scholarly journals Ubiquitination of p53 and p21 is differentially affected by ionizing and UV radiation.

1997 ◽  
Vol 17 (1) ◽  
pp. 355-363 ◽  
Author(s):  
C G Maki ◽  
P M Howley
Keyword(s):  
Gamma Radiation ◽  
Uv Radiation ◽  
Radiation Effects ◽  
P53 Protein ◽  
Proteolytic Pathway ◽  
Radiation Induced ◽  
The Stability ◽  
Gamma Irradiated ◽  
In Cells

Levels of the tumor suppressor protein p53 are normally quite low due in part to its short half-life. p53 levels increase in cells exposed to DNA-damaging agents, such as radiation, and this increase is thought to be responsible for the radiation-induced G1 cell cycle arrest or delay. The mechanisms by which radiation causes an increase in p53 are currently unknown. The purpose of this study was to compare the effects of gamma and UV radiation on the stability and ubiquitination of p53 in vivo. Ubiquitin-p53 conjugates could be detected in nonirradiated and gamma-irradiated cells but not in cells which were UV treated, despite the fact that both treatments resulted in the stabilization of the p53 protein. These results demonstrate that UV and gamma radiation have different effects on ubiquitinated p53 and suggest that the UV-induced stabilization of p53 results from a loss of p53 ubiquitination. Ubiquitinated forms of p21, an inhibitor of cyclin-dependent kinases, were detected in vivo, demonstrating that p21 is also a target for degradation by the ubiquitin-dependent proteolytic pathway. However, UV and gamma radiation had no effect on the stability or in vivo ubiquitination of p21, indicating that the radiation effects on p53 are specific.

scholarly journals DBC1 (Deleted in Breast Cancer 1) modulates the stability and function of the nuclear receptor Rev-erbα

2013 ◽  
Vol 451 (3) ◽  
pp. 453-461 ◽  
Author(s):  
Claudia C. S. Chini ◽  
Carlos Escande ◽  
Veronica Nin ◽  
Eduardo N. Chini
Keyword(s):  
Breast Cancer ◽  
Nuclear Receptor ◽  
Clock Genes ◽  
Mrna Levels ◽  
Protein Levels ◽  
The Stability ◽  
And Function ◽  
Interfering Rna ◽  
In Cells

The nuclear receptor Rev-erbα has been implicated as a major regulator of the circadian clock and integrates circadian rhythm and metabolism. Rev-erbα controls circadian oscillations of several clock genes and Rev-erbα protein degradation is important for maintenance of the circadian oscillations and also for adipocyte differentiation. Elucidating the mechanisms that regulate Rev-erbα stability is essential for our understanding of these processes. In the present paper, we report that the protein DBC1 (Deleted in Breast Cancer 1) is a novel regulator of Rev-erbα. Rev-erbα and DBC1 interact in cells and in vivo, and DBC1 modulates the Rev-erbα repressor function. Depletion of DBC1 by siRNA (small interfering RNA) in cells or in DBC1-KO (knockout) mice produced a marked decrease in Rev-erbα protein levels, but not in mRNA levels. In contrast, DBC1 overexpression significantly enhanced Rev-erbα protein stability by preventing its ubiquitination and degradation. The regulation of Rev-erbα protein levels and function by DBC1 depends on both the N-terminal and C-terminal domains of DBC1. More importantly, in cells depleted of DBC1, there was a dramatic decrease in circadian oscillations of both Rev-erbα and BMAL1. In summary, our data identify DBC1 as an important regulator of the circadian receptor Rev-erbα and proposes that Rev-erbα could be involved in mediating some of the physiological effects of DBC1.

scholarly journals Differential Regulation of Ferritin Subunits and Iron Transport Proteins: An Effect of Targeted Hepatic X-Irradiation

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Naila Naz ◽  
Shakil Ahmad ◽  
Silke Cameron ◽  
Federico Moriconi ◽  
Margret Rave-Fränk ◽  
...  
Keyword(s):  
Radiation Effects ◽  
Complete Blood Count ◽  
Mrna Level ◽  
Isolated Hepatocytes ◽  
Serum Marker ◽  
Neutrophil Granulocytes ◽  
Early Increase ◽  
Radiation Induced

