title: Intracellular amyloid formation in muscle cells of Abeta-transgenic Caenorhabditis elegans: determinants and physiological role in copper detoxification.
abstract: BACKGROUND
  The amyloid beta-peptide is a ubiquitous peptide, which is prone to aggregate forming soluble toxic oligomers and insoluble less-toxic aggregates. The intrinsic and external/environmental factors that determine Abeta aggregation in vivo are poorly understood, as well as the cellular meaning of this process itself. Genetic data as well as cell biological and biochemical evidence strongly support the hypothesis that Abeta is a major player in the onset and development of Alzheimer's disease. In addition, it is also known that Abeta is involved in Inclusion Body Myositis, a common myopathy of the elderly in which the peptide accumulates intracellularly.
  
  
  RESULTS
  In the present work, we found that intracellular Abeta aggregation in muscle cells of Caenorhabditis elegans overexpressing Abeta peptide is affected by two single amino acid substitutions, E22G (Arctic) and V18A (NIC). Both variations show decrease intracellular amyloidogenesis compared to wild type Abeta. We show that intracellular amyloid aggregation of wild type Abeta is accelerated by Cu2+ and diminished by copper chelators. Moreover, we demonstrate through toxicity and behavioral assays that Abeta-transgenic worms display a higher tolerance to Cu2+ toxic effects and that this resistance may be linked to the formation of amyloid aggregates.
  
  
  CONCLUSIONS
  Our data show that intracellular Abeta amyloid aggregates may trap excess of free Cu2+ buffering its cytotoxic effects and that accelerated intracellular Abeta aggregation may be part of a cell protective mechanism.
authors.affiliation: Centro de Regulación Celular y Patología "Joaquín V, Luco" (CRCP), MIFAB, Centro de Envejecimiento y Regeneración (CARE), Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, 8331010 Santiago, Chile. ninestrosa@bio.puc.cl.
authors.forename: Alicia N
authors.initials: AN
authors.lastname: Minniti
authors.forename: Daniela L
authors.initials: DL
authors.lastname: Rebolledo
authors.forename: Paula M
authors.initials: PM
authors.lastname: Grez
authors.forename: Ricardo
authors.initials: R
authors.lastname: Fadic
authors.forename: Rebeca
authors.initials: R
authors.lastname: Aldunate
authors.forename: Irene
authors.initials: I
authors.lastname: Volitakis
authors.forename: Robert A
authors.initials: RA
authors.lastname: Cherny
authors.forename: Carlos
authors.initials: C
authors.lastname: Opazo
authors.forename: Colin
authors.initials: C
authors.lastname: Masters
authors.forename: Ashley I
authors.initials: AI
authors.lastname: Bush
authors.forename: Nibaldo C
authors.initials: NC
authors.lastname: Inestrosa