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Singh VK, Newman VL, Romaine PLP, Wise SY, Seed TM. Radiation countermeasure agents: an update (2011-2014). Expert Opin Ther Pat 2014; 24:1229-55. [PMID: 25315070 PMCID: PMC4438421 DOI: 10.1517/13543776.2014.964684] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
INTRODUCTION Despite significant scientific advances over the past 60 years towards the development of a safe, nontoxic and effective radiation countermeasure for the acute radiation syndrome (ARS), no drug has been approved by the US FDA. A radiation countermeasure to protect the population at large from the effects of lethal radiation exposure remains a significant unmet medical need of the US citizenry and, thus, has been recognized as a high priority area by the government. AREA COVERED This article reviews relevant publications and patents for recent developments and progress for potential ARS treatments in the area of radiation countermeasures. Emphasis is placed on the advanced development of existing agents since 2011 and new agents identified as radiation countermeasure for ARS during this period. EXPERT OPINION A number of promising radiation countermeasures are currently under development, seven of which have received US FDA investigational new drug status for clinical investigation. Four of these agents, CBLB502, Ex-RAD, HemaMax and OrbeShield, are progressing with large animal studies and clinical trials. G-CSF has high potential and well-documented therapeutic effects in countering myelosuppression and may receive full licensing approval by the US FDA in the future.
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Affiliation(s)
- Vijay K Singh
- Armed Forces Radiobiology Research Institute , 8901 Wisconsin Ave, Bethesda, MD 20889-5603 , USA +1 301 295 2347 ; +1 301 295 6503 ;
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Moulder JE. 2013 Dade W. Moeller lecture: medical countermeasures against radiological terrorism. HEALTH PHYSICS 2014; 107:164-71. [PMID: 24978287 PMCID: PMC4076685 DOI: 10.1097/hp.0000000000000082] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Soon after the 9-11 attacks, politicians and scientists began to question our ability to cope with a large-scale radiological terrorism incident. The outline of what was needed was fairly obvious: the ability to prevent such an attack, methods to cope with the medical consequences, the ability to clean up afterward, and the tools to figure out who perpetrated the attack and bring them to justice. The medical response needed three components: the technology to determine rapidly the radiation doses received by a large number of people, methods for alleviating acute hematological radiation injuries, and therapies for mitigation and treatment of chronic radiation injuries. Research done to date has shown that a realistic medical response plan is scientifically possible, but the regulatory and financial barriers to achieving this may currently be insurmountable.
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Affiliation(s)
- John E. Moulder
- Center for Medical Countermeasures Against Radiological Terrorism, Radiation Oncology, Medical College of Wisconsin, 8701 Watertown Plank Road, Milwaukee, Wisconsin, 53226 U. S. A
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Batra V, Verma P. Dietary l-methionine supplementation mitigates gamma-radiation induced global DNA hypomethylation: Enhanced metabolic flux towards S-adenosyl-l-methionine (SAM) biosynthesis increases genomic methylation potential. Food Chem Toxicol 2014; 69:46-54. [DOI: 10.1016/j.fct.2014.03.040] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 03/11/2014] [Accepted: 03/28/2014] [Indexed: 01/23/2023]
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Chen JJ, Gao Y, Tian Q, Liang YM, Yang L. Platelet factor 4 protects bone marrow mesenchymal stem cells from acute radiation injury. Br J Radiol 2014; 87:20140184. [PMID: 24922360 DOI: 10.1259/bjr.20140184] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVE The aim of this study was to find a new radiation protector, platelet factor 4 (PF4) and to identify its effect on haemopoietic microenvironment in vitro and in vivo. METHODS Radiation damage on bone marrow mesenchymal stem cells ex and in vitro was set up as models. Growth curve analysis, clonogenic survival assay, FACSCalibur™ (BD Immunocytometry Systems, San Jose, CA), 5-ethynyl-2'-deoxyuridine immunofluorescence staining and quantitative reverse transcription-polymerase chain reaction were employed to assess the characterization of bone marrow mesenchymal stem cells (BMSCs), proliferation, apoptosis, cell cycle and gene expression. RESULTS A dose- and time-dependent enhancement of cell viability and survival was observed for PF4 treatment along with 500 cGy γ-radiation in vitro. The same phenomena were noted in vivo, including enhancement of adherence and proliferation ability while inhibition of cell apoptosis, which were associated with a short-term decrease in the G0/G1 ratio owing to S phase arrest. These were accompanied with enhanced Bcl-2 expression and p53/p21 loss. CONCLUSION These results uncover that PF4 might be a novel therapeutic approach, which could reduce DNA damage and increase survival of BMSCs, in part, by inhibiting p53/p21 axis and facilitating DNA damage repair. ADVANCES IN KNOWLEDGE This study explores the feasibility of a new radioprotector and hence may be clinically important.
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Affiliation(s)
- J-J Chen
- 1 Department of Hematology, Tangdu Hospital, Fourth Military Medical University, Xi'an, China
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Singh VK, Wise SY, Fatanmi OO, Beattie LA, Seed TM. Preclinical development of a bridging therapy for radiation casualties: appropriate for high risk personnel. HEALTH PHYSICS 2014; 106:689-698. [PMID: 24776901 DOI: 10.1097/hp.0000000000000089] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The authors demonstrate the efficacy of a bridging therapy in a preclinical animal model that allows the lymphohematopoietic system of severely immunocompromised individuals exposed to acute, high-dose ionizing irradiation to recover and to survive. CD2F1 mice were irradiated acutely with high doses causing severe, potentially fatal hematopoietic or gastrointestinal injuries and then transfused intravenously with progenitor-enriched, whole blood, or peripheral blood mononuclear cells from mice injected with tocopherol succinate- and AMD3100- (a chemokine receptor anatogonist used to improve the yield of mobilized progenitors). Survival of these mice over a 30-d period was used as the primary measured endpoint of therapeutic effectiveness. The authors demonstrate that tocopherol succinate and AMD3100 mobilize progenitors into peripheral circulation and that the infusion of mobilized progenitor enriched blood or mononuclear cells acts as a bridging therapy for lymphohematopoietic system recovery in mice exposed to whole-body ionizing irradiation. The results demonstrate that infusion of whole blood or blood mononuclear cells from tocopherol succinate (TS)- and AMD3100-injected mice improved the survival of mice receiving high radiation doses significantly. The efficacy of TS-injected donor mice blood or mononuclear cells was comparable to that of blood or cells obtained from mice injected with granulocyte colony-stimulating factor. Donor origin-mobilized progenitors were found to localize in various tissues. The authors suggest that tocopherol succinate is an optimal agent for mobilizing progenitors with significant therapeutic potential. The extent of progenitor mobilization that tocopherol succinate elicits in experimental mice is comparable quantitatively to clinically used drugs such as granulocyte-colony stimulating factor and AMD3100. Therefore, it is proposed that tocopherol succinate be considered for further translational development and ultimately for use in humans.
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Affiliation(s)
- Vijay K Singh
- *Armed Forces Radiobiology Research Institute, Bethesda, MD; †Department of Radiation Biology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD; ‡Tech Micro Services, 4417 Maple Avenue, Bethesda, MD
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Drouet M, Hérodin F. Mitigating radiation-induced toxicity: an overview of new approaches developed at the French Military Biomedical Research Institute. HEALTH PHYSICS 2014; 106:682-688. [PMID: 24776900 DOI: 10.1097/hp.0000000000000039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
Acute radiation syndrome represents the clinical response of radiation-sensitive key tissues (i.e., hematopoietic, gastrointestinal and neurovascular) following exposure to high doses of ionizing radiation. In this context, the hematopoietic syndrome remains the first therapeutic challenge. Today, identifying new drugs and developing new strategies to cope with acute radiation syndrome remain a priority, especially to prevent/cure the radiation-induced multiple organ dysfunction syndrome then failure. Cytokine, non-cytokine drugs, and cell/gene therapy represent a pattern of sophisticated approaches developed by this group and others to achieve this goal.
