title: Exogenous Nitric Oxide Suppresses in Vivo X-ray-Induced Targeted and Non-Targeted Effects in Zebrafish Embryos.
abstract: The present paper studied the X-ray-induced targeted effect in irradiated zebrafish embryos (Danio rerio), as well as a non-targeted effect in bystander naïve embryos partnered with irradiated embryos, and examined the influence of exogenous nitric oxide (NO) on these targeted and non-targeted effects. The exogenous NO was generated using an NO donor, S-nitroso-N-acetylpenicillamine (SNAP). The targeted and non-targeted effects, as well as the toxicity of the SNAP, were assessed using the number of apoptotic events in the zebrafish embryos at 24 h post fertilization (hpf) revealed through acridine orange (AO) staining. SNAP with concentrations of 20 and 100 µM were first confirmed to have no significant toxicity on zebrafish embryos. The targeted effect was mitigated in zebrafish embryos if they were pretreated with 100 µM SNAP prior to irradiation with an X-ray dose of 75 mGy but was not alleviated in zebrafish embryos if they were pretreated with 20 µM SNAP. On the other hand, the non-targeted effect was eliminated in the bystander naïve zebrafish embryos if they were pretreated with 20 or 100 µM SNAP prior to partnering with zebrafish embryos having been subjected to irradiation with an X-ray dose of 75 mGy. These findings revealed the importance of NO in the protection against damages induced by ionizing radiations or by radiation-induced bystander signals, and could have important impacts on development of advanced cancer treatment strategies.
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, Hong Kong, China. yikong3-c@my.cityu.edu.hk.
authors.forename: E Y
authors.initials: EY
authors.lastname: Kong
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, Hong Kong, China. wkyeung46-c@my.cityu.edu.hk.
authors.forename: W K
authors.initials: WK
authors.lastname: Yeung
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, Hong Kong, China. kayauchan4-c@my.cityu.edu.hk.
authors.forename: T K Y
authors.initials: TK
authors.lastname: Chan
authors.affiliation: Department of Biomedical Sciences, City University of Hong Kong, Hong Kong, China. bhcheng@cityu.edu.hk.|State Key Laboratory in Marine Pollution, City University of Hong Kong, Hong Kong, China. bhcheng@cityu.edu.hk.
authors.forename: S H
authors.initials: SH
authors.lastname: Cheng
authors.affiliation: Department of Physics and Materials Science, City University of Hong Kong, Hong Kong, China. peter.yu@cityu.edu.hk.|State Key Laboratory in Marine Pollution, City University of Hong Kong, Hong Kong, China. peter.yu@cityu.edu.hk.
authors.forename: K N
authors.initials: KN
authors.lastname: Yu
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects / Q000528:radiation effects; D004307:Dose-Response Relationship, Radiation; D004625:Embryo, Nonmammalian / Q000187:drug effects* / Q000528:radiation effects; D009569:Nitric Oxide / Q000378:metabolism*; D011839:Radiation, Ionizing; D026423:S-Nitroso-N-Acetylpenicillamine / Q000494:pharmacology; D014965:X-Rays; D015027:Zebrafish
chemical_list: D009569:Nitric Oxide; D026423:S-Nitroso-N-Acetylpenicillamine
keywords: bystander effect; ionizing radiation; nitric oxide; zebrafish embryos