Intestinal stem cells respond to food by supersizing the gut
An NIH-funded study at the University of California, Berkeley, shows that intestinal stem cells can reshape the gut in response to food, a finding that could have implications for diabetes and obesity.
Balintfy: The current understanding of how stem cells work is that once they mature into adult stem cells, they simply replace cells that die or are injured. That thinking is changing.
O'Brien: So what our team has found out is that the stem cells can do more than just maintain organs. They can actually cause organs to grow.
Balintfy: That's Lucy O'Brien, an assistant researcher in the lab of Professor David Bilder at UC Berkeley. Through NIH funded research with fruit flies, her research team has found that intestinal stem cells respond to increased food intake by making more intestinal cells.
O'Brien: What we found is that in flies, intestinal stem cells cause the intestine to grow when the animal eats. So the trigger for intestinal growth is feeding. When a fly eats a meal like a rotten banana and this banana arrives in the intestine, the intestinal stem cells sense this. They start to divide and divide and divide. They go into overdrive and they make extra intestinal cells which get added into the intestine and make a bigger organ.
Balintfy: She adds that a fly that has been eating has four times more cells in its intestine than a fly that hasn't been feeding; without food, the stem cells shut off, and over time the intestine will shrink back down. O'Brien says this research could have implications for obesity and diabetes.
O'Brien: These are diseases that often involve problems with insulin regulation, and it turns out that the way that fly intestinal stem cells go into growth-activating overdrive is through an insulin signal. When they fly eats and food arrives in the intestine, the intestine itself secretes insulin and its intestinal insulin talk to the stem cells and tells them that it's time to activate growth.
Balintfy: She also points out that it wasn't just the intestinal cells that were activated to grow.
O'Brien: And this was very surprising to us when we found this out -- when the stem cells are causing growth, not only are they making more intestinal cells but they're actually also at the same time making more of themselves. So they're increasing their own numbers.
Balintfy: Though working with fruit flies and intestinal stem cells, O'Brien says these findings may also have implications for other tissues as well, for example blood and mammary glands.
O'Brien: I think by expanding our view of what stem cells are capable of, it gives us more ideas about how we can harness the potential stem cells and apply them to human disease.
Balintfy: O'Brien and Bilder are coauthors on a paper in the journal Cell. For more information on this research, visit www.nigms.nih.gov. And to hear more from the interview with Lucy O'Brien, tune in to episode 149 of the NIH Research Radio podcast. This is Joe Balintfy, at the NIH in Bethesda, Maryland.
About This Audio Report
Reporter: Joe Balintfy
Sound Bite: Dr. Lucy O'Brien
Topic: intestine, stem cell, intestinal, intestinal stem cell, gut, stem cells, food, food intake, insulin, fly, fruit fly