Elsevier

Journal of Hepatology

Volume 61, Issue 4, October 2014, Pages 867-875
Journal of Hepatology

Research Article
Kinetics of the bile acid transporter and hepatitis B virus receptor Na+/taurocholate cotransporting polypeptide (NTCP) in hepatocytes

https://doi.org/10.1016/j.jhep.2014.05.018Get rights and content
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Background & Aims

The human liver bile acid transporter Na+/taurocholate cotransporting polypeptide (NTCP) has recently been identified as liver-specific receptor for infection of hepatitis B virus (HBV), which attaches via the myristoylated preS1 (myr-preS1) peptide domain of its large surface protein to NTCP. Since binding of the myr-preS1 peptide to NTCP is an initiating step of HBV infection, we investigated if this process interferes with the physiological bile acid transport function of NTCP.

Methods

HBV infection, myr-preS1 peptide binding, and bile acid transport assays were performed with primary Tupaia belangeri (PTH) and human (PHH) hepatocytes as well as NTCP-transfected human hepatoma HepG2 cells allowing regulated NTCP expression, in the presence of various bile acids, ezetimibe, and myr-preS1 peptides.

Results

The myr-preS1 peptide of HBV inhibited bile acid transport in PTH and PHH as well as in NTCP-expressing HEK293 and HepG2 cells. Inversely, HBV infection of PTH, PHH, and NTCP-transfected HepG2 cells was inhibited in a concentration-dependent manner by taurine and glycine conjugates of cholic acid and ursodeoxycholic acid as well as by ezetimibe. In NTCP-HepG2 cells and PTH, NTCP expression, NTCP transport function, myr-preS1 peptide binding, and HBV infection followed comparable kinetics.

Conclusions

Myr-preS1 virus binding to NTCP, necessary for productive HBV infection, interferes with the physiological bile acid transport function of NTCP. Therefore, HBV infection via NTCP may be lockable by NTCP substrates and NTCP-inhibiting drugs. This opens a completely new way for an efficient management of HBV infection by the use of NTCP-directed drugs.

Abbreviations

HBV
hepatitis B virus
WMHBV
woolly monkey hepatitis B virus
WHV
woodchuck hepatitis B virus
myr-preS1
N-terminal myristoylated and C-terminal strep-tagged preS1-lipopeptide from N-terminal amino acids 2-48 of the large surface protein of the respective HBV
myr-preS1-AX594
N-terminal myristoylated and C-terminal fluorescently labelled with dye Alexa594 from N-terminal amino acids 2-48 of the large surface protein of HBV
NTCP
Na+/taurocholate cotransporting polypeptide
SLC
solute carrier
ASBT
apical sodium-dependent bile acid transporter
SOAT
sodium-dependent organic anion transporter
DHEAS
dehydroepiandrosterone sulfate
TMD
transmembrane domain
TBHBV
tent-making bat HBV
PTH
primary Tupaia belangeri hepatocytes
PHH
primary human hepatocytes
HDV
hepatitis D virus
tNtcp
Tupaia belangeri Ntcp
HEK293
human embryonic kidney 293 cells
HepG2
human hepatocellular liver carcinoma cell line
DMEM
Dulbecco’s modified Eagle medium
FCS
fetal calf serum
TC
taurocholic acid
HGM
hepatocyte growth medium
HbeAg
hepatitis B e antigen
HbsAg
Hepatitis B surface antigen
GE
genome equivalents
ELISA
enzyme linked immunosorbent assay
PFA
paraformaldehyde
PBS
phosphate buffered saline
RT
room temperature
HbcAg
Hepatitis B core antigen
BSA
bovine serum albumin
PCC
Pearson’s correlation coefficient
GC
glycocholic acid
UDC
ursodeoxycholic acid
TUDC
tauroursodeoxycholic acid
GUDC
glycoursodeoxycholic acid
DHC
dehydrocholic acid
EZ
ezetimibe
TLC
taurolithocholic acid
OATP
organic anion transporting polypeptide
PBC
primary biliary cirrhosis
pp
post preparation
DOX
Doxycycline

Keywords

Hepatitis B virus
Receptor
Infection
NTCP
ASBT
SOAT
Therapy
Bile acids
Ezetimibe
Transport

Cited by (0)

These authors contributed equally to the work.

These authors share senior authorship.