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:The endothelium is the barrier separating blood and tissue. Radiation-induced enhanced inflammation leading to permeability of this barrier may increase the risk of cardiovascular disease. The aim of this study was to investigate the onset of endothelial inflammatory pathways after radiation exposure. Human coronary artery endothelial cells (HCECest2) were exposed to radiation doses of 0, 0.25, 0.5, 2.0 and 10 Gy (60Co-γ). The cells were harvested 4 h, 24 h, 48 h and 1 wk post-irradiation. The proteomics analysis was performed in a label-free data-independent acquisition mode. The data were validated using bioinformatics and immunoblotting. The low- and moderate-dose-treated samples showed only small proteome changes. In contrast, an activation of DNA-damage repair, inflammation, and oxidative stress pathways was seen after high-dose treatments (2 and 10 Gy). The level of the DNA damage response protein DDB2 was enhanced early at the 10 Gy dose. The expression of proteins belonging to the inflammatory response or cGAS-STING pathway (STING, STAT1, ICAM1, ISG15) increased in a dose-dependent manner showing the strongest effects at 10 Gy after one week. This study suggests a connection between radiation-induced DNA damage and induction of inflammation and supports inhibition of cGAS-STING pathway in the prevention of radiation-induced cardiovascular disease.
Project description:Background: Non-human primates, such as Rhesus macaques, are a powerful model for studies of the cellular and physiological effects of radiation, development of radiation biodosimetry, and for understanding the impact of radiation on human health. Here, we study the effects of 4 Gy total body irradiation (TBI) at the molecular level out to 28 days and at the cytogenetic level out to 56 days after exposure. We combine the global transcriptomic and proteomic responses in peripheral whole blood to assess the impact of acute TBI exposure at extended times post irradiation. Results: The overall mRNA response in the first week reflects a strong inflammatory reaction, infection response with neutrophil and platelet activation. At 1 week, cell cycle arrest and re-entry processes were enriched among mRNA changes, oncogene-induced senescence and MAPK signaling among the proteome changes. Influenza life cycle and infection pathways initiate earlier in mRNA and are reflected among the proteomic changes during the first week. Transcription factor proteins SRC, TGF and NFATC2 were immediately induced at 1 day after irradiation with increased transcriptional activity as predicted by mRNA changes persisting up to 1 week. Cell counts revealed a mild / moderate hematopoietic acute radiation syndrome (H-ARS) reaction to irradiation with expected lymphopenia, neutropenia and thrombocytopenia that resolved within 30 days. Measurements of micronuclei per binucleated cell levels in cytokinesis-blocked T-lymphocytes remained high in the range 0.27-0.33 up to 28 days and declined to 0.1 by day 56. Conclusions: Overall, we show that the TBI 4 Gy dose in NHPs induces many cellular changes that persist up to 1 month after exposure, consistent with damage, death, and repopulation of blood cells.
Project description:Accumulating data suggest that the biological responses to high and low doses of radiation are qualitatively different, necessitating the direct study of low dose responses. Most such studies have utilized 2-dimensional culture systems, which may not fully represent responses in 3-dimensional tissues. To gain insight into low dose responses in tissue, we have profiled global gene expression in EPI-200, a 3-dimensional tissue model that imitates the structure and function of human epidermis, at 4, 16 and 24 hours after exposure to high (2.5 Gy) and low (0.1 Gy) doses of low LET protons. The most significant gene ontology groups among genes altered in expression were consistent with effects observed at the tissue level, where the low dose was associated with gradual recovery and tissue remodeling, while the high dose resulted in loss of structural integrity and terminal differentiation. Network analysis of the significantly responding genes suggested that TP53 dominated the response to 2.5 Gy, while HNF4A, a novel transcription factor not previously associated with radiation response, was most prominent in the low dose response. Thus, these studies address the molecular basis of response to low versus high dose low LET radiation exposure.
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.
Project description:Accumulating data suggest that the biological responses to high and low doses of radiation are qualitatively different, necessitating the direct study of low dose responses. Most such studies have utilized 2-dimensional culture systems, which may not fully represent responses in 3-dimensional tissues. To gain insight into low dose responses in tissue, we have profiled global gene expression in EPI-200, a 3-dimensional tissue model that imitates the structure and function of human epidermis, at 4, 16 and 24 hours after exposure to high (2.5 Gy) and low (0.1 Gy) doses of low LET protons. The most significant gene ontology groups among genes altered in expression were consistent with effects observed at the tissue level, where the low dose was associated with gradual recovery and tissue remodeling, while the high dose resulted in loss of structural integrity and terminal differentiation. Network analysis of the significantly responding genes suggested that TP53 dominated the response to 2.5 Gy, while HNF4A, a novel transcription factor not previously associated with radiation response, was most prominent in the low dose response. Thus, these studies address the molecular basis of response to low versus high dose low LET radiation exposure. Radiation induced gene expression in 3-dimensional tissue model, Epi-200, was measured at 4, 16 and 24 hours after exposure to doses of 0, 0.1 and 2.5 Gy of protons. Three independent experiments were performed in the each time (4, 16 and 24 hours) using one tissue sample per a data point.
Project description:Transcriptional profiling of human mesenchymal stem cells comparing normoxic MSCs cells with hypoxic MSCs cells. Hypoxia may inhibit senescence of MSCs during expansion. Goal was to determine the effects of hypoxia on global MSCs gene expression.
Project description:Gene expression profiles of peripheral blood samples from C57BL/6 mice exposed with ionizing radiation. We used mice as model animal to study biologial recovery response after radiation damage. Therefore, we obtained gene expression profiles from C57BL/6 mice exposed with various levels of ionizing radiation, including low and high doses and control groups. In order to measure recovery rate, we collected peripheral blood samples at different time durations after the exposure. In order to obtain robust signatures specific to radiation response, we are interested in knowing if the radiation signarures will be present in the presence of confounders. Therefore, mice were given intraperitoneal injections of lipopolysaccharide endotoxin (LPS), or treated with granulocyte colony-stimulating factor (GCSF), otherwise no treatment after ionizing radiation exposure. The underlying mechanism of confounder treatment is that LPS induces strong immune response resembling the effect of infection, and GCSF stimulates mobilization of HSCs. Exploratory analysis shows that the confounding effects did affect the radiation signature to some extent. This study provides insights into the molecular basis of time- and dose- dependent response to ionizing radiation in mice hematopoietic system. A total of 536 C57BL/6 mice peripheral blood gene expression profiles were measured in 3 different batches using the Affymetrix mouse 430A 2.0 microarray. The experiment is designed to assess blood gene expression changes after exposure to ionizing radiation of 0, 100, 150, 200, 300, 450, 600, 800 and 1050 cGy. Samples were collected at 6, 24, 48, 72, 120 and 168hrs after a single dose exposure.