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Clark GC, Lai A, Agarwal A, Liu Z, Wang XY. Biopterin metabolism and nitric oxide recoupling in cancer. Front Oncol 2024; 13:1321326. [PMID: 38469569 PMCID: PMC10925643 DOI: 10.3389/fonc.2023.1321326] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2023] [Accepted: 12/26/2023] [Indexed: 03/13/2024] Open
Abstract
Tetrahydrobiopterin is a cofactor necessary for the activity of several enzymes, the most studied of which is nitric oxide synthase. The role of this cofactor-enzyme relationship in vascular biology is well established. Recently, tetrahydrobiopterin metabolism has received increasing attention in the field of cancer immunology and immunotherapy due to its involvement in the cytotoxic T cell response. Past research has demonstrated that when the availability of BH4 is low, as it is in chronic inflammatory conditions and tumors, electron transfer in the active site of nitric oxide synthase becomes uncoupled from the oxidation of arginine. This results in the production of radical species that are capable of a direct attack on tetrahydrobiopterin, further depleting its local availability. This feedforward loop may act like a molecular switch, reinforcing low tetrahydrobiopterin levels leading to altered NO signaling, restrained immune effector activity, and perpetual vascular inflammation within the tumor microenvironment. In this review, we discuss the evidence for this underappreciated mechanism in different aspects of tumor progression and therapeutic responses. Furthermore, we discuss the preclinical evidence supporting a clinical role for tetrahydrobiopterin supplementation to enhance immunotherapy and radiotherapy for solid tumors and the potential safety concerns.
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Affiliation(s)
- Gene Chatman Clark
- Department of Biochemistry, Virginia Commonwealth University, Richmond, VA, United States
- School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | - Alan Lai
- School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
| | | | - Zheng Liu
- Department of Human Molecular Genetics, Virginia Commonwealth University, Richmond, VA, United States
- Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, United States
| | - Xiang-Yang Wang
- Department of Human Molecular Genetics, Virginia Commonwealth University, Richmond, VA, United States
- Massey Cancer Center, Virginia Commonwealth University, Richmond, VA, United States
- Institute of Molecular Medicine, Virginia Commonwealth University, Richmond, VA, United States
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2
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Bansal K, Singh V, Mishra S, Bajpai M. Articulating the Pharmacological and Nanotechnological Aspects of Genistein: Current and Future Prospectives. Curr Pharm Biotechnol 2024; 25:807-824. [PMID: 38902930 DOI: 10.2174/0113892010265344230919170611] [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: 06/02/2023] [Revised: 08/10/2023] [Accepted: 08/19/2023] [Indexed: 06/22/2024]
Abstract
Throughout the past several centuries, herbal constituents have been the subject of scientific interest and the latest research into their therapeutic potential is underway. Genistein is a soy-derived isoflavone found in huge amounts in soy, along with the plants of the Fabaceae family. Scientific studies have demonstrated the beneficial effects of genistein on various health conditions. Genistein presents a broad range of pharmacological activities, including anticancer, neuroprotective, cardioprotective, antiulcer, anti-diabetic, wound healing, anti-bacterial, antiviral, skin, and radioprotective effects. However, the hydrophobic nature of genistein results in constrained absorption and restricts its therapeutic potential. In this review, the number of nanocarriers for genistein delivery has been explored, such as polymeric nanoparticles, nanostructured lipid carriers, solid lipid nanoparticles, liposomes, micelles, transferosomes, and nanoemulsions and nanofibers. These nano-formulations of genistein have been utilized as a potential strategy for various disorders, employing a variety of ex vivo, in vitro, and in vivo models and various administration routes. This review concluded that genistein is a potential therapeutic agent for treating various diseases, including cancer, neurodegenerative disorders, cardiovascular disorders, obesity, diabetes, ulcers, etc., when formulated in suitable nanocarriers.
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Affiliation(s)
- Keshav Bansal
- Institute of Pharmaceutical Research, GLA University, Mathura, 281406, Uttar Pradesh, India
| | - Vanshita Singh
- Institute of Pharmaceutical Research, GLA University, Mathura, 281406, Uttar Pradesh, India
| | - Samiksha Mishra
- Institute of Pharmaceutical Research, GLA University, Mathura, 281406, Uttar Pradesh, India
| | - Meenakshi Bajpai
- Institute of Pharmaceutical Research, GLA University, Mathura, 281406, Uttar Pradesh, India
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3
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Garg TK, Garg S, Miousse IR, Wise SY, Carpenter AD, Fatanmi OO, van Rhee F, Singh VK, Hauer-Jensen M. Modulation of Hematopoietic Injury by a Promising Radioprotector, Gamma-Tocotrienol, in Rhesus Macaques Exposed to Partial-Body Radiation. Radiat Res 2024; 201:55-70. [PMID: 38059553 DOI: 10.1667/rade-23-00075.2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2023] [Accepted: 11/03/2023] [Indexed: 12/08/2023]
Abstract
Currently, no radioprotectors have been approved to mitigate hematopoietic injury after exposure to ionizing radiation. Acute ionizing radiation results in damage to both hematopoietic and immune system cells. Pre-exposure prophylactic agents are needed for first responders and military personnel. In this study, the ability of gamma-tocotrienol (GT3), a promising radioprotector and antioxidant, to ameliorate partial-body radiation-induced damage to the hematopoietic compartment was evaluated in a nonhuman primate (NHP) model. A total of 15 rhesus NHPs were divided into two groups, and were administered either GT3 or vehicle 24 h prior to 4 or 5.8 Gy partial-body irradiation (PBI), with 5% bone marrow (BM) sparing. Each group consisted of four NHPs, apart from the vehicle-treated group exposed to 5.8 Gy, which had only three NHPs. BM samples were collected 8 days prior to irradiation in addition to 2, 7, 14, and 30 days postirradiation. To assess the clonogenic ability of hematopoietic stem and progenitor cells (HSPCs), colony forming unit (CFU) assays were performed, and lymphoid cells were immunophenotyped using flow cytometry. As a result of GT3 treatment, an increase in HSPC function was evident by an increased recovery of CFU-granulocyte macrophages (CFU-GM). Additionally, GT3 treatment was shown to increase the percentage of CD34+ cells, including T and NK-cell subsets. Our data further affirm GT3's role in hematopoietic recovery and suggest the need for its further development as a prophylactic radiation medical countermeasure.
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Affiliation(s)
- Tarun K Garg
- UAMS Myeloma Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Sarita Garg
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Isabelle R Miousse
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Stephen Y Wise
- Division of Radioprotectants, Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814
| | - Alana D Carpenter
- Division of Radioprotectants, Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814
| | - Oluseyi O Fatanmi
- Division of Radioprotectants, Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814
| | - Frits van Rhee
- UAMS Myeloma Center, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
| | - Vijay K Singh
- Division of Radioprotectants, Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, Maryland 20814
| | - Martin Hauer-Jensen
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas 72205
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Shrum SA, Nukala U, Shrimali S, Pineda EN, Krager KJ, Thakkar S, Jones DE, Pathak R, Breen PJ, Aykin-Burns N, Compadre CM. Tocotrienols Provide Radioprotection to Multiple Organ Systems through Complementary Mechanisms of Antioxidant and Signaling Effects. Antioxidants (Basel) 2023; 12:1987. [PMID: 38001840 PMCID: PMC10668991 DOI: 10.3390/antiox12111987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2023] [Revised: 10/31/2023] [Accepted: 11/07/2023] [Indexed: 11/26/2023] Open
Abstract
Tocotrienols have powerful radioprotective properties in multiple organ systems and are promising candidates for development as clinically effective radiation countermeasures. To facilitate their development as clinical radiation countermeasures, it is crucial to understand the mechanisms behind their powerful multi-organ radioprotective properties. In this context, their antioxidant effects are recognized for directly preventing oxidative damage to cellular biomolecules from ionizing radiation. However, there is a growing body of evidence indicating that the radioprotective mechanism of action for tocotrienols extends beyond their antioxidant properties. This raises a new pharmacological paradigm that tocotrienols are uniquely efficacious radioprotectors due to a synergistic combination of antioxidant and other signaling effects. In this review, we have covered the wide range of multi-organ radioprotective effects observed for tocotrienols and the mechanisms underlying it. These radioprotective effects for tocotrienols can be characterized as (1) direct cytoprotective effects, characteristic of the classic antioxidant properties, and (2) other effects that modulate a wide array of critical signaling factors involved in radiation injury.
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Affiliation(s)
- Stephen A. Shrum
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Tocol Pharmaceuticals, LLC, Little Rock, AR 77205, USA
| | - Ujwani Nukala
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Joint Bioinformatics Graduate Program, University of Arkansas at Little Rock, Little Rock, AR 72204, USA
| | - Shivangi Shrimali
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Joint Bioinformatics Graduate Program, University of Arkansas at Little Rock, Little Rock, AR 72204, USA
| | - Edith Nathalie Pineda
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Joint Bioinformatics Graduate Program, University of Arkansas at Little Rock, Little Rock, AR 72204, USA
| | - Kimberly J. Krager
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Shraddha Thakkar
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Darin E. Jones
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Rupak Pathak
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Philip J. Breen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Nukhet Aykin-Burns
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
| | - Cesar M. Compadre
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA; (U.N.); (S.S.); (E.N.P.); (K.J.K.); (S.T.); (D.E.J.); (R.P.); (P.J.B.); (N.A.-B.)
- Tocol Pharmaceuticals, LLC, Little Rock, AR 77205, USA
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Sinitsky M, Asanov M, Sinitskaya A, Shishkova D, Khutornaya M, Minina V, Ponasenko A. Atorvastatin Can Modulate DNA Damage Repair in Endothelial Cells Exposed to Mitomycin C. Int J Mol Sci 2023; 24:ijms24076783. [PMID: 37047754 PMCID: PMC10094919 DOI: 10.3390/ijms24076783] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2023] [Revised: 03/15/2023] [Accepted: 04/04/2023] [Indexed: 04/14/2023] Open
Abstract
HMG-CoA reductase inhibitors (statins) are widely used in the therapy of atherosclerosis and have a number of pleiotropic effects, including DNA repair regulation. We studied the cytogenetic damage and the expression of DNA repair genes (DDB1, ERCC4, and ERCC5) in human coronary artery (HCAEC) and internal thoracic artery endothelial cells (HITAEC) in vitro exposed to mitomycin C (MMC) (positive control), MMC and atorvastatin (MMC+Atv), MMC followed by atorvastatin treatment (MMC/Atv) and 0.9% NaCl (negative control). MMC/Atv treated HCAEC were characterized by significantly decreased micronuclei (MN) frequency compared to the MMC+Atv group and increased nucleoplasmic bridges (NPBs) frequency compared to both MMC+Atv treated cells and positive control; DDB1, ERCC4, and ERCC5 genes were upregulated in MMC+Atv and MMC/Atv treated HCAEC in comparison with the positive control. MMC+Atv treated HITAEC were characterized by reduced MN frequency compared to positive control and decreased NPBs frequency in comparison with both the positive control and MMC/Atv group. Nuclear buds (NBUDs) frequency was significantly lower in MMC/Atv treated cells than in the positive control. The DDB1 gene was downregulated in the MMC+Atv group compared to the positive control, and the ERCC5 gene was upregulated in MMC/Atv group compared to both the positive control and MMC+Atv group. We propose that atorvastatin can modulate the DNA damage repair response in primary human endothelial cells exposed to MMC in a cell line- and incubation scheme-dependent manner that can be extremely important for understanding the fundamental aspects of pleoitropic action of atorvastatin and can also be used to correct the therapy of patients with atherosclerosis characterized by a high genotoxic load.
