RESUMO
Analysis of intracellular cholesterol transport by fluorescence microscopy requires suitable fluorescent analogues of cholesterol. Most existing cholesterol analogues contain lipophilic dyes which can compromise the sterol properties in membranes. An alternative strategy is to introduce additional double bonds into the sterol ring system resulting in intrinsic fluorescence, while at the same time keeping the cholesterol-like properties of the analogues. Existing polyene sterols, such as dehydroergosterol (DHE) or cholestatrienol (CTL), however, contain only three double bonds and suffer from low brightness, significant photobleaching and excitation/emission in the ultraviolet region. Thus, special equipment is required to image such sterols. Here, we describe synthesis, characterization and intracellular imaging of new polyene sterols containing four conjugated double bonds in the sterol ring system. We show that such analogues have red-shifted excitation and emission by â¼20 nm compared to DHE or CTL. The red shift was even more pronounced when preventing keto-enol tautomer equilibration by protecting the 3'-hydroxy group with acetate. We show that the latter analogue can be imaged on a conventional wide field microscope with a DAPI/filipin filter cube. The new polyene sterols show reduced photobleaching compared to DHE or CTL allowing for improved deconvolution microscopy of sterol containing cellular membranes.
Assuntos
Colesterol/química , Microscopia de Fluorescência/métodos , Polienos/química , Esteróis/química , Transporte Biológico , Membrana Celular/química , Colesterol/análogos & derivados , Citoplasma/química , Fluorescência , Humanos , Fotodegradação , Esteróis/síntese químicaRESUMO
BACKGROUND: Sarcopenia and frailty are often used interchangeably in clinical practice yet represent two distinct conditions and require different therapeutic approaches. The literature regarding the co-occurrence of both conditions in older patients is scarce as most studies have investigated the prevalence of sarcopenia and frailty separately. OBJECTIVES: We aim to evaluate the prevalence and co-occurrence of sarcopenia and frailty in a large sample of acutely admitted older medical patients. DESIGN: Secondary analyses using cross-sectional data from the Copenhagen PROTECT study. SETTING: Patients were included from the acute medical ward at Copenhagen University Hospital, Bispebjerg and Frederiksberg, Copenhagen, Denmark, between November 2019 and November 2021. PARTICIPANTS: Acutely admitted older medical patients (≥65 years). MEASUREMENTS: Handgrip strength (HGS) was investigated using a handheld dynamometer. Lean mass (SMI) was investigated using direct-segmental multifrequency bioelectrical impedance analyses (DSM-BIA). Low HGS, low SMI, and sarcopenia were defined according to the recent definitions from the European Working Group on Sarcopenia in Older People (EWGSOP2). The Clinical Frailty Scale (CFS) was used to evaluate frailty, with a value > 5 indicating the presence of frailty. Patients were enrolled and tested within 24 hours of admission. RESULTS: This study included 638 patients (mean age: 78.2±7.6, 55% female) with complete records of SMI, HGS, and the CFS. The prevalence of low HGS, low SMI, sarcopenia, and frailty were 39.0%, 33.1%, 19.7%, and 39.0%, respectively. Sarcopenia and frailty co-occurred in 12.1% of the patients. CONCLUSIONS: It is well-known that sarcopenia and frailty represent clinical manifestations of ageing and overlap in terms of the impairment in physical function observed in both conditions. Our results demonstrate that sarcopenia and frailty do not necessarily co-occur within the older acutely admitted patient, highlighting the need for separate assessments of frailty and sarcopenia to ensure the accurate characterization of the health status of older patients.
