Laminin 伪1 domains LG4-5 are essential for the complete differentiation of visceral endoderm
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- 作者：Mikael 脜kerlund ; Virginie Carmignac ; Susanne Sch茅ele and Madeleine Durbeej
- 关键词：Visceral endoderm ; Laminin alpha1 ; Microarray ; Endocytosis ; Secreted plasma proteins ; Embryonic stem cells ; Embryoid bodies ; Mouse
- 刊名：Cell and Tissue Research
- 出版时间：October, 2009
- 出版年：2009
- 期刊代码：30_0302-766X
- 类别：med
- 卷：338
- 期：1
- 页码：129-137
- 数据来源：sp
摘要
The heterotrimeric basement membrane protein laminin-111 is essential for early mouse embryogenesis. Its β1 and γ1 chains are crucial for endoderm differentiation and for the formation of basement membranes, whereas α1 chain null mice only lack the extraembryonic Reichert’s membrane. Nevertheless, mice deficient in the cell-binding α1 globular domains 4-5 (LG4-5) have a more severe phenotype than animals devoid of the whole α1 chain, as these domains are required for the formation of a polarized ectoderm. However, the influence of the α1LG4-5 domains on endoderm differentiation is unclear. We have used microarray analysis to compare the expression profiles of normal and α1LG4-5-deficient embryoid bodies and show that genes encoding secreted plasma proteins and proteins involved in endocytosis are reduced in α1LG4-5-deficient embryoid bodies, indicating incomplete differentiation of the visceral endoderm. Moreover, mice lacking α1LG4-5 display endoderm disorganization and a defective expression of the endoderm marker Dab2. We hypothesize that α1LG4-5 domains provide an autocrine signal necessary for the complete differentiation of a functional visceral endoderm and vital signals for the polarization of the epiblast.