Influence of physical activity and dietary habits on lipid profile, blood pressure and BMI in subjects with metabolic syndrome

BACKGROUND The present study was determined the influence of physical activity and dietary habits on lipid profile, blood pressure (BP) and body mass index (BMI) in subjects with metabolic syndrome (MS). AIMS Identify the relationship between physical activity and proper nutrition and the probability of suffering from myocardial infarction (MI). METHODS Hundred chronically ill with MS who were active and followed a healthy diet were classified as compliant, while the remaining subjects were classified as non-compliant. RESULTS The compliant subjects show lower BMI values (30.8±4.9 vs 32.5±4.6), as well as lower levels of triacylglycerol (130.4±48.2 vs 242.1±90.1), total cholesterol (193.5±39 vs 220.2±52.3) and low-density lipoprotein cholesterol (105.2±38.3 vs 139.2±45). They show higher values in terms of high-density lipoprotein cholesterol levels (62.2±20.1 vs 36.6±15.3), with statistically significant differences. In terms of both systolic and diastolic pressure, no differences were revealed between the groups; however, those who maintain proper dietary habits show lower systolic blood pressure levels than the inactive subjects. The probability of suffering from MI greatly increases among the group of non-compliant subjects. CONCLUSIONS Our results demonstrate how performing aerobic physical activity and following an individualized, Mediterranean diet significantly reduces MS indicators and the chances of suffering from MI.

Impact of dietary betaine and conjugated linoleic acid on insulin sensitivity, protein and fat metabolism of obese pigs.

To determine possible mechanisms of action that might explain the nutrient partitioning effect of betaine and conjugated linoleic acid (CLA) in Iberian pigs and to address potential adverse effects, twenty gilts were restrictively fed from 20 to 50 kg BW Control, 0.5% betaine, 1% CLA or 0.5% betaine + 1% CLA diets. Serum hormones and metabolites profile were determined at 30 kg BW and an oral glucose test was performed before slaughter. Pigs were slaughtered at 50 kg BW and livers were obtained for chemical and histological analysis. Decreased serum urea in pigs fed betaine and betaine + CLA diets (11%; P = 0.0001) indicated a more efficient N utilization. The increase in serum triacylglycerol (58% and 28%, respectively; P = 0.0098) indicated that CLA and betaine + CLA could have reduced adipose tissue triacylglycerol synthesis from preformed fatty acids. Serum glucose, low-density lipoprotein (LDL) cholesterol and non-esterified fatty acids were unaffected. CLA and betaine + CLA altered serum lipids profile, although liver of pigs fed CLA diet presented no histopathological changes and triglyceride content was not different from Control pigs. Compared with controls, serum growth hormone decreased (20% to 23%; P = 0.0209) for all treatments. Although serum insulin increased in CLA, and especially in betaine + CLA pigs (28% and 83%; P = 0.0001), indices of insulin resistance were unaffected. In conclusion, CLA, and especially betaine + CLA, induced changes in biochemical parameters and hormones that may partially explain a nutrient partitioning effect in young pigs. Nevertheless, they exhibited weak, although detrimental, effects on blood lipids. Moreover, although livers were chemically and histologically normal, pigs fed CLA diet challenged with a glucose load had higher serum glucose than controls.

Comprehensive analysis of NRG1 common and rare variants in Hirschsprung patients.

Hirschsprung disease (HSCR, OMIM 142623) is a developmental disorder characterized by the absence of ganglion cells along variable lengths of the distal gastrointestinal tract, which results in tonic contraction of the aganglionic gut segment and functional intestinal obstruction. The RET proto-oncogene is the major gene for HSCR with differential contributions of its rare and common, coding and noncoding mutations to the multifactorial nature of this pathology. Many other genes have been described to be associated with the pathology, as NRG1 gene (8p12), encoding neuregulin 1, which is implicated in the development of the enteric nervous system (ENS), and seems to contribute by both common and rare variants. Here we present the results of a comprehensive analysis of the NRG1 gene in the context of the disease in a series of 207 Spanish HSCR patients, by both mutational screening of its coding sequence and evaluation of 3 common tag SNPs as low penetrance susceptibility factors, finding some potentially damaging variants which we have functionally characterized. All of them were found to be associated with a significant reduction of the normal NRG1 protein levels. The fact that those mutations analyzed alter NRG1 protein would suggest that they would be related with HSCR disease not only in Chinese but also in a Caucasian population, which reinforces the implication of NRG1 gene in this pathology.

