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1.
BMC Public Health ; 22(1): 1997, 2022 11 01.
Artículo en Inglés | MEDLINE | ID: mdl-36319990

RESUMEN

BACKGROUND: The preconception period provides a window of opportunity for interventions aiming to reduce unhealthy lifestyle behaviours and their negative effect on pregnancy outcomes. This study aimed to assess the effectiveness of a locally tailored preconception care (PCC) intervention in a hybrid-II effectiveness implementation design. METHODS: A stepped-wedge cluster randomized controlled trial was performed in four Dutch municipalities. The intervention contained a social marketing strategy aiming to improve the uptake (prospective parents) and the provision (healthcare providers) of PCC. Prospective parents participated by administering a questionnaire in early pregnancy recalling their preconceptional behaviours. Experiences of healthcare providers were also evaluated through questionnaires. The composite primary outcome was adherence to at least three out of four preconceptional lifestyle recommendations (early initiation of folic acid supplements, healthy nutrition, no smoking or alcohol use). Secondary outcomes were preconceptional lifestyle behaviour change, (online) reach of the intervention and improved knowledge among healthcare providers. RESULTS: A total of 850 women and 154 men participated in the control phase and 213 women and 39 men in the intervention phase. The composite primary outcome significantly improved among women participating in the municipality where the reach of the intervention was highest (Relative Risk (RR) 1.57 (95% Confidence Interval (CI) 1.11-2.22). Among women, vegetable intake had significantly improved in the intervention phase (RR 1.82 (95%CI 1.14-2.91)). The aimed online reach- and engagement rate of the intervention was achieved most of the time. Also, after the intervention, more healthcare providers were aware of PCC-risk factors (54.5% vs. 47.7%; p = 0.040) and more healthcare providers considered it easier to start a conversation about PCC (75.0% vs. 47.9%; p = 0.030). CONCLUSION: The intervention showed some tentative positive effects on lifestyle behaviours among prospective parents. Primarily on vegetable intake and the knowledge and competence of healthcare providers. The results of this study contribute to the evidence regarding successfully implementing PCC-interventions to optimize the health of prospective parents and future generations. TRIAL REGISTRATION: Dutch Trial Register: NL7784 (Registered 06/06/2019).


Asunto(s)
Estilo de Vida , Atención Preconceptiva , Embarazo , Masculino , Femenino , Humanos , Atención Preconceptiva/métodos , Estudios Prospectivos , Países Bajos , Atención Prenatal
3.
Psychophysiology ; 56(12): e13460, 2019 12.
Artículo en Inglés | MEDLINE | ID: mdl-31435961

RESUMEN

Recent studies suggest that individuals with dyslexia may be impaired in probability learning and performance monitoring. These observations are consistent with findings indicating atypical neural activations in frontostriatal circuits in the brain, which are important for associative learning. The current study further examined probability learning and performance monitoring in adult individuals with dyslexia (n = 23) and typical readers (n = 31) using two varieties of a typical probabilistic learning task. In addition to performance measures, we measured heart rate, focusing on cardiac slowing with negative feedback as a manifestation of the automatic performance monitoring system. One task required participants to learn associations between artificial script and speech sounds and the other task required them to learn associations between geometric forms and bird sounds. Corrective feedback (informative or random) was provided in both tasks. Performance results indicated that individuals with dyslexia and typical readers learned the associations equally well in contrast to expectations. We found the typical cardiac response associated with feedback processing consisting of a heart rate slowing with the presentation of the feedback and a return to baseline thereafter. Interestingly, the heart rate slowing associated with feedback was less pronounced and the return to baseline was delayed in individuals with dyslexia relative to typical readers. These findings were interpreted in relation to current theorizing of performance monitoring linking the salience network in the brain to autonomic functioning.


Asunto(s)
Aprendizaje por Asociación/fisiología , Corteza Cerebral/fisiología , Disfunción Cognitiva/fisiopatología , Dislexia/fisiopatología , Retroalimentación Psicológica/fisiología , Frecuencia Cardíaca/fisiología , Aprendizaje por Probabilidad , Desempeño Psicomotor/fisiología , Adulto , Disfunción Cognitiva/etiología , Dislexia/complicaciones , Electrocardiografía , Electroencefalografía , Femenino , Humanos , Masculino , Adulto Joven
5.
Sci Rep ; 7(1): 9685, 2017 08 29.
Artículo en Inglés | MEDLINE | ID: mdl-28852152

RESUMEN

Resting-state functional connectivity patterns are highly stable over time within subjects. This suggests that such 'functional fingerprints' may have strong genetic component. We investigated whether the functional (FC) or effective (EC) connectivity patterns of one monozygotic twin could be used to identify the co-twin among a larger sample and determined the overlap in functional fingerprints within monozygotic (MZ) twin pairs using resting state magnetoencephalography (MEG). We included 32 cognitively normal MZ twin pairs from the Netherlands Twin Register who participate in the EMIF-AD preclinAD study (average age 68 years). Combining EC information across multiple frequency bands we obtained an identification rate over 75%. Since MZ twin pairs are genetically identical these results suggest a high genetic contribution to MEG-based EC patterns, leading to large similarities in brain connectivity patterns between two individuals even after 60 years of life or more.


Asunto(s)
Encéfalo/fisiología , Conectoma , Magnetoencefalografía , Gemelos Monocigóticos , Femenino , Humanos , Masculino , Países Bajos
6.
Psychol Med ; 47(6): 1085-1096, 2017 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-27974054

RESUMEN

BACKGROUND: Genetic-epidemiological studies that estimate the contributions of genetic factors to variation in tic symptoms are scarce. We estimated the extent to which genetic and environmental influences contribute to tics, employing various phenotypic definitions ranging between mild and severe symptomatology, in a large population-based adult twin-family sample. METHOD: In an extended twin-family design, we analysed lifetime tic data reported by adult mono- and dizygotic twins (n = 8323) and their family members (n = 7164; parents and siblings) from 7311 families in the Netherlands Twin Register. We measured tics by the abbreviated version of the Schedule for Tourette and Other Behavioral Syndromes. Heritability was estimated by genetic structural equation modeling for four tic disorder definitions: three dichotomous and one trichotomous phenotype, characterized by increasingly strictly defined criteria. RESULTS: Prevalence rates of the different tic disorders in our sample varied between 0.3 and 4.5% depending on tic disorder definition. Tic frequencies decreased with increasing age. Heritability estimates varied between 0.25 and 0.37, depending on phenotypic definitions. None of the phenotypes showed evidence of assortative mating, effects of shared environment or non-additive genetic effects. CONCLUSIONS: Heritabilities of mild and severe tic phenotypes were estimated to be moderate. Overlapping confidence intervals of the heritability estimates suggest overlapping genetic liabilities between the various tic phenotypes. The most lenient phenotype (defined only by tic characteristics, excluding criteria B, C and D of DSM-IV) rendered sufficiently reliable heritability estimates. These findings have implications in phenotypic definitions for future genetic studies.


Asunto(s)
Predisposición Genética a la Enfermedad , Núcleo Familiar , Sistema de Registros , Trastornos de Tic/genética , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Niño , Femenino , Humanos , Masculino , Persona de Mediana Edad , Países Bajos/epidemiología , Linaje , Trastornos de Tic/epidemiología , Adulto Joven
7.
Transl Psychiatry ; 6: e731, 2016 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-26859814

