocytes. The gene responsible for NF1 encodes the protein neurofibromin, which contains a domain with amino acid sequence homology to the ras-guanosine triphosphatase activating protein, suggesting that neurofibromin may play a role in intracellular signaling pathways regulating cellular proliferation or differentiation, or both. To determine whether neurofibromin plays a role in NC cell development, we used antibodies raised against human neurofibromin fusion proteins in western blot and immunocytochemical studies of early avian embryos. These antibodies specifically recognized the 235 kD chicken neurofibromin protein, which was expressed in migrating trunk and cranial NC cells of early embryos (E1.5 to E2), as well as in endothelial and smooth muscle cells of blood vessels and in a subpopulation of non-NC-derived cells in the dermamyotome. At slightly later stages (E3 to E5), neurofibromin immunostaining was observed in various NC derivatives, including dorsal root ganglia and peripheral nerves, as well as non-NC-derived cell types, including heart, skeletal muscle, and kidney. At still later stages (E7 to E9), neurofibromin immunoreactivity was found in almost all tissues in vivo. To determine whether the levels of neurofibromin changed during melanocyte and Schwann cell development, tissue culture experiments were performed. Cultured NC cells were found to express neurofibromin at early time points in culture, but the levels of immunoreactivity decreased as the cells underwent pigmentation. Schwann cells, on the other hand, continued to express neurofibromin in culture. These data suggest, therefore, that neurofibromin may play a role in the development of both NC cells and a variety of non-NC-derived tissues.
1型神经纤维瘤病（NF1）是一种常见的人类遗传病，涉及多种神经嵴（NC）来源的细胞类型，特别是施万细胞和黑素细胞。导致NF1的基因编码神经纤维瘤蛋白，该蛋白含有一个与ras - 鸟苷三磷酸酶激活蛋白具有氨基酸序列同源性的结构域，这表明神经纤维瘤蛋白可能在调节细胞增殖或分化或两者的细胞内信号通路中发挥作用。为了确定神经纤维瘤蛋白是否在NC细胞发育中起作用，我们在早期鸡胚的蛋白质印迹和免疫细胞化学研究中使用了针对人神经纤维瘤蛋白融合蛋白产生的抗体。这些抗体特异性识别235 kD的鸡神经纤维瘤蛋白，该蛋白在早期胚胎（E1.5至E2）迁移的躯干和颅神经嵴细胞中表达，也在血管的内皮细胞和平滑肌细胞以及真皮肌节中非NC来源的细胞亚群中表达。在稍晚阶段（E3至E5），在各种神经嵴衍生物中观察到神经纤维瘤蛋白免疫染色，包括背根神经节和周围神经，以及非神经嵴来源的细胞类型，包括心脏、骨骼肌和肾脏。在更晚阶段（E7至E9），在体内几乎所有组织中都发现了神经纤维瘤蛋白免疫反应性。为了确定神经纤维瘤蛋白水平在黑素细胞和施万细胞发育过程中是否发生变化，进行了组织培养实验。发现培养的神经嵴细胞在培养早期表达神经纤维瘤蛋白，但随着细胞色素沉着，免疫反应性水平下降。另一方面，施万细胞在培养中继续表达神经纤维瘤蛋白。因此，这些数据表明神经纤维瘤蛋白可能在神经嵴细胞和多种非神经嵴来源组织的发育中起作用。
