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1.
Am J Hum Genet ; 108(4): 739-748, 2021 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-33711248

RESUMO

Neurochondrin (NCDN) is a cytoplasmatic neural protein of importance for neural growth, glutamate receptor (mGluR) signaling, and synaptic plasticity. Conditional loss of Ncdn in mice neural tissue causes depressive-like behaviors, impaired spatial learning, and epileptic seizures. We report on NCDN missense variants in six affected individuals with variable degrees of developmental delay, intellectual disability (ID), and seizures. Three siblings were found homozygous for a NCDN missense variant, whereas another three unrelated individuals carried different de novo missense variants in NCDN. We assayed the missense variants for their capability to rescue impaired neurite formation in human neuroblastoma (SH-SY5Y) cells depleted of NCDN. Overexpression of wild-type NCDN rescued the neurite-phenotype in contrast to expression of NCDN containing the variants of affected individuals. Two missense variants, associated with severe neurodevelopmental features and epilepsy, were unable to restore mGluR5-induced ERK phosphorylation. Electrophysiological analysis of SH-SY5Y cells depleted of NCDN exhibited altered membrane potential and impaired action potentials at repolarization, suggesting NCDN to be required for normal biophysical properties. Using available transcriptome data from human fetal cortex, we show that NCDN is highly expressed in maturing excitatory neurons. In combination, our data provide evidence that bi-allelic and de novo variants in NCDN cause a clinically variable form of neurodevelopmental delay and epilepsy, highlighting a critical role for NCDN in human brain development.


Assuntos
Alelos , Epilepsia/genética , Deficiência Intelectual/genética , Mutação/genética , Proteínas do Tecido Nervoso/genética , Transtornos do Neurodesenvolvimento/genética , Adolescente , Sequência de Bases , Linhagem Celular , Pré-Escolar , Consanguinidade , Feminino , Humanos , Lactente , Transtornos do Desenvolvimento da Linguagem/genética , Masculino , Mutação de Sentido Incorreto , Neuritos , Paquistão
3.
PLoS Genet ; 13(7): e1006897, 2017 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-28686597

RESUMO

Claudins constitute the major component of tight junctions and regulate paracellular permeability of epithelia. Claudin-10 occurs in two major isoforms that form paracellular channels with ion selectivity. We report on two families segregating an autosomal recessive disorder characterized by generalized anhidrosis, severe heat intolerance and mild kidney failure. All affected individuals carry a rare homozygous missense mutation c.144C>G, p.(N48K) specific for the claudin-10b isoform. Immunostaining of sweat glands from patients suggested that the disease is associated with reduced levels of claudin-10b in the plasma membranes and in canaliculi of the secretory portion. Expression of claudin-10b N48K in a 3D cell model of sweat secretion indicated perturbed paracellular Na+ transport. Analysis of paracellular permeability revealed that claudin-10b N48K maintained cation over anion selectivity but with a reduced general ion conductance. Furthermore, freeze fracture electron microscopy showed that claudin-10b N48K was associated with impaired tight junction strand formation and altered cis-oligomer formation. These data suggest that claudin-10b N48K causes anhidrosis and our findings are consistent with a combined effect from perturbed TJ function and increased degradation of claudin-10b N48K in the sweat glands. Furthermore, affected individuals present with Mg2+ retention, secondary hyperparathyroidism and mild kidney failure that suggest a disturbed reabsorption of cations in the kidneys. These renal-derived features recapitulate several phenotypic aspects detected in mice with kidney specific loss of both claudin-10 isoforms. Our study adds to the spectrum of phenotypes caused by tight junction proteins and demonstrates a pivotal role for claudin-10b in maintaining paracellular Na+ permeability for sweat production and kidney function.


