Identification of gene variants associated with hypoxia pathway in acute coronary syndrome: a pilot study.

Hypoxic condition is known to play an important role in the development of acute coronary syndrome (ACS) and understanding mechanism of hypoxic effects is essential to develop new treatment strategies for ACS. Based on the phenotypic features of cardiovascular diseases, it is claimed that genetic factors play an important role in the development genome-wide association studies have been studied to clarify the molecular mechanisms underlying heritable and prevalent phenotype. The claim was to investigate possible roles of gene polymorphisms involving in hypoxia pathway on ACS in this pilot study. DNA samples of 100 ACS cases and 100 controls from a Department of Cardiology, Istanbul University, were genotyped with Illumina CytoSNP-12 BeadChip 300 K Array. The additive model used for statistical analysis, and Correlation/Trend Test selected as a statistical process. It was determined different criteria for association analysis as case/control and number of plugged vessels. P value calculated with each SNP and score generated with -log10(P). Also, hypoxia pathway analysis was applied to find statistically significant genes. As a result of bioinformatic analysis, it was claimed that PIAS4 (rs735842) and VEGFA (rs699947) were the most statistically significant variants associated in hypoxia pathway analysis. Due to the information of literature, there have been no prior studies of possible interactions of hypoxia pathways the etiology of acute coroner syndromes in the same research. Detailed studies with larger sample groups are necessary to clarify the role of hypoxia in the development of disease.

Association between genetic variants of DNA repair genes and coronary artery disease.

Polymorphisms in DNA repair genes may be associated with differences in the repair efficiency of DNA damage and may influence an individual's risk of atherosclerosis. Genetic research on coronary artery disease (CAD) has traditionally focused on investigation aimed at identifying disease-susceptibility genes. The aim of this study was to investigate the relationship between AP-endonuclease-1 (Asp148Glu), XRCC1 (Arg399Gln), XRCC3 (Thr241Met), XPD (Lys751Gln), XPG (Asp1104His), and hOGG1 (Ser326Cys), gene polymorphisms and the risk of developing CAD in a Turkish population. The study population consisted of 197 patients with acute coronary syndrome (ACS) with chronic CAD and 135 healthy subjects' age and sex matched. Gene polymorphisms were determined by the polymerase chain reaction-restriction fragment length polymorphism method. We demonstrated for the first time, a positive association of XRCC3 and hOGG1 DNA repair gene variants with CAD risk. XRCC3 Thr/Thr genotype and Thr allele frequencies were significantly increased in ACS and chronic CAD patients compared with the control group (p<0.05). It was also observed that there is a protective role of XRCC3 Met alleles against both ACS and chronic CAD (p<0.05). hOGG1 Cys alleles were found significantly higher in ACS patients than in the control group and carriers of the Cys allele had a 1.7-fold increased risk for ACS. In addition, we confirmed the association of XRCC3 Thr241Met and hOGG1 Ser326Cys gene variants with CAD by haplotype analysis. We found that CAD risk is associated with XRCC3 Thr: hOGG1 Cys haplotype, whereas XRCC3 Met: hOGG1 Ser haplotype was found to be protective against the disease. The preliminary results suggested that XRCC3 and hOGG1 genetic variants may be risk factors by affecting the enzyme's function that may lead to development of CAD.

The role of chemokine and chemokine receptor gene variants on the susceptibility and clinicopathological characteristics of bladder cancer.

