Gene therapy will cure parkinsonism
Nose drops from Parkinson's
A cure for Parkinson's disease has been created that needs to be instilled into the nose;
it was presented at a major conference in BostonNadezhda Markina, Newspaper.
To cope with Parkinson's disease, scientists have proposed using not the drug itself, but a gene that provides synthesis of this drug. And in order to get to the brain bypassing the blood-brain barrier, they proposed to bury the gene in the DNA nanoparticles in the nose. The drug has been successfully tested on rats.
Symptoms of Parkinson's disease – muscle weakness, coordination disorder, tremor – are the result of neurons of a certain specialization dying in the brain. They synthesize and use the neurotransmitter dopamine to transmit a nerve signal. The cluster of these neurons is located in the subcortical region of the brain – the so-called black matter (substantia nigra). According to statistics, the disease affects more than 1% of the population over 60 years old. Treatment of parkinsonism is aimed at restoring dopamine levels in the brain, usually dopamine precursor substances (L-DOPA) are used for this.
Medications do not solve the problem radically – they only replenish dopamine reserves, but they cannot stop the progressive death of neurons. Even with constant medication, a person can expect paralysis and death.
An alternative approach is being developed by scientists from Northeastern University in Boston. In a previous study, they found a remedy that can save neurons from death. This is GDNF (glial cell line-derived neurotrophic factor), a protein so named because it is secreted by glial cells – another type of nerve tissue cells that create the bulk of the brain, nourish neurons and do many other useful things. The difficulty of using GDNF for treatment is that it is a fairly large protein molecule that does not pass through the blood–brain barrier (BBB) - a barrier between the blood and the brain that prevents harmful substances from entering the brain. The way out is to inject GDNF directly into the brain.
But it can be easier – to drip into the nose, since the epithelium of the nasal cavity is a "gateway to the brain" bypassing the BBB. Scientists have shown that GDNF works with this method of administration. They tested it in Parkinson's disease, modeled in rats. In this model, the death of dopaminergic neurons is caused by a neurotoxin (6-OHDA) – as a result, rats have the same symptoms as sick people. GDNF, when instilled into the nose, protects rat neurons from degradation, and the symptoms of the disease significantly weaken. The medicine helps, but again not forever. To maintain the GDNF level, it must be entered constantly.
Developing this approach, Brendan Harmon and his colleagues from the laboratory of Northeastern University proposed a way in which the content of matter in the brain is constantly maintained at a high level. The scientists spoke about the results of their work at the Experimental Biology 2013 conference, which is currently taking place in Boston (A noninvasive avenue for Parkinson's disease gene therapy).
We are talking about gene therapy, when the deficiency of a protein is corrected by the introduction of the corresponding gene encoding this protein. In this case, biologists suggested introducing the GDNF gene into the brain. To deliver the gene, they used a non-viral vector (everyone tries to get away from the help of viruses because of their potential danger). These are the so-called Copernicus nanoparticles produced by Copernicus Therapeutics, Inc. Nanoparticles are DNA molecules tightly packed into a ball, into which the desired gene is inserted. Experts have learned how to make DNA so compact that the size of nanoparticles is smaller than the pores in the membrane of the cell nucleus. Due to this, they penetrate into the nucleus and deliver the necessary gene to it.
In an experiment on rats with simulated Parkinson's disease, the method has shown its effectiveness. A solution with DNA nanoparticles was dropped into the rats' noses, along with which the GDNF gene entered their brains. The gene began to work and increase the level of GDNF in the brain, the substance had a protective effect on the neurons, and they resisted the neurotoxin. Since the introduced gene will constantly provide protein synthesis, one instillation of "gene drops" is enough for treatment.
The authors believe that the method of noninvasive gene therapy created by them can be used for the effective treatment of Parkinson's disease, and possibly other diseases of the central nervous system.
Portal "Eternal youth" http://vechnayamolodost.ru23.04.2013