Chinese researchers have designed a gene therapy that can reduce the symptoms associated with Parkinson’s disease.
- Parkinson’s disease causes significant motor disorders (rigidity, slowness of movements, tremors, etc.).
- There is no cure, but therapies and medications can alleviate the symptoms.
- A Chinese scientific team has developed a gene therapy, which helps reduce the symptoms of Parkinson’s disease.
It concerns more than 270,000 people in France. Parkinson’s disease is a neurodegenerative pathology, which results in the destruction of dopamine neurons in the substantia nigra of the brain, which participate in the control of movements. This pathology can manifest itself by three major symptoms: slowness in movements, rigidity and tremors at rest.
Gene therapy to reduce the manifestations of Parkinson’s disease
No treatment can stop the progression of the disease, but therapies exist to improve the quality of life of patients. In a recent study published in the journal cell, Researchers from the Shenzhen Institute of Advanced Technology (China) have developed a gene therapy, which makes it possible to selectively manipulate the circuits affected by Parkinson’s disease, and thus to alleviate the motor symptoms of the disease in non-human primates. Gene therapy is a technique of introducing genetic material into cells to treat a disease.
There are two receptors that modulate the action of dopamine: D1 which is an activator and D2 which is an inhibitor. D1, which projects towards the internal segment of the globus pallidus, a subcortical structure of the brain, and the substantia nigra, constitutes the direct pathway and promotes movement while D2, which projects towards the external segment of the globus pallidus, forms the indirect pathway and mediates movement inhibition. The globus pallidus is involved with the striatum and the substantia nigra in a striato-pallido-nigral circuit, which constitutes the core of the primate basal ganglia system.
Parkinson’s and gene therapy: the disappearance of tremors linked to the disease
As the scientists explained, the substantia nigra receives a projection from the D1 receptor, but no projection from the D2 receptor. They then considered selectively marking the D1 receptor by injecting a very effective retrograde adeno-associated virus into the substantia nigra, then manipulating it exclusively by introducing regulatory elements of neuronal activity into the retrograde adeno-associated virus.
The Chinese team has therefore developed a gene therapy strategy, in order to specifically activate the D1 receptor and therefore to control the direct pathway mediated by this receptor. The researchers tested their therapy in non-human primates suffering from Parkinson’s disease. They then found that motor symptoms were significantly improved in the subjects. In particular, tremors were completely eliminated and motor skills were restored.
After administration of the drug, the alleviation of symptoms lasted more than 24 hours while the therapeutic window of levodopa, the drug considered the most effective in reducing the manifestations, is approximately six hours.
