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1.
Exp Dermatol ; 31(6): 906-917, 2022 06.
Artigo em Inglês | MEDLINE | ID: mdl-35119146

RESUMO

Androgenetic alopecia (AGA) is a prevalent hair loss condition in males that develops due to the influence of androgens and genetic predisposition. With the aim of elucidating genes involved in AGA pathogenesis, we modelled AGA with three-dimensional culture of keratinocyte-surrounded dermal papilla (DP) cells. We co-cultured immortalised balding and non-balding human DP cells (DPCs) derived from male AGA patients with epidermal keratinocyte (NHEK) using multi-interfacial polyelectrolyte complexation technique. We observed up-regulated mitochondria-related gene expression in balding compared with non-balding DP aggregates which indicated altered mitochondria metabolism. Further observation of significantly reduced electron transport chain complex activity (complexes I, IV and V), ATP levels and ability to uptake metabolites for ATP generation demonstrated compromised mitochondria function in balding DPC. Balding DP was also found to be under significantly higher oxidative stress than non-balding DP. Our experiments suggest that application of antioxidants lowers oxidative stress levels and improves metabolite uptake in balding DPC. We postulate that the observed up-regulation of mitochondria-related genes in balding DP aggregates resulted from an over-compensatory effort to rescue decreased mitochondrial function in balding DP through the attempted production of new functional mitochondria. In all, our three-dimensional co-culturing revealed mitochondrial dysfunction in balding DPC, suggesting a metabolic component in the aetiology of AGA.


Assuntos
Alopecia , Androgênios , Trifosfato de Adenosina/metabolismo , Alopecia/patologia , Androgênios/metabolismo , Folículo Piloso/metabolismo , Humanos , Queratinócitos/metabolismo , Masculino , Mitocôndrias/metabolismo
2.
Nature ; 462(7269): 58-64, 2009 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-19890323

RESUMO

Genomes are organized into high-level three-dimensional structures, and DNA elements separated by long genomic distances can in principle interact functionally. Many transcription factors bind to regulatory DNA elements distant from gene promoters. Although distal binding sites have been shown to regulate transcription by long-range chromatin interactions at a few loci, chromatin interactions and their impact on transcription regulation have not been investigated in a genome-wide manner. Here we describe the development of a new strategy, chromatin interaction analysis by paired-end tag sequencing (ChIA-PET) for the de novo detection of global chromatin interactions, with which we have comprehensively mapped the chromatin interaction network bound by oestrogen receptor alpha (ER-alpha) in the human genome. We found that most high-confidence remote ER-alpha-binding sites are anchored at gene promoters through long-range chromatin interactions, suggesting that ER-alpha functions by extensive chromatin looping to bring genes together for coordinated transcriptional regulation. We propose that chromatin interactions constitute a primary mechanism for regulating transcription in mammalian genomes.


Assuntos
Cromatina/genética , Cromatina/metabolismo , Receptor alfa de Estrogênio/metabolismo , Genoma Humano/genética , Sítios de Ligação , Linhagem Celular , Imunoprecipitação da Cromatina , Reagentes de Ligações Cruzadas , Formaldeído , Humanos , Regiões Promotoras Genéticas/genética , Ligação Proteica , Reprodutibilidade dos Testes , Análise de Sequência de DNA , Transcrição Gênica , Ativação Transcricional
3.
Hum Mutat ; 35(11): 1311-20, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25137640

RESUMO

MED13L is a component subunit of the Mediator complex, an important regulator of transcription that is highly conserved across eukaryotes. Here, we report MED13L disruption in a translocation t(12;19) breakpoint of a patient with Pierre-Robin syndrome, moderate intellectual disability, craniofacial anomalies, and muscular defects. The phenotype is similar to previously described patients with MED13L haploinsufficiency. Knockdown of MED13L orthologue in zebrafish, med13b, showed early defective migration of cranial neural crest cells (NCCs) that contributed to cartilage structure deformities in the later stage, recapitulating craniofacial anomalies seen in human patients. Notably, we observed abnormal distribution of developing neurons in different brain regions of med13b morphant embryos, which could be rescued upon introduction of full-length human MED13L mRNA. To compare with mammalian system, we suppressed MED13L expression by short-hairpin RNA in ES-derived human neural progenitors, and differentiated them into neurons. Transcriptome analysis revealed differential expression of components of Wnt and FGF signaling pathways in MED13L-deficient neurons. Our finding provides a novel insight into the mechanism of overlapping phenotypic outcome targeting NCCs derivatives organs in patients with MED13L haploinsufficiency, and emphasizes a clinically recognizable syndromic phenotype in these patients.


