Your browser doesn't support javascript.
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 69.389
Filtrar
1.
J Agric Food Chem ; 68(2): 530-540, 2020 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-31891490

RESUMO

The influence of ß-hydroxy-ß-methylbutyrate (HMB) on proliferation and differentiation of myogenic cells has been well-studied. However, the role of HMB in myofiber specification and potential mechanisms is largely unknown. Thus, the objective of this research was to explore the role of HMB supplementation in myofiber specification. Results showed that HMB treatment significantly increased the fast MyHC protein level (mice: 1.59 ± 0.08, P < 0.01; C2C12: 2.26 ± 0.11, P < 0.001), decreased the slow MyHC protein level (mice: 0.76 ± 0.05, P < 0.05; C2C12: 0.52 ± 0.02, P < 0.001), and increased the miR-199a-3p level (mice: 4.93 ± 0.37, P < 0.001; C2C12: 11.25 ± 0.57, P < 0.001). Besides, we also observed that HMB promoted the activity of glycolysis-related enzymes and reduced the activities of oxidation-related enzymes in mice and C2C12 cells. Overexpression of miR-199a-3p downregulated the slow MyHC protein level (0.71 ± 0.02, P < 0.01) and upregulated the fast MyHC protein level (2.13 ± 0.09, P < 0.001), while repression of miR-199a-3p exhibited the opposite effect. Target identification results verified that miR-199a-3p targets the 3'UTR of the TEA domain family member 1 (TEAD1) to cause its post-transcriptional inhibition (0.41 ± 0.07, P < 0.01). Knockdown of TEAD1 exhibited a similar effect with miR-199a-3p on myofiber specification. Moreover, suppression of miR-199a-3p blocked slow-to-fast myofiber type transition induced by HMB. Together, our finding revealed that miR-199-3p is induced by HMB and contributes to the action of HMB on slow-to-fast myofiber type conversion via targeting TEAD1.


Assuntos
MicroRNAs/metabolismo , Fibras Musculares Esqueléticas/efeitos dos fármacos , Mioblastos Esqueléticos/efeitos dos fármacos , Valeratos/farmacologia , Regiões 3' não Traduzidas , Animais , Diferenciação Celular/efeitos dos fármacos , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Camundongos , MicroRNAs/genética , Fibras Musculares Esqueléticas/citologia , Fibras Musculares Esqueléticas/metabolismo , Mioblastos Esqueléticos/citologia , Mioblastos Esqueléticos/metabolismo , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação para Cima/efeitos dos fármacos
2.
Biosci Biotechnol Biochem ; 84(1): 76-84, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31478783

RESUMO

The circadian clock enables plants to adapt to their environment and control numerous physiological processes, including plant-pathogen interactions. However, it is unknown if the circadian clock controls nonhost resistance (NHR) in plants. To find out, we analyzed microarray data with the web-based tool DIURNAL to reveal that NHR-related genes show rhythmic expression patterns in the absence of a pathogen challenge. Our clock mutant analyses found that cca1-1 lhy-11 double mutant showed compromised NHR to Pyricularia oryzae, suggesting that two components of the circadian clock, CCA1 and LHY, are involved in regulating penetration resistance in Arabidopsis thaliana. By analyzing pen2 double mutants, we revealed that CCA1 contributes to time-of-day-dependent penetration resistance as a positive regulator and that LHY regulates post-penetration resistance as a positive regulator. Taken together, our results suggest that the circadian clock regulates the time-of-day-dependent NHR to P. oryzae and thus enables A. thaliana to counteract pathogen attacks.Abbreviations: EE: evening element; ETI: effector-triggered immunity; NHR: nonhost resistance; PAMP: pathogen-associated molecular pattern; PTI: PAMP-triggered immunity; SAR: systemic acquired resistance.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/microbiologia , Relógios Circadianos/genética , Ritmo Circadiano/genética , Proteínas de Ligação a DNA/genética , Resistência à Doença/genética , Magnaporthe/fisiologia , Fatores de Transcrição/genética , Regulação da Expressão Gênica de Plantas , Genótipo , Interações Hospedeiro-Patógeno , Mutação , N-Glicosil Hidrolases/genética , Fotoperíodo , Folhas de Planta/microbiologia , Temperatura Ambiente
3.
Equine Vet J ; 52(1): 34-40, 2020 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30903710