Assuntos
Claudinas/genética , Rim/metabolismo , Isoformas de Proteínas/genética , Insuficiência Renal/genética , Animais , Transporte Biológico/genética , Cátions/metabolismo , Claudinas/metabolismo , Células Epiteliais/metabolismo , Humanos , Hipo-Hidrose , Rim/patologia , Camundongos , Microscopia Eletrônica , Mutação de Sentido Incorreto , Permeabilidade , Isoformas de Proteínas/metabolismo , Insuficiência Renal/metabolismo , Insuficiência Renal/patologia , Junções Íntimas
4.
Hum Mutat ; 40(7): 899-903, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-30927481

RESUMO

Biallelic and pathogenic variants in the RTTN gene, encoding the centrosomal protein Rotatin, are associated with variable degrees of neurodevelopmental abnormalities, microcephaly, and extracranial malformations. To date, no reported case has reached their third decade. Herein, we report on a consanguineous family with three adult members, age 43, 57, and 60 years respectively, with primary microcephaly, developmental delay, primordial dwarfism, and brachydactyly segregating a homozygous splice site variant NM_173630.3:c.5648-5T>A in RTTN. The variant RTTN allele results in a nonhypomorphic skipping of exon 42 and a frameshift [(NP_775901.3:p.Ala1883Glyfs*6)]. Brain MRI of one affected individual showed markedly reduced volume of cerebral lobes and enlarged sulci but without signs of neural migration defects. Our assessment of three adult cases with a biallelic RTTN variant shows that a predicted shortened Rotatin, lacking the C-terminal end, are associated with stationary clinical features into the seventh decade. Furthermore, our report adds brachydactyly to the phenotypic spectrum in this pleiotropic entity.


Assuntos
Braquidactilia/genética , Proteínas de Ciclo Celular/genética , Nanismo/genética , Mutação da Fase de Leitura , Microcefalia/genética , Adulto , Alelos , Proteínas de Ciclo Celular/química , Consanguinidade , Éxons , Feminino , Predisposição Genética para Doença , Humanos , Masculino , Pessoa de Meia-Idade , Linhagem
5.
Neurobiol Dis ; 132: 104583, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31445158

RESUMO

Dravet syndrome (DS) is an early onset refractory epilepsy typically caused by de novo heterozygous variants in SCN1A encoding the α-subunit of the neuronal sodium channel Nav1.1. The syndrome is characterized by age-related progression of seizures, cognitive decline and movement disorders. We hypothesized that the distinct neurodevelopmental features in DS are caused by the disruption of molecular pathways in Nav1.1 haploinsufficient cells resulting in perturbed neural differentiation and maturation. Here, we established DS-patient and control induced pluripotent stem cell derived neural progenitor cells (iPSC NPC) and GABAergic inter-neuronal (iPSC GABA) cells. The DS-patient iPSC GABA cells showed a shift in sodium current activation and a perturbed response to induced oxidative stress. Transcriptome analysis revealed specific dysregulations of genes for chromatin structure, mitotic progression, neural plasticity and excitability in DS-patient iPSC NPCs and DS-patient iPSC GABA cells versus controls. The transcription factors FOXM1 and E2F1, positive regulators of the disrupted pathways for histone modification and cell cycle regulation, were markedly up-regulated in DS-iPSC GABA lines. Our study highlights transcriptional changes and disrupted pathways of chromatin remodeling in Nav1.1 haploinsufficient GABAergic cells, providing a molecular framework that overlaps with that of neurodevelopmental disorders and other epilepsies.


Assuntos
Montagem e Desmontagem da Cromatina/genética , Epilepsias Mioclônicas/genética , Neurônios GABAérgicos/metabolismo , Neurogênese/genética , Células Cultivadas , Epilepsias Mioclônicas/metabolismo , Haploinsuficiência , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Células-Tronco Neurais/metabolismo , Plasticidade Neuronal/fisiologia , Estresse Oxidativo/fisiologia , Transcriptoma
6.
J Med Genet ; 52(9): 599-606, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-26142438

RESUMO

BACKGROUND: Keratosis pilaris atrophicans (KPA) is a group of rare genodermatoses characterised by perifollicular keratosis and inflammation that progresses to atrophy and scars of the facial skin. Keratosis pilaris of extensor areas of limbs is a common associated finding. Most cases with KPA are sporadic and no consistent inheritance pattern has been documented. METHODS: A large consanguineous Pakistani pedigree segregating autosomal recessive KPA of a mixed type was subject to autozygosity mapping and whole exome sequencing. Quantification of mRNA and protein levels was performed on fibroblasts from affected individuals. Cellular uptake of the low-density lipoprotein (LDL) receptor-related protein 1 (LRP1) ligand α2-macroglobulin (α(2)M) was quantified using fluorescence confocal microscopy. RESULTS: Genetic analyses identified a unique homozygous missense variant (K1245R) in the LRP1 in all affected family members. LRP1 encodes the LRP1, a multifunctional cell surface receptor with endocytic functions that belongs to the LDL receptor family. The LRP1 mRNA and LRP1 protein levels in fibroblasts of affected individuals were markedly reduced when compared with controls. Similarly, the LRP1-mediated cellular uptake of α(2)M was reduced in patient fibroblasts. CONCLUSIONS: This is the first report on LRP1 as a pathogenic gene for autosomal recessive KPA and keratosis pilaris. The inflammatory characteristics of the KPA entity in our family suggest a link to the immune-regulatory functions of LRP1.


