A systems-level study reveals host-targeted repurposable drugs against SARS-CoV-2 infection.

Understanding the mechanism of SARS-CoV-2 infection and identifying potential therapeutics are global imperatives. Using a quantitative systems pharmacology approach, we identified a set of repurposable and investigational drugs as potential therapeutics against COVID-19. These were deduced from the gene expression signature of SARS-CoV-2-infected A549 cells screened against Connectivity Map and prioritized by network proximity analysis with respect to disease modules in the viral-host interactome. We also identified immuno-modulating compounds aiming at suppressing hyperinflammatory responses in severe COVID-19 patients, based on the transcriptome of ACE2-overexpressing A549 cells. Experiments with Vero-E6 cells infected by SARS-CoV-2, as well as independent syncytia formation assays for probing ACE2/SARS-CoV-2 spike protein-mediated cell fusion using HEK293T and Calu-3 cells, showed that several predicted compounds had inhibitory activities. Among them, salmeterol, rottlerin, and mTOR inhibitors exhibited antiviral activities in Vero-E6 cells; imipramine, linsitinib, hexylresorcinol, ezetimibe, and brompheniramine impaired viral entry. These novel findings provide new paths for broadening the repertoire of compounds pursued as therapeutics against COVID-19.

Antiviral drug screen identifies DNA-damage response inhibitor as potent blocker of SARS-CoV-2 replication.

SARS-CoV-2 has currently precipitated the COVID-19 global health crisis. We developed a medium-throughput drug-screening system and identified a small-molecule library of 34 of 430 protein kinase inhibitors that were capable of inhibiting the SARS-CoV-2 cytopathic effect in human epithelial cells. These drug inhibitors are in various stages of clinical trials. We detected key proteins involved in cellular signaling pathways mTOR-PI3K-AKT, ABL-BCR/MAPK, and DNA-damage response that are critical for SARS-CoV-2 infection. A drug-protein interaction-based secondary screen confirmed compounds, such as the ATR kinase inhibitor berzosertib and torin2 with anti-SARS-CoV-2 activity. Berzosertib exhibited potent antiviral activity against SARS-CoV-2 in multiple cell types and blocked replication at the post-entry step. Berzosertib inhibited replication of SARS-CoV-1 and the Middle East respiratory syndrome coronavirus (MERS-CoV) as well. Our study highlights key promising kinase inhibitors to constrain coronavirus replication as a host-directed therapy in the treatment of COVID-19 and beyond as well as provides an important mechanism of host-pathogen interactions.

AMP-Activated Protein Kinase Restricts Zika Virus Replication in Endothelial Cells by Potentiating Innate Antiviral Responses and Inhibiting Glycolysis.

Viruses are known to perturb host cellular metabolism to enable their replication and spread. However, little is known about the interactions between Zika virus (ZIKV) infection and host metabolism. Using primary human retinal vascular endothelial cells and an established human endothelial cell line, we investigated the role of AMP-activated protein kinase (AMPK), a master regulator of energy metabolism, in response to ZIKV challenge. ZIKV infection caused a time-dependent reduction in the active phosphorylated state of AMPK and of its downstream target acetyl-CoA carboxylase. Pharmacological activation of AMPK using 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), metformin, and a specific AMPKα activator (GSK621) attenuated ZIKV replication. This activity was reversed by an AMPK inhibitor (compound C). Lentivirus-mediated knockdown of AMPK and the use of AMPKα-/- mouse embryonic fibroblasts provided further evidence that AMPK has an antiviral effect on ZIKV replication. Consistent with its antiviral effect, AMPK activation potentiated the expression of genes with antiviral properties (e.g., IFNs, OAS2, ISG15, and MX1) and inhibited inflammatory mediators (e.g., TNF-α and CCL5). Bioenergetic analysis showed that ZIKV infection evokes a glycolytic response, as evidenced by elevated extracellular acidification rate and increased expression of key glycolytic genes (GLUT1, HK2, TPI, and MCT4); activation of AMPK by AICAR treatment reduced this response. Consistent with this, 2-deoxyglucose, an inhibitor of glycolysis, augmented AMPK activity and attenuated ZIKV replication. Thus, our study demonstrates that the anti-ZIKV effect of AMPK signaling in endothelial cells is mediated by reduction of viral-induced glycolysis and enhanced innate antiviral responses.