IU researchers found increased cell growth that causes larger intestines in those with fragile X syndrome through examining fruit flies.
People with fragile X syndrome have gastrointestinal issues, and this study shows that these problems stem from having larger intestines.
Fragile X syndrome is a genetic disease that causes learning disabilities and neurological problems, such as epilepsy, due to the mutation of a single gene on the X chromosome.
Arthur Luhur, research associate in the biology department, and Nicholas Sokol, an associate professor in the biology department, conducted a study that focused on an unexplored area of fragile X syndrome. They looked at the gastrointestinal effect of the disease by focusing on the intestines of fruit flies, modified to have an absence of the FMRP protein, a result of fragile X syndrome.
“Most of the studies with fragile X syndrome focus on neurological symptoms,” Luhur said. “We have looked at the other problems that go with this disease.”
In their study, the researchers looked at the intestines of fruit flies which had been modified to lack the same protein that humans with the disorder do. He said the absence of this protein caused cells to build up to the point where the intestines were larger, Luhur said.
"They were ready to divide more often and more quickly, and they tended to divide symmetrically, causing the intestine to be bigger than normal," Sokol said in the Dec. 5 press release.
He said this study stemmed from a paper the two researchers published about two years ago which looked at another protein that had the opposite effect – the intestines did not absorb nutrients and did not grow.
From here, Luhur said they knew there must be factors that promote growth, which is how they discovered the FMRP protein.
“We need those two proteins to make sure intestinal organ size is optimal,” Luhur said.
Luhur said the combination of these two proteins is like the acceleration and brakes on a car – with only one, the vehicle cannot function properly.
He said their key finding is this phenomenon of irregular intestinal stem cells.
“What we’re interested in is how that connects into the physiology of the animal,” Luhur said, adding that this will then allow them to compare with the bodies of humans.
Some of the neurological effects of fragile X syndrome have been shown to be relieved by Metformin, a drug typically used as treatment for diabetes, Luhur said. He said there is potential that this drug could help with other symptoms as well, leading to possible medical advances.
“We did not test that in the intestinal context,” Luhur said, “We think it’s quite promising.”
Luhur said the research has potential to expand to other organs than just how the lack of this protein affects the intestines.
“There are so many other things to look at,” Luhur said.
