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1.
Am J Hum Genet ; 107(1): 164-172, 2020 07 02.
Artigo em Inglês | MEDLINE | ID: mdl-32553196

RESUMO

CNOT1 is a member of the CCR4-NOT complex, which is a master regulator, orchestrating gene expression, RNA deadenylation, and protein ubiquitination. We report on 39 individuals with heterozygous de novo CNOT1 variants, including missense, splice site, and nonsense variants, who present with a clinical spectrum of intellectual disability, motor delay, speech delay, seizures, hypotonia, and behavioral problems. To link CNOT1 dysfunction to the neurodevelopmental phenotype observed, we generated variant-specific Drosophila models, which showed learning and memory defects upon CNOT1 knockdown. Introduction of human wild-type CNOT1 was able to rescue this phenotype, whereas mutants could not or only partially, supporting our hypothesis that CNOT1 impairment results in neurodevelopmental delay. Furthermore, the genetic interaction with autism-spectrum genes, such as ASH1L, DYRK1A, MED13, and SHANK3, was impaired in our Drosophila models. Molecular characterization of CNOT1 variants revealed normal CNOT1 expression levels, with both mutant and wild-type alleles expressed at similar levels. Analysis of protein-protein interactions with other members indicated that the CCR4-NOT complex remained intact. An integrated omics approach of patient-derived genomics and transcriptomics data suggested only minimal effects on endonucleolytic nonsense-mediated mRNA decay components, suggesting that de novo CNOT1 variants are likely haploinsufficient hypomorph or neomorph, rather than dominant negative. In summary, we provide strong evidence that de novo CNOT1 variants cause neurodevelopmental delay with a wide range of additional co-morbidities. Whereas the underlying pathophysiological mechanism warrants further analysis, our data demonstrate an essential and central role of the CCR4-NOT complex in human brain development.


Assuntos
Deficiências do Desenvolvimento/genética , Expressão Gênica/genética , Transtornos do Neurodesenvolvimento/genética , Membro 2 do Grupo A da Subfamília 4 de Receptores Nucleares/genética , RNA/genética , Receptores CCR4/genética , Fatores de Transcrição/genética , Alelos , Feminino , Variação Genética/genética , Haploinsuficiência/genética , Heterozigoto , Humanos , Masculino , Malformações do Sistema Nervoso/genética , Fenótipo , Estabilidade Proteica
2.
PLoS Biol ; 18(4): e3000717, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32353004

RESUMO

Extensive evidence links Glutamate receptor, ionotropic, NMDA2B (GRIN2B), encoding the GluN2B/NR2B subunit of N-methyl-D-aspartate receptors (NMDARs), with various neurodevelopmental disorders, including autism spectrum disorders (ASDs), but the underlying mechanisms remain unclear. In addition, it remains unknown whether mutations in GluN2B, which starts to be expressed early in development, induces early pathophysiology that can be corrected by early treatments for long-lasting effects. We generated and characterized Grin2b-mutant mice that carry a heterozygous, ASD-risk C456Y mutation (Grin2b+/C456Y). In Grin2b+/C456Y mice, GluN2B protein levels were strongly reduced in association with decreased hippocampal NMDAR currents and NMDAR-dependent long-term depression (LTD) but unaltered long-term potentiation, indicative of mutation-induced protein degradation and LTD sensitivity. Behaviorally, Grin2b+/C456Y mice showed normal social interaction but exhibited abnormal anxiolytic-like behavior. Importantly, early, but not late, treatment of young Grin2b+/C456Y mice with the NMDAR agonist D-cycloserine rescued NMDAR currents and LTD in juvenile mice and improved anxiolytic-like behavior in adult mice. Therefore, GluN2B-C456Y haploinsufficiency decreases GluN2B protein levels, NMDAR-dependent LTD, and anxiety-like behavior, and early activation of NMDAR function has long-lasting effects on adult mouse behavior.


Assuntos
Ansiedade/genética , Hipocampo/fisiologia , Depressão Sináptica de Longo Prazo/fisiologia , Receptores de N-Metil-D-Aspartato/genética , Animais , Ansiedade/fisiopatologia , Comportamento Animal/efeitos dos fármacos , Ciclosserina/farmacologia , Potenciais Pós-Sinápticos Excitadores/genética , Técnicas de Introdução de Genes , Haploinsuficiência/genética , Heterozigoto , Hipocampo/metabolismo , Depressão Sináptica de Longo Prazo/efeitos dos fármacos , Camundongos Mutantes , Mutação , Proteínas do Tecido Nervoso/metabolismo , Receptores de N-Metil-D-Aspartato/agonistas , Receptores de N-Metil-D-Aspartato/metabolismo
3.
PLoS One ; 15(5): e0232789, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32407325

