Metabolomics,Unknown,Transcriptomics,Genomics,Proteomics

Dataset Information

Expression data in mouse liver exposed to low dose-rate radiation

ABSTRACT: Expression profiles in mouse liver exposed to long-term gamma-irradiation were examined to assess in vivo effects of low dose-rate radiation. Three groups of male C57BL/6J mice were exposed to whole body irradiation at dose-rates of 17-20 mGy/day, 0.86-1.0 mGy/day or 0.042-0.050 mGy/day for 401-485 days (cumulative doses were approximately 8 Gy, 0.4 Gy or 0.02 Gy, respectively). Expression profiles were produced for RNA isolated from irradiated individual animals and for pooled RNA from sham-irradiated 3 animals for control. The expression levels of 6 irradiated animals for each dose were compared individually with those of 2 pooled controls (3 irradiated samples to one pooled control in first and second experiments). The experiments were conducted twice at similar dose-rates. In the first experiment, three groups of 8 weeks old male C57BL/6J mice were exposed to whole body irradiation at dose-rates of either 16.6 mGy/day (H1), 0.858 mGy/day (M1) or 0.042 mGy/day (L1) for 485 days (cumulative doses were 8030 mGy, 416 mGy or 20.6 mGy, respectively). In the second experiment, the doe-rates were slightly elevated as 20.0 mGy/day (H2), 1.000 mGy/day (M2) or 0.050 mGy/day (L2) for 401 days (doses were 8015 mGy, 401 mGy or 20 mGy, respectively). A group of control unirradiated mice were set for each experiment (C1, C2).

ORGANISM(S): Mus musculus

SUBMITTER: Yoshihiko Uehara

PROVIDER: E-GEOD-20562 | biostudies-arrayexpress |

REPOSITORIES: biostudies-arrayexpress

ACCESS DATA

Publications

Gene expression profiles in mouse liver after long-term low-dose-rate irradiation with gamma rays.

Uehara Yoshihiko Y Ito Yasuko Y Taki Keiko K Nenoi Mitsuru M Ichinohe Kazuaki K Nakamura Shingo S Tanaka Satoshi S Oghiso Yoichi Y Tanaka Kimio K Matsumoto Tsuneya T Paunesku Tatjana T Woloschak Gayle E GE Ono Tetsuya T

Radiation research 20100830 5

Changes in gene expression profiles in mouse liver induced by long-term low-dose-rate γ irradiation were examined by microarray analysis. Three groups of male C57BL/6J mice were exposed to whole-body radiation at dose rates of 17-20 mGy/day, 0.86-1.0 mGy/day or 0.042-0.050 mGy/day for 401-485 days with cumulative doses of approximately 8 Gy, 0.4 Gy or 0.02 Gy, respectively. The gene expression levels in the livers of six animals from each exposure group were compared individually with that of po ...[more]

PMID: 20954861

Similar Datasets

Project description:Measuring global gene expression using cDNA or oligonucleotide microarrays is an effective approach to understanding the complex mechanisms of the effects of radiation. However, few studies have been carried out that investigate gene expression in vivo after prolonged exposure to low-dose-rate radiation. In this study, C57BL/6J mice were continuously irradiated with ?-rays for 485 days at dose-rates of 0.032 – 13 ?Gy/min. Gene expression profiles in the kidney and testis from irradiated and unirradiated mice were analyzed, and differentially expressed genes were identified. A combination of pathway analysis and hierarchical clustering of differentially expressed genes revealed that expression of genes involved in mitochondrial oxidative phosphorylation was elevated in the kidney after irradiation at the dose-rates of 0.65 ?Gy/min and 13 ?Gy/min. Expression of cell cycle-associated genes was not profoundly modulated in the kidney, in contrast to the response to acute irradiation, suggesting a threshold in the dose-rate for modulation of the expression of cell cycle-related genes in vivo following exposure to radiation. We demonstrated that changes to the gene expression profile in the testis were largely different from those in the kidney. The Gene Ontology categories “DNA metabolism”, “response to DNA damage” and “DNA replication” overlapped significantly with the clusters of genes whose expression decreased with an increase in the dose-rate to the testis. These observations provide a fundamental insight into the organ-specific responses to low-dose-rate radiation. Key Words: kidney, low-dose-rate, radiation, microarray, mitochondrial oxidative phosphorylation, testis 3 biological replicates for each experimental group were analysed. GSE14290_Kidney_raw_data.csv contains the raw data for GSM357146, GSM357425, GSM357426, GSM357452 to GSM357460. GSE14290_Testis_raw_data.csv contains the raw data for GSM357471 to GSM357482. In these files, the sample identifiers are included in the column headers.

