Pericyte-specific vascular expression of SARS-CoV-2 receptor ACE2 – implications for microvascular inflammation and hypercoagulopathy in COVID-19

Accumulating clinical observations implicatevascular inflammation as an underlyingcause of coagulopathyin severely ill COVID-19 patientsand it was recently suggested that SARS-CoV-2 virus particles infect endothelial cells.Here, we show thatendothelial cells do not expressangiotensin-converting enzyme-2 (ACE2), the SARS-CoV-2 receptor. Instead, pericytes and microvascular smooth muscle cells express ACE2 in an organotypic manner.Pericyte deficiency leads toincreased endothelial expression and releaseof Von Willebrand factorand intravascular platelet and fibrin aggregation,suggesting thatpericyteslimit endothelial pro-thromboticresponses. That pericytes and not endothelial cells express ACE2 may provide important clues tothe pathologyofCOVID-19, as pericytes are normally shielded behind anendothelial barrier and may get infected only whenthis barrier is compromisedby COVID-19 risk factors.