In a study published recently in the journal Cell Stem Cell, it has been revealed that Cambridge researchers have found the strongest evidence to date that human pluripotent stem cells will develop normally once transplanted into an embryo. Human pluripotent stem cells are cells that can give rise to all tissues of the body and the findings of this study could have significant implications for regenerative medicine.
These stem cells have promising therapeutic uses in regenerative medicine to treat devastating conditions that affect various organs and tissues, particularly those that have poor regenerative capacity, such as the heart, brain and pancreas. The human pluripotent stem cells used in regenerative medicine or biomedical research typically come from two sources – and induced pluripotent stem cells, where skin cells are ‘reset’ to their original, pluripotent form and embryonic stem cells, derived from fertilised egg cells discarded from IVF procedures.
There have been doubts and concerns by many scientists that it might give rise to tumors in case the cells are not incorporated properly into the body they might not distribute themselves. The present study dispels the doubts and suggests that when the stem cells are transplanted appropriately, they are likely to be safe for use in regenerative medicine. The research is funded by the British Heart Foundation.
This study provides strong evidence to suggest that human stem cells will develop in a normaland importantly, safe way commented Professor Roger Pedersen from the Anne McLaren Laboratory for Regenerative Medicine at the University of Cambridge.
Since, it is unethical to carry out the transplantation into an early-stage human embryo, researchers use mouse embryos. The gold standard test, developed in Cambridge in the 1980s, involves putting the stem cells into a mouse blastocyst, a very early stage embryo after fertilization, then assessing stem cell contribution to the various tissues of the body. In previous researches scientists were not successful in getting human pluripotent stem cells incorporated into mouse embryos. However, in this study Professor Pedersen and co-author Victoria Mascetti and have shown that it is possible to successfully transplant human pluripotent stem cells into the mouse embryo and that they then develop and grow normally.
The reason why stem cell research is so significant is because it holds great promise for treating serious conditions like heart disease and Parkinson’s disease. Till now, the big question mark on such research has been how safe and effective they will be. Through this research, Mascetti has been able to demonstrate that human pluripotent stem cells are equivalent to an embryonic counterpart.
The reason why previous attempts to incorporate human pluripotent stem cells failed is that the stem cells had not been matched to the correct stage of embryo development. Previously, the cells were transplanted into the mouse embryo earlier than ideal. But, when they were transplanted at the right stage (gastrulation stage of embryonic development), the stem cells went on to grow and proliferate normally, to integrate into the embryo and to distribute themselves correctly across relevant tissues.
These results substantially strengthen the view that induced pluripotent stem cells from adult tissue are suitable for use in regenerative medicinelike in attempts to repair damaged heart muscle after a heart attack opined Professor Jeremy Pearson, Associate Medical Director at the British Heart Foundation.
Mascetti was excited about the study's finding and said that their finding that human stem cells integrate and develop normally in the mouse embryo will allow them to study aspects of human development during a window in time that would otherwise be inaccessible.