RT Journal Article SR Electronic T1 Zinc supplement augments the suppressive effects of repurposed drugs of NF-kappa B inhibitor on ACE2 expression in human lung cell lines in vitro JF bioRxiv FD Cold Spring Harbor Laboratory SP 2021.01.27.428372 DO 10.1101/2021.01.27.428372 A1 Ming-Cheng Lee A1 Yin-Kai Chen A1 Yih-Jen Hsu A1 Bor-Ru Lin YR 2021 UL http://biorxiv.org/content/early/2021/01/27/2021.01.27.428372.abstract AB Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) causes a vast number of infections and fatalities worldwide. As the development and safety validation of effective vaccines are ongoing, drug repurposing is most efficient approach to search FDA approved agents against coronavirus disease 2019 (COVID-19). In the present study, we found that endogenous ACE2 expressions could be detected in H322M and Calu-3 cell lines, as well as their ACE2 mRNA and protein expressions were suppressed by pyrrolidine dithiocarbamate (PDTC), a NF-kappa B inhibitor, in dose- and time-dependent manners. Moreover, N-acetyl-cysteine (NAC) pretreatment reversed PDTC-induced ACE2 suppression, as well as the combined treatment of hydrogen peroxide and knockdown of p50 subunit of NF-kappa B by siRNA reduced ACE2 expression in H322M cells. In addition, anthelmintic drug triclabendazole and antiprotozoal drug emetine, repurposed drugs of NF-kappa B inhibitor, also inhibited ACE2 mRNA and protein expressions in H322M cells. Moreover, zinc supplement augmented the suppressive effects of triclabendazole and emetine on ACE2 suppression in H322M and Calu-3 cells. Taken together, these results indicate that ACE2 expression is modulated by reactive oxygen species (ROS) and NF-kappa B signal in human lung cell lines, and zinc combination with triclabendazole or emetine has the clinical potential for the prevention and treatment of COVID-19.Competing Interest StatementThe authors have declared no competing interest.