Assuntos
Haploinsuficiência , Deficiência Intelectual/genética , Complexo Mediador/genética , Crista Neural/metabolismo , Animais , Diferenciação Celular/genética , Movimento Celular/genética , Pré-Escolar , Pontos de Quebra do Cromossomo , Modelos Animais de Doenças , Células-Tronco Embrionárias/metabolismo , Feminino , Expressão Gênica , Perfilação da Expressão Gênica , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Estudos de Associação Genética , Humanos , Deficiência Intelectual/diagnóstico , Complexo Mediador/metabolismo , Crista Neural/embriologia , Neurônios/citologia , Neurônios/metabolismo , Fenótipo , RNA Mensageiro/genética , Análise de Sequência de DNA , Transcriptoma , Translocação Genética , Peixe-Zebra
4.
Nat Commun ; 8: 14694, 2017 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-28272467

RESUMO

Male-pattern baldness (MPB) is a common and highly heritable trait characterized by androgen-dependent, progressive hair loss from the scalp. Here, we carry out the largest GWAS meta-analysis of MPB to date, comprising 10,846 early-onset cases and 11,672 controls from eight independent cohorts. We identify 63 MPB-associated loci (P<5 × 10-8, METAL) of which 23 have not been reported previously. The 63 loci explain ∼39% of the phenotypic variance in MPB and highlight several plausible candidate genes (FGF5, IRF4, DKK2) and pathways (melatonin signalling, adipogenesis) that are likely to be implicated in the key-pathophysiological features of MPB and may represent promising targets for the development of novel therapeutic options. The data provide molecular evidence that rather than being an isolated trait, MPB shares a substantial biological basis with numerous other human phenotypes and may deserve evaluation as an early prognostic marker, for example, for prostate cancer, sudden cardiac arrest and neurodegenerative disorders.


Assuntos
Alopecia/genética , 3-Oxo-5-alfa-Esteroide 4-Desidrogenase/genética , Adipogenia/genética , Estudos de Casos e Controles , Fator 5 de Crescimento de Fibroblastos/genética , Estudos de Associação Genética , Estudo de Associação Genômica Ampla , Genótipo , Humanos , Peptídeos e Proteínas de Sinalização Intercelular/genética , Fatores Reguladores de Interferon/genética , Masculino , Melatonina , Proteínas de Membrana/genética , Fenótipo , Transdução de Sinais/genética , Transativadores/genética
5.
J Invest Dermatol ; 136(8): 1559-1567, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27060448

RESUMO

Androgenetic alopecia (AGA) is a common heritable and androgen-dependent hair loss condition in men. Twelve genetic risk loci are known to date, but it is unclear which genes at these loci are relevant for AGA. Dermal papilla cells (DPCs) located in the hair bulb are the main site of androgen activity in the hair follicle. Widely used monolayer-cultured primary DPCs in hair-related studies often lack dermal papilla characteristics. In contrast, immortalized DPCs have high resemblance to intact dermal papilla. We derived immortalized human DPC lines from balding (BAB) and non-balding (BAN) scalp. Both BAB and BAN retained high proportions of dermal papilla signature gene and versican protein expression. We performed expression analysis of BAB and BAN and annotated AGA risk loci with differentially expressed genes. We found evidence for AR but not EDA2R as the candidate gene at the AGA risk locus on chromosome X. Further, our data suggest TWIST1 (twist family basic helix-loop-helix transcription factor 1) and SSPN (sarcospan) to be the functionally relevant AGA genes at the 7p21.1 and 12p12.1 risk loci, respectively. Down-regulated genes in BAB compared to BAN were highly enriched for vasculature-related genes, suggesting that deficiency of DPC from balding scalps in fostering vascularization around the hair follicle may contribute to the development of AGA.