Assuntos
Fragilidade , Sarcopenia , Humanos , Feminino , Idoso , Idoso de 80 Anos ou mais , Masculino , Sarcopenia/diagnóstico , Sarcopenia/epidemiologia , Estudos Transversais , Fragilidade/diagnóstico , Fragilidade/epidemiologia , Força da Mão , HospitalizaçãoRESUMO
To investigate if short-term block-structured training consisting of alternating weeks of blood flow restricted low-load resistance training (BFR-RT) and conventional free-flow heavy-load resistance training (HL-RT) leads to superior gains in mechanical muscle function, myofiber size, and satellite cell (SC) content and myonuclear number compared with HL-RT alone. Eighteen active young participants (women/men: 5/13, 23 ± 1.2 yr) were randomized to 6 wk (22 sessions) of lower limb HL-RT [70-90% one repetition maximum (1-RM)] (HRT, n = 9) or block-structured training alternating weekly between BFR-RT (20% 1-RM) and HL-RT (BFR-HRT, n = 9). Maximal isometric knee extensor strength (MVC) and muscle biopsies (VL) were obtained pre- and posttraining to examine changes in muscle strength, myofiber cross-sectional area (CSA), myonuclear (MN) number, and SC content. MVC increased in both training groups (BFR-HRT: +12%, HRT: +7%; P < 0.05). Type II myofiber CSA increased similarly (+16%) in BFR-HRT and HRT (P < 0.05), while gains in type I CSA were observed following HRT only (+12%, P < 0.05). In addition, myonuclear number remained unchanged, whereas SC content increased in type II myofibers following HRT (+59%, P < 0.05). Short-term alternating BFR-RT and HL-RT did not produce superior gains in muscle strength or myofiber size compared with HL-RT alone. Noticeably, however, conventional HL-RT could be periodically replaced by low-load BFR-RT without compromising training-induced gains in maximal muscle strength and type II myofiber size, respectively.NEW & NOTEWORTHY The present data demonstrate that periodically substituting heavy-load resistance training (HL-RT) with low-load blood flow restricted resistance training (BFR-RT) leads to similar gains in type II myofiber CSA and muscle strength as achieved by HL-RT alone. Furthermore, we have for the first time evaluated myonuclear content and myonuclear domain size before and after training intervention across separate fiber size clusters and found no within-cluster changes for these parameters with training.
Assuntos
Treinamento Resistido , Feminino , Hemodinâmica , Humanos , Masculino , Força Muscular , Músculo Esquelético , Músculos , Fluxo Sanguíneo RegionalRESUMO
Coordinate activation of transcription by multiple enhancer binding factors is essential for the regulation of pattern formation during development of Drosophila melanogaster. Cell-free transcription reactions are described that recapitulate transcriptional synergism directed by the Drosophila developmental regulators Bicoid (BCD) and Hunchback (HB). Within the basal transcription factor complex TFIID, two specific targets, TAFII110 and TAFII60, served as coactivators to mediate transcriptional activation by these two enhancer binding proteins. A quadruple complex containing TATA binding protein (TBP), TAFII250, TAFII110, and TAFII60 mediated transcriptional synergism by BCD and HB, whereas triple TBP-TAFII complexes lacking one or the other target coactivator failed to support synergistic activation. Deoxyribonuclease I footprint protection experiments revealed that an integral step leading to transcriptional synergism involves the recruitment of TBP-TAFII complexes to the promoter by way of multivalent contacts between activators and selected TAFIIs. Thus, the concerted action of multiple regulators with different coactivators helps to establish the pattern and level of segmentation gene transcription during Drosophila development.
Assuntos
Proteínas de Drosophila , Regulação da Expressão Gênica no Desenvolvimento , Proteínas de Homeodomínio , Hormônios de Inseto/genética , Hormônios Juvenis/genética , Transativadores , Fatores de Transcrição/metabolismo , Ativação Transcricional , Animais , Linhagem Celular , Proteínas de Ligação a DNA/metabolismo , Drosophila melanogaster/embriologia , Drosophila melanogaster/genética , Elementos Facilitadores Genéticos , Ligação Proteica , Proteínas Recombinantes , TATA Box , Proteína de Ligação a TATA-Box , Fator de Transcrição TFIIDRESUMO
The template and coactivator requirements for synergistic transcription directed by a single activator, Bicoid (BCD), bound to multiple sites have been determined. Mutagenesis studies in combination with protein binding experiments and reconstituted transcription reactions identified two independent activation domains of BCD that target different coactivator subunits (TAFII110 and TAFII60) of the basal transcription factor IID (TFIID). The presence of both coactivators is required for BCD to recruit the TATA binding protein (TBP)-TAF complex to the promoter and direct synergistic activation of transcription. Thus, contact between multiple activation domains of BCD and different targets within the TFIID complex can mediate transcriptional synergism.
