Serine palmitoyltransferase inhibitor suppresses HCV replication in a mouse model
Section snippets
Materials and methods
Inhibition assay of replication in HCV replicon cells by myriocin. Myriocin (Sigma, St. Louis, MO, USA) was added in the growth medium of HCV subgenomic replicon cells FLR3-1 (genotype 1b, Con-1; [12]) at a final concentration of 0.2, 1.0, 3.9, 15.6 or 62.5 nM. After 72 h incubation, we performed luciferase assays using the Bright-Glo luciferase assay kit (Promega, Madison, WI, USA).
Measurement of cell viability using the Tetra Color One (WST-8) assay. Myriocin was added to FLR3-1 cells as
Anti-HCV effect of the SPT inhibitor, myriocin
We examined the anti-HCV effect and cell toxicity of myriocin in the HCV subgenomic replicon cells FLR3-1. Luciferase activity was greatly decreased by myriocin in a dose-dependent manner without affecting cell viability (Fig. 2A) or cell growth (data not shown). The maximum inhibition rate was about 80% in the presence of over 62.5 nM myriocin (Fig. 2A), while the 50% inhibitory concentration (IC50) was about 5.8 nM (Table 1). Reduction of NS3 protein, which plays a key role in HCV replication,
Discussion
In the present study, the SPT inhibitor myriocin was shown to inhibit replication of intact HCV in vivo. We initially investigated the fundamental inhibitory effects and mechanisms of myriocin against replication of the HCV replicon and found that inhibition of HCV replicon replication is compatible with a decrease in ceramide and sphingomyelin in the cells. The inhibitory effect of myriocin on replication of the HCV replicon differed slightly from that on de novo biosynthesis of ceramide and
Acknowledgments
The authors thank PhenixBio Co., Ltd. for maintenance of the humanized-liver mice. We thank for I. Kusanagi for technical assistance and F. Ford for editorial assistance. This study was supported by grants from the Ministry of Education, Culture, Sports, Science, and Technology of Japan; the Program for Promotion of Fundamental Studies in Health Sciences of the National Institute of Biomedical Innovation of Japan; and the Ministry of Health, Labor and Welfare of Japan.
References (19)
- et al.
A dose-ranging study of pegylated interferon alfa-2b and ribavirin in chronic hepatitis C. The Hepatitis C Intervention Therapy Group
Hepatology
(2000) - et al.
Efficacy and safety of pegylated (40-kd) interferon alpha-2a compared with interferon alpha-2a in noncirrhotic patients with chronic hepatitis C
Hepatology
(2001) Recent advances in the molecular biology of hepatitis C virus
J. Mol. Biol.
(2001)- et al.
Characterization of the hepatitis C virus RNA replication complex associated with lipid rafts
Virology
(2004) - et al.
Serine palmitoyltransferase is the primary target of a sphingosine-like immunosuppressant, ISP-1/myriocin
Biochem. Biophys. Res. Commun.
(1995) - et al.
Near completely humanized liver in mice shows human-type metabolic responses to drugs
Am. J. Pathol.
(2004) - et al.
Real-time detection system for quantification of hepatitis C virus genome
Gastroenterology
(1999) - et al.
Interrelationship of blood transfusion, non-A, non-B hepatitis and hepatocellular carcinoma: analysis by detection of antibody to hepatitis C virus
Hepatology
(1990) - et al.
Hepatitis C virus infection is associated with the development of hepatocellular carcinoma
Proc. Natl. Acad. Sci. USA
(1990)