Expression of the SARS-CoV-2 Receptor ACE2 and Protease TMPRSS2 in Ocular Hypertension Eyes of Nonhuman Primate and Human

Purpose: Coronavirus disease 2019 is a disease caused by the novel severe acute respiratory syndrome coronavirus 2. The double-positive of angiotensin-converting enzyme 2 and transmembrane protease serine type 2 have a higher risk of being infected by severe acute respiratory syndrome coronavirus 2. The susceptibility of coronavirus disease 2019 in patients with chronic diseases, especially in different tissues of ocular hypertension eyes like glaucoma, is not yet known.

Methods: An ocular hypertension model was established by laser photocoagulation in rhesus monkeys. The expression of angiotensin-converting enzyme 2 and transmembrane protease serine type 2 in three ocular hypertension eyes and the three control eyes were analyzed using immunofluorescence.

Results: No difference was observed between ocular hypertension and control eyes in the expression of angiotensin-converting enzyme 2 and transmembrane protease serine type 2 in the conjunctival epithelium, corneal epithelium, and ciliary muscle. In ocular hypertension eyes and control eyes, angiotensin-converting enzyme 2 and transmembrane protease serine type 2 expression were both observed in the retina. Angiotensin-converting enzyme 2 staining of retinal ganglion cells was found to be significantly higher in ocular hypertension eyes than in control eyes. However, there was no difference in angiotensin-converting enzyme 2 and transmembrane protease serine type 2 expression in retinal vessels and choroidal vessels between ocular hypertension and control eyes. In our study, the expression and distribution of angiotensin-converting enzyme 2 and TMPREE2 in human retina were similar to that of non-human primates as expected.

Conclusion: Our study confirmed that angiotensin-converting enzyme 2 and transmembrane protease serine type 2 were expressed widely in rhesus monkey eyes. When compared with controls eyes, the expression of angiotensin-converting enzyme 2 was higher in the retinal ganglion cells in ocular hypertension eyes, suggesting that high ocular pressure may affect the patients' ocular susceptibility to severe acute respiratory syndrome coronavirus 2 infection.