Molecular profiling of the basement membrane of pluripotent epiblast cells in post-implantation stage mouse embryos
Molecular profiling of the basement membrane of pluripotent epiblast cells in post-implantation stage mouse embryos
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DOI：
10.1016/j.reth.2019.04.010
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发表时间：
2019-12-15
影响因子：
4.3
通讯作者：
Sekiguchi, Kiyotoshi
中科院分区：
文献类型：
--
作者：
Futaki, Sugiko;Nakano, Itsuko;Sekiguchi, Kiyotoshi
简介：基底膜（BM）是一种片状细胞外基质（ECM），衬于上皮细胞和内皮细胞的基底侧。随着胚胎发育的进行，BM的分子组成多样化，为单个细胞类型提供优化的微环境。在植入后阶段的胚胎中，胚胎BM对于外胚层（一层多能胚胎干细胞）的分化和随后的胚胎发生是必不可少的。为了更好地理解BM和细胞-BM相互作用在早期胚胎发生中的作用，必须积累关于胚胎BM的分子实体的信息。我们分析了20个主要BM蛋白的表达和定位（11个层粘连蛋白亚基，6个IV型胶原亚基，巢蛋白-1和-2，和串珠素）和其他ECM相关蛋白如纤维连接蛋白和整合素在植入后胚胎中的表达。我们发现一组BM蛋白，层粘连蛋白α 5，β 1和γ 1，（包含层粘连蛋白-511）、IV型胶原α 1和α 2（产生IV型胶原α 1（2）α 2 [IV]）、巢蛋白-1和巢蛋白-2以及串珠素在整个早期植入后阶段始终存在于上胚层/外胚层BM中。与此相反，层粘连蛋白α 1在E5.5时在上胚层BM中检测到，但在后期阶段减少，表明层粘连蛋白-511是早期胚胎BM中的主要层粘连蛋白同种型。此外，纤连蛋白，一种间充质ECM蛋白，在内胚层BM中富集，表明外胚层和内胚层之间的BM组成不同。与这些观察结果一致，整合素α 5，一种纤维连接蛋白的高亲和力受体，位于内胚层，而整合素α 6，一种层粘连蛋白-511的受体，位于外胚层。上胚层/外胚层下面的胚胎BM包含共同的工具包，其包括层粘连蛋白-511、IV型胶原蛋白（α 1（2）α 2 [IV]）、巢蛋白-1和-2以及串珠素，为层粘连蛋白-511作为多能干细胞的培养底物的效用提供了生理学基础。层粘连蛋白-511和纤连蛋白与内胚层和外胚层细胞的独特关联，以及整合素α 5和α 6在这些细胞中的差异表达，表明外胚层和内胚层细胞分别依赖于它们与层粘连蛋白-511和纤连蛋白的整合素依赖性相互作用，以确保它们在胚胎发育中的命运特化。(C)2019年，日本再生医学学会。制作和主办：Elsevier B. V.
Introduction: The basement membrane (BM) is a sheet-like extracellular matrix (ECM) lining the basal side of epithelial and endothelial cells. The molecular composition of the BM diversifies as embryonic development proceeds, providing optimized microenvironments for individual cell types. In post-implantation stage embryos, the embryonic BMs are essential for differentiation of the epiblast, a layer of multipotent embryonic stem cells, and subsequent embryogenesis. To better understand the role of BMs and cell-BM interactions in early embryogenesis, it is imperative to accumulate information on the molecular entities of the embryonic BMs.Methods: We analyzed the expressions and localizations of 20 major BM proteins (11 laminin subunits, 6 type IV collagen subunits, nidogen-1 and -2, and perlecan) and other ECM-related proteins such as fibronectin and integrins in post-implantation stage embryos by immunohistochemistry.Results: We found that a set of BM proteins, laminin alpha 5, beta 1, and gamma 1 (comprising laminin-511), type IV collagen alpha 1 and alpha 2 (yielding type IV collagen alpha 1(2)alpha 2 [IV]), nidogen-1 and -2, and perlecan, were consistently present in the epiblast/ectoderm BMs throughout the early post-implantation stages. In contrast, laminin alpha 1 was detected in the epiblast BM at E5.5 but decreased in later stages, suggesting that laminin-511 is a major laminin isoform in the early embryonic BM. In addition, fibronectin, a mesenchymal ECM protein, was enriched in the endoderm BM, indicating that the BM compositions differ between the ectoderm and the endoderm. Consistent with these observations, integrin alpha 5, a high-affinity receptor for fibronectin, was localized in the endoderm, while integrin alpha 6, a receptor for laminin-511, was localized in the ectoderm.Conclusions: The embryonic BMs underlying the epiblast/ectoderm contain a common toolkit comprising laminin-511, type IV collagen (alpha 1(2)alpha 2 [IV]), nidogen-1 and -2, and perlecan, providing a physiological basis for the utility of laminin-511 as a culture substrate for pluripotent stem cells. The distinctive association of laminin-511 and fibronectin with endodermal and ectodermal cells, together with the differential expression of integrin alpha 5 and alpha 6 in these cells, suggests that the ectodermal and endodermal cells rely on their integrin-dependent interactions with laminin-511 and fibronectin, respectively, to ensure their fate specification in embryonic development. (C) 2019, The Japanese Society for Regenerative Medicine. Production and hosting by Elsevier B.V.