cvt-6883 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

Remodeling occurs after myocardial infarction (MI), leading to fibrosis, dysfunction, and ventricular tachycardias (VTs). Adenosine via the A2B adenosine receptor (A2BAdoR) has been implicated in promoting fibrosis.. To determine the effects of GS-6201, a potent antagonist of the A2BAdoR, on arrhythmogenic and functional cardiac remodeling after MI.. Rats underwent ischemia-reperfusion MI and were randomized into 4 groups: control (treated with vehicle), angiotensin-converting enzyme inhibitor (treated with enalapril 1 day after MI), GS-6201-1d (treated with GS-6201 1 day after MI), GS-6201-1w (treated with GS-6201 administered 1 week after MI) . Echocardiography was performed at baseline and 1 and 5 weeks after MI. Optical mapping, VT inducibility, and histologic analysis were conducted at follow-up.. Treatment with the angiotensin-converting enzyme inhibitor improved ejection fraction (57.8% ± 2.5% vs 43.3% ± 1.7% in control; P < .01), but had no effect on VT inducibility. Treatment with GS-6201 improved ejection fraction (55.6% ± 2.6% vs 43.3% ± 1.7% in control; P < .01) and decreased VT inducibility (9.1% vs 68.4% in control; P < .05). Conduction velocities were significantly higher at border and infarct zones in hearts of rats treated with GS-6201 than in those of other groups. The conduction heterogeneity index was also significantly lower in hearts of rats treated with GS-6201. Histologic analysis showed that while both GS-6201 and enalapril decreased fibrosis in the noninfarct zone, only GS-6201 reduced the heterogeneity of fibrosis at the border, which is consistent with its effect on VT reduction.. Treatment with an A2BAdoR antagonist at 1 week results in the improvement in cardiac function and decreased substrate for VT. The inhibition of fibrogenesis by A2BAdoR antagonists may be a new target for the prevention of adverse remodeling after MI.

Topics: Adenosine A2 Receptor Antagonists; Animals; Disease Models, Animal; Electrocardiography; Follow-Up Studies; Heart Conduction System; Male; Myocardial Infarction; Purines; Pyrazoles; Rats; Rats, Sprague-Dawley; Stroke Volume; Tachycardia, Ventricular; Time Factors; Treatment Outcome; Ventricular Dysfunction, Left; Ventricular Remodeling

Chronic obstructive pulmonary disease (COPD) is the fourth leading cause of death worldwide. The development of pulmonary hypertension (PH) in patients with COPD is strongly associated with increased mortality. Chronic inflammation and changes to the lung extracellular matrix (ECM) have been implicated in the pathogenesis of COPD, yet the mechanisms that lead to PH secondary to COPD remain unknown. Our experiments using human lung tissue show increased expression levels of the adenosine A2B receptor (ADORA2B) and a heightened deposition of hyaluronan (HA; a component of the ECM) in remodeled vessels of patients with PH associated with COPD. We also demonstrate that the expression of HA synthase 2 correlates with mean pulmonary arterial pressures in patients with COPD, with and without a secondary diagnosis of PH. Using an animal model of airspace enlargement and PH, we show that the blockade of ADORA2B is able to attenuate the development of a PH phenotype that correlates with reduced levels of HA deposition in the vessels and the down-regulation of genes involved in the synthesis of HA.

Topics: Adenosine A2 Receptor Antagonists; Adenosine Deaminase; Aged; Animals; Collagen Type I; Collagen Type I, alpha 1 Chain; Disease Models, Animal; Female; Humans; Hyaluronic Acid; Hypertension, Pulmonary; Lung; Male; Mice; Mice, Knockout; Middle Aged; Pulmonary Disease, Chronic Obstructive; Purines; Pyrazoles; Receptor, Adenosine A2B; RNA, Messenger