Circulating antioxidant defences are decreased in healthy people after a high-fat meal.

The aim of this study was to examine the responses of uric acid, antioxidant defences and pro-oxidant variables after a high-fat meal. Twenty-five healthy persons without criteria for the metabolic syndrome, underwent a high-fat meal with Supracal (60 g fat). Measurements were made at baseline and 3 h after the meal of TAG, uric acid, HDL-cholesterol, total proteins and oxidative stress. Following the high-fat meal, we detected a significant increase in pro-oxidative variables and a decrease in antioxidative variables. The uric acid concentrations were significantly lower after the high-fat meal and the reduction correlated significantly with the oxidative stress variables. The inverse relation between reduced uric acid and increased carbonylated proteins remained in multiple regression analysis. We conclude that uric acid is a powerful antioxidant and its reduction following a high-fat meal may be related with its acute antioxidative action.

Biochemical characterization of recombinant human telomerase

Résumé Les télomères sont les structures ADN-protéines des extrémités des chromosomes des eucaryotes. L'ADN télomérique est constitué de courtes séquences répétitives. L'intégrité des télomères est essentielle pour protéger les extrémités des chromosomes contre les systèmes de dégradations et pour les distinguer des cassures de l'ADN double brin. Parce que la machinerie de la réplication de l'ADN n'est pas capable de répliquer l'extrémité des chromosomes, les télomères raccourcissent au fur et à mesure des cycles de réplication. Dès que les télomères atteignent une longueur critique, leur structure protectrice est perdue. Cela induit un signal de dommage de l'ADN et l'arrêt du cycle cellulaire. Pour contrebalancer le raccourcissement des télomères, les cellules qui s'auto régénèrent, dont les cellules de la moelle osseuse, les lymphocytes activés et 80-90% des cellules cancéreuses, expriment la télomérase. C'est une ribonucléoprotéine qui a la capacité de synthétiser des séquences télomériques par transcription inverse d'une courte séquence contenue dans sa propre sous-unité ARN avec laquelle elle est associée. La télomérase humaine est une enzyme processive au niveau de l'addition des nucléotides et aussi des répétitions télomériques. La télomérase de levure et la télomérase humaine sont toutes deux dimériques et il a été montré que la télomérase humaine recombinante contient deux ARN qui coopèrent pour fonctionner ainsi que deux sous-unités catalytiques. Cependant, il n'a pas encore été montré quel est le rôle de la dimérisation dans l'activité de la télomérase. Afin d'élucider ce rôle, nous avons exprimé, reconstitué et purifié la télomérase humaine dimérique recombinante. Et pour étudier l'effet d'ARN mutants sur l'activité de la télomérase, nous avons développé une méthode pour reconstituer et enrichir en hétérodimères de télomérase. Les hétérodimères contiennent une sous-unité ARN sauvage et une sous-unité ARN mutée au niveau de la séquence de la matrice. Sur l'ARN muté nous avons introduit une étiquette aptamer ARN-S1 puis nous avons purifié la télomérase via l'etiquette Si. Nous avons montré que la dimérisation est essentielle pour l'activité de la télomérase. Nos données indiquent que chaque télomérase du dimère allonge leur substrat, l'ADN télomérique, indépendamment l'une de l'autre à chaque cycle d'élongation mais que l'addition itérative de répétitions télomériques nécessite une coopération entre les deux télomérases du dimère. Nous proposons donc un modèle dans lequel les deux télomérases du dimères se lient et allongent deux substrats télomères et que pendant l'élongation processive les deux enzymes subissent un