scholarly journals Formation of γH2AX and pATM Foci in Human Mesenchymal Stem Cells Exposed to Low Dose-Rate Gamma-Radiation

2019 ◽  
Vol 20 (11) ◽  
pp. 2645 ◽  
Author(s):  
Stepan Ulyanenko ◽  
Margarita Pustovalova ◽  
Sergey Koryakin ◽  
Evgenii Beketov ◽  
Anatolii Lychagin ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Gamma Radiation ◽  
Dose Rate ◽  
Low Dose ◽  
Human Mesenchymal Stem Cells ◽  
Linear Dose ◽  
Low Dose Rate ◽  
Acute Irradiation ◽  
Non Linear

DNA double-strand breaks (DSB) are among the most harmful DNA lesions induced by ionizing radiation (IR). Although the induction and repair of radiation-induced DSB is well studied for acute irradiation, responses to DSB produced by chronic IR exposures are poorly understood, especially in human stem cells. The aim of this study was to examine the formation of DSB markers (γH2AX and phosphorylated kinase ATM, pATM, foci) in human mesenchymal stem cells (MSCs) exposed to chronic gamma-radiation (0.1 mGy/min) in comparison with acute irradiation (30 mGy/min) at cumulative doses of 30, 100, 160, 240 and 300 mGy. A linear dose-dependent increase in the number of both γH2AX and pATM foci, as well as co-localized γH2AX/pATM foci (“true” DSB), were observed after an acute radiation exposure. In contrast, the response of MSCs to a chronic low dose-rate IR exposure deviated from linearity towards a threshold model, for γH2AX, pATM foci and γH2AX/pATM foci, with an indication of a “plateau”. The state of equilibrium between newly formed DSB at a low rate during the protracted exposure time and the elimination of a fraction of DSB is proposed as a mechanistic explanation of the non-linear DSB responses following a low dose-rate irradiation. This notion is supported by the observation of the elimination of a substantial fraction of DSB 6 h after the cessation of the exposures. Our results demonstrate non-linear dose responses for γH2AX and pATM foci in human MSCs exposed to low dose-rate IR and showed the existence of a threshold, which may have implications for radiation protection in humans.

scholarly journals Изменение характеристик переизлучающих волокон Y-11 и O-2 под действием гамма облучения

2020 ◽  
Vol 128 (12) ◽  
pp. 1973
Author(s):  
А.Ю. Афанасьев ◽  
А.Ю. Бояринцев ◽  
И.А. Голутвин ◽  
Э.М. Ибрагимова ◽  
А.И. Малахов ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Dose Rate ◽  
Room Temperature ◽  
Low Dose ◽  
Low Dose Rate ◽  
60Co Gamma ◽  
60Co Gamma Radiation

The effect of 60Co gamma radiation on the intensity of the reemitted light at the exit from WLS-fibers of Y-11 M and O-2 M type WLS fibers and the subsequent restoration of the characteristics of irradiated fibers after exposure to room temperature are investigated. Irradiation of a low dose rate (0.048 Mrad / h) to a dose of 1 Mrad leads to a slight decrease in the intensity of the reemitted light at the exit of both types of fibers, and with a further increase in the dose, the curve does not change. When irradiated with a dose rate of 0.158 Mrad / h, the characteristics of both types of fibers deteriorate significantly. When the irradiated samples are held at room temperature, fiber characteristics are restored.

Lenticular Opacities in Populations Exposed to Chronic Low-Dose-Rate Gamma Radiation from Radiocontaminated Buildings in Taiwan

2001 ◽  
Vol 156 (1) ◽  
pp. 71-77 ◽  
Author(s):  
Wei-Li Chen ◽  
Jing-Shiang Hwang ◽  
Trey-Hwa Hu ◽  
Muh-Shy Chen ◽  
Wushou P. Chang
Keyword(s):  
Gamma Radiation ◽  
Dose Rate ◽  
Low Dose ◽  
Low Dose Rate

Comparison of holes trapping and protons transport induced by low dose rate gamma radiation in oxide on different SiGe processes

2019 ◽  
Vol 103 ◽  
pp. 113499
Author(s):  
Pei Li ◽  
ChaoHui He ◽  
HongXia Guo ◽  
JinXin Zhang ◽  
YongHong Li ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Dose Rate ◽  
Low Dose ◽  
Low Dose Rate

Photo biostimulatory effect of low dose photodynamic therapy on human mesenchymal stem cells

