Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

UNC studies identify key genes involved in blood vessel development

08.08.2003


New research from the University of North Carolina at Chapel Hill has identified two genes that play key roles in regulating blood vessel development.



The research appears in two reports published in the Aug. 15 issue of Molecular and Cellular Biology, a professional journal. Dr. Cam Patterson, professor of medicine and director of the Carolina Cardiovascular Biology Center and a member of the UNC Lineberger Comprehensive Cancer Center, led both studies.

Both research papers focus on angiogenesis, the molecular program by which endothelial cells lining blood vessels develop or differentiate from their precursor stem cells.


"I think of endothelial cells as the ’intelligent cells’ of blood vessels," Patterson said. "They are communicators between the blood vessel wall and bloodstream. They are the cells that determine what a blood vessel does. For example, during angiogenesis, when new blood vessels are being formed, it’s the endothelial cells that determine where they go and how big they get."

And as communicators, Patterson added, endothelial cells also help determine what passes through the blood-brain barrier, through the endothelium and into the brain, and what does not.

"One study in this issue of the journal sheds important new light on the molecular process that prevents a particular cell type from overrunning the developing embryo," Patterson said. "The findings from this study also offer tantalizing possibilities for new treatments aimed at putting the brakes on blood vessel development in tumors and other disorders having important vascular growth components, such as diabetes."

The second paper focuses on what activates the endothelial cell program, and it reports having found a possible answer in a single protein, a known transcription factor that has never been characterized functionally.

"This has really been a ’holy grail’ finding for us," Patterson said. "No other research group has found a single transcription factor that by itself is both necessary and sufficient to activate the endothelial cell program." For the first study, co-authors were Patterson and School of Medicine research colleagues Drs. Martin Moser, Olav Binder, Yaxu Wu, Julius Aitsebaomo, Rongqin Ren, Victoria Bautch and Frank L. Conlon. Dr. Christoph Bode of Freiburg University in Germany also served as co-author. The study team discovered a gene they called BMPER for BMP-binding endothelial precursor-derived regulator. The molecule was found using "a sophisticated molecular approach to separate out endothelial cell precursors from non-endothelial cell cells in a stem-cell model," Patterson said.

In a series of experiments, the researchers demonstrated that only endothelial cells and their precursors express the BMPER gene. Endothelial cells secrete the protein as they differentiate, issuing a molecular "stop" order to inhibit further differentiation.

"This was shown very clearly when we used stem cells to generate endothelial cells and then added BMPER. We found that BMPER inhibited the whole process," Patterson said.

In the second study, co-authors Wu, Moser, Bautch and Patterson looked at the gene flk1, a molecular marker for early endothelial cell precursors. "Flk1 is important because it’s a receptor for vascular endothelial growth factor, which is an angiogenic factor," Patterson said.

"But it’s also important to us because it’s the first gene that gets turned on in endothelial progenitor cells. So we wanted to know what transcription factors turn on flk1 and are those factors themselves sufficient enough to turn on the whole endothelial cell gene program - that is, can you use those factors to take a precursor cell and turn it into an endothelial cell?"

The study team used a screening procedure (yeast-1 hybrid screen) in which a piece of DNA was employed as a kind of bait to screen a library containing a variety of transcription factors.

"And the protein we pulled out with the bait is called HOXB5, a transcription factor that’s known but that has never been functionally characterized," Patterson said.

The researchers then asked whether HOXB5 would increase expression of flk1 by binding to genetic regulatory elements in the gene. "And indeed that was the case in our in vitro studies," Patterson said. "But the really important findings came when we over-expressed HOXB5 in stem cells. We used a stem cell model developed a few years ago here at UNC and found we could double or triple the number of flk1-positive cells that were produced from stem cells.

"But most importantly, if we look at actual vessel formation in stem cell cultures, we found vessel formation is hugely increased." Thus, the findings indicate that simply over-expressing HOXB5 by itself not only increases expression of the regulatory protein, but also increases the number of endothelial cells that will form from the precursors.

"We’re especially excited about the possibility that we can use this transcription factor to create renewable populations of endothelial cell precursors. I think this will be very important, as it would be analogous to hematopoietic (blood cell-forming) stem cells," Patterson said.

"And if we can create an analogous endothelial stem cell line, we can use that for gene therapy applications, for example, as a regenerative therapy for aged blood vessels.

"The therapeutic potentials for this research are many."

A grant from the National Heart, Lung and Blood Institute, a component of the National Institutes of Health, supported this research.

Contact: Les Lang, phone: +1-919-843-9687, email: llang@med.unc.edu

Leslie Lang | EurekAlert!
Further information:
http://www.med.unc.edu

More articles from Life Sciences:

nachricht What happens in the cell nucleus after fertilization
06.12.2016 | Helmholtz Zentrum München - Deutsches Forschungszentrum für Gesundheit und Umwelt

nachricht Researchers uncover protein-based “cancer signature”
05.12.2016 | Universität Basel

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

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

Im Focus: Shape matters when light meets atom

Mapping the interaction of a single atom with a single photon may inform design of quantum devices

Have you ever wondered how you see the world? Vision is about photons of light, which are packets of energy, interacting with the atoms or molecules in what...

Im Focus: Novel silicon etching technique crafts 3-D gradient refractive index micro-optics

A multi-institutional research collaboration has created a novel approach for fabricating three-dimensional micro-optics through the shape-defined formation of porous silicon (PSi), with broad impacts in integrated optoelectronics, imaging, and photovoltaics.

Working with colleagues at Stanford and The Dow Chemical Company, researchers at the University of Illinois at Urbana-Champaign fabricated 3-D birefringent...

Im Focus: Quantum Particles Form Droplets

In experiments with magnetic atoms conducted at extremely low temperatures, scientists have demonstrated a unique phase of matter: The atoms form a new type of quantum liquid or quantum droplet state. These so called quantum droplets may preserve their form in absence of external confinement because of quantum effects. The joint team of experimental physicists from Innsbruck and theoretical physicists from Hannover report on their findings in the journal Physical Review X.

“Our Quantum droplets are in the gas phase but they still drop like a rock,” explains experimental physicist Francesca Ferlaino when talking about the...

Im Focus: MADMAX: Max Planck Institute for Physics takes up axion research

The Max Planck Institute for Physics (MPP) is opening up a new research field. A workshop from November 21 - 22, 2016 will mark the start of activities for an innovative axion experiment. Axions are still only purely hypothetical particles. Their detection could solve two fundamental problems in particle physics: What dark matter consists of and why it has not yet been possible to directly observe a CP violation for the strong interaction.

The “MADMAX” project is the MPP’s commitment to axion research. Axions are so far only a theoretical prediction and are difficult to detect: on the one hand,...

Im Focus: Molecules change shape when wet

Broadband rotational spectroscopy unravels structural reshaping of isolated molecules in the gas phase to accommodate water

In two recent publications in the Journal of Chemical Physics and in the Journal of Physical Chemistry Letters, researchers around Melanie Schnell from the Max...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

ICTM Conference 2017: Production technology for turbomachine manufacturing of the future

16.11.2016 | Event News

Innovation Day Laser Technology – Laser Additive Manufacturing

01.11.2016 | Event News

#IC2S2: When Social Science meets Computer Science - GESIS will host the IC2S2 conference 2017

14.10.2016 | Event News

 
Latest News

Speed data for the brain’s navigation system

06.12.2016 | Health and Medicine

What happens in the cell nucleus after fertilization

06.12.2016 | Life Sciences

IHP presents the fastest silicon-based transistor in the world

05.12.2016 | Power and Electrical Engineering

VideoLinks
B2B-VideoLinks
More VideoLinks >>>