RESUMO

BACKGROUND: Belgian horses are commonly affected with ocular squamous cell carcinoma (SCC), the most common cancer of the equine eye. A missense mutation in damage-specific DNA binding protein 2 (DDB2 c.1013C>T, p.Thr338Met) has been established as a recessive genetic risk factor for ocular SCC in the Haflinger breed. A sample of Belgian horses with unknown SCC phenotype was shown to possess this variant at a similar frequency to the Haflinger breed. Retrospective studies indicate that chestnut coat colour may predispose to the development of SCC. OBJECTIVES: To determine if DDB2 c.1013C>T is a risk factor for ocular SCC in a strictly phenotyped sample of Belgian horses. To investigate associations between coat colour loci genotypes and ocular SCC. STUDY DESIGN: Retrospective and prospective case identification, genetic investigation. METHODS: Genomic DNA was isolated from blood, hair or formalin-fixed paraffin-embedded tissue from 25 Belgian horses with histologically confirmed ocular SCC and 18 unaffected Belgian horses. Association testing of 34 single nucleotide variants from 11 genomic loci and genotyping for DDB2 c.1013C>T and coat colour alleles were performed. Exons of DDB2 were sequenced in four cases and two controls. Associations were analysed by Chi-square or Fisher's exact tests and relative risk was calculated. RESULTS: Homozygosity for DDB2 c.1013C>T was significantly associated with ocular SCC (P = 7.4 × 10-7 ). Seventy-six per cent of affected horses were homozygous for the variant. Relative risk for homozygous horses developing SCC was 4.0 (P = 1.0 × 10-4 ). Sequencing DDB2 did not identify a variant more concordant with disease phenotype. An association between disease and coat colour loci was not identified. MAIN LIMITATIONS: Phenotyping was determined at a single timepoint. Each included horse genotyped as chestnut, so association with this MC1R variant could not be investigated. CONCLUSIONS: A missense variant, DDB2 c.1013C>T, p.Thr338Met, is a risk factor for ocular SCC in Belgian horses. A genetic risk test is commercially available.


Assuntos
Carcinoma de Células Escamosas/veterinária , Proteínas de Ligação a DNA/genética , Neoplasias Oculares/veterinária , Predisposição Genética para Doença , Doenças dos Cavalos/genética , Mutação de Sentido Incorreto , Animais , Cavalos
4.
J Surg Oncol ; 120(8): 1427-1435, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31729037

RESUMO

BACKGROUND AND OBJECTIVES: Mucinous adenocarcinoma is a distinct subtype of colorectal cancer (CRC) with a worse prognosis when compared with non-mucinous adenocarcinoma. The aim of this study was to compare somatic mutations and copy number alteration (CNA) between mucinous and non-mucinous CRC. METHODS: Data from The Cancer Genome Atlas-colon adenocarcinoma and rectum adenocarcinoma projects were utilized. Mucinous and non-mucinous CRC were compared with regard to microsatellite status, overall mutation rate, the most frequently mutated genes, mutations in genes coding for mismatch repair (MMR) proteins and genes coding for mucin glycoproteins. CNA analysis and pathway analysis was undertaken. RESULTS: Mucinous CRC was more likely to be microsatellite instability-high (MSI-H) and hypermutated. When corrected for microsatellite status the single-nucleotide variation and insertion-deletion rate was similar between the two cohorts. Mucinous adenocarcinoma was more likely to have mutations in genes coding for MMR proteins and mucin glycoproteins. Pathway analysis revealed further differences between the two histological subtypes in the cell cycle, RTK-RAS, transforming growth factor-ß, and TP53 pathways. CONCLUSIONS: Mucinous CRC has some distinct genomic aberrations when compared with non-mucinous adenocarcinoma, many of which are driven by the increased frequency of MSI-H tumors. These genomic aberrations may play an important part in the difference seen in response to treatment and prognosis in mucinous adenocarcinoma.


Assuntos
Adenocarcinoma Mucinoso/genética , Adenocarcinoma/genética , Neoplasias do Colo/genética , Genômica , Neoplasias Retais/genética , Adenocarcinoma/patologia , Adenocarcinoma Mucinoso/patologia , Estudos de Coortes , Neoplasias do Colo/patologia , Variações do Número de Cópias de DNA , Proteínas de Ligação a DNA/genética , Conjuntos de Dados como Assunto , Regulação Neoplásica da Expressão Gênica , Humanos , Mutação INDEL , Instabilidade de Microssatélites , Mucinas/genética , Mutação , Polimorfismo de Nucleotídeo Único , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas p21(ras)/genética , Neoplasias Retais/patologia , Proteína Smad4/genética , Fator de Crescimento Transformador beta/genética , Proteína Supressora de Tumor p53/genética
5.
Brain Nerve ; 71(11): 1289-1301, 2019 Nov.
Artigo em Japonês | MEDLINE | ID: mdl-31722315

RESUMO

Protein misfolding crucially underlies the pathogenesis of amyotrophic lateral sclerosis (ALS). Mutant superoxide dismutase 1 (SOD1) and TAR DNA-binding protein 43kDa (TDP-43) are major causal proteins for familial and sporadic ALS, respectively, provoking diverse pathogenic pathways in both intracellular and extracellular environments. Of note, cell-to-cell spreading behavior is implicated in the progression of neurodegeneration, suggesting application in immunotherapies including vaccination, and antibody application as a molecular targeting therapy, due to strict antigen-specificity. Although immunotherapy of intravenous application of full-length immunoglobulin is aimed at targeting the extracellular proteins because of low access to the cytosol, it is therefore necessary to generate expression vectors for variable single chain fragments (scFv) that target intracellular proteins. Despite the advantages of scFv, such as low molecular size and the ability to apply molecular modifications adding proteolytic signals, safety and efficacy should be cautiously estimated in preclinical studies, using appropriate animal models. In ALS, we firstly succeeded in the vaccination of mutant SOD1 transgenic mice, which was followed by accumulating evidence showing the efficacy of immunization against misfolded SOD1. In TDP-43 proteinopathy, we are developing immunotherapy using intrabodies with proteolytic properties against mislocalized or aggregated forms of TDP-43 inside cells.