Assuntos
DNA/metabolismo , Proteínas de Drosophila , Drosophila/genética , Proteínas de Homeodomínio , Hormônios de Inseto/metabolismo , Transativadores/metabolismo , Transcrição Gênica , Animais , Sítios de Ligação , Linhagem Celular , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Drosophila/metabolismo , Elementos Facilitadores Genéticos , Escherichia coli , Hormônios de Inseto/genética , Hormônios Juvenis/genética , Hormônios Juvenis/metabolismo , Mutagênese , Fragmentos de Peptídeos/genética , Fragmentos de Peptídeos/metabolismo , Regiões Promotoras Genéticas , Ligação Proteica , Proteínas Recombinantes de Fusão/genética , Proteínas Recombinantes de Fusão/metabolismo , Proteína de Ligação a TATA-Box , Moldes Genéticos , Fator de Transcrição TFIID , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismoRESUMO
Genes from Drosophila melanogaster have been identified that encode proteins homologous to Orc2p and Orc5p of the Saccharomyces cerevisiae origin recognition complex (ORC). The abundance of the Drosophila Orc2p homolog DmORC2 is developmentally regulated and is greatest during the earliest stages of embryogenesis, concomitant with the highest rate of DNA replication. Fractionation of embryo nuclear extracts revealed that DmORC2 is found in a tightly associated complex with five additional polypeptides, much like the yeast ORC. These studies will enable direct testing of the initiator-based model of replication in a metazoan.
Assuntos
Replicação do DNA , Proteínas de Ligação a DNA/química , Proteínas de Ligação a DNA/genética , Drosophila melanogaster/genética , Genes de Insetos , Origem de Replicação , Proteínas Repressoras/química , Proteínas Repressoras/genética , Sequência de Aminoácidos , Animais , Clonagem Molecular , DNA Complementar/genética , Proteínas de Ligação a DNA/análise , Proteínas de Ligação a DNA/fisiologia , Drosophila melanogaster/química , Drosophila melanogaster/embriologia , Embrião não Mamífero/química , Dados de Sequência Molecular , Peso Molecular , Complexo de Reconhecimento de Origem , Proteínas Repressoras/análise , Proteínas Repressoras/fisiologia , Saccharomyces cerevisiae/genética , Homologia de SequênciaRESUMO
HeLa cells contain a DNA-binding activity which associates with a kappa B-like DNA element, termed Rel-related protein-binding element (RRBE), localized upstream of the human urokinase promoter. We have purified this activity from the HeLa cell cytosol and have shown that it represents a performed heteromeric complex between p65 (RelA) and c-Rel. Coexpression of c-Rel and p65 (RelA) by in vitro translation formed a DNA-binding complex indistinguishable from purified cellular c-Rel-p65 (RelA) in mobility shift assays. The c-Rel-p65 (RelA) complex was also formed in COS7 cells upon coexpression of c-Rel and p65 (RelA) cDNAs. Cotransfection experiments with COS7 cells, using expression plasmids encoding p50, p65 (RelA), or c-Rel and reporter constructs containing a trimerized RRBE, revealed that c-Rel-p65 (RelA) is a potent activator of the RRBE, giving rise to transcriptional activity higher than that observed with NF-kappa B (p50-p65). In the cytosol, the c-Rel-p65 (RelA) complex existed in a latent, non-DNA-binding form but could be activated by detergent treatment, suggesting that it was associated with an I kappa B protein. Recombinant I kappa B-alpha inhibited the DNA-binding activity of c-Rel-p65 (RelA) via association with either c-Rel or p65 (RelA). Finally, NF-kappa B and c-Rel-p65 (RelA) complexes were found to be differentially expressed and regulated in different cells. The two complexes were present in equimolar amounts in HeLa cells and K562 cells. Stimulation with tetradecanoyl phorbol acetate (TPA) resulted in the nuclear translocation of both NF-kappa B and c-Rel-p65 (RelA) in HeLa cells and of NF-kappa B in HepG2 cells but had no effect on either complex in K562 cells. In addition, TPA stimulation of HepG2 cells induced the expression of a cytosolic latent c-Rel-p65 (RelA) complex which, however, was not translocated to the nucleus. In conclusion, our findings show that c-Rel-p65 (RelA) is an inducible and very potent transcriptional activator which is differentially activated in a cell-type-specific manner.
