Table II. Regulatory effect of TPA and ionomycin on the expression of rat AGP-CAT construct in transiently transfected HepG2 cells.

HepG2 cells in 6-well cluster plates were transformed with a mixture of plasmid DNAs (18 μg of pAGP(3×DRE)-140-CAT or pAGP(140)-CAT and 2 μg of pIE-MUP/ml) and subsequently cultured as described in the legend to Fig. 3. The treatments with the indicated components were carried out for 8 h in serum-free MEM containing 0.1 μM dexamethasone. The following concentrations were used where not indicated: ionomycin, 0.35 μM; IL-6, 100 units/ml; IL-1, 250 units/ml. The chloramphenicol acetyltransferase activities in the cell extract were normalized to the amount of MUP secreted into the medium of the same cells during the final 24 h culture period. Mean values and standard deviations of three separate but identically treated wells are shown. Values for cells transfected with pAGP(140)-CAT represent the average of duplicate wells.

Treatment	Specific chloramphenicol acetyltransferase activity
	% conversion/h × ng MUP
pAGP(3×DRE)-140-CAT
No addition	0.10 ± 0.02
TPA
1.50 μM	0.44 ± 0.02
0.50 μM	0.40 ± 0.01
0.15 μM	0.32 ± 0.03
0.05 μM	0.21 ± 0.02
Ionomycin	0.13 ± 0.05
TPA (0.5 μM) + ionomycin	0.37 ± 0.02
IL-6	1.37 ± 0.12
IL-6 + TPA (0.5 μM)	4.08 ± 0.25
IL-6 + TPA (0.5 μM) + ionomycin	4.46 ± 0.84
IL-1α	2.88 ± 0.35
IL-1α + TPA (0.5 μM)	1.15 ± 0.10
IL-1α + TPA (0.5 μM) + ionomycin	1.26 ± 0.05
IL-1α + IL-6	9.93 ± 1.08
IL-1α + IL-6 + TPA (0.5 μM)	5.97 ± 0.40
IL-1α + IL-6 + TPA (0.5 μM) + ionomycin	5.63 ± 0.65
pAGP(140)-CAT
No addition	0.05
TPA (0.5 μM)	0.02
IL-6	0.09
IL-6 + TPA	0.07
IL-1α	0.04
IL-1α + IL-6	0.10