TUESDAY, Nov. 2 (HealthDay News) -- A new genetic analysis has
uncovered specific regions in the DNA of certain human pancreatic
cells that appear central to the regulation of insulin and other
functions of the pancreas.
The new effort -- conducted by researchers at the National Human
Genome Research Institute (NHGRI) -- takes scientists a step closer
towards understanding the complex genetic underpinnings of insulin
deficiency and the onset of type 2 diabetes, which accounts for
most of the 23 million cases of diabetes among Americans and the
more than 170 million cases worldwide.
By honing in on clusters of hormone-producing pancreatic cells
known as islets, the investigators were able to detect about 18,000
"molecular on-off switches" (or so-called "promoters") that control
gene behavior. Several hundred of these gene-adjacent switches were
previously unknown.
In a U.S. National Institutes of Health (NIH) news release,
study co-author Michael Stitzel explained that previous
gene-mapping work has pointed out some genetic differences between
type 2 diabetic and non-diabetic individuals in specific regions of
the genome.
"But substantial efforts are required to understand how these differences contribute to disease," he said. "Defining regulatory elements in human islets is a critical first step to understanding the molecular and biological effects for some of the genetic variants statistically associated with type 2 diabetes."
Stitzel and colleagues from the NIH Intramural Sequencing
Center, Duke University in Durham, N.C., and the University of
Michigan in Ann Arbor report their findings in the Nov. 3 issue of
Cell Metabolism.
The new work has also enabled the authors to identify another
34,000 regulatory "modules" located slightly farther away (than the
18,000 on-off switches) from the genes they control. They believe
that these distinct "regulatory elements" may be critical to proper
blood glucose levels.
Upwards of 50 genetic abnormalities believed to have an
association with islet-related pancreatic dysfunction were also
uncovered.
"These findings represent important strides that were not possible just five years ago, but that are now realized with advances in genome sequencing technologies," Dr. Eric D. Green, NHGRI director, noted in the NIH news release.
"Very exciting" is how Dr. Stuart Weiss, an endocrinologist at New York University Medical Center and a clinical assistant professor at the NYU School of Medicine in New York City, described the current effort.
"It's clearly the future of medicine," he said. "However, the fact of the matter is that all sorts of factors are involved in the development of diabetes, and different people require different treatments. And just when you think that you understand it, another curve comes at you. So it's very difficult to think that we're going to find a magic bullet. And I would think that the clinical applications from any of this are probably years and years away."
More information
For more on genetics and diabetes, visit the
American Diabetes Association.