Assuntos
Esclerose Amiotrófica Lateral/terapia , Imunoterapia , Animais , Proteínas de Ligação a DNA/genética , Camundongos , Camundongos Transgênicos , Mutação , Dobramento de Proteína , Superóxido Dismutase-1/genética
6.
Zhonghua Yi Xue Yi Chuan Xue Za Zhi ; 36(10): 993-995, 2019 Oct 10.
Artigo em Chinês | MEDLINE | ID: mdl-31598943

RESUMO

OBJECTIVE: To explore the genetic etiology of a pedigree affected with tricho-rhino-phalangeal syndrome. METHODS: Next-generation sequencing (NGS) using a gene panel for hereditary osteopathies was carried out for the proband. Suspected mutation was validated in the proband and her parents by Sanger sequencing. RESULTS: A heterozygous frameshift variation c.1995dupA (p.Gly666Argfs*20) of the TRPS1 gene was detected in the proband but not in her parents. CONCLUSION: The novel c.1995dupA (p.Gly666Argfs*20) mutation of the TRPS1 gene probably underlies the disease in the proband.


Assuntos
Proteínas de Ligação a DNA/genética , Dedos/anormalidades , Mutação da Fase de Leitura , Doenças do Cabelo/genética , Síndrome de Langer-Giedion/genética , Nariz/anormalidades , Fatores de Transcrição/genética , Feminino , Humanos , Linhagem
7.
DNA Cell Biol ; 38(11): 1374-1386, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31599655

RESUMO

This study was conducted using TagSNPs to systematically explore the relationship between ARID5B polymorphisms and the occurrence, clinical characterization, and prognosis of acute myeloid leukemia (AML). A total of 569 unrelated AML patients and 410 healthy individuals from West China were recruited, and ARID5B TagSNPs were genotyped using iMLDR® (improved multiplex ligation detection reaction). It was found that the association of ARID5B polymorphisms with AML was most significant in acute promyelocytic leukemia (APL), and exclusively in males, the mutant alleles of rs6415872, rs2393726, rs7073837, rs10821936, and rs7089424 were found to increase the risk of developing APL in men, the odds ratio (OR) were 1.36, 1.74, 1.45, 1.53, and 1.56 (all p < 0.05), respectively. Haplotype analysis revealed that haplotype [AACCG] increased the risk of male APL with an OR of 1.53 (95% confidence interval: 1.10-2.14, p = 0.012). Besides, there was a strong positive additive interaction between rs6415872 and rs10821936, rs7089424, respectively, and cases attributed to the interaction of rs6415872, rs10821936, and rs7089424 accounted for 100%. Furthermore, ARID5B single nucleotide polymorphisms were found associated with clinical features of AML, and rs6415872 was shown to be an independent prognosis factor in APL patients. Besides, dual luciferase report assay showed that rs6415872 may affect the binding activity of PPARG with ARID5B. ARID5B polymorphisms contribute to male APL risk, clinical feature, and prognosis, suggesting the importance of ARDI5B in AML pathogenesis and development, and the gender and subtype preference may prompt some specific mechanisms of ARID5B. Besides, ARID5B polymorphisms might be a potential prognosis biomarker.


Assuntos
Proteínas de Ligação a DNA/genética , Leucemia Promielocítica Aguda/diagnóstico , Leucemia Promielocítica Aguda/genética , Polimorfismo de Nucleotídeo Único , Fatores de Transcrição/genética , Adulto , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Genótipo , Células HEK293 , Humanos , Leucemia Mieloide Aguda/diagnóstico , Leucemia Mieloide Aguda/epidemiologia , Leucemia Mieloide Aguda/genética , Leucemia Promielocítica Aguda/epidemiologia , Desequilíbrio de Ligação , Masculino , Pessoa de Meia-Idade , Prognóstico , Caracteres Sexuais , Análise de Sobrevida
8.
Zhonghua Bing Li Xue Za Zhi ; 48(10): 784-790, 2019 Oct 08.
Artigo em Chinês | MEDLINE | ID: mdl-31594043

RESUMO

Objective: To investigate the histological features and prognostic factors of angioimmunoblastic T-cell lymphoma (AITL). Methods: The pathological data of 62 patients with AITL with complete follow-up information were retrospectively collected and analyzed from Changhai Hospital during September 2012 and September 2017. Histological and immunohistochemical (IHC) examination, in situ hybridization (ISH), and single nucleotide polymorphisms (SNP) gene mutation analysis were done. Subgroup evaluation with histology, IHC, ISH, SNP gene mutation, and association with clinical progression were performed. Results: The cohort included 62 cases of AITL, including 46 males and 16 females patients, with a median age of 64 years. Follicular dendritic cells (FDC) area showed significantly expansion (≥30%) in 40 cases; increased plasma cells (≥10%) was seen in 37 cases; B cells were distributed around blood vessels in 37 cases; and increased p53 mutation positive cells (≥40%) were seen in 39 cases; high Ki-67 index (≥40%) was seen in 39 cases; RHOA mutation was seen in 19 cases; TET2 mutation was seen in 9 cases. Overall survival analysis showed these factors were significantly correlated with tumor prognosis (P<0.05). Multivariate analysis showed that CD38 positive cells<10%, Ki-67≥40%, RHOA and TET2 mutations were risk factors associated with overall survival. Conclusions: AITL could be divided into two different prognostic groups, low-grade and high-grade, with statistically significance outcome, based on the FDC area expansion, degree of plasma cell proliferation, B cells distribution pattern combined with gene mutations and clinical progression. Low-grade malignant group progresses slowly, and high-grade malignant group is highly invasive.


Assuntos
Linfadenopatia Imunoblástica/patologia , Linfoma de Células T/patologia , Proteínas de Ligação a DNA/genética , Células Dendríticas , Feminino , Humanos , Linfadenopatia Imunoblástica/diagnóstico , Hibridização In Situ , Linfoma de Células T/diagnóstico , Masculino , Pessoa de Meia-Idade , Plasmócitos , Polimorfismo de Nucleotídeo Único , Prognóstico , Proteínas Proto-Oncogênicas/genética , Estudos Retrospectivos , Proteína rhoA de Ligação ao GTP/genética
9.
J Chem Phys ; 151(12): 125101, 2019 Sep 28.
Artigo em Inglês | MEDLINE | ID: mdl-31575173

RESUMO

Gene regulation is one of the most important fundamental biological processes in living cells. It involves multiple protein molecules that locate specific sites on DNA and assemble gene initiation or gene repression multimolecular complexes. While the protein search dynamics for DNA targets has been intensively investigated, the role of intermolecular interactions during the genetic activation or repression remains not well quantified. Here, we present a simple one-dimensional model of target search for two interacting molecules that can reversibly form a dimer molecular complex, which also participates in the search process. In addition, the proteins have finite residence times on specific target sites, and the gene is activated or repressed when both proteins are simultaneously present at the target. The model is analyzed using first-passage analytical calculations and Monte Carlo computer simulations. It is shown that the search dynamics exhibit a complex behavior depending on the strength of intermolecular interactions and on the target residence times. We also found that the search time shows a nonmonotonic behavior as a function of the dissociation rate for the molecular complex. Physical-chemical arguments to explain these observations are presented. Our theoretical approach highlights the importance of molecular interactions in the complex process of gene activation/repression by multiple transcription factor proteins.


Assuntos
DNA/química , Modelos Químicos , Simulação por Computador , DNA/genética , DNA/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Cinética , Método de Monte Carlo , Proteína Supressora de Tumor p53/química , Proteína Supressora de Tumor p53/genética , Proteína Supressora de Tumor p53/metabolismo
10.
Nature ; 574(7777): 273-277, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31578525

RESUMO

Transcription and pre-mRNA splicing are key steps in the control of gene expression and mutations in genes regulating each of these processes are common in leukaemia1,2. Despite the frequent overlap of mutations affecting epigenetic regulation and splicing in leukaemia, how these processes influence one another to promote leukaemogenesis is not understood and, to our knowledge, there is no functional evidence that mutations in RNA splicing factors initiate leukaemia. Here, through analyses of transcriptomes from 982 patients with acute myeloid leukaemia, we identified frequent overlap of mutations in IDH2 and SRSF2 that together promote leukaemogenesis through coordinated effects on the epigenome and RNA splicing. Whereas mutations in either IDH2 or SRSF2 imparted distinct splicing changes, co-expression of mutant IDH2 altered the splicing effects of mutant SRSF2 and resulted in more profound splicing changes than either mutation alone. Consistent with this, co-expression of mutant IDH2 and SRSF2 resulted in lethal myelodysplasia with proliferative features in vivo and enhanced self-renewal in a manner not observed with either mutation alone. IDH2 and SRSF2 double-mutant cells exhibited aberrant splicing and reduced expression of INTS3, a member of the integrator complex3, concordant with increased stalling of RNA polymerase II (RNAPII). Aberrant INTS3 splicing contributed to leukaemogenesis in concert with mutant IDH2 and was dependent on mutant SRSF2 binding to cis elements in INTS3 mRNA and increased DNA methylation of INTS3. These data identify a pathogenic crosstalk between altered epigenetic state and splicing in a subset of leukaemias, provide functional evidence that mutations in splicing factors drive myeloid malignancy development, and identify spliceosomal changes as a mediator of IDH2-mutant leukaemogenesis.


