Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Culprit found for increased stroke injury with diabetes

24.01.2011
Finding may lead the way toward treatments that minimize adverse outcomes

Strokes are a leading cause of mortality and adult disability. Those that involve intracerebral hemorrhage (bleeding in the brain) are especially deadly, and there are no effective treatments to control such bleeding.

Moreover, diabetes and hyperglycemia (high blood glucose levels) are associated with increases in bleeding during hemorrhagic stroke and worse clinical outcomes.

But Joslin Diabetes Center researchers now have identified one key player that contributes to this increased bleeding, a discovery that may pave the way toward treatments that minimize adverse stroke outcomes both for people with pre-existing diabetes and those with hyperglycemia identified at the time of stroke.

Studies in the lab of Joslin Investigator Edward Feener, Ph.D., pinpointed a new mechanism involving a protein called plasma kallikrein that interferes with the normal clotting process in the brain following blood vessel injury with diabetes. Their work is reported online in the journal Nature Medicine.

The scientists began by injecting a small amount of blood into the brains of rats with diabetes and of control animals without diabetes. The difference was dramatic—the diabetic animals bled over a much greater area of the brain.

Work in the Feener lab had previously implicated plasma kallikrein in diabetic eye complications. When the experimenters pre-treated the diabetic animals with a molecule that inhibits the protein's effects, brain damage from the blood injections dropped to levels similar to that in the control animals. Conversely, when pure plasma kallikrein was injected into the brain, it produced little impact on the control animals but rapidly increased major bleeding in the animals with diabetes.

Further studies by the Joslin researchers showed that normalizing blood glucose levels in diabetic animals could block the effect from plasma kallikrein, and that rapidly inducing hyperglycemia in control animals mimicked the effects of diabetes on brain hemorrhage. This suggests that high blood sugar at the time of brain hemorrhage, rather than diabetes per se, is responsible for the increased bleeding.

"Given the prevalence of strokes and the damage they inflict, these findings are exciting because they suggest the possibility that rapid control of blood sugar levels may provide an opportunity to reduce intracerebral hemorrhage, which is a clinical situation that has very limited treatment options," says Dr. Feener, who is also an associate professor of medicine at Harvard Medical School. "This work could have broad implications since about half of patients with acute hemorrhagic stroke have hyperglycemia, whether or not they have pre-existing diabetes."

The work also raises the possibility of developing drugs that target plasma kallikrein and may provide protective measures in people with diabetes or others at high risk for stroke. Such drugs might also prove useful for patients suffering from the more common ischemic strokes, which usually begin as blocked vessels in the brain but can transform into hemorrhages.

Surprisingly, while plasma kallikrein has been studied for decades, the Joslin scientists found that the protein boosts brain bleeding through a previously unknown mechanism—by blocking platelet activation near damaged blood vessels.

Joslin's Jia Liu and Ben-Bo Gao were co-lead authors on the Nature Medicine paper. Other contributors include Joslin's Allen Clermont, and Price Blair and Robert Flaumenhaft of Beth Israel Deaconess Medical Center, and Tamie Chilcote and Sukanto Sinha of ActiveSite Pharmaceuticals. Lead funding came from the National Institutes of Health and the American Heart Association.

Eric Bender | EurekAlert!
Further information:
http://www.joslin.harvard.edu

More articles from Health and Medicine:

nachricht Antibiotic effective against drug-resistant bacteria in pediatric skin infections
17.02.2017 | University of California - San Diego

nachricht Tiny magnetic implant offers new drug delivery method
14.02.2017 | University of British Columbia

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

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

Im Focus: Breakthrough with a chain of gold atoms

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

In the field of nanoscience, an international team of physicists with participants from Konstanz has achieved a breakthrough in understanding heat transport

Im Focus: DNA repair: a new letter in the cell alphabet

Results reveal how discoveries may be hidden in scientific “blind spots”

Cells need to repair damaged DNA in our genes to prevent the development of cancer and other diseases. Our cells therefore activate and send “repair-proteins”...

Im Focus: Dresdner scientists print tomorrow’s world

The Fraunhofer IWS Dresden and Technische Universität Dresden inaugurated their jointly operated Center for Additive Manufacturing Dresden (AMCD) with a festive ceremony on February 7, 2017. Scientists from various disciplines perform research on materials, additive manufacturing processes and innovative technologies, which build up components in a layer by layer process. This technology opens up new horizons for component design and combinations of functions. For example during fabrication, electrical conductors and sensors are already able to be additively manufactured into components. They provide information about stress conditions of a product during operation.

The 3D-printing technology, or additive manufacturing as it is often called, has long made the step out of scientific research laboratories into industrial...

Im Focus: Mimicking nature's cellular architectures via 3-D printing

Research offers new level of control over the structure of 3-D printed materials

Nature does amazing things with limited design materials. Grass, for example, can support its own weight, resist strong wind loads, and recover after being...

Im Focus: Three Magnetic States for Each Hole

Nanometer-scale magnetic perforated grids could create new possibilities for computing. Together with international colleagues, scientists from the Helmholtz Zentrum Dresden-Rossendorf (HZDR) have shown how a cobalt grid can be reliably programmed at room temperature. In addition they discovered that for every hole ("antidot") three magnetic states can be configured. The results have been published in the journal "Scientific Reports".

Physicist Dr. Rantej Bali from the HZDR, together with scientists from Singapore and Australia, designed a special grid structure in a thin layer of cobalt in...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Booth and panel discussion – The Lindau Nobel Laureate Meetings at the AAAS 2017 Annual Meeting

13.02.2017 | Event News

Complex Loading versus Hidden Reserves

10.02.2017 | Event News

International Conference on Crystal Growth in Freiburg

09.02.2017 | Event News

 
Latest News

Biocompatible 3-D tracking system has potential to improve robot-assisted surgery

17.02.2017 | Medical Engineering

Real-time MRI analysis powered by supercomputers

17.02.2017 | Medical Engineering

Antibiotic effective against drug-resistant bacteria in pediatric skin infections

17.02.2017 | Health and Medicine

VideoLinks
B2B-VideoLinks
More VideoLinks >>>