brl-15572 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 5-HT1B/1D receptor antagonist, GR-127935, inhibits hypotensive responses produced by the 5-HT1A, 5-HT1B/1D and 5-HT7 receptor agonist, and 5-HT5A/5B receptor ligand, 5-carboxamidotryptamine (5-CT), in rats. This work further characterized the above mechanism using more selective 5-HT1B and 5-HT1D receptor antagonists. Also, expression of 5-HT5A and 5-HT5B receptor mRNAs in blood vessels was searched by reverse transcription polymerase chain reaction. Decreases in diastolic blood pressure induced by 5-CT (0.001-10 μg/kg, intravenously) were analyzed in anesthetized rats that had received intravenous vehicle (1 mL/kg), SB-224289 (5-HT1B antagonist; 0.3 and 1.0 mg/kg), BRL15572 (5-HT1D antagonist; 0.3 and 1.0 mg/kg), SB-224289 + BRL15572 (0.3 mg/kg, each), or SB-224289 + BRL15572 (0.3 mg/kg, each) + GR-127935 (1 mg/kg). Because only the latter treatment inhibited 5-CT-induced hypotension, suggestive of a mechanism unrelated to 5-HT1B/1D receptors, the effects of antagonists/ligands at 5-HT5A (SB-699551, 1 mg/kg), 5-HT6 (SB-399885, 1 mg/kg), and 5-HT1B/1D/5A/5B/7 receptors (ergotamine, 0.1 mg/kg) on 5-CT-induced hypotension were tested. Interestingly, only ergotamine blocked 5-CT-induced responses; this effect closely paralleled that of SB-224289 + BRL-15572 + GR-127935. Neither did ergotamine nor GR-127935 inhibit hypotensive responses induced by the 5-HT7 receptor agonist, LP-44. Faint but clear bands corresponding to 5-HT5A and 5-HT5B receptor mRNAs in aorta and mesenteric arteries were detected. Results suggest that the GR-127935-sensitive mechanism mediating hypotension in rats is unrelated to 5-HT1B, 5-HT1D, 5-HT5A, 5-HT6, and 5-HT7 receptors. This mechanism, however, resembles putative 5-HT5B receptors.

Topics: Animals; Biphenyl Compounds; Blood Pressure; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Therapy, Combination; Ergotamine; Hypotension; Oxadiazoles; Piperazines; Piperidones; Rats; Receptors, Serotonin; Serotonin; Serotonin Antagonists; Serotonin Receptor Agonists; Spiro Compounds

The present study analyzed the potential antinociceptive effect of the antimigraine drugs sumatriptan, dihydroergotamine or methysergide in rats submitted to the formalin test. Moreover, by using selective antagonists, the role of 5-HT1B/1D serotonergic receptors was investigated in the antinociception induced by these antimigraine drugs.. The formalin test was used to assess the nociceptive activity. Overt pain-like behavior (flinching, 1h) and evoked nociception (long-lasting secondary mechanical allodynia and hyperalgesia, 6 days) were determined in the same rat.. Ipsilateral, but not contralateral, pre-treatment (in μg/paw) with sumatriptan (10-300), methysergide (1-30) or dihydroergotamine (1-30) significantly prevented flinching behavior (at 1h) as well as secondary allodynia and hyperalgesia (at day 6) induced by formalin. Interestingly, the antinociceptive (flinching), antiallodynic and antihyperalgesic effects of sumatriptan were completely prevented by peripheral pre-treatment with selective antagonists at the 5-HT1B (SB 224289; 100) or 5-HT1D (BRL 15572; 100) receptors. In contrast, the acute antinociceptive effects of methysergide and dihydroergotamine were partially prevented by SB 224289 and BRL 15572. The antiallodynic and antihyperalgesic effects of both drugs were completely prevented by BRL 15572 and partially prevented by SB 224289. Given alone, SB 224289 or BRL 15572 did not modify per se the long-lasting secondary allodynia and hyperalgesia.. The above findings suggest that: (i) the antimigraine drugs sumatriptan, methysergide and dihydroergotamine reduce the acute and chronic nociception induced by formalin; and (ii) this antinociceptive effect results from activation of peripheral 5-HT1B/1D serotonergic receptors.

Topics: Acute Pain; Animals; Biphenyl Compounds; Chronic Pain; Dihydroergotamine; Disease Models, Animal; Drug Therapy, Combination; Female; Formaldehyde; Hyperalgesia; Methysergide; Nociceptive Pain; Piperazines; Piperidones; Rats; Rats, Wistar; Receptor, Serotonin, 5-HT1B; Receptor, Serotonin, 5-HT1D; Serotonin Antagonists; Spiro Compounds; Sumatriptan