Ticagrelor reverses the mitochondrial dysfunction through preventing accumulated autophagosomes-dependent apoptosis and ER stress in insulin-resistant H9c2 myocytes

Molecular and Cellular Biochemistry - Obesity was originally considered a disease endemic to developed countries but has since emerged as a global health problem. Obesity is characterized by...     

Frequency of angiotensin II type 1 receptor gene polymorphism in Turkish acute stroke patients

This study was performed in acute stroke patients in the Turkish population to determine the frequency of the A1166C polymorphism in the AT1 gene and to examine the role of this polymorphism in acute stroke development. In this study, 257 genomic DNA samples were analysed (from 206 acute stroke patients and 51 healthy individuals). Genomic DNA was prepared from peripheral blood using the salt‐extraction method. The presence of the A1166C polymorphism in the AT1 gene was determined using the polymerase chain reaction (PCR)‐restriction fragment length polymorphism (RFLP) method. PCR products were separated by 2% agarose gel electrophoresis and visualized by a charge‐coupled device (CCD) camera. In this study, the allele frequency at the A1166C position was 92% A and 8% C for control and 97% A and 3% C for patients. This difference in allele frequency between the control group and the patient group was not statistically significant. However, genotype and allele frequencies showed a significant difference (P < 0.001) in the control and the patient groups. The results of this study show no relationship between the A1166C polymorphism in the AT1 gene and acute stroke in the Turkish population.     

Biosorption of Ni (II) by Schizosaccharomyces pombe: kinetic and thermodynamic studies

The potential of the dried yeast, wild-type Schizosaccharomyces pombe, to remove Ni(II) ion was investigated in batch mode under varying experimental conditions including pH, temperature, initial metal ion concentration and biosorbent dose. Optimum pH for biosorption was determined as 5.0. The highest equilibrium uptake of Ni(II) on S. pombe, q _e, was obtained at 25 °C as 33.8 mg g⁻¹. It decreased with increasing temperature within a range of 25–50 °C denoting an exothermic behaviour. Increasing initial Ni(II) concentration up to 400 mg L⁻¹ also elevated equilibrium uptake. No more adsorption took place beyond 400 mg L⁻¹. Equilibrium data fitted better to Langmuir model rather than Freundlich model. Sips, Redlich–Peterson, and Kahn isotherm equations modelled the investigated system with a performance not better than Langmuir. Kinetic model evaluations showed that Ni(II) biosorption process followed the pseudo-second order rate model while rate constants decreased with increasing temperature. Gibbs free energy changes (ΔG°) of the system at 25, 30, 35 and 50 °C were found as −1.47E + 4, −1.49E + 4, −1.51E + 4, and −1.58E + 4 J mol⁻¹, respectively. Enthalpy change (ΔH°) was determined as −2.57E + 3 J mol⁻¹ which also supports the observed exothermic behaviour of the biosorption process. Entropy change (ΔS°) had a positive value (40.75 J mol⁻¹ K⁻¹) indicating an increase in randomness during biosorption process. Consequently, S. pombe was found to be a potential low-cost agent for Ni(II) in slightly acidic aqueous medium. In parallel, it has been assumed to act as a separating agent for Ni(II) recovery from its aqueous solution.     

Investigation of relationship between IL-6 gene variants and hypertension in Turkish population

Hypertension (HT) is a common and life threating health problem worldwide leading to stroke, heart attack and renal failure. It is characterized by elevated blood pressure forced heart load. Human interleukin-6 (IL-6) and C- reactive protein (CRP) are known to be involved in inflammatory processes. IL-6 gene is a polymorphic gene which −174 G/C is a common and −572 G/C is a rare polymorphisms identified in promoter region. Publications on IL-6 gene polymorphisms raised the question whether this gene polymorphisms lead to susceptibility to HT or not. To investigate the effects of IL-6 gene −174 G/C (rs 1800795) and −572 G/C (rs1800796) polymorphisms on plasma IL-6 and CRP levels and their associations with hypertension disease in Turkish population we analyzed −174 G/C and −572 G/C polymorphisms and plasma IL-6 and CRP levels in 111 healthy controls and 108 hypertension patients from Adıyaman, Turkey. We determined the genotypes using polymerase chain reaction-restriction fragment length polymorphism and analyzed plasma levels of IL-6 by ELISA and CRP by automated standard biochemical methods. We have found no statistically significant differences between IL-6 gene −174 G/C and −572 G/C genotypes and allelic frequencies and IL-6 and CRP plasma levels and HT (p > 0.05). No CC genotype was found in control subjects for −572 G/C polymorphism. In conclusion, we found relation to −174 G/C and −572 G/C gene variants between neither IL-6 and CRP levels nor hypertension. The −572 G allele and GG genotype are predominant in Turkish population in Adıyaman, Turkey whereas the CC genotype is very rare.     

Characterization of urease from Sporosarcina ureae

Alkaline stable (pH 7.75–12.5) urease from Sporosarcina ureae was purified over 400-fold by ion exchange and hydrophobic interaction chromatography. The cytoplasmic enzyme was remarkably active with a specific activity of greater than 9300 μmol urea degraded min^-1 mg protein^-1 at pH 7.5, where it has optimal activity. Although S. ureae is closely related to Bacillus pasteurii, known to posses a homopolymeric urease containing 1 nickel per subunit [M _r=65000], the S. ureae enzyme is comprised of three subunits [apparent M _r=63100 (α), 14500 (β), and 8500 (γ)] in an estimated ∝βγ stoichiometry and contains 2.1±0.6 nickel ions per ∝βγ unit as measured by atomic absorption spectrometry. Stationary phase cultures sometimes possessed low levels of urease activity, but the specific activity of cell extracts of partially purified urease preparations from such cultures could be elevated by heat treatment, dilution, or dialysis to values comparable to those observed in samples from exponentially grown cells.     

The relationship between nitric oxide and leptin in the lung of rat with streptozotocin-induced diabetes

Lung structural changes and immunoreactivity of endothelial (eNOS)- and inducible nitric oxide synthase (iNOS) were investigated by light microscopy in lungs of treated and untreated diabetic rats. Diabetes was induced by a single intraperitoneal (i.p.) injection of 65 mg kg(-1) streptozotocin (STZ) in Wistar albino male rats. Diabetic rats received daily i.p. doses of dexamethasone (2 mg kg(-1)), leptin (0.5 microg kg(-1)) and intramuscular insulin (20 U kg(-1)) or a combination of these drugs for 1 week starting 4 weeks after the STZ injections. After treatment, the blood levels of glucose, leptin, insulin and nitrate/nitrite (NO(3) (-)/NO(2) (-)) were measured. Dilatation of alveoli and alveolar ducts, partial alveolar wall thickening and increased eNOS- and iNOS characterized the diabetic rat lungs. High blood glucose and nitrate/nitrite levels as well as low insulin and leptin levels were also present. Treatment with insulin, dexamethasone and a combination of these drugs resulted in improvement of the structural and immunohistochemical abnormalities. The most effective treatment was insulin therapy. Leptin administration resulted in increased relative amounts of extracellular material, which led to noticeable respiratory efficiency in the diabetic rat lungs. All treatments except leptin lowered blood glucose levels. The combination of insulin and dexamethasone increased blood leptin and insulin, while the remaining diabetic rats had blood with low leptin and insulin concentrations. These results suggest that therapy with insulin plus dexamethasone but not therapy with leptin is beneficial for diabetics.     

Expression of human cytochrome p450 3A4 gene in Schizosaccharomyces pombe

Heterologous expression systems can be utilized to great advantage in the study of cytochrome P450 enzymes. P450 3A4 is one of the major forms of cytochrome P450 found in liver. It is also involved in the metabolism of numerous widely used drugs and xenobiotics. In the present study human liver cytochrome P450 3A4 gene was transferred into the fission yeast Schizosaccharomyces pombe via two different S. pombe expression vectors carrying thiamine repressible promoter — nmt1 (pREP42) and constitutive promoter — adh1 (pART1). Heterologously expressed cytochrome P450 3A4 was detected in the cells grown in minimal (EMM) or rich medium (YEL) containing 0.5% (w/v) glucose. A typical cytochrome P450 peak for 3A4 was observed at 448 nm in microsomal fraction. The presence of heterologous expression of 3A4 form was also determined by SDS-PAGE and it molecular mass was identified as 52 kDa. The enzyme activity was confirmed by HPLC analysis, using testosterone as substrate.     

p21-activated kinase 1 regulates microtubule dynamics by phosphorylating tubulin cofactor B

p21-activated kinase 1 (Pak1) induces cytoskeleton reorganization in part by regulating microtubule dynamics through an elusive mechanism. Using a yeast two-hybrid screen, we identified tubulin cofactor B (TCoB) (a cofactor in the assembly of the alpha/beta-tubulin heterodimers) as an interacting substrate of Pak1. Pak1 directly phosphorylated TCoB in vitro and in vivo on serines 65 and 128 and colocalized with TCoB on newly polymerized microtubules and on centrosomes. TCoB interacted with the GTPase-binding domain of Pak1 and activated Pak1 in vitro and in vivo. In contrast to wild-type TCoB, an S65A, S128A double mutant and knock-down of the endogenous TCoB or Pak1 reduced microtubule polymerization, suggesting that Pak1 phosphorylation is necessary for normal TCoB function. Overexpression of TCoB dramatically increased the number of gamma-tubulin-containing microtubule-organizing centers, a phenotype reminiscent of cells overexpressing Pak1. TCoB was overexpressed and phosphorylated in breast tumors. These findings reveal a novel role for TCoB and Pak1 in regulating microtubule dynamics.