8-(3-chlorostyryl)caffeine 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 present work showed the effects of 8-(-3-chlorostyryl)-caffeine (CSC), an A(2A) receptors antagonist and MAO B inhibitor, on behavior and biochemical alterations in 6-OHDA-lesioned rats. Male Wistar rats (280 g) were injected with CSC (1 and 5 mg/kg, i.p.) alone or combined with l-DOPA (50 mg/kg+benserazide 12.5 mg/kg), starting 6 days after the striatal 6-OHDA lesions, and once daily for the next 7 days. Fourteen days after the 6-OHDA lesion (and 24 h after CSC or vehicle), the number of net body rotations/h (after the apomorphine challenge) was recorded and, at the next day, animals were sacrificed. The ipsilateral striatum was used for HPLC measurements of monoamines and amino acids or for determination of nitrite contents and lipid peroxidation. Results showed that the increase in body rotation, induced by the 6-OHDA lesion, after the apomorphine challenge, was significantly and dose-dependently reversed by CSC. Furthermore, the decreased striatal levels of DA and metabolites, in the 6-OHDA-lesioned rats, were reversed after CSC treatment, and these effects were potentiated after the combination with l-DOPA. Similar results were observed with NE, 5-HT and 5-HIAA. While glutamate and GABA were increased in the 6-OHDA-lesioned group, CSC alone or mainly combined with l-DOPA reversed these alterations. In addition, the CSC treatment of 6-OHDA-lesioned rats reversed the increased nitrite formation and lipid peroxidation induced by 6-OHDA. In conclusion, CSC by means of its dual action as A(2A) antagonist and MAO-B inhibitor reversed behavior and biochemical alterations, observed in the 6-OHDA-lesioned rats, pointing out to its potential benefit for the treatment of PD.

Topics: Adenosine A2 Receptor Agonists; Animals; Behavior, Animal; Biogenic Monoamines; Caffeine; Disease Models, Animal; Dose-Response Relationship, Drug; Hydroxyindoleacetic Acid; Lipid Peroxidation; Male; Monoamine Oxidase; Monoamine Oxidase Inhibitors; Neostriatum; Neuroprotective Agents; Nitrites; Norepinephrine; Oxidopamine; Parkinson Disease; Rats; Rats, Wistar; Receptors, Adenosine A2; Rotation; Serotonin

In the present study, we sought to evaluate whether the antiadrenergic action of adenosine in the heart is altered in pressure overload hypertrophy produced in rats by suprarenal aortic banding. Epicardial and coronary effluent adenosine and inosine concentrations and release were significantly elevated in compensated pressure overload hypertrophy but not in hearts with left ventricular failure. In pressure overload hearts, the contractile response to beta-adrenergic stimulation was less inhibited by incremental concentrations of either adenosine or the selective A(1) receptor agonist chloro-N:(6)-cyclopentyl adenosine than in controls. Furthermore, the extent of desensitization to the antiadrenergic actions of adenosine in pressure overload hypertrophy appeared to be proportional to the extent of chamber dilation and dysfunction. A 60-minute infusion of adenosine produced a sustained antiadrenergic effect that lasted up to 45 minutes after the infusion was terminated in both controls and hearts with compensated hypertrophy. This effect was not observed in the decompensated left ventricular failure group. Subsequent infusion with adenosine of the A(2A) receptor antagonist 8-(3-chlorostyryl)-caffeine to counteract the proadrenergic effect of A(2A) receptor stimulation did not alter the decreased sensitivity to the antiadrenergic actions of adenosine in hypertrophied hearts. Finally, isolated myocytes from hypertrophied hearts demonstrated a decreased ability to suppress isoproterenol-elicited increases in [Ca(2+)](i) transients in the presence of adenosine and the A(2A) receptor antagonist compared with myocytes from control hearts. Myocardial adenosine concentrations increase during the compensated phase of pressure overload hypertrophy but then decrease when there is evidence of decompensation. The antiadrenergic actions of adenosine transduced via the myocardial A(1) receptor are diminished in pressure overload hypertrophied hearts. These factors may render these hearts more vulnerable to the detrimental effects of chronically increased sympathetic activity.

