U Raju1, G J Gumin, P J Tofilon. 1. Department of Experimental Radiation Oncology, The University of Texas M. D. Anderson Cancer Center, Houston 77030, USA.
Abstract
PURPOSE: To determine the effects of ionising radiation on the DNA-binding activity of the injury-related transcription factors AP-1, Sp-1, p53 and NFkappaB in the rat brain. MATERIALS AND METHODS: Male Sprague-Dawley rats were irradiated with 137Cs gamma-rays at 3.8Gy/min and the cerebral cortex was isolated at intervals up to 24h. Nuclear protein extract of the cerebral cortex was analysed by electrophoretic mobility shift assay for DNA-binding activity of AP-1, Sp-1, p53 and NFkappaB. In addition, total RNA was extracted from the cerebral cortex and subjected to northern analysis. RESULTS: The DNA-binding activity of each of the transcription factors increased in a time- and dose-dependent manner after irradiation. Maximum increase in the activity of AP-1, Sp-1, and p53 DNA binding was seen after exposure to 10Gy and then decreased after higher doses. In contrast, NFkappaB DNA-binding activity continued to increase out to at least 30Gy. The levels of bFGF and p21WAF-1 mRNA increased after irradiation, suggesting an increase in the transactivating activity of AP-1, Sp-1, and p53. CONCLUSIONS: These data indicate that the response of the CNS to irradiation includes the activation of a similar set of transcription factors as previously observed after other types of insults.
PURPOSE: To determine the effects of ionising radiation on the DNA-binding activity of the injury-related transcription factors AP-1, Sp-1, p53 and NFkappaB in the rat brain. MATERIALS AND METHODS: Male Sprague-Dawley rats were irradiated with 137Cs gamma-rays at 3.8Gy/min and the cerebral cortex was isolated at intervals up to 24h. Nuclear protein extract of the cerebral cortex was analysed by electrophoretic mobility shift assay for DNA-binding activity of AP-1, Sp-1, p53 and NFkappaB. In addition, total RNA was extracted from the cerebral cortex and subjected to northern analysis. RESULTS: The DNA-binding activity of each of the transcription factors increased in a time- and dose-dependent manner after irradiation. Maximum increase in the activity of AP-1, Sp-1, and p53 DNA binding was seen after exposure to 10Gy and then decreased after higher doses. In contrast, NFkappaB DNA-binding activity continued to increase out to at least 30Gy. The levels of bFGF and p21WAF-1 mRNA increased after irradiation, suggesting an increase in the transactivating activity of AP-1, Sp-1, and p53. CONCLUSIONS: These data indicate that the response of the CNS to irradiation includes the activation of a similar set of transcription factors as previously observed after other types of insults.
Authors: Roshan Karunamuni; Hauke Bartsch; Nathan S White; Vitali Moiseenko; Ruben Carmona; Deborah C Marshall; Tyler M Seibert; Carrie R McDonald; Nikdokht Farid; Anithapriya Krishnan; Joshua Kuperman; Loren Mell; James B Brewer; Anders M Dale; Jona A Hattangadi-Gluth Journal: Int J Radiat Oncol Biol Phys Date: 2015-10-21 Impact factor: 7.038
Authors: Arif Ali Chishti; Christa Baumstark-Khan; Christine E Hellweg; Günther Reitz Journal: Radiat Environ Biophys Date: 2014-06-01 Impact factor: 1.925