Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Discovery of fruit fly pancreas points to possible diabetes cures

16.09.2004


Fruit flies have cells that function like a miniature pancreas. That’s good news not only for the flies, but also for researchers hoping to use the tiny insects to develop cures for diabetes.



Almost two years ago Seung Kim, MD, PhD, assistant professor of developmental biology and of medicine at the Stanford University School of Medicine, and colleagues including then-postdoctoral scholar Eric Rulifson, PhD, found cells in the fruit fly brain that make insulin. These cells tell the fly’s energy-storing organ, called a fat body, to store sugar and fat after a meal. In research published in the Sept. 16 issue of Nature the scientists report finding the other crucial half of the pancreatic equation - cells producing a glucagonlike hormone.

Together, glucagon and insulin act as a thermostat keeping blood sugar within a normal range. Islet cells produce insulin to lower blood sugar after a meal. When the amount of sugar in the blood dips between meals, other pancreatic cells produce glucagon to raise it. "Without glucagon or insulin you’re in big trouble," Kim said. "We found that’s also true in flies."


Kim thinks the two cell types in flies represent a primordial pancreas that scientists can study to better understand how the insulin- and glucagon-producing cells develop and function in humans. An immediate application could be testing new drugs before trying them in more expensive lab animals such as mice.

The flies could also provide insights into how pancreatic islet cells form - information that could help Kim and his colleagues devise ways of coaxing stem cells to develop into pancreatic cells. "We can try to find out what regulates the development of those cells and use that information to help make human islet cells," he said, adding that stem cells could potentially be used to replace the lost insulin-producing cells in people with diabetes.

About 300,000 people in the United States have type-1 diabetes, in which the body’s immune system destroys pancreatic cells that produce insulin. Without insulin, the muscles and liver don’t receive a signal to take up sugar from the blood after a meal. The excess sugar binds to proteins including those that line the blood vessels. If people don’t carefully control their blood sugar using injected insulin they can end up with heart disease, blindness, kidney disease or require amputations.

Although the insulin- and glucagon-making cells in fruit flies aren’t clumped together in a solid organ such as the human pancreas, they faithfully mimic the functions of their human counterparts. When Kim and Rulifson destroyed the insulin-producing cells, causing the equivalent of human diabetes, the fat body no longer received a signal to store sugar and the fly’s blood sugar skyrocketed. Wiping out the glucagon-producing cells caused the blood sugar to plummet, as in the potentially fatal human condition known as hypoglycemia.

In addition to producing similar molecules, flies and humans have a comparable mechanism for regulating blood sugar, the researchers found. A protein on the insulin-producing and glycogen-producing cells in humans alters its shape when it detects changes in energy levels within the cell. This change triggers the cell to release insulin or glucagon as needed to keep blood sugar and energy levels within a normal range.

Fruit flies have that same protein, but it’s found only on the cell that makes the glucagonlike protein, called AKH. Kim and Rulifson, now an assistant professor at the University of Pennsylvania, speculate this means that the most ancient hormonal regulators of metabolism first secreted glucose.

Kim and Rulifson found that the conserved protein, called the sulfonylurea receptor or Sur, regulates the release of AKH, similar to its role in human cells. They found that the protein in flies is so similar to the human protein that it responds to common drugs used by diabetics called sulfonylureas. Prescribed to millions of people with diabetes, these drugs work by helping Sur change shape and allow islet cells to release insulin. These same drugs act on Sur in flies, but the result is a release of AKH rather than insulin.

With so many similarities in how the cells detect and regulate blood sugar, Kim thinks the fruit fly’s primordial pancreas will be a useful tool for scientists studying both diabetes and hypoglycemia in humans. "This innovative research by Drs. Kim and Rulifson raises the exciting possibility that the fruit fly may serve as a model organism for discovering drugs that affect glucose regulation and hypoglycemia and for better understanding beta cell and islet development," said Richard Insel, MD, executive vice president for research at the Juvenile Diabetes Research Foundation in New York.

Mitzi Baker | EurekAlert!
Further information:
http://www.stanford.edu

More articles from Life Sciences:

nachricht Fingerprint' technique spots frog populations at risk from pollution
27.03.2017 | Lancaster University

nachricht Parallel computation provides deeper insight into brain function
27.03.2017 | Okinawa Institute of Science and Technology (OIST) Graduate University

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: Giant Magnetic Fields in the Universe

Astronomers from Bonn and Tautenburg in Thuringia (Germany) used the 100-m radio telescope at Effelsberg to observe several galaxy clusters. At the edges of these large accumulations of dark matter, stellar systems (galaxies), hot gas, and charged particles, they found magnetic fields that are exceptionally ordered over distances of many million light years. This makes them the most extended magnetic fields in the universe known so far.

The results will be published on March 22 in the journal „Astronomy & Astrophysics“.

Galaxy clusters are the largest gravitationally bound structures in the universe. With a typical extent of about 10 million light years, i.e. 100 times the...

Im Focus: Tracing down linear ubiquitination

Researchers at the Goethe University Frankfurt, together with partners from the University of Tübingen in Germany and Queen Mary University as well as Francis Crick Institute from London (UK) have developed a novel technology to decipher the secret ubiquitin code.

Ubiquitin is a small protein that can be linked to other cellular proteins, thereby controlling and modulating their functions. The attachment occurs in many...

Im Focus: Perovskite edges can be tuned for optoelectronic performance

Layered 2D material improves efficiency for solar cells and LEDs

In the eternal search for next generation high-efficiency solar cells and LEDs, scientists at Los Alamos National Laboratory and their partners are creating...

Im Focus: Polymer-coated silicon nanosheets as alternative to graphene: A perfect team for nanoelectronics

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are less stable. Now researchers at the Technical University of Munich (TUM) have, for the first time ever, produced a composite material combining silicon nanosheets and a polymer that is both UV-resistant and easy to process. This brings the scientists a significant step closer to industrial applications like flexible displays and photosensors.

Silicon nanosheets are thin, two-dimensional layers with exceptional optoelectronic properties very similar to those of graphene. Albeit, the nanosheets are...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

International Land Use Symposium ILUS 2017: Call for Abstracts and Registration open

20.03.2017 | Event News

CONNECT 2017: International congress on connective tissue

14.03.2017 | Event News

ICTM Conference: Turbine Construction between Big Data and Additive Manufacturing

07.03.2017 | Event News

 
Latest News

Northern oceans pumped CO2 into the atmosphere

27.03.2017 | Earth Sciences

Fingerprint' technique spots frog populations at risk from pollution

27.03.2017 | Life Sciences

Big data approach to predict protein structure

27.03.2017 | Life Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>