Study Rationale:
The dysfunction of the systems responsible for the clearance of the protein alpha-synuclein plays a major role in Parkinson’s disease (PD). The lysosome is an important sub-cellular compartment for alpha-synuclein disposal. Among the many lysosomal enzymes responsible for this degradation, major attention has been given to glucocerebrosidase (GCase). Several reports have consistently shown the significant decrease of its activity in PD brain; likewise, subjects carrying mutations in the gene encoding GCase (GBA1) have a higher risk of developing PD. GCase activity was found to be significantly reduced in cerebrospinal fluid (CSF) of PD patients in the earlier stages of the disease, suggesting its possible role as biomarker of the disease.
Hypothesis:
We will confirm the potential role as PD biomarker of CSF lysosomal enzyme activities, with special interest in GCase, and assess the impact of genetic factors (GBA1) on that activity.
Study Design:
We will measure the activity of some lysosomal enzymes, including GCase, in CSF from PD patients and controls. We will also assess the impact of genetic factors (GBA1) on the activities measured. The time samples spend in the freezer will be also considered, since it may influence the enzymatic activity measured in CSF.
Impact on Diagnosis/Treatment of Parkinson’s Disease:
Research assessing the molecular links between lysosomal dysfunction and neurodegeneration offers interesting perspectives toward drug development aimed at counteracting neurodegenerative mechanisms causing PD.
Next Steps for Development:
Should this investigation confirm the role of CSF measurement of GCase and/or other lysosomal enzymes activity as diagnostic biomarkers of PD, the next step would be a large multi-center study to validate this biochemical analysis.