ACE and ACE2 in kidney disease

Figure 1 Roles of angiotensin-converting enzyme and angiotensin-converting enzyme 2 in the renin angiotensin system. Angiotensinogen is cleaved by renin to form angiotensin I (Ang I), which is converted to Ang II by ACE. The main function of ACE2 is to synthesize inactive Ang 1-9 from Ang I and to produce the vasodilatory and antiproliferative molecule Ang 1-7 from Ang II. Ang I acts a substrate for neprilysin, which cleaves it to form Ang 1-7. Ang II binds to the Ang II type 1 receptor (AT1-R) and AT2-R. The Mas receptor (MAS-R) is a specific receptor for Ang 1-7. The ACE2-Ang 1-7-MAS axis counteracts the effects of the ACE-Ang II-AT1 axis. ACE: Angiotensin-converting enzyme; NO: Nitric oxide; NEP: Neprilysin; ROS: Reactive oxygen species.