Abstract
Human embryonic stem cells (hESCs) have the ability to differentiate into all human cells, however controlling the differentiation has always been a challenge. In the present study we have investigated the direct differentiation of hESCs on MEFs by using TGF-beta signaling pathway activators Activin A and Activin B. Activation of the TGF-beta pathway with Activin B in low serum highly induced primitive streak and mesendoderm formation after 24 h, which included up-regulation of SOX 17 and BRACHYURY protein and gene expression. Continuous stimulation with Activin B in 2% serum further induced mesendoderm formation by increased gene expression of Brachyury, SOX17, MEOX and FOX at the same time we found down-regulation of neuroectodermal marker genes. Further, by stimulating the mesodermal cells by BMP-2 we succeeded to induce mesenchymal like cells with high expression of mesenchymal markers including; MEOX, FOX, RUNX2, COL1 and OSTEOPONTIN. In conclusion we have directed the differentiation of hESCs as monolayer to primitive streak like cells with Activin B and further into pure mesoderm and mesenchymal like cells by BMP-2. (C) 2015 The Authors. Production and hosting by Elsevier B.V. on behalf of King Saud University. This is an open access article under the CC BY-NC-ND license.