TY - JOUR
T1 - Deletion of astrocyte connexins 43 and 30 leads to a dysmyelinating phenotype and hippocampal CA1 vacuolation
AU - Lutz, Sarah E.
AU - Zhao, Yongmei
AU - Gulinello, Maria
AU - Lee, Sunhee C.
AU - Raine, Cedric S.
AU - Brosnan, Celia F.
PY - 2009/6/17
Y1 - 2009/6/17
N2 - Astrocytes are coupled via gap junctions (GJs) comprising connexin 43 (Cx43) (Gja1) and Cx30 (Gjb6), which facilitate intercellular exchange of ions. Astrocyte connexins also form heterotypic GJs with oligodendrocytic somata and lamellae. Loss of oligodendrocyte gap junctions results in oligodendrocyte and myelin pathology. However, whether loss of astrocyte GJs affects oligodendrocytes and myelin is not known. To address this question, mice with astrocyte-targeted deletion of Cx43 and global loss of Cx30 [double knock-out (dKO)] were studied using Western blotting, immunohistochemistry, electron microscopy, and functional assays. Commencing around postnatal day 23 and persisting into old age, we found widespread pathology of white matter tracts comprising vacuolated oligodendrocytes and intramyelinic edema. In contrast, gray matter pathology was restricted to theCA1region of the hippocampus, and consisted of edematous astrocytes. No differences were observed in synaptic density or total NeuN+ cells in the hippocampus, or olig2+ cells in the corpus callosum. However, in dKO mice, fewer CC1-positive mature oligodendrocytes were detected, and Western blotting indicated reduced myelin basic protein. Pathology was not noted in mice expressing a single allele of either Cx43 or Cx30. When compared with single connexin knock-outs, dKO mice were impaired in sensorimotor (rotarod, balance beam assays) and spatial memory tasks (object recognition assays). We conclude that loss of astrocytic GJs can result in white matter pathology that has functional consequences.
AB - Astrocytes are coupled via gap junctions (GJs) comprising connexin 43 (Cx43) (Gja1) and Cx30 (Gjb6), which facilitate intercellular exchange of ions. Astrocyte connexins also form heterotypic GJs with oligodendrocytic somata and lamellae. Loss of oligodendrocyte gap junctions results in oligodendrocyte and myelin pathology. However, whether loss of astrocyte GJs affects oligodendrocytes and myelin is not known. To address this question, mice with astrocyte-targeted deletion of Cx43 and global loss of Cx30 [double knock-out (dKO)] were studied using Western blotting, immunohistochemistry, electron microscopy, and functional assays. Commencing around postnatal day 23 and persisting into old age, we found widespread pathology of white matter tracts comprising vacuolated oligodendrocytes and intramyelinic edema. In contrast, gray matter pathology was restricted to theCA1region of the hippocampus, and consisted of edematous astrocytes. No differences were observed in synaptic density or total NeuN+ cells in the hippocampus, or olig2+ cells in the corpus callosum. However, in dKO mice, fewer CC1-positive mature oligodendrocytes were detected, and Western blotting indicated reduced myelin basic protein. Pathology was not noted in mice expressing a single allele of either Cx43 or Cx30. When compared with single connexin knock-outs, dKO mice were impaired in sensorimotor (rotarod, balance beam assays) and spatial memory tasks (object recognition assays). We conclude that loss of astrocytic GJs can result in white matter pathology that has functional consequences.
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U2 - 10.1523/JNEUROSCI.0341-09.2009
DO - 10.1523/JNEUROSCI.0341-09.2009
M3 - Article
C2 - 19535586
AN - SCOPUS:67449119205
SN - 0270-6474
VL - 29
SP - 7743
EP - 7752
JO - Journal of Neuroscience
JF - Journal of Neuroscience
IS - 24
ER -