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1.
Nucleic Acids Res ; 51(D1): D167-D178, 2023 01 06.
Artículo en Inglés | MEDLINE | ID: mdl-36399497

RESUMEN

Dysregulation of RNA splicing contributes to both rare and complex diseases. RNA-sequencing data from human tissues has shown that this process can be inaccurate, resulting in the presence of novel introns detected at low frequency across samples and within an individual. To enable the full spectrum of intron use to be explored, we have developed IntroVerse, which offers an extensive catalogue on the splicing of 332,571 annotated introns and a linked set of 4,679,474 novel junctions covering 32,669 different genes. This dataset has been generated through the analysis of 17,510 human control RNA samples from 54 tissues provided by the Genotype-Tissue Expression Consortium. IntroVerse has two unique features: (i) it provides a complete catalogue of novel junctions and (ii) each novel junction has been assigned to a specific annotated intron. This unique, hierarchical structure offers multiple uses, including the identification of novel transcripts from known genes and their tissue-specific usage, and the assessment of background splicing noise for introns thought to be mis-spliced in disease states. IntroVerse provides a user-friendly web interface and is freely available at https://rytenlab.com/browser/app/introverse.


Asunto(s)
Bases de Datos Genéticas , Intrones , Empalme del ARN , Humanos , Empalme Alternativo , Secuencia de Bases , Intrones/genética , ARN , Empalme del ARN/genética
2.
Brain ; 146(12): 4974-4987, 2023 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-37522749

RESUMEN

Genetic variants conferring risks for Parkinson's disease have been highlighted through genome-wide association studies, yet exploration of their specific disease mechanisms is lacking. Two Parkinson's disease candidate genes, KAT8 and KANSL1, identified through genome-wide studies and a PINK1-mitophagy screen, encode part of the histone acetylating non-specific lethal complex. This complex localizes to the nucleus, where it plays a role in transcriptional activation, and to mitochondria, where it has been suggested to have a role in mitochondrial transcription. In this study, we sought to identify whether the non-specific lethal complex has potential regulatory relationships with other genes associated with Parkinson's disease in human brain. Correlation in the expression of non-specific lethal genes and Parkinson's disease-associated genes was investigated in primary gene co-expression networks using publicly-available transcriptomic data from multiple brain regions (provided by the Genotype-Tissue Expression Consortium and UK Brain Expression Consortium), whilst secondary networks were used to examine cell type specificity. Reverse engineering of gene regulatory networks generated regulons of the complex, which were tested for heritability using stratified linkage disequilibrium score regression. Prioritized gene targets were then validated in vitro using a QuantiGene multiplex assay and publicly-available chromatin immunoprecipitation-sequencing data. Significant clustering of non-specific lethal genes was revealed alongside Parkinson's disease-associated genes in frontal cortex primary co-expression modules, amongst other brain regions. Both primary and secondary co-expression modules containing these genes were enriched for mainly neuronal cell types. Regulons of the complex contained Parkinson's disease-associated genes and were enriched for biological pathways genetically linked to disease. When examined in a neuroblastoma cell line, 41% of prioritized gene targets showed significant changes in mRNA expression following KANSL1 or KAT8 perturbation. KANSL1 and H4K8 chromatin immunoprecipitation-sequencing data demonstrated non-specific lethal complex activity at many of these genes. In conclusion, genes encoding the non-specific lethal complex are highly correlated with and regulate genes associated with Parkinson's disease. Overall, these findings reveal a potentially wider role for this protein complex in regulating genes and pathways implicated in Parkinson's disease.


Asunto(s)
Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/metabolismo , Estudio de Asociación del Genoma Completo , Mitocondrias/metabolismo , Encéfalo/metabolismo , Redes Reguladoras de Genes
3.
Brain ; 146(7): 2869-2884, 2023 07 03.
Artículo en Inglés | MEDLINE | ID: mdl-36624280

