Environmental radiation on large Japanese field mice in Fukushima reduced colony forming potential in hematopoietic progenitor cells without inducing genomic instability

Abstract

Purpose

To study the environmental radiation effects of wild animals after the Fukushima Dai-ichi nuclear power plant accident, we assessed effects on hematopoietic progenitor cells (HPCs) in large Japanese field mice (Apodemus speciosus).

Materials and methods

A. speciosus were collected from three contaminated sites and control area. The air dose-rates at the control and contaminated areas were 0.96 ± 0.05 μGy/d (Hirosaki), 14.4 ± 2.4 μGy/d (Tanashio), 208.8 ± 31.2 μGy/d (Ide), 470.4 ± 93.6 μGy/d (Omaru), respectively. We investigated possible DNA damage and pro-inflammatory markers in the bone marrow (BM) cells. The colony-forming potential of BM cells was estimated by the number of HPC colony-forming cells. Radiation-induced genomic instability (RIGI) in HPCs was also analyzed by quantifying delayed DNA damage in CFU-GM clones.

Results

Although no significant differences in DNA damage and inflammation markers in BM cells from control and contaminated areas, the number of HPC colonies exhibited an inverse correlation with air dose-rate. With regard to RIGI, no significant differences in DNA damage of CFU-GM clones between the mice from the control and the three contaminated areas.

Conclusions

Our study suggests that low dose-rate radiation of more than 200 Gy/d reduced HPCs, possibly eliminating genomically unstable HPCs.

Keywords:

• Radiation effect
• wild animal
• Apodemus speciosus
• hematopoietic progenitor cells
• radiation-induced genomic instability

Acknowledgments

The authors express their deep appreciation of Namie Town’s local government in Fukushima Prefecture, Japan. The authors thank the laboratory staff for technical and secretarial assistance. The authors would also like to thank Editage (www.editage.jp) for English language editing.

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This work was supported in part by the Japan Society for the Promotion of Science Grant-in-Aid for Scientific Research (C) [19K12354].

Notes on contributors

Kentaro Ariyoshi

Kentaro Ariyoshi, Ph.D., is an associate professor at the Integrated Center for Science and Humanities, Fukushima Medical University.

Tomisato Miura

Tomisato Miura, Ph.D., is an associate professor at Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences.

Kosuke Kasai

Kosuke Kasai, Ph.D., is a senior lecturer at Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences.

Valerie Swee Ting Goh

Valerie Swee Ting Goh, M.Sc., is a doctoral student at Department of Bioscience and Laboratory Medicine, Hirosaki University Graduate School of Health Sciences, and a post-graduate research scholar with the Singapore Nuclear Research and Safety Initiative (SNRSI).

Yohei Fujishima

Yohei Fujishima, Ph.D., is an assistant professor at Department of Radiation Biology, Tohoku University School of Medicine.

Akifumi Nakata

Akifumi Nakata, Ph.D., is an associate professor at Faculty of Pharmaceutical Science, Department of Pharmacy, Hokkaido University of Science.

Atsushi Takahashi

Atsushi Takahashi, Ph.D., is an assistant professor at Tohoku University Hospital.

Yoshinaka Shimizu

Yoshinaka Shimizu, Ph.D., is an assistant professor at Department of Oral Medicine and Surgery, Graduate School of Dentistry, Tohoku University.

Hisashi Shinoda

Hisashi Shinoda, Ph.D., is a professor emeritus at Graduate School of Dentistry, Tohoku University.

Hideaki Yamashiro

Hideaki Yamashiro, Ph.D., is an associate professor at Faculty of Agriculture, Niigata University

Colin Seymour

Colin Seymour, Ph.D., is a professor at Medical Physics & Applied Radiation Sciences, McMaster University.

Carmel Mothersill

Carmel Mothersill, Ph.D., is a professor at Department of Biology, McMaster University; Medical Physics & Applied Radiation Sciences, McMaster University.

Mitsuaki A. Yoshida

Mitsuaki A. Yoshida, Ph.D., is a professor in Hirosaki University Institute of Radiation Emergency Medicine Department of Radiation Biology.