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Affiliation(s)
- Maxim Sinitsky
- Laboratory of Genome Medicine, Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo 650002, Russia
| | - Maxim Asanov
- Laboratory of Genome Medicine, Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo 650002, Russia
| | - Anna Sinitskaya
- Laboratory of Genome Medicine, Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo 650002, Russia
| | - Daria Shishkova
- Laboratory for Molecular, Translation and Digital Medicine, Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo 650002, Russia
| | - Maria Khutornaya
- Laboratory of Genome Medicine, Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo 650002, Russia
| | - Varvara Minina
- Department of Genetic and Fundamental Medicine, Kemerovo State University, Kemerovo 650000, Russia
| | - Anastasia Ponasenko
- Laboratory of Genome Medicine, Research Institute for Complex Issues of Cardiovascular Diseases, Kemerovo 650002, Russia
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Bruno JG, Sivils JC, Mohan S, Natarajan M. Alpha-thiol deoxynucleotide triphosphates (S-dNTPs) as radioprotective agents: A novel approach. Biochem Biophys Res Commun 2023; 660:6-12. [PMID: 37058844 DOI: 10.1016/j.bbrc.2023.03.071] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2023] [Revised: 03/17/2023] [Accepted: 03/29/2023] [Indexed: 04/09/2023]
Abstract
In this study, the ability of a mixture of four different alpha-thiol deoxynucleotide triphosphates (S-dNTPs) each at a concentration of 10μM when incorporated into the genomic DNA of proliferating human HL-60 and Mono-Mac-6 (MM-6) cells in vitro to provide protection from 2, 5, and 10 Gy of gamma radiation was investigated. Incorporation of the four different S-dNTPs into nuclear DNA at 10 μM concentration for five days was validated by agarose gel electrophoretic band shift analysis. S-dNTP-treated genomic DNA reacted with BODIPY-iodoacetamide demonstrated a band shift to higher molecular weight to confirm the presence of sulfur moieties in the resultant phosphorothioate DNA backbones. No overt signs of toxicity or obvious morphologic cellular differentiation were noted in the presence of 10 μM S-dNTPs even after 8 days in culture. Significantly reduced radiation-induced persistent DNA damage measured at 24 and 48 h post-exposure by γ-H2AX histone phosphorylation using FACS analysis in S-dNTP incorporated HL-60 and MM6 cells indicated protection against radiation-induced direct and indirect DNA damage. Statistically significant protection by S-dNTPs was noted at the cellular level by CellEvent™ Caspase-3/7 assay, which assess the extent of apoptotic events, and by trypan blue dye exclusion to assed cell viability. The results appear to support an innocuous antioxidant thiol radioprotective effect built into genomic DNA backbones as the last line of defense against ionizing radiation and free radical-induced DNA damage.
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Singh VK, Seed TM. Development of gamma-tocotrienol as a radiation medical countermeasure for the acute radiation syndrome: current status and future perspectives. Expert Opin Investig Drugs 2023; 32:25-35. [PMID: 36655861 DOI: 10.1080/13543784.2023.2169127] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
INTRODUCTION The possibility of exposure to high doses of total- or partial-body ionizing radiation at a high dose rate due to radiological/nuclear accidents or terrorist attacks is increasing. Despite research and development during the last six decades, there is a shortage of nontoxic, safe, and effective radiation medical countermeasures (MCMs) for radiological and nuclear emergencies. To date, the US Food and Drug Administration (US FDA) has approved only four agents for the mitigation of hematopoietic acute radiation syndrome (H-ARS). AREA COVERED We present the current status of a promising radiation countermeasure, gamma-tocotrienol (GT3; a component of vitamin E) as a radiation MCM that has been investigated in murine and nonhuman primate models of H-ARS. There is significant work with this agent using various omic platforms during the last few years to identify its efficacy biomarkers. EXPERT OPINION GT3 is a newer type of radioprotector having significant injury-countering potential and is currently under advanced development for H-ARS. As a pre-exposure drug, it requires only single doses, lacks significant toxicity, and has minimal, ambient temperature storage requirements; thus, GT3 appears to be an ideal MCM for military and first responders as well as for storage in the Strategic National Stockpile.
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Affiliation(s)
- Vijay K Singh
- Division of Radioprotectants, Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA.,Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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8
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Jit BP, Pattnaik S, Arya R, Dash R, Sahoo SS, Pradhan B, Bhuyan PP, Behera PK, Jena M, Sharma A, Agrawala PK, Behera RK. Phytochemicals: A potential next generation agent for radioprotection. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2022; 106:154188. [PMID: 36029645 DOI: 10.1016/j.phymed.2022.154188] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2021] [Revised: 03/13/2022] [Accepted: 05/17/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Radiation hazards are accountable for extensive damage in the biological system and acts as a public health burden. Owing to the rapid increasing in radiation technology, both Ionizing radiation (IR) from natural and man made source poses detrimental outcome to public health. IR releases free radicals which induces oxidative stress and deleterious biological damage by modulating radiation induced signalling intermediates. The efficacy of existing therapeutic approach and treatment strategy are limited owing to their toxicity and associated side effects. Indian system of traditional medicine is enriched with prospective phytochemicals with potential radioprotection ability. PURPOSE The present review elucidated and summarized the potential role of plant derived novel chemical compound with prospective radioprotective potential. METHOD So far as the traditional system of Indian medicine is concerned, plant kingdom is enriched with potential bioactive molecules with diverse pharmacological activities. We reviewed several compounds mostly secondary metabolites from plant origin using various search engines. RESULTS Both compounds from land plants and marine source exhibited antioxidant antiinflammatory, free radical scavenging ability. These compounds have tremendous potential in fine-tuning of several signalling intermediates, which are actively participated in the progression and development of a pathological condition associated with radiation stress. CONCLUSION Development and explore of an operational radioprotective agent from originated from plant source that can be used as a novel molecular tool to eliminate the widespread damage caused by space exploration, ionizing radiation, nuclear war and radiotherapy has been significantly appreciated. Through extensive literature search we highlighted several compounds from both land plant and marine origin can be implemented for a better therapeutic potential against radiation induced injury. Furthermore, extensive clinical trials must be carried out in near future for better therapeutic modality and clinical efficacy.
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Affiliation(s)
- Bimal Prasad Jit
- Department of Biochemistry, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India; School of Life Sciences, Sambalpur University, Jyoti Vihar, Burla 768019, India
| | - Subhaswaraj Pattnaik
- Department of Microbiology, School of Life Sciences, Pondicherry University, Puducherry 605014, India; Centre of Excellence in Natural Products and Therapeutics, Department of Biotechnology and Bioinformatics, Sambalpur University, Jyoti Vihar, Burla, Odisha 768019, India
| | - Rakesh Arya
- Department of Biochemistry, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India; School of Life Sciences, Sambalpur University, Jyoti Vihar, Burla 768019, India
| | - Rutumbara Dash
- Departement of Gastroenterology, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | | | - Biswajita Pradhan
- Algal Biotechnology and Molecular Systematic Laboratory, Post Graduate Department of Botany, Berhampur University, Bhanja Bihar, Berhampur, Odisha 760007, India; Department of Biotechnology, Sangmyung University, Seoul 03016, South Korea
| | - Prajna Paramita Bhuyan
- Department of Botany, Maharaja Sriram Chandra Bhanja Deo University, Baripada, Odisha 757003, India
| | - Pradyota Kumar Behera
- Department of Chemistry, Berhampur University, Bhanja Bihar, Berhampur, Odisha 760007, India
| | - Mrutyunjay Jena
- Algal Biotechnology and Molecular Systematic Laboratory, Post Graduate Department of Botany, Berhampur University, Bhanja Bihar, Berhampur, Odisha 760007, India
| | - Ashok Sharma
- Department of Biochemistry, All India Institute of Medical Sciences, Ansari Nagar, New Delhi 110029, India
| | - Paban Kumar Agrawala
- Institute of Nuclear Medicine and Allied Science, Defence Research and Development Organization, New Delhi 110054, India
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9
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Garg S, Garg TK, Miousse IR, Wise SY, Fatanmi OO, Savenka AV, Basnakian AG, Singh VK, Hauer-Jensen M. Effects of Gamma-Tocotrienol on Partial-Body Irradiation-Induced Intestinal Injury in a Nonhuman Primate Model. Antioxidants (Basel) 2022; 11:1895. [PMID: 36290618 PMCID: PMC9598988 DOI: 10.3390/antiox11101895] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2022] [Revised: 09/16/2022] [Accepted: 09/19/2022] [Indexed: 11/17/2022] Open
Abstract
Exposure to high doses of radiation, accidental or therapeutic, often results in gastrointestinal (GI) injury. To date, there are no therapies available to mitigate GI injury after radiation exposure. Gamma-tocotrienol (GT3) is a promising radioprotector under investigation in nonhuman primates (NHP). We have shown that GT3 has radioprotective function in intestinal epithelial and crypt cells in NHPs exposed to 12 Gy total-body irradiation (TBI). Here, we determined GT3 potential in accelerating the GI recovery in partial-body irradiated (PBI) NHPs using X-rays, sparing 5% bone marrow. Sixteen rhesus macaques were treated with either vehicle or GT3 24 h prior to 12 Gy PBI. Structural injuries and crypt survival were examined in proximal jejunum on days 4 and 7. Plasma citrulline was assessed using liquid chromatography-tandem mass spectrometry (LC-MS/MS). Crypt cell proliferation and apoptotic cell death were evaluated using Ki-67 and TUNEL staining. PBI significantly decreased mucosal surface area and reduced villous height. Interestingly, GT3 increased crypt survival and enhanced stem cell proliferation at day 4; however, the effects seemed to be minimized by day 7. GT3 did not ameliorate a radiation-induced decrease in citrulline levels. These data suggest that X-rays induce severe intestinal injury post-PBI and that GT3 has minimal radioprotective effect in this novel model.
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Affiliation(s)
- Sarita Garg
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Tarun K. Garg
- UAMS Myeloma Center, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Isabelle R. Miousse
- Department of Biochemistry and Molecular Biology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Stephen Y. Wise
- Division of Radioprotectants, Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Oluseyi O. Fatanmi
- Division of Radioprotectants, Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Alena V. Savenka
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
| | - Alexei G. Basnakian
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
- John L. McClellan Memorial VA Hospital, Central Arkansas Veterans Healthcare System, Little Rock, AR 72205, USA
| | - Vijay K. Singh
- Division of Radioprotectants, Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA
| | - Martin Hauer-Jensen
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA
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10
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Feng Y, Feng Y, Gu L, Liu P, Cao J, Zhang S. The Critical Role of Tetrahydrobiopterin (BH4) Metabolism in Modulating Radiosensitivity: BH4/NOS Axis as an Angel or a Devil. Front Oncol 2021; 11:720632. [PMID: 34513700 PMCID: PMC8429800 DOI: 10.3389/fonc.2021.720632] [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: 06/04/2021] [Accepted: 08/12/2021] [Indexed: 12/16/2022] Open
Abstract
Ionizing radiation and radioactive materials have been widely used in industry, medicine, science and military. The efficacy of radiotherapy and adverse effects of normal tissues are closed related to cellular radiosensitivity. Molecular mechanisms underlying radiosensitivity are of significance to tumor cell radiosensitization as well as normal tissue radioprotection. 5,6,7,8-Tetrahydrobiopterin (BH4) is an essential cofactor for nitric oxide synthases (NOS) and aromatic amino acid hydroxylases, and its biosynthesis involves de novo biosynthesis and a pterin salvage pathway. In this review we overview the role of BH4 metabolism in modulating radiosensitivity. BH4 homeostasis determines the role of NOS, affecting the production of nitric oxide (NO) and oxygen free radicals. Under conditions of oxidative stress, such as UV-radiation and ionizing radiation, BH4 availability is diminished due to its oxidation, which subsequently leads to NOS uncoupling and generation of highly oxidative free radicals. On the other hand, BH4/NOS axis facilitates vascular normalization, a process by which antiangiogenic therapy corrects structural and functional flaws of tumor blood vessels, which enhances radiotherapy efficacy. Therefore, BH4/NOS axis may serve as an angel or a devil in regulating cellular radiosensitivity. Finally, we will address future perspectives, not only from the standpoint of perceived advances in treatment, but also from the potential mechanisms. These advances have demonstrated that it is possible to modulate cellular radiosensitivity through BH4 metabolism.
