Ionizing radiation exposure of developing mouse brain and cultured neurons
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ABSTRACT: The mammalian brain is especially sensitive to ionizing radiation during development, as shown by the increased occurrence of mental retardation and small head size in children who were in utero exposed to ionizing radiation after the atomic bombings of Hiroshima and Nagasaki. These effects of prenatal irradiation can be mimicked by irradiation of mouse embryos during the organogenesis period. In order to better understand the early effects of ionizing radiation on the embryonic brain and immature neurons, we performed a microarray analysis on brains from mice irradiated with different doses at E11 and E14, as well as primary cortical neuron cultures after 14 h in vitro. RNA was extracted at either 2 h (brains) or 6 h (neurons) post-irradiation.
Project description:The mammalian brain is especially sensitive to ionizing radiation during development, as shown by the increased occurrence of mental retardation and small head size in children who were in utero exposed to ionizing radiation after the atomic bombings of Hiroshima and Nagasaki. These effects of prenatal irradiation can be mimicked by irradiation of mouse embryos during the organogenesis period. In order to better understand the early effects of ionizing radiation on the embryonic brain and immature neurons, we performed a microarray analysis on brains from mice irradiated with different doses (0.0, 0.1, 0.2, 0.5 and 1.0 Gy) at E11. RNA was extracted at either 2 or 24 h post-irradiation.
Project description:The bystander effect from ionizing radiation consists of cellular responses generated from unirradiated cells to the irradiation of their neighbors. The bystander effect can lead to DNA damage and genomic instability in the affected cells. This non-targeted effect of radiation has received attention due to its potential implications for cancer therapy and radiation protection. Although studied extensively, a complete understanding of its molecular mechanism is the subject of ongoing research. While many studies have targeted specific factors which are suggested to be involved in the bystander effect, few have looked at whole genome gene expression in bystander cells. Furthermore, even fewer studies have looked at the expression in noncancerous human cell lines. In this study we have used a genome-wide microarray approach to investigate transcriptional responses in irradiated and bystander immortalized human fibroblasts following 0.1 Gy ?-particle irradiation. Total RNA was isolated from F11hTERT fibroblasts irradiated with 0.1 Gy ?-particles and bystander fibroblasts receiving medium from control (sham irradiated) and irradiated cells (0.1 Gy). RNA was isolated 4, 8 and 26 h after irradiation.
Project description:The bystander effect from ionizing radiation consists of cellular responses generated from non-irradiated cells to the irradiation of their neighbors. The bystander effect is predominant at low doses and can lead to DNA damage and genomic instability in the affected cells. This non-targeted effect of radiation has received attention due to its potential implications for cancer therapy and radiation protection. Although studied extensively, a complete understanding of its molecular mechanism is the subject of ongoing research. While many studies have targeted specific factors which are suggested to be involved in the bystander effect, few have looked at whole genome gene expression in bystander cells. Furthermore, even fewer studies have looked at the expression in normal human cell lines. In this study, we have monitored transcriptional responses to γ-radiation in irradiated and bystander normal fibroblasts simultaneously using a genome-wide microarray approach. Bystander fibroblasts incubated in medium from irradiated cells, showed transient enrichment (less than 1.5 fold) in ribosome and oxidative phosphorylation pathways, and neurodegenerative disease pathways associated with mitochondrial dysfunctions. Bystander fibroblasts did not, however, display increases in oxidative stress, a phenomenon often linked with the radiation induced bystander effect. Total RNA was isolated from normal human fibroblasts irradiated with 2.0 Gy and fibroblasts incubated with medium from sham irradiated and irradiated cells 2 h after irradiation. RNA was isolated 4, 8 and 26 h after irradiation and there are 4 replicates for each sample for a total of 36 samples.
Project description:MicroRNA expression was assessed in human cancer cells (K562, Me45, HCT116 wt and HCT116 p53-/-) treated with 4Gy of ionizing radiation. RNA was extracted from the cells 12 hours after irradiation and after 1h from non-treated controls.
Project description:Tardigrades can survive remarkable doses of ionizing radiation, up to about 1000 times the lethal dose for humans. How they do so is incompletely understood. We found that the tardigrade Hypsibius exemplaris suffers DNA damage upon gamma irradiation, but damage is repaired. We show that tardigrades have a specific and robust response to ionizing radiation: irradiation induces a rapid, dramatic upregulation of many DNA repair genes. By expressing tardigrade genes in bacteria, we validate that increased expression of some repair genes can suffice to increase radiation tolerance. We show that at least one such gene is necessary for tardigrade radiation tolerance. Tardigrades’ ability to sense ionizing radiation and massively upregulate specific DNA repair pathway genes may represent an evolved solution for maintaining DNA integrity.