Assuntos
Processamento Alternativo/genética , Carcinogênese/genética , Epigênese Genética , Leucemia Mieloide Aguda/genética , Animais , Linhagem Celular Tumoral , Proliferação de Células , Metilação de DNA , Proteínas de Ligação a DNA/genética , Feminino , Regulação Neoplásica da Expressão Gênica , Humanos , Isocitrato Desidrogenase/genética , Masculino , Mutação/genética , RNA Polimerase II/metabolismo , Fatores de Processamento de Serina-Arginina/genética , Transcriptoma
11.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(5): 1574-1579, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31607314

RESUMO

OBJECTIVE: To investigate the relationship between the polymorphism of TET2 gene SNP rs3733609 and JAK2V617F allele burden in patients with myeloproliferative neoplasms (MPN). METHODS: The exon 9 of TET2 gene was amplified by RT-PCR, and the nucleotide sequence of SNP rs3733609 site was analyzed by gene sequencing. The MGB Taqman probe PCR method was used to detect the JAK2V617F allele burden. The correlation of TET2 gene SNP rs3733609 C/T with the JAK2V617F allele burden and clinical parameters was analyzed. RESULTS: TET2 gene rs3733609 C/T heterozygosity (normal T/T) could be detected in 19 cases of 85 cases of JAK2V617F positive MPN (22.4%) patients, while the TET2 gene rs3733609 C/T heterozygosity could be detected only in 9 of the 106 healthy volunteers, and the incidence was only 8.5% (9/106). Compared with the negative group (TET2 rs3733609 T/T), there was no significant difference in the median age, hemoglobin level and platelet count in the patients with TET2 gene SNP rs3733609 (CT/TC) positive, but the WBC count of peripheral blood and JAK2V617F allele burden significantly increased. In JAK2V617F high allele burden group, TET2 gene SNP rs3733609 was positive in 7 cases (36.8%, 7/19), the ratio was higher than that in the low allele burden group(18.2%, 12/66). CONCLUSION: TET2 SNP rs3733609 C/T may be a new susceptible allelee, which affects the clinical characteristics and clonal evolution of MPN patients.


Assuntos
Proteínas de Ligação a DNA/genética , Janus Quinase 2/genética , Transtornos Mieloproliferativos , Proteínas Proto-Oncogênicas/genética , Alelos , Éxons , Humanos , Mutação , Transtornos Mieloproliferativos/genética , Neoplasias
12.
Zhongguo Shi Yan Xue Ye Xue Za Zhi ; 27(5): 1627-1632, 2019 Oct.
Artigo em Chinês | MEDLINE | ID: mdl-31607324

RESUMO

OBJECTIVE: To study the regulatory effect of deubiquitinase MYSM1 on differentiation of B cells to plasma cells. METHODS: The interfering and overexpression plasmids of MYSM1 were constructed and then the corresponding lentiviruses were packaged. Human CD19+ B cells were isolated from human peripheral blood with Miltenyi B cell isolation kit. Purified CD19+ B cells were transduced with lentiviruses and then treated with LPS, the CD138 expression was detected by flow cytometry. The expression of transcription factor was determined by quantitative PCR. RESULTS: The differentiation of B cells to plasma cells was enhanced after interfering in MYSM1 expression. Quantitative PCR showed that mRNA levels of Pax5 and Bach2 in cells with interfering in MYSM1 were much lower than their counterpart (P<0.01), and mRNA levels of Prdm1 and Xbp1 in cells with interfering in MYSM1 were much higher than their counterpart (P<0.01). On the contrary, the differentiation of B cells to plasma cells was inhibited after the overexpression of MYSM1. Quantitative PCR showed that mRNA levels of Pax5 and Bach2 in cells with MYSM1 overexpression were higher than those in control cells (P<0.01), and mRNA levels of Prdm1 and Xbp1 in cells with MYSM1 overexpression were much lower than those in their counterpart (P<0.01). CONCLUSION: MYSM1 negatively regulates differentiation of human B cells to plasma cells.