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Affiliation(s)
- Yang Feng
- School of Radiation Medicine and Protection, State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, China
| | - Yahui Feng
- China National Nuclear Corporation 416 Hospital (Second Affiliated Hospital of Chengdu Medical College), Chengdu, China
| | - Liming Gu
- School of Radiation Medicine and Protection, State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, China
| | - Pengfei Liu
- School of Radiation Medicine and Protection, State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, China
| | - Jianping Cao
- School of Radiation Medicine and Protection, State Key Laboratory of Radiation Medicine, Soochow University, Suzhou, China
| | - Shuyu Zhang
- China National Nuclear Corporation 416 Hospital (Second Affiliated Hospital of Chengdu Medical College), Chengdu, China.,West China Second University Hospital, Sichuan University, Chengdu, China.,West China School of Basic Medical Sciences and Forensic Medicine, Sichuan University, Chengdu, China
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11
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Rabender CS, Mezzaroma E, Yakovlev VA, Mauro AG, Bonaventura A, Abbate A, Mikkelsen RB. Mitigation of Radiation-Induced Lung and Heart Injuries in Mice by Oral Sepiapterin after Irradiation. Radiat Res 2021; 195:463-473. [PMID: 33822229 DOI: 10.1667/rade-20-00249.1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 02/21/2021] [Indexed: 01/12/2023]
Abstract
After radiation exposure, endothelium-dependent vasorelaxation is impaired due to impaired nitric oxide production. Endothelial dysfunction is characterized by uncoupled endothelial nitric oxide synthase activity, oxidation of the reduced cofactor tetrahydrobiopterin to dihydrobiopterin as one well recognized mechanism. Oral treatment with sepiapterin, a tetrahydrobiopterin precursor, decreased infiltrating inflammatory cells and cytokine levels in mice with colitis. We therefore tested whether a synthetic sepiapterin, PTC923, might mitigate radiation-induced cardiac and pulmonary injuries. C57L/J wild-type 6-8-week-old mice of both sexes received 5 Gy total-body irradiation (TBI), followed by a top-up dose of 6.5 Gy to the thorax (total thoracic dose of 11.5 Gy). Starting from 24 h postirradiation, mice were treated once daily with 1 mg/kg PTC923 for six days by oral gavage. Assessment of lung injury by breathing rate was measured every other week and echocardiography to assess heart function was performed at different time points (8, 30, 60, 90 and 180 days). Plasma proteins (fibrinogen, neutrophil elastase, C-reactive protein, and IL-6) were assessed as well. TBI induced a reduction in cardiac contractile reserve and an impairment in diastolic function restored by daily oral PTC923. Postirradiation lung injury was significantly delayed by PTC923. TBI mice treated with PTC923 experienced a longer survival compared to nonirradiated mice (71% vs. 40% of mice alive after 180 days). PTC923-treated mice showed a reduction in inflammatory mediators, especially IL-6 and IL-1b. In conclusion, these findings support the proposal that PTC923 is a potential mitigator of cardiac and lung injury caused by TBI.
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Affiliation(s)
- Christopher S Rabender
- Department of Radiation Oncology, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Eleonora Mezzaroma
- Department of Pharmacotherapy and Outcomes Science, School of Pharmacy, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Vasily A Yakovlev
- Department of Radiation Oncology, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Adolfo G Mauro
- Internal Medicine, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Aldo Bonaventura
- Internal Medicine, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Antonio Abbate
- Internal Medicine, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
| | - Ross B Mikkelsen
- Department of Radiation Oncology, Division of Cardiology, Pauley Heart Center, Virginia Commonwealth University, Richmond, Virginia
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12
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Thabet NM, Rashed ER, Abdel-Rafei MK, Moustafa EM. Modulation of the Nitric Oxide/BH4 Pathway Protects Against Irradiation-Induced Neuronal Damage. Neurochem Res 2021; 46:1641-1658. [PMID: 33755856 DOI: 10.1007/s11064-021-03306-0] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/11/2021] [Accepted: 03/17/2021] [Indexed: 12/15/2022]
Abstract
The kynurenine pathway (KP, IDO/Kyn pathway) is an important metabolic pathway related to many diseases. Although cranial radiotherapy is the mainstay in metastatic tumors management, its efficacy is limited owing to the associated neuropsychiatric disorders. Sildenafil (SD) and simvastatin (SV) were reported to have antioxidant/anti-inflammatory effects and to serve as NO donor/BH4 regulator, respectively. Fluoxetine (Fx) is an FDA-approved anti-depressant agent and one of the selective serotonin reuptake inhibitor drugs (SSRI), used in neurological disorder treatment. The study objective was to investigate the role of cranial irradiation (C-IR) on KP signaling impairment and the possible intervention by SD and/or SV (as nitric oxide (NO) donor/Tetrahydrobiopterin (BH4) regulatory) on KP following C-IR-induced disruption compared with Fx (as standard drug).Herein, rats were exposed to C-IR at a single dose level of 25 Gy, then treated with sildenafil (SD) and/or simvastatin (SV), and fluoxetine (Fx) at doses of 75, 20, 10 mg/kg/day, respectively. The body weight gain and forced swimming test (FST) were used for evaluation along with the biochemical quantifications of KP intermediates and histopathological examination of cortex and hippocampus. The results indicated a significant activation of KP following C-IR as manifested by decreased Trp content and increased activities of indoleamine 2,3-dioxygenase (IDO) and tryptophan 2,3-dioxygenase (TDO) with a rise in kynurenine (KYN) and quinolinic acid (QA) hippocampal contents. In addition, a state of C-IR-induced oxidative stress, inflammation, NO-pathway dysregulation and neuronal apoptosis were observed as compared to the control group. However, significant modulations were recorded after the combined administration of SD and SV than those offered by each of them alone and by Fx. The biochemical assessment results were supported by the histopathological tissue examination. It could be concluded that the co-administration of SV and SD offers a neuroprotective effect against irradiation-induced brain injury due to its NO donor/BH4 regulatory activities, anti-inflammatory and antioxidant properties that modulate IDO/KYN pathway.
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Affiliation(s)
- Noura Magdy Thabet
- Radiation Biology Department, National Centre for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority, Cairo, Egypt
| | - Engy Refaat Rashed
- Drug Radiation Research Department, National Centre for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority, Cairo, Egypt.
| | - Mohamed Khairy Abdel-Rafei
- Radiation Biology Department, National Centre for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority, Cairo, Egypt
| | - Enas Mahmoud Moustafa
- Radiation Biology Department, National Centre for Radiation Research and Technology (NCRRT), Egyptian Atomic Energy Authority, Cairo, Egypt
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13
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Lei G, Mao C, Yan Y, Zhuang L, Gan B. Ferroptosis, radiotherapy, and combination therapeutic strategies. Protein Cell 2021; 12:836-857. [PMID: 33891303 PMCID: PMC8563889 DOI: 10.1007/s13238-021-00841-y] [Citation(s) in RCA: 204] [Impact Index Per Article: 68.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2021] [Accepted: 03/29/2021] [Indexed: 12/19/2022] Open
Abstract
Ferroptosis, an iron-dependent form of regulated cell death driven by peroxidative damages of polyunsaturated-fatty-acid-containing phospholipids in cellular membranes, has recently been revealed to play an important role in radiotherapy-induced cell death and tumor suppression, and to mediate the synergy between radiotherapy and immunotherapy. In this review, we summarize known as well as putative mechanisms underlying the crosstalk between radiotherapy and ferroptosis, discuss the interactions between ferroptosis and other forms of regulated cell death induced by radiotherapy, and explore combination therapeutic strategies targeting ferroptosis in radiotherapy and immunotherapy. This review will provide important frameworks for future investigations of ferroptosis in cancer therapy.
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Affiliation(s)
- Guang Lei
- Department of Radiation Oncology, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, 410013, China.,Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Chao Mao
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Yuelong Yan
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Li Zhuang
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA
| | - Boyi Gan
- Department of Experimental Radiation Oncology, The University of Texas MD Anderson Cancer Center, Houston, TX, 77030, USA. .,The University of Texas MD Anderson UTHealth Graduate School of Biomedical Sciences, Houston, TX, USA.
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14
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Korkushko OV, Gorban EM, Bondarenko OV, Antonyuk-Shcheglova IA, Naskalova SS, Parshykov OV, Utko NO, Gavalko AV, Shatilo VB, Duzhak GV. APPLICATION OF QUERCETIN FOR CORRECTION OF THE IMPAIRMENT OF THE FUNCTIONAL STATE OF THE ENDOTHELIUS OF VESSELS (CLINICAL AND EXPERIMENTAL STUDY). PROBLEMY RADIAT︠S︡IĬNOÏ MEDYT︠S︡YNY TA RADIOBIOLOHIÏ 2020; 25:321-337. [PMID: 33361844 DOI: 10.33145/2304-8336-2020-25-321-337] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/03/2020] [Indexed: 11/10/2022]
Abstract
OBJECTIVE in the experiment, to investigate the effect of Quercetin on the NO-dependent reactions of isolated vessels involving endothelium and perivascular adipose tissue (PVAT) after a single X-ray irradiation of rats at a sublethal dose. In a clinical study, to investigate the effect of long-term use of Quercetin on the functional state of themicrovascular endothelium in the elderly patients with metabolic syndrome (MS). MATERIAL AND METHODS Experimental studies were performed on vascular fragments obtained from adult male rats(7-8 months) of the control group, in animals exposed to a single R-irradiation at a dose of 7 Gy and animals irradiated in the same dose, which received Quercetin orally for 14 days three times a week based on 10 mg/kg bodyweight. Fragments of the thoracic aorta (TA) and mesenteric artery (MA) were cleaned of perivascular adipose tissue (PVAT-) or left uncleaned (PVAT+), and then were cut into rings (up to 2 mm). The amplitude of the contractionof the rings TA and MA under the influence of phenylephrine (PE, 3 x 10-6 M), the amplitude of the contraction of therings TA and MA in the presence of a competitive blocker of NO-synthase methyl ester of N-nitro-L-arginine(L-NAME, 10-5 M), the amplitude of relaxation of the rings TA and MA in the presence of N-acetylcysteine (NAC, 10-4 M)were measured. The clinical study examined 110 patients with MS criteria in accordance with ATP III (2001).Patients in the main group for 3 months received Quercetin from the same manufacturer, 80 mg three times a day,patients in the control group received placebo. RESULTS Single R-irradiation disrupts the regulation of the contractile function of TA and MA, which is evidenced bychanges in the contractile reactions of isolated fragments of these vessels as a response to the action of vasoactivecompounds. Course use of Quercetin in irradiated rats leads to the normalization of contractile and dilatory vascular responses due to partial correction of NO metabolism in the endothelium and PVAT. For the majority of patients(69 %) who received Quercetin, a post-occlusive hyperemia test showed a statistically significant increase of maximal volumetric velocity of the skin blood flow rate and duration of the recovery period to the baseline, which indicates about improvement of vasomotor vascular endothelial function. CONCLUSIONS Course use of Quercetin improves the functional state of the microvascular endothelium among theelderly people with MS, normalizes contractile and dilatory vascular responses in irradiated rats due to partial correction of NO metabolism in the endothelium and PVAT.
