title: Gap junctional communication is required to maintain mouse cortical neural progenitor cells in a proliferative state.
abstract: The mechanisms that determine whether neural stem cells remain in a proliferative state or differentiate into neurons or glia are largely unknown. Here we establish a pivotal role for gap junction-mediated intercellular communication in determining the proliferation and survival of mouse neural progenitor cells (NPCs). When cultured in the presence of basic fibroblast growth factor (bFGF), NPCs express the gap junction protein connexin 43 and are dye-coupled. Upon withdrawal of bFGF, levels of connexin 43 and dye coupling decrease, and the cells cease proliferating and differentiate into neurons; the induction of gap junctions by bFGF is mediated by p42/p44 mitogen-activated protein kinases. Inhibition of gap junctions abolishes the ability of bFGF to maintain NPCs in a proliferative state resulting in cell differentiation or cell death, while overexpression of connexin 43 promotes NPC self-renewal in the absence of bFGF. In addition to promoting their proliferation, gap junctions are required for the survival of NPCs. Gap junctional communication is therefore both necessary and sufficient to maintain NPCs in a self-renewing state.
authors.affiliation: Laboratory of Neurosciences, National Institute on Aging Intramural Research Program, Baltimore, MD 21224, USA. chengai@grc.nia.nih.gov
authors.forename: Aiwu
authors.initials: A
authors.lastname: Cheng
authors.forename: Hongyan
authors.initials: H
authors.lastname: Tang
authors.forename: Jingli
authors.initials: J
authors.lastname: Cai
authors.forename: Min
authors.initials: M
authors.lastname: Zhu
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Zhang
authors.forename: Mahendra
authors.initials: M
authors.lastname: Rao
authors.forename: Mark P
authors.initials: MP
authors.lastname: Mattson
mesh_terms: D000818:Animals; D002450:Cell Communication; D002455:Cell Division / Q000502:physiology; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology* / Q000196:embryology; D018031:Connexin 43 / Q000378:metabolism; D004789:Enzyme Activation; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D005456:Fluorescent Dyes / Q000378:metabolism; D017629:Gap Junctions / Q000502:physiology*; D051379:Mice; D008810:Mice, Inbred C57BL; D020928:Mitogen-Activated Protein Kinases / Q000187:drug effects / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000502:physiology; D013234:Stem Cells / Q000166:cytology* / Q000187:drug effects / Q000502:physiology
chemical_list: D018031:Connexin 43; D005456:Fluorescent Dyes; D016222:Fibroblast Growth Factor 2; D020928:Mitogen-Activated Protein Kinases