1
|
Vidal LM, Pimentel E, Cruces MP, Sánchez-Meza JC. Evaluating the effect of low dose rate of gamma rays in germ cells of Drosophila melanogaster. Int J Radiat Biol 2020; 96:1068-1075. [PMID: 32338555 DOI: 10.1080/09553002.2020.1761566] [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: 10/24/2022]
Abstract
Purpose: Evaluation of genetic risk in germ cells is still matter of research, mainly due to their role in the transmission of genetic information from one generation to another. Although numerous experiments have been carried out in Drosophila in order to study the effect of radiation on germ cells, the role of dose rate (DR) has not been fully explored. The purpose of this study was to evaluate the action of DR on the radioprotection induction on male germ cell of D. melanogaster.Material and method: The productivity and the sex-linked recessive lethal (SLRL) tests were used to evaluate the radio-sensitivity of different states of the germ line of males. Two-day-old males of Canton-S wild type strain were pretreated with 0.2 Gy at 5.4 or 34.3 Gy/h of gamma rays from a 60Co source, three hours later, they were irradiated with 20 Gy at 907.7 Gy/h. Thereafter, each single male was crossed with 3 five-day old Basc virgin females, that were replaced every other day by new females. This procedure was conducted three times, to test the whole germ cell stages.Results: Females crossed with males irradiated with 0.2 Gy at both DR tested, laid a higher number of eggs than control, but egg-viability was reduced. On the other hand, in the group of 0.2 Gy + 20 Gy -combined treatments- the total number of eggs laid decreased only when 0.2 Gy were delivered at 34.3 Gy/h however, the egg-viability increased. The dose of 0.2 Gy at both DR did not modify the baseline frequency of SLRL. A tendency to decrease in the frequency of lethals in brood III was found in combined treatments at both DR.Conclusion: The fact that 0.2 Gy at 5.4 or 34.3 Gy/h induced an increase in the egg-viability and a tendency to decrease the genetic damage in pre-meiotic cells provoked by 20 Gy, might indicate the induction of any mechanism that could be interpreted as radioprotection in male germ cells of D. melanogaster. Results emphasize the need to carry out more studies on the effect of the DR on the induction of genetic damage in germ cells.
Collapse
Affiliation(s)
- Luz Ma Vidal
- Instituto Nacional de Investigaciones Nucleares, Ocoyoacac, México
| | - Emilio Pimentel
- Instituto Nacional de Investigaciones Nucleares, Ocoyoacac, México
| | - Martha P Cruces
- Instituto Nacional de Investigaciones Nucleares, Ocoyoacac, México
| | - Juan C Sánchez-Meza
- Facultad de Química, Universidad Autónoma del Estado de México, Toluca, México
| |
Collapse
|
2
|
Rakici SY, Guzel AI, Tumkaya L, Sevim Nalkiran H, Mercantepe T. Pelvic Radiation-Induced Testicular Damage: An Experimental Study at 1 Gray. Syst Biol Reprod Med 2019; 66:89-98. [PMID: 31657243 DOI: 10.1080/19396368.2019.1679909] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Therapeutic radiation of the pelvic region has been shown to cause damage to testicular germ cells. In this study we aimed to evaluate the effects of a low therapeutic dose of 1 Gy on the induction of cellular and histological damage in early-stage testicular germ cells and the impact of this radiation on offspring sex ratio. Unirradiated and irradiated male rats were mated with unirradiated female rats. Female rats were followed and the sex of the offspring was determined. The male rats were sacrificed at the end of the second week, and the testicular germ cells were subjected to genetic analysis along with cytological and histopathological examination. Sperm DNA was amplified with primers specific to testis-specific Y-linked protein, rat actin beta and testis-specific X-linked genes. The resulting products were separated by capillary electrophoresis. Histopathological changes were investigated by light microscopy along with the TUNEL assay and immunohistochemical staining for caspase-3. There was no significant difference between the two groups for sex ratio and size of offspring. The number of sperm cells bearing X or Y chromosomes' did not differ significantly between these two groups. However, a 1 Gy dose of radiation caused significant cytopathological and histopathological changes in the testicular tissue. In the irradiated group, edematous regions were evident. The number of caspase-3 positive cells in the germinal epithelium of the seminiferous tubules was also significantly higher in the irradiated group. Our results showed that low-dose radiation induced apoptosis and caused significant cyto- and histopathological changes in the testicular tissue. Further research is required to fully elucidate their contribution to apoptosis and if low-dose radiation may potentially lead to long-term effects in the offspring. These results may also lead us to develop a new technique using the caspase-3 staining to monitor the susceptibility to low dose radiation.
Collapse
Affiliation(s)
- Sema Yilmaz Rakici
- Department of Radiation Oncology, Recep Tayyip Erdogan University Faculty of Medicine, Rize, Turkey
| | - Ali Irfan Guzel
- Department of Medical Biology, Recep Tayyip Erdogan University Faculty of Medicine, Rize, Turkey
| | - Levent Tumkaya
- Department of Histology and Embryology, Recep Tayyip Erdogan University Faculty of Medicine, Rize, Turkey
| | - Hatice Sevim Nalkiran
- Department of Medical Biology, Recep Tayyip Erdogan University Faculty of Medicine, Rize, Turkey
| | - Tolga Mercantepe
- Department of Histology and Embryology, Recep Tayyip Erdogan University Faculty of Medicine, Rize, Turkey
| |
Collapse
|
3
|
Ji K, Wang Y, Du L, Xu C, Liu Y, He N, Wang J, Liu Q. Research Progress on the Biological Effects of Low-Dose Radiation in China. Dose Response 2019; 17:1559325819833488. [PMID: 30833876 PMCID: PMC6393828 DOI: 10.1177/1559325819833488] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2018] [Revised: 12/19/2018] [Accepted: 12/29/2018] [Indexed: 01/07/2023] Open
Abstract
Human are exposed to ionizing radiation from natural and artificial sources, which consequently poses a possible risk to human health. However, accumulating evidence indicates that the biological effects of low-dose radiation (LDR) are different from those of high-dose radiation (HDR). Low-dose radiation–induced hormesis has been extensively observed in different biological systems, including immunological and hematopoietic systems. Adaptive responses in response to LDR that can induce cellular resistance to genotoxic effects from subsequent exposure to HDR have also been described and researched. Bystander effects, another type of biological effect induced by LDR, have been shown to widely occur in many cell types. Furthermore, the influence of LDR-induced biological effects on certain diseases, such as cancer and diabetes, has also attracted the interest of researchers. Many studies have suggested that LDR has the potential antitumor and antidiabetic complications effects. In addition, the researches on whether LDR could induce stochastic effects were also debated. Studies on the biological effects of LDR in China started in 1970s and considerable progress has been made since. In the present article, we provide an overview of the research progress on the biological effects of LDR in China.
Collapse
Affiliation(s)
- Kaihua Ji
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Department of Radiobiology, Institute of Radiation Medicine of Chinese Academy of Medical Science & Pecking Union Medical College, Tianjin, PR China
| | - Yan Wang
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Department of Radiobiology, Institute of Radiation Medicine of Chinese Academy of Medical Science & Pecking Union Medical College, Tianjin, PR China
| | - Liqing Du
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Department of Radiobiology, Institute of Radiation Medicine of Chinese Academy of Medical Science & Pecking Union Medical College, Tianjin, PR China
| | - Chang Xu
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Department of Radiobiology, Institute of Radiation Medicine of Chinese Academy of Medical Science & Pecking Union Medical College, Tianjin, PR China
| | - Yang Liu
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Department of Radiobiology, Institute of Radiation Medicine of Chinese Academy of Medical Science & Pecking Union Medical College, Tianjin, PR China
| | - Ningning He
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Department of Radiobiology, Institute of Radiation Medicine of Chinese Academy of Medical Science & Pecking Union Medical College, Tianjin, PR China
| | - Jinhan Wang
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Department of Radiobiology, Institute of Radiation Medicine of Chinese Academy of Medical Science & Pecking Union Medical College, Tianjin, PR China
| | - Qiang Liu
- Tianjin Key Laboratory of Radiation Medicine and Molecular Nuclear Medicine, Department of Radiobiology, Institute of Radiation Medicine of Chinese Academy of Medical Science & Pecking Union Medical College, Tianjin, PR China
| |
Collapse
|
4
|
Premkumar K, Nair J, Shankar BS. Differential radio-adaptive responses in BALB/c and C57BL/6 mice: pivotal role of calcium and nitric oxide signalling. Int J Radiat Biol 2019; 95:655-666. [PMID: 30676176 DOI: 10.1080/09553002.2019.1571647] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Purpose: Our earlier studies demonstrated that transient radio-adaptive responses (RAR) in BALB/c mice were due to MAPK hyperactivation. The objective of this study was to determine the time duration of this low dose induced MAPK activation in BALB/c mice and to find out if similar adaptive responses are observed in C57BL/6 mice. Materials and methods: Mice were irradiated with 0.1 Gy priming dose (PD), 2 Gy challenge dose (CD) with an interval of 4 h (P + CD) and radiation induced immunosuppression in splenic lymphocytes was monitored as the endpoint for RAR. Results: Time kinetics following 0.1 Gy demonstrated persistence of MAPK hyperactivation till 48 h. Similar experiments in C57BL/6 mice indicated absence of RAR at 24 h following CD, in spite of MAPK activation which was also confirmed by time kinetics. Therefore, upstream activators of MAPK, viz., reactive oxygen and nitrogen species (ROS, RNS) and calcium levels were estimated. There was increased intracellular calcium (Ca2+) and nitric oxide (NO) in BALB/c and an increase in intracellular ROS in C57BL/6 mice 24 h after PD. Inhibition of NO and calcium chelation abrogated RAR in BALB/c mice. In vitro treatment of spleen cells with combination of NO donor and Ca2+ ionophore mimicked the effect of PD and induced adaptive response after 2 Gy not only in BALB/c but also in C57BL/6 mice confirming their crucial role in RAR. Conclusions: These results suggest that low dose induced differential induction of Ca2+ and NO signaling along with MAPK was responsible for contrasting RAR with respect to immune system of BALB/c and C57BL/6 mice. Abbreviations [3H]-TdR: 3H-methyl-thymidine; BAPTA: 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; CD: Challenge Dose; CFSE: Carboxy Fluorescein Succinamidyl Ester; on A: Concanavalin A; DAF-FM: 4-amino-5-methylamino-2',7'-difluorescein; DCF-DA: 2',7'-dichlorofluorescein diacetate; DSB: Double Strand Break; ELISA: Enzyme Linked ImmunoSorbent Assay; ERK: Extracellular signal-Regulated protein Kinase; FBS: Fetal Bovine Serum; HIF-1A: Hypoxia-Inducible Factor 1-alpha; LDR: Low Dose Radiation; MAPK: Mitogen Activated Protein Kinase; MAPKK/MKK: MAPK Kinase; MAPKKK: MAPK Kinase Kinase; NO: Nitric Oxide; NOS: Nitric Oxide Synthase; P + CD: Priming + Challenge dose; PBS: Phosphate Buffered Saline; PBST: Phosphate Buffered Saline-Tween 20; PD: Priming Dose; PI3K: Phosphatidyl Inositol 3-Kinase; PKC: Protein Kinase C; RAR: Radio Adaptive Response; RNS: Reactive Nitrogen Species; ROS: Reactive Oxygen Species; RPMI-1640: Roswell Park Memorial Institute-1640 medium; SAPK/JNK: Stress-Activated Protein Kinase/ c-Jun NH2-terminal Kinase; SEM: Standard Error of Mean; SNAP: S-nitro amino penicillamine; TP53: Tumor Protein 53; γ-H2AX: Gamma- H2A histone family member X; Th1: Type 1 helper T cell responses; Th2: Type 2 helper T cell responses.
Collapse
Affiliation(s)
- Kavitha Premkumar
- a Immunology Section, Radiation Biology & Health Sciences Division , Bio-Science Group, Bhabha Atomic Research Centre , Mumbai , India
| | - Jisha Nair
- a Immunology Section, Radiation Biology & Health Sciences Division , Bio-Science Group, Bhabha Atomic Research Centre , Mumbai , India
| | - Bhavani S Shankar
- a Immunology Section, Radiation Biology & Health Sciences Division , Bio-Science Group, Bhabha Atomic Research Centre , Mumbai , India
| |
Collapse
|
5
|
Cho SJ, Kang H, Hong EH, Kim JY, Nam SY. Transcriptome analysis of low-dose ionizing radiation-impacted genes in CD4+ T-cells undergoing activation and regulation of their expression of select cytokines. J Immunotoxicol 2019; 15:137-146. [DOI: 10.1080/1547691x.2018.1521484] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Affiliation(s)
- Seong-Jun Cho
- Low-Dose Radiation Research Team, KHNP Radiation Health Institute, Korea Hydro & Nuclear Power Co., LTD, Seoul, South Korea
| | - Hana Kang
- Low-Dose Radiation Research Team, KHNP Radiation Health Institute, Korea Hydro & Nuclear Power Co., LTD, Seoul, South Korea
| | - Eun-Hee Hong
- Low-Dose Radiation Research Team, KHNP Radiation Health Institute, Korea Hydro & Nuclear Power Co., LTD, Seoul, South Korea
| | - Ji Young Kim
- Low-Dose Radiation Research Team, KHNP Radiation Health Institute, Korea Hydro & Nuclear Power Co., LTD, Seoul, South Korea
| | - Seon Young Nam
- Low-Dose Radiation Research Team, KHNP Radiation Health Institute, Korea Hydro & Nuclear Power Co., LTD, Seoul, South Korea
| |
Collapse
|
6
|
Yang G, Li W, Jiang H, Liang X, Zhao Y, Yu D, Zhou L, Wang G, Tian H, Han F, Cai L, Cui J. Low-dose radiation may be a novel approach to enhance the effectiveness of cancer therapeutics. Int J Cancer 2016; 139:2157-68. [PMID: 27299986 DOI: 10.1002/ijc.30235] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Revised: 05/01/2016] [Accepted: 06/06/2016] [Indexed: 12/26/2022]
Abstract
It has been generally accepted that both natural and man-made sources of ionizing radiation contribute to human exposure and consequently pose a possible risk to human health. However, accumulating evidence has shown that the biological effects of low-dose radiation (LDR) are different from those of high-dose radiation. LDR can stimulate proliferation of normal cells and activate their defense systems, while these biological effects are not observed in some cancer cell types. Although there is still no concordance on this matter, the fact that LDR has the potential to enhance the effects of cancer therapeutics and reduce the toxic side effects of anti-cancer therapy has garnered significant interest. Here, we provide an overview of the current knowledge regarding the experimental data detailing the different responses of normal and cancer tissues to LDR, the underlying mechanisms, and its significance in clinical application.
Collapse
Affiliation(s)
- Guozi Yang
- Cancer Center, The First Hospital of Jilin University, Changchun, 130021, China.,Department of Radiation-Oncology, The First Hospital of Jilin University, Changchun, 130021, China
| | - Wei Li
- Cancer Center, The First Hospital of Jilin University, Changchun, 130021, China
| | - Hongyu Jiang
- Health Examination Center, The First Hospital of Jilin University, Changchun, 130021, China
| | - Xinyue Liang
- Cancer Center, The First Hospital of Jilin University, Changchun, 130021, China
| | - Yuguang Zhao
- Cancer Center, The First Hospital of Jilin University, Changchun, 130021, China
| | - Dehai Yu
- Cancer Center, The First Hospital of Jilin University, Changchun, 130021, China
| | - Lei Zhou
- Cancer Center, The First Hospital of Jilin University, Changchun, 130021, China
| | - Guanjun Wang
- Cancer Center, The First Hospital of Jilin University, Changchun, 130021, China
| | - Huimin Tian
- Cancer Center, The First Hospital of Jilin University, Changchun, 130021, China
| | - Fujun Han
- Cancer Center, The First Hospital of Jilin University, Changchun, 130021, China
| | - Lu Cai
- Cancer Center, The First Hospital of Jilin University, Changchun, 130021, China. .,Kosair Children's Hospital Research Institute, Departments of Pediatrics, Radiation Oncology, Pharmacology and Toxicology of the University of Louisville, Louisville, KY, 40202.
| | - Jiuwei Cui
- Cancer Center, The First Hospital of Jilin University, Changchun, 130021, China.
| |
Collapse
|
7
|
Cho SJ, Kang H, Kim MY, Lee JE, Kim SJ, Nam SY, Kim JY, Kim HS, Pyo S, Yang KH. Site-Specific Phosphorylation of Ikaros Induced by Low-Dose Ionizing Radiation Regulates Cell Cycle Progression of B Lymphoblast Through CK2 and AKT Activation. Int J Radiat Oncol Biol Phys 2016; 94:1207-18. [DOI: 10.1016/j.ijrobp.2016.01.008] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Revised: 12/30/2015] [Accepted: 01/06/2016] [Indexed: 11/17/2022]
|
8
|
Shao M, Yu L, Zhang F, Lu X, Li X, Cheng P, Lin X, He L, Jin S, Tan Y, Yang H, Zhang C, Cai L. Additive protection by LDR and FGF21 treatment against diabetic nephropathy in type 2 diabetes model. Am J Physiol Endocrinol Metab 2015; 309:E45-54. [PMID: 25968574 PMCID: PMC4490332 DOI: 10.1152/ajpendo.00026.2015] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/22/2015] [Accepted: 05/05/2015] [Indexed: 12/20/2022]
Abstract
The onset of diabetic nephropathy (DN) is associated with both systemic and renal changes. Fibroblast growth factor (FGF)-21 prevents diabetic complications mainly by improving systemic metabolism. In addition, low-dose radiation (LDR) protects mice from DN directly by preventing renal oxidative stress and inflammation. In the present study, we tried to define whether the combination of FGF21 and LDR could further prevent DN by blocking its systemic and renal pathogeneses. To this end, type 2 diabetes was induced by feeding a high-fat diet for 12 wk followed by a single dose injection of streptozotocin. Diabetic mice were exposed to 50 mGy LDR every other day for 4 wk with and without 1.5 mg/kg FGF21 daily for 8 wk. The changes in systemic parameters, including blood glucose levels, lipid profiles, and insulin resistance, as well as renal pathology, were examined. Diabetic mice exhibited renal dysfunction and pathological abnormalities, all of which were prevented significantly by LDR and/or FGF21; the best effects were observed in the group that received the combination treatment. Our studies revealed that the additive renal protection conferred by the combined treatment against diabetes-induced renal fibrosis, inflammation, and oxidative damage was associated with the systemic improvement of hyperglycemia, hyperlipidemia, and insulin resistance. These results suggest that the combination treatment with LDR and FGF21 prevented DN more efficiently than did either treatment alone. The mechanism behind these protective effects could be attributed to the suppression of both systemic and renal pathways.