RESUMEN

Variation in obsessive-compulsive symptoms (OCS) has a heritable basis, with genetic association studies starting to yield the first suggestive findings. We contribute to insights into the genetic basis of OCS by performing an extensive series of genetic analyses in a homogeneous, population-based sample from the Netherlands. First, phenotypic and genetic longitudinal correlations over a 6-year period were estimated by modeling OCS data from twins and siblings. Second, polygenic risk scores (PRS) for 6931 subjects with genotype and OCS data were calculated based on meta-analysis results from IOCDF-GC, to investigate their predictive value. Third, the contribution of measured single nucleotide polymorphisms (SNPs) to the heritability was estimated using random-effects modeling. Last, we performed an exploratory genome-wide association study (GWAS) of OCS, testing for SNP- and for gene-based associations. Stability in OCS (test-retest correlation 0.63) was mainly explained by genetic stability. The PRS based on clinical samples predicted OCS in our population-based twin-family sample. SNP-based heritability was estimated at 14%. GWAS revealed one SNP (rs8100480), located within the MEF2BNB gene, associated with OCS (P=2.56 × 10(-8)). Additional gene-based testing resulted in four significantly associated genes, which are located in the same chromosomal region on chromosome 19p13.11: MEF2BNB, RFXANK, MEF2BNB-MEF2B and MEF2B. Thus, common genetic variants explained a significant proportion of OCS trait variation. Genes significantly associated with OCS are expressed in the brain and involved in development and control of immune system functions (RFXANK) and regulation of gene expression of muscle-specific genes (MEF2BNB). MEF2BNB also showed a suggestive association with OCD in an independent case-control study, suggesting a role for this gene in the development of OCS.


Asunto(s)
Herencia Multifactorial/genética , Trastorno Obsesivo Compulsivo/genética , Polimorfismo de Nucleótido Simple/genética , Gemelos/genética , Adulto , Estudios de Casos y Controles , Femenino , Estudios de Asociación Genética , Estudio de Asociación del Genoma Completo/métodos , Humanos , Masculino , Países Bajos
8.
Oncogene ; 30(27): 3036-48, 2011 Jul 07.
Artículo en Inglés | MEDLINE | ID: mdl-21358674

RESUMEN

The use of adherent monolayer cultures have produced many insights into melanoma cell growth and differentiation, but often novel therapeutics demonstrated to act on these cells are not active in vivo. It is imperative that new methods of growing melanoma cells that reflect growth in vivo are investigated. To this end, a range of human melanoma cell lines passaged as adherent cultures or induced to form melanoma spheres (melanospheres) in stem cell media have been studied to compare cellular characteristics and protein expression. Melanoma spheres and tumours grown from cell lines as mouse xenografts had increased heterogeneity when compared with adherent cells and 3D-spheroids in agar (aggregates). Furthermore, cells within the melanoma spheres and mouse xenografts each displayed a high level of reciprocal BRN2 or MITF expression, which matched more closely the pattern seen in human melanoma tumours in situ, rather than the propensity for co-expression of these important melanocytic transcription factors seen in adherent cells and 3D-spheroids. Notably, when the levels of the BRN2 and MITF proteins were each independently repressed using siRNA treatment of adherent melanoma cells, members of the NOTCH pathway responded by decreasing or increasing expression, respectively. This links BRN2 as an activator, and conversely, MITF as a repressor of the NOTCH pathway in melanoma cells. Loss of the BRN2-MITF axis in antisense-ablated cell lines decreased the melanoma sphere-forming capability, cell adhesion during 3D-spheroid formation and invasion through a collagen matrix. Combined, this evidence suggests that the melanoma sphere-culture system induces subpopulations of cells that may more accurately portray the in vivo disease, than the growth as adherent melanoma cells.


Asunto(s)
Proteínas de Homeodominio/genética , Melanoma/genética , Factor de Transcripción Asociado a Microftalmía/genética , Factores del Dominio POU/genética , Receptores Notch/metabolismo , Animales , Línea Celular Tumoral , Humanos , Melanoma/metabolismo , Melanoma/patología , Ratones , Trasplante Heterólogo
9.
Behav Genet ; 40(2): 167-77, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20111993

RESUMEN

We examined the longitudinal genetic architecture of three parameters of functional brain connectivity. One parameter described overall connectivity (synchronization likelihood, SL). The two others were derived from graph theory and described local (clustering coefficient, CC) and global (average path length, L) aspects of connectivity. We measured resting state EEG in 1,438 subjects from four age groups of about 16, 18, 25 and 50 years. Developmental curves for SL and L indicate that connectivity is more random at adolescence and old age, and more structured in middle-aged adulthood. Individual variation in SL and L were moderately to highly heritable at each age (SL: 40-82%; L: 29-63%). Genetic factors underlying these phenotypes overlapped. CC was also heritable (25-49%) but showed no systematic overlap with SL and L. SL, CC, and L in the alpha band showed high phenotypic and genetic stability from 16 to 25 years. Heritability for parameters in the beta band was lower, and less stable across ages, but genetic stability was high. We conclude that the connectivity parameters SL, CC, and L in the alpha band show the hallmarks of a good endophenotype for behavior and developmental disorders.