Project description:Background and Purpose: Cardiotoxicity is a well-known adverse effect of radiation therapy. Measurable abnormalities in the heart function indicate advanced and often irreversible heart damage. Therefore, early detection of cardiac toxicity is necessary to delay and alleviate the development of the disease. The present study investigated long-term serum proteome alterations following local heart irradiation using a mouse model with the aim to detect biomarkers of radiation-induced cardiac toxicity. Materials and Methods: Serum samples from C57BL/6J mice were collected 20 weeks after local heart irradiation with 8 Gy or 16 Gy X-ray; the controls were sham-irradiated. The samples were analyzed by quantitative proteomics based on data-independent acquisition mass spectrometry. The proteomics data were further investigated using bioinformatics and ELISA. Results: The analysis showed radiation-induced changes in the level of several serum proteins involved in the acute phase response, inflammation and cholesterol metabolism. We found significantly enhanced expression of pro-inflammatory cytokines (TNF-, TGF-, IL-1 and IL-6) in the serum of the irradiated mice. The level of free fatty acids, total cholesterol, low density lipoprotein (LDL) and oxidized LDL was increased whereas that of high density lipoprotein was decreased by irradiation. Conclusions: This study provides information on systemic effects of heart irradiation. It elucidates a radiation fingerprint in the serum that may be used to elucidate adverse cardiac effects after radiation therapy.
Project description:In the present study, the susceptibility of the purple pigmented photosynthetic alphaproteobacterium Rhodospirillum rubrum S1H to gamma irradiation was investigated and its molecular response was characterised by means of gene expression analysis. R. rubrum S1H appears to be about 4 times more sensitive than the model strain Escherichia coli MG1655 to cobalt-60 gamma irradiation. Whole genome response of R. rubrum to 25 Gy revealed the common expression of SOS response related genes in both rich and minimal media. Quantitative expression of the lexA gene was followed after various recovery time following gamma irradiation and showed differential gene expression pattern between minimal and rich medium. This work paves the way for forthcoming molecular studies on the effect of ionizing radiation on R. rubrum S1H and the other MELiSSA strains. Keywords: Rhodospirillum rubrum; ionizing radiation tolerance; microarray; quantitative PCR. Two-condition experiments. Comparing samples after exposure to gamma (Co-60) irradiation with a non-irradiated sample. At least biological duplicates. Each array contains 3 technical replicates.
Project description:In recent years there is a growing epidemiological indication of excess risk of cardiovascular disease at low doses of ionizing radiation without a clear-cut threshold. It is proposed that damage to the vascular endothelium is critical in radiation-related cardiovascular diseases. In order to identify and better understand the underlying molecular mechanisms of high LET (Fe ions) and low LET (X-ray) radiation on endothelial cells, we performed a microarray analysis on immortalized human coronary artery endothelial cells irradiated with 2.00 Gy and compared them with sham-irradiated samples. RNA was extracted at different time points after irradiation (1 day, 7 days).
Project description:In recent years there is a growing epidemiological indication of excess risk of cardiovascular disease at low doses of ionizing radiation without a clear-cut threshold. It is proposed that damage to the vascular endothelium is critical in radiation-related cardiovascular diseases. In order to identify and better understand the underlying molecular mechanisms of ionizing radiation on endothelial cells, we performed a microarray analysis on immortalized human coronary artery endothelial cells irradiated with different doses (0.00, 0.05, 0.10, 0.50 and 2.0 Gy). RNA was extracted at different time points after irradiation (1 day, 7 days, 14 days).
Project description:Primary term human trophoblasts were derived from placentas after a healthy pregnancy, and exposed to ionizing irradiation (vs sham) in vitro Primary human trophoblasts were irradiated 24 h after initial plating, defined as time zero. Cells were irradiated at 10 Gy using a Clinac 600C (Varian Medical Systems, Palo Alto, CA) with a 6 MV photon beam and a dose rate of 250 cGy/min. The flasks containing the cells were placed on 1.5 cm of bolus (a tissue equivalent material) since the maximum irradiation depth was 1.5 cm, which corresponded to the plated cell layer. Cells were analyzed 4, 8, and 24 h after irradiation or sham.