Sano M, Iwanaga M
Institute for Development Research, Aichi Human Service Center, Japan.
Brain Res. 1996 Aug 19;730(1-2):212-22. doi: 10.1016/0006-8993(96)00449-0.
We have examined the local control by nerve growth factor (NGF) of the outgrowth of neurites from clonal cells, PC12D, a subline whose phenotype resembles that of the parent PC12 cell line in the NGF-primed state. We show here that (i) the outgrowth of neurites, and their survival can be induced by NGF in enucleated PC12D cells (ii) individual neurites of a single 'giant cell', produced by cell fusion of PC12D cells, can respond independently to the NGF in the local environment, (iii) dissected neurites from giant cells survive for longer in medium that contains NGF than in medium that does not, (iv) in PC12D cells, the rapid formation of ruffles in response to NGF, which appears to be based on increased cell-substratum adhesion, leads to the subsequent formation of neurites, and (v) upon addition of NGF, the movement of short processes displaces polylysine-coated beads in the vicinity of neurites. These observations suggest that the NGF-dependent maintenance or extension of neurites might be controlled within the neurites themselves and might not require the direct involvement of the cell body, even in PC12 cells. It seems possible that any NGF-induced changes that promote an increase in cell-substratum adhesion might be responsible for the initiation and elongation of neurites. It also seems possible that the growth of neurites towards a source of NGF might be based on repeated rounds of extension and retraction of filopodia and neurites in a manner that depends on the concentration of NGF.
我们研究了神经生长因子（NGF）对克隆细胞PC12D神经突生长的局部调控，PC12D是一个亚系，其表型在NGF预处理状态下类似于亲本PC12细胞系。我们在此表明：（i）在去核的PC12D细胞中，NGF可诱导神经突生长及其存活；（ii）由PC12D细胞融合产生的单个“巨细胞”的单个神经突可独立响应局部环境中的NGF；（iii）从巨细胞分离的神经突在含有NGF的培养基中比在不含NGF的培养基中存活时间更长；（iv）在PC12D细胞中，对NGF快速形成的褶皱似乎基于细胞与底物粘附增加，随后导致神经突形成；（v）加入NGF后，短突起的运动会使神经突附近的聚赖氨酸包被的珠子发生位移。这些观察结果表明，即使在PC12细胞中，NGF依赖的神经突维持或延长可能在神经突自身内部受到调控，可能不需要细胞体的直接参与。似乎任何由NGF诱导的促进细胞与底物粘附增加的变化都可能是神经突起始和延长的原因。神经突向NGF来源生长也似乎可能基于丝状伪足和神经突以依赖于NGF浓度的方式反复进行延伸和回缩。
