1
|
Anikina VA, Sorokina SS, Shemyakov AE, Zamyatina EA, Taskaeva IS, Teplova PO, Popova NR. An Experimental Model of Proton-Beam-Induced Radiation Dermatitis In Vivo. Int J Mol Sci 2023; 24:16373. [PMID: 38003561 PMCID: PMC10671732 DOI: 10.3390/ijms242216373] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2023] [Revised: 11/13/2023] [Accepted: 11/13/2023] [Indexed: 11/26/2023] Open
Abstract
Radiation dermatitis (RD) is one of the most common side effects of radiation therapy. However, to date, there is a lack of both specific treatments for RD and validated experimental animal models with the use of various sources of ionizing radiation (IR) applied in clinical practice. The aim of this study was to develop and validate a model of acute RD induced using proton radiation in mice. Acute RD (Grade 2-4) was obtained with doses of 30, 40, and 50 Gy, either with or without depilation. The developed model of RD was characterized by typical histological changes in the skin after irradiation. Moreover, the depilation contributed to a skin histology alteration of the irradiated mice. The assessment of animal vital signs indicated that there was no effect of proton irradiation on the well-being or general condition of the animals. This model can be used to develop effective therapeutic agents and study the pathogenesis of radiation-induced skin toxicity, including that caused by proton irradiation.
Collapse
Affiliation(s)
- Viktoriia A. Anikina
- Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, 3 Institutskaya St., Pushchino 142290, Russia; (V.A.A.); (S.S.S.); (A.E.S.); (E.A.Z.)
| | - Svetlana S. Sorokina
- Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, 3 Institutskaya St., Pushchino 142290, Russia; (V.A.A.); (S.S.S.); (A.E.S.); (E.A.Z.)
| | - Alexander E. Shemyakov
- Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, 3 Institutskaya St., Pushchino 142290, Russia; (V.A.A.); (S.S.S.); (A.E.S.); (E.A.Z.)
- Branch “Physical-Technical Center” of P.N. Lebedev Physical Institute of the Russian Academy of Sciences, 2 Akademichesky Proezd, Protvino 142281, Russia
| | - Elizaveta A. Zamyatina
- Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, 3 Institutskaya St., Pushchino 142290, Russia; (V.A.A.); (S.S.S.); (A.E.S.); (E.A.Z.)
| | - Iuliia S. Taskaeva
- Research Institute of Clinical and Experimental Lymphology—Branch of the Institute of Cytology and Genetics, Siberian Branch of the Russian Academy of Sciences, 2 Timakova St., Novosibirsk 630060, Russia;
| | - Polina O. Teplova
- Institute of Cell Biophysics of the Russian Academy of Sciences, 3 Institutskaya St., Pushchino 142290, Russia;
| | - Nelli R. Popova
- Institute of Theoretical and Experimental Biophysics of the Russian Academy of Sciences, 3 Institutskaya St., Pushchino 142290, Russia; (V.A.A.); (S.S.S.); (A.E.S.); (E.A.Z.)
| |
Collapse
|
2
|
Abay Z, Nurpeisova A, Shorayeva K, Sadikaliyeva S, Yespembetov B, Syrym N, Sarmykova M, Jekebekov K, Abitayev R, Tokkarina G, Kalimolda E, Absatova Z, Moldagulova S, Yoo HS, Kassenov M, Zakarya K, Abduraimov Y. Safety and Protective Efficacy of a Candidate Vector-Based Vaccine for Bovine Tuberculosis. Vaccines (Basel) 2023; 11:1199. [PMID: 37515015 PMCID: PMC10385609 DOI: 10.3390/vaccines11071199] [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: 04/05/2023] [Revised: 06/30/2023] [Accepted: 07/01/2023] [Indexed: 07/30/2023] Open
Abstract
This study presents the results of a survey of the safety and protective efficacy of a candidate vector-based vaccine for bovine tuberculosis, using an influenza vector with the NS1 mutation and expressing M. bovis protective antigens ESAT-6 and TB10.4. We vaccinated Balb/c outbred mice two times at 21 days apart. Our experimental design includes mice immunised with the candidate vaccine with or without adjuvant 15% Montanide Gel. The candidate vaccine's safety was determined by biometric analysis, and protective efficacy was assessed by bacteriological and histological experiments following a virulent M. bovis-8 strain challenge. Our data indicated that the adjuvant-free version of the vaccine ensured complete protection from the M. bovis-8 infection in mice.
Collapse
Affiliation(s)
- Zhandos Abay
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
- Department of Biotechnology, Al-Farabi Kazakh National University, Almaty 050040, Kazakhstan
| | - Ainur Nurpeisova
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| | - Kamshat Shorayeva
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| | | | - Bolat Yespembetov
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| | - Nazym Syrym
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| | - Makhpal Sarmykova
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| | - Kuanysh Jekebekov
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| | - Ruslan Abitayev
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| | - Gaukhar Tokkarina
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| | - Elina Kalimolda
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| | - Zharkinay Absatova
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| | - Sabina Moldagulova
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| | - Han Sang Yoo
- College of Veterinary Medicine, Seoul National University, Seoul 08826, Republic of Korea
| | - Markhabat Kassenov
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| | - Kunsulu Zakarya
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| | - Yergali Abduraimov
- Research Institute for Biological Safety Problems, Guardeyskiy uts 080409, Kazakhstan
| |
Collapse
|
3
|
Ma L. From Photon Beam to Accelerated Particle Beam: Antimetastasis Effect of Combining Radiotherapy With Immunotherapy. Front Public Health 2022; 10:847119. [PMID: 35425754 PMCID: PMC9002008 DOI: 10.3389/fpubh.2022.847119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Accepted: 02/25/2022] [Indexed: 12/18/2022] Open
Abstract
Cancer is one of the major diseases that seriously threaten the human health. Radiotherapy is a common treatment for cancer. It is noninvasive and retains the functions of the organ where the tumor is located. Radiotherapy includes photon beam radiotherapy, which uses X-rays or gamma rays, and particle beam radiotherapy, using beams of protons and heavy ions. Compared with photon beam radiotherapy, particle beam radiotherapy has excellent dose distribution, which enables it to kill the primary tumor cells more effectively and simultaneously minimize the radiation-induced damage to normal tissues and organs surrounding the tumor. Despite the excellent therapeutic effect of particle beam radiotherapy on the irradiated tumors, it is not an effective treatment for metastatic cancers. Therefore, developing novel and effective treatment strategies for cancer is urgently needed to save patients with distant cancer metastasis. Immunotherapy enhances the body's own immune system to fight cancer by activating the immune cells, and consequently, to achieve the systemic anticancer effects, and it is considered to be an adjuvant therapy that can enhance the efficacy of particle beam radiotherapy. This review highlights the research progress of the antimetastasis effect and the mechanism of the photon beam or particle beam radiotherapy combined with immunotherapy and predicts the development prospects of this research area.
