Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Cytokine resistance contributes to pathology of type 2 diabetes

15.06.2007
In a study appearing this month in the Journal of Immunology, researchers at the University of Illinois describe how an impaired anti-inflammatory response plays a role in the pathology of type 2 diabetes.

Type 2 diabetes is classified as a metabolic disorder, but a growing number of researchers are beginning to think of it also as a disease of the innate immune system. Inflammation, a key component of the early immune response, is chronically elevated in people with type 2 diabetes. While the pro-inflammatory pathways of type 2 diabetes have received much attention, the anti-inflammatory side of the equation is less well known.

The new study focused on a number of cytokines, protein signals that bind to specific receptors on cells and set off a cascade of biochemical reactions within the cell. Interleukins, interferons, tumor necrosis factors and some growth factors are among the cytokines that direct many aspects of the immune response. Cytokines are secreted by many types of cells, including the immune cells known as macrophages.

In earlier studies, the researchers had shown that macrophages in diabetic and obese (diabese) mice secrete more pro-inflammatory and less anti-inflammatory cytokines than those of nondiabese mice. The team, led by pathology professor and department head Gregory Freund, also had demonstrated that human monocytes cultured under type 2 diabetic conditions had impaired interleukin-4 signaling. Interleukin

4 (IL-4) is an important player in the immune response in that it steers macrophages toward the production of other anti-inflammatory cytokines. It also inhibits secretion of the pro-inflammatory cytokines.

When IL-4 binds to its receptor on a target cell, it sets off one of two cascades of intracellular events.

The first of these signal transduction pathways, the Jak-STAT pathway, is well studied and well understood. The second, called the insulin receptor substrate 2 / phosphatidylinositol-3 kinase (IRS-2/PI3K) pathway, was more of a mystery, and of greater interest to Freund and his colleagues.

What drew them to this pathway was its potential role in the anti-inflammatory response, and its similarity to the cascade initiated when cells respond to insulin.

"One of the actions of diabetes is to create intracellular insulin resistance," Freund said. "Some of the cytokines that work on cells share the same pathways as the insulin receptor." Since diabetes causes insulin resistance, Freund said, "shouldn't there be a resistance to cytokines, too? And that is what we found."

The research team showed, for the first time, that the IRS-2 signaling arm of the interleukin-4 pathway directed the up-regulation of a key anti-inflammatory molecule in primary macrophages, and that this pathway was disrupted in type 2 diabetic conditions. They also showed that the loss of IL-4 function in diabese mice caused chronic over-expression of an important suppressor of cytokine signaling (SOCS) protein. This SOCS-3 protein aborts the cascade of events that normally leads to insulin uptake and/or cytokine signaling in a balanced inflammatory response.

This study supports earlier findings that inflammation is a key part of the pathology of diabetes, Freund said. Pro-inflammatory cytokines are elevated in type 2 diabetes, but the anti-inflammatory mechanisms are also impaired, leading to a multitude of major and minor health issues in the diabese.

"They get a cold. They get injured. Something happens. And it's worse in those people with obesity or diabetes and lasts longer than it does in others," Freund said. "Why? The imbalance may be the elevation in pro-inflammation. But it probably also includes a loss of anti-inflammatory function."

This research was supported by grants from the National Institutes of Health, American Heart Association, and the U. of I. Agricultural Experiment Station.

Diana Yates | University of Illinois
Further information:
http://www.uiuc.edu

Further reports about: CASCADE Cytokine Diabetes anti-inflammatory macrophages receptor

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 >>>