Collapse
Affiliation(s)
- Minglong Shao
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China; Ruian Center of Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China
| | - Lechu Yu
- Ruian Center of Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China
| | - Fangfang Zhang
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China; Ruian Center of Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China
| | - Xuemian Lu
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China; Ruian Center of Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China
| | - Xiaokun Li
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China
| | - Peng Cheng
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China; Ruian Center of Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China
| | - Xiufei Lin
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China; Ruian Center of Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China
| | - Luqing He
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China; Ruian Center of Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China
| | - Shunzi Jin
- Key Laboratory of Radiobiology (Ministry of Health), School of Public Health of Jilin University, Changchun, China; and
| | - Yi Tan
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China; Ruian Center of Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China; Kosair Children's Hospital Research Institute, Department of Pediatrics, the University of Louisville School of Medicine, Louisville, Kentucky
| | - Hong Yang
- Ruian Center of Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China
| | - Chi Zhang
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China; Ruian Center of Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China;
| | - Lu Cai
- Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China; Ruian Center of Chinese-American Research Institute for Diabetic Complications, Wenzhou Medical University, Wenzhou, China; Kosair Children's Hospital Research Institute, Department of Pediatrics, the University of Louisville School of Medicine, Louisville, Kentucky
| |
Collapse
|
9
|
Edin NJ, Altaner Č, Altanerova V, Ebbesen P. TGF-B3 Dependent Modification of Radiosensitivity in Reporter Cells Exposed to Serum From Whole-Body Low Dose-Rate Irradiated Mice. Dose Response 2015; 13:10.2203_dose-response.14-015.Edin. [PMID: 26673923 PMCID: PMC4674161 DOI: 10.2203/dose-response.14-015.edin] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Prior findings in vitro of a TGF-β3 dependent mechanism induced by low dose-rate irradiation and resulting in increased radioresistance and removal of low dose hyper-radiosensitivity (HRS) was tested in an in vivo model. DBA/2 mice were given whole-body irradiation for 1 h at low dose-rates (LDR) of 0.3 or 0.03 Gy/h. Serum was harvested and added to RPMI (4% mouse serum and 6% bovine serum).This medium was transferred to reporter cells (T-47D breast cancer cells or T98G glioblastoma cells). The response to subsequent challenge irradiation of the reporter cells was measured by the colony assay. While serum from unirradiated control mice had no effect on the radiosensitivity in the reporter cells, serum from mice given 0.3 Gy/h or 0.03 Gy/h for 1 h removed HRS and also increased survival in response to doses up to 5 Gy. The effect lasted for at least 15 months after irradiation. TGF-β3 neutralizer added to the medium containing mouse serum inhibited the effect. Serum from mice given irradiation of 0.3 Gy/h for 1 h and subsequently treated with iNOS inhibitor 1400W did not affect radiosensitivity in reporter cells; neither did serum from the unirradiated progeny of mice given 1h LDR whole-body irradiation.
Collapse
Affiliation(s)
- Nina Jeppesen Edin
- Department of Physics, University of Oslo, 0316 Oslo, Norway ; Department of Radiation Biology, Institute for Cancer Research, Oslo University Hospital, Montebello, 0310 Oslo, Norway
| | - Čestmír Altaner
- Cancer Research Institute, Slovak Academy of Sciences, Bratislava, Slovakia
| | | | - Peter Ebbesen
- Department of Physics, University of Oslo, 0316 Oslo, Norway ; Laboratory for Stem Cell Research, Aalborg University, Fredrik Bajers Vej 3B, 9220 Aalborg Ø. Denmark
| |
Collapse
|
10
|
Hou J, Wang F, Kong P, Yu PKN, Wang H, Han W. Gene profiling characteristics of radioadaptive response in AG01522 normal human fibroblasts. PLoS One 2015; 10:e0123316. [PMID: 25886619 PMCID: PMC4401551 DOI: 10.1371/journal.pone.0123316] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Accepted: 03/02/2015] [Indexed: 12/20/2022] Open
Abstract
Radioadaptive response (RAR) in mammalian cells refers to the phenomenon where a low-dose ionizing irradiation alters the gene expression profiles, and protects the cells from the detrimental effects of a subsequent high dose exposure. Despite the completion of numerous experimental studies on RAR, the underlying mechanism has remained unclear. In this study, we aimed to have a comprehensive investigation on the RAR induced in the AG01522 human fibroblasts first exposed to 5 cGy (priming dose) and then followed by 2 Gy (challenge dose) of X-ray through comparisons to those cells that had only received a single 2 Gy dose. We studied how the priming dose affected the expression of gene transcripts, and to identify transcripts or pathways that were associated with the reduced chromosomal damages (in terms of the number of micronuclei) after application of the challenging dose. Through the mRNA and microRNA microarray analyses, the transcriptome alteration in AG01522 cells was examined, and the significantly altered genes were identified for different irradiation procedures using bioinformatics approaches. We observed that a low-dose X-ray exposure produced an alert, triggering and altering cellular responses to defend against subsequent high dose-induced damages, and accelerating the cell repair process. Moreover, the p53 signaling pathway was found to play critial roles in regulating DNA damage responses at the early stage after application of the challenging dose, particularly in the RAR group. Furthermore, microRNA analyses also revealed that cell communication and intercellular signaling transduction played important roles after low-dose irradiation. We conclude that RAR benefits from the alarm mechanisms triggered by a low-dose priming radation dose.
Collapse
Affiliation(s)
- Jue Hou
- Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| | - Fan Wang
- Department of Radiation Oncology, First Affiliated Hospital, Anhui Medical University, Hefei, China
| | - Peizhong Kong
- Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| | - Peter K. N. Yu
- Department of Physics and Materials Science, City University of Hong Kong, Tat Chee Avenue, Kowloon Tong, Hong Kong
| | - Hongzhi Wang
- Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
- Cancer Hospital, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| | - Wei Han
- Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
- Cancer Hospital, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei, China
| |
Collapse
|
11
|
Zhao Y, Zhong R, Sun L, Jia J, Ma S, Liu X. Ionizing radiation-induced adaptive response in fibroblasts under both monolayer and 3-dimensional conditions. PLoS One 2015; 10:e0121289. [PMID: 25807079 PMCID: PMC4373882 DOI: 10.1371/journal.pone.0121289] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Accepted: 01/29/2015] [Indexed: 01/01/2023] Open
Abstract
To observe the adaptive response (AR) induced by ionizing radiation in human fibroblasts under monolayer and 3-dimensional (3-D) condition. Three kinds of fibroblasts were cultured under both monolayer and 3-D condition. Immunofluorescent staining was used to detect the γ-H2AX foci and the morphological texture. Trypan blue staining was used to detect the cell death. Western blot was used to detect the expressions of γ-H2AX, p53 and CDKN1A/p21 (p21). We found that DNA damage increased in a dose-dependent and time-dependent manner after high doses of radiation. When cells were pretreated with a priming low dose of radiation followed by high dose radiation, DNA damage was attenuated under both monolayer and 3-D condition, and the adaptive response (AR) was induced. Additionally, the morphology of cells under monolayer and 3-D conditions were different, and radiation also induced AR according to morphological texture analysis. Priming low dose radiation induced AR both under monolayer and 3-D condition. Interestingly, 3-D microenvironment made cells more sensitive to radiation. The expression of p53 and p21 was changed and indicated that they might participate in the regulation of AR.