Collapse
Affiliation(s)
- Liqiu Ma
- Department of Nuclear Physics, China Institute of Atomic Energy, Beijing, China.,National Innovation Center of Radiation Application, Beijing, China
| |
Collapse
|
4
|
Krukowski K, Grue K, Becker M, Elizarraras E, Frias ES, Halvorsen A, Koenig-Zanoff M, Frattini V, Nimmagadda H, Feng X, Jones T, Nelson G, Ferguson AR, Rosi S. The impact of deep space radiation on cognitive performance: From biological sex to biomarkers to countermeasures. SCIENCE ADVANCES 2021; 7:eabg6702. [PMID: 34652936 PMCID: PMC8519563 DOI: 10.1126/sciadv.abg6702] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Accepted: 08/20/2021] [Indexed: 05/13/2023]
Abstract
In the coming decade, astronauts will travel back to the moon in preparation for future Mars missions. Exposure to galactic cosmic radiation (GCR) is a major obstacle for deep space travel. Using multivariate principal components analysis, we found sex-dimorphic responses in mice exposed to accelerated charged particles to simulate GCR (GCRsim); males displayed impaired spatial learning, whereas females did not. Mechanistically, these GCRsim-induced learning impairments corresponded with chronic microglia activation and synaptic alterations in the hippocampus. Temporary microglia depletion shortly after GCRsim exposure mitigated GCRsim-induced deficits measured months after the radiation exposure. Furthermore, blood monocyte levels measured early after GCRsim exposure were predictive of the late learning deficits and microglia activation measured in the male mice. Our findings (i) advance our understanding of charged particle–induced cognitive challenges, (ii) provide evidence for early peripheral biomarkers for identifying late cognitive deficits, and (iii) offer potential therapeutic strategies for mitigating GCR-induced cognitive loss.
Collapse
Affiliation(s)
- Karen Krukowski
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA, USA
- Brain and Spinal Injury Center, University of California, San Francisco, San Francisco, CA, USA
| | - Katherine Grue
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA, USA
- Brain and Spinal Injury Center, University of California, San Francisco, San Francisco, CA, USA
| | - McKenna Becker
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA, USA
- Brain and Spinal Injury Center, University of California, San Francisco, San Francisco, CA, USA
| | - Edward Elizarraras
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA, USA
- Brain and Spinal Injury Center, University of California, San Francisco, San Francisco, CA, USA
| | - Elma S. Frias
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA, USA
- Brain and Spinal Injury Center, University of California, San Francisco, San Francisco, CA, USA
| | - Aaron Halvorsen
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA, USA
- Brain and Spinal Injury Center, University of California, San Francisco, San Francisco, CA, USA
| | - McKensie Koenig-Zanoff
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA, USA
- Brain and Spinal Injury Center, University of California, San Francisco, San Francisco, CA, USA
| | - Valentina Frattini
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA, USA
- Brain and Spinal Injury Center, University of California, San Francisco, San Francisco, CA, USA
| | - Hasitha Nimmagadda
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA, USA
- Brain and Spinal Injury Center, University of California, San Francisco, San Francisco, CA, USA
| | - Xi Feng
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA, USA
- Brain and Spinal Injury Center, University of California, San Francisco, San Francisco, CA, USA
| | - Tamako Jones
- Department of Basic Sciences, Division of Biomedical Engineering Sciences, Loma Linda University, Loma Linda, CA, USA
| | - Gregory Nelson
- Department of Basic Sciences, Division of Biomedical Engineering Sciences, Loma Linda University, Loma Linda, CA, USA
| | - Adam R. Ferguson
- Brain and Spinal Injury Center, University of California, San Francisco, San Francisco, CA, USA
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
- Weill Institute for Neuroscience, University of California, San Francisco, San Francisco, CA, USA
- San Francisco Veterans Affairs Healthcare System, San Francisco, CA, USA
| | - Susanna Rosi
- Department of Physical Therapy and Rehabilitation Science, University of California, San Francisco, San Francisco, CA, USA
- Brain and Spinal Injury Center, University of California, San Francisco, San Francisco, CA, USA
- Department of Neurological Surgery, University of California, San Francisco, San Francisco, CA, USA
- Weill Institute for Neuroscience, University of California, San Francisco, San Francisco, CA, USA
- Kavli Institute of Fundamental Neuroscience, University of California, San Francisco, San Francisco, CA, USA
| |
Collapse
|
5
|
Patel RB, Hernandez R, Carlson P, Grudzinski J, Bates AM, Jagodinsky JC, Erbe A, Marsh IR, Arthur I, Aluicio-Sarduy E, Sriramaneni RN, Jin WJ, Massey C, Rakhmilevich AL, Vail D, Engle JW, Le T, Kim K, Bednarz B, Sondel PM, Weichert J, Morris ZS. Low-dose targeted radionuclide therapy renders immunologically cold tumors responsive to immune checkpoint blockade. Sci Transl Med 2021; 13:13/602/eabb3631. [PMID: 34261797 DOI: 10.1126/scitranslmed.abb3631] [Citation(s) in RCA: 90] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 02/10/2021] [Accepted: 06/24/2021] [Indexed: 12/12/2022]
Abstract
Molecular and cellular effects of radiotherapy on tumor microenvironment (TME) can help prime and propagate antitumor immunity. We hypothesized that delivering radiation to all tumor sites could augment response to immunotherapies. We tested an approach to enhance response to immune checkpoint inhibitors (ICIs) by using targeted radionuclide therapy (TRT) to deliver radiation semiselectively to tumors. NM600, an alkylphosphocholine analog that preferentially accumulates in most tumor types, chelates a radioisotope and semiselectively delivers it to the TME for therapeutic or diagnostic applications. Using serial 86Y-NM600 positron emission tomography (PET) imaging, we estimated the dosimetry of 90Y-NM600 in immunologically cold syngeneic murine models that do not respond to ICIs alone. We observed strong therapeutic efficacy and reported optimal dose (2.5 to 5 gray) and sequence for 90Y-NM600 in combination with ICIs. After combined treatment, 45 to 66% of mice exhibited complete response and tumor-specific T cell memory, compared to 0% with 90Y-NM600 or ICI alone. This required expression of STING in tumor cells. Combined TRT and ICI activated production of proinflammatory cytokines in the TME, promoted tumor infiltration by and clonal expansion of CD8+ T cells, and reduced metastases. In mice bearing multiple tumors, combining TRT with moderate-dose (12 gray) external beam radiotherapy (EBRT) targeting a single tumor augmented response to ICIs compared to combination of ICIs with either TRT or EBRT alone. The safety of TRT was confirmed in a companion canine study. Low-dose TRT represents a translatable approach to promote response to ICIs for many tumor types, regardless of location.
Collapse
Affiliation(s)
- Ravi B Patel
- Department of Radiation Oncology, University of Pittsburgh Hillman Cancer Center, Pittsburgh, PA 15213, USA.
| | - Reinier Hernandez
- Department of Radiology, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Peter Carlson
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Joseph Grudzinski
- Department of Radiology, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Amber M Bates
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Justin C Jagodinsky
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Amy Erbe
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Ian R Marsh
- Department of Medical Physics, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Ian Arthur
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI 53792, USA
| | | | - Raghava N Sriramaneni
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Won Jong Jin
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Christopher Massey
- Department of Radiology, University of Wisconsin-Madison, Madison, WI 53792, USA
| | | | - David Vail
- Department of Medical Sciences, School of Veterinary Medicine, University of Wisconsin-Madison, Madison, WI 53792, USA.,Barbara A. Suran Comparative Oncology Institute, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Johnathan W Engle
- Department of Radiology, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Trang Le
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - KyungMann Kim
- Department of Biostatistics and Medical Informatics, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Bryan Bednarz
- Department of Radiology, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Paul M Sondel
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI 53792, USA.,Department of Pediatrics, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Jamey Weichert
- Department of Radiology, University of Wisconsin-Madison, Madison, WI 53792, USA
| | - Zachary S Morris
- Department of Human Oncology, University of Wisconsin-Madison, Madison, WI 53792, USA.
