title: Increased extracellular amyloid deposition and neurodegeneration in human amyloid precursor protein transgenic mice deficient in receptor-associated protein.
abstract: The low-density lipoprotein receptor-related protein (LRP) is an abundant neuronal cell surface receptor that regulates amyloid beta-protein (Abeta) trafficking into the cell. Specifically, LRP binds secreted Abeta complexes and mediates its degradation. Previously, we have shown in vitro that the uptake of Abeta mediated by LRP is protective and that blocking this receptor significantly enhances neurotoxicity. To further characterize the effects of LRP and other lipoprotein receptors on Abeta deposition, an in vivo model of decreased LRP expression, receptor-associated protein (RAP)-deficient (RAP-/-) mice was crossed with human amyloid protein precursor transgenic (hAPP tg) mice, and plaque formation and neurodegeneration were analyzed. We found that, although the age of onset for plaque formation was the same in hAPP tg and hAPP tg/RAP-/- mice, the amount of amyloid deposited doubled in the hAPP tg/RAP-/- background. Moreover, these mice displayed increased neuronal damage and astrogliosis. Together, these results further support the contention that LRP and other lipoprotein receptors might be neuroprotective against Abeta toxicity and that this receptor might play an integral role in Abeta clearance.
authors.affiliation: Department of Neurosciences, University of California, San Diego, School of Medicine, La Jolla, California 92093-0624, USA.
authors.forename: Emily
authors.initials: E
authors.lastname: Van Uden
authors.forename: Margaret
authors.initials: M
authors.lastname: Mallory
authors.forename: Isaac
authors.initials: I
authors.lastname: Veinbergs
authors.forename: Michael
authors.initials: M
authors.lastname: Alford
authors.forename: Edward
authors.initials: E
authors.lastname: Rockenstein
authors.forename: Eliezer
authors.initials: E
authors.lastname: Masliah
mesh_terms: D000682:Amyloid / Q000378:metabolism*; D016564:Amyloid beta-Protein Precursor / Q000235:genetics*; D000818:Animals; D003712:Dendrites / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D018450:Disease Progression; D005110:Extracellular Space / Q000378:metabolism*; D006624:Hippocampus / Q000378:metabolism / Q000473:pathology; D006720:Homozygote; D006801:Humans; D007150:Immunohistochemistry; D026563:LDL-Receptor Related Protein-Associated Protein / Q000172:deficiency* / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D008869:Microtubule-Associated Proteins / Q000096:biosynthesis; D019579:Neocortex / Q000378:metabolism / Q000473:pathology; D019636:Neurodegenerative Diseases / Q000235:genetics / Q000473:pathology / Q000503:physiopathology*
chemical_list: D000682:Amyloid; D016564:Amyloid beta-Protein Precursor; D026563:LDL-Receptor Related Protein-Associated Protein; D008869:Microtubule-Associated Proteins