Basic FGF increases communication between cells of the developing neocortex.
We have found that basic fibroblast growth factor (bFGF), applied to cortical progenitor cells in vitro, produces an increase in the expression of the gap junction protein connexin (Cx) 43 and in the mRNA encoding Cx 43. This effect was evident in both proliferating and nonproliferating cells. The elevated levels of mRNA suggest that bFGF is likely to exert its effect by upregulating the rate of transcription of the Cx 43 gene. We have further shown that the increase in Cx 43 expression is mediated through the receptor tyrosine kinase pathway and is associated with enhanced intercellular dye-coupling mediated by gap junctions. These results suggest that gap junction channels provide a direct conduit for mitogens released in response to bFGF to effectively regulate proliferation during corticogenesis.
Nadarajah
B
B
Department of Anatomy and Developmental Biology, University College London, London WC1E 6BT, United Kingdom.
Makarenkova
H
H
Becker
D L
DL
Evans
W H
WH
Parnavelas
J G
JG
D000818:Animals; D002450:Cell Communication / Q000187:drug effects*; D002478:Cells, Cultured; D018031:Connexin 43 / Q000032:analysis / Q000235:genetics; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology*; D005456:Fluorescent Dyes; D017629:Gap Junctions / Q000737:chemistry; D015870:Gene Expression / Q000187:drug effects; D007546:Isoquinolines; D019579:Neocortex / Q000166:cytology*; D009474:Neurons / Q000737:chemistry / Q000166:cytology*; D012333:RNA, Messenger / Q000032:analysis; D051381:Rats; D013234:Stem Cells / Q000737:chemistry / Q000166:cytology
D018031:Connexin 43; D005456:Fluorescent Dyes; D007546:Isoquinolines; D012333:RNA, Messenger; D016222:Fibroblast Growth Factor 2; C017475:lucifer yellow