Induction of primitive streak and mesendoderm formation in monolayer hESC culture by activation of TGF-b signaling pathway by activin B

الملخص EN

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-b signaling pathway activators Activin A and Activin B.

Activation of the TGF-b pathway with Activin B in low serum highly induced primitive streak and mesendoderm formation after 24 h, which included upregulation 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.