Gene Therapy and Parkinson's
Can Parkinson's disease be treated with gene therapy? Possibly -- research on this topic is currently being performed, and some of the studies show promise. Although gene therapy may someday be an approach to treating this disease, researchers must first develop efficient and safe means of delivering genes to brain cells in order for this treatment to be used successfully in humans.
Gene therapy offers great potential for Parkinson's disease and many other brain disorders. With gene therapy, viruses are engineered to deliver genes that increase the supply of dopamine, prevent cell death, or promote regeneration of neurons.
Although gene therapy is a promising approach to treating Parkinson's, researchers need to develop efficient and safe means of delivering genes to brain cells in order for gene therapy to be used in humans. Many researchers are working to develop better viral vectors -- viruses that can carry genes into the targeted cells -- and to find ways of improving the transfer of these vectors to the brain.
As researchers accumulate more information about the safety and efficacy of different delivery systems, research on gene therapy for Parkinson's disease can move forward.
Investigators have found that using a genetically modified virus to deliver specific growth factors to primates with a parkinsonian condition leads to dramatic improvements in symptoms.
Another group of researchers has shown that engineering a virus to deliver enzymes that are important for the production of levodopa can have beneficial effects in rats with Parkinson's.
Investigators are also experimenting with the gene for 1-amino acid decarboxylase (AADC), an enzyme that converts levodopa into dopamine. Animal research has shown that neurons in the striatum of the brain can be given the AADC gene using a viral vector, causing the neurons to convert levodopa to dopamine. This essentially mimics the function of the dopamine neurons that are lost in Parkinson's disease and may reduce the need for drugs that increase the level of dopamine in the brain.
Parkinson's disease research scientists are also experimenting with therapy to deliver a protein called GDNF (glial cell-derived neurotrophic factor) to the brain. When used in monkeys, GDNF prevented dopamine neurons from dying and the monkeys regained some of their lost motor skills.