Adenosine (Ado) is released in response to tissue injury, promotes hyperemia, and modulates inflammation. The proinflammatory effects of Ado, which are mediated by the A(2B) Ado receptor (AdoR), may exacerbate tissue damage. We hypothesized that selective blockade of the A(2B) AdoR with 3-ethyl-1-propyl-8-(1-(3-trifluoromethylbenzyl)-1H-pyrazol-4-yl)-3,7-dihydropurine-2,6-dione (GS-6201) during acute myocardial infarction (AMI) would reduce adverse cardiac remodeling. Male ICR mice underwent coronary artery ligation or sham surgery (n = 10-12 per group). The selective A(2B) AdoR antagonist GS-6201 (4 mg/kg) was given intraperitoneally twice daily starting immediately after surgery and continuing for 14 days. Transthoracic echocardiography was performed before surgery and after 7, 14, and 28 days. A subgroup of mice was killed 72 h after surgery, and the activity of caspase-1, a key proinflammatory mediator, was measured in the cardiac tissue. All sham-operated mice were alive at 4 weeks, whereas 50% of vehicle-treated mice and 75% of GS-6201-treated mice were alive at 4 weeks after surgery. Compared with vehicle, treatment with GS-6201 prevented caspase-1 activation in the heart at 72 h after AMI (P < 0.001) and significantly limited the increase in left ventricular (LV) end-diastolic diameter by 40% (P < 0.001), the decrease in LV ejection fraction by 18% (P < 0.01) and the changes in the myocardial performance index by 88% (P < 0.001) at 28 days after AMI. Selective blockade of A(2B) AdoR with GS-6201 reduces caspase-1 activity in the heart and leads to a more favorable cardiac remodeling after AMI in the mouse.

Topics: Adenosine A2 Receptor Antagonists; Animals; Caspase 1; Disease Models, Animal; Drug Administration Schedule; Echocardiography; Enzyme Activation; Hemodynamics; Injections, Intraperitoneal; Male; Mice; Mice, Inbred ICR; Myocardial Infarction; Purines; Pyrazoles; Receptor, Adenosine A2B; Treatment Outcome; Ventricular Remodeling

It has been previously proposed that adenosine plays an important role in the pathogenesis of asthma. The proposed mechanism of action for nucleoside adenosine is to activate A(2B) adenosine receptors (AR) and to indirectly modulate levels of mediators in the lung. In vivo data supporting the role of A(2B) AR in airway reactivity and inflammation in allergic animal models are lacking. The present study describes the effects of a selective A(2B) AR antagonist, CVT-6883 [3-ethyl-1-propyl-8-[1-(3-trifluoromethylbenzyl)-1H-pyrazol-4-yl]-3,7-dihydropurine-2,6-dione], on airway reactivity and inflammation in an allergic mouse model of asthma. Mice were sensitized with ragweed (i.p.) on days 1 and 6 and challenged with 0.5% ragweed on days 11, 12, and 13. On day 14, airway reactivity to 5'-N-ethylcarboxamidoadenosine (NECA), AMP, or allergen challenge was measured in terms of enhanced pause (Penh). Aerosolized NECA elicited concentration-dependent increases in Penh, which were significantly attenuated by CVT-6883 (0.4, 1.0, or 2.5 mg/kg i.p.). Aerosolized AMP elicited significant increases in Penh in sensitized mice, and the effect was significantly attenuated by either CVT-6883 (1 mg/kg i.p.) or montelukast (1 mg/kg i.p.). Allergen challenge induced late allergic response in sensitized mice, which was inhibited by CVT-6883 (1 mg/kg i.p.). Allergen challenge also increased the number of cells in bronchoalveolar lavage fluid obtained from sensitized mice, and that was reduced by either CVT-6883 (6 mg/ml aerosolization for 5 min) or theophylline (36 mg/ml aerosolization for 5 min). These results suggest that A(2B)AR antagonism plays an important role in inhibition of airway reactivity and inflammation in this model of allergic asthma.

Topics: Adenosine; Adenosine A2 Receptor Antagonists; Adenosine Monophosphate; Adenosine-5'-(N-ethylcarboxamide); Administration, Inhalation; Aerosols; Allergens; Animals; Asthma; Bronchoalveolar Lavage Fluid; Bronchoconstriction; Bronchodilator Agents; Disease Models, Animal; Dose-Response Relationship, Drug; Mice; Mice, Inbred Strains; Plethysmography; Purines; Pyrazoles