Fig. 2

Ectopic NTCP is induced by HMM treatment. A RT-qPCR of NTCP mRNA levels in HepG2 and HepG2-NTCP cells after being culturing with D10/2%DMSO medium or HMM for 24 or 72 h. Untreated, D10 medium without 2% DMSO. B Immunofluorescence images of NTCP protein expression in HepG2-NTCP or parental HepG2 cells after being cultured in indicated medium for 24, 48, or 72 h. Primary hepatocyte maintenance medium (PMM) contains 10% FBS, 1% Penicillin/Streptomycin, 0.17 μM of human Insulin, 10 μM of hydrocortisone 21-hemisuccinate and 1.8% DMSO [31]. C HepG2-NTCP cells were left uninfected, or pretreated with HMM or PMM for 16 h before inoculating with HBV (500 GE/cell) in PMM containing 4% PEG 8000 for 24 h. The HBV inocula were removed and cells were maintained in PMM for 7 days. D Expression of NTCP, HBc (red) and HBs (green) in different HepG2-NTCP clones at 10 d post-HBV infection. Clone 12 was used in most experiments in this study. E GFP expression in HepG2-NTCP cells transfected with GFP-encoding plasmids under the control of either a CMV-IE promoter or an EF1α promoter and subsequently cultured in indicated medium for indicated times. Scale bar  =  50 μm