1
|
Goh VST, Takebayashi K, Nakayama R, Fujishima Y, Yoshida MA, Kasai K, Ariyoshi K, Miura T. Cytokinesis-block micronucleus assay performed in 0 and 2 Gy irradiated whole blood and isolated PBMCs in a six-well transwell co-culture system. Int J Radiat Biol 2021; 97:1631-1640. [PMID: 34554021 DOI: 10.1080/09553002.2021.1981555] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
Abstract
PURPOSE Cytokinesis-block micronucleus (CBMN) assay in cytogenetic biodosimetry uses micronucleus (MN) frequency scored in binucleated cells (BNC) for dose estimation. Cell-cycle progression parameters of nuclear division index (NDI) and percentage of BNC (% BNC) are also evaluated. Whole blood (WB) or peripheral mononuclear cells (PBMCs) isolated from WB can be used for lymphocyte culture. Previously, 2 Gy PBMCs showed higher NDI and lower MN frequency than WB in 15 ml polypropylene tube single cultures. In this follow-up study, we wanted to assess if soluble factors present in WB but absent in PBMCs could increase MN frequency or decrease NDI in PBMCs co-cultured with WB. MATERIALS AND METHODS Peripheral blood from four healthy donors (two males: 25, 51; two females: 23, 26 years old) was irradiated with X-ray at 1 Gy/min. CBMN assay was performed with different combinations of 0 and 2 Gy WB and PBMC (WB, WB-IR, PBMC, PBMC-IR) mono- and co-cultures in a polystyrene six-well plate. Co-cultures were separated by 0.4 µm transwell inserts. Log2 fold changes and values of NDI, % BNC and MN frequency analyzed by three scorers were obtained. RESULTS As upper and lower wells of the same culture condition showed some significant differences, wells of the same level were compared. NDI of PBMCs increased when PBMC or PBMC-IR was co-cultured with WB or WB-IR, respectively, as compared to mono-cultures. There was no increase in PBMC-IR's MN frequency when co-cultured with WB or WB-IR. MN frequency was consistently higher in WB-IR than PBMC-IR in both mono- and co-cultures. NDI, % BNC and MN frequency were similar when WB or PBMC were co-cultured with PBMC-IR or WB-IR, respectively. Significantly lower NDI and % BNC, and higher MN frequency were also seen in some conditions of 15 ml cultures than six-well mono-cultures. CONCLUSIONS Instead of the hypothesized decrease in NDI and increase in MN frequency, our co-culture set-up showed that in the absence of direct cell-cell interaction, soluble factors in WB increased NDI but not MN frequency in PBMCs. Moreover, radiation-induced bystander effects could not be observed. As the type of cell culture (WB, PBMC) and culture vessels could influence NDI and MN frequency, CBMN culture protocols should be kept consistent for dose-response calibration curve construction and dose estimation.
Collapse
Affiliation(s)
- Valerie Swee Ting Goh
- Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences, Hirosaki, Japan.,Department of Radiobiology, Singapore Nuclear Research and Safety Initiative (SNRSI), Singapore
| | - Kai Takebayashi
- Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences, Hirosaki, Japan.,Department of Risk Analysis and Biodosimetry, Institute of Radiation Emergency Medicine (IREM), Hirosaki, Japan
| | - Ryo Nakayama
- Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences, Hirosaki, Japan.,Department of Risk Analysis and Biodosimetry, Institute of Radiation Emergency Medicine (IREM), Hirosaki, Japan
| | - Yohei Fujishima
- Department of Risk Analysis and Biodosimetry, Institute of Radiation Emergency Medicine (IREM), Hirosaki, Japan
| | | | - Kosuke Kasai
- Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences, Hirosaki, Japan
| | - Kentaro Ariyoshi
- Center for Integrated Science and Humanities, Fukushima Medical University, Fukushima, Japan
| | - Tomisato Miura
- Department of Risk Analysis and Biodosimetry, Institute of Radiation Emergency Medicine (IREM), Hirosaki, Japan
| |
Collapse
|
2
|
Marino M, Gigliotti L, Møller P, Riso P, Porrini M, Del Bo C. Impact of 12-month cryopreservation on endogenous DNA damage in whole blood and isolated mononuclear cells evaluated by the comet assay. Sci Rep 2021; 11:363. [PMID: 33432000 PMCID: PMC7801598 DOI: 10.1038/s41598-020-79670-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 12/07/2020] [Indexed: 11/17/2022] Open
Abstract
The comet assay is an electrophoretic technique used to assess DNA damage, as a marker of genotoxicity and oxidative stress, in tissues and biological samples including peripheral blood mononuclear cells (PBMCs) and whole blood (WB). Although numerous studies are performed on stored samples, the impact of cryopreservation on artifactual formation of DNA damage is not widely considered. The present study aims to evaluate the impact of storage at different time-points on the levels of strand breaks (SBs) and formamidopyrimidine DNA glycosylase (Fpg)-sensitive sites in isolated PBMCs and WB. Samples were collected, aliquoted and stored at − 80 °C. DNA damage was analyzed on fresh samples, and subsequently on frozen samples every 2 months up to a year. Results have shown no changes in DNA damage in samples of PBMCs and WB stored for up to 4 months, while a significant increase in SBs and Fpg-sensitive sites was documented starting from 6-month up to 12-month storage of both the samples. In addition, fresh and frozen WB showed higher basal levels of DNA damage compared to PBMCs. In conclusion, WB samples show high levels of DNA damage compared to PBMCs. One-year of storage increased the levels of SBs and Fpg-sensitive sites especially in the WB samples. Based on these findings, the use of short storage times and PBMCs should be preferred because of low background level of DNA damage in the comet assay.
Collapse
Affiliation(s)
- Mirko Marino
- Division of Human Nutrition, Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, 20133, Milan, Italy
| | - Letizia Gigliotti
- Division of Human Nutrition, Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, 20133, Milan, Italy
| | - Peter Møller
- Department of Public Health, Section of Environmental Health, University of Copenhagen, 1014, Copenhagen K, Denmark
| | - Patrizia Riso
- Division of Human Nutrition, Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, 20133, Milan, Italy
| | - Marisa Porrini
- Division of Human Nutrition, Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, 20133, Milan, Italy
| | - Cristian Del Bo
- Division of Human Nutrition, Department of Food, Environmental and Nutritional Sciences (DeFENS), Università degli Studi di Milano, 20133, Milan, Italy.
