Expression levels of HCV receptors were determined with real-time PCR, western blot, and flow cytometry. Results: HCVcc infection and

HCVpp entry were severely impaired in Selleckchem BAY 80-6946 DGAT1 knock-down and DGAT1 KO Huh-7.5 cells. The expression levels of known HCV receptors were examined, including CD81, SR-BI, claudin-1 (CLDN1), and occludin (OCLN). The surface expression of CLDN1 was nearly undetectable in DGAT1 knock-down and DGAT1 KO Huh-7.5 cells. The downregulation of CLDN1 expression in DGAT1-deficient cells was also observed in another human hepatoma cell line, HepG2. Moreover, we confirmed lack of CLDN1 in DGAT1-deficient cells by evaluating transepithelial electrical resistance. Finally, HCV infection was restored in DGAT1 knock-down Huh-7.5 cells by forced expression of CLDN1, suggesting

that downregulation of CLDN1 is a critical factor in the mechanism of impaired HCV entry in DGAT1-deficient cells. Conclusions: In the present study, we demonstrated that HCV entry is impaired in DGAT1-deficient cells by down-regulation LY2157299 in vitro of CLDN1. Thus DGAT1 is involved not only in HCV particle formation, but also in HCV entry to host cells. Disclosures: The following people have nothing to disclose: Pil Soo Sung, Asako Murayama, Wonseok Kang, Myung-Sun Kim, Seung Kew Yoon, Hyongbum Kim, Takanobu Kato, Eui-Cheol Shin Background & Aims: Hepatitis C virus (HCV) infection is a serious health problem leading to cirrhosis and hepatocellular MCE公司 carcinoma. HCV establishes a chronic infection in 80% of infected individuals, and not only viral but also host genetic factors are

assumed to partially explain the heterogeneity in HCV persistence or clearance. Although many researchers have mainly examined the effect of human leukocyte antigen (HLA) on viral persistence because of its critical role for the immune response against exposure to HCV, almost all of them have been proven to be inconclusive. On the other hand, a recent study revealed a strong association between HCV clearance and genetic variation in IL28B. In spite of these great efforts, not all genetic factors have been elucidated. Methods: To identify genetic markers associated with chronic HCV infection in the Japanese population, we conducted a case control study consisting of a genome-wide association study (GWAS) and two replication studies using a total of 36,1 12 Japanese individuals. At first, we analyzed 458,207 single nucleotide polymorphisms (SNPs) in 481 chronic HCV patients and 2,963 HCV-negative controls in a Japanese cohort. Next, we performed a replication study with an independent panel of 4,358 cases and 1,114 controls using multiplex-PCR-based Invader assays. We further confirmed the association in 1,379 cases and 25,81 7 controls. Results: In the GWAS phase, we found 25 SNPs that showed suggestive association (P < 1 x 1 0-5).