Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 34
Filtrar
1.
Mar Drugs ; 21(7)2023 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-37504910

RESUMO

We examined the effect of a dietary seaweed extract-sulfated xylorhamnoglucuronan (SXRG84)-on individuals with inflammatory skin conditions. A subgroup analysis of a larger trial was undertaken, where 44 participants with skin conditions were enrolled in a double-blind placebo-controlled crossover design. Subjects ingested either SXRG84 extract (2 g/day) for six weeks and placebo for six weeks, or vice versa. At baseline, six- and twelve-weeks inflammatory markers and the gut microbiota were assessed, as well as skin assessments using the dermatology quality of life index (DQLI), psoriasis area severity index (PASI) and visual analogue scales (VAS). There were significant differences at weeks six and twelve for pro-inflammatory cytokines IFN-γ (p = 0.041), IL-1ß (p = 0.030), TNF-α (p = 0.008) and the anti-inflammatory cytokine IL-10 (p = 0.026), determined by ANCOVA. These cytokines were all significantly higher at six weeks post placebo compared to twelve weeks post placebo followed by SXRG84 treatment. A total of 23% of participants reported skin improvements, as measured by VAS (mean difference 3.1, p = 0.0005) and the DQLI score (mean difference -2.0, p = 0.049), compared to the 'non-responders'. Thus, the ingestion of SXRG84 for 6 weeks reduced inflammatory cytokines, and a subset of participants saw improvements.


Assuntos
Psoríase , Qualidade de Vida , Humanos , Psoríase/tratamento farmacológico , Citocinas , Fator de Necrose Tumoral alfa , Suplementos Nutricionais , Método Duplo-Cego , Resultado do Tratamento
2.
Nutrients ; 15(8)2023 Apr 19.
Artigo em Inglês | MEDLINE | ID: mdl-37111193

RESUMO

Maintaining blood glucose within the target range is the primary treatment goal for women with gestational diabetes mellitus (GDM). Foods with low glycaemic loads are recommended in clinical practice; however, the relative importance of other key lifestyle variables is unexplored. This pilot study explored the associations of glycaemic load, carbohydrates and physical activity parameters on blood glucose concentrations in free-living women with GDM. Twenty-nine women (28-30 weeks gestation, 34 ± 4 years) with GDM were enrolled. Continuous glucose monitoring, physical activity (ActivPAL inclinometer) and dietary intake and dietary quality were measured concurrently for 3 days. Pearson correlation analyses determined the association between glucose levels and lifestyle variables. Despite all receiving the same nutrition education, only 55% of women were following a low glycaemic load diet with a large range of carbohydrate intakes (97-267 g/day). However, the glycaemic load did not correlate with 3-hr postprandial glucose (r2 = 0.021, p = 0.56) or 24-h glucose iAUC (r2 = 0.021, p = 0.58). A significant relationship between total stepping time and lower 24-h glucose iAUC (r2 = 0.308, p = 0.02) and nocturnal glucose (r2 = 0.224, p = 0.05) was found. In free-living women with diet-controlled GDM, more physical activity, i.e., steps accumulated across the day, may be a simple and effective strategy for improving maternal blood glucose concentrations.


Assuntos
Diabetes Gestacional , Gravidez , Feminino , Humanos , Glicemia , Automonitorização da Glicemia , Controle Glicêmico , Projetos Piloto , Exercício Físico
3.
Genetics ; 220(2)2022 02 04.
Artigo em Inglês | MEDLINE | ID: mdl-35100381

RESUMO

Abnormalities in chromosome number have the potential to disrupt the balance of gene expression and thereby decrease organismal fitness and viability. Such abnormalities occur in most solid tumors and also cause severe developmental defects and spontaneous abortions. In contrast to the imbalances in chromosome dose that cause pathologies, the difference in X-chromosome dose used to determine sexual fate across diverse species is well tolerated. Dosage compensation mechanisms have evolved in such species to balance X-chromosome gene expression between the sexes, allowing them to tolerate the difference in X-chromosome dose. This review analyzes the chromosome counting mechanism that tallies X-chromosome number to determine sex (XO male and XX hermaphrodite) in the nematode Caenorhabditis elegans and the associated dosage compensation mechanism that balances X-chromosome gene expression between the sexes. Dissecting the molecular mechanisms underlying X-chromosome counting has revealed how small quantitative differences in intracellular signals can be translated into dramatically different fates. Dissecting the process of X-chromosome dosage compensation has revealed the interplay between chromatin modification and chromosome structure in regulating gene expression over vast chromosomal territories.


