Decrease in ACE2 mRNA expression in aged mouse lung

ACE2 is a critical SARS-CoV-2 receptor, and age-related ACE2 expression has been proposed to affect COVID-19 susceptibility and severity. Human age-dependent ACE2 expression data are limited, so cell-type-resolved mouse lung data were used to examine age-associated ACE2 mRNA differences. Old mouse lungs show reduced ACE2 mRNA, with ciliated-cell expression and abundance shifts contributing to the decrease, while TMPRSS2 mRNA does not change significantly with age.