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Affiliation(s)
- Michel Drouet
- *Institut de Recherche Biomédicale des Armées, Department of Radiobiology, BP73, 91223, Brétigny sur Orge, France
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Hofer M, Pospíšil M, Komůrková D, Hoferová Z. Granulocyte colony-stimulating factor in the treatment of acute radiation syndrome: a concise review. Molecules 2014; 19:4770-8. [PMID: 24743934 PMCID: PMC6270858 DOI: 10.3390/molecules19044770] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2014] [Revised: 03/17/2014] [Accepted: 04/11/2014] [Indexed: 02/07/2023] Open
Abstract
This article concisely summarizes data on the action of one of the principal and best known growth factors, the granulocyte colony-stimulating factor (G-CSF), in a mammalian organism exposed to radiation doses inducing acute radiation syndrome. Highlighted are the topics of its real or anticipated use in radiation accident victims, the timing of its administration, the possibilities of combining G-CSF with other drugs, the ability of other agents to stimulate endogenous G-CSF production, as well as of the capability of this growth factor to ameliorate not only the bone marrow radiation syndrome but also the gastrointestinal radiation syndrome. G-CSF is one of the pivotal drugs in the treatment of radiation accident victims and its employment in this indication can be expected to remain or even grow in the future.
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Affiliation(s)
- Michal Hofer
- Department of Molecular Cytology and Cytometry, Institute of Biophysics, v.v.i., Academy of Sciences of the Czech Republic, Královopolská 135, Brno CZ-612 65, Czech Republic.
| | - Milan Pospíšil
- Department of Molecular Cytology and Cytometry, Institute of Biophysics, v.v.i., Academy of Sciences of the Czech Republic, Královopolská 135, Brno CZ-612 65, Czech Republic.
| | - Denisa Komůrková
- Department of Molecular Cytology and Cytometry, Institute of Biophysics, v.v.i., Academy of Sciences of the Czech Republic, Královopolská 135, Brno CZ-612 65, Czech Republic.
| | - Zuzana Hoferová
- Department of Molecular Cytology and Cytometry, Institute of Biophysics, v.v.i., Academy of Sciences of the Czech Republic, Královopolská 135, Brno CZ-612 65, Czech Republic.
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Gluzman-Poltorak Z, Mendonca SR, Vainstein V, Kha H, Basile LA. Randomized comparison of single dose of recombinant human IL-12 versus placebo for restoration of hematopoiesis and improved survival in rhesus monkeys exposed to lethal radiation. J Hematol Oncol 2014; 7:31. [PMID: 24708888 PMCID: PMC4108131 DOI: 10.1186/1756-8722-7-31] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2014] [Accepted: 03/25/2014] [Indexed: 02/02/2023] Open
Abstract
Background The hematopoietic syndrome of the acute radiation syndrome (HSARS) is a life-threatening condition in humans exposed to total body irradiation (TBI); no drugs are approved for treating this condition. Recombinant human interleukin-12 (rHuIL-12) is being developed for HSARS mitigation under the FDA Animal Rule, where efficacy is proven in an appropriate animal model and safety is demonstrated in humans. Methods In this blinded study, rhesus monkeys (9 animals/sex/dose group) were randomized to receive a single subcutaneous injection of placebo (group 1) or rHuIL-12 at doses of 50, 100, 250, or 500 ng/kg (groups 2–5, respectively), without antibiotics, fluids or blood transfusions, 24–25 hours after TBI (700 cGy). Results Survival rates at Day 60 were 11%, 33%, 39%, 39%, and 50% for groups 1–5, respectively (log rank p < 0.05 for each dose vs. control). rHuIL-12 also significantly reduced the incidences of severe neutropenia, severe thrombocytopenia, and sepsis (positive hemoculture). Additionally, bone marrow regeneration following TBI was significantly greater in monkeys treated with rHuIL-12 than in controls. Conclusions Data from this study demonstrate that a single injection of rHuIL-12 delivered one day after TBI can significantly increase survival and reduce radiation-induced hematopoietic toxicity and infections. These data significantly advance development of rHuIL-12 toward approval under the Animal Rule as an effective stand-alone medical countermeasure against the lethal effects of radiation exposure.
