Identification of a pharmacological approach to reduce ACE2 expression and development of an in vitro COVID-19 viral entry model

by Selleckchem | Oct 31 2023

Because of rapid emergence and circulation of the SARS-CoV-2 variants, especially Omicron which shows increased transmissibility and resistant to antibodies, there is an urgent need to develop novel therapeutic drugs to treat COVID-19. In this study we developed an in vitro cellular model to explore the regulation of ACE2 expression and its correlation with ACE2-mediated viral entry. We examined ACE2 expression in a variety of human cell lines, some of which are commonly used to study SARS-CoV-2. Using the developed model, we identified a number of inhibitors which reduced ACE2 protein expression. The greatest reduction of ACE2 expression was observed when CK869, an inhibitor of the actin-related protein 2/3 (ARP2/3) complex, was combined with 5-(N-ethyl-N-isopropyl)-amiloride (EIPA), an inhibitor of sodium-hydrogen exchangers (NHEs), after treatment for 24 h. Using pseudotyped lentivirus expressing the SARS-CoV-2 full-length spike protein, we found that ACE2-dependent viral entry was inhibited in CK869 + EIPA-treated Calu-3 and MDA-MB-468 cells. This study provides an in vitro model that can be used for the screening of novel therapeutic candidates that may be warranted for further pre-clinical and clinical studies on COVID-19 countermeasures.

Comments:

The study you described focuses on the development of an in vitro cellular model to investigate the regulation of ACE2 expression and its relationship to ACE2-mediated viral entry, specifically in the context of SARS-CoV-2 infection. ACE2 is the receptor that the SARS-CoV-2 virus uses to enter human cells, making it an important target for therapeutic interventions.

The researchers examined ACE2 expression in various human cell lines commonly used in SARS-CoV-2 studies. They aimed to identify inhibitors that could reduce ACE2 protein expression, thereby potentially limiting viral entry into cells. They found that a combination of two inhibitors, CK869 (which targets the actin-related protein 2/3 complex) and EIPA (which inhibits sodium-hydrogen exchangers), resulted in the most significant reduction of ACE2 expression when applied for 24 hours.

To evaluate the effectiveness of the inhibitors in preventing viral entry, the researchers used a pseudotyped lentivirus expressing the full-length spike protein of SARS-CoV-2. They found that treatment with CK869 + EIPA effectively inhibited ACE2-dependent viral entry in Calu-3 and MDA-MB-468 cells, two cell lines commonly used in SARS-CoV-2 research.

Overall, this study provides an in vitro cellular model that can be utilized for screening potential therapeutic candidates in the search for effective treatments against COVID-19. The identified inhibitors, CK869 and EIPA, show promise in reducing ACE2 expression and inhibiting ACE2-dependent viral entry. Further pre-clinical and clinical studies may be warranted to explore the potential of these inhibitors as COVID-19 countermeasures.