1
|
Bhagi S, Chandna S. A simplified protocol for gene expression-based biological dosimetry using peripheral whole blood. Int J Radiat Biol 2023; 99:1692-1701. [PMID: 37436720 DOI: 10.1080/09553002.2023.2231531] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 06/08/2023] [Indexed: 07/13/2023]
Abstract
PURPOSE Assessing alterations in the expression of radiation-responsive genes in peripheral blood cells is considered a promising approach for high-throughput radiation biodosimetry. However, optimization of conditions for storage and transport of blood samples would be critical for obtaining reliable results. Recent studies involved the incubation of isolated peripheral blood mononuclear cells (in cell culture medium) and/or use of RNA stabilizing agents for sample storage, immediately after the ex vivo irradiation of whole blood. We used a simpler protocol by incubating undiluted peripheral whole blood without any RNA stabilizing agent, and studied the impact of storage temperature and incubation time on the expression levels of 19 known radiation responsive genes. MATERIALS & METHODS Peripheral whole blood was γ-irradiated ex vivo at room temperature at low (0.5 Gy), moderate (1 Gy, 2 Gy) and high (4 Gy) doses and immediately incubated at two different temperatures at 4 °C or 37 °C for 2h, 4h and 24 h. Using qRT-PCR, mRNA expression levels of CDKN1A, DDB2, GADD45A, FDXR, BAX, BBC3, MYC, PCNA, XPC, ZMAT3, AEN, TRIAP1, CCNG1, RPS27L, CD70, EI24, C12orf5, TNFRSF10B, ASCC3 were analyzed at respective time-points and compared with the sham-irradiated controls. RESULTS Transcriptional responses of all 19 genes did not alter significantly upon incubation of whole blood samples at 4 °C, as compared to untreated controls. However, incubation at 37 °C for 24 h resulted in significant radiation-induced overexpression in 14 out of the 19 genes analyzed (except CDKN1A, BBC3, MYC, CD 70 and EI24). Detailed patterns during incubation at 37 °C revealed time-dependent up-regulation of these genes, with DDB2 and FDXR showing significant up-regulation both at 4 and 24 h with the highest fold-change observed. CONCLUSION Overall, the undiluted whole blood incubated at 37 °C for 24 h was found to elicit most optimal transcriptional response in the genes studied, with most profound overexpression of DDB2 and FDXR. We propose that sample storage/transport/post-transit incubation at the physiological temperature for up to 24 h may enhance the sensitivity of gene expression based biodosimetry and facilitate its usage for triage application.
Collapse
Affiliation(s)
- Shuchi Bhagi
- Division of Molecular & Radiation Biosciences, Institute of Nuclear Medicine & Allied Sciences (INMAS), Defence Research & Development Organization (DRDO), Brig SK Mazumdar Marg, Delhi, 110054, India
| | - Sudhir Chandna
- Division of Molecular & Radiation Biosciences, Institute of Nuclear Medicine & Allied Sciences (INMAS), Defence Research & Development Organization (DRDO), Brig SK Mazumdar Marg, Delhi, 110054, India
| |
Collapse
|
2
|
Cerri M, Hitrec T, Luppi M, Amici R. Be cool to be far: Exploiting hibernation for space exploration. Neurosci Biobehav Rev 2021; 128:218-232. [PMID: 34144115 DOI: 10.1016/j.neubiorev.2021.03.037] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Revised: 03/23/2021] [Accepted: 03/26/2021] [Indexed: 01/08/2023]
Abstract
In mammals, torpor/hibernation is a state that is characterized by an active reduction in metabolic rate followed by a progressive decrease in body temperature. Torpor was successfully mimicked in non-hibernators by inhibiting the activity of neurons within the brainstem region of the Raphe Pallidus, or by activating the adenosine A1 receptors in the brain. This state, called synthetic torpor, may be exploited for many medical applications, and for space exploration, providing many benefits for biological adaptation to the space environment, among which an enhanced protection from cosmic rays. As regards the use of synthetic torpor in space, to fully evaluate the degree of physiological advantage provided by this state, it is strongly advisable to move from Earth-based experiments to 'in the field' tests, possibly on board the International Space Station.
Collapse
Affiliation(s)
- Matteo Cerri
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum -University of Bologna, Piazza di Porta S.Donato, 2 40126, Bologna, Italy.
| | - Timna Hitrec
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum -University of Bologna, Piazza di Porta S.Donato, 2 40126, Bologna, Italy.
| | - Marco Luppi
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum -University of Bologna, Piazza di Porta S.Donato, 2 40126, Bologna, Italy.
| | - Roberto Amici
- Department of Biomedical and NeuroMotor Sciences, Alma Mater Studiorum -University of Bologna, Piazza di Porta S.Donato, 2 40126, Bologna, Italy.
