title: Establishment of an improved mouse model for infantile neuroaxonal dystrophy that shows early disease onset and bears a point mutation in Pla2g6.
abstract: Calcium-independent group VIA phospholipase A(2) (iPLA(2)beta), encoded by PLA2G6, has been shown to be involved in various physiological and pathological processes, including immunity, cell death, and cell membrane homeostasis. Mutations in the PLA2G6 gene have been recently identified in patients with infantile neuroaxonal dystrophy (INAD). Subsequently, it was reported that similar neurological impairment occurs in gene-targeted mice with a null mutation of iPLA(2)beta, whose disease onset became apparent approximately 1 to 2 years after birth. Here, we report the establishment of an improved mouse model for INAD that bears a point mutation in the ankyrin repeat domain of Pla2g6 generated by N-ethyl-N-nitrosourea mutagenesis. These mutant mice developed severe motor dysfunction, including abnormal gait and poor performance in the hanging grip test, as early as 7 to 8 weeks of age, in a manner following Mendelian law. Neuropathological examination revealed widespread formation of spheroids containing tubulovesicular membranes similar to human INAD. Molecular and biochemical analysis revealed that the mutant mice expressed Pla2g6 mRNA and protein, but the mutated Pla2g6 protein had no glycerophospholipid-catalyzing enzyme activity. Because of the significantly early onset of the disease, this mouse mutant (Pla2g6-inad) could be highly useful for further studies of pathogenesis and experimental interventions in INAD and neurodegeneration.
authors.affiliation: Division of Bioregulation Research, Institute of Medical Science, St. Marianna University School of Medicine, Kawasaki-City, Kanagawa, Japan.
authors.forename: Haruka
authors.initials: H
authors.lastname: Wada
authors.forename: Takuwa
authors.initials: T
authors.lastname: Yasuda
authors.forename: Ikuo
authors.initials: I
authors.lastname: Miura
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Watabe
authors.forename: Chika
authors.initials: C
authors.lastname: Sawa
authors.forename: Hajime
authors.initials: H
authors.lastname: Kamijuku
authors.forename: Satoshi
authors.initials: S
authors.lastname: Kojo
authors.forename: Masaru
authors.initials: M
authors.lastname: Taniguchi
authors.forename: Ichizo
authors.initials: I
authors.lastname: Nishino
authors.forename: Shigeharu
authors.initials: S
authors.lastname: Wakana
authors.forename: Hisahiro
authors.initials: H
authors.lastname: Yoshida
authors.forename: Ken-ichiro
authors.initials: K
authors.lastname: Seino
mesh_terms: D017668:Age of Onset; D000818:Animals; D001483:Base Sequence; D015153:Blotting, Western; D004195:Disease Models, Animal; D054522:Group VI Phospholipases A2 / Q000235:genetics*; D051379:Mice; D008817:Mice, Mutant Strains; D046529:Microscopy, Electron, Transmission; D019150:Neuroaxonal Dystrophies / Q000235:genetics* / Q000473:pathology*; D017354:Point Mutation; D016133:Polymerase Chain Reaction
chemical_list: D054522:Group VI Phospholipases A2; C516476:Pla2g6 protein, mouse