Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Blood Vessels Contribute to Their Own Growth and Oxygen Delivery to Tissues and Tumors

16.09.2009
Researchers at the University of North Carolina at Chapel Hill School of Medicine and the College of Arts & Sciences have identified a new biological process that spurs the growth of new blood vessels.

Vascular networks form and expand by “sprouting,” similar to the way trees grow new branches. The process allows fresh oxygen and nutrients to be delivered to tissues, whether in a developing embryo or a cancerous tumor.

Up until now, scientists thought that the molecular signals to form new sprouts came from outside the vessel. But new research from UNC has shown that signals can also come from within the blood vessel, pushing new blood vessel sprouts outward.

The findings, published in the Sept. 15 issue of the journal Developmental Cell, could give important insights into the formation of the vasculature needed to feed new tumors.

In experiments using mouse embryonic stem cells and mouse retinas, the researchers found that defects in a protein called Flt-1 lead to abnormal sprouts and poor vessel networks. Other research recently showed that levels of Flt-1 protein are particularly low in the dilated and leaky blood vessels that supply tumors with oxygen.

“The blood vessels themselves seem to participate in the process guiding the formation of the vascular network,” said senior study author Victoria L. Bautch, Ph.D., professor of biology at UNC. “They do not just passively sit there getting acted upon by signals coming from the outside in. Rather, they produce internal cues that interact with external cues to grow.”

The growth of new blood vessels can be stimulated by cascades of events within the cell – known as pathways – the most notable of which centers around the three proteins Flt-1, Flk-1 and VEGF. Scientists have known for years that Flk-1 is a positive regulator that responds to VEGF by pulling the emerging sprout outward from its parent blood vessel.

The role of its sister protein Flt-1, however, was not clearly understood. Bautch and colleagues hypothesized that Flt-1 is a negative regulator -- soaking up VEGF molecules so they are not available to interact with Flk-1 and signal for new blood vessels.

The researchers mixed two different types of mouse embryonic stem cells – one batch with normal Flt-1 protein levels, the other with no Flt-1 protein. They found that the genetic makeup of the area at the base of the sprout – rather than at the sprout itself – determined whether the sprout behaved normally or abnormally.

“The cells on each side of sprout produce and send out the soluble form of the protein, blocking the sprout from forming anywhere but in one spot and in one direction,” says Bautch. “So when the sprout first forms, instead of flopping back onto its parent vessel, it has a corridor to push it forward away from the parent.”

Bautch, who is also a member of the Program in Molecular Biology and Biotechnology, the UNC McAllister Heart Institute and UNC Lineberger Comprehensive Cancer Center, notes that the more scientists understand about the sophistication and complexity of the mechanisms guiding the formation of blood vessel sprouts, the better equipped they will be to develop therapeutic interventions to produce or to halt new blood vessels.

Funding for study came from the National Institutes of Health and the American Heart Association. Study co-authors from UNC include John C. Chappell, Ph.D., postdoctoral fellow; and Sarah M. Taylor, graduate student.

Les Lang | Newswise Science News
Further information:
http://www.unc.edu

More articles from Life Sciences:

nachricht How brains surrender to sleep
23.06.2017 | IMP - Forschungsinstitut für Molekulare Pathologie GmbH

nachricht A new technique isolates neuronal activity during memory consolidation
22.06.2017 | Spanish National Research Council (CSIC)

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Can we see monkeys from space? Emerging technologies to map biodiversity

An international team of scientists has proposed a new multi-disciplinary approach in which an array of new technologies will allow us to map biodiversity and the risks that wildlife is facing at the scale of whole landscapes. The findings are published in Nature Ecology and Evolution. This international research is led by the Kunming Institute of Zoology from China, University of East Anglia, University of Leicester and the Leibniz Institute for Zoo and Wildlife Research.

Using a combination of satellite and ground data, the team proposes that it is now possible to map biodiversity with an accuracy that has not been previously...

Im Focus: Climate satellite: Tracking methane with robust laser technology

Heatwaves in the Arctic, longer periods of vegetation in Europe, severe floods in West Africa – starting in 2021, scientists want to explore the emissions of the greenhouse gas methane with the German-French satellite MERLIN. This is made possible by a new robust laser system of the Fraunhofer Institute for Laser Technology ILT in Aachen, which achieves unprecedented measurement accuracy.

Methane is primarily the result of the decomposition of organic matter. The gas has a 25 times greater warming potential than carbon dioxide, but is not as...

Im Focus: How protons move through a fuel cell

Hydrogen is regarded as the energy source of the future: It is produced with solar power and can be used to generate heat and electricity in fuel cells. Empa researchers have now succeeded in decoding the movement of hydrogen ions in crystals – a key step towards more efficient energy conversion in the hydrogen industry of tomorrow.

As charge carriers, electrons and ions play the leading role in electrochemical energy storage devices and converters such as batteries and fuel cells. Proton...

Im Focus: A unique data centre for cosmological simulations

Scientists from the Excellence Cluster Universe at the Ludwig-Maximilians-Universität Munich have establised "Cosmowebportal", a unique data centre for cosmological simulations located at the Leibniz Supercomputing Centre (LRZ) of the Bavarian Academy of Sciences. The complete results of a series of large hydrodynamical cosmological simulations are available, with data volumes typically exceeding several hundred terabytes. Scientists worldwide can interactively explore these complex simulations via a web interface and directly access the results.

With current telescopes, scientists can observe our Universe’s galaxies and galaxy clusters and their distribution along an invisible cosmic web. From the...

Im Focus: Scientists develop molecular thermometer for contactless measurement using infrared light

Temperature measurements possible even on the smallest scale / Molecular ruby for use in material sciences, biology, and medicine

Chemists at Johannes Gutenberg University Mainz (JGU) in cooperation with researchers of the German Federal Institute for Materials Research and Testing (BAM)...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Plants are networkers

19.06.2017 | Event News

Digital Survival Training for Executives

13.06.2017 | Event News

Global Learning Council Summit 2017

13.06.2017 | Event News

 
Latest News

Quantum thermometer or optical refrigerator?

23.06.2017 | Physics and Astronomy

A 100-year-old physics problem has been solved at EPFL

23.06.2017 | Physics and Astronomy

Equipping form with function

23.06.2017 | Information Technology

VideoLinks
B2B-VideoLinks
More VideoLinks >>>