Comparison of cellular responses to ionizing radiation in keratinocytes isolated from healthy donors and type II diabetes patients

AbstractPurpose Due to the expanding repertoire of treatment devices that use radiation, the possibility of exposure to both low-dose and high-dose radiation continues to increase. Skin is the outermost part of the body and thus directly exposed to radiation-induced damage. In particular, the skin of diabetes patients is fragile and easily damaged by external stimuli, such as radiation. However, damage and cellular responses induced by ionizing irradiation in diabetic skin have not been explored in detail. In this study, we investigated the effects of several irradiation dose on normal keratinocytes and those from type II diabetes patients, with particular focus on DNA damage.Materials and methods Cellular responses to low-dose radiation (0.1 Gy) and high-dose radiation (0.5 and 2 Gy) were evaluated. Cell cycle analysis was conducted via flow cytometry and cell viability analyzed using the 3-[4,5-dimethylthiazol-2-yl]-2,5 diphenyl tetrazolium bromide (MTT) assay. Proteins related to the DNA damage response (DDR) and repair signaling pathways and apoptosis were detected via immunoblot analysis. Apoptosis and cell differentiation were additionally examined in 3D skin organoids using immunohistochemistry.Results Compared to respective control groups, no significant changes were observed in cell cycle, DDR and repair mechanisms, cell survival, and differentiation in response to 0.1 Gy irradiation in both normal and diabetes type II keratinocytes. On the other hand, the cell cycle showed an increase in the G2/M phase in both cell types following exposure to 2 Gy irradiation. At radiation doses 2 Gy, activation of the DDR and repair signaling pathways, apoptosis, and cell differentiation were increased and viability was decreased in both cell types. Notably, these differences were more pronounced in normal than diabetes type II keratinocytes.Conclusions Normal keratinocytes respond more strongly to radiation-induced damage and recovery than diabetes type II keratinocytes.Keywords: Keratinocytetype II diabetesionizing radiationcell cycleDNA damage and repair3D skin organoidsskin differentiation Disclosure statementAll the authors declare that they have no conflicts of interest.Author contributionsConception and design: JY YiAcquisition of data: HJ Lee, JY YiAnalysis and interpretation of data: HJ Lee, H-J Lee, H Kim, JY YiWriting, review, and/or revision of the manuscript: HJ Lee, JY YiTechnical and material support: H Im, HJ LeeStudy supervision: JY YiAll authors have read and approved the final manuscript.Data availability statementAll the data and materials are available from the authors on reasonable request.Additional informationFundingThis study was supported by grants from the Korea Institute of Radiological and Medical Sciences (KIRAMS; No.50531-2023) and the National Research Foundation of Korea (NRF-2020M2C8A2069337) funded by the Ministry of Science and ICT (MSIT), Republic of Korea.This work was supported by National Research Foundation of Korea funded by the Ministry of Science and ICT (MSIT). Notes on contributorsHae Jin LeeHae Jin Lee, MS, is studying at the Korea Institute of Radiological and Medical Sciences.Hyuntaik ImHyuntaik Im, PhD candidate, is studying at the Korea Institute of Radiological and Medical Sciences and University of Seoul.Hae-June LeeHae-June Lee, PhD, is a principal researcher at the Korea Institute of Radiological and Medical Sciences.Hyunggee KimHyunggee Kim, PhD, is a professor at the Department of Biotechnology, Korea University.Jae Youn YiJae Youn Yi, PhD, is a principal researcher at the Korea Institute of Radiological and Medical Sciences.