The absence of ABCA1 decreases soluble ApoE levels but does not diminish amyloid deposition in two murine models of Alzheimer disease.

摘要

J Biol Chem. 2005 Dec 30;280(52):43243-56. Epub 2005 Oct 5.The absence of ABCA1 decreases soluble ApoE levels but does not diminish amyloid deposition in two murine models of Alzheimer disease.Hirsch-Reinshagen V, Maia LF, Burgess BL, Blain JF, Naus KE, McIsaac SA, Parkinson PF, Chan JY, Tansley GH, Hayden MR, Poirier J, Van Nostrand W, Wellington CL.Department of Pathology and Laboratory Medicine, University of British Columbia, Vancouver, British Columbia V4Z 5H5, Canada.AbstractABCA1, a cholesterol transporter expressed in the brain, has been shown recently to be required to maintain normal apoE levels and lipidation in the central nervous system. In addition, ABCA1 has been reported to modulate beta-amyloid (Abeta) production in vitro. These observations raise the possibility that ABCA1 may play a role in the pathogenesis of Alzheimer disease. Here we report that the deficiency of ABCA1 does not affect soluble or guanidine-extractable Abeta levels in Tg-SwDI/B or amyloid precursor protein/presenilin 1 (APP/PS1) mice, but rather is associated with a dramatic reduction in soluble apoE levels in brain. Although this reduction in apoE was expected to reduce the amyloid burden in vivo, we observed that the parenchymal and vascular amyloid load was increased in Tg-SwDI/B animals and was not diminished in APP/PS1 mice. Furthermore, we observed an increase in the proportion of apoE retained in the insoluble fraction, particularly in the APP/PS1 model. These data suggested that ABCA1-mediated effects on apoE levels and lipidation influenced amyloidogenesis in vivo.PMID: 16207707 [PubMed - indexed for MEDLINE]