| |
Collapse
|
6
|
Gopalakrishnan V, Sharma S, Ray U, Manjunath M, Lakshmanan D, Vartak SV, Gopinatha VK, Srivastava M, Kempegowda M, Choudhary B, Raghavan SC. SCR7, an inhibitor of NHEJ can sensitize tumor cells to ionization radiation. Mol Carcinog 2021; 60:627-643. [PMID: 34192388 DOI: 10.1002/mc.23329] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2021] [Revised: 06/01/2021] [Accepted: 06/07/2021] [Indexed: 12/30/2022]
Abstract
Nonhomologous end joining (NHEJ), one of the major DNA double-strand break repair pathways, plays a significant role in cancer cell proliferation and resistance to radio and chemotherapeutic agents. Previously, we had described a small molecule inhibitor, SCR7, which inhibited NHEJ in a DNA Ligase IV dependent manner. Here, we report that SCR7 potentiates the effect of γ-radiation (IR) that induces DNA breaks as intermediates to eradicate cancer cells. Dose fractionation studies revealed that coadministration of SCR7 and IR (0.5 Gy) in mice Dalton's lymphoma (DLA) model led to a significant reduction in mice tumor cell proliferation, which was equivalent to that observed for 2 Gy dose when both solid and liquid tumor models were used. Besides, co-treatment with SCR7 and 1 Gy of IR further improved the efficacy. Notably, there was no significant change in blood parameters, kidney and liver functions upon combinatorial treatment of SCR7 and IR. Further, the co-treatment of SCR7 and IR resulted in a significant increase in unrepaired DSBs within cancer cells compared to either of the agent alone. Anatomy, histology, and other studies in tumor models confirmed the cumulative effects of both agents in activating apoptotic pathways to induce cytotoxicity by modulating DNA damage response and repair pathways. Thus, we report that SCR7 has the potential to reduce the side effects of radiotherapy by lowering its effective dose ex vivo and in mice tumor models, with implications in cancer therapy.
Collapse
Affiliation(s)
- Vidya Gopalakrishnan
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka, India.,Institute of Bioinformatics and Applied Biotechnology, Electronics City, Bangalore, Karnataka, India.,Department of Zoology, St. Joseph's College (Autonomous), Irinjalakuda, Kerala, India
| | - Shivangi Sharma
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka, India.,Institute of Bioinformatics and Applied Biotechnology, Electronics City, Bangalore, Karnataka, India
| | - Ujjayinee Ray
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka, India
| | - Meghana Manjunath
- Institute of Bioinformatics and Applied Biotechnology, Electronics City, Bangalore, Karnataka, India.,Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Divya Lakshmanan
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka, India
| | - Supriya V Vartak
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka, India
| | - Vindya K Gopinatha
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka, India
| | - Mrinal Srivastava
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka, India.,Tata Institute of Fundamental Research, Hyderabad, Telangana, India
| | | | - Bibha Choudhary
- Institute of Bioinformatics and Applied Biotechnology, Electronics City, Bangalore, Karnataka, India
| | - Sathees C Raghavan
- Department of Biochemistry, Indian Institute of Science, Bangalore, Karnataka, India
| |
Collapse
|
7
|
Rahman M, Brůža P, Langen KM, Gladstone DJ, Cao X, Pogue BW, Zhang R. Characterization of a new scintillation imaging system for proton pencil beam dose rate measurements. ACTA ACUST UNITED AC 2020; 65:165014. [DOI: 10.1088/1361-6560/ab9452] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
|
8
|
Harrold J, Gisleskog PO, Perez-Ruixo JJ, Delor I, Chow A, Jacqmin P, Melhem M. Prediction of Survival Benefit of Filgrastim in Adult and Pediatric Patients With Acute Radiation Syndrome. Clin Transl Sci 2020; 13:807-817. [PMID: 32112517 PMCID: PMC7359936 DOI: 10.1111/cts.12777] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2019] [Accepted: 01/22/2020] [Indexed: 12/30/2022] Open
Abstract
Acute exposure to high doses of radiation leads to severe myelosuppression, but few treatments are currently available to treat hematopoietic syndrome of acute radiation syndrome. Granulocyte colony stimulating factors (e.g., filgrastim) stimulate proliferation of neutrophil precursors and enhance mature neutrophil function. Owing to ethical constraints on conducting clinical research in lethally irradiated humans, we developed a model‐based strategy to integrate preclinical experience in irradiated nonhuman primates (NHPs) and other clinical myelosuppressive conditions to inform filgrastim dosing to treat hematopoietic syndrome of acute radiation syndrome. Models predicting neutrophil counts and overall survival based on drug exposures were calibrated and scaled from NHPs to adult and pediatric human subjects. Several scenarios were examined investigating variations in filgrastim doses, dose frequency, treatment initiation, and duration, as well as the effect of age and radiation dose rate. Model‐based simulations and established safety profiles supported that a subcutaneous filgrastim dose of 10 µg/kg once daily provides a significant survival benefit (50%) over placebo in both adults and children, provided that the treatment is initiated within 1–14 days after radiation exposure and lasts 2–3 weeks. For treatment durations of longer than 3 weeks, filgrastim treatment is not expected to provide significantly greater benefit. This survival benefit is expected to hold for the wide range of radiation doses and dose rates (0.01–1,000 Gy/hours) examined.
Collapse
Affiliation(s)
- John Harrold
- Department of Clinical Pharmacology, Modeling and Simulation, Amgen Inc., Thousand Oaks, California, USA
| | | | - Juan Jose Perez-Ruixo
- Department of Clinical Pharmacology, Modeling and Simulation, Amgen Inc., Thousand Oaks, California, USA
| | | | - Andrew Chow
- Department of Clinical Pharmacology, Modeling and Simulation, Amgen Inc., Thousand Oaks, California, USA
| | | | - Murad Melhem
- Department of Clinical Pharmacology, Modeling and Simulation, Amgen Inc., Thousand Oaks, California, USA
| |
Collapse
|
9
|
Lambin P, Lieverse RIY, Eckert F, Marcus D, Oberije C, van der Wiel AMA, Guha C, Dubois LJ, Deasy JO. Lymphocyte-Sparing Radiotherapy: The Rationale for Protecting Lymphocyte-rich Organs When Combining Radiotherapy With Immunotherapy. Semin Radiat Oncol 2020; 30:187-193. [PMID: 32381298 PMCID: PMC8412054 DOI: 10.1016/j.semradonc.2019.12.003] [Citation(s) in RCA: 51] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
There is now strong clinical and preclinical evidence that lymphocytes, for example, CD8+ T cells, are key effectors of immunotherapy and that irradiation of large blood vessels, the heart, and lymphoid organs (including nodes, spleen, bones containing bone marrow, and thymus in children) causes transient or persistent lymphopenia. Furthermore, there is extensive clinical evidence, across multiple cancer sites and treatment modalities, that lymphopenia correlates strongly with decreased overall survival. At the moment, we lack quantitative evidence to establish the relationship between dose-volume and dose-rate to critical normal structures and lymphopenia. Therefore, we propose that data should be systematically recorded to characterise a possible quantitative relationship. This might enable us to improve the efficacy of radiotherapy and develop strategies to predict and prevent treatment-related lymphopenia. In anticipation of more quantitative data, we recommend the application of the principle of As Low As Reasonably Achievable to lymphocyte-rich regions for radiotherapy treatment planning to reduce the radiation doses to these structures, thus moving toward "Lymphocyte-Sparing Radiotherapy."