RESUMO

BAHD1 is a heterochomatinization factor recently described as a component of a multiprotein complex associated with histone deacetylases HDAC1/2. The physiological and patho-physiological functions of BAHD1 are not yet well characterized. Here, we examined the consequences of BAHD1 deficiency in the brains of male mice. While Bahd1 knockout mice had no detectable defects in brain anatomy, RNA sequencing profiling revealed about 2500 deregulated genes in Bahd1-/- brains compared to Bahd1+/+ brains. A majority of these genes were involved in nervous system development and function, behavior, metabolism and immunity. Exploration of the Allen Brain Atlas and Dropviz databases, assessing gene expression in the brain, revealed that expression of the Bahd1 gene was limited to a few territories and cell subtypes, particularly in the hippocampal formation, the isocortex and the olfactory regions. The effect of partial BAHD1 deficiency on behavior was then evaluated on Bahd1 heterozygous male mice, which have no lethal or metabolic phenotypes. Bahd1+/- mice showed anxiety-like behavior and reduced prepulse inhibition (PPI) of the startle response. Altogether, these results suggest that BAHD1 plays a role in chromatin-dependent gene regulation in a subset of brain cells and support recent evidence linking genetic alteration of BAHD1 to psychiatric disorders in a human patient.


Assuntos
Ansiedade/genética , Encéfalo/metabolismo , Proteínas Cromossômicas não Histona/genética , Reflexo de Sobressalto/genética , Animais , Ansiedade/fisiopatologia , Encéfalo/patologia , Cromatina/genética , Regulação da Expressão Gênica/genética , Haploinsuficiência/genética , Histona Desacetilase 1/genética , Histona Desacetilase 2/genética , Humanos , Camundongos , Camundongos Knockout , Fenótipo , Análise de Sequência de RNA
4.
Nat Commun ; 11(1): 2289, 2020 05 08.
Artigo em Inglês | MEDLINE | ID: mdl-32385263

RESUMO

The osteoblast differentiation capacity of skeletal stem cells (SSCs) must be tightly regulated, as inadequate bone formation results in low bone mass and skeletal fragility, and over-exuberant osteogenesis results in heterotopic ossification (HO) of soft tissues. RUNX2 is essential for tuning this balance, but the mechanisms of posttranslational control of RUNX2 remain to be fully elucidated. Here, we identify that a CK2/HAUSP pathway is a key regulator of RUNX2 stability, as Casein kinase 2 (CK2) phosphorylates RUNX2, recruiting the deubiquitinase herpesvirus-associated ubiquitin-specific protease (HAUSP), which stabilizes RUNX2 by diverting it away from ubiquitin-dependent proteasomal degradation. This pathway is important for both the commitment of SSCs to osteoprogenitors and their subsequent maturation. This CK2/HAUSP/RUNX2 pathway is also necessary for HO, as its inhibition blocked HO in multiple models. Collectively, active deubiquitination of RUNX2 is required for bone formation and this CK2/HAUSP deubiquitination pathway offers therapeutic opportunities for disorders of inappropriate mineralization.


Assuntos
Subunidade alfa 1 de Fator de Ligação ao Core/metabolismo , Ossificação Heterotópica/metabolismo , Osteogênese , Adulto , Idoso , Animais , Caseína Quinase II/genética , Caseína Quinase II/metabolismo , Diferenciação Celular , Displasia Cleidocraniana/genética , Displasia Cleidocraniana/patologia , Feminino , Deleção de Genes , Haploinsuficiência/genética , Membro Posterior/metabolismo , Humanos , Masculino , Camundongos Endogâmicos C57BL , Pessoa de Meia-Idade , Ossificação Heterotópica/genética , Ossificação Heterotópica/patologia , Osteoblastos/metabolismo , Fosforilação , Estabilidade Proteica , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Peptidase 7 Específica de Ubiquitina/metabolismo
5.
Nature ; 581(7809): 452-458, 2020 05.
Artigo em Inglês | MEDLINE | ID: mdl-32461655

RESUMO

The acceleration of DNA sequencing in samples from patients and population studies has resulted in extensive catalogues of human genetic variation, but the interpretation of rare genetic variants remains problematic. A notable example of this challenge is the existence of disruptive variants in dosage-sensitive disease genes, even in apparently healthy individuals. Here, by manual curation of putative loss-of-function (pLoF) variants in haploinsufficient disease genes in the Genome Aggregation Database (gnomAD)1, we show that one explanation for this paradox involves alternative splicing of mRNA, which allows exons of a gene to be expressed at varying levels across different cell types. Currently, no existing annotation tool systematically incorporates information about exon expression into the interpretation of variants. We develop a transcript-level annotation metric known as the 'proportion expressed across transcripts', which quantifies isoform expression for variants. We calculate this metric using 11,706 tissue samples from the Genotype Tissue Expression (GTEx) project2 and show that it can differentiate between weakly and highly evolutionarily conserved exons, a proxy for functional importance. We demonstrate that expression-based annotation selectively filters 22.8% of falsely annotated pLoF variants found in haploinsufficient disease genes in gnomAD, while removing less than 4% of high-confidence pathogenic variants in the same genes. Finally, we apply our expression filter to the analysis of de novo variants in patients with autism spectrum disorder and intellectual disability or developmental disorders to show that pLoF variants in weakly expressed regions have similar effect sizes to those of synonymous variants, whereas pLoF variants in highly expressed exons are most strongly enriched among cases. Our annotation is fast, flexible and generalizable, making it possible for any variant file to be annotated with any isoform expression dataset, and will be valuable for the genetic diagnosis of rare diseases, the analysis of rare variant burden in complex disorders, and the curation and prioritization of variants in recall-by-genotype studies.