The gene variants of the chemokine and chemokine receptor genes associated with inflammation may be involved in cancer initiation and progression. The aim of this study was to explore the possible association of monocyte chemoattractant protein-1 (MCP-1) A2518G, stromal cell derived factor 1 (SDF-1) 3'A and chemokine receptors CCR2A V64I, CCR5 Δ32, CCR5 59029 and CXCR4 gene polymorphisms with the risk and clinicopathological characteristics of bladder cancer (BC) in a Turkish population. The genotyping was done by PCR and PCR-Restriction Fragment Length Polymorphism (RFLP) methods in 142 histologically confirmed BC patients and 197 controls. The SDF-1 3'AA genotype conferred significantly increased susceptibility to BC. The carriers with AA genotype or at least one A allele of CCR2 had an increased risk of developing BC. CCR5 wt/Δ32 genotype and CCR5 Δ32 allele were also observed to be involved in the susceptibility to BC. Additionally, the combination of CCR2 V64I and CCR5 Δ32 (i.e., GG-wt/Δ32) was found to be associated with BC risk. With respect to the stage of BC, the AA genotype of SDF-1 and at least one T allele of CXCR4 were significantly associated with high T stage as compared to GG genotype of SDF-1 and CC genotype of CXCR4. Furthermore, BC patients with AA genotype or at least one A allele of CCR2 had an increased risk of high grade and stage tumors as compared to those with GG genotype. Our results suggest that the genetic variants of SDF-1 3'A, CCR2A V64I and CCR5 Δ32 gene polymorphisms may modify the BC risk. Furthermore, SDF-1 3'A, CCR2A V64I and CXCR4 gene polymorphisms may contribute to the muscle invasive BC in a Turkish population.

Hormone replacement therapy: relation to homocysteine and prooxidant-antioxidant status in healthy postmenopausal women.

OBJECTIVES: Studies have consistently shown a lower cardiovascular risk in women who received postmenopausal hormone replacement therapy (HRT). DESIGN AND METHODS: In this study, the effects of HRT were investigated on plasma total homocysteine (tHcy) and the oxidant-antioxidant status in postmenopausal women. 35 of postmenopausal receiving (2 mg estrodiol valerate + 1 mg cyproterone acetate) HRT group, the remaining 25 received orally placebo (NHRT group). RESULTS: There was no significant change in plasma tHcy levels between HRT and NHRT groups. Malondialdehyde (MDA) and total thiol (t-SH) correlated significantly with tHcy (0.388 and 0.478, respectively) content, and there was a significant negative correlation between E2 level and glutathione transferase (GST) activity (-0.425) in HRT group. Superoxide dismutase (SOD) and HDL-C correlated significantly with t-SH level (0.339 and 0.336, respectively) in plasma after HRT. CONCLUSION: Our results show that HRT is beneficial in the protection against oxidative damage, and prevents atherosclerotic complications.

The benefits of hormone replacement therapy on plasma and platelet antioxidant status and fatty acid composition in healthy postmenopausal women.

Oxidative stress is suggested to play an important role in the pathogenesis of cardiovascular disease (CVD). Various hormone replacement therapy (HRT) protocols are used to reduce the CVD risk in postmenopausal women. Recent studies found that HRT lowers lipid levels and improves vascular endothelial function in postmenopausal women. In this study the effects of HRT on plasma and platelet membrane fatty acid composition and the oxidant-antioxidant system in postmenopausal women are investigated. Blood samples were obtained from 50 postmenopausal women. Before starting treatment, all participants underwent clinical, biochemical and hormonal screening procedures including gynecologic and physical breast examination. Then oral HRT (2 mg estrodiol valerate + 1 mg cyproterone acetate) were given to all subjects for 1 year. Levels of malondialdehyde (MDA), total thiol (t-SH) and fatty acid contents, activities of glutathione-Stransferase (GST) and superoxide dismutase (SOD) were measured before and after treatment. Platelet membrane palmitic, stearic and oleic acid contents decreased (6.5%, 22.5% and 21.9% respectively) and linoleic and arachidonic acid contents increased (21.2% and 25.4% respectively) after HRT. Platelet MDA, GST and SOD levels were lower and t-SH content was higher than pre-treatment levels. These results indicate that hormone replacement therapy may affect platelet membrane fatty acid content and oxidant-antioxidant balance in postmenopausal women.

Homocysteine and pro-inflammatory cytokine concentrations in acute heart disease.

