title: The extracellular matrix controls gap junction protein expression and function in postnatal hippocampal neural progenitor cells.
abstract: BACKGROUND
  Gap junction protein and extracellular matrix signalling systems act in concert to influence developmental specification of neural stem and progenitor cells. It is not known how these two signalling systems interact. Here, we examined the role of ECM components in regulating connexin expression and function in postnatal hippocampal progenitor cells.
  
  
  RESULTS
  We found that Cx26, Cx29, Cx30, Cx37, Cx40, Cx43, Cx45, and Cx47 mRNA and protein but only Cx32 and Cx36 mRNA are detected in distinct neural progenitor cell populations cultured in the absence of exogenous ECM. Multipotential Type 1 cells express Cx26, Cx30, and Cx43 protein. Their Type 2a progeny but not Type 2b and 3 neuronally committed progenitor cells additionally express Cx37, Cx40, and Cx45. Cx29 and Cx47 protein is detected in early oligodendrocyte progenitors and mature oligodendrocytes respectively. Engagement with a laminin substrate markedly increases Cx26 protein expression, decreases Cx40, Cx43, Cx45, and Cx47 protein expression, and alters subcellular localization of Cx30. These changes are associated with decreased neurogenesis. Further, laminin elicits the appearance of Cx32 protein in early oligodendrocyte progenitors and Cx36 protein in immature neurons. These changes impact upon functional connexin-mediated hemichannel activity but not gap junctional intercellular communication.
  
  
  CONCLUSIONS
  Together, these findings demonstrate a new role for extracellular matrix-cell interaction, specifically laminin, in the regulation of intrinsic connexin expression and function in postnatal neural progenitor cells.
authors.affiliation: Neural Regeneration Laboratory and Ottawa Institute of Systems Biology, Dept. of Biochemistry, Microbiology, and Immunology, University of Ottawa, ON, Canada. even_grable@hotmail.com
authors.forename: Sophie
authors.initials: S
authors.lastname: Imbeault
authors.forename: Lianne G
authors.initials: LG
authors.lastname: Gauvin
authors.forename: Hadi D
authors.initials: HD
authors.lastname: Toeg
authors.forename: Alexandra
authors.initials: A
authors.lastname: Pettit
authors.forename: Catherine D
authors.initials: CD
authors.lastname: Sorbara
authors.forename: Lamiaa
authors.initials: L
authors.lastname: Migahed
authors.forename: Rebecca
authors.initials: R
authors.lastname: DesRoches
authors.forename: A Sheila
authors.initials: AS
authors.lastname: Menzies
authors.forename: Kiyomasa
authors.initials: K
authors.lastname: Nishii
authors.forename: David L
authors.initials: DL
authors.lastname: Paul
authors.forename: Alexander M
authors.initials: AM
authors.lastname: Simon
authors.forename: Steffany Al
authors.initials: SA
authors.lastname: Bennett
mesh_terms: D000818:Animals; D015153:Blotting, Western; D002450:Cell Communication / Q000502:physiology; D002478:Cells, Cultured; D017630:Connexins / Q000235:genetics / Q000378:metabolism*; D005109:Extracellular Matrix / Q000502:physiology*; D005434:Flow Cytometry; D006624:Hippocampus / Q000502:physiology*; D007150:Immunohistochemistry; D007797:Laminin / Q000378:metabolism; D051379:Mice; D018345:Mice, Knockout; D055495:Neurogenesis / Q000502:physiology; D009474:Neurons / Q000502:physiology*; D009836:Oligodendroglia / Q000502:physiology; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013234:Stem Cells / Q000502:physiology*
chemical_list: D017630:Connexins; D007797:Laminin; D012333:RNA, Messenger