ACE2 overexpressing mesenchymal stem cells alleviates COVID-19 lung injury by inhibiting pyroptosis. Wei et al.

We proposed that exogenous supplementation of ACE2 via MSCs (ACE2-MSCs) might have better therapeutic effects. We constructed SARS-CoV-2 spike glycoprotein stably transfected AT-II and Beas-2B cells, and used SARS-CoV-2 spike pseudovirus to infect hACE2 transgenic mice.

The results showed that 1) Spike glycoprotein of SARS-CoV-2-transfected AT-II and Beas-2B cells induced pyroptosis and apoptosis; 2) SARS-CoV-2 spike protein activates pyroptosis and the inflammatory response in both AT-II cells and Beas-2B cells and LPS treatment augments the responses; 3) The main factors of the inflammatory response and pyroptosis were downregulated in LPS-treated AT-II and Beas-2B cells by ACE2-MSCs application; 4) SARS-CoV-2 pseudovirus deteriorates mouse lung injury induced by LPS and increases the transcript expression levels of the main factors of cytokine storm and pyroptosis; 5) ACE2-MSCs alleviate SARS-CoV-2 pseudovirus-induced lung injury and inhibit the main factors mRNA of cytokine storm and pyroptosis.