Asunto(s)
Encéfalo/patología , Adolescente , Adulto , Conducta , Mapeo Encefálico/métodos , Análisis por Conglomerados , Discapacidades del Desarrollo/genética , Electroencefalografía/métodos , Genotipo , Humanos , Persona de Mediana Edad , Modelos Genéticos , Fenotipo , Gemelos Dicigóticos , Gemelos Monocigóticos
10.
Ned Tijdschr Geneeskd ; 152(28): 1568, 2008 Jul 12.
Artículo en Holandés | MEDLINE | ID: mdl-18712224

RESUMEN

Folic acid supplementation was recommended in the Netherlands after it had been demonstrated that periconceptional use of folic acid protected against foetal neural tube defects; this recommendation led to a slight decrease in prevalence only. According to the Dutch Health Council, fortification of bread should now be considered. Policy-making is complicated by uncertainties regarding potential side effects, such as adverse effects in children, for which scientific evidence is lacking however.


Asunto(s)
Deficiencia de Ácido Fólico/prevención & control , Ácido Fólico/administración & dosificación , Alimentos Fortificados , Defectos del Tubo Neural/prevención & control , Complejo Vitamínico B/administración & dosificación , Relación Dosis-Respuesta a Droga , Ácido Fólico/efectos adversos , Deficiencia de Ácido Fólico/complicaciones , Humanos , Países Bajos , Defectos del Tubo Neural/epidemiología , Necesidades Nutricionales , Prevención Primaria , Complejo Vitamínico B/efectos adversos
11.
Int J Psychophysiol ; 66(3): 196-204, 2007 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-17669532

RESUMEN

Previous studies have reported that individual variation in N1 amplitude is related to attentional problems and alcoholism. Using data from 651 twins and siblings from 292 families we examined whether variation in N1 amplitude and latency can be explained by genetic factors. In half of the subjects the age centered around 26 (young adult cohort), in the other half the age centered around 49 (middle-aged adult cohort). Two visual N1 components were identified by a spatial PCA -- an early anterior component peaking from 88 to 168 ms after stimulus presentation and a posterior one peaking from 132 to 220 ms. Significant heritability was found for anterior N1 amplitude (22%) and posterior amplitude (50%), and for anterior latency (45%) and posterior latency (43%). We conclude that visual N1 amplitude and latency may serve as endophenotypes to detect genetic variation in susceptibility to psychiatric disorders.


Asunto(s)
Mapeo Encefálico , Electroencefalografía , Potenciales Evocados Visuales/genética , Lóbulo Parietal/fisiología , Tiempo de Reacción/genética , Adulto , Factores de Edad , Familia , Femenino , Humanos , Masculino , Persona de Mediana Edad , Lóbulo Parietal/anatomía & histología , Estimulación Luminosa/métodos , Tiempo de Reacción/fisiología , Factores Sexuales , Estudios en Gemelos como Asunto , Percepción Visual/genética
12.
Biol Psychol ; 74(1): 26-33, 2007 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-16875773

RESUMEN

Frontal asymmetry of EEG alpha power (FA) may index the risk for anxiety and depression. Evidence linking FA to the underlying biological mechanisms is scarce. This is unfortunate because FA has potential as a biological marker to support gene finding in anxiety and depression. We examined the heritability of FA in 732 twins and their singleton siblings, and established the genetic and environmental contribution to the relation between FA and the risk for anxiety and depression. Multivariate models showed that FA is heritable only in young adults (males 32% and females 37%) but not in middle-aged adults. A significant relation between FA and the risk for anxiety and depression was only found in young adult females. This relation was explained by shared genes influencing both EEG and disease risk. Future studies on asymmetry of left and right frontal brain activation should carefully consider the effects of sex and age.


Asunto(s)
Trastornos de Ansiedad/fisiopatología , Trastorno Depresivo/fisiopatología , Electroencefalografía , Lóbulo Frontal/anatomía & histología , Lóbulo Frontal/fisiopatología , Lateralidad Funcional/fisiología , Adulto , Femenino , Humanos , Masculino , Persona de Mediana Edad , Inventario de Personalidad , Fenotipo , Factores de Riesgo , Encuestas y Cuestionarios , Gemelos/fisiología
14.
Pigment Cell Res ; 19(3): 226-31, 2006 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-16704456

RESUMEN

To date, a role for agouti signalling protein (ASIP) in human pigmentation has not been well characterized. It is known that agouti plays a pivotal role in the pigment switch from the dark eumelanin to the light pheomelanin in the mouse. However, because humans do not have an agouti banded hair pattern, its role in human pigmentation has been questioned. We previously identified a single polymorphism in the 3'-untranslated region (UTR) of ASIP that was found at a higher frequency in African-Americans compared with other population groups. To compare allele frequencies between European-Australians and indigenous Australians, the g.8818A --> G polymorphism was genotyped. Significant differences were seen in allele frequencies between these groups (P < 0.0001) with carriage of the G allele highest in Australian Aborigines. In the Caucasian sample set a strong association was observed between the G allele and dark hair colour (P = 0.004) (odds ratio 4.6; 95% CI 1.4-15.27). The functional consequences of this polymorphism are not known but it was postulated that it might result in message instability and premature degradation of the transcript. To test this hypothesis, ASIP mRNA levels were quantified in melanocytes carrying the variant and non-variant alleles. Using quantitative real-time polymerase chain reaction the mean ASIP mRNA ratio of the AA genotype to the AG genotype was 12 (P < 0.05). This study suggests that the 3'-UTR polymorphism results in decreased levels of ASIP and therefore less pheomelanin production.


Asunto(s)
Regulación de la Expresión Génica/genética , Péptidos y Proteínas de Señalización Intercelular/genética , Polimorfismo de Nucleótido Simple/genética , Transcripción Genética , Proteína de Señalización Agouti , Pueblo Asiatico/genética , Células Cultivadas , Frecuencia de los Genes , Genotipo , Humanos , Melaninas/biosíntesis , Melaninas/genética , Melanocitos/fisiología , Nativos de Hawái y Otras Islas del Pacífico/genética , Pigmentación/genética , ARN Mensajero/metabolismo , Población Blanca/genética
15.
Psychophysiology ; 42(6): 691-7, 2005 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-16364064

RESUMEN

We estimated the genetic and nongenetic (environmental) contributions to individual differences in the background EEG power spectrum in two age cohorts with mean ages of 26.2 and 49.4 years. Nineteen-lead EEG was recorded with eyes closed from 142 monozygotic and 167 dizygotic twin pairs and their siblings, totaling 760 subjects. We obtained power spectra in 24 bins of 1 Hz ranging from 1.0 to 25.0 Hz. Generally, heritability was highest around the alpha peak frequency and lower in the theta and delta bands. In the beta band heritability gradually decreased with increasing frequency, especially in the temporal regions. Genetic correlations between power in the classical broad bands indicated that half to three-quarters of the genetic variance can be attributed to a common source. We conclude that across the scalp and most of the frequency spectrum, individual differences in adult EEG are largely determined by genetic factors.


Asunto(s)
Electroencefalografía , Genética , Adulto , Algoritmos , Ritmo alfa , Interpretación Estadística de Datos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Gemelos Dicigóticos , Gemelos Monocigóticos
16.
Reprod Toxicol ; 20(3): 411-5, 2005.
Artículo en Inglés | MEDLINE | ID: mdl-15978774

RESUMEN

Randomized controlled trials have proven that periconceptional folic acid intake reduces the risk of neural tube defects (NTDs). This lead to different public health policies: fortification of foods in many countries and supplementation in some others. We concentrate here on pro's and con's of fortification policies. Meanwhile, new beneficial but also potential adverse effects are being hypothesized. Highest level evidence is available for the protective effect of folic acid on NTDs. Lower level evidence suggests other protective effects, but also some potential adverse effects, such as masking Vitamin B-12 deficiency, increasing twinning rates and an 'acceleration phenomenon' in pre-existing malignant neoplasms. While observational studies show lower cancer rates associated with increased folate intake, some case reports and animal experiments suggest opposite effects. Thus, public health policy makers are facing the question of balancing beneficial and potential adverse effects repeatedly. We propose that the scientific debate no longer focuses on NTDs alone, but that a comprehensive evaluation be undertaken by a public health authority with experience in complex meta-analyses and technology assessment.


Asunto(s)
Suplementos Dietéticos , Ácido Fólico/administración & dosificación , Alimentos Fortificados , Defectos del Tubo Neural/prevención & control , Política Nutricional , Salud Pública , Adulto , Animales , Femenino , Ácido Fólico/efectos adversos , Humanos , Embarazo
17.
J Anim Sci ; 80(11): 2931-41, 2002 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-12462261

RESUMEN

Experiments were conducted to determine the total residues remaining in ocular tissues of cattle and turkeys after oral administration of [14C]ractopamine HCl. Twelve cattle were intraruminally dosed with 0.9 mg x kg(-1) x d(-1) of [14C]ractopamine HCl for 7 d. Four cattle each were slaughtered with withdrawal periods of 48,96, and 144 h. Radioactive residues were not detectable in whole-eye homogenates from the cattle. Eight male and eight female turkeys per treatment received either 7.5, 22.5, or 30 ppm dietary [14C]ractopamine HCl (0.33, 1.02, and 1.36 mg x kg(-1) x d(-1); treatment groups 1, 2, and 3, respectively) for 7 d, and the birds were slaughtered with a 0-d withdrawal period. Eyes were dissected into retina/choroid/schlera (RCS), cornea/iris (CI), and aqueous humor (AH) fractions. Residues in RCS, CI, and AH of treatment 1 turkeys were not detectable. Residues in AH were < 0.02 ppm in treatment groups 2 and 3. Mean residues in RCS ranged from 0.15 to 0.26 ppm, and mean CI residues ranged from <0.09 to 0.17 ppm for treatment groups 2 and 3, respectively. The propensities of ractopamine and synthetic ractopamine metabolites to bind to melanin were studied in vitro using radiolabeled ligands with centrifugal filtration to separate melanin from unbound ligand. In vitro studies showed that [14C]ractopamine HCl binds to melanin rapidly and was displaced from melanin by other beta-agonists. Glucuronidation of ractopamine, which produced the major biotransformation product of ractopamine in all species studied to date, prevented binding to melanin. These studies demonstrate that the propensity for the in vivo binding of ractopamine HCl to pigmented ocular tissues is less than that reported for clenbuterol.


Asunto(s)
Agonistas Adrenérgicos beta/farmacocinética , Bovinos/metabolismo , Residuos de Medicamentos/análisis , Ojo/metabolismo , Melaninas/metabolismo , Fenetilaminas/farmacocinética , Pavos/metabolismo , Administración Oral , Agonistas Adrenérgicos beta/administración & dosificación , Agonistas Adrenérgicos beta/química , Animales , Radioisótopos de Carbono , Relación Dosis-Respuesta a Droga , Ojo/química , Femenino , Masculino , Fenetilaminas/administración & dosificación , Fenetilaminas/química , Distribución Tisular
18.
Gene ; 281(1-2): 81-94, 2001 Dec 27.
Artículo en Inglés | MEDLINE | ID: mdl-11750130

RESUMEN

The complete sequence of the MC1R locus has been assembled, the coding region of the gene is intronless and placed within a 12 kb region flanked by the NULP1 and TUBB4 genes. The immediate promoter region has an E-box site with homology to the M-box consensus known to bind the microphthalmia transcription factor (MITF); however, promoter deletion analysis and transactivation studies have failed to show activation through this element by MITF. Polymorphism within the coding region, immediate 5' promoter region and a variable number tandem repeat (VNTR) minisatellite within the locus have been examined in a collection of Caucasian families and African individuals. Haplotype analysis shows linkage disequilibrium between the VNTR and MC1R coding region red hair variant alleles which can be used to estimate the age of these missense changes. Assuming a mean VNTR mutation rate of 1% and a star phylogeny, we estimate the Arg151Cys variant arose 7500 years before the present day, suggesting these variants may have arisen in the Caucasian population more recently than previously thought.


Asunto(s)
Receptores de Corticotropina/genética , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Northern Blotting , Células Cultivadas , ADN/química , ADN/genética , ADN/aislamiento & purificación , Evolución Molecular , Expresión Génica , Haplotipos , Células HeLa , Humanos , Luciferasas/genética , Luciferasas/metabolismo , Masculino , Melanocitos/citología , Melanocitos/metabolismo , Ratones , Datos de Secuencia Molecular , Poli A/genética , Polimorfismo Genético , Regiones Promotoras Genéticas/genética , ARN Mensajero/genética , ARN Mensajero/metabolismo , Receptores de Melanocortina , Proteínas Recombinantes de Fusión/genética , Proteínas Recombinantes de Fusión/metabolismo , Análisis de Secuencia de ADN , Homología de Secuencia de Ácido Nucleico , Sitio de Iniciación de la Transcripción , Transcripción Genética , Células Tumorales Cultivadas
19.
Eur J Biochem ; 267(21): 6413-22, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11029584

RESUMEN

The class III POU gene brn-2, encoding the Brn-2/N-Oct-3 transcription factor, is widely expressed in the developing mammalian central nervous system. Brn-2 has also been found to regulate the melanocytic phenotype with N-Oct-3 DNA binding activity elevated in malignant melanoma, however, its mode of action is yet to be defined. The functional role of the Brn-2 transcription factor has been investigated through the analysis of protein-protein interactions it forms with a number of basal and melanocytic transcriptional regulatory proteins. In vivo interactions were tested by gene-cotransfection using the mammalian GAL4-Herpes Simplex viral protein 16 (VP16) two hybrid formation and direct protein binding by in vitro glutathione S-transferase (GST)-pull down assay. The Brn-2 protein was found to homodimerize in vivo with high affinity, using Brn-2 deletion constructs dimer complex formation was found to be dependent on the presence of both the homeodomain and linker regions of the POU-domain. However, the POU-homoedomain was dispensable for the formation of the dimerization interface in one of the partner molecules but not both, when the POU-linker region was removed the ability to interact was lost irrespective of the presence of the homeodomain. Dimerization of Brn-2/N-Oct-3 was also found to occur in DNA binding assays using melanoma cell line nuclear extracts and a recently reported dimer target sequence probe, which may have significant consequences for gene regulation in melanocytic tumours. Low affinity Brn-2 protein contacts have also been found with the basal transcription complex, including TATA binding protein (TBP) and the transcriptional coactivator p300, and with the Sox-10 and Pax-3 transcription factors that are known to play an important role in melanocyte cell formation.


Asunto(s)
Factores de Transcripción/química , Factores de Transcripción/metabolismo , Sitios de Unión , Extractos Celulares , ADN/genética , ADN/metabolismo , Proteínas de Unión al ADN/genética , Proteínas de Unión al ADN/metabolismo , Dimerización , Proteínas del Grupo de Alta Movilidad/genética , Proteínas del Grupo de Alta Movilidad/metabolismo , Proteínas de Homeodominio , Humanos , Melanoma/metabolismo , Melanoma/patología , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Factor 3 de Transcripción de Unión a Octámeros , Factor de Transcripción PAX3 , Factores del Dominio POU , Factores de Transcripción Paired Box , Unión Proteica , Estructura Terciaria de Proteína , Factores de Transcripción SOXE , Eliminación de Secuencia/genética , Proteína de Unión a TATA-Box , Moldes Genéticos , Transactivadores/genética , Transactivadores/metabolismo , Factor de Transcripción TFIIB , Factores de Transcripción/genética , Células Tumorales Cultivadas
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