title: Single high-dose irradiation aggravates eosinophil-mediated fibrosis through IL-33 secreted from impaired vessels in the skin compared to fractionated irradiation.
abstract: We have revealed in a porcine skin injury model that eosinophil recruitment was dose-dependently enhanced by a single high-dose irradiation. In this study, we investigated the underlying mechanism of eosinophil-associated skin fibrosis and the effect of high-dose-per-fraction radiation. The dorsal skin of a mini-pig was divided into two sections containing 4-cm(2) fields that were irradiated with 30 Gy in a single fraction or 5 fractions and biopsied regularly over 14 weeks. Eosinophil-related Th2 cytokines such as interleukin (IL)-4, IL-5, and C-C motif chemokine-11 (CCL11/eotaxin) were evaluated by quantitative real-time PCR. RNA-sequencing using 30 Gy-irradiated mouse skin and functional assays in a co-culture system of THP-1 and irradiated-human umbilical vein endothelial cells (HUVECs) were performed to investigate the mechanism of eosinophil-mediated radiation fibrosis. Single high-dose-per-fraction irradiation caused pronounced eosinophil accumulation, increased profibrotic factors collagen and transforming growth factor-β, enhanced production of eosinophil-related cytokines including IL-4, IL-5, CCL11, IL-13, and IL-33, and reduced vessels compared with 5-fraction irradiation. IL-33 notably increased in pig and mouse skin vessels after single high-dose irradiation of 30 Gy, as well as in irradiated HUVECs following 12 Gy. Blocking IL-33 suppressed the migration ability of THP-1 cells and cytokine secretion in a co-culture system of THP-1 cells and irradiated HUVECs. Hence, high-dose-per-fraction irradiation appears to enhance eosinophil-mediated fibrotic responses, and IL-33 may be a key molecule operating in eosinophil-mediated fibrosis in high-dose-per fraction irradiated skin.
authors.affiliation: Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752, South Korea. Electronic address: forejs2@yuhs.ac.
authors.forename: Eun-Jung
authors.initials: EJ
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752, South Korea. Electronic address: JUNWON@yuhs.ac.
authors.forename: Jun Won
authors.initials: JW
authors.lastname: Kim
authors.affiliation: Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752, South Korea. Electronic address: gochunghee@yuhs.ac.
authors.forename: Hyun
authors.initials: H
authors.lastname: Yoo
authors.affiliation: Interdisciplinary Program in Bioinformatics, Seoul National University, Seoul 151-747, South Korea. Electronic address: asleo02@snu.ac.kr.
authors.forename: Woori
authors.initials: W
authors.lastname: Kwak
authors.affiliation: Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752, South Korea. Electronic address: wonhoon@yuhs.ac.
authors.forename: Won Hoon
authors.initials: WH
authors.lastname: Choi
authors.affiliation: C&K Genomics, Seoul National University Mt.4-2, Main Bldg. #514, SNU Research Park, NakSeoungDae, Gwanakgu, Seoul 151-919, South Korea. Electronic address: seoae@cnkgenomics.com.
authors.forename: Seoae
authors.initials: S
authors.lastname: Cho
authors.affiliation: Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752, South Korea. Electronic address: yunk9275@daum.net.
authors.forename: Yu Jeong
authors.initials: YJ
authors.lastname: Choi
authors.affiliation: Division of Radiation Effects, Research Center for Radiotherapy, Korea Institute of Radiological & Medical Sciences, Seoul 139-760, South Korea. Electronic address: yjlee8@kirams.re.kr.
authors.forename: Yoon-Jin
authors.initials: YJ
authors.lastname: Lee
authors.affiliation: Department of Radiation Oncology, Yonsei University College of Medicine, Seoul 120-752, South Korea. Electronic address: jjhmd@yuhs.ac.
authors.forename: Jaeho
authors.initials: J
authors.lastname: Cho
mesh_terms: D000818:Animals; D000906:Antibodies / Q000494:pharmacology; D002465:Cell Movement / Q000187:drug effects / Q000528:radiation effects; D054413:Chemokine CCL11 / Q000235:genetics / Q000378:metabolism; D018920:Coculture Techniques; D004307:Dose-Response Relationship, Radiation; D004804:Eosinophils / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D005260:Female; D005355:Fibrosis; D015870:Gene Expression; D061307:Human Umbilical Vein Endothelial Cells / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D006801:Humans; D000067596:Interleukin-33; D015847:Interleukin-4 / Q000235:genetics / Q000378:metabolism; D015848:Interleukin-5 / Q000235:genetics / Q000378:metabolism; D007378:Interleukins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D008264:Macrophages / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000528:radiation effects*; D051379:Mice; D011829:Radiation Dosage; D012867:Skin / Q000098:blood supply / Q000187:drug effects / Q000473:pathology* / Q000528:radiation effects*; D013552:Swine; D016212:Transforming Growth Factor beta / Q000235:genetics / Q000378:metabolism; D014965:X-Rays
chemical_list: D000906:Antibodies; D054413:Chemokine CCL11; C506535:Il33 protein, mouse; D000067596:Interleukin-33; D015848:Interleukin-5; D007378:Interleukins; D016212:Transforming Growth Factor beta; D015847:Interleukin-4
keywords: Eosinophil-mediated fibrosis; Interleukin-33; Radiotherapy; Skin injury