RESUMEN

Improvements in functional genomic annotation have led to a critical mass of neurogenetic discoveries. This is exemplified in hereditary ataxia, a heterogeneous group of disorders characterised by incoordination from cerebellar dysfunction. Associated pathogenic variants in more than 300 genes have been described, leading to a detailed genetic classification partitioned by age-of-onset. Despite these advances, up to 75% of patients with ataxia remain molecularly undiagnosed even following whole genome sequencing, as exemplified in the 100 000 Genomes Project. This study aimed to understand whether we can improve our knowledge of the genetic architecture of hereditary ataxia by leveraging functional genomic annotations, and as a result, generate insights and strategies that raise the diagnostic yield. To achieve these aims, we used publicly-available multi-omics data to generate 294 genic features, capturing information relating to a gene's structure, genetic variation, tissue-specific, cell-type-specific and temporal expression, as well as protein products of a gene. We studied these features across genes typically causing childhood-onset, adult-onset or both types of disease first individually, then collectively. This led to the generation of testable hypotheses which we investigated using whole genome sequencing data from up to 2182 individuals presenting with ataxia and 6658 non-neurological probands recruited in the 100 000 Genomes Project. Using this approach, we demonstrated a high short tandem repeat (STR) density within childhood-onset genes suggesting that we may be missing pathogenic repeat expansions within this cohort. This was verified in both childhood- and adult-onset ataxia patients from the 100 000 Genomes Project who were unexpectedly found to have a trend for higher repeat sizes even at naturally-occurring STRs within known ataxia genes, implying a role for STRs in pathogenesis. Using unsupervised analysis, we found significant similarities in genomic annotation across the gene panels, which suggested adult- and childhood-onset patients should be screened using a common diagnostic gene set. We tested this within the 100 000 Genomes Project by assessing the burden of pathogenic variants among childhood-onset genes in adult-onset patients and vice versa. This demonstrated a significantly higher burden of rare, potentially pathogenic variants in conventional childhood-onset genes among individuals with adult-onset ataxia. Our analysis has implications for the current clinical practice in genetic testing for hereditary ataxia. We suggest that the diagnostic rate for hereditary ataxia could be increased by removing the age-of-onset partition, and through a modified screening for repeat expansions in naturally-occurring STRs within known ataxia-associated genes, in effect treating these regions as candidate pathogenic loci.


Asunto(s)
Ataxia Cerebelosa , Degeneraciones Espinocerebelosas , Adulto , Humanos , Degeneraciones Espinocerebelosas/genética , Ataxia Cerebelosa/diagnóstico , Ataxia Cerebelosa/genética , Ataxia/diagnóstico , Ataxia/genética , Genómica , Pruebas Genéticas
4.
Brain ; 146(5): 1873-1887, 2023 05 02.
Artículo en Inglés | MEDLINE | ID: mdl-36348503

RESUMEN

Parkinson's disease is one of the most common age-related neurodegenerative disorders. Although predominantly a motor disorder, cognitive impairment and dementia are important features of Parkinson's disease, particularly in the later stages of the disease. However, the rate of cognitive decline varies among Parkinson's disease patients, and the genetic basis for this heterogeneity is incompletely understood. To explore the genetic factors associated with rate of progression to Parkinson's disease dementia, we performed a genome-wide survival meta-analysis of 3923 clinically diagnosed Parkinson's disease cases of European ancestry from four longitudinal cohorts. In total, 6.7% of individuals with Parkinson's disease developed dementia during study follow-up, on average 4.4 ± 2.4 years from disease diagnosis. We have identified the APOE ε4 allele as a major risk factor for the conversion to Parkinson's disease dementia [hazard ratio = 2.41 (1.94-3.00), P = 2.32 × 10-15], as well as a new locus within the ApoE and APP receptor LRP1B gene [hazard ratio = 3.23 (2.17-4.81), P = 7.07 × 10-09]. In a candidate gene analysis, GBA variants were also identified to be associated with higher risk of progression to dementia [hazard ratio = 2.02 (1.21-3.32), P = 0.007]. CSF biomarker analysis also implicated the amyloid pathway in Parkinson's disease dementia, with significantly reduced levels of amyloid ß42 (P = 0.0012) in Parkinson's disease dementia compared to Parkinson's disease without dementia. These results identify a new candidate gene associated with faster conversion to dementia in Parkinson's disease and suggest that amyloid-targeting therapy may have a role in preventing Parkinson's disease dementia.


Asunto(s)
Disfunción Cognitiva , Demencia , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/genética , Demencia/complicaciones , Disfunción Cognitiva/etiología , Apolipoproteínas E/genética , Biomarcadores , Receptores de LDL
5.
Neurobiol Dis ; 180: 106082, 2023 05.
Artículo en Inglés | MEDLINE | ID: mdl-36925053

RESUMEN

Humans are thought to be more susceptible to neurodegeneration than equivalently-aged primates. It is not known whether this vulnerability is specific to anatomically-modern humans or shared with other hominids. The contribution of introgressed Neanderthal DNA to neurodegenerative disorders remains uncertain. It is also unclear how common variants associated with neurodegenerative disease risk are maintained by natural selection in the population despite their deleterious effects. In this study, we aimed to quantify the genome-wide contribution of Neanderthal introgression and positive selection to the heritability of complex neurodegenerative disorders to address these questions. We used stratified-linkage disequilibrium score regression to investigate the relationship between five SNP-based signatures of natural selection, reflecting different timepoints of evolution, and genome-wide associated variants of the three most prevalent neurodegenerative disorders: Alzheimer's disease, amyotrophic lateral sclerosis and Parkinson's disease. We found no evidence for enrichment of positively-selected SNPs in the heritability of Alzheimer's disease, amyotrophic lateral sclerosis and Parkinson's disease, suggesting that common deleterious disease variants are unlikely to be maintained by positive selection. There was no enrichment of Neanderthal introgression in the SNP-heritability of these disorders, suggesting that Neanderthal admixture is unlikely to have contributed to disease risk. These findings provide insight into the origins of neurodegenerative disorders within the evolution of Homo sapiens and addresses a long-standing debate, showing that Neanderthal admixture is unlikely to have contributed to common genetic risk of neurodegeneration in anatomically-modern humans.