Assuntos
Anormalidades Múltiplas/genética , Doença de Darier/genética , Éxons , Sobrancelhas/anormalidades , Proteína-1 Relacionada a Receptor de Lipoproteína de Baixa Densidade/genética , Mutação Puntual , Transtornos Cromossômicos/genética , Consanguinidade , Exoma , Genes Recessivos , Humanos , Paquistão , Linhagem , Análise de Sequência de DNA
7.
FASEB J ; 28(5): 2293-305, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24500924

RESUMO

Frizzleds (FZDs) are classified as G-protein-coupling receptors, but how signals are initiated and specified through heterotrimeric G proteins is unknown. FZD6 regulates convergent extension movements, and its C-terminal Arg511Cys mutation causes nail dysplasia in humans. We investigated the functional relationship between FZD6, Disheveled (DVL), and heterotrimeric G proteins. Live cell imaging combined with fluorescence recovery after photobleaching (FRAP) revealed that inactive human FZD6 precouples to Gαi1 and Gαq but not to GαoA,Gαs, and Gα12 proteins. G-protein coupling is measured as a 10-20% reduction in the mobile fraction of fluorescently tagged G proteins on chemical receptor surface cross-linking. The FZD6 Arg511Cys mutation is incapable of G-protein precoupling, even though it still binds DVL. Using both FRAP and Förster resonance energy transfer (FRET) technology, we showed that the FZD6-Gαi1 and FZD-Gαq complexes dissociate on WNT-5A stimulation. Most important, G-protein precoupling of FZD6 and WNT-5A-induced signaling to extracellular signal-regulated kinase1/2 were impaired by DVL knockdown or overexpression, arguing for a strict dependence of FZD6-G-protein coupling on DVL levels and identifying DVL as a master regulator of FZD/G-protein signaling. In summary, we propose a mechanistic connection between DVL and G proteins integrating WNT, FZD, G-protein, and DVL function.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Receptores Frizzled/metabolismo , Proteínas Heterotriméricas de Ligação ao GTP/metabolismo , Fosfoproteínas/metabolismo , Membrana Celular/metabolismo , Proteínas Desgrenhadas , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Recuperação de Fluorescência Após Fotodegradação , Transferência Ressonante de Energia de Fluorescência , Proteínas de Fluorescência Verde/metabolismo , Células HEK293 , Humanos , Mutação , Ligação Proteica , Proteínas Proto-Oncogênicas/metabolismo , Proteínas Wnt/metabolismo , Proteína Wnt-5a
8.
Am J Hum Genet ; 88(6): 852-860, 2011 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-21665003

RESUMO

Inherited and isolated nail malformations are rare and heterogeneous conditions. We identified two consanguineous pedigrees in which some family members were affected by isolated nail dysplasia that suggested an autosomal-recessive inheritance pattern and was characterized by claw-shaped nails, onychauxis, and onycholysis. Genome-wide SNP array analysis of affected individuals from both families showed an overlapping and homozygous region of 800 kb on the long arm of chromosome 8. The candidate region spans eight genes, and DNA sequence analysis revealed homozygous nonsense and missense mutations in FZD(6), the gene encoding Frizzled 6. FZD(6) belongs to a family of highly conserved membrane-bound WNT receptors involved in developmental processes and differentiation through several signaling pathways. We expressed the FZD(6) missense mutation and observed a quantitative shift in subcellular distribution from the plasma membrane to the lysosomes, where the receptor is inaccessible for signaling and presumably degraded. Analysis of human fibroblasts homozygous for the nonsense mutation showed an aberrant response to both WNT-3A and WNT-5A stimulation; this response was consistent with an effect on both canonical and noncanonical WNT-FZD signaling. A detailed analysis of the Fzd(6)(-/-) mice, previously shown to have an altered hair pattern, showed malformed claws predominantly of the hind limbs. Furthermore, a transient Fdz6 mRNA expression was observed in the epidermis of the digital tips at embryonic day 16.5 during early claw morphogenesis. Thus, our combined results show that FZD6 mutations can result in severe defects in nail and claw formation through reduced or abolished membranous FZD(6) levels and several nonfunctional WNT-FZD pathways.


