Gene Expression of Angiotensin-Converting Enzyme 2 Receptor in Skin and the Implications for COVID-19

BACKGROUND: Binding to the angiotensin-converting enzyme 2 (ACE2) receptor is a critical step for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) to enter target cells. This enzyme is expressed in many human tissues including the lungs, but no research has demonstrated that SARS-CoV-2 can infect human skin or subcutaneous fat tissue, despite the increasing number of reported skin manifestations. The aim of this study was to investigate ACE2 gene expression in skin using a public database. METHODS: A search of transcriptomic data sets from a public gene expression database to investigate ACE2 gene expression in human tissues. RESULTS: Human skin keratinocytes and basal cells express more ACE2 than lung epithelial cells. In contrast, both fibroblasts and melanocytes from human skin express less ACE2 than human lung epithelial cells. CONCLUSIONS: The high expression of ACE2 in keratinocytes and basal cells of human skin indicates that they may be directly susceptible to SARS-CoV-2 infection via the ACE2 receptor, especially in conditions of skin barrier dysfunction, and are therefore a potential target for the coronavirus.