Amyloid precursor protein knockdown by siRNA impairs spontaneous alternation in adult mice.
The cleavage-product of amyloid precursor protein (APP) constitutes the core component of plaques found in the brains of Alzheimer's disease (AD) patients. APP is ubiquitously expressed and its precise physiological functions remain unclear. This protein has been proposed to regulate synaptic function and processes underlying learning and memory. While APP knockout mice show behavioral impairments, these may occur due to early changes during development and/or due to abolition of APP function in adult. To investigate the acute effects of APP knockdown without involving developmental processes, APP expression was reduced using RNA interference in adult mouse brain. Small interfering RNAs (siRNAs) that down-regulated mouse APP protein levels (APP-siRNA) were identified using an APP plasmid-siRNA co-transfection assay in mouse NIH/3T3 fibroblast cells. Infusion of APP-siRNAs into the ventricular system for 2 weeks also down-regulated APP mRNA in mouse brain. Highest knockdown of APP mRNA levels was found in the CA2-CA3 regions of the hippocampus. Mice treated with the most active APP-siRNA showed a significant reduction in spontaneous alternation rate in the Y-maze, without effects on forelimb grip strength or locomotor activity. These data suggest that acute knockdown of APP in adult mouse brain impairs hippocampus-dependent spatial working memory.
Senechal
Yann
Y
Department of Neuroscience Research, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Lichtstrasse, Basel, SwitzerlandDepartment of Functional Genomics, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Lichtstrasse, Basel, Switzerland.
Kelly
Peter H
PH
Department of Neuroscience Research, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Lichtstrasse, Basel, SwitzerlandDepartment of Functional Genomics, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Lichtstrasse, Basel, Switzerland.
Cryan
John F
JF
Department of Neuroscience Research, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Lichtstrasse, Basel, SwitzerlandDepartment of Functional Genomics, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Lichtstrasse, Basel, Switzerland.
Natt
Francois
F
Department of Neuroscience Research, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Lichtstrasse, Basel, SwitzerlandDepartment of Functional Genomics, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Lichtstrasse, Basel, Switzerland.
Dev
Kumlesh K
KK
Department of Neuroscience Research, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Lichtstrasse, Basel, SwitzerlandDepartment of Functional Genomics, Novartis Institutes for BioMedical Research, Novartis Pharma AG, Lichtstrasse, Basel, Switzerland.
D000544:Alzheimer Disease / Q000235:genetics / Q000378:metabolism / Q000503:physiopathology; D016564:Amyloid beta-Protein Precursor / Q000235:genetics* / Q000378:metabolism*; D000818:Animals; D001522:Behavior, Animal / Q000187:drug effects / Q000502:physiology; D015536:Down-Regulation / Q000235:genetics*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism* / Q000503:physiopathology; D008297:Male; D018782:Maze Learning / Q000502:physiology; D008569:Memory Disorders / Q000235:genetics / Q000378:metabolism* / Q000503:physiopathology; D008570:Memory, Short-Term / Q000502:physiology; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D041681:NIH 3T3 Cells; D034622:RNA Interference / Q000502:physiology; D034741:RNA, Small Interfering / Q000235:genetics* / Q000494:pharmacology
D016564:Amyloid beta-Protein Precursor; D034741:RNA, Small Interfering