Differentiated Neural Cells Have Long Life

Differentiated Neural Cells Have Long Life

Researchers at New York University’s Howard Hughes Institute of Medicine have shown that stem cells which differentiated into brain tissue in mice were still living at least a year later. In the study, the researchers examined how neural stem cells that had proliferated interacted with a protein called Shh (Sonic hedgehog). The Shh protein is a regulatory protein which controls gene activity during brain development and also plays a role in stem-cell self-renewal.

The mechanism of Shh’s action upon stem cells was unknown. The researchers labeled the neural stem cells in the adult mice so that they could tell which ones were responding to Shh at what time. They did not know whether the cells that responded were ones which were rapidly dividing or those which were in a quiescent stage, so they used a chemical to kill the quickly dividing cells. When the quiescent cells continued to respond to Shh signaling, it became clear that stem cells were still capable of self-renewal even after a year.

The study also showed that the neural stem cells differentiated to form neural cell types in addition to neurons. The research appears in this week’s journal Nature. Short articles on the study can be found on Physorg.com (a UPI story) and News-Medical.Net.