Connexin43 repression following epithelium-to-mesenchyme transition in embryonal carcinoma cells requires Snail1 transcription factor.
Embryonic stem (ES) cells and embryonal carcinoma (EC) cells express high amounts of functional connexin43 (Cx43). During mesoderm formation and subsequent cardiac differentiation, Cx43 is initially down-regulated but is up-regulated again as the emerging cardiomyocytes mature. In this study, we investigated the regulation of Cx43 expression during early phases of differentiation in F9 and P19 EC cells. We found a striking inverse correlation between the expression of Cx43 and that of the transcriptional repressor Snail1. No clear relationship was found with Smad-interacting-protein1 (SIP1), another transcription factor inducing epithelium-to-mesenchyme transition (EMT). Promoter-reporter assays indicated Cx43 repression at the promoter level by ectopically expressed Snail1. To establish whether the Cx43 down-regulation depends on endogenous Snail1, MES-1 cells, differentiated derivatives of P19 EC, were stably transfected by an siRNA construct silencing Snail1 expression. This resulted in a mesenchyme-to-epithelium transition, which was accompanied by increased levels of Cx43 mRNA and protein and enhanced metabolic and electrical coupling. We conclude that Snail1-mediated EMT results in a Cx43 repression.
de Boer
Teun P
TP
Department of Medical Physiology, University Medical Center Utrecht, Yalelaan 50, 3584 CM Utrecht, The Netherlands.
van Veen
Toon A B
TA
Bierhuizen
Marti F A
MF
Kok
Bart
B
Rook
Martin B
MB
Boonen
Kristel J M
KJ
Vos
Marc A
MA
Doevendans
Pieter A
PA
de Bakker
Jacques M T
JM
van der Heyden
Marcel A G
MA
D000818:Animals; D018236:Carcinoma, Embryonal; D045744:Cell Line, Tumor; D018031:Connexin 43 / Q000235:genetics* / Q000378:metabolism; D015536:Down-Regulation; D053595:Embryonic Stem Cells / Q000166:cytology / Q000378:metabolism*; D004848:Epithelium / Q000378:metabolism*; D005455:Fluorescent Antibody Technique; D020868:Gene Silencing; D008648:Mesoderm / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D011401:Promoter Regions, Genetic; D012333:RNA, Messenger / Q000378:metabolism; D034741:RNA, Small Interfering / Q000378:metabolism; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism*; D014162:Transfection
D018031:Connexin 43; D012333:RNA, Messenger; D034741:RNA, Small Interfering; C000604429:Snai1 protein, mouse; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors