Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 5 de 5
Mais filtros

Base de dados
Intervalo de ano de publicação
Hum Mol Genet ; 29(18): 3032-3043, 2020 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-32879944


The human UBE3A gene, which is essential for normal neurodevelopment, encodes three Ubiquitin E3 ligase A (UBE3A) protein isoforms. However, the subcellular localization and relative abundance of these human UBE3A isoforms are unknown. We found, as previously reported in mice, that UBE3A is predominantly nuclear in human neurons. However, this conserved subcellular distribution is achieved by strikingly distinct cis-acting mechanisms. A single amino-acid deletion in the N-terminus of human hUBE3A-Iso3, which is homologous to cytosolic mouse mUBE3A-Iso2, results in its translocation to the nucleus. This singe amino-acid deletion is shared with apes and Old World monkeys and was preceded by the appearance of the cytosolic hUBE3A-Iso2 isoform. This hUBE3A-Iso2 isoform arose after the lineage of New World monkeys and Old World monkeys separated from the Tarsiers (Tarsiidae). Due to the loss of a single nucleotide in a non-coding exon, this exon became in frame with the remainder of the UBE3A protein. RNA-seq analysis of human brain samples showed that the human UBE3A isoforms arise by alternative splicing. Consistent with the predominant nuclear enrichment of UBE3A in human neurons, the two nuclear-localized isoforms, hUBE3A-Iso1 and -Iso3, are the most abundantly expressed isoforms of UBE3A, while hUBE3A-Iso2 maintains a small pool of cytosolic UBE3A. Our findings provide new insight into UBE3A localization and evolution and may have important implications for gene therapy approaches in Angelman syndrome.

Elife ; 82019 11 26.
Artigo em Inglês | MEDLINE | ID: mdl-31763980


The human face represents a combined set of highly heritable phenotypes, but knowledge on its genetic architecture remains limited, despite the relevance for various fields. A series of genome-wide association studies on 78 facial shape phenotypes quantified from 3-dimensional facial images of 10,115 Europeans identified 24 genetic loci reaching study-wide suggestive association (p < 5 × 10-8), among which 17 were previously unreported. A follow-up multi-ethnic study in additional 7917 individuals confirmed 10 loci including six unreported ones (padjusted < 2.1 × 10-3). A global map of derived polygenic face scores assembled facial features in major continental groups consistent with anthropological knowledge. Analyses of epigenomic datasets from cranial neural crest cells revealed abundant cis-regulatory activities at the face-associated genetic loci. Luciferase reporter assays in neural crest progenitor cells highlighted enhancer activities of several face-associated DNA variants. These results substantially advance our understanding of the genetic basis underlying human facial variation and provide candidates for future in-vivo functional studies.

Face/anatomia & histologia , Loci Gênicos/genética , Desenvolvimento Maxilofacial/genética , Fenótipo , Adolescente , Adulto , Pontos de Referência Anatômicos , Padronização Corporal/genética , Criança , Pré-Escolar , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Ontologia Genética , Variação Genética , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Imageamento Tridimensional , Masculino , Pessoa de Meia-Idade , Herança Multifatorial , Polimorfismo de Nucleotídeo Único , Adulto Jovem
Hum Mutat ; 40(11): 2131-2145, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31322790


Noncoding RNAs have been widely recognized as essential mediators of gene regulation. However, in contrast to protein-coding genes, much less is known about the influence of noncoding RNAs on human diseases. Here we examined the association of genetic variants located in primary microRNA sequences and long noncoding RNAs (lncRNAs) with Alzheimer disease (AD) by leveraging data from the largest genome-wide association meta-analysis of late-onset AD. Variants annotated to 5 miRNAs and 10 lncRNAs (in seven distinct loci) exceeded the Bonferroni-corrected significance threshold (p < 1.02 × 10-6 ). Among these, a leading variant (rs2526377:A>G) at the 17q22 locus annotated to two noncoding RNAs (MIR142 and BZRAP1-AS) was significantly associated with a reduced risk of AD and fulfilled predefined criteria for being a functional variant. Our functional genomic analyses revealed that rs2526377 affects the promoter activity and decreases the expression of miR-142. Moreover, differential expression analysis by RNA-Seq in human iPSC-derived neural progenitor cells and the hippocampus of miR-142 knockout mice demonstrated multiple target genes of miR-142 in the brain that are likely to be involved in the inflammatory and neurodegenerative manifestations of AD. These include TGFBR1 and PICALM, of which their derepression in the brain due to reduced expression levels of miR-142-3p may reduce the risk of AD.