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Affiliation(s)
| | | | | | | | - Lena A Basile
- Neumedicines Inc,, 133 North Altadena Drive, Suite 310, 91107 Pasadena, CA, USA.
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Singh VK, Wise SY, Scott JR, Romaine PL, Newman VL, Fatanmi OO. Radioprotective efficacy of delta-tocotrienol, a vitamin E isoform, is mediated through granulocyte colony-stimulating factor. Life Sci 2014; 98:113-22. [DOI: 10.1016/j.lfs.2014.01.065] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2013] [Revised: 11/29/2013] [Accepted: 01/16/2014] [Indexed: 12/31/2022]
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Singh VK, Wise SY, Fatanmi OO, Beattie LA, Ducey EJ, Seed TM. Alpha-tocopherol succinate- and AMD3100-mobilized progenitors mitigate radiation combined injury in mice. JOURNAL OF RADIATION RESEARCH 2014; 55:41-53. [PMID: 23814114 PMCID: PMC3885121 DOI: 10.1093/jrr/rrt088] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Revised: 05/23/2013] [Accepted: 05/27/2013] [Indexed: 05/28/2023]
Abstract
The purpose of this study was to elucidate the role of alpha-tocopherol succinate (TS)- and AMD3100-mobilized progenitors in mitigating combined injury associated with acute radiation exposure in combination with secondary physical wounding. CD2F1 mice were exposed to high doses of cobalt-60 gamma-radiation and then transfused intravenously with 5 million peripheral blood mononuclear cells (PBMCs) from TS- and AMD3100-injected mice after irradiation. Within 1 h after irradiation, mice were exposed to secondary wounding. Mice were observed for 30 d after irradiation and cytokine analysis was conducted by multiplex Luminex assay at various time-points after irradiation and wounding. Our results initially demonstrated that transfusion of TS-mobilized progenitors from normal mice enhanced survival of acutely irradiated mice exposed 24 h prior to transfusion to supralethal doses (11.5-12.5 Gy) of (60)Co gamma-radiation. Subsequently, comparable transfusions of TS-mobilized progenitors were shown to significantly mitigate severe combined injuries in acutely irradiated mice. TS administered 24 h before irradiation was able to protect mice against combined injury as well. Cytokine results demonstrated that wounding modulates irradiation-induced cytokines. This study further supports the conclusion that the infusion of TS-mobilized progenitor-containing PBMCs acts as a bridging therapy in radiation-combined-injury mice. We suggest that this novel bridging therapeutic approach involving the infusion of TS-mobilized hematopoietic progenitors following acute radiation exposure or combined injury might be applicable to humans.
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Affiliation(s)
- Vijay K. Singh
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, 8901 Wisconsin Ave, Bethesda, MD 20889-5603, USA
- Department of Radiation Biology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4417 Maple Avenue, Bethesda, MD, USA
| | - Stephen Y. Wise
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, 8901 Wisconsin Ave, Bethesda, MD 20889-5603, USA
| | - Oluseyi O. Fatanmi
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, 8901 Wisconsin Ave, Bethesda, MD 20889-5603, USA
| | - Lindsay A. Beattie
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, 8901 Wisconsin Ave, Bethesda, MD 20889-5603, USA
| | - Elizabeth J. Ducey
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, 8901 Wisconsin Ave, Bethesda, MD 20889-5603, USA
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Singh VK, Beattie LA, Seed TM. Vitamin E: tocopherols and tocotrienols as potential radiation countermeasures. JOURNAL OF RADIATION RESEARCH 2013; 54:973-88. [PMID: 23658414 PMCID: PMC3823775 DOI: 10.1093/jrr/rrt048] [Citation(s) in RCA: 69] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
Despite the potential devastating health consequences of intense total-body irradiation, and the decades of research, there still remains a dearth of safe and effective radiation countermeasures for emergency, radiological/nuclear contingencies that have been fully approved and sanctioned for use by the US FDA. Vitamin E is a well-known antioxidant, effective in scavenging free radicals generated by radiation exposure. Vitamin E analogs, collectively known as tocols, have been subject to active investigation for a long time as radioprotectors in patients undergoing radiotherapy and in the context of possible radiation accidents or terrorism scenarios. Eight major isoforms comprise the tocol group: four tocopherols and four tocotrienols. A number of these agents and their derivatives are being investigated actively as radiation countermeasures using animal models, and several appear promising. Although the tocols are well recognized as potent antioxidants and are generally thought to mediate radioprotection through 'free radical quenching', recent studies have suggested several alternative mechanisms: most notably, an 'indirect effect' of tocols in eliciting specific species of radioprotective growth factors/cytokines such as granulocyte colony-stimulating factor (G-CSF). The radioprotective efficacy of at least two tocols has been abrogated using a neutralizing antibody of G-CSF. Based on encouraging results of radioprotective efficacy, laboratory testing of γ-tocotrienol has moved from a small rodent model to a large nonhuman primate model for preclinical evaluation. In this brief review we identify and discuss selected tocols and their derivatives currently under development as radiation countermeasures, and attempt to describe in some detail their in vivo efficacy.
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Affiliation(s)
- Vijay K. Singh
- Radiation Countermeasures Program, Scientific Research Department, Armed Forces Radiobiology Research Institute, 8901 Wisconsin Ave, Bethesda, MD 20889-5603, USA
- Department of Radiation Biology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
- Corresponding author. Radiation Countermeasures Program, Armed Forces Radiobiology Research Institute, 8901 Wisconsin Ave, Bethesda, MD 20889-5603, USA. Tel: +1-301-295-2347; Fax: +1-301-295-6503;
| | - Lindsay A. Beattie
- Radiation Countermeasures Program, Scientific Research Department, Armed Forces Radiobiology Research Institute, 8901 Wisconsin Ave, Bethesda, MD 20889-5603, USA
| | - Thomas M. Seed
- Tech Micro Services, 4417 Maple Avenue, Bethesda, MD, USA
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Gamma tocotrienol, a potent radioprotector, preferentially upregulates expression of anti-apoptotic genes to promote intestinal cell survival. Food Chem Toxicol 2013; 60:488-96. [PMID: 23941772 DOI: 10.1016/j.fct.2013.08.011] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2013] [Revised: 08/02/2013] [Accepted: 08/04/2013] [Indexed: 01/03/2023]
Abstract
Gamma tocotrienol (GT3) has been reported as a potent ameliorator of radiation-induced gastrointestinal (GI) toxicity when administered prophylactically. This study aimed to evaluate the role of GT3 mediated pro- and anti-apoptotic gene regulation in protecting mice from radiation-induced GI damage. Male 10- to 12-weeks-old CD2F1 mice were administered with a single dose of 200 mg/kg of GT3 or equal volume of vehicle (5% Tween-80) 24 h before exposure to 11 Gy of whole-body γ-radiation. Mouse jejunum was surgically removed 4 and 24h after radiation exposure, and was used for PCR array, histology, immunohistochemistry, and immunoblot analysis. Results were compared among vehicle pre-treated no radiation, vehicle pre-treated irradiated, and GT3 pre-treated irradiated groups. GT3 pretreated irradiated groups, both 4h and 24h after radiation, showed greater upregulation of anti-apoptotic gene expression than vehicle pretreated irradiated groups. TUNEL staining and intestinal crypt analysis showed protection of jejunum after GT3 pre-treatment and immunoblot results were supportive of PCR data. Our study demonstrated that GT3-mediated protection of intestinal cells from a GI-toxic dose of radiation occurred via upregulation of antiapoptotic and downregulation of pro-apoptotic factors, both at the transcript as well as at the protein levels.
