Swallowing Center, the University of Tokyo Hospital, Tokyo, Japan.
Department of Otolaryngology and Head and Neck Surgery, Faculty of Medicine, the University of Tokyo, Tokyo, Japan.
Front Cell Infect Microbiol. 2022 Jun 13;12:924725. doi: 10.3389/fcimb.2022.924725. eCollection 2022.
Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections can cause long-lasting anosmia, but the impact of SARS-CoV-2 infection, which can spread to the nasal cavity the oral route, on the olfactory receptor neuron (ORN) lineage and olfactory bulb (OB) remains undetermined. Using Syrian hamsters, we explored whether oral SARS-CoV-2 inoculation can lead to nasal viral infection, examined how SARS-CoV-2 affects the ORN lineage by site, and investigated whether SARS-CoV-2 infection can spread to the OB and induce inflammation. On post-inoculation day 7, SARS-CoV-2 presence was confirmed in the lateral area (OCAM-positive) but not the nasal septum of NQO1-positive and OCAM-positive areas. The virus was observed partially infiltrating the olfactory epithelium, and ORN progenitor cells, immature ORNs, and mature ORNs were fewer than in controls. The virus was found in the olfactory nerve bundles to the OB, suggesting the nasal cavity as a route for SARS-CoV-2 brain infection. We demonstrated that transoral SARS-CoV-2 infection can spread from the nasal cavity to the central nervous system and the possibility of central olfactory dysfunction due to SARS-CoV-2 infection. The virus was localized at the infection site and could damage all ORN-lineage cells.
严重急性呼吸综合征冠状病毒 2（SARS-CoV-2）感染可导致长期嗅觉障碍，但 SARS-CoV-2 感染（可通过鼻腔和口腔途径传播）对嗅觉受体神经元（ORN）谱系和嗅球（OB）的影响仍不清楚。我们使用叙利亚仓鼠探索了口服 SARS-CoV-2 接种是否会导致鼻腔病毒感染，检查了 SARS-CoV-2 如何通过部位影响 ORN 谱系，并研究了 SARS-CoV-2 感染是否可以传播到 OB 并引发炎症。在接种后第 7 天，在 NQO1 阳性和 OCAM 阳性区域的侧区（OCAM 阳性）但不在鼻中隔中证实存在 SARS-CoV-2。观察到病毒部分浸润嗅上皮，嗅前体细胞、未成熟 ORN 和成熟 ORN 少于对照组。在嗅神经束中发现了病毒到达 OB，提示鼻腔可能是 SARS-CoV-2 脑感染的途径。我们证明了经口 SARS-CoV-2 感染可以从鼻腔传播到中枢神经系统，并且由于 SARS-CoV-2 感染可能导致中枢嗅觉功能障碍。病毒定位于感染部位，可损伤所有 ORN 谱系细胞。
