Figure 2.

Overview of the ACE2/Ang-(1–7)/MasR Axis: (A) Healthy State (Anti-Inflammatory): In a healthy state, ACE II (ANG2) cleaves ANG II to ANG-(1-7) in a controlled balance against angiotensin receptor 1 (AT1R). TGF-β is responsible for fibroblast to myofibroblast differentiation and activation. ANG-(1-7) sequesters TGF-β, thus decreasing fibroblast differentiation. Increases in ANG-(1-7) maintain high levels of ACE2 and MasR (MAS1). (B) Disease State (Inflammatory): In the disease state, SARS-CoV2 binds ACE2, causing internalization and downregulation. Decreased levels of ACE II result in decreased ANG-(1-7), allowing TGF-B concentrations to rise. The increased TGF-beta, along with increased ANG II, causes increased fibrosis development.