title: Increased brain beta-amyloid load, phosphorylated tau, and risk of Alzheimer disease associated with an intronic CYP46 polymorphism.
abstract: BACKGROUND
  CYP46, the gene encoding cholesterol 24-hydroxylase, plays a key role in the hydroxylation of cholesterol and thereby mediates its removal from brain.
  
  
  OBJECTIVE
  To study the association of polymorphic sites on CYP46 with Alzheimer disease (AD) traits and with the risk of the development of AD.
  
  
  METHODS
  Alzheimer disease traits (beta-amyloid load, beta-amyloid peptides, hyperphosphorylated tau protein) were assessed in brain tissues and in the cerebrospinal fluid of patients with AD and control subjects. Genetic associations were studied in 2 independent populations.
  
  
  METHODS
  Specialized centers for memory disorders in Switzerland, Greece, and Italy.
  
  
  METHODS
  Fifty-five brain tissues from nondemented elderly patients for the histopathological studies; 38 patients with AD and 25 control subjects for the cerebrospinal fluid studies; 201 patients with AD and 248 control subjects for the genetic association studies.
  
  
  RESULTS
  A polymorphism of CYP46 was associated with increased beta-amyloid load in brain tissues as well as with increased cerebrospinal fluid levels of beta-amyloid peptides and phosphorylated tau protein. Moreover, this CYP46 polymorphism was associated with higher risk of late-onset sporadic AD in 2 independent populations (odds ratio, 2.16; 95% confidence interval [CI], 1.41-3.32; P<.001). The additional presence of 1 or 2 apolipoprotein E epsilon4 alleles synergistically increased the risk of AD to an odds ratio of 9.6 (95% CI, 4.9-18.9; P<.001) as compared with 4.4 for apolipoprotein E epsilon4 alone (95% CI, 2.8-6.8; P<.001).
  
  
  CONCLUSIONS
  CYP46 influences brain beta-amyloid load, cerebrospinal fluid levels of beta-amyloid peptides and phosphorylated tau, and the genetic risk of late-onset sporadic AD.
authors.affiliation: Division of Pychiatry Research, University of Zurich, Switzerland. papas@bli.unizh.ch
authors.forename: Andreas
authors.initials: A
authors.lastname: Papassotiropoulos
authors.forename: Johannes R
authors.initials: JR
authors.lastname: Streffer
authors.forename: Magdalini
authors.initials: M
authors.lastname: Tsolaki
authors.forename: Simon
authors.initials: S
authors.lastname: Schmid
authors.forename: Dietmar
authors.initials: D
authors.lastname: Thal
authors.forename: Francesca
authors.initials: F
authors.lastname: Nicosia
authors.forename: Vassiliki
authors.initials: V
authors.lastname: Iakovidou
authors.forename: Alessia
authors.initials: A
authors.lastname: Maddalena
authors.forename: Dieter
authors.initials: D
authors.lastname: Lütjohann
authors.forename: Estifanos
authors.initials: E
authors.lastname: Ghebremedhin
authors.forename: Thomas
authors.initials: T
authors.lastname: Hegi
authors.forename: Thomas
authors.initials: T
authors.lastname: Pasch
authors.forename: Muriel
authors.initials: M
authors.lastname: Träxler
authors.forename: Annette
authors.initials: A
authors.lastname: Brühl
authors.forename: Luisa
authors.initials: L
authors.lastname: Benussi
authors.forename: Giuliano
authors.initials: G
authors.lastname: Binetti
authors.forename: Heiko
authors.initials: H
authors.lastname: Braak
authors.forename: Roger M
authors.initials: RM
authors.lastname: Nitsch
authors.forename: Christoph
authors.initials: C
authors.lastname: Hock
mesh_terms: D017668:Age of Onset; D000368:Aged; D000369:Aged, 80 and over; D000544:Alzheimer Disease / Q000453:epidemiology / Q000235:genetics* / Q000378:metabolism; D016229:Amyloid beta-Peptides / Q000134:cerebrospinal fluid / Q000378:metabolism*; D001921:Brain / Q000378:metabolism* / Q000473:pathology; D002784:Cholesterol / Q000134:cerebrospinal fluid; D000072556:Cholesterol 24-Hydroxylase; D005260:Female; D020022:Genetic Predisposition to Disease / Q000453:epidemiology; D005838:Genotype; D006801:Humans; D006888:Hydroxycholesterols / Q000134:cerebrospinal fluid; D007438:Introns / Q000235:genetics; D008297:Male; D010446:Peptide Fragments / Q000134:cerebrospinal fluid; D010766:Phosphorylation; D011110:Polymorphism, Genetic; D012307:Risk Factors; D013250:Steroid Hydroxylases / Q000235:genetics*; D016875:tau Proteins / Q000134:cerebrospinal fluid*
chemical_list: D016229:Amyloid beta-Peptides; D006888:Hydroxycholesterols; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D016875:tau Proteins; C044563:24-hydroxycholesterol; D002784:Cholesterol; D013250:Steroid Hydroxylases; D000072556:Cholesterol 24-Hydroxylase