Embryonic stem cells help reduce the effects of stroke
Scientists at Stanford University, working under the guidance of Professor Gary Steinberg, have demonstrated that nerve cells derived from human embryonic stem cells contribute to the restoration of brain areas damaged by stroke in rats and improve their physical condition without causing the formation of tumors.
Embryonic stem cells are a very attractive material for regenerative therapy, but their directed differentiation into nerve cells has so far caused serious difficulties for scientists. In addition, the use of these cells in the clinic is hindered by their tendency to form tumors in the recipient's body, which are a cluster of cells of various types into which embryonic cells tend to differentiate.
The authors managed to overcome these difficulties by growing embryonic stem cells in the presence of a combination of growth hormones that stimulated their maturation into stable neural stem cells. Even after six months of cultivation in the laboratory, the resulting cells retained the ability to differentiate into only three types of cells of the nervous system (neurons, astrocytes and oligodendrocytes) and did not form tumors.
Having thus made sure of the safety of the cells, the scientists transplanted them into the brains of 10 rats with induced stroke. An analysis of animal brain tissue conducted two months after the procedure showed that the cells migrated to the damaged region of the brain and integrated into the surrounding tissue. The formation of tumors was not observed.
The brain of the animals was damaged in the area responsible for the movements of one of the forelimbs. Testing of experimental group animals 4 and 8 weeks after cell transplantation showed that they used the affected limbs more effectively than the control group rats. This indicates that the transplanted cells contributed to the restoration of the functions of the damaged area of the brain.
In earlier studies, the authors injected umbilical cord blood cells, bone marrow, embryonic and adult brain tissue, as well as mouse embryos into stroke zones, but the most impressive results were obtained using human embryonic cells differentiated into neural stem cells.
According to Steinberg, before starting clinical trials of the proposed stroke treatment method, it is necessary to prove its effectiveness and safety in other animal models of the disease. He also emphasizes that the embryonic stem cells used in the work were obtained from cell lines approved for research.
Portal "Eternal youth" www.vechnayamolodost.ru based on the materials of ScienceDaily
21.02.2008