A group of researchers from John Hopkins have reported that they’ve identified a protein that enables toxins to spread between the brain cells of mammals, and that they’ve also found a way to block the action of the protein by using a drug that’s currently being tested in clinical trials as a potential therapy for cancer. This discovery gives hope that this drug could also be tested and used to slow down the progress of Parkinson’s disease.
Several years ago, a study from the Goethe University in Germany suggested that the progression of Parkinson’s disease was due to the spread of a-synuclein aggregates from one brain cell to another. These aggregates gradually spread from the brain structures responsible for basic functions and movement to the areas of the brain which are associated with memory, learning and reasoning. While at the time, these findings were met with a great deal of scepticism, other research began to show that it was possible for this spread of aggregates to occur.
As a result of these findings, lead author of this new study, Ted Dawson, M.D. PhD and his team from the Institute of Cell Engineering at John Hopkins wanted to find out more about how these particular aggregates can enter the brain cells. From their research, the team already knew that they were looking for a certain kind of protein which is found on the outside of the cell, which is known as a transmembrane receptor, and which is responsible for admitting certain proteins into the cells. The team used cells which did not allow entry to the a-synuclein aggregates, and then added genes for transmembrane receptors to see whether the situation would change. Three of the proteins added allowed the aggregates to enter, with one protein known as LAG3, attaching itself to the a-synuclein aggregates.
The next step was for the team to breed mice without the gene for LAG3 and to inject them with the aggregates. Usually mice will develop typical symptoms of Parkinson’s after they’ve been injected. However, the mice without the LAG3 appeared to be protected from the disease. Furthermore, the team found that antibodies that blocked LAG3 could be used to bring about a similar effect.
Currently clinical trials are already underway to determine whether the antibodies that block LAG3 can help to strengthen the immune system during chemotherapy treatments for cancer. If the drug is deemed safe in these trials, then it will be possible to fast track the trials for testing them as a potential therapy for Parkinson’s disease.
The study was published in a recent edition of the journal Science.