Collapse
Affiliation(s)
- Yinlong Zhao
- Key Laboratory of Radiobiology (Ministry of Health), School of Public Health, Jilin University, Changchun, China
- Dept. Nuclear Medicine, 2nd Hospital Jilin University, Changchun, China
| | - Rui Zhong
- Key Laboratory of Radiobiology (Ministry of Health), School of Public Health, Jilin University, Changchun, China
| | - Liguang Sun
- Dept. Translational Medicine, 1st Hospital Jilin University, Changchun, China
| | - Jie Jia
- Dept. Ultrasound, China-Japan Union Hospital, Changchun, China
| | - Shumei Ma
- Key Laboratory of Radiobiology (Ministry of Health), School of Public Health, Jilin University, Changchun, China
- * E-mail: (SM); (XL)
| | - Xiaodong Liu
- Key Laboratory of Radiobiology (Ministry of Health), School of Public Health, Jilin University, Changchun, China
- * E-mail: (SM); (XL)
| |
Collapse
|
12
|
Sasaki MS, Tachibana A, Takeda S. Cancer risk at low doses of ionizing radiation: artificial neural networks inference from atomic bomb survivors. JOURNAL OF RADIATION RESEARCH 2014; 55:391-406. [PMID: 24366315 PMCID: PMC4014156 DOI: 10.1093/jrr/rrt133] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 08/04/2013] [Revised: 10/20/2013] [Accepted: 10/22/2013] [Indexed: 06/03/2023]
Abstract
Cancer risk at low doses of ionizing radiation remains poorly defined because of ambiguity in the quantitative link to doses below 0.2 Sv in atomic bomb survivors in Hiroshima and Nagasaki arising from limitations in the statistical power and information available on overall radiation dose. To deal with these difficulties, a novel nonparametric statistics based on the 'integrate-and-fire' algorithm of artificial neural networks was developed and tested in cancer databases established by the Radiation Effects Research Foundation. The analysis revealed unique features at low doses that could not be accounted for by nominal exposure dose, including (i) the presence of a threshold that varied with organ, gender and age at exposure, and (ii) a small but significant bumping increase in cancer risk at low doses in Nagasaki that probably reflects internal exposure to (239)Pu. The threshold was distinct from the canonical definition of zero effect in that it was manifested as negative excess relative risk, or suppression of background cancer rates. Such a unique tissue response at low doses of radiation exposure has been implicated in the context of the molecular basis of radiation-environment interplay in favor of recently emerging experimental evidence on DNA double-strand break repair pathway choice and its epigenetic memory by histone marking.
Collapse
Affiliation(s)
- Masao S. Sasaki
- Kyoto University, 17-12 Shironosato, Nagaokakyo-shi, Kyoto 617-0835, Japan
| | - Akira Tachibana
- Department of Biology, Faculty of Science, Ibaraki University, Bunkyo 2-1-1, Mito, Ibaraki 310-8512, Japan
| | - Shunichi Takeda
- Department of Radiation Genetics, Graduate School of Medicine, Kyoto University, Yoshida-konoecho, Sakyo-ku, Kyoto 606-8501, Japan
| |
Collapse
|
13
|
Park HS, Seong KM, Kim JY, Kim CS, Yang KH, Jin YW, Nam SY. Chronic low-dose radiation inhibits the cells death by cytotoxic high-dose radiation increasing the level of AKT and acinus proteins via NF-κB activation. Int J Radiat Biol 2013. [DOI: 10.3109/09553002.2013.754560] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
|
14
|
Hertel-Aas T, Brunborg G, Jaworska A, Salbu B, Oughton DH. Effects of different gamma exposure regimes on reproduction in the earthworm Eisenia fetida (Oligochaeta). THE SCIENCE OF THE TOTAL ENVIRONMENT 2011; 412-413:138-147. [PMID: 22033357 DOI: 10.1016/j.scitotenv.2011.09.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/22/2011] [Revised: 09/06/2011] [Accepted: 09/14/2011] [Indexed: 05/31/2023]
Abstract
Ecological risk assessment of ionising radiation requires knowledge about the responses of individuals and populations to chronic exposures, including situations when exposure levels change over time. The present study investigated processes such as recovery and the adaptive response with respect to reproduction endpoints in the earthworm Eisenia fetida exposed to (60)Co γ-radiation. Furthermore, a crossed experiment was performed to investigate the influence of F0 parental and F1 embryonic irradiation history on the response of irradiated or non-irradiated F1 offspring. Recovery: The sterility induced by sub-chronic exposure at 17 m Gy/h (accumulated dose: 25 Gy) was temporary, and 8 weeks after irradiation the worms had regained their reproductive capacity (number of viable offspring produced per adult per week). Adaptive response: Adult worms were continuously exposed at a low priming dose rate of 0.14 mGy/h for 12 weeks (accumulated dose: 0.24 Gy), followed by 14 weeks exposure at a challenge dose rate of 11 mGy/h. The results suggest a lack of adaptive response, since there were no significant differences in the effects on reproduction capacity between the primed and the unprimed groups after challenge doses ranging from 7.6 to 27 Gy. Crossed experiment: The effects of exposure at 11 mGy/h for 21 weeks on growth, sexual maturation and reproduction of offspring, derived either from parent worms and cocoons both exposed at 11 mGy/h, or from non-irradiated parents and cocoons (total accumulated dose 44 and 38 Gy, respectively) were compared. There were no significant differences between the two exposed offspring groups for any of the endpoints. The reproduction capacity was very low for both groups compared to the controls, but the reproduction seemed to be maintained at the reduced level, which could indicate acclimatisation or stabilisation. Finally, parental and embryonic exposures at 11 mGy/h did not affect reproduction in the F1 offspring as adults.
Collapse
Affiliation(s)
- Turid Hertel-Aas
- Department of Plant and Environmental Sciences, Norwegian University of Life Sciences, P.O. Box 5003, 1432 Aas, Norway.
| | | | | | | | | |
Collapse
|
15
|
Phan N, De Lisio M, Parise G, Boreham DR. Biological effects and adaptive response from single and repeated computed tomography scans in reticulocytes and bone marrow of C57BL/6 mice. Radiat Res 2011; 177:164-75. [PMID: 22059980 DOI: 10.1667/rr2532.1] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
This study investigated the biological effects and adaptive responses induced by single and repeated in vivo computed tomography (CT) scans. We postulated that, through the induction of low-level oxidative stress, repeated low-dose CT scans (20 mGy, 2 days/week, 10 weeks) could protect mice (C57BL/6) from acute effects of high-dose radiation (1 Gy, 2 Gy). The micronucleated reticulocyte (MN-RET) count increased linearly after exposure to single CT scans of doses ranging from 20 to 80 mGy (P = 0.033). Ten weeks of repeated CT scans (total dose 400 mGy) produced a slight reduction in spontaneous MN-RET levels relative to levels in sham CT-scanned mice (P = 0.04). Decreases of nearly 10% in γ-H2AX fluorescence levels were observed in the repeated CT-scanned mice after an in vitro challenge dose of 1 Gy (P = 0.017) and 2 Gy (P = 0.026). Spontaneous apoptosis levels (caspase 3 and 7 activation) were also significantly lower in the repeated CT-scanned mice than the sham CT-scanned mice (P < 0.01). In contrast, mice receiving only a single CT scan showed a 19% elevation in apoptosis (P < 0.02) and a 10% increase in γ-H2AX fluorescence levels after a 2-Gy challenge (P < 0.05) relative to sham CT controls. Overall, repeated CT scans seemed to confer resistance to larger doses in mice, whereas mice exposed to single CT scans exhibited transient genotoxicity, enhanced apoptosis, and characteristics of radiation sensitization.
Collapse
Affiliation(s)
- Nghi Phan
- Department of Medical Physics and Applied Radiation Sciences, Nuclear Research Building Room 227, 1280 Main St. West, McMaster University, Hamilton, Ontario, Canada, L8S 4K1.
| | | | | | | |
Collapse
|
16
|
Guo WY, Wang GJ, Wang P, Chen Q, Tan Y, Cai L. Acceleration of diabetic wound healing by low-dose radiation is associated with peripheral mobilization of bone marrow stem cells. Radiat Res 2010; 174:467-79. [PMID: 20726708 DOI: 10.1667/rr1980.1] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
In this study we investigated the effect of repeated low-dose radiation exposure (75 mGy X ray) on skin wound healing in a rat model of diabetes. A skin wound was made on the backs of diabetic and age-matched control rats 60 days after diabetes was induced by a single injection of streptozotocin. Rats with skin wounds were immediately treated with whole-body radiation daily for 5, 10 or 15 days with a 2-day break every 5 days. Wound size was estimated 5, 10 and 15 days after wound formation. Repeated exposure of diabetic rats to low-dose radiation significantly accelerated skin wound healing compared to the nonirradiated diabetic group. Furthermore, low-dose radiation-induced improvement in healing was associated with increases in bone marrow and circulating CD31(+)/CD34(+) stem cells, vessel regeneration and cell proliferation in the wound tissue, and matrix metalloproteinase 2 and 9 expression. Therefore, we conclude that the acceleration of wound healing in diabetic rats by repeated exposure to low-dose radiation is associated with stimulation of bone marrow stem cell proliferation and peripheral mobilization.
Collapse
Affiliation(s)
- Wei-Ying Guo
- Department of Endocrinology, Jilin University, Changchun, 130021, China
| | | | | | | | | | | |
Collapse
|
17
|
Zhao H, Xu S, Wang Z, Li Y, Guo W, Lin C, Gong S, Li C, Wang G, Cai L. Repetitive exposures to low-dose X-rays attenuate testicular apoptotic cell death in streptozotocin-induced diabetes rats. Toxicol Lett 2009; 192:356-64. [PMID: 19931367 DOI: 10.1016/j.toxlet.2009.11.011] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2009] [Revised: 11/06/2009] [Accepted: 11/09/2009] [Indexed: 11/17/2022]
Abstract
To define whether repetitive exposures to low-dose radiation (LDR) can attenuate diabetes-induced testicular cell death, Type 1 diabetic rats were produced by single injection of streptozotocin (STZ). Once hyperglycemia was diagnosed, diabetic rats were treated with and without LDR (25 and 50 mGy X-rays) daily for 4 weeks. Eight and 12 weeks after diabetes onset, testicular apoptotic cell death was examined by flow cytometry with Annexin V/PI staining, Western blotting assay for caspase-3 cleavage, and TUNEL staining for localization of apoptotic cells. Diabetes induced a significant increase in testicular apoptotic cell death, which was able to be attenuated by repetitive exposures to LDR. Diabetes-induced testicular cell death was associated with increased mitochondrial dysfunction, shown by the decreased mitochondrial potential and increased expressions of Bax mRNA and protein. All these changes were significantly attenuated in certain extends by repetitive exposures to LDR. To investigate the mechanisms by which LDR attenuates diabetes-induced testicular apoptotic cell death, serum sex hormone (testosterone, luteinizing hormone and follicle stimulating hormone) levels, and both serum and testicular oxidative damage (lipid peroxides) and antioxidant contents (superoxide dismutase, catalase and glutathione) were measured. Serum sex hormones were significantly decreased in diabetic rats, but not significantly in diabetic rats with multiple exposures to LDR; serum and testicular oxidative damage was significantly increased along with significant decreases in serum and testicular antioxidants in diabetic rats; however, these changes were significantly prevented by repetitive exposures to LDR. Furthermore, diabetic effects on the testicular oxidative damage and cell death were all attenuated by antioxidant N-acetylcysteine. These results suggest that diabetes-induced testicular cell death is probably mediated by increased oxidative stress. LDR protection from diabetes-induced testicular cell death is most likely mediated by its preserving antioxidants.
Collapse
Affiliation(s)
- Hongguang Zhao
- Nuclear Medicine, The First Hospital of Jilin University, Changchun, China
| | | | | | | | | | | | | | | | | | | |
Collapse
|
18
|
Xie Y, Zhang H, Wang YL, Zhou QM, Qiu R, Yuan ZG, Zhou GM. Alterations of immune functions induced by 12C6+ ion irradiation in mice. Int J Radiat Biol 2009; 83:577-81. [PMID: 17654099 DOI: 10.1080/09553000701481774] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
PURPOSE To estimate the biological risks to the immune system of the type of space radiation, 12C6+, encountered by cosmonauts during long-term travel in space. MATERIALS AND METHODS The Kun-Ming strain mice were whole-body irradiated by 12C6+ ion with 0, 0.01, 0.05, 0.075, 0.2, 0.3, 0.5, 0.75, 1 or 2 Gy, at a dose rate of 1 Gy/min. At 35 days after irradiation, the thymus and spleen weights were measured, the natural killer (NK) cells activity of spleen was determined by 3-(4, 5-dimethylthiazol-2-yl)- 2, 5-diphenyl tetrazolium bromide (MTT), and the interferon-gamma (IFN-gamma) levels in serum and thymus were detected with enzyme-linked immunosorbent assays (ELISA). RESULTS The results showed that the thymus weight, IFN-gamma levels in serum and the activity of splenic NK-cells had significantly increased at a dose of 0.05 Gy. With further dose increase, the weight of spleen continued to increase but the weight of thymus, IFN-gamma level and NK-cells activity declined. CONCLUSIONS These results suggest that the dose of 0.05 Gy irradiation has a stimulatory effect on mouse immunity; this effect declined with increasing dose.
Collapse
Affiliation(s)
- Y Xie
- Department of Radiology, Institute of Modern Physics, the Chinese Academy of Science, Lanzhou, Gansu Province, PR China
| | | | | | | | | | | | | |
Collapse
|
19
|
Shin SC, Kang YM, Jin YW, Kim HS. Relative morphological abnormalities of sperm in the caudal epididymis of high- and low-dose-rate gamma-irradiated ICR mice. JOURNAL OF RADIATION RESEARCH 2009; 50:261-266. [PMID: 19531924 DOI: 10.1269/jrr.09005] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
This study evaluated the effects of low dose radiation on spermatogenic cells using the morphological characteristics of sperm in the caudal epididymis of ICR mice. In this study, six abnormal sperm shapes (amorphous heads, blunt hooks, excessive hooks, two heads and tails, folded tails and short tails) were observed at eight days after gamma-irradiation ((137)Cs, 0, 0.2, 0.5, 1, 2 or 4 Gy) with both a high-dose-rate (0.8 Gy/min) and a low-dose-rate (0.7 mGy/hr). Fewer abnormal forms of sperm were observed in low-dose-rate irradiated mice than in mice that received a high-dose-rate irradiation (P = 0.002). The ratio of the dose rate effect among low-dose-rate irradiated mice to high-dose-rate irradiated mice was approximately 0.6. In addition, sperm with blunt hooks and two heads and tails significantly increased in number after irradiation, potentially providing an endpoint marker for estimating the effects of radiation. This study suggests that low-dose-rate (0.7 mGy/hr) radiation does not damage stem spermatogonia and probably stimulates repair in damaged spermatogonial stem cells in male mice.
Collapse
Affiliation(s)
- Suk Chul Shin
- Radiation Health Research Institute, Korea Hydro & Nuclear Power Co., Ltd., 388-1 Ssangmun-dong, Dobong-gu, Seoul, Korea
| | | | | | | |
Collapse
|
20
|
Liu G, Gong P, Bernstein LR, Bi Y, Gong S, Cai L. Apoptotic Cell Death Induced by Low-Dose Radiation in Male Germ Cells: Hormesis and Adaptation. Crit Rev Toxicol 2008; 37:587-605. [PMID: 17674213 DOI: 10.1080/10408440701493061] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
Abstract
Biological effects of low-dose radiation (LDR) in somatic cells have captured the interest of radiobiologists for the last two decades. Apoptosis of germ cells is required for normal spermatogenesis and often occurs through highly conserved events, including the transfer of vital cellular materials to the growing gametes following death of neighboring cells. Apoptosis of germ cells also functions in diverse processes, including removal of abnormal or superfluous cells at specific checkpoints, establishment of caste differentiation, and individualization of gametes. Moreover, germ cells are very sensitive to radiation-induced genomic and cytological effects. Therefore, induction of germ-cell apoptosis has been observed in the testis of animals exposed to both high-dose radiation (HDR) and LDR. Exposure of male germ cells to LDR induces a stimulating effect, while exposure to HDR causes an inhibitory effect on the metabolism, antioxidant capacity, and proliferation and maturation of cells, a phenomenon termed hormesis. Preexposure to LDR also protects cells from subsequently HDR-induced genomic and cytological effects, a phenomenon termed adaptive response. This review describes the features of male germ-cell apoptosis. It reviews the evidence that LDR induces the hormesis and adaptive responses in the male germ cells in terms of apoptosis. This review also discusses the possible effects of LDR-induced apoptotic hormesis and adaptive response on the modulation of inheritable genomic damage caused by subsequent radiation exposure to male germ cells.
Collapse
Affiliation(s)
- Guangwei Liu
- Ministry of Health Radiobiology Research Unit, School of Public Health, Jilin University, Changchun, China
| | | | | | | | | | | |
Collapse
|
21
|
Jiang H, Xu Y, Li W, Ma K, Cai L, Wang G. Low-Dose Radiation Does Not Induce Proliferation in Tumor CellsIn VitroandIn Vivo. Radiat Res 2008; 170:477-87. [DOI: 10.1667/rr1132.1] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
|
22
|
Wang GJ, Li XK, Sakai K, Lu Cai. Low-dose radiation and its clinical implications: diabetes. Hum Exp Toxicol 2008; 27:135-42. [PMID: 18480138 DOI: 10.1177/0960327108090752] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Induction of hormesis and adaptive response by low-dose radiation (LDR) has been extensively indicated. Adaptive response induced by LDR was not only resistant to damage caused by a subsequently high-dose radiation, but also cross-resistant to other non-radiation challenges, such as chemicals. Mechanisms by which LDR induces the preventive effect on radiation- or chemical-induced tissue damage include induced or up-regulated expression of protective proteins, such as heat shock proteins and antioxidants. Since oxidative damage to tissues is a major pathogenesis of many human diseases including diabetes, this review will summarize the available data with an emphasis of the preventive effect of LDR on the development of diabetes and the therapeutic effect of LDR on diabetic cardiovascular complications. The available data indicated that pre-exposure of mice to LDR reduced the incidence of alloxan-induced diabetes, and also delayed the onset of hyperglycaemia in diabetes-prone non-obese diabetic mice. Experiments with animals indicated the effectively therapeutic effect of low-intensity or power laser (LIL or LPL) radiation on skin wound healing, which has stimulated clinical use of LIL to cure skin ulcer in diabetic patients. Mechanisms by which LDR prevents diabetes, though are unclear now, may include the induction of pancreatic antioxidants to prevent beta cell from oxidative damage and immunomodulation to preserve pancreatic function. For LIL therapeutic effect on diabetic wound healing, mechanisms may include its antioxidant action, immunomodulation, cell proliferation stimulation as well as improvement of systemic and wound-regional microcirculation. Therefore, although only a few studies indicating LDR prevention of the development of diabetes, many studies have demonstrated LDR, specifically LIL, therapeutic effectiveness of diabetic wound healing. These preliminary results are really encouraging for us to further pursue the clinical implication of LDT to diabetes-related areas.
