RESUMO
AIMS/HYPOTHESIS: The association between low birthweight (LBW) and risk of developing type 2 diabetes may involve epigenetic mechanisms, with skeletal muscle being a prime target tissue. Differential DNA methylation patterns have been observed in single genes in muscle tissue from type 2 diabetic and LBW individuals, and we recently showed multiple DNA methylation changes during short-term high-fat overfeeding in muscle of healthy people. In a randomised crossover study, we analysed genome-wide DNA promoter methylation in skeletal muscle of 17 young LBW men and 23 matched normal birthweight (NBW) men after a control and a 5 day high-fat overfeeding diet. METHODS: DNA methylation was measured using Illumina's Infinium BeadArray covering 27,578 CpG sites representing 14,475 different genes. RESULTS: After correction for multiple comparisons, DNA methylation levels were found to be similar in the LBW and NBW groups during the control diet. Whereas widespread DNA methylation changes were observed in the NBW group in response to high-fat overfeeding, only a few methylation changes were seen in the LBW group (χ(2), p < 0.001). CONCLUSIONS/INTERPRETATION: Our results indicate lower DNA methylation plasticity in skeletal muscle from LBW vs NBW men, potentially contributing to understanding the link between LBW and increased risk of type 2 diabetes.
Assuntos
Metilação de DNA/genética , Dieta Hiperlipídica/efeitos adversos , Recém-Nascido de Baixo Peso/fisiologia , Adulto , DNA (Citosina-5-)-Metiltransferase 1 , DNA (Citosina-5-)-Metiltransferases/genética , DNA Metiltransferase 3A , Diabetes Mellitus Tipo 2/genética , Epigênese Genética/genética , Humanos , Resistência à Insulina/genética , Resistência à Insulina/fisiologia , Masculino , Músculo Esquelético/metabolismo , Adulto Jovem , DNA Metiltransferase 3BRESUMO
The longevity-promoting NAD+-dependent class III histone deacetylase Sirtuin 1 (SIRT1) is involved in stem cell function by controlling cell fate decision and/or by regulating the p53-dependent expression of NANOG. We show that SIRT1 is down-regulated precisely during human embryonic stem cell differentiation at both mRNA and protein levels and that the decrease in Sirt1 mRNA is mediated by a molecular pathway that involves the RNA-binding protein HuR and the arginine methyltransferase coactivator-associated arginine methyltransferase 1 (CARM1). SIRT1 down-regulation leads to reactivation of key developmental genes such as the neuroretinal morphogenesis effectors DLL4, TBX3, and PAX6, which are epigenetically repressed by this histone deacetylase in pluripotent human embryonic stem cells. Our results indicate that SIRT1 is regulated during stem cell differentiation in the context of a yet-unknown epigenetic pathway that controls specific developmental genes in embryonic stem cells.
Assuntos
Diferenciação Celular , Células-Tronco Embrionárias/citologia , Células-Tronco Embrionárias/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Sirtuína 1/metabolismo , Animais , Proteínas Adaptadoras de Sinalização CARD/metabolismo , Linhagem Celular , Guanilato Ciclase/metabolismo , Humanos , Camundongos , Camundongos Knockout , Células-Tronco Pluripotentes/citologia , Células-Tronco Pluripotentes/metabolismo , Estabilidade de RNA , Sirtuína 1/deficiência , Sirtuína 1/genéticaRESUMO
Epigenetics is a new and expanding science that studies the chromatin-based regulation of gene expression. It is achieving considerable importance, especially with regard to developmental mechanisms that drive cell and organ differentiation, as well as in all those biological processes that involve response and adaptation to environmental stimuli. One of the most interesting biological questions concerning animals, especially human beings, is the ability to distinguish self from nonself. This ability has developed throughout evolution, both as the main function of the immune system, which defends against attack by foreign organisms and at the level of consciousness of oneself as an individual, one of the highest functions of the brain that enables social life. Here we will attempt to dissect the epigenetic mechanisms involved in establishing these higher functions and describe some alterations of the epigenetic machinery responsible for the impairment of correct self-recognition and self-identity.
