Yale University researchers found that the speed of the cell cycle acts as a major obstacle in the reconversion of cells to their youthful state
Previously it was believed that the fate of a cell is fixed. Once it committed to become a muscle, skin or blood cell, it remained so for the rest of its life. In 2006, Nobel Laureate Shinya Yamanak conducted a study that showed that by introducing four simple factors into the cell, it was possible to covert it back to an embryonic-like state capable of becoming almost any cell type in the body.
Ever since, scientists have been trying to utilize the discovery and formulate ways to making aging cells young again. The process has been very slow and not many "breaking discoveries" have been made.
Recently, Yale University researchers conducted a study where they found the speed of the cell cycle acts as a major obstacle and makes it difficult to covert cells back to their youthful state. According to a press statement, when cell cycle accelerates to a certain speed, the barriers responsible for keeping a cell's fate on a one-way path lessen. This gives cells an opportunity to become pluripotent (capable of changing into multiple cell types).
For the study, researchers looked at blood forming cells. As these cells divide, the cell cycle undergoes certain changes allowing them to become new blood cells. However, sometimes (not always) when Yamanak's factors are introduced these cells are capable of becoming any other cell type. Researchers noted that this is possible only when the cell cycle is completed in eight hours or less, which is quite unusual in adults.
"One analogy may be that when temperature increases to sufficient degrees, even a very hard piece of steel can be malleable so that you can give it a new shape easily," said Shangqin Guo, lead author of the paper in a statement. "Once cells are cycling extremely fast, they do not seem to face the same barriers to becoming pluripotent."
"This discovery changes the way people think about how to change cell fate and reveals that a basic 'house-keeping' function of a cell, such as its cell cycle length, can actually have a major impact on switching the fate of a cell," said Haifan Lin, director of the Yale Stem Cell Center.
The research was funded by the National Institutes of Health and the Connecticut Stem Cell Research Program.