Collapse
Affiliation(s)
- Philippe Lambin
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW - School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands.
| | - Relinde I Y Lieverse
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW - School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
| | - Franziska Eckert
- Department of Radiation Oncology, University Hospital and Medical Faculty Tübingen, Eberhard Karls University Tübingen, Tübingen, Germany
| | - Damiënne Marcus
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW - School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
| | - Cary Oberije
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW - School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
| | - Alexander M A van der Wiel
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW - School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
| | - Chandan Guha
- Department of Radiation Oncology, Montefiore Medical Center, Bronx, NY
| | - Ludwig J Dubois
- The D-Lab and The M-Lab, Department of Precision Medicine, GROW - School for Oncology and Developmental Biology, Maastricht University, Maastricht, The Netherlands
| | - Joseph O Deasy
- Department of Medical Physics, Memorial Sloan Kettering Cancer Center, New York, NY
| |
Collapse
|
10
|
Иванов А, Ivanov A, Бычкова Т, Bichkova T, Никитенко О, Nikitenko O, Ушаков И, Ushakov I. Radiobiological Proton Effects. ACTA ACUST UNITED AC 2019. [DOI: 10.12737/article_5cf2306a3b26d6.36140627] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
The article contains an analysis of literature data and the author’s own results on the radiobiological effects of protons at the cellular, systemic (intercellular) and organismic levels, as applied to the practical tasks of radiation therapy of oncological diseases and the protons effects on the astronauts’ organism.
It is established that the proton RBE is a variable value, depending on the LET of the particles, the amount and dose rate, the presence or absence of oxygen. Proton RBE varies depending on the object of study, the type of tissue, proton energy and particle penetration depth, as well as the method for evaluating the biological efficiency of protons. which corresponds to general radiobiology.
In particular, it has been shown that the RBE of protons adopted in radiation therapy at the level of 1.1 is conditional. A firmly established and repeatedly confirmed is an increase in RBE with a decrease in proton energy and, accordingly, an increase in LET.
The use of elements of the physical protection of a spacecraft during exposure to protons with an energy of 170 MeV leads to an increase in LET and RBE of protons in terms of the cellularity of the bone marrow.
Pharmacological agents effective in photon irradiation are also effective when exposed to a proton beam. It has been shown that natural melanin pigment and recombinant manganese superoxide dismutase helps to preserve and accelerate the resumption of blood formation in animals irradiated by protons. The Grippol vaccine increases radioresistance during proton irradiation. Neuropeptide Semax has a positive effect on the central nervous system and the strength of the forepaws of animals irradiated with protons at Bragg’s peak.
Collapse
Affiliation(s)
- А. Иванов
- Объединенный институт ядерных исследований
- Институт медико-биологических проблем РАН
- Федеральный медицинский биофизический центр им. А.И.Бурназяна ФМБА России
| | - A. Ivanov
- Joint Institute for Nuclear Research
- Institute for Biomedical Problems
- A.I. Burnasyan Federal Medical Biophysical Center (FMBC) FMBA
| | - Т. Бычкова
- Федеральный медицинский биофизический центр им. А.И. Бурназяна ФМБА России
- Институт медико-биологических проблем РАН
| | - T. Bichkova
- A.I. Burnasyan Federal Medical Biophysical Center of FMBA
- Institute of Biomedical Problems, Russian Academy of Sciences
| | - О. Никитенко
- Федеральный медицинский биофизический центр им. А.И. Бурназяна ФМБА России
- Институт медико-биологических проблем РАН
| | - O. Nikitenko
- A.I. Burnasyan Federal Medical Biophysical Center of FMBA
- Institute of Biomedical Problems, Russian Academy of Sciences
| | - И. Ушаков
- Федеральный медицинский биофизический центр им. А.И. Бурназяна ФМБА России
| | - I. Ushakov
- A.I. Burnasyan Federal Medical Biophysical Center of FMBA
| |
Collapse
|
11
|
El-Shanshoury H, El-Shanshoury G, Abaza A. Evaluation of low dose ionizing radiation effect on some blood components in animal model. JOURNAL OF RADIATION RESEARCH AND APPLIED SCIENCES 2019. [DOI: 10.1016/j.jrras.2016.01.001] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- H. El-Shanshoury
- Radiation Safety Department, Nuclear and Radiological Regulatory Authority, Cairo, Egypt
- Laser Sciences (Department of Medical Applications of Laser), National Institute of Laser Sciences, Cairo University, Cairo, Egypt
| | - G. El-Shanshoury
- Applied Statistic in Radiation Safety Department, Nuclear and Radiological Regulatory Authority, Cairo, Egypt
- Applied Statistic, Ain-Shams University, Cairo, Egypt
| | - A. Abaza
- Safety and Prevention of Oncology in Radiation Protection Department, Nuclear and Radiological Regulatory Authority, Cairo, Egypt
- Childhood Studies & Pediatric Oncology, Ain-Shams University, Cairo, Egypt
| |
Collapse
|
12
|
Krukowski K, Jones T, Campbell-Beachler M, Nelson G, Rosi S. Peripheral T Cells as a Biomarker for Oxygen-Ion-Radiation-Induced Social Impairments. Radiat Res 2018; 190:186-193. [DOI: 10.1667/rr15046.1] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
| | - Tamako Jones
- Department of Basic Sciences, Division of Biomedical Engineering Sciences, Loma Linda University, Loma Linda, California
| | - Mary Campbell-Beachler
- Department of Basic Sciences, Division of Biomedical Engineering Sciences, Loma Linda University, Loma Linda, California
| | - Gregory Nelson
- Department of Basic Sciences, Division of Biomedical Engineering Sciences, Loma Linda University, Loma Linda, California
| | - Susanna Rosi
- Department of Physical Therapy and Rehabilitation Science
| |
Collapse
|
13
|
Wang Y, Chang J, Li X, Pathak R, Sridharan V, Jones T, Mao XW, Nelson G, Boerma M, Hauer-Jensen M, Zhou D, Shao L. Low doses of oxygen ion irradiation cause long-term damage to bone marrow hematopoietic progenitor and stem cells in mice. PLoS One 2017; 12:e0189466. [PMID: 29232383 PMCID: PMC5726652 DOI: 10.1371/journal.pone.0189466] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2017] [Accepted: 11/28/2017] [Indexed: 11/19/2022] Open
Abstract
During deep space missions, astronauts will be exposed to low doses of charged particle irradiation. The long-term health effects of these exposures are largely unknown. We previously showed that low doses of oxygen ion (16O) irradiation induced acute damage to the hematopoietic system, including hematopoietic progenitor and stem cells in a mouse model. However, the chronic effects of low dose 16O irradiation remain undefined. In the current study, we investigated the long-term effects of low dose 16O irradiation on the mouse hematopoietic system. Male C57BL/6J mice were exposed to 0.05 Gy, 0.1 Gy, 0.25 Gy and 1.0 Gy whole body 16O (600 MeV/n) irradiation. The effects of 16O irradiation on bone marrow (BM) hematopoietic progenitor cells (HPCs) and hematopoietic stem cells (HSCs) were examined three months after the exposure. The results showed that the frequencies and numbers of BM HPCs and HSCs were significantly reduced in 0.1 Gy, 0.25 Gy and 1.0 Gy irradiated mice compared to 0.05 Gy irradiated and non-irradiated mice. Exposure of mice to low dose 16O irradiation also significantly reduced the clongenic function of BM HPCs determined by the colony-forming unit assay. The functional defect of irradiated HSCs was detected by cobblestone area-forming cell assay after exposure of mice to 0.1 Gy, 0.25 Gy and 1.0 Gy of 16O irradiation, while it was not seen at three months after 0.5 Gy and 1.0 Gy of γ-ray irradiation. These adverse effects of 16O irradiation on HSCs coincided with an increased intracellular production of reactive oxygen species (ROS). However, there were comparable levels of cellular apoptosis and DNA damage between irradiated and non-irradiated HPCs and HSCs. These data suggest that exposure to low doses of 16O irradiation induces long-term hematopoietic injury, primarily via increased ROS production in HSCs.
Collapse
Affiliation(s)
- Yingying Wang
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Jianhui Chang
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Xin Li
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Rupak Pathak
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Vijayalakshmi Sridharan
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Tamako Jones
- Department of Basic Sciences, Division of Radiation Research, School of Medicine, Loma Linda University, Loma Linda, CA, United States of America
| | - Xiao Wen Mao
- Department of Basic Sciences, Division of Radiation Research, School of Medicine, Loma Linda University, Loma Linda, CA, United States of America
| | - Gregory Nelson
- Department of Basic Sciences, Division of Radiation Research, School of Medicine, Loma Linda University, Loma Linda, CA, United States of America
| | - Marjan Boerma
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Martin Hauer-Jensen
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Daohong Zhou
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
| | - Lijian Shao
- Division of Radiation Health, Department of Pharmaceutical Sciences, University of Arkansas for Medical Sciences, Little Rock, AR, United States of America
- * E-mail:
| |
Collapse
|
14
|
Hu S. Linking Doses with Clinical Scores of Hematopoietic Acute Radiation Syndrome. HEALTH PHYSICS 2016; 111:337-347. [PMID: 27575346 DOI: 10.1097/hp.0000000000000529] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
In radiation accidents, determining the radiation dose the victim received is a key step for medical decision making and patient prognosis. To reconstruct and evaluate the absorbed dose, researchers have developed many physical devices and biological techniques during the last decades. However, using the physical parameter "absorbed dose" alone is not sufficient to predict the clinical development of the various organs injured in an individual patient. In operational situations for radiation accidents, medical responders need more urgently to classify the severity of the radiation injury based on the signs and symptoms of the patient. In this work, the author uses a unified hematopoietic model to describe dose-dependent dynamics of granulocytes, lymphocytes, and platelets, and the corresponding clinical grading of hematopoietic acute radiation syndrome. This approach not only visualizes the time course of the patient's probable outcome in the form of graphs but also indirectly gives information of the remaining stem and progenitor cells, which are responsible for the autologous recovery of the hematopoietic system. Because critical information on the patient's clinical evolution can be provided within a short time after exposure and only peripheral cell counts are required for the simulation, these modeling tools will be useful to assess radiation exposure and injury in human-involved radiation accident/incident scenarios.
Collapse
Affiliation(s)
- Shaowen Hu
- *KBRwyle Science, Technology and Engineering, Houston, TX 77058
| |
Collapse
|
15
|
Muralidharan S, Sasi SP, Zuriaga MA, Hirschi KK, Porada CD, Coleman MA, Walsh KX, Yan X, Goukassian DA. Ionizing Particle Radiation as a Modulator of Endogenous Bone Marrow Cell Reprogramming: Implications for Hematological Cancers. Front Oncol 2015; 5:231. [PMID: 26528440 PMCID: PMC4604322 DOI: 10.3389/fonc.2015.00231] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2015] [Accepted: 10/01/2015] [Indexed: 12/15/2022] Open
Abstract
Exposure of individuals to ionizing radiation (IR), as in the case of astronauts exploring space or radiotherapy cancer patients, increases their risk of developing secondary cancers and other health-related problems. Bone marrow (BM), the site in the body where hematopoietic stem cell (HSC) self-renewal and differentiation to mature blood cells occurs, is extremely sensitive to low-dose IR, including irradiation by high-charge and high-energy particles. Low-dose IR induces DNA damage and persistent oxidative stress in the BM hematopoietic cells. Inefficient DNA repair processes in HSC and early hematopoietic progenitors can lead to an accumulation of mutations whereas long-lasting oxidative stress can impair hematopoiesis itself, thereby causing long-term damage to hematopoietic cells in the BM niche. We report here that low-dose 1H- and 56Fe-IR significantly decreased the hematopoietic early and late multipotent progenitor (E- and L-MPP, respectively) cell numbers in mouse BM over a period of up to 10 months after exposure. Both 1H- and 56Fe-IR increased the expression of pluripotent stem cell markers Sox2, Nanog, and Oct4 in L-MPPs and 10 months post-IR exposure. We postulate that low doses of 1H- and 56Fe-IR may induce endogenous cellular reprogramming of BM hematopoietic progenitor cells to assume a more primitive pluripotent phenotype and that IR-induced oxidative DNA damage may lead to mutations in these BM progenitors. This could then be propagated to successive cell lineages. Persistent impairment of BM progenitor cell populations can disrupt hematopoietic homeostasis and lead to hematologic disorders, and these findings warrant further mechanistic studies into the effects of low-dose IR on the functional capacity of BM-derived hematopoietic cells including their self-renewal and pluripotency.
Collapse
Affiliation(s)
- Sujatha Muralidharan
- Whitaker Cardiovascular Institute, Boston University School of Medicine , Boston, MA , USA
| | - Sharath P Sasi
- Cardiovascular Research Center, GeneSys Research Institute , Boston, MA , USA
| | - Maria A Zuriaga
- Whitaker Cardiovascular Institute, Boston University School of Medicine , Boston, MA , USA
| | - Karen K Hirschi
- Yale Cardiovascular Research Center, Yale School of Medicine , New Haven, CT , USA
| | - Christopher D Porada
- Wake Forest Institute for Regenerative Medicine, Wake Forest School of Medicine , Winston-Salem, NC , USA
| | - Matthew A Coleman
- Radiation Oncology, School of Medicine, University of California Davis , Sacramento, CA , USA ; Lawrence Livermore National Laboratory , Livermore, CA , USA
| | - Kenneth X Walsh
- Whitaker Cardiovascular Institute, Boston University School of Medicine , Boston, MA , USA
| | - Xinhua Yan
- Cardiovascular Research Center, GeneSys Research Institute , Boston, MA , USA ; Tufts University School of Medicine , Boston, MA , USA
| | - David A Goukassian
- Whitaker Cardiovascular Institute, Boston University School of Medicine , Boston, MA , USA ; Cardiovascular Research Center, GeneSys Research Institute , Boston, MA , USA ; Tufts University School of Medicine , Boston, MA , USA
| |
Collapse
|
16
|
Sanzari JK, Krigsfeld GS, Shuman AL, Diener AK, Lin L, Mai W, Kennedy AR. Effects of a granulocyte colony stimulating factor, Neulasta, in mini pigs exposed to total body proton irradiation. LIFE SCIENCES IN SPACE RESEARCH 2015; 5:13-20. [PMID: 25909052 PMCID: PMC4402939 DOI: 10.1016/j.lssr.2015.03.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Astronauts could be exposed to solar particle event (SPE) radiation, which is comprised mostly of proton radiation. Proton radiation is also a treatment option for certain cancers. Both astronauts and clinical patients exposed to ionizing radiation are at risk for loss of white blood cells (WBCs), which are the body's main defense against infection. In this report, the effect of Neulasta treatment, a granulocyte colony stimulating factor, after proton radiation exposure is discussed. Mini pigs exposed to total body proton irradiation at a dose of 2 Gy received 4 treatments of either Neulasta or saline injections. Peripheral blood cell counts and thromboelastography parameters were recorded up to 30 days post-irradiation. Neulasta significantly improved WBC loss, specifically neutrophils, in irradiated animals by approximately 60% three days after the first injection, compared to the saline treated, irradiated animals. Blood cell counts quickly decreased after the last Neulasta injection, suggesting a transient effect on WBC stimulation. Statistically significant changes in hemostasis parameters were observed after proton radiation exposure in both the saline and Neulasta treated irradiated groups, as well as internal organ complications such as pulmonary changes. In conclusion, Neulasta treatment temporarily alleviates proton radiation-induced WBC loss, but has no effect on altered hemostatic responses.
Collapse
Affiliation(s)
- Jenine K. Sanzari
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA
| | | | - Anne L. Shuman
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA
| | - Antonia K. Diener
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA
| | - Liyong Lin
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA
| | - Wilfried Mai
- Radiology, University of Pennsylvania School of Veterinary Medicine, Philadelphia, PA
| | - Ann R. Kennedy
- Department of Radiation Oncology, University of Pennsylvania, Philadelphia, PA
| |
Collapse
|
17
|
Broad-spectrum antibiotic or G-CSF as potential countermeasures for impaired control of bacterial infection associated with an SPE exposure during spaceflight. PLoS One 2015; 10:e0120126. [PMID: 25793272 PMCID: PMC4368688 DOI: 10.1371/journal.pone.0120126] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2014] [Accepted: 02/04/2015] [Indexed: 12/31/2022] Open
Abstract
A major risk for astronauts during prolonged space flight is infection as a result of the combined effects of microgravity, situational and confinement stress, alterations in food intake, altered circadian rhythm, and radiation that can significantly impair the immune system and the body’s defense systems. We previously reported a massive increase in morbidity with a decrease in the ability to control a bacterial challenge when mice were maintained under hindlimb suspension (HS) conditions and exposed to solar particle event (SPE)-like radiation. HS and SPE-like radiation treatment alone resulted in a borderline significant increase in morbidity. Therefore, development and testing of countermeasures that can be used during extended space missions in the setting of exposure to SPE radiation becomes a serious need. In the present study, we investigated the efficacy of enrofloxacin (an orally bioavailable antibiotic) and Granulocyte colony stimulating factor (G-CSF) (Neulasta) on enhancing resistance to Pseudomonas aeruginosa infection in mice subjected to HS and SPE-like radiation. The results revealed that treatment with enrofloxacin or G-CSF enhanced bacterial clearance and significantly decreased morbidity and mortality in challenged mice exposed to suspension and radiation. These results establish that antibiotics, such as enrofloxacin, and G-CSF could be effective countermeasures to decrease the risk of bacterial infections after exposure to SPE radiation during extended space flight, thereby reducing both the risk to the crew and the danger of mission failure.
Collapse
|
18
|
Chang J, Feng W, Wang Y, Luo Y, Allen AR, Koturbash I, Turner J, Stewart B, Raber J, Hauer-Jensen M, Zhou D, Shao L. Whole-body proton irradiation causes long-term damage to hematopoietic stem cells in mice. Radiat Res 2015; 183:240-8. [PMID: 25635345 DOI: 10.1667/rr13887.1] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Space flight poses certain health risks to astronauts, including exposure to space radiation, with protons accounting for more than 80% of deep-space radiation. Proton radiation is also now being used with increasing frequency in the clinical setting to treat cancer. For these reasons, there is an urgent need to better understand the biological effects of proton radiation on the body. Such improved understanding could also lead to more accurate assessment of the potential health risks of proton radiation, as well as the development of improved strategies to prevent and mitigate its adverse effects. Previous studies have shown that exposure to low doses of protons is detrimental to mature leukocyte populations in peripheral blood, however, the underlying mechanisms are not known. Some of these detriments may be attributable to damage to hematopoietic stem cells (HSCs) that have the ability to self-renew, proliferate and differentiate into different lineages of blood cells through hematopoietic progenitor cells (HPCs). The goal of this study was to investigate the long-term effects of low-dose proton irradiation on HSCs. We exposed C57BL/6J mice to 1.0 Gy whole-body proton irradiation (150 MeV) and then studied the effects of proton radiation on HSCs and HPCs in the bone marrow (BM) 22 weeks after the exposure. The results showed that mice exposed to 1.0 Gy whole-body proton irradiation had a significant and persistent reduction of BM HSCs compared to unirradiated controls. In contrast, no significant changes were observed in BM HPCs after proton irradiation. Furthermore, irradiated HSCs and their progeny exhibited a significant impairment in clonogenic function, as revealed by the cobblestone area-forming cell (CAFC) and colony-forming cell assays, respectively. These long-term effects of proton irradiation on HSCs may be attributable to the induction of chronic oxidative stress in HSCs, because HSCs from irradiated mice exhibited a significant increase in NADPH oxidase 4 (NOX4) mRNA expression and reactive oxygen species (ROS) production. In addition, the increased production of ROS in HSCs was associated with a significant reduction in HSC quiescence and an increase in DNA damage. These findings indicate that exposure to proton radiation can lead to long-term HSC injury, probably in part by radiation-induced oxidative stress.
Collapse
|
19
|
Sanzari JK, Cengel KA, Wan XS, Rusek A, Kennedy AR. Acute Hematological Effects in Mice Exposed to the Expected Doses, Dose-rates, and Energies of Solar Particle Event-like Proton Radiation. LIFE SCIENCES IN SPACE RESEARCH 2014; 2:86-91. [PMID: 25202654 PMCID: PMC4155507 DOI: 10.1016/j.lssr.2014.01.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/06/2023]
Abstract
NASA has funded several projects that have provided evidence for the radiation risk in space. One radiation concern arises from solar particle event (SPE) radiation, which is composed of energetic electrons, protons, alpha particles and heavier particles. SPEs are unpredictable and the accompanying SPE radiation can place astronauts at risk of blood cell death, contributing to a weakened immune system and increased susceptibility to infection. The doses, dose rates, and energies of the proton radiation expected to occur during a SPE have been simulated at the NASA Space Radiation Laboratory, Brookhaven National Laboratory, delivering total body doses to mice. Hematological values were evaluated at acute time points, up to 24 hrs. post-radiation exposure.
Collapse
Affiliation(s)
- Jenine K. Sanzari
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, 3620 Hamilton Walk, 183 John Morgan Building, Philadelphia, Pennsylvania, 19104-6072, USA
| | - Keith A. Cengel
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, 3620 Hamilton Walk, 183 John Morgan Building, Philadelphia, Pennsylvania, 19104-6072, USA
| | - X. Steven Wan
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, 3620 Hamilton Walk, 183 John Morgan Building, Philadelphia, Pennsylvania, 19104-6072, USA
| | - Adam Rusek
- NASA Space Radiation Laboratory, Brookhaven National Laboratory, Upton, New York, USA
| | - Ann R. Kennedy
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, 3620 Hamilton Walk, 183 John Morgan Building, Philadelphia, Pennsylvania, 19104-6072, USA
| |
Collapse
|
20
|
Sweet TB, Panda N, Hein AM, Das SL, Hurley SD, Olschowka JA, Williams JP, O'Banion MK. Central Nervous System Effects of Whole-Body Proton Irradiation. Radiat Res 2014; 182:18-34. [DOI: 10.1667/rr13699.1] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Tara Beth Sweet
- Department of Neurobiology and Anatomy, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Nirlipta Panda
- Department of Neurobiology and Anatomy, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Amy M. Hein
- Department of Neurobiology and Anatomy, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Shoshana L. Das
- Department of Neurobiology and Anatomy, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Sean D. Hurley
- Department of Neurobiology and Anatomy, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - John A. Olschowka
- Department of Neurobiology and Anatomy, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - Jacqueline P. Williams
- Department of Environmental Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| | - M. Kerry O'Banion
- Department of Neurobiology and Anatomy, University of Rochester School of Medicine and Dentistry, Rochester, New York 14642
| |
Collapse
|
21
|
Kennedy AR. Biological Effects of Space Radiation and Development of Effective Countermeasures. LIFE SCIENCES IN SPACE RESEARCH 2014; 1:10-43. [PMID: 25258703 PMCID: PMC4170231 DOI: 10.1016/j.lssr.2014.02.004] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
As part of a program to assess the adverse biological effects expected from astronaut exposure to space radiation, numerous different biological effects relating to astronaut health have been evaluated. There has been major focus recently on the assessment of risks related to exposure to solar particle event (SPE) radiation. The effects related to various types of space radiation exposure that have been evaluated are: gene expression changes (primarily associated with programmed cell death and extracellular matrix (ECM) remodeling), oxidative stress, gastrointestinal tract bacterial translocation and immune system activation, peripheral hematopoietic cell counts, emesis, blood coagulation, skin, behavior/fatigue (including social exploration, submaximal exercise treadmill and spontaneous locomotor activity), heart functions, alterations in biological endpoints related to astronaut vision problems (lumbar puncture/intracranial pressure, ocular ultrasound and histopathology studies), and survival, as well as long-term effects such as cancer and cataract development. A number of different countermeasures have been identified that can potentially mitigate or prevent the adverse biological effects resulting from exposure to space radiation.
Collapse
Affiliation(s)
- Ann R Kennedy
- Department of Radiation Oncology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104-6072
| |
Collapse
|
22
|
Sanzari JK, Wan XS, Krigsfeld GS, Wroe AJ, Gridley DS, Kennedy AR. The Effects of Gamma and Proton Radiation Exposure on Hematopoietic Cell Counts in the Ferret Model. GRAVITATIONAL AND SPACE RESEARCH : PUBLICATION OF THE AMERICAN SOCIETY FOR GRAVITATIONAL AND SPACE RESEARCH 2013; 1:79-94. [PMID: 25356435 PMCID: PMC4209750] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Exposure to total-body radiation induces hematological changes, which can detriment one's immune response to wounds and infection. Here, the decreases in blood cell counts after acute radiation doses of γ-ray or proton radiation exposure, at the doses and dose-rates expected during a solar particle event (SPE), are reported in the ferret model system. Following the exposure to γ-ray or proton radiation, the ferret peripheral total white blood cell (WBC) and lymphocyte counts decreased whereas neutrophil count increased within 3 hours. At 48 hours after irradiation, the WBC, neutrophil, and lymphocyte counts decreased in a dose-dependent manner but were not significantly affected by the radiation type (γ-rays verses protons) or dose rate (0.5 Gy/minute verses 0.5 Gy/hour). The loss of these blood cells could accompany and contribute to the physiological symptoms of the acute radiation syndrome (ARS).
Collapse
Affiliation(s)
- Jenine K. Sanzari
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - X. Steven Wan
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Gabriel S. Krigsfeld
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Andrew J. Wroe
- Department of Radiation Medicine, Radiation Research Laboratories, Loma Linda University and Medical Center, Loma Linda, CA
| | - Daila S. Gridley
- Department of Radiation Medicine, Radiation Research Laboratories, Loma Linda University and Medical Center, Loma Linda, CA
| | - Ann R. Kennedy
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| |
Collapse
|
23
|
Sanzari JK, Romero-Weaver AL, James G, Krigsfeld G, Lin L, Diffenderfer ES, Kennedy AR. Leukocyte activity is altered in a ground based murine model of microgravity and proton radiation exposure. PLoS One 2013; 8:e71757. [PMID: 23977138 PMCID: PMC3743739 DOI: 10.1371/journal.pone.0071757] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Accepted: 07/01/2013] [Indexed: 02/06/2023] Open
Abstract
Immune system adaptation during spaceflight is a concern in space medicine. Decreased circulating leukocytes observed during and after space flight infer suppressed immune responses and susceptibility to infection. The microgravity aspect of the space environment has been simulated on Earth to study adverse biological effects in astronauts. In this report, the hindlimb unloading (HU) model was employed to investigate the combined effects of solar particle event-like proton radiation and simulated microgravity on immune cell parameters including lymphocyte subtype populations and activity. Lymphocytes are a type of white blood cell critical for adaptive immune responses and T lymphocytes are regulators of cell-mediated immunity, controlling the entire immune response. Mice were suspended prior to and after proton radiation exposure (2 Gy dose) and total leukocyte numbers and splenic lymphocyte functionality were evaluated on days 4 or 21 after combined HU and radiation exposure. Total white blood cell (WBC), lymphocyte, neutrophil, and monocyte counts are reduced by approximately 65%, 70%, 55%, and 70%, respectively, compared to the non-treated control group at 4 days after combined exposure. Splenic lymphocyte subpopulations are altered at both time points investigated. At 21 days post-exposure to combined HU and proton radiation, T cell activation and proliferation were assessed in isolated lymphocytes. Cell surface expression of the Early Activation Marker, CD69, is decreased by 30% in the combined treatment group, compared to the non-treated control group and cell proliferation was suppressed by approximately 50%, compared to the non-treated control group. These findings reveal that the combined stressors (HU and proton radiation exposure) result in decreased leukocyte numbers and function, which could contribute to immune system dysfunction in crew members. This investigation is one of the first to report on combined proton radiation and simulated microgravity effects on hematopoietic, specifically immune cells.
Collapse
Affiliation(s)
- Jenine K. Sanzari
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Ana L. Romero-Weaver
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Gabrielle James
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Gabriel Krigsfeld
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Liyong Lin
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Eric S. Diffenderfer
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
| | - Ann R. Kennedy
- Department of Radiation Oncology, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, United States of America
- * E-mail:
| |
Collapse
|
24
|
Lack of genomic instability in bone marrow cells of SCID mice exposed whole-body to low-dose radiation. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2013; 10:1356-77. [PMID: 23549227 PMCID: PMC3709322 DOI: 10.3390/ijerph10041356] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2013] [Revised: 03/05/2013] [Accepted: 03/12/2013] [Indexed: 11/17/2022]
Abstract
It is clear that high-dose radiation is harmful. However, despite extensive research, assessment of potential health-risks associated with exposure to low-dose radiation (at doses below or equal to 0.1 Gy) is still challenging. Recently, we reported that 0.05 Gy of 137Cs gamma rays (the existing limit for radiation-exposure in the workplace) was incapable of inducing significant in vivo genomic instability (measured by the presence of late-occurring chromosomal damage at 6 months post-irradiation) in bone marrow (BM) cells of two mouse strains, one with constitutively high and one with intermediate levels of the repair enzyme DNA-dependent protein-kinase catalytic-subunit (DNA-PKcs). In this study, we present evidence for a lack of genomic instability in BM cells of the severely combined-immunodeficiency (SCID/J) mouse (which has an extremely low-level of DNA-PKcs activity) exposed whole-body to low-dose radiation (0.05 Gy). Together with our previous report, the data indicate that low-dose radiation (0.05 Gy) is incapable of inducing genomic instability in vivo (regardless of the levels of DNA-PKcs activity of the exposed mice), yet higher doses of radiation (0.1 and 1 Gy) do induce genomic instability in mice with intermediate and extremely low-levels of DNA-PKcs activity (indicating an important role of DNA-PKcs in DNA repair).
Collapse
|
25
|
Yu Z, Vanstalle M, La Tessa C, Jiang GL, Durante M. Biophysical characterization of a relativistic proton beam for image-guided radiosurgery. JOURNAL OF RADIATION RESEARCH 2012; 53:620-627. [PMID: 22843629 PMCID: PMC3393345 DOI: 10.1093/jrr/rrs007] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/17/2012] [Accepted: 02/27/2012] [Indexed: 06/01/2023]
Abstract
We measured the physical and radiobiological characteristics of 1 GeV protons for possible applications in stereotactic radiosurgery (image-guided plateau-proton radiosurgery). A proton beam was accelerated at 1 GeV at the Brookhaven National Laboratory (Upton, NY) and a target in polymethyl methacrylate (PMMA) was used. Clonogenic survival was measured after exposures to 1-10 Gy in three mammalian cell lines. Measurements and simulations demonstrate that the lateral scattering of the beam is very small. The lateral dose profile was measured with or without the 20-cm plastic target, showing no significant differences up to 2 cm from the axis A large number of secondary swift protons are produced in the target and this leads to an increase of approximately 40% in the measured dose on the beam axis at 20 cm depth. The relative biological effectiveness at 10% survival level ranged between 1.0 and 1.2 on the beam axis, and was slightly higher off-axis. The very low lateral scattering of relativistic protons and the possibility of using online proton radiography during the treatment make them attractive for image-guided plateau (non-Bragg peak) stereotactic radiosurgery.
Collapse
Affiliation(s)
- Zhan Yu
- Biophysics Department, GSI Helmholtz Center for Heavy Ions Research, Planckstraße 1, 64291 Darmstadt, Germany
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, 270 Dong An Road, 200032 Shanghai, China
| | - Marie Vanstalle
- Biophysics Department, GSI Helmholtz Center for Heavy Ions Research, Planckstraße 1, 64291 Darmstadt, Germany
| | - Chiara La Tessa
- Biophysics Department, GSI Helmholtz Center for Heavy Ions Research, Planckstraße 1, 64291 Darmstadt, Germany
| | - Guo-Liang Jiang
- Department of Radiation Oncology, Fudan University Shanghai Cancer Center, 270 Dong An Road, 200032 Shanghai, China
| | - Marco Durante
- Biophysics Department, GSI Helmholtz Center for Heavy Ions Research, Planckstraße 1, 64291 Darmstadt, Germany
- Institute of Condensed Matter Physics, Darmstadt University of Technology, Hochshulstraße 3, 64289 Darmstadt, Germany
| |
Collapse
|
26
|
Gridley DS, Freeman TL, Makinde AY, Wroe AJ, Luo-Owen X, Tian J, Mao XW, Rightnar S, Kennedy AR, Slater JM, Pecaut MJ. Comparison of proton and electron radiation effects on biological responses in liver, spleen and blood. Int J Radiat Biol 2011; 87:1173-81. [PMID: 22035456 DOI: 10.3109/09553002.2011.624393] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
PURPOSE To determine whether differences exist between proton and electron radiations on biological responses after total-body exposure. MATERIALS AND METHODS ICR mice (n=45) were irradiated to 2 Gray (Gy) using fully modulated 70 MeV protons (0.5 Gy/min) and 21 MeV electrons (3 Gy/min). At 36 h post-irradiation liver gene expression, white blood cell (WBC), natural killer (NK) cell and other analyses were performed. RESULTS Oxidative stress-related gene expression patterns were strikingly different for irradiated groups compared to 0 Gy (P<0.05). Proton radiation up-regulated 15 genes (Ctsb, Dnm2, Gpx5, Il19, Il22, Kif9, Lpo, Nox4, Park7, Prdx4, Prdx6, Rag2, Sod3, Srxn1, Xpa) and down-regulated 2 genes (Apoe, Prdx1). After electron irradiation, 20 genes were up-regulated (Aass, Ctsb, Dnm2, Gpx1, Gpx4, Gpx5, Gpx6, Gstk1, Il22, Kif9, Lpo, Nox4, Park7, Prdx3, Prdx4, Prdx5, Rag2, Sod1, Txnrd3, Xpa) and 1 was down-regulated (Mpp4). Of the modified genes, only 11 were common to both forms of radiation. Comparison between the two irradiated groups showed that electrons significantly up-regulated three genes (Gstk1, Prdx3, Scd1). Numbers of WBC and major leukocyte types were low in the irradiated groups (P<0.001 vs. 0 Gy). Hemoglobin and platelet counts were low in the electron-irradiated group (P<0.05 vs. 0 Gy). However, spleens from electron-irradiated mice had higher WBC and lymphocyte counts, as well as enhanced NK cell cytotoxicity, compared to animals exposed to protons (P<0.05). There were no differences between the two irradiated groups in body mass, organ masses, and other assessed parameters, although some differences were noted compared to 0 Gy. CONCLUSION Collectively, the data demonstrate that at least some biological effects induced by electrons may not be directly extrapolated to protons.
Collapse
Affiliation(s)
- Daila S Gridley
- Department of Radiation Medicine, Radiation Research Laboratories, Loma Linda University and Medical Center, Loma Linda, CA 92354, USA.
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
27
|
Stisova V, Abele WH, Thompson KH, Bennett PV, Sutherland BM. Response of primary human fibroblasts exposed to solar particle event protons. Radiat Res 2011; 176:217-25. [PMID: 21557667 DOI: 10.1667/rr2490.1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
Solar particle events (SPEs) present a major radiation-related risk for manned exploratory missions in deep space. Within a short period the astronauts may absorb doses that engender acute effects, in addition to the risk of late effects, such as the induction of cancer. Using primary human cells, we studied clonogenic survival and the induction of neoplastic transformation after exposure to a worst case scenario SPE. We simulated such an SPE with monoenergetic protons (50, 100, 1000 MeV) delivered at a dose rate of 1.65 cGy min⁻¹ in a dose range from 0 to 3 Gy. For comparison, we exposed the cells to a high dose rate of 33.3 cGy min⁻¹. X rays (100 kVp, 8 mA, 1.7 mm Al filter) were used as a reference radiation. Overall, we observed a significant sparing effect of the SPE dose rate on cell survival. High-dose-rate protons were also more efficient in induction of transformation in the dose range below 30 cGy. However, as dose accumulated at high dose rate, the transformation levels declined, while at the SPE dose rate, the number of transformants continued to increase up to about 1 Gy. These findings suggest that considering dose-rate effects may be important in evaluating the biological effects of exposure to space radiation. Our analyses of the data based on particle fluence showed that lethality and transforming potential per particle clearly increased with increasing linear energy transfer (LET) and thus with the decreasing energy of protons. Further, we found that the biological response was determined not only by LET but also type of radiation, e.g. particles and photons. This suggests that using γ or X rays may not be ideal for assessing risk associated with SPE exposures.
Collapse
Affiliation(s)
- Viktorie Stisova
- Biology Department, Brookhaven National Laboratory, Upton, New York 11973-5000, USA.
| | | | | | | | | |
Collapse
|
28
|
Maks CJ, Wan XS, Ware JH, Romero-Weaver AL, Sanzari JK, Wilson JM, Rightnar S, Wroe AJ, Koss P, Gridley DS, Slater JM, Kennedy AR. Analysis of white blood cell counts in mice after gamma- or proton-radiation exposure. Radiat Res 2011; 176:170-6. [PMID: 21476859 DOI: 10.1667/rr2413.1] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
In the coming decades human space exploration is expected to move beyond low-Earth orbit. This transition involves increasing mission time and therefore an increased risk of radiation exposure from solar particle event (SPE) radiation. Acute radiation effects after exposure to SPE radiation are of prime importance due to potential mission-threatening consequences. The major objective of this study was to characterize the dose-response relationship for proton and γ radiation delivered at doses up to 2 Gy at high (0.5 Gy/min) and low (0.5 Gy/h) dose rates using white blood cell (WBC) counts as a biological end point. The results demonstrate a dose-dependent decrease in WBC counts in mice exposed to high- and low-dose-rate proton and γ radiation, suggesting that astronauts exposed to SPE-like radiation may experience a significant decrease in circulating leukocytes.
Collapse
Affiliation(s)
- Casey J Maks
- Department of Radiation Oncology, University of Pennsylvania School of Medicine, Philadelphia, Pennsylvania, USA
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|