Stem cells restored brain after stroke
The ideal object of biotechnological manipulation is embryonic stem cells, from which all types of adult cells are formed. But these few universal cells are present only at the early stages of intrauterine development. Therefore, scientists create cells with almost unlimited abilities – induced pluripotent stem cells (iPSCs).
Unfortunately, biologists do not always manage to cope with the "cellular memory", which strives to knock IPSC off the "route" of development conceived by doctors. Therefore, it is safer to use not almost universal reprogrammed cells, but "native" stem cells of the organ. After all, they have already gone through several stages of specific differentiation, so they will not form, for example, bone cells instead of the expected muscle cells.
Regenerative neuromedicineNot so long ago (in the late 90s), scientists discovered a "storehouse" of brain stem cells - the dentate gyrus.
By investigating the mechanisms of neurogenesis (the formation of neurons from neuronal progenitor cells), researchers are developing effective methods for the treatment of degenerative diseases and injuries of the nervous system. Thus, biotechnologies have already reported on the possibility of growing and transplanting motor neurons to patients with paralysis and amyotrophic lateral sclerosis.
Italian researchers led by Laura Nodari (Laura Rota Nodari) The University of Milano Bicocca has shown that brain stem cells can be used to restore the nervous system after cerebral ischemia – local anemia of the brain, as a result of which neurons die. Cerebral ischemia develops due to traumatic brain injuries, prolonged hypoxia or stroke. The consequences of cerebral ischemia range from painless hyperexcitability to paralysis, loss of speech skills and loss of cognitive functions. The severity of post-ischemic pathologies depends on how long the brain has not received oxygen and nutrients.
It is worth noting that the idea to treat the consequences of cerebral ischemia was borrowed by scientists from an animal organism. The fact is that after ischemia, neuronal stem cells are activated and partially restore dead neurons. But the process is too slow, and their own stem cells are not enough to restore large-scale losses of neurons. Therefore, scientists decided to help the brain with injections of neuronal stem cells.
Experimental injectionFor the experiment, the scientists used a population of human neuronal stem cells (IhNSCs), which in previous in vitro experiments quite productively differentiated into neurons and oligodendrocytes.
In the present study, biologists used IhNSCs cells to restore the brains of laboratory rats that had suffered a stroke – cerebral ischemia three days before the experimental procedures.
The experimenters injected IhNSCs into the brain, after which they monitored the migration of cells and the restoration of the structures of the nervous system. It turned out that about 20% of the injected cells survive and begin to actively spread. New neurons form connections with neighboring cells and quite effectively cope with their new functions.
Scientists note that therapeutic cells migrated only in the damaged brain. In the brains of healthy animals, stem cells have not gone far from the injection site. That is, IhNSCs cells restore the structure and functions of the brain after ischemia (stroke), and at the same time do not degenerate into malignant cells.
For more information about which cells scientists managed to restore the brain of laboratory animals, see the article Long-term survival of human neural stem cells in the ischemic rat brain upon transient immunosuppression in the journal PLoS One.
Portal "Eternal youth" http://vechnayamolodost.ru29.11.2010