Inflammation is involved in development and progression of atherosclerosis. Interleukin-2 (IL-2) and interleukin-6 (IL-6) have been correlated with various cardiovascular diseases. Hyperhomocysteinemia is an important risk factor for atherosclerosis and thrombotic disease. Recent studies have demonstrated that homocysteine (Hcy) enhances productions of several pro-inflammatory cytokines. In the light of these findings, we decided to determine if any relationship exists between IL-2 and IL-6, the pro-inflammatory cytokines, and total homocysteine (tHcy) in acute coronary syndrome (ACS). A total of 102 patients with ACS and 90 healthy subjects were included in the study. The levels of tHcy, IL-2 and IL-6 were higher and folic acid was lower in patients as compared with those of controls. Furthermore, data of the area under ROC plot for IL-2 demonstrated that IL-2 had higher sensitivity. These data suggest that enhanced inflammation may be associated with tHcy-related cardiovascular disease.

Influences of genetic variants in interleukin-15 gene and serum interleukin-15 levels on coronary heart disease.

Interleukin-15 (IL-15) is a potent proinflammatory cytokine that is now considered a key component of atherosclerosis. Proinflammatory gene polymorphisms lead to variations in the production and level of the proteins. In light of these findings, we hypothesized that variations in the gene coding for IL-15 influence the risk of coronary heart disease (CHD) by modulating the IL-15 levels. To test this hypothesis, we examined 5 single nucleotide polymorphisms (SNPs) in IL-15 gene and IL-15 levels in 102 patients with acute coronary syndrome (ACS), 102 patients with chronic ischemic stable CHD and 162 healthy control subjects. This study is the first report showing the influences of IL-15 gene variants and IL-15 levels on CHD. The five single nucleotide polymorphisms (SNPs) within the IL-15 gene, G367A, C267T, A14035T, C13687A, and A10504G were carried out by polymerase chain reaction/restriction fragment length polymorphism (PCR/RFLP). Serum IL-15 levels were significantly higher in both acute and chronic patients than in controls. Genetic variants of IL-15 gene and IL-15 levels were associated with CHD. In conclusion, our study supports the hypothesis that genetic variation in IL-15 gene and IL-15 levels influence the risk of CHD. Further studies are needed to confirm our hypothesis.

Association of genetic variants in Methylenetetrahydrofolate Reductase and Paraoxonase-1 genes with homocysteine, folate and vitamin B12 in coronary artery disease.

BACKGROUND: The aim of the present study was to investigate the association between genetic variants in metylenetetrahydrofolate reductase (MTHFR) and Paraoxonase-1 (PON1) 55/192 genes and total homocysteine (tHcy), folate, B12 vitamin, and PON1 levels in patients with coronary artery disease (CAD). METHODS: The study included 235 patients with CAD and 268 healthy control subjects. RESULTS: LL and LM genotypes and L allele of PON1 55 were over-represented in patients. In contrast, MM genotype and M allele were more frequent in controls. QQ genotype and Q allele of PON1 192 and CT genotype of MTHFR were significantly diminished and QR genotype and R allele were significantly elevated in CAD patients compared with controls. The plasma tHcy were elevated but B12 levels were diminished in patients. PON1 55 and 192 genetic variants were significantly associated with PON1 activity, triglyceride, total cholesterol, tHcy and, high-density lipoprotein-cholesterol and low-density lipoprotein-cholesterol in patients, respectively. CONCLUSION: Genetic variants of PON1 55/192 and MTHFR were associated with CAD.

Comparison of rheological parameters in patients with post hepatitic and alcoholic cirrhosis.

It is well known that various constituents of blood, especially lipids and proteins, and hematological parameters are altered in chronic liver diseases. These alterations have been shown to affect rheological parameters in various studies. However, it is not clear whether the etiology of chronic liver has any specific influence on flow dynamics of blood. In the present study, we analysed erythrocyte rigidity (ER), whole blood and plasma viscosity, and other factors related to blood rheology (including hematological parameters, plasma lipids and proteins) in healthy controls (n=20) and patients with post hepatitic and alcoholic cirrhosis (n=15 in each group). ER was significantly higher (p<0.05) in both groups compared to controls. Although blood viscosity was found to be low in both groups, the difference reached statistical significance only in patients with alcoholic cirrhosis. On the other hand, when compared to controls, plasma viscosity was significantly lower in patients with alcoholic cirrhosis and significantly higher in patients with posthepatitic cirrhosis (p<0.05). When we compare post hepatic and alcoholic cirrhosis with each other, there was no significant difference in ER between the two groups.