Project description:Although radiation effects have been extensively studied, the biological effects of low-dose radiation (LDR) are controversial. This study investigates LDR-induced alterations in locomotive behavior and gene expression profiles of Drosophila melanogaster. We measured locomotive behavior using larval pupation height and rapid iterative negative geotaxis (RING) assay after exposure to 0.1 Gy gamma-radiation (dose rate of 16.7 mGy/h). We also observed chronic LDR effects on development (pupation and eclosion rates) and longevity (life span). To identify chronic LDR effects on gene expression, we performed whole-genome expression analysis using gene-expression microarrays, and confirmed the results using quantitative real-time PCR. Pupation height was significantly higher after LDR treatment at the first larval instar. Locomotive behavior of male flies was significantly greater approximately 3M-BM--5 weeks after LDR, but pupation and eclosion rates and life spans were not significantly different. Genome-wide expression analysis identified 344 genes that were differentially expressed in irradiated larvae compared with those of controls. We identified several genes belonging to larval behavior functional groups such as locomotive behavior and oxidation reduction, and genes involved in conventional functional groups modulated by irradiation such as defense response, sensory and perception. Four candidate genes were confirmed as differentially expressed genes in irradiated larvae using qRT-PCR. These data suggest that LDR stimulates locomotion-related genes, and these genes can be used as potential markers for LDR. Eggs were collected from 5-day-old female flies and cultivated for 24 h on standard medium. Then, twenty larvae were manually selected and seeded on fresh standard medium in a new vial. After transfer, the experimental group of first-instar larvae was immediately irradiated with chronic gamma-radiation at a dose rate of 16.7 mGy/h. After treatment, gamma-irradiated flies and non-irradiated control flies were maintained in the same incubator at 25degC.

Project description:In the current study a systematic investigation of life stage, tissue and cell dependent sensitivity to ionizing radiation in the nematode Caenorhabditis elegans was conducted. This revealed that individuals that have reached the post-mitotic L4 stage showed no significant effects with respect to mortality, morbidity or reproduction when subjected to either acute dose ≤6 Gy(1500 mGy/h) or chronic exposure ≤4 Gy( ≤ 100 mGy/h). In contrast, chronic exposure from embryo to young adult stage caused a dose and dose rate dependent reprotoxicitiy with 43% reduction in total brood size at 6.7Gy (107 mGy/h). Systematic targeted irradiation of developmental stages showed that exposure during L1 to young L4 was sufficient to induce reprotoxic effects. Exposure during these stages was associated with a dose rate dependent genotoxic effects on gonads with 1.7 to 3.2 fold increase in germ cell apoptosis in larvae subjected to 40-100 mGy/h, respectively. Importantly, exposure to gamma radiation significantly impaired spermatogenesis in a dose rate dependent manner. The observed reduction in the number of spermatids accounted for xx% of the reprotoxic effects, thus signifying spermatids as the most radiosensitive cell type in C. elegans. Molecular responses analyzed by RNAseq of nematodes irradiated from L1 to L4 stage revealed a significant enrichment of genes related to both male and hermaphrodite reproductive processes. Gene network analysis identified adverse genotoxic effects related to down-regulation of genes required for spindle formation and sperm meiosis/maturation, including smz-1, smz-2 and htas-1. The expression of a subset of 28 set-17 regulated Major Sperm Proteins (MSP) required for spermatids production was correlated to the reduction in reproduction and the number of spermatids, thus corroborating the impairment of spermatogenesis as the major cause of gamma radiation induced life-stage dependent reprotoxic effect. Furthermore, the progeny of irradiated nematodes showed significant embryonal DNA damage that was associated with persistent effect on somatic growth. Unexpectedly, these nematodes did however maintain much of their reproductive capacity in spite of the reduced growth.

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.

Dataset Information

Expression data in mouse liver exposed to low dose-rate radiation

Publications

Gene expression profiles in mouse liver after long-term low-dose-rate irradiation with gamma rays.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure