Quantification of apolipoprotein E receptors in human brain-derived cell lines by real-time polymerase chain reaction.

Apolipoprotein (apo) E4 is a risk factor for Alzheimer's disease (AD) and other neurodegenerative diseases, compared to wild-type apoE3. The mechanism(s) is unknown. One possibility, demonstrated in peripheral tissue cell lines, is that apoE stimulates nitric oxide synthase (NOS) via a receptor-dependent signalling pathway and that apoE4 generates inappropriate amounts of nitric oxide (NO) compared to apoE3.