| |
Collapse
|
3
|
Nasser F, Cruz-Garcia L, O'Brien G, Badie C. Role of blood derived cell fractions, temperature and sample transport on gene expression-based biological dosimetry. Int J Radiat Biol 2021; 97:675-686. [PMID: 33826469 DOI: 10.1080/09553002.2021.1906464] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2020] [Revised: 03/05/2021] [Accepted: 03/10/2021] [Indexed: 02/06/2023]
Abstract
PURPOSE For triage purposes following a nuclear accident or a terrorist event, gene expression biomarkers in blood have been demonstrated to be good bioindicators of ionizing radiation (IR) exposure and can be used to assess the dose received by exposed individuals. Many IR-sensitive genes are regulated by the DNA damage response pathway, and modulators of this pathway could potentially affect their expression level and therefore alter accurate dose estimations. In the present study, we addressed the potential influence of temperature, sample transport conditions and the blood cell fraction analyzed on the transcriptional response of the following radiation-responsive genes: FDXR, CCNG1, MDM2, PHPT1, APOBEC3H, DDB2, SESN1, P21, PUMA, and GADD45. MATERIALS AND METHODS Whole blood from healthy donors was exposed to a 2 Gy X-ray dose with a dose rate of 0.5 Gy/min (output 13 mA, 250 kV peak, 0.2 mA) and incubated for 24 h at either 37, 22, or 4 °C. For mimicking the effect of transport conditions at different temperatures, samples incubated at 37 °C for 24 h were kept at 37, 22 or 4 °C for another 24 h. Comparisons of biomarker responses to IR between white blood cells (WBCs), peripheral blood mononuclear cells (PBMCs) and whole blood were carried out after a 2 Gy X-ray exposure and incubation at 37 °C for 24 hours. RESULTS Hypothermic conditions (22 or 4 °C) following irradiation drastically inhibited transcriptional responses to IR exposure. However, sample shipment at different temperatures did not affect gene expression level except for SESN1. The transcriptional response to IR of specific genes depended on the cell fraction used, apart from FDXR, CCNG1, and SESN1. CONCLUSION In conclusion, temperature during the incubation period and cell fraction but not the storing conditions during transport can influence the transcriptional response of specific genes. However, FDXR and CCNG1 showed a consistent response under all the different conditions tested demonstrating their reliability as individual biological dosimetry biomarkers.
Collapse
Affiliation(s)
- Farah Nasser
- Radiation Effects Department, Cancer Mechanisms and Biomarkers Group, Centre for Radiation, Chemical & Environmental Hazards, Public Health England, Chilton, Oxfordshire, United Kingdom
| | - Lourdes Cruz-Garcia
- Radiation Effects Department, Cancer Mechanisms and Biomarkers Group, Centre for Radiation, Chemical & Environmental Hazards, Public Health England, Chilton, Oxfordshire, United Kingdom
| | - Grainne O'Brien
- Radiation Effects Department, Cancer Mechanisms and Biomarkers Group, Centre for Radiation, Chemical & Environmental Hazards, Public Health England, Chilton, Oxfordshire, United Kingdom
| | - Christophe Badie
- Radiation Effects Department, Cancer Mechanisms and Biomarkers Group, Centre for Radiation, Chemical & Environmental Hazards, Public Health England, Chilton, Oxfordshire, United Kingdom
| |
Collapse
|
4
|
Dias IB, Bouma HR, Henning RH. Unraveling the Big Sleep: Molecular Aspects of Stem Cell Dormancy and Hibernation. Front Physiol 2021; 12:624950. [PMID: 33867999 PMCID: PMC8047423 DOI: 10.3389/fphys.2021.624950] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Accepted: 03/11/2021] [Indexed: 12/14/2022] Open
Abstract
Tissue-resident stem cells may enter a dormant state, also known as quiescence, which allows them to withstand metabolic stress and unfavorable conditions. Similarly, hibernating mammals can also enter a state of dormancy used to evade hostile circumstances, such as food shortage and low ambient temperatures. In hibernation, the dormant state of the individual and its cells is commonly known as torpor, and is characterized by metabolic suppression in individual cells. Given that both conditions represent cell survival strategies, we here compare the molecular aspects of cellular quiescence, particularly of well-studied hematopoietic stem cells, and torpor at the cellular level. Critical processes of dormancy are reviewed, including the suppression of the cell cycle, changes in metabolic characteristics, and cellular mechanisms of dealing with damage. Key factors shared by hematopoietic stem cell quiescence and torpor include a reversible activation of factors inhibiting the cell cycle, a shift in metabolism from glucose to fatty acid oxidation, downregulation of mitochondrial activity, key changes in hypoxia-inducible factor one alpha (HIF-1α), mTOR, reversible protein phosphorylation and autophagy, and increased radiation resistance. This similarity is remarkable in view of the difference in cell populations, as stem cell quiescence regards proliferating cells, while torpor mainly involves terminally differentiated cells. A future perspective is provided how to advance our understanding of the crucial pathways that allow stem cells and hibernating animals to engage in their 'great slumbers.'
Collapse
Affiliation(s)
- Itamar B. Dias
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Hjalmar R. Bouma
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
- Department of Internal Medicine, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| | - Robert H. Henning
- Department of Clinical Pharmacy and Pharmacology, University Medical Center Groningen, University of Groningen, Groningen, Netherlands
| |
Collapse
|
5
|
Shi Z, Qin M, Huang L, Xu T, Chen Y, Hu Q, Peng S, Peng Z, Qu LN, Chen SG, Tuo QH, Liao DF, Wang XP, Wu RR, Yuan TF, Li YH, Liu XM. Human torpor: translating insights from nature into manned deep space expedition. Biol Rev Camb Philos Soc 2020; 96:642-672. [PMID: 33314677 DOI: 10.1111/brv.12671] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 11/09/2020] [Accepted: 11/17/2020] [Indexed: 12/12/2022]
Abstract
During a long-duration manned spaceflight mission, such as flying to Mars and beyond, all crew members will spend a long period in an independent spacecraft with closed-loop bioregenerative life-support systems. Saving resources and reducing medical risks, particularly in mental heath, are key technology gaps hampering human expedition into deep space. In the 1960s, several scientists proposed that an induced state of suppressed metabolism in humans, which mimics 'hibernation', could be an ideal solution to cope with many issues during spaceflight. In recent years, with the introduction of specific methods, it is becoming more feasible to induce an artificial hibernation-like state (synthetic torpor) in non-hibernating species. Natural torpor is a fascinating, yet enigmatic, physiological process in which metabolic rate (MR), body core temperature (Tb ) and behavioural activity are reduced to save energy during harsh seasonal conditions. It employs a complex central neural network to orchestrate a homeostatic state of hypometabolism, hypothermia and hypoactivity in response to environmental challenges. The anatomical and functional connections within the central nervous system (CNS) lie at the heart of controlling synthetic torpor. Although progress has been made, the precise mechanisms underlying the active regulation of the torpor-arousal transition, and their profound influence on neural function and behaviour, which are critical concerns for safe and reversible human torpor, remain poorly understood. In this review, we place particular emphasis on elaborating the central nervous mechanism orchestrating the torpor-arousal transition in both non-flying hibernating mammals and non-hibernating species, and aim to provide translational insights into long-duration manned spaceflight. In addition, identifying difficulties and challenges ahead will underscore important concerns in engineering synthetic torpor in humans. We believe that synthetic torpor may not be the only option for manned long-duration spaceflight, but it is the most achievable solution in the foreseeable future. Translating the available knowledge from natural torpor research will not only benefit manned spaceflight, but also many clinical settings attempting to manipulate energy metabolism and neurobehavioural functions.
