title: Age-dependent neurovascular abnormalities and altered microglial morphology in the YAC128 mouse model of Huntington disease.
abstract: Central nervous system (CNS) inflammatory processes including microglial activation have been implicated in the pathogenesis of neurodegenerative diseases such as Huntington Disease (HD). We report age-dependent changes in striatal microglial morphology and vasculature in the YAC128 mouse model of HD. Decreases in microglial ramification along with a decrease in vessel diameter and increased vessel density and length suggest the presence of microgliosis and proangiogenic activity in YAC128 mice. Our hypothesis for this study was that the changes in microglial morphology and perturbations in vasculature may be involved in the pathogenesis of HD and that peripheral challenge with the bacterial endotoxin, lipopolysaccharide (LPS), will exacerbate these microglial and vascular changes as well as the HD phenotype in YAC128 mice at 12 months. Chronic peripheral LPS (1mg/kg) potentiated microglial activation indicated by an increase in microglial cell body size and retraction of processes. This potentiation in microglial activation with chronic peripheral LPS challenge was paralleled with vascular remodeling including dilatation, increased vessel wall thickness, increased BBB permeability and fibrinogen deposition in YAC128 striatum. Although peripheral LPS caused an increase in microglial activation and degenerative changes in cerebrovasculature, the phenotypic hallmarks of HD in YAC128 mice such as motor coordination deficits and decreased striatal volume were not exacerbated by chronic peripheral LPS exposure. This study identifies age-dependent increases in microglial activation and angiogenesis in YAC128 at 12 months. Peripheral inflammation induced by chronic LPS causes similar changes but does not influence the HD phenotype in YAC128 mice.
authors.affiliation: Centre for Molecular Medicine and Therapeutics and Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, BC, Canada V5Z 4H4.
authors.forename: Sonia
authors.initials: S
authors.lastname: Franciosi
authors.forename: Jae K
authors.initials: JK
authors.lastname: Ryu
authors.forename: Yaein
authors.initials: Y
authors.lastname: Shim
authors.forename: Austin
authors.initials: A
authors.lastname: Hill
authors.forename: Colum
authors.initials: C
authors.lastname: Connolly
authors.forename: Michael R
authors.initials: MR
authors.lastname: Hayden
authors.forename: James G
authors.initials: JG
authors.lastname: McLarnon
authors.forename: Blair R
authors.initials: BR
authors.lastname: Leavitt
mesh_terms: D000367:Age Factors; D000818:Animals; D001812:Blood-Brain Barrier / Q000378:metabolism / Q000473:pathology; D001921:Brain / Q000098:blood supply* / Q000378:metabolism / Q000473:pathology*; D048430:Cell Shape; D003342:Corpus Striatum / Q000098:blood supply / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D005260:Female; D006816:Huntington Disease / Q000235:genetics / Q000378:metabolism / Q000473:pathology*; D008297:Male; D051379:Mice; D008822:Mice, Transgenic; D017628:Microglia / Q000378:metabolism / Q000473:pathology*; D010641:Phenotype