Obesity-related brain atrophy is independent of Alzheimer's disease protein pathways.

BackgroundObesity increases the risk for Alzheimer's disease (AD) and other dementias. Obesity causes structural brain injury, and it has been suggested that this may contribute to the development of AD pathology. Neurodegeneration in AD results from the aggregation of misfolded and dysfunctional tau and amyloid-β.

Coffee Consumption Is Associated With Later Age-at-Onset of Parkinson's Disease.

Observation studies suggest that coffee consumption may lower the risk and delay the age-at-onset (AAO) of Parkinson's disease (PD). The aim of this study was to explore the causal relationship and genetic association between coffee consumption and the AAO, risk, and progression of PD. Using Mendelian randomization, we identified a significant association between coffee consumption and delayed PD AAO (IVW: OR, 1.

LRRK2 rare-variant per-domain genetic burden in Parkinson's Disease: association confined to the kinase domain.

LRRK2 variants are key genetic risk factors for Parkinson's Disease (PD). We conducted a per-domain rare coding variant burden analysis, including 8,888 PD cases and 69,412 controls. In meta-analysis, the Kinase domain was strongly associated with PD (Exonic: P = 1.

Genome-Wide Association Study of Glucocerebrosidase Activity Modifiers.

One of the most common genetic risk factors for Parkinson's disease (PD) is variants in GBA1, which encodes the lysosomal enzyme glucocerebrosidase (GCase). GCase deficiency has been associated with an increased PD risk, but not all individuals with low GCase activity are carriers of GBA1 mutations, suggesting other factors may be acting as modifiers. We aimed to discover common variants associated with GCase activity, as well as replicate previously reported associations, by performing a genome-wide association study using two independent cohorts: a Columbia University cohort consisting of 697 PD cases and 347 controls and the Parkinson's Progression Markers Initiative (PPMI) cohort consisting of 357 PD cases and 163 controls.

Plasma Glucosylceramide Levels Are Regulated by ATP10D and Are Not Involved in Parkinson's Disease Pathogenesis.

GBA1 variants and decreased glucocerebrosidase activity are implicated in Parkinson's disease (PD). We investigated the hypothesis that increased levels of glucosylceramide (GlcCer), a main substrate of glucocerebrosidase, are involved in PD pathogenesis. Using multiple genetic methods, we show that ATPase phospholipid transporting 10D (ATP10D), not GBA1, is the main regulator of plasma GlcCer levels, yet it is not involved in PD pathogenesis.

Coffee consumption is associated with later age-at-onset of Parkinson's disease.

Observation studies suggest that coffee consumption may lower the risk of Parkinson's disease (PD). The aim of this study was to explore the causal relationship and genetic association between coffee consumption and the age-at-onset (AAO), risk, and progression of PD. Using Mendelian randomization, we identified a significant association between coffee consumption and delayed PD AAO (IVW: OR, 1.

Are rare heterozygous SYNJ1 variants associated with Parkinson's disease?

Previous studies have established that rare biallelic SYNJ1 mutations cause autosomal recessive parkinsonism and Parkinson's disease (PD). We analyzed 8165 PD cases, 818 early-onset-PD (EOPD, < 50 years) and 70,363 controls. Burden meta-analysis revealed an association between rare nonsynonymous variants and variants with high Combined Annotation-Dependent Depletion score (> 20) in the Sac1 SYNJ1 domain and PD (Pfdr = 0.

Plasma glucosylceramide levels are regulated by and are not involved in Parkinson's disease pathogenesis.

variants and decreased glucocerebrosidase (GCase) activity are implicated in Parkinson's disease (PD). We investigated the hypothesis that increased levels of glucosylceramide (GlcCer), one of GCase main substrates, are involved in PD pathogenesis. Using multiple genetic methods, we show that not , is the main regulator of plasma GlcCer levels, yet it is not involved in PD pathogenesis.

Are rare heterozygous variants associated with Parkinson's disease?

Previous studies have suggested that rare biallelic mutations may cause autosomal recessive parkinsonism and Parkinson's disease (PD). Our study explored the impact of rare variants in non-familial settings, including 8,165 PD cases, 818 early-onset PD (EOPD, <50 years) and 70,363 controls. Burden meta-analysis using optimized sequence Kernel association test (SKAT-O) revealed an association between rare nonsynonymous variants in the Sac1 SYNJ1 domain and PD (P=0.

