Kupke Alexandra, Wenisch Sabine, Failing Klaus, Herden Christiane
Institute of Veterinary Pathology, Faculty of Veterinary Medicine, Justus Liebig University GiessenGiessen, Germany; Institute of Virology, Philipps University MarburgMarburg, Germany.
Small Animal Clinic c/o Institute of Veterinary Anatomy, Histology and Embryology, Department of Veterinary Clinical Sciences, Justus Liebig University Giessen Giessen, Germany.
Front Neuroanat. 2016 Oct 13;10:97. doi: 10.3389/fnana.2016.00097. eCollection 2016.
The olfactory epithelium (OE) is the only body site where neurons contact directly the environment and are therefore exposed to a broad variation of substances and insults. It can serve as portal of entry for neurotropic viruses which spread via the olfactory pathway to the central nervous system. For horses, it has been proposed and concluded mainly from rodent studies that different viruses, e.g., Borna disease virus, equine herpesvirus 1 (EHV-1), hendra virus, influenza virus, rabies virus, vesicular stomatitis virus can use this route. However, little is yet known about cytoarchitecture, protein expression and the intranasal location of the equine OE. Revealing differences in cytoarchitecture or protein expression pattern in comparison to rodents, canines, or humans might help to explain varying susceptibility to certain intranasal virus infections. On the other hand, disclosing similarities especially between rodents and other species, e.g., horses would help to underscore transferability of rodent models. Analysis of the complete noses of five adult horses revealed that in the equine OE two epithelial subtypes with distinct marker expression exist, designated as and which resemble those previously described in dogs. Detailed statistical analysis was carried out to confirm the results obtained on the descriptive level. The equine OE was predominantly located in caudodorsal areas of the nasal turbinates with a significant decline in rostroventral direction, especially for . Immunohistochemically, olfactory marker protein and doublecortin (DCX) expression was found in more cells of OE , whereas expression of proliferating cell nuclear antigen and tropomyosin receptor kinase A was present in more cells of . Accordingly, resembles the mature epithelium, in contrast to the more juvenile . Protein expression profile was comparable to canine and rodent OE but equine and were located differently within the nose and revealed differences in its cytoarchitecture when compared to canine OE. Equine OE closely resembles rat OE. Whether the observed differences contribute to species-specific susceptibility to intranasal insults such as virus infections has to be further investigated.
嗅觉上皮（OE）是身体中唯一神经元直接接触外界环境的部位，因此会接触到各种各样的物质和侵害。它可作为嗜神经病毒的进入门户，这些病毒通过嗅觉途径传播至中枢神经系统。对于马来说，主要基于啮齿动物研究提出并得出结论，不同病毒，如博尔纳病病毒、马疱疹病毒1型（EHV - 1）、亨德拉病毒、流感病毒、狂犬病病毒、水疱性口炎病毒可利用此途径。然而，关于马OE的细胞结构、蛋白表达及鼻内位置，目前所知甚少。揭示与啮齿动物、犬类或人类相比细胞结构或蛋白表达模式的差异，可能有助于解释对某些鼻内病毒感染易感性的不同。另一方面，揭示相似之处，尤其是啮齿动物与其他物种（如马）之间的相似之处，将有助于强调啮齿动物模型的可转移性。对五匹成年马的完整鼻部进行分析发现，马OE中存在两种具有不同标志物表达的上皮亚型，分别命名为 和 ，它们与先前在犬类中描述的亚型相似。进行了详细的统计分析以确认在描述水平上获得的结果。马OE主要位于鼻甲的尾背侧区域，在吻腹侧方向显著减少，尤其是对于 。免疫组织化学分析发现，嗅觉标记蛋白和双皮质素（DCX）在OE 的更多细胞中表达，而增殖细胞核抗原和原肌球蛋白受体激酶A的表达则在 的更多细胞中存在。因此， 类似于成熟上皮，而 则更具幼稚性。蛋白表达谱与犬类和啮齿动物的OE相当，但马的 和 在鼻内的位置不同，与犬类OE相比，其细胞结构也存在差异。马OE 与大鼠OE非常相似。观察到的这些差异是否导致对鼻内侵害（如病毒感染）的物种特异性易感性，还有待进一步研究。
