%A 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 %T Degradation of SARS-CoV-2 receptor ACE2 by the E3 ubiquitin ligase Skp2 in lung epithelial cells %0 Journal Article %D 2021 %J Front. Med. %J Frontiers of Medicine %@ 2095-0217 %R 10.1007/s11684-021-0837-6 %P 252-263 %V 15 %N 2 %U {https://journal.hep.com.cn/fmd/EN/10.1007/s11684-021-0837-6 %8 2021-04-15 %X

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.