changement de conformation de manière coordonnée, ce changement va permettre le repositionnement des substrats pour d'autres cycles d'additions de répétitions télomériques. Dyskeratosis congenita est une maladie mortelle due majoritairement au disfonctionnement de la moelle osseuse. Dans la forme autosomale de la maladie, l'ARN de la télomérase contient des mutations. En utilisant notre système de reconstitution, nous avons montré que ces ARN mutés, qui ont perdu leur activité enzymatique dans le cas d'un homodimère de mutants, sont dominant négatifs quand ils sont présents dans les hétérodimères sauvage/mutant. Cet effet trans-dominant négatif pourrait contribuer à la progression de la maladie. Abstract Telomeres are protein-DNA structures at the ends of linear eukaryotic chromosomes. The telomeric DNA consists of tandemly repeated sequences. Telomeric integrity is essential to protect chromosomal ends from nucleolytic degradation and to prevent their recognition as DNA double strand breaks. Due to the inability of the conventional DNA replication machinery to replicate terminal DNA stretches, telomeres shorten with continuous rounds of DNA replication. As soon as telomeres reach a critical length, their protective structure is lost and the deprotected telomeres will induce a DNA damage response leading to cell cycle arrest. To counteract telomere shortening, self-renewing cells, including bone marrow cells, activated lymphocytes and 80-90% of cancer cells express the cellular reverse transcriptase telomerase, which has the capacity to synthesize telomeric repeats by reverse transcription of a short template sequence encoded by its stably associated RNA subunit. Human telomerase is a processive enzyme for nucleotide as well as repeat addition. Both yeast and human telomerase are dimeric enzymes and recombinant human telomerase has been shown to contain two functionally cooperating RNAs and most probably also two protein subunits. However, it has remained unclear how dimerization may contribute to telomerase activity. To study the role of dimerization, we expressed, reconstituted and purified recombinant human telomerase. We also developed a new method to reconstitute and enrich for telomerase heterodimers containing wild-type (wt) and mutant telomerase RNA subunits. To this end we introduced an S1-RNA-aptamer tag into telomerase RNA and purified telomerase reconstituted with a mixture of untagged and tagged RNA via the S1-tag. Using this experimental system, we introduced template mutations in the tagged RNA subunit and examined the effect of mutant RNAs on wt telomerase activity in wt/mutant heterodimers. We obtained evidence that dimerization is essential for telomerase activity. Our data indicate that the two subunits elongate telomere substrates independently of each other during single rounds of elongation, but that iterative addition of telomeric repeats requires cooperation between the two subunits. We suggest a model, in which dimeric telomerases bind and elongate two telomere substrates and that the two subunits undergo coordinated conformational changes during processive elongation that enable repositioning the substrates for subsequent rounds of repeat addition. Dyskeratosis congenita is a multisystemic disease with bone marrow failure as the major cause of death. The autosomal form of this disease was found to harbor mutations in the telomerase RNA. Using our reconstitution system, we tested whether mutant dyskeratosis telomerase RNAs behaved in a dominant negative manner. We observed that dyskeratosis telomerase RNA mutants, which lacked enzymatic activity were dominant negative, when present in wt/ mutant heterodimers. The transdominant negative effect of these mutants may contribute to disease progression.

Perimicrovillar membrane assembly: the fate of phospholipids synthesised by the midgut of Rhodnius prolixus

In this study, we describe the fate of fatty acids that are incorporated from the lumen by the posterior midgut epithelium of Rhodnius prolixus and the biosynthesis of lipids. We also demonstrate that neutral lipids (NL) are transferred to the haemolymphatic lipophorin (Lp) and that phospholipids remain in the tissue in which they are organised into perimicrovillar membranes (PMMs). 3H-palmitic acid added at the luminal side of isolated midguts of R. prolixus females was readily absorbed and was used to synthesise phospholipids (80%) and NL (20%). The highest incorporation of 3H-palmitic acid was on the first day after a blood meal. The amounts of diacylglycerol (DG) and triacylglycerol synthesised by the tissue decreased in the presence of Lp in the incubation medium. The metabolic fates of 3H-lipids synthesised by the posterior midgut were followed and it was observed that DG was the major lipid released to Lp particles. However, the majority of phospholipids were not transferred to Lp, but remained in the tissue. The phospholipids that were synthesised and accumulated in the posterior midgut were found to be associated with Rhodnius luminal contents as structural components of PMMs.

Impact of obesity-related genes in Spanish population

Background: The objective was to investigate the association between BMI and single nucleotide polymorphisms previously identified of obesity-related genes in two Spanish populations. Forty SNPs in 23 obesity-related genes were evaluated in a rural population characterized by a high prevalence of obesity (869 subjects, mean age 46 yr, 62% women, 36% obese) and in an urban population (1425 subjects, mean age 54 yr, 50% women, 19% obese). Genotyping was assessed by using SNPlex and PLINK for the association analysis. Results: Polymorphisms of the FTO were significantly associated with BMI, in the rural population (beta 0.87, p-value <0.001). None of the other SNPs showed significant association after Bonferroni correction in the two populations or in the pooled analysis. A weighted genetic risk score (wGRS) was constructed using the risk alleles of the Tag-SNPs with a positive Beta parameter in both populations. From the first to the fifth quintile of the score, the BMI increased 0.45 kg/m2 in Hortega and 2.0 kg/m2 in Pizarra. Overall, the obesity predictive value was low (less than 1%). Conclusion: The risk associated with polymorphisms is low and the overall effect on BMI or obesity prediction is minimal. A weighted genetic risk score based on genes mainly acting through central nervous system mechanisms was associated with BMI but it yields minimal clinical prediction for the obesity risk in the general population.

Examining ERBB2 as a candidate gene for susceptibility to leprosy (Hansen’s disease) in Brazil

Leprosy remains prevalent in Brazil. ErbB2 is a receptor for leprosy bacilli entering Schwann cells, which mediates Mycobacterium leprae-induced demyelination and the ERBB2 gene lies within a leprosy susceptibility locus on chromosome 17q11-q21. To determine whether polymorphisms at the ERBB2 locus contribute to this linkage peak, three haplotype tagging single nucleotide polymorphisms (tag-SNPs) (rs2517956, rs2952156, rs1058808) were genotyped in 72 families (208 cases; 372 individuals) from the state of Pará (PA). All three tag-SNPs were associated with leprosy per se [best SNP rs2517959 odds ratio (OR) = 2.22; 95% confidence interval (CI) 1.37-3.59; p = 0.001]. Lepromatous (LL) (OR = 3.25; 95% CI 1.37-7.70; p = 0.007) and tuberculoid (TT) (OR = 1.79; 95% CI 1.04-3.05; p = 0.034) leprosy both contributed to the association, which is consistent with the previous linkage to chromosome 17q11-q21 in the population from PA and supports the functional role of ErbB2 in disease pathogenesis. To attempt to replicate these findings, six SNPs (rs2517955, rs2517956, rs1810132, rs2952156, rs1801200, rs1058808) were genotyped in a population-based sample of 570 leprosy cases and 370 controls from the state of Rio Grande do Norte (RN) and the results were analysed using logistic regression analysis. However, none of the associations were replicated in the RN sample, whether analysed for leprosy per se, LL leprosy, TT leprosy, erythema nodosum leprosum or reversal reaction conditions. The role of polymorphisms at ERBB2 in controlling susceptibility to leprosy in Brazil therefore remains unclear.

Construction of three new Gateway&#174; expression plasmids for Trypanosoma cruzi

We present here three expression plasmids for Trypanosoma cruzi adapted to the Gateway® recombination cloning system. Two of these plasmids were designed to express trypanosomal proteins fused to a double tag for tandem affinity purification (TAPtag). The TAPtag and Gateway® cassette were introduced into an episomal (pTEX) and an integrative (pTREX) plasmid. Both plasmids were assayed by introducing green fluorescent protein (GFP) by recombination and the integrity of the double-tagged protein was determined by western blotting and immunofluorescence microscopy. The third Gateway adapted vector assayed was the inducible pTcINDEX. When tested with GFP, pTcINDEX-GW showed a good response to tetracycline, being less leaky than its precursor (pTcINDEX).

HLA and non-HLA genes in Behçet's disease: a multicentric study in the Spanish population.