Assuntos
Doença/genética , Haploinsuficiência/genética , Mutação com Perda de Função/genética , Anotação de Sequência Molecular , Transcrição Genética , Transcriptoma/genética , Transtorno do Espectro Autista/genética , Conjuntos de Dados como Assunto , Deficiências do Desenvolvimento/genética , Éxons/genética , Feminino , Genótipo , Humanos , Deficiência Intelectual/genética , Masculino , Anotação de Sequência Molecular/normas , Distribuição de Poisson , RNA Mensageiro/análise , RNA Mensageiro/genética , Doenças Raras/diagnóstico , Doenças Raras/genética , Reprodutibilidade dos Testes , Sequenciamento Completo do Exoma
6.
Zhonghua Er Ke Za Zhi ; 58(3): 218-222, 2020 Mar 02.
Artigo em Chinês | MEDLINE | ID: mdl-32135594

RESUMO

Objective: To explore the clinical phenotype, immunological features, pathogenesis and gene variation of a case with A20 haploinsufficiency (HA20). Methods: A patient diagnosed with tumor necrosis factor α-induced protein 3 (TNFAIP3) mutated HA20 was admitted into Shenzhen Children's Hospital in May,2019.The clinical data was analyzed. Flow cytometry was used to detect the patient's peripheral blood lymphocyte subsets, and also, the percentage of follicular helper T cell (TFH) cells in the patient and thirteen healthy controls. After the construction of empty vector, wild-type and mutant plasmid vectors, a wild-type or mutant overexpression system of the TNFAIP3 gene was established in 293T cells and Hela cells. Then, the expression level of A20 in 293T cells and the expression of inhibitor K binding α (IKBα) in green fluorescent protein (GFP)+Hela cells before and after tumor necrosis factor α (TNF-α) stimulation were measured, to verify the pathogenicity of this variation. Results: A 5 years and 11 months old boy, presented with recurrent oral ulcer, abdominal pain, joint swelling and arthralgia. Oral ulcer, chronic skin rashes, knee joint swelling were observed. The levels of inflammatory markers were increased. Colonoscopy showed congestion of mucosa and multiple ulcers in terminal ileum and ileocecus. The absolute number of naive B cells was 124×10(6) cells/L (reference range 147×10(6)-431×10(6) cells/L), accounting for 0.430 of the total B cells (reference range 0.484-0.758). Compared to healthy controls (0.016-0.071), the percentage of TFH cells in CD4(+)T cells was much lower (0.008).A heterozygous mutation of TNFAIP3 gene (c.909_913 del, p.L303fs) was identified by genetic analysis. In vitro study showed that truncated A20 protein was expressed in TNFAIP3 mutant overexpressed 293T cells, which verified the pathogenicity of this variation. Besides, after TNF-α stimulation, the degradation rate of IkBα protein in mutant overexpressed Hela cells (35%) was between the other two groups (15% in the wild-type group and 57% in the non-loaded group). Conclusions: This case with HA20 due to a de novo TNFAIP3 gene mutation presents with early onset Behcet-like autoinflammatory syndrome. This variation leads to expression of truncated A20 protein, enhanced degradation of IkBα, and further activation of nuclear factor κB signaling pathway.


Assuntos
Doenças Autoimunes , Haploinsuficiência , NF-kappa B , Proteína 3 Induzida por Fator de Necrose Tumoral alfa , Doenças Autoimunes/diagnóstico , Doenças Autoimunes/genética , Pré-Escolar , Haploinsuficiência/genética , Células HeLa , Heterozigoto , Humanos , Masculino , Fenótipo , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética
7.
Clin Dysmorphol ; 29(2): 97-100, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-31929334

RESUMO

Deletion of the 1q43q44 chromosomal region has been related to a clinical syndrome characterized by neurodevelopmental delay, intellectual disability, microcephaly, congenital abnormality of the corpus callosum, and epilepsy and dysmorphic features. A wide variability of the clinical features have been linked to the contiguous deleted genes and incomplete penetrance has been observed too. Here, we report a 4-years-old boy with microcephaly, neurodevelopmental delay, and cardiac atrial septal defect, who had a de-novo 117 Kb 1q43-q44 microdeletion. The deleted chromosomal region encompassed the two genes SDCCAG8 and AKT3. The characteristics of the deletion and the clinical condition of the patient suggest a pathogenic role of the 1q43-q44 deletion, supporting a pivotal role of AKT3 gene in the expression of the clinical phenotype.


Assuntos
Deleção Cromossômica , Cromossomos Humanos Par 1 , Haploinsuficiência/genética , Microcefalia/diagnóstico , Microcefalia/genética , Proteínas Proto-Oncogênicas c-akt/genética , Transtornos Psicomotores/diagnóstico , Transtornos Psicomotores/genética , Pré-Escolar , Hibridização Genômica Comparativa , Estudos de Associação Genética , Predisposição Genética para Doença , Humanos , Masculino
8.
Oncogene ; 39(1): 176-186, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31462704

RESUMO

Somatic missense mutations of the CSNK1A1 gene encoding casein kinase 1 alpha (CK1α) occur in a subset of myelodysplastic syndrome (MDS) with del(5q) karyotype. The chromosomal deletion causes CSNK1A1 haplo-insufficiency. CK1α mutations have also been observed in a variety of solid and hematopoietic tumors at low frequency. The functional consequence of CK1α mutation remains unknown. Here we show that tumor-associated CK1α mutations exclusively localize to the substrate-binding cleft. Functional analysis of recurrent mutants E98K and D140A revealed enhanced binding to the p53 inhibitor MDMX, increased ability to stimulate MDMX-p53 binding, and increased suppression of p21 expression. Furthermore, E98K and D140A mutants have reduced ability to promote phosphorylation of ß-catenin, resulting in enhanced Wnt signaling. The results suggest that the CK1α mutations observed in tumors cause gain-of-function in cooperating with MDMX and inhibiting p53, and partial loss-of-function in suppressing Wnt signaling. These functional changes may promote expansion of abnormal myeloid progenitors in del(5q) MDS, and in rare cases drive the progression of other tumors.


Assuntos
Caseína Quinase Ialfa/genética , Síndromes Mielodisplásicas/genética , Proteínas Proto-Oncogênicas c-mdm2/genética , Proteína Supressora de Tumor p53/genética , Animais , Linhagem Celular Tumoral , Deleção Cromossômica , Haploinsuficiência/genética , Xenoenxertos , Humanos , Camundongos , Mutação de Sentido Incorreto/genética , Síndromes Mielodisplásicas/patologia , Fosforilação/genética , Ligação Proteica/genética , Via de Sinalização Wnt/genética , beta Catenina/genética
9.
Neurobiol Aging ; 85: 154.e9-154.e11, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31262553

RESUMO

GRN null mutations are among the main genetic causes of frontotemporal dementia through progranulin haploinsufficiency. Most missense mutations are considered not pathogenic. The p.Trp7Arg substitution is localized within the signal peptide domain and no formal evidence for its pathogenicity has yet been provided. We identified the p.Trp7Arg substitution in 3 carriers with low plasma progranulin levels. This evidences that this missense mutation leads to functional haploinsufficiency and should thus be considered pathogenic. Assessing the pathogenicity of variants of unknown significance has significant implications for clinical practice, genetic counseling, and future therapeutic interventions.


Assuntos
Demência Frontotemporal/etiologia , Haploinsuficiência/genética , Mutação de Sentido Incorreto , Progranulinas/genética , Proteína C9orf72/genética , Proteínas de Ligação a DNA/genética , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
10.
Rev. neurol. (Ed. impr.) ; 69(12): 492-496, 16 dic., 2019. ilus, tab
Artigo em Espanhol | IBECS | ID: ibc-187118

RESUMO

Introducción: La etiología del retraso mental autosómico dominante 1, también conocido como pseudo-Angelman, trastorno del neurodesarrollo asociado a MBD5 o haploinsuficiencia MBD5, radica en una microdeleción del cromosoma 2q23.1 o en una alteración específica del gen MBD5, que constituye la mínima región afectada en la citada microdeleción. Objetivo: Comunicar el caso de una niña con una mutación heterocigota y de novo en el gen MBD5 asociada a heterotopía en banda bilateral y polimicrogiria. Caso clínico: Niña de 8 años, seguida evolutivamente desde los 18 meses por presentar la asociación de discapacidad intelectual y retraso motor graves, ausencia de desarrollo del lenguaje, hipotonía segmentaria, frente ancha y cifoescoliosis. En la resonancia magnética cerebral se observó la presencia de una heterotopía en banda bilateral y polimicrogiria parietooccipital de predominio izquierdo. En el exoma se detectó la variante de novo c.397+1G > C en heterocigosis en el gen MBD5. Conclusión: Constituye la primera observación con una mutación heterocigota en el gen MBD5 asociada a un trastorno en la migración neuronal


