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p53-dependent stimulation of redox-related genes in the lymphoid organs of gamma-irradiated--mice identification of Haeme-oxygenase 1 as a direct p53 target gene.

Meiller A, Alvarez S, Drané P, Lallemand C, Blanchard B, Tovey M, May E - Nucleic Acids Res. (2007)

Bottom Line: Results presented in this article illustrate an additional degree of complexity.Moreover, induction of HO-1 occurs later than that of Waf1/p21.Finally, the higher stimulation of HO-1 is reached when Waf1/p21 stimulation starts to decrease.

View Article: PubMed Central - PubMed

Affiliation: Commissariat à l'Energie Atomique (CEA), Centre National de la Recherche Scientifique (CNRS), UMR217, route du Panorama BP6, 92265 Fontenay-aux-Roses Cedex and CNRS FRE2937, Institut André Lwoff, 7, rue Guy Moquet, BP8, 94801 Villejuif Cedex, France.

ABSTRACT
Recent data showed that p53 stimulates the expression of genes encoding not only pro- but also antioxidant enzymes. It was suggested that antioxidant genes could be induced under physiologic levels of stress while the prooxidant ones respond to higher level of stress. Results presented in this article illustrate an additional degree of complexity. We show that the expression of Haeme-oxygenase 1 (HO-1), a stress-inducible gene that codes for an enzyme having antioxidant properties, is stimulated in a p53-dependent manner in the thymus and spleen of irradiated mice. We prove that HO-1 is a direct p53 target gene by showing that the p53RE identified within human and mouse genes is specifically bound by p53. The threshold of irradiation dose required to induce a significant response of HO-1 in the lymphoid organs of the irradiated mice is higher than that for Waf1/p21 that encodes an universal inhibitor of cell cycle. Moreover, induction of HO-1 occurs later than that of Waf1/p21. Finally, the higher stimulation of HO-1 is reached when Waf1/p21 stimulation starts to decrease.

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Kinetics of HO-1 and p21/Waf1 stimulation in the spleen of whole body-irradiated mice. Mice irradiated at a dose of 1 Gy were sacrificed at the indicated time post-irradiation. (A) HO-1 and p21/Waf1 mRNA levels determinate by real-time quantitative RT-PCR (see Material and Methods section) and normalized relative to GAPDH mRNA. The graphs represent the mean of four independent experiments with their respective standard deviation. (B) HO-1 and p21/Waf1 protein levels analysed by western blot using anti-p21/Waf1, anti-p53 and anti-actin (to control loading).
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Figure 4: Kinetics of HO-1 and p21/Waf1 stimulation in the spleen of whole body-irradiated mice. Mice irradiated at a dose of 1 Gy were sacrificed at the indicated time post-irradiation. (A) HO-1 and p21/Waf1 mRNA levels determinate by real-time quantitative RT-PCR (see Material and Methods section) and normalized relative to GAPDH mRNA. The graphs represent the mean of four independent experiments with their respective standard deviation. (B) HO-1 and p21/Waf1 protein levels analysed by western blot using anti-p21/Waf1, anti-p53 and anti-actin (to control loading).

Mentions: Kinetics of HO-1 and p21/Waf1 mRNA accumulation was measured in the spleens of p53+/+ mice following whole body irradiation at 1 Gy. Results are presented in Figure 4A. The stimulation of p21/Waf1 reached a maximum as soon as 1 h after irradiation, while a significant stimulation (2.5 ± 0.3) of HO-1 was detectable starting at 3 h post-irradiation. Similar results were obtained while assaying the RNA extracted from thymus of irradiated mice. As in the spleen, stimulation of p21/Waf1 is readily detectable at 1 h post-irradiation, while a significant stimulation of HO-1 was noticeable at 3 h only (data not shown).Figure 4.


p53-dependent stimulation of redox-related genes in the lymphoid organs of gamma-irradiated--mice identification of Haeme-oxygenase 1 as a direct p53 target gene.

Meiller A, Alvarez S, Drané P, Lallemand C, Blanchard B, Tovey M, May E - Nucleic Acids Res. (2007)

Kinetics of HO-1 and p21/Waf1 stimulation in the spleen of whole body-irradiated mice. Mice irradiated at a dose of 1 Gy were sacrificed at the indicated time post-irradiation. (A) HO-1 and p21/Waf1 mRNA levels determinate by real-time quantitative RT-PCR (see Material and Methods section) and normalized relative to GAPDH mRNA. The graphs represent the mean of four independent experiments with their respective standard deviation. (B) HO-1 and p21/Waf1 protein levels analysed by western blot using anti-p21/Waf1, anti-p53 and anti-actin (to control loading).
© Copyright Policy - creative-commons
Related In: Results  -  Collection

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Figure 4: Kinetics of HO-1 and p21/Waf1 stimulation in the spleen of whole body-irradiated mice. Mice irradiated at a dose of 1 Gy were sacrificed at the indicated time post-irradiation. (A) HO-1 and p21/Waf1 mRNA levels determinate by real-time quantitative RT-PCR (see Material and Methods section) and normalized relative to GAPDH mRNA. The graphs represent the mean of four independent experiments with their respective standard deviation. (B) HO-1 and p21/Waf1 protein levels analysed by western blot using anti-p21/Waf1, anti-p53 and anti-actin (to control loading).
Mentions: Kinetics of HO-1 and p21/Waf1 mRNA accumulation was measured in the spleens of p53+/+ mice following whole body irradiation at 1 Gy. Results are presented in Figure 4A. The stimulation of p21/Waf1 reached a maximum as soon as 1 h after irradiation, while a significant stimulation (2.5 ± 0.3) of HO-1 was detectable starting at 3 h post-irradiation. Similar results were obtained while assaying the RNA extracted from thymus of irradiated mice. As in the spleen, stimulation of p21/Waf1 is readily detectable at 1 h post-irradiation, while a significant stimulation of HO-1 was noticeable at 3 h only (data not shown).Figure 4.

Bottom Line: Results presented in this article illustrate an additional degree of complexity.Moreover, induction of HO-1 occurs later than that of Waf1/p21.Finally, the higher stimulation of HO-1 is reached when Waf1/p21 stimulation starts to decrease.

View Article: PubMed Central - PubMed

Affiliation: Commissariat à l'Energie Atomique (CEA), Centre National de la Recherche Scientifique (CNRS), UMR217, route du Panorama BP6, 92265 Fontenay-aux-Roses Cedex and CNRS FRE2937, Institut André Lwoff, 7, rue Guy Moquet, BP8, 94801 Villejuif Cedex, France.

ABSTRACT
Recent data showed that p53 stimulates the expression of genes encoding not only pro- but also antioxidant enzymes. It was suggested that antioxidant genes could be induced under physiologic levels of stress while the prooxidant ones respond to higher level of stress. Results presented in this article illustrate an additional degree of complexity. We show that the expression of Haeme-oxygenase 1 (HO-1), a stress-inducible gene that codes for an enzyme having antioxidant properties, is stimulated in a p53-dependent manner in the thymus and spleen of irradiated mice. We prove that HO-1 is a direct p53 target gene by showing that the p53RE identified within human and mouse genes is specifically bound by p53. The threshold of irradiation dose required to induce a significant response of HO-1 in the lymphoid organs of the irradiated mice is higher than that for Waf1/p21 that encodes an universal inhibitor of cell cycle. Moreover, induction of HO-1 occurs later than that of Waf1/p21. Finally, the higher stimulation of HO-1 is reached when Waf1/p21 stimulation starts to decrease.

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