Development of fish cell lines for use in ecotoxicology and fish health: the case for fish olfactory cells

嗅觉或嗅觉对鱼类觅食、迁徙、繁殖和/或逃脱捕食至关重要，但可能受到环境污染物的损害。嗅觉细胞是嗅觉上皮（OE）中的嗅觉感觉神经元（OSNs）。OE是嗅觉粘膜（OM）的外层，在鼻腔内折叠成玫瑰花状。osn包含气味感受器，在检测到气味后，通过轴突向嗅球发送信号，在那里它们被处理并传递到大脑的其他区域。OE可以被认为是环境-大脑的接口，环境是鱼的水和人类的空气。因此，鱼的OE很容易暴露于水中的有毒物质和病原体。我建议开发鱼类嗅觉细胞培养，包括连续或不朽的细胞系，以便用于嗅觉的基础和应用研究。细胞培养使研究人员能够在简化的系统上进行实验，在简化的系统中，细胞输入得到更好的控制，输出更容易读取，从而产生更可解释的结果。连续的细胞系还有另外的优点：允许不使用动物进行研究（满足社会减少动物研究的愿望），使对濒临灭绝或难以在实验室中维持的鱼类的研究成为可能，并提供来自组织的无限细胞供应，这些组织可能太小而无法进行研究。虽然osn具有气味受体蛋白，但其他OM细胞类型也很重要，因为它们支持osn的持续生产，这是必要的，因为osn不断死亡和更新。除了OSN培养外，我将尝试获得产生OSN的干细胞和祖细胞、OE中的支持细胞（SCs）和保护和引导OSN轴突的嗅鞘细胞（oec）的细胞系。白细胞培养也将寻求从固有层。鱼类OM培养物的应用可能有助于改善未来水产养殖用鼻内疫苗的开发。目前，我建议使用这些细胞培养物来研究一类新兴的环境污染物：新烟碱类（neonicotinoids, NNs）。神经网络是目前最常用的杀虫剂，但由于其广泛使用，而水是最终的水槽，神经网络可能对鱼类产生脱靶作用。神经网络对嗅觉细胞的任何有害作用都可能对鱼类的行为和野生鱼类种群的健康产生影响，特别是对严重依赖嗅觉的洄游鲑鱼。了解环境污染物对海洋的有害作用也可能对人类健康产生影响。嗅觉系统功能障碍与多种人类疾病有关，包括精神分裂症、阿尔茨海默氏症和自闭症，比较细胞模型可能有助于理解和治疗这些复杂的疾病。

The sense of smell or olfaction is critical for fish to feed, migrate, reproduce and/or escape predation but could be impaired by environmental contaminants. The cells responsible for olfaction are olfactory sensory neurons (OSNs) in the olfactory epithelium (OE). The OE is the outer layer of the olfactory mucosa (OM) folded as rosettes within the nasal cavity. OSNs contain odour receptors and upon detecting odours, send signals through axons to the olfactory bulb from where they get processed and relayed to other brain regions. The OE can be considered the environmental-brain interface, with the environment being water for fish and air for humans. Therefore, the fish OE is readily exposed to toxicants and pathogens in water. I am proposing to develop fish olfactory cell cultures, including continuous or immortal cell lines, so that they can be used in basic and applied research on the OM. Cell cultures allow researchers to do experiments on simplified systems in which cellular inputs are better controlled and outputs are more easily read, leading to more interpretable results. Continuous cell lines have the additional advantages of permitting research without using animals (fulfilling a societal desire to reduce animal use in research), of making possible studies on fish that are endangered or difficult to maintain in the lab, and of providing an unlimited supply of cells from tissues that may be too small to study otherwise. Although OSNs have the odorant receptor proteins, other OM cell types are also important because they support the continuous production of OSNs, which is necessary because OSNs are constantly dying and renewing. In addition to OSN cultures, I will try to get cell lines of stem and progenitor cells that give rise to OSNs and of supporting cells (SCs) in the OE and of olfactory ensheathing cells (OECs) that protect and guide the OSN axons. Leucocyte cultures from the lamina propria will also be sought. An applied use of fish OM cultures could be to help improve development of intranasal vaccines for fish aquaculture in the future.For now, I am proposing to use these cell cultures to study an emerging class of environmental contaminants: neonicotinoids (NNs). NNs are currently the most commonly used insecticides but because of their wide use, and water being the ultimate sink, NNs might have off-target actions on fish. Any detrimental actions of NNs on the olfactory cells could have implications for fish behaviour and the health of fish populations in the wild, especially for migrating salmonids that depend heavily on olfaction. Understanding detrimental actions of environmental contaminants on the OM could also have implications for human health. Olfactory system dysfunction has been implicated in several human medical conditions, including schizophrenia, Alzheimer's and autism, and comparative cellular models could contribute to the understanding and treatment of these complex disorders.