Assuntos
Cromossomos Humanos Par 8/genética , Receptores Frizzled/genética , Receptores Acoplados a Proteínas G/genética , Sequência de Aminoácidos , Animais , Códon sem Sentido , Receptores Frizzled/metabolismo , Estudo de Associação Genômica Ampla , Células HEK293 , Membro Posterior/anormalidades , Casco e Garras/anormalidades , Humanos , Camundongos , Camundongos Mutantes , Dados de Sequência Molecular , Mutação de Sentido Incorreto , Doenças da Unha/congênito , Doenças da Unha/genética , Doenças da Unha/patologia , Linhagem , Polimorfismo de Nucleotídeo Único , Proteínas Proto-Oncogênicas/metabolismo , Receptores Acoplados a Proteínas G/metabolismo , Proteínas Wnt/metabolismo , Proteína Wnt-5a , Proteína Wnt3 , Proteína Wnt3A
9.
BMC Med Genet ; 15: 71, 2014 Jun 24.
Artigo em Inglês | MEDLINE | ID: mdl-24961962

RESUMO

BACKGROUND: Exome sequencing has become more and more affordable and the technique has emerged as an important diagnostic tool for monogenic disorders at early stages of investigations, in particular when clinical information is limited or unspecific as well as in cases of genetic heterogeneity. METHODS: We identified a consanguineous Pakistani family segregating an autosomal recessive phenotype characterized by muscular hypertrophy, mild mental retardation and skeletal abnormalities. The available clinical information was incomplete and we applied whole exome sequencing in an affected family member for the identification of candidate gene variants. RESULTS: Exome sequencing identified a previously unreported homozygous mutation in the acceptor splice site of intron 5 in the BSCL2 gene (c.574-2A > G). Expression analysis revealed that the mutation was associated with skipping of exon 6. BSCL2 mutations are associated with Berardinelli-Seip congenital lipodystrophy and a clinical re-evaluation of affected individuals confirmed the diagnosis. CONCLUSIONS: Exome sequencing is a powerful technique for the identification of candidate gene variants in Mendelian traits. We applied this technique on a single individual affected by a likely autosomal recessive disorder without access to complete clinical details. A homozygous and truncating mutation was identified in the BSCL2 gene suggesting congenital generalized lipodystrophy. Incomplete phenotypic delineations are frequent limiting factors in search for a diagnosis and may lead to inappropriate care and follow-up. Our study exemplifies exome sequencing as a powerful diagnostic tool in Mendelian disorders that may complement missing clinical information and accelerate clinical diagnosis.


Assuntos
Exoma , Subunidades gama da Proteína de Ligação ao GTP/genética , Sequenciamento de Nucleotídeos em Larga Escala , Lipodistrofia Generalizada Congênita/diagnóstico , Lipodistrofia Generalizada Congênita/genética , Mutação , Consanguinidade , Análise Mutacional de DNA , Feminino , Expressão Gênica , Ordem dos Genes , Homozigoto , Humanos , Masculino , Linhagem , Fenótipo , Polimorfismo de Nucleotídeo Único , Sítios de Splice de RNA
10.
Am J Hum Genet ; 86(4): 596-603, 2010 Apr 09.
Artigo em Inglês | MEDLINE | ID: mdl-20226437

RESUMO

KLICK syndrome is a rare autosomal-recessive skin disorder characterized by palmoplantar keratoderma, linear hyperkeratotic papules, and ichthyosiform scaling. In order to establish the genetic cause of this disorder, we collected DNA samples from eight European probands. Using high-density genome-wide SNP analysis, we identified a 1.5 Mb homozygous candidate region on chromosome 13q. Sequence analysis of the ten annotated genes in the candidate region revealed homozygosity for a single-nucleotide deletion at position c.-95 in the proteasome maturation protein (POMP) gene, in all probands. The deletion is included in POMP transcript variants with long 5' untranslated regions (UTRs) and was associated with a marked increase of these transcript variants in keratinocytes from KLICK patients. POMP is a ubiquitously expressed protein and functions as a chaperone for proteasome maturation. Immunohistochemical analysis of skin biopsies from KLICK patients revealed an altered epidermal distribution of POMP, the proteasome subunit proteins alpha 7 and beta 5, and the ER stress marker CHOP. Our results suggest that KLICK syndrome is caused by a single-nucleotide deletion in the 5' UTR of POMP resulting in altered distribution of POMP in epidermis and a perturbed formation of the outermost layers of the skin. These findings imply that the proteasome has a prominent role in the terminal differentiation of human epidermis.


