LiU researchers discover new mechanism in stem cell regulation

A hitherto unknown function that regulates how stem cells produce different types of cells in different parts of the nervous system has been discovered by researchers at Linköping University. The results improve our understanding of how stem cells work which is crucial for our ability to use stem cells to treat and repair organs.

Stefan Thor, professor of Developmental Biology, and graduate students Daniel Karlsson and Magnus Baumgardt are now publishing the findings of their research in the prestigious scientific journal PLoS Biology.

The stem cells' task is to create new cells to replace those that have aged or become damaged. Previous research has shown that stem cells give rise to different types of cells in different parts of the nervous system. This process is partly regulated by the so-called Hox genes, which are active in various parts of the body and work to give each piece its unique regional identity - a kind of GPS system of the body. But how does a stem cell know that it is in a certain region? How does it read the body's GPS signals? And how is this information used to control the creation of specific nerve cells?

In order to address these issues, the LiU researchers studied a specific stem cell in the nervous system of the fruit fly. It is available in all parts of the nervous system, but it is only in the thorax, or chest region, that it produces a certain type of nerve cells. To investigate why this type is not created in the stomach or head region they manipulated the Hox genes' activity in the fly embryo. 

It turned out that the Hox genes in the stomach region stop the stem cells from splitting before the specific cells are produced. In contrast, it was found that the specific nerve cells are actually produced in the head region, but that here the Hox genes turn them into another, unknown, type of cells. Hox genes can exert their influence both on the genes that control stem cell division behaviour and on the genes that control the type of nerve cells that are created.

"We constantly find new regulating mechanisms, and it is probably more difficult than previously thought to routinely use stem cells in treating diseases and repairing organs", says Stefan Thor.