Introduction: The aetiology of autosomal dominant mental retardation type 1, also known as pseudo-Angelman, MBD5-associated neurodevelopmental disorder or MBD5 haploinsufficiency, lies in a microdeletion of chromosome 2q23.1 or in a specific alteration of the MBD5 gene, which constitutes the minimum region affected in the aforementioned microdeletion. Aim: To report the case of a girl with a heterozygous de novo mutation in the MBD5 gene associated with bilateral band heterotopia and polymicrogyria. Case Report: We report the case of an 8-year-old girl who was submitted to a developmental follow-up from the age of 18 months after presenting the association of severe intellectual disability and motor delay, lack of language development, segmental hypotonia, a wide forehead and kyphoscoliosis. Magnetic resonance imaging of the brain revealed the presence of a bilateral band heterotopia and parietooccipital polymicrogiria predominant on the left side. In the exome the de novo heterozygous variant c.397+1G > C was detected in the MBD5 gene. Conclusion: This is the first observation of a heterozygous mutation in the MBD5 gene associated with a neuronal migration disorder


Assuntos
Humanos , Feminino , Criança , Lissencefalias Clássicas e Heterotopias Subcorticais em Banda/genética , Polimicrogiria/complicações , Deficiência Intelectual/diagnóstico , Transtornos do Desenvolvimento da Linguagem/complicações , Haploinsuficiência/genética , Polimicrogiria/genética , Transtornos do Desenvolvimento da Linguagem/genética , Lissencefalias Clássicas e Heterotopias Subcorticais em Banda/diagnóstico por imagem , Neuroimagem
11.
Ital J Pediatr ; 45(1): 100, 2019 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-31412912

RESUMO

Children with chromosome translocations, concerning X chromosome, have a genetic pattern different from Turner syndrome; however, when a translocation involves the of part of X chromosome including short stature homeobox-containing Sex-determining Region Y gene, growth may be severely compromised.We describe the clinical case of a 2.2-year-old-female, arrived at our paediatric unit for a decrease of height velocity. The karyotype was 46,XX,add(X)(p36.3). Array comparative genomic hybridization showed a fragment of Y chromosome, extended from 8.803.981 (Yp11.2) to 28.767.604 (Yq11.23). The final karyotype was 46,XX,add(X)(p36),t(X;Y)(p36.3;p11.2). Fluorescence in situ Hybridization analysis using Sex-determining Region Y probe revealed no signal on the derivative Y chromosome.At the admittance, height was 84.5 cm (- 1.24 SDS); SPAN was 79 cm; sitting height: 72.4 cm; weight was 17.5 kg. Bone age was 1.2 years. Multiplex Ligation Probe Amplification showed a heterozygous deletion of the Short Stature Homeobox-containing gene and of the pseudoautosomal region-1. This result correlated with Leri-Weill Syndrome. She started Growth Hormone treatment, with a good response.The case described shows a rare translocation, involving the X chromosome and including SHOX gene and the pseudoautosomal region-1. At our knowledge, this is the first case of a patient with a karyotype 46,XX,add(X)(p36),t(X;Y)(p36.3;p11.2) and Short Stature Homeobox-containing gene haploinsufficiency, successfully treated with Growth Hormone.


Assuntos
Transtornos do Crescimento/tratamento farmacológico , Transtornos do Crescimento/genética , Haploinsuficiência/genética , Hormônio do Crescimento Humano/uso terapêutico , Proteína de Homoeobox de Baixa Estatura/genética , Pré-Escolar , Hibridização Genômica Comparativa , Feminino , Humanos , Hibridização in Situ Fluorescente , Itália , Cariotipagem
12.
Int J Mol Sci ; 20(17)2019 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-31438494

RESUMO

Human variants in plakophilin-2 (PKP2) associate with most cases of familial arrhythmogenic cardiomyopathy (ACM). Recent studies show that PKP2 not only maintains intercellular coupling, but also regulates transcription of genes involved in Ca2+ cycling and cardiac rhythm. ACM penetrance is low and it remains uncertain, which genetic and environmental modifiers are crucial for developing the cardiomyopathy. In this study, heterozygous PKP2 knock-out mice (PKP2-Hz) were used to investigate the influence of exercise, pressure overload, and inflammation on a PKP2-related disease progression. In PKP2-Hz mice, protein levels of Ca2+-handling proteins were reduced compared to wildtype (WT). PKP2-Hz hearts exposed to voluntary exercise training showed right ventricular lateral connexin43 expression, right ventricular conduction slowing, and a higher susceptibility towards arrhythmias. Pressure overload increased levels of fibrosis in PKP2-Hz hearts, without affecting the susceptibility towards arrhythmias. Experimental autoimmune myocarditis caused more severe subepicardial fibrosis, cell death, and inflammatory infiltrates in PKP2-Hz hearts than in WT. To conclude, PKP2 haploinsufficiency in the murine heart modulates the cardiac response to environmental modifiers via different mechanisms. Exercise upon PKP2 deficiency induces a pro-arrhythmic cardiac remodeling, likely based on impaired Ca2+ cycling and electrical conduction, versus structural remodeling. Pathophysiological stimuli mainly exaggerate the fibrotic and inflammatory response.


