The Roles and Therapeutic Application of ACE2 in SARS-CoV-2 Infection and Cardiovascular Diseases

Angiotensin-converting enzyme 2 (ACE2) is an essential receptor for infection by the novel coronavirus (SARS-CoV-2) and the 2003 SARS coronavirus, but is also a homologue of angiotensin-converting enzyme (ACE), which degrades angiotensin II peptide at the cell membrane surface. The enzymatic activity of ACE2 has an anti-pathogenic effect by suppressing the RAS system in acute respiratory distress syndrome (ARDS) as well as in cardiovascular diseases. The 2003 SARS coronavirus caused severe lung inflammation in most cases of infection and a high frequency of ARDS, making it easy to identify infected individuals. In contrast, the new coronavirus (SARS-CoV-2), while highly infectious, is difficult to isolate and contain as was the case with the SARS coronavirus because of the wide range of COVID-19 symptoms, from many asymptomatic and mildly ill individuals to some moderately and severely ill individuals. The molecular mechanisms underlying the onset of COVID-19 from infection to severe illness and sequelae are still largely unknown. In this paper, we will outline the bifunctional nature of the ACE2 enzyme and viral receptor and present the role of ACE2 in COVID-19 and respiratory cardiovascular diseases and its potential therapeutic application, focusing on our research results.