Collapse
Affiliation(s)
- Guan-Jun Wang
- Department of Hematology and Oncology, The First University Hospital, Jilin University Medical College, Changchun 130021, People's Republic of China
| | | | | | | |
Collapse
|
23
|
Abstract
The genetic consequences resulting from environmental exposure to ionizing radiation have a significant impact on both radiation regulatory policies and the comprehension of the human health risks associated with radiation exposure. The primary objectives of the study were to assess 1) genotoxicity of exposure to radiation as a function of absorbed dose and dose rate, and 2) induction of a radio-adaptive response following a priming dose at varying dose rates. Results demonstrated that sub-acute environmental exposures of 10cGy gamma radiation resulted in indistinguishable levels of chromosomal damage as compared to controls. A radio-adaptive response was observed in all experimental groups, exposed to a subsequent acute challenge dose of 1.5 Gy, demonstrating that low dose rates of low energy transfer (LET) radiation are effective in reducing genetic damage from a subsequent acute low-LET radiation exposure. Furthermore, the data presented herein demonstrate a potential beneficial effect of sub-chronic exposure to low levels of low-LET radiation in an environmental setting and do not support the Linear No Threshold (LNT) hypothesis.
Collapse
Affiliation(s)
- Brenda E Rodgers
- Department of Biological Sciences, Center for Environmental Radiation Studies, Texas Tech University, Lubbock, TX 79409, USA.
| | | |
Collapse
|
24
|
Maguire P, Mothersill C, McClean B, Seymour C, Lyng FM. Modulation of radiation responses by pre-exposure to irradiated cell conditioned medium. Radiat Res 2007; 167:485-92. [PMID: 17388689 DOI: 10.1667/rr0159.1] [Citation(s) in RCA: 58] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2006] [Accepted: 10/16/2006] [Indexed: 11/03/2022]
Abstract
The aim of this study was to investigate whether exposure of HPV-G cells to irradiated cell conditioned medium (ICCM) could induce an adaptive response if the cells were subsequently challenged with a higher ICCM dose. Clonogenic survival and major steps in the cascade leading to apoptosis, such as calcium influx and loss of mitochondrial membrane potential, were examined to determine whether these events could be modified by giving a priming dose of ICCM before the challenge dose. Clonogenic survival data indicated an ICCM-induced adaptive response in HPV-G cells "primed" with 5 mGy or 0.5 Gy ICCM for 24 h and then exposed to 0.5 Gy or 5 Gy ICCM. Reactive oxygen species (ROS) were found to be involved in the bystander-induced cell death. Calcium fluxes varied in magnitude across the exposed cell population, and a significant number of the primed HPV-G cells did not respond to the challenge ICCM dose. No significant loss of mitochondrial membrane potential was observed when HPV-G cells were exposed to 0.5 Gy ICCM for 24 h followed by exposure to 5 Gy ICCM for 6 h. Exposure of HPV-G cells to 5 mGy ICCM for 24 h followed by exposure to 0.5 Gy ICCM for 18 h caused a significant increase in mitochondrial mass and a change in mitochondrial location, events associated with the perpetuation of genomic instability. This study has shown that a priming dose of ICCM has the ability to induce an adaptive response in HPV-G cells subsequently exposed to a challenge dose of ICCM.
Collapse
Affiliation(s)
- Paula Maguire
- Radiation and Environmental Science Centre, Dublin Institute of Technology, Ireland.
| | | | | | | | | |
Collapse
|
25
|
Liu G, Gong P, Zhao H, Wang Z, Gong S, Cai L. Effect of low-level radiation on the death of male germ cells. Radiat Res 2006; 165:379-89. [PMID: 16579650 DOI: 10.1667/rr3528.1] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Hormetic and adaptive responses induced by low-level radiation in hematopoietic and immune systems have been observed, as shown by stimulatory effects on cell growth and resistance to subsequent radiation-induced cytogenetic damage. However, in terms of cell death by apoptosis, the effects of low-level radiation are controversial: Some studies showed decreased apoptosis in response to low-level radiation while others showed increased apoptosis. This controversy may be related to the radiation doses or dose rates and also, more importantly, to the cell types. Testes are one of the most radiosensitive organs. The loss of male germ cells after exposure to ionizing radiation has been attributed to apoptosis. In the present study, the effects of low-level radiation at doses up to 200 mGy on mouse male germ cells in terms of apoptosis and the expression of apoptosis-related proteins were examined at different times after whole-body exposure of mice to low-level radiation. In addition, the effect of pre-exposure to low-level radiation on subsequent cell death induced by high doses of radiation was examined to explore the possibility of low-level radiation-induced adaptive response. The results showed that low-level radiation in the dose range of 25-200 mGy induced significant increases in apoptosis in both spermatogonia and spermatocytes, with the maximal effect at 75 mGy. The increased apoptosis is most likely associated with Trp53 protein expression. Furthermore, 75 mGy low-level radiation given pre-irradiation led to an adaptive response of seminiferous germ cells to subsequent high-level radiation-induced apoptosis. These results suggest that low-level radiation induces increased apoptosis in male germ cells but also induces a significant adaptive response that decreases cell death after a subsequent high-dose irradiation.
Collapse
Affiliation(s)
- Guangwei Liu
- Ministry of Health Radiobiology Research Unit, School of Public Health, Jilin University, Changchun, China 130021
| | | | | | | | | | | |
Collapse
|
26
|
Klokov D, Criswell T, Leskov KS, Araki S, Mayo L, Boothman DA. IR-inducible clusterin gene expression: a protein with potential roles in ionizing radiation-induced adaptive responses, genomic instability, and bystander effects. Mutat Res 2005; 568:97-110. [PMID: 15530543 DOI: 10.1016/j.mrfmmm.2004.06.049] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2004] [Revised: 06/04/2004] [Accepted: 06/16/2004] [Indexed: 11/19/2022]
Abstract
Clusterin (CLU) plays numerous roles in mammalian cells after stress. A review of the recent literature strongly suggests potential roles for CLU proteins in low dose ionizing radiation (IR)-inducible adaptive responses, bystander effects, and delayed death and genomic instability. Its most striking and evident feature is the inducibility of the CLU promoter after low, as well as high, doses of IR. Two major forms of CLU, secreted (sCLU) and nuclear (nCLU), possess opposite functions in cellular responses to IR: sCLU is cytoprotective, whereas nCLU (a byproduct of alternative splicing) is a pro-death factor. Recent studies from our laboratory and others demonstrated that down-regulation of sCLU by specific siRNA increased cytotoxic responses to chemotherapy and IR. sCLU was induced after low non-toxic doses of IR (0.02-0.5 Gy) in human cultured cells and in mice in vivo. The low dose inducibility of this survival protein suggests a possible role for sCLU in radiation adaptive responses, characterized by increased cell radioresistance after exposure to low adapting IR doses. Although it is still unclear whether the adaptive response is beneficial or not to cells, survival of damaged cells after IR may lead to genomic instability in the descendants of surviving cells. Recent studies indicate a link between sCLU accumulation and cancer incidence, as well as aging, supporting involvement of the protein in the development of genomic instability. Secreted after IR, sCLU may also alter intracellular communication due to its ability to bind cell surface receptors, such as the TGF-beta receptors (types I and II). This interference with signaling pathways may contribute to IR-induced bystander effects. We hypothesize that activation of the TGF-beta signaling pathway, which often occurs after IR exposure, can in turn activate the CLU promoter. TGF-beta and IR-inducible de novo synthesized sCLU may then bind the TGF-beta receptors and suppress downstream growth arrest signaling. This complicated negative feedback regulation most certainly depends on the cellular microenvironment, but undoubtedly represents a potential link between IR-induced adaptive responses, genomic instability and bystander effects. Further elucidation of clusterin protein functions in IR responses are clearly warranted.
