scholarly journals Gamma Low-Dose-Rate Ionizing Radiation Stimulates Adaptive Functional and Molecular Response in Human Aortic Endothelial Cells in a Threshold-, Dose-, and Dose Rate–Dependent Manner

Dose-Response ◽  
2018 ◽  
Vol 16 (1) ◽  
pp. 155932581875523 ◽  
Author(s):  
Juliana Vieira Dias ◽  
Celine Gloaguen ◽  
Dimitri Kereselidze ◽  
Line Manens ◽  
Karine Tack ◽  
...  
Keyword(s):  
Cardiovascular Disease ◽  
Endothelial Cells ◽  
Ionizing Radiation ◽  
Dose Rate ◽  
Low Dose ◽  
Human Aorta ◽  
Dependent Manner ◽  
Inflammatory Genes ◽  
Low Dose Rate ◽  
Anti Inflammatory

A central question in radiation protection research is whether low-dose and low-dose-rate (LDR) exposures to ionizing radiation play a role in progression of cardiovascular disease. The response of endothelial cells to different LDR exposures may help estimate risk of cardiovascular disease by providing the biological mechanism involved. We investigated the effect of chronic LDR radiation on functional and molecular responses of human aorta endothelial cells (HAoECs). Human aorta endothelial cells were continuously irradiated at LDR (6 mGy/h) for 15 days and analyzed at time points when the cumulative dose reached 0.05, 0.5, 1.0, and 2.0 Gy. The same doses were administered acutely at high-dose rate (HDR; 1 Gy/min). The threshold for the loss of angiogenic capacity for both LDR and HDR radiations was between 0.5 and 1.0 Gy. At 2.0 Gy, angiogenic capacity returned to normal only for HAoEC exposed to LDR radiation, associated with increased expression of antioxidant and anti-inflammatory genes. Pre-LDR, but not pre-HDR, radiation, followed by a single acute 2.0 Gy challenge dose sustained the expression of antioxidant and anti-inflammatory genes and stimulated angiogenesis. Our results suggest that dose rate is important in cellular response and that a radioadaptive response is involved for a 2.0 Gy dose at LDR.

scholarly journals The Effects of Low Dose-Rate Ionizing Radiation on the Shapes of Transients in the L>M124 Operational Amplifier

2008 ◽  
Vol 55 (6) ◽  
pp. 3314-3320 ◽  
Author(s):  
Stephen Buchner ◽  
Dale McMorrow ◽  
Nicholas Roche ◽  
Laurent Dusseau ◽  
Ron L. Pease
Keyword(s):  
Ionizing Radiation ◽  
Dose Rate ◽  
Operational Amplifier ◽  
Low Dose ◽  
Low Dose Rate

scholarly journals Increased Frequency of Copy Number Variations Revealed by Array Comparative Genomic Hybridization in the Offspring of Male Mice Exposed to Low Dose-Rate Ionizing Radiation

2021 ◽  
Vol 22 (22) ◽  
pp. 12437
Author(s):  
Keiji Ogura ◽  
Yoshiko Ayabe ◽  
Chihiro Harada ◽  
Ignacia Braga Tanaka ◽  
Satoshi Tanaka ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Dose Rate ◽  
Copy Number ◽  
Array Comparative Genomic Hybridization ◽  
Low Dose ◽  
De Novo ◽  
Copy Number Variations ◽  
Comparative Genomic ◽  
Male Mice ◽  
Low Dose Rate

There is very little information on the transgenerational or genetic effects of low dose-rate ionizing radiation. We report the detection of the transgenerational effects of chronic low dose-rate irradiation in mice, at the molecular level in the whole genome, using array comparative genomic hybridization technology. We observed that the number of the mice with de novo copy number variations (specifically, deletions) was significantly increased in the offspring of C57BL/6J male mice exposed to 20 mGy/day gamma-rays for 400 days (total dose: 8000 mGy), as compared to non-irradiated controls. We did not detect any difference in the size of the de novo deletions between the irradiated and the non-irradiated groups. An analysis of the life span of the offspring suggested a possibility that de novo copy-number variations may be associated with shorter life spans.

scholarly journals Association between low doses of ionizing radiation, administered acutely or chronically, and time to onset of stroke in a rat model