The current study aimed to investigate radiation-induced regulation of iron proteins including ferritin subunits in rats. Rat livers were selectively irradiatedin vivoat 25 Gy. This dose can be used to model radiation effects to the liver without inducing overt radiation-induced liver disease. Sham-irradiated rats served as controls. Isolated hepatocytes were irradiated at 8 Gy. Ferritin light polypeptide (FTL) was detectable in the serum of sham-irradiated rats with an increase after irradiation. Liver irradiation increased hepatic protein expression of both ferritin subunits. A rather early increase (3 h) was observed for hepatic TfR1 and Fpn-1 followed by a decrease at 12 h. The increase in TfR2 persisted over the observed time. Parallel to the elevation of AST levels, a significant increase (24 h) in hepatic iron content was measured. Complete blood count analysis showed a significant decrease in leukocyte number with an early increase in neutrophil granulocytes and a decrease in lymphocytes.In vitro, a significant increase in ferritin subunits at mRNA level was detected after irradiation which was further induced with a combination treatment of irradiation and acute phase cytokine. Irradiation can directly alter the expression of ferritin subunits and this response can be strongly influenced by radiation-induced proinflammatory cytokines. FTL can be used as a serum marker for early phase radiation-induced liver damage.

Investigation of Gamma Radiation on Hydroxyapatite Synthesized from Chicken Eggshell by ESR Spectroscopy

2015 ◽  
Vol 1125 ◽  
pp. 416-420
Author(s):  
Kanokwan Boonsook ◽  
Weeranuch Kaewwiset ◽  
Ekachai Hoonnivathana ◽  
Pichet Limsuwan ◽  
Kittisakchai Naemchanthara
Keyword(s):  
Electron Spin Resonance ◽  
Gamma Radiation ◽  
Electron Spin ◽  
Esr Spectroscopy ◽  
Chemical Precipitation ◽  
Precipitation Method ◽  
Spin Resonance ◽  
Chicken Eggshell ◽  
Radiation Induced ◽  
Gamma Irradiated

The purpose of this work was investigated the properties and characteristic of gamma radiation on hydroxyapatite which synthesized from biowaste chicken eggshell via the chemical precipitation method. The hydroxyapatite from biowaste chicken eggshell was gamma irradiated in rage 10 Gy to 1 kGy and analyzed by electron spin resonance (ESR). The optimize parameter set ESR read out of Hydroxyapatite were such as microwave power and modulate amplitude corresponded 63.34 mW and 2 mT, respectively. The ESR signal based on the measurement of the concentration of radiation induced radicals CO2- molecular ion also formed in hydroxyapatite. The relative of ESR intensity and dose response was linear. These experiments indicated that the hydroxyapatite from biowaste chicken eggshell could be used good dosimeter in rage 20 to 100 Gy.

scholarly journals Thymoquinone Rescues T Lymphocytes from Gamma Irradiation-Induced Apoptosis and Exhaustion by Modulating Pro-Inflammatory Cytokine Levels and PD-1, Bax, and Bcl-2 Signaling

2016 ◽  
Vol 38 (2) ◽  
pp. 786-800 ◽  
Author(s):  
Mona Samy Guida ◽  
Ali Abd El-Aal ◽  
Yehya Kafafy ◽  
Safwat Farid Salama ◽  
Badr Mohamed Badr ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
T Cell ◽  
Gamma Radiation ◽  
Inflammatory Cytokine ◽  
Caspase 3 ◽  
Flow Cytometry Analysis ◽  
Tnf Α ◽  
Cytokine Levels ◽  
Radiation Induced ◽  
Gamma Irradiated