Asunto(s)
Enfermedad de Alzheimer , Esclerosis Amiotrófica Lateral , Hombre de Neandertal , Enfermedades Neurodegenerativas , Enfermedad de Parkinson , Animales , Humanos , Hombre de Neandertal/genética , Enfermedades Neurodegenerativas/genética , Selección Genética
6.
Bioinformatics ; 38(15): 3844-3846, 2022 08 02.
Artículo en Inglés | MEDLINE | ID: mdl-35751589

RESUMEN

MOTIVATION: The advent of long-read sequencing technologies has increased demand for the visualization and interpretation of transcripts. However, tools that perform such visualizations remain inflexible and lack the ability to easily identify differences between transcript structures. Here, we introduce ggtranscript, an R package that provides a fast and flexible method to visualize and compare transcripts. As a ggplot2 extension, ggtranscript inherits the functionality and familiarity of ggplot2 making it easy to use. AVAILABILITY AND IMPLEMENTATION: ggtranscript is an R package available at https://github.com/dzhang32/ggtranscript (DOI: https://doi.org/10.5281/zenodo.6374061) via an open-source MIT licence. Further documentation is available at https://dzhang32.github.io/ggtranscript/.


Asunto(s)
Programas Informáticos , Análisis de Secuencia de ADN/métodos , Isoformas de Proteínas/genética
7.
Prenat Diagn ; 43(4): 544-552, 2023 04.
Artículo en Inglés | MEDLINE | ID: mdl-36759743

RESUMEN

INTRODUCTION: Whole exome sequencing (WES) has increasingly become integrated into prenatal care and genetic testing pathways. Current studies of prenatal WES have focused on diagnostic yield. The possibility of obtaining a variant of uncertain significance and lack of provider expertise are frequently described as common barriers to clinical integration of prenatal WES. We describe the implementation and workflow for a multidisciplinary approach to effectively integrate prenatal WES into maternal-fetal care to overcome these barriers. METHODS: A multidisciplinary team reviews and approves potential cases for WES. This team reviews WES results, reclassifying variants as appropriate and provides recommendations for postnatal care. A detailed description of this workflow is provided, and a case example is included to demonstrate effectiveness of this approach. Our team has approved 62 cases for WES with 45 patients ultimately pursuing WES. We have achieved a diagnostic yield of 40% and the multidisciplinary team has played a role in variant interpretation in 50% of the reported variants of uncertain significance. CONCLUSIONS: This approach facilitates communication between prenatal and postnatal care teams and provides accurate interpretation and recommendations for identified fetal variants. This model can be replicated to ensure appropriate patient care and effective integration of novel genomic technologies into prenatal settings.


Asunto(s)
Feto , Atención Prenatal , Embarazo , Femenino , Humanos , Secuenciación del Exoma , Flujo de Trabajo , Pruebas Genéticas
8.
Bioinformatics ; 37(18): 2905-2911, 2021 09 29.
Artículo en Inglés | MEDLINE | ID: mdl-33734320

RESUMEN

MOTIVATION: Co-expression networks are a powerful gene expression analysis method to study how genes co-express together in clusters with functional coherence that usually resemble specific cell type behavior for the genes involved. They can be applied to bulk-tissue gene expression profiling and assign function, and usually cell type specificity, to a high percentage of the gene pool used to construct the network. One of the limitations of this method is that each gene is predicted to play a role in a specific set of coherent functions in a single cell type (i.e. at most we get a single for each gene). We present here GMSCA (Gene Multifunctionality Secondary Co-expression Analysis), a software tool that exploits the co-expression paradigm to increase the number of functions and cell types ascribed to a gene in bulk-tissue co-expression networks. RESULTS: We applied GMSCA to 27 co-expression networks derived from bulk-tissue gene expression profiling of a variety of brain tissues. Neurons and glial cells (microglia, astrocytes and oligodendrocytes) were considered the main cell types. Applying this approach, we increase the overall number of predicted triplets by 46.73%. Moreover, GMSCA predicts that the SNCA gene, traditionally associated to work mainly in neurons, also plays a relevant function in oligodendrocytes. AVAILABILITYAND IMPLEMENTATION: The tool is available at GitHub, https://github.com/drlaguna/GMSCA as open-source software. SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.