Assuntos
NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas/isolamento & purificação , Proteínas Proto-Oncogênicas/metabolismo , Fatores de Transcrição , Transcrição Gênica , Animais , Sequência de Bases , Linhagem Celular , Cromatografia de Afinidade , Cromatografia por Troca Iônica , Citosol/metabolismo , Células HeLa , Humanos , Immunoblotting , Cinética , Substâncias Macromoleculares , Dados de Sequência Molecular , NF-kappa B/biossíntese , NF-kappa B/isolamento & purificação , Sondas de Oligonucleotídeos , Plasmídeos , Biossíntese de Proteínas , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas c-rel , Mapeamento por Restrição , Fator de Transcrição RelA , Fator de Transcrição RelB , Transfecção , Células Tumorais CultivadasRESUMO
BACKGROUND: This study attempts to determine if enough pathological abnormalities in gastric remnants from sleeve gastrectomy exist to warrant full pathologic evaluation in all remnants. METHODS: Data was collected on patients undergoing sleeve gastrectomy between 08/01/2011 and 06/30/2014. Significant abnormalities were classified as any pathology that might require follow-up or treatment beyond standard follow-up. Age, comorbidities, gender, and Helicobacter pylori titers were analyzed and compared with pathology specimens using 95% confidence intervals and Phi contingency coefficients. RESULTS: Full pathologic evaluation was available for 351/387 patients (91.2%). No examples of malignancy or dysplasia were identified. Gastritis was the most common abnormality. There was a statistically significant association between preoperative H. pylori and significantly abnormal pathology (p = 0.003). Other comorbidities had no association. CONCLUSIONS: These results suggest that full pathologic evaluation of the gastric remnant following sleeve gastrectomy is unnecessary, particularly when gross pathology is not noted at initial operation.
Assuntos
Gastrectomia/métodos , Coto Gástrico/patologia , Obesidade Mórbida/cirurgia , Gastropatias/patologia , Feminino , Gastrite/microbiologia , Gastrite/patologia , Humanos , Laparoscopia , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Gastropatias/microbiologia , Procedimentos DesnecessáriosRESUMO
In a previous study, a model was developed to describe the transfer and survival of Salmonella during grinding of pork (Møller, C.O.A., Nauta, M.J., Christensen, B.B., Dalgaard, P., Hansen, T.B., 2012. Modelling transfer of Salmonella typhimurium DT104 during simulation of grinding of pork. Journal of Applied Microbiology 112 (1), 90-98). The robustness of this model is now evaluated by studying its performance for predicting the transfer and survival of Salmonella spp. and Listeria monocytogenes during grinding of different types of meat (pork and beef), using two different grinders, different sizes and different numbers of pieces of meats to be ground. A total of 19 grinding trials were collected. Acceptable Simulation Zone (ASZ), visual inspection of the data, Quantitative Microbiological Risk Assessment (QMRA), as well as the Total Transfer Potential (TTP) were used as approaches to evaluate model performance and to access the quality of the cross contamination model predictions. Using the ASZ approach and considering that 70% of the observed counts have to be inside a defined acceptable zone of ±0.5 log10CFU per portion, it was found that the cross contamination parameters suggested by Møller et al. (2012) were not able to describe all 19 trials. However, for each of the collected grinding trials, the transfer event was well described when fitted to the model structure proposed by Møller et al. (2012). Parameter estimates obtained by fitting observed trials performed at different conditions, such as size and number of pieces of meat to be ground, may not be applied to describe cross contamination of unlike processing. Nevertheless, the risk estimates, as well as the TTP, revealed that the risk of disease may be reduced when the grinding of meat is performed in a grinder made of stainless steel (for all surfaces in contact with the meat), using a well-sharpened knife and holding at room temperatures lower than 4°C.
