Macrophage- and adipocyte-specific induction of ApoE expression
by LXR and LXR ligands. (A) Differentiation-dependent
induction of apoE expression by LXR ligands. Undifferentiated
(monocyte) or differentiated (macrophage) THP-1 cells were incubated in
RPMI medium 1640 containing 10% (vol/vol) LPDS and 2.0 μg/ml
22(S)HC, 2.0 μg/ml 20(S)HC, 2.0
μg/ml 22(R)HC, or vehicle control (ctrl) for 48
h. (B and C) Retroviral expression and
activation of LXRα induces apoE expression in preadipocytes but not
in fibroblasts. NIH 3T3 fibroblasts and 3T3-F442A preadipocytes were
transduced with a retroviral vector encoding LXRα (NIH-LXRα,
442A-LXRα) or the empty vector alone (NIH-vector, 442A-vector).
Stable cell lines were cultured for 48 h in DMEM containing 10%
(vol/vol) LPDS in the presence of 50 nM LG268 (LG), 2.0 μg/ml
22(R)HC, or vehicle control (ctrl). Northern analysis
was performed as described above.