Fibronectin-mediated upregulation of α5β1 integrin and cell adhesion during differentiation of mouse embryonic stem cells
Fibronectin-mediated upregulation of α5β1 integrin and cell adhesion during differentiation of mouse embryonic stem cells
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DOI：
10.4161/cam.5.1.13704
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发表时间：
2011-01-01
影响因子：
3.2
通讯作者：
Lelkes, Peter I.
中科院分区：
文献类型：
--
作者：
Pimton, Pimchanok;Sarkar, Saheli;Lelkes, Peter I.
胚胎干细胞在再生医学中具有广泛的应用前景，可以分化为所有三个胚层的细胞。ES细胞与细胞外基质（ECM）蛋白的粘附对于分化途径是必不可少的;细胞-ECM粘附由具有激活许多细胞内信号传导途径的能力的整合素介导。因此，我们推测整合素受体的表达和功能是ES分化的关键步骤。使用功能性细胞粘附试验，我们的研究表明，α 5 β 1是一个主要的功能性整合素受体表达在未分化的小鼠ES-D3细胞的细胞表面，这表明显着更高的结合纤连蛋白相比，胶原蛋白。这种粘附是由整联蛋白α 5 β 1特异性介导的，这从对这种特定整联蛋白具有选择性的去整联蛋白的抑制中可以看出。ES-D3细胞在纤连蛋白或1型胶原/纤连蛋白基质上的分化引起α 5 β 1整联蛋白的进一步选择性上调。通过免疫荧光、FACS分析和定量RT-PCR评价的细胞分化伴随着间充质（Flk 1、同种凝集素B4、α-SMA、波形蛋白）和内胚层标志物（FoxA 2、SOX 17、细胞角蛋白）的上调，同时α 5 β 1整联蛋白的表达增加。总之，数据表明，纤连蛋白介导的α 5 β 1整联蛋白的上调和ES-D3细胞与特定ECM分子的粘附与小鼠胚胎干细胞向中-内胚层分化的早期阶段有关。
Embryonic stem (ES) cells have a broad potential application in regenerative medicine and can be differentiated into cells of all three germ layers. Adhesion of ES cells to extracellular matrix (ECM) proteins is essential for the differentiation pathway; cell-ECM adhesion is mediated by integrins that have the ability to activate many intracellular signaling pathways. Therefore, we hypothesize that the expression and function of integrin receptors is a critical step in ES differentiation. Using functional cell adhesion assays, our study demonstrates that alpha 5 beta 1 is a major functional integrin receptor expressed on the cell surface of undifferentiated mouse ES-D3 cells, which showed significantly higher binding to fibronectin as compared to collagens. This adhesion was specifically mediated by integrin alpha 5 beta 1 as evident from the inhibition with a disintegrin selective for this particular integrin. Differentiation of ES-D3 cells on fibronectin or on a collagen type1/fibronectin matrix, caused further selective upregulation of the alpha 5 beta 1 integrin. Differentiation of the cells, as evaluated by immunofluorescence, FACS analysis and quantitative RT-PCR, was accompanied by the upregulation of mesenchymal (Flk1, isolectin B4, alpha-SMA, vimentin) and endodermal markers (FoxA2, SOX 17, cytokeratin) in parallel to increased expression of alpha 5 beta 1 integrin. Taken together, the data indicate that fibronectin-mediated, upregulation of alpha 5 beta 1 integrin and adhesion of ES-D3 cells to specific ECM molecules are linked to early stages of mouse embryonic stem cells commitment to meso-endodermal differentiation.