Effects of Nutlin-3a on endothelial cells in the presence of inflammation

Angiotensin-converting enzyme 2 (ACE2) is a cell surface receptor with anti-inflammatory activity that recent reports identified downregulated under inflammation like during SARS-CoV-2 infection. Our preliminary data showed the ability of MDM2 inhibitors to reduce inflammation in an alveolar epithelium model (A549-hACE2). Based on these data, the present study aims to investigate the effect of the MDM2 inhibitor, nutlin-3a, in a model of inflamed endothelium. Human Umbilical Vein Endothelial Cells (HUVECs) were treated with 1ng/mL TNF-α alone or in combination with different concentrations of nutlin-3a. Cells were collected 24 and 48 hours after treatments to evaluate biological events (viability, cell cycle, apoptosis) by flow-cytometry. Supernatants were collected to analyze the release of pro-inflammatory cytokines. Protein levels of ACE2 and MDM2/p53 pathway were assayed by western blotting, in parallel ACE2 was investigated through immunofluorescence. The results highlighted that nutlin-3 up-regulates ACE2 and controls inflammation, without significant cytotoxicity. Our data suggest MDM2 inhibitors as a possible therapeutic use to counteract acute inflammation.