[Lipoproteins and their receptors in the central nervous system]

Central nervous system(CNS) has nearly a quarter of total body cholesterol, although its weight is only 2% of the whole body. In the adult brain, cholesterol synthesis is extremely low, and a half life of cholesterol is about 5 years. In the cerebrospinal fluid(CSF), the only lipoprotein is high-density lipoprotein (HDL). CSF-HDL is larger than plasma HDL, and rich in apolipoprotein E (apoE). In CNS, neurons and glia cells express several lipoprotein receptors and ATP-binding cassette (ABC) transporters. These lipoprotein receptors can bind to and take up CSF-HDL for cholesterol recycling. Recent research has focused on investigating the role of CSF-HDL and lipoprotein receptors in the pathogenesis of Alzheimer disease.