Assuntos
Proteínas de Caenorhabditis elegans , Mecanismo Genético de Compensação de Dose , Animais , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Transtornos do Desenvolvimento Sexual , Feminino , Genes Ligados ao Cromossomo X , Masculino , Cromossomo X/genética , Cromossomo X/metabolismo
4.
Cancers (Basel) ; 12(6)2020 May 28.
Artigo em Inglês | MEDLINE | ID: mdl-32481537

RESUMO

The prostate is surrounded by periprostatic adipose tissue (PPAT), the thickness of which has been associated with more aggressive prostate cancer (PCa). There are limited data regarding the functional characteristics of PPAT, how it compares to subcutaneous adipose tissue (SAT), and whether in a setting of localized PCa, these traits are altered by obesity or disease aggressiveness. PPAT and SAT were collected from 60 men (age: 42-78 years, BMI: 21.3-35.6 kg/m2) undergoing total prostatectomy for PCa. Compared to SAT, adipocytes in PPAT were smaller, had the same basal rates of fatty acid release (lipolysis) yet released less polyunsaturated fatty acid species, and were more sensitive to isoproterenol-stimulated lipolysis. Basal lipolysis of PPAT was increased in men diagnosed with less aggressive PCa (Gleason score (GS) ≤ 3 + 4) compared to men with more aggressive PCa (GS ≥ 4 + 3) but no other measured adipocyte parameters related to PCa aggressiveness. Likewise, there was no difference in PPAT lipid biology between lean and obese men. In conclusion, lipid biological features of PPAT do differ from SAT; however, we did not observe any meaningful difference in ex vivo PPAT biology that is associated with PCa aggressiveness or obesity. As such, our findings do not support a relationship between altered PCa behavior in obese men and the metabolic reprogramming of PPAT.

5.
Schizophr Res ; 226: 44-51, 2020 12.
Artigo em Inglês | MEDLINE | ID: mdl-31301881

RESUMO

People classified as ultra-high risk (UHR) of developing psychosis have reduced cellular membrane omega-3 and omega-6 polyunsaturated fatty acids (PUFA). We aimed to compare omega-3 index, fatty acids and molecular phospholipid species from erythrocytes of people with UHR (n = 285) with age-matched healthy controls (n = 120) assessed by mass spectrometry. Lower proportions of PUFA were observed in the UHR group compared to healthy controls; specifically, eicosapentaenoic acid (EPA) was 29.3% lower, docosahexaenoic acid (DHA) was 27.2% lower, arachidonic acid (AA) was 15.8% lower and the omega-3 index was 26.9% lower. The AA to EPA ratio was higher in the UHR group compared to the healthy group. Smoking status had no significant effect on PUFA levels in healthy or the UHR groups. BMI was associated with PUFA levels in the UHR group only and the statistical model only explains 2% of the variance of the PUFA levels. The proportion of nervonic acid was 64.4% higher in the UHR group compared to healthy controls. At a lipid class level, the UHR group had 16% higher concentrations of sphingomyelin (SM) and 46% lower concentrations phosphatidylethanolamine (PE) compared to healthy group. Of the 49 individual molecular phospholipids, twenty-seven phospholipid species were lower in the UHR group. In conclusion, there are clear differences in the proportions of erythrocyte fatty acids and phospholipids between UHR and healthy controls and UHR had higher concentrations of SM and lower concentrations of PE. These differences may represent a promising prodromal risk biomarker in the UHR population to aid clinical diagnosis.


Assuntos
Ácidos Graxos Ômega-3 , Transtornos Psicóticos , Ácidos Docosa-Hexaenoicos , Ácido Eicosapentaenoico , Eritrócitos , Ácidos Graxos , Humanos , Fosfolipídeos
6.
Dev Cell ; 51(2): 192-207.e6, 2019 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-31495695

RESUMO

Mechanisms establishing higher-order chromosome structures and their roles in gene regulation are elusive. We analyzed chromosome architecture during nematode X chromosome dosage compensation, which represses transcription via a dosage-compensation condensin complex (DCC) that binds hermaphrodite Xs and establishes megabase-sized topologically associating domains (TADs). We show that DCC binding at high-occupancy sites (rex sites) defines eight TAD boundaries. Single rex deletions disrupted boundaries, and single insertions created new boundaries, demonstrating that a rex site is necessary and sufficient to define DCC-dependent boundary locations. Deleting eight rex sites (8rexΔ) recapitulated TAD structure of DCC mutants, permitting analysis when chromosome-wide domain architecture was disrupted but most DCC binding remained. 8rexΔ animals exhibited no changes in X expression and lacked dosage-compensation mutant phenotypes. Hence, TAD boundaries are neither the cause nor the consequence of DCC-mediated gene repression. Abrogating TAD structure did, however, reduce thermotolerance, accelerate aging, and shorten lifespan, implicating chromosome architecture in stress responses and aging.


