acipimox 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

Obstructive sleep apnea (OSA) is associated with insulin resistance, glucose intolerance, and type 2 diabetes. Causal mechanisms mediating this association are not well defined; however, augmented lipolysis in adipose might be involved. Here, we investigated the effect of acipimox treatment (lipolysis inhibitor) on glucose tolerance and insulin sensitivity in mice exposed to intermittent hypoxia (IH). C57BL6/J mice were exposed for 14 days to IH or control conditions. IH was created by decreasing the fraction of inspired oxygen from 20.9 to 6.5%, 60 times/h. Control exposure was air (fraction of inspired oxygen, 20.9%) delivered at an identical flow rate. Acipimox was provided in drinking water (0.5 g/ml) during exposures. After exposures, intraperitoneal insulin (0.5 IU/kg) and glucose (1 g/kg) tolerance tests were performed, and primary adipocytes were isolated for lipolysis experiments. IH elevated fasting glucose by 51% and worsened glucose tolerance and insulin sensitivity by 33 and 102%, respectively. In parallel, IH increased spontaneous lipolysis by 264%, and reduced epididymal fat mass by 15% and adipocyte size by 8%. Acipimox treatment prevented IH-induced lipolysis and increased epididymal fat mass and adipocyte size by 19 and 10%, respectively. Acipimox fully prevented IH-induced impairments in fasting glycemia, glucose tolerance, and insulin sensitivity. For all reported results, P less than 0.05 was considered significant. Augmented lipolysis contributes to insulin resistance and glucose intolerance observed in mice exposed to IH. Acipimox treatment ameliorated the metabolic consequences of IH and might represent a novel treatment option for patients with obstructive sleep apnea.

Topics: Adipocytes; Adiposity; Animals; Diabetes Mellitus, Experimental; Disease Models, Animal; Fatty Acids; Gene Expression Regulation; Glucose; Hypoxia; Insulin; Lipolysis; Male; Mice, Inbred C57BL; Phenotype; Pyrazines; Signal Transduction; Sleep Apnea, Obstructive

Spontaneously hypertensive heart failure rats (SHHF) appear to constitute an original model for analyzing the evolution of the metabolic syndrome towards heart failure. This study aimed to characterize early cardiac dysfunction and remodeling in SHHF rats: (1) as compared with spontaneously hypertensive rats (SHR) and with a control group of Kyoto rats (WKY), and (2) by using the 3-dimensional quantitative analysis provided by acipimox-enhanced positron emission tomography (PET) with (18)F-fluorodesoxyglucose (FDG). Left ventricular (LV) ejection fraction (EF) and volume were quantified by automatic software on the FDG-PET images recorded in SHR (n = 20), SHHF (n = 18) and WKY-rats (n = 19) at ages 3 or 10 months old. Arterial blood pressure was determined by cardiac catheterization and cardiac fibrosis was quantified after sacrifice. Blood pressure was similarly elevated in SHR and SHHF rats (respective systolic blood pressures at 10-months: 199 ± 39 vs. 205 ± 2 mmHg), but SHHF rats had higher body mass than SHR rats (at 10-months, 630 ± 36 vs. 413 ± 27 g, p < 0.05) and higher blood levels of cholesterol and of triglycerides. At 3 months, cardiac parameters did not show significant differences between groups but at 10-months, SHHF and SHR rats exhibited an enhancement in myocardial mass and fibrosis associated with a clear decline in LV-EF (SHHF: 46 ± 6 %; SHR: 47 ± 5 %) as compared with WKY (56 ± 6 %, p < 0.01 for both comparisons). Cardiac remodeling of SHHF rats was clearly observable by FDG-PET from the age of 10-months, but in a similar way to that observed for SHR rats, suggesting a predominant role of hypertension.

Topics: Animals; Arterial Pressure; Cardiac Catheterization; Disease Models, Animal; Fibrosis; Fluorodeoxyglucose F18; Heart Failure; Heart Ventricles; Hypertension; Imaging, Three-Dimensional; Lipid Metabolism; Male; Positron-Emission Tomography; Predictive Value of Tests; Pyrazines; Radiographic Image Interpretation, Computer-Assisted; Radiopharmaceuticals; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Stroke Volume; Time Factors; Ventricular Function, Left; Ventricular Remodeling

The rat myocardial infarction (MI) model is widely used to study left ventricular (LV) remodeling. In this study, acipimox-enhanced (18)F-Fluorodeoxyglucose (FDG) gated-positron emission tomography (PET) was assessed for characterizing and predicting early remodeling in the rat infarct model. Nineteen Wistar rats had surgical occlusion of the left anterior descending coronary artery and 7 were sham-operated. PET was scheduled 48 h and 2 weeks later for quantifying MI area and LV function. Segments with <50% of FDG uptake had histological evidence of MI (74 ± 9% decrease in parietal thickness, fibrosis development). At 48 h, MI area was large (>35% of LV) in 6 rats, moderate (15-35% of LV) in 8 rats, limited (<15% of LV) in 5 rats and absent in the 7 sham rats. LV remodeling, assessed through the 2 weeks increase in end-diastolic volume, increased between rats with limited, moderate and large MI (+72 ± 25, +109 ± 56, +190 ± 69 μl, respectively, P = 0.007). This 3-groups classification allowed predicting 44% of the 2 weeks increase in end-diastolic volume, and additional 34% were predicted by heart rate at 48 h. The acipimox-enhanced FDG gated-PET technique provides efficient characterization and prediction of early remodeling in the rat infarct model.

Topics: Animals; Diastole; Disease Models, Animal; Fluorodeoxyglucose F18; Hypolipidemic Agents; Male; Myocardial Infarction; Myocardium; Positron-Emission Tomography; Predictive Value of Tests; Pyrazines; Radiopharmaceuticals; Rats; Rats, Wistar; Time Factors; Ventricular Function, Left; Ventricular Remodeling