Doença de Alzheimer/genética , Predisposição Genética para Doença , Variação Genética , MicroRNAs/genética , Regiões Promotoras Genéticas , Alelos , Doença de Alzheimer/metabolismo , Animais , Linhagem Celular , Mapeamento Cromossômico , Biologia Computacional/métodos , Modelos Animais de Doenças , Regulação da Expressão Gênica , Estudos de Associação Genética , Estudo de Associação Genômica Ampla , Hipocampo/metabolismo , Humanos , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Camundongos , Camundongos Knockout , Modelos Biológicos , Células-Tronco Neurais/citologia , Células-Tronco Neurais/metabolismo , Polimorfismo de Nucleotídeo Único , Interferência de RNA , RNA não Traduzido
Mol Psychiatry ; 24(5): 757-771, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-29302076


Schizophrenia is highly heritable, yet its underlying pathophysiology remains largely unknown. Among the most well-replicated findings in neurobiological studies of schizophrenia are deficits in myelination and white matter integrity; however, direct etiological genetic and cellular evidence has thus far been lacking. Here, we implement a family-based approach for genetic discovery in schizophrenia combined with functional analysis using induced pluripotent stem cells (iPSCs). We observed familial segregation of two rare missense mutations in Chondroitin Sulfate Proteoglycan 4 (CSPG4) (c.391G > A [p.A131T], MAF 7.79 × 10-5 and c.2702T > G [p.V901G], MAF 2.51 × 10-3). The CSPG4A131T mutation was absent from the Swedish Schizophrenia Exome Sequencing Study (2536 cases, 2543 controls), while the CSPG4V901G mutation was nominally enriched in cases (11 cases vs. 3 controls, P = 0.026, OR 3.77, 95% CI 1.05-13.52). CSPG4/NG2 is a hallmark protein of oligodendrocyte progenitor cells (OPCs). iPSC-derived OPCs from CSPG4A131T mutation carriers exhibited abnormal post-translational processing (P = 0.029), subcellular localization of mutant NG2 (P = 0.007), as well as aberrant cellular morphology (P = 3.0 × 10-8), viability (P = 8.9 × 10-7), and myelination potential (P = 0.038). Moreover, transfection of healthy non-carrier sibling OPCs confirmed a pathogenic effect on cell survival of both the CSPG4A131T (P = 0.006) and CSPG4V901G (P = 3.4 × 10-4) mutations. Finally, in vivo diffusion tensor imaging of CSPG4A131T mutation carriers demonstrated a reduction of brain white matter integrity compared to unaffected sibling and matched general population controls (P = 2.2 × 10-5). Together, our findings provide a convergence of genetic and functional evidence to implicate OPC dysfunction as a candidate pathophysiological mechanism of familial schizophrenia.

Proteoglicanas de Sulfatos de Condroitina/genética , Proteínas de Membrana/genética , Células Precursoras de Oligodendrócitos/metabolismo , Esquizofrenia/genética , Adulto , Antígenos/genética , Diferenciação Celular/fisiologia , Proteoglicanas de Sulfatos de Condroitina/metabolismo , Imagem de Tensor de Difusão , Família , Feminino , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Masculino , Proteínas de Membrana/metabolismo , Mutação/genética , Células Precursoras de Oligodendrócitos/fisiologia , Oligodendroglia/metabolismo , Linhagem , Proteoglicanas/genética , Esquizofrenia/metabolismo , Substância Branca/metabolismo
Stem Cell Reports ; 10(2): 655-672, 2018 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-29337119


Scarce access to primary samples and lack of efficient protocols to generate oligodendrocytes (OLs) from human pluripotent stem cells (hPSCs) are hampering our understanding of OL biology and the development of novel therapies. Here, we demonstrate that overexpression of the transcription factor SOX10 is sufficient to generate surface antigen O4-positive (O4+) and myelin basic protein-positive OLs from hPSCs in only 22 days, including from patients with multiple sclerosis or amyotrophic lateral sclerosis. The SOX10-induced O4+ population resembles primary human OLs at the transcriptome level and can myelinate neurons in vivo. Using in vitro OL-neuron co-cultures, myelination of neurons by OLs can also be demonstrated, which can be adapted to a high-throughput screening format to test the response of pro-myelinating drugs. In conclusion, we provide an approach to generate OLs in a very rapid and efficient manner, which can be used for disease modeling, drug discovery efforts, and potentially for therapeutic OL transplantation.

Diferenciação Celular/genética , Oligodendroglia/metabolismo , Células-Tronco Pluripotentes/metabolismo , Fatores de Transcrição SOXE/genética , Esclerose Amiotrófica Lateral/genética , Esclerose Amiotrófica Lateral/terapia , Antígenos de Superfície/genética , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Esclerose Múltipla/genética , Esclerose Múltipla/patologia , Esclerose Múltipla/terapia , Proteína Básica da Mielina/genética , Neurônios/patologia , Neurônios/transplante , Oligodendroglia/citologia , Oligodendroglia/transplante , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/transplante , Transcriptoma/genética