I. Wybranska

Number of Microparticles Generated During Acute Myocardial Infarction and Stable Angina Correlates with Platelet Activation

BACKGROUND AND AIMS Elevated levels of circulating microparticles (MPs) have been reported in patients with acute myocardial infarction (AMI) and coronary artery disease. Platelet activation and inflammation have been recognized during AMI and stable angina (SA). We hypothesize that the origin and count of MPs in AMI and SA patients are related to markers of inflammation and platelet activation. METHODS Platelet, monocytes and endothelial MPs and surface P-selectin were determined in 12 AMI patients, 10 SA patients and 9 controls by flow cytometry. Plasma P-selectin, CD40 ligand (sCD40L) and interleukin 6 (IL-6) levels were evaluated by ELISA methods. RESULTS The total MP count was compared in control subjects, AMI, and SA patients: 12,765 (8465) vs. 38,750 (11,931) vs. 29,715 (12,072) counts/μl (p = 0.01), respectively. Patients with AMI displayed higher levels of total and platelet origin- tissue factor-positive (CD42/CD142) MPs than patients with SA: 72.8 (6.2) vs. 56.2 (6.4) %, p = 0.001. Levels of soluble P-selectin were significantly elevated in patients with AMI as compared to SA patients: 146 (6.5) vs. 107 (2.7) ng/mL, p = 0.005; significant correlation between total MP count and relative number of CD34, CD51, CD42-positive MPs, and the P-selectin expression was observed in patients with AMI. CONCLUSIONS Platelet activation in AMI is associated with increased generation of MPs not only from platelets, but also monocytes and endothelial cells. It suggests that interactions between platelets, monocytes and endothelial cells play an important role in the pathogenesis of myocardial ischemia.

Nutrigenomic approaches for benefit-risk analysis of foods and food components:defining markers of health

To be able to perform a comprehensive and rigorous benefit-risk analysis of individual food components, and of foods, a number of fundamental questions need to be addressed first. These include whether it is feasible to detect all relevant biological effects of foods and individual food components, how such effects can confidently be categorised into benefits and risks in relation to health and, for that matter, how health can be quantified. This article examines the last of these issues, focusing upon concepts for the development of new biomarkers of health. Clearly, there is scope for refinement of classical biomarkers so that they may be used to detect even earlier signs of disease, but this approach defines health solely as the absence of detectable disease or disease risk. We suggest that the health of a biological system may better be reflected by its ability to withstand and manage relevant physiological challenges so that homeostasis is maintained. We discuss the potential for expanding the range of current challenge tests for use in conjunction with functional genomic technologies to develop new types of biomarkers of health.

Pleiotropic effects of TCF7L2 gene variants and its modulation in the metabolic syndrome: From the LIPGENE study

AIMS/HYPOTHESIS Variants of the TCF7L2 gene predict the development of type 2 diabetes mellitus (T2DM). We investigated the associations between gene variants of TCF7L2 and clinical features of the metabolic syndrome (MetS) (an entity often preceding T2DM), and their interaction with non-genetic factors, including plasma saturated fatty acids (SFA) concentration and insulin resistance (IR). METHODS Fasting lipid profiles, insulin sensitivity, insulin secretion, anthropometrics, blood pressure and 10 gene variations of the TCF7L2 gene were determined in 450 subjects with MetS. RESULTS Several single nucleotide polymorphisms (SNP) showed phenotypic associations independent of SFA or IR. Carriers of the rare T allele of rs7903146, and of three other SNPs in linkage disequilibrium with rs7903146, had lower blood pressure and insulin secretion. High IR and the presence of the T-allele of rs7903146 acted synergistically to define those with reduced insulin secretion. Carriers of the minor allele of rs290481 exhibited an altered lipid profile, with increased plasma levels of apolipoprotein B, non-esterified fatty acids, cholesterol and apolipoprotein B in triglyceride rich lipoproteins, and LDL cholesterol. Carriers of the minor allele of rs11196224 that had higher plasma SFA levels showed elevated procoagulant/proinflammatory biomarkers, impaired insulin secretion and increased IR, whereas carriers of the minor allele of rs17685538 with high plasma SFA levels exhibited higher blood pressure. CONCLUSIONS/INTERPRETATION SNP in the TCF7L2 gene are associated with differences in insulin secretion, blood pressure, blood lipids and coagulation in MetS patients, and may be modulated by SFA in plasma or IR.

The TNF-alpha gene NcoI polymorphism at position -308 of the promoter influences insulin resistance, and increases serum triglycerides after postprandial lipaemia in familiar obesity.

Abstract Tumour necrosis factor alpha (TNF-α), acting as a modulator of gene expression in adipocytes, has been linked to the development of insulin resistance and obesity. The aim of this study was to investigate whether the A/G variation at position −308 in the TNFα promoter influences the body weight, insulin resistance, and postprandial lipaemia in Polish Caucasians. One hundred twenty one subjects, 38 men and 83 women, representing 40 obese families, were genotyped by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). TNF-1 (GG) and TNF-2 (GA and AA) allele carriers were compared with respect to body mass index, fat/lean body mass composition, waist-to-hip ratio, as well as fasting lipids, glucose, leptin, and insulin fasting, and during the oral glucose tolerance test (4 points within 2 hours) and oral lipid tolerance test (OLTT; 5 points within 8 hours). The insulin sensitivity indices HOMA-IR (homeostasis model assessment of insulin resistance), ISI-COMP (whole body insulin sensitivity index), ISI-HOMA (hepatic insulin sensitivity), and DELTA (early secretory response to an oral glucose load) were calculated. We detected 64 GG, 56 GA, and 1 AA genotypes. Significant increases of insulin resistance parameters in obese female TNF-2 allele carriers were observed (significantly increased HOMA-IR and decreased ISI-HOMA, ISI-composite). The male TNF-2 carriers were characterised by significantly increased levels of triglyceride and free fatty acids during OLTT as well as fasting glucose. The A/G variation at position −308 in the promoter region of the TNF-α gene could be an important genetic factor predisposing to insulin resistance in obese women and increased levels of glucose, triglyceride, and free fatty acids in men.

The Microarray Expression Analysis Identifies BAX as a Mediator of β-Carotene Effects on Apoptosis

Abstract: β-Carotene is a ubiquitous compound rich in foods. However, there are conflicting reports regarding its role in carcinogenesis. We performed a microarray expression analysis in normal [human umbilical vein endothelial cells (HUVECs)] and neoplastic (melanoma A375 and myelomonocytic leukemia U937) actively proliferating cells and found evidence that β-carotene stimulated vital cellular functions in the former and suppressed them in the latter. These differential effects correlated with the expression of the proapoptotic BCL2-associated X protein (BAX), which was downregulated in HUVECs and upregulated in the two neoplastic cell lines. The quantitative expression analysis using real-time polymerase chain reaction largely confirmed the inhibition of B-cell CLL/lymphoma 2 (BCL2) pathway-mediated apoptosis in HUVECs and its activation in melanoma and leukemic cells. The assays for apoptosis, detecting DNA breaks and caspase activation, showed consistent proapoptotic and antiapoptotic effects in U937 and HUVEC lines, respectively. However, β-carotene–induced expression changes of BAX and other BCL2 pathway genes did not lead to the predicted induction of apoptosis in the A375 cells.

Dexamethasone Inhibits TNF-α Synthesis More Effectively in Alzheimer’s Disease Patients than in Healthy Individuals

Inflammatory mechanisms are involved in the pathogenesis of Alzheimer’s disease (AD). It is postulated that cytokine synthesis is altered in AD patients compared with nondemented subjects. Glucocorticoids play an important role in cytokine synthesis. We assessed the release of tumor necrosis factor-alpha (TNF-α), interleukin-10 (IL-10) and interleukin-12 (IL-12) and its regulation by dexamethasone in AD patients in vitro. Cytokine levels were measured using the ELISA method in unstimulated, LPS-stimulated or whole-blood samples incubated with LPS and dexamethasone from 18 AD patients and 12 controls. The cytokine levels spontaneously produced by blood cells after incubation with LPS or LPS and dexamethasone did not differ significantly between groups. Dexamathasone inhibited TNF-α synthesis by LPS-stimulated blood cells more effectively in AD patients than in controls. These results suggest that cytokine synthesis in AD patients could be regulated by glucocorticoids in a different way than in nondemented subjects.

Analysis of candidate genes in Polish families with obesity.