Assuntos
Adaptação Fisiológica/imunologia , Imunidade Adaptativa/fisiologia , Epigênese Genética/imunologia , Evolução Molecular , Tolerância a Antígenos Próprios/fisiologia , Adaptação Fisiológica/genética , Animais , HumanosRESUMO
Based on the transactional and salutogenic perspectives, we explored individual profiles that integrate psychosocial factors and compositional elements of the built home environment. Adults with different socio-demographic characteristics completed several self-report measures on psychological factors (personality traits, self-efficacy, mental health, and happiness) and architectural elements constituting the ideal home environment. Adopting an individual-centered perspective, three distinct intra-individual psycho-architectural (person-environment) profiles were found with different compositional preferences and psychosocial characteristics in terms of functioning, health, and well-being: endopathic (characterized by higher levels of psychosocial resources and well-being indicating a highly adapted and successful profile, and architectural preferences corresponding to their identities and experiences-expression through spaces), assimilative (characterized by average levels in all regulatory parameters indicating moderately adaptive individuals, and architectural preferences of spaces created in interactive processes-introjection of spaces), and additive individuals (characterized by a comparatively dysfunctional, poorer psychosocial profile, and architectural preferences in line with provoking a restorative effect-change with spaces). An awareness of the psychosocial features of the users for whom the homes are built can help in designing spaces to inhabit that are adapted to them for an enhancement of their overall well-being. Therefore, a better understanding of the interconnections between psychology and architecture will help in designing healthy spaces.
Assuntos
Ambiente Construído , Felicidade , Adaptação Fisiológica , Adulto , Humanos , Saúde MentalRESUMO
BACKGROUND: Wnt factors control cell differentiation through semi-independent molecular cascades known as the beta-catenin-dependent (canonical) and -independent (non-canonical) Wnt signalling pathways. Genetic and epigenetic alteration of components of the canonical Wnt signalling pathway is one of the primary mechanisms underlying colon cancer. Despite increasing evidence of the role of the non-canonical pathways in tumourigenesis, however, the underlying molecular mechanisms are poorly understood. RESULTS: Here we report that the receptor tyrosine kinase-like orphan receptor 2 (ROR2), a transmembrane receptor for Wnt factors that activates non-canonical pathways, is frequently repressed by aberrant promoter hypermethylation in human colon cancer cell lines and primary tumours. By restoring ROR2 activity in colon cancer cells harbouring ROR2 promoter hypermethylation, we show that the role of ROR2 in colon cancer cells is mediated, at least in part, by canonical Wnt and that its epigenetic-dependent loss can be pro-tumourigenic. CONCLUSIONS: Our data show the importance of epigenetic alterations of ROR2 in colon cancer, highlighting the close interconnection between canonical and non-canonical Wnt signalling pathways in this type of tumour.
Assuntos
Neoplasias do Colo/genética , Epigênese Genética , Receptores Órfãos Semelhantes a Receptor Tirosina Quinase/genética , Proteínas Wnt/fisiologia , Neoplasias do Colo/patologia , Metilação de DNA , Humanos , Regiões Promotoras GenéticasRESUMO
Zoonotic diseases represent a significant public health concern worldwide due to the emergence/re-emergence of vector-borne diseases in the last decade. Ticks are the most important vectors in the northern hemisphere and can transmit diseases such as Lyme disease, human granulocytic anaplasmosis, and spotted fever rickettsioses, among others. Therefore, there is a growing need to develop better and faster diagnostic tools that can detect zoonotic human pathogens in clinical samples. In this study, we present the results for a new kit tick-borne bacteria flow chip (TBFC), which allows the simultaneous screening of seven different bacterial pathogens in human samples using a DNA flow technology platform (hybriSpot system). The analytical sensitivity and specificity of the TBFC were calculated spiking bacterial DNA in human DNA samples, and the results were compared with an in-house single PCR-reverse line blot (RLB) routinely used for diagnosis at the National Center for Microbiology in Spain. The analytical sensitivity and specificity of the TBFC were almost identical to the PCR-RLBs used in diagnosis. In addition, samples from patients (n = 212) with a wide range of clinical signs/symptoms consistent with multisystem disorders suggestive of a tick-borne infection were tested using the TBFC, and the results were compared with those obtained by PCR-RLB. The concordance of both methods using patient samples was 97.2%. The TBFC kit is a rapid new and cost-efficient diagnostic molecular tool capable of detecting tick-borne pathogens in clinical samples.
