pf-4778574 and Disease-Models--Animal

When Zika virus emerged as a public health emergency there were no drugs or vaccines approved for its prevention or treatment. We used a high-throughput screen for Zika virus protease inhibitors to identify several inhibitors of Zika virus infection. We expressed the NS2B-NS3 Zika virus protease and conducted a biochemical screen for small-molecule inhibitors. A quantitative structure-activity relationship model was employed to virtually screen ∼138,000 compounds, which increased the identification of active compounds, while decreasing screening time and resources. Candidate inhibitors were validated in several viral infection assays. Small molecules with favorable clinical profiles, especially the five-lipoxygenase-activating protein inhibitor, MK-591, inhibited the Zika virus protease and infection in neural stem cells. Members of the tetracycline family of antibiotics were more potent inhibitors of Zika virus infection than the protease, suggesting they may have multiple mechanisms of action. The most potent tetracycline, methacycline, reduced the amount of Zika virus present in the brain and the severity of Zika virus-induced motor deficits in an immunocompetent mouse model. As Food and Drug Administration-approved drugs, the tetracyclines could be quickly translated to the clinic. The compounds identified through our screening paradigm have the potential to be used as prophylactics for patients traveling to endemic regions or for the treatment of the neurological complications of Zika virus infection.

Topics: Animals; Antiviral Agents; Artificial Intelligence; Chlorocebus aethiops; Disease Models, Animal; Drug Evaluation, Preclinical; High-Throughput Screening Assays; Immunocompetence; Inhibitory Concentration 50; Methacycline; Mice, Inbred C57BL; Protease Inhibitors; Quantitative Structure-Activity Relationship; Small Molecule Libraries; Vero Cells; Zika Virus; Zika Virus Infection

Working memory impairments are a core aspect of schizophrenia, yet current medicines do not address such cognitive dysfunction. We have developed a model of these working memory deficits by acutely disrupting glutamatergic synaptic transmission by administration of the N-methyl-d-aspartate (NMDA) antagonist ketamine in the nonhuman primate. The current studies evaluated the effect of positive allosteric modulators ("potentiators") of the alpha-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid (AMPA) receptors on the working memory and behavioral effects of ketamine. AMPA receptors mediate fast excitatory synaptic transmission throughout the brain and play a critical role in the activity-dependent regulation of NMDA receptors. We find that positive modulation of AMPA receptors with LY451646 (0.1-1.0mg/kg, SC) and structurally distinct PF-4778574 (0.01mg/kg, SC) robustly ameliorates ketamine-induced working memory impairments without altering behavioral effects of acute ketamine we consider related to positive- and negative-like symptoms. These results support AMPA receptor potentiators as a potential adjunctive treatment for cognitive impairment associated with schizophrenia (CIAS).

Topics: alpha-Amino-3-hydroxy-5-methyl-4-isoxazolepropionic Acid; Analysis of Variance; Animals; Animals, Newborn; Area Under Curve; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Administration Schedule; Excitatory Amino Acid Agonists; Ketamine; Macaca fascicularis; Macaca mulatta; Memory Disorders; Memory, Short-Term; Motor Activity; Neuropsychological Tests; Reaction Time; Sulfonamides; Thiophenes; Time Factors