Deletion of Irs2 reduces amyloid deposition and rescues behavioural deficits in APP transgenic mice.
As impaired insulin signalling (IIS) is a risk factor for Alzheimer's disease we crossed mice (Tg2576) over-expressing human amyloid precursor protein (APP), with insulin receptor substrate 2 null (Irs2(-/-)) mice which develop insulin resistance. The resulting Tg2576/Irs2(-/-) animals had increased tau phosphorylation but a paradoxical amelioration of Abeta pathology. An increase of the Abeta binding protein transthyretin suggests that increased clearance of Abeta underlies the reduction in plaques. Increased tau phosphorylation correlated with reduced tau-phosphatase PP2A, despite an inhibition of the tau-kinase glycogen synthase kinase-3. Our findings demonstrate that disruption of IIS in Tg2576 mice has divergent effects on pathological processes-a reduction in aggregated Abeta but an increase in tau phosphorylation. However, as these effects are accompanied by improvement in behavioural deficits, our findings suggest a novel protective effect of disrupting IRS2 signalling in AD which may be a useful therapeutic strategy for this condition.
Killick
Richard
R
King's College London, MRC Centre for Neurodegenerative Research, Institute of Psychiatry, De Crespigny Park, London, SE5 8AF, UK.
Scales
Georgie
G
Leroy
Karelle
K
Causevic
Mirsada
M
Hooper
Claudie
C
Irvine
Elaine E
EE
Choudhury
Agharul I
AI
Drinkwater
Laura
L
Kerr
Fiona
F
Al-Qassab
Hind
H
Stephenson
John
J
Yilmaz
Zehra
Z
Giese
K Peter
KP
Brion
Jean-Pierre
JP
Withers
Dominic J
DJ
Lovestone
Simon
S
D000544:Alzheimer Disease / Q000378:metabolism / Q000523:psychology*; D016229:Amyloid beta-Peptides / Q000378:metabolism*; D000818:Animals; D017353:Gene Deletion; D006624:Hippocampus / Q000378:metabolism / Q000503:physiopathology*; D055504:Insulin Receptor Substrate Proteins / Q000235:genetics / Q000378:metabolism*; D008568:Memory; D051379:Mice; D008822:Mice, Transgenic; D010766:Phosphorylation; D016875:tau Proteins / Q000378:metabolism
D016229:Amyloid beta-Peptides; D055504:Insulin Receptor Substrate Proteins; C526298:Irs2 protein, mouse; D016875:tau Proteins