MicroRNAs (miRNAs) are molecules that control the production of proteins from genes in the cell. We have found that the blood of people with Parkinson's disease (PD) contains a lower than average amount of miRNA. This is also true for people with rapid eye movement (REM) sleep behavior disorder, which is linked to Parkinson's. In this study, we aim to understand this connection further by measuring the amount of miRNA in the blood in people at risk of developing PD, including healthy people with a change (mutation) in the LRRK2 gene. Although mutations in the LRRK2 gene are a leading genetic cause of Parkinson's, not everyone with an LRRK2 mutation has Parkinson's (those people are called asymptomatic carriers).
Having a lower than average amount of miRNA in the blood may predict the onset and progression of motor symptoms of PD and could help identify people likely to develop Parkinson's in the future.
We plan to conduct two studies. In the first study, we will measure the amount of three different miRNAs in the blood of asymptomatic carriers every 12 to 18 months over the course of three to four and a half years. In this study, we aim to find out how quickly Parkinson's begins and progresses in these people. In the second study, hundreds of novel miRNAs will be analyzed in asymptomatic carriers and people with PD at one point in time. The goal of this study is to identify new candidate miRNA biomarkers, objective measures of pre-clinical (occurring before the onset of symptoms) and early Parkinson's disease.
Impact on Diagnosis/Treatment of Parkinson's Disease:
Studying the pre-clinical stage of PD can help researchers understand the earliest stages of disease and find the urgently needed biomarkers. We aim to identify miRNA biomarkers able to predict symptom onset and disease progression in asymptomatic carriers, potentially providing a new diagnostic tool and opening avenues for early clinical intervention.
Next Steps for Development:
Reliable miRNA biomarkers of pre-clinical Parkinson's would help track the effect of future PD therapies capable of preventing the disease or slowing its progression. These properties would also make the miRNA biomarkers a cost effective tool useful in clinical trials.