title: Mice that produce ApoB100 lipoproteins in the RPE do not develop drusen yet are still a valuable experimental system.
abstract: OBJECTIVE
  Mice typically produce apolipoprotein B (apoB)-48 and not apoB100. Apolipoprotein B100 accumulates in Bruch's membrane prior to basal deposit and drusen formation during the onset of AMD, raising the possibility that they are a trigger for these Bruch's membrane alterations. The purpose herein, was to determine whether mice that predominantly produce apoB100 develop features of AMD.
  
  
  METHODS
  The eyes of mice that produce apoB100 were examined for apoB100 synthesis, cholesteryl esterase/filipin labeling for cholesteryl esters, and transmission electron microscopy for lipid particles and phenotype.
  
  
  RESULTS
  Apolipoprotein B100 was abundant in the RPE-choroid of apoB100, but not wild-type mice by Western blot analysis. The apolipoprotein B100,(35)S-radiolabeled and immunoprecipitated from RPE explants, confirmed that apoB100 was synthesized by RPE. Apolipoprotein B100, but not control mice, had cholesteryl esters and lipid particles in Bruch's membrane. Immunoreactivity of ApoB100 was present in the RPE and Bruch's membrane, but not choroidal endothelium of apoB100 mice. Ultrastructural changes were consistent with aging, but not AMD when aged up to 18 months. The induction of advanced glycation end products to alter Bruch's membrane, did not promote basal linear deposit or drusen formation.
  
  
  CONCLUSIONS
  Mice that produce apoB100 in the RPE and liver secrete lipoproteins into Bruch's membrane, but not to the extent that distinct features of AMD develop, which suggests that either additional lipoprotein accumulation or additional factors are necessary to initiate their formation.
authors.affiliation: Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland, United States.
authors.forename: Masashi
authors.initials: M
authors.lastname: Fujihara
authors.affiliation: Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland, United States.
authors.forename: Marisol
authors.initials: M
authors.lastname: Cano
authors.affiliation: Wilmer Eye Institute, Johns Hopkins School of Medicine, Baltimore, Maryland, United States.
authors.forename: James T
authors.initials: JT
authors.lastname: Handa
mesh_terms: D000818:Animals; D053299:Apolipoprotein B-100 / Q000096:biosynthesis / Q000235:genetics*; D015153:Blotting, Western; D004195:Disease Models, Animal; D005260:Female; D005786:Gene Expression Regulation; D007150:Immunohistochemistry; D008268:Macular Degeneration / Q000235:genetics* / Q000378:metabolism / Q000473:pathology; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D017348:Microscopy, Electron, Scanning Transmission; D012313:RNA / Q000235:genetics*; D060888:Real-Time Polymerase Chain Reaction; D055213:Retinal Pigment Epithelium / Q000378:metabolism* / Q000648:ultrastructure
chemical_list: D053299:Apolipoprotein B-100; D012313:RNA
keywords: age-related macular degeneration; aging; apolipoprotein B; lipoproteins; retinal pigmented epithelium