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 Laser activated gold pyramids could deliver drugs, DNA into cells without harm
24.03.2017 | Harvard John A. Paulson School of Engineering and Applied Sciences

nachricht What does congenital Zika syndrome look like?
24.03.2017 | University of California - San Diego

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: 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...

Im Focus: Researchers Imitate Molecular Crowding in Cells

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to simulate these confined natural conditions in artificial vesicles for the first time. As reported in the academic journal Small, the results are offering better insight into the development of nanoreactors and artificial organelles.

Enzymes behave differently in a test tube compared with the molecular scrum of a living cell. Chemists from the University of Basel have now been able to...

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

Argon is not the 'dope' for metallic hydrogen

24.03.2017 | Materials Sciences

Astronomers find unexpected, dust-obscured star formation in distant galaxy

24.03.2017 | Physics and Astronomy

Gravitational wave kicks monster black hole out of galactic core

24.03.2017 | Physics and Astronomy

VideoLinks
B2B-VideoLinks
More VideoLinks >>>