| |
Collapse
|
3
|
Goh VST, Nakayama R, Blakely WF, Abe Y, Chua CEL, Chew ZH, Nakata A, Fujishima Y, Yoshida MA, Kasai K, Ariyoshi K, Miura T. Improved harvest and fixation methodology for isolated human peripheral blood mononuclear cells in cytokinesis-block micronucleus assay. Int J Radiat Biol 2020; 97:194-207. [PMID: 33135957 DOI: 10.1080/09553002.2021.1844338] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE In suspected radiation exposures, cytokinesis-block micronucleus (CBMN) assay is used for biodosimetry by detecting micronuclei (MN) in binucleated (BN) cells in whole blood and isolated peripheral blood mononuclear cell (PBMC) cultures. Standardized harvest protocols for whole blood were published by the International Atomic Energy Agency (IAEA) in 2001 (Technical report no. 405) and 2011 (EPR-Biodosimetry). For isolated PBMC harvest, cytocentrifugation of fresh cells is recommended to preserve cytoplasmic boundaries for MN scoring. However, cytocentrifugation utilizes specialized equipment and long-term cell suspension storage is difficult. In this study, an alternative CBMN harvest protocol is proposed for laboratories interested in culturing PBMCs and storing fixed cells with routine biodosimetry methods. MATERIALS AND METHODS Peripheral blood from 4 males (24, 34, 41, 51 y.o.) and females (26, 37, 44, 56 y.o.) was irradiated with 0 and 2 Gy X-rays. For cells harvested with IAEA 2001 and 2011 protocols, whole blood was used. For cells harvested with our protocol (CRG), isolated PBMCs were used. CRG protocol was validated in DAPI, acridine orange and Giemsa stain, and in three other laboratories. Cytoplasm status, nuclear division index (NDI) and induced MN frequency (MN frequency at 2 Gy - background MN frequency at 0 Gy) (MN/1000 BN) of Giemsa-stained BN cells were compared in IAEA 2001, IAEA 2011, IAEA 2011 + formaldehyde (FA) and CRG protocols. Effects of low and high humidity spreading were evaluated. RESULTS >94% of 1000 BN cells were scorable with clear cytoplasmic boundaries in all donors harvested with CRG protocol. FA addition in IAEA 2011 protocol reduced cell rupture in whole blood cultures, but cell rupture was affected by age, sex and humidity. Almost all cells harvested with IAEA 2001 protocol had cytoplasm loss. PBMCs harvested with CRG protocol stained well in DAPI, acridine orange and Giemsa, and showed high scorable BN frequency in all laboratories. A higher NDI and a lower induced MN frequency were seen in 2 Gy isolated PBMC than whole blood cultures. CONCLUSION This quick CBMN harvest protocol for isolated PBMCs is a viable alternative to cytocentrifugation, as many scorable BN cells were obtained with routine biodosimetry reagents and equipment. IAEA 2011 + FA protocol should be used to improve CBMN harvest in whole blood cultures. Humidity during spreading should be optimized depending on the harvest protocol. NDI and MN frequency should be separately evaluated for whole blood and isolated PBMC cultures.
Collapse
Affiliation(s)
- Valerie Swee Ting Goh
- Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences, Hirosaki, Japan
| | - Ryo Nakayama
- Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences, Hirosaki, Japan
| | - William F Blakely
- Scientific Research Department, Armed Forces Radiobiology Research Institute (AFRRI), Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Yu Abe
- Department of Radiation Life Sciences, Fukushima Medical University School of Medicine, Fukushima, Japan
| | - Christelle En Lin Chua
- Department of Radiobiology, Singapore Nuclear Research and Safety Initiative (SNRSI), Singapore, Singapore
| | - Zi Huai Chew
- Department of Radiobiology, Singapore Nuclear Research and Safety Initiative (SNRSI), Singapore, Singapore
| | - Akifumi Nakata
- Department of Basic Pharmacy, Hokkaido Pharmaceutical University School of Pharmacy, Otaru, Japan
| | - Yohei Fujishima
- Department of Radiation Biology, Tohoku University School of Medicine, Sendai, Japan
| | | | - Kosuke Kasai
- Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences, Hirosaki, Japan
| | - Kentaro Ariyoshi
- Integrated Center for Science and Humanities, Fukushima Medical University, Fukushima, Japan
| | - Tomisato Miura
- Department of Risk Analysis and Biodosimetry, Institute of Radiation Emergency Medicine, Hirosaki, Japan
| |
Collapse
|
4
|
Sato I, Sasaki J, Satoh H, Natsuhori M, Murata T, Okada K. Assessments of DNA Damage and Radiation Exposure Dose in Cattle Living in the Contaminated Area Caused by the Fukushima Nuclear Accident. BULLETIN OF ENVIRONMENTAL CONTAMINATION AND TOXICOLOGY 2020; 105:496-501. [PMID: 32844262 DOI: 10.1007/s00128-020-02968-w] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Accepted: 08/13/2020] [Indexed: 06/11/2023]
Abstract
Since the Fukushima nuclear accident in 2011, various abnormalities have been reported in animals living in the contaminated area. In the present study, we examined DNA damage in cattle living in the "difficult-to-return zone" by 8-hydroxy-2'-deoxyguanosine, comet, and micronucleus assays using their peripheral blood. The radiation exposure dose rate at the sampling time was approximately 0.25 or 0.38 mGy/day and the cumulative dose was estimated at approximately 1000 mGy. Significant increase in DNA damage was not detected by any of the three methods. As DNA damage is a stochastic effect of radiation, it might be occurring in animals living in the contaminated area. However, the present results suggest that radiation-induced DNA damage in the cattle did not increase to the level detectable by the assays we used due to the low dose rate in this area.
Collapse
Affiliation(s)
- Itaru Sato
- Faculty of Agriculture, Iwate University, Morioka, 020-8550, Japan.
| | - Jun Sasaki
- Faculty of Agriculture, Iwate University, Morioka, 020-8550, Japan
| | - Hiroshi Satoh
- Faculty of Agriculture, Iwate University, Morioka, 020-8550, Japan
| | - Masahiro Natsuhori
- School of Veterinary Medicine, Kitasato University, Towada, 034-8628, Japan
| | - Takahisa Murata
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, 113-8657, Japan
| | - Keiji Okada
- Faculty of Agriculture, Iwate University, Morioka, 020-8550, Japan
| |
Collapse
|
5
|
Koppen G, De Prins S, Jacobs A, Nelen V, Schoeters G, Langie SAS. The comet assay in human biomonitoring: cryopreservation of whole blood and comparison with isolated mononuclear cells. Mutagenesis 2017; 33:41-47. [DOI: 10.1093/mutage/gex034] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Affiliation(s)
- Gudrun Koppen
- Health Unit, Flemish Institute for Technological Research (VITO), Belgium
| | - Sofie De Prins
- Health Unit, Flemish Institute for Technological Research (VITO), Belgium
- VITO - Sustainable Health, Belgium
| | - An Jacobs
- Health Unit, Flemish Institute for Technological Research (VITO), Belgium
| | - Vera Nelen
- Environment and Health Unit, Provincial Institute of Hygiene, Belgium
| | - Greet Schoeters
- Health Unit, Flemish Institute for Technological Research (VITO), Belgium
- VITO - Sustainable Health, Belgium
- Department of Environmental Medicine, Institute of Public Health, University of Southern Denmark, Denmark
| | - Sabine A S Langie
- Health Unit, Flemish Institute for Technological Research (VITO), Belgium
- Faculty of Sciences, Hasselt University, Belgium
| |
Collapse
|
6
|
Toprani SM, Das B. Role of base excision repair genes and proteins in gamma-irradiated resting human peripheral blood mononuclear cells. Mutagenesis 2014; 30:247-61. [DOI: 10.1093/mutage/geu065] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
|
7
|
Gutzkow KB, Langleite TM, Meier S, Graupner A, Collins AR, Brunborg G. High-throughput comet assay using 96 minigels. Mutagenesis 2013; 28:333-40. [PMID: 23462850 DOI: 10.1093/mutage/get012] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The single-cell gel electrophoresis--the comet assay--has proved to be a sensitive and relatively simple method that is much used in research for the analysis of specific types of DNA damage, and its use in genotoxicity testing is increasing. The efficiency of the comet assay, in terms of number of samples processed per experiment, has been rather poor, and both research and toxicological testing should profit from an increased throughput. We have designed and validated a format involving 96 agarose minigels supported by a hydrophilic polyester film. Using simple technology, hundreds of samples may be processed in one experiment by one person, with less time needed for processing, less use of chemicals and requiring fewer cells per sample. Controlled electrophoresis, including circulation of the electrophoresis solution, improves the homogeneity between replicate samples in the 96-minigel format. The high-throughput method described in this paper should greatly increase the overall capacity, versatility and robustness of the comet assay.
