Dietary cholesterol and estrogen administration elevate brain apolipoprotein E in mice by different mechanisms.

Apolipoprotein (apo) E plays an important role in the whole body cholesterol homeostasis. Recent studies suggest that it may also be involved in the local cholesterol transport in the brain, and influence the pathogenesis of Alzheimer's disease (AD) by interacting with the beta-amyloid protein and brain lipoprotein receptors. Since apoE expression is highest in the brain, next only to the liver and associated with the pathogenesis of AD, we hypothesized that dietary and hormonal intervention, known to regulate hepatic apoE expression may also regulate brain apoE and thereby influence local cholesterol transport. To test this hypothesis, groups of male C57BL mice were fed either regular rode…