Collapse
Affiliation(s)
- Zhe Shi
- National Clinical Research Center for Mental Disorders, and Department of Psychaitry, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China.,Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China.,State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China.,Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, 200030, China
| | - Meng Qin
- College of Life Science and Technology, Beijing University of Chemical Technology, Beijing, 100029, China
| | - Lu Huang
- Guangdong-Hongkong-Macau Institute of CNS Regeneration, Ministry of Education CNS Regeneration Collaborative Joint Laboratory, Jinan University, Guangzhou, 510632, China
| | - Tao Xu
- Department of Anesthesiology, Shanghai Jiao Tong University Affiliated Sixth People's Hospital, Shanghai, 200233, China
| | - Ying Chen
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, 100700, China
| | - Qin Hu
- College of Life Sciences and Bio-Engineering, Beijing University of Technology, Beijing, 100024, China
| | - Sha Peng
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Zhuang Peng
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Li-Na Qu
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Shan-Guang Chen
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Qin-Hui Tuo
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Duan-Fang Liao
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China
| | - Xiao-Ping Wang
- National Clinical Research Center for Mental Disorders, and Department of Psychaitry, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China
| | - Ren-Rong Wu
- National Clinical Research Center for Mental Disorders, and Department of Psychaitry, The Second Xiangya Hospital of Central South University, Changsha, Hunan, 410011, China
| | - Ti-Fei Yuan
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiaotong University School of Medicine, Shanghai, 200030, China.,Co-innovation Center of Neuroregeneration, Nantong University, Nantong, 226000, China
| | - Ying-Hui Li
- State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China
| | - Xin-Min Liu
- Key Laboratory for Quality Evaluation of Bulk Herbs of Hunan Province, Hunan University of Chinese Medicine, Changsha, Hunan, 410208, China.,State Key Laboratory of Space Medicine Fundamentals and Application, China Astronaut Research and Training Center, Beijing, 100094, China.,Research Center for Pharmacology and Toxicology, Institute of Medicinal Plant Development (IMPLAD), Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing, 100193, China
| |
Collapse
|
6
|
The Effect of Low Temperatures on Environmental Radiation Damage in Living Systems: Does Hypothermia Show Promise for Space Travel? Int J Mol Sci 2020; 21:ijms21176349. [PMID: 32882991 PMCID: PMC7504535 DOI: 10.3390/ijms21176349] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2020] [Revised: 08/31/2020] [Accepted: 08/31/2020] [Indexed: 12/23/2022] Open
Abstract
Low-temperature treatments (i.e., hypothermia) may be one way of regulating environmental radiation damage in living systems. With this in mind, hibernation under hypothermic conditions has been proposed as a useful approach for long-term human space flight. However, the underlying mechanisms of hypothermia-induced radioresistance are as yet undetermined, and the conventional risk assessment of radiation exposure during hibernation remains insufficient for estimating the effects of chronic exposure to galactic cosmic rays (GCRs). To promote scientific discussions on the application of hibernation in space travel, this literature review provides an overview of the progress to date in the interdisciplinary research field of radiation biology and hypothermia and addresses possible issues related to hypothermic treatments as countermeasures against GCRs. At present, there are concerns about the potential effects of chronic radiation exposure on neurological disorders, carcinogenesis, ischemia heat failures, and infertility in astronauts; these require further study. These concerns may be resolved by comparing and integrating data gleaned from experimental and epidemiological studies.
Collapse
|
7
|
Wilbur SM, Barnes BM, Kitaysky AS, Williams CT. Tissue-specific telomere dynamics in hibernating arctic ground squirrels ( Urocitellus parryii). ACTA ACUST UNITED AC 2019; 222:jeb.204925. [PMID: 31515236 DOI: 10.1242/jeb.204925] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2019] [Accepted: 09/03/2019] [Indexed: 01/25/2023]
Abstract
Hibernation is used by a variety of mammals to survive seasonal periods of resource scarcity. Reactive oxygen species (ROS) released during periodic rewarming throughout hibernation, however, may induce oxidative damage in some tissues. Telomeres, which are the terminal sequences of linear chromosomes, may shorten in the presence of ROS, and thus the telomere length of an individual reflects the degree of accrued oxidative damage. This study quantified telomere length dynamics throughout hibernation in arctic ground squirrels (Urocitellus parryii). We hypothesized that telomere dynamics are tissue specific and predicted that telomere shortening would be most pronounced in brown adipose tissue (BAT), the organ that directly supports non-shivering thermogenesis during arousals. We used qPCR to determine relative telomere length (RTL) in DNA extracted from liver, heart, skeletal muscle (SM) and BAT of 45 juvenile and adult animals sampled either at mid- or late hibernation. Age did not have a significant effect on RTL in any tissue. At mid-hibernation, RTL of juvenile females was longer in BAT and SM than in liver and heart. In juvenile females, RTL in BAT and SM, but not in liver and heart, was shorter at late hibernation than at mid-hibernation. At late hibernation, juvenile males had longer RTL in BAT than did juvenile females, perhaps due to the naturally shorter hibernation duration of male arctic ground squirrels. Finally, BAT RTL at late hibernation negatively correlated with arousal frequency. Overall, our results suggest that, in a hibernating mammal, telomere shortening is tissue specific and that metabolically active tissues might incur higher levels of molecular damage.