Asunto(s)
Redes Reguladoras de Genes , Programas Informáticos , Humanos , Encéfalo , Perfilación de la Expresión Génica/métodos
9.
Neuropathol Appl Neurobiol ; 48(1): e12758, 2022 02.
Artículo en Inglés | MEDLINE | ID: mdl-34388852

RESUMEN

AIMS: The causes of distinct patterns of reduced cortical thickness in the common human epilepsies, detectable on neuroimaging and with important clinical consequences, are unknown. We investigated the underlying mechanisms of cortical thinning using a systems-level analysis. METHODS: Imaging-based cortical structural maps from a large-scale epilepsy neuroimaging study were overlaid with highly spatially resolved human brain gene expression data from the Allen Human Brain Atlas. Cell-type deconvolution, differential expression analysis and cell-type enrichment analyses were used to identify differences in cell-type distribution. These differences were followed up in post-mortem brain tissue from humans with epilepsy using Iba1 immunolabelling. Furthermore, to investigate a causal effect in cortical thinning, cell-type-specific depletion was used in a murine model of acquired epilepsy. RESULTS: We identified elevated fractions of microglia and endothelial cells in regions of reduced cortical thickness. Differentially expressed genes showed enrichment for microglial markers and, in particular, activated microglial states. Analysis of post-mortem brain tissue from humans with epilepsy confirmed excess activated microglia. In the murine model, transient depletion of activated microglia during the early phase of the disease development prevented cortical thinning and neuronal cell loss in the temporal cortex. Although the development of chronic seizures was unaffected, the epileptic mice with early depletion of activated microglia did not develop deficits in a non-spatial memory test seen in epileptic mice not depleted of microglia. CONCLUSIONS: These convergent data strongly implicate activated microglia in cortical thinning, representing a new dimension for concern and disease modification in the epilepsies, potentially distinct from seizure control.


Asunto(s)
Epilepsia , Microglía , Animales , Encéfalo , Células Endoteliales , Epilepsia/metabolismo , Ratones , Microglía/metabolismo , Convulsiones
10.
Ann Neurol ; 89(5): 942-951, 2021 05.
Artículo en Inglés | MEDLINE | ID: mdl-33502028

RESUMEN

OBJECTIVE: Understanding how different parts of the immune system contribute to pathogenesis in Parkinson's disease is a burning challenge with important therapeutic implications. We studied enrichment of common variant heritability for Parkinson's disease stratified by immune and brain cell types. METHODS: We used summary statistics from the most recent meta-analysis of genomewide association studies in Parkinson's disease and partitioned heritability using linkage disequilibrium score regression, stratified for specific cell types, as defined by open chromatin regions. We also validated enrichment results using a polygenic risk score approach and intersected disease-associated variants with epigenetic data and expression quantitative loci to nominate and explore a putative microglial locus. RESULTS: We found significant enrichment of Parkinson's disease risk heritability in open chromatin regions of microglia and monocytes. Genomic annotations overlapped substantially between these 2 cell types, and only the enrichment signal for microglia remained significant in a joint model. We present evidence suggesting P2RY12, a key microglial gene and target for the antithrombotic agent clopidogrel, as the likely driver of a significant Parkinson's disease association signal on chromosome 3. INTERPRETATION: Our results provide further support for the importance of immune mechanisms in Parkinson's disease pathogenesis, highlight microglial dysregulation as a contributing etiological factor, and nominate a targetable microglial gene candidate as a pathogenic player. Immune processes can be modulated by therapy, with potentially important clinical implications for future treatment in Parkinson's disease. ANN NEUROL 2021;89:942-951.


Asunto(s)
Microglía/inmunología , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/inmunología , Cromatina/genética , Cromosomas Humanos Par 3/genética , Clopidogrel/farmacología , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Humanos , Inmunidad Celular , Desequilibrio de Ligamiento , Microglía/patología , Monocitos/patología , Herencia Multifactorial , Enfermedad de Parkinson/patología , Polimorfismo de Nucleótido Simple/genética , Receptores Purinérgicos P2Y12/genética , Medición de Riesgo
11.
Brain ; 144(12): 3727-3741, 2021 12 31.
Artículo en Inglés | MEDLINE | ID: mdl-34619763

RESUMEN

Recently, we reported oligoadenylate synthetase 1 (OAS1) contributed to the risk of Alzheimer's disease, by its enrichment in transcriptional networks expressed by microglia. However, the function of OAS1 within microglia was not known. Using genotyping from 1313 individuals with sporadic Alzheimer's disease and 1234 control individuals, we confirm the OAS1 variant, rs1131454, is associated with increased risk for Alzheimer's disease. The same OAS1 locus has been recently associated with severe coronavirus disease 2019 (COVID-19) outcomes, linking risk for both diseases. The single nucleotide polymorphisms rs1131454(A) and rs4766676(T) are associated with Alzheimer's disease, and rs10735079(A) and rs6489867(T) are associated with severe COVID-19, where the risk alleles are linked with decreased OAS1 expression. Analysing single-cell RNA-sequencing data of myeloid cells from Alzheimer's disease and COVID-19 patients, we identify co-expression networks containing interferon (IFN)-responsive genes, including OAS1, which are significantly upregulated with age and both diseases. In human induced pluripotent stem cell-derived microglia with lowered OAS1 expression, we show exaggerated production of TNF-α with IFN-γ stimulation, indicating OAS1 is required to limit the pro-inflammatory response of myeloid cells. Collectively, our data support a link between genetic risk for Alzheimer's disease and susceptibility to critical illness with COVID-19 centred on OAS1, a finding with potential implications for future treatments of Alzheimer's disease and COVID-19, and development of biomarkers to track disease progression.


