title: Regulation of mesodermal differentiation of mouse embryonic stem cells by basement membranes.
abstract: Basement membranes (BMs) have been implicated in cell fate determination during development. Embryoid bodies (EBs) derived from mouse embryonic stem cells deficient in the laminin gamma1 chain are incapable of depositing a BM, resulting in failure of primitive ectoderm epithelialization. To elucidate the mechanisms involved in this phenomenon, we compared the gene expression profiles of EBs with or without a BM to identify the genes showing BM-dependent expression. We found that the expressions of marker genes for the epithelial-mesenchymal transition (EMT), including the transcription factor Snai2, were up-regulated in LAMC1(-/-) EBs, whereas restoration of a BM to LAMC1(-/-) EBs suppressed the up-regulation of these genes. Overexpression of Snai2 induced the EMT in control EBs by molecular and morphological criteria, suggesting that suppression of the EMT regulatory genes is involved in BM-dependent epithelialization of primitive ectoderm. Despite the failure of primitive ectoderm epithelialization in BM-deficient EBs, mesodermal differentiation was not compromised, but rather accelerated. Furthermore, at later stages of control EB differentiation, the BM was disrupted at the gastrulation site where mesodermal markers were strongly expressed only in cells that had lost contact with the BM. Taken together, these results indicate that the BM prevents the EMT and precocious differentiation of primitive ectoderm toward mesoderm in EBs, implying that BMs are important for the control of mammalian gastrulation.
authors: Institute for Protein Research, Osaka University, Osaka 565-0871, Japan.
authors: Hironobu
authors: H
authors: Fujiwara
authors: Yoshitaka
authors: Y
authors: Hayashi
authors: Noriko
authors: N
authors: Sanzen
authors: Reiko
authors: R
authors: Kobayashi
authors: Charles N
authors: CN
authors: Weber
authors: Tomomi
authors: T
authors: Emoto
authors: Sugiko
authors: S
authors: Futaki
authors: Hitoshi
authors: H
authors: Niwa
authors: Patricia
authors: P
authors: Murray
authors: David
authors: D
authors: Edgar
authors: Kiyotoshi
authors: K
authors: Sekiguchi
mesh_terms: D000818:Animals; D001485:Basement Membrane / Q000378:metabolism*; D002454:Cell Differentiation; D019070:Cell Lineage; D004475:Ectoderm / Q000378:metabolism; D053595:Embryonic Stem Cells / Q000166:cytology*; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental; D007797:Laminin / Q000502:physiology; D008648:Mesoderm / Q000378:metabolism*; D051379:Mice; D008822:Mice, Transgenic; D012097:Repressor Proteins / Q000378:metabolism; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors / Q000502:physiology; D051879:Twist-Related Protein 1 / Q000378:metabolism
chemical_list: D007797:Laminin; D012097:Repressor Proteins; C000604449:Snai2 protein, mouse; D000071250:Snail Family Transcription Factors; D014157:Transcription Factors; D051879:Twist-Related Protein 1; C096852:Twist2 protein, mouse; C089141:laminin gamma 1