Wang Wen-Der, Hsu Hwei-Jan, Li Yi-Fang, Wu Chang-Yi
Department of Bio-Agricultural Sciences, National Chiayi University, Chiayi City 60004, Taiwan.
Institute of Cellular and Organismic Biology, Academia Sinica, Taipei City 11529, Taiwan.
Int J Mol Sci. 2017 Jan 11;18(1):130. doi: 10.3390/ijms18010130.
Paclobutrazol (PBZ) is a widely used fungicide that shows toxicity to aquatic embryos, probably through rain-wash. Here, we specifically focus on its toxic effect on eye development in zebrafish, as well as the role of retinoic acid (RA), a metabolite of vitamin A that controls proliferation and differentiation of retinal photoreceptor cells, in this toxicity. Embryos were exposed to PBZ with or without RA from 2 to 72 h post-fertilization (hpf), and PBZ-treated embryos (2-72 hpf) were exposed to RA for additional hours until 120 hpf. Eye size and histology were examined. Expression levels of (rod photoreceptor marker), (cone photoreceptor marker), (encoding key enzymes for RA synthesis), and phospho-histone H3 (an M-phase marker) in the eyes of control and treated embryos were examined. PBZ exposure dramatically reduces photoreceptor proliferation, thus resulting in a thinning of the photoreceptor cell layer and leading to a small eye. Co-treatment of PBZ with RA, or post-treatment of PBZ-treated embryos with RA, partially rescues photoreceptor cells, revealed by expression levels of marker proteins and by retinal cell proliferation. PBZ has strong embryonic toxicity to retinal photoreceptors, probably via suppressing the production of RA, with effects including impaired retinal cell division.
多效唑（PBZ）是一种广泛使用的杀菌剂，可能通过雨水冲刷对水生胚胎表现出毒性。在此，我们特别关注其对斑马鱼眼睛发育的毒性作用，以及视黄酸（RA）在这种毒性中的作用，视黄酸是维生素A的一种代谢产物，可控制视网膜光感受器细胞的增殖和分化。在受精后2至72小时（hpf），将胚胎暴露于含或不含RA的PBZ中，并且将经PBZ处理的胚胎（2至72 hpf）再暴露于RA数小时直至120 hpf。检查眼睛大小和组织学。检测对照胚胎和处理后胚胎眼睛中（视杆光感受器标记物）、（视锥光感受器标记物）、（编码RA合成关键酶）和磷酸化组蛋白H3（M期标记物）的表达水平。暴露于PBZ会显著降低光感受器的增殖，从而导致光感受器细胞层变薄并导致眼睛变小。通过标记蛋白的表达水平和视网膜细胞增殖显示，PBZ与RA共同处理，或对经PBZ处理的胚胎进行RA后处理，可部分挽救光感受器细胞。PBZ可能通过抑制RA产生而对视网膜光感受器具有很强的胚胎毒性，其影响包括视网膜细胞分裂受损。