Asunto(s)
2',5'-Oligoadenilato Sintetasa/genética , Enfermedad de Alzheimer/genética , COVID-19/genética , Ligamiento Genético/genética , Predisposición Genética a la Enfermedad/genética , Gravedad del Paciente , Adolescente , Anciano , Anciano de 80 o más Años , Enfermedad de Alzheimer/diagnóstico , Enfermedad de Alzheimer/epidemiología , COVID-19/diagnóstico , COVID-19/epidemiología , Células Cultivadas , Femenino , Redes Reguladoras de Genes/genética , Predisposición Genética a la Enfermedad/epidemiología , Humanos , Células Madre Pluripotentes Inducidas/fisiología , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple/genética , Adulto Joven
12.
Fetal Diagn Ther ; 49(9-10): 411-418, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36198283

RESUMEN

INTRODUCTION: The advent of novel fetal interventions has increased interest in interventions for previously "lethal" anomalies such as bilateral renal agenesis or other congenital anomalies of the kidney and urinary tract (CAKUT) associated with in utero renal failure. While there have been rare reports of successful births following intervention in these cases, there is a paucity of data regarding the risks, benefits, and outcomes of intervention. To address this gap, this study presents our experience with fetal intervention for anatomic or functional renal agenesis. CASE PRESENTATION: A retrospective review was conducted for patients referred to the Colorado Fetal Care Center (CFCC) between 2013 and 2019 for evaluation of CAKUT anomalies. Eligibility was determined by a multidisciplinary team. Amnioinfusion was scheduled prior to 24 weeks gestation, with normal saline or lactated ringers infused as needed to obtain a "normal" amniotic fluid volume. During this time period, a total of 5 cases received fetal amnioinfusion for treatment of bilateral renal agenesis or bladder outlet obstruction. All 5 cases reached birth. 3/5 cases expired on day one of life. 1/2 of the remaining infants expired at 3 months secondary to peritoneal dialysis failure. The remaining infant is 4 years. Developmentally, she is on track with cognitive and language skills but is behind with general motor skills. We observed a 30-day mortality of 60% and 1-year mortality of 80%. CONCLUSIONS: Individuals carrying a pregnancy complicated by CAKUT anomalies face a difficult choice when considering intervention. Morbidity and mortality remain high at this stage of this evolving therapy, including difficulty with retaining infused intra-amniotic fluid >72 h and complications with peritoneal dialysis after birth. The surviving infant in this case series is 4 years. She currently awaits renal transplantation. These findings reinforce that treatment of these cases should remain experimental and large-scale multicenter trials are needed to determine the optimal indications for prenatal intervention.


Asunto(s)
Líquido Amniótico , Riñón , Lactante , Embarazo , Femenino , Humanos , Riñón/diagnóstico por imagen , Riñón/anomalías , Ultrasonografía Prenatal
13.
Acta Neuropathol ; 142(3): 449-474, 2021 09.
Artículo en Inglés | MEDLINE | ID: mdl-34309761

RESUMEN

Parkinson's disease (PD), Parkinson's disease with dementia (PDD) and dementia with Lewy bodies (DLB) are three clinically, genetically and neuropathologically overlapping neurodegenerative diseases collectively known as the Lewy body diseases (LBDs). A variety of molecular mechanisms have been implicated in PD pathogenesis, but the mechanisms underlying PDD and DLB remain largely unknown, a knowledge gap that presents an impediment to the discovery of disease-modifying therapies. Transcriptomic profiling can contribute to addressing this gap, but remains limited in the LBDs. Here, we applied paired bulk-tissue and single-nucleus RNA-sequencing to anterior cingulate cortex samples derived from 28 individuals, including healthy controls, PD, PDD and DLB cases (n = 7 per group), to transcriptomically profile the LBDs. Using this approach, we (i) found transcriptional alterations in multiple cell types across the LBDs; (ii) discovered evidence for widespread dysregulation of RNA splicing, particularly in PDD and DLB; (iii) identified potential splicing factors, with links to other dementia-related neurodegenerative diseases, coordinating this dysregulation; and (iv) identified transcriptomic commonalities and distinctions between the LBDs that inform understanding of the relationships between these three clinical disorders. Together, these findings have important implications for the design of RNA-targeted therapies for these diseases and highlight a potential molecular "window" of therapeutic opportunity between the initial onset of PD and subsequent development of Lewy body dementia.


