Project description:Microarray data to compare the gene expression in HepG2-NTCP and Huh-106 cell lines Knowledge of HBV virus-host interactions is still limited. Here, we performed a genome-wide gain-of-function screen using weakly permissive Huh-106 cells to uncover novel HBV host factors.
Project description:In order to profile the transcriptomic change in NTCP-reconstituted HepG2 cells after the treatment with hepatocyte maintanace medium. HMM-pretreated HepG2/NTCP cells turned to be more susceptible to hepatitis B virus infection.
Project description:Aim: Hepatitis B virus (HBV) infection is one of the most serious global health problems. Our previous study revealed that an increase in the miR-6126 serum level over one year of pegylated interferon therapy predicted a decrease in hepatitis B surface (HBs) antigens. We aimed to clarify whether miR-6126 downregulated the expression level of sodium taurocholate cotransporting polypeptide (NTCP), a host cell receptor required for HBV entry. Methods: HepG2-NTCP and PXB cells were utilized to evaluate the expression level of NTCP after transfection with miR-6126. The protein expression level of NTCP was evaluated using Western blot analysis and immunostaining. The expression profile of messenger RNAs was evaluated using next-generation sequencing to search for direct targets of miR-6126.
Project description:Chronic hepatitis B, C and D virus (HBV, HCV, HDV) infections are leading causes of liver disease and cancer worldwide. Although these viruses differ markedly in their life cycle and genomic organization, they exclusively infect hepatocytes. Recently, the sodium taurocholate cotransporting polypeptide (NTCP) was identified as the first functional receptor for HBV and HDV. Here, we report that NTCP also facilitates HCV entry into human hepatocytes, by augmenting the bile acid-mediated repression of IFN-stimulated genes (ISGs), including IFITM2 and IFITM3, to increase the susceptibility of cells to HCV entry. Furthermore, an HBV-derived preS1 peptide, known to bind NTCP and to inhibit bile acid uptake and HBV infection, inhibits HCV entry by enhancing the expression of ISGs. Our study highlights NTCP as a novel player linking bile acid metabolism to the interferon response in hepatocytes and establishes a role for NTCP in the entry process of multiple hepatotropic viruses, via distinct mechanisms. Collectively, these findings enhance our understanding of hepatitis virus-host interactions and suggest NTCP as an attractive antiviral target for HBV/HCV co-infection. Transcriptome profiling by DNA microarray of Huh7.5.1 cells transduced to express NTCP.
Project description:Impaired bile flow (cholestasis) leads to transcriptional downregulation of the bile acid importer Na+-taurocholate co-transporting protein (NTCP) and to ER-stress in the liver. Here, we show that ER-stress induction strongly reduces NTCP protein expression, plasma membrane abundance and NTCP-mediated bile acid uptake. This is not controlled via a single specific UPR-pathway but mainly depends on the interaction of NTCP with calnexin, an ER chaperone involved in folding of N-glycosylated proteins. In mice, expression of both Ntcp and calnexin was reduced by thapsigargin-induced ER-stress. Calnexin downregulation in HepG2 and U2OS cells results in a decreased NTCP expression and a reduced bile acid uptake. Calreticulin shows partial functional redundancy with calnexin as it also interacts with NTCP, and is downregulated upon ER-stress, but specifically in calnexin-depleted cells. In conclusion, ER stress-induced downregulation of calnexin provides an additional mechanism to dampen NTCP-mediated bile acid uptake during cholestasis.
Project description:Hepatic cell lines serve as economical and reproducible alternatives for primary human hepatocytes. However, the utility of hepatic cell lines to examine bile acid homeostasis and cholestatic toxicity is limited due to abnormal expression and function of bile acid-metabolizing enzymes, transporters, and the absence of canalicular formation. Previously, addition of dexamethasone (DEX) and Matrigel™ overlay restored expression, localization, and function of the bile salt export pump (BSEP), and formation of bile canalicular-like structures in four-week cultures of HuH-7 human hepatoma cells. We present here an improved differentiation process with the addition of 0.5% dimethyl sulfoxide (DMSO), which increased the expression and function of the major bile acid uptake and efflux transporters, sodium taurocholate co-transporting polypeptide (NTCP) and BSEP, respectively, in two-week HuH-7 cell cultures. This in vitro model was further characterized for expression of cytochrome P450 enzymes (CYP450s), uridine 5'-diphospho-glucuronosyltransferase (UGTs) and transporters using quantitative targeted proteomics.
Project description:Chronic hepatitis B virus (HBV) infections remain a health burden affecting ~250 million people worldwide. Thus far, available interferon-alpha (IFNα)-based therapies have shown unsatisfactory cure rates, and alternative therapeutic molecules are still required. However, their development has been hampered because accessible cell models supporting relevant HBV replication and appropriate antiviral activity are lacking. Strategies that reverse epigenetic alterations offer a unique opportunity for cell reprogramming, which is valuable for restoring altered cellular functions in human cell lines. This work aimed to investigate the feasibility of converting HepG2 cells that stably overexpress the HBV entry receptor (sodium/taurocholate cotransporting polypeptide, NTCP) toward IFNα-responsive cells using epigenetic reprogramming. Herein, we showed that an epigenetic regimen with non-cytotoxic doses of the demethylating compound 5-azacytidine restored the anti-HBV action of IFNα in epigenetically reprogrammed HepG2-NTCP-C4 cells, named REP-HepG2-NTCP cells. Thus, a significant inhibition in HBV DNA levels was measured in REP-HepG2-NTCP cells after IFNα treatment. This inhibitory effect was associated with the enhancement of IFNα-mediated induction of critical interferon-stimulated genes (ISGs), which was limited in non-reprogrammed cells. In particular, our data indicated that re-expression of 2’-5’-oligoadenylate synthetase 1 (OAS1) and interferon regulatory factor 9 (IRF9) was the result of an epigenetically driven unmasking of these genes in reprogrammed cells. At last, we evaluated the therapeutic potential of the IFN analog CDM-3008 in REP-HepG2-NTCP cells and demonstrated the efficiency of this chemical compound in triggering ISG induction and HBV inhibition. In summary, this study shows that epigenetic reprogramming promotes the IFNα response in HBV-infected cells and is potentially attractive for cell-based experimental screening of IFN-like compounds.