Assuntos
Cálcio/metabolismo , Cardiomiopatias/metabolismo , Haploinsuficiência/fisiologia , Doença Autoimune do Sistema Nervoso Experimental/etiologia , Doença Autoimune do Sistema Nervoso Experimental/metabolismo , Placofilinas/metabolismo , Animais , Western Blotting , Cardiomiopatias/etiologia , Cardiomiopatias/patologia , Ecocardiografia , Eletrocardiografia , Fibrose/etiologia , Fibrose/metabolismo , Fibrose/patologia , Haploinsuficiência/genética , Imuno-Histoquímica , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Doença Autoimune do Sistema Nervoso Experimental/patologia , Placofilinas/genética , Reação em Cadeia da Polimerase
13.
Dis Model Mech ; 12(8)2019 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-31439573

RESUMO

Amyotrophic lateral sclerosis (ALS) is a late-onset neuromuscular disease with no cure and limited treatment options. Patients experience a gradual paralysis leading to death from respiratory complications on average only 2-5 years after diagnosis. There is increasing evidence that skeletal muscle is affected early in the disease process, yet the pathological processes occurring in the skeletal muscle of ALS patients are still mostly unknown. Specifically, the most common genetic cause of ALS, a hexanucleotide repeat expansion in the C9ORF72 gene, has yet to be fully characterized in the context of skeletal muscle. In this study, we used the protocol previously developed in our lab to differentiate skeletal myocytes from induced pluripotent stem cells (iPSCs) of C9ORF72 ALS (C9-ALS) patients in order to create an in vitro disease model of C9-ALS skeletal muscle pathology. Of the three C9ORF72 mutation hallmarks, we did not see any evidence of haploinsufficiency, but we did detect RNA foci and dipeptide repeat (DPR) proteins. Additional abnormalities included changes in the expression of mitochondrial genes and a susceptibility to oxidative stress, indicating that mitochondrial dysfunction may be a critical feature of C9-ALS skeletal muscle pathology. Finally, the C9-ALS myocytes had increased expression and aggregation of TDP-43. Together, these data show that skeletal muscle cells experience pathological changes due to the C9ORF72 mutation. Our in vitro model could facilitate further study of cellular and molecular pathology in ALS skeletal muscle in order to discover new therapeutic targets against this devastating disease.This article has an associated First Person interview with the first author of the paper.


Assuntos
Esclerose Amiotrófica Lateral/patologia , Proteína C9orf72/metabolismo , Células-Tronco Pluripotentes Induzidas/patologia , Fibras Musculares Esqueléticas/metabolismo , Fibras Musculares Esqueléticas/patologia , Diferenciação Celular , Linhagem Celular , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica , Haploinsuficiência/genética , Humanos , Células-Tronco Pluripotentes Induzidas/metabolismo , Mitocôndrias/metabolismo , Fibras Musculares Esqueléticas/ultraestrutura , Estresse Oxidativo , Agregados Proteicos , RNA/metabolismo
15.
Invest Ophthalmol Vis Sci ; 60(10): 3283-3296, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31369031

RESUMO

Purpose: Glaucoma is a complex disease with major risk factors including advancing age and increased intraocular pressure (IOP). Dissecting these earliest events will likely identify new avenues for therapeutics. Previously, we performed transcriptional profiling in DBA/2J (D2) mice, a widely used mouse model relevant to glaucoma. Here, we use these data to identify and test regulators of early gene expression changes in DBA/2J glaucoma. Methods: Upstream regulator analysis (URA) in Ingenuity Pathway Analysis was performed to identify potential master regulators of differentially expressed genes. The function of one putative regulator, mesenchyme homeobox 2 (Meox2), was tested using a combination of genetic, biochemical, and immunofluorescence approaches. Results: URA identified Meox2 as a potential regulator of early gene expression changes in the optic nerve head (ONH) of DBA/2J mice. Meox2 haploinsufficiency did not affect the characteristic diseases of the iris or IOP elevation seen in DBA/2J mice but did cause a significant increase in the numbers of eyes with axon damage compared to controls. While young mice appeared normal, aged Meox2 haploinsufficient DBA/2J mice showed a 44% reduction in MEOX2 protein levels. This correlated with modulation of age- and disease-specific vascular and myeloid alterations. Conclusions: Our data support a model whereby Meox2 controls IOP-dependent vascular remodeling and neuroinflammation to promote axon survival. Promoting these earliest responses prior to IOP elevation may be a viable neuroprotective strategy to delay or prevent human glaucoma.


