Degradation of SARS-CoV-2 receptor ACE2 by the E3 ubiquitin ligase Skp2 in lung epithelial cells

• DOI: 10.1007/s11684-021-0837-6
• Publication Date: 2021-01-29T02:11:05Z
• Authors: Guizhen Wang; Qun Zhao; Hui Zhang; Fan Liang; Chen Zhang; Jun Wang; Zhenyin Chen; Ran Wu; Hong Yu; Beibei Sun; Hua Guo; Ruie Feng; Kaifeng Xu; Guangbiao Zhou
• Keywords: Adult; 0301 basic medicine; SARS-CoV-2; Ubiquitin-Protein Ligases; COVID-19; Epithelial Cells; General Medicine; Peptidyl-Dipeptidase A; 3. Good health; Mice; 03 medical and health sciences; Spike Glycoprotein, Coronavirus; Animals; Humans; Lung; Pandemics; Research Article

An unexpected observation among the COVID-19 pandemic is that smokers constituted only 1.4%-18.5% of hospitalized adults, calling for an urgent investigation to determine the role of smoking in SARS-CoV-2 infection. Here, we show that cigarette smoke extract (CSE) and carcinogen benzo(a)pyrene (BaP) increase ACE2 mRNA but trigger ACE2 protein catabolism. BaP induces an aryl hydrocarbon receptor (AhR)-dependent upregulation of the ubiquitin E3 ligase Skp2 for ACE2 ubiquitination. ACE2 in lung tissues of non-smokers is higher than in smokers, consistent with the findings that tobacco carcinogens downregulate ACE2 in mice. Tobacco carcinogens inhibit SARS-CoV-2 spike protein pseudovirions infection of the cells. Given that tobacco smoke accounts for 8 million deaths including 2.1 million cancer deaths annually and Skp2 is an oncoprotein, tobacco use should not be recommended and cessation plan should be prepared for smokers in COVID-19 pandemic.