Cell Analysis Reveals Complex Variations In Stem Cells

By: Cherry Jia

Author: Kat J. McAlpine

Publication Date: December 4, 2014

Website: Wyss Institute

URL: http://wyss.harvard.edu/viewpressrelease/182

Summary:

Stem cells, which can multiply indefinitely, have the potential to to differentiate and develop into any kind of human cell and bodily tissue. Recently, scientists at the Wyss Institute for Biology Inspired Engineering at Harvard University discovered that stem cell colonies actually contain a lot of variability between individual cells. They learned that there are small fluctuations in the state of a stem cell’s pluripotency that can influence the development path that the cell eventually follows. The researchers have captured a detailed molecular profile of the different states of stem cells. The Broad Institute provided them with the new technologies used for studying individual cells. The researchers learned about stem cell development through these technologies by perturbing the cells with variants such as different chemicals, culture environments, and genetic knockouts. They then analyzed the individual genetic makeup of each cell to find that there were microfluctuations in each stem cell’s state of pluripotency. The scientists observed small differences in the way the stem cells were influenced by internal, chemical, and environmental cues. This led to the discovery of a complex “decision making” circuit of developmental regulators. Since, the scientists now understood the causes and consequences of differences between individual stem cells and how the balance of key regulators within a cell can affect that cell’s developmental outcome, they realized that there must be a “code” that relates patterns of dynamic behavior in stem cell regulatory circuits to the developmental  path a cell ends up taking. By using that code, they hope to dial in precisely to specific individual cell states. They also hope to use this new technology for purposes such as making better regenerative medicines by making stem cell engineering more predictable. Scientists are already able to precisely classify cells, identify the regulatory circuits that control their cell states, and balance the key regulators within a cell that can affect a cell’s developmental outcome. So all they need to do is apply this. If this is successful, they hope to use stem cells to overcome a wide range of diseases and injuries in the future.

Relevance:

During our unit on the applications of DNA technology and molecular biology, we learned that stem cell clusters present after birth are no longer capable of making the full range of new tissues with the ease that embryonic stem cells (before birth) can. We also learned that because of laboratory experiments, scientists can develop bone marrow stem cells into nerve cells under the right conditions. However, this procedure did not have a good success rate as it was mostly trial and error. This connects to the article because now that scientists have a much better understanding of stem cells and how they operate by the “code,” they can dial in precisely to specific individual cell states and be able to grow stem cells in the way that works with the stem cell’s regulatory circuits. This will boost the success rate of stem cell development, whereas before, this kind of technology was much less predictable and controllable.