Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Joslin researchers clarify mechanisms for beta-cell formation

17.09.2004


A new study by researchers at Joslin Diabetes Center sheds light on the key mechanisms by which new pancreatic beta cells normally form in response to insulin resistance. These findings may some day help researchers devise ways of staving off full-blown diabetes.



Insulin resistance is a condition in which the body needs increasing amounts of insulin to function properly, including keeping blood glucose levels in the normal range. It is a major contributor to type 2 diabetes, obesity and the metabolic syndrome, which affect nearly one-quarter of the American population.

For years, the body compensates for insulin resistance in order to delay the onset of clinical type 2 diabetes: The pancreas secretes more insulin and, in fact, more insulin-producing beta cells form within the pancreas. This formation of new beta cells is the focus of intensive research: Which cells give rise to these new beta cells and how? (Some researchers, for example, theorize that the new cells are derived from immature ductal cells--the cells that line the ducts of the pancreas.) And what signals this replication of beta cells to occur?


To study these questions, Rohit N. Kulkarni, M.D., Ph.D., Jonathon N. Winnay, and C. Ronald Kahn, M.D., of Joslin Diabetes Center in Boston; Ulupi S. Jhala Ph.D., of The Whittier Institute of the University of California in La Jolla, Calif.; Stan Krajewski Ph.D., at the Burnham Institute in La Jolla; and Marc Montminy M.D., Ph.D., at The Salk Institute for Biological Studies in San Diego, Calif., studied this compensatory growth in two different genetically engineered animal models of insulin resistance called IR/IRS-1 mice and LIRKO mice. Dr. Kahn is the Mary K. Iacocca Professor of Medicine at Harvard Medical School.

The results of immunohistochemical staining suggest that these new beta cells are not derived from duct cells. Rather, the beta-cell growth in insulin-resistant states occurs by "epithelial-to-mesenchymal transition," a mechanism in which cells take on a more primitive form and begin replicating. It is possible that the response originates from potential beta-cell stem cells, a more primitive cell that has yet to differentiate into a beta cell. They also showed that insufficiency of a protein called PDX-1, which is critical for the development of pancreatic islets that contain beta cells, limited the growth response in insulin-resistant states--suggesting that PDX-1 likely plays an important role in regulating this growth.

The results were published in the September 2004 issue of The Journal of Clinical Investigation. The research was funded by the National Institutes of Health, the Juvenile Diabetes Research Foundation Center for Islet Transplantation at Harvard Medical School, the Beta Cell Biology Consortium and the Larry Hillblom Foundation.

"Our paper clearly demonstrates a potential mechanism for beta-cell growth during insulin resistance, which in turn, occurs as a normal protective response to delay the onset of type 2 diabetes in obese and other susceptible individuals," says Dr. Kulkarni, an Investigator in the Cellular and Molecular Physiology Section at Joslin, Assistant Professor of Medicine of Harvard Medical School, and the lead and corresponding author of the study. "Using two different animal models of insulin resistance, we have identified the key players that are involved in this crucial compensatory response. Dissecting the pathways that regulate the process of epithelial-to-mesenchymal transition will have therapeutic implications for both type 1 and type 2 diabetes. For example, modulating one or more proteins involved in this critical transition process may allow us to enhance the ability of beta cells to replicate in the body or to formulate methods to expand the formation of new cells as a source for transplantation in type 1 diabetes."

There are two major types of diabetes. An estimated 800,000 Americans have type 1 diabetes, in which the pancreas is unable to produce insulin. People with type 1 diabetes must take daily insulin injections to survive. An estimated 18 million Americans have type 2 diabetes, in which the pancreas doesn’t produce enough insulin and/or the body is unable to use insulin properly (insulin resistance). Poorly controlled diabetes can lead to a host of complications, including heart attacks, strokes, blindness, kidney failure, blood vessel damage and nerve damage.

Marjorie Dwyer | EurekAlert!
Further information:
http://www.joslin.harvard.edu

More articles from Life Sciences:

nachricht Bolstering fat cells offers potential new leukemia treatment
17.10.2017 | McMaster University

nachricht Ocean atmosphere rife with microbes
17.10.2017 | King Abdullah University of Science & Technology (KAUST)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Neutron star merger directly observed for the first time

University of Maryland researchers contribute to historic detection of gravitational waves and light created by event

On August 17, 2017, at 12:41:04 UTC, scientists made the first direct observation of a merger between two neutron stars--the dense, collapsed cores that remain...

Im Focus: Breaking: the first light from two neutron stars merging

Seven new papers describe the first-ever detection of light from a gravitational wave source. The event, caused by two neutron stars colliding and merging together, was dubbed GW170817 because it sent ripples through space-time that reached Earth on 2017 August 17. Around the world, hundreds of excited astronomers mobilized quickly and were able to observe the event using numerous telescopes, providing a wealth of new data.

Previous detections of gravitational waves have all involved the merger of two black holes, a feat that won the 2017 Nobel Prize in Physics earlier this month....

Im Focus: Smart sensors for efficient processes

Material defects in end products can quickly result in failures in many areas of industry, and have a massive impact on the safe use of their products. This is why, in the field of quality assurance, intelligent, nondestructive sensor systems play a key role. They allow testing components and parts in a rapid and cost-efficient manner without destroying the actual product or changing its surface. Experts from the Fraunhofer IZFP in Saarbrücken will be presenting two exhibits at the Blechexpo in Stuttgart from 7–10 November 2017 that allow fast, reliable, and automated characterization of materials and detection of defects (Hall 5, Booth 5306).

When quality testing uses time-consuming destructive test methods, it can result in enormous costs due to damaging or destroying the products. And given that...

Im Focus: Cold molecules on collision course

Using a new cooling technique MPQ scientists succeed at observing collisions in a dense beam of cold and slow dipolar molecules.

How do chemical reactions proceed at extremely low temperatures? The answer requires the investigation of molecular samples that are cold, dense, and slow at...

Im Focus: Shrinking the proton again!

Scientists from the Max Planck Institute of Quantum Optics, using high precision laser spectroscopy of atomic hydrogen, confirm the surprisingly small value of the proton radius determined from muonic hydrogen.

It was one of the breakthroughs of the year 2010: Laser spectroscopy of muonic hydrogen resulted in a value for the proton charge radius that was significantly...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ASEAN Member States discuss the future role of renewable energy

17.10.2017 | Event News

World Health Summit 2017: International experts set the course for the future of Global Health

10.10.2017 | Event News

Climate Engineering Conference 2017 Opens in Berlin

10.10.2017 | Event News

 
Latest News

Ocean atmosphere rife with microbes

17.10.2017 | Life Sciences

Neutrons observe vitamin B6-dependent enzyme activity useful for drug development

17.10.2017 | Life Sciences

NASA finds newly formed tropical storm lan over open waters

17.10.2017 | Earth Sciences

VideoLinks
B2B-VideoLinks
More VideoLinks >>>