INTRODUCTION According to genome wide association (GWA) studies as well as candidate gene approaches, Behçet's disease (BD) is associated with human leukocyte antigen (HLA)-A and HLA-B gene regions. The HLA-B51 has been consistently associated with the disease, but the role of other HLA class I molecules remains controversial. Recently, variants in non-HLA genes have also been associated with BD. The aims of this study were to further investigate the influence of the HLA region in BD and to explore the relationship with non-HLA genes recently described to be associated in other populations. METHODS This study included 304 BD patients and 313 ethnically matched controls. HLA-A and HLA-B low resolution typing was carried out by PCR-SSOP Luminex. Eleven tag single nucleotide polymorphisms (SNPs) located outside of the HLA-region, previously described associated with the disease in GWA studies and having a minor allele frequency in Caucasians greater than 0.15 were genotyped using TaqMan assays. Phenotypic and genotypic frequencies were estimated by direct counting and distributions were compared using the χ(2) test. RESULTS In addition to HLA-B*51, HLA-B*57 was found as a risk factor in BD, whereas, B*35 was found to be protective. Other HLA-A and B specificities were suggestive of association with the disease as risk (A*02 and A*24) or protective factors (A*03 and B*58). Regarding the non-HLA genes, the three SNPs located in IL23R and one of the SNPs in IL10 were found to be significantly associated with susceptibility to BD in our population. CONCLUSION Different HLA specificities are associated with Behçet's disease in addition to B*51. Other non-HLA genes, such as IL23R and IL-10, play a role in the susceptibility to the disease.

Long-range heterogeneity at the 3' ends of human mRNAs.

The publication of a draft of the human genome and of large collections of transcribed sequences has made it possible to study the complex relationship between the transcriptome and the genome. In the work presented here, we have focused on mapping mRNA 3' ends onto the genome by use of the raw data generated by the expressed sequence tag (EST) sequencing projects. We find that at least half of the human genes encode multiple transcripts whose polyadenylation is driven by multiple signals. The corresponding transcript 3' ends are spread over distances in the kilobase range. This finding has profound implications for our understanding of gene expression regulation and of the diversity of human transcripts, for the design of cDNA microarray probes, and for the interpretation of gene expression profiling experiments.

Comparative analysis of human and mouse expression data illuminates tissue-specific evolutionary patterns of miRNAs.

MicroRNAs (miRNAs) constitute an important class of gene regulators. While models have been proposed to explain their appearance and expansion, the validation of these models has been difficult due to the lack of comparative studies. Here, we analyze miRNA evolutionary patterns in two mammals, human and mouse, in relation to the age of miRNA families. In this comparative framework, we confirm some predictions of previously advanced models of miRNA evolution, e.g. that miRNAs arise more frequently de novo than by duplication, or that the number of protein-coding gene targeted by miRNAs decreases with evolutionary time. We also corroborate that miRNAs display an increase in expression level with evolutionary time, however we show that this relation is largely tissue-dependent, and especially low in embryonic or nervous tissues. We identify a bias of tag-sequencing techniques regarding the assessment of breadth of expression, leading us, contrary to predictions, to find more tissue-specific expression of older miRNAs. Together, our results refine the models used so far to depict the evolution of miRNA genes. They underline the role of tissue-specific selective forces on the evolution of miRNAs, as well as the potential co-evolution patterns between miRNAs and the protein-coding genes they target.

CATMA, a comprehensive genome-scale resource for silencing and transcript profiling of Arabidopsis genes.

BACKGROUND: The Complete Arabidopsis Transcript MicroArray (CATMA) initiative combines the efforts of laboratories in eight European countries 1 to deliver gene-specific sequence tags (GSTs) for the Arabidopsis research community. The CATMA initiative offers the power and flexibility to regularly update the GST collection according to evolving knowledge about the gene repertoire. These GST amplicons can easily be reamplified and shared, subsets can be picked at will to print dedicated arrays, and the GSTs can be cloned and used for other functional studies. This ongoing initiative has already produced approximately 24,000 GSTs that have been made publicly available for spotted microarray printing and RNA interference. RESULTS: GSTs from the CATMA version 2 repertoire (CATMAv2, created in 2002) were mapped onto the gene models from two independent Arabidopsis nuclear genome annotation efforts, TIGR5 and PSB-EuGène, to consolidate a list of genes that were targeted by previously designed CATMA tags. A total of 9,027 gene models were not tagged by any amplified CATMAv2 GST, and 2,533 amplified GSTs were no longer predicted to tag an updated gene model. To validate the efficacy of GST mapping criteria and design rules, the predicted and experimentally observed hybridization characteristics associated to GST features were correlated in transcript profiling datasets obtained with the CATMAv2 microarray, confirming the reliability of this platform. To complete the CATMA repertoire, all 9,027 gene models for which no GST had yet been designed were processed with an adjusted version of the Specific Primer and Amplicon Design Software (SPADS). A total of 5,756 novel GSTs were designed and amplified by PCR from genomic DNA. Together with the pre-existing GST collection, this new addition constitutes the CATMAv3 repertoire. It comprises 30,343 unique amplified sequences that tag 24,202 and 23,009 protein-encoding nuclear gene models in the TAIR6 and EuGène genome annotations, respectively. To cover the remaining untagged genes, we identified 543 additional GSTs using less stringent design criteria and designed 990 sequence tags matching multiple members of gene families (Gene Family Tags or GFTs) to cover any remaining untagged genes. These latter 1,533 features constitute the CATMAv4 addition. CONCLUSION: To update the CATMA GST repertoire, we designed 7,289 additional sequence tags, bringing the total number of tagged TAIR6-annotated Arabidopsis nuclear protein-coding genes to 26,173. This resource is used both for the production of spotted microarrays and the large-scale cloning of hairpin RNA silencing vectors. All information about the resulting updated CATMA repertoire is available through the CATMA database http://www.catma.org.

