Biology subjects

Compta, Y.

Publications and source records attributed to Compta, Y..

5 recordsLinked to original sources

bioRxiv2025

Phospho-signalling deregulation of the mTOR pathway in fibroblasts from LRRK2 Parkinson s patients

Activating mutations at the leucine-rich repeat kinase 2 (LRRK2) gene are the most frequent genetic cause of Parkinsons Disease (PD). Using in-depth mass-spectrometry, here we analysed the impact of LRRK2 mutations on the proteome and phospho-proteome of skin fibroblasts from a large LRRK2 clinical cohort from Spain. The cohort encompassed G2019S LRRK2-associated PD (L2PD) (n=15), G2019S LRRK2 non-manifesting carriers (L2NMCs) (n=13), idiopathic PD (iPD) (n=12), and control subjects (n=14) (total n=54). The proteome analysis revealed 89 differential proteins in G2019S L2PD (58 down/ 31 up) and 168 in G2019S L2NMCs (127 down / 41 up) compared to controls. Most of these proteome changes involved deficits in proteins related to mitochondrial energy and ribosomal protein synthesis. At the phospho-proteome level, we identified 394 differential phospho-sites in G2019S L2PD (188 hyper / 206 hypo), 367 in G2019S L2NMCs (215 hyper / 152 hypo), and 428 in iPD (214 hyper / 214 hypo) compared with controls. These phospho-proteomic changes included hyper-phosphorylated proteins associated with the mTOR and Rho GTPase pathways. Notably, the top hyper-phosphorylated hit in G2019S carriers was pThr37/46 4E-BP1, a key effector of the mTOR pathway controlling protein synthesis, and this protein was also deregulated in iPD. In summary, our study uncovers peripheral deregulation of mTOR phospho-signalling associated with LRRK2 mutations, which is related to deficits in mitochondrial and ribosomal proteins, and affects converging pathways altered in iPD.

neuroscience↗

bioRxiv2023

Mitochondrial complex I deficiency stratifies idiopathic Parkinson's disease

Idiopathic Parkinsons disease (iPD) is believed to have a heterogeneous pathophysiology, but molecular disease subtypes have not been identified. Here, we show that iPD can be stratified according to the severity of neuronal respiratory complex I (CI) deficiency, and identify two emerging disease subtypes with distinct molecular and clinical profiles. The CI deficient (CI-PD) subtype accounts for approximately a fourth of all cases, and is characterized by anatomically widespread neuronal CI deficiency, a distinct cell type-specific gene expression profile, increased load of neuronal mtDNA deletions, and a predilection for non-tremor dominant motor phenotypes. In contrast, the non-CI deficient (nCI-PD) subtype exhibits no evidence of mitochondrial impairment outside the dopaminergic substantia nigra and has a predilection for a tremor dominant phenotype. These findings constitute a step towards resolving the biological heterogeneity of iPD with implications for both mechanistic understanding and treatment strategies.

neuroscience↗

bioRxiv2019

The genetic architecture of Parkinson disease in Spain: characterizing population-specific risk, differential haplotype structures, and providing etiologic insight

BackgroundThe Iberian Peninsula stands out as having variable levels of population admixture and isolation, making Spain an interesting setting for studying the genetic architecture of neurodegenerative diseases.\n\nObjectivesTo perform the largest Parkinson disease (PD) genome-wide association study (GWAS) restricted to a single country.\n\nMethodsWe performed a GWAS for both risk of PD and age-at-onset (AAO) in 7,849 Spanish individuals. Further analyses included population-specific risk haplotype assessments, polygenic risk scoring through machine learning, Mendelian randomization of expression and methylation data to gain insight into disease-associated loci, heritability estimates, genetic correlations and burden analyses.\n\nResultsWe identified a novel population-specific GWAS signal at PARK2 associated with AAO. We replicated four genome-wide independent signals associated with PD risk, including SNCA, LRRK2, KANSL1/MAPT and HLA-DQB1. A significant trend for smaller risk haplotypes at known loci was found compared to similar studies of non-Spanish origin. Seventeen PD-related genes showed functional consequence via two-sample Mendelian randomization in expression and methylation datasets. Long runs of homozygosity at 28 known genes/loci were found to be enriched in cases versus controls.\n\nConclusionsOur data demonstrate the utility of the Spanish risk haplotype substructure for future fine-mapping efforts, showing how leveraging unique and diverse population histories can benefit genetic studies of complex diseases. The present study points to PARK2 as a major hallmark of PD etiology in Spain.