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Affiliation(s)
- O V Korkushko
- State Enterprise «Institute of Gerontology DF Chebotareva NAMS of Ukraine», 67 Vyshgorodska St., Kyiv, 04114, Ukraine
| | - E M Gorban
- State Enterprise «Institute of Gerontology DF Chebotareva NAMS of Ukraine», 67 Vyshgorodska St., Kyiv, 04114, Ukraine
| | - O V Bondarenko
- State Enterprise «Institute of Gerontology DF Chebotareva NAMS of Ukraine», 67 Vyshgorodska St., Kyiv, 04114, Ukraine
| | - I A Antonyuk-Shcheglova
- State Enterprise «Institute of Gerontology DF Chebotareva NAMS of Ukraine», 67 Vyshgorodska St., Kyiv, 04114, Ukraine
| | - S S Naskalova
- State Enterprise «Institute of Gerontology DF Chebotareva NAMS of Ukraine», 67 Vyshgorodska St., Kyiv, 04114, Ukraine
| | - O V Parshykov
- State Enterprise «Institute of Pharmacology and Toxicology NAMS of Ukraine», 14 Antona Tsedika St., Kyiv, 02000, Ukraine
| | - N O Utko
- State Enterprise «Institute of Gerontology DF Chebotareva NAMS of Ukraine», 67 Vyshgorodska St., Kyiv, 04114, Ukraine
| | - A V Gavalko
- State Enterprise «Institute of Gerontology DF Chebotareva NAMS of Ukraine», 67 Vyshgorodska St., Kyiv, 04114, Ukraine
| | - V B Shatilo
- State Enterprise «Institute of Gerontology DF Chebotareva NAMS of Ukraine», 67 Vyshgorodska St., Kyiv, 04114, Ukraine
| | - G V Duzhak
- State Enterprise «Institute of Gerontology DF Chebotareva NAMS of Ukraine», 67 Vyshgorodska St., Kyiv, 04114, Ukraine
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15
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Kumar VP, Stone S, Biswas S, Sharma N, Ghosh SP. Gamma Tocotrienol Protects Mice From Targeted Thoracic Radiation Injury. Front Pharmacol 2020; 11:587970. [PMID: 33343356 PMCID: PMC7748112 DOI: 10.3389/fphar.2020.587970] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2020] [Accepted: 10/06/2020] [Indexed: 01/20/2023] Open
Abstract
Radiation injury will result in multiorgan dysfuntion leading to multiorgan failure. In addition to many factors such as radiation dose, dose rate, the severity of the injury will also depend on organ systems which are exposed. Here, we report the protective property of gamma tocotrienol (GT3) in total as well as partial body irradiation (PBI) model in C3H/HeN male mice. We have carried out PBI by targeting thoracic region (lung-PBI) using Small Animal Radiation Research Platform, an X-ray irradiator with capabilities of an image guided irradiation with a variable collimator with minimized exposure to non-targeted tissues and organs. Precise and accurate irradiation of lungs was carried out at either 14 or 16 Gy at an approximate dose rate of 2.6 Gy/min. Though a low throughput model, it is amenable to change the field size on the spot. No damage to other non-targeted organs was observed in histopathological evaluation. There was no significant change in peripheral blood counts of irradiated mice in comparison to naïve mice. Femoral bone marrow cells had no damage in irradiated mice. As expected, damage to the targeted tissue was observed in the histopathological evaluation and non-targeted tissue was found normal. Regeneration and increase of cellularity and megakaryocytes on GT3 treatment was compared to significant loss of cellularity in saline group. Peak alveolitis was observed on day 14 post-PBI and protection from alveolitis by GT3 was noted. In irradiated lung tissue, thirty proteins were found to be differentially expressed but modulated by GT3 to reverse the effects of irradiation. We propose that possible mode of action of GT3 could be Angiopoietin 2-Tie2 pathway leading to AKT/ERK pathways resulting in disruption in cell survival/angiogenesis.
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Affiliation(s)
- Vidya P Kumar
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Sasha Stone
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Shukla Biswas
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Neel Sharma
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
| | - Sanchita P Ghosh
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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16
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Gamma Radiation-Induced Disruption of Cellular Junctions in HUVECs Is Mediated through Affecting MAPK/NF- κB Inflammatory Pathways. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:1486232. [PMID: 31467629 PMCID: PMC6701340 DOI: 10.1155/2019/1486232] [Citation(s) in RCA: 23] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 04/08/2019] [Accepted: 07/02/2019] [Indexed: 12/15/2022]
Abstract
Ionizing radiation-induced cardiovascular diseases (CVDs) have been well documented. However, the mechanisms of CVD genesis are still not fully understood. In this study, human umbilical vein endothelial cells (HUVECs) were exposed to gamma irradiation at different doses ranging from 0.2 Gy to 5 Gy. Cell viability, migration ability, permeability, oxidative and nitrosative stresses, inflammation, and nuclear factor kappa-light-chain-enhancer of activated B cell (NF-κB) pathway activation were evaluated postirradiation. It was found that gamma irradiation at doses ranging from 0.5 Gy to 5 Gy inhibited the migration ability of HUVECs without any significant effects on cell viability at 6 h and 24 h postirradiation. The decreased transendothelial electrical resistance (TEER), increased permeability, and disruption of cellular junctions were observed in HUVECs after gamma irradiation accompanied by the lower levels of junction-related proteins such as ZO-1, occludin, vascular endothelial- (VE-) cadherin, and connexin 40. The enhanced oxidative and nitrosative stresses, e.g., ROS and NO2 - levels and inflammatory cytokines IL-6 and TNF-α were demonstrated in HUVECs after gamma irradiation. Western blot results showed that protein levels of mitogen-activated protein kinase (MAPK) pathway molecules p38, p53, p21, and p27 increased after gamma irradiation, which further induced the activation of the NF-κB pathway. BAY 11-7085, an inhibitor of NF-κB activation, was demonstrated to partially block the effects of gamma radiation in HUVECs examined by TEER and FITC-dextran permeability assay. We therefore concluded that the gamma irradiation-induced disruption of cellular junctions in HUVECs was through the inflammatory MAPK/NF-κB signaling pathway.
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17
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Pathak R, Kumar VP, Hauer-Jensen M, Ghosh SP. Enhanced Survival in Mice Exposed to Ionizing Radiation by Combination of Gamma-Tocotrienol and Simvastatin. Mil Med 2019; 184:644-651. [PMID: 30901461 DOI: 10.1093/milmed/usy408] [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: 08/02/2018] [Revised: 10/18/2018] [Indexed: 12/27/2022] Open
Abstract
Ionizing radiation exposure is a major concern for active military service members, as well as civilian population. Considering that the exposure is not predictable, it is imperative that strategies to counteract radiation damage must be discovered. Recent in vitro studies performed in our laboratory demonstrated that the vitamin E analog gamma-tocotrienol (GT3) in combination with cholesterol-lowering drugs (Statins), synergistically induced endothelial thrombomodulin, an anticoagulant with radio-protective efficacy. It was hypothesized that the combination of treatment with both GT3 along with Statins would provide better radiation protection in vivo than each drug individually. CD2F1 mice were injected subcutaneously with either vehicle or single dose of GT3 (200 mg/kg body weight) 24 hours before irradiation followed by oral or subcutaneous administration of various doses of simvastatin (25, 50, and 100 mg/kg body weight) before exposure to lethal doses (11.5 and 12 Gy) of Cobalt-60 (60Co) gamma-irradiation. The combined treatment group exhibited enhanced radiation lethality protection substantially, accelerated white blood cell recovery, and augmented restoration of bone marrow cellularity when compared to the animals treated with either drug exclusively. This information clearly suggests that combined treatment could be used as a safeguard for military personnel from exposure to harmful ionizing radiation.
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Affiliation(s)
- Rupak Pathak
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, 4301 W Markham St, Little Rock, AR
| | - Vidya Prasanna Kumar
- Armed Forces Radiobiology Research Institute, USUHS, 4555 South Palmer Road Bldg 42, Bethesda, MD
| | - Martin Hauer-Jensen
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, 4301 W Markham St, Little Rock, AR
| | - Sanchita Purohit Ghosh
- Armed Forces Radiobiology Research Institute, USUHS, 4555 South Palmer Road Bldg 42, Bethesda, MD
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18
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Garg S, Sadhukhan R, Banerjee S, Savenka AV, Basnakian AG, McHargue V, Wang J, Pawar SA, Ghosh SP, Ware J, Hauer-Jensen M, Pathak R. Gamma-Tocotrienol Protects the Intestine from Radiation Potentially by Accelerating Mesenchymal Immune Cell Recovery. Antioxidants (Basel) 2019; 8:antiox8030057. [PMID: 30845647 PMCID: PMC6466604 DOI: 10.3390/antiox8030057] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 02/24/2019] [Accepted: 02/28/2019] [Indexed: 12/12/2022] Open
Abstract
Natural antioxidant gamma-tocotrienol (GT3), a vitamin E family member, provides intestinal radiation protection. We seek to understand whether this protection is mediated via mucosal epithelial stem cells or sub-mucosal mesenchymal immune cells. Vehicle- or GT3-treated male CD2F1 mice were exposed to total body irradiation (TBI). Cell death was determined by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay. Villus height and crypt depth were measured with computer-assisted software in tissue sections. Functional activity was determined with an intestinal permeability assay. Immune cell recovery was measured with immunohistochemistry and Western blot, and the regeneration of intestinal crypts was assessed with ex vivo organoid culture. A single dose of GT3 (200 mg/kg body weight (bwt)) administered 24 h before TBI suppressed cell death, prevented a decrease in villus height, increased crypt depth, attenuated intestinal permeability, and upregulated occludin level in the intestine compared to the vehicle treated group. GT3 accelerated mesenchymal immune cell recovery after irradiation, but it did not promote ex vivo organoid formation and failed to enhance the expression of stem cell markers. Finally, GT3 significantly upregulated protein kinase B or AKT phosphorylation after TBI. Pretreatment with GT3 attenuates TBI-induced structural and functional damage to the intestine, potentially by facilitating intestinal immune cell recovery. Thus, GT3 could be used as an intestinal radioprotector.
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Affiliation(s)
- Sarita Garg
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Ratan Sadhukhan
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Sudip Banerjee
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Alena V Savenka
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Alexei G Basnakian
- Department of Pharmacology and Toxicology, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
- Central Arkansas Veterans Healthcare System, Little Rock, AR 72205, USA.
| | - Victoria McHargue
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Junru Wang
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Snehalata A Pawar
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Sanchita P Ghosh
- Armed Forces Radiobiology Research Institute, USUHS, Bethesda, MD 20814, USA.
| | - Jerry Ware
- Department of Physiology and Biophysics, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Martin Hauer-Jensen
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Rupak Pathak
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
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19
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Hanedan Uslu G, Canyilmaz E, Serdar L, Ersöz Ş. Protective effects of genistein and melatonin on mouse liver injury induced by whole-body ionising radiation. Mol Clin Oncol 2018; 10:261-266. [PMID: 30680205 DOI: 10.3892/mco.2018.1790] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2018] [Accepted: 12/04/2018] [Indexed: 12/25/2022] Open
Abstract
The aim of the present study was to investigate the effectiveness of melatonin and genistein in preventing radiation therapy (RT)-induced liver injury in mice. A total of 70 Swiss Albino male mice were divided into 7 equal groups (n=10/group) as follows: Melatonin (M group, G3), genistein (G group, G4), polyethylene glycol-400 (P group, G5), RT only (RT group, G2) and sham irradiation (C group, G1). RT plus genistein (RT+G group, G7) and RT plus melatonin (RT+M group, G6) were the co-treatment groups. Firstly, hepatic tissue damage was induced in mice via exposure to a single dose of 6-Gy irradiation. RT was performed with a cobalt-60 teletherapy machine (80 cm fixed source-to-surface distance, 2.5-cm depth). Melatonin was processed (100 mg/kg, intraperitoneal) 30 min before and genistein was administered (200 mg/kg, SC) one day prior to the single dose of irradiation. Six months following irradiation, all mice were sacrificed. The degree of liver injury was measured using histological liver sections. Liver injury was significantly worse in the RT group than in the control group (C; RT vs. C; P<0.05); however, liver injury decreased following co-treatment with melatonin or genistein vs. RT alone (RT+M and RT+G vs. RT; P<0.05). No difference was observed between the RT+M and RT+G groups (P>0.05). The present study revealed that melatonin and genistein administration prior to irradiation protects mice against liver injury, which may have therapeutic implications for RT-induced injuries.