Collapse
Affiliation(s)
- Sara M Wilbur
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Brian M Barnes
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Alexander S Kitaysky
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| | - Cory T Williams
- Institute of Arctic Biology, University of Alaska Fairbanks, Fairbanks, AK 99775, USA
| |
Collapse
|
8
|
Hibernation and Radioprotection: Gene Expression in the Liver and Testicle of Rats Irradiated under Synthetic Torpor. Int J Mol Sci 2019; 20:ijms20020352. [PMID: 30654467 PMCID: PMC6359347 DOI: 10.3390/ijms20020352] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2018] [Revised: 12/23/2018] [Accepted: 01/11/2019] [Indexed: 01/02/2023] Open
Abstract
Hibernation has been proposed as a tool for human space travel. In recent years, a procedure to induce a metabolic state known as “synthetic torpor” in non-hibernating mammals was successfully developed. Synthetic torpor may not only be an efficient method to spare resources and reduce psychological problems in long-term exploratory-class missions, but may also represent a countermeasure against cosmic rays. Here we show the preliminary results from an experiment in rats exposed to ionizing radiation in normothermic conditions or synthetic torpor. Animals were irradiated with 3 Gy X-rays and organs were collected 4 h after exposure. Histological analysis of liver and testicle showed a reduced toxicity in animals irradiated in torpor compared to controls irradiated at normal temperature and metabolic activity. The expression of ataxia telangiectasia mutated (ATM) in the liver was significantly downregulated in the group of animal in synthetic torpor. In the testicle, more genes involved in the DNA damage signaling were downregulated during synthetic torpor. These data show for the first time that synthetic torpor is a radioprotector in non-hibernators, similarly to natural torpor in hibernating animals. Synthetic torpor can be an effective strategy to protect humans during long term space exploration of the solar system.
Collapse
|
9
|
Abramenkovs A, Stenerlöw B. Removal of heat-sensitive clustered damaged DNA sites is independent of double-strand break repair. PLoS One 2018; 13:e0209594. [PMID: 30592737 PMCID: PMC6310273 DOI: 10.1371/journal.pone.0209594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 12/07/2018] [Indexed: 11/21/2022] Open
Abstract
DNA double-strand breaks (DSBs) are the most deleterious lesions that can arise in cells after ionizing radiation or radiometric drug treatment. In addition to prompt DSBs, DSBs may also be produced during repair, evolving from a clustered DNA damaged site, which is composed of two or more distinct lesions that are located within two helical turns. A specific type of cluster damage is the heat-sensitive clustered site (HSCS), which transforms into DSBs upon treatment at elevated temperatures. The actual lesions or mechanisms that mediate the HSCS transformation into DSBs are unknown. However, there are two possibilities; either these lesions are transformed into DSBs due to DNA lesion instability, e.g., transfer of HSCS into single-strand breaks (SSBs), or they are formed due to local DNA structure instability, e.g., DNA melting, where two SSBs on opposite strands meet and transform into a DSB. The importance of these processes in living cells is not understood, but they significantly affect estimates of DSB repair capacity. In this study, we show that HSCS removal in human cells is not affected by defects in DSB repair or inhibition of DSB repair. Under conditions where rejoining of prompt DSBs was almost completely inhibited, heat-sensitive DSBs were successfully rejoined, without resulting in increased DSB levels, indicating that HSCS do not transfer into DSB in cells under physiological conditions. Furthermore, analysis by atomic force microscopy suggests that prolonged heating of chromosomal DNA can induce structural changes that facilitate transformation of HSCS into DSB. In conclusion, the HSCS do not generate additional DSBs at physiological temperatures in human cells, and the repair of HSCS is independent of DSB repair.
Collapse
Affiliation(s)
- Andris Abramenkovs
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| | - Bo Stenerlöw
- Department of Immunology, Genetics and Pathology, Rudbeck Laboratory, Uppsala University, Uppsala, Sweden
| |
Collapse
|
10
|
Griko Y, Regan MD. Synthetic torpor: A method for safely and practically transporting experimental animals aboard spaceflight missions to deep space. LIFE SCIENCES IN SPACE RESEARCH 2018; 16:101-107. [PMID: 29475515 DOI: 10.1016/j.lssr.2018.01.002] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Revised: 01/09/2018] [Accepted: 01/11/2018] [Indexed: 06/08/2023]
Abstract
Animal research aboard the Space Shuttle and International Space Station has provided vital information on the physiological, cellular, and molecular effects of spaceflight. The relevance of this information to human spaceflight is enhanced when it is coupled with information gleaned from human-based research. As NASA and other space agencies initiate plans for human exploration missions beyond low Earth orbit (LEO), incorporating animal research into these missions is vitally important to understanding the biological impacts of deep space. However, new technologies will be required to integrate experimental animals into spacecraft design and transport them beyond LEO in a safe and practical way. In this communication, we propose the use of metabolic control technologies to reversibly depress the metabolic rates of experimental animals while in transit aboard the spacecraft. Compared to holding experimental animals in active metabolic states, the advantages of artificially inducing regulated, depressed metabolic states (called synthetic torpor) include significantly reduced mass, volume, and power requirements within the spacecraft owing to reduced life support requirements, and mitigated radiation- and microgravity-induced negative health effects on the animals owing to intrinsic physiological properties of torpor. In addition to directly benefitting animal research, synthetic torpor-inducing systems will also serve as test beds for systems that may eventually hold human crewmembers in similar metabolic states on long-duration missions. The technologies for inducing synthetic torpor, which we discuss, are at relatively early stages of development, but there is ample evidence to show that this is a viable idea and one with very real benefits to spaceflight programs. The increasingly ambitious goals of world's many spaceflight programs will be most quickly and safely achieved with the help of animal research systems transported beyond LEO; synthetic torpor may enable this to be done as practically and inexpensively as possible.
