Researchers at the Max Delbrück Center for Molecular Medicine (MDC) Berlin-Buch and collaborating institutions have discovered what enables embryonic stem cells to differentiate into diverse cell types and thus to be pluripotent. This pluripotency depends on a specific molecule – E-cadherin – hitherto primarily known for its role in mediating cell-cell adhesion as a kind of “intracellular glue”. If E-cadherin is absent, the stem cells lose their pluripotency. The molecule also plays a crucial role in the reprogramming of somatic cells (body cells) into pluripotent stem cells. The work was reported online in EMBO Reports on May 27, 2011. Dr. Daniel Besser, Prof. Walter Birchmeier, and Torben Redmer from the MDC, a member of the Helmholtz Association, used mouse embryonic fibroblasts (MEFs) in their stem cell experiments. In a first step they showed that the pluripotency of these stem cells is directly associated with the cell-adhesion molecule E-cadherin. If E-cadherin is absent, the stem cells lose their pluripotency. In a second step, the researchers investigated what happens when somatic cells that normally neither have E-cadherin nor are pluripotent are reprogrammed into a pluripotent stem cell state. In this reprogramming technique, somatic cells are converted into induced pluripotent stem cells (iPSCs). This new technique may help researchers avoid the controversies that come with the use of human embryos to produce human embryonic stem cells for research purposes. The MDC researchers found that in contrast to the original cells, the new pluripotent cells derived from mouse connective tissue contained E-cadherin. “Thus, we have double proof that E-cadherin is directly associated with stem-cell pluripotency.
Login Or Register To Read Full Story