Regulation of hepatic EAAT-2 glutamate transporter expression in human liver cholestasis

Figure 1 Characterization of Na⁺-dependent D-[³H]-aspartate uptake in HepG2 hepatoblastoma cells. A: D-[³H]-aspartate (30 nmol/L) uptake was measured after 6 min incubation with intact HepG2 cells treated with vehicle (controls), t-PDC (1 mmol/L), TBOA (1 mmol/L) or DHK (100 μmol/L) for 15 min. Data shown are mean ± SE of at least three independent experiments performed in quadruplicate. ^bP < 0.001 as compared to control (paired student t-test); B: Saturation isotherms for D-[³H]-aspartate (1-100 μmol/L) uptake measured in HepG2 cells. Data shown correspond to mean values with SE from quadruplicate measures on four independent series; C: Immunofluorescence detection of EAAT2 transporter on HepG2 cells using specific polyclonal antibody. Immunoreactivity was visualized using a FITC-conjugated rabbit anti-goat antibody, and cell nuclei appear in blue (DNA staining with DAPI) (original magnification × 200). t-PDC: L-trans-pyrrolidine-2,4-dicarboxylic acid; TBOA: Threo-beta-benzyloxyaspartate; DHK: Dihydrokainic acid; DAPI: 4’,6-diamidino-2-phenylindole.