Assuntos
Linfócitos B , Proteínas de Ligação a DNA/genética , Plasmócitos , Fatores de Transcrição/genética , Diferenciação Celular , Enzimas Desubiquitinantes , Humanos
13.
Cytogenet Genome Res ; 159(1): 1-11, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31658463

RESUMO

The switch/sucrose non-fermenting (SWI/SNF) complex is an ATP-dependent chromatin remodeller that regulates the spacing of nucleosomes and thereby controls gene expression. Heterozygous mutations in genes encoding subunits of the SWI/SNF complex have been reported in individuals with Coffin-Siris syndrome (CSS), with the majority of the mutations in ARID1B. CSS is a rare congenital disorder characterized by facial dysmorphisms, digital anomalies, and variable intellectual disability. We hypothesized that mutations in genes encoding subunits of the ubiquitously expressed SWI/SNF complex may lead to alterations of the nucleosome profiles in different cell types. We performed the first study on CSS-patient samples and investigated the nucleosome landscapes of cell-free DNA (cfDNA) isolated from blood plasma by whole-genome sequencing. In addition, we studied the nucleosome landscapes of CD14+ monocytes from CSS-affected individuals by nucleosome occupancy and methylome-sequencing (NOMe-seq) as well as their expression profiles. In cfDNA of CSS-affected individuals with heterozygous ARID1B mutations, we did not observe major changes in the nucleosome profile around transcription start sites. In CD14+ monocytes, we found few genomic regions with different nucleosome occupancy when compared to controls. RNA-seq analysis of CD14+ monocytes of these individuals detected only few differentially expressed genes, which were not in proximity to any of the identified differential nucleosome-depleted regions. In conclusion, we show that heterozygous mutations in the human SWI/SNF subunit ARID1B do not have a major impact on the nucleosome landscape or gene expression in blood cells. This might be due to functional redundancy, cell-type specificity, or alternative functions of ARID1B.


Assuntos
Anormalidades Múltiplas/genética , Proteínas de Ligação a DNA/genética , Face/anormalidades , Deformidades Congênitas da Mão/genética , Deficiência Intelectual/genética , Micrognatismo/genética , Pescoço/anormalidades , Proteínas Nucleares/genética , Nucleossomos/genética , Fatores de Transcrição/genética , Adolescente , Ácidos Nucleicos Livres/sangue , Ácidos Nucleicos Livres/genética , Criança , Pré-Escolar , Feminino , Genoma Humano/genética , Estudo de Associação Genômica Ampla , Humanos , Masculino , Monócitos/citologia , Adulto Jovem
14.
Nat Cell Biol ; 21(10): 1273-1285, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31548606

RESUMO

Chromosome translocation is a major cause of the onset and progression of diverse types of cancers. However, the mechanisms underlying this process remain poorly understood. Here, we identified a non-homologous end-joining protein, IFFO1, which structurally forms a heterotetramer with XRCC4. IFFO1 is recruited to the sites of DNA damage by XRCC4 and promotes the repair of DNA double-strand breaks in a parallel pathway with XLF. Interestingly, IFFO1 interacts with lamin A/C, forming an interior nucleoskeleton. Inactivating IFFO1 or its interaction with XRCC4 or lamin A/C leads to increases in both the mobility of broken ends and the frequency of chromosome translocation. Importantly, the destruction of this nucleoskeleton accounts for the elevated frequency of chromosome translocation in many types of cancer cells. Our results reveal that the lamin A/C-IFFO1-constituted nucleoskeleton prevents chromosome translocation by immobilizing broken DNA ends during tumorigenesis.


Assuntos
Carcinogênese/genética , Quebras de DNA de Cadeia Dupla , Reparo do DNA por Junção de Extremidades , Proteínas de Ligação a DNA/metabolismo , Lamina Tipo A/metabolismo , Translocação Genética , Animais , Carcinoma/genética , Cromossomos Humanos , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Células HEK293 , Humanos , Proteínas de Filamentos Intermediários/genética , Camundongos , Matriz Nuclear/metabolismo , Proteínas Associadas à Matriz Nuclear/química , Proteínas Associadas à Matriz Nuclear/metabolismo , Proteínas Associadas à Matriz Nuclear/fisiologia
15.
Genes Dev ; 33(19-20): 1367-1380, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31488578

RESUMO

Fat storage in adult mammals is a highly regulated process that involves the mobilization of adipocyte progenitor cells (APCs) that differentiate to produce new adipocytes. Here we report a role for the broadly conserved miR-26 family of microRNAs (miR-26a-1, miR-26a-2, and miR-26b) as major regulators of APC differentiation and adipose tissue mass. Deletion of all miR-26-encoding loci in mice resulted in a dramatic expansion of adipose tissue in adult animals fed normal chow. Conversely, transgenic overexpression of miR-26a protected mice from high-fat diet-induced obesity. These effects were attributable to a cell-autonomous function of miR-26 as a potent inhibitor of APC differentiation. miR-26 blocks adipogenesis, at least in part, by repressing expression of Fbxl19, a conserved miR-26 target without a previously known role in adipocyte biology that encodes a component of SCF-type E3 ubiquitin ligase complexes. These findings have therefore revealed a novel pathway that plays a critical role in regulating adipose tissue formation in vivo and suggest new potential therapeutic targets for obesity and related disorders.


