Ionizing Irradiation Induces Vascular Damage in the Aorta of Wild-Type Mice
Radiation Safety Research Center, Nuclear Technology Research Laboratory, Central Research Institute of Electric Power Industry (CRIEPI), Tokyo 201-8511, Japan
Department of Cardiovascular Regeneration and Medicine, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima 734-8551, Japan
Biostatistics Center, Kurume University, Kurume 830-0011, Japan
Department of Stem Cell Biology and Medicine, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima 734-8551, Japan
Natural Science Center for Basic Research and Development, Hiroshima 739-8526, Japan
Department of Radiation Biophysics, Research Institute for Radiation Biology and Medicine, Hiroshima University, Hiroshima 734-8551, Japan
Division of Regeneration and Medicine, Medical Center for Translational and Clinical Research, Hiroshima University Hospital, Hiroshima 734-8551, Japan
Author to whom correspondence should be addressed.
Received: 1 October 2020 / Revised: 14 October 2020 / Accepted: 16 October 2020 / Published: 18 October 2020
There has been renewed interest in radiation effects on the circulatory system. Here, we analyzed prelesional changes in the descending thoracic aorta of wild-type mice up to six months after a single acute exposure to 0 or 5 Gy of 137Cs γ-rays. We found that irradiation promoted structural disorganizations and detachment of the aortic endothelium, enhanced vascular permeability, and led to partial loss of the aortic endothelium, decreases in endothelial nitric oxide synthase, and adherens junction proteins in the aortic endothelium, and increases in inflammation and macrophage markers in the aorta. These findings suggest that irradiation causes vascular damage manifested as endothelial cell loss and increased vascular permeability, and that a decrease in adherens junction and an increase in inflammation lead to macrophage recruitment, which is thought to be involved in the early stage of atherosclerosis.