Assuntos
Axônios/patologia , Glaucoma/genética , Haploinsuficiência/genética , Proteínas de Homeodomínio/genética , Degeneração Neural/genética , Disco Óptico/patologia , Células Ganglionares da Retina/patologia , Animais , Pressão Sanguínea/fisiologia , Western Blotting , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica/fisiologia , Glaucoma/patologia , Pressão Intraocular/fisiologia , Masculino , Camundongos , Camundongos Endogâmicos DBA , Degeneração Neural/patologia , Microscopia com Lâmpada de Fenda
16.
BMC Med Genet ; 20(1): 124, 2019 07 12.
Artigo em Inglês | MEDLINE | ID: mdl-31299923

RESUMO

BACKGROUND: The association between mutations in the TNFAIP3 gene and a new autoinflammatory disease (called A20 haploinsufficiency, HA20) has recently been recognized. Here, we describe four patients with HA20 from two unrelated Chinese families. CASE PRESENTATION: A total of four patients from two families were included. The average age at onset was 5.9 years. All patients had no signs of eye or skin problems, such as uveitis, rash, folliculitis and dermal abscess. Prior to the recognition of HA20, P1 was diagnosed with SLE, liver fibrosis and hypothyroidism. She also had no oral, genital or perineal ulcers. P2 was diagnosed with Crohn's disease and inflammatory bowel disease-related arthritis (IBD-RA). He had a perianal abscess but no oral or genital ulcers. P3, the father of P1 and P2, only had mild oral ulcers, arthralgia, and archosyrinx. P4 was diagnosed with polyarticular juvenile idiopathic arthritis (JIA), macrophage activation syndrome (MAS) and interstitial lung disease (ILD). Whole exome sequencing (WES) was performed in two families. WES revealed heterozygous c.559C > T in the TNFAIP3 gene in P1, P2 and P3, while the c.259C > T mutation in the TNFAIP3 gene was identified in P4. The c.259C > T mutations is novel. CONCLUSION: HA20 had a different phenotype between families and even between family members with the same mutation. Liver fibrosis, hypothyroidism, ILD and MAS in the patients with HA20 were first reported in this study. Our results expanded the phenotype and genotype spectrum of A20 haploinsufficiency.


Assuntos
Grupo com Ancestrais do Continente Asiático/genética , Predisposição Genética para Doença/genética , Haploinsuficiência/genética , Proteína 3 Induzida por Fator de Necrose Tumoral alfa/genética , Artralgia , Artrite , Artrite Juvenil , Sequência de Bases , Criança , Pré-Escolar , Feminino , Heterozigoto , Humanos , Hipotireoidismo , Doenças Inflamatórias Intestinais , Cirrose Hepática/patologia , Doenças Pulmonares Intersticiais , Síndrome de Ativação Macrofágica , Masculino , Mutação , Úlceras Orais , Linhagem , Fenótipo , Sequenciamento Completo do Exoma
17.
Genet Med ; 21(12): 2755-2764, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31263215

RESUMO

PURPOSE: Haploinsufficiency of DYRK1A causes a recognizable clinical syndrome. The goal of this paper is to investigate congenital anomalies of the kidney and urinary tract (CAKUT) and genital defects (GD) in patients with DYRK1A variants. METHODS: A large database of clinical exome sequencing (ES) was queried for de novo DYRK1A variants and CAKUT/GD phenotypes were characterized. Xenopus laevis (frog) was chosen as a model organism to assess Dyrk1a's role in renal development. RESULTS: Phenotypic details and variants of 19 patients were compiled after an initial observation that one patient with a de novo pathogenic variant in DYRK1A had GD. CAKUT/GD data were available from 15 patients, 11 of whom presented with CAKUT/GD. Studies in Xenopus embryos demonstrated that knockdown of Dyrk1a, which is expressed in forming nephrons, disrupts the development of segments of embryonic nephrons, which ultimately give rise to the entire genitourinary (GU) tract. These defects could be rescued by coinjecting wild-type human DYRK1A RNA, but not with DYRK1AR205* or DYRK1AL245R RNA. CONCLUSION: Evidence supports routine GU screening of all individuals with de novo DYRK1A pathogenic variants to ensure optimized clinical management. Collectively, the reported clinical data and loss-of-function studies in Xenopus substantiate a novel role for DYRK1A in GU development.


Assuntos
Deficiência Intelectual/genética , Proteínas Serina-Treonina Quinases/genética , Proteínas Tirosina Quinases/genética , Anormalidades Urogenitais/genética , Adolescente , Adulto , Animais , Criança , Pré-Escolar , Bases de Dados Genéticas , Modelos Animais de Doenças , Exoma/genética , Feminino , Haploinsuficiência/genética , Humanos , Deficiência Intelectual/complicações , Rim/anormalidades , Rim/embriologia , Masculino , Néfrons/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/metabolismo , Sistema Urinário/embriologia , Sistema Urinário/metabolismo , Sequenciamento Completo do Exoma/métodos , Xenopus laevis/genética , Xenopus laevis/metabolismo , Adulto Jovem
18.
Stem Cell Res ; 39: 101488, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31272037

RESUMO

Autism spectrum disorders (ASDs) are a group of diseases that affect social interaction, communication and behavior. Molecular mechanisms involved in the pathogenesis of ASDs are complex due to genetic heterogeneity. Recently, pathogenic variants of SCN2A have been strongly associated with ASDs. Here, we generated iPSCs from a patient with ASD and a heterozygous nonsense mutation in SCN2A, by reprogramming mesenchymal stromal cells with non-integrating vectors. The generated iPSC line expresses pluripotency markers, presents a normal karyotype and is able to differentiate into the three germ layers. This iPSC line is a useful tool for modeling ASD and drug screening studies.


