Project description:Low-LET radiation can cause cardiovascular dysfunctions at high-dose rates. For example, photons used in thoracic radiotherapy are known to cause acute cardiac tissue damage with elevated serum cardiac Troponin I level and long-term cardiac complications when delivered as fractionated exposures at high-dose rates. However, the effects of continuous low-dose rate radiation exposure on the heart, which simulate the space radiation environment, have not been well-studied. In this study, we aim to model low-LET space radiation-induced cardiovascular dysfunction using human induced pluripotent stem cell (iPSC)-derived engineered heart tissues (EHTs) exposed to protracted γ-ray irradiation. The investigation of pathophysiological changes in this model may provide insights and guide the development of countermeasures. As a proof-of-principle for the application of this model in drug development, we also tested the protective effect of a mitochondrial-specific antioxidant, MitoTempo, on irradiated EHTs.
Project description:Normal lung tissue tolerance constitutes a limiting factor in delivering the required dose of radiotherapy to cure thoracic and chest wall malignancies. Patient genetic predisposition, the volume of irradiated lung and combination regimens consisting of concurrent chemotherapy are correlated with increased risk of radiation induced toxicity in lung. The main purpose of this study is to investigate dose-response regulations of mouse lung irradiation based on a comprehensive dose-escalation program, for a better understanding of molecular mechanism governing radiation induced lung fibrosis by high-LET carbon-ions versus conventional low-LET X-ray.
Project description:We performed comparative RNA sequencing of the early (4 hrs) dose response (0.5 – 200 cGy whole body dose, 10 dose levels) of the mouse aorta to proton and gamma radiation. Total-body proton radiation of conscious animals was performed using a proton beam produced by a cyclotron system, while total-body gamma radiation of animals was performed using a Caesium-137 gamma source. A trend analysis identified genes that showed a dose response, using data permutation to estimate a false discovery rate (q-value) for each gene. We identified 29 and 194 genes (q-value ≤ 0.1) that were upregulated with increasing doses of proton and gamma radiation, respectively. No genes were down-regulated. While fewer genes were dose-responsive to proton radiation, the magnitude of the effect was greater than with gamma radiation. These highly responsive genes were enriched for pathways involved in the response to DNA damage, apoptosis, cellular stress and inflammation (p < 0.01). Gamma radiation responsive genes included the same pathways, but extended to genes in vasculature specific pathways. Genes responsive to both radiation types (19 genes at q-value ≤ 0.1) showed almost perfectly superimposable dose-response relationships. We observed the same superimposable dose response relationship of gamma and proton radiations in a subset of genes validated by quantitative PCR not only in the aorta but also in liver, lung, heart and kidney. Despite a relative similar relative biological effectiveness of protons and gamma photons and the activation of canonical radiation response pathways by both radiation types, we detected marked differences in the genomic response. It seems plausible that these genomic differences translate into differences in the biological processes leading to cardiovascular pathologies.
Project description:Here, male and female B6C3F1 mice were given single or fractionated whole-body exposure(s) to a monoenergetic carbon ion radiotherapy beam at the Heavy Ion Medical Accelerator in Chiba, Japan, matching the radiation quality delivered to the normal tissue ahead of the tumour volume. These mice were then monitored for the remainder of their lifespan and a large number of T cell lymphomas were analysed, alongside those arising in mice exposed to equivalent doses of standard Cs137 gamma ray-irradiation. Using genome-wide DNA copy number analysis to identify genomic loci involved in radiation-induced lymphomagenesis and subsequent detailed analysis of Notch1, Ikaros, Pten, Trp53 and Bcl11b genes we compared the genetic profile of the carbon ion- and gamma ray-induced tumours. The canonical set of genes previously associated with radiation-induced T cell lymphoma was identified in both radiation groups. While the pattern of disruption of the various pathways was somewhat different between the radiation types, most notably Pten mutation frequency and loss of heterozygosity flanking Bcl11b, the most striking finding was the observation of large interstitial deletions at various sites across the genome in carbon ion-induced tumours, which were only seen infrequently in the gamma ray-induced tumours analysed. 32 unique tumours (12 gamma ray-induced, 20 carbon ion-induced) each with sex-matched reference DNA
Project description:This dataset is composed by the transcriptomic, proteomic and phosphoproteomic profile of primary human fibroblasts exposed to two different doses of radiation: an acute X-ray radiation dose, and an accumulative X-ray radiation dose. These data were employed to apply and evaluate different computational approaches to model and infer cellular signaling processes through the combination of prior knowledge and omic data. We employed RNA-Seq and Mass Spectrometry (MS) to generate the transcriptomic and proteomic data from the RNA and protein samples, respectively.