Collapse
Affiliation(s)
- Yuri Griko
- NASA Ames Research Center, Moffett Field, CA 94035, United States.
| | - Matthew D Regan
- University of Wisconsin-Madison, School of Veterinary Medicine, Madison, WI 53706, United States
| |
Collapse
|
11
|
Sabel M, Kalm M, Björk-Eriksson T, Lannering B, Blomgren K. Hypothermia after cranial irradiation protects neural progenitor cells in the subventricular zone but not in the hippocampus. Int J Radiat Biol 2017; 93:771-783. [PMID: 28452566 DOI: 10.1080/09553002.2017.1321810] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
PURPOSE To explore if hypothermia can reduce the harmful effects of ionizing radiation on the neurogenic regions of the brain in young rats. MATERIALS AND METHODS Postnatal day 9 rats were randomized into two treatment groups, hypo- and normothermia, or a control group. Treatment groups were placed in chambers submerged in temperature-controlled water baths (30 °C and 36 °C) for 8 h, after receiving a single fraction of 8 Gy to the left hemisphere. Seven days' post-irradiation, we measured the sizes of the subventricular zone (SVZ) and the granule cell layer (GCL) of the hippocampus, and counted the number of proliferating (phospho-histone H3+) cells and microglia (Iba1 + cells). RESULTS Irradiation caused a 53% reduction in SVZ size in the normothermia group compared to controls, as well as a reduction of proliferating cell numbers by >50%. These effects were abrogated in the hypothermia group. Irradiation reduced the number of microglia in both treatment groups, but resulted in a lower cell density of Iba1 + cells in the SVZs of the hypothermia group. In the GCL, irradiation decreased both GCL size and the proliferating cell numbers, but with no difference between the treatment groups. The number of microglia in the GCL did not change. CONCLUSIONS Hypothermia immediately after irradiation protects the SVZ and its proliferative cell population but the GCL is not protected, one week post-irradiation.
Collapse
Affiliation(s)
- Magnus Sabel
- a Department of Pediatrics , Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden.,b Childhood Cancer Centre , Queen Silvia Children's Hospital , Gothenburg , Sweden
| | - Marie Kalm
- c Department of Pharmacology , Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden
| | - Thomas Björk-Eriksson
- d Regional Cancer Centre west , Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden
| | - Birgitta Lannering
- a Department of Pediatrics , Institute of Clinical Sciences, Sahlgrenska Academy, University of Gothenburg , Gothenburg , Sweden.,b Childhood Cancer Centre , Queen Silvia Children's Hospital , Gothenburg , Sweden
| | - Klas Blomgren
- e Department of Women's and Children's Health , Karolinska Institutet , Stockholm , Sweden.,f Department of Pediatric Oncology , Karolinska University Hospital , Stockholm , Sweden
| |
Collapse
|
12
|
Hrycushko BA, Bing C, Futch C, Wodzak M, Stojadinovic S, Medin PM, Chopra R. Technical Note: System for evaluating local hypothermia as a radioprotector of the rectum in a small animal model. Med Phys 2017; 44:3932-3938. [PMID: 28513855 DOI: 10.1002/mp.12353] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2017] [Revised: 03/26/2017] [Accepted: 05/08/2017] [Indexed: 11/10/2022] Open
Abstract
PURPOSE The protective effects of induced or even accidental hypothermia on the human body are widespread with several medical uses currently under active research. In vitro experiments using human cell lines have shown hypothermia provides a radioprotective effect that becomes more pronounced at large, single-fraction doses common to stereotactic body radiotherapy (SBRT) and stereotactic radiosurgery (SRS) treatments. This work describes the development of a system to evaluate local hypothermia for a radioprotective effect of the rat rectum during a large dose of radiation relevant to prostate SBRT. This includes the evaluation of a 3D-printed small animal rectal cooling device and the integration with a small animal irradiator. METHODS A 3-cm long, dual-lumen rectal temperature control apparatus (RTCA) was designed in SOLIDWORKS CAD for 3D printing. The RTCA was capable of recirculating flow in a device small enough for insertion into the rat rectum, with a metal support rod for strength as well as visibility during radiation treatment planning. The outer walls of the RTCA comprised of thin heat shrink plastic, achieving efficient heat transfer into adjacent tissues. Following leak-proof testing, fiber optic temperature probes were used to evaluate the temperature over time when placed adjacent to the cooling device within the rat rectum. MRI thermometry characterized the relative temperature distribution in concentric ROIs surrounding the probe. Integration with an image-guided small animal irradiator and associated treatment planning system included evaluation for imaging artifacts and effect of brass tubing on dose calculation. RESULTS The rectal temperature adjacent to the cooling device decreased from body temperature to 15°C within 10-20 min from device insertion and was maintained at 15 ± 3°C during active cooling for the evaluated time of one hour. MR thermometry revealed a steep temperature gradient with increasing distance from the cooling device with the desired temperature range maintained within the surrounding few millimeters. CONCLUSIONS A 3D-printed rectal cooling device was fabricated for the purpose of inducing local hypothermia in the rat rectum. The RTCA was simply integrated with an image-guided small animal irradiator and Monte Carlo-based treatment planning system to facilitate an in vivo investigation of the radioprotective effect of hypothermia for late rectal toxicity following a single large dose of radiation.
