title: Morphological alterations of the cornea in the mouse model of niemann-pick disease type c1.
abstract: OBJECTIVE
  Niemann-Pick disease type C1 (NPC1) is a genetic neurovisceral disorder characterized by abnormalities in intracellular sterol trafficking. A knockout mouse model (NPC1) is an important tool for the study of pathogenesis and treatment strategies. In the present study, NPC1 mice were examined for pathological changes in the cornea.
  
  
  METHODS
  Fifteen inbred homozygous NPC1 knockout mice (NPC1, 5-10 weeks old), 5 age-matched heterozygous mice (NPC1), and 14 wild-type control mice (NPC1) were examined. In vivo confocal laser scanning microscopy (CLSM) was performed on both eyes of each animal; afterward, the eyes were processed for histology, electron microscopy, and lipid analysis.
  
  
  RESULTS
  In vivo CLSM disclosed hyperreflective intracellular deposits in the intermediate and basal cell layers of corneal epithelium in all NPC1 mice. At the electron microscopy level, however, vacuolated cytoplasmic structures, 200-500 nm in diameter, with electron-dense material appeared in all structures investigated, including all epithelial layers and stromal keratocytes. These deposits were negative for filipin, a marker for unesterified cholesterol. Lipid analysis showed a marked increase in disialotetrahexosylganglioside 2 (GM2) level in NPC1 mice corneas, whereas no changes were detected in free cholesterol and disialotetrahexosylganglioside 3 (GM3) levels when compared with controls.
  
  
  CONCLUSIONS
  Morphological changes characteristic for the NPC1 mouse cornea were visualized in all epithelial layers and keratocytes. In vivo CLSM findings were confirmed by other techniques. In vivo detection of ocular manifestations and analysis of ocular tissue have the potential to aid the diagnosis of NPC1 disease and to monitor the efficacy of treatment.
authors.affiliation: Department of Ophthalmology, University of Rostock, Rostock, Germany. marine.hovakimyan@uni-rostock.de
authors.forename: Marine
authors.initials: M
authors.lastname: Hovakimyan
authors.forename: Oliver
authors.initials: O
authors.lastname: Stachs
authors.forename: Maria
authors.initials: M
authors.lastname: Reichard
authors.forename: Hermann
authors.initials: H
authors.lastname: Mascher
authors.forename: Jan
authors.initials: J
authors.lastname: Lukas
authors.forename: Moritz Johannes
authors.initials: MJ
authors.lastname: Frech
authors.forename: Rudolf
authors.initials: R
authors.lastname: Guthoff
authors.forename: Martin
authors.initials: M
authors.lastname: Witt
authors.forename: Arndt
authors.initials: A
authors.lastname: Rolfs
authors.forename: Andreas
authors.initials: A
authors.lastname: Wree
mesh_terms: D000818:Animals; D002784:Cholesterol / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D003316:Corneal Diseases / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D004195:Disease Models, Animal; D005678:G(M2) Ganglioside / Q000378:metabolism; D005679:G(M3) Ganglioside / Q000378:metabolism; D047908:Intracellular Signaling Peptides and Proteins; D008055:Lipids / Q000097:blood; D013058:Mass Spectrometry; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D018613:Microscopy, Confocal; D000077296:Niemann-Pick C1 Protein; D052556:Niemann-Pick Disease, Type C / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D011506:Proteins / Q000235:genetics
chemical_list: D005679:G(M3) Ganglioside; D047908:Intracellular Signaling Peptides and Proteins; D008055:Lipids; D000077296:Niemann-Pick C1 Protein; C106831:Npc1 protein, mouse; D011506:Proteins; D005678:G(M2) Ganglioside; D002784:Cholesterol