RNA Interference for Parkinson's Disease

Parkinson's disease is a fairly devastating illness. Dopaminergic brain cells die off over the course of this brain disorder. As brain dopamine levels fall, patients often have increasing difficult moving. They may show signs of tremor, muscle rigidity, a slowing of physical movement and sometimes a complete loss of physical movement. Patients become increasingly trapped in a body that ceases to function normally. There are a variety of drugs that are used to artificially increase the neurotransmitter dopamine in the brain. These drugs include dopamine agonists, dopamine precursors and drugs that inhibit the breakdown or reuptake of dopamine. In the future, successful treatment of parkinson's disease will need to be able to slow down the death of dopaminergic brain cells that synthesize dopamine and not just replace the missing dopamine. Doing this would allow a patient to retain their functioning without a large decline.

Now researchers at the Mayo Clinic are testing RNA interference to reduce the alpha-synuclein protein in the brain. Too much of the alpha-synuclein protein can accumulate in certain parkinson's patients and this is believed to be the cause of some of the brain cell death in these people. RNA interference is a way of selectively knocking down the functioning of a specific gene. It can selectively reduce the amount of protein being synthesized by that gene by introducing a short RNA strand. In a recent study, scientists infused small interfering RNA's into the brains of mice. They found that the RNA Interference was able to silence the alpha-synuclein gene and reduce the production of the alpha-synuclein protein for approximately 3 weeks.

There are quite a few problems with RNA interference. Problems include making sure that the RNA interference knocks down the correct gene and doesn't target any other genes. Also it is difficult to find a proper delivery mechanism for the RNA interference. RNA strands can easily be degraded in the body. Scientists have really been working hard at getting RNA interference to work for many disorders. However, it is currently not clear if they will be able to overcome these hurdles to get RNA interference to be used in real patients. Researchers have recently created oral pills that can deliver RNA interference. So RNA interference may eventually be used for certain brain disorders where knock down of a specific protein is necessary.

Here's a video about this new paper.