Abstract This study analyzes the relationship between risk factors related to overweight/obesity, insulin resistance, lipid tolerance, hypertension, endothelial function and genetic polymorphisms associated with: i) appetite regulation (leptin, melanocortin-3-receptor (MCR-3), dopamine receptor 2 (D2R)); ii) adipocyte differentiation and insulin sensitivity (peroxisome proliferator-activated receptor-γ2 (PPAR-γ2), tumor necrosis factor-α (TNF-α)); iii) thermogenesis and free fatty acid (FFA) transport/catabolism (uncoupling protein-1 (UCP1), lipoprotein lipase (LPL), β2- and β3-adrenergic receptor (β2AR, β3AR), fatty acid transport protein-1 (FATP-1) and iv) lipoproteins (apoliprotein E (apoE), apo CIII). The 122 members of 40 obese Caucasian families from southern Poland participated in the study. The genotypes were analyzed by restriction fragment length polymorphism-polymerase chain reaction (RFLP-PCR) or by direct sequencing. Phenotypes related to obesity (body mass index (BMI), fat/lean body mass composition, waist-to-hip ratio (WHR)), fasting lipids, glucose, leptin and insulin, as well as insulin during oral glucose tolerance test (OGTT) (4 points within 2 hours) and during oral lipid tolerance test (OLTT) (5 points within 8 hours) were assessed. The insulin sensitivity indexes: homeostasis model assessment of insulin resistance, whole body insulin sensitivity index, hepatic insulin sensitivity and early secretory response to an oral glucose load (HOMA-IR, ISI-COMP, ISI-HOMA and DELTA) were calculated. The single gene mutations such as C105 T OB and Pro115 Gln PPAR-γ2 linked to morbid obesity were not detected in our group. A weak correlation between obesity and certain gene polymorphisms was observed. Being overweight (25<BMI≤30 kg/m2) significantly correlated with worse FFA tolerance in male PPAR-γ2 12Pro, LPL-H (G) allele carriers. Insulin resistance was found in female PPAR-γ2 Pro12, TNF-α (−308A) and LPL-H (G) allele carriers. Hypertension linked to the PPAR-γ2 Pro allele carriers was characterized by high leptin output during OLTT. We conclude that the polymorphisms we investigated were weakly correlated with obesity but significantly modified the risk factors of the metabolic syndrome.

Gold–Oxoborate Nanocomposites and Their Biomedical Applications

A novel inorganic nanocomposite material, called BOA, which has the form of small building blocks composed of gold nanoparticles embedded in a polyoxoborate matrix, is presented. It is demonstrated that cotton wool decorated with the BOA nanocomposite displays strong antibacterial activity toward both Gram-positive and -negative bacteria strains. Importantly, the modified cotton does not release any toxic substances, and the bacteria are killed upon contact with the fibers coated with the BOA. Toxicity tests show that the nanocomposite--in spite of its antiseptic properties--is harmless for mammalian cells. The presented method of surface modification utilizes mild, environmentally friendly fabrication conditions. Thus, it offers a facile approach to obtain durable nontoxic antiseptic coatings for biomedical applications.

Induction of Nitric Oxide Synthase (NOS) and Vascular Endothelial Growth Factor (VEGF) in Experimental Model of Angioplasty and Heart Ischemia

Balloon angioplasty (e. g. PTCA) leads to the activation of a number of genes in injured vessels1. As a consequence of the endothelium damage several characteristic reactions, such as thrombus formation, vasoconstriction and finally - vascular smooth muscle cell (VSMC) proliferation, lead to restenosis1. Among other things, the diminished generation of nitric oxide (NO), due to the lack of constitutively expressed endothelial NO synthase (eNOS) is causatively connected with this process.

Characterisation of atherogenic effects of low carbohydrate, high protein diet (LCHP) in apoE/LDLR−/− mice

IntroductionLow Carbohydrate High Protein diet represents a popular strategy to achieve weight loss.ObjectiveThe aim of this study was to characterize effects of low carbohydrate, high protein diet (LCHP) on atherosclerotic plaque development in brachiocephalic artery (BCA) in apoE/LDLR−/− mice and to elucidate mechanisms of proatherogenic effects of LCHP diet.Materials and MethodsAtherosclerosis plaques in brachiocephalic artery (BCA) as well as in aortic roots, lipoprotein profile, inflammation biomarkers, expression of SREBP-1 in the liver as well as mortality were analyzed in Control diet (AIN-93G) or LCHP (Low Carbohydrate High Protein) diet fed mice.ResultsArea of atherosclerotic plaques in aortic roots or BCA from LCHP diet fed mice was substantially increased as compared to mice fed control diet and was characterized by increased lipids and cholesterol contents (ORO staining, FT-IR analysis), increased macrophage infiltration (MOMA-2) and activity of MMPs (zymography). Pro-atherogenic phenotype of LCHP fed apoE/LDLR−/− mice was associated with increased plasma total cholesterol concentration, and in LDL and VLDL fractions, increased TG contents in VLDL, and a modest increase in plasma urea. LCHP diet increased SCD-1 index, activated SREBP-1 transcription factor in the liver and triggered acute phase response as evidence by an increased plasma concentration of haptoglobin, CRP or AGP. Finally, in long-term experiment survival of apoE/LDLR−/− mice fed LCHP diet was substantially reduced as compared to their counterparts fed control diet suggesting overall detrimental effects of LCHP diet on health.ConclusionsThe pro-atherogenic effect of LCHP diet in apoE/LDLR−/− mice is associated with profound increase in LDL and VLDL cholesterol, VLDL triglicerides, liver SREBP-1 upregulation, and systemic inflammation.