title: Epidermal growth factor down-regulates connexin-43 expression in cultured rat cortical astrocytes.
abstract: Astrocytes are coupled via gap junction channels, predominantly formed by connexin-43 (Cx43), and contribute to neuronal function in the normal and diseased brain. In this study, we demonstrate that epidermal growth factor (EGF), applied to cortical astrocytes, results in a decrease in the expression of Cx43 mRNA and protein. We have further shown that the decrease is associated with the receptor tyrosine kinase pathway and the MEK inhibitor prevents EGF-stimulated down-regulation of Cx43 expression. These findings demonstrate a previously unknown function of EGF on cultured astrocytes, which may be relevant to the regulation of astrocytic growth and differentiation.
authors.affiliation: Department of Bioregulation Research, Nagoya City University Medical School, 1 Kawasumi, Mizuho-cho, Mizuho-ku, Nagoya, Aichi 467-8601, Japan. uetaka@med.nagoya-cu.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Ueki
authors.forename: M
authors.initials: M
authors.lastname: Fujita
authors.forename: K
authors.initials: K
authors.lastname: Sato
authors.forename: K
authors.initials: K
authors.lastname: Asai
authors.forename: K
authors.initials: K
authors.lastname: Yamada
authors.forename: T
authors.initials: T
authors.lastname: Kato
mesh_terms: D000818:Animals; D001253:Astrocytes / Q000166:cytology / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D018031:Connexin 43 / Q000235:genetics* / Q000378:metabolism; D015536:Down-Regulation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004815:Epidermal Growth Factor / Q000494:pharmacology*; D005419:Flavonoids / Q000494:pharmacology; D015870:Gene Expression / Q000187:drug effects; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases / Q000037:antagonists & inhibitors; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D017208:Rats, Wistar
chemical_list: D018031:Connexin 43; D004791:Enzyme Inhibitors; D005419:Flavonoids; D012333:RNA, Messenger; D004815:Epidermal Growth Factor; D017346:Protein Serine-Threonine Kinases; D020928:Mitogen-Activated Protein Kinases; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one