Overcoming the heterologous bias: an in vivo functional analysis of multidrug efflux transporter, CgCdr1p in matched pair clinical isolates of Candida glabrata.

We have taken advantage of the natural milieu of matched pair of azole sensitive (AS) and azole resistant (AR) clinical isolates of Candida glabrata for expressing its major ABC multidrug transporter, CgCdr1p for structure and functional analysis. This was accomplished by tagging a green fluorescent protein (GFP) downstream of ORF of CgCDR1 and integrating the resultant fusion protein at its native chromosomal locus in AS and AR backgrounds. The characterization confirmed that in comparison to AS isolate, CgCdr1p-GFP was over-expressed in AR isolates due to its hyperactive native promoter and the GFP tag did not affect its functionality in either construct. We observed that in addition to Rhodamine 6 G (R6G) and Fluconazole (FLC), a recently identified fluorescent substrate of multidrug transporters Nile Red (NR) could also be expelled by CgCdr1p. Competition assays with these substrates revealed the presence of overlapping multiple drug binding sites in CgCdr1p. Point mutations employing site directed mutagenesis confirmed that the role played by unique amino acid residues critical to ATP catalysis and localization of ABC drug transporter proteins are well conserved in C. glabrata as in other yeasts. This study demonstrates a first in vivo novel system where over-expression of GFP tagged MDR transporter protein can be driven by its own hyperactive promoter of AR isolates. Taken together, this in vivo system can be exploited for the structure and functional analysis of CgCdr1p and similar proteins wherein the artefactual concerns encountered in using heterologous systems are totally excluded.

Association Study of Common Genetic Variants and HIV-1 Acquisition in 6,300 Infected Cases and 7,200 Controls.

Multiple genome-wide association studies (GWAS) have been performed in HIV-1 infected individuals, identifying common genetic influences on viral control and disease course. Similarly, common genetic correlates of acquisition of HIV-1 after exposure have been interrogated using GWAS, although in generally small samples. Under the auspices of the International Collaboration for the Genomics of HIV, we have combined the genome-wide single nucleotide polymorphism (SNP) data collected by 25 cohorts, studies, or institutions on HIV-1 infected individuals and compared them to carefully matched population-level data sets (a list of all collaborators appears in Note S1 in Text S1). After imputation using the 1,000 Genomes Project reference panel, we tested approximately 8 million common DNA variants (SNPs and indels) for association with HIV-1 acquisition in 6,334 infected patients and 7,247 population samples of European ancestry. Initial association testing identified the SNP rs4418214, the C allele of which is known to tag the HLA-B*57:01 and B*27:05 alleles, as genome-wide significant (p = 3.6×10(-11)). However, restricting analysis to individuals with a known date of seroconversion suggested that this association was due to the frailty bias in studies of lethal diseases. Further analyses including testing recessive genetic models, testing for bulk effects of non-genome-wide significant variants, stratifying by sexual or parenteral transmission risk and testing previously reported associations showed no evidence for genetic influence on HIV-1 acquisition (with the exception of CCR5Δ32 homozygosity). Thus, these data suggest that genetic influences on HIV acquisition are either rare or have smaller effects than can be detected by this sample size.