ACE2

About ACE2

ACE2 on chromosome Xp22.2 encodes angiotensin converting enzyme 2, a membrane bound carboxypeptidase discovered in 2000 that converts angiotensin II into angiotensin 1 7. It thereby counterbalances the classic renin angiotensin system, since angiotensin 1 7 acting through the Mas receptor promotes vasodilation and has anti fibrotic and anti inflammatory effects. ACE2 is expressed in the lungs, heart, kidneys, intestine, and blood vessels, and in the intestine it also has a separate role in absorption of neutral amino acids together with the transporter B0AT1. ACE2 was identified in 2003 as the cell entry receptor for SARS coronavirus, and in 2020 as the receptor for SARS CoV 2, the virus that causes COVID 19. The viral spike protein binds ACE2, and the host protease TMPRSS2 then cleaves the spike to allow membrane fusion. ACE2 is found in nasal, airway, and alveolar cells and in intestinal, kidney, and heart cells. Expression varies with age, sex, and tissue, and differences have been studied as possible contributors to variation in COVID 19 severity. Soluble ACE2 was investigated as a decoy to block viral entry. Viral binding can reduce ACE2 at the cell surface, which may contribute to lung injury. Despite early concern, ACE inhibitors and angiotensin receptor blockers, which act elsewhere in the system, were not found to worsen COVID 19 outcomes.