2020 ◽  
Vol 61 (5) ◽  
pp. 666-673
Author(s):  
Norio Takahashi ◽  
Munechika Misumi ◽  
Hideko Murakami ◽  
Yasuharu Niwa ◽  
Waka Ohishi ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Radiation Exposure ◽  
Dose Rate ◽  
Low Dose ◽  
Gamma Ray ◽  
Spontaneously Hypertensive Rat ◽  
Onset Time ◽  
High Sensitivity ◽  
Low Dose Rate ◽  
Model Animal

Abstract Exposure to high-doses of ionizing radiation has been reported to be associated with the risk of stroke. However, risks associated with lower dose exposures remain unclear, and there is little information available for the risk modification according to the dose-rate. There are few studies using animal models which might be able to provide complementary information on this association. In this study, the male stroke-prone spontaneously hypertensive rat (SHRSP) was used as a model animal. The rats were acutely irradiated with doses between 0 and 1.0 Gy or chronically irradiated with a cumulative dose of 0.5 or 1.0 Gy (at a dose rate of 0.05 or 0.1 Gy/day, respectively). The onset time of stroke related symptoms in SHRSP was used as an endpoint for evaluating the effects of low dose and the low dose-rate gamma-ray exposures. With respect to acute exposure, the time to the onset of stroke in the irradiated rats suggested the presence of a threshold around 0.1 Gy. For the low dose-rate chronically exposed, no significant increase in stroke symptom was observed. These findings are novel and demonstrate that the SHRSP system can be used to determine the association between the risk of stroke and radiation exposure with high sensitivity. Moreover, these studies provide important information regarding the association between the low dose and low dose-rate radiation exposure and circulatory diseases, especially stroke.

Low Dose External γ Ionizing Radiation Regulates Mouse Immune Cells in a Dose and Dose-rate- Dependent Manner

2018 ◽  
Vol 32 ◽  
pp. 67
Author(s):  
Teni Ebrahimian ◽  
C. Demarquay ◽  
T. Ebrahimian ◽  
J. Vieira Dias ◽  
D. Kereselidze ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Dose Rate ◽  
Immune Cells ◽  
Low Dose ◽  
Dependent Manner ◽  
Rate Dependent

scholarly journals Perturbed transcriptional profiles after chronic low dose rate radiation in mice

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256667
Author(s):  
Hildegunn Dahl ◽  
Dag M. Eide ◽  
Torstein Tengs ◽  
Nur Duale ◽  
Jorke H. Kamstra ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Dose Rate ◽  
Low Dose ◽  
High Dose Rate ◽  
High Dose ◽  
Transcriptional Responses ◽  
Transcriptional Profiles ◽  
Dose Rates ◽  
Low Dose Rate ◽  
Genome Wide

Adverse health outcomes of ionizing radiation given chronically at low dose rates are highly debated, a controversy also relevant for other stressors. Increased knowledge is needed for a more comprehensive understanding of the damaging potential of ionizing radiation from all dose rates and doses. There is a lack of relevant low dose rate data that is partly ascribed to the rarity of exposure facilities allowing chronic low dose rate exposures. Using the FIGARO facility, we assessed early (one day post-radiation) and late (recovery time of 100–200 days) hepatic genome-wide transcriptional profiles in male mice of two strains (CBA/CaOlaHsd and C57BL/6NHsd) exposed chronically to a low dose rate (2.5 mGy/h; 1200h, LDR), a mid-dose rate (10 mGy/h; 300h, MDR) and acutely to a high dose rate (100 mGy/h; 30h, HDR) of gamma irradiation, given to an equivalent total dose of 3 Gy. Dose-rate and strain-specific transcriptional responses were identified. Differently modulated transcriptional responses across all dose rate exposure groups were evident by the representation of functional biological pathways. Evidence of changed epigenetic regulation (global DNA methylation) was not detected. A period of recovery markedly reduced the number of differentially expressed genes. Using enrichment analysis to identify the functional significance of the modulated genes, perturbed signaling pathways associated with both cancer and non-cancer effects were observed, such as lipid metabolism and inflammation. These pathways were seen after chronic low dose rate and were not restricted to the acute high dose rate exposure. The transcriptional response induced by chronic low dose rate ionizing radiation suggests contribution to conditions such as cardiovascular diseases. We contribute with novel genome wide transcriptional data highlighting dose-rate-specific radiation responses and emphasize the importance of considering both dose rate, duration of exposure, and variability in susceptibility when assessing risks from ionizing radiation.

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