Transcription factors DNA-binding activity in rat thymocytes undergoing apoptosis after heat-shock or dexamethasone treatment.
The onset of apoptosis is generally thought to require the induction of a novel genetic program. Accordingly, we studied the kinetic of DNA-binding activity of several transcription factors in rat thymocytes undergoing apoptosis induced by dexamethasone (DEX) or heat shock (HS) treatment. Here we report that: 1) early activation of AP-1 occurred in both models of apoptosis, even if the intensity of activation and AP-1 complex composition were different and much less evident in HS-treated thymocytes; 2) early NFkB DNA-binding activity was also observed in both types of apoptosis; 3) downregulation of other transcription factors, such as OCT-1 and CREB, with high constitutive activity, was recorded in both models of apoptosis. The fact that some TFs are up-regulated while others are down-regulated suggests that apoptosis is the result of a complex combination of positive and negative signals regulating gene expression.
Sikora
E
E
Institute of General Pathology, University of Modena, Italy.
Grassilli
E
E
Radziszewska
E
E
Bellesia
E
E
Barbieri
D
D
Franceschi
C
C
D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000502:physiology*; D017362:Cyclic AMP Response Element-Binding Protein / Q000378:metabolism; D004268:DNA-Binding Proteins / Q000302:isolation & purification / Q000378:metabolism*; D003907:Dexamethasone / Q000494:pharmacology*; D004591:Electrophoresis, Polyacrylamide Gel; D051863:Host Cell Factor C1; D006358:Hot Temperature; D016328:NF-kappa B / Q000378:metabolism; D050811:Octamer Transcription Factor-1; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D011519:Proto-Oncogenes; D051381:Rats; D017207:Rats, Sprague-Dawley; D013601:T-Lymphocytes / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism*; D014157:Transcription Factors / Q000302:isolation & purification / Q000378:metabolism*
D017362:Cyclic AMP Response Element-Binding Protein; D004268:DNA-Binding Proteins; D051863:Host Cell Factor C1; D016328:NF-kappa B; D050811:Octamer Transcription Factor-1; C494168:Pou2f1 protein, rat; D016755:Proto-Oncogene Proteins c-jun; D014157:Transcription Factors; D003907:Dexamethasone