Anticancer pan-ErbB inhibitors reduce inflammation and tissue injury and exert broad-spectrum antiviral effects.

Targeting host factors exploited by multiple viruses could offer broad-spectrum solutions for pandemic preparedness. Seventeen candidates targeting diverse functions emerged in a screen of 4,413 compounds for SARS-CoV-2 inhibitors. We demonstrated that lapatinib and other approved inhibitors of the ErbB family receptor tyrosine kinases suppress replication of SARS-CoV-2, Venezuelan equine encephalitis virus (VEEV), and other emerging viruses with a high barrier to resistance. Lapatinib suppressed SARS-CoV-2 entry and later stages of the viral life cycle and showed synergistic effect with the direct-acting antiviral nirmatrelvir. We discovered that ErbB1, 2 and 4 bind SARS-CoV-2 S1 protein and regulate viral and ACE2 internalization, and they are required for VEEV infection. In human lung organoids, lapatinib protected from SARS-CoV-2-induced activation of ErbB-regulated pathways implicated in non-infectious lung injury, pro-inflammatory cytokine production, and epithelial barrier injury. Lapatinib suppressed VEEV replication, cytokine production and disruption of the blood-brain barrier integrity in microfluidic-based human neurovascular units, and reduced mortality in a lethal infection murine model. We validated lapatinib-mediated inhibition of ErbB activity as an important mechanism of antiviral action. These findings reveal regulation of viral replication, inflammation, and tissue injury via ErbBs and establish a proof-of-principle for a repurposed, ErbB-targeted approach to combat emerging viruses.

Identification of Inhibitors of SARS-CoV-2 3CL-Pro Enzymatic Activity Using a Small Molecule in Vitro Repurposing Screen.

Compound repurposing is an important strategy for the identification of effective treatment options against SARS-CoV-2 infection and COVID-19 disease. In this regard, SARS-CoV-2 main protease (3CL-Pro), also termed M-Pro, is an attractive drug target as it plays a central role in viral replication by processing the viral polyproteins pp1a and pp1ab at multiple distinct cleavage sites. We here report the results of a repurposing program involving 8.7 K compounds containing marketed drugs, clinical and preclinical candidates, and small molecules regarded as safe in humans. We confirmed previously reported inhibitors of 3CL-Pro and have identified 62 additional compounds with IC50 values below 1 µM and profiled their selectivity toward chymotrypsin and 3CL-Pro from the Middle East respiratory syndrome virus. A subset of eight inhibitors showed anticytopathic effect in a Vero-E6 cell line, and the compounds thioguanosine and MG-132 were analyzed for their predicted binding characteristics to SARS-CoV-2 3CL-Pro. The X-ray crystal structure of the complex of myricetin and SARS-Cov-2 3CL-Pro was solved at a resolution of 1.77 Å, showing that myricetin is covalently bound to the catalytic Cys145 and therefore inhibiting its enzymatic activity.

Anti-inflammatory activity of a pteridine derivative (4AZA2096) alleviates TNBS-induced colitis in mice.

Elevated production of tumor necrosis factor (TNF) plays a central role in the pathogenesis of many inflammatory diseases, such as rheumatoid arthritis and Crohn's disease. Naturally occurring pteridine analogs have been reported to have potent immunomodulatory activity, especially on TNF production. The aim of this study is to identify small molecule TNF inhibitiors derived from pteridine and to prove their in vivo efficacy in an inflammatory model. A focused chemical library based on the pteridine scaffold was screened in vitro on lipopolysaccharide (LPS)-induced TNF production in peripheral blood mononuclear cells (PBMC). One synthetic pteridine analog (4AZA2096), shown to have strong inhibitory activity, was selected and tested for its efficacy to treat trinitrobenzenesulfonate (TNBS)-induced colitis in mice, a model of Crohn's disease. Colitis was induced by rectal administration of 1 mg TNBS in 50% ethanol after presensitization via the skin. The synthetic pteridine analog 4AZA2096 was shown to potently inhibit LPS-induced TNF production in vitro. Colitic mice treated with 4AZA2096 orally (20 mg/kg/day) recovered more rapidly and, histologically, had a reduction of inflammatory lesions, less edema, a reduction of goblet cell loss, and reduced wall thickness. Cell infiltration in the colon, especially infiltration of neutrophils, as shown by myeloperoxidase (MPO) activity, was reduced in 4AZA2096-treated animals. Intralesional TNF production was lower in mice of the treated groups, whereas interleukin-18 (IL-18) and interferon-gamma (IFN-gamma) mRNA were not affected. Treatment had no effect on anti-TNBS antibody production, arguing against generalized immunosuppression. In conclusion, we identified a pteridine derivative, 4AZA2096, with strong inhibitory activity on TNF production and a remission- inducing effect in TNBS colitis, supporting further preclinical and clinical development of this novel TNF inhibitor for treatment of inflammatory diseases.