Fig. 1
From: Is the use of RAS inhibitors safe in the current era of COVID-19 pandemic?
Angiotensin Converting Enzyme 2 in Classical Renin Angiotensin System and SARS-CoV-1. Panel a. In classical renin angiotensin system, ACE2 convert angiotensin I and II to Angiotensin 1–9 and 1–7, respectively. Panel b. Complex interaction among SARS-CoV-1, ACE2, TMPRSS2, and ADAM17 in lung epithelial cells. In SARS-CoV-1 infection and presumably in SARS-CoV-2 infection, binding of spike protein to ACE2 together with lysosome degradation resulting in ACE2 down regulation, ADAM17 mediated ACE2 shedding from cell membrane resulting in promotion of viral entry, facilitation of ACE2 mediated viral entry by TMPRSS2 make a complex expression or interplay between ACE2 and the virus. ACE, angiotensin converting enzyme; ADAM17, a disintegrin and metallopeptidase domain 17; ARB; angiotensin receptor blocker; S, spike protein; SARS-CoV, severe acute respiratory syndrome corona virus; TMPRSS2, The type II transmembrane serine proteases