GP2: The Global Parkinson's Genetics Program

in Movement Disorders (2021), 36(4), 842-851

To facilitate the rapid expansion of our understanding of the genetic architecture of PD, both in terms of the depth and global context of this knowledge, we have created the Global Parkinson's Genetics ... [more ▼]

To facilitate the rapid expansion of our understanding of the genetic architecture of PD, both in terms of the depth and global context of this knowledge, we have created the Global Parkinson's Genetics Program (GP2; www.gp2.org). GP2 is the first supported resource project of the Aligning Science Across Parkinson's (ASAP) initiative, an audacious effort supporting PD research.9 GP2 is geared toward creating a worldwide collaborative effort that will first dramatically accelerate the identification of genetic contributors to disease and second establish a network of researchers who can best leverage this understanding to research, diagnose, and treat PD worldwide. Here we describe our mission, the path we have proposed to achieve this, and the core principles of data democratization, transparency, and diversity. [less ▲]

Peripheral decarboxylase inhibitors paradoxically induce aromatic L-amino acid decarboxylase

in NPJ Parkinson's Disease (2021)

Peripheral decarboxylase inhibitors (PDIs) prevent the conversion of levodopa to dopamine in the blood by the enzyme aromatic L-amino acid decarboxylase (AADC). Alterations in enzyme activity may ... [more ▼]

Peripheral decarboxylase inhibitors (PDIs) prevent the conversion of levodopa to dopamine in the blood by the enzyme aromatic L-amino acid decarboxylase (AADC). Alterations in enzyme activity may contribute to the required higher dosages of levodopa observed in many patients with Parkinson’s disease. We evaluated the effect of levodopa/PDI use on serum AADC enzyme activity. Serum AADC enzyme activity was evaluated in three independent cohorts of patients with Parkinson’s disease or parkinsonism (n = 301) and compared between patients on levodopa/PDI vs. patients not on this medication. AADC enzyme activity was elevated in 62% of patients on levodopa/PDI treatment, compared to 19% of patients not on levodopa/PDI (median 90 mU/L vs. 50 mU/L, p < 0.001). Patients with elevated AADC activity had longer disease duration and higher doses of levodopa/PDI. These findings may implicate that peripheral AADC induction could underlie a waning effect of levodopa, necessitating dose increases to maintain a sustained therapeutic effect. [less ▲]

Genome sequencing analysis identifies new loci associated with Lewy body dementia and provides insights into its genetic architecture

in Nature Genetics (2021)

The genetic basis of Lewy body dementia (LBD) is not well understood. Here, we performed whole-genome sequencing in large cohorts of LBD cases and neurologically healthy controls to study the genetic ... [more ▼]

The genetic basis of Lewy body dementia (LBD) is not well understood. Here, we performed whole-genome sequencing in large cohorts of LBD cases and neurologically healthy controls to study the genetic architecture of this understudied form of dementia, and to generate a resource for the scientific community. Genome-wide association analysis identified five independent risk loci, whereas genome-wide gene-aggregation tests implicated mutations in the gene GBA. Genetic risk scores demonstrate that LBD shares risk profiles and pathways with Alzheimer’s disease and Parkinson’s disease, providing a deeper molecular understanding of the complex genetic architecture of this age-related neurodegenerative condition. [less ▲]

The Role of DJ-1 in Cellular Metabolism and Pathophysiological Implications for Parkinson’s Disease

in Cells (2021)

Quantifying activities of daily living impairment in Parkinson’s disease using the Functional Activities Questionnaire

in Neurological Sciences (2021)

Objective Cognitive-driven activity of daily living (ADL) impairment in Parkinson’s disease (PD) is increasingly discussed as prodromal marker for dementia. Diagnostic properties of assessments for this ... [more ▼]

