ver-155008 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

The outcome for gait recovery from paralysis due to spinal lesion remains uncertain even when damage is limited. One critical factor is the survival of motoneurons, which are very vulnerable cells. To clarify the early pathophysiological mechanisms of spinal damage, an in vitro injury model of the rat spinal cord caused by moderate excitotoxicity was used. With this preparation we investigated whether motoneuron survival was dependent on the expression of the neuroprotective protein HSP70. In the present study excitotoxicity evoked by kainate induced delayed (24 h) loss (35%) of motoneurons, which became pyknotic with translocation of the cell death biomarker apoptosis-inducing factor (AIF) to the nucleus. This process was concomitant with suppression of locomotor network electrical activity. Surviving cells showed strong expression of HSP70 without nuclear AIF. The HSP70 inhibitor VER155008 per se induced neurotoxicity similar to that of kainate, while the HSP90 inhibitor geldanamycin did not damage spinal tissue. Electrophysiological recording following kainate or VER155008 indicated depression of motoneuron field potentials, with decreased excitability and impaired synaptic transmission. When these two drugs were applied together, more intense neurotoxicity emerged. Our data indicate that HSP70 was one important contributor to motoneuron survival and suggest that enhancing HSP70 activity is a potential future strategy for neuroprotecting these cells.

Topics: Animals; Animals, Newborn; Apoptosis Inducing Factor; Benzoquinones; Cell Death; Cell Survival; Central Nervous System Agents; Disease Models, Animal; Female; HSP70 Heat-Shock Proteins; Kainic Acid; Lactams, Macrocyclic; Locomotion; Lumbar Vertebrae; Male; Microelectrodes; Motor Neurons; Purine Nucleosides; Rats, Wistar; Spinal Cord; Spinal Cord Injuries; Thoracic Vertebrae

Traumatic Brain injury affects at least 1.7 million people in the United States alone each year. The majority of injuries are categorized as mild but these still produce lasting symptoms that plague the patient and the medical field. Currently treatments are aimed at reducing a patient's symptoms, but there is no effective method to combat the source of the problem, neuronal loss. We tested a mild, closed head traumatic brain injury model for the effects of modulation of the antioxidant transcription factor Nrf2 by the chemical activator, tert-butylhydroquinone (tBHQ). We found that post-injury visual memory was improved by a 7 day course of treatment and that the level of activated caspase-3 in the hippocampus was reduced. The injury-induced memory loss was also reversed by a single injection at 30 min after injury. Since the protective stress response molecule, HSP70, can be upregulated by Nrf2, we examined protein levels in the hippocampus, and found that HSP70 was elevated by the injury and then further increased by the treatment. To test the possible role of HSP70, model neurons in culture exposed to a mild injury and treated with the Nrf2 activator displayed improved survival that was blocked by the HSP70 inhibitor, VER155008. Following mild traumatic brain injury, there may be a partial protective response and patients could benefit from directed enhancement of regulatory pathways such as Nrf2 for neuroprotection.

Topics: Analysis of Variance; Animals; Antioxidants; Avoidance Learning; Brain; Brain Injuries; Caspase 3; Cell Line, Tumor; Cell Survival; Cognition Disorders; Disease Models, Animal; Gene Expression Regulation; Glial Fibrillary Acidic Protein; HSP70 Heat-Shock Proteins; Humans; Hydroquinones; Male; Maze Learning; Mice; Mice, Inbred ICR; Motor Activity; Neuroblastoma; NF-E2-Related Factor 2; Proto-Oncogene Proteins c-jun; Purine Nucleosides; Recognition, Psychology; RNA, Messenger; Rotarod Performance Test; Time Factors