Fig. 3.

Schema showing the mechanisms of endothelial damage caused by SARS-CoV-2. These mechanisms include direct SARS-CoV-2 infection of the endothelial cells causing endothelial injury and vessel wall inflammation; down-regulation of ACE-2 caused by endothelial infection leading to vascular inflammation, thrombosis, increased vascularity, and microvascular dysfunction; vascular inflammation and endothelial injury induced by high circulating levels of cytokines; endothelial injury induced by high circulating levels of reactive oxygen species released by activated leucocytes; and SARS-CoV-2-induced pericytes loss leading to endothelial dysfunction and increased leakiness of the microvasculature. All these injuries contribute to hypercoagulability and increased intravascular clot formation