Asunto(s)
Perfilación de la Expresión Génica/métodos , Enfermedad por Cuerpos de Lewy/genética , Enfermedad por Cuerpos de Lewy/patología , Patología Molecular/métodos , Anciano , Empalme Alternativo , Enfermedad de Alzheimer , Bancos de Muestras Biológicas , Núcleo Celular/genética , Núcleo Celular/ultraestructura , Giro del Cíngulo/patología , Humanos , Cuerpos de Lewy/patología , Microglía/patología , Microglía/ultraestructura , Miocitos del Músculo Liso/patología , Miocitos del Músculo Liso/ultraestructura , Enfermedad de Parkinson , ARN/genética , Transcriptoma
14.
Mov Disord ; 36(2): 424-433, 2021 02.
Artículo en Inglés | MEDLINE | ID: mdl-33111402

RESUMEN

BACKGROUND: There are currently no treatments that stop or slow the progression of Parkinson's disease (PD). Case-control genome-wide association studies have identified variants associated with disease risk, but not progression. The objective of the current study was to identify genetic variants associated with PD progression. METHODS: We analyzed 3 large longitudinal cohorts: Tracking Parkinson's, Oxford Discovery, and the Parkinson's Progression Markers Initiative. We included clinical data for 3364 patients with 12,144 observations (mean follow-up 4.2 years). We used a new method in PD, following a similar approach in Huntington's disease, in which we combined multiple assessments using a principal components analysis to derive scores for composite, motor, and cognitive progression. These scores were analyzed in linear regression in genome-wide association studies. We also performed a targeted analysis of the 90 PD risk loci from the latest case-control meta-analysis. RESULTS: There was no overlap between variants associated with PD risk, from case-control studies, and PD age at onset versus PD progression. The APOE ε4 tagging variant, rs429358, was significantly associated with composite and cognitive progression in PD. Conditional analysis revealed several independent signals in the APOE locus for cognitive progression. No single variants were associated with motor progression. However, in gene-based analysis, ATP8B2, a phospholipid transporter related to vesicle formation, was nominally associated with motor progression (P = 5.3 × 10-6 ). CONCLUSIONS: We provide early evidence that this new method in PD improves measurement of symptom progression. We show that the APOE ε4 allele drives progressive cognitive impairment in PD. Replication of this method and results in independent cohorts are needed. © 2020 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.


Asunto(s)
Enfermedad de Parkinson , Biomarcadores , Cognición , Progresión de la Enfermedad , Estudio de Asociación del Genoma Completo , Humanos , Enfermedad de Parkinson/genética
15.
Brain ; 143(11): 3435-3448, 2020 12 05.
Artículo en Inglés | MEDLINE | ID: mdl-33118028

RESUMEN

Visual hallucinations are common in Parkinson's disease and are associated with poorer prognosis. Imaging studies show white matter loss and functional connectivity changes with Parkinson's visual hallucinations, but the biological factors underlying selective vulnerability of affected parts of the brain network are unknown. Recent models for Parkinson's disease hallucinations suggest they arise due to a shift in the relative effects of different networks. Understanding how structural connectivity affects the interplay between networks will provide important mechanistic insights. To address this, we investigated the structural connectivity changes that accompany visual hallucinations in Parkinson's disease and the organizational and gene expression characteristics of the preferentially affected areas of the network. We performed diffusion-weighted imaging in 100 patients with Parkinson's disease (81 without hallucinations, 19 with visual hallucinations) and 34 healthy age-matched controls. We used network-based statistics to identify changes in structural connectivity in Parkinson's disease patients with hallucinations and performed an analysis of controllability, an emerging technique that allows quantification of the influence a brain region has across the rest of the network. Using these techniques, we identified a subnetwork of reduced connectivity in Parkinson's disease hallucinations. We then used the Allen Institute for Brain Sciences human transcriptome atlas to identify regional gene expression patterns associated with affected areas of the network. Within this network, Parkinson's disease patients with hallucinations showed reduced controllability (less influence over other brain regions), than Parkinson's disease patients without hallucinations and controls. This subnetwork appears to be critical for overall brain integration, as even in controls, nodes with high controllability were more likely to be within the subnetwork. Gene expression analysis of gene modules related to the affected subnetwork revealed that down-weighted genes were most significantly enriched in genes related to mRNA and chromosome metabolic processes (with enrichment in oligodendrocytes) and upweighted genes to protein localization (with enrichment in neuronal cells). Our findings provide insights into how hallucinations are generated, with breakdown of a key structural subnetwork that exerts control across distributed brain regions. Expression of genes related to mRNA metabolism and membrane localization may be implicated, providing potential therapeutic targets.