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Affiliation(s)
- Gonca Hanedan Uslu
- Department of Radiation Oncology, Health Sciences University Kanuni Training and Research Hospital, Trabzon 61250, Turkey
| | - Emine Canyilmaz
- Department of Radiation Oncology, Faculty of Medicine, Karadeniz Technical University, Trabzon 61080, Turkey
| | - Lasif Serdar
- Department of Radiation Oncology, Health Sciences University Kanuni Training and Research Hospital, Trabzon 61250, Turkey
| | - Şafak Ersöz
- Department of Medical Pathology, Faculty of Medicine, Karadeniz Technical University, Trabzon 61080, Turkey
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20
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Soloviev AI, Kizub IV. Mechanisms of vascular dysfunction evoked by ionizing radiation and possible targets for its pharmacological correction. Biochem Pharmacol 2018; 159:121-139. [PMID: 30508525 DOI: 10.1016/j.bcp.2018.11.019] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2018] [Accepted: 11/28/2018] [Indexed: 12/20/2022]
Abstract
Ionizing radiation (IR) leads to a variety of the cardiovascular diseases, including the arterial hypertension. A number of studies have demonstrated that blood vessels represent important target for IR, and the endothelium is one of the most vulnerable components of the vascular wall. IR causes an inhibition of nitric oxide (NO)-mediated endothelium-dependent vasodilatation and generation of reactive oxygen (ROS) and nitrogen (RNS) species trigger this process. Inhibition of NO-mediated vasodilatation could be due to endothelial NO synthase (eNOS) down-regulation, inactivation of endothelium-derived NO, and abnormalities in diffusion of NO from the endothelial cells (ECs) leading to a decrease in NO bioavailability. Beside this, IR suppresses endothelial large conductance Ca2+-activated K+ channels (BKCa) activity, which control NO synthesis. IR also leads to inhibition of the BKCa current in vascular smooth muscle cells (SMCs) which is mediated by protein kinase C (PKC). On the other hand, IR-evoked enhanced vascular contractility may result from PKC-mediated increase in SMCs myofilament Ca2+ sensitivity. Also, IR evokes vascular wall inflammation and atherosclerosis development. Vascular function damaged by IR can be effectively restored by quercetin-filled phosphatidylcholine liposomes and mesenchymal stem cells injection. Using RNA-interference technique targeted to different PKC isoforms can also be a perspective approach for pharmacological treatment of IR-induced vascular dysfunction.
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Affiliation(s)
- Anatoly I Soloviev
- Department of Pharmacology of Cellular Signaling Systems and Experimental Therapy, Institute of Pharmacology and Toxicology, National Academy of Medical Sciences of Ukraine, 14 Eugene Pottier Street, Kiev 03068, Ukraine
| | - Igor V Kizub
- Department of Pharmacology, New York Medical College, 15 Dana Road, Valhalla 10595, NY, United States.
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21
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Montay-Gruel P, Meziani L, Yakkala C, Vozenin MC. Expanding the therapeutic index of radiation therapy by normal tissue protection. Br J Radiol 2018; 92:20180008. [PMID: 29694234 DOI: 10.1259/bjr.20180008] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Normal tissue damages induced by radiation therapy remain dose-limiting factors in radiation oncology and this is still true despite recent advances in treatment planning and delivery of image-guided radiation therapy. Additionally, as the number of long-term cancer survivors increases, unacceptable complications emerge and dramatically reduce the patients' quality of life. This means that patients and clinicians expect discovery of new options for the therapeutic management of radiation-induced complications. Over the past four decades, research has enhanced our understanding of the pathophysiological, cellular and molecular processes governing normal tissue toxicity. Those processes are complex and involve the cross-talk between the various cells of a tissue, including fibroblasts, endothelial, immune and epithelial cells as well as soluble paracrine factors including growth factors and proteases. We will review the translatable pharmacological approaches that have been developed to prevent, mitigate, or reverse radiation injuries based upon the targeting of cellular and signalling pathways. We will summarize the different steps of the research strategy, from the definition of initial biological hypotheses to preclinical studies and clinical translation. We will also see how novel research and therapeutic hypotheses emerge along the way as well as briefly highlight innovative approaches based upon novel radiotherapy delivery procedures.
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Affiliation(s)
- Pierre Montay-Gruel
- Laboratoire de Radio-Oncologie, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Lydia Meziani
- INSERM, U1030, F-94805, Villejuif, Paris, France.,Université Paris Sud, Université Paris Saclay, Faculté de médecine du Kremlin-Bicêtre, Labex LERMIT, DHU TORINO, Paris, France
| | - Chakradhar Yakkala
- Laboratoire de Radio-Oncologie, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
| | - Marie-Catherine Vozenin
- Laboratoire de Radio-Oncologie, Centre Hospitalier Universitaire Vaudois, Lausanne, Switzerland
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22
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Nukala U, Thakkar S, Krager KJ, Breen PJ, Compadre CM, Aykin-Burns N. Antioxidant Tocols as Radiation Countermeasures (Challenges to be Addressed to Use Tocols as Radiation Countermeasures in Humans). Antioxidants (Basel) 2018; 7:E33. [PMID: 29473853 PMCID: PMC5836023 DOI: 10.3390/antiox7020033] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2018] [Revised: 02/19/2018] [Accepted: 02/22/2018] [Indexed: 01/08/2023] Open
Abstract
Radiation countermeasures fall under three categories, radiation protectors, radiation mitigators, and radiation therapeutics. Radiation protectors are agents that are administered before radiation exposure to protect from radiation-induced injuries by numerous mechanisms, including scavenging free radicals that are generated by initial radiochemical events. Radiation mitigators are agents that are administered after the exposure of radiation but before the onset of symptoms by accelerating the recovery and repair from radiation-induced injuries. Whereas radiation therapeutic agents administered after the onset of symptoms act by regenerating the tissues that are injured by radiation. Vitamin E is an antioxidant that neutralizes free radicals generated by radiation exposure by donating H atoms. The vitamin E family consists of eight different vitamers, including four tocopherols and four tocotrienols. Though alpha-tocopherol was extensively studied in the past, tocotrienols have recently gained attention as radiation countermeasures. Despite several studies performed on tocotrienols, there is no clear evidence on the factors that are responsible for their superior radiation protection properties over tocopherols. Their absorption and bioavailability are also not well understood. In this review, we discuss tocopherol's and tocotrienol's efficacy as radiation countermeasures and identify the challenges to be addressed to develop them into radiation countermeasures for human use in the event of radiological emergencies.
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Affiliation(s)
- Ujwani Nukala
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
- Joint Bioinformatics Graduate Program, University of Arkansas at Little Rock, Little Rock, AR 72204, USA.
| | - Shraddha Thakkar
- Division of Bioinformatics and Biostatistics, National Center for Toxicological Research, US Food and Drug Administration, Jefferson, AR 72079, USA.
| | - Kimberly J Krager
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
| | - Philip J Breen
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
- Tocol Pharmaceuticals, LLC, Little Rock, AR 77205, USA.
| | - Cesar M Compadre
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
- Tocol Pharmaceuticals, LLC, Little Rock, AR 77205, USA.
| | - Nukhet Aykin-Burns
- Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, AR 72205, USA.
- Tocol Pharmaceuticals, LLC, Little Rock, AR 77205, USA.
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23
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Cheema AK, Mehta KY, Fatanmi OO, Wise SY, Hinzman CP, Wolff J, Singh VK. A Metabolomic and Lipidomic Serum Signature from Nonhuman Primates Administered with a Promising Radiation Countermeasure, Gamma-Tocotrienol. Int J Mol Sci 2017; 19:E79. [PMID: 29283379 PMCID: PMC5796029 DOI: 10.3390/ijms19010079] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2017] [Revised: 12/20/2017] [Accepted: 12/27/2017] [Indexed: 12/13/2022] Open
Abstract
The development of radiation countermeasures for acute radiation syndrome (ARS) has been underway for the past six decades, leading to the identification of multiple classes of radiation countermeasures. However, to date, only two growth factors (Neupogen and Neulasta) have been approved by the United States Food and Drug Administration (US FDA) for the mitigation of hematopoietic acute radiation syndrome (H-ARS). No radioprotector for ARS has been approved by the FDA yet. Gamma-tocotrienol (GT3) has been demonstrated to have radioprotective efficacy in murine as well as nonhuman primate (NHP) models. Currently, GT3 is under advanced development as a radioprotector that can be administered prior to radiation exposure. We are studying this agent for its safety profile and efficacy using the NHP model. In this study, we analyzed global metabolomic and lipidomic changes using ultra-performance liquid chromatography (UPLC) quadrupole time-of-flight mass spectrometry (QTOF-MS) in serum samples of NHPs administered GT3. Our study, using 12 NHPs, demonstrates that alterations in metabolites manifest only 24 h after GT3 administration. Furthermore, metabolic changes are associated with transient increase in the bioavailability of antioxidants, including lactic acid and cholic acid and anti-inflammatory metabolites 3 deoxyvitamin D3, and docosahexaenoic acid. Taken together, our results show that the administration of GT3 to NHPs causes metabolic shifts that would provide an overall advantage to combat radiation injury. This initial assessment also highlights the utility of metabolomics and lipidomics to determine the underlying physiological mechanisms involved in the radioprotective efficacy of GT3.
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Affiliation(s)
- Amrita K Cheema
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA.
- Department of Biochemistry, Molecular and Cellular Biology, Georgetown University Medical Center, Washington, DC 20057, USA.
| | - Khyati Y Mehta
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA.
| | - Oluseyi O Fatanmi
- Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
| | - Stephen Y Wise
- Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
| | - Charles P Hinzman
- Department of Biochemistry, Molecular and Cellular Biology, Georgetown University Medical Center, Washington, DC 20057, USA.
| | - Josh Wolff
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University Medical Center, Washington, DC 20057, USA.
| | - Vijay K Singh
- Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20814, USA.
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24
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Patyar RR, Patyar S. Role of drugs in the prevention and amelioration of radiation induced toxic effects. Eur J Pharmacol 2017; 819:207-216. [PMID: 29221951 DOI: 10.1016/j.ejphar.2017.12.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2017] [Revised: 11/25/2017] [Accepted: 12/04/2017] [Indexed: 10/18/2022]
Abstract
As the use of radiation technology for nuclear warfare or for the benefits of mankind (e.g. in radiotherapy or radio-diagnosis) is increasing tremendously, the risk of associated side effects is becoming a cause of concern. These effects, ranging from nausea/vomiting to death, may result from accidental or deliberate exposure and begin in seconds. Through this review paper, efforts have been done to critically review different compounds which have been investigated as radioprotectors and radiation mitigators. Radioprotectors are compounds which are administered just before or at the time of irradiation so as to minimize the radiation induced damage to normal tissues. And radiation mitigators are the compounds which can even minimize or ameliorate post irradiaion-toxicity provided they are administered before the onset of toxic symptoms. A variety of agents have been investigated for their preventive and ameliorative potential against radiation induced toxic effects. This review article has focused on various aspects of the promising representative agents belonging to different classes of radioprotectors and mitigators. Many compounds have shown promising results, but till date only amifostine and palifermin are clinically approved by FDA. To fill this void in pharmacological armamentarium, focus should be shifted towards novel approaches.
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Affiliation(s)
| | - Sazal Patyar
- School of Pharmaceutical Sciences, Lovely Professional University, Phagwara, India.
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25
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Yun KL, Wang ZY. Target/signalling pathways of natural plant-derived radioprotective agents from treatment to potential candidates: A reverse thought on anti-tumour drugs. Biomed Pharmacother 2017; 91:1122-1151. [DOI: 10.1016/j.biopha.2017.05.001] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2017] [Revised: 04/15/2017] [Accepted: 05/01/2017] [Indexed: 02/07/2023] Open
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26
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Singh VK, Garcia M, Seed TM. A review of radiation countermeasures focusing on injury-specific medicinals and regulatory approval status: part II. Countermeasures for limited indications, internalized radionuclides, emesis, late effects, and agents demonstrating efficacy in large animals with or without FDA IND status. Int J Radiat Biol 2017; 93:870-884. [DOI: 10.1080/09553002.2017.1338782] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Vijay K. Singh
- Division of Radioprotection, Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
| | - Melissa Garcia
- Division of Radioprotection, Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD, USA
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27
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Singh VK, Hanlon BK, Santiago PT, Seed TM. A review of radiation countermeasures focusing on injury-specific medicinals and regulatory approval status: part III. Countermeasures under early stages of development along with 'standard of care' medicinal and procedures not requiring regulatory approval for use. Int J Radiat Biol 2017; 93:885-906. [PMID: 28657400 DOI: 10.1080/09553002.2017.1332440] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
PURPOSE Terrorist attacks, with their intent to maximize psychological and economic damage as well as inflicting sickness and death on given targeted populations, are an ever-growing worldwide concern in government and public sectors as they become more frequent, violent, and sensational. If given the chance, it is likely that terrorists will use radiological or nuclear weapons. To thwart these sinister efforts, both physical and medical countermeasures against these weapons are currently being researched and developed so that they can be utilized by the first responders, military, and medical providers alike. This is the third article of a three-part series in which we have reviewed additional radiation countermeasures that are currently under early preclinical phases of development using largely animal models and have listed and discussed clinical support measures, including agents used for radiation-induced emesis, as well as countermeasures not requiring Food and Drug Administration approval. CONCLUSIONS Despite the significant progress that has been made in this area during the last several years, additional effort is needed in order to push promising new agents, currently under development, through the regulatory pipeline. This pipeline for new promising drugs appears to be unreasonably slow and cumbersome; possible reasons for this inefficiency are briefly discussed. Significant and continued effort needs to be afforded to this research and development area, as to date, there is no approved radioprotector that can be administered prior to high dose radiation exposure. This represents a very significant, unmet medical need and a significant security issue. A large number of agents with potential to interact with different biological targets are under development. In the next few years, several additional radiation countermeasures will likely receive Food and Drug Administration approval, increasing treatment options for victims exposed to unwanted ionizing irradiation.
