α-Synuclein Gene Hypomethylation in LRRK2 Parkinson's Disease Patients.

Background: α-Synuclein (SNCA) gene hypomethylation was reported in idiopathic Parkinson's disease (iPD). Based on a high clinical resemblance between iPD and leucine-rich repeat kinase 2 (LRRK2)-driven Parkinson's disease (L2PD), we investigated the epigenetic status of SNCA in an extensive LRRK2 clinical cohort from Spain.

Methods: We assessed the methylation levels of 23 CpG sites in the SNCA promoter region using peripheral blood DNA from L2PD patients (n = 151), LRRK2 nonmanifesting carriers (n = 55), iPD patients (n = 115), and healthy control subjects (n = 154) (total: N = 475).

In-depth mass-spectrometry reveals phospho-RAB12 as a blood biomarker of G2019S LRRK2-driven Parkinson's disease.

Leucine-rich repeat kinase 2 (LRRK2) inhibition is a promising disease-modifying therapy for LRRK2-associated Parkinson's disease (L2PD) and idiopathic PD (iPD). However, pharmaco-dynamic readouts and progression biomarkers for clinical trials aiming for disease modification are insufficient since no endogenous marker reflecting enhanced kinase activity of the most common LRRK2 G2019S mutation has been reported yet in L2PD patients. Employing phospho-/proteomic analyses we assessed the impact that LRRK2 activating mutations had in peripheral blood mononuclear cells (PBMCs) from a LRRK2 clinical cohort from Spain (n=174).

Fluid and tissue biomarkers in Parkinson's disease: Immunodetection or seed amplification? Central or peripheral?

Over the last two decades there have been meaningful developments on biomarkers of neurodegenerative diseases, extensively (but not solely) focusing on their proteinopathic nature. Accordingly, in Alzheimer's disease determination of levels of total and phosphorylated tau (τ and p-τ, usually p-τ181) along with amyloid-beta1-42 (Aβ1-42) by immunodetection in cerebrospinal fluid (CSF) and currently even in peripheral blood, have been widely accepted and introduced to routine diagnosis. In the case of Parkinson's disease, α-synuclein as a potential biomarker (both for diagnosis and progression tracking) has proved more elusive under the immunodetection approach.