title: Can the rDNA methylation pattern be used as a marker for Alzheimer's disease?
abstract: BACKGROUND
  Differential methylation activity of the human rDNA in Alzheimer's disease (AD) patients has been demonstrated by classic cytogenetic tools, indicating a decrease in rRNA gene expression. Methylation of CpGs is an important epigenetic mechanism involved in gene expression repression of tandem repeating genes during ageing. Thus, rDNA specific methylation pattern could be involved in AD and be used as a marker of the disease or of its progression.
  
  
  METHODS
  The methylation pattern of three rDNA regions, including the promoter, 18S, and 28S, was investigated with the use of restriction endonucleases sensitive to methylation and Southern blotting from DNA extracted from total peripheral blood cells of 28 AD patients and 28 elderly and young controls.
  
  
  RESULTS
  We did not find a significant divergence in the methylation pattern of the studied regions and in the relative amount of rDNA methylated copies among the individuals' groups.
  
  
  CONCLUSIONS
  No differential methylation pattern of rDNA genes was observed in total peripheral blood cells in aged and AD subjects by the methodology used.
authors.affiliation: Disciplina de Biologia Molecular, Marília Medical School, Marília, SP, Brazil. speranca@famema.br
authors.forename: Márcia Aparecida
authors.initials: MA
authors.lastname: Sperança
authors.forename: Lisandra Mesquita
authors.initials: LM
authors.lastname: Batista
authors.forename: Ricardo da Silva
authors.initials: Rda S
authors.lastname: Lourenço
authors.forename: Wagner Malagó
authors.initials: WM
authors.lastname: Tavares
authors.forename: Paulo Henrique Ferreira
authors.initials: PH
authors.lastname: Bertolucci
authors.forename: Valdeci de Oliveira Santos
authors.initials: Vde O
authors.lastname: Rigolin
authors.forename: Spencer Luiz Marques
authors.initials: SL
authors.lastname: Payão
authors.forename: Marília de Arruda Cardoso
authors.initials: Mde A
authors.lastname: Smith
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000235:genetics*; D000544:Alzheimer Disease / Q000175:diagnosis* / Q000235:genetics*; D015139:Blotting, Southern; D016022:Case-Control Studies; D019175:DNA Methylation; D004275:DNA, Ribosomal / Q000235:genetics*; D005260:Female; D015870:Gene Expression; D006801:Humans; D008297:Male; D008875:Middle Aged; D011401:Promoter Regions, Genetic; D012337:RNA, Ribosomal, 18S / Q000235:genetics*; D012339:RNA, Ribosomal, 28S / Q000235:genetics*
chemical_list: D004275:DNA, Ribosomal; D012337:RNA, Ribosomal, 18S; D012339:RNA, Ribosomal, 28S