ACE2 expression is regulated by AhR in SARS-CoV-2-infected macaques

During the current outbreak of coronavirus disease 2019(COVID-19)caused by severe acute respiratory syndrome coronavirus 2(SARS-CoV-2),more than 115 million people have been infected,and 2.5 million have died.1,2 Despite such great harm to human health,the pathogenesis of COVID-19 remains unclear.As the first step in the pathogenetic process,viral entry is mediated by the binding of the SARS-CoV-2 surface spike(S)protein to angiotensin-converting enzyme 2(ACE2)on host cells,such as lung epithelial cells.As an alternative to S protein-blocking strategies,manipulating host cell ACE2 expression may exert an inhibitory effect on SARS-CoV-2 infection.However,the molecular mechanism regulating ACE2 expression remains unclear.