Collapse
Affiliation(s)
- Brian A Hrycushko
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Chenchen Bing
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Cecil Futch
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Michelle Wodzak
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA
| | | | - Paul M Medin
- Department of Radiation Oncology, UT Southwestern Medical Center, Dallas, TX, USA
| | - Rajiv Chopra
- Department of Radiology, UT Southwestern Medical Center, Dallas, TX, USA.,Advanced Imaging Research Center, UT Southwestern Medical Center, Dallas, TX, USA
| |
Collapse
|
13
|
Hrycushko BA, Chopra R, Sayre JW, Richardson JA, Folkert MR, Timmerman RD, Medin PM. Local Hypothermia as a Radioprotector of the Rectal Wall During Prostate Stereotactic Body Radiation Therapy. Int J Radiat Oncol Biol Phys 2017; 98:75-82. [DOI: 10.1016/j.ijrobp.2017.01.017] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2016] [Revised: 12/09/2016] [Accepted: 01/02/2017] [Indexed: 11/16/2022]
|
14
|
Cerri M, Tinganelli W, Negrini M, Helm A, Scifoni E, Tommasino F, Sioli M, Zoccoli A, Durante M. Hibernation for space travel: Impact on radioprotection. LIFE SCIENCES IN SPACE RESEARCH 2016; 11:1-9. [PMID: 27993187 DOI: 10.1016/j.lssr.2016.09.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2016] [Revised: 09/02/2016] [Accepted: 09/06/2016] [Indexed: 06/06/2023]
Abstract
Hibernation is a state of reduced metabolic activity used by some animals to survive in harsh environmental conditions. The idea of exploiting hibernation for space exploration has been proposed many years ago, but in recent years it is becoming more realistic, thanks to the introduction of specific methods to induce hibernation-like conditions (synthetic torpor) in non-hibernating animals. In addition to the expected advantages in long-term exploratory-class missions in terms of resource consumptions, aging, and psychology, hibernation may provide protection from cosmic radiation damage to the crew. Data from over half century ago in animal models suggest indeed that radiation effects are reduced during hibernation. We will review the mechanisms of increased radioprotection in hibernation, and discuss possible impact on human space exploration.
Collapse
Affiliation(s)
- Matteo Cerri
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Piazza di Porta S.Donato 2, 40126 Bologna, Italy; National Institute of Nuclear Physics (INFN), Section of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy
| | - Walter Tinganelli
- National Institute of Nuclear Physics (INFN), Trento Institute for Fundamental Physics and Applications (TIFPA), Via Sommarive 14, 38123 Trento, Italy
| | - Matteo Negrini
- National Institute of Nuclear Physics (INFN), Section of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy
| | - Alexander Helm
- National Institute of Nuclear Physics (INFN), Trento Institute for Fundamental Physics and Applications (TIFPA), Via Sommarive 14, 38123 Trento, Italy
| | - Emanuele Scifoni
- National Institute of Nuclear Physics (INFN), Trento Institute for Fundamental Physics and Applications (TIFPA), Via Sommarive 14, 38123 Trento, Italy
| | - Francesco Tommasino
- National Institute of Nuclear Physics (INFN), Trento Institute for Fundamental Physics and Applications (TIFPA), Via Sommarive 14, 38123 Trento, Italy; Department of Physics, University of Trento, Via Sommarive 14, 38123 Trento, Italy
| | - Maximiliano Sioli
- National Institute of Nuclear Physics (INFN), Section of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy ; Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy
| | - Antonio Zoccoli
- National Institute of Nuclear Physics (INFN), Section of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy ; Department of Physics and Astronomy, University of Bologna, Viale Berti Pichat 6/2, 40127 Bologna, Italy
| | - Marco Durante
- National Institute of Nuclear Physics (INFN), Trento Institute for Fundamental Physics and Applications (TIFPA), Via Sommarive 14, 38123 Trento, Italy.
| |
Collapse
|
15
|
Effects of hyperthermia as a mitigation strategy in DNA damage-based cancer therapies. Semin Cancer Biol 2016; 37-38:96-105. [PMID: 27025900 DOI: 10.1016/j.semcancer.2016.03.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2016] [Revised: 03/25/2016] [Accepted: 03/25/2016] [Indexed: 12/25/2022]
Abstract
Utilization of thermal therapy (hyperthermia) is defined as the application of exogenous heat induction and represents a concept that is far from new as it goes back to ancient times when heat was used for treating various diseases, including malignancies. Such therapeutic strategy has gained even more popularity (over the last few decades) since various studies have shed light into understanding hyperthermia's underlying molecular mechanism(s) of action. In general, hyperthermia is applied as complementary (adjuvant) means in therapeutic protocols combining chemotherapy and/or irradiation both of which can induce irreversible cellular DNA damage. Furthermore, according to a number of in vitro, in vivo and clinical studies, hyperthermia has been shown to enhance the beneficial effects of DNA targeting therapeutic strategies by interfering with DNA repair response cascades. Therefore, the continuously growing evidence supporting hyperthermia's beneficial role in cancer treatment can also encourage its application as a DNA repair mitigation strategy. In this review article, we aim to provide detailed information on how hyperthermia acts on DNA damage and repair pathways and thus potentially contributing to various adjuvant therapeutic protocols relevant to more efficient cancer treatment strategies.
Collapse
|
16
|
Systemic DNA damage accumulation under in vivo tumor growth can be inhibited by the antioxidant Tempol. Cancer Lett 2014; 353:248-57. [PMID: 25069035 DOI: 10.1016/j.canlet.2014.07.030] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2014] [Revised: 07/16/2014] [Accepted: 07/16/2014] [Indexed: 12/18/2022]
Abstract
Recently we found that mice bearing subcutaneous non-metastatic tumors exhibited elevated levels of two types of complex DNA damage, i.e., double-strand breaks and oxidatively-induced clustered DNA lesions in various tissues throughout the body, both adjacent to and distant from the tumor site. This DNA damage was dependent on CCL2, a cytokine involved in the recruitment and activation of macrophages, suggesting that this systemic DNA damage was mediated via tumor-induced chronic inflammatory responses involving cytokines, activation of macrophages, and consequent free radical production. If free radicals are involved, then a diet containing an antioxidant may decrease the distant DNA damage. Here we repeated our standard protocol in cohorts of two syngeneic tumor-bearing C57BL/6NCr mice that were on a Tempol-supplemented diet. We show that double-strand break and oxidatively-induced clustered DNA lesion levels were considerably decreased, about two- to three fold, in the majority of tissues studied from the tumor-bearing mice fed the antioxidant Tempol compared to the control tumor-bearing mice. Similar results were also observed in nude mice suggesting that the Tempol effects are independent of functioning adaptive immunity. This is the first in vivo study demonstrating the effect of a dietary antioxidant on abscopal DNA damage in tissues distant from a localized source of genotoxic stress. These findings may be important for understanding the mechanisms of genomic instability and carcinogenesis caused by chronic stress-induced systemic DNA damage and for developing preventative strategies.