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Batra V, Kislay B. Mitigation of gamma-radiation induced abasic sites in genomic DNA by dietary nicotinamide supplementation: metabolic up-regulation of NAD(+) biosynthesis. Mutat Res 2013; 749:28-38. [PMID: 23891603 DOI: 10.1016/j.mrfmmm.2013.07.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/09/2012] [Revised: 06/14/2013] [Accepted: 07/09/2013] [Indexed: 01/25/2023]
Abstract
The search for non-toxic radio-protective drugs has yielded many potential agents but most of these compounds have certain amount of toxicity. The objective of the present study was to investigate dietary nicotinamide enrichment dependent adaptive response to potential cytotoxic effect of (60)Co γ-radiation. To elucidate the possible underlying mechanism(s), male Swiss mice were maintained on control diet (CD) and nicotinamide supplemented diet (NSD). After 6 weeks of CD and NSD dietary regimen, we exposed the animals to γ-radiation (2, 4 and 6Gy) and investigated the profile of downstream metabolites and activities of enzymes involved in NAD(+) biosynthesis. Increased activities of nicotinamide phosphoribosyltransferase (NAMPT) and nicotinamide mononucleotide adenylyltransferase (NMNAT) were observed up to 48h post-irradiation in NSD fed irradiated mice. Concomitant with increase in liver NAMPT and NMNAT activities, NAD(+) levels were replenished in NSD fed and irradiated animals. However, NAMPT and NMNAT-mediated NAD(+) biosynthesis and ATP levels were severely compromised in liver of CD fed irradiated mice. Another major finding of these studies revealed that under γ-radiation stress, dietary nicotinamide supplementation might induce higher and long-lasting poly(ADP)-ribose polymerase 1 (PARP1) and poly(ADP-ribose) glycohydrolase (PARG) activities in NSD fed animals compared to CD fed animals. To investigate liver DNA damage, number of apurinic/apyrimidinic sites (AP sites) and level of 8-hydroxy-2'-deoxyguanosine (8-oxo-dG) residues were quantified. A significant increase in liver DNA AP sites and 8-oxo-dG levels with concomitant increase in caspase-3 was observed in CD fed and irradiated animals compared to NSD fed and irradiated mice. In conclusion present studies show that under γ-radiation stress conditions, dietary nicotinamide supplementation restores DNA excision repair activity via prolonged activation of PARP1 and PARG activities. Present results clearly indicated that hepatic NAD(+) replenishment might be a novel and potent approach to reduce radiation injury.
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Affiliation(s)
- Vipen Batra
- Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400085, India.
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Granulocyte colony-stimulating factor antibody abrogates radioprotective efficacy of gamma-tocotrienol, a promising radiation countermeasure. Cytokine 2013; 62:278-85. [DOI: 10.1016/j.cyto.2013.03.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Revised: 01/10/2013] [Accepted: 03/08/2013] [Indexed: 12/11/2022]
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Singh VK, Wise SY, Singh PK, Posarac A, Fatanmi OO, Ducey EJ, Bolduc DL, Elliott TB, Seed TM. Alpha-tocopherol succinate-mobilized progenitors improve intestinal integrity after whole body irradiation. Int J Radiat Biol 2013; 89:334-45. [PMID: 23270472 DOI: 10.3109/09553002.2013.762137] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
PURPOSE The objective of this study was to elucidate the action of α-tocopherol succinate (TS)- and AMD3100-mobilized progenitors in mitigating radiation-induced injuries. MATERIAL AND METHODS CD2F1 mice were exposed to a high dose of radiation and then transfused intravenously with 5 million peripheral blood mononuclear cells (PBMC) from TS- and AMD3100-injected mice after irradiation. Intestinal and splenic tissues were harvested after irradiation and cells of those tissues were analyzed for markers of apoptosis and mitosis. Bacterial translocation from gut to heart, spleen, and liver in TS-treated and irradiated mice was evaluated by bacterial culture. RESULTS We observed that the infusion of PBMC from TS- and AMD3100-injected mice significantly inhibited apoptosis, increased cell proliferation in the analyzed tissues of recipient mice, and inhibited bacterial translocation to various organs compared to mice receiving cells from vehicle-mobilized cells. This study further supports our contention that the infusion of TS-mobilized progenitor-containing PBMC acts as a bridging therapy by inhibiting radiation-induced apoptosis, enhancing cell proliferation, and inhibiting bacterial translocation in irradiated mice. CONCLUSIONS We suggest that this novel bridging therapeutic approach that involves the infusion of TS-mobilized hematopoietic progenitors following acute radiation injury might be applicable to humans as well.