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Affiliation(s)
- Vijay K Singh
- a Division of Radioprotection, Department of Pharmacology and Molecular Therapeutics , F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences , Bethesda , MD , U.S.A.,b Armed Forces Radiobiology Research Institute , Uniformed Services University of the Health Sciences , Bethesda , MD , U.S.A
| | - Briana K Hanlon
- a Division of Radioprotection, Department of Pharmacology and Molecular Therapeutics , F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences , Bethesda , MD , U.S.A.,b Armed Forces Radiobiology Research Institute , Uniformed Services University of the Health Sciences , Bethesda , MD , U.S.A
| | - Paola T Santiago
- a Division of Radioprotection, Department of Pharmacology and Molecular Therapeutics , F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences , Bethesda , MD , U.S.A.,b Armed Forces Radiobiology Research Institute , Uniformed Services University of the Health Sciences , Bethesda , MD , U.S.A
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28
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Singh VK, Fatanmi OO, Wise SY, Newman VL, Romaine PLP, Seed TM. THE POTENTIATION OF THE RADIOPROTECTIVE EFFICACY OF TWO MEDICAL COUNTERMEASURES, GAMMA-TOCOTRIENOL AND AMIFOSTINE, BY A COMBINATION PROPHYLACTIC MODALITY. RADIATION PROTECTION DOSIMETRY 2016; 172:302-310. [PMID: 27542813 PMCID: PMC5444681 DOI: 10.1093/rpd/ncw223] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
This study was designed to evaluate the possible potentiation of survival protection afforded by relatively low-dose amifostine prophylaxis against total body irradiation in combination with a protective, less toxic agent, gamma-tocotrienol (GT3). Mice were administered amifostine and/or GT3, then exposed to 9.2 Gy 60Co γ-irradiation and monitored for survival for 30 days. To investigate cytokine stimulation, mice were administered amifostine or GT3; serum samples were collected and analyzed for cytokines. Survival studies show single treatments of GT3 or amifostine significantly improved survival, compared to the vehicle, and combination treatments resulted in significantly higher survival compared to single treatments. In vivo studies with GT3 confirmed prior work indicating GT3 induces granulocyte colony-stimulating factor (G-CSF). This approach, the prophylactic combination of amifostine and GT3, which act through different mechanisms, shows promise and should be investigated further as a potential countermeasure for acute radiation syndrome.
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Affiliation(s)
- Vijay K Singh
- Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine 'America's Medical School', Services University of the Health Sciences , Bethesda, MD, USA
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences , Bethesda, MD, USA
| | - Oluseyi O Fatanmi
- Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine 'America's Medical School', Services University of the Health Sciences , Bethesda, MD, USA
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences , Bethesda, MD, USA
| | - Stephen Y Wise
- Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine 'America's Medical School', Services University of the Health Sciences , Bethesda, MD, USA
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences , Bethesda, MD, USA
| | - Victoria L Newman
- Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine 'America's Medical School', Services University of the Health Sciences , Bethesda, MD, USA
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences , Bethesda, MD, USA
| | - Patricia L P Romaine
- Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine 'America's Medical School', Services University of the Health Sciences , Bethesda, MD, USA
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences , Bethesda, MD, USA
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29
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Protection against Radiotherapy-Induced Toxicity. Antioxidants (Basel) 2016; 5:antiox5030022. [PMID: 27399787 PMCID: PMC5039571 DOI: 10.3390/antiox5030022] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2016] [Revised: 06/27/2016] [Accepted: 06/28/2016] [Indexed: 01/18/2023] Open
Abstract
Radiation therapy is a highly utilized therapy in the treatment of malignancies with up to 60% of cancer patients receiving radiation therapy as a part of their treatment regimen. Radiation therapy does, however, cause a wide range of adverse effects that can be severe and cause permanent damage to the patient. In an attempt to minimize these effects, a small number of compounds have been identified and are in use clinically for the prevention and treatment of radiation associated toxicities. Furthermore, there are a number of emerging therapies being developed for use as agents that protect against radiation-induced toxicities. The aim of this review was to evaluate and summarise the evidence that exists for both the known radioprotectant agents and the agents that show promise as future radioprotectant agents.
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30
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Pathak R, Bachri A, Ghosh SP, Koturbash I, Boerma M, Binz RK, Sawyer JR, Hauer-Jensen M. The Vitamin E Analog Gamma-Tocotrienol (GT3) Suppresses Radiation-Induced Cytogenetic Damage. Pharm Res 2016; 33:2117-25. [PMID: 27216753 PMCID: PMC4967083 DOI: 10.1007/s11095-016-1950-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Accepted: 05/13/2016] [Indexed: 01/24/2023]
Abstract
Purpose Ionizing radiation (IR) generates reactive oxygen species (ROS), which cause DNA double-strand breaks (DSBs) that are responsible for cytogenetic alterations. Because antioxidants are potent ROS scavengers, we determined whether the vitamin E isoform γ-tocotrienol (GT3), a radio-protective multifunctional dietary antioxidant, can suppress IR-induced cytogenetic damage. Methods We measured DSB formation in irradiated primary human umbilical vein endothelial cells (HUVECs) by quantifying the formation of γ-H2AX foci. Chromosomal aberrations (CAs) were analyzed in irradiated HUVECs and in the bone marrow cells of irradiated mice by conventional and fluorescence-based chromosome painting techniques. Gene expression was measured in HUVECs with quantitative reverse transcriptase polymerase chain reaction (qRT-PCR). Results GT3 pretreatment reduced DSB formation in HUVECS, and also decreased CAs in HUVECs and mouse bone marrow cells after irradiation. Moreover, GT3 increased expression of the DNA-repair gene RAD50 and attenuated radiation-induced RAD50 suppression. Conclusions GT3 attenuates radiation-induced cytogenetic damage, possibly by affecting RAD50 expression. GT3 should be explored as a therapeutic to reduce the risk of developing genetic diseases after radiation exposure.
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Affiliation(s)
- Rupak Pathak
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Biomed I, Suite 238, 4301 West Markham, Slot 522-3, Little Rock, Arkansas, 72205, USA.
| | - Abdel Bachri
- Department of Engineering and Engineering Physics, Southern Arkansas University, Magnolia, Arkansas, USA
| | - Sanchita P Ghosh
- Armed Forces Radiobiology Research Institute, USUHS, Bethesda, Maryland, USA
| | - Igor Koturbash
- Department of Environmental and Occupational Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Marjan Boerma
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Biomed I, Suite 238, 4301 West Markham, Slot 522-3, Little Rock, Arkansas, 72205, USA
| | - Regina K Binz
- Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Jeffrey R Sawyer
- Department of Pathology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| | - Martin Hauer-Jensen
- Division of Radiation Health, Department of Pharmaceutical Sciences, College of Pharmacy, University of Arkansas for Medical Sciences, Biomed I, Suite 238, 4301 West Markham, Slot 522-3, Little Rock, Arkansas, 72205, USA
- Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, USA
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31
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Singh VK, Hauer-Jensen M. γ-Tocotrienol as a Promising Countermeasure for Acute Radiation Syndrome: Current Status. Int J Mol Sci 2016; 17:E663. [PMID: 27153057 PMCID: PMC4881489 DOI: 10.3390/ijms17050663] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2016] [Revised: 04/03/2016] [Accepted: 04/25/2016] [Indexed: 01/13/2023] Open
Abstract
The hazard of ionizing radiation exposure due to nuclear accidents or terrorist attacks is ever increasing. Despite decades of research, still, there is a shortage of non-toxic, safe and effective medical countermeasures for radiological and nuclear emergency. To date, the U.S. Food and Drug Administration (U.S. FDA) has approved only two growth factors, Neupogen (granulocyte colony-stimulating factor (G-CSF), filgrastim) and Neulasta (PEGylated G-CSF, pegfilgrastim) for the treatment of hematopoietic acute radiation syndrome (H-ARS) following the Animal Efficacy Rule. Promising radioprotective efficacy results of γ-tocotrienol (GT3; a member of the vitamin E family) in the mouse model encouraged its further evaluation in the nonhuman primate (NHP) model. These studies demonstrated that GT3 significantly aided the recovery of radiation-induced neutropenia and thrombocytopenia compared to the vehicle controls; these results particularly significant after exposure to 5.8 or 6.5 Gray (Gy) whole body γ-irradiation. The stimulatory effect of GT3 on neutrophils and thrombocytes (platelets) was directly and positively correlated with dose; a 75 mg/kg dose was more effective compared to 37.5 mg/kg. GT3 was also effective against 6.5 Gy whole body γ-irradiation for improving neutrophils and thrombocytes. Moreover, a single administration of GT3 without any supportive care was equivalent, in terms of improving hematopoietic recovery, to multiple doses of Neupogen and two doses of Neulasta with full supportive care (including blood products) in the NHP model. GT3 may serve as an ultimate radioprotector for use in humans, particularly for military personnel and first responders. In brief, GT3 is a promising radiation countermeasure that ought to be further developed for U.S. FDA approval for the ARS indication.
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Affiliation(s)
- Vijay K Singh
- Department of Pharmacology and Molecular Therapeutics, F. Edward Hébert School of Medicine, Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, MD 20889, USA.
| | - Martin Hauer-Jensen
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare Systems, Little Rock, AR 72205, USA.
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32
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Singh VK, Kulkarni S, Fatanmi OO, Wise SY, Newman VL, Romaine PLP, Hendrickson H, Gulani J, Ghosh SP, Kumar KS, Hauer-Jensen M. Radioprotective Efficacy of Gamma-Tocotrienol in Nonhuman Primates. Radiat Res 2016; 185:285-98. [DOI: 10.1667/rr14127.1] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Vijay K. Singh
- Department of Radiation Biology, F. Edward Hébert School of Medicine, “America's Medical School” Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Shilpa Kulkarni
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland
| | | | - Stephen Y. Wise
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland
| | | | | | - Howard Hendrickson
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare Systems, Little Rock, Arkansas; and
| | - Jatinder Gulani
- Veterinary Sciences Department, Armed Forces Radiobiology Research Institute, Bethesda, Maryland
| | | | - K. Sree Kumar
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland
| | - Martin Hauer-Jensen
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences and Central Arkansas Veterans Healthcare Systems, Little Rock, Arkansas; and
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Tocotrienol-Rich Fraction from Rice Bran Demonstrates Potent Radiation Protection Activity. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:148791. [PMID: 26425129 PMCID: PMC4573888 DOI: 10.1155/2015/148791] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2015] [Accepted: 05/18/2015] [Indexed: 12/03/2022]
Abstract
The vitamin E analogs δ-tocotrienol (DT3) and γ-tocotrienol (GT3) have significant protective and mitigative capacity against the detrimental effects of ionizing radiation (IR). However, the expense of purification limits their potential use. This study examined the tocotrienol-rich fraction of rice bran (TRFRB) isolated from rice bran deodorizer distillate, a rice oil refinement waste product, to determine its protective effects against IR induced oxidative damage and H2O2. Several cell lines were treated with tocotrienols or TRFRB prior to or following exposure to H2O2 or IR. To determine the radioprotective capacity cells were analyzed for morphology, mitochondrial bioenergetics, clonogenic survival, glutathione oxidation, cell cycle, and migration rate. TRFRB displayed similar antioxidant activity compared to pure tocotrienols. Cells pretreated with TRFRB or DT3 exhibited preserved cell morphology and mitochondrial respiration when exposed to H2O2. Oxidized glutathione was decreased in TRFRB treated cells exposed to IR. TRFRB reversed mitochondrial uncoupling and protected cells migration rates following IR exposure. The protective antioxidant capacity of TRFRB treated cells against oxidative injury was similar to that of purified DT3. TRFRB effectively protects normal cells against IR induced injury suggesting that rice bran distillate may be an inexpensive and abundant alternate source.
