Synaptojanin 1-linked phosphoinositide dyshomeostasis and cognitive deficits in mouse models of Down's syndrome.
Phosphatidylinositol-4,5-bisphosphate [PtdIns(4,5)P(2)] is a signaling phospholipid implicated in a wide variety of cellular functions. At synapses, where normal PtdIns(4,5)P(2) balance is required for proper neurotransmission, the phosphoinositide phosphatase synaptojanin 1 is a key regulator of its metabolism. The underlying gene, SYNJ1, maps to human chromosome 21 and is thus a candidate for involvement in Down's syndrome (DS), a complex disorder resulting from the overexpression of trisomic genes. Here, we show that PtdIns(4,5)P(2) metabolism is altered in the brain of Ts65Dn mice, the most commonly used model of DS. This defect is rescued by restoring Synj1 to disomy in Ts65Dn mice and is recapitulated in transgenic mice overexpressing Synj1 from BAC constructs. These transgenic mice also exhibit deficits in performance of the Morris water maze task, suggesting that PtdIns(4,5)P(2) dyshomeostasis caused by gene dosage imbalance for Synj1 may contribute to brain dysfunction and cognitive disabilities in DS.
Voronov
Sergey V
SV
Department of Pathology and Cell Biology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY 10032, USA.
Frere
Samuel G
SG
Giovedi
Silvia
S
Pollina
Elizabeth A
EA
Borel
Christelle
C
Zhang
Hong
H
Schmidt
Cecilia
C
Akeson
Ellen C
EC
Wenk
Markus R
MR
Cimasoni
Laurent
L
Arancio
Ottavio
O
Davisson
Muriel T
MT
Antonarakis
Stylianos E
SE
Gardiner
Katheleen
K
De Camilli
Pietro
P
Di Paolo
Gilbert
G
D000818:Animals; D001921:Brain / Q000201:enzymology / Q000473:pathology; D003072:Cognition Disorders / Q000201:enzymology*; D004195:Disease Models, Animal; D004314:Down Syndrome / Q000201:enzymology*; D018628:Gene Dosage; D006706:Homeostasis; D007858:Learning; D008297:Male; D018782:Maze Learning; D051379:Mice; D008810:Mice, Inbred C57BL; D008822:Mice, Transgenic; D009419:Nerve Tissue Proteins / Q000235:genetics / Q000378:metabolism*; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000378:metabolism*; D010744:Phosphoric Monoester Hydrolases / Q000235:genetics / Q000378:metabolism*; D000099182:Phosphoinositide 5-Phosphatases
D009419:Nerve Tissue Proteins; D019269:Phosphatidylinositol 4,5-Diphosphate; D010744:Phosphoric Monoester Hydrolases; D000099182:Phosphoinositide 5-Phosphatases; C097702:synaptojanin