Scientists in Japan showed stem cells can now be made quickly just by dipping blood cells into acid. The latest development, published in the journal Nature, could make the technology cheaper, faster and safer.
The researchers report a unique cellular reprogramming phenomenon, called stimulus-triggered acquisition of pluripotency (STAP), which requires neither nuclear transfer nor the introduction of transcription factors. In STAP, strong external stimuli such as a transient low-pH stressor reprogrammed mammalian somatic cells, resulting in the generation of pluripotent cells. Through real-time imaging of STAP cells derived from purified lymphocytes, as well as gene rearrangement analysis, the scientists found that committed somatic cells give rise to STAP cells by reprogramming rather than selection. STAP cells showed a substantial decrease in DNA methylation in the regulatory regions of pluripotency marker genes. Blastocyst injection showed that STAP cells efficiently contribute to chimaeric embryos and to offspring via germline transmission. They could also demonstrate the derivation of robustly expandable pluripotent cell lines from the obtained STAP cells. Thus, these findings indicate that epigenetic fate determination of mammalian cells can be markedly converted in a context-dependent manner by strong environmental cues.
The finding has been described as "remarkable" by the Medical Research Council's Prof Robin Lovell-Badge and as "a major scientific discovery" by Dr Dusko Ilic, a reader in stem cell science at Kings College London.
Dr Ilic added: "The approach is indeed revolutionary.
"It will make a fundamental change in how scientists perceive the interplay of environment and genome." But he added: "It does not bring stem cell-based therapy closer. We will need to use the same precautions for the cells generated in this way as for the cells isolated from embryos or reprogrammed with a standard method."
And Prof Lovell-Badge said: "It is going to be a while before the nature of these cells are understood, and whether they might prove to be useful for developing therapies, but the really intriguing thing to discover will be the mechanism underlying how a low pH shock triggers reprogramming - and why it does not happen when we eat lemon or vinegar or drink cola?"