Grassilli E, Desiderio M A, Bellesia E, Salomoni P, Benatti F, Franceschi C
Department of Biomedical Sciences, University of Modena, Italy.
Biochem Biophys Res Commun. 1995 Nov 13;216(2):708-14. doi: 10.1006/bbrc.1995.2679.
Here we report that in rat thymocytes undergoing apoptosis upon two different stimuli, such as heat shock treatment and gamma irradiation, an early mRNA accumulation of ornithine decarboxylase (ODC)--the rate-limiting enzyme of polyamine biosynthesis--was followed by a very marked increase in ODC activity (28-40 and 6-8-fold, respectively). However, polyamine levels started to decrease before the appearance of DNA laddering, being putrescine and spermidine strongly diminished (8-12 hs), and spermine even depleted (12 hs). Taken together with our previous data on another model of apoptosis, i.e., glucocorticoid-induced cell death (Desiderio et al., Cell Growth Differ. 6: 505-513, 1995), these results suggest that an imbalance of polyamine metabolism, i.e., a strong activation of ODC and a paradoxical decrease of the intracellular polyamine content, might be a general feature of the apoptotic process.
在此我们报告，在经历两种不同刺激（如热休克处理和γ射线照射）而发生凋亡的大鼠胸腺细胞中，鸟氨酸脱羧酶（ODC，多胺生物合成的限速酶）的mRNA早期积累之后，ODC活性显著增加（分别增加28 - 40倍和6 - 8倍）。然而，在DNA梯形条带出现之前，多胺水平就开始下降，腐胺和亚精胺大幅减少（8 - 12小时），精胺甚至耗尽（12小时）。结合我们之前关于另一种凋亡模型（即糖皮质激素诱导的细胞死亡，Desiderio等人，《细胞生长与分化》6: 505 - 513, 1995）的数据，这些结果表明多胺代谢失衡，即ODC的强烈激活和细胞内多胺含量的反常降低，可能是凋亡过程的一个普遍特征。