Collapse
Affiliation(s)
- Kristine B Gutzkow
- Department of Chemicals and Radiation, National Institute of Public Health, PO Box 4404 Nydalen, Oslo N-0403, Norway
| | | | | | | | | | | |
Collapse
|
8
|
Lu Y, Takeshita T, Morimoto K. Single-cell gel electrophoresis (SCG)-A review and discussion. Environ Health Prev Med 2012; 2:53-8. [PMID: 21432452 DOI: 10.1007/bf02931964] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/1997] [Accepted: 03/06/1997] [Indexed: 11/28/2022] Open
Abstract
Single-cell gel electrophoresis (SCG) is a simple, sensitive and effective technique. Being able to reflect quantitatively the genotoxicity of many hazardous agents, it is promising for application in environmental genotoxic monitoring and the study of carcinogenesis. In clinics, it can be used to evaluate the DNA repair ability and monitor DNA breaks during cancer therapy. As a biomarker, it has its own merits and limitations, being different from other biomarkers such as sister chromatid exchange (SCE) test and micronuclei (MN) assay. In many studies, it is more sensitive than SCE or MN. Combination studies with other biomarkers like SCE, MN, chromosomal aberration, bcl-2 and genetic polymorphisms have begun to demonstrate its great importance for the understanding of carcinogenesis and the genotoxicities of environmental factors.
Collapse
Affiliation(s)
- Y Lu
- Department of Hygiene and Preventive Medicine, Osaka University School of Medicine, 2-2 Yamadaoka, Suita, 565, Osaka, Japan
| | | | | |
Collapse
|
9
|
Bagatini PB, Palazzo RP, Rodrigues MT, Costa CH, Maluf SW. Induction and removal of DNA damage in blood leukocytes of patients with type 2 diabetes mellitus undergoing hemodialysis. MUTATION RESEARCH-GENETIC TOXICOLOGY AND ENVIRONMENTAL MUTAGENESIS 2008; 657:111-5. [DOI: 10.1016/j.mrgentox.2008.08.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Revised: 08/06/2008] [Accepted: 08/07/2008] [Indexed: 01/06/2023]
|
10
|
Frenzilli G, Ferrucci M, Giorgi FS, Blandini F, Nigro M, Ruggieri S, Murri L, Paparelli A, Fornai F. DNA fragmentation and oxidative stress in the hippocampal formation: a bridge between 3,4-methylenedioxymethamphetamine (ecstasy) intake and long-lasting behavioral alterations. Behav Pharmacol 2007; 18:471-81. [PMID: 17762515 DOI: 10.1097/fbp.0b013e3282d518aa] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Intake of 3,4-methylenedioxymethamphetamine (MDMA, ecstasy) in humans leads to marked behavioral alterations. In a recent paper, we demonstrated that chronic MDMA intake produces a latent hippocampal hyperexcitability that parallels a reduced threshold for limbic seizures and a slowing of electroencephalographic activity. These phenomena suggest an alteration in hippocampal function. So far, only a few studies have focused on the hippocampal formation as a potential target for the effects induced by MDMA. In this study we sought to evaluate whether the intrinsic cells of the hippocampus might be modified chronically by ecstasy intake. In particular, we examined whether administration of MDMA, at doses producing hippocampal hyperexcitability also produces rearrangements of DNA strands measured by the comet assay. We found that MDMA, at very low doses, comparable with those self-administered by humans, produces acute oxidative stress and DNA single and double-strand breaks, which persist together with long-lasting metabolic changes in the hippocampal formation. These persisting effects are accompanied by behavioral sensitization, reduced seizure threshold and long-lasting slowing of electroencephalographic activity, and hyperexcitability of the hippocampus, without affecting the basal ganglia. The present data indicate that the intake of very low doses of MDMA, comparable to those consumed by humans, produces selective hippocampal alterations which may underlie cognitive impairment and seizure susceptibility.
Collapse
Affiliation(s)
- Giada Frenzilli
- Department of Human Morphology and Applied Biology, University of Pisa, Pisa, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
11
|
Mozdarani H, Nasirian B, Haeri SA. In vivo gamma-rays induced initial DNA damage and the effect of famotidine in mouse leukocytes as assayed by the alkaline comet assay. JOURNAL OF RADIATION RESEARCH 2007; 48:129-34. [PMID: 17299251 DOI: 10.1269/jrr.06055] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
Ionizing radiation induces a variety of lesions in DNA, each of which can be used as a bio-indicator for biological dosimetry or the study of the radioprotective effects of substances. To assess gamma ray-induced DNA damage in vivo in mouse leukocytes at various doses and the effect of famotidine, blood was collected from Balb/c male mice after irradiation with 4 Gy gamma-rays at different time intervals post-irradiation. To assess the response, mice were irradiated with doses of gamma-rays at 1 to 4 Grays. Famotidine was injected intra-peritoneally (i.p) at a dose of 5 mg/kg at various time intervals before irradiation. Four slides were prepared from each sample and alkaline comet assay was performed using standard protocols. Results obtained show that radiation significantly increases DNA damage in leukocytes in a dose dependent manner (p < 0.01) when using appropriate sampling time after irradiation, because increasing sampling time after irradiation resulted in a time dependent disappearance of DNA damage. Treatment with only 5 mg/kg famotidine before 4 Gy irradiation led to almost 50% reduction in DNA damage when compared with those animals which received radiation alone. The radioprotective capability of famotidine might be attributed to radical scavenging properties and an anti-oxidation mechanism.
Collapse
Affiliation(s)
- Hossein Mozdarani
- Dept. of Medical Genetics, School of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
| | | | | |
Collapse
|
12
|
Sudprasert W, Navasumrit P, Ruchirawat M. Effects of low-dose gamma radiation on DNA damage, chromosomal aberration and expression of repair genes in human blood cells. Int J Hyg Environ Health 2006; 209:503-11. [PMID: 16872898 DOI: 10.1016/j.ijheh.2006.06.004] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2005] [Revised: 05/31/2006] [Accepted: 06/13/2006] [Indexed: 10/24/2022]
Abstract
Exposure to low-dose gamma radiation is common in certain occupations but the biological and health effects from such exposure remain to be determined. The aim of this study was to investigate the effects of low-dose gamma radiation on DNA damage, chromosomal aberration and DNA repair gene expressions in whole blood and peripheral lymphocytes. The study revealed a dose-dependent effect of gamma radiation on DNA damage. Significant increases in DNA strand breaks and oxidative base damage, determined as formamidopyrimidine-DNA-glycosylase (FPG)-sensitive sites, were observed at absorbed doses of 5 and 10cGy, respectively. However, gamma radiation at doses up to 500cGy did not significantly increase the level of 8-oxo-7, 8-dihydro-2'-deoxyguanosine (8-oxodG) determined by HPLC with electrochemical detection (HPLC-ECD). Gamma radiation as low as 5cGy caused chromosomal aberrations determined as dicentric and deletion frequencies. This finding is significant since the genotoxic effects of gamma radiation can be observed even at a low dose of 5cGy. Furthermore, gamma radiation decreased the mRNA expression of both hOGG1 and XRCC1 repair genes determined by reverse transcriptase-polymerase chain reaction (RT-PCR), with a significant decrease of expression being observed at 20cGy. The expression levels of hOGG1 and XRCC1 mRNA were inversely correlated with the levels of FPG-sensitive sites and DNA strand breaks. The finding of decreased expression levels for hOGG1 and XRCC1 in gamma-irradiated lymphocytes has not been reported elsewhere. Our observations suggest that the genotoxic effects of gamma radiation may be due to a combination of DNA-damaging effects and reduced DNA repair capacity, and may explain the significant increase in health risk from high doses of ionizing radiation.