The relationship between erythropoietin pretreatment with blood-brain barrier and lipid peroxidation after ischemia/reperfusion in rats.

Blood-brain barrier (BBB) leakage plays a role in the pathogenesis of many pathological states of the brain including ischemia and some neurodegenerative disorders. In recent years, erythropoietin (EPO) has been shown to exert neuroprotection in many pathological conditions including ischemia in the brain. This study aimed to investigate the effects of EPO on BBB integrity, infarct size and lipid peroxidation following global brain ischemia/reperfusion in rats. Wistar male rats were divided into four groups (each group n=8); Group I; control group (sham-operated), Group II; ischemia/reperfusion group, Group III; EPO treated group (24 h before decapitation--000 U/kg r-Hu EPO i.p.), Group IV; EPO+ ischemia/reperfusion group (24 h before ischemia/reperfusion--3000 U/kg r-Hu EPO i.p.). Global brain ischemia was produced by the combination of bilateral common carotid arteries occlusion and hemorrhagic hypotension. Macroscopical and spectrophotometrical measurement of Evans Blue (EB) leakage was observed for BBB integrity. Infarct size was calculated based on 2,3,5-triphenyltetrazolium chloride (TTC) staining. Lipid peroxidation in the brain tissue was determined as the concentration of thiobarbituric acid-reactive substances (TBARS) for each group. Ischemic insult caused bilateral and regional BBB breakdown (hippocampus, cortex, corpus striatum, midbrain, brain stem and thalamus). EPO pretreatment reduced BBB disruption, infarct size and lipid peroxide levels in brain tissue with 20 min ischemia and 20 min reperfusion. These results suggest that EPO plays an important role in protecting against brain ischemia/reperfusion through inhibiting lipid peroxidation and decreasing BBB disruption.

Effects of cyclosporine A on deformability and oxidative stress in the peripheral lymphocytes of rats.

UNLABELLED: The aim of this study is to investigate the effects of CsA on lymphocyte deformability and oxidant-antioxidant system in peripheral lymphocytes in rats. Female Wistar Albino rats were injected 10 mg/kg/30 days Sandimmun i.p. the control rats were injected 0.9% NaCl. CsA administration caused a significant reduction in the deformability of lymphocytes, and produced a significant increase in peripheral lymphocytes lipid peroxide level and a significant decrease in nitric oxide (NO) level. The activity of superoxide dismutase (SOD) in peripheral lymphocytes did not show significant differences between CsA administrated and control rats. However the total thiol (t-SH) content of lymphocytes was significantly lower in CsA administrated rats. CONCLUSIONS: The present data demonstrate that CsA administration increased lipid peroxidation and decreased the NO levels and t-SH contents in the peripheral lymphocytes of rats. This effect was accompanied by a decrease in lymphocytes deformability. These results support the hypothesis that sufficient cellular t-SH concentrations may be important to prevent cyclosporin toxicity, and indicate that disturbances in lymphocytes rheology may be an additional risk factor in the pathogenesis of side effects associated with CsA.

Cyclosporin A-associated changes in red blood cell membrane composition, deformability, blood and plasma viscosity in rats.

Most of the studies concerning the effects of cyclosporin A (Cs A) on red blood cell (RBC) rheology were carried out in human transplant recipients who may still have residual insufficiency and concomitant administration of other immunosuppressive and antihypertensive drugs. The aim of this study is to evaluate the effects of Cs A on red cell rheology and membrane composition in nontransplant healthy rats. Female Wistar albino rats were divided into two groups of 10 animals each. Rats received 10 mg/kg Cs A, i.p. or saline for 4 weeks. Cs A administration significantly increased the RBC deformability, and plasma and blood viscosity (p < 0.001, p < 0.01 and p < 0.01, respectively). Cs A administration to the rats increased RBC membrane cholesterol (CHO) levels and the CHO/phospholipid (PL) ratio significantly (p < 0.01 and p < 0.05, respectively) but did not change RBC membrane proteins and membrane PL levels. These results suggest that Cs A changes the rheological functions of RBC and lipid content of RBC membrane in healthy rats and thereby it may play an important role in the regulation of microcirculation.

