Non-oncogenic embryonic stem cells
Embryonic stem cells made safe
for the treatment of Parkinson's disease
To do this, as it turned out, it is enough to treat them at the earliest stage of development with an anti-cancer drug, Infox reports.
Scientists conducted an experiment on mice with Parkinson's disease. In the future, the authors hope, this approach will accelerate the introduction of regenerative medicine methods into clinical practice.
In Parkinson's disease, a severe neurodegenerative disease, nerve cells synthesizing dopamine are destroyed in the brain. Dopamine is the most important neurotransmitter, that is, an intermediary in the transmission of a nerve impulse from neuron to neuron. Due to the lack of dopamine, patients have serious problems with movement, coordination is disrupted, muscle rigidity occurs, tremor appears, cognitive functions deteriorate, and mental disorders often occur.
Currently, this disease is considered incurable, and the existing drug therapy can only reduce the symptoms of the disease, and even then not in all cases. Therefore, scientists all over the world are searching for methods of treating this serious disease.
All hope is for stem cellsNumerous modern studies show that in the treatment of Parkinson's disease, the most promising method may be cell therapy using stem cells – cells that can transform into almost any cells and tissues.
Neurons synthesizing dopamine are grown from them, and then transplanted into the body.
A lot has already been done in this direction. For example, bioengineers have learned to obtain dopaminergic neurons from human skin cells using direct reprogramming, without the stem cell stage. There are known methods of growing such neurons from both induced pluripotent animal stem cells and human embryonic stem cells.
One of the important stages of such experiments is to check how the neurons obtained in this way will work in the body – that is, whether they will perform their main function – to synthesize dopamine. For a long time, it was not possible to carry out the implantation of such cells into the body of animals. But recently, success was achieved – neurons obtained from pluripotent stem cells of a monkey with Parkinson's disease were implanted into her. These neurons have taken root in the animal's body and have started working. The same result was achieved when dopaminergic neurons derived from human embryonic stem cells were implanted into the body of mice with Parkinson's disease.
What is the danger of stem cellsThere is one serious reason that hinders the use of these methods in clinical practice.
The fact is that there is a serious danger in embryonic and pluripotent stem cells: there is always a risk that they will not cope with pluripotence and develop into a cancerous tumor.
In their current study, Brazilian scientists led by specialists from the Federal University of Rio de Janeiro have come up with a way to solve this problem.
How to control the processTo do this, they treated mouse embryonic stem cells (ESCs) even before they began to differentiate with a drug that is used to treat cancer.
Then they acted according to the traditional scheme – they treated ESCs with transcription factors, after which the process of their transformation into dopaminergic neurons began.
The next stage of the experiment was the implantation of about 50 thousand of these neurons into the body of mice with Parkinson's disease. Scientists divided all the animals into three groups. One group was implanted with neurons derived from ESCs that were treated with an anti-cancer drug. The second group was implanted with neurons obtained from conventional ESCs without any processing. And the third group did not receive any treatment at all.
Some time after implantation, the animals from the second group noticeably improved their well-being and motor function was restored. But, unfortunately, all these animals died after seven weeks due to the development of cancerous tumors.
The mice implanted with ESCs treated with an anti-cancer drug also recovered motor function. And most importantly, after 15 weeks, scientists found no cancer cells in their bodies.
"This simple strategy, when stem cells are treated with an anti–cancer drug, makes the transplantation process safer, the risk of cancer tumors during stem cell therapy disappears," says the head of the study, Professor Steven Rehen (Stevens Rehen).
Scientists hope that this technology will accelerate the use of ESCs in clinical practice, in particular, in the treatment of Parkinson's disease.
The article by Brazilian scientists was published in the latest issue of the journal Frontiers in Cellular Neuroscience (Acquarone et al., Mitomycin-treated undifferentiated embryonic stem cells as a safe and effective therapeutic strategy in a mouse model of Parkinson's disease).
Portal "Eternal youth" http://vechnayamolodost.ru06.04.2015