The Parkinson's disease risk gene cathepsin B promotes fibrillar alpha-synuclein clearance, lysosomal function and glucocerebrosidase activity in dopaminergic neurons.

Background: Variants in the gene encoding the lysosomal hydrolase cathepsin B (catB) are associated with increased risk of Parkinson's disease (PD). However, neither the specific variants driving these associations nor the functional pathways that link catB to PD pathogenesis have been characterized. CatB activity contributes to lysosomal protein degradation and regulates signaling processes involved in autophagy and lysosome biogenesis.

The Parkinson's disease risk gene cathepsin B promotes fibrillar alpha-synuclein clearance, lysosomal function and glucocerebrosidase activity in dopaminergic neurons.

Variants in the gene encoding the lysosomal hydrolase cathepsin B (catB) are associated with increased risk of Parkinson's disease (PD). However, neither the specific variants driving these associations nor the functional pathways that link catB to PD pathogenesis have been characterized. CatB activity contributes to lysosomal protein degradation and regulates signaling processes involved in autophagy and lysosome biogenesis.

Lack of genetic evidence for NLRP3-inflammasome involvement in Parkinson's disease pathogenesis.

Activation of the NLRP3-inflammasome has been implicated in Parkinson's disease based on and studies. Clinical trials targeting the NLRP3-inflammasome in Parkinson's disease are ongoing. However, the evidence supporting NLRP3's involvement in Parkinson's disease from human genetics data is limited.

4R-Tau seeding activity unravels molecular subtypes in patients with Progressive Supranuclear Palsy.

Progressive Supranuclear palsy (PSP) is a 4-repeat (4-R) tauopathy. We hypothesized that the molecular diversity of tau could explain the heterogeneity seen in PSP disease progression. To test this hypothesis, we performed an extensive biochemical characterisation of the high molecular weight tau species (HMW-Tau) in 20 different brain regions of 25 PSP patients.

Machine learning nominates the inositol pathway and novel genes in Parkinson's disease.

There are 78 loci associated with Parkinson's disease in the most recent genome-wide association study (GWAS), yet the specific genes driving these associations are mostly unknown. Herein, we aimed to nominate the top candidate gene from each Parkinson's disease locus and identify variants and pathways potentially involved in Parkinson's disease. We trained a machine learning model to predict Parkinson's disease-associated genes from GWAS loci using genomic, transcriptomic and epigenomic data from brain tissues and dopaminergic neurons.

DNA Methylation Age Acceleration as a Potential Biomarker for Early Onset of Rapid Eye Movement Sleep Behavior Disorder.

Rapid eye movement sleep behavior disorder (RBD) is the strongest prodromal marker for α-synucleinopathies. The Horvath DNA methylation age (DNAm-age) is an epigenetic clock reflecting biological aging. We found an association of DNAm-age acceleration with RBD age at onset at baseline (N = 162, B = -0.

MerTK is a mediator of alpha-synuclein fibril uptake by human microglia.

Mer tyrosine kinase (MerTK) is a receptor tyrosine kinase that mediates non-inflammatory, homeostatic phagocytosis of diverse types of cellular debris. Highly expressed on the surface of microglial cells, MerTK is of importance in brain development, homeostasis, plasticity and disease. Yet, involvement of this receptor in the clearance of protein aggregates that accumulate with ageing and in neurodegenerative diseases has yet to be defined.

Association of Rare Variants in ARSA with Parkinson's Disease.

Background: Several lysosomal genes are associated with Parkinson's disease (PD), yet the association between PD and ARSA remains unclear.

Objectives: To study rare ARSA variants in PD.

Methods: To study rare ARSA variants (minor allele frequency < 0.

Potential Protective Link Between Type I Diabetes and Parkinson's Disease Risk and Progression.

Background: Epidemiological studies suggested an association between Parkinson's disease (PD) and type 2 diabetes, but less is known about type 1 diabetes (T1D) and PD.

Objective: This study sought to explore the association between T1D and PD.

Methods: We used Mendelian randomization, linkage disequilibrium score regression, and multi-tissue transcriptome-wide analysis to examine the association between PD and T1D.