Asunto(s)
Regulación de la Expresión Génica/genética , Alucinaciones/genética , Alucinaciones/fisiopatología , Red Nerviosa/fisiopatología , Enfermedad de Parkinson/genética , Enfermedad de Parkinson/fisiopatología , Anciano , Algoritmos , Mapeo Cromosómico , Conectoma , Imagen de Difusión por Resonancia Magnética , Femenino , Alucinaciones/etiología , Humanos , Procesamiento de Imagen Asistido por Computador , Masculino , Persona de Mediana Edad , Red Nerviosa/diagnóstico por imagen , Pruebas Neuropsicológicas , Enfermedad de Parkinson/complicaciones , ARN Mensajero/genética , ARN Mensajero/metabolismo , Transcriptoma
16.
Brain ; 143(9): 2771-2787, 2020 09 01.
Artículo en Inglés | MEDLINE | ID: mdl-32889528

RESUMEN

Dystonia is a neurological disorder characterized by sustained or intermittent muscle contractions causing abnormal movements and postures, often occurring in absence of any structural brain abnormality. Psychiatric comorbidities, including anxiety, depression, obsessive-compulsive disorder and schizophrenia, are frequent in patients with dystonia. While mutations in a fast-growing number of genes have been linked to Mendelian forms of dystonia, the cellular, anatomical, and molecular basis remains unknown for most genetic forms of dystonia, as does its genetic and biological relationship to neuropsychiatric disorders. Here we applied an unbiased systems-biology approach to explore the cellular specificity of all currently known dystonia-associated genes, predict their functional relationships, and test whether dystonia and neuropsychiatric disorders share a genetic relationship. To determine the cellular specificity of dystonia-associated genes in the brain, single-nuclear transcriptomic data derived from mouse brain was used together with expression-weighted cell-type enrichment. To identify functional relationships among dystonia-associated genes, we determined the enrichment of these genes in co-expression networks constructed from 10 human brain regions. Stratified linkage-disequilibrium score regression was used to test whether co-expression modules enriched for dystonia-associated genes significantly contribute to the heritability of anxiety, major depressive disorder, obsessive-compulsive disorder, schizophrenia, and Parkinson's disease. Dystonia-associated genes were significantly enriched in adult nigral dopaminergic neurons and striatal medium spiny neurons. Furthermore, 4 of 220 gene co-expression modules tested were significantly enriched for the dystonia-associated genes. The identified modules were derived from the substantia nigra, putamen, frontal cortex, and white matter, and were all significantly enriched for genes associated with synaptic function. Finally, we demonstrate significant enrichments of the heritability of major depressive disorder, obsessive-compulsive disorder and schizophrenia within the putamen and white matter modules, and a significant enrichment of the heritability of Parkinson's disease within the substantia nigra module. In conclusion, multiple dystonia-associated genes interact and contribute to pathogenesis likely through dysregulation of synaptic signalling in striatal medium spiny neurons, adult nigral dopaminergic neurons and frontal cortical neurons. Furthermore, the enrichment of the heritability of psychiatric disorders in the co-expression modules enriched for dystonia-associated genes indicates that psychiatric symptoms associated with dystonia are likely to be intrinsic to its pathophysiology.


Asunto(s)
Trastornos Distónicos/genética , Redes Reguladoras de Genes/genética , Trastornos Mentales/genética , Neuronas/fisiología , Trastornos Distónicos/diagnóstico , Trastornos Distónicos/epidemiología , Humanos , Trastornos Mentales/diagnóstico , Trastornos Mentales/epidemiología
17.
Curr Opin Pediatr ; 32(4): 619-624, 2020 08.
Artículo en Inglés | MEDLINE | ID: mdl-32692057

RESUMEN

PURPOSE OF REVIEW: Fetal intervention is a dynamic field with wide-reaching implications on neonatal ICU admissions and the care of neonates with congenital anomalies. The aim of this review is to summarize recent advancements in fetal surgery and provide a broad understanding of how these topics interrelate. RECENT FINDINGS: Advancements in prenatal imaging and diagnosis have dramatically expanded the indications for fetal intervention. Most recently, there has been a large focus on evaluating minimally invasive strategies of fetal intervention, notably fetoscopic surgery, and the use of stem cells for fetal treatment of myelomeningocele. With the advances in fetal intervention, neonatal care has adapted to the needs of these various patients to help improve the outcomes of this unique population. SUMMARY: Fetal intevention relies on a multidisciplinary team from prenatal imaging and maternal fetal medicine to fetal surgery and postnatal subspecialty care, particuarly neonatology. Fetal intervention uniquely involves two patients, both mother and fetus, and therefore, has unique risks and considerations, particularly in the advancement of the field. As the number of conditions suited to fetal intervention grows, awareness and advancement of the postnatal intensive care necessary for these patients are essential.


