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 Transport of molecular motors into cilia
28.03.2017 | Aarhus University

nachricht Asian dust providing key nutrients for California's giant sequoias
28.03.2017 | University of California - Riverside

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: A Challenging European Research Project to Develop New Tiny Microscopes

The Institute of Semiconductor Technology and the Institute of Physical and Theoretical Chemistry, both members of the Laboratory for Emerging Nanometrology (LENA), at Technische Universität Braunschweig are partners in a new European research project entitled ChipScope, which aims to develop a completely new and extremely small optical microscope capable of observing the interior of living cells in real time. A consortium of 7 partners from 5 countries will tackle this issue with very ambitious objectives during a four-year research program.

To demonstrate the usefulness of this new scientific tool, at the end of the project the developed chip-sized microscope will be used to observe in real-time...

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...

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

Transport of molecular motors into cilia

28.03.2017 | Life Sciences

A novel hybrid UAV that may change the way people operate drones

28.03.2017 | Information Technology

NASA spacecraft investigate clues in radiation belts

28.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>