The main stumbling blocks to the conservative holy grail of adult stem cell research are efficiency and fidelity. Induced pluripotent stem cells (iPSC, or adult stem cells) are much more difficult to deal with than embryonic stem cells (pluripotent cells), which can be more easily programmed into whatever cell is required. Adult stem cells require quite a bit more finesse, as researchers are essentially taking a differentiated cell and reverting it back to a blank slate.
These iPSCs were first discovered in the lab by Shinya Yamanaka’s team at Tokyo University and John Gurdon’s Oxford University team. Gurdon, it should be noted, is simultaneously a self-professed agnostic and supporter of the Church of England’s ethics. Important in that he is not a religious true believer attempting to desperately make adult stem cell a workable alternative to embryonic stem cell research.
Gurdon and Yamanaka shared the 2012 Nobel Prize in Physiology or Medicine for their research into adult stem cell reprogramming. Now Gurdon’s team has made new advances in the field, discovering that chromatin remodeling (accessing of DNA) is likely vital to reverting adult stem cells to a pluripotent state.
Gurdon and his team transferred mammalian somatic cell nuclei (which can be taken from any human organ) into Xenopus oocytes (immature Xenopus frog egg cells) and observed what happened to the chromatin. They then focused their attention on H3.3 (a histone protein thought to be critical in the regulation of genes) and HIRA, which chaperones H3.3 into chromatin. Researchers believe that H3.3 and HIRA are critical in the reprogramming process, and conclude that further research will need to be carried out for adult stem cell research to overcome consistent roadblocks to reverting cells to the pluripotent state.
One conclusion to draw from this is that a combination of embryonic and adult stem cell research is required, regardless of the moral reservations of the faithful.
Gurdon’s research was published today in BioMed Central’s open access journal Epigenetics & Chromatin.