Transcriptional regulation of apoE and ABCA1 expression by LXR in brain, glia and neurons. A: 7-month old APP23 mice were treated with 50 mg/kg T0 for 24 hours. Total RNA was extracted separately from cortices and hippocampi and mRNA expression of ABCA1, apoE and ABCG1 were determined by RT-QPCR; h-v, (black bars) – vehicle treatment, hippocampi; h-T0, (white bars) – T0 treatment, hippocampi, c-v (grey bars), vehicle treatment, cortex; c-T0 (hatched bars), T0 treatment, cortex. B, C and D: Primary neurons, astrocytes and microglia were established from wild type (wt) and LXRα-/-β-/- double knockout mice (dko). Cells were treated with 10 μM T0 for 24 hours and mRNA expression of ABCA1 (B) and apoE (D) measured by RT-QPCR. Values are means ± SEM and represent fold of vehicle for the corresponding genotype. C: ABCA1 protein level in wild type (wt) and LXRα-/-β-/- (dko) neurons was determined by WB. The level of ABCA1 was normalized to the level of GAPDH, and presented (means ± SEM) as fold of vehicle of the corresponding genotype in the graph bellow.