Effects of nerve growth factor on cultured adult dorsal root ganglion neurons evaluated by enzyme immunoassay for neurofilament protein
Effects of nerve growth factor on cultured adult dorsal root ganglion neurons evaluated by enzyme immunoassay for neurofilament protein
复制标题
神经丝蛋白酶联免疫分析法评价神经生长因子对培养成体背根神经节神经元的影响
作者：
M. Tanaka;H. Kanai;S. Hirai
本研究应用新近发展的神经丝蛋白酶免疫分析法（EIA），观察了神经生长因子（NGF）对培养的10、72和114周龄小鼠背根神经节（DRG）神经元的影响。用EIA估计的神经丝蛋白水平被证明依赖于神经突长度以及神经元数量。神经丝蛋白水平随着添加的NGF的增加而增加，而存活的神经元数量不受NGF的影响。这表明，NGF加速神经突起的伸长，但不是成年DRG神经元存活所必需的。我们还发现，依赖于神经生长因子的神经突起延伸能力随着年龄的增长而降低，但即使在114周龄的小鼠中，大量的神经生长因子也能显著刺激神经突起延伸。因此，老年动物神经组织损伤后神经突再生减少可能部分与生长诱导物质如可能由靶细胞分泌的NGF的减少以及神经元合成或组装修复所需材料的能力降低有关。
We examined the effects of nerve growth factor (NGF) on cultured dorsal root ganglion (DRG) neurons obtained from 10-, 72-and 114-week-old mice by using a newly developed enzyme immunoassay (EIA) for neurofilament protein. Neurofilament protein levels estimated with EIA were demonstrated to depend on neurite length as well as on the neuronal number. Neurofilament protein levels increased with increasing NGF added, while surviving neuronal numbers were not affected by NGF. This indicates that NGF accelerated neurite elongation, but was not required for survival of adult DRG neurons. We also revealed that neurite-extending capacity dependent on NGF was reduced with aging, but a large amount of NGF significantly stimulated neurite extension even in 114-week old mice. Accordingly, diminished neurite regeneration after damage to neural tissue of aged animals may be related in part to a reduction of growth-inducing substances such as NGF possibly secreted by target cells as well as a reduction in the ability of neurons to synthesize or to assemble materials necessary for repair.