Angiotensin-converting enzyme 2: from a vasoactive peptide to the gatekeeper of a global pandemic

PURPOSE OF REVIEW: We provide a comprehensive overview of angiotensin-converting enzyme 2 (ACE2) as a possible candidate for pharmacological approaches to halt inflammatory processes in different pathogenic conditions. RECENT FINDINGS: ACE2 has quickly gained prominence in basic research as it has been identified as the main entry receptor for Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2). This novel pathogen causes Coronavirus Disease 2019 (COVID-19), a pathogenic condition that reached pandemic proportion and is associated with unprecedented morbidity and mortality. SUMMARY: The renin-angiotensin system is a complex, coordinated hormonal cascade that plays a pivotal role in controlling individual cell behaviour and multiple organ functions. ACE2 acts as an endogenous counter-regulator to the pro-inflammatory and pro-fibrotic pathways triggered by ACE through the conversion of Ang II into the vasodilatory peptide Ang 1-7. We discuss the structure, function and expression of ACE2 in different tissues. We also briefly describe the role of ACE2 as a pivotal driver across a wide spectrum of pathogenic conditions, such as cardiac and renal diseases. Furthermore, we provide the most recent data concerning the possible role of ACE2 in mediating SARS-CoV-2 infection and dictating COVID-19 severity.