9 research outputs found
Prediction of wastewater quality using amperometric bioelectronic tongues
Wastewater samples from a Swedish chemi-thermo-mechanical pulp (CTMP) mill collected at different purification stages in a wastewater treatment plant (WWTP) were analyzed with an amperometric enzyme-based biosensor array in a flow-injection system. In order to resolve the complex composition of the wastewater, the array consists of several sensing elements which yield a multidimensional response. We used principal component analysis (PCA) to decompose the array's responses, and found that wastewater with different degrees of pollution can be differentiated. With the help of partial least squares regression (PLS-R), we could link the sensor responses to the Microtox (R) toxicity parameter, as well as to global organic pollution parameters (COD, BOD, and TOC). From investigating the influences of individual sensors in the array, it was found that the best models were in most cases obtained when all sensors in the array were included in the PLS-R model. We find that fast simultaneous determination of several global environmental parameters characterizing wastewaters is possible with this kind of biosensor array, in particular because of the link between the sensor responses and the biological effect onto the ecosystem into which the wastewater would be released. In conjunction with multivariate data analysis tools, there is strong potential to reduce the total time until a result is yielded from days to a few minutes. (C) 2015 Elsevier B.V. All rights reserved
DMT1-Mutant Erythrocytes have Shortened Life Span, Accelerated Glycolysis and Increased Oxidative Stress
Background/Aims: Deficiency of the divalent metal transporter 1 (DMT1) leads to hypochromic microcytic anemia. We have previously shown that DMT1 deficiency impairs erythroid differentiation and induces apoptosis of erythroid cells. Here we analyzed metabolic processes and survival of mature erythrocytes in order to address potential involvement of erythrocyte defect in the pathophysiology of the disease. Methods: FACS analysis was used to determine the half-life of erythrocytes (CFSE fluorescence), phosphatidylserine exposure (Annexin V binding), cytosolic Ca2+ (Fluo3/AM fluorescence) and reactive oxygen species (ROS; DCF fluorescence). Enzyme activities were determined by standard biochemical methods. The concentration of ATP and ADP was measured on HPLC-MS/MS. Results: We observed an accelerated clearance of CFSE-labeled DMT1-mutant erythrocytes from circulating blood when compared to wild-type erythrocytes. In vitro, DMT1-mutant erythrocytes showed significantly increased Annexin V binding after exposure to hyperosmotic shock and glucose depletion. Despite exaggerated anti-oxidative defense, higher ROS levels were present in DMT1-mutant erythrocytes. Accelerated anaerobic glycolysis and reduced ATP/ADP ratio detected in DMT1-mutant erythrocytes indicate enhanced demand for ATP. Conclusions: We propose that DMT1 deficiency negatively affects metabolism and life span of mature erythrocytes; two other aspects of defective erythropoiesis which contribute to the pathophysiology of the disease
Recurrent episodes of myoglobinuria, mental retardation and seizures but no hemolysis in two brothers with phosphoglycerate kinase deficiency
We report two brothers with mild intellectual deficiency, exercise intolerance, rhabdomyolysis, seizures and no hemolysis. Phosphoglycerate kinase (PGK) activity was strongly decreased in their red blood cells. Subsequent molecular analysis of PGK1 revealed hemizygosity for a novel mutation c.756+3A>G, in intron 7. Analysis of the effect of this mutation on pre-mRNA processing demonstrated markedly decreased levels of normal PGK1 mRNA. In addition, the c.756+3A>G change resulted in abnormally spliced transcripts. If translated, these transcripts mostly encode for C-terminally truncated proteins. The consequences of the c.756+3A>G mutation is discussed, as well as the genotype-to-phenotype correlation with regard to previously described mutations (PGK Fukuroi and PGK Antwerp), which also result in C-terminal truncated proteins.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Role of DNA Damage Response in Suppressing Malignant Progression of Chronic Myeloid Leukemia and Polycythemia Vera: Impact of Different Oncogenes
Inflammatory and oncogenic signaling, both known to challenge genome stability, are key drivers of BCR-ABL-positive chronic myeloid leukemia (CML) and JAK2 V617F-positive chronic myeloproliferative neoplasms (MPNs). Despite similarities in chronic inflammation and oncogene signaling, major differences in disease course exist. Although BCR-ABL has robust transformation potential, JAK2 V617F-positive polycythemia vera (PV) is characterized by a long and stable latent phase. These differences reflect increased genomic instability of BCR-ABL-positive CML, compared to genome-stable PV with rare cytogenetic abnormalities. Recent studies have implicated BCR-ABL in the development of a "mutator" phenotype fueled by high oxidative damage, deficiencies of DNA repair, and defective ATR-Chk1-dependent genome surveillance, providing a fertile ground for variants compromising the ATM-Chk2-p53 axis protecting chronic phase CML from blast crisis. Conversely, PV cells possess multiple JAK2 V617F-dependent protective mechanisms, which ameliorate replication stress, inflammation-mediated oxidative stress and stress-activated protein kinase signaling, all through up-regulation of RECQL5 helicase, reactive oxygen species buffering system, and DUSP1 actions. These attenuators of genome instability then protect myeloproliferative progenitors from DNA damage and create a barrier preventing cellular stress-associated myelofibrosis. Therefore, a better understanding of BCR-ABL and JAK2 V617F roles in the DNA damage response and disease pathophysiology can help to identify potential dependencies exploitable for therapeutic interventions
The specific PKC-α inhibitor chelerythrine blunts costunolide-induced eryptosis
Costunolide, a natural sesquiterpene lactone, has multiple pharmacological activities such as neuroprotection or induction of apoptosis and eryptosis. However, the effects of costunolide on pro-survival factors and enzymes in human erythrocytes, e.g. glutathione and glucose-6-phosphate dehydrogenase (G6PDH) respectively, