Forum for Science, Industry and Business

Important mechanism identified in the formation of blood vessels

The key to many medical problems, like preventing tumour development, is therefore to obstruct the spread of the blood vessels. Research scientists at Karolinska Institutet have now discovered a heretofore unknown mechanism for how the body links together its blood vessels.

New blood vessels are formed when a “shoot” sprouts from an already existing vessel. These shoots lengthen, branch off and contact other vessels as they form communicating networks of channels. The process is called “angiogenesis” and is important in foetal development and normal tissue formation in connection with the healing of wounds, the menstrual cycle and so on. However, it also plays a critical part in morbid tissue formation, such as cancer and chronic inflammatory diseases.

The inhibition of morbid angiogenesis therefore has very attractive therapeutic potential for a variety of diseases. Tumours, for instance, can grow no larger than 1 or 2 mm without new blood vessels, upon which they are dependent for their proliferation. To date, anti-angiogenic therapy has proved effective in the treatment of colon cancer and the common eye disease AMD (Age-dependent Macula Degeneration).

All therapies have so far targeted the growth factor VEGF (Vascular Endothelial Growth Factor). VEGF controls several important functions during the formation of blood vessels by signalling via receptors on the surface of the endothelial cells, the specialised layer of cells on the interior surface of the blood vessels.

Swedish scientists at Karolinska Institutet and the biotech company AngioGenetics AB have now shown that another factor called Dll4 (Delta-like 4) has a similarly fundamental role in blood vessel formation as VEGF. The results are published in Nature no. 28 (January 2007) and can mean that Dll4 is just as important a target for anti-angiogenic drugs as VEGF.

“We can now develop ways of boosting the effect of existing anti-angiogenic therapies, and maybe we can even start to treat tumour types that do not currently respond to anti-angiogenic drugs,” says Mats Hellström, one of the scientists involved in the study.

The researchers have found that Dll4 signalling determines how many sprouts bud off from the parent vessel. This principle is critical to the number of branches and links that form and to attaining the correct density of vessels. Too great a blood supply to a tissue is just as devastating as too little.

Katarina Sternudd | alfa
Further information:
http://ki.se

Im Focus: Exotic quantum states made from light: Physicists create optical “wells” for a super-photon

Physicists at the University of Bonn have managed to create optical hollows and more complex patterns into which the light of a Bose-Einstein condensate flows. The creation of such highly low-loss structures for light is a prerequisite for complex light circuits, such as for quantum information processing for a new generation of computers. The researchers are now presenting their results in the journal Nature Photonics.

Light particles (photons) occur as tiny, indivisible portions. Many thousands of these light portions can be merged to form a single super-photon if they are...

Im Focus: Circular RNA linked to brain function

For the first time, scientists have shown that circular RNA is linked to brain function. When a RNA molecule called Cdr1as was deleted from the genome of mice, the animals had problems filtering out unnecessary information – like patients suffering from neuropsychiatric disorders.

While hundreds of circular RNAs (circRNAs) are abundant in mammalian brains, one big question has remained unanswered: What are they actually good for? In the...

Im Focus: RAVAN CubeSat measures Earth's outgoing energy

An experimental small satellite has successfully collected and delivered data on a key measurement for predicting changes in Earth's climate.

The Radiometer Assessment using Vertically Aligned Nanotubes (RAVAN) CubeSat was launched into low-Earth orbit on Nov. 11, 2016, in order to test new...

Im Focus: Scientists shine new light on the “other high temperature superconductor”

A study led by scientists of the Max Planck Institute for the Structure and Dynamics of Matter (MPSD) at the Center for Free-Electron Laser Science in Hamburg presents evidence of the coexistence of superconductivity and “charge-density-waves” in compounds of the poorly-studied family of bismuthates. This observation opens up new perspectives for a deeper understanding of the phenomenon of high-temperature superconductivity, a topic which is at the core of condensed matter research since more than 30 years. The paper by Nicoletti et al has been published in the PNAS.

Since the beginning of the 20th century, superconductivity had been observed in some metals at temperatures only a few degrees above the absolute zero (minus...

Im Focus: Scientists improve forecast of increasing hazard on Ecuadorian volcano

Researchers from the University of Miami (UM) Rosenstiel School of Marine and Atmospheric Science, the Italian Space Agency (ASI), and the Instituto Geofisico--Escuela Politecnica Nacional (IGEPN) of Ecuador, showed an increasing volcanic danger on Cotopaxi in Ecuador using a powerful technique known as Interferometric Synthetic Aperture Radar (InSAR).

The Andes region in which Cotopaxi volcano is located is known to contain some of the world's most serious volcanic hazard. A mid- to large-size eruption has...