Collapse
|
17
|
Krystal AD, Schopler B, Kobbe S, Williams C, Rakatondrainibe H, Yoder AD, Klopfer P. The relationship of sleep with temperature and metabolic rate in a hibernating primate. PLoS One 2013; 8:e69914. [PMID: 24023713 PMCID: PMC3762832 DOI: 10.1371/journal.pone.0069914] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2013] [Accepted: 06/13/2013] [Indexed: 11/18/2022] Open
Abstract
STUDY OBJECTIVES It has long been suspected that sleep is important for regulating body temperature and metabolic-rate. Hibernation, a state of acute hypothermia and reduced metabolic-rate, offers a promising system for investigating those relationships. Prior studies in hibernating ground squirrels report that, although sleep occurs during hibernation, it manifests only as non-REM sleep, and only at relatively high temperatures. In our study, we report data on sleep during hibernation in a lemuriform primate, Cheirogaleus medius. As the only primate known to experience prolonged periods of hibernation and as an inhabitant of more temperate climates than ground squirrels, this animal serves as an alternative model for exploring sleep temperature/metabolism relationships that may be uniquely relevant to understanding human physiology. MEASUREMENTS AND RESULTS We find that during hibernation, non-REM sleep is absent in Cheirogaleus. Rather, periods of REM sleep occur during periods of relatively high ambient temperature, a pattern opposite of that observed in ground squirrels. Like ground squirrels, however, EEG is marked by ultra-low voltage activity at relatively low metabolic-rates. CONCLUSIONS These findings confirm a sleep-temperature/metabolism link, though they also suggest that the relationship of sleep stage with temperature/metabolism is flexible and may differ across species or mammalian orders. The absence of non-REM sleep suggests that during hibernation in Cheirogaleus, like in the ground squirrel, the otherwise universal non-REM sleep homeostatic response is greatly curtailed or absent. Lastly, ultra-low voltage EEG appears to be a cross-species marker for extremely low metabolic-rate, and, as such, may be an attractive target for research on hibernation induction.
Collapse
Affiliation(s)
- Andrew D. Krystal
- Department of Psychiatry and Behavioral Sciences, Duke University School of Medicine, Durham, North Carolina, United States of America
| | - Bobby Schopler
- Lemur Center, Duke University, Durham, North Carolina, United States of America
| | - Susanne Kobbe
- Department of Animal Ecology and Conservation, Hamburg University, Hamburg, Germany
| | - Cathy Williams
- Lemur Center, Duke University, Durham, North Carolina, United States of America
| | - Hajanirina Rakatondrainibe
- Lemurs Biomedical Monitoring Environmental Department, Biodiversity Section, Ambatovy, Mineral Society Anonym, Antananarivo, Madagascar
| | - Anne D. Yoder
- Lemur Center, Duke University, Durham, North Carolina, United States of America
- Departments of Biology and Evolutionary Anthropology, Duke University, Durham, North Carolina, United States of America
| | - Peter Klopfer
- Lemur Center, Duke University, Durham, North Carolina, United States of America
- Department of Biology, Duke University, Durham, North Carolina, United States of America
| |
Collapse
|
18
|
Kam WWY, Lake V, Banos C, Davies J, Banati R. Apparent polyploidization after gamma irradiation: pitfalls in the use of quantitative polymerase chain reaction (qPCR) for the estimation of mitochondrial and nuclear DNA gene copy numbers. Int J Mol Sci 2013; 14:11544-59. [PMID: 23722662 PMCID: PMC3709747 DOI: 10.3390/ijms140611544] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2013] [Revised: 04/18/2013] [Accepted: 05/16/2013] [Indexed: 12/12/2022] Open
Abstract
Quantitative polymerase chain reaction (qPCR) has been widely used to quantify changes in gene copy numbers after radiation exposure. Here, we show that gamma irradiation ranging from 10 to 100 Gy of cells and cell-free DNA samples significantly affects the measured qPCR yield, due to radiation-induced fragmentation of the DNA template and, therefore, introduces errors into the estimation of gene copy numbers. The radiation-induced DNA fragmentation and, thus, measured qPCR yield varies with temperature not only in living cells, but also in isolated DNA irradiated under cell-free conditions. In summary, the variability in measured qPCR yield from irradiated samples introduces a significant error into the estimation of both mitochondrial and nuclear gene copy numbers and may give spurious evidence for polyploidization.
Collapse
Affiliation(s)
- Winnie W. Y. Kam
- Australian Nuclear Science and Technology Organisation, Lucas Heights, Sydney, New South Wales 2234, Australia; E-Mails: (V.L.); (C.B.); (J.D.); (R.B.)
- Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, Cumberland, Sydney, New South Wales 2141, Australia
- Author to whom correspondence should be addressed; E-Mail: or ; Tel.: +61-2-9717-7241; Fax: +61-2-9717-9262
| | - Vanessa Lake
- Australian Nuclear Science and Technology Organisation, Lucas Heights, Sydney, New South Wales 2234, Australia; E-Mails: (V.L.); (C.B.); (J.D.); (R.B.)
| | - Connie Banos
- Australian Nuclear Science and Technology Organisation, Lucas Heights, Sydney, New South Wales 2234, Australia; E-Mails: (V.L.); (C.B.); (J.D.); (R.B.)
| | - Justin Davies
- Australian Nuclear Science and Technology Organisation, Lucas Heights, Sydney, New South Wales 2234, Australia; E-Mails: (V.L.); (C.B.); (J.D.); (R.B.)