Assuntos
Regiões 5' não Traduzidas/genética , Epiderme/patologia , Ictiose/genética , Ceratose/genética , Chaperonas Moleculares/genética , Polimorfismo de Nucleotídeo Único , Complexo de Endopeptidases do Proteassoma/metabolismo , Esclerodermia Localizada/genética , Transcrição Gênica , Adulto , Sequência de Bases , Estudos de Casos e Controles , Células Cultivadas , Epiderme/metabolismo , Família , Deleção de Genes , Homozigoto , Humanos , Ictiose/metabolismo , Queratinócitos/citologia , Queratinócitos/metabolismo , Ceratose/metabolismo , Masculino , Dados de Sequência Molecular , Esclerodermia Localizada/metabolismo , Homologia de Sequência do Ácido Nucleico , Síndrome
11.
Stem Cell Res ; 60: 102712, 2022 04.
Artigo em Inglês | MEDLINE | ID: mdl-35203050

RESUMO

Dravet syndrome is an early onset devastating epilepsy syndrome usually caused by heterozygous mutations in SCN1A. We generated a human iPSC line (UUIGPi015-A) from dermal fibroblasts of a patient with Dravet syndrome carrying a deletion on chromosome 2 encompassing SCN1A and 9 flanking genes. Characterization of the iPSC line confirmed expression of pluripotency markers, tri-lineage differentiation capacity and absence of exogenous reprogramming factors. The iPSC line retained the deletion and was genomically stable. The iPSC line UUIGPi015-A provides a useful resource for studies on the pathophysiology of Dravet syndrome and seizures caused by haploinsufficiency of SCN1A and flanking gene products.


Assuntos
Epilepsias Mioclônicas , Células-Tronco Pluripotentes Induzidas , Cromossomos Humanos Par 2 , Epilepsias Mioclônicas/genética , Síndromes Epilépticas , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Mutação , Canal de Sódio Disparado por Voltagem NAV1.1/genética , Espasmos Infantis
12.
Front Mol Neurosci ; 15: 988993, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36353360

RESUMO

Mowat-Wilson syndrome (MWS) is a severe neurodevelopmental disorder caused by heterozygous variants in the gene encoding transcription factor ZEB2. Affected individuals present with structural brain abnormalities, speech delay and epilepsy. In mice, conditional loss of Zeb2 causes hippocampal degeneration, altered migration and differentiation of GABAergic interneurons, a heterogeneous population of mainly inhibitory neurons of importance for maintaining normal excitability. To get insights into GABAergic development and function in MWS we investigated ZEB2 haploinsufficient induced pluripotent stem cells (iPSC) of MWS subjects together with iPSC of healthy donors. Analysis of RNA-sequencing data at two time points of GABAergic development revealed an attenuated interneuronal identity in MWS subject derived iPSC with enrichment of differentially expressed genes required for transcriptional regulation, cell fate transition and forebrain patterning. The ZEB2 haploinsufficient neural stem cells (NSCs) showed downregulation of genes required for ventral telencephalon specification, such as FOXG1, accompanied by an impaired migratory capacity. Further differentiation into GABAergic interneuronal cells uncovered upregulation of transcription factors promoting pallial and excitatory neurons whereas cortical markers were downregulated. The differentially expressed genes formed a neural protein-protein network with extensive connections to well-established epilepsy genes. Analysis of electrophysiological properties in ZEB2 haploinsufficient GABAergic cells revealed overt perturbations manifested as impaired firing of repeated action potentials. Our iPSC model of ZEB2 haploinsufficient GABAergic development thus uncovers a dysregulated gene network leading to immature interneurons with mixed identity and altered electrophysiological properties, suggesting mechanisms contributing to the neuropathogenesis and seizures in MWS.

