A pilot study of radiation-induced bystander effect in radio-adapting frogs at a radiologically contaminated site located on the chalk river laboratories property
Autor: | Marilyne Stuart, Carmel Mothersill, Colin Seymour, Nguyen T.K. Vo, Harleen Singh |
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Rok vydání: | 2021 |
Předmět: |
Amphibian
Canada Cell Survival Pilot Projects 010501 environmental sciences 01 natural sciences Calcium Carbonate Andrology 03 medical and health sciences Tissue culture 0302 clinical medicine Rivers Gentamicin protection assay biology.animal Calcium flux Bystander effect Humans Radiology Nuclear Medicine and imaging Clonogenic assay 0105 earth and related environmental sciences Reporter gene Radiological and Ultrasound Technology biology Papillomavirus Infections Dose-Response Relationship Radiation Bystander Effect Culture Media Proto-Oncogene Proteins c-bcl-2 030220 oncology & carcinogenesis Calcium Laboratories Biomarkers Explant culture |
Zdroj: | International Journal of Radiation Biology. 98:1139-1146 |
ISSN: | 1362-3095 0955-3002 |
Popis: | PURPOSE To measure medium borne bystander effects, to study the influence of radioadaptive response (RAR) on bystander response, and to discover reliable radioresponsive biomarkers in radio-adapting frogs from Duke Swamp contaminated with an above-background radiation level and in naive frogs from Twin Lake as the background control site. MATERIALS AND METHODS Frogs were captured at Duke Swamp and Twin Lake and brought to the lab at the Canadian Nuclear Laboratories facility. Half of the frogs from each site were irradiated with 4 Gy while the other half of the frogs were left with no further radiation treatment. Frog bladders were removed and placed in sterile culture media. Upon arrival at McMaster University, the bladders were processed for tissue cultures. After 48 h, the culture media conditioned by the bladder explants were harvested for clonogenic reporter survival assay and calcium flux measurements for assessing bystander effects. HPV-G cells were used as bystander reporter cells in all radiation-induced bystander effect (RIBE) assays. The frog bladder cultures were incubated for another 10-12 days followed by immunochemical staining for bcl-2 and c-myc expressions to analyze cellular anti-apoptotic (pro-survival) and pro-apoptotic (pro-death) responses, respectively. RESULTS Only culture media conditioned by bladders from 4-Gy-irradiated naive frogs from Twin Lake induced bystander effects (reduction of HPV-G reporter cells' clonogenic survival and presence of strong calcium flux activities). The 4 Gy irradiation dose increased pro-apoptotic c-myc expression in naive frogs' bladder explants. Culture media conditioned by bladders from radio-adapting frogs from Duke Swamp enhanced HPV-G's clonogenic survival and a 4 Gy irradiation challenge did not change the enhanced clonogenic survival nature nor induce calcium flux. In bladder explants from both control and 4-Gy-irradiated radio-adapting frogs, anti-apoptotic bcl-2 expression for pro-survival responses was ubiquitous while c-myc expression for pro-death responses was limited to a small fraction of cells. CONCLUSION The clonogenic RIBE reporter assay using HPV-G and calcium flux measurements are useful diagnostic tools for RIBE assessment of field biological samples, specifically those from frogs. RAR induced by environmentally relevant low-dose radiation induces protective bystander response. Bcl-2 and c-myc are reliable biomarkers for evaluating low dose radiation responses in wild populations of amphibians. Overall, this pilot study emphasizes the importance of looking at non-targeted effects (NTEs) in natural populations of non-human biota that could be vulnerable to chronic low-dose radiation exposures. |
Databáze: | OpenAIRE |
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