Background/Aims: Recent studies have shown that thymoquinone (TQ) exerts protective effects against ionizing radiation-induced cataracts in lens after total cranium irradiation of rats. Nevertheless, there is no published work investigated the effects of TQ on T cell development and biology in animal models exposed to gamma radiation. Therefore, in the present study we focused on determining the effects of TQ on radiation damage in the thymus, radiation-induced T cell imbalance, and on immune dysfunction induced by gamma-rays. Methods: Three groups of rats were used: a control group, a gamma-irradiated group, and a gamma-irradiated group that was orally supplemented with TQ. Serum lipid profiles, malondialdehyde (MDA) levels, and pro-inflammatory cytokine levels were measured to assess gamma irradiation-induced oxidative stress and inflammatory capacity. T cell apoptosis was evaluated by annexin V/propidium iodide staining followed by flow cytometry analysis. The expression of pro-apoptotic proteins such as Bax and caspase-3, the anti-apoptotic protein Bcl-2, and an exhaustion marker of T cells (PD-1) in CD4+ and CD8+ T cell populations was evaluated using flow cytometry analysis. The T cell architecture of the thymus gland was evaluated by histological analysis. Results: Exposure to gamma radiation increased triglyceride, cholesterol, LDL-C, MDA, TNF-α and IL-6 levels and decreased HDL-C levels. The altered lipid profile and MDA and pro-inflammatory cytokine (TNF-α and IL-6) levels induced by exposure to gamma radiation were significantly restored in TQ-treated gamma-irradiated rats. Rats exposed to gamma radiation exhibited increased exhaustion of T lymphocytes via down-regulation of Bcl-2 expression and upregulation of PD-1, Bax, and caspase-3 expression, which sensitized these cells to apoptosis. Interestingly, treatment of gamma-irradiated rats with TQ decreased T cell exhaustion and apoptosis by modulating the expression of Bcl-2, PD-1, Bax, and caspase-3. Conclusions: Our results provide evidence for the beneficial effects of TQ as an effective radioprotective candidate that enhances cellular immunity.

Preventive effect of ALA-PDT on UV radiation-induced skin carcinoma ¿C in vivo study in a mouse model

2011 ◽  
Vol 8 (2) ◽  
pp. 151-152
Author(s):  
X.L. Wang ◽  
T. Lv ◽  
H.W. Wang ◽  
F. Miao ◽  
J.J. Li ◽  
...  
Keyword(s):  
Mouse Model ◽  
Uv Radiation ◽  
In Vivo Study ◽  
Skin Carcinoma ◽  
Preventive Effect ◽  
Radiation Induced

scholarly journals The knockout effect of low doses of gamma radiation on hepatotoxicity induced by Echis Coloratus snake venom in rats

2019 ◽  
Author(s):  
Esraa M. Samy ◽  
Esmat A. Shaaban ◽  
Sanaa A. Kenawy ◽  
Walaa H. Salama ◽  
Mai A. Abd El Fattah
Keyword(s):  
Gamma Radiation ◽  
Biochemical Parameters ◽  
Sublethal Dose ◽  
Low Doses ◽  
Histological Studies ◽  
Gamma Irradiated ◽  
Native Group ◽  
Histological Architecture ◽  
Dose Injection

ABSTRACTEchis Coloratus is the most medically important viper in Egypt causing several pathological effects leading to death. Gamma radiation has been used as a venom detoxifying tool in order to extend the lifespan of the immunized animals used in antivenin production process. Thus, the aim of this study is to assess the effects of increasing doses of gamma radiation on Echis Coloratus in vivo through biochemical and histological studies. The results revealed a significant increase in the levels of AST, ALT, ALP and glucose of sera collected from the rats injected with native Echis Coloratus venom compared with the non-envenomed group. On the other hand, biochemical parameters of sera of rats administrated with either 1.5 kGy or 3 kGy irradiated venom were significantly decrease compared with the native venom envenomed group at 2h, 4h and 24h post envenomation. In addition, these results were confirmed by histological studies of rats’ livers. Correspondingly, the sublethal dose injection of native Echis Coloratus venom induced significant alterations in the histological architecture of liver after 2, 4 and 24 h of injection. Concurrently, the administration of both 1.5 kGy and 3 kGy gamma irradiated venom showed fewer histological alterations compared with the native group. In conclusion, the present findings support the idea of using gamma radiation as an effective venom detoxification tool.

scholarly journals Pheomelanin Effect on UVB Radiation-Induced Oxidation/Nitration of L-Tyrosine

2021 ◽  
Vol 23 (1) ◽  
pp. 267
Author(s):  
Alessia Mariano ◽  
Irene Bigioni ◽  
Anna Scotto d’Abusco ◽  
Alessia Baseggio Conrado ◽  
Simonetta Maina ◽  
...  
Keyword(s):  
Uv Radiation ◽  
Photochemical Reactions ◽  
Uvb Radiation ◽  
Natural Pigment ◽  
Experimental Conditions ◽  
Tyrosine Oxidation ◽  
Radiation Induced ◽  
Cellular Components ◽  
Catalyzed Oxidation