13.
Neurogenetics ; 12(1): 65-72, 2011 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-21225301

RESUMO

Adult-onset autosomal dominant leukodystrophy (ADLD) with autonomic symptoms features micturition urgency, constipation, erectile dysfunction, and orthostatic hypotension, usually followed by pyramidal signs and ataxia. Peripheral nerve conduction is normal. The disease is often mistaken for multiple sclerosis in the initial phase. There is a characteristic pattern of white matter changes in the brain and spinal cord on magnetic resonance imaging (MRI), mild atrophy of the brain, and a more marked atrophy of the spinal cord. ADLD is associated with duplications of the lamin B1 (LMNB1) gene but the mechanism by which the rearrangement conveys the phenotype is not fully defined. We analyzed four unrelated families segregating ADLD with autonomic symptoms for duplications of the LMNB1 gene. A single nucleotide polymorphism (SNP) array analysis revealed novel duplications spanning the entire LMNB1 gene in probands from each of the four families. We then analyzed the expression of lamin B1 in peripheral leukocytes by Western blot analysis in five patients from two available families. The protein levels of lamin B1 were found significantly increased. These results indicate that the ADLD phenotype associated with LMNB1 duplications is mediated by increased levels of the lamin B1 protein. Furthermore, we show that a molecular diagnosis for ADLD with autonomic symptoms can be obtained by a direct analysis of lamin B1 in peripheral leukocytes.


Assuntos
Doenças do Sistema Nervoso Autônomo/genética , Duplicação Gênica , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/genética , Lamina Tipo B/genética , Adulto , Doenças do Sistema Nervoso Autônomo/sangue , Doenças do Sistema Nervoso Autônomo/patologia , Encéfalo/patologia , Estudos de Casos e Controles , Cromossomos Humanos Par 5/genética , Feminino , Expressão Gênica , Genes Dominantes , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/sangue , Doenças Desmielinizantes Hereditárias do Sistema Nervoso Central/patologia , Humanos , Lamina Tipo B/sangue , Leucócitos/metabolismo , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Linhagem , Fenótipo , Polimorfismo de Nucleotídeo Único , RNA Mensageiro/sangue , RNA Mensageiro/genética
14.
Stem Cell Res ; 57: 102577, 2021 Oct 19.
Artigo em Inglês | MEDLINE | ID: mdl-34688129

RESUMO

Heterozygous variants in POLR2A, encoding the largest subunit of RNA polymerase II, cause severe neurodevelopmental and multisystem abnormalities in humans. Using CRISPR/Cas9 we generated the human iPSC line KICRi002A-5 with a heterozygous truncating 4 bp insertion in exon 5 of the POLR2A gene. Analysis using qRT-PCR confirmed reduced POLR2A mRNA in KICRi002A-5 vs. the isogenic WT iPSC line. The edited iPSC line expressed pluripotency markers and exhibited differentiation capacity into the three germ layers. Assessment of genomic integrity revealed a normal karyotype and OFF-target editing was excluded. The iPSC line KICRi002A-5 provides a useful resource to study mechanisms underlying developmental defects caused by RBP1 insufficiency.

15.
J Agric Food Chem ; 69(38): 11382-11394, 2021 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-34533305

RESUMO

Aromatized wines and regular table wines are often filled on the same bottling line. Sealing polymers in the filling line absorb volatiles from aromatized wines and may migrate due to insufficient cleaning into the subsequently bottled regular wine. Unintentional carryover of volatiles may lead to accusation of illegal aromatization of wine. Absorption, cleaning efficacy, and migration of volatiles into ethylene propylene diene monomer rubber were investigated in a model system. Direct thermal desorption-gas chromatography-mass spectrometry analysis of seven aroma compounds monitored variation in the polymer (µg/g). Absorption of volatiles was mostly driven by their octanol/water partition coefficients. Cleaning of polymers removed 11 to 62% of the absorbed volatiles. Subsequent immersion of cleaned polymers into model wine revealed migration of 20 to 57% of the remaining volatiles. Sensory tests suggested the impact of transferred volatiles into subsequent model wine. For α-ionone, an odor activity value of 1.03 indicated a potential sensory impact.