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Vitamin E Analogs as Radiation Response Modifiers. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:741301. [PMID: 26366184 PMCID: PMC4558447 DOI: 10.1155/2015/741301] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2015] [Revised: 05/06/2015] [Accepted: 07/22/2015] [Indexed: 02/07/2023]
Abstract
The potentially life-threatening effects of total body ionizing radiation exposure have been known for more than a century. Despite considerable advances in our understanding of the effects of radiation over the past six decades, efforts to identify effective radiation countermeasures for use in case of a radiological/nuclear emergency have been largely unsuccessful. Vitamin E is known to have antioxidant properties capable of scavenging free radicals, which have critical roles in radiation injuries. Tocopherols and tocotrienols, vitamin E analogs together known as tocols, have shown promise as radioprotectors. Although the pivotal mechanisms of action of tocols have long been thought to be their antioxidant properties and free radical scavenging activities, other alternative mechanisms have been proposed to drive their activity as radioprotectors. Here we provide a brief overview of the effects of ionizing radiation, the mechanistic mediators of radiation-induced damage, and the need for radiation countermeasures. We further outline the role for, efficacy of, and mechanisms of action of tocols as radioprotectors, and we compare and contrast their efficacy and mode of action with that of another well-studied chemical radioprotector, amifostine.
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Kordsmeier M, Howard LR, Brownmiller C, Proctor A, Hauer-Jensen M. Isolation of Gamma and Delta Tocotrienols from Rice Bran Oil Deodorizer Distillate Using Flash Chromatography. J AM OIL CHEM SOC 2015. [DOI: 10.1007/s11746-015-2696-2] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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Singh VK, Romaine PL, Seed TM. Medical Countermeasures for Radiation Exposure and Related Injuries: Characterization of Medicines, FDA-Approval Status and Inclusion into the Strategic National Stockpile. HEALTH PHYSICS 2015; 108:607-630. [PMID: 25905522 PMCID: PMC4418776 DOI: 10.1097/hp.0000000000000279] [Citation(s) in RCA: 98] [Impact Index Per Article: 10.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 01/05/2015] [Indexed: 05/28/2023]
Abstract
World events over the past decade have highlighted the threat of nuclear terrorism as well as an urgent need to develop radiation countermeasures for acute radiation exposures and subsequent bodily injuries. An increased probability of radiological or nuclear incidents due to detonation of nuclear weapons by terrorists, sabotage of nuclear facilities, dispersal and exposure to radioactive materials, and accidents provides the basis for such enhanced radiation exposure risks for civilian populations. Although the search for suitable radiation countermeasures for radiation-associated injuries was initiated more than half a century ago, no safe and effective radiation countermeasure for the most severe of these injuries, namely acute radiation syndrome (ARS), has been approved by the United States Food and Drug Administration (FDA). The dearth of FDA-approved radiation countermeasures has prompted intensified research for a new generation of radiation countermeasures. In this communication, the authors have listed and reviewed the status of radiation countermeasures that are currently available for use, or those that might be used for exceptional nuclear/radiological contingencies, plus a limited few medicines that show early promise but still remain experimental in nature and unauthorized for human use by the FDA.
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Affiliation(s)
- Vijay K. Singh
- *Radiation Countermeasures Program, 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, Bethesda, MD
| | - Patricia L.P. Romaine
- *Radiation Countermeasures Program, 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, Bethesda, MD
| | - Thomas M. Seed
- *Radiation Countermeasures Program, 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, Bethesda, MD
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Tocotrienol Rich Palm Oil Extract Is More Effective Than Pure Tocotrienols at Improving Endothelium-Dependent Relaxation in the Presence of Oxidative Stress. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2015; 2015:150829. [PMID: 26075031 PMCID: PMC4449936 DOI: 10.1155/2015/150829] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 04/24/2015] [Accepted: 04/24/2015] [Indexed: 12/16/2022]
Abstract
Oxidative endothelial dysfunction is a critical initiator of vascular disease. Vitamin E is an effective antioxidant but attempts to use it to treat vascular disorders have been disappointing. This study investigated whether tocotrienols, the less abundant components of vitamin E compared to tocopherols, might be more effective at preserving endothelial function. Superoxide generated by hypoxanthine/xanthine oxidase or rat aorta was measured using lucigenin-enhanced chemiluminescence. The effect of α-tocopherol, α-, δ-, and γ-tocotrienols and a tocotrienol rich palm oil extract (tocomin) on levels of superoxide was assessed. Endothelial function in rat aorta was assessed in the presence of the auto-oxidant pyrogallol. Whilst all of the compounds displayed antioxidant activity, the tocotrienols were more effective when superoxide was produced by hypoxanthine/xanthine oxidase whereas tocomin and α-tocopherol were more effective in the isolated aorta. Tocomin and α-tocopherol restored endothelial function in the presence of oxidant stress but α-, δ-, and γ-tocotrienols were ineffective. The protective effect of tocomin was replicated when the tocotrienols were present with, but not without, α-tocopherol. Tocotrienol rich tocomin is more effective than α-tocopherol at reducing oxidative stress and restoring endothelium-dependent relaxation in rat aortae and although α-, δ-, and γ-tocotrienols effectively scavenged superoxide, they did not improve endothelial function.
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Modulation of Radiation Response by the Tetrahydrobiopterin Pathway. Antioxidants (Basel) 2015; 4:68-81. [PMID: 26785338 PMCID: PMC4665563 DOI: 10.3390/antiox4010068] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2014] [Revised: 01/07/2015] [Accepted: 01/13/2015] [Indexed: 02/07/2023] Open
Abstract
Ionizing radiation (IR) is an integral component of our lives due to highly prevalent sources such as medical, environmental, and/or accidental. Thus, understanding of the mechanisms by which radiation toxicity develops is crucial to address acute and chronic health problems that occur following IR exposure. Immediate formation of IR-induced free radicals as well as their persistent effects on metabolism through subsequent alterations in redox mediated inter- and intracellular processes are globally accepted as significant contributors to early and late effects of IR exposure. This includes but is not limited to cytotoxicity, genomic instability, fibrosis and inflammation. Damage to the critical biomolecules leading to detrimental long-term alterations in metabolic redox homeostasis following IR exposure has been the focus of various independent investigations over last several decades. The growth of the "omics" technologies during the past decade has enabled integration of "data from traditional radiobiology research", with data from metabolomics studies. This review will focus on the role of tetrahydrobiopterin (BH4), an understudied redox-sensitive metabolite, plays in the pathogenesis of post-irradiation normal tissue injury as well as how the metabolomic readout of BH4 metabolism fits in the overall picture of disrupted oxidative metabolism following IR exposure.
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Singh VK, Wise SY, Fatanmi OO, Scott J, Romaine PLP, Newman VL, Verma A, Elliott TB, Seed TM. Progenitors mobilized by gamma-tocotrienol as an effective radiation countermeasure. PLoS One 2014; 9:e114078. [PMID: 25423021 PMCID: PMC4244184 DOI: 10.1371/journal.pone.0114078] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 11/03/2014] [Indexed: 11/18/2022] Open
Abstract
The purpose of this study was to elucidate the role of gamma-tocotrienol (GT3)-mobilized progenitors in mitigating damage to mice exposed to a supralethal dose of cobalt-60 gamma-radiation. CD2F1 mice were transfused 24 h post-irradiation with whole blood or isolated peripheral blood mononuclear cells (PBMC) from donors that had received GT3 72 h prior to blood collection and recipient mice were monitored for 30 days. To understand the role of GT3-induced granulocyte colony-stimulating factor (G-CSF) in mobilizing progenitors, donor mice were administered a neutralizing antibody specific to G-CSF or its isotype before blood collection. Bacterial translocation from gut to heart, spleen and liver of irradiated recipient mice was evaluated by bacterial culture on enriched and selective agar media. Endotoxin in serum samples also was measured. We also analyzed the colony-forming units in the spleens of irradiated mice. Our results demonstrate that whole blood or PBMC from GT3-administered mice mitigated radiation injury when administered 24 h post-irradiation. Furthermore, administration of a G-CSF antibody to GT3-injected mice abrogated the efficacy of blood or PBMC obtained from such donors. Additionally, GT3-mobilized PBMC inhibited the translocation of intestinal bacteria to the heart, spleen, and liver, and increased colony forming unit-spleen (CFU-S) numbers in irradiated mice. Our data suggests that GT3 induces G-CSF, which mobilizes progenitors and these progenitors mitigate radiation injury in recipient mice. This approach using mobilized progenitor cells from GT3-injected donors could be a potential treatment for humans exposed to high doses of radiation.
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Affiliation(s)
- Vijay K. Singh
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
- Department of Radiation Biology, F. Edward Hébert School of Medicine, Uniformed Services University of the Health Sciences, Bethesda, Maryland, United States of America
- * E-mail:
| | - Stephen Y. Wise
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Oluseyi O. Fatanmi
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Jessica Scott
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Patricia L. P. Romaine
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Victoria L. Newman
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Amit Verma
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Thomas B. Elliott
- Armed Forces Radiobiology Research Institute, Bethesda, Maryland, United States of America
| | - Thomas M. Seed
- Tech Micro Services, Bethesda, Maryland, United States of America
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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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Cheema AK, Pathak R, Zandkarimi F, Kaur P, Alkhalil L, Singh R, Zhong X, Ghosh S, Aykin-Burns N, Hauer-Jensen M. Liver metabolomics reveals increased oxidative stress and fibrogenic potential in gfrp transgenic mice in response to ionizing radiation. J Proteome Res 2014; 13:3065-74. [PMID: 24824572 PMCID: PMC4053308 DOI: 10.1021/pr500278t] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
![]()
Although radiation-induced tissue-specific
injury is well documented,
the underlying molecular changes resulting in organ dysfunction and
the consequences thereof on overall metabolism and physiology have
not been elucidated. We previously reported the generation and characterization
of a transgenic mouse strain that ubiquitously overexpresses Gfrp
(GTPH-1 feedback regulatory protein) and exhibits higher oxidative
stress, which is a possible result of decreased tetrahydrobiopterin
(BH4) bioavailability. In this study, we report genotype-dependent
changes in the metabolic profiles of liver tissue after exposure to
nonlethal doses of ionizing radiation. Using a combination of untargeted
and targeted quantitative mass spectrometry, we report significant
accumulation of metabolites associated with oxidative stress, as well
as the dysregulation of lipid metabolism in transgenic mice after
radiation exposure. The radiation stress seems to exacerbate lipid
peroxidation and also results in higher expression of genes that facilitate
liver fibrosis, in a manner that is dependent on the genetic background
and post-irradiation time interval. These findings suggest the significance
of Gfrp in regulating redox homeostasis in response to stress induced
by ionizing radiation affecting overall physiology.
