[Hepatitis C virus core protein upregulates the transcription of PCK1 through FOXO1/PGC-1alpha pathway]

We analyzed the effect of the stable expressed Hepatitis C virus core protein on PCK1 mRNA expression level and the molecular mechanisms involved in Huh7-lunet cells.

A retroviral vector mediated mammalian cell expression cell line of the HCV core protein was constructed. The mRNA and protein levels of PCK1, FOXO1 and PGC-1alpha were analyzed by Real-time PCR and luciferase assay in Huh7-lunet-core cells.

HCV CORE upregulated the mRNA levels of PCK1 significantly. Both the mRNA and protein levels of FOXO1 were not affected in Huh7-lunet-core cells, whereas a decreased phosphorylation status of FOXO1 was exhibited. Moreover, activation of FOXO1 by HCV CORE was detected. Further, the mRNA level of PGC-1alpha was found to be significantly elevated in Huh7-lunet-core cells.

Our results revealed for the first time that HCV core protein expression-mediated FOXO1 activation and the increased PGC-1alpha leaded to the elevation of PCK1 at the mRNA level, which suggesting the immoderate gluconeogenesis in HCV-infected hepatocytes. Our findings contributed to the understanding of the molecular mechanisms of HCV-related insulin resistance and provided potential new clues for the prevention and therapy of diabetes.