Long-Smith, Caitriona M. and Manning, Sean and McClean, Paula L. and Coakley, Meghan F. and O'Halloran, Domhnall J. and Holscher, Christian and O'Neill, Cora (2013) The diabetes drug liraglutide ameliorates aberrant insulin receptor localisation and signalling in parallel with decreasing both amyloid-β plaque and glial pathology in a mouse model of Alzheimer's disease. NeuroMolecular Medicine, 15 (1). pp. 102-114. ISSN 1559-1174
Full text not available from this repository.Abstract
Alzheimer's disease (AD) has been shown to involve desensitised insulin receptor (IR) signalling. Liraglutide, a novel glucagon-like peptide 1 (GLP-1) analogue that facilitates insulin signalling, is currently approved for use in type 2 diabetes mellitus. In the present study, we show that distinctive alterations in the localisation and distribution of the IR and increased levels of insulin receptor substrate (IRS)-1 phosphorylated at serine 616 (IRS-1 pS(616)), a key marker of insulin resistance, are associated with amyloid-β plaque pathology in the frontal cortex of a mouse model of AD, APPSWE/PS1dE9. Altered IR status in APPSWE/PS1dE9 is most evident in extracellular deposits with the appearance of dystrophic neurites, with significantly increased IRS-1 pS(616) levels detected within neurons and neurites. The IR and IRS-1 pS(616) changes occur in the vicinity of all plaques in the APPSWE/PS1dE9 brain, and a significant upregulation of astrocytes and microglia surround this pathology. We show that liraglutide treatment for 8 weeks at 25 nmol/kg body weight i.p. once daily in 7-month-old mice significantly decreases IR aberrations in conjunction with a concomitant decrease in amyloid plaque load and levels of IRS-1 pS(616). Liraglutide also induces a highly significant reduction in astrocytosis and microglial number associated with both plaques and IR pathology. The amelioration of IR aberrations and attenuation of IRS-1 pS(616) upregulation, plaque and glial activation in APPSWE/PS1dE9 mice treated with liraglutide support the investigation of the therapeutic potential of liraglutide and long-lasting GLP-1 agonists in patients with AD.