Astrocytes cholesterol synthesis

The lipid compositions of plasma membranes, endoplasmic reticulum and Golgi membranes are distinct 26 Cholesterol transport and regulation in the central nervous system is distinct from that of peripheral tissues 26 In adult brain most cholesterol synthesis occurs in astrocytes 26 The astrocytic cholesterol supply to neurons is important for neuronal development and remodeling 27 The structure and roles of membrane microdomains (rafts) in cell membranes are under intensive study but many aspects are still unresolved 28... 

In adult brain most cholesterol synthesis occurs in astrocytes. Apoprotein E (apoE) is the major apolipopro-tein of the CNS and it is secreted by astrocytes. In astrocyte cultures apoE appears in the media as cholesterol-rich particles of a size similar to peripheral HDL (5-12 nm) (Fig. 2-7). The ATP-dependent transporter ABCA1, expressed by both astrocytes and neurons, promotes the formation of the apoE-stabilized high-density lipoprotein (HDL)-sized particles from astrocytic cholesterol. 

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