Assuntos
Mecanismo Genético de Compensação de Dose/genética , Regulação da Expressão Gênica/genética , Longevidade/fisiologia , Cromossomo X/genética , Adenosina Trifosfatases/genética , Adenosina Trifosfatases/metabolismo , Animais , Caenorhabditis elegans/metabolismo , Proteínas de Caenorhabditis elegans/genética , Proteínas de Caenorhabditis elegans/metabolismo , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Complexos Multiproteicos/genética , Complexos Multiproteicos/metabolismo
7.
Front Psychiatry ; 10: 393, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31244693

RESUMO

Background: Deficiencies in membrane polyunsaturated fatty acids (PUFA) such as omega-3 (n-3) fatty acids are thought to contribute to the pathophysiological processes underlying psychotic disorders. Emerging evidence suggests that the levels of PUFA are related to clinical symptoms but significant heterogeneity exists between studies. Here, we investigated associations of membrane PUFA with clinical symptoms and functioning in a large sample of individuals at ultra-high risk (UHR) for psychosis. Methods: A total of 285 participants of the NEURAPRO clinical trial were investigated for erythrocyte PUFA levels, including the n-3 index, n-6/n-3 PUFA ratio, docosahexaenoic acid (DHA), and eicosapentaenoic acid (EPA). Severity of general psychopathology [Brief Psychiatric Rating Scale (BPRS)], psychotic symptoms (BPRS psychosis subscale), negative symptoms [Scale for the Assessment of Negative Symptoms (SANS)], manic symptoms [Young Mania Rating Scale (YMRS)], depressive symptoms [Montgomery Asberg Depression Rating Scale (MADRS)], and functioning [Social and Occupational Functioning Scale (SOFAS), Global Functioning Social (GF-S) and Role (GF-R) scales] were assessed concurrently. Partial correlation taking into account the effects of gender, age, and smoking was used to examine the relationship between PUFAs and symptoms severity. Results: The n-3 index negatively correlated with the severity of general psychopathology, psychotic symptoms, depressive symptoms, and manic symptoms. The n-6/n-3 PUFA ratio positively correlated with severity of psychotic and depressive symptoms. The n-3 PUFA DHA negatively correlated with the severity of general psychopathology, positive, manic, and depressive symptoms. EPA negatively correlated with manic symptoms. Nervonic acid, an n-9 monounsaturated fatty acid, positively correlated with general psychopathology, positive and negative symptoms, depressive symptoms, and manic symptoms. The long-chain saturated fatty acid tetracosanoic acid positively correlated with general psychopathology, positive, manic, and depressive symptoms. Conclusions: Partially consistent with a previous study, psychotic symptoms, depressive symptoms, and symptoms of mania were associated with several classes of FAs in the present study. These findings support the relevance of membrane fatty acids for the onset of psychotic symptoms and indicate that FAs should be further evaluated as biomarkers in the UHR for psychosis group. Clinical Trial Registration: ANZCTR, identifier: 12608000475347.

8.
Br J Nutr ; 121(7): 793-808, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30688181

RESUMO

Numerous health benefits are attributed to the n-3 long-chain PUFA (n-3 LCPUFA); EPA and DHA. A systematic literature review was conducted to investigate factors, other than diet, that are associated with the n-3 LCPUFA levels. The inclusion criteria were papers written in English, carried out in adult non-pregnant humans, n-3 LCPUFA measured in blood or tissue, data from cross-sectional studies, or baseline data from intervention studies. The search revealed 5076 unique articles of which seventy were included in the qualitative synthesis. Three main groups of factors potentially associated with n-3 LCPUFA levels were identified: (1) unmodifiable factors (sex, genetics, age), (2) modifiable factors (body size, physical activity, alcohol, smoking) and (3) bioavailability factors (chemically bound form of supplements, krill oil v. fish oil, and conversion of plant-derived α-linolenic acid (ALA) to n-3 LCPUFA). Results showed that factors positively associated with n-3 LCPUFA levels were age, female sex (women younger than 50 years), wine consumption and the TAG form. Factors negatively associated with n-3 LCPUFA levels were genetics, BMI (if erythrocyte EPA and DHA levels are <5·6 %) and smoking. The evidence for girth, physical activity and krill oil v. fish oil associated with n-3 LCPUFA levels is inconclusive. There is also evidence that higher ALA consumption leads to increased levels of EPA but not DHA. In conclusion, sex, age, BMI, alcohol consumption, smoking and the form of n-3 LCPUFA are all factors that need to be taken into account in n-3 LCPUFA research.


