Gene expression in mouse blood following low dose-rate or acute x-ray exposure
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ABSTRACT:
ORGANISM(S): Mus musculus
PROVIDER: GSE62623 | GEO | 2015/05/14
SECONDARY ACCESSION(S): PRJNA264562
REPOSITORIES: GEO
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Project description:Radiation biodosimetry can play a critical role in the response to a large-scale radiologic emergency, and gene expression profiles have shown promise for providing biodosimetric information. This study was designed to test if gene expression could be used to distinguish between doses received from acute exposures and more protracted exposures, such as those that would result from fallout. Mice were exposed to whole body X-rays at low dose rate (LDR, 3.09 mGy/min) for 6, 12, or 24 hours (1.1, 2.2, or 4.4 Gy), or to equivalent doses delivered at high dose rate (HDR, 1.03 Gy/min). Global gene expression was measured in their blood 24 h after the start of exposure, and genes with the potential to classify samples by radiation dose and dose rate were identified. Data consist of 48 samples, representing 6 independent samples each from 3 doses delivered as either acute or low dose rate x-rays, plus 12 controls representing both acute and low dose rate sham treatments.
2015-05-14 | E-GEOD-62623 | biostudies-arrayexpress
Project description:Background: The effects of dose-rate and its implications on radiation biodosimetry methods are not well studied in the context of large-scale radiological scenarios. There are significant health risks to individuals exposed to an acute dose in such an event, but the most realistic scenario would be a combination of exposure to both high and low dose-rates, from both external and internal radioactivity. It is important therefore, to understand the biological response to prolonged exposure; and further, discover biomarkers that can be used to estimate the extent of damage from low-dose rate exposure and propose appropriate clinical treatment. Methods: We irradiated human whole blood ex vivo to three doses, 0.56 Gy, 2.25 Gy and 4.45 Gy, using two dose rates: 1.1Gy/min and 3.1mGy/min. After 24 hours, we isolated RNA from blood cells and hybridized these to Agilent Whole Human genome microarrays. We validated the microarray results using qRT-PCR. Results: Microarray results showed that there were 454 significantly differentially expressed genes after prolonged exposure to all doses. After acute exposure, 598 genes were differentially expressed to all doses combined. Gene ontology terms enriched in both sets of genes were related to immune processes and B cell mediated immunity. Genes responding to acute exposure was also enriched in functions related to natural killer cell activation and cell-to-cell signaling. As expected, p53 pathway was found to be significantly enriched at all doses and by both dose-rates of radiation. Prediction algorithms were able to distinguish between low dose-rate and acute exposures, on the basis of a group of genes. These maybe candidates for preliminary testing as markers for differences in gene expression based on dose-rate. Radiation induced gene expression was measured in ex vivo irradiated human blood, at the 24hr time point after irradiation. Doses (0.56 Gy, 2.2 Gy and 4.45 Gy) were delivered by two dose rates, acute dose rate of 1Gy/min and low dose rate of 3.1 mGy/min.
2015-04-28 | E-GEOD-65292 | biostudies-arrayexpress
Project description:Purpose: The International Commission on Radiological Protection (ICRP) recently recommended reducing the occupational equivalent dose limit for the lens of the eye. Based primarily on a review of epidemiological data, the absorbed dose threshold is now considered to be 0.5 Gy for induction of acute opacities, reduced from the previous threshold of 2 Gy. However, direct mechanistic evidence to support an understanding of the underlying molecular mechanisms of damage is still lacking. To this end, we explored the effects of a broad dose-range of ionizing radiation exposure on gene expression changes in a human lens epithelial (HLE) cell-line in order to better understand the shape of the dose-response relationship and identify transcriptional thresholds of effects. Methods: HLE cells were exposed to doses of 0, 0.01, 0.05, 0.25, 0.5, 2, and 5 Gy of X-ray radiation at two dose rates (1.62 cGy/min and 38.2 cGy/min). Cell culture lysates were collected 20 h post-exposure and analysed using whole-genome RNA-sequencing. Pathways and dose-thresholds of biological effects were identified using benchmark dose (BMD) modeling. Results: Transcriptional responses were minimal at doses less than 2 Gy. At higher doses there were a significant number of differentially expressed genes (DEGs) (p < 0.05, fold change > |1.5|) at both dose rates, with 1308 DEGs for the low dose rate (LDR) and 840 DEGs for the high dose rate (HDR) exposure. Dose-response modeling showed that a number of genes exhibited non-linear bi-phasic responses, which was verified by digital droplet PCR. BMD analysis showed the majority of the pathways responded at BMD median values in the dose range of 1.5-2.5 Gy, with the lowest BMD median value being 0.6 Gy for the HDR exposure. The minimum pathway BMD median value for LDR exposure, however, was 2.5 Gy. Although the LDR and HDR exposures shared pathways involved in extracellular matrix reorganization and collagen production with BMD median value of 2.9 Gy, HDR exposures were more effective in activating pathways associated with DNA damage response, apoptosis, and cell cycling relative to LDR exposure. Conclusion: Overall, the results suggest that radiation induces complex non-linear transcriptional dose-response relationships that are dose-rate dependent. Pathways shared between the two dose rates may be important contributors to radiation-induced cataractogenesis. BMD analysis suggests that the majority of pathways are activated above 0.6 Gy, which supports current ICRP identified dose thresholds for deterministic effects to the lens of the eye of 0.5 Gy.