- School of Physics, University of Sydney, Camperdown, Sydney, New South Wales 2006, Australia
| | - Richard Banati
- Australian Nuclear Science and Technology Organisation, Lucas Heights, Sydney, New South Wales 2234, Australia; E-Mails: (V.L.); (C.B.); (J.D.); (R.B.)
- Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, Cumberland, Sydney, New South Wales 2141, Australia
- National Imaging Facility at Brain and Mind Research Institute (BMRI), University of Sydney, Camperdown, Sydney, New South Wales 2050, Australia
| |
Collapse
|
19
|
Vasilyev SA, Kubes M, Markova E, Belyaev I. DNA damage response in CD133 + stem/progenitor cells from umbilical cord blood: low level of endogenous foci and high recruitment of 53BP1. Int J Radiat Biol 2013. [PMID: 23206244 DOI: 10.3109/09553002.2013.754555] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
UNLABELLED Abstract Purpose: Human hematopoietic stem cells (HSC) are thought to be a major target of radiation-induced leukemogenesis and also provide a relevant cellular model for assessing cancer risk. Cluster of designation 133+ (CD133+) is a marker found in human progenitor and hematopoietic stem cells. Our study examined the repair of radiation-induced DNA double-strand breaks (DSB) in CD133 + umbilical cord blood cells (UCBC). MATERIALS AND METHODS After γ-irradiation, endogenous and induced DSB were evaluated in CD133 + UCBC, CD133 - UCBC and peripheral blood lymphocytes (PBL) in terms of phosphorylated histone 2A family member X (γH2AX) and tumor suppressor p53 binding protein 1 (53BP1) foci. RESULTS We found that repair signaling in CD133 + UCBC is different from CD133 - UCBC and PBL. These differences include lower endogenous DSB levels and higher 53BP1 recruitment. CONCLUSIONS Our data, together with a recent report on radiation-induced γH2AX and 53BP1 foci in CD34 + cells, indicate enhanced DNA repair capacity in HSC as compared to mature lymphocytes.
Collapse
Affiliation(s)
- Stanislav A Vasilyev
- Laboratory of Molecular Genetics, Cancer Research Institute, Bratislava, Slovak Republic
| | | | | | | |
Collapse
|
20
|
Purdy PD, Novakovic RL, Giles BP, Miller SL, Riegel MS. Spinal cord hypothermia without systemic hypothermia. AJNR Am J Neuroradiol 2012; 34:252-6. [PMID: 22766669 DOI: 10.3174/ajnr.a3175] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
BACKGROUND AND PURPOSE Hypothermia has been shown to be beneficial in the setting of acute SCI. However, widespread use has been hindered by the need for systemic hypothermia as the vehicle for achieving spinal cord hypothermia. This study demonstrates that localized spinal cord hypothermia can be achieved via a percutaneous approach while maintaining systemic normothermia. MATERIALS AND METHODS Five Yucatan swine underwent catheterization of the subarachnoid space and infusion of room temperature, chilled, and iced PL solutions into the cervical spinal canal, with drainage from the lumbar canal. Thermocouples were placed within the spinal cord and in the subarachnoid space and recorded during infusions and recovery from hypothermia. RESULTS Results demonstrated that hypothermia as low as 16.8°C is feasible in the spinal cord with retention of systemic normothermia, with strong (r = 0.95) correlation between the spinal cord temperature and the CSF temperature. Degrees of cooling varied with flow rates and with infusate temperature. CONCLUSIONS While the data are preliminary in a small group of animals, the ability to rapidly create a wide range of controlled spinal cord hypothermia while preserving normal body temperature warrants wider exploration. The study also indicates that further investigation of the hypothesis that CSF temperature monitoring may be an acceptable surrogate for direct spinal cord temperature monitoring should be pursued.
Collapse
Affiliation(s)
- P D Purdy
- Department of Radiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA.
| | | | | | | | | |
Collapse
|
21
|
Georgakilas A. Detection of clustered DNA lesions: Biological and clinical applications. World J Biol Chem 2011; 2:173-6. [PMID: 21915368 PMCID: PMC3158867 DOI: 10.4331/wjbc.v2.i7.173] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Revised: 05/07/2011] [Accepted: 05/14/2011] [Indexed: 02/05/2023] Open
Abstract
Humans are daily exposed to background radiation and various sources of oxidative stress. My research has focused in the last 12 years on the effects of ionizing radiation on DNA, which is considered as the key target of radiation in the cell. Ionizing radiation and endogenous cellular oxidative stress can also induce closely spaced oxidatively induced DNA lesions called “clusters” of DNA damage or locally multiply damage sites, as first introduced by John Ward. I am now interested in the repair mechanisms of clustered DNA damage, which is considered as the most difficult for the cell to repair. A main part of my research is devoted to evaluating the role of clustered DNA damage in the promotion of carcinogenesis in vitro and in vivo. Currently in my laboratory, there are two main ongoing projects. (1) Study of the role of BRCA1 and DNA-dependent protein kinase catalytic subunit repair proteins in the processing of clustered DNA damage in human cancer cells. For this project, we use several tumor cell lines, such as breast cancer cell lines MCF-7 and HCC1937 (BRCA1 deficient) and human glioblastoma cells MO59J/K; and (2) Possible use of DNA damage clusters as novel cancer biomarkers for prognostic and therapeutic applications related to modulation of oxidative stress. In this project human tumor and mice tissues are being used.
Collapse
Affiliation(s)
- Alexandros Georgakilas
- Alexandros Georgakilas, DNA Damage and Repair Laboratory, Department of Biology, Thomas Harriot College of Arts and Sciences, Howell Science Complex, East Carolina University, Greenville, NC 27858, United States
| |
Collapse
|