TY - JOUR AB - Astronauts are inevitably exposed to two major risks during space flight, microgravity and radiation. Exposure to microgravity has been discovered to lead to rapid and vigorous bone loss due to elevated osteoclastic activity. In addition, long‑term exposure to low‑dose‑rate space radiation was identified to promote DNA damage accumulation that triggered chronic inflammation, resulting in an increased risk for bone marrow suppression and carcinogenesis. In our previous study, melatonin, a hormone known to regulate the sleep‑wake cycle, upregulated calcitonin expression levels and downregulated receptor activator of nuclear factor‑κB ligand expression levels, leading to improved osteoclastic activity in a fish scale model. These results indicated that melatonin may represent a potential drug or lead compound for the prevention of bone loss under microgravity conditions. However, it is unclear whether melatonin affects the biological response induced by space radiation. The aim of the present study was to evaluate the effect of melatonin on the expression levels of genes responsive to space radiation. In the present study, to support the previous data regarding de novo transcriptome analysis of goldfish scales, a detailed and improved experimental method (e.g., PCR duplicate removal followed by de novo assembly, global normalization and calculation of statistical significance) was applied for the analysis. In addition, the transcriptome data were analyzed via global normalization, functional categorization and gene network construction to determine the impact of melatonin on gene expression levels in irradiated fish scales cultured in space. The results of the present study demonstrated that melatonin treatment counteracted microgravity‑ and radiation‑induced alterations in the expression levels of genes associated with DNA replication, DNA repair, proliferation, cell death and survival. Thus, it was concluded that melatonin may promote cell survival and ensure normal cell proliferation in cells exposed to space radiation. AD - Department of Liberal Arts and Sciences, Toyama Prefectural University, Toyama 939‑0398, Japan Noto Marine Laboratory, Division of Marine Environmental Studies, Institute of Nature and Environmental Technology, Kanazawa University, Ishikawa 927‑0553, Japan College of Liberal Arts and Sciences, Tokyo Medical and Dental University, Chiba 272‑0827, Japan Department of Clinical Engineering, Faculty of Health Sciences, Komatsu University, Ishikawa 923‑0961, Japan Division of Molecular Genetics Research, Life Science Research Center, University of Toyama, Toyama 930‑0194, Japan AU - Furusawa,Yukihiro AU - Yamamoto,Tatsuki AU - Hattori,Atsuhiko AU - Suzuki,Nobuo AU - Hirayama,Jun AU - Sekiguchi,Toshio AU - Tabuchi,Yoshiaki AU - Furusawa,Yukihiro AU - Yamamoto,Tatsuki AU - Hattori,Atsuhiko AU - Suzuki,Nobuo AU - Hirayama,Jun AU - Sekiguchi,Toshio AU - Tabuchi,Yoshiaki AU - Furusawa,Yukihiro AU - Yamamoto,Tatsuki AU - Hattori,Atsuhiko AU - Suzuki,Nobuo AU - Hirayama,Jun AU - Sekiguchi,Toshio AU - Tabuchi,Yoshiaki DA - 2020/10/01 DO - 10.3892/mmr.2020.11363 EP - 2636 IS - 4 JO - Mol Med Rep KW - space radiation transcriptome de novo assembly fish scale gene network melatonin PY - 2020 SN - 1791-2997 1791-3004 SP - 2627 ST - De novo transcriptome analysis and gene expression profiling of fish scales isolated from Carassius auratus during space flight: Impact of melatonin on gene expression in response to space radiation T2 - Molecular Medicine Reports TI - De novo transcriptome analysis and gene expression profiling of fish scales isolated from Carassius auratus during space flight: Impact of melatonin on gene expression in response to space radiation UR - https://doi.org/10.3892/mmr.2020.11363 VL - 22 ER -