Eryptosis in polycythemia vera and essential thrombocythemia

Aim: Polycythemia vera (PV) and essential thrombocythemia (ET) are Philadelphia–negative myeloproliferative neoplasms with documented apoptosis impairment at the level of hematopoietic stem cell. However, so far no study has evaluated apoptosis of circulating blood neoplastic cells, including the suicidal death of erythrocytes – eryptosis. Material/Methods: Erythrocytes from 61 patients (24 PV and 37 ET) naïve to and treated with hydroxyurea (HU) and 13 healthy individuals were analysed using flow cytometry to quantify phosphatidylserine (PS) externalization from Annexin-V-binding, calpain activity from 7-amino-4-chloromethylcoumarin (CMAC)-fluorescence, cell volume from forward scattered light (FSC) and cell shape from side scattered light (SSC). Results: Significantly increased levels of calpain activity and PS exposure were observed in both ET and PV naïve patients, indicating enhanced eryptosis. Among HU-treated patients, a significant increase in calpain activity in the ET group and a decrease in the PV group were observed compared to patients without cytoreductive therapy. Among PV patients, FSC was substantially higher in the HU-treated group than in the naïve group, whereas no significant differences were found between HU-treated and HU-naïve groups of ET patients. Conclusions: The enhanced eryptosis in ET and PV patients may be a form of systemic compensation of the pathological bone marrow overproduction of erythrocytes. HU, the basic cytoreductive drug used in ET and PV, may affect eryptosis in PV and ET in different ways depending on disease. The JAK2V617F mutation was not observed to have any effect on eryptosis in ET.The study was supported by Medical University of Lodz grant number: 502-03/1-093-02/502-14-347

Oxidative stress biomarkers and acetylcholinesterase activity in human erythrocytes exposed to clomazone (in vitro)

The aim of this study was to investigate the effect of clomazone herbicide on oxidative stress biomarkers and acetylcholinesterase activity in human erythrocytes in in vitro conditions. The activity of catalase (CAT), superoxide dismutase (SOD) and acetylcholinesterase (AChE), as well as the levels of thiobarbituric acid reactive substances (TBARS) and reduced glutathione (GSH) were measured in human erythrocytes exposed (in vitro) to clomazone at varying concentrations in the range of 0, 100, 250 and 500 µg/L for 1 h at 37 °C.TBARS levels were significantly higher in erythrocytes incubated with clomazone at 100, 250 and 500 µg/L. However, erythrocyte CAT and AChE activities were decreased at all concentrations tested. SOD activity was increased only at 100 µg/L of clomazone. GSH levels did not change with clomazone exposure. These results clearly showed clomazone to induce oxidative stress and AChE inhibition in human erythrocytes (in vitro). We, thus, suggest a possible role of ROS on toxicity mechanism induced by clomazone in humans

Studies on degradation products of Paraquat and Gramoxone interactions with hum an and carp hemoglobins

In this work the effect of Paraquat (PQ) and Graraoxone (GX) on isolated human and carp hemoglobins was studied. Degradation products of PQ were isolated from GX solution by thin layer chromatography on silica gel platelets. Purity of the GX fractions obtained was verified on the basis of silica gel rechromatography. The fractions were identified by IR, UV and visible spectra. Binding of PQ degradation products to hemoglobin was studied by molecular filtration through a Sephadex G-50 column. Interaction of GX fractions with hemoglobin was studied by the spectrophotometric method. Absorption spectra were recorded in the X = 200-900 nm range in 30-min intervals, between 0 and 3 hrs of incubation. Effect of pH of the medium on the amount of hemoglobin-bound ligand was determined, and the reactivity of the GX fractions obtained was compared with those of PQ and GX. Conditions of the strongest and the weakest binding of the ligands were identified. The studies performed point to a considerable importance of Hb in the transport of PQ and its degradation products to various tissues. The stronger binding of these ligands by carp Hb confirms that fishes are more sensitive to poisoning by bipyridyl derivatives as compared with mammals (primates).Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 dofinansowane zostało ze środków MNiSW w ramach działalności upowszechniającej naukę

Molecular Mechanisms of Action of Selected Substances Involved in the Reduction of Benzo[a]pyrene-Induced Oxidative Stress

Benzo[a]pyrene (BaP) is a polycyclic aromatic hydrocarbon (PAH) primarily formed by burning of fossil fuels, wood and other organic materials. BaP as group I carcinogen shows mutagenic and carcinogenic effects. One of the important mechanisms of action of (BaP) is its free radical activity, the effect of which is the induction of oxidative stress in cells. BaP induces oxidative stress through the production of reactive oxygen species (ROS), disturbances of the activity of antioxidant enzymes, and the reduction of the level of non-enzymatic antioxidants as well as of cytokine production. Chemical compounds, such as vitamin E, curcumin, quercetin, catechin, cyanidin, kuromanin, berberine, resveratrol, baicalein, myricetin, catechin hydrate, hesperetin, rhaponticin, as well as taurine, atorvastatin, diallyl sulfide, and those contained in green and white tea, lower the oxidative stress induced by BaP. They regulate the expression of genes involved in oxidative stress and inflammation, and therefore can reduce the level of ROS. These substances remove ROS and reduce the level of lipid and protein peroxidation, reduce formation of adducts with DNA, increase the level of enzymatic and non-enzymatic antioxidants and reduce the level of pro-inflammatory cytokines. BaP can undergo chemical modification in the living cells, which results in more reactive metabolites formation. Some of protective substances have the ability to reduce BaP metabolism, and in particular reduce the induction of cytochrome (CYP P450), which reduces the formation of oxidative metabolites, and therefore decreases ROS production. The aim of this review is to discuss the oxidative properties of BaP, and describe protective activities of selected chemicals against BaP activity based on of the latest publications

Fundamental questions on the evolution of haemoglobin

The paper presents problems concerning the evolution of haemoglobin. The main stages of Hb evolution: globin gene evolution, formation and solubility of Hb tetramer and functional Hb regulation by allosteric effectors have been presented. The gene duplication, occuring during the formation of fetal and embryonal Hb as well as the evolution rate of vertebrate Hb were discussed. The authors presented the role of exons, introns and pseudogens in the evoluing of globin and discussed the posibility of the acceleration of evolutionary process by means of exon-intron recombinations.Zadanie pt. „Digitalizacja i udostępnienie w Cyfrowym Repozytorium Uniwersytetu Łódzkiego kolekcji czasopism naukowych wydawanych przez Uniwersytet Łódzki” nr 885/P-DUN/2014 dofinansowane zostało ze środków MNiSW w ramach działalności upowszechniającej naukę