Very low density lipoprotein receptor in Alzheimer disease.

The apolipoprotein (APO) E4 isoform is associated with an accelerated rate of Alzheimer disease (AD) expression in sporadic as well as late-onset familial forms of the disease but the precise mechanism is unknown. In an attempt to approach the possible mechanisms involved, APOE receptors have been studied. They all belong to the low density lipoprotein (LDL) receptor family and share the same structural motifs. Some of them are preferentially expressed in the brain such as the LDL receptor related protein, the apolipoprotein E receptor 2, and the very low density lipoprotein (VLDL) receptor. These receptors have been suspected to be involved in Alzheimer disease at various levels. Among them, the VLDL receptor was extensively explored. Although genetic studies conducted on a polymorphism in the promoter of the VLDL receptor in Japanese and Caucasian populations gave divergent results, this does not exclude a possible involvement of the VLDL receptor in AD.