Project description:Previously, we used mouse and non-human primate models to show that serum miRNAs may predict the biological impact of lethal and sublethal radiation doses. We hypothesized that these results can be replicated in humans treated with total body irradiation (TBI), and that miRNAs may be used as clinically feasible biodosimeters. To test this hypothesis, serial serum samples were obtained from 25 patients who underwent allogeneic stem-cell transplantation and profiled for miRNA expression using next-generation sequencing. Differential expression results were largely consistent with previous studies and allowed us to select miRNAs, including miR-150-5p, miR-126-5p, miR-375, miR-215-5p, miR-144-5p, miR-122-5p, miR-320d and miR-10b-5p to build classifiers using qPCR-based quantification. We therefore conclude that serum miRNAs reflect radiation exposure and dose for humans undergoing TBI and may be used as functional biodosimeters for precise identification of people exposed to clinically significant radiation doses.
Project description:Exposure to high-dose radiation causes life-threatening serious intestinal damage. Histological analysis is the most accurate method for judging the extent of intestinal damage after death. However, it is difficult to predict the extent of intestinal damage to body samples. Here we focused on extracellular microRNAs (miRNAs) released from cells and investigated miRNA species that increased or decreased in serum and feces using a radiation-induced intestinal injury mouse model. A peak of small RNA of 25–200 nucleotides was detected in mouse serum and feces 72 h after radiation exposure, and miRNA presence in serum and feces was inferred. MiRNAs expressed in the small intestine and were increased by more than 2.0-fold in serum or feces following a 10 Gy radiation exposure were detected by microarray analysis and were 4 in serum and 19 in feces. In this study, miR-375-3p, detected in serum and feces, was identified as the strongest candidate for a high-dose radiation biomarker in serum and/or feces using a radiation-induced intestinal injury model.
Project description:Radiation therapy is an effective cancer treatment although damage to healthy tissues is common. Here we establish sequencing-based, cell-type specific DNA methylation reference maps of human and mouse tissues to infer the origins of cell-free DNA fragments released from dying cells into the circulation. We find cell-type specific DNA blocks mostly hypomethylated and located within genes intrinsic to cellular identity. In a mouse model, thoracic radiation-induced tissue damages were reflected by dose-dependent increases in lung endothelial, cardiomyocyte and hepatocyte methylated DNA in serum. The analysis of serum samples from breast cancer patients undergoing radiation treatment revealed distinct tissue-specific epithelial and endothelial responses to radiation across multiple organs. Strikingly, patients treated for right-sided breast cancers also showed increased hepatocyte and liver endothelial DNA in the circulation indicating the impact on liver tissues. Thus, cell-free methylated DNA in serum can uncover cell-type specific effects of radiation on healthy tissues and inform treatment.
Project description:Radiation therapy is an effective cancer treatment although damage to healthy tissues is common. Here we establish sequencing-based, cell-type specific DNA methylation reference maps of human and mouse tissues to infer the origins of cell-free DNA fragments released from dying cells into the circulation. We find cell-type specific DNA blocks mostly hypomethylated and located within genes intrinsic to cellular identity. In a mouse model, thoracic radiation-induced tissue damages were reflected by dose-dependent increases in lung endothelial, cardiomyocyte and hepatocyte methylated DNA in serum. The analysis of serum samples from breast cancer patients undergoing radiation treatment revealed distinct tissue-specific epithelial and endothelial responses to radiation across multiple organs. Strikingly, patients treated for right-sided breast cancers also showed increased hepatocyte and liver endothelial DNA in the circulation indicating the impact on liver tissues. Thus, cell-free methylated DNA in serum can uncover cell-type specific effects of radiation on healthy tissues and inform treatment.
Project description:Exposures to low doses of ionizing radiation are relevant since most environmental, diagnostic radiology and occupational exposures lie in this region. However, the molecular mechanisms that drive cellular responses at these doses, and the subsequent health outcomes, remain unclear. A local monazite-rich high level natural radiation area (HLNRA) in the state of Kerala on the south-west coast of Indian subcontinent show radiation doses extending from ≤1 to ≥45 mGy/y and thus, serve as a model resource to understand low dose mechanisms directly on healthy humans. We performed quantitative discovery proteomics based on multiplexed isobaric tags (iTRAQ) coupled with LC-MS/MS on human peripheral blood mononuclear cells from HLNRA individuals. Several proteins involved in diverse biological processes such as DNA repair, RNA processing, chromatin modifications and cytoskeletal organization showed distinct expression in HLNRA individuals, suggestive of both recovery and adaptation to low dose radiation. In protein-protein interaction (PPI) networks, YWHAZ (14-3-3ζ) emerged as the top-most hub protein that may direct phosphorylation driven pro-survival cellular processes against radiation stress. PPI networks also identified an integral role for the cytoskeletal protein ACTB, signaling protein PRKACA; and the molecular chaperone HSPA8. The data will allow better integration of radiation biology and epidemiology for risk assessment.
Project description:Radiation therapy (RT) induces pleiotropic effects on the tumor immune microenvironment, but how these changes are modulated by radiation dose-fractionation is not well understood. Our in vivo data murine data suggests that while changes evoked by RT in the tumor immune compartment are largely concordant between radiation regimens, several key immunological processes are differentially regulated by radiation dose-fractionation.
Project description:Low-dose radiation refers to exposure to ionizing radiation at levels that are generally considered safe and not expected to cause immediate health effects. However, the effects of low-dose radiation are still not fully understood and research in this area is ongoing. In this study, we investigated changes in gene expression in diabetic human aortic endothelial cells (T2D-HAECs) derived from type 2 diabetes patients. To this end, we used RNA-seq to profile the transcriptomes of cells exposed to varying doses of low-dose radiation (0.1Gy, 0.5Gy, and 2.0Gy) and compared them to a control group with no radiation exposure. Differentially expressed genes and enriched pathways were identified using the DESeq2 and gene set enrichment analysis (GSEA) methods, respectively. The data generated in this study are publicly available through the gene expression omnibus (GEO) database. This study provides a valuable resource for studying the effects of low-dose radiation on T2D-HAECs and can contribute to a better understanding of the potential human health risks associated with low-dose radiation exposure.
Project description:We developed scalable radiation dosimeter based on non-coding miR-150 (radiation sensitive) normalized to endogenous miR-23a (radiation insensitive). This nanoString assay revealed the expression of miR-150 and miR-23a in normal healthy volunteers serum blood cell subsets.
Project description:Skin is usually exposed during human exposures to ionizing radiation, however there are few experiments that evaluate the radiation responsiveness of the cells of the epidermis (keratinocytes) and those of the dermis (fibroblasts) in the same studies. We evaluated the transcriptional responses of quiesent primary keratinocytes and fibroblasts from the same individual and compared them with quiescent keratinocytes and fibroblasts that were immortalized by human telomerase (hTert). The primary transcriptional responses to 10-500 cGy ionizing radiation were p53-mediated responses; however, we did identify distinct responses between the keratinocytes and the fibroblasts. Keywords: keratinocytes and fibroblasts - dose response to ionizing radiation
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.