Objectives: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) entry into the host cells depends on the expression of angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2). We investigated the distribution of ACE2-and TMPRSS2-expressing cells in various oral tissues to identify the underlying mechanism of oral manifestations in patients with coronavirus disease 2019.
Subjects:We analyzed the expression patterns of ACE2 and TMPRSS2 in the oral mucosa (tongue, palate, and buccal mucosa), trigeminal ganglion, vessels, and salivary glands of 9 Sprague-Dawley rats using immunohistochemistry and immunofluorescence.Results: ACE2 and TMPRSS2 were strongly expressed in the intermediate layer of the squamous epithelia of tongue papillae and buccal mucosa. ACE2-and TMPRSS2positive cells were observed in the taste buds of the tongue. Additionally, ACE2 and TMPRSS2 were co-expressed in the ductal epithelium and acinar cells of salivary glands. Furthermore, both ACE2 and TMPRSS2 were stained in the neuronal cell body of trigeminal ganglia, but not in Schwann cells. Moreover, ACE2 and TMPRSS2 were expressed in capillaries, but not in venules/arterioles. Conclusions: SARS-CoV-2 can spread the suprabasal area of squamous epithelia of the oral mucosa, invades taste bud, trigeminal nerve, parotid gland, and microvessel, resulting in oral manifestations.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.