Assuntos
Adipogenia/genética , Diferenciação Celular/genética , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Proteínas F-Box/genética , Proteínas F-Box/metabolismo , MicroRNAs/metabolismo , Obesidade/genética , Células-Tronco/citologia , Animais , Dieta Hiperlipídica , Expressão Gênica , Técnicas de Silenciamento de Genes , Camundongos , MicroRNAs/genética
16.
Nat Chem Biol ; 15(10): 992-1000, 2019 10.
Artigo em Inglês | MEDLINE | ID: mdl-31527837

RESUMO

Post-translational modifications of histone variant H2A.Z accompany gene transactivation, but its modifying enzymes still remain elusive. Here, we reveal a hitherto unknown function of human KAT2A (GCN5) as a histone acetyltransferase (HAT) of H2A.Z at the promoters of a set of transactivated genes. Expression of these genes also depends on the DNA repair complex XPC-RAD23-CEN2. We established that XPC-RAD23-CEN2 interacts both with H2A.Z and KAT2A to drive the recruitment of the HAT at promoters and license H2A.Z acetylation. KAT2A selectively acetylates H2A.Z.1 versus H2A.Z.2 in vitro on several well-defined lysines and we unveiled that alanine-14 in H2A.Z.2 is responsible for inhibiting the activity of KAT2A. Notably, the use of a nonacetylable H2A.Z.1 mutant shows that H2A.Z.1ac recruits the epigenetic reader BRD2 to promote RNA polymerase II recruitment. Our studies identify KAT2A as an H2A.Z.1 HAT in mammals and implicate XPC-RAD23-CEN2 as a transcriptional co-activator licensing the reshaping of the promoter epigenetic landscape.


Assuntos
Reparo do DNA/fisiologia , Histona Acetiltransferases/metabolismo , Histonas/metabolismo , Acetilação , Proteínas de Ligação ao Cálcio/genética , Proteínas de Ligação ao Cálcio/metabolismo , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular , Enzimas Reparadoras do DNA/genética , Enzimas Reparadoras do DNA/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Fibroblastos , Regulação da Expressão Gênica , Humanos , Lisina Acetiltransferase 5
17.
DNA Cell Biol ; 38(11): 1323-1337, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31536386

RESUMO

Our previous study has indicated that the parathyroid hormone type 1 receptor (PTHR1) may play important roles in development and progression of osteosarcoma (OS) by regulating Wnt, angiogenesis, and inflammation pathway genes. The goal of this study was to further illuminate the roles of PTHR1 in OS by investigating upstream regulation mechanisms (including microRNA [miRNA] and transcription factors [TFs]) of crucial genes. The microarray dataset GSE46861 was downloaded from the Gene Expression Omnibus database, in which six tumors with short hairpin RNA (shRNA) PTHR1 knockdown (PTHR1.358) and six tumors with shRNA control knockdown (Ren.1309) were collected from mice. Differentially expressed genes (DEGs) between PTHR1.358 and Ren.1309 were identified using the linear models for microarray data (LIMMA) method, and then the miRNA-TF-mRNA regulatory network was constructed using data from corresponding databases, followed by module analysis, to screen crucial regulatory relationships. OS-related human miRNAs were extracted from the curated Osteosarcoma Database. Gene ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways were enriched using the Database for Annotation, Visualization, and Integrated Discovery (DAVID) tool. As a result, the miRNA-TF-mRNA regulatory network, including 1049 nodes (516 miRNA, 25 TFs, and 508 DEGs) and 15942 edges (interaction relationships, such as Pparg-Abca1 and miR-590-3p-AXIN2), was constructed, from which three significant modules were extracted and modules 2 and 3 contained interactions between miRNAs/TFs and DEGs such as miR-103-3p-AXIN2, miR-124-3p-AR-Tgfb1i1, and miR-27a-3p-PPARG-Abca1. miR-27a-3p was a known miRNA associated with OS. Abca1, AR, and miR-124-3p were hub genes in the miRNA-TF-mRNA network. Tgfb1i1 was involved in cell proliferation, Abca1 participated in the cholesterol metabolic process, and AXIN2 was associated with the canonical Wnt signaling pathway. Furthermore, we also confirmed upregulation of miR-590-3p and downregulation of AXIN2 in the mouse OS cell line K7M2-WT transfected with PTHR1 shRNA. In conclusion, PTHR1 may play important roles in progression of OS by activating miR-124-3p-AR-Tgfb1i1, miR-27a-3p-PPARG-Abca1, and miR-103/590-3p-AXIN2 axes.


Assuntos
Neoplasias Ósseas , Osteossarcoma , Receptor Tipo 1 de Hormônio Paratireóideo/fisiologia , Transportador 1 de Cassete de Ligação de ATP/genética , Transportador 1 de Cassete de Ligação de ATP/fisiologia , Animais , Proteína Axina/genética , Proteína Axina/fisiologia , Neoplasias Ósseas/genética , Neoplasias Ósseas/patologia , Proteínas do Citoesqueleto/genética , Proteínas do Citoesqueleto/fisiologia , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/fisiologia , Progressão da Doença , Perfilação da Expressão Gênica , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Células HEK293 , Humanos , Proteínas com Domínio LIM/genética , Proteínas com Domínio LIM/fisiologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Nus , MicroRNAs/genética , MicroRNAs/fisiologia , Osteossarcoma/genética , Osteossarcoma/patologia , PPAR gama/genética , PPAR gama/fisiologia , Receptor Tipo 1 de Hormônio Paratireóideo/genética , Receptores Androgênicos/genética , Receptores Androgênicos/fisiologia , Transdução de Sinais/genética , Células Tumorais Cultivadas
18.
Chem Commun (Camb) ; 55(78): 11671-11674, 2019 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-31497827

RESUMO

We report the design and optimisation of novel oligonucleotide substrates for a sensitive fluorescence assay for high-throughput screening and functional studies of the DNA repair enzyme, XPF-ERCC1, with a view to accelerating inhibitor and drug discovery.


Assuntos
Reparo do DNA , Proteínas de Ligação a DNA/metabolismo , Endonucleases/metabolismo , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Dimerização , Endonucleases/química , Endonucleases/genética , Humanos , Oligonucleotídeos/química , Oligonucleotídeos/metabolismo , Especificidade por Substrato , Temperatura Ambiente
19.
Nucleic Acids Res ; 47(18): 9829-9841, 2019 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-31396626

RESUMO

Elevated temperatures activate a heat shock response (HSR) to protect cells from the pathological effects of protein mis-folding, cellular mis-organization, organelle dysfunction and altered membrane fluidity. This response includes activation of the conserved transcription factor heat shock factor 1 (HSF-1), which binds heat shock elements (HSEs) in the promoters of genes induced by heat shock (HS). The upregulation of protein-coding genes (PCGs), such as heat shock proteins and cytoskeletal regulators, is critical for cellular survival during elevated temperatures. While the transcriptional response of PCGs to HS has been comprehensively analyzed in a variety of organisms, the effect of this stress on the expression of non-coding RNAs (ncRNAs) has not been systematically examined. Here we show that in Caenorhabditis elegans HS induces up- and downregulation of specific ncRNAs from multiple classes, including miRNA, piRNA, lincRNA, pseudogene and repeat elements. Moreover, some ncRNA genes appear to be direct targets of the HSR, as they contain HSF-1 bound HSEs in their promoters and their expression is regulated by this factor during HS. These results demonstrate that multiple ncRNA genes respond to HS, some as direct HSF-1 targets, providing new candidates that may contribute to organismal survival during this stress.


Assuntos
Caenorhabditis elegans/genética , Fatores de Transcrição de Choque Térmico/genética , RNA não Traduzido/genética , Transcriptoma/genética , Animais , Proteínas de Caenorhabditis elegans/genética , Proteínas de Ligação a DNA/genética , Regulação da Expressão Gênica/genética , Fatores de Transcrição de Choque Térmico/química , Resposta ao Choque Térmico/genética , Regiões Promotoras Genéticas , Ativação Transcricional/genética
20.
Nucleic Acids Res ; 47(18): 9696-9707, 2019 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-31400115

RESUMO

Ubiquitous Structural Maintenance of Chromosomes (SMC) complexes use a proteinaceous ring-shaped architecture to organize and individualize chromosomes, thereby facilitating chromosome segregation. They utilize cycles of adenosine triphosphate (ATP) binding and hydrolysis to transport themselves rapidly with respect to DNA, a process requiring protein conformational changes and multiple DNA contact sites. By analysing changes in the architecture and stoichiometry of the Escherichia coli SMC complex, MukBEF, as a function of nucleotide binding to MukB and subsequent ATP hydrolysis, we demonstrate directly the formation of dimer of MukBEF dimer complexes, dependent on dimeric MukF kleisin. Using truncated and full length MukB, in combination with MukEF, we show that engagement of the MukB ATPase heads on nucleotide binding directs the formation of dimers of heads-engaged dimer complexes. Complex formation requires functional interactions between the C- and N-terminal domains of MukF with the MukB head and neck, respectively, and MukE, which organizes the complexes by stabilizing binding of MukB heads to MukF. In the absence of head engagement, a MukF dimer bound by MukE forms complexes containing only a dimer of MukB. Finally, we demonstrate that cells expressing MukBEF complexes in which MukF is monomeric are Muk-, with the complexes failing to associate with chromosomes.


Assuntos
Proteínas Cromossômicas não Histona/química , Proteínas de Escherichia coli/genética , Proteínas Repressoras/genética , Proteínas Cromossômicas não Histona/genética , Cromossomos/química , Cromossomos/genética , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Escherichia coli/química , Escherichia coli/genética , Proteínas de Escherichia coli/química , Complexos Multiproteicos/química , Complexos Multiproteicos/genética , Ligação Proteica , Proteínas Repressoras/química
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA