Co-expression of peripheral olfactory receptors with SARS-CoV-2 infection mediators: Potential implications beyond loss of smell as a COVID-19 symptom

Abstract Severe acute respiratory syndrome (SARS) coronavirus-2 (SARS-CoV-2) enters into human host cells via mechanisms facilitated mostly by angiotensin-converting enzyme 2 (ACE2) and transmembrane protease serine 2 (TMPRSS2). New loss of smell (anosmia/hyposmia) is now recognized as a COVID-19 related symptom, which may be caused by SARS-CoV-2 infection and damage of the olfactory receptor (OR) cells in the nasal neuroepithelium and/or central involvement of the olfactory bulb. ORs are also expressed peripherally (e.g., in tissues of the gastrointestinal and respiratory