Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada.
Department of Biological Sciences, University of Lethbridge, Lethbridge, Alberta, Canada.
Ecotoxicol Environ Saf. 2021 Dec 20;227:112876. doi: 10.1016/j.ecoenv.2021.112876. Epub 2021 Oct 8.
Olfactory epithelial cells are in direct contact with myriad environmental contaminants which may consequently disrupt their structure and function. Copper ions (Cu) and copper nanoparticles (CuNPs) are two types of olfactory neurotoxicants. However, their effects on the structure of olfactory epithelium are largely uninvestigated. The density of olfactory goblet cells in CuNP- and Cu - exposed rainbow trout was assessed using light microscopy throughout time. In both copper (Cu) treatments, the number of goblet cells increased initially over the 24 h exposure and then recovered to normal throughout the 96 h exposure. These data suggested the 96 h exposure to Cu contaminants interfered with protective barrier provided by goblet cells. Nonetheless, lamellar and epithelial thickness of olfactory rosette did not change in the Cu-exposed fish. The gene transcript profile of olfactory mucosa studied by RNA-seq indicated Cu and CuNPs differentially targeted the molecular composition of cell junctions. In the Cu treatment, reduced mRNA abundances of tight junctions, adherens junction, desmosomes and hemidesmosomes, suggest that Cu-exposed olfactory mucosal cells had weak junctional complexes. In the CuNP treatment, on the other hand, the transcript abundances of cell junction compositions, except adherens junction, were upregulated. Transcripts associated with gap junctional channels were increased in both Cu treatments. The elevated transcript levels of gap junctions in both Cu treatments suggested that the demand for intercellular communication was increased in the Cu-exposed olfactory mucosa. Overall, our findings suggested that Cu induced greater adverse effects on the molecular composition of olfactory cell junctions relative to CuNPs. Impairment of junctional complexes may disrupt the structural integrity of olfactory mucosa.
嗅上皮细胞直接与无数环境污染物接触，这些污染物可能会破坏其结构和功能。铜离子 (Cu) 和铜纳米颗粒 (CuNPs) 是两种嗅神经毒物。然而，它们对嗅上皮结构的影响在很大程度上尚未得到研究。使用光学显微镜在整个时间内评估了暴露于铜纳米颗粒和铜中的虹鳟鱼嗅上皮中杯状细胞的密度。在两种铜 (Cu) 处理中，杯状细胞的数量最初在 24 小时暴露期间增加，然后在 96 小时暴露期间恢复正常。这些数据表明，96 小时暴露于铜污染物会干扰杯状细胞提供的保护屏障。尽管如此，暴露于铜的鱼的嗅绒球的层状和上皮厚度没有变化。通过 RNA-seq 研究的嗅黏膜基因转录谱表明，Cu 和 CuNPs 对细胞连接的分子组成有不同的靶向作用。在 Cu 处理中，紧密连接、黏着连接、桥粒和半桥粒的 mRNA 丰度降低，表明暴露于 Cu 的嗅黏膜细胞的连接复合体较弱。另一方面，在 CuNP 处理中，除黏着连接外，细胞连接成分的转录丰度上调。两种 Cu 处理中间隙连接通道相关的转录物增加。两种 Cu 处理中间隙连接的转录水平升高表明，暴露于 Cu 的嗅黏膜中细胞间通讯的需求增加。总的来说，我们的研究结果表明，Cu 对嗅细胞连接的分子组成产生了比 CuNPs 更大的不利影响。连接复合体的损伤可能会破坏嗅黏膜的结构完整性。
