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 How molecules teeter in a laser field
18.01.2019 | Forschungsverbund Berlin

nachricht Discovery of enhanced bone growth could lead to new treatments for osteoporosis
18.01.2019 | University of California - Los Angeles

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Ten-year anniversary of the Neumayer Station III

The scientific and political community alike stress the importance of German Antarctic research

Joint Press Release from the BMBF and AWI

The Antarctic is a frigid continent south of the Antarctic Circle, where researchers are the only inhabitants. Despite the hostile conditions, here the Alfred...

Im Focus: Ultra ultrasound to transform new tech

World first experiments on sensor that may revolutionise everything from medical devices to unmanned vehicles

The new sensor - capable of detecting vibrations of living cells - may revolutionise everything from medical devices to unmanned vehicles.

Im Focus: Flying Optical Cats for Quantum Communication

Dead and alive at the same time? Researchers at the Max Planck Institute of Quantum Optics have implemented Erwin Schrödinger’s paradoxical gedanken experiment employing an entangled atom-light state.

In 1935 Erwin Schrödinger formulated a thought experiment designed to capture the paradoxical nature of quantum physics. The crucial element of this gedanken...

Im Focus: Nanocellulose for novel implants: Ears from the 3D-printer

Cellulose obtained from wood has amazing material properties. Empa researchers are now equipping the biodegradable material with additional functionalities to produce implants for cartilage diseases using 3D printing.

It all starts with an ear. Empa researcher Michael Hausmann removes the object shaped like a human ear from the 3D printer and explains:

Im Focus: Elucidating the Atomic Mechanism of Superlubricity

The phenomenon of so-called superlubricity is known, but so far the explanation at the atomic level has been missing: for example, how does extremely low friction occur in bearings? Researchers from the Fraunhofer Institutes IWM and IWS jointly deciphered a universal mechanism of superlubricity for certain diamond-like carbon layers in combination with organic lubricants. Based on this knowledge, it is now possible to formulate design rules for supra lubricating layer-lubricant combinations. The results are presented in an article in Nature Communications, volume 10.

One of the most important prerequisites for sustainable and environmentally friendly mobility is minimizing friction. Research and industry have been dedicated...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Our digital society in 2040

16.01.2019 | Event News

11th International Symposium: “Advanced Battery Power – Kraftwerk Batterie” Aachen, 3-4 April 2019

14.01.2019 | Event News

ICTM Conference 2019: Digitization emerges as an engineering trend for turbomachinery construction

12.12.2018 | Event News

 
Latest News

Additive manufacturing reflects fundamental metallurgical principles to create materials

18.01.2019 | Materials Sciences

How molecules teeter in a laser field

18.01.2019 | Life Sciences

The cytoskeleton of neurons has been found to be involved in Alzheimer's disease

18.01.2019 | Health and Medicine

VideoLinks
Science & Research
Overview of more VideoLinks >>>