Assuntos
Manipulação de Alimentos/normas , Microbiologia de Alimentos/métodos , Listeria monocytogenes/fisiologia , Salmonella/fisiologia , Animais , Bovinos , Humanos , Carne/microbiologia , Modelos Biológicos , Medição de Risco , Aço Inoxidável , SuínosRESUMO
Ethanolic extracts from dried leaves of sage (Salvia officinalis) showed inhibition of [35S]tertiary-butylbicyclophosphorothionate ([35S]TBPS) binding to rat brain membranes in vitro. This ligand is considered to bind to the chloride channel of the GABA/benzodiazepine receptor complex in brain tissue. Substances having inhibitory activity were purified and their chemical structure identified as the diterpenes carnosic acid and carnosol (IC50 values of 33 +/- 3 microM and 57 +/- 4 microM, respectively). The two compounds did not affect binding of the ligands [3H]muscimol and [3H]diazepam to the GABA/benzodiazepine complex in vitro. Saturation experiments of [35S]TBPS binding indicated that carnosic acid decreases the binding affinity.
Assuntos
Compostos Bicíclicos Heterocíclicos com Pontes , Compostos Bicíclicos com Pontes/metabolismo , Córtex Cerebral/metabolismo , Cloretos/metabolismo , Diterpenos/farmacologia , Canais Iônicos/metabolismo , Plantas Medicinais/química , Abietanos , Animais , Córtex Cerebral/efeitos dos fármacos , Diterpenos/química , Diterpenos/isolamento & purificação , Canais Iônicos/efeitos dos fármacos , Cinética , Espectroscopia de Ressonância Magnética , Masculino , Espectrometria de Massas , Fenantrenos/farmacologia , Extratos Vegetais/química , Ensaio Radioligante , Ratos , Ratos Endogâmicos , Receptores de GABA-A/efeitos dos fármacos , Receptores de GABA-A/metabolismoRESUMO
Kawasaki syndrome (KS) is an acute, febrile, exanthemous illness characterized by vasculitis of unknown origin mostly seen in children younger than four years of age. We describe a 24-year-old white male who fulfilled the diagnostic criteria for KS. In addition to the diagnostic symptoms of KS this patient had symptoms from the liver and lungs.
Assuntos
Síndrome de Linfonodos Mucocutâneos/diagnóstico , Adulto , Fatores Etários , Humanos , Fígado/patologia , Pulmão/patologia , Masculino , Síndrome de Linfonodos Mucocutâneos/imunologia , Síndrome de Linfonodos Mucocutâneos/patologiaRESUMO
Milker's nodule is a parapox virus infection seen mostly on the hands of dairy farmers. We saw 15 cases over a period of two years in the County of North Jutland. Clinically, milker's nodule goes through a papular, a nodular and a crusted stage. Most patients were seen when the infection was in the nodular stage, an often painful condition requiring treatment. Three patients developed an erythema multiformelike secondary eruption. Lesions from nine patients were removed for histological examination. The histology of all lesions was consistent with milker's nodule. In three of seven patients parapox virus was demonstrated by electron microscopy. Treatment was commonly curettage followed by cauterization.
