New data on endothelial stem cells

The development of effective methods for isolating and growing endothelial stem cells discovered by researchers at the University of Helsinki, which play a key role in angiogenesis – the formation of new blood vessels – will open up new prospects in the treatment of diseases of the cardiovascular system and cancer.

In an adult body, the need for new vessels arises in places of tissue or organ damage, resulting, for example, from a heart attack or stroke. At the same time, cancerous tumors have the ability to grow their own blood vessels, ensuring their rapid growth. Therefore, in clinical practice there is a need for two types of mechanisms: both stimulation and blocking the growth of new vessels. A number of angiogenesis inhibitors are already used in oncology.

For a long time it has been assumed that new cells of the walls of blood vessels of an adult organism originate from mesenchymal stem cells of the bone marrow. However, Associate Professor Petri Salven, who devoted two decades of his work to the search for methods of stimulating and blocking angiogenesis, and his group refuted this hypothesis back in 2008.

The results of the latest work of researchers indicate that stem cells are found among normal endothelial cells in the walls of blood vessels of adult mammals. They were able to isolate endothelial cells with exceptionally high proliferative potential from the walls of blood vessels of mice. After that, they found the same cells in the vascular walls of adults, as well as in the walls of growing vessels of human malignant tumors.

When culturing putative stem cells in the laboratory, scientists have demonstrated that one such cell can give rise to tens of millions of new cells that form the walls of blood vessels.

Experiments on mice have also confirmed the importance of the role played by these cells. Mice with fewer endothelial stem cells were characterized by weak angiogenesis, as well as slow growth of malignant tumors. At the same time, the introduction of new stem cells led to the formation of a large number of new blood vessels in the area of their implantation.

The study of endothelial stem cells is progressing very slowly due to the difficulty of detecting them among other types of cells forming the walls of blood vessels. The authors identified several molecular structures on their cell membranes, which are the only markers of endothelial stem cells. They are currently searching for new markers that would increase the efficiency of their allocation. According to Salven, to transfer the results obtained into clinical practice, it is necessary to increase the efficiency and accuracy of the isolation of these cells tenfold compared to existing methods.

Article by Shentong Fang et al. Generation of Functional Blood Vessels from a Single c-kit+ Adult Vascular Endothelial Stem Cell is published in the journal Plos Biology.

Evgeniya Ryabtseva
Portal "Eternal youth" http://vechnayamolodost.ru based on the materials of the University of Helsinki:
Researchers track down stem cells in blood vessel walls.

19.10.2012