Collapse
Affiliation(s)
- Dmitry Klokov
- Laboratory of Molecular Stress Responses, Department of Radiation Oncology, Case Western Reserve University, 2103 Cornell Road, Wolstein Research Building 3-531, Cleveland, OH 44106-4942, USA
| | | | | | | | | | | |
Collapse
|
27
|
Li W, Wang G, Cui J, Xue L, Cai L. Low-dose radiation (LDR) induces hematopoietic hormesis: LDR-induced mobilization of hematopoietic progenitor cells into peripheral blood circulation. Exp Hematol 2005; 32:1088-96. [PMID: 15539087 DOI: 10.1016/j.exphem.2004.07.015] [Citation(s) in RCA: 71] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2003] [Revised: 07/14/2004] [Accepted: 07/21/2004] [Indexed: 01/13/2023]
Abstract
OBJECTIVE The aim of this study was to investigate the stimulating effect of low-dose radiation (LDR) on bone marrow hematopoietic progenitor cell (HPC) proliferation and peripheral blood mobilization. METHODS Mice were exposed to 25- to 100-mGy x-rays. Bone marrow and peripheral blood HPCs (BFU-E, CFU-GM, and c-kit+ cells) were measured, and GM-CSF, G-CSF, and IL-3 protein and mRNA expression were detected using ELISA, slot blot hybridization, and Northern blot methods. To functionally evaluate LDR-stimulated and -mobilized HPCs, repopulation of peripheral blood cells in lethally irradiated recipients after transplantation of LDR-treated donor HPCs was examined by WBC counts, animal survival, and colony-forming units in the recipient spleens (CFUs-S). RESULTS 75-mGy x-rays induced a maximal stimulation for bone marrow HPC proliferation (CFU-GM and BFU-E formation) 48 hours postirradiation, along with a significant increase in HPC mobilization into peripheral blood 48 to 72 hours postradiation, as shown by increases in CFU-GM formation and proportion of c-kit+ cells in the peripheral mononuclear cells. 75-mGy x-rays also maximally induced increases in G-CSF and GM-CSF mRNA expression in splenocytes and levels of serum GM-CSF. To define the critical role of these hematopoietic-stimulating factors in HPC peripheral mobilization, direct administration of G-CSF at a dose of 300 microg/kg/day or 150 microg/kg/day was applied and found to significantly stimulate GM-CFU formation and increase c-kit+ cells in the peripheral mononuclear cells. More importantly, 75-mGy x-rays plus 150 microg/kg/day G-CSF (LDR/150-G-CSF) produced a similar effect to that of 300 microg/kg/day G-CSF alone. Furthermore, the capability of LDR-mobilized donor HPCs to repopulate blood cells was confirmed in lethally irradiated recipient mice by counting peripheral WBC and CFUs-S. CONCLUSION These results suggest that LDR induces hematopoietic hormesis, as demonstrated by HPC proliferation and peripheral mobilization, providing a potential approach to clinical application for HPC peripheral mobilization.
Collapse
Affiliation(s)
- Wei Li
- Department of Hematology and Oncology, First University Hospital, PR China
| | | | | | | | | |
Collapse
|
28
|
Wang B, Ohyama H, Shang Y, Fujita K, Tanaka K, Nakajima T, Aizawa S, Yukawa O, Hayata I. Adaptive Response in Embryogenesis: IV. Protective and Detrimental Bystander Effects Induced by X Radiation in Cultured Limb Bud Cells of Fetal Mice. Radiat Res 2004; 161:9-16. [PMID: 14680401 DOI: 10.1667/rr3106] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The radioadaptive response and the bystander effect represent important phenomena in radiobiology that have an impact on novel biological response mechanisms and risk estimates. Micromass cultures of limb bud cells provide an in vitro cellular maturation system in which the progression of cell proliferation and differentiation parallels that in vivo. This paper presents for the first time evidence for the correlation and interaction in a micromass culture system between the radioadaptive response and the bystander effect. A radioadaptive response was induced in limb bud cells of embryonic day 11 ICR mice. Conditioning irradiation of the embryonic day 11 cells with 0.3 Gy resulted in a significant protective effect against the occurrence of apoptosis, inhibition of cell proliferation, and differentiation induced by a challenging dose of 5 Gy given the next day. Both protective and detrimental bystander effects were observed; namely, irradiating 50% of the embryonic day 11 cells with 0.3 Gy led to a successful induction of the protective effect, and irradiating 70% of the embryonic day 12 cells with 5 Gy produced a detrimental effect comparable to that seen when all the cells were irradiated. Further, the bystander effect was markedly decreased by pretreatment of the cells with an inhibitor to block the gap junction-mediated intercellular communication. These results indicate that the bystander effect plays an important role in both the induction of a protective effect by the conditioning dose and the detrimental effect of the challenge irradiation. Gap junction-mediated intercellular communication was suggested to be involved in the induction of the bystander effect.
Collapse
Affiliation(s)
- Bing Wang
- Radiation Hazards Research Group, Radiation Safety Research Center, National Institute of Radiological Sciences, Chiba 263-8555, Japan.
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Sorensen KJ, Attix CM, Christian AT, Wyrobek AJ, Tucker JD. Adaptive response induction and variation in human lymphoblastoid cell lines. Mutat Res 2002; 519:15-24. [PMID: 12160888 DOI: 10.1016/s1383-5718(02)00110-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Adaptive response is a term used to describe the ability of a low, priming dose of ionizing radiation to modify the effects of a subsequent higher, challenge dose, but it has been observed to be highly variable in both presence and magnitude. To examine this variability, 10 human lymphoblastoid cell lines were screened for adaptability to 137Cs radiation by determining the frequency of micronuclei in binucleated cells. Of these, six adapted, three did not adapt and one was synergistic. The assay was then repeated on each of the cell lines to test for reproducibility. Five cell lines showed the same result both times; four of these adapted and one did not. To determine whether fluctuations in the cell cycle distribution in the irradiated population of cells could alter the adaptive response, and therefore explain some of the observed variability, two of the cell lines were tested for adaptation after enriching the population, by synchronization, for a given cell cycle stage. In both cell lines, the direction of the response was altered when the distribution of cells within the cell cycle was changed, suggesting that the adaptive response can be affected by cell cycle stage at the time of irradiation.
Collapse
Affiliation(s)
- Karen J Sorensen
- Biology and Biotechnology Research Program, L-448 Lawrence Livermore National Laboratory, P.O. Box 808, 7000 East Ave., CA 94551-9900, USA.
| | | | | | | | | |
Collapse
|
30
|
Sasaki MS, Ejima Y, Tachibana A, Yamada T, Ishizaki K, Shimizu T, Nomura T. DNA damage response pathway in radioadaptive response. Mutat Res 2002; 504:101-18. [PMID: 12106651 DOI: 10.1016/s0027-5107(02)00084-2] [Citation(s) in RCA: 117] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Radioadaptive response is a biological defense mechanism in which low-dose ionizing irradiation elicits cellular resistance to the genotoxic effects of subsequent irradiation. However, its molecular mechanism remains largely unknown. We previously demonstrated that the dose recognition and adaptive response could be mediated by a feedback signaling pathway involving protein kinase C (PKC), p38 mitogen activated protein kinase (p38MAPK) and phospholipase C (PLC). Further, to elucidate the downstream effector pathway, we studied the X-ray-induced adaptive response in cultured mouse and human cells with different genetic background relevant to the DNA damage response pathway, such as deficiencies in TP53, DNA-PKcs, ATM and FANCA genes. The results showed that p53 protein played a key role in the adaptive response while DNA-PKcs, ATM and FANCA were not responsible. Wortmannin, a specific inhibitor of phosphatidylinositol 3-kinase (PI3K), mimicked the priming irradiation in that the inhibitor alone rendered the cells resistant against the induction of chromosome aberrations and apoptosis by the subsequent X-ray irradiation. The adaptive response, whether it was afforded by low-dose X-rays or wortmannin, occurred in parallel with the reduction of apoptotic cell death by challenging doses. The inhibitor of p38MAPK which blocks the adaptive response did not suppress apoptosis. These observations indicate that the adaptive response and apoptotic cell death constitute a complementary defense system via life-or-death decisions. The p53 has a pivotal role in channeling the radiation-induced DNA double-strand breaks (DSBs) into an adaptive legitimate repair pathway, where the signals are integrated into p53 by a circuitous PKC-p38MAPK-PLC damage sensing pathway, and hence turning off the signals to an alternative pathway to illegitimate repair and apoptosis. A possible molecular mechanism of adaptive response to low-dose ionizing irradiation has been discussed in relation to the repair of DSBs and implicated to the current controversial observations on the expression of adaptive response.
