title: The effect of low dose ionizing radiation on homeostasis and functional integrity in an organotypic human skin model.
abstract: Outside the protection of Earth's atmosphere, astronauts are exposed to low doses of high linear energy transfer (LET) radiation. Future NASA plans for deep space missions or a permanent settlement on the moon are limited by the health risks associated with space radiation exposures. There is a paucity of direct epidemiological data for low dose exposures to space radiation-relevant high LET ions. Health risk models are used to estimate the risk for such exposures, though these models are based on high dose experiments. There is increasing evidence, however, that low and high dose exposures result in different signaling events at the molecular level, and may involve different response mechanisms. Further, despite their low abundance, high LET particles have been identified as the major contributor to health risk during manned space flight. The human skin is exposed in every external radiation scenario, making it an ideal epithelial tissue model in which to study radiation induced effects. Here, we exposed an in vitro three dimensional (3-D) human organotypic skin tissue model to low doses of high LET oxygen (O), silicon (Si) and iron (Fe) ions. We measured proliferation and differentiation profiles in the skin tissue and examined the integrity of the skin's barrier function. We discuss the role of secondary particles in changing the proportion of cells receiving a radiation dose, emphasizing the possible impact on radiation-induced health issues in astronauts.
authors.affiliation: German Cancer Consortium (DKTK) partner site Dresden, OncoRay - National Center for Radiation Research in Oncology, Faculty of Medicine and University Hospital Carl Gustav Carus, Technische Universität Dresden, Fetscherstrasse 74, 01307 Dresden, Germany; German Cancer Research Center (DKFZ), Im Neuenheimer Feld 280, 69120 Heidelberg, Germany.
authors.forename: Claere
authors.initials: C
authors.lastname: von Neubeck
authors.affiliation: Molecular and Cellular Biology Program, Oregon State University, Corvallis OR 97331, USA.
authors.forename: Matthew J
authors.initials: MJ
authors.lastname: Geniza
authors.affiliation: Health Impacts and Exposure Science, Pacific Northwest National Laboratory, Richland WA 99352, USA.
authors.forename: Paula M
authors.initials: PM
authors.lastname: Kauer
authors.affiliation: Health Impacts and Exposure Science, Pacific Northwest National Laboratory, Richland WA 99352, USA.
authors.forename: R Joe
authors.initials: RJ
authors.lastname: Robinson
authors.affiliation: Health Impacts and Exposure Science, Pacific Northwest National Laboratory, Richland WA 99352, USA.
authors.forename: William B
authors.initials: WB
authors.lastname: Chrisler
authors.affiliation: Health Impacts and Exposure Science, Pacific Northwest National Laboratory, Richland WA 99352, USA. Electronic address: marianne.sowa@pnnl.gov.
authors.forename: Marianne B
authors.initials: MB
authors.lastname: Sowa
mesh_terms: D002454:Cell Differentiation / Q000528:radiation effects*; D002460:Cell Line; D049109:Cell Proliferation / Q000528:radiation effects*; D004307:Dose-Response Relationship, Radiation; D006706:Homeostasis / Q000528:radiation effects*; D006801:Humans; D008954:Models, Biological; D011839:Radiation, Ionizing; D012867:Skin / Q000378:metabolism* / Q000473:pathology
keywords: 3D skin equivalent; Differentiation profile; Heavy ion; Ionizing radiation; Radiation quality