Assuntos
Bactérias/isolamento & purificação , Reação em Cadeia da Polimerase/métodos , Doenças Transmitidas por Carrapatos/diagnóstico , Bactérias/classificação , Bactérias/genética , Técnicas de Tipagem Bacteriana , DNA Bacteriano/isolamento & purificação , Humanos , Sensibilidade e Especificidade , Doenças Transmitidas por Carrapatos/microbiologiaRESUMO
Chemical changes performed on 1a (sirtinol) led to a series of SIRT1/2 inhibitors, in some cases more potent than 1a mainly against SIRT1. Tested in human leukemia U937 cells, the benzamide and anilide derivatives 1b, 1c, 2b, and 2c as well as the 4-(2-phenylpropyl)thioanalogue 4c showed huge apoptosis induction, while some sulfinyl and sulfonyl derivatives (5b, 5c, and 6a-c) were highly efficient in granulocytic differentiation. When assayed in human leukemia MOLT4 as well as in human breast MDA-MB-231 and colon RKO cancer cell lines, the anilide 2b (salermide) and the phenylpropylthio analogue 4b emerged as the most potent antiproliferative agents. Tested on colorectal carcinoma and glioblastoma multiforme cancer stem cells (CSCs) from patients, 2b was particularly potent against colorectal carcinoma CSCs, while 4b, 6a, and the SIRT2-selective inhibitor AGK-2 showed the highest effect against glioblastoma multiforme CSCs. Such compounds will be further explored for their broad-spectrum anticancer properties.
Assuntos
Antineoplásicos/síntese química , Naftóis/síntese química , Células-Tronco Neoplásicas/efeitos dos fármacos , Fenilpropionatos/síntese química , Sirtuína 1/antagonistas & inibidores , Sirtuína 2/antagonistas & inibidores , Antineoplásicos/química , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Diferenciação Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Ensaios de Seleção de Medicamentos Antitumorais , Granulócitos/citologia , Granulócitos/efeitos dos fármacos , Humanos , Simulação de Acoplamento Molecular , Naftóis/química , Naftóis/farmacologia , Células-Tronco Neoplásicas/citologia , Fenilpropionatos/química , Fenilpropionatos/farmacologia , Ligação Proteica , Relação Estrutura-AtividadeRESUMO
BACKGROUND: Monozygotic twins discordant for type 2 diabetes constitute an ideal model to study environmental contributions to type 2 diabetic traits. We aimed to examine whether global DNA methylation differences exist in major glucose metabolic tissues from these twins. METHODOLOGY/PRINCIPAL FINDINGS: Skeletal muscle (n = 11 pairs) and subcutaneous adipose tissue (n = 5 pairs) biopsies were collected from 53-80 year-old monozygotic twin pairs discordant for type 2 diabetes. DNA methylation was measured by microarrays at 26,850 cytosine-guanine dinucleotide (CpG) sites in the promoters of 14,279 genes. Bisulfite sequencing was applied to validate array data and to quantify methylation of intergenic repetitive DNA sequences. The overall intra-pair variation in DNA methylation was large in repetitive (LINE1, D4Z4 and NBL2) regions compared to gene promoters (standard deviation of intra-pair differences: 10% points vs. 4% points, P<0.001). Increased variation of LINE1 sequence methylation was associated with more phenotypic dissimilarity measured as body mass index (r = 0.77, P = 0.007) and 2-hour plasma glucose (r = 0.66, P = 0.03) whereas the variation in promoter methylation did not associate with phenotypic differences. Validated methylation changes were identified in the promoters of known type 2 diabetes-related genes, including PPARGC1A in muscle (13.9±6.2% vs. 9.0±4.5%, P = 0.03) and HNF4A in adipose tissue (75.2±3.8% vs. 70.5±3.7%, P<0.001) which had increased methylation in type 2 diabetic individuals. A hypothesis-free genome-wide exploration of differential methylation without correction for multiple testing identified 789 and 1,458 CpG sites in skeletal muscle and adipose tissue, respectively. These methylation changes only reached some percentage points, and few sites passed correction for multiple testing. CONCLUSIONS/SIGNIFICANCE: Our study suggests that likely acquired DNA methylation changes in skeletal muscle or adipose tissue gene promoters are quantitatively small between type 2 diabetic and non-diabetic twins. The importance of methylation changes in candidate genes such as PPARGC1A and HNF4A should be examined further by replication in larger samples.
