???aural:Bildanfang???Protein-induced pluripotent stem cells (piPS) from young murine fibroblasts. The green-fluorescent marker gene Oct4 shows specifically pluripotent cells © Max Planck Institute for Molecular Biomedicine / Jin Young Joo???aural:Bildende???

US and German researchers found a new way to create protein-induced
pluripotent stem cells. These stem cells, so-called piPS, have been produced for the first time without genetically modifying the cells' genome. Hans Schöler's group at the MPI for Molecular Biomedicine in Münster showed that cells from the Scripps Research Institute in California can turn into all cell types. This method of reprogramming somatic cells is easier and safer than previous procedures.

It is another major step towards cancer-resistant stem cell cultures and maybe future stem cell treatment. "The research is dynamic. Landmarks are published almost monthly, in international cooperation," said Schöler, who has been working with Professor Sheng Ding of the Scripps Research Institute since 2004. The Scripps Research Institute supplied embryonic mouse fibroblasts, i.e. precursors to skin cells, with a protein cocktail in vitro. In some genes, the skin cells’ genome was reversed. This is a key to reprogramming skin cells. They can "switch" nearly all cell types.

The MPI scientists first gave the US colleagues their mouse fibroblasts and later tested the reprogrammed cells for pluripotency. "The findings are great. We no longer need gene ferries for murine cells. We can trigger the process by adding special proteins combined with a 'small molecule'," explained Schöler. It helps them bind to the DNA. Genes are the proteins' blueprint. They may become inactive or de generate due to genetic interference. Proteins pose no risk to the genetic material. The US scientists used a short protein link to channel them into the cells. It helps them cross the cellular membrane.

Once in the cell's plasma, the proteins soon die. This is repeated over several days so that the desired stem cell colonies can grow. IPS and piPS stem cells can turn into any cell type and may open up therapies for Parkinson’s, diabetes, or for paraplegic patients for neural function. "We now want to translate this to human cells. That will keep us busy in Münster from early 2010," said Schöler, with extra funding from NRW and the Max Planck Society.

More information: www.mpi-muenster.mpg.de/pr/pressee.shtml

Contact: Dr. Jeanine Müller-Keuker (press officer) presse@mpi-muenster.mpg.de