A UC San Diego student examines a bacteria culture. Photo courtesy UCSD
A UC San Diego student examines a bacteria culture. Photo courtesy UCSD

Researchers at the UC San Diego School of Medicine announced Thursday they’ve discovered why it’s so hard to use stem cells to make liver and pancreatic cells, and their findings could lead to new treatments for diseases such as type-1 diabetes.

It turns out that the chromosomes in laboratory stem cells open slowly over time, in the same sequence that occurs during embryonic development. It isn’t until certain chromosomal regions have reached the open state that they are able to respond to added growth factors and become liver or pancreatic cells, the researchers said.

“Our ability to generate liver and pancreatic cells from stem cells has fallen behind the advances we’ve made for other cell types,” said Dr. Maike Sander, a professor of pediatrics and cellular and molecular medicine, and director of the Pediatric Diabetes Research Center at UCSD.

“So we haven’t yet been able to do things like test new drugs on stem cell-derived liver and pancreatic cells,” Sander said. “What we have learned is that if we want to make specific cells from stem cells, we need ways to predict how those cells and their chromosomes will respond to the growth factors.”

Researchers have focused on stem cells for treating disease because they can be altered into hundreds of types of cells.

According to UCSD, it sometimes takes up to seven carefully orchestrated steps of adding certain growth factors at specific times to coax stem cells into the desired cell type.

Sander said the study found that the chromosomal regions that need to open before a stem cell can fully differentiate are linked to regions where there are variations in certain disease states. That means if a genetic variation in someone’s chromosomal region doesn’t open at the right time, they could be more susceptible to a disease affecting that cell type.

Her team is now working to further investigate what role, if any, the chromosomal regions and their variations play in diabetes.

Researchers with the University of Pennsylvania, Penn State University and Ludwig Institute for Cancer Research assisted with the study, funded by the National Institutes of Health, California Institute for Regenerative Medicine, the Helmsley Charitable Trust and Juvenile Diabetes Research Foundation.

— City News Service