Collapse
Affiliation(s)
- Wanwisa Sudprasert
- Laboratory of Environmental Toxicology, Chulabhorn Research Institute, Bangkok, Thailand
| | | | | |
Collapse
|
13
|
Amendola R, Basso E, Pacifici PG, Piras E, Giovanetti A, Volpato C, Romeo G. Ret, Abl1 (cAbl) and Trp53 gene fragmentations in comet-FISH assay act as in vivo biomarkers of radiation exposure in C57BL/6 and CBA/J mice. Radiat Res 2006; 165:553-61. [PMID: 16669710 DOI: 10.1667/rr3544.1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The International Commission on Radiation Protection (ICRP) has lowered the dose limits for workers and for the general public exposed to ionizing radiation. Consequently, a reliable dosimetric method for monitoring possible radiation-induced damage is of great importance in radioprotection. The counting of dicentric chromosomal aberrations and of micronuclei in peripheral blood lymphocytes is unreliable when it is applied to in vivo biopsies and for low-dose exposures. Single-cell gel electrophoresis (SCGE or comet assay), although sensitive and rapid, shows high variability when applied in vivo, probably due to prompt repair of the DNA breaks and confounding environmental factors. In this paper, we describe specific in situ hybridization of Ret, Abl1 (cAbl), and Trp53 gene fragmentations on SCGE slides (comet-FISH assay) in peripheral blood cells from C57BL/6 and CBA/J mice as an indicator of radiation-induced DNA damage. The results obtained from four mice for each experimental point (0, 1, 2 and 4 Gy of X rays) discriminated in a statistically significant way the effects of all doses when fragmentations were analyzed for the Ret, Ab1 and Trp53 genes. SCGE alone, when applied to the same specimens, produced no significant results because of interindividual and experimental variability.
Collapse
|
14
|
Husseini GA, O'Neill KL, Pitt WG. The comet assay to determine the mode of cell death for the ultrasonic delivery of doxorubicin to human leukemia (HL-60 Cells) from Pluronic P105 micelles. Technol Cancer Res Treat 2006; 4:707-11. [PMID: 16292892 PMCID: PMC1363380 DOI: 10.1177/153303460500400616] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
This notes examines the mode of cell death of HL-60 cells exposed to 70 kHz and 1.3 W/cm(2) ultrasound in the presence of 1% Pluronic P105 and 1.67 microg/ml doxorubicin (Dox). The cells were ultrasonicated for 30, 60, and 120 minutes. They were then lysed, electrophorised, stained using propidium iodide, and their DNA profile captured using a fluorescent microscope. The gradual DNA damage observed and the comet tails captured after one and two hours of insonation suggest that the mode of cell killing is apoptosis.
Collapse
Affiliation(s)
- Ghaleb A Husseini
- Department of Chemical Engineering, American University of Sharjah, United Arab Emirates.
| | | | | |
Collapse
|
15
|
Frenzilli G, Lenzi P, Scarcelli V, Fornai F, Pellegrini A, Soldani P, Paparelli A, Nigro M. Effects of loud noise exposure on DNA integrity in rat adrenal gland. ENVIRONMENTAL HEALTH PERSPECTIVES 2004; 112:1671-2. [PMID: 15579411 PMCID: PMC1253657 DOI: 10.1289/ehp.7249] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2004] [Accepted: 09/22/2004] [Indexed: 05/22/2023]
Abstract
Loud noise is generally considered an environmental stressor causing negative effects on acoustic, cardiovascular, nervous, and endocrine systems. In this study, we investigated the effects of noise exposure on DNA integrity in rat adrenal gland evaluated by the comet assay. The exposure to loud noise (100 dBA) for 12 hr caused a significant increase of DNA damage in the adrenal gland. Genetic alterations did not decrease 24 hr after the cessation of the stimulus. We hypothesize that an imbalance of redox cell status is responsible for the induction and persistence of noise-induced cellular damage.
Collapse
Affiliation(s)
- Giada Frenzilli
- Dipartimento di Morfologia Umana e Biologia Applicata, University of Pisa, Pisa, Italy.
| | | | | | | | | | | | | | | |
Collapse
|
16
|
Giovannelli L, Bellandi S, Pitozzi V, Fabbri P, Dolara P, Moretti S. Increased oxidative DNA damage in mononuclear leukocytes in vitiligo. Mutat Res 2004; 556:101-6. [PMID: 15491637 DOI: 10.1016/j.mrfmmm.2004.07.005] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2004] [Revised: 07/08/2004] [Accepted: 07/14/2004] [Indexed: 05/01/2023]
Abstract
Vitiligo is an acquired pigmentary disorder of the skin of unknown aetiology. The autocytotoxic hypothesis suggests that melanocyte impairment could be related to increased oxidative stress. Evidences have been reported that in vitiligo oxidative stress might also be present systemically. We used the comet assay (single cell alkaline gel electrophoresis) to evaluate DNA strand breaks and DNA base oxidation, measured as formamidopyrimidine DNA glycosylase (FPG)-sensitive sites, in peripheral blood cells from patients with active vitiligo and healthy controls. The basal level of oxidative DNA damage in mononuclear leukocytes was increased in vitiligo compared to normal subjects, whereas DNA strand breaks (SBs) were not changed. This alteration was not accompanied by a different capability to respond to in vitro oxidative challenge. No differences in the basal levels of DNA damage in polymorphonuclear leukocytes were found between patients and healthy subjects. Thus, this study supports the hypothesis that in vitiligo a systemic oxidative stress exists, and demonstrates for the first time the presence of oxidative alterations at the nuclear level. The increase in oxidative DNA damage shown in the mononuclear component of peripheral blood leukocytes from vitiligo patients was not particularly severe. However, these findings support an adjuvant role of antioxidant treatment in vitiligo.
Collapse
Affiliation(s)
- Lisa Giovannelli
- Department of Preclinical and Clinical Pharmacology, University of Florence, Viale Pieraccini 6, 50139 Firenze, Florence, Italy.
| | | | | | | | | | | |
Collapse
|
17
|
Abstract
BACKGROUND We wanted to investigate the effect of X-rays on mononuclear blood cells (MNCs) and red blood cells (RBCs) of radiology technicians exposed to X-rays in hospital. METHODS DNA damage was detected by fluorometric analysis of DNA unwinding. Glutathione levels were measured with enzymatic method in mononuclear blood cells. Glutathione content and catalase (CAT) activity of erythrocytes, and plasma malondialdehyde (MDA) levels were determined by spectrophometric methods. RESULTS An insignificant increase in plasma malondialdehyde levels and a significant decrease in mononuclear blood cells glutathione levels were observed in nonsmoking radiology technicians. In smoking radiology technicians, on the other hand, in addition to an increase in plasma malondialdehyde levels, DNA damage was also significantly apparent. Besides mononuclear blood cells' glutathione depletion, the glutathione content of red blood cells was also found to be decreased. CONCLUSION It can be suggested that smoking seems to augment the toxic effects of radiation.
Collapse
Affiliation(s)
- Ayfer Akköse
- Faculty of Medicine, Department of Biochemistry, Istanbul University, Capa-Istanbul 34390, Turkey
| | | | | |
Collapse
|
18
|
Giovannelli L, Pitozzi V, Riolo S, Dolara P. Measurement of DNA breaks and oxidative damage in polymorphonuclear and mononuclear white blood cells: a novel approach using the comet assay. Mutat Res 2003; 538:71-80. [PMID: 12834756 DOI: 10.1016/s1383-5718(03)00090-1] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
DNA damage is thought to play a relevant role in degenerative diseases and aging. Therefore, measuring DNA damage in living cells without artifacts is a critical issue, especially with very sensitive methods, such as the comet assay, which can detect very low levels of DNA damage. We show here that the procedures of cell subtype isolation increase DNA damage measured in human white blood cells (WBC) with the comet assay. We describe a novel and simple method to measure DNA strand breaks and oxidative damage separately in polymorphonuclear and mononuclear leukocytes, using whole blood without previous cell isolation. This method can be useful for measuring DNA damage in different subtypes of human peripheral leukocytes, avoiding the artifacts and the time involved in the cell separation procedures.
