Signaling Mechanisms in Embryonic Stem Cells
Research Team Daniel Besser
Max-Delbrück-Center for Molecular Medicine, Berlin-Buch, Germany
Embryonic stem cells (ESC) are pluripotent cells, which can proliferate indefinitely and participate in the formation of most cell types. Studies on human ESCs (hESC) provide an insight into human embryogenesis and allow the development of tools for pharmacology and regenerative medicine. The focus of our studies is the maintenance of the pluripotent state in murine ESCs (mESCs) and hESCs. We found that the Activin/Nodal pathway is activated in pluripotent hESCs and blocked upon differentiation. Pluripotent cells require these signaling regulating a specific subset of target genes. In addition, the BMP pathway is in the off-state in pluripotent cells and activated upon differentiation. This pathway counteracts the effects of Activin signaling. Moreover, it has been shown that somatic cells for various sources can be reprogrammed by transfection of four defined transcription factors, i.e. Oct4, Sox2, Klf4, and c-Myc, to a pluripotent state. These induced pluripotent stem cells (iPS) are very exciting new cell populations for stem cell research.
Research Projects