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Affiliation(s)
- Vijay K Singh
- Armed Forces Radiobiology Research Institute, Bethesda, MD 20889-5603, USA.
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Blockade of CD47 increases survival of mice exposed to lethal total body irradiation. Sci Rep 2013; 3:1038. [PMID: 23301159 PMCID: PMC3539147 DOI: 10.1038/srep01038] [Citation(s) in RCA: 57] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2012] [Accepted: 12/14/2012] [Indexed: 11/08/2022] Open
Abstract
Accidental or therapeutic total body exposure to ionizing radiation has profound pathophysiological consequences including acute radiation syndrome. Currently only investigational drugs are available in case of radiological or nuclear accidents or terrorism. Lack of selective radioprotectants for normal tissues also limits the therapeutic doses that can be delivered to treat cancers. CD47 is a receptor for the secreted protein thrombospondin-1. Blockade of thrombospondin-1 or CD47 provides local radioprotection of soft tissues and bone marrow. We now report that suppression of CD47 using an antisense morpholino increases survival of mice exposed to lethal total body irradiation. Increased survival is associated with increased peripheral circulating blood cell counts and increased proliferative capacity of bone marrow derived cells. Moreover, CD47 blockade decreased cell death while inducing a protective autophagy response in radiosensitive gastrointestinal tissues. Thus, CD47 is a new target for radiomitigation that prevents both hematopoietic and gastrointestinal radiation syndromes.
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Katoch O, Dwarakanath BS, K Agrawala P. HDAC inhibitors: applications in oncology and beyond. ACTA ACUST UNITED AC 2013. [DOI: 10.7243/2050-0874-2-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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Krivokrysenko VI, Shakhov AN, Singh VK, Bone F, Kononov Y, Shyshynova I, Cheney A, Maitra RK, Purmal A, Whitnall MH, Gudkov AV, Feinstein E. Identification of granulocyte colony-stimulating factor and interleukin-6 as candidate biomarkers of CBLB502 efficacy as a medical radiation countermeasure. J Pharmacol Exp Ther 2012; 343:497-508. [PMID: 22837010 DOI: 10.1124/jpet.112.196071] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Given an ever-increasing risk of nuclear and radiological emergencies, there is a critical need for development of medical radiation countermeasures (MRCs) that are safe, easily administered, and effective in preventing and/or mitigating the potentially lethal tissue damage caused by acute high-dose radiation exposure. Because the efficacy of MRCs for this indication cannot be ethically tested in humans, development of such drugs is guided by the Food and Drug Administration's Animal Efficacy Rule. According to this rule, human efficacious doses can be projected from experimentally established animal efficacious doses based on the equivalence of the drug's effects on efficacy biomarkers in the respective species. Therefore, identification of efficacy biomarkers is critically important for drug development under the Animal Efficacy Rule. CBLB502 is a truncated derivative of the Salmonella flagellin protein that acts by triggering Toll-like receptor 5 (TLR5) signaling and is currently under development as a MRC. Here, we report identification of two cytokines, granulocyte colony-stimulating factor (G-CSF) and interleukin-6 (IL-6), as candidate biomarkers of CBLB502's radioprotective/mitigative efficacy. Induction of both G-CSF and IL-6 by CBLB502 1) is strictly TLR5-dependent, 2) occurs in a CBLB502 dose-dependent manner within its efficacious dose range in both nonirradiated and irradiated mammals, including nonhuman primates, and 3) is critically important for the ability of CBLB502 to rescue irradiated animals from death. After evaluation of CBLB502 effects on G-CSF and IL-6 levels in humans, these biomarkers will be useful for accurate prediction of human efficacious CBLB502 doses, a key step in the development of this prospective radiation countermeasure.
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Singh VK, Christensen J, Fatanmi OO, Gille D, Ducey EJ, Wise SY, Karsunky H, Sedello AK. Myeloid Progenitors: A Radiation Countermeasure that is Effective when Initiated Days after Irradiation. Radiat Res 2012; 177:781-91. [DOI: 10.1667/rr2894.1] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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