Collapse
Affiliation(s)
- Lisa Giovannelli
- Dipartimento di Farmacologia Preclinica e Clinica, Università di Firenze, Italy.
| | | | | | | |
Collapse
|
19
|
Moretti M, Marcarelli M, Villarini M, Fatigoni C, Scassellati-Sforzolini G, Pasquini R. In vitro testing for genotoxicity of the herbicide terbutryn: cytogenetic and primary DNA damage. Toxicol In Vitro 2002; 16:81-8. [PMID: 11812643 DOI: 10.1016/s0887-2333(01)00092-3] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Terbutryn is a widely used preemergence and postemergence s-triazine herbicide. This pesticide is used in agriculture as a control agent for most grasses and many annual broadleaf weeds in cereal and legume fields, and under fruit trees. Unexpectedly, this compound was found to persist in the environment (240 and 180 days in pond and river sediment, respectively) and to have the tendency to move from treated soils to water compartments through water runoff and leaching. However, only scant information is available about the genotoxic properties of terbutryn. In the present in vitro study, we investigated the relationship between cytogenetic damage, as evaluated in the sister-chromatid exchange (SCE) assay and the micronucleus (MN) test, and primary DNA damage (as evaluated by the "comet" assay). Cytogenetic and primary DNA damage were recorded in vitro in freshly isolated human peripheral blood leukocytes. Our results showed that the tested compound failed to produce any significant increases in SCE or MN, neither in the absence nor in the presence of S9-mix. However, terbutryn was found to induce primary DNA damage, more pronounced without S9 mix, even though in the absence of a clear trend for dose-dependence and in the presence of a concomitant mild cytotoxic effect.
Collapse
Affiliation(s)
- M Moretti
- Department of Hygiene, University of Perugia, Via del Giochetto, I-06126 Perugia, Italy
| | | | | | | | | | | |
Collapse
|
20
|
He JL, Chen WL, Jin LF, Jin HY. Comparative evaluation of the in vitro micronucleus test and the comet assay for the detection of genotoxic effects of X-ray radiation. Mutat Res 2000; 469:223-31. [PMID: 10984683 DOI: 10.1016/s1383-5718(00)00077-2] [Citation(s) in RCA: 79] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
The genotoxic effects of X-ray radiation on human lymphocytes were measured using the single cell gel electrophoresis (SCGE) assay (comet assay) and the cytokinesis-blocked micronucleus (CBMN) test; both were carried out in vitro on isolated human lymphocytes in order to compare the relationship and sensitivity of these two detecting methods. The radiation-doses were 0.00, 0.02, 0.05, 0.10, 0.25, 0.50, 1.00 and 2.00 Gy. In the comet assay, the average comet length (38.6+/-0.8 microm) of 0.05 Gy was significantly longer than that (29.4+/-1.1 microm) of 0 Gy (P<0.01), moreover, the average comet length increased with the dose of X-ray radiation. In the CBMN, both the average micronucleus rate (MN) and micronucleated cell rate (MNC) of 0.05 Gy were 11.5+/-4.5 per thousand, which showed no difference with that (7.5+/-0.5 per thousand) of 0 Gy (P>0.05). The lowest dose, which induced significant increase of average MN and MNC, was 0.25 Gy. The average MN and MNC rates increased with radiation-dose. The results showed that there was correlation between SCGE and CBMN, and the sensitivity of SCGE was significantly higher than that of CBMN.
Collapse
Affiliation(s)
- J L He
- Division of Environmental Health, School of Medicine, Zhejiang University, 310006, Zhejiang, Hangzhou, China.
| | | | | | | |
Collapse
|
21
|
Abstract
The present study describes modifications to the basic comet protocol that increase productivity and efficiency without sacrificing assay reliability. A simple technique is described for rapidly preparing up to 96 comet assay samples simultaneously. The sample preparation technique allows thin layers of agarose-embedded cells to be prepared in multiple wells attached to a flexible film of Gelbond, which improves the ease of manipulating and processing samples. To evaluate the effect of these modifications on assay sensitivity, dose-response curves are presented for DNA damage induced by exposure of TK6 cells to low concentrations of hydrogen peroxide (0-10 microM) and for exposure of human lymphocytes to X-irradiation (0-100 cGy). The limit of detection of DNA damage induced by hydrogen peroxide in TK6 cells was observed to be 1 uM for all parameters (tail ratio, tail moment, tail length and comet length) while the limit of detection of DNA damage in human lymphocytes was 10 cGy for tail and comet length parameters, but 50 cGy for tail ratio and tail moment parameters. These results are similar to those previously reported using the conventional alkaline comet assay. The application of SYBR Gold for detection of DNA damage was compared to that of propidium iodide. Measurements of matching samples for tail length and comet length were similar using both stains. However, comets stained with SYBR Gold persisted longer and were much brighter than those obtained with propidium iodide. SYBR Gold was found to be ideal for measuring tail length and comet length but, under present assay conditions, impractical for measuring tail ratio or tail moment due to saturation of staining in the head region of the comets.
Collapse
Affiliation(s)
- J P McNamee
- Health Canada, Radiation Protection Bureau, 775 Brookfield Road, Postal Locator 6303B, Ottawa, Ontario, Canada.
| | | | | | | |
Collapse
|
22
|
Visvardis E, Haveles KS, Pataryas TA, Margaritis LH, Sophianopoulou V, Sideris EG. Diversity of peripheral blood mononuclear cells as revealed by a novel multiple microgel "comet assay". ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 2000; 36:32-39. [PMID: 10918357 DOI: 10.1002/1098-2280(2000)36:1<32::aid-em5>3.0.co;2-o] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Multiple microgel comet assay (MMCA) is a metho-dological adaptation of the single-cell gel electrophoresis assay in which we have introduced the use of standard agarose plug molds in an attempt to improve and expand the applications of the assay. We focused on the study of the heterogeneity of peripheral blood mononuclear cells (PBMC) at the level of the basal single-strand breakage and the DNA damage induction caused by ionizing radiation. Differences among subpopulations were also investigated at the level of chromatin organization and methylation after NotI digestion of microgel-embedded cells. In parallel experiments, the NotI-digested nucleoids were also analyzed with the use of pulsed-field gel electrophoresis (PFGE) and the DNA migration patterns were compared with the corresponding patterns from the MMCA. Significant heterogeneity in the distribution of the oxidative DNA damage, as well as intracellular variations in the NotI digestion patterns were observed in the cell population of PBMC. The combined use of both the comet assay and PFGE provides a useful model for analysis of variation in DNA damage in individual cells as well as information on size of DNA fragments.
Collapse
Affiliation(s)
- E Visvardis
- Institute of Biology, NCSR "Demokritos," Athens, Greece
| | | | | | | | | | | |
Collapse
|
23
|
Hellman B, Friis L, Vaghef H, Edling C. Alkaline single cell gel electrophoresis and human biomonitoring for genotoxicity: a study on subjects with residential exposure to radon. Mutat Res 1999; 442:121-32. [PMID: 10393281 DOI: 10.1016/s1383-5718(99)00083-2] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
Based on theoretical estimates and various correlation studies, it has been suggested that ingestion of radon in drinking water represents an increased risk for cancer. Such a risk has never been conclusively shown in epidemiological or experimental animal studies, however, and it has been questioned whether the radon level in the drinking water is of any significance in terms of overall radon exposure. Using primary DNA damage as a biological marker for an ongoing exposure to ionising radiation, the present study was undertaken to investigate whether people with different types of residential radon exposures differed with regard to their levels of DNA damage in circulating lymphocytes. DNA damage was measured in coded blood samples from 125 residents living in 45 households with different levels of radon-222 in the drinking water (10-2410 Bq/l) and indoor air (35-1025 Bq/m3) using alkaline single cell gel electrophoresis (the 'Comet' assay). Increased levels of radon in indoor air (>200 Bq/m3) were found to be associated with an increased level of DNA damage in peripheral lymphocytes (P</=0.05). No such correlation was seen for the radon concentrations in the drinking water, and there was no obvious relationship between the radon levels in drinking water and in indoor air. The results of the present study suggest that measures taken to reduce residential radon exposures should be focused on reducing radon levels in indoor air rather than minimising radon levels in drinking water.