Project description:Radiation lung injury is characterized by early inflammation and late fibrosis. The causes underlying the chronic, progressive nature of radiation injury are poorly understood. Here, we report that the gene expression of irradiated lung tissue correlates with that observed in the lungs in aged animals. We demonstrate that NOX4 expression and superoxide elaboration is increased in irradiated lungs and pneumocytes in a dose dependent fashion. We used microarrays to detail the global programme of gene expression and report that irradiated lung tissue correlates with that observed in the lungs in aged animals. Female C57Bl/Ncr mice, aged 10 weeks were treated with/ without radiation to the thorax with a X-RAD 320 x-ray irradiator at a dose rate of 2.61 Gy/minute. An age-matched cohort of mice received no IR while additional cohorts received 5 Gy in a single dose, 17.5 Gy in a single dose. RNA was extracted and hybridization done on Affymetrix Mouse430_2 microarrays.
Project description:While modern radiotherapy technologies can precisely deliver higher doses of radiation to tumors; thus, reducing overall radiation exposure to normal tissues, moderate dose and normal tissue toxicity still remains a significant limitation. The present study profiled the global effects on transcript and miR expression in Human Coronary Artery Endothelial Cells (HCAECs) using single-dose irradiation (SD, 10Gy) or multi-fractionated irradiation (MF, 2Gy x 5) regimens. Longitudinal timepoints were collected after a SD or final dose of MF irradiation for analysis using Agilent Human Gene Expression and miRNA microarray platforms. Compared to SD, the exposure to MF resulted in robust transcript and miR expression changes in terms of the number and magnitude. For data analysis, statistically significant mRNAs (2-fold) and miRs (1.5-fold) were processed by Ingenuity Pathway Analysis (IPA) to uncover miRs associated with target transcripts from several cellular pathways post-irradiation. Interestingly, MF radiation induced a cohort of mRNAs and miRs that coordinate the induction of immune response pathway under tight regulation. Additionally, mRNAs and miRs associated with DNA replication, recombination and repair, apoptosis, cardiovascular events and angiogenesis were revealed. Human Coronary Artery Endothelial Cells (HCAECs) were irradiated in a PANTAK high frequency X-ray generator (Precision X-ray Inc., N. Bedford, CT), operated at 300kV and 10MA. The dose rate was 1.6 Gy per min. Cells were plated into T75cm2 flasks (1-1.5 x 10^6 for single dose radiation and 0.6-0.8 x 10^6 for fractionated radiation). After 24h, cells were exposed to a total of 10 Gy radiation administered either as a single-dose radiation (SD), or as multi-fractionated radiation of 2 Gy x 5 (MF). These non-isoeffective doses were selected to simulate clinical hypofractionated and conventionally fractionated radiotherapy regimens. For the MF protocol, cells were exposed to 2 Gy radiation twice a day, at 6h interval. The cells were approximately 90% confluent at the time of harvesting. For both protocols, radiation-induced changes were analyzed at 6h and 24h after a SD and 6h and 24h after the final dose of fractionated irradiation. Separate controls were maintained for SD and MF radiation protocols.
Project description:While modern radiotherapy technologies can precisely deliver higher doses of radiation to tumors; thus, reducing overall radiation exposure to normal tissues, moderate dose and normal tissue toxicity still remains a significant limitation. The present study profiled the global effects on transcript and miR expression in Human Coronary Artery Endothelial Cells (HCAECs) using single-dose irradiation (SD, 10Gy) or multi-fractionated irradiation (MF, 2Gy x 5) regimens. Longitudinal timepoints were collected after a SD or final dose of MF irradiation for analysis using Agilent Human Gene Expression and miRNA microarray platforms. Compared to SD, the exposure to MF resulted in robust transcript and miR expression changes in terms of the number and magnitude. For data analysis, statistically significant mRNAs (2-fold) and miRs (1.5-fold) were processed by Ingenuity Pathway Analysis (IPA) to uncover miRs associated with target transcripts from several cellular pathways post-irradiation. Interestingly, MF radiation induced a cohort of mRNAs and miRs that coordinate the induction of immune response pathway under tight regulation. Additionally, mRNAs and miRs associated with DNA replication, recombination and repair, apoptosis, cardiovascular events and angiogenesis were revealed. Human Coronary Artery Endothelial Cells (HCAECs) were irradiated in a PANTAK high frequency X-ray generator (Precision X-ray Inc., N. Bedford, CT), operated at 300kV and 10MA. The dose rate was 1.6 Gy per min. Cells were plated into T75cm2 flasks (1-1.5 x 10^6 for single dose radiation and 0.6-0.8 x 10^6 for fractionated radiation). After 24h, cells were exposed to a total of 10 Gy radiation administered either as a single-dose radiation (SD), or as multi-fractionated radiation of 2 Gy x 5 (MF). These non-isoeffective doses were selected to simulate clinical hypofractionated and conventionally fractionated radiotherapy regimens. For the MF protocol, cells were exposed to 2 Gy radiation twice a day, at 6h interval. The cells were approximately 90% confluent at the time of harvesting. For both protocols, radiation-induced changes were analyzed at 6h and 24h after a SD and 6h and 24h after the final dose of fractionated irradiation. Separate controls were maintained for SD and MF radiation protocols.
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.