Objective Cognitive-driven activity of daily living (ADL) impairment in Parkinson’s disease (PD) is increasingly discussed as prodromal marker for dementia. Diagnostic properties of assessments for this specifc ADL impairment are sparsely investigated in PD. The ability of the Functional Activities Questionnaire (FAQ) for diferentiating between PD patients with normal cognition and with mild cognitive impairment (PD-MCI), according to informant and self-reports, was examined. Global cognitive function in groups with and without mild ADL impairment was compared according to diferent cut-ofs. Methods Multicenter data of 589 patients of an international cohort (CENTRE-PD) were analyzed. Analyses were run separately for informant-rated and self-rated FAQ. Receiver operating characteristic (ROC) analysis was conducted to defne the optimal FAQ cut-of for PD-MCI (≥1), and groups were additionally split according to reported FAQ cut-ofs for PD-MCI in the literature (≥3,≥5). Binary logistic regressions examined the efect of the Montreal Cognitive Assessment (MoCA) score in PD patients with and without mild ADL impairment. Results Two hundred and twenty-fve (38.2%) patients were classifed as PD-MCI. For all three cut-of values, sensitivity was moderate to low (<0.55), but specifcity was moderately high (>0.54) with a tendency of higher values for self-reported defcits. For the self-report, the cut-of≥3 showed a signifcant efect of the MoCA (B= −0.31, p=0.003), where FAQ≥3 patients had worse cognition. No efect for group diferences based on informant ratings was detected. Conclusion Our data argue that self-reported ADL impairments assessed by the FAQ show a relation to the severity of cognitive impairment in PD. [less ▲]

The Moderating Role of Resilience in the Personality-Mental Health Relationship During the COVID-19 Pandemic

in Frontiers in Psychiatry (2021)

Integrated, automated maintenance, expansion and differentiation of 2D and 3D patient-derived cellular models for high throughput drug screening

in Scientific Reports (2021)

Adverse Life Trajectories Are a Risk Factor for SARS-CoV-2 IgA Seropositivity.

in Journal of clinical medicine (2021), 10(10),

Asymptomatic individuals, called "silent spreaders" spread SARS-CoV-2 efficiently and have complicated control of the ongoing COVID-19 pandemic. As seen in previous influenza pandemics, socioeconomic and ... [more ▼]

Asymptomatic individuals, called "silent spreaders" spread SARS-CoV-2 efficiently and have complicated control of the ongoing COVID-19 pandemic. As seen in previous influenza pandemics, socioeconomic and life-trajectory factors are important in disease progression and outcome. The demographics of the asymptomatic SARS-CoV-2 carriers are unknown. We used the CON-VINCE cohort of healthy, asymptomatic, and oligosymptomatic individuals that is statistically representative of the overall population of Luxembourg for age, gender, and residency to characterise this population. Gender (male), not smoking, and exposure to early-life or adult traumatic experiences increased the risk of IgA seropositivity, and the risk associated with early-life exposure was a dose-dependent metric, while some other known comorbidities of active COVID-19 do not impact it. As prior exposure to adversity is associated with negative psychobiological reactions to external stressors, we recorded psychological wellbeing during the study period. Exposure to traumatic events or concurrent autoimmune or rheumatic disease were associated with a worse evolution of anxiety and depressive symptoms throughout the lockdown period. The unique demographic profile of the "silent spreaders" highlights the role that the early-life period plays in determining our lifelong health trajectory and provides evidence that the developmental origins of health and disease is applicable to infectious diseases. [less ▲]

GDAP1 loss of function inhibits the mitochondrial pyruvate dehydrogenase complex by altering the actin cytoskeleton 2021.03.04.433895

E-print/Working paper (2021)

Charcot-Marie-Tooth (CMT) disease 4A is an autosomal-recessive polyneuropathy caused by mutations of ganglioside-induced differentiation-associated protein 1 (GDAP1), a putative glutathione transferase ... [more ▼]

Charcot-Marie-Tooth (CMT) disease 4A is an autosomal-recessive polyneuropathy caused by mutations of ganglioside-induced differentiation-associated protein 1 (GDAP1), a putative glutathione transferase, which affects mitochondrial shape and alters cellular Ca2+ homeostasis. Here, we identify the underlying mechanism. We found that patient-derived motoneurons and GDAP1 knockdown SH-SY5Y cells display two phenotypes: more tubular mitochondria and a metabolism characterized by glutamine dependence and fewer cytosolic lipid droplets. GDAP1 interacts with the actin-depolymerizing protein Cofilin-1 in a redoxdependent manner, suggesting a role for actin signaling. Consistently, GDAP1 loss causes less F-actin close to mitochondria, which restricts mitochondrial localization of the fission factor dynamin-related protein 1, instigating tubularity. Changes in the actin cytoskeleton also disrupt mitochondria-ER contact sites. This results in lower mitochondrial Ca2+ levels and inhibition of the pyruvate dehydrogenase complex, explaining the metabolic changes upon GDAP1 loss of function. Together, these findings reconcile GDAP1-associated phenotypes and implicate disrupted actin signaling in CMT4A pathophysiology. [less ▲]

Analysis and visualisation of tremor dynamics in deep brain stimulation patients

in Current Directions in Biomedical Engineering (2020), 6(3), 4