Collapse
Affiliation(s)
- B Hellman
- Department of Occupational and Environmental Medicine, University Hospital, S-751 85, Uppsala, Sweden.
| | | | | | | |
Collapse
|
24
|
Rojas E, Lopez MC, Valverde M. Single cell gel electrophoresis assay: methodology and applications. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1999; 722:225-54. [PMID: 10068143 DOI: 10.1016/s0378-4347(98)00313-2] [Citation(s) in RCA: 322] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Abstract
The single cell gel electrophoresis or Comet assay is a sensitive, reliable, and rapid method for DNA double- and single-strand breaks, alkali-labile sites and delayed repair site detection, in eukaryotic individual cells. Given its overall characteristics, this method has been widely used over the past few years in several different areas. In this paper we review the studies published to date about the principles, the basic methodology with currently used variations. We also explore the applications of this assay in: genotoxicology, clinical area, DNA repair studies, environmental biomonitoring and human monitoring.
Collapse
Affiliation(s)
- E Rojas
- Departamento de Genética y Toxicología Ambiental, Instituto de Investigaciones Biomedicas, UNAM, Mexico DF, Mexico
| | | | | |
Collapse
|
25
|
Affiliation(s)
- S M Piperakis
- DNA Repair Laboratory, Institute of Biology, NCSR Demokritos, Athens, Greece
| | | | | |
Collapse
|
26
|
Jacobs GP. A review on the effects of ionizing radiation on blood and blood components. Radiat Phys Chem Oxf Engl 1993 1998. [DOI: 10.1016/s0969-806x(98)00185-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
|
27
|
Villarini M, Moretti M, Pasquini R, Scassellati-Sforzolini G, Fatigoni C, Marcarelli M, Monarca S, Rodríguez AV. In vitro genotoxic effects of the insecticide deltamethrin in human peripheral blood leukocytes: DNA damage ('comet' assay) in relation to the induction of sister-chromatid exchanges and micronuclei. Toxicology 1998; 130:129-39. [PMID: 9865480 DOI: 10.1016/s0300-483x(98)00097-3] [Citation(s) in RCA: 88] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
Deltamethrin, a synthetic dibromo-pyrethroid insecticide, is extensively used in agriculture, forestry and in household products because of its high activity against a broad spectrum of insect pests (both adults and larvae), its low animal toxicity and its lack of persistence in the environment. Data on the genotoxicity and carcinogenicity of deltamethrin are rather controversial, depending on the genetic system or the assay used. The aim of this study was to further evaluate the potential genotoxic activity of deltamethrin. The in vitro genotoxicity of deltamethrin has been evaluated by assessing the ability of the insecticide to damage DNA (as evaluated using the single-cell microgel-electrophoresis or 'comet' assay) or induce sister-chromatid exchanges (SCE) and micronuclei (MN) in human peripheral blood leukocytes. All treatments were conducted with and without the presence of an external bioactivation source (+/- S9mix). The results indicate that deltamethrin, in the presence of metabolic activation (+ S9mix), is able to induce DNA damage (double- and single-strand breaks, alkali-labile sites and open excision repair sites) as revealed by the increasing tail moment values observed with increasing doses. The frequency of SCE and MN were not statistically increased in deltamethrin-treated cells as compared to controls, both with and without S9mix. However, lower deltamethrin doses were tested, as compared to 'comet' assay, because of cytotoxicity.
Collapse
Affiliation(s)
- M Villarini
- Department of Hygiene, University of Perugia, Italy
| | | | | | | | | | | | | | | |
Collapse
|
28
|
Gutiérrez S, Carbonell E, Galofré P, Creus A, Marcos R. The alkaline single-cell gel electrophoresis (SCGE) assay applied to the analysis of radiation-induced DNA damage in thyroid cancer patients treated with 131I. Mutat Res 1998; 413:111-9. [PMID: 9639687 DOI: 10.1016/s1383-5718(98)00010-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The alkaline single-cell gel electrophoresis (SCGE or Comet) assay appears to be a promising tool for measuring DNA damage at the individual cell level in both in vitro and in vivo studies. To provide further data on the possible applicability of this assay in human biomonitoring studies, we have evaluated the eventual genetic damage induced by therapeutic exposure to 131I, by measuring the Comet length and the amount of DNA damage in peripheral blood leukocytes from a group of 28 thyroid cancer patients who received 131I sodium iodide via oral administration. Blood samples were taken just before the treatment and 1 week after it. From the results obtained after radioiodine therapy, a small increase in the Comet length and in the grade of DNA damage is observed; however, this increase is not statistically significant because of inter-individual variability and the variable responses before and after 131I treatment. Considering our previous studies showing significant increases in the frequency of cytogenetic damage (when measured as micronuclei) in patients treated with relatively low doses of 131I, the results obtained in the present work by using the Comet assay could indicate that 1 week after the exposure most of the radioiodine-induced DNA lesions, that can be detected with this assay, have already been repaired.
Collapse
Affiliation(s)
- S Gutiérrez
- Grup de Mutagènesi, Departament de Genètica i de Microbiologia, Edifici Cn, Universitat Autònoma de Barcelona, 08193 Bellaterra, Spain
| | | | | | | | | |
Collapse
|
29
|
Reiter RJ, Herman TS, Meltz ML. Melatonin reduces gamma radiation-induced primary DNA damage in human blood lymphocytes. Mutat Res 1998; 397:203-8. [PMID: 9541644 DOI: 10.1016/s0027-5107(97)00211-x] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Peripheral blood samples were collected from human volunteers 5-10 min before, and at 1 and 2 h after a single oral dose of 300 mg of melatonin. At each time point: (1) the concentration of melatonin in the serum and in the leukocytes was determined; and (2) the whole blood was exposed in vitro to 100 cGy of gamma radiation. Immediately after exposure to the radiation, the lymphocytes were examined to determine the extent of primary DNA damage, viz., single strand breaks and alkali labile lesions (determined from the length of DNA migration and fluorescence intensity of migrated DNA in the comet tail), using the alkaline comet assay. For each volunteer, the results showed a significant increase in the concentration of melatonin in the serum and in the leukocytes at 1 h after the oral dose of melatonin, as compared to the sample collected at 0 hour. The lymphocytes in the blood samples collected at 1 and 2 h after melatonin ingestion and exposed in vitro to 100 cGy gamma radiation exhibited a significant decrease in the extent of primary DNA damage, as compared with similarly irradiated lymphocytes from the blood sample collected before melatonin ingestion. The extent of the melatonin-associated decrease in primary DNA damage did not correspond with the decrease reported earlier in the incidence of chromosomal aberrations and micronuclei; the latter assays required an additional postirradiation incubation of the cells at 37 +/- 1 degrees C for 48 and 72 h, respectively.
Collapse
|
30
|
Lankinen MH, Vilpo JA. Repair of gamma-irradiation-induced DNA single-strand breaks in human bone marrow cells: analysis of unfractionated and CD34+ cells using single-cell gel electrophoresis. Mutat Res 1997; 377:177-85. [PMID: 9247613 DOI: 10.1016/s0027-5107(97)00066-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Human bone marrow mononuclear cells (BMMNCs) were separated by density gradient centrifugation, and a subpopulation of progenitor cells was further isolated using anti-CD34-coated magnetic beads. The cells were irradiated with gamma-rays (0.93-5.43 Gy) from a 137Cs source. The extent of DNA damage, i.e., single-strand breaks (SSBs) and alkali-labile lesions of individual cells, was investigated using the alkaline single-cell gel electrophoresis technique. The irradiation resulted in a dose-dependent increase in DNA migration, reflecting the number of detectable DNA lesions. An approximately similar extent of SSB formation was observed in BMMNCs and CD34 + cells. Damage was repaired when the cells were incubated at 37 degrees C: a fast initial repair phase was followed by a slower rejoining of SSBs in both BMMNC and CD34 + cell populations. A significantly longer time was required to repair the lesions caused by 5.43 Gy than those caused by 0.93 Gy. In the present work we report, for the first time, the induction and repair of DNA SSBs at the level of single human bone marrow cells when exposed to ionizing radiation at clinically relevant doses. These data, together with our previous results with human blood granulocytes and lymphocytes, indicate an approximately similar extent of formation and repair of gamma-irradiation-induced DNA SSBs in immature and mature human hematopoietic cells.