neuroscience↗

bioRxiv2019

Neuropathological validation of the MDS-PSP criteria with PSP and other frontotemporal lobar degeneration

BackgroundProgressive supranuclear palsy (PSP) is clinically heterogeneous. Clinical diagnostic criteria were revised in 2017, to increase sensitivity and operationalize the diagnosis of PSP Richardsons syndrome (PSP-RS) and \"variant\" syndromes (vPSP).\n\nObjectivesTo determine the (1) sensitivity and specificity of the 1996 NINDS-SPSP and 2017 MDS-PSP criteria; (2) false positive rates in frontotemporal dementia with frontotemporal lobar degeneration (FTLD); and (3) clinical evolution of variant PSP syndromes (vPSP).\n\nMethodsRetrospective multicenter review of 108 neuropathologically-confirmed PSP patients and 81 patients with other forms of FTLD: 38 behavioral variant frontotemporal dementia (bvFTD), 14 non-fluent/agrammatic variant primary progressive aphasia (nfvPPA), and 29 corticobasal degeneration (CBD), Sensitivity and specificity of the MDS-PSP criteria were compared to the NINDS-SPSP criteria at baseline. In a subset of cases, the timing and frequency of clinical features were compared across groups over six years.\n\nResultsSensitivity for recognition of probable and possible PSP pathology was higher by MDS-PSP criteria (72.2-100%) than NINDS-SPSP criteria (48.1-61.1%). Specificity was higher by NINDS-SPSP criteria (97.5-100%) than MDS-PSP criteria (53.1-95.1%). False positives by MDS-PSP criteria were few for bvFTD (10.5-18.4%) but common for CBD and nfvPPA (fulfilling \"suggestive of PSP). Most vPSP cases developed PSP-RS-like features within six years, including falls and supranuclear gaze palsy, distinguishing frontal presentations of PSP from bvFTD, and speech/language presentations of PSP from nfvPPA.\n\nConclusionsThe 2017 MDS-PSP criteria successfully identify PSP, including variant phenotypes. This independent validation of the revised clinical diagnostic criteria strengthens the case for novel therapeutic strategies against PSP to include variant presentations.

neuroscience↗

bioRxiv2018

Heritability and genetic variance of dementia with Lewy bodies

Recent large-scale genetic studies have allowed for the first glimpse of the effects of common genetic variability in dementia with Lewy bodies (DLB), identifying risk variants with appreciable effect sizes. However, it is currently well established that a substantial portion of the genetic heritable component of complex traits is not captured by genome-wide significant SNPs. To overcome this issue, we have estimated the proportion of phenotypic variance explained by genetic variability (SNP heritability) in DLB using a method that is unbiased by allele frequency or linkage disequilibrium properties of the underlying variants. This shows that the heritability of DLB is nearly twice as high as previous estimates based on common variants only (31% vs 59.9%). We also determine the amount of phenotypic variance in DLB that can be explained by recent polygenic risk scores from either Parkinsons disease (PD) or Alzheimers disease (AD), and show that, despite being highly significant, they explain a low amount of variance. Additionally, to identify pleiotropic events that might improve our understanding of the disease, we performed genetic correlation analyses of DLB with over 200 diseases and biomedically relevant traits. Our data shows that DLB has a positive correlation with education phenotypes, which is opposite to what occurs in AD. Overall, our data suggests that novel genetic risk factors for DLB should be identified by larger GWAS and these are likely to be independent from known AD and PD risk variants.

neuroscience↗