Triphasic low-dose response in zebrafish embryos irradiated by microbeam protons

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review

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Author(s)

  • Viann Wing Yan Choi
  • Emily Hoi Wa Yum
  • Teruaki Konishi
  • Masakazu Oikawa

Detail(s)

Original languageEnglish
Pages (from-to)475-481
Journal / PublicationJournal of Radiation Research
Volume53
Issue number3
Publication statusPublished - May 2012

Abstract

The microbeam irradiation system (Single-Particle Irradiation System to Cell, acronym as SPICE) at the National Institute of Radiological Sciences (NIRS), Japan, was employed to irradiate dechorionated zebrafish embryos at the 2-cell stage at 0.75 h post fertilization (hpf) by microbeam protons. Either one or both of the cells of the embryos were irradiated with 10, 20, 40, 50, 80, 100, 160, 200, 300 and 2000 protons each with an energy of 3.37 MeV. The embryos were then returned back to the incubator until 24 hpf for analyses. The levels of apoptosis in zebrafish embryos at 25 hpf were quantified through terminal dUTP transferase-mediated nick end-labeling (TUNEL) assay, with the apoptotic signals captured by a confocal microscope. The results revealed a triphasic dose-response for zebrafish embryos with both cells irradiated at the 2-cell stage, namely, (1) increase in apoptotic signals for <200 protons (<30 mGy), (2) hormesis to reduce the apoptotic signals below the spontaneous number for 200-400 protons (at doses of 30-60 mGy), and (3) increase in apoptotic signals again for > 600 protons (at doses > 90 mGy). The dose response for zebrafish embryos with only one cell irradiated at the 2-cell stage was also likely a triphasic one, but the apoptotic signals in the first zone (<200 protons or <30 mGy) did not have significant differences from those of the background. At the same time, the experimental data were in line with induction of radiation-induced bystander effect as well as rescue effect in the zebrafish embryos, particular in those embryos with unirradiated cells.

Research Area(s)

  • Daniormo, Hormetic effect, Microbeam, Protons, Subhormetic zond, Zebrafish embryos

Citation Format(s)

Triphasic low-dose response in zebrafish embryos irradiated by microbeam protons. / Choi, Viann Wing Yan; Yum, Emily Hoi Wa; Konishi, Teruaki; Oikawa, Masakazu; Cheng, Shuk Han; Yu, Kwan Ngok.

In: Journal of Radiation Research, Vol. 53, No. 3, 05.2012, p. 475-481.

Research output: Journal Publications and Reviews (RGC: 21, 22, 62)21_Publication in refereed journalpeer-review