Collapse
Affiliation(s)
- M H Lankinen
- Department of Clinical Chemistry, Tampere University Hospital, Finland
| | | |
Collapse
|
31
|
Abt G, Vaghef H, Gebhart E, Dahlgren CV, Hellman B. The role of N-acetylcysteine as a putative radioprotective agent on X-ray-induced DNA damage as evaluated by alkaline single-cell gel electrophoresis. Mutat Res 1997; 384:55-64. [PMID: 9201273 DOI: 10.1016/s0921-8777(97)00013-x] [Citation(s) in RCA: 24] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Samples of human whole blood from 8 different donors were incubated with physiological saline or N-acetyl-L-cysteine (NAC, 1 x 10(-3) M) before being irradiated in vitro with high-energy X-rays (0.7 or 2.0 Gy). Primary DNA damage was evaluated in isolated lymphocytes using alkaline single-cell gel electrophoresis. Whereas the lymphocytes from non-irradiated blood samples showed a similar 'background level' of damage, there was a difference in sensitivity towards the radiation-induced DNA damage, especially at 2.0 Gy. When the data were pooled there was a clear and dose-related increase (p < 0.001) in damage, both in the absence and presence of NAC. Using the two most sensitive 'comet parameters' for DNA damage, i.e., the tail inertia and tail moment, the radiation-induced damage was found to be significantly increased already at 0.7 Gy in the samples that had been irradiated without NAC. Overall, NAC was found to be without radioprotective effects. Instead, the incubation with NAC itself was found to be associated with a slightly increased level of DNA damage. If the present findings are relevant also in an in vivo situation using peripheral lymphocytes as a surrogate for non-malignant cells in the body, NAC seems to be of limited value as a radioprotective agent in the clinic, at least when it comes to the acute DNA-damaging effects of therapeutic doses of high-energy X-rays.
Collapse
Affiliation(s)
- G Abt
- Institute of Human Genetics, University of Erlangen-Nürnberg, Germany
| | | | | | | | | |
Collapse
|
32
|
Yendle JE, Tinwell H, Elliott BM, Ashby J. The genetic toxicity of time: importance of DNA-unwinding time to the outcome of single-cell gel electrophoresis assays. Mutat Res 1997; 375:125-36. [PMID: 9202723 DOI: 10.1016/s0027-5107(97)00008-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Single-cell gel electrophoresis assays (comet assays) are described in which DNA damage is assessed in mouse skin keratinocytes treated with N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) and beta-propiolactone (BPL) either in vitro or in vivo. The positive results observed under both conditions of test encourage the further development of the mouse skin comet assay as a screen for direct-acting in vivo genotoxins. From the outset of the present experiments we were struck by the compacted nature of the DNA in mouse skin keratinocytes. Under similar conditions of assay, rodent hepatocytes presented a uniform 'unwound' distribution of DNA over the whole nuclear region. In order to study this effect we varied what seemed to be the most obviously related assay parameter: the DNA-unwinding time. A series of experiments was conducted in which control and MNNG-treated cells were exposed to a range of alkaline DNA-unwinding times (0.3-18 h) followed by measurement of the three comet tail parameters (length, DNA content, and their product, tail moment). Each of these parameters increased with increasing time of unwinding such that the tails observed for MNNG-treated cells with 0.3 h of DNA unwinding were similar in length to the tails of control cells exposed to an 8 h DNA-unwinding time. It is concluded that DNA-unwinding time is a critical parameter of the comet assay and that it may require optimisation for each tissue/cell type studied. Further, the data alert to the prospect that agents that uniquely affect chromosomal protein superstructure may increase comet tail length/DNA content in the absence of chemically induced DNA damage. Thus, there may be two discrete classes of chemical interaction with chromosomal DNA that yield identical comet assay results, but which have different implications for the genetic toxicity of the test agent. Similar effects were observed for rat hepatocytes or mouse lymphoma cells exposed to an 18 h DNA-unwinding time, but no comet tails were produced by exposure of cells to the lysis conditions (pH 10.0) for 18 h.
Collapse
Affiliation(s)
- J E Yendle
- Zeneca Central Toxicology Laboratory, Macclesfield, Cheshire, UK
| | | | | | | |
Collapse
|
33
|
Visvardis EE, Tassiou AM, Piperakis SM. Study of DNA damage induction and repair capacity of fresh and cryopreserved lymphocytes exposed to H2O2 and gamma-irradiation with the alkaline comet assay. Mutat Res 1997; 383:71-80. [PMID: 9042421 DOI: 10.1016/s0921-8777(96)00047-x] [Citation(s) in RCA: 121] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
The alkaline SCGE assay was evaluated for use with cryopreserved lymphocytes in order to obtain results similar to the freshly isolated ones. The induction of DNA damage as well as the repair capacity of gamma-rays and H2O2 exposed cryopreserved human lymphocytes was found to be the same to that of the freshly isolated. Human lymphocytes (fresh or cryopreserved) responded differently to the effects of gamma-irradiation if compared to the H2O2 treatment. The distribution of DNA damage among gamma-irradiated lymphocytes was more homogeneous compared to H2O2, both in freshly isolated and in cryopreserved cells. 2.4 micrograms/ml phytohemagglutinin at the start of a 2-h incubation in RPMI of cryopreserved samples gave similar DNA repair and distribution patterns to the 2-h post-exposure incubation of freshly isolated lymphocytes. H2O2-induced DNA damage was not repaired completely. However, the repair of gamma-rays-induced DNA damage was more efficient. These findings confirm the different mode of action of the two agents on the induction of DNA damage, as well as, the different response of the lymphocytes' DNA repair system.
Collapse
Affiliation(s)
- E E Visvardis
- Department of Biology, National Centre for Scientific Research Demokritos, Aghia Paraskevi, Athens, Greece
| | | | | |
Collapse
|
34
|
Plappert UG, Stocker B, Fender H, Fliedner TM. Changes in the repair capacity of blood cells as a biomarker for chronic low-dose exposure to ionizing radiation. ENVIRONMENTAL AND MOLECULAR MUTAGENESIS 1997; 30:153-160. [PMID: 9329640 DOI: 10.1002/(sici)1098-2280(1997)30:2<153::aid-em8>3.0.co;2-o] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The purpose of this study was to examine whether changes in the repair capacity of blood cells could be used as a valuable biomarker for radiation exposure. To characterize the repair kinetics in nonirradiated and irradiated cells we first performed in vitro split dose experiments. DNA damage and DNA repair capacity were analysed using the comet assay. Our results showed that the first in vitro irradiation affects the repair system of the cells, resulting in a decreased repair capacity after the second irradiation. Furthermore, the second irradiation results in a large amount of DNA damage in the blood cells. To test whether the analysis of the DNA repair capacity after in vitro irradiation is also a valuable method for in vivo studies of donors exposed to radiation, we analysed the repair capacity of blood cells of two exposed groups: patients subjected to a radioiodine therapy and chronically irradiated volunteers from the Chernobyl region. Both groups also showed a significantly impaired repair capacity indicating a stress on the hematopoietic system. In addition, in the group of the Ukrainians DNA damage after in vitro irradiation was significantly higher than in a control group. These results lead to the presumption that the repair capacity and the DNA damage after in vitro irradiation might be a very useful biological marker for radiation exposure in population monitoring.
