al-8810 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

Previously, we have demonstrated that prostamide/PGF synthase, which catalyzes the reduction of prostaglandin (PG) H2 to PGF2α, is constitutively expressed in myelin sheaths and cultured oligodendrocytes, suggesting that PGF2α has functional significance in myelin-forming oligodendrocytes. To investigate the effects of PGF2α/FP receptor signaling on demyelination, we administrated FP receptor agonist and antagonist to cuprizone-exposed mice, a model of multiple sclerosis. Mice were fed a diet containing 0.2% cuprizone for 5 weeks, which induces severe demyelination, glial activation, proinflammatory cytokine expression, and motor dysfunction. Administration of the FP receptor antagonist AL-8810 attenuated cuprizone-induced demyelination, glial activation, and TNFα expression in the corpus callosum, and also improved the motor function. These data suggest that during cuprizone-induced demyelination, PGF2α/FP receptor signaling contributes to glial activation, neuroinflammation, and demyelination, resulting in motor dysfunction. Thus, FP receptor inhibition may be a useful symptomatic treatment in multiple sclerosis.

Topics: Animals; Corpus Callosum; Cuprizone; Demyelinating Diseases; Dinoprost; Disease Models, Animal; Humans; Mice; Motor Activity; Multiple Sclerosis; Myelin Sheath; Oligodendroglia; Prostaglandin H2; Receptors, Prostaglandin; Tumor Necrosis Factor-alpha

Injuries to the brain promote upregulation of prostaglandins, notably the proinflammatory PGF2α, and overactivation of their cognate G-protein-coupled FP receptor, which could exacerbate neuronal damage. Our study is focused on investigation of the FP receptor as a target for novel neuroprotective drugs in a preclinical animal traumatic brain injury (TBI) model.. Accordingly, the effects of acute intraperitoneal post-treatment with selective FP antagonist AL-8810 were studied in wildtype (WT) and FP receptor knockout (FP-/-) mice after controlled cortical impact (CCI). Neurological impairments were evaluated using neurological deficit scores (NDS) and the grip strength test. Cortical lesions and overall brain pathology were assessed using immunohistochemistry.. Morphological analyses of cerebral vasculature and anastomoses revealed no differences between WT and FP-/- mice. CCI produced cortical lesions characterized by cavitation, neuronal loss, and hematoma with a volume of 20.0 ± 1.0 mm(3) and significant hippocampal swelling (146.5 ± 7.4% of contralateral) compared with sham (P < 0.05). Post-treatment with AL-8810 (1 to 10 mg/kg) had no significant effect on cortical lesions, which suggests the irreversible effect of primary CCI injury, but significantly reduced hippocampal swelling to a size not significantly different from the sham group. Post-treatment with AL-8810 at a dose of 10 mg/kg significantly improved NDS at 24 and 48 hours after CCI (P < 0.001 and P < 0.01, respectively). In the AL-8810 group, CCI-induced decrease in grip strength was three-fold (2.93 ± 1.71) less and significantly different than in the saline-treated group. The FP-/- mice had significantly less hippocampal swelling, but not NDS, compared with WT mice. In addition, immunohistochemistry showed that pharmacologic blockade and genetic deletion of FP receptor led to attenuation of CCI-induced gliosis and microglial activation in selected brain regions.. This study provides, for the first time, demonstration of the unique role of the FP receptor as a potential target for disease-modifying CNS drugs for treatment of acute traumatic injury.

Topics: Animals; Brain; Brain Injuries; Dinoprost; Disease Models, Animal; Immunohistochemistry; Male; Maze Learning; Mice; Mice, Knockout; Neuroprotective Agents; Receptors, Prostaglandin

COX-2 and prostaglandins (PGs) might play important roles in epilepsy. In kainic acid-induced seizures, the brain largely increases PGD(2), first from COX-1 and later COX-2-induced PGF(2alpha). Pre-treatment with COX-2 inhibitors such as indomethacin, nimesulide, and celecoxib is known to aggravate kainic acid (KA)-induced seizure activity. However it is not known whether the proconvulsant effect of those non-steroidal anti-inflammatory drugs (NSAIDs) is due to changes in endogenous prostaglandins (PGs), or what types of PGs are involved. The purpose of this study was to determine the effect of intracisternally administered PGs on KA-induced seizures aggravated by pre- or post-treatment with COX-2 inhibitors. Systemic KA injection (10 mg/kg i.p.) in mice evoked mild seizure activity within 15 min. PGs were administrated intracisternally 20 min prior to KA administration. COX inhibitors (indomethacin, nimesulide, and ketoprofen, 10 mg/kg i.p.) were injected 1 h before or 15 min after KA. An additional COX-2 inhibitor, celecoxib, was administered orally. Intracisternally administered PGF(2alpha) (700 ng), but not PGD(2) (700 ng) or PGE(2) (700 ng) completely alleviated KA-induced seizures potentiated by COX-2 inhibitors, and also reduced KA-induced hippocampal neuronal death aggravated by indomethacin. PGF(2alpha) alone did not affect KA-induced seizures. However, an FP receptor antagonist, AL 8810 (10 or 50 ng) which is an 11beta-fluoro analogue of PGF(2alpha) potentiated KA-induced seizure activity dose-dependently. In summary, pre- or post-treatment with COX-2 inhibitors aggravates KA-induced seizures, which suggests to change the endogenous PGF(2alpha). Seizure-induced PGF(2alpha) might act as an endogenous anticonvulsant through FP receptors.

Topics: Analysis of Variance; Animals; Cell Survival; Cyclooxygenase Inhibitors; Dinoprost; Disease Models, Animal; Dose-Response Relationship, Drug; Drug Interactions; Electroencephalography; Kainic Acid; Male; Mice; Mice, Inbred ICR; Receptors, Prostaglandin; Seizures