January 29, 2014
Japanese Scientists Dip Blood Cells In Acid To Create Stem Cells
Lee Rannals for redOrbit.com - Your Universe Online
In 2006, another team of Japanese scientists discovered that skin cells could be genetically reprogrammed to become stem cells, which is now known as induced pluripotent stem cells, or iPS cells.
The latest research details a method in which cells can be made even more malleable than iPS cells and it can be done faster and more efficiently.
Stimulus-triggered acquisition of pluripotency (STAP) cells involves shocking blood cells with acid to trigger the transformation into stem cells.
“It’s amazing. I would have never thought external stress could have this effect,” Yoshiki Sasai, a stem-cell researcher at the RIKEN Center for Developmental Biology in Kobe, Japan, and a co-author of the latest studies, said in a statement.
Haruko Obokata, a young stem-cell biologist at RIKEN, said it took five years in order to develop the method, as well as convince the other scientists that it worked.
“Everyone said it was an artefact — there were some really hard days,” Obokata said in a statement.
She said the inspiration for this method came when she was culturing cells and noticed that some would shrink to a size similar to that of stem cells. She tried applying different kinds of stress, including heat, starvation and a high-calcium environment, to try and turn them into stem cells. The right concoction ended up being a bacterial toxin that perforates the cell membrane, exposure to low pH and physical squeezing.
The team found that STAP cells can also form placental tissue, which is something that neither iPS cells nor embryonic stem cells can do. One day this could actually make cloning easier by transferring the placenta directly to the surrogate.
“The findings are important to understand nuclear reprogramming,” Shinya Yamanaka, who pioneered iPS cell research, said in a statement. “From a practical point of view toward clinical applications, I see this as a new approach to generate iPS-like cells.”
The team said STAP cells showed a substantial decrease in DNA methylation in the regulatory regions of pluripotency marker genes.
“We also demonstrate the derivation of robustly expandable pluripotent cell lines from STAP cells,” the team wrote in the journal. “Thus, our findings indicate that epigenetic fate determination of mammalian cells can be markedly converted in a context-dependent manner by strong environmental cues.”