Assuntos
Tecido Adiposo/metabolismo , Metilação de DNA , Diabetes Mellitus Tipo 2/metabolismo , Estudo de Associação Genômica Ampla , Músculo Esquelético/metabolismo , Gêmeos Monozigóticos , Diabetes Mellitus Tipo 2/genética , HumanosRESUMO
Mutations in the nuclear envelope protein lamin A or in its processing protease ZMPSTE24 cause human accelerated aging syndromes, including Hutchinson-Gilford progeria syndrome. Similarly, Zmpste24-deficient mice accumulate unprocessed prelamin A and develop multiple progeroid symptoms, thus representing a valuable animal model for the study of these syndromes. Zmpste24-deficient mice also show marked transcriptional alterations associated with chromatin disorganization, but the molecular links between both processes are unknown. We report herein that Zmpste24-deficient mice show a hypermethylation of rDNA that reduces the transcription of ribosomal genes, being this reduction reversible upon treatment with DNA methyltransferase inhibitors. This alteration has been previously described during physiological aging in rodents, suggesting its potential role in the development of the progeroid phenotypes. We also show that Zmpste24-deficient mice present global hypoacetylation of histones H2B and H4. By using a combination of RNA sequencing and chromatin immunoprecipitation assays, we demonstrate that these histone modifications are associated with changes in the expression of several genes involved in the control of cell proliferation and metabolic processes, which may contribute to the plethora of progeroid symptoms exhibited by Zmpste24-deficient mice. The identification of these altered genes may help to clarify the molecular mechanisms underlying aging and progeroid syndromes as well as to define new targets for the treatment of these dramatic diseases.
Assuntos
Envelhecimento/genética , Núcleo Celular/enzimologia , Epigênese Genética , Proteínas de Membrana/genética , Metaloendopeptidases/genética , Membrana Nuclear/enzimologia , Animais , Núcleo Celular/metabolismo , Metaloproteases/genética , Camundongos , Camundongos Knockout , Membrana Nuclear/metabolismoRESUMO
The role of epigenetics in aging and age-related diseases is a key issue in molecular physiology and medicine because certain epigenetic factors are thought to mediate, at least in part, the relationship between the genome and the environment. An active role for epigenetics in aging must meet two prior conditions: there must be specific epigenetic changes during aging and they must be functionally associated with the aged phenotype. Assuming that specific epigenetic modifications can have a direct functional outcome in aging, it is also essential to establish whether they depend on genetic, environmental or stochastic factors, and if they can be transmitted from one generation to the next. Here we discuss current knowledge about these matters and future directions in the field.
Assuntos
Envelhecimento/genética , Cromatina/genética , Doença , Epigênese Genética/genética , Histonas/genética , Metilação de DNA , Meio Ambiente , Histonas/metabolismo , Humanos , FenótipoRESUMO
Ibuprofen is widely commercialized in racemic form. Although metabolic chiral inversion occurs through the conversion of R(-)-ibuprofen to S(+)-ibuprofen and the latter enantiomer is considered the active form, clinical trials involving the administration of a racemate to S-enantiomer dosage ratio of 1:0.5 have demonstrated that S(+)-ibuprofen is as efficacious as the racemic formulation. Moreover, the R(-)-enantiomer has been implicated in adverse gastrointestinal effects found with the racemic form, but the mechanisms involved in this process are not yet fully understood. The aim of the present study was to evaluate the anti-inflammatory activity of a racemate to S(+)-ibuprofen dosage ratio of 1:0.5 using the carrageenan air pouch model of inflammation and determine both ulcerogenic activity and the chiral conversion rate in rats. An in vitro study of the cytotoxicity of racemate and S(+)-ibuprofen in gastric cells was also performed. Although the plasma level of S(+)-ibuprofen was raised after racemate administration, no significant difference was found in anti-inflammatory activity, as assessed by exudate formation, PGE2 production and leukocyte migration to the air pouches. Fewer gastric lesions were found after S(+)-ibuprofen administration, despite the low gastric PGE2 content. In the in vitro study, the racemic compound proved more cytotoxic than S(+)-ibuprofen. The present findings suggest that the S-enantiomer of ibuprofen could be considered a therapeutic alternative to minimize gastrointestinal side effects, since the chiral inversion of R(-)-ibuprofen to S(+)-ibuprofen did not result in an improved anti-inflammatory response.