Assuntos
Doenças dos Trabalhadores Agrícolas/patologia , Infecções por Poxviridae/patologia , Dermatopatias Virais/patologia , Adulto , Doenças dos Trabalhadores Agrícolas/terapia , Doenças dos Trabalhadores Agrícolas/virologia , Feminino , Humanos , Masculino , Infecções por Poxviridae/etiologia , Infecções por Poxviridae/terapia , Dermatopatias Virais/etiologia , Dermatopatias Virais/terapiaRESUMO
Review of all of the abortion consultations from 1986 revealed that 46 of the young women under the age of 18 years utilised the possibility of applying for abortion without permission from their parents which the Danish legislation on termination of pregnancy in 1973 permits. Forty-two of the young women were granted permission for abortion without permission from the parents as it was considered that the relationship between the girl and her parents would otherwise deteriorate. This was not considered to be the case in the four girls for whom application for termination of pregnancy was refused. This material, which is focussed on a problem which has not previously been illustrated, is too limited to permit drawing of any conclusions but there is no information about whether the requirement of parental permission is beneficial or deleterious for the parent/daughter relationship. Relevant investigations are required.
PIP: A review of all of the abortion consultations from 1986 revealed that 46 of the young women under age 18 utilized the possibility of applying for abortion without permission from their parents, which is permitted by virtue of the 1973 Danish legislation on termination of pregnancy. 42 of the young women were granted permission for abortion without permission from the parents, as it was considered that the relationships between the girl and her parents would otherwise deteriorate. This was not considered to be the case for 4 girls for whom application for termination of pregnancy was refused. The article which is focused on a problem which has not been previously illustrated, is too limited to permit drawing any conclusions; there is no information about whether the requirement of parental permission is beneficial or deleterious for the parent/daughter relationships. Relevant investigations are required. (author's modified)
Assuntos
Aspirantes a Aborto/psicologia , Relações Pais-Filho , Gravidez na Adolescência/psicologia , Adolescente , Fatores Etários , Dinamarca , Feminino , Humanos , GravidezRESUMO
The object of this study was to describe a group of women applying for legal abortion in relation to their use of contraception and reasons for choosing an abortion. During a period of 13 months (1991-92) a questionnaire was distributed to women applying for legal abortion at Hillerød Hospital in Denmark. Three hundred and thirty-nine women participated. Fifty-nine percent of the women had become pregnant although they had used contraception. As seen in other studies, women still state demographic factors as their most important reasons for choosing an abortion. Women with two or more children do not want to have more children. Single women do not want children without being in a stable relationship. Furthermore occupation and education were frequently stated as important reasons for having an abortion. Economy and housing were not main reasons but contributory factors. Thirty percent of the women expressed ambivalence about the choice of abortion at the time when the abort was due.
Assuntos
Aspirantes a Aborto/psicologia , Comportamento Contraceptivo , Adolescente , Adulto , Dinamarca , Feminino , Humanos , Gravidez , Fatores Socioeconômicos , Inquéritos e QuestionáriosRESUMO
Despite intensive eradication therapy, some CF patients with early Pseudomonas aeruginosa infection rapidly develop a chronic infection. To elucidate factors associated with this persistence, bacterial characteristics of early P. aeruginosa isolates were analysed that were either eradicated rapidly or persisted despite multiple antimicrobial treatments. Eighty-six early infection episodes were studied. First P. aeruginosa isolates from patients with eradication (36) or persistent infection (16) were included; isolates from patients with intermittent infection (34) were omitted from the study. Virulence assays, antimicrobial resistance, cytotoxicity and mutation frequencies were analysed in vitro. P. aeruginosa was genotyped by SNP-array. Transcriptomic profiles of two eradicated and two persistent strains were compared. Nineteen per cent of patients developed persistent infection; 42% achieved eradication. Secretion of virulence factors and mutation frequencies were highly variable among both eradicated and persistent isolates and were not different between the groups. Cytotoxicity was present in 57% of eradicated vs. 100% of persistent isolates (p <0.01). None of the isolates were resistant to antibiotics. The isolates were genotypically highly diverse. Multivariate analysis showed that in vitro determined bacterial characteristics could not predict persistence after first P. aeruginosa infection. Preliminary transcriptomic data showed increased expression of some genes related to a metabolic pathway. The early onset of chronic infection was not associated with (in vitro determined) bacterial characteristics only. Although the persistent isolates were more often cytotoxic, for the individual patient it was not possible to predict the risk of persistence based on bacterial characteristics. Unknown factors such as host-pathogen and pathogen-pathogen interactions should be further explored.
