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Reversing EphB2 depletion rescues cognitive functions in Alzheimer model.

22:13 EDT 23rd May 2013 | BioPortfolio

Summary of "Reversing EphB2 depletion rescues cognitive functions in Alzheimer model."

Amyloid-β oligomers may cause cognitive deficits in Alzheimer's disease by impairing neuronal NMDA-type glutamate receptors, whose function is regulated by the receptor tyrosine kinase EphB2. Here we show that amyloid-β oligomers bind to the fibronectin repeats domain of EphB2 and trigger EphB2 degradation in the proteasome. To determine the pathogenic importance of EphB2 depletions in Alzheimer's disease and related models, we used lentiviral constructs to reduce or increase neuronal expression of EphB2 in memory centres of the mouse brain. In nontransgenic mice, knockdown of EphB2 mediated by short hairpin RNA reduced NMDA receptor currents and impaired long-term potentiation in the dentate gyrus, which are important for memory formation. Increasing EphB2 expression in the dentate gyrus of human amyloid precursor protein transgenic mice reversed deficits in NMDA receptor-dependent long-term potentiation and memory impairments. Thus, depletion of EphB2 is critical in amyloid-β-induced neuronal dysfunction. Increasing EphB2 levels or function could be beneficial in Alzheimer's disease.

Affiliation

Gladstone Institute of Neurological Disease, San Francisco, California 94158, USA.

Journal Details

This article was published in the following journal.

Name: Nature
ISSN: 1476-4687
Pages: 47-52

Links

Medical and Biotech [MESH] Definitions

Aphasia, Primary Progressive

A progressive form of dementia characterized by the global loss of language abilities and initial preservation of other cognitive functions. Fluent and nonfluent subtypes have been described. Eventually a pattern of global cognitive dysfunction, similar to ALZHEIMER DISEASE, emerges. Pathologically, there are no Alzheimer or PICK DISEASE like changes, however, spongiform changes of cortical layers II and III are present in the TEMPORAL LOBE and FRONTAL LOBE. (From Brain 1998 Jan;121(Pt 1):115-26)

Neuropil Threads

Abnormal structures located chiefly in distal dendrites and, along with NEUROFIBRILLARY TANGLES and SENILE PLAQUES, constitute the three morphological hallmarks of ALZHEIMER DISEASE. Neuropil threads are made up of straight and paired helical filaments which consist of abnormally phosphorylated microtubule-associated tau proteins. It has been suggested that the threads have a major role in the cognitive impairment seen in Alzheimer disease.

Likelihood Functions

Functions constructed from a statistical model and a set of observed data which give the probability of that data for various values of the unknown model parameters. Those parameter values that maximize the probability are the maximum likelihood estimates of the parameters.

Receptor, Ephb2

An eph family receptor found widely expressed in embryonic and adult tissues. High levels of EphB2 receptor are observed in growing AXONS and NERVE FIBERS. Several isoforms of the protein exist due to multiple alternative mRNA splicing.

Papio Papio

A species of baboon in the family CERCOPITHECIDAE, often used as an animal model for cognitive studies.

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