O Ibuprofeno é normalmente comercializado na forma racêmica. Embora ocorra inversão quiral convertendo a forma R(-)- em S(+)-ibuprofeno e, a última seja considerada a forma ativa, a administração da proporção 1:0,5 (racemato: S-enantiômero) demonstrou que o S(+)-ibuprofeno é mais eficaz que a formulação racêmica. Adicionalmente, o R(-)-enantiômero está envolvido nos efeitos adversos gastrintestinais descritos para a formulação racêmica, embora os mecanismos não sejam complemente compreendidos. O objetivo deste estudo foi avaliar a atividade antiinflamatória da proporção 1:0,5 (racemato:S-ibuprofeno) utilizando o modelo experimental de bolsa de ar, a atividade ulcerogênica e a taxa de conversão quiral em ratos. Também estudamos in vitro, a citotoxicidade provocada pelo racemato e S(+)-ibuprofeno em células gástricas. Embora os níveis plasmáticos de S(+)-ibuprofeno tenham aumentado após a administração do racemato, a atividade antiinflamatória avaliada pela formação de exsudato, produção de PGE2 e migração de leucócitos para a bolsa de ar não foram diferentes. As lesões gástricas foram reduzidas após a administração de S(+)-ibuprofeno, apesar da inibição de PGE2 gástrica. In vitro, o composto racêmico foi mais citotóxico que o S(+)-ibuprofeno. Nossos resultados sugerem que o S-enantiômero do ibuprofeno pode ser considerado uma alternativa terapêutica visando a redução dos efeitos colaterais gastrintestinais, visto que a inversão quiral do R(-)- para o S(+)-ibuprofeno não resultou em melhora do efeito antiinflamatório observado.
Assuntos
Animais , Masculino , Ratos , Dinoprostona , Ibuprofeno/administração & dosagem , Ibuprofeno/uso terapêutico , Úlcera Gástrica/tratamento farmacológicoRESUMO
Developmental genes are silenced in embryonic stem cells by a bivalent histone-based chromatin mark. It has been proposed that this mark also confers a predisposition to aberrant DNA promoter hypermethylation of tumor suppressor genes (TSGs) in cancer. We report here that silencing of a significant proportion of these TSGs in human embryonic and adult stem cells is associated with promoter DNA hypermethylation. Our results indicate a role for DNA methylation in the control of gene expression in human stem cells and suggest that, for genes repressed by promoter hypermethylation in stem cells in vivo, the aberrant process in cancer could be understood as a defect in establishing an unmethylated promoter during differentiation, rather than as an anomalous process of de novo hypermethylation.
Assuntos
Metilação de DNA , Células-Tronco Embrionárias/citologia , Regulação da Expressão Gênica no Desenvolvimento , Neoplasias/genética , Neoplasias/metabolismo , Diferenciação Celular , Linhagem Celular , Cromatina/metabolismo , Inativação Gênica , Genes Neoplásicos , Células HL-60 , Células HeLa , Humanos , Regiões Promotoras Genéticas , Fatores de Tempo , Células U937RESUMO
Our knowledge of the mechanisms underlying tumor-specific immune response and tumor escape has considerably increased. HLA class I antigen defects remain an important tumor escape mechanism since they influence the interactions between tumor cells and specific T and NK cells in the course of malignant disease. We have studied here HLA class I expression in six subcutaneous metastases obtained from a melanoma patient immunized with an autologous melanoma cell vaccine (M-VAX). We report in this paper that HLA class I antigen expression on these metastatic lesions strongly correlated with the course of the disease. The three metastases that were partially regressing at the time of their excision showed a strong HLA class I expression, whereas the progressing ones showed a very weak or negative staining with most of the anti-HLA class I mAbs used. Real-time quantitative PCR of the samples obtained from microdissected tumor tissue revealed a significant difference in the mRNA levels of HLA-ABC heavy chain and beta2m between the two types of metastases, i.e., lower levels in progressing metastases and high levels in regressing ones, confirming the immunohistological findings. This is, to our knowledge, the first report where the clinical outcome of different HLA class I positive and negative melanoma metastases can be clearly correlated with the regression and progression of the disease, respectively.