Scientists have made a breakthrough in creating stem cells crucial to regenerative medicine.
British and Japanese academics have successfully “reset” human pluripotent stem cells, considered useful because they can become human cells or tissues within the body, to the earliest developmental state.
These pristine cells have previously been impossible to replicate in a laboratory, so their creation has been hailed as a “significant milestone in regenerative medicine”.
Experts say the discovery, published in the Cell medical journal, will lead to a better understanding of human development and could allow the production of safe and more reproducible starting materials for a wide range of uses including cell therapies.
Professor Smith, director of the Wellcome Trust-MRC Cambridge Stem Cell Institute, which worked on the research, said: “Our findings suggest that it is possible to rewind the clock to achieve true ground state pluripotency in human cells.
“These cells may represent the real starting point for formation of tissues in the human embryo. We hope that in time they will allow us to unlock the fundamental biology of early development, which is impossible to study directly in people.”
Dr Rob Buckle, head of regenerative medicine at the Medical Research Council, added: “Achieving a true ground state in human pluripotent stem cells is seen as a significant milestone in regenerative medicine.
“With further refinement, this method for creating ‘blank’ pluripotent cells could provide a more reliable and renewable raw material for a range of cellular therapies, diagnostics and drug safety screening tools.
“This is likely to be a highly attractive prospect to industry and regulators.”
Generating stem cells in a laboratory is much easier to control in mouse cells, which can be frozen in a state of early pluripotency using a protein called LIF.
Human cells are not as responsive to LIF, so they must be controlled in a different way that involves switching key genes on and off. For this reason, scientists have been unable to generate human pluripotent cells that are as primitive or as consistent as mouse embryonic stem cells.
The researchers overcame this problem by introducing two genes causing the network of genes that control the cell to reboot and induce the pristine state.
By studying the reset cells, scientists will be able to learn more about how normal embryo development progresses and also how it can go wrong, leading to miscarriage and developmental disorders.
Experts say the breakthrough would allow the cells to serve as a blank canvas for creating specialised cells and tissues for use in regenerative medicine.