Relationship between plasma Cystatin C and creatinine in chronic renal diseases and Tx-transplant patients.

OBJECTIVES: Glomerular filtration rate (GFR) is the best overall index of renal function in health and disease. Recently, Cystatin C (Cyst C), a low molecular weight protein freely filtered through the glomerulus, and almost completely reabsorbed and catabolized by tubular cells, has been proposed as a new and very sensitive serum marker of change in GFR. This study investigated the relationship between Cyst C and creatinine (CR) in renal disease patients. METHODS: Serum Cyst C was determined by particle-enhanced immunoturbidimetry using the Cyst C PET-kit. The results could be obtained within 1 h. Cuvettes were washed before the Cyst C assay as recommended. Serum CR, BUN and albumin were determined by auto-analyzer. RESULTS: A strong correlation was observed between Cyst C and CR (P = 0.001, r = 0.764 and P = 0.0001, r = 0.888, respectively) in prehemodialysis (pre-HD) and kidney transplantation (Tx-kidney), whereas there was a weak correlation in continuous ambulatory peritoneal dialysis (CAPD) (P = 0.05, r = 0.535). CONCLUSION: These findings suggest that serum Cyst C may be considered as a sensitive predictive parameter for reduced GFR. It is of value for the laboratory diagnosis of chronic renal failure and should be preferentially used for CR clearance.

The evaluation of lipid peroxidation and acute effect of octreotide on lipid peroxidation in patients with active acromegaly.

BACKGROUND: Although lipid peroxidation has been suggested to play a role in the etiology of many diseases, there is no report about its role in acromegaly in the literature. In the present study, we analyzed the basal levels of lipid peroxides (LPO) in newly diagnosed acromegalic patients, and to evaluate whether octreotide (OCT) has any effect on lipid peroxidation in these patients. METHODS: Plasma lipid peroxide levels before and after acute OCT administration were measured in 12 newly diagnosed acromegalic patients. Blood samples were drawn at basal and 4, 8, and 24 h after octreotide injection (100 microg s.c.). Plasma concentrations of lipid peroxides were estimated from measurement of thiobarbituric acid reactive substance (TBARS), using 1,1,3,3-tetra-ethoxypropane as a standard. RESULTS: This study shows that acromegalic patients have significantly higher basal plasma lipid peroxides levels compared to hours after OCT injection (p<0.001). Although a significant decrease was observed after 8 and 24 h in comparison to basal level (p<0.001), the lipid peroxide levels tended to increase at 24 h though still low when compared to basal level. CONCLUSION: Acromegalic patients have high basal lipid peroxide levels, which was significantly decreased after OCT administration.

Changes of oxidative stress in various tissues by long-term administration of vitamin E in hypercholesterolemic rats.

BACKGROUND: Free radical-mediated oxidative stress has been implicated in the genesis and progression of atherosclerosis. METHODS: The lipid peroxides and antioxidant status of various tissues were investigated in hypercholesterolemic rats and the effect of vitamin E supplementation on defense systems. RESULTS: Cholesterol-feeding caused a significant increase in the lipid peroxide concentrations of plasma, erythrocytes, liver and brain. In addition, a significant decrease in glutathione (GSH) content, glutathione peroxidase (GSH-Px) and glutathione transferase (GSH-ST) activities were found in erythrocytes and liver but superoxide dismutase (SOD) activity remained unchanged in these tissues in comparison to the control group. Vitamin E supplementation to hypercholesterolemic rats induced a significantly decrease in lipid peroxide concentrations and a significant increase in the GSH content, GSH-Px and GSH-ST activities in erythrocytes and liver. CONCLUSIONS: Long-term administration of vitamin E may play an important role in suppressing oxidative stress, and thus, may be useful for the prevention and/or early treatment of hypercholesterolemia.