Assuntos
Ácidos Graxos Ômega-3/sangue , Adulto , Fatores Etários , Consumo de Bebidas Alcoólicas/sangue , Índice de Massa Corporal , Feminino , Humanos , Masculino , Fatores Sexuais , Fumar/sangue
9.
Nutrients ; 10(10)2018 Oct 08.
Artigo em Inglês | MEDLINE | ID: mdl-30297663

RESUMO

Omega-3 long chain polyunsaturated fatty acid (n-3 LCPUFA) supplementation has been shown to improve plasma lipid profiles in men and post-menopausal women, however, data for pre-menopausal women are lacking. The benefits of intakes less than 1 g/day have not been well studied, and dose⁻response data is limited. The aim of this study was to determine the effect of low doses of docosahexaenoic acid (DHA)-rich tuna oil on plasma triglyceride (TG) lowering in pre-menopausal women, and investigate if low dose DHA-rich tuna oil supplementation would increase the low-density lipoprotein (LDL) and high-density lipoprotein (HDL) particle sizes. A randomized, double-blind, placebo-controlled trial was conducted, in which 53 healthy pre-menopausal women with mildly elevated plasma TG levels consumed 0, 0.35, 0.7, or 1 g/day n-3 LCPUFA as HiDHA™ tuna oil or placebo (Sunola oil) capsules for 8 weeks. Supplementation with 1 g/day n-3 LCPUFA, but not lower doses, reduced plasma TG by 23% in pre-menopausal women. This was reflected in a dose-dependent reduction in very-low-density lipoprotein (VLDL)-TG (R² = 0.20, p = 0.003). A weak dose-dependent shift in HDL (but not LDL) particle size was identified (R² = 0.05, p = 0.04). The results of this study indicate that DHA-rich n-3 LCPUFA supplementation at a dose of 1 g/day is an effective TG-lowering agent and increases HDL particle size in pre-menopausal women.


Assuntos
HDL-Colesterol/sangue , VLDL-Colesterol/sangue , Ácidos Docosa-Hexaenoicos/farmacologia , Óleos de Peixe/farmacologia , Lipoproteínas/sangue , Pré-Menopausa , Triglicerídeos/sangue , Adulto , Animais , LDL-Colesterol/sangue , Suplementos Nutricionais , Ácidos Docosa-Hexaenoicos/sangue , Relação Dose-Resposta a Droga , Método Duplo-Cego , Feminino , Óleos de Peixe/sangue , Humanos , Lipídeos/sangue , Lipoproteínas VLDL/sangue , Tamanho da Partícula , Atum , Adulto Jovem
10.
J Vis Exp ; (135)2018 05 25.
Artigo em Inglês | MEDLINE | ID: mdl-29889198

RESUMO

Site-specific eukaryotic genome editing with CRISPR (clustered regularly interspaced short palindromic repeats)-Cas (CRISPR-associated) systems has quickly become a commonplace amongst researchers pursuing a wide variety of biological questions. Users most often employ the Cas9 protein derived from Streptococcus pyogenes in a complex with an easily reprogrammed guide RNA (gRNA). These components are introduced into cells, and through a base pairing with a complementary region of the double-stranded DNA (dsDNA) genome, the enzyme cleaves both strands to generate a double-strand break (DSB). Subsequent repair leads to either random insertion or deletion events (indels) or the incorporation of experimenter-provided DNA at the site of the break. The use of a purified single-guide RNA and Cas9 protein, preassembled to form an RNP and delivered directly to cells, is a potent approach for achieving highly efficient gene editing. RNP editing particularly enhances the rate of gene insertion, an outcome that is often challenging to achieve. Compared to the delivery via a plasmid, the shorter persistence of the Cas9 RNP within the cell leads to fewer off-target events. Despite its advantages, many casual users of CRISPR gene editing are less familiar with this technique. To lower the barrier to entry, we outline detailed protocols for implementing the RNP strategy in a range of contexts, highlighting its distinct benefits and diverse applications. We cover editing in two types of primary human cells, T cells and hematopoietic stem/progenitor cells (HSPCs). We also show how Cas9 RNP editing enables the facile genetic manipulation of entire organisms, including the classic model roundworm Caenorhabditis elegans and the more recently introduced model crustacean, Parhyale hawaiensis.


Assuntos
Sistemas CRISPR-Cas/genética , Edição de Genes/métodos , Ribonucleoproteínas/genética , Humanos , Ribonucleoproteínas/metabolismo
11.
Life Sci ; 155: 123-32, 2016 Jun 15.
Artigo em Inglês | MEDLINE | ID: mdl-27155397

