Scientists at the University of Virginia have broken a major biological barrier by turning stem cells into a fully developed fish embryo. The research could be revolutionary for the field of regenerative medicine. University of Virginia Health System Press Release
A husband and wife team at UVA's School of Medicine is heading up work centered on controlling cell development. By focusing on just two factors, they can direct the growth of organs and tissues.
Bernard and Christine Thisse have discovered that only two signals are needed to create a zebra-fish embryo out of stem cells. By instructing the embryonic cells in a specific way, they were able to produce Petri dishes of animals with a beating heart and functional nervous system. The researchers say this could be a major step in making human organs needed for transplants.
“It gives lots of hope for regenerative medicine because if you are sick and you have a bad heart, and you're waiting for a transplant and you don't have a donor for you - you wait and maybe you will die. But if we can build a heart from your own cell, then I think you're on a good way,” Christine Thisse stated.
The couple can also direct development by controlling signal locations and concentrations. The zebra-fish embryos are almost at full size within just about 24 hours.
The next step for the scientists is to reproduce their results in mice. They say they are confident the study will be successful now that they have the basic rules.
Scientists at the University of Virginia School of Medicine have overcome one of the greatest challenges in biology and taken a major step toward being able to grow whole organs and tissues from stem cells. By manipulating the appropriate signaling, the UVA researchers have turned embryonic stem cells into a fish embryo, essentially controlling embryonic development.
The research will have dramatic impact on the future use of stem cells to better the human condition, providing a framework for future studies in the field of regenerative medicine aimed at constructing tissues and organs from populations of cultured pluripotent cells.
In accomplishing this, UVA scientists Bernard and Chris Thisse have overcome the most massive of biological barriers. “We have generated an animal by just instructing embryonic cells the right way,” said Chris Thisse, PhD, of the School of Medicine’s Department of Cell Biology.
The importance of that is profound. “If we know how to instruct embryonic cells,” she said, “we can pretty much do what we want.” For example, scientists will be able one day to instruct stem cells to grow into organs needed for transplant.Directing Embryonic Development:
The researchers were able to identify the signals sufficient for starting the cascade of molecular and cellular processes that lead to a fully developed fish embryo. With this study came an answer to the longstanding question of how few signals can initiate the processes of development: amazingly, only two.
The study has shed light on the important roles these two signals play for the formation of organs and full development of a zebrafish embryo. Moreover, the Thisses are now able to direct embryonic development and formation of tissues and organs by controlling signal locations and concentrations.
The embryo they generated was smaller than a normal embryo, because they instructed a small pool of embryonic stem cells, but “otherwise he has everything” in terms of appropriate development, said Bernard Thisse, PhD, of the Department of Cell Biology.
Their next steps will be to attempt to reproduce their findings using mice. They expect molecular and cellular mechanisms will be extremely similar in mice and other mammals – including humans.Published in Science :
The findings have been published online by Science and will appear in a forthcoming print edition of the prestigious journal. The article was authored by UVA’s Peng-Fei Xu, Nathalie Houssin, Karine F. Ferri-Lagneau, Bernard Thisse and Christine Thisse.