Sa1024 Predictors of Insulin Resistance Using Direct Measurement in At-Risk Latinos With and Without Hepatitis C (HCV) Infection

Abstract

Background:Host cytoskeletal proteins of the ezrin-moesin-radixin (EMR) family have been shown to modulate single stranded RNA virus (HIV) infection through regulating stable microtubule formation. Previous studies indicate that antibody engagement of CD81, a key receptor regulating HCV infection, induces ezrin phosphorylation. Here we tested the role of EMR proteins in regulating HCV infection and explored their targeting for therapeutic potential. Methods: Gene regulation methods including real-time quantitative PCR, western blot and fluorescent microscopy analysis were used for experimental analysis. Results: We show that proteins of the EMR family differentially regulate HCV infection in the J6/JFH1/Huh7.5 cell system. Moesin and radixin, but not ezrin, expression were decreased in HCV infected compared to uninfected Huh7.5 cells and this was associated with a significant increase in stable microtubules. Over-expression of moesin or radixin or knockdown of ezrin significantly reduced HCV protein expression. In contrast, transient knockdown of moesin or radixin augmented HCV infection. We found that the infectious HCV virus (J6/ JFH-1) induces rapid ezrin and radixin phosphorylation via spleen tyrosine kinase (SYK). SYK phosphorylation contributed to HCV infection because HCV replication was inhibited by a SYK inhibitor (BAY 61-3606). Making use of the Con1 HCV replicon system, we tested the effect of EMR proteins on HCV replication. We found that transient knockdown of moesin increased HCV RNA expression while over-expression of EMR showed no significant effect on HCV replication. Finally, we designed and evaluated the therapeutic potential of a novel moesin-radixin peptide that exhibited anti-HCV properties by blocking HCV infection but not HCV replication. Conclusion: In conclusion, our novel data demonstrate that EMR proteins modulate HCV infection and identify EMR as possible therapeutic targets to inhibit HCV entry. (supported by NIHAAA)