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Affiliation(s)
- Amrita K Cheema
- Departments of Oncology, ‡Biochemistry, Molecular and Cellular Biology, and ∥Department of Biostatistics, Bioinformatics and Biomathematics, Georgetown University Medical Center , Washington DC 20057, United States
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Tissue distribution of emulsified γ-tocotrienol and its long-term biological effects after subcutaneous administration. Lipids Health Dis 2014; 13:66. [PMID: 24712339 PMCID: PMC4040479 DOI: 10.1186/1476-511x-13-66] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2013] [Accepted: 04/05/2014] [Indexed: 01/11/2023] Open
Abstract
Background γ-tocotrienol (GT3), an analogue of vitamin E, has gained increasing scientific interest recently as it provides significant health benefits. It has been shown that emulsified GT3, after subcutaneous administration, has long-term biological effects. However, whether the effects are due to the increase of GT3 level in the early phase following administration or the persistent functions after accumulation in tissues is unknown. This study was conducted to determine the levels of GT3 in different tissues by high performance liquid chromatography (HPLC) with a fluorescence detector after a single-dose of GT3 with polyethylene glycol (PEG-400) emulsion via subcutaneous injection. Previous studies have explored that GT3 has favorable effects on bone and can inhibit osteoclast formation. To confirm the persistent biological activity of accumulated GT3 in tissues, receptor activator of NF-κB ligand (RANKL) and osteoprotegerin (OPG) gene expressions, which have an important role in regulating osteoclast formation, were also evaluated in bone tissue on day 1, 3, 7 and 14 after a signal subcutaneous injection of GT3. Methods C57BL/6 female mice were administrated GT3 (100 mg/kg body weight) with PEG-400 emulsion by subcutaneous injection. GT3 levels in different tissues were determined by HPLC with a fluorescence detector. Gene expressions were measured by real-time PCR. Results GT3 predominantly accumulated in adipose and heart tissue, and was maintained at a relatively stable level in bone tissues after a single-dose administration. Accumulated GT3 in bone tissues significantly inhibited the increase in RANKL expression and the decrease in OPG expression induced by db-cAMP. Conclusions We investigated the tissue distribution of GT3 with PEG emulsion by subcutaneous administration, which has never been reported so far. Our results suggest that GT3 with PEG emulsion accumulated in tissues is able to carry out a long-term biological effect and has therapeutic value for treating and preventing osteoporosis.
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Pathak R, Pawar SA, Fu Q, Gupta PK, Berbée M, Garg S, Sridharan V, Wang W, Biju PG, Krager KJ, Boerma M, Ghosh SP, Cheema AK, Hendrickson HP, Aykin-Burns N, Hauer-Jensen M. Characterization of transgenic Gfrp knock-in mice: implications for tetrahydrobiopterin in modulation of normal tissue radiation responses. Antioxid Redox Signal 2014; 20:1436-46. [PMID: 23521531 PMCID: PMC3936502 DOI: 10.1089/ars.2012.5025] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2012] [Revised: 02/22/2013] [Accepted: 03/22/2013] [Indexed: 01/17/2023]
Abstract
AIMS The free radical scavenger and nitric oxide synthase cofactor, 5,6,7,8-tetrahydrobiopterin (BH4), plays a well-documented role in many disorders associated with oxidative stress, including normal tissue radiation responses. Radiation exposure is associated with decreased BH4 levels, while BH4 supplementation attenuates aspects of radiation toxicity. The endogenous synthesis of BH4 is catalyzed by the enzyme guanosine triphosphate cyclohydrolase I (GTPCH1), which is regulated by the inhibitory GTP cyclohydrolase I feedback regulatory protein (GFRP). We here report and characterize a novel, Cre-Lox-driven, transgenic mouse model that overexpresses Gfrp. RESULTS Compared to control littermates, transgenic mice exhibited high transgene copy numbers, increased Gfrp mRNA and GFRP expression, enhanced GFRP-GTPCH1 interaction, reduced BH4 levels, and low glutathione (GSH) levels and differential mitochondrial bioenergetic profiles. After exposure to total body irradiation, transgenic mice showed decreased BH4/7,8-dihydrobiopterin ratios, increased vascular oxidative stress, and reduced white blood cell counts compared with controls. INNOVATION AND CONCLUSION This novel Gfrp knock-in transgenic mouse model allows elucidation of the role of GFRP in the regulation of BH4 biosynthesis. This model is a valuable tool to study the involvement of BH4 in whole body and tissue-specific radiation responses and other conditions associated with oxidative stress.
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Affiliation(s)
- Rupak Pathak
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Snehalata A. Pawar
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Qiang Fu
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Prem K. Gupta
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Maaike Berbée
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Sarita Garg
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Vijayalakshmi Sridharan
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Wenze Wang
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Prabath G. Biju
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Kimberly J. Krager
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Marjan Boerma
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Sanchita P. Ghosh
- Armed Forces Radiobiology Research Institute, Uniformed Services University of the Health Sciences, Bethesda, Maryland
| | - Amrita K. Cheema
- Department of Oncology, Georgetown University Medical Center, Washington, District of Columbia
| | - Howard P. Hendrickson
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Nukhet Aykin-Burns
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
| | - Martin Hauer-Jensen
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas
- Surgical Service, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas
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Anzai K, Ueno M, Matsumoto KI, Ikota N, Takata J. Gamma-tocopherol-N,N-dimethylglycine ester as a potent post-irradiation mitigator against whole body X-irradiation-induced bone marrow death in mice. JOURNAL OF RADIATION RESEARCH 2014; 55:67-74. [PMID: 23908555 PMCID: PMC3885127 DOI: 10.1093/jrr/rrt094] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2013] [Revised: 06/05/2013] [Accepted: 06/24/2013] [Indexed: 06/02/2023]
Abstract
We examined the radioprotective and mitigative effects of gamma-tocopherol-N,N-dimethylglycine ester (GTDMG), a novel water-soluble gamma-tocopherol derivative, against X-irradiation-induced bone marrow death in mice. Mice (C3H, 10 weeks, male) were injected intraperitoneally with GTDMG suspended in a 0.5% methyl cellulose solution before or after receiving of 7.5-Gy whole body X-irradiation. GTDMG significantly enhanced the 30-day survival rate when given 30 min before or immediately after the irradiation. Its mitigative activity (administered after exposure) was examined further in detail. The optimal concentration of GTDMG given immediately after irradiation was around 100 mg/kg body weight (bw) and the 30-day survival rate was 97.6 ± 2.4%. When GTDMG was administered 1, 10 and 24 h post-irradiation, the survival rate was 85.7 ± 7.6, 75.0 ± 9.7 and 36.7 ± 8.8%, respectively, showing significant mitigation even at 24 h after irradiation (P < 0.05). The value of the dose reduction factor (100 mg/kg bw, given intraperitoneally (i.p.) immediately after irradiation) was 1.25. GTDMG enhanced the recovery of red blood cell-, white blood cell-, and platelet-counts after irradiation and significantly increased the number of endogenous spleen colonies (P < 0.05). Subcutaneous (s.c.) administration also had mitigative effects. In conclusion, GTDMG is a potent radiation mitigator.
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Affiliation(s)
- Kazunori Anzai
- Nihon Pharmaceutical University
- National Institute of Radiological Sciences
| | | | | | | | - Jiro Takata
- Faculty of Pharmaceutical Sciences, Fukuoka University
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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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Sridharan V, Tripathi P, Sharma S, Corry PM, Moros EG, Singh A, Compadre CM, Hauer-Jensen M, Boerma M. Effects of late administration of pentoxifylline and tocotrienols in an image-guided rat model of localized heart irradiation. PLoS One 2013; 8:e68762. [PMID: 23894340 PMCID: PMC3718790 DOI: 10.1371/journal.pone.0068762] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 06/02/2013] [Indexed: 01/15/2023] Open
Abstract
Radiation-induced heart disease (RIHD) is a long-term side effect of radiotherapy of intrathoracic, chest wall and breast tumors when radiation fields encompass all or part of the heart. Previous studies have shown that pentoxifylline (PTX) in combination with α-tocopherol reduced manifestations of RIHD in rat models of local heart irradiation. The relative contribution of PTX and α-tocopherol to these beneficial effects are not known. This study examined the effects of PTX alone or in combination with tocotrienols, forms of vitamin E with potential potent radiation mitigation properties. Rats received localized X-irradiation of the heart with an image-guided irradiation technique. At 3 months after irradiation rats received oral treatment with vehicle, PTX, or PTX in combination with a tocotrienol-enriched formulation. At 6 months after irradiation, PTX-treated rats showed arrhythmia in 5 out of 14 animals. PTX alone or in combination with tocotrienols did not alter cardiac radiation fibrosis, left ventricular protein expression of the endothelial markers von Willebrand factor and neuregulin-1, or phosphorylation of the signal mediators Akt, Erk1/2, or PKCα. On the other hand, tocotrienols reduced cardiac numbers of mast cells and macrophages, but enhanced the expression of tissue factor. While this new rat model of localized heart irradiation does not support the use of PTX alone, the effects of tocotrienols on chronic manifestations of RIHD deserve further investigation.
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Affiliation(s)
- Vijayalakshmi Sridharan
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Preeti Tripathi
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Sunil Sharma
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Peter M. Corry
- Department of Radiation Oncology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Eduardo G. Moros
- Department of Radiation Oncology, Moffitt Cancer Center and Research Institute, Tampa, Florida, United States of America
| | - Awantika Singh
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Cesar M. Compadre
- Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
| | - Martin Hauer-Jensen
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
- Surgical Service, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, United States of America
| | - Marjan Boerma
- Division of Radiation Health, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States of America
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Zhang Y, Janssens SP, Wingler K, Schmidt HHHW, Moens AL. Modulating endothelial nitric oxide synthase: a new cardiovascular therapeutic strategy. Am J Physiol Heart Circ Physiol 2011; 301:H634-46. [PMID: 21622818 DOI: 10.1152/ajpheart.01315.2010] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The pathogenesis of many cardiovascular diseases is associated with reduced nitric oxide (NO) bioavailability and/or increased endothelial NO synthase (eNOS)-dependent superoxide formation. These findings support that restoring and conserving adequate NO signaling in the heart and blood vessels is a promising therapeutic intervention. In particular, modulating eNOS, e.g., through increasing the bioavailability of its substrate and cofactors, enhancing its transcription, and interfering with other modulators of eNOS pathway, such as netrin-1, has a high potential for effective treatments of cardiovascular diseases. This review provides an overview of the possibilities for modulating eNOS and how this may be translated to the clinic in addition to describing the genetic models used to study eNOS modulation.
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Affiliation(s)
- Yixuan Zhang
- Department of Cardiology, Maastricht University Medical Centre, Cardiovascular Research Institute Maastricht, Maastricht, The Netherlands
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Mechanisms underlying the radioprotective properties of γ-tocotrienol: comparative gene expression profiling in tocol-treated endothelial cells. GENES AND NUTRITION 2011; 7:75-81. [PMID: 21516479 DOI: 10.1007/s12263-011-0228-8] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 04/08/2011] [Indexed: 01/04/2023]
Abstract
Among the eight naturally occurring vitamin E analogs, γ-tocotrienol (GT3) is a particularly potent radioprophylactic agent in vivo. Moreover, GT3 protects endothelial cells from radiation injury not only by virtue of its antioxidant properties but also by inhibition of 3-hydroxy-3-methyl-glutaryl-CoA (HMG-CoA) reductase and by improving the availability of the nitric oxide synthase cofactor tetrahydrobiopterin. Nevertheless, the precise mechanisms underlying the superior radioprotective properties of GT3 compared with other tocols are not known. This study, therefore, examined the differences in gene expression profiles between GT3 and its tocopherol counterpart, γ-tocopherol, as well as between GT3 and α-tocopherol in human endothelial cells. Cells were treated with vehicle or the appropriate tocol for 24 h, after which total RNA was isolated and genome-wide gene expression profiles were obtained using the Illumina platform. GT3 was far more potent in inducing gene-expression changes than α-tocopherol or γ-tocopherol. In particular, GT3 induced multiple changes in pathways known to be of importance in the cellular response to radiation exposure. Affected GO functional clusters included response to oxidative stress, response to DNA damage stimuli, cell cycle phase, regulation of cell death, regulation of cell proliferation, hematopoiesis, and blood vessel development. These results form the basis for further studies to determine the exact importance of differentially affected GO functional clusters in endothelial radioprotection by GT3.
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