Early-Onset Formation of Parenchymal Plaque Amyloid Abrogates Cerebral Microvascular Amyloid Accumulation in Transgenic Mice.

Journal of Biological Chemistry (Impact Factor: 4.6). 05/2014; 289(25). DOI: 10.1074/jbc.M113.536565
Source: PubMed

ABSTRACT The fibrillar assembly and deposition of amyloid β-protein (Aβ), a key pathology of Alzheimers disease (AD), can occur in the form of parenchymal amyloid plaques and cerebral amyloid angiopathy (CAA). Familial forms of CAA exist in the absence of appreciable parenchymal amyloid pathology. The molecular interplay between parenchymal amyloid plaques and CAA is unclear. Here we investigated how early-onset parenchymal amyloid plaques impact the development of microvascular amyloid in transgenic mice. Tg-5xFAD mice, which produce non-mutated human Aβ and develop early-onset parenchymal amyloid plaques, were bred to Tg-SwDI mice, which produce familial CAA mutant human Aβ and develop cerebral microvascular amyloid. The bigenic mice presented with elevated accumulation of Aβ and fibrillar amyloid in brain compared to either single transgenic line. Tg-SwDI/Tg-5xFAD mice were devoid of microvascular amyloid, the prominent pathology of Tg-SwDI mice, but exhibited larger parenchymal amyloid plaques compared to Tg-5xFAD mice. The larger parenchymal amyloid deposits were associated with a higher loss of cortical neurons and elevated activated microglia in the bigenic Tg-SwDI/Tg-5xFAD mice. The periphery of parenchymal amyloid plaques was largely composed of CAA mutant Aβ. Non-mutated Aβ fibril seeds promoted CAA mutant Aβ fibril formation in vitro. Further, intrahippocampal administration of biotin-labeled CAA mutant Aβ peptide accumulated on and adjacent to pre-existing parenchymal amyloid plaques in Tg-5xFAD mice. These findings indicate that early-onset parenchymal amyloid plaques can serve as a scaffold to capture CAA mutant Aβ peptides and prevent their accumulation in cerebral microvessels.

  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Protein misfolding is common to most neurodegenerative diseases, including Alzheimer's and Parkinson's diseases. Recent work using animal models with intracellular α-synuclein and tau inclusions adds decisively to a growing body of evidence that misfolded protein aggregates can induce a self-perpetuating process that leads to amplification and spreading of pathological protein assemblies. When coupled with the progressive nature of neurodegeneration, recognition of such cell-to-cell aggregate spread suggests a unifying mechanism underlying the pathogenesis of these disorders.
    Journal of Experimental Medicine 05/2012; 209(5):889-93. DOI:10.1084/jem.20120741 · 13.91 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: Amyloid fibers and oligomers are associated with a great variety of human diseases including Alzheimer's disease and the prion conditions. Here we attempt to connect recent discoveries on the molecular properties of proteins in the amyloid state with observations about pathological tissues and disease states. We summarize studies of structure and nucleation of amyloid and relate these to observations on amyloid polymorphism, prion strains, coaggregation of pathogenic proteins in tissues, and mechanisms of toxicity and transmissibility. Molecular studies have also led to numerous strategies for biological and chemical interventions against amyloid diseases.
    Cell 03/2012; 148(6):1188-203. DOI:10.1016/j.cell.2012.02.022 · 31.96 Impact Factor
  • Source
    [Show abstract] [Hide abstract]
    ABSTRACT: It has been more than 10 years since it was first proposed that the neurodegeneration in Alzheimer's disease (AD) may be caused by deposition of amyloid beta-peptide (Abeta) in plaques in brain tissue. According to the amyloid hypothesis, accumulation of Abeta in the brain is the primary influence driving AD pathogenesis. The rest of the disease process, including formation of neurofibrillary tangles containing tau protein, is proposed to result from an imbalance between Abeta production and Abeta clearance.
    Science 08/2002; 297(5580):353-6. DOI:10.1126/science.1072994 · 31.48 Impact Factor


Available from
Jan 9, 2015