Document Detail


Linking cell-cycle dysfunction in Alzheimer's disease to a failure of synaptic plasticity.
MedLine Citation:
PMID:  17236750     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Higher cerebral functions are based upon a dynamic organization of neuronal networks. To form synaptic connections and to continuously re-shape them in a process of ongoing structural adaptation, neurons must permanently withdraw from the cell cycle. In other words, synaptic plasticity can only occur on the expense of the ability to proliferate. Previously, we have put forward a hypothesis, coined "Dr. Jekyll and Mr. Hyde concept" that differentiated neurons after having withdrawn from the cell cycle are able to use those molecular mechanisms primarily developed to control proliferation alternatively to control synaptic plasticity [T. Arendt, Synaptic plasticity and cell cycle activation in neurons are alternative effector pathways The Dr. Jekyll and Mr. Hyde Theory of Alzheimer's disease or The yin and yang of Neuroplasticity. Progr. Neurobiol. 71 (2003) 83-248]. The existence of these alternative effector pathways within a neuron might put it on the risk to erroneously convert signals derived from plastic synaptic changes into cell cycle activation which subsequently leads to cell death. Here we add further evidence to this hypothesis demonstrating a tight association of the origin recognition complex (ORC) with neurofibrillar pathology in AD. The ORC is a critical "guard" of DNA replication and point of convergence of numerous functionally redundant signaling pathways involved in cell cycle progression and transcriptional silencing of apoptotic programmes. ORC subunits in the mammalian brain and their homologes in Drosophila, however, have further been implicated in the regulation of structural neuronal plasticity and cognitive function. We propose that the abnormal subcellular distribution and segregation of ORC proteins in AD might compromise their physiological function in gene silencing and plasticity. This might result in cell cycle activation, DNA-replication and de-repression of apoptotic programmes. ORC subunits might, thus, provide a direct molecular link between synaptic plasticity, DNA replication and cell death.
Authors:
Thomas Arendt; Martina K Brückner
Publication Detail:
Type:  Journal Article; Review     Date:  2006-12-15
Journal Detail:
Title:  Biochimica et biophysica acta     Volume:  1772     ISSN:  0006-3002     ISO Abbreviation:  Biochim. Biophys. Acta     Publication Date:  2007 Apr 
Date Detail:
Created Date:  2007-03-19     Completed Date:  2007-04-26     Revised Date:  2007-10-15    
Medline Journal Info:
Nlm Unique ID:  0217513     Medline TA:  Biochim Biophys Acta     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  413-21     Citation Subset:  IM    
Affiliation:
Paul Flechsig Institute of Brain Research, Department of Neuroanatomy, University of Leipzig, Jahnallee 59, D-04109 Leipzig, Germany. aret@medizin.uni-leipzig.de
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MeSH Terms
Descriptor/Qualifier:
Alzheimer Disease / pathology*,  physiopathology
Brain / pathology*,  physiopathology
Cell Cycle*
Humans
Models, Neurological
Neuronal Plasticity / physiology*
Origin Recognition Complex / analysis
Synapses / pathology*,  physiology
Chemical
Reg. No./Substance:
0/Origin Recognition Complex
Comments/Corrections
Erratum In:
Biochim Biophys Acta. 2007 Sep;1772(9):1119

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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