2018-10-04 | GSE120805 | GEO
Project description:Background: The effects of dose-rate and its implications on radiation biodosimetry methods are not well studied in the context of large-scale radiological scenarios. There are significant health risks to individuals exposed to an acute dose in such an event, but the most realistic scenario would be a combination of exposure to both high and low dose-rates, from both external and internal radioactivity. It is important therefore, to understand the biological response to prolonged exposure; and further, discover biomarkers that can be used to estimate the extent of damage from low-dose rate exposure and propose appropriate clinical treatment. Methods: We irradiated human whole blood ex vivo to three doses, 0.56 Gy, 2.25 Gy and 4.45 Gy, using two dose rates: 1.1Gy/min and 3.1mGy/min. After 24 hours, we isolated RNA from blood cells and hybridized these to Agilent Whole Human genome microarrays. We validated the microarray results using qRT-PCR. Results: Microarray results showed that there were 454 significantly differentially expressed genes after prolonged exposure to all doses. After acute exposure, 598 genes were differentially expressed to all doses combined. Gene ontology terms enriched in both sets of genes were related to immune processes and B cell mediated immunity. Genes responding to acute exposure was also enriched in functions related to natural killer cell activation and cell-to-cell signaling. As expected, p53 pathway was found to be significantly enriched at all doses and by both dose-rates of radiation. Prediction algorithms were able to distinguish between low dose-rate and acute exposures, on the basis of a group of genes. These maybe candidates for preliminary testing as markers for differences in gene expression based on dose-rate.
2015-04-28 | GSE65292 | GEO
Project description:An important component of ionizing radiation (IR) exposure after a radiological incident may include low-dose rate (LDR) exposures either externally or internally, such as from 137Cs deposition. LDR exposures can have different effects compared to acute high-dose rate exposures from a health and biodosimetry perspective. In this study, a novel irradiation system, VAriable Dose-rate External 137Cs irradiatoR (VADER), was used to expose male and female mice to a variable LDR over a 30-day time span to cumulative doses of 1 (only in males), 2, 2.8, 4.1, 8.8 (only in males), or 9.7 Gy to simulate fall-out type exposures. Urine and serum from mice exposed to an acute dose (~0.8 Gy/min) of x-rays were collected in parallel. Radiation markers were identified by global mass spectrometry based metabolomics and the machine learning algorithm Random Forests.
2021-05-12 | ST001792 | MetabolomicsWorkbench
Project description:An important component of ionizing radiation (IR) exposure after a radiological incident may include low-dose rate (LDR) exposures either externally or internally, such as from 137Cs deposition. LDR exposures can have different effects compared to acute high-dose rate exposures from a health and biodosimetry perspective. In this study, a novel irradiation system, VAriable Dose-rate External 137Cs irradiatoR (VADER), was used to expose male and female mice to a variable LDR over a 30-day time span to cumulative doses of 1 (only in males), 2, 2.8, 4.1, 8.8 (only in males), or 9.7 Gy to simulate fall-out type exposures. Urine and serum from mice exposed to an acute dose (~0.8 Gy/min) of x-rays were collected in parallel. Radiation markers were identified by global mass spectrometry based metabolomics and the machine learning algorithm Random Forests.
