School of Pharmacy, Changzhou University, Changzhou, Jiangsu Province, PR China.
School of Pharmacy, Changzhou University, Changzhou, Jiangsu Province, PR China; Biology Institute, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong Province, PR China; Engineering Research Center of Zebrafish Models for Human Diseases and Drug Screening of Shandong Province, Jinan, Shandong Province, PR China.
Chemosphere. 2021 Feb;265:129109. doi: 10.1016/j.chemosphere.2020.129109. Epub 2020 Nov 28.
This study evaluated the neurodevelopmental toxicity of isoniazid (INH) in zebrafish embryos and the underlying mechanism.
Zebrafish embryos were exposed to different concentrations (2 mM, 4 mM, 8 mM, 16 mM, 32 mM) INH for 120 hpf. During the exposure period, the percentage of embryo/larva mortality, hatching, and morphological malformation were checked every 24 h until 120 hpf. The development of blood vessels in the brain was observed at 72 hpf and 120 hpf, and behavioral capacity and acridine orange (AO) staining were measured at 120 hpf. Alterations in the mRNA expression of apoptosis and dopamine signaling pathway related genes were assessed by real-time quantitative PCR (qPCR).
INH considerably inhibited zebrafish embryo hatching and caused zebrafish larval malformation (such as brain malformation, delayed yolk sac absorption, spinal curvature, pericardial edema, and swim bladder defects). High concentration of INH (16 mM, 32 mM) even induced death of zebrafish. In addition, INH exposure markedly restrained the ability of the zebrafish autonomous movement, shortened the length of dopamine neurons and inhibited vascular development in the brain. No obvious apoptotic cells were observed in the control group, whereas considerable numbers of apoptotic cells appeared in the head of INH-treated larvae at 120 hpf. PCR results indicated that INH significantly raised the transcription levels of caspase-3, -8, -9, and bax and significantly decreased bcl-2 and bcl-2/bax in the zebrafish apoptotic signaling pathway. INH also markedly decreased the genes related to dopamine signaling pathway (th1, dat, drd1, drd2a, drd3, and drd4b).
Experimental results indicated that INH had obvious neurodevelopmental toxicity in zebrafish. Persistent exposure to INH for 120 h caused apoptosis, decreased dopaminergic gene expression, altered vasculature, and reduced behaviors.
本研究评估了异烟肼（INH）对斑马鱼胚胎的神经发育毒性及其潜在机制。
斑马鱼胚胎在不同浓度（2 mM、4 mM、8 mM、16 mM、32 mM）的 INH 中暴露 120 hpf。在暴露期间，每 24 h 检查胚胎/幼虫死亡率、孵化率和形态畸形率，直到 120 hpf。在 72 hpf 和 120 hpf 观察大脑血管发育，在 120 hpf 测量行为能力和吖啶橙（AO）染色。通过实时定量 PCR（qPCR）评估凋亡和多巴胺信号通路相关基因的 mRNA 表达变化。
INH 显著抑制斑马鱼胚胎孵化，并导致斑马鱼幼虫畸形（如脑畸形、延迟卵黄囊吸收、脊柱弯曲、心包水肿和鳔缺陷）。高浓度 INH（16 mM、32 mM）甚至导致斑马鱼死亡。此外，INH 暴露显著抑制了斑马鱼自主运动能力，缩短了多巴胺神经元的长度，并抑制了大脑血管发育。在对照组中未观察到明显的凋亡细胞，而在 INH 处理的幼虫头部在 120 hpf 时出现了大量凋亡细胞。PCR 结果表明，INH 显著提高了凋亡信号通路中 caspase-3、-8、-9 和 bax 的转录水平，并显著降低了 bcl-2 和 bcl-2/bax 的水平。INH 还显著降低了多巴胺信号通路相关基因（th1、dat、drd1、drd2a、drd3 和 drd4b）的表达。
实验结果表明，INH 对斑马鱼具有明显的神经发育毒性。持续暴露于 INH 120 h 可引起凋亡、降低多巴胺能基因表达、改变血管结构和降低行为能力。
