6533b853fe1ef96bd12ac202

RESEARCH PRODUCT

Functional role of the low-density lipoprotein receptor-related protein in Alzheimer's disease.

subject

description

Alzheimer’s disease (AD) is the most common age-related neurodegenerative disorder, characterized by neuronal loss, neurofibrillary tangle formation and the extracellular deposition of amyloid-β (Aβ) plaques. The amyloid precursor protein (APP) and the enzymes responsible for Aβ generation seem to be the base elements triggering the destructive processes. Initially, the low-density lipoprotein receptor-related protein (LRP) was genetically linked to AD and later it emerged to impact on many fundamental events related to this disease. LRP is not only involved in Aβ clearance but is also the major receptor of several AD-associated ligands, e.g. apolipoprotein E and α<sub>2</sub>-macroglobulin. APP processing is mediated by LRP on many levels. Enhanced APP internalization through LRP decreases cell surface APP levels and thereby reduces APP shedding. As a consequence of increased APP internalization LRP enhances Aβ secretion. These effects could be attributed to the cytoplasmic tails of LRP and APP. The receptors bind via their NPXY motifs to the two PID domains of FE65 and form a tripartite complex. However, it appears that the second NPVY motif of LRP is the one responsible for the observed influence over APP metabolism. A more in-depth knowledge of the mechanisms regulating APP cleavage may offer additional targets for therapeutic intervention.