Assuntos
Compostos Orgânicos Voláteis , Vinho , Alcenos , Etilenos , Odorantes/análise , Polímeros , Borracha , Compostos Orgânicos Voláteis/análise , Vinho/análise
16.
Commun Biol ; 4(1): 624, 2021 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-34035432

RESUMO

Combined measurements of mRNA and protein expression in single cells enable in-depth analysis of cellular states. We present SPARC, an approach that combines single-cell RNA-sequencing with proximity extension essays to simultaneously measure global mRNA and 89 intracellular proteins in individual cells. We show that mRNA expression fails to accurately reflect protein abundance at the time of measurement, although the direction of changes is in agreement during neuronal differentiation. Moreover, protein levels of transcription factors better predict their downstream effects than do their corresponding transcripts. Finally, we highlight that protein expression variation is overall lower than mRNA variation, but relative protein variation does not reflect the mRNA level. Our results demonstrate that mRNA and protein measurements in single cells provide different and complementary information regarding cell states. SPARC presents a state-of-the-art co-profiling method that overcomes current limitations in throughput and protein localization, including removing the need for cell fixation.


Assuntos
Perfilação da Expressão Gênica/métodos , Proteômica/métodos , Análise de Célula Única/métodos , Humanos , Proteínas/genética , Proteínas/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Análise de Sequência de RNA/métodos , Transcrição Gênica/genética
17.
Biochim Biophys Acta ; 1792(10): 1036-42, 2009 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19689926

RESUMO

Diamond-Blackfan anemia (DBA) is a severe congenital anemia characterized by a specific decrease of erythroid precursors. The disease is also associated with growth retardation, congenital malformations, a predisposition for malignant disease and heterozygous mutations in either of the ribosomal protein (RP) genes RPS7, RPS17, RPS19, RPS24, RPL5, RPL11 and RPL35a. We show herein that primary fibroblasts from DBA patients with truncating mutations in RPS19 or in RPS24 have a marked reduction in proliferative capacity. Mutant fibroblasts are associated with extended cell cycles and normal levels of p53 when compared to w.t. cells. RPS19 mutant fibroblasts accumulate in the G1 phase, whereas the RPS24 mutant cells show an altered progression in the S phase resulting in reduced levels in the G2/M phase. RPS19 deficient cells exhibit reduced levels of Cyclin-E, CDK2 and retinoblastoma (Rb) protein supporting a cell cycle arrest in the G1 phase. In contrast, RPS24 deficient cells show increased levels of the cell cycle inhibitor p21 and a seemingly opposing increase in Cyclin-E, CDK4 and CDK6. In combination, our results show that RPS19 and RPS24 insufficient fibroblasts have an impaired growth caused by distinct blockages in the cell cycle. We suggest this proliferative constraint to be an important contributing mechanism for the complex extra-hematological features observed in DBA.


Assuntos
Anemia de Diamond-Blackfan/metabolismo , Anemia de Diamond-Blackfan/patologia , Ciclo Celular , Proteínas Ribossômicas/metabolismo , Western Blotting , Proteínas de Ciclo Celular/metabolismo , Proliferação de Células , Células Cultivadas , Regulação para Baixo , Fibroblastos/metabolismo , Fibroblastos/patologia , Humanos , Mutação/genética , RNA Ribossômico/metabolismo
18.
Hum Mol Genet ; 17(23): 3776-83, 2008 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-18782852

RESUMO

Premature ovarian failure (POF) is characterized by hypergonadotropic hypogonadism and amenorrhea before the age of 40. The condition has a heterogeneous background but genetic factors are demonstrated by the occurrence of familial cases. We identified a mother and daughter with POF both of whom carry an X;autosome translocation [t(X;11)(q24;q13)]. RNA expression studies of genes flanking the X-chromosome breakpoint revealed that both patients have reduced expression levels of the gene Progesterone Receptor Membrane Component-1 (PGRMC1). Mutation screening of 67 females with idiopathic POF identified a third patient with a missense mutation (H165R) located in the cytochrome b5 domain of PGRMC1. PGRMC1 mediates the anti-apoptotic action of progesterone in ovarian cells and it acts as a positive regulator of several cytochrome P450 (CYP)-catalyzed reactions. The CYPs are critical for intracellular sterol metabolism, including biosynthesis of steroid hormones. We show that the H165R mutation associated with POF abolishes the binding of cytochrome P450 7A1 (CYP7A1) to PGRMC1. In addition, the missense mutation attenuates PGRMC1's ability to mediate the anti-apoptotic action of progesterone in ovarian cells. These findings suggest that mutant or reduced levels of PGMRC1 may cause POF through impaired activation of the microsomal cytochrome P450 and increased apoptosis of ovarian cells.