Assuntos
Alopecia/genética , Derme/citologia , Regulação da Expressão Gênica , Pele/citologia , Androgênios/metabolismo , Biópsia , Proteínas de Transporte/genética , Linhagem Celular , Núcleo Celular/metabolismo , Análise por Conglomerados , Perfilação da Expressão Gênica , Folículo Piloso/metabolismo , Humanos , Masculino , Proteínas de Membrana/genética , Proteínas de Neoplasias/genética , Proteínas Nucleares/genética , Análise de Sequência com Séries de Oligonucleotídeos , Regiões Promotoras Genéticas , Receptores Androgênicos/genética , Couro Cabeludo , Proteína 1 Relacionada a Twist/genética , Receptor Xedar
6.
Cell Rep ; 12(2): 272-85, 2015 Jul 14.
Artigo em Inglês | MEDLINE | ID: mdl-26146084

RESUMO

Genome rearrangements, a hallmark of cancer, can result in gene fusions with oncogenic properties. Using DNA paired-end-tag (DNA-PET) whole-genome sequencing, we analyzed 15 gastric cancers (GCs) from Southeast Asians. Rearrangements were enriched in open chromatin and shaped by chromatin structure. We identified seven rearrangement hot spots and 136 gene fusions. In three out of 100 GC cases, we found recurrent fusions between CLDN18, a tight junction gene, and ARHGAP26, a gene encoding a RHOA inhibitor. Epithelial cell lines expressing CLDN18-ARHGAP26 displayed a dramatic loss of epithelial phenotype and long protrusions indicative of epithelial-mesenchymal transition (EMT). Fusion-positive cell lines showed impaired barrier properties, reduced cell-cell and cell-extracellular matrix adhesion, retarded wound healing, and inhibition of RHOA. Gain of invasion was seen in cancer cell lines expressing the fusion. Thus, CLDN18-ARHGAP26 mediates epithelial disintegration, possibly leading to stomach H(+) leakage, and the fusion might contribute to invasiveness once a cell is transformed.


Assuntos
Claudinas/genética , Proteínas Ativadoras de GTPase/genética , Proteínas de Fusão Oncogênica/metabolismo , Neoplasias Gástricas/patologia , Sequência de Aminoácidos , Animais , Adesão Celular , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Clatrina/farmacologia , Claudinas/metabolismo , Cães , Endocitose/efeitos dos fármacos , Células Epiteliais/citologia , Células Epiteliais/metabolismo , Transição Epitelial-Mesenquimal , Proteínas Ativadoras de GTPase/metabolismo , Células HeLa , Humanos , Células MCF-7 , Células Madin Darby de Rim Canino , Dados de Sequência Molecular , Proteínas de Fusão Oncogênica/genética , Fenótipo , Neoplasias Gástricas/metabolismo , Proteína rhoA de Ligação ao GTP/antagonistas & inibidores , Proteína rhoA de Ligação ao GTP/metabolismo
7.
PLoS One ; 9(6): e90852, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-24603971

RESUMO

Delineating candidate genes at the chromosomal breakpoint regions in the apparently balanced chromosome rearrangements (ABCR) has been shown to be more effective with the emergence of next-generation sequencing (NGS) technologies. We employed a large-insert (7-11 kb) paired-end tag sequencing technology (DNA-PET) to systematically analyze genome of four patients harbouring cytogenetically defined ABCR with neurodevelopmental symptoms, including developmental delay (DD) and speech disorders. We characterized structural variants (SVs) specific to each individual, including those matching the chromosomal breakpoints. Refinement of these regions by Sanger sequencing resulted in the identification of five disrupted genes in three individuals: guanine nucleotide binding protein, q polypeptide (GNAQ), RNA-binding protein, fox-1 homolog (RBFOX3), unc-5 homolog D (C.elegans) (UNC5D), transmembrane protein 47 (TMEM47), and X-linked inhibitor of apoptosis (XIAP). Among them, XIAP is the causative gene for the immunodeficiency phenotype seen in the patient. The remaining genes displayed specific expression in the fetal brain and have known biologically relevant functions in brain development, suggesting putative candidate genes for neurodevelopmental phenotypes. This study demonstrates the application of NGS technologies in mapping individual gene disruptions in ABCR as a resource for deciphering candidate genes in human neurodevelopmental disorders (NDDs).


Assuntos
Pontos de Quebra do Cromossomo , Deficiências do Desenvolvimento/genética , Transtornos do Desenvolvimento da Linguagem/genética , Sequência de Bases , Inversão Cromossômica , Variações do Número de Cópias de DNA , Feminino , Estudos de Associação Genética , Sequenciamento de Nucleotídeos em Larga Escala , Humanos , Masculino , Dados de Sequência Molecular , Linhagem , Análise de Sequência de DNA , Translocação Genética
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