Assuntos
Broncopneumonia/epidemiologia , Fibrose Cística/complicações , Infecções por Pseudomonas/epidemiologia , Pseudomonas aeruginosa/isolamento & purificação , Pseudomonas aeruginosa/patogenicidade , Adolescente , Antibacterianos/farmacologia , Toxinas Bacterianas/metabolismo , Broncopneumonia/microbiologia , Sobrevivência Celular , Criança , Pré-Escolar , Doença Crônica , Células Epiteliais/microbiologia , Feminino , Humanos , Lactente , Masculino , Testes de Sensibilidade Microbiana , Infecções por Pseudomonas/microbiologia , Pseudomonas aeruginosa/classificação , Transcriptoma , Virulência , Fatores de Virulência/metabolismo , Adulto JovemRESUMO
AIMS/HYPOTHESIS: The hepatocyte nuclear factor (HNF)-4alpha is an orphan nuclear receptor, which plays crucial roles in regulating hepatic gluconeogenesis and insulin secretion. The gene encoding HNF-4alpha (HNF4A) is located on chromosome 20q12-q13 in a region that in several studies has shown linkage with type 2 diabetes. Recently, two independent studies identified single nucleotide polymorphisms (SNPs) in a 90-kb region spanning HNF4A, which showed strong association with type 2 diabetes in the Finnish and Ashkenazi Jewish populations. In an attempt to replicate and extend these findings, we selected four SNPs in the same HNF4A region, which in the Finnish and Ashkenazi Jewish populations were associated with type 2 diabetes, and examined their relationships with type 2 diabetes and prediabetic phenotypes in the Danish Caucasian population. METHODS: The rs1884614, rs2425637, rs1885088 and rs3818247 were analysed in case-control studies of 1387, 1429, 1417 and 1371 type 2 diabetic patients and 4766, 4727, 4665 and 4748 glucose-tolerant subjects respectively. Genotype-quantitative trait analyses comprised 4430, 4394, 4336 and 4413 middle-aged glucose-tolerant subjects from the population-based Inter99 cohort for the rs1884614, rs2425637, rs1885088 and rs3818247 respectively. RESULTS: The risk allele of the rs1884614, which is located 4 kb upstream of the HNF4A P2 promoter, was associated with type 2 diabetes (odds ratio [OR]=1.14, p=0.02) and with a subtle increase in post-OGTT plasma glucose levels in glucose-tolerant subjects (additive model, p=0.05). CONCLUSIONS/INTERPRETATION: Consistent with results from studies of Finnish and Ashkenazi Jewish subjects, variation near the P2 region of HNF4A is associated with type 2 diabetes in the Danish population.
