Objective: To evaluate the presence of leucine-rich repeat kinase 2 (LRRK2) in human biosamples, including cerebrospinal fluid (CSF) and urine, as a first step towards developing LRRK2 expression or LRRK2 phosphorylation as biomarkers in Parkinson’s disease.

Background: Leucine-rich repeat kinase 2 (LRRK2) is a complex signaling protein that is a key therapeutic target, particularly in Parkinson’s disease (PD). In addition, there is now evidence showing that LRRK2 expression or LRRK2 phosphorylation levels have potential as disease marker or marker of target engagement. Reports show increases in LRRK2 protein levels in the prefrontal cortex of PD patients relative to controls, suggesting that increase in total LRRK2 protein expression is correlated with the disease. LRRK2 phosphorylation levels are reduced for most disease mutants and LRRK2 is also rapidly dephosphorylated upon LRRK2 inhibitor treatment, considered as potential therapeutics.

Methods: With CSF and urine collected from test individuals, we have applied an ultracentrifugation based fractionation protocol to isolate ectosome and exosome fractions. We next used immunogold labeling in electron microscopy and western blot with antibodies directed against LRRK2 and phosphoSer935-LRRK2 in order to detect LRRK2 in these fluids.

Results: We thus could confirm the presence of LRRK2 in urinary exosomes, showing by western blot detection of LRRK2 protein phosphorylated at S935 in these samples. In addition, imunogold analysis in electron microscopy shows the association of LRRK2 with both vesicular and filamentous structures in urine fractions. Analysis of LRRK2 in CSF samples is ongoing.

Conclusions: This study lays the groundwork to assess LRRK2 as a disease marker in human cerebrospinal fluid and urine samples.

« Back to 2016 International Congress

MDS Abstracts - https://www.mdsabstracts.org/abstract/detection-of-leucine-rich-repeat-kinase-2-in-human-biofluids/