Pheomelanin is a natural yellow-reddish sulfur-containing pigment derived from tyrosinase-catalyzed oxidation of tyrosine in presence of cysteine. Generally, the formation of melanin pigments is a protective response against the damaging effects of UV radiation in skin. However, pheomelanin, like other photosensitizing substances, can trigger, following exposure to UV radiation, photochemical reactions capable of modifying and damaging cellular components. The photoproperties of this natural pigment have been studied by analyzing pheomelanin effect on oxidation/nitration of tyrosine induced by UVB radiation at different pH values and in presence of iron ions. Photoproperties of pheomelanin can be modulated by various experimental conditions, ranging from the photoprotection to the triggering of potentially damaging photochemical reactions. The study of the photomodification of l-Tyrosine in the presence of the natural pigment pheomelanin has a special relevance, since this tyrosine oxidation/nitration pathway can potentially occur in vivo in tissues exposed to sunlight and play a role in the mechanisms of tissue damage induced by UV radiation.

MORTALITY OF GAMMA IRRADIATED LARVAL TRIBOLIUM CONFUSUM SUBJECTED TO VARIOUS GASES OR PHYSICAL STRESSES1

1985 ◽  
Vol 20 (4) ◽  
pp. 465-469
Author(s):  
E. W. Tilton ◽  
H. H. Vardell ◽  
R. D. Jones
Keyword(s):  
Carbon Dioxide ◽  
Gamma Radiation ◽  
Tribolium Confusum ◽  
Cold Air ◽  
First Instar ◽  
Radiation Induced ◽  
Gamma Irradiated ◽  
Radiation Time ◽  
Partial Vacuum

Treatment by gamma radiation, cold air, partial vacuum, phosphine, nitrogen, and carbon dioxide have all been proposed to control insects in stored food. There is some evidence that radiation-induced mortality of some insects can be inhibited by these gases, partial vacuum, or cold treatments. Collateral exposure of first-instar larvae of Tribolium confusum Jacquelin du Val to CO2 and 75 Gy gamma radiation produced a significant reduction in radiation-induced mortality when compared with radiation alone. Mortality produced by gamma radiation simultaneous with treatment by nitrogen, partial vacuum of 3.33 kPa (25 Torr) or cold air (2°) for 30 min., which included radiation time, did not differ significantly from that of gamma radiation alone. The treatments with phosphine and phosphine with gamma radiation did not differ significantly.

Ionizing Radiation Effects on Interfaces in Carbon Nanotube-Polymer Composites

2001 ◽  
Vol 697 ◽  
Author(s):  
Julie P. Harmon ◽  
Patricia Anne O. Muisener ◽  
LaNetra Clayton ◽  
John D'Angelo ◽  
Arun K. Sikder ◽  
...  
Keyword(s):  
Carbon Nanotube ◽  
Gamma Radiation ◽  
Total Dose ◽  
Dose Rate ◽  
Polymer Composites ◽  
Radiation Effects ◽  
Mechanical Analysis ◽  
Scanning Calorimetry ◽  
Radiation Induced ◽  
Radiation Induced Chemistry

AbstractThe purpose of this research was to probe nanotube-polymer composites for evidences of radiation induced chemistry at the interface of the host polymer and the nanotube structures. Single wall carbon nanotube (SWNT) / poly (methyl methacrylate) (PMMA) composites were fabricated and exposed to gamma radiation with a Co60 source at a dose rate of 1.28 X 106 rad/hour in an air environment for a total dose of 5.9 Mrads. Neat nanotube paper and neat PMMA were also exposed. Spun coat films of SWNT/PMMA were exposed to gamma radiation with a Ce157at a dose rate of 4.46 x 103 rad/hr for a total dose of 3.86 Mrads. Both irradiated and non-irradiated samples were compared. Glass transition temperatures were characterized by differential scanning calorimetry. Dynamic mechanical analysis and dielectric analysis evidenced changes in relaxations induced by irradiation. Irradiated composites exhibited radiation induced chemistry distinct from degradation effects noted in the pure polymer. Scanning electron microscopy provided images of the SWNTs and SWNT/PMMA interface before and after irradiation. This investigation imparts insight into the nature of radiation induced events in nanotubes and nanocomposites.

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