Collapse
Affiliation(s)
- U G Plappert
- Department of Clinical Physiology, Occupational and Social Medicine, University of Ulm, Germany.
| | | | | | | |
Collapse
|
35
|
Lankinen MH, Vilpo LM, Vilpo JA. UV- and gamma-irradiation-induced DNA single-strand breaks and their repair in human blood granulocytes and lymphocytes. Mutat Res 1996; 352:31-8. [PMID: 8676912 DOI: 10.1016/0027-5107(95)00172-7] [Citation(s) in RCA: 54] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
Ionizing irradiation and UV-irradiation cause DNA damage. Ionizing irradiation induces single-strand breaks, much less abundantly double-strand breaks, alkali-labile sites, and various oxidized purines and pyrimidines. UV-irradiation, on the other hand, causes cyclobutane pyrimidine dimers, (6-4) photoproducts, and various monomeric base damages. The deposition of energy in DNA may result directly in single-strand breaks (predominant form after ionizing radiation), or the strand breaks may be generated during the repair process (predominant form after UV-irradiation). We investigated the formation and repair of DNA single-strand breaks in human blood granulocytes and lymphocytes by the single-cell gel electrophoresis or comet assay. The induction and repair of DNA lesions by gamma-irradiation was comparable in human blood granulocytes and lymphocytes. The finding is consistent with the expression of the pertinent base excision repair proteins in these cells. In contrast to gamma-irradiation, fewer single-strand breaks were observed immediately after UV-irradiation; the maximum number of breaks were seen when the cells were incubated for 30-60 min. After an incubation period of 150 min, a significant reduction of single-strand breaks was noted. It is conceivable that the first 30-60 min represented a period during which the incision-excision phase of nucleotide excision repair (NER) predominated. After that, strand joining was dominant, evidently representing the synthesis and ligation phase of NER. These results indicate that the approx. 30 different polypeptides required for complete NER are functional in these mature blood cells. This is the first demonstration of the expression of global NER in human granulocytes.
Collapse
Affiliation(s)
- M H Lankinen
- Department of Clinical Chemistry, Tampere University Hospital, Finland
| | | | | |
Collapse
|
36
|
Kreja L, Selig C, Nothdurft W. Assessment of DNA damage in canine peripheral blood and bone marrow after total body irradiation using the single-cell gel electrophoresis technique. Mutat Res 1996; 359:63-70. [PMID: 8569803 DOI: 10.1016/s0165-1161(96)90010-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
DNA damage in single peripheral blood (pb) and bone marrow (bm) cells was studied in dogs which were exposed to total body X-ray irradiation (TBI) with a lethal dose of 3.9 Gy. The changes in pb and bm cell numbers were measured within 9 days after TBI. Using the alkaline single-cell gel electrophoresis technique ('comet' assay), DNA strand breaks and alkali labile sites were assessed in single cells derived from the blood before TBI, 1 h and 4 h after TBI and on days 1, 3 and 9 after TBI. Bone marrow cells subjected to the assay were collected before and on days 1 and 9 after TBI. Cells expressing the strongest DNA damage were most frequent in the blood 1 h after TBI and in the bone marrow 1 day after exposure. Thereafter, a continuous reduction of DNA damage in individual cells was observed in the course of progressive leukopenia and granulocytopenia.
Collapse
Affiliation(s)
- L Kreja
- Institute for Occupational and Social Medicine, University of Ulm, Germany
| | | | | |
Collapse
|
37
|
Tuo J, Loft S, Thomsen MS, Poulsen HE. Ex vivo time-dependent cell DNA-degradation shown by single cell gel electrophoresis. PHARMACOLOGY & TOXICOLOGY 1996; 78:55-7. [PMID: 8685088 DOI: 10.1111/j.1600-0773.1996.tb00180.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Affiliation(s)
- J Tuo
- Department of Pharmacology, Panum Institute, University of Copenhagen, Denmark
| | | | | | | |
Collapse
|
38
|
Holz O, Jörres R, Kästner A, Magnussen H. Differences in basal and induced DNA single-strand breaks between human peripheral monocytes and lymphocytes. Mutat Res 1995; 332:55-62. [PMID: 7500992 DOI: 10.1016/0027-5107(95)00154-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
The aim of this study was to compare the susceptibility of peripheral monocytes and lymphocytes to oxidant-induced DNA single-strand breaks (SSB). DNA damage was assessed by the alkaline single-cell gel electrophoresis (SCGE) assay. Total peripheral mononuclear leukocytes (PML), PML enriched in lymphocytes and PML enriched in monocytes were used. The basal rate of SSB was measured after in vitro incubation of cells for 1 h in phosphate-buffered saline, and the induced rate after incubation in 10 microM or 50 microM H2O2. Incubation was performed at 4 degrees C to limit the possible influence of DNA repair. Lymphocyte-enriched PML were obtained after adhesion of the monocytes to tissue-culture treated plastic, and monocyte-enriched PML by removal of monocytes from the plastic through trypsin. In all samples, cell differentiation was performed using an immunofluorescence technique with antibodies against T- and B-lymphocytes and cytospin preparations. The rate of SSB was determined by visual scoring according to 6 predefined categories of DNA damage and was expressed as mean score (range 0-500) per 100 cells. There was a linear relationship between the percentage of lymphocytes in the samples and the basal rate of SSB (p < 0.001, slope 0.67 score units per %). The same was true for induced DNA damage after incubation in 10 microM H2O2 (p < 0.001, slope 3.80 score units per %) or 50 microM H2O2 (p < 0.001, slope 3.22 score units per %). These regression analyses revealed a 2.9-fold greater rate of basal DNA damage in lymphocytes compared to monocytes and an 11.3-fold greater rate for the damage induced by 10 microM H2O2. We conclude that there are marked differences in the rate of basal and induced SSB between lymphocytes and monocytes, suggesting differences in antioxidant capacity between the two cell populations. These findings indicate that the assessment of SSB for biomonitoring and genotoxicity testing using PML has to take into account possible changes in cellular composition.
Collapse
Affiliation(s)
- O Holz
- Krankenhaus Grosshansdorf, Zentrum für Pneumologie und Thoraxchirurgie, LVA-Freie und Hansestadt Hamburg, Germany
| | | | | | | |
Collapse
|
39
|
Cadet J, Girault I, Gromova M, Molko D, Odin F, Polverelli M. Effects of heavy ions on nucleic acids: measurement of the damage. RADIATION AND ENVIRONMENTAL BIOPHYSICS 1995; 34:55-57. [PMID: 7604162 DOI: 10.1007/bf01210547] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
In this short survey the main, available information on the molecular mechanisms of action of heavy ions on DNA is critically reviewed. Formation of single- and double-stranded DNA breaks in cells exposed to heavy particles is well established. On the other hand, base damage and, in a more general way, clustered lesions, whose formation should be increased upon exposure to heavy ions, have not yet been isolated and characterized. Efforts should be made to identify this important class of DNA damage in both isolated and cellular DNA. Sensitive and specific assays involving chemical and biochemical approaches have to be developed for such a purpose.
Collapse
Affiliation(s)
- J Cadet
- CEA/Département de Recherche Fondamentale sur la Matière Condensée, SESAM/LAN, Grenoble, France
| | | | | | | | | | | |
Collapse
|
40
|
Abstract
The comet assay is a sensitive and rapid method for DNA strand break detection in individual cells. Its use has increased significantly in the past few years. This paper is a review of the studies published to date that have made use of the comet assay. The principles of strand break detection using both the alkaline and neutral versions of the technique are discussed, and a basic methodology with currently used variations is presented. Applications in different fields are reviewed and possible future directions of the technique are briefly explored.
Collapse
Affiliation(s)
- D W Fairbairn
- Department of Microbiology, Brigham Young University, Provo, UT 84602
| | | | | |
Collapse
|