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Ewing LE, Miousse IR, Pathak R, Skinner CM, Boerma M, Hauer-Jensen M, Koturbash I. NZO/HlLtJ as a novel model for the studies on the role of metabolic syndrome in acute radiation toxicity. Int J Radiat Biol 2020; 96:93-99. [PMID: 30561233 PMCID: PMC6581619 DOI: 10.1080/09553002.2018.1547437] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2018] [Revised: 10/22/2018] [Accepted: 10/23/2018] [Indexed: 12/22/2022]
Abstract
Purpose: Growing rates of metabolic syndrome and associated obesity warrant the development of appropriate animal models for better understanding of how those conditions may affect sensitivity to IR exposure.Materials and methods: We subjected male NZO/HlLtJ mice, a strain prone to spontaneous obesity and diabetes, to 0, 5.5, 6.37, 7.4 or 8.5 Gy (137Cs) of total body irradiation (TBI). Mice were monitored for 30 days, after which proximal jejunum and colon tissues were collected for further histological and molecular analysis.Results: Obese NZO/HlLtJ male mice are characterized by their lower sensitivity to IR at doses of 6.37 Gy and under, compared to other strains. Further escalation of the dose, however, results in a steep survival curve, reaching LD100/30 values at a dose of 8.5 Gy. Alterations in the expression of various tight junction-related proteins coupled with activation of inflammatory responses and cell death were the main contributors to the gastrointestinal syndrome.Conclusions: We demonstrate that metabolic syndrome with exhibited hyperglycemia but without alterations to the microvasculature is not a pre-requisite of the increased sensitivity to TBI at high doses. Our studies indicate the potential of NZO/HlLtJ mice for the studies on the role of metabolic syndrome in acute radiation toxicity.
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Affiliation(s)
- Laura E. Ewing
- Department of Environmental and Occupational Health, College of Public Health, University of Arkansas for Medical Sciences, Little Rock, United States of America
- Department of Pharmacology and Toxicology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, United States of America
| | - Isabelle R. Miousse
- Department of Environmental and Occupational Health, College of Public Health, University of Arkansas for Medical Sciences, Little Rock, United States of America
- Department of Biochemistry and Molecular Biology, College of Medicine, University of Arkansas for Medical Sciences, Little Rock, United States of America
| | - Rupak Pathak
- Division of Radiation Health, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, United States of America
| | - Charles M. Skinner
- Department of Environmental and Occupational Health, College of Public Health, University of Arkansas for Medical Sciences, Little Rock, United States of America
| | - Marjan Boerma
- Division of Radiation Health, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, United States of America
| | - Martin Hauer-Jensen
- Division of Radiation Health, College of Pharmacy, University of Arkansas for Medical Sciences, Little Rock, United States of America
| | - Igor Koturbash
- Department of Environmental and Occupational Health, College of Public Health, University of Arkansas for Medical Sciences, Little Rock, United States of America
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Zhao YY, Zhao LN, Wang P, Miao YS, Liu YH, Wang ZH, Ma J, Li Z, Li ZQ, Xue YX. Overexpression of miR-18a negatively regulates myocyte enhancer factor 2D to increase the permeability of the blood-tumor barrier via Krüppel-like factor 4-mediated downregulation of zonula occluden-1, claudin-5, and occludin. J Neurosci Res 2015; 93:1891-902. [PMID: 26356851 DOI: 10.1002/jnr.23628] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2015] [Revised: 07/28/2015] [Accepted: 07/28/2015] [Indexed: 01/23/2023]
Abstract
miR-18a represses angiogenesis and tumor evasion by weakening vascular endothelial growth factor and transforming growth factor-β signaling to prolong the survival of glioma patients, although it is thought to be an oncogene. This study investigates the potential effects of miR-18a on the permeability of the blood-tumor barrier (BTB) and its possible molecular mechanisms. An in vitro BTB model was successfully established. The endogenous expression of miR-18a in glioma vascular endothelial cells (GECs) was significantly lower than that in normal vascular ECs, and the overexpression of miR-18a significantly increased the permeability of the BTB as well as downregulating the mRNA and protein expressions of tight junction-related proteins zonula occluden-1 (ZO-1), claudin-5, and occludin in GECs. Dual luciferase reporter assays revealed that miR-18a bound to the 3'-untranslated region (3'UTR) of myocyte enhancer factor 2D (MEF2D). The overexpression of both miR-18a and MEF2D with the 3'UTR significantly weakened the effect caused by miR-18a of decreasing the mRNA and protein expressions of ZO-1, claudin-5 and occludin and of increasing the permeability of the BTB. Chromatin immunoprecipitation showed that MEF2D could directly bind to KLF4 promoter. This study shows that miR-18a targets and negatively regulates MEF2D, which further regulates tight junction-related proteins ZO-1, claudin-5, and occludin through transactivation of KLF4 and, finally, changes the permeability of the BTB. MiR-18a should garner growing attention because it might serve as a potential target in opening the BTB and providing a new strategy for the treatment of gliomas.
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Affiliation(s)
- Ying-Yu Zhao
- Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, China.,Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China
| | - Li-Ni Zhao
- Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, China.,Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China
| | - Ping Wang
- Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, China.,Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China
| | - Yin-Sha Miao
- Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, China.,Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China
| | - Yun-Hui Liu
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, China
| | - Zhen-Hua Wang
- Department of Physiology, College of Basic Medicine, China Medical University, Shenyang, China
| | - Jun Ma
- Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, China.,Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China
| | - Zhen Li
- Department of Neurosurgery, Shengjing Hospital of China Medical University, Shenyang, China
| | - Zhi-Qing Li
- Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, China.,Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China
| | - Yi-Xue Xue
- Department of Neurobiology, College of Basic Medicine, China Medical University, Shenyang, China.,Institute of Pathology and Pathophysiology, China Medical University, Shenyang, China
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