Collapse
Affiliation(s)
- Masao S Sasaki
- Radiation Biology Center, Kyoto University, Yoshida-konoecho, Sakyo-ku, Kyoto, Japan.
| | | | | | | | | | | | | |
Collapse
|
31
|
Cai L. Research of the adaptive response induced by low-dose radiation: where have we been and where should we go? Hum Exp Toxicol 1999; 18:419-25. [PMID: 10454070 DOI: 10.1191/096032799678840291] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- L Cai
- Department of Pathology, The University of Western Ontario, London, Canada
| |
Collapse
|
32
|
Olivieri G. Adaptive response and its relationship to hormesis and low dose cancer risk estimation. Hum Exp Toxicol 1999; 18:440-2. [PMID: 10454074 DOI: 10.1191/096032799678840336] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Affiliation(s)
- G Olivieri
- Instituto de Genetica, Dip. to Genetica e Biol Molec., Universita' di Roma La Sapienza, Italy
| |
Collapse
|
33
|
Cell-cycle perturbations following low-dose x-rays. Radiography (Lond) 1999. [DOI: 10.1016/s1078-8174(99)90039-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
|
34
|
Chen S, Cai L, Li X, Liu S. Low-dose whole-body irradiation induces alteration of protein expression in mouse splenocytes. Toxicol Lett 1999; 105:141-52. [PMID: 10221276 DOI: 10.1016/s0378-4274(98)00393-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
In previous studies, the stimulatory effect on immunological function and adaptive response in splenocytes were found after exposure of mice to low-dose whole-body irradiation (LD-WBI). Protein synthesis was found to be required for these responses. The present study, therefore, attempts to investigate the protein changes in mouse splenocytes after exposure to LD-WBI. Two-dimensional gel electrophoresis was used to show the alterations of proteins in nuclei, cytoplasm and extracellular fluid of the splenocytes at 4 h after mice exposed to 75 mGy X-rays. As compared to control, changed expressions of 20, 15 and 6 proteins, in sizes ranging from 10 to 69 kDa with pI of 5.0-8.2, were found in the nuclei, cytoplasm and extracellular fluid of splenocytes, respectively. One protein, shown in the cytoplasm of splenocytes of control mice, appeared in extracellular fluid of splenocytes after LD-WBI. Two proteins, shown in cytoplasm, and one protein, shown in extracellular fluid of splenocytes in control mice, appeared in the nuclei after LD-WBI. Time-course of protein synthesis varied in different proteins after LD-WBI. These results suggest that alterations of protein expressions and redistribution of proteins between intracellular and extracellular compartments occurred in the splenocytes after LD-WBI. Protein extract from LD-WBI splenocytes was fractionated by Sephadex G-100. Fractions 61-80 contained proteins able to protect lymphocytes in vitro from radiation-induced chromosome aberrations. These findings are of importance in elucidating mechanisms of immuno-enhancement and adaptive response induced by low-dose radiation. although the features and the functions of these proteins remain to be elucidated in future studies.
Collapse
Affiliation(s)
- S Chen
- Institute of Radiation Medicine, Norman Bethune University of Medical Sciences, Changchun, People's Republic of China
| | | | | | | |
Collapse
|
35
|
Cai L, Satoh M, Tohyama C, Cherian MG. Metallothionein in radiation exposure: its induction and protective role. Toxicology 1999; 132:85-98. [PMID: 10433372 DOI: 10.1016/s0300-483x(98)00150-4] [Citation(s) in RCA: 149] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Since its discovery about 40 years ago, there has been a wide interdisciplinary research interest in metallothionein (MT) on its physiological and toxicological aspects. Functionally, MT is involved not only in metal detoxification and homeostasis, but also in scavenging free radicals during oxidative damage. Among over 4500 publications which can be retrieved by Medline search, only about 50 reports have been published on the relationship of MT with ionizing and UV radiation. In this review, we have evaluated critically the published data on the induced synthesis of MT by radiation, and the potential functions of MT in radiation induced cell damage. MT mRNA expression or MT synthesis was found to be induced by exposure of cells in vitro or tissues in vivo to ionizing or UV radiation. In most of the studies in animals and tissue cultures, high doses of ionizing radiation were used to induce MT, and, therefore, it is difficult to extrapolate these results to low level of repeated exposures to radiation in humans. Induced synthesis of MT is considered as one of the mechanisms involved in the adaptive response to low dose radiation exposure. The presence of MT in normal cells may provide protective effects from radiation-induced genotoxicity and cytotoxicity. However, in tumor cells, the presence of MT can result in drug and radiation resistance as well. These effects are modulated by other cellular factors, besides MT, such as antioxidants, and by the cell cycle stages in cell proliferation and differentiation.
Collapse
Affiliation(s)
- L Cai
- Department of Pathology, The University of Western Ontario, London, Canada
| | | | | | | |
Collapse
|
36
|
Fleck CM, Schöllnberger H, Kottbauer MM, Dockal T, Prüfert U. Modeling radioprotective mechanisms in the dose effect relation at low doses and low dose rates of ionizing radiation. Math Biosci 1999; 155:13-44. [PMID: 10024833 DOI: 10.1016/s0025-5564(98)10053-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
A new model (Random Coincidence Model--Radiation Adapted (RCM-RA)) is proposed which explains a possible pseudo threshold for stochastic radiation effects. It describes the formation of cancer in the case of multistep fixation of lesions in the critical regions of tumor associated genes such as proto-oncogenes or tumor-suppressor genes. The RCM-RA contains two different possibilities of DNA damage to complementary nucleotides. The damage may be caused either by radiation or by natural processes such as cellular radicals or thermal damage or by chemical cytotoxins. The model is based on the premise that radiation initially is bionegative, damaging organisms at their different levels of organization. The radiation, however, also induces various cellular radioprotective mechanisms which decrease the damage by natural processes. Considering both effects together, the theory explains apparent thresholds in the dose-response relation for radiation carcinogenesis without contradiction to the classical assumption that radiation is predominantly bionegative at doses typically found in occupational exposures.
Collapse
Affiliation(s)
- C M Fleck
- Atominstitut der Osterreichischen Universitäten, Wien, Austria
| | | | | | | | | |
Collapse
|
37
|
Affiliation(s)
- S C Short
- Mount Vernon Hospital, Northwood, Middlesex, UK
| | | |
Collapse
|
38
|
Stecca C, Gerber GB. Adaptive response to DNA-damaging agents: a review of potential mechanisms. Biochem Pharmacol 1998; 55:941-51. [PMID: 9605418 DOI: 10.1016/s0006-2952(97)00448-6] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The study of the adaptive response, i.e. a reduced effect from a higher challenging dose of a stressor when a smaller inducing dose had been applied a few hours earlier, has opened many new vistas into the mechanisms by which cells can adapt to hazardous environments. Although the entire chain from the initial event, supposedly the presence of DNA damage, to the end effect, presumably improved DNA repair, has not been fully elucidated, many individual links have been postulated. Initial elements--following the still unknown signal for the presence of radiation damage--are various kinases (protein kinase C and stress-activated protein kinases), which, in turn, induce early response genes whose products initiate a cascade of protein-DNA interactions that regulate gene transcription and ultimately result in specific biological responses. These responses include the activation of later genes that can promote production of growth factors and cytokines, trigger DNA repair, and regulate progress through the cell cycle. Indeed, there appears to be a relation between the induction of the adaptive response and the effects of radiation and cytostatic agents on the cell cycle, although these effects, especially the G1 delay, occur at much higher doses than the adaptive response, and one may not indiscriminately extrapolate mechanisms responsible for cell cycle changes observed at high doses, e.g. for radiation in the order of grays, to those involved in the adaptive responses at much lower doses, i.e. some tens of milligrays.
Collapse
Affiliation(s)
- C Stecca
- Teratogenicity and Mutagenicity Unit, Catholic University of Louvain, Brussels, Belgium.
| | | |
Collapse
|
39
|
Cong XL, Wang XL, Su Q, Yan S, Cai L. Protective effects of extracted human-liver RNA, a known interferon inducer, against radiation-induced cytogenetic damage in male mice. Toxicol Lett 1998; 94:189-98. [PMID: 9609322 DOI: 10.1016/s0378-4274(98)00007-1] [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: 02/07/2023]
Abstract
Cells in vitro or in vivo pre-exposed to low-dose radiation (LDR) or low concentrations of chemical mutagens became more resistant to large-dose radiation-induced DNA or chromosome damage. This was known as radio-adaptive response, for which the exact mechanism was unclear. However, multiple cellular and molecular responses to LDR have been documented, for instance, the induction of some cytokines such as interferon (IFN). Administration of exogenous IFN to cultured cells or mice showed marked radio-protection. In the present study, we investigated the in vivo radio-protective effects of extracted human liver RNA (HL-RNA), a known IFN inducer, indirectly to determine the radio-protective action of endogenous IFN. First, mice were administered with 6.25 mg/kg HL-RNA at different times before exposure to radiation and the 24 h pretreatment offered the optimal protective action for HL-RNA on cytogenetic effects in bone marrow cells. When the mice were treated with different concentrations of HL-RNA for 24 h, a wide dose-range (25-100 mg/kg) of HL-RNA resulted in a marked protection from X-ray-induced chromosome aberrations in both bone marrow cells and germ cells. In subsequent experiments, a protective effect of pretreatment with 25 mg/kg HL-RNA for 24 h was also found for radiation-induced micronuclei in polychromatic erythrocytes (PCE), and inhibition of DNA repair ability (unscheduled DNA synthesis, UDS). These results demonstrated that HL-RNA, an IFN inducer, is able to offer significant cytogenetic protection from radiation, implying indirectly that the induction of IFN by LDR may also play a protective role as one of the mechanisms in the induction of the cytogenetic adaptive response.
Collapse
Affiliation(s)
- X L Cong
- Institute of Radiation Medicine, Norman Bethune University of Medical Sciences, Changchun, PR China
| | | | | | | | | |
Collapse
|