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Zhou S, Ding X, Zhang Y, Liu Y, Wang X, Guo Y, Zhang J, Liu X, Gong G, Su Y, Wang L, Zhao M, Hu M. Evaluation of specific RBE in different cells of hippocampus under high-dose proton irradiation in rats. Sci Rep 2024; 14:8193. [PMID: 38589544 PMCID: PMC11001863 DOI: 10.1038/s41598-024-58831-z] [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: 01/23/2024] [Accepted: 04/03/2024] [Indexed: 04/10/2024] Open
Abstract
The study aimed to determine the specific relative biological effectiveness (RBE) of various cells in the hippocampus following proton irradiation. Sixty Sprague-Dawley rats were randomly allocated to 5 groups receiving 20 or 30 Gy of proton or photon irradiation. Pathomorphological neuronal damage in the hippocampus was assessed using Hematoxylin-eosin (HE) staining. The expression level of NeuN, Nestin, Caspase-3, Olig2, CD68 and CD45 were determined by immunohistochemistry (IHC). The RBE range established by comparing the effects of proton and photon irradiation at equivalent biological outcomes. Proton20Gy induced more severe damage to neurons than photon20Gy, but showed no difference compared to photon30Gy. The RBE of neuron was determined to be 1.65. Similarly, both proton20Gy and proton30Gy resulted in more inhibition of oligodendrocytes and activation of microglia in the hippocampal regions than photon20Gy and photon30Gy. However, the expression of Olig2 was higher and CD68 was lower in the proton20Gy group than in the photon30Gy group. The RBE of oligodendrocyte and microglia was estimated to be between 1.1 to 1.65. For neural stem cells (NSCs) and immune cells, there were no significant difference in the expression of Nestin and CD45 between proton and photon irradiation (both 20 and 30 Gy). Therefore, the RBE for NSCs and immune cell was determined to be 1.1. These findings highlight the varying RBE values of different cells in the hippocampus in vivo. Moreover, the actual RBE of the hippocampus may be higher than 1.1, suggesting that using as RBE value of 1.1 in clinical practice may underestimate the toxicities induced by proton radiation.
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Affiliation(s)
- Shengying Zhou
- School of Clinical Medicine, Shandong Second Medical University, Weifang, 261053, Shandong, China
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, NO.440 Ji Yan Road, Jinan, 250117, Shandong, China
| | - Xingchen Ding
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, NO.440 Ji Yan Road, Jinan, 250117, Shandong, China
| | - Yiyuan Zhang
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, NO.440 Ji Yan Road, Jinan, 250117, Shandong, China
| | - Yuanyuan Liu
- Department of Pathology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, 250117, Shandong, China
| | - Xiaowen Wang
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, NO.440 Ji Yan Road, Jinan, 250117, Shandong, China
- Shandong University cancer center, Jinan, 250100, Shandong, China
| | - Yujiao Guo
- Affiliated Hospital of Jining Medical College, Jining, 272067, Shandong, China
| | | | - Xiao Liu
- 960 Hospital of the Joint Logistics Support Force of the Chinese People's Liberation Army, Jinan, 250031, Shandong, China
| | - Guanzhong Gong
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, NO.440 Ji Yan Road, Jinan, 250117, Shandong, China
| | - Ya Su
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, NO.440 Ji Yan Road, Jinan, 250117, Shandong, China
| | - Lizhen Wang
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, NO.440 Ji Yan Road, Jinan, 250117, Shandong, China
| | - Miaoqing Zhao
- Department of Pathology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, 250117, Shandong, China.
| | - Man Hu
- Department of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, NO.440 Ji Yan Road, Jinan, 250117, Shandong, China.
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Vorhees CV, Williams MT. Tests for learning and memory in rodent regulatory studies. Curr Res Toxicol 2024; 6:100151. [PMID: 38304257 PMCID: PMC10832385 DOI: 10.1016/j.crtox.2024.100151] [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: 08/07/2023] [Revised: 01/11/2024] [Accepted: 01/16/2024] [Indexed: 02/03/2024] Open
Abstract
For decades, regulatory guidelines for safety assessment in rodents for drugs, chemicals, pesticides, and food additives with developmental neurotoxic potential have recommended a single test of learning and memory (L&M). In recent years some agencies have requested two such tests. Given the importance of higher cognitive function to health, and the fact that different types of L&M are mediated by different brain regions assessing higher functions represents a step forward in providing better evidence-based protection against adverse brain effects. Given the myriad of tests available for assessing L&M in rodents this leads to the question of which tests best fit regulatory guidelines. To address this question, we begin by describing the central role of two types of L&M essential to all mammalian species and the regions/networks that mediate them. We suggest that the tests recommended possess characteristics that make them well suited to the needs in regulatory safety studies. By brain region, these are (1) the hippocampus and entorhinal cortex for spatial navigation, which assesses explicit L&M for reference and episodic memory and (2) the striatum and related structures for egocentric navigation, which assesses implicit or procedural memory and path integration. Of the tests available, we suggest that in this context, the evidence supports the use of water mazes, specifically, the Morris water maze (MWM) for spatial L&M and the Cincinnati water maze (CWM) for egocentric/procedural L&M. We review the evidentiary basis for these tests, describe their use, and explain procedures that optimize their sensitivity.
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Affiliation(s)
- Charles V. Vorhees
- Corresponding author at: Div. of Neurology, Cincinnati Children’s Hospital Medical Center, 3333 Burnet Ave., Cincinnati, OH 45229, USA.
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Sorokina SS, Malkov AE, Rozanova OM, Smirnova EN, Shemyakov AE. Behavioral performance and microglial status in mice after moderate dose of proton irradiation. RADIATION AND ENVIRONMENTAL BIOPHYSICS 2023; 62:497-509. [PMID: 37794305 DOI: 10.1007/s00411-023-01044-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/30/2022] [Accepted: 09/19/2023] [Indexed: 10/06/2023]
Abstract
Cognitive impairment is a remote effect of gamma radiation treatment of malignancies. The major part of the studies on the effect of proton irradiation (a promising alternative in the treatment of radio-resistant tumors and tumors located close to critical organs) on the cognitive abilities of laboratory animals and their relation to morphological changes in the brain is rather contradictory. The aim of this study was to investigate cognitive functions and the dynamics of changes in morphological parameters of hippocampal microglial cells after 7.5 Gy of proton irradiation. Two months after the cranial irradiation, 8- to 9-week-old male SHK mice were tested for total activity, spatial learning, as well as long- and short-term hippocampus-dependent memory. To estimate the morphological parameters of microglia, brain slices of control and irradiated animals each with different time after proton irradiation (24 h, 7 days, 1 month) were stained for microglial marker Iba-1. No changes in behavior or deficits in short-term and long-term hippocampus-dependent memory were found, but an impairment of episodic memory was observed. A change in the morphology of hippocampal microglial cells, which is characteristic of the transition of cells to an activated state, was detected. One day after proton exposure in the brain tissue, a slight decrease in cell density was observed, which was restored to the control level by the 30th day after treatment. The results obtained may be promising with regard to the future use of using high doses of protons per fraction in the irradiation of tumors.
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Affiliation(s)
- S S Sorokina
- Laboratory of Isotope Investigations, Institute of Theoretical and Experimental Biophysics RAS, Pushchino, Moscow Region, Russia.
| | - A E Malkov
- Laboratory of Neurons Systematic Organization, Institute of Theoretical and Experimental Biophysics RAS, Pushchino, Moscow Region, Russia
| | - O M Rozanova
- Laboratory of Cell Engineering, Institute of Theoretical and Experimental Biophysics RAS, Pushchino, Moscow Region, Russia
| | - E N Smirnova
- Laboratory of Cell Engineering, Institute of Theoretical and Experimental Biophysics RAS, Pushchino, Moscow Region, Russia
| | - A E Shemyakov
- Theranostics and Nuclear Medicine Laboratory, Institute of Theoretical and Experimental Biophysics RAS, Pushchino, Moscow Region, Russia
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Williams MT, Sugimoto C, Regan SL, Pitzer EM, Fritz AL, Sertorio M, Mascia AE, Vatner RE, Perentesis JP, Vorhees CV. Cognitive and behavioral effects of whole brain conventional or high dose rate (FLASH) proton irradiation in a neonatal Sprague Dawley rat model. PLoS One 2022; 17:e0274007. [PMID: 36112695 PMCID: PMC9481014 DOI: 10.1371/journal.pone.0274007] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Accepted: 08/22/2022] [Indexed: 11/18/2022] Open
Abstract
Recent studies suggest that ultra-high dose rates of proton radiation (>40 Gy/s; FLASH) confer less toxicity to exposed healthy tissue and reduce cognitive decline compared with conventional radiation dose rates (~1 Gy/s), but further preclinical data are required to demonstrate this sparing effect. In this study, postnatal day 11 (P11) rats were treated with whole brain irradiation with protons at a total dose of 0, 5, or 8 Gy, comparing a conventional dose rate of 1 Gy/s vs. a FLASH dose rate of 100 Gy/s. Beginning on P64, rats were tested for locomotor activity, acoustic and tactile startle responses (ASR, TSR) with or without prepulses, novel object recognition (NOR; 4-object version), striatal dependent egocentric learning ([configuration A] Cincinnati water maze (CWM-A)), prefrontal dependent working memory (radial water maze (RWM)), hippocampal dependent spatial learning (Morris water maze (MWM)), amygdala dependent conditioned freezing, and the mirror image CWM [configuration B (CWM-B)]. All groups had deficits in the CWM-A procedure. Weight reductions, decreased center ambulation in the open-field, increased latency on day-1 of RWM, and deficits in CWM-B were observed in all irradiated groups, except the 5 Gy FLASH group. ASR and TSR were reduced in the 8 Gy FLASH group and day-2 latencies in the RWM were increased in the FLASH groups compared with controls. There were no effects on prepulse trials of ASR or TSR, NOR, MWM, or conditioned freezing. The results suggest striatal and prefrontal cortex are sensitive regions at P11 to proton irradiation, with reduced toxicity from FLASH at 5 Gy.
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Affiliation(s)
- Michael T. Williams
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America
- Division of Neurology, Cincinnati Children’s Research Foundation, Cincinnati, OH, United States of America
- Cincinnati Children’s/University of Cincinnati Proton Therapy and Research Center, Cincinnati, OH, United States of America
- * E-mail:
| | - Chiho Sugimoto
- Division of Neurology, Cincinnati Children’s Research Foundation, Cincinnati, OH, United States of America
| | - Samantha L. Regan
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America
- Division of Neurology, Cincinnati Children’s Research Foundation, Cincinnati, OH, United States of America
| | - Emily M. Pitzer
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America
- Division of Neurology, Cincinnati Children’s Research Foundation, Cincinnati, OH, United States of America
| | - Adam L. Fritz
- Division of Neurology, Cincinnati Children’s Research Foundation, Cincinnati, OH, United States of America
| | - Mathieu Sertorio
- Cincinnati Children’s/University of Cincinnati Proton Therapy and Research Center, Cincinnati, OH, United States of America
- Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America
| | - Anthony E. Mascia
- Cincinnati Children’s/University of Cincinnati Proton Therapy and Research Center, Cincinnati, OH, United States of America
- Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America
| | - Ralph E. Vatner
- Cincinnati Children’s/University of Cincinnati Proton Therapy and Research Center, Cincinnati, OH, United States of America
- Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America
| | - John P. Perentesis
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America
- Cincinnati Children’s/University of Cincinnati Proton Therapy and Research Center, Cincinnati, OH, United States of America
- Division of Oncology, Cincinnati Children’s Research Foundation, Cincinnati, OH, United States of America
| | - Charles V. Vorhees
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH, United States of America
- Division of Neurology, Cincinnati Children’s Research Foundation, Cincinnati, OH, United States of America
- Cincinnati Children’s/University of Cincinnati Proton Therapy and Research Center, Cincinnati, OH, United States of America
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Vorhees CV, Vatner RE, Williams MT. Review of Conventional and High Dose Rate Brain Radiation (FLASH): Neurobehavioural, Neurocognitive and Assessment Issues in Rodent Models. Clin Oncol (R Coll Radiol) 2021; 33:e482-e491. [PMID: 34548203 PMCID: PMC10114147 DOI: 10.1016/j.clon.2021.09.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2021] [Revised: 07/29/2021] [Accepted: 09/02/2021] [Indexed: 10/20/2022]
Abstract
Ionising radiation causes secondary tumours and/or enduring cognitive deficits, especially in children. Proton radiotherapy reduces exposure of the developing brain in children but may still cause some lasting effects. Recent observations show that ultra-high dose rate radiation treatment (≥40 Gy/s), called the FLASH effect, is equally effective at tumour control but less damaging to surrounding tissue compared with conventional dose rate protons (0.03-3 Gy/s). Most studies on the FLASH effect in brain and other tissues with different radiation modalities (electron and photon radiation), show FLASH benefits in these preclinical rodent models, but the data are limited, especially for proton FLASH, including for dose, dose rate and neurochemical and neurobehavioural outcomes. Tests of neurocognitive outcomes have been limited despite clinical evidence that this is the area of greatest concern. The FLASH effect in the context of proton exposure is promising, but a more systematic and comprehensive approach to outcomes is needed.
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Affiliation(s)
- C V Vorhees
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA; Cincinnati Children's/University of Cincinnati Proton Therapy and Research Center, Cincinnati, Ohio, USA.
| | - R E Vatner
- Cincinnati Children's/University of Cincinnati Proton Therapy and Research Center, Cincinnati, Ohio, USA; Department of Radiation Oncology, University of Cincinnati College of Medicine, Cincinnati, Ohio, USA
| | - M T Williams
- Department of Pediatrics, University of Cincinnati College of Medicine and Division of Neurology, Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio, USA; Cincinnati Children's/University of Cincinnati Proton Therapy and Research Center, Cincinnati, Ohio, USA
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Suckert T, Nexhipi S, Dietrich A, Koch R, Kunz-Schughart LA, Bahn E, Beyreuther E. Models for Translational Proton Radiobiology-From Bench to Bedside and Back. Cancers (Basel) 2021; 13:4216. [PMID: 34439370 PMCID: PMC8395028 DOI: 10.3390/cancers13164216] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Revised: 08/09/2021] [Accepted: 08/17/2021] [Indexed: 12/25/2022] Open
Abstract
The number of proton therapy centers worldwide are increasing steadily, with more than two million cancer patients treated so far. Despite this development, pending questions on proton radiobiology still call for basic and translational preclinical research. Open issues are the on-going discussion on an energy-dependent varying proton RBE (relative biological effectiveness), a better characterization of normal tissue side effects and combination treatments with drugs originally developed for photon therapy. At the same time, novel possibilities arise, such as radioimmunotherapy, and new proton therapy schemata, such as FLASH irradiation and proton mini-beams. The study of those aspects demands for radiobiological models at different stages along the translational chain, allowing the investigation of mechanisms from the molecular level to whole organisms. Focusing on the challenges and specifics of proton research, this review summarizes the different available models, ranging from in vitro systems to animal studies of increasing complexity as well as complementing in silico approaches.
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Affiliation(s)
- Theresa Suckert
- OncoRay—National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, 01309 Dresden, Germany; (T.S.); (S.N.); (A.D.); (L.A.K.-S.)
- German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Sindi Nexhipi
- OncoRay—National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, 01309 Dresden, Germany; (T.S.); (S.N.); (A.D.); (L.A.K.-S.)
- Helmholtz-Zentrum Dresden-Rossendorf, Institute of Radiooncology-OncoRay, 01309 Dresden, Germany
| | - Antje Dietrich
- OncoRay—National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, 01309 Dresden, Germany; (T.S.); (S.N.); (A.D.); (L.A.K.-S.)
- German Cancer Consortium (DKTK), Partner Site Dresden, and German Cancer Research Center (DKFZ), 69120 Heidelberg, Germany
| | - Robin Koch
- Heidelberg Institute of Radiation Oncology (HIRO), 69120 Heidelberg, Germany; (R.K.); (E.B.)
- Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
| | - Leoni A. Kunz-Schughart
- OncoRay—National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, 01309 Dresden, Germany; (T.S.); (S.N.); (A.D.); (L.A.K.-S.)
- National Center for Tumor Diseases (NCT), Partner Site Dresden, 01307 Dresden, Germany
| | - Emanuel Bahn
- Heidelberg Institute of Radiation Oncology (HIRO), 69120 Heidelberg, Germany; (R.K.); (E.B.)
- Department of Radiation Oncology, Heidelberg University Hospital, 69120 Heidelberg, Germany
- National Center for Tumor Diseases (NCT), 69120 Heidelberg, Germany
- German Cancer Research Center (DKFZ), Clinical Cooperation Unit Radiation Oncology, 69120 Heidelberg, Germany
| | - Elke Beyreuther
- OncoRay—National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Helmholtz-Zentrum Dresden-Rossendorf, 01309 Dresden, Germany; (T.S.); (S.N.); (A.D.); (L.A.K.-S.)
- Helmholtz-Zentrum Dresden—Rossendorf, Institute of Radiation Physics, 01328 Dresden, Germany
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