Assuntos
Proteínas de Ligação a DNA/genética , Diabetes Mellitus Tipo 2/genética , Variação Genética , Fosfoproteínas/genética , Fatores de Transcrição/genética , Estudos de Coortes , Dinamarca , Feminino , Finlândia , Fator 4 Nuclear de Hepatócito , Humanos , Judeus/genética , Masculino , Pessoa de Meia-Idade , População Branca/genéticaRESUMO
AIMS: Recently, a novel human G protein-coupled receptor 40 (GPR40), which is predominantly expressed in pancreatic islets, was shown to mediate an amplifying effect of long-chain fatty acids on glucose-induced insulin secretion. The present aim was to examine the coding region of GPR40 for variation and to assess whether identified variants confer an increased risk of Type 2 diabetes or altered insulin release. METHODS: Mutation analysis was performed in 43 patients with Type 2 diabetes, 18 normal glucose-tolerant subjects, and 3 maturity-onset of diabetes in the young (MODY) X patients using direct sequencing. Genotyping was performed using polymerase chain reaction (PCR)-generated primer extension products analysis by high throughput chip-based mass spectrometry (MALDI-TOF). The potential impact of GPR40 mutations on [(3)H]-myo-inositol turnover was estimated in COS-7 cells after stimulation with various concentrations of 5,8,11-eicosatriynoic acid. RESULTS: Two nucleotide substitutions, an Arg211His polymorphism and a rare Asp175Asn mutation, were identified. Both variants showed EC(50) values similar to the wild type. However, the maximal efficacy of the rare Asp175Asn was 39% lower compared with the wild type (P = 0.01). The Arg211His polymorphism had a similar allele frequency among 1384 Type 2 diabetic patients [MAF%; 23.4 (95% CI: 21.8-25.0)] and 4424 middle-aged glucose-tolerant subjects [24.1% (23.2-25.0)]. A genotype-quantitative trait study of 5597 non-diabetic, middle-aged subjects from the Inter99 cohort showed no significant differences in oral glucose tolerance test (OGTT)-derived estimates of insulin release between carriers of various GPR40 genotypes. CONCLUSIONS: Variations in the coding region of GPR40 do not appear to be associated with Type 2 diabetes or insulin release alterations.
Assuntos
Diabetes Mellitus Tipo 2/genética , Insulina/metabolismo , Mutação/genética , Polimorfismo de Nucleotídeo Único/genética , Receptores Acoplados a Proteínas G/genética , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/metabolismo , Humanos , Pessoa de Meia-Idade , LinhagemRESUMO
The D. melanogaster alcohol dehydrogenase (Adh) gene is transcribed from two tandem promoters that are differentially utilized at various stages during development. To determine the mechanism of promoter selectivity, we have analyzed the activity of the Adh promoters both in vitro and in transfected cells. We found that selective promoter utilization is controlled by distinct initiator elements. Reconstitution of Adh transcription with purified components requires a specific TBP-TAF complex that, in concert with TFIIA, directs differential Adh promoter transcription. Fractionation of this TBP-TAF complex reveals that TAFII150 is required for discrimination between the proximal and distal promoters. We propose a mechanism for regulating differential promoter utilization during Drosophila development that involves the recognition of specific initiator elements by TAFs in the TFIID complex.
Assuntos
Álcool Desidrogenase/genética , Proteínas de Ligação a DNA/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/metabolismo , Animais , Sequência de Bases , Linhagem Celular , DNA/genética , Drosophila melanogaster/embriologia , Drosophila melanogaster/genética , Drosophila melanogaster/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Genes de Insetos , Modelos Genéticos , Dados de Sequência Molecular , Fator de Transcrição TFIIARESUMO
A (G + C)-rich density satellite DNA (rho = 1.713 gm/cc) has been purified from splenic DNA of Przewalski's horse, Equus przewalskii, by successive equilibrium density gradient centrifugations. The purified satellite, which may comprise as much as 29% of the total DNA, renatures rapidly; however, analyses of native, single-stranded, and reassociated molecules by analytical ultracentrifugation and melting properties suggest that some sequence heterogeniety exists in the 1.713 gm/cc satellite. Complementary RNA (cRNA) transcribed from satellite DNA has been utilized for in situ hybridization studies with E. przewalskii metaphase chromosomes previously identified by quinacrine-banding. These studies establish that sequences complementary to the 1.713 g/cc satellite are greatly enriched in the centromeres of some, but not all, chromosomes. The differential distribution of satellite DNA sequences over heterochromatic regions allows discrimination of three classes of heterochromatin and serves to define three types of pericentromeric regions in the karyotype of this endangered equine species. Additionally, apparent polymorphism in concentrations of satellite DNA sequences between homologs in the same karyotype is noted.