RESUMO

AIMS: Cannabinoid 1(CB1) receptors are closely correlated to the dopaminergic system and involved in cognitive function. Since statins have been used to regulate the progression of Parkinson's disease (PD) via its anti-inflammation and neuroprotective effects, we asked if statins affect the CB1 receptors in the 6-hydroxydopamine (6-OHDA) lesioned rat. METHODS: The PD rat model was established by injecting 6-OHDA into the unilateral medial forebrain bundle; while rats were orally pre-treated with simvastatin (1 or 10mg/kg/day), or saline for 5days before surgery, and the same treatments for each group were continued for 3weeks post-surgery. [(3)H] SR141716A binding autoradiography was adopted to investigate the alterations in CB1 receptor density in the brains. FINDINGS: The 6-OHDA induced a remarkable downregulation of CB1 receptor density in the prefrontal cortex, caudate putamen, nucleus accumbens, cingulate cortex, hippocampus, and substantia nigra; while simvastatin (10mg/kg/day) significantly ameliorated this downregulation in those regions. Furthermore, simvastatin (1mg/kg/day) reversed the 6-OHDA-induced downregulation of CB1 receptors in the substantia nigra and hippocampus. Simvastatin showed minimal changes in [(3)H] SR141716A binding in the examined regions in sham rats, but did reveal a significant down-regulation of binding density within the striatum, prefrontal cortex and substantia nigra. SIGNIFICANCE: Alterations in the [(3)H] SR141716A binding in the examined brain areas may represent the specific regions that mediate motor and cognitive dysfunctions in PD via the endocannabinoid system. Our data suggest a critical role of CB1 receptors in treating PD with simvastatin, and implicate CB1 receptors as a potential therapeutic target in the treatment of PD.


Assuntos
Encéfalo/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Oxidopamina/farmacologia , Receptor CB1 de Canabinoide/metabolismo , Sinvastatina/farmacologia , Animais , Encéfalo/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley
12.
Nutrients ; 8(3): 111, 2016 Feb 24.
Artigo em Inglês | MEDLINE | ID: mdl-26927162

RESUMO

Health benefits have been attributed to omega-3 long chain polyunsaturated fatty acids (n-3 LCPUFA). Therefore it is important to know if Australians are currently meeting the recommended intake for n-3 LCPUFA and if they have increased since the last National Nutrition Survey in 1995 (NNS 1995). Dietary intake data was obtained from the recent 2011-2012 National Nutrition and Physical Activity Survey (2011-2012 NNPAS). Linoleic acid (LA) intakes have decreased whilst alpha-linolenic acid (LNA) and n-3 LCPUFA intakes have increased primarily due to n-3 LCPUFA supplements. The median n-3 LCPUFA intakes are less than 50% of the mean n-3 LCPUFA intakes which highlights the highly-skewed n-3 LCPUFA intakes, which shows that there are some people consuming high amounts of n-3 LCPUFA, but the vast majority of the population are consuming much lower amounts. Only 20% of the population meets the recommended n-3 LCPUFA intakes and only 10% of women of childbearing age meet the recommended docosahexaenoic acid (DHA) intake. Fish and seafood is by far the richest source of n-3 LCPUFA including DHA.


Assuntos
Dieta , Suplementos Nutricionais , Exercício Físico , Ácidos Graxos Ômega-3/administração & dosagem , Comportamento Alimentar , Estado Nutricional , Recomendações Nutricionais , Adolescente , Adulto , Fatores Etários , Idoso , Austrália , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Inquéritos Nutricionais , Gravidez , Alimentos Marinhos , Fatores Sexuais , Fatores de Tempo , Adulto Jovem
14.
Nature ; 523(7559): 240-4, 2015 Jul 09.
Artigo em Inglês | MEDLINE | ID: mdl-26030525

RESUMO

The three-dimensional organization of a genome plays a critical role in regulating gene expression, yet little is known about the machinery and mechanisms that determine higher-order chromosome structure. Here we perform genome-wide chromosome conformation capture analysis, fluorescent in situ hybridization (FISH), and RNA-seq to obtain comprehensive three-dimensional (3D) maps of the Caenorhabditis elegans genome and to dissect X chromosome dosage compensation, which balances gene expression between XX hermaphrodites and XO males. The dosage compensation complex (DCC), a condensin complex, binds to both hermaphrodite X chromosomes via sequence-specific recruitment elements on X (rex sites) to reduce chromosome-wide gene expression by half. Most DCC condensin subunits also act in other condensin complexes to control the compaction and resolution of all mitotic and meiotic chromosomes. By comparing chromosome structure in wild-type and DCC-defective embryos, we show that the DCC remodels hermaphrodite X chromosomes into a sex-specific spatial conformation distinct from autosomes. Dosage-compensated X chromosomes consist of self-interacting domains (∼1 Mb) resembling mammalian topologically associating domains (TADs). TADs on X chromosomes have stronger boundaries and more regular spacing than on autosomes. Many TAD boundaries on X chromosomes coincide with the highest-affinity rex sites and become diminished or lost in DCC-defective mutants, thereby converting the topology of X to a conformation resembling autosomes. rex sites engage in DCC-dependent long-range interactions, with the most frequent interactions occurring between rex sites at DCC-dependent TAD boundaries. These results imply that the DCC reshapes the topology of X chromosomes by forming new TAD boundaries and reinforcing weak boundaries through interactions between its highest-affinity binding sites. As this model predicts, deletion of an endogenous rex site at a DCC-dependent TAD boundary using CRISPR/Cas9 greatly diminished the boundary. Thus, the DCC imposes a distinct higher-order structure onto X chromosomes while regulating gene expression chromosome-wide.


Assuntos
Adenosina Trifosfatases/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Proteínas de Ligação a DNA/metabolismo , Mecanismo Genético de Compensação de Dose/fisiologia , Complexos Multiproteicos/metabolismo , Cromossomo X/metabolismo , Animais , Proteínas de Caenorhabditis elegans/genética , Mecanismo Genético de Compensação de Dose/genética , Feminino , Regulação da Expressão Gênica , Hibridização in Situ Fluorescente , Masculino , Ligação Proteica , Análise de Sequência de RNA , Cromossomo X/genética
15.
Proc Natl Acad Sci U S A ; 110(40): E3810-9, 2013 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-24043781

RESUMO

The essential process of dosage compensation equalizes X-chromosome gene expression between Caenorhabditis elegans XO males and XX hermaphrodites through a dosage compensation complex (DCC) that is homologous to condensin. The DCC binds to both X chromosomes of hermaphrodites to repress transcription by half. Here, we show that posttranslational modification by the SUMO (small ubiquitin-like modifier) conjugation pathway is essential for sex-specific assembly and function of the DCC on X. Depletion of SUMO in vivo severely disrupts binding of particular DCC subunits and causes changes in X-linked gene expression similar to those caused by deleting genes encoding DCC subunits. Three DCC subunits are SUMOylated, and SUMO depletion preferentially reduces their binding to X, suggesting that SUMOylation of DCC subunits is essential for robust association with X. DCC SUMOylation is triggered by the signal that initiates DCC assembly onto X. The initial step of assembly-binding of X-targeting factors to recruitment sites on X-is independent of SUMOylation, but robust binding of the complete complex requires SUMOylation. SUMOylated DCC subunits are enriched at recruitment sites, and SUMOylation likely enhances interactions between X-targeting factors and condensin subunits that facilitate DCC binding beyond the low level achieved without SUMOylation. DCC subunits also participate in condensin complexes essential for chromosome segregation, but their SUMOylation occurs only in the context of the DCC. Our results reinforce a newly emerging theme in which multiple proteins of a complex are collectively SUMOylated in response to a specific stimulus, leading to accelerated complex formation and enhanced function.


Assuntos
Proteínas de Caenorhabditis elegans/genética , Caenorhabditis elegans/genética , Mecanismo Genético de Compensação de Dose/genética , Complexos Multiproteicos/genética , Sumoilação/genética , Cromossomo X/genética , Adenosina Trifosfatases/metabolismo , Animais , Proteínas de Caenorhabditis elegans/metabolismo , Imunoprecipitação da Cromatina , Proteínas Cromossômicas não Histona , Proteínas de Ligação a DNA/metabolismo , Organismos Hermafroditas , Masculino , Complexos Multiproteicos/metabolismo , Análise Serial de Proteínas , Caracteres Sexuais
16.
Elife ; 2: e00808, 2013 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-23795297

RESUMO

The X-chromosome gene regulatory process called dosage compensation ensures that males (1X) and females (2X) express equal levels of X-chromosome transcripts. The mechanism in Caenorhabditis elegans has been elusive due to improperly annotated transcription start sites (TSSs). Here we define TSSs and the distribution of transcriptionally engaged RNA polymerase II (Pol II) genome-wide in wild-type and dosage-compensation-defective animals to dissect this regulatory mechanism. Our TSS-mapping strategy integrates GRO-seq, which tracks nascent transcription, with a new derivative of this method, called GRO-cap, which recovers nascent RNAs with 5' caps prior to their removal by co-transcriptional processing. Our analyses reveal that promoter-proximal pausing is rare, unlike in other metazoans, and promoters are unexpectedly far upstream from the 5' ends of mature mRNAs. We find that C. elegans equalizes X-chromosome expression between the sexes, to a level equivalent to autosomes, by reducing Pol II recruitment to promoters of hermaphrodite X-linked genes using a chromosome-restructuring condensin complex. DOI:http://dx.doi.org/10.7554/eLife.00808.001.


Assuntos
Adenosina Trifosfatases/fisiologia , Proteínas de Ligação a DNA/fisiologia , Mecanismo Genético de Compensação de Dose , Complexos Multiproteicos/fisiologia , Nematoides/genética , RNA Polimerase II/metabolismo , Cromossomo X , Animais , Genoma , Regiões Promotoras Genéticas , Transcrição Gênica
17.
Nutrition ; 29(3): 491-6, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-22929186

RESUMO

OBJECTIVE: Polyunsaturated fatty acids (PUFAs), including the long-chain (LC) ω-3 PUFAs, are important for health. The aim was to assess if the Anti-Cancer Council of Victoria Dietary Questionnaire (ACC DQ) accurately determines PUFA intakes compared with the recently validated electronic PUFA food-frequency questionnaire (FFQ). METHODS: Forty-one study volunteers were recruited from the local Illawarra region of New South Wales, Australia. The method of triads was used to determine validity coefficients by comparing the ACC DQ intakes against a 3-d weighed food record and appropriate blood biomarkers (erythrocytes and plasma fatty acids). These validity coefficients were subsequently compared with previously published validity coefficients from the PUFA FFQ. RESULTS: Using erythrocytes as the biomarker, the electronic PUFA FFQ had much higher validity coefficients compared with the ACC DQ for eicosapentaenoic acid (0.92 versus 0.19), docosahexaenoic acid (0.69 versus 0.26), and total LC ω-3 PUFAs (0.78 versus 0.23), respectively, whereas ω-6 PUFAs were comparable. Using plasma as the biomarker, the electronic PUFA FFQ had much higher validity coefficients compared with the ACC DQ for α-linolenic acid (0.96 versus 0.49), eicosapentaenoic acid (0.87 versus 0.19), docosahexaenoic acid (0.64 versus 0.24), and total LC ω-3 PUFAs (0.73 versus 0.21), respectively, whereas ω-6 PUFAs were comparable. CONCLUSION: The validated electronic PUFA FFQ is better suited to determine ω-3 PUFA intakes than the ACC DQ.


Assuntos
Registros de Dieta , Ácidos Graxos Ômega-3/administração & dosagem , Adulto , Idoso , Biomarcadores/sangue , Ácidos Docosa-Hexaenoicos/sangue , Ácido Eicosapentaenoico/sangue , Eritrócitos/química , Ácidos Graxos Ômega-6/sangue , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , New South Wales , Reprodutibilidade dos Testes , Inquéritos e Questionários , Ácido alfa-Linolênico/sangue
18.
J Am Coll Nutr ; 31(2): 117-25, 2012 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-22855917

RESUMO

OBJECTIVE: The recommended composition of a hypocaloric diet for obese women with polycystic ovary syndrome (PCOS) is unclear. The aim of this study was to investigate the effects of a high-protein, low-glycemic-load diet compared with a conventional hypocaloric diet on reproductive hormones, inflammatory markers, lipids, glucose, and insulin levels in obese women with PCOS. METHODS: A total of 60 overweight and obese women with PCOS who did not use insulin-sensitizing agents were recruited and randomly assigned to 1 of the 2 hypocaloric diet groups for a single-blind clinical trial. The groups included a conventional hypocaloric diet (CHCD) (15% of daily energy from protein) and a modified hypocaloric diet (MHCD) with a high-protein, low-glycemic load (30% of daily energy from protein plus low-glycemic-load foods selected from a list) that was prescribed via counseling visits weekly during 12 weeks of study. Anthropometric assessments and biochemical measurements including reproductive hormones, inflammatory factors, lipids, glucose, and insulin were performed on fasting blood samples at baseline and after 12 weeks of dietary intervention. RESULTS: Weight loss was significant and similar in the 2 groups. Mean of testosterone in the MHCD and CHCD groups decreased from 1.78 ± 0.32 to 1.31 ± 0.26 ng/ml and from 1.51 ± 0.12 to 1.15 ± 0.11 ng/ml, respectively (p < 0.001). Follicle sensitizing hormone (FSH), luteinizing hormone (LH), and blood lipids concentrations were not changed except low-density lipoprotein cholesterol (LDL-C) was reduced by 24.5% ± 12.3% (p < 0.001 for both) after 12 weeks of intervention. MHCD resulted in a significant reduction in insulin level, homeostatic model assessment for insulin resistance (HOMA), and high-sensitivity C- reactive protein (hsCRP) concentration (p < 0.001). CONCLUSIONS: In this study both hypocaloric diets significantly led to reduced body weight and androgen levels in these two groups of women with PCOS. The combination of high-protein and low-glycemic-load foods in a modified diet caused a significant increase in insulin sensitivity and a decrease in hsCRP level when compared with a conventional diet.


