Maxwell G D, Reid K, Elefanty A, Bartlett P F, Murphy M
Department of Anatomy, University of Connecticut Health Center, Farmington 06032, USA.
Proc Natl Acad Sci U S A. 1996 Nov 12;93(23):13274-9. doi: 10.1073/pnas.93.23.13274.
Growth of mouse neural crest cultures in the presence of glial cell line-derived neurotrophic factor (GDNF) resulted in a dramatic dose-dependent increase in the number of tyrosine hydroxylase (TH)-positive cells that developed when 5% chicken embryo extract was present in the medium. In contrast, growth in the presence of bone morphogenetic protein (BMP)-2, BMP-4, BMP-6, transforming growth factor (TGF) beta 1, TGF-beta 2, and TGF-beta 3 elicited no increase in the number of TH-positive cells. The TH-positive cells that developed in the presence of GDNF had neuronal morphology and contained the middle and low molecular weight neurofilament proteins. Numerous TH-negative cells with the morphology of neurons also were observed in GDNF-treated cultures. Analysis revealed that the period from 6 to 12 days in vitro was the critical time for exposure to GDNF to generate the increase in TH-positive cell number. The growth factors neurotrophin-3 and fibroblast growth factor-2 elicited increases in the number of TH-positive cells similar to that seen in response to GDNF. In contrast, nerve growth factor was unable to substitute for GDNF. These findings extend the previously reported biological activities of GDNF by showing that it can act on mouse neural crest cultures to promote the development of neurons.
在胶质细胞系源性神经营养因子（GDNF）存在的情况下培养小鼠神经嵴细胞，当培养基中含有5%鸡胚提取物时，酪氨酸羟化酶（TH）阳性细胞的数量会呈显著的剂量依赖性增加。相比之下，在骨形态发生蛋白（BMP）-2、BMP-4、BMP-6、转化生长因子（TGF）β1、TGF-β2和TGF-β3存在的情况下培养，TH阳性细胞的数量没有增加。在GDNF存在的情况下发育的TH阳性细胞具有神经元形态，并含有中、低分子量神经丝蛋白。在GDNF处理的培养物中也观察到许多具有神经元形态的TH阴性细胞。分析表明，体外培养6至12天是接触GDNF以增加TH阳性细胞数量的关键时期。神经营养因子-3和成纤维细胞生长因子-2引起的TH阳性细胞数量增加与GDNF引起的相似。相比之下，神经生长因子不能替代GDNF。这些发现扩展了先前报道的GDNF的生物学活性，表明它可以作用于小鼠神经嵴细胞培养物以促进神经元的发育。
