Induction of ornithine decarboxylase by nerve growth factor dissociated from effects on survival and neurite outgrowth
Induction of ornithine decarboxylase by nerve growth factor dissociated from effects on survival and neurite outgrowth
复制标题
神经生长因子诱导鸟氨酸脱羧酶与对存活和神经突生长的影响无关
作者：
L. Greene;J. McGuire
几种真核细胞类型通过快速诱导鸟氨酸脱羧酶（ODC）活性对多种激素或生长促进剂作出反应（综述见参考文献1，2）。这种酶2和它催化合成的多胺1又被认为在介导随后对这些激素或复制因子的细胞反应中起作用。影响ODC活性的药物包括神经生长因子（NGF），这是一种影响交感神经元和反应性感觉神经元分化和存活的蛋白质3。MacDonnell等4已经证明，用NGF处理大鼠上级颈神经节导致ODC活性的快速（最大6-7小时）、转录依赖性增加。也有报道称，NGF治疗可增加大鼠脑中ODC的活性5。这些发现提示ODC可能介导神经元对NGF 4的其他反应。然而，我们在这里表明，抑制ODC活性及其诱导不干扰其他几种对NGF的反应，如促进神经突生长，维持生存和增加细胞大小。这些发现可能与ODC诱导在其他分化系统中的可能作用有关。
SEVERAL eukaryotic cell types respond to a variety of hormones or growth-promoting agents by a rapid induction of ornithine decarboxylase (ODC) activity (for reviews see refs 1, 2). This enzyme2 and the polyamines whose synthesis it catalyses1 have been suggested in turn to play a part in mediating subsequent cellular responses to such hormone or replication factors. Among the agents shown to affect ODC activity is nerve growth factor (NGF), a protein which affects the differentiation and survival of sympathetic and responsive sensory neurones3. MacDonnell et al.4 have demonstrated that treatment of rat superior cervical ganglia with NGF causes a rapid (maximal by 6–7 h), transcription-dependent increase in ODC activity. NGF treatment has also been reported to increase ODC activity in rat brain5. Such findings have led to the suggestion that ODC may mediate other responses of neurones to NGF4. We show here, however, that suppression of ODC activity and of its induction do not interfere with several other responses to NGF such as promotion of neurite outgrowth, maintenance of survival and increase in cell size. Such findings may be relevant to the possible role of ODC induction in other differentiating systems.