MITOCHONDRIAL ANTIOXIDANTS ABATE SARS-COV-2 LETHALITY IN MICE

SARS-CoV-2 infection inhibits mitochondrial oxidative phosphorylation (OXPHOS), elevates mitochondrial reactive oxygen species (mROS) which activates HIF-1α shifting metabolism toward glycolysis, and causes release of mtDNA which activates the innate immune system. To determine if mitochondrially targeted antioxidants could mitigate these viral effects, we combined in mice hACE2 with mitochondrially-targeted-catalase (mCAT) and showed that SARS-CoV-2 infected hACE2-mCAT mice had decreased weight loss; decreased circulating levels of mtDNA, IL-1β, and INF-β; and decreased lung HIF-1α and nucleocapsid protein levels. RNA-sequencing of infected lungs revealed that mCAT upregulated OXPHOS gene expression and downregulated glycolytic, innate immune, and HIF-1α-target gene expression. The mitochondrial antioxidant drug EUK8 had the same effect as mCAT potentially providing a pharmacological therapy for COVID-19 which is not subject to viral mutational resistance. RNA sequencing analysis on hACE2-transgenic (hACE2) and mitochondrial targeted catalase (mCAT)-transgenic hACE2 mice (hACE2-mCAT), intranasally infected with 2.5x10^4 PFU of the SARS-CoV-2 Washington Variant (WA1) or a mock-control. 4 days-post-infection (dpi) RNA was collected using TRIzol™ Reagent (Invitrogen, 15596026) from 5 infected and 3 uninfected hACE2 and hACE2-mCAT lung samples. The RNA was assessed by NanoDrop spectrophotometer (ThermoFisher Scientific) and quantified by Qubit Flex (Thermofisher Scientific) using the Qubit RNA HS Assay Kit (Thermofisher Scientific, Q32855). The RNA was diluted to 1.43 ng/ul and reverse transcribed into cDNA using the Ion Torrent™ NGS Reverse Transcription Kit (Cat. No. A45003). The RNA library was prepared using the Ion Torrent S5 Chef and Ion AmpliSeq Kit for Chef DL8 (Thermofisher Scientific, A29024) and sequenced using the Ion Torrent S5 Sequencer and Ion 540 Kit (Thermofisher Scientific, A30011).