Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:


Joslin researchers clarify mechanisms for beta-cell formation


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:

More articles from Life Sciences:

nachricht First time-lapse footage of cell activity during limb regeneration
25.10.2016 | eLife

nachricht Phenotype at the push of a button
25.10.2016 | Institut für Pflanzenbiochemie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Etching Microstructures with Lasers

Ultrafast lasers have introduced new possibilities in engraving ultrafine structures, and scientists are now also investigating how to use them to etch microstructures into thin glass. There are possible applications in analytics (lab on a chip) and especially in electronics and the consumer sector, where great interest has been shown.

This new method was born of a surprising phenomenon: irradiating glass in a particular way with an ultrafast laser has the effect of making the glass up to a...

Im Focus: Light-driven atomic rotations excite magnetic waves

Terahertz excitation of selected crystal vibrations leads to an effective magnetic field that drives coherent spin motion

Controlling functional properties by light is one of the grand goals in modern condensed matter physics and materials science. A new study now demonstrates how...

Im Focus: New 3-D wiring technique brings scalable quantum computers closer to reality

Researchers from the Institute for Quantum Computing (IQC) at the University of Waterloo led the development of a new extensible wiring technique capable of controlling superconducting quantum bits, representing a significant step towards to the realization of a scalable quantum computer.

"The quantum socket is a wiring method that uses three-dimensional wires based on spring-loaded pins to address individual qubits," said Jeremy Béjanin, a PhD...

Im Focus: Scientists develop a semiconductor nanocomposite material that moves in response to light

In a paper in Scientific Reports, a research team at Worcester Polytechnic Institute describes a novel light-activated phenomenon that could become the basis for applications as diverse as microscopic robotic grippers and more efficient solar cells.

A research team at Worcester Polytechnic Institute (WPI) has developed a revolutionary, light-activated semiconductor nanocomposite material that can be used...

Im Focus: Diamonds aren't forever: Sandia, Harvard team create first quantum computer bridge

By forcefully embedding two silicon atoms in a diamond matrix, Sandia researchers have demonstrated for the first time on a single chip all the components needed to create a quantum bridge to link quantum computers together.

"People have already built small quantum computers," says Sandia researcher Ryan Camacho. "Maybe the first useful one won't be a single giant quantum computer...

All Focus news of the innovation-report >>>



Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

Agricultural Trade Developments and Potentials in Central Asia and the South Caucasus

14.10.2016 | Event News

World Health Summit – Day Three: A Call to Action

12.10.2016 | Event News

Latest News

Ice shelf vibrations cause unusual waves in Antarctic atmosphere

25.10.2016 | Earth Sciences

Fluorescent holography: Upending the world of biological imaging

25.10.2016 | Power and Electrical Engineering

Etching Microstructures with Lasers

25.10.2016 | Process Engineering

More VideoLinks >>>