Gastrointestinal and kidney manifestations in SARS-CoV and SARS-CoV-2 infections: role of angiotensin-converting enzyme 2

The emergence of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in 2020, which has a substantial structural similarity to severe acute respiratory syndrome coronavirus (SARS-CoV) that caused the outbreak in 2003, is currently a threat to global health. Lung involvement is the principal clinical feature in infected patients but extra-pulmonary clinical presentations are also common. The reasons for the extensive involvement of other organs are not yet clear. Angiotensin-converting enzyme 2 (ACE2), the key peptide of renin–angiotensin system (RAS), has recently identified as a major receptor for the both SARS-CoV and SARS-CoV-2 that might be a main target of coronavirus infection. ACE2 is mainly expressed in the pulmonary pneumocytes, the small intestine enterocytes as well as the proximal tubule epithelial cells of the kidneys. In addition to the respiratory tract infection symptoms, the noticeable prevalence of gastrointestinal symptoms as well as kidney impairment in hospitalized infected patients highlights other routes of infection/transmission. In present review, we discussed the role of RAS with emphasis on ACE2 in the pathogenesis of SARS-CoV and SARS-CoV-2, particularly in gastrointestinal and kidney manifestations of the diseases.