Assuntos
Expressão Gênica , Proteínas de Membrana/química , Proteínas de Membrana/metabolismo , Insuficiência Ovariana Primária/genética , Receptores de Progesterona/química , Receptores de Progesterona/metabolismo , Adolescente , Adulto , Apoptose , Cromossomos Humanos X/genética , Sistema Enzimático do Citocromo P-450/genética , Sistema Enzimático do Citocromo P-450/metabolismo , Metilação de DNA , Feminino , Humanos , Proteínas de Membrana/genética , Mutação de Sentido Incorreto , Insuficiência Ovariana Primária/metabolismo , Insuficiência Ovariana Primária/fisiopatologia , Estrutura Terciária de Proteína , Receptores de Progesterona/genética , Translocação Genética , Adulto Jovem
19.
Blood Cells Mol Dis ; 45(1): 23-8, 2010 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-20395159

RESUMO

Heterozygous mutations in the ribosomal protein S19 (RPS19) gene are associated with Diamond-Blackfan anemia (DBA). The mechanism by which RPS19 mediates anemia are still unclear, as well as the regulation of RPS19 expression. We show herein that RPS19 binds specifically to the 5' untranslated region of its own mRNA with an equilibrium binding constant (K(D)) of 4.1+/-1.9 nM. We investigated the mRNA binding properties of two mutant RPS19 proteins (W52R and R62W) identified in DBA patients. We observed a significant increase in K(D) for both proteins (16.1+/-2.1 and 14.5+/-4.9 nM, respectively), indicating a reduced RNA binding capability (p<0.05). We suggest that the binding of RPS19 to its mRNA has a regulatory function and hypothesize that the weaker RNA binding of mutant rRPS19 may have implications for the pathophysiological mechanisms in DBA.


Assuntos
Anemia de Diamond-Blackfan/metabolismo , Mutação de Sentido Incorreto , RNA Mensageiro/metabolismo , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Regiões 5' não Traduzidas , Anemia de Diamond-Blackfan/genética , Humanos , Ligação Proteica
20.
Reprod Biol Endocrinol ; 8: 58, 2010 Jun 10.
Artigo em Inglês | MEDLINE | ID: mdl-20537145

RESUMO

BACKGROUND: Progesterone receptor membrane component 1 (PGRMC1) is a member of a progesterone-binding complex implicated in female reproduction. We aimed i) to determine the natural expression of PGRMC1 in peripheral nucleated blood cells throughout the menstrual cycle and ii) to investigate any association between PGRMC1 levels in leukocytes and conditions characterized by reduced fertility. METHODS: We analyzed PGRMC1 expression in peripheral leukocytes from 15 healthy cycling women over four weeks. Additionally, we determined PGRMC1 levels in samples from patients with premature ovarian failure (POF) and polycystic ovary syndrome (PCOS) as well as in healthy postmenopausal women and male controls. The levels of PGRMC1 protein in nucleated peripheral blood cells were quantified by Western blot analysis. RESULTS: PGRMC1 levels did not vary significantly throughout the menstrual cycle. We observed a significant down-regulation of PGRMC1 in postmenopausal women and in patients with premature ovarian failure (POF) and polycystic ovary syndrome (PCOS) when compared to early follicular phase of healthy women. CONCLUSION: This study suggests that reduced levels of PGRMC1 in peripheral leukocytes are associated with perturbed ovulatory function.


Assuntos
Células Sanguíneas/metabolismo , Proteínas de Membrana/metabolismo , Síndrome do Ovário Policístico/metabolismo , Insuficiência Ovariana Primária/metabolismo , Receptores de Progesterona/metabolismo , Adulto , Estudos de Casos e Controles , Regulação para Baixo , Feminino , Humanos , Leucócitos Mononucleares/metabolismo , Leucócitos Mononucleares/patologia , Masculino , Proteínas de Membrana/sangue , Ciclo Menstrual/sangue , Ciclo Menstrual/metabolismo , Síndrome do Ovário Policístico/sangue , Síndrome do Ovário Policístico/patologia , Insuficiência Ovariana Primária/sangue , Insuficiência Ovariana Primária/patologia , Receptores de Progesterona/sangue , Adulto Jovem
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