August 15, 2003

Scientists at the Howard Hughs Medical Institute think they may have found a cure for the common genetic disorder Hirschsprung disease. Hirschsprung disease, a medical disorder that is found in one in five-thousand live births, occurs when a cell defect causes the neural stem cells not to form the nerves that control the lower intestines. This potenticially life threatening disorder, then causes the colon to grow larger than normal which doesn't allow for food to transport through the gut. Scientists now think they may be able to cure this disease by transfering neural stem cells from a different part of the diseased person's gut.
The research just done by the Howard Hughs Medical Institute along with HHMI associate Toshihide Iwashita, and graduate student Eve Kruger at the University of Michigan has shed light on how the neural crest stem cells (NCSCs) are controlled. The neural crest stem cells are the cells that mature into neurons that support the neural cells found in the gut. After applying thousands of "gene chips" to probe the activity of specific genes, The researchers found that of the ten genes that were highly expressed by the gut NCSCs, four of them had been linked to Hirschsprung disease in humans. They then focused on the Ret gene because this gene has code for a receptor protein that enables stem cells to respond to a neuronal guidance protein called GDNF (glial-derived neurotrophic factor). They believe they could eradicate the disorder on this gene by taking stem cells from the foregut, expanding them in culture, and then transplanting them into the hindgut. Sean J. Morrison of the Howard Hughs Medical Institute said that the findings show the value of a relatively new approach that uses microarrays for identifying activated genes and then taking out those activated genes in mice to determine how those genes regulate stem cell function.

Evan Carter
March 14, 2010