Assuntos
Dieta , Proteínas Alimentares/administração & dosagem , Ingestão de Energia , Obesidade/dietoterapia , Sobrepeso/dietoterapia , Síndrome do Ovário Policístico/dietoterapia , Adulto , Androgênios/sangue , Glicemia/análise , Composição Corporal , Índice de Massa Corporal , Proteína C-Reativa/análise , Proteína C-Reativa/metabolismo , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/fisiopatologia , Doenças Cardiovasculares/prevenção & controle , Carboidratos da Dieta/administração & dosagem , Feminino , Índice Glicêmico , Humanos , Insulina/sangue , Resistência à Insulina , Lipídeos/sangue , Hormônio Luteinizante/sangue , Obesidade/complicações , Obesidade/fisiopatologia , Sobrepeso/complicações , Sobrepeso/fisiopatologia , Síndrome do Ovário Policístico/complicações , Síndrome do Ovário Policístico/fisiopatologia , Fatores de Risco , Método Simples-Cego , Testosterona/sangue , Redução de Peso/efeitos dos fármacos , Adulto Jovem
19.
Genes Dev ; 25(5): 499-515, 2011 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-21363964

RESUMO

Here we analyze the essential process of X-chromosome dosage compensation (DC) to elucidate mechanisms that control the assembly, genome-wide binding, and function of gene regulatory complexes that act over large chromosomal territories. We demonstrate that a subunit of Caenorhabditis elegans MLL/COMPASS, a gene activation complex, acts within the DC complex (DCC), a condensin complex, to target the DCC to both X chromosomes of hermaphrodites for chromosome-wide reduction of gene expression. The DCC binds to two categories of sites on X: rex (recruitment element on X) sites that recruit the DCC in an autonomous, sequence-dependent manner, and dox (dependent on X) sites that reside primarily in promoters of expressed genes and bind the DCC robustly only when attached to X. We find that DC mutations that abolish rex site binding greatly reduce dox site binding but do not eliminate it. Instead, binding is diminished to the low level observed at autosomal sites in wild-type animals. Changes in DCC binding to these non-rex sites occur throughout development and correlate directly with transcriptional activity of adjacent genes. Moreover, autosomal DCC binding is enhanced by rex site binding in cis in X-autosome fusion chromosomes. Thus, dox and autosomal sites have similar binding potential but are distinguished by linkage to rex sites. We propose a model for DCC binding in which low-level DCC binding at dox sites is dictated by intrinsic properties correlated with high transcriptional activity. Sex-specific DCC recruitment to rex sites then enhances the magnitude of DCC binding to dox sites in cis, which lack high affinity for the DCC on their own. We also show that the DCC balances X-chromosome gene expression between sexes by controlling transcription.


Assuntos
Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/genética , Caenorhabditis elegans/metabolismo , Mecanismo Genético de Compensação de Dose/genética , Regulação da Expressão Gênica , Adenosina Trifosfatases/metabolismo , Animais , Proteínas de Ligação a DNA/metabolismo , Feminino , Genoma Helmíntico/genética , Masculino , Complexos Multiproteicos/metabolismo , Mutação , Proteínas Nucleares , Ligação Proteica , Subunidades Proteicas/metabolismo , Cromossomo X/genética , Cromossomo X/metabolismo
20.
Lipids ; 45(8): 669-81, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20652432

RESUMO

Fish are a rich source of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), two long-chain polyunsaturated n-3 fatty acids (LC n-3 PUFA) with cardiovascular benefits. A related but less-investigated LC n-3 PUFA, docosapentaenoic acid (DPA), is more common in seal oil and pasture-fed red meats. This study compared indicators of platelet function and plasma lipids in healthy volunteers given supplements containing these different fatty acids (FA) for 14 days. Subjects, randomised into three groups of ten, consumed capsules of tuna oil (210 mg EPA, 30 mg DPA, 810 mg DHA), seal oil (340 mg EPA, 230 mg DPA, 450 mg DHA) or placebo (sunola) oil. Supplementary LC n-3 PUFA levels were approximately 1 g/day in both fish and seal oil groups. Baseline dietary FA and other nutrient intakes were similar in all groups. Both fish and seal oil elevated platelet DHA levels (P < 0.01). Seal oil also raised platelet DPA and EPA levels (P < 0.01), and decreased p-selectin (P = 0.01), a platelet activation marker negatively associated with DPA (P = 0.03) and EPA (P < 0.01) but not DHA. Plasma triacylglycerol decreased (P = 0.03) and HDL-cholesterol levels increased (P = 0.01) with seal oil only. Hence, seal oil may be more efficient than fish oil at promoting healthy plasma lipid profiles and lowering thrombotic risk, possibly due to its high DPA as well as EPA content.


Assuntos
Gorduras na Dieta/farmacologia , Óleos de Peixe/farmacologia , Ativação Plaquetária/efeitos dos fármacos , Adulto , Animais , Proteína C-Reativa/metabolismo , Ácidos Graxos Ômega-3/farmacologia , Ácidos Graxos Insaturados/farmacologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Selectina-P/sangue , Focas Verdadeiras , Triglicerídeos/sangue , Atum , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA