title: Divergent roles of GSK3 and CDK5 in APP processing.
abstract: Glycogen synthase kinase-3 (GSK3) and cyclin-dependent kinase 5 (CDK5) are related serine/threonine kinases that have been well studied for their role in tau hyperphosphorylation, however, little is known about their significance in APP processing. Here we report that GSK3 and CDK5 are involved in APP processing in a divergent manner. Specific inhibition of cellular GSK3 by lithium or GSK3beta antisense elicits a reduction in Abeta. Conversely, negative modulation of cellular CDK5 activity by CDK5 inhibitor, roscovitine, or CDK5 antisense stimulates Abeta production. Neither GSK3 nor CDK5 inhibition by these means significantly affected cellular APP levels or APP maturation. Moreover, oral administration of lithium significantly reduces Abeta production whereas direct ICV administration of roscovitine augmented Abeta production in the brains of PDAPP (APP(V717F)) mice. Our data support a function for both GSK3 and CDK5 in APP processing, further implicating these two kinases in the pathogenesis of Alzheimer's disease.
authors.affiliation: Neuroscience Discovery Research, Lilly Research Laboratories, Indianapolis, IN 46285, USA. ryder_john_w@lilly.com
authors.forename: John
authors.initials: J
authors.lastname: Ryder
authors.forename: Yuan
authors.initials: Y
authors.lastname: Su
authors.forename: Feng
authors.initials: F
authors.lastname: Liu
authors.forename: Baolin
authors.initials: B
authors.lastname: Li
authors.forename: Yan
authors.initials: Y
authors.lastname: Zhou
authors.forename: Binhui
authors.initials: B
authors.lastname: Ni
mesh_terms: D000544:Alzheimer Disease / Q000201:enzymology*; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D000818:Animals; D002460:Cell Line; D051360:Cyclin-Dependent Kinase 5; D018844:Cyclin-Dependent Kinases / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D004305:Dose-Response Relationship, Drug; D038362:Glycogen Synthase Kinase 3 / Q000037:antagonists & inhibitors* / Q000378:metabolism*; D008094:Lithium / Q000494:pharmacology; D051379:Mice; D008822:Mice, Transgenic; D011687:Purines / Q000494:pharmacology; D000077546:Roscovitine
chemical_list: D016564:Amyloid beta-Protein Precursor; D011687:Purines; D000077546:Roscovitine; D008094:Lithium; D051360:Cyclin-Dependent Kinase 5; C495906:Cdk5 protein, mouse; D018844:Cyclin-Dependent Kinases; D038362:Glycogen Synthase Kinase 3