Featured Research

from universities, journals, and other organizations

Blood Vessels Contribute To Their Own Growth And Oxygen Delivery To Tissues And Tumors

Date:
September 15, 2009
Source:
University of North Carolina School of Medicine
Summary:
Researchers 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 has shown that signals can also come from within the blood vessel, pushing new blood vessel sprouts outward.

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.


Story Source:

The above story is based on materials provided by University of North Carolina School of Medicine. Note: Materials may be edited for content and length.


Cite This Page:

University of North Carolina School of Medicine. "Blood Vessels Contribute To Their Own Growth And Oxygen Delivery To Tissues And Tumors." ScienceDaily. ScienceDaily, 15 September 2009. <www.sciencedaily.com/releases/2009/09/090914173014.htm>.
University of North Carolina School of Medicine. (2009, September 15). Blood Vessels Contribute To Their Own Growth And Oxygen Delivery To Tissues And Tumors. ScienceDaily. Retrieved September 21, 2014 from www.sciencedaily.com/releases/2009/09/090914173014.htm
University of North Carolina School of Medicine. "Blood Vessels Contribute To Their Own Growth And Oxygen Delivery To Tissues And Tumors." ScienceDaily. www.sciencedaily.com/releases/2009/09/090914173014.htm (accessed September 21, 2014).

Share This



More Health & Medicine News

Sunday, September 21, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Sierra Leone's Nationwide Ebola Curfew Underway

Sierra Leone's Nationwide Ebola Curfew Underway

Newsy (Sep. 20, 2014) Sierra Leone is locked down as aid workers and volunteers look for new cases of Ebola. Video provided by Newsy
Powered by NewsLook.com
Changes Found In Brain After One Dose Of Antidepressants

Changes Found In Brain After One Dose Of Antidepressants

Newsy (Sep. 19, 2014) A study suggest antidepressants can kick in much sooner than previously thought. Video provided by Newsy
Powered by NewsLook.com
Could Grief Affect The Immune Systems Of Senior Citizens?

Could Grief Affect The Immune Systems Of Senior Citizens?

Newsy (Sep. 19, 2014) The study found elderly people are much more likely to become susceptible to infection than younger adults going though a similar situation. Video provided by Newsy
Powered by NewsLook.com
Jury Delivers Verdict in Salmonella Trial

Jury Delivers Verdict in Salmonella Trial

AP (Sep. 19, 2014) A federal jury has convicted three people in connection with an outbreak of salmonella poisoning five years ago that sickened hundreds of people and was linked to a number of deaths. (Sept. 19) Video provided by AP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins