The effect of ABCA1 gene polymorphisms on ischaemic stroke risk and relationship with lipid profile

<p>Abstract</p> <p>Background</p> <p>Ischaemic stroke is a common disorder with genetic and environmental components contributing to overall risk. Atherothromboembolic abnormalities, which play a crucial role in the pathogenesis of ischaemic stroke, are often the end result of dysregulation of lipid metabolism. The ATP Binding Cassette Transporter (<it>ABCA1</it>) is a key gene involved in lipid metabolism. It encodes the cholesterol regulatory efflux protein which mediates the transfer of cellular phospholipids and cholesterol to acceptor apolipoproteins such as apolipoprotein A-I (ApoA-I). Common polymorphisms in this gene affect High Density Lipoprotein Cholesterol (HDL-C) and Apolipoprotein A-I levels and so influence the risk of atherosclerosis. This study has assessed the distribution of <it>ABCA1 </it>polymorphisms and haplotype arrangements in patients with ischaemic stroke and compared them to an appropriate control group. It also examined the relationship of these polymorphisms with serum lipid profiles in cases and controls.</p> <p>Methods</p> <p>We studied four common polymorphisms in <it>ABCA1 </it>gene: G/A-L158L, G/A-R219K, G/A-G316G and G/A-R1587K in 400 Caucasian ischaemic stroke patients and 487 controls. Dynamic Allele Specific Hybridisation (DASH) was used as the genotyping assay.</p> <p>Results</p> <p>Genotype and allele frequencies of all polymorphisms were similar in cases and controls, except for a modest difference in the <it>ABCA1 </it>R219K allele frequency (P-value = 0.05). Using the PHASE2 program, haplotype frequencies for the four loci (158, 219, 316, and 1587) were estimated in cases and controls. There was no significant difference in overall haplotypes arrangement in patients group compared to controls (p = 0.27). 2211 and 1211 haplotypes (1 = common allele, 2 = rare allele) were more frequent in cases (p = 0.05). Adjusted ORs indicated 40% and 46% excess risk of stroke for these haplotypes respectively. However, none of the adjusted ORs were statistically significant. Individuals who had R219K "22" genotype had a higher LDL level (p = 0.001).</p> <p>Conclusion</p> <p>Our study does not support a major role for the <it>ABCA1 </it>gene as a risk factor for ischaemic stroke. Some haplotypes may confer a minor amount of increased risk or protection. Polymorphisms in this gene may influence serum lipid profile.</p

γ-Catenin is overexpressed in acute myeloid leukemia and promotes the stabilization and nuclear localization of β-catenin

Canonical Wnt signaling regulates the transcription of T-cell factor (TCF)-responsive genes through the stabilization and nuclear translocation of the transcriptional co-activator, β-catenin. Overexpression of β-catenin features prominently in acute myeloid leukemia (AML) and has previously been associated with poor clinical outcome. Overexpression of γ-catenin mRNA (a close homologue of β-catenin) has also been reported in AML and has been linked to the pathogenesis of this disease, however, the relative roles of these catenins in leukemia remains unclear. Here we report that overexpression and aberrant nuclear localization of γ-catenin is frequent in AML. Significantly, γ-catenin expression was associated with β-catenin stabilization and nuclear localization. Consistent with this, we found that ectopic γ-catenin expression promoted the stabilization and nuclear translocation of β-catenin in leukemia cells. β-Catenin knockdown demonstrated that both γ- and β-catenin contribute to TCF-dependent transcription in leukemia cells. These data indicate that γ-catenin expression is a significant factor in the stabilization of β-catenin in AML. We also show that although normal cells exclude nuclear translocation of both γ- and β-catenin, this level of regulation is lost in the majority of AML patients and cell lines, which allow nuclear accumulation of these catenins and inappropriate TCF-dependent transcription

The desmosome and pemphigus

Desmosomes are patch-like intercellular adhering junctions (“maculae adherentes”), which, in concert with the related adherens junctions, provide the mechanical strength to intercellular adhesion. Therefore, it is not surprising that desmosomes are abundant in tissues subjected to significant mechanical stress such as stratified epithelia and myocardium. Desmosomal adhesion is based on the Ca2+-dependent, homo- and heterophilic transinteraction of cadherin-type adhesion molecules. Desmosomal cadherins are anchored to the intermediate filament cytoskeleton by adaptor proteins of the armadillo and plakin families. Desmosomes are dynamic structures subjected to regulation and are therefore targets of signalling pathways, which control their molecular composition and adhesive properties. Moreover, evidence is emerging that desmosomal components themselves take part in outside-in signalling under physiologic and pathologic conditions. Disturbed desmosomal adhesion contributes to the pathogenesis of a number of diseases such as pemphigus, which is caused by autoantibodies against desmosomal cadherins. Beside pemphigus, desmosome-associated diseases are caused by other mechanisms such as genetic defects or bacterial toxins. Because most of these diseases affect the skin, desmosomes are interesting not only for cell biologists who are inspired by their complex structure and molecular composition, but also for clinical physicians who are confronted with patients suffering from severe blistering skin diseases such as pemphigus. To develop disease-specific therapeutic approaches, more insights into the molecular composition and regulation of desmosomes are required

Cell Cycle- and Cancer-Associated Gene Networks Activated by Dsg2: Evidence of Cystatin A Deregulation and a Potential Role in Cell-Cell Adhesion

This work was supported by grants from the National Institutes of Health (Mahoney, R01AR056067; Riobo, RO1 GM088256). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript

Desmoglein 2 mutant mice develop cardiac fibrosis and dilation

Desmosomes are cell–cell adhesion sites and part of the intercalated discs, which couple adjacent cardiomyocytes. The connection is formed by the extracellular domains of desmosomal cadherins that are also linked to the cytoskeleton on the cytoplasmic side. To examine the contribution of the desmosomal cadherin desmoglein 2 to cardiomyocyte adhesion and cardiac function, mutant mice were prepared lacking a part of the extracellular adhesive domain of desmoglein 2. Most live born mutant mice presented normal overall cardiac morphology at 2 weeks. Some animals, however, displayed extensive fibrotic lesions. Later on, mutants developed ventricular dilation leading to cardiac insufficiency and eventually premature death. Upon histological examination, cardiomyocyte death by calcifying necrosis and replacement by fibrous tissue were observed. Fibrotic lesions were highly proliferative in 2-week-old mutants, whereas the fibrotic lesions of older mutants showed little proliferation indicating the completion of local muscle replacement by scar tissue. Disease progression correlated with increased mRNA expression of c-myc, ANF, BNF, CTGF and GDF15, which are markers for cardiac stress, remodeling and heart failure. Taken together, the desmoglein 2-mutant mice display features of dilative cardiomyopathy and arrhythmogenic right ventricular cardiomyopathy, an inherited human heart disease with pronounced fibrosis and ventricular arrhythmias that has been linked to mutations in desmosomal proteins including desmoglein 2

Pharmacogenomics of GLP-1 receptor agonists: a genome-wide analysis of observational data and large randomised controlled trials

Background: In the treatment of type 2 diabetes, GLP-1 receptor agonists lower blood glucose concentrations, body weight, and have cardiovascular benefits. The efficacy and side effects of GLP-1 receptor agonists vary between people. Human pharmacogenomic studies of this inter-individual variation can provide both biological insight into drug action and provide biomarkers to inform clinical decision making. We therefore aimed to identify genetic variants associated with glycaemic response to GLP-1 receptor agonist treatment. Methods: In this genome-wide analysis we included adults (aged ≥18 years) with type 2 diabetes treated with GLP-1 receptor agonists with baseline HbA1c of 7% or more (53 mmol/mol) from four prospective observational cohorts (DIRECT, PRIBA, PROMASTER, and GoDARTS) and two randomised clinical trials (HARMONY phase 3 and AWARD). The primary endpoint was HbA1c reduction at 6 months after starting GLP-1 receptor agonists. We evaluated variants in GLP1R, then did a genome-wide association study and gene-based burden tests. Findings: 4571 adults were included in our analysis, of these, 3339 (73%) were White European, 449 (10%) Hispanic, 312 (7%) American Indian or Alaskan Native, and 471 (10%) were other, and around 2140 (47%) of the participants were women. Variation in HbA1c reduction with GLP-1 receptor agonists treatment was associated with rs6923761G→A (Gly168Ser) in the GLP1R (0·08% [95% CI 0·04–0·12] or 0·9 mmol/mol lower reduction in HbA1c per serine, p=6·0 × 10−5) and low frequency variants in ARRB1 (optimal sequence kernel association test p=6·7 × 10−8), largely driven by rs140226575G→A (Thr370Met; 0·25% [SE 0·06] or 2·7 mmol/mol [SE 0·7] greater HbA1c reduction per methionine, p=5·2 × 10−6). A similar effect size for the ARRB1 Thr370Met was seen in Hispanic and American Indian or Alaska Native populations who have a higher frequency of this variant (6–11%) than in White European populations. Combining these two genes identified 4% of the population who had a 30% greater reduction in HbA1c than the 9% of the population with the worse response. Interpretation: This genome-wide pharmacogenomic study of GLP-1 receptor agonists provides novel biological and clinical insights. Clinically, when genotype is routinely available at the point of prescribing, individuals with ARRB1 variants might benefit from earlier initiation of GLP-1 receptor agonists. Funding: Innovative Medicines Initiative and the Wellcome Trus

Genome-Wide and Abdominal MRI-Imaging Data Provides Evidence that a Genetically Determined Favourable Adiposity Phenotype is Characterized by Lower Ectopic Liver Fat and Lower Risk of Type 2 Diabetes, Heart Disease and Hypertension

Recent genetic studies have identified alleles associated with opposite effects on adiposity and risk of type 2 diabetes. We aimed to identify more of these variants and test the hypothesis that such “favourable adiposity” alleles are associated with higher subcutaneous fat and lower ectopic fat. We combined magnetic resonance imaging (MRI) data with genome-wide association studies (GWAS) of body fat % and metabolic traits. We report 14 alleles, including 7 newly characterized alleles, associated with higher adiposity, but a favourable metabolic profile. Consistent with previous studies, individuals carrying more “favourable adiposity” alleles had higher body fat % and higher BMI, but lower risk of type 2 diabetes, heart disease and hypertension. These individuals also had higher subcutaneous fat, but lower liver fat and lower visceral-to-subcutaneous adipose tissue ratio. Individual alleles associated with higher body fat % but lower liver fat and lower risk of type 2 diabetes included those in PPARG, GRB14 and IRS1, whilst the allele in ANKRD55 was paradoxically associated with higher visceral fat but lower risk of type 2 diabetes. Most identified “favourable adiposity” alleles are associated with higher subcutaneous and lower liver fat, a mechanism consistent with the beneficial effects of storing excess triglyceride in metabolically low risk depots.Diabetes UK RD Lawrence fellowship, European Research Council, Wellcome Trust and Royal Society grant, European Regional Development Fund, Medical Research Council, German Federal Ministry of Education and Research, German Research Foundation, Innovative Medicines Initiative Joint Undertaking, European Union's Seventh Framework Programme, Dutch Science Organisation, Scottish Government Health Directorates, Scottish Funding Council and Medical Research Council UK and the Wellcome Trust

Dietary Pattern and Food Consumption among Kermanshah Households, 2011

Abstract: Background & Aims: Identification of dietary patterns and food groups' consumption can be beneficial in improving public health. This study aimed to evaluate the daily dietary pattern of households in Kermanshah, 2011. Methods: A total of 500 households in Kermanshah/Iran were selected through multi-stage cluster-sampling. Data were collected using demographic questionnaire and food frequency questionnaire (FFQ) and through face to face interview. Regression and X2 tests were applied for statistical analysis. Results: In whole, 477 households with mean family size of 4.3±1.5 person completed the study. Consumption of vegetables in 78%, fruits in 23.3%, meat in 34.7%, dairy products in 44% and grains in 25% of families were less than the recommended levels in food guide pyramid. Consumption of dairy products showed a significant positive correlation with socio-economic statues (P=0.009) and educational level of the father of family (p<0.01). Furthermore, significant correlation was seen between fruits consumption and parents educational level (p=0.002). In general, consumption of one or more food groups was less than the dietary guide line level in 40% of households, while it was acceptable in 44% and was more than the recommended level in 16% of households. Conclusion: In Spite of all efforts for modifying dietary pattern, there is still a big gap between guidelines and national dietary habits. Increasing public nutritional knowledge in regard to healthy eating is necessary and highly recommended. Keywords: Cereals, Diary products, Meats, Fruits & Vegtabeles, Dietary habit

Comparison of the Teaching Quality Aspects by Student Evaluation of Education Quality (SEEQ) and Students Survey Questionnaires Health School, Kermanshah University of Medical Sciences

Aims: The purpose of the professors&rsquo; evaluation which partly left up to the students is to improve the teaching quality and enhance the educational level in universities. Regarding this, the use of valid evaluation forms that lead to the recognition of the problems of teaching and learning is important. This study aimed to compare the teaching quality aspects between Student Evaluation of Education Quality and Students Survey questionnaires. Instrument & Methods: In this descriptive-analytic study by correlation type that was performed during the second semester of 2012-13 academic year, 251 students of Health Department of Kermanshah University of Medical Sciences participated by census method. The research tools were the Student Evaluation of Education Quality and Students Survey questionnaires. For data analysis, independent- and paired T, Chi-square, Mann-Whitney U, Kruskal-Wallis, Pearson correlation coefficient and Tukey tests were utilized.&nbsp; Findings: The difference of total evaluation scores of the professors based on their scientific degree and also the education level and major of students was significant between 2 questionnaires (p<0.05). There was also a significant relationship between the workload and level of interest for each course and the total evaluation score of the professors based on student evaluation of education quality questionnaire (p<0.001). Conclusion: Both questionnaires have acceptable reliability, but the student evaluation of education quality questionnaire highlights the multi aspects of teaching better and is more efficient in demonstrating the strength and weaknesses of teaching