Topics: Adenosine; Adrenergic Antagonists; Adrenergic beta-Agonists; Animals; Blood Pressure; Body Weight; Caffeine; Calcium; Cardiomegaly; Cells, Cultured; Coronary Circulation; Disease Models, Animal; Echocardiography; In Vitro Techniques; Inosine; Isoproterenol; Male; Myocardial Contraction; Myocardium; Organ Size; Perfusion; Purinergic P1 Receptor Agonists; Purinergic P1 Receptor Antagonists; Rats; Rats, Sprague-Dawley

Cerebral ischemia of 5 min duration was induced in unanesthetized Mongolian gerbils by bilateral occlusion of the carotid arteries. The extent of ischemic injury was assessed behaviorally by measuring the increases in locomotor activity following ischemia and by a histopathological assessment of the extent of CA1 hippocampal pyramidal cell injury and loss 5 days after ischemia. The A2a adenosine receptor selective antagonists 8-(3-chlorostyryl) caffeine (CSC; 0.1 mg/kg i.p.) and 4-amino-1-phenyl[1,2,4]-triazolo[4,3-a] quinoxaline (CP 66,713; 0.1 mg/kg i.p.) reduced the extent of ischemia-induced injury. An A1 selective receptor antagonist, 8-cyclopentyl-1,3-dipropylxanthine (DPCPX; 1.0 mg/kg i.p.), enhanced ischemia-evoked injury. These results suggest that adenosine A2a receptor antagonists may be useful for the prevention of cerebral injuries resulting from stroke or cardiac arrest.

Topics: Animals; Behavior, Animal; Caffeine; Carotid Arteries; Cerebral Cortex; Cerebrovascular Disorders; Dimethyl Sulfoxide; Disease Models, Animal; Dose-Response Relationship, Drug; Gerbillinae; Locomotion; Male; Purinergic P1 Receptor Antagonists; Pyrazines; Reperfusion Injury; Xanthines

Despite significant progress in understanding of the potential of adenosine A1 receptor-based therapies in treatment of cerebral ischemia and stroke, very little is known about the effect of selective stimulation of adenosine A2A receptors on the outcome of a cerebrovascular arrest. In view of a major role played by adenosine A2 receptors in the regulation of cerebral blood flow, we have investigated the effect of both acute and chronic administration of the selective adenosine receptor agonist 2-[(2-aminoethylamino)-carbonylethylphenylethylamino]-5'-N- ethylcarboxoamidoadenosine (APEC) and antagonist 8-(3-chlorostyryl)caffeine (CSC) on the outcome of 10 min ischemia in gerbils. Acute treatment with APEC improved recovery of postischemic blood flow and survival without affecting neuronal preservation in the hippocampus. Acute treatment with CSC had no effect on the cerebral blood flow but resulted in a very significant protection of hippocampal neurons. Significant improvement of survival was present during the initial 10 days postischemia. Due to subsequent deaths of animals treated acutely with CSC, the end-point mortality (14 days postischemia) in this group did not differ statistically from that seen in the controls. It is, however, possible that the late mortality in the acute CSC group was caused by the systemic effects of brain ischemia that are not subject to the treatment with this drug. Chronic treatment with APEC resulted in a statistically significant improvement in all studied measures. Although chronic treatment with CSC improved postischemic blood flow, its effect on neuronal preservation was minimal and statistically insignificant. Mortality remained unaffected. The results indicate that the acute treatment with adenosine A2A receptor antagonists may have a limited value in treatment of global ischemia. However, since administered CSC has no effect on the reestablishment of postischemic blood flow, treatment of stroke with adenosine A2A receptor antagonists may not be advisable. Additional studies are necessary to elucidate whether chronically administered drugs acting at adenosine A2 receptors may be useful in treatment of stroke and other neurodegenerative disorders.

Topics: Adenosine; Animals; Brain Ischemia; Caffeine; Cell Survival; Cerebrovascular Circulation; Cerebrovascular Disorders; Disease Models, Animal; Female; Gerbillinae; Hippocampus; Laser-Doppler Flowmetry; Neurons; Phenethylamines; Purinergic P1 Receptor Antagonists; Receptors, Purinergic P1; Treatment Outcome