Zebrafish: A model animal for analyzing the impact of environmental pollutants on muscle and brain mitochondrial bioenergetics
Zebrafish: A model animal for analyzing the impact of environmental pollutants on muscle and brain mitochondrial bioenergetics
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DOI：
10.1016/j.biocel.2012.07.021
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发表时间：
2013-01-01
影响因子：
4
通讯作者：
Brethes, D.
中科院分区：
文献类型：
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作者：
Bourdineaud, Jean-Paul;Rossignol, R.;Brethes, D.
汞、铀(U)的人为释放和纳米颗粒构成危险的环境污染物，能够沿着水生食物链积累，对动物和人类健康构成严重风险。到目前为止，这些污染物对生物体的影响一直是通过经典毒理学来研究的，在经典毒理学中，与环境无关的大剂量有毒化合物通过在生物体的生命周期中从未发生过的途径（例如，向动物注射汞丸，尽管主要途径是通过猎物和食用鱼类）。我们希望在现实条件下，以前所未有的低剂量，利用水生模型动物斑马鱼来研究这些污染物对肌肉和大脑线粒体生物能量的影响。我们发明了一种测量大脑线粒体呼吸的原始方法：将单个大脑放入1.5 mL含有呼吸缓冲液的锥形管中。大脑用锥形塑料杵轻轻拍打13下均匀，均匀后立即用于呼吸测量。采用皂苷渗透法制备皮肤肌纤维。斑马鱼被含有13 μ g甲基汞(MeHg)/g的食物污染，这是一个与环境相关的剂量。在渗透肌纤维中，我们观察到MeHg暴露49天后，状态3线粒体呼吸和细胞色素c氧化酶活性均受到强烈抑制。我们测量到皮肤肌肉纤维释放ATP的速率急剧下降。与肌肉相反，尽管大脑累积的甲基汞是肌肉的两倍，但大脑线粒体呼吸并没有受到甲基汞暴露的影响。当暴露于30 μ g/L水中U时，暴露28 d后，斑马鱼肌肉基底线粒体呼吸控制率降低。这是由于线粒体内膜通透性增加所致。每天定量食用含有两种大小的金纳米颗粒的食物(在非常低的剂量下（40 ng金/鱼/天）进行了60天的研究。两种测试尺寸的大脑和肌肉都出现了线粒体功能障碍。总之，在低环境剂量下，饮食或水中的重金属会影响斑马鱼组织线粒体呼吸。由于其令人难以置信的简单性，避免了繁琐和耗时的线粒体分离，我们的一锅法允许脑呼吸分析，这应该会给同事们使用斑马鱼大脑作为生物能量学模型的动力。这篇文章是一个定向问题的一部分，题为：生物能量功能障碍，适应和治疗。(C) 2012 Elsevier Ltd.版权所有。
Mercury, anthropogenic release of uranium (U), and nanoparticles constitute hazardous environmental pollutants able to accumulate along the aquatic food chain with severe risk for animal and human health. The impact of such pollutants on living organisms has been up to now approached by classical toxicology in which huge doses of toxic compounds, environmentally irrelevant, are displayed through routes that never occur in the lifespan of organisms (for instance injecting a bolus of mercury to an animal although the main route is through prey and fish eating). We wanted to address the effect of such pollutants on the muscle and brain mitochondrial bioenergetics under realistic conditions, at unprecedented low doses, using an aquatic model animal, the zebrafish Danio rerio.We developed an original method to measure brain mitochondrial respiration: a single brain was put in 1.5 mL conical tube containing a respiratory buffer. Brains were gently homogenized by 13 strokes with a conical plastic pestle, and the homogenates were immediately used for respiration measurements. Skinned muscle fibers were prepared by saponin permeabilization.Zebrafish were contaminated with food containing 13 mu g of methylmercury (MeHg)/g, an environmentally relevant dose. In permeabilized muscle fibers, we observed a strong inhibition of both state 3 mitochondrial respiration and cytochrome c oxidase activity after 49 days of MeHg exposure. We measured a dramatic decrease in the rate of ATP release by skinned muscle fibers. Contrarily to muscles, brain mitochondrial respiration was not modified by MeHg exposure although brain accumulated twice as much MeHg than muscles.When zebrafish were exposed to 30 mu g/L of waterborne U, the basal mitochondrial respiratory control ratio was decreased in muscles after 28 days of exposure. This was due to an increase of the inner mitochondrial membrane permeability.The impact of a daily ration of food containing gold nanoparticles of two sizes (.12 and 50 nm) was investigated at a very low dose for 60 days (40 ng gold/fish/day). Mitochondrial dysfunctions appeared in brain and muscle for both tested sizes.In conclusion, at low environmental doses, dietary or waterborne heavy metals impinged on zebrafish tissue mitochondrial respiration. Due to its incredible simplicity avoiding tedious and time-consuming mitochondria isolation, our one-pot method allowing brain respiratory analysis should give colleagues the incentive to use zebrafish brain as a model in bioenergetics. This article is part of a Directed Issue entitled: Bioenergetic dysfunction, adaptation and therapy. (C) 2012 Elsevier Ltd. All rights reserved.