Novel Ranking System for Identifying Efficacious Anti-Influenza Virus PB2 Inhibitors

Through antigenic drift and shifts, influenza virus infections continue to be an annual cause of morbidity in healthy populations and of death among elderly and at-risk patients. The emergence of highly pathogenic avian influenza viruses such as H5N1 and H7N9 and the rapid spread of the swine-origin H1N1 influenza virus in 2009 demonstrate the continued need for effective therapeutic agents for influenza. While several neuraminidase inhibitors have been developed for the treatment of influenza virus infections, these have shown a limited window for treatment initiation, and resistant variants have been noted in the population. In addition, an older class of antiviral drugs for influenza, the adamantanes, are no longer recommended for treatment due to widespread resistance. There remains a need for new influenza therapeutic agents with improved efficacy as well as an expanded window for the initiation of treatment. Azaindole compounds targeting the influenza A virus PB2 protein and demonstrating excellent in vitro and in vivo properties have been identified. To evaluate the in vivo efficacy of these PB2 inhibitors, we utilized a mouse influenza A virus infection model. In addition to traditional endpoints, i.e., death, morbidity, and body weight loss, we measured lung function using whole-body plethysmography, and we used these data to develop a composite efficacy score that takes compound exposure into account. This model allowed the rapid identification and ranking of molecules relative to each other and to oseltamivir. The ability to identify compounds with enhanced preclinical properties provides an opportunity to develop more-effective treatments for influenza in patients.     

n-3 Fatty Acids Attenuate the Risk of Diabetes Associated With Elevated Serum Nonesterified Fatty Acids: The Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

Chronically high nonesterified fatty acids (NEFAs) are a marker of metabolic dysfunction and likely increase risk of type 2 diabetes. By comparison, n-3 fatty acids (FAs) have been shown to have various health benefits and may protect against disease development. In 5,697 participants of the Multi-Ethnic Study of Atherosclerosis (MESA), we examined whether serum levels of NEFAs relate to risk of incident type 2 diabetes and further tested whether plasma n-3 FA levels may interact with this relation.

RESEARCH DESIGN AND METHODS

NEFAs were measured in fasting serum using an enzymatic colorimetric assay and phospholipid n-3 FAs eicosapentaenoic and docosahexaenoic acids were determined in plasma through gas chromatography-flame ionization detection in 5,697 MESA participants. Cox proportional hazards regression evaluated the association between NEFA levels and incident type 2 diabetes and whether plasma n-3 FAs modified this association adjusting for age, sex, race, education, field center, smoking, and alcohol use.

RESULTS

Over a mean 11.4 years of the study period, higher diabetes incidence was found across successive NEFA quartiles (Q) (hazard ratio [95% CI]): Q1, 1.0; Q2, 1.35 (1.07, 1.71); Q3, 1.58 (1.24, 2.00); and Q4, 1.86 (1.45, 2.38) (P_trend < 0.001). A significant interaction of n-3 FAs on the relation between NEFAs and type 2 diabetes was also observed (P_interaction = 0.03). For individuals with lower n-3 levels (<75th percentile), a higher risk of type 2 diabetes was observed across quartiles of NEFAs: Q1, 1.0; Q2, 1.41 (1.07, 1.84); Q3, 1.77 (1.35, 2.31); and Q4, 2.18 (1.65, 2.88) (P_trend < 0.001). No significant associations were observed in those with n-3 FAs ≥75th percentile (P_trend = 0.54).

CONCLUSIONS

NEFAs are a marker of type 2 diabetes and may have clinical utility for detecting risk of its development. The modifying influence of n-3 FAs suggests a protective effect against disease and/or metabolic dysfunction related to NEFAs and requires further study.