目的:我们的目的是评估泪道引流系统(LDS)作为SARS-CoV-2在人感染中的入口和导管的潜在作用。我们还研究了粘膜表面积。封闭系统中相对较长的泪液接触时间增加了该途径可能导致全身感染的可能性。我们寻找ACE2的表达,SARS-CoV-2的主要受体,以及辅助因子,如TMPRSS2和其他酶,如组织蛋白酶B,CD147,弹性酶1,弗林,Neuropilin1,Neuropilin2,TMPRSS11D和胰蛋白酶也在SARS-CoV-2感染中发挥作用,在这个系统中。
方法:通过RT-PCR分析来自身体供体的引流泪腺的人体组织样本,Westernblot和免疫组织化学。目前尚不清楚各自的捐献者是否在任何时候都是Sars-Cov-2阳性;他们进入研究所时是阴性的。此外,测量身体供体的引流LDS以确定泪腺系统中的粘膜表面。
结果:研究的主要受体的表达,ACE2,辅助因子如TMPRSS2和其他酶如组织蛋白酶B,CD147,弹性酶1,弗林,Neuropilin1,Neuropilin2,TMPRSS11D和胰蛋白酶均在基因和蛋白质水平上检测到。计算泪囊和鼻泪管的平均粘膜表面积为110mm2。
结论:结果显示在传出LDS中存在所有分析的受体。平均泪液通过时间为3分钟,粘膜表面积相对较大,因此,LDS可以被视为SARS-CoV-2的入口和管道。此外,它表示在局部施用药物到眼表面的施用中应当考虑的表面。
OBJECTIVE: Our aim was to evaluate a potential role for the lacrimal drainage system (LDS) as a portal of entry and conduit for SARS-CoV-2 in human infection. We also investigate the mucosal surface area. The relatively long tear contact time in a closed system raises the possibility that this pathway may contribute to the initiation of systemic infection. We looked for expression of ACE2, the main receptor for SARS-CoV-2, as well as cofactors such as TMPRSS2 and other enzymes such as cathepsinB, CD147, elastase1, furin, neuropilin1, neuropilin2, TMPRSS11D and trypsin which also play a role in SARS-CoV-2 infection, in this system.
METHODS: Human tissue samples of the draining tear ducts from body donors were analyzed by RT-PCR, Western blot and immunohistochemistry. It is not known whether the respective body donors were Sars-Cov-2 positive at any time; they were negative when they entered the institute. Besides, the draining LDS of body donors were measured to determine the mucosal surface in the lacrimal system.
RESULTS: The expression of the main receptor studied, ACE2, cofactors such as TMPRSS2 and other enzymes such as cathepsinB, CD147, elastase1, furin, neuropilin1, neuropilin2, TMPRSS11D and trypsin were all detected at the gene and protein level. The average mucosal surface area of the lacrimal sac and nasolacrimal duct was calculated to be 110 mm2.
CONCLUSIONS: The results show the presence of all analyzed receptors in the efferent LDS. With an average tear passage time of 3 min and a relatively large mucosal surface area, the LDS could therefore be considered as a portal of entry and conduit for SARS-CoV-2. In addition, it represents a surface that should be taken into consideration in the administration of topically applied medication to the ocular surface.