2021-05-11 | ST001791 | MetabolomicsWorkbench
Project description:An important component of ionizing radiation (IR) exposure after a radiological incident may include low-dose rate (LDR) exposures either externally or internally, such as from 137Cs deposition. LDR exposures can have different effects compared to acute high-dose rate exposures from a health and biodosimetry perspective. In this study, a novel irradiation system, VAriable Dose-rate External 137Cs irradiatoR (VADER), was used to expose male and female mice to a variable LDR over a 30-day time span to cumulative doses of 1 (only in males), 2, 2.8, 4.1, 8.8 (only in males), or 9.7 Gy to simulate fall-out type exposures. Urine and serum from mice exposed to an acute dose (~0.8 Gy/min) of x-rays were collected in parallel. Radiation markers were identified by global mass spectrometry based metabolomics and the machine learning algorithm Random Forests.
2021-05-11 | ST001790 | MetabolomicsWorkbench
Project description:An important component of ionizing radiation (IR) exposure after a radiological incident may include low-dose rate (LDR) exposures either externally or internally, such as from 137Cs deposition. LDR exposures can have different effects compared to acute high-dose rate exposures from a health and biodosimetry perspective. In this study, a novel irradiation system, VAriable Dose-rate External 137Cs irradiatoR (VADER), was used to expose male and female mice to a variable LDR over a 30-day time span to cumulative doses of 1 (only in males), 2, 2.8, 4.1, 8.8 (only in males), or 9.7 Gy to simulate fall-out type exposures. Urine and serum from mice exposed to an acute dose (~0.8 Gy/min) of x-rays were collected in parallel. Radiation markers were identified by global mass spectrometry based metabolomics and the machine learning algorithm Random Forests.
2021-05-12 | ST001793 | MetabolomicsWorkbench
Project description:An important component of ionizing radiation (IR) exposure after a radiological incident may include low-dose rate (LDR) exposures either externally or internally, such as from 137Cs deposition. LDR exposures can have different effects compared to acute high-dose rate exposures from a health and biodosimetry perspective. In this study, a novel irradiation system, VAriable Dose-rate External 137Cs irradiatoR (VADER), was used to expose male and female mice to a variable LDR over a 30-day time span to cumulative doses of 1 (only in males), 2, 2.8, 4.1, 8.8 (only in males), or 9.7 Gy to simulate fall-out type exposures. Urine and serum from mice exposed to an acute dose (~0.8 Gy/min) of x-rays were collected in parallel. Radiation markers were identified by global mass spectrometry based metabolomics and the machine learning algorithm Random Forests.
2021-05-18 | ST001806 | MetabolomicsWorkbench
Project description:The development of a biodosimetric assay based on the combined gene expression analysis of ex vivo-irradiated human peripheral blood (PB) and humans treated with total body irradiation has been developed. Gene expression profile signature of human radiation injury into a rapid and high-throughput chemical ligation-dependent probe amplification assay (CLPA) has been shown to discriminate 6 radiation dose levels in human PB. Candidate gene lists were first developed assaying human ex vivo and human TBI samples on the Affymetrix platform. For the Ex Vivo samples, healthy consented adult donor was randomly assigned to a radiation group and labeled with the target dose of 0 cGy, 150 cGy, 300 cGy, or 600 cGy. In addition to the radiation exposures, the samples were also treated with either no treatment, GCSF, or LPS at time points 6 hours and 24 hours. Radiation expire times from the Cs137 irradiator were calculated to achieve target doses specific for tubes filled with blood and inserted in the roaring test tube holder. The dose rate was 480 cGy/min for the duration of the study. The healthy donors were enrolled to participate in this study following a protocol to collect PB samples that was previously approved by the Duke University Institutional Review Board. For the TBI samples, adult patients, ages 21 to 66, were evaluated at the Duke University Adult Bone Marrow Transplantation Program enrolled in a Duke IRB-approved protocol to collect PB prior to and post TBI conditioning. With approval from the Duke University Institutional Review Board (IRB), between 5-12 mL of peripheral blood was collected from consented patients prior to and 6 hours following TBI with 150-200 cGy as part of their pre-transplantation conditioning. All patients receiving non-myeloablative conditioning were treated with 200 cGy of TBI from a linear accelerator at a dose rate of 20 cGy/min. All patients who underwent TBI-based myeloablative allogeneic or autologous stem-cell transplantation received radiation fractionated at 150 cGy per fraction at 20 cGy/min. All patients had PB collected (50 ml) prior to and 6 hours following exposure to either 200 cGy or 150 cGy radiation treatment. The dose exposure for TBI patients used in this study were 0 cGy, 150 cGy, 450 cGy and 1050 cGy at 0, 6, 30 and 78 hours post irradiation. Total RNA was extracted and assayed on the Affymetrix platform.
2014-10-21 | E-GEOD-58613 | biostudies-arrayexpress