Assuntos
Transtorno do Espectro Autista/metabolismo , Células-Tronco Pluripotentes Induzidas/citologia , Células-Tronco Pluripotentes Induzidas/metabolismo , Canal de Sódio Disparado por Voltagem NAV1.2/genética , Transtorno do Espectro Autista/genética , Linhagem Celular , Reprogramação Celular/genética , Reprogramação Celular/fisiologia , Citometria de Fluxo , Haploinsuficiência/genética , Haploinsuficiência/fisiologia , Humanos , Cariótipo , Repetições de Microssatélites/genética , Mutação/genética , Reação em Cadeia da Polimerase em Tempo Real
19.
Nature ; 572(7769): 335-340, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31316208

RESUMO

Lamin A/C (LMNA) is one of the most frequently mutated genes associated with dilated cardiomyopathy (DCM). DCM related to mutations in LMNA is a common inherited cardiomyopathy that is associated with systolic dysfunction and cardiac arrhythmias. Here we modelled the LMNA-related DCM in vitro using patient-specific induced pluripotent stem cell-derived cardiomyocytes (iPSC-CMs). Electrophysiological studies showed that the mutant iPSC-CMs displayed aberrant calcium homeostasis that led to arrhythmias at the single-cell level. Mechanistically, we show that the platelet-derived growth factor (PDGF) signalling pathway is activated in mutant iPSC-CMs compared to isogenic control iPSC-CMs. Conversely, pharmacological and molecular inhibition of the PDGF signalling pathway ameliorated the arrhythmic phenotypes of mutant iPSC-CMs in vitro. Taken together, our findings suggest that the activation of the PDGF pathway contributes to the pathogenesis of LMNA-related DCM and point to PDGF receptor-ß (PDGFRB) as a potential therapeutic target.


Assuntos
Cardiomiopatia Dilatada/genética , Lamina Tipo A/genética , Mutação , Fator de Crescimento Derivado de Plaquetas/metabolismo , Receptor beta de Fator de Crescimento Derivado de Plaquetas/metabolismo , Transdução de Sinais , Arritmias Cardíacas/metabolismo , Arritmias Cardíacas/patologia , Cálcio/metabolismo , Células Cultivadas , Cromatina/química , Cromatina/genética , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina/genética , Haploinsuficiência/genética , Homeostase , Humanos , Técnicas In Vitro , Células-Tronco Pluripotentes Induzidas/patologia , Modelos Biológicos , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Degradação do RNAm Mediada por Códon sem Sentido , RNA Mensageiro/análise , RNA Mensageiro/genética , Análise de Célula Única
20.
G3 (Bethesda) ; 9(9): 2835-2850, 2019 09 04.
Artigo em Inglês | MEDLINE | ID: mdl-31270132

RESUMO

Loss of heterozygosity (LOH) is a phenomenon commonly observed in cancers; the loss of chromosomal regions can be both causal and indicative of underlying genome instability. Yeast has long been used as a model organism to study genetic mechanisms difficult to study in mammalian cells. Studying gene deletions leading to increased LOH in yeast aids our understanding of the processes involved, and guides exploration into the etiology of LOH in cancers. Yet, before in-depth mechanistic studies can occur, candidate genes of interest must be identified. Utilizing the heterozygous Saccharomyces cerevisiae deletion collection (≈ 6500 strains), 217 genes whose disruption leads to increased LOH events at the endogenously heterozygous mating type locus were identified. Our investigation to refine this list of genes to candidates with the most definite impact on LOH includes: secondary testing for LOH impact at an additional locus, gene ontology analysis to determine common gene characteristics, and positional gene enrichment studies to identify chromosomal regions important in LOH events. Further, we conducted extensive comparisons of our data to screens with similar, but distinct methodologies, to further distinguish genes that are more likely to be true contributors to instability due to their reproducibility, and not just identified due to the stochastic nature of LOH. Finally, we selected nine candidate genes and quantitatively measured their impact on LOH as a benchmark for the impact of genes identified in our study. Our data add to the existing body of work and strengthen the evidence of single-gene knockdowns contributing to genome instability.


Assuntos
Deleção de Genes , Instabilidade Genômica , Perda de Heterozigosidade , Proteínas de Saccharomyces cerevisiae/genética , Saccharomyces cerevisiae/genética , Cromossomos Fúngicos , Cisteína Sintase/genética , Ontologia Genética , Genoma Fúngico , Haploinsuficiência/genética , Humanos , Neoplasias/genética , Reprodutibilidade dos Testes
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