Is polyamine decrease a common feature of apoptosis? Evidence from gamma rays- and heat shock-induced cell death.
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.
D000704:Analysis of Variance; D000818:Animals; D017209:Apoptosis / Q000528:radiation effects; D016923:Cell Death / Q000187:drug effects*; D002478:Cells, Cultured; D002851:Chromatography, High Pressure Liquid; D004247:DNA / Q000302:isolation & purification / Q000528:radiation effects; D004587:Electrophoresis, Agar Gel; D005720:Gamma Rays; D006358:Hot Temperature; D007700:Kinetics; D009955:Ornithine Decarboxylase / Q000378:metabolism; D011073:Polyamines / Q000378:metabolism*; D011700:Putrescine / Q000378:metabolism; D051381:Rats; D017207:Rats, Sprague-Dawley; D013095:Spermidine / Q000378:metabolism; D013096:Spermine / Q000378:metabolism; D013950:Thymus Gland / Q000166:cytology / Q000473:pathology / Q000528:radiation effects*; D013997:Time Factors
D011073:Polyamines; D013096:Spermine; D004247:DNA; D009955:Ornithine Decarboxylase; D013095:Spermidine; D011700:Putrescine