2020 ◽  
Vol 31 ◽  
pp. 101886
Author(s):  
Reza Fekrazad ◽  
Sohrab Asefi ◽  
Khatereh Khorsandi ◽  
Marzieh Nejatifard
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Photodynamic Therapy ◽  
Low Dose ◽  
Human Mesenchymal Stem Cells

Low dose-rate irradiation specifically affects hematopoietic stem cells

2016 ◽  
Vol 44 (9) ◽  
pp. S101-S102
Author(s):  
Yoshihiro Takihara ◽  
Yoshinori Ohno ◽  
Kyoko Suzuki-Takedachi ◽  
Mimoko Santo ◽  
Shin’ichiro Yasunaga ◽  
...  
Keyword(s):  
Stem Cells ◽  
Hematopoietic Stem Cells ◽  
Dose Rate ◽  
Low Dose ◽  
Hematopoietic Stem ◽  
Low Dose Rate

The influence of very low dose rate gamma-radiation on genetic structures of mice: molecular and cytogenetic study

2004 ◽  
Vol 1 (3) ◽  
pp. 300 ◽  
Author(s):  
A.N. Osipov ◽  
A.L. Elakov ◽  
P.V. Puchkov ◽  
V.D. Sypin ◽  
M.D. Pomerantseva ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Dose Rate ◽  
Low Dose ◽  
Cytogenetic Study ◽  
Low Dose Rate ◽  
Genetic Structures

scholarly journals Cellular responses and gene expression profiles of colonic Lgr5+ stem cells after low-dose/low-dose-rate radiation exposure

2017 ◽  
Vol 59 (suppl_2) ◽  
pp. ii18-ii22 ◽  
Author(s):  
Kensuke Otsuka ◽  
Keiji Suzuki ◽  
Yuki Fujimichi ◽  
Masanori Tomita ◽  
Toshiyasu Iwasaki
Keyword(s):  
Gene Expression ◽  
Stem Cells ◽  
Radiation Exposure ◽  
Dose Rate ◽  
Low Dose ◽  
Expression Profiles ◽  
Gene Expression Profiles ◽  
Cellular Responses ◽  
Low Dose Rate

scholarly journals Gamma radiation at a human relevant low dose rate is genotoxic in mice

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Anne Graupner ◽  
Dag M. Eide ◽  
Christine Instanes ◽  
Jill M. Andersen ◽  
Dag A. Brede ◽  
...  
Keyword(s):  
Gamma Radiation ◽  
Dose Rate ◽  
Low Dose ◽  
Low Dose Rate

scholarly journals Effect of Low-Dose Ionizing Radiation on the Expression of Mitochondria-Related Genes in Human Mesenchymal Stem Cells

2021 ◽  
Vol 23 (1) ◽  
pp. 261
Author(s):  
Svetlana V. Kostyuk ◽  
Elena V. Proskurnina ◽  
Marina S. Konkova ◽  
Margarita S. Abramova ◽  
Andrey A. Kalianov ◽  
...  
Keyword(s):  
Stem Cells ◽  
Mesenchymal Stem Cells ◽  
Ionizing Radiation ◽  
Low Dose ◽  
Human Mesenchymal Stem Cells ◽  
Mitochondrial Respiratory Chain ◽  
Respiratory Chain Complexes ◽  
Cell Free Dna ◽  
X Ray ◽  
Free Dna

The concept of hormesis describes a phenomenon of adaptive response to low-dose ionizing radiation (LDIR). Similarly, the concept of mitohormesis states that the adaptive program in mitochondria is activated in response to minor stress effects. The mechanisms of hormesis effects are not clear, but it is assumed that they can be mediated by reactive oxygen species. Here, we studied effects of LDIR on mitochondria in mesenchymal stem cells. We have found that X-ray radiation at a dose of 10 cGy as well as oxidized fragments of cell-free DNA (cfDNA) at a concentration of 50 ng/mL resulted in an increased expression of a large number of genes regulating the function of the mitochondrial respiratory chain complexes in human mesenchymal stem cells (MSC). Several genes remained upregulated within hours after the exposure. Both X-ray radiation and oxidized cfDNA resulted in upregulation of FIS1 and MFN1 genes, which regulated fusion and fission of mitochondria, within 3–24 h after the exposure. Three hours after the exposure, the number of copies of mitochondrial DNA in cells had increased. These findings support the hypothesis that assumes oxidized cell-free DNA as a mediator of MSC response to low doses of radiation.

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