triprolidine 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

There is a major clinical need for new therapies for the treatment of chronic itch. Many of the molecular components involved in itch neurotransmission are known, including the neuropeptide NPPB, a transmitter required for normal itch responses to multiple pruritogens in mice. Here, we investigated the potential for a novel strategy for the treatment of itch that involves the inhibition of the NPPB receptor NPR1 (natriuretic peptide receptor 1). Because there are no available effective human NPR1 (hNPR1) antagonists, we performed a high-throughput cell-based screen and identified 15 small-molecule hNPR1 inhibitors. Using in vitro assays, we demonstrated that these compounds specifically inhibit hNPR1 and murine NPR1 (mNPR1). In vivo, NPR1 antagonism attenuated behavioral responses to both acute itch- and chronic itch-challenged mice. Together, our results suggest that inhibiting NPR1 might be an effective strategy for treating acute and chronic itch.

Topics: Animals; Behavior, Animal; Cell-Free System; Dermatitis, Contact; Disease Models, Animal; Ganglia, Spinal; Humans; Mice, Inbred C57BL; Mice, Knockout; Neurons; Pruritus; Receptors, Atrial Natriuretic Factor; Reproducibility of Results; Signal Transduction; Small Molecule Libraries

The central histaminergic neuronal system is a powerful modulator of brain activity, and its functional disturbance is related to e.g. epilepsy. We have recently shown in the slice culture system that histaminergic neurons attenuate kainic acid (KA)-induced epileptiform activity and neuronal damage in the hippocampus through histamine 1 (H1) receptors. We now further examined the role of H1 receptors in the regulation of KA-induced seizures and neuronal damage in immature 9-day-old H1 receptor knock out (KO) mice. In the H1 receptor KO mice, behavioral seizures were significantly more severe and duration of seizures was significantly longer when compared to the wild type (WT) mice at the KA dose of 2mg/kg. Moreover, neuronal damage correlated with seizure severity, and it was significantly increased in the thalamus and retrosplenial granular cortex (RGC) of the KO mice. The H1 receptor antagonist triprolidine treatment supported these findings by showing significantly increased seizures severity and neuronal damage in the septum, thalamus, CA3 region of the hippocampus, and RGC in the KA-treated WT mice. Our present novel findings suggest that H1 receptors play a pivotal role in the regulation of seizure intensity and duration as well as seizure-induced neuronal damage in the immature P9 mice.

Topics: Animals; Animals, Newborn; Brain; Cell Count; Chi-Square Distribution; Disease Models, Animal; Disease Susceptibility; Dose-Response Relationship, Drug; Fluoresceins; Histamine H1 Antagonists; Kainic Acid; Mice; Mice, Inbred C57BL; Mice, Knockout; Organic Chemicals; Receptors, Histamine H1; Seizures; Triprolidine