Asunto(s)
Enfermedades Fetales/cirugía , Unidades de Cuidado Intensivo Neonatal/estadística & datos numéricos , Femenino , Enfermedades Fetales/diagnóstico por imagen , Fetoscopía , Humanos , Recién Nacido , Meningomielocele/cirugía , Embarazo , Atención Prenatal
18.
Brain ; 142(12): 3694-3712, 2019 12 01.
Artículo en Inglés | MEDLINE | ID: mdl-31603214

RESUMEN

The past decade has seen a surge in the number of disease/trait-associated variants, largely because of the union of studies to share genetic data and the availability of electronic health records from large cohorts for research use. Variant discovery for neurological and neuropsychiatric genome-wide association studies, including schizophrenia, Parkinson's disease and Alzheimer's disease, has greatly benefitted; however, the translation of these genetic association results to interpretable biological mechanisms and models is lagging. Interpreting disease-associated variants requires knowledge of gene regulatory mechanisms and computational tools that permit integration of this knowledge with genome-wide association study results. Here, we summarize key conceptual advances in the generation of brain-relevant functional genomic annotations and amongst tools that allow integration of these annotations with association summary statistics, which together provide a new and exciting opportunity to identify disease-relevant genes, pathways and cell types in silico. We discuss the opportunities and challenges associated with these developments and conclude with our perspective on future advances in annotation generation, tool development and the union of the two.


Asunto(s)
Encefalopatías/genética , Predisposición Genética a la Enfermedad , Estudio de Asociación del Genoma Completo , Fenotipo , Polimorfismo de Nucleótido Simple , Simulación por Computador , Genómica , Humanos
19.
Ann Neurol ; 84(4): 485-496, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-30066433

RESUMEN

OBJECTIVE: The basis for clinical variation related to underlying progressive supranuclear palsy (PSP) pathology is unknown. We performed a genome-wide association study (GWAS) to identify genetic determinants of PSP phenotype. METHODS: Two independent pathological and clinically diagnosed PSP cohorts were genotyped and phenotyped to create Richardson syndrome (RS) and non-RS groups. We carried out separate logistic regression GWASs to compare RS and non-RS groups and then combined datasets to carry out a whole cohort analysis (RS = 367, non-RS = 130). We validated our findings in a third cohort by referring to data from 100 deeply phenotyped cases from a recent GWAS. We assessed the expression/coexpression patterns of our identified genes and used our data to carry out gene-based association testing. RESULTS: Our lead single nucleotide polymorphism (SNP), rs564309, showed an association signal in both cohorts, reaching genome-wide significance in our whole cohort analysis (odds ratio = 5.5, 95% confidence interval = 3.2-10.0, p = 1.7 × 10-9 ). rs564309 is an intronic variant of the tripartite motif-containing protein 11 (TRIM11) gene, a component of the ubiquitin proteasome system (UPS). In our third cohort, minor allele frequencies of surrogate SNPs in high linkage disequilibrium with rs564309 replicated our findings. Gene-based association testing confirmed an association signal at TRIM11. We found that TRIM11 is predominantly expressed neuronally, in the cerebellum and basal ganglia. INTERPRETATION: Our study suggests that the TRIM11 locus is a genetic modifier of PSP phenotype and potentially adds further evidence for the UPS having a key role in tau pathology, therefore representing a target for disease-modifying therapies. Ann Neurol 2018;84:485-496.


Asunto(s)
Sitios Genéticos/genética , Variación Genética/genética , Fenotipo , Parálisis Supranuclear Progresiva/diagnóstico , Parálisis Supranuclear Progresiva/genética , Proteínas de Motivos Tripartitos/genética , Ubiquitina-Proteína Ligasas/genética , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Polimorfismo de Nucleótido Simple
20.
Mol Cell Neurosci ; 88: 118-129, 2018 04.
Artículo en Inglés | MEDLINE | ID: mdl-29289683

RESUMEN

The three factors, p53, the microRNA-34 family and Sirtuin 1 (SIRT1), interact in a positive feedback loop involved in cell cycle progression, cellular senescence and apoptosis. Each factor in this triad has roles in metabolic regulation, maintenance of mitochondrial function, and regulation of brain-derived neurotrophic factor (BDNF). Thus, this regulatory network holds potential importance for the pathophysiology of Huntington's disease (HD), an inherited neurodegenerative disorder in which both mitochondrial dysfunction and impaired neurotrophic signalling are observed. We investigated expression of the three members of this regulatory triad in the R6/2 HD mouse model. Compared to wild-type littermates, we found decreased levels of miR-34a-5p, increased SIRT1 mRNA and protein levels, and increased levels of p53 protein in brain tissue from R6/2 mice. The upregulation of SIRT1 did not appear to lead to an increased activity of the enzyme, as based on measures of p53 acetylation. In other words, the observed changes did not reflect the known interactions between these factors, indicating a general perturbation of the p53, miR-34a and SIRT1 pathway in HD. This is the first study investigating the entire triad during disease progression in an HD model. Given the importance of these three factors alone and within the triad, our results indicate that outside factors are regulating - or dysregulating - this pathway in HD.


Asunto(s)
Enfermedad de Huntington/genética , MicroARNs/genética , Sirtuina 1/genética , Proteína p53 Supresora de Tumor/genética , Animales , Apoptosis/fisiología , Línea Celular , Modelos Animales de Enfermedad , Enfermedad de Huntington/metabolismo , Ratones Transgénicos , Transducción de Señal , Sirtuina 1/metabolismo , Proteína p53 Supresora de Tumor/metabolismo , Regulación hacia Arriba
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