Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
43
pubmed:dateCreated
2006-10-26
pubmed:abstractText
Cultured neurons exposed to synthetic beta-amyloid (Abeta) fragments reenter the cell cycle and initiate a pathway of DNA replication that involves the repair enzyme DNA polymerase-beta (DNA pol-beta) before undergoing apoptotic death. In this study, by performing coimmunoprecipitation experiments on cross-linked nucleoprotein fragments from Abeta-treated neurons, we demonstrate that DNA pol-beta coimmunoprecipitates with cell division cycle 45 (Cdc45) and with DNA primase in short nucleoprotein fragments. This indicates that DNA pol-beta is loaded into neuronal DNA replication forks after Abeta treatment. In response to Abeta the canonical DNA-synthesizing enzyme DNA pol-delta also was loaded into neuronal replication forks, but at later times than DNA pol-beta. Methoxyamine, an inhibitor of the apurinic/apyrimidinic endonuclease that allows for the recruitment of DNA pol-beta during the process of base excision repair (BER), failed to affect coimmunoprecipitation between DNA pol-beta and Cdc45, indicating that DNA pol-beta loading to the replication forks is independent of DNA breaks. However, methoxyamine reduced DNA replication and ensuing apoptosis in neurons exposed to Abeta, suggesting that an efficient BER process allows DNA replication to proceed up to the threshold for death. These data demonstrate that DNA pol-beta is an essential component of the DNA replication machinery in Abeta-treated neurons and additionally support the hypothesis of a close association of cell cycle events with neuronal death in Alzheimer's disease (AD). Accordingly, by investigating the neuronal expression of DNA pol-beta, along with phosphorylated retinoblastoma protein and neurofibrillary changes in AD brain, we show an early involvement of DNA pol-beta in the pathogenesis of AD.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
1529-2401
pubmed:author
pubmed:issnType
Electronic
pubmed:day
25
pubmed:volume
26
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
10949-57
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
2006
pubmed:articleTitle
DNA polymerase-beta is expressed early in neurons of Alzheimer's disease brain and is loaded into DNA replication forks in neurons challenged with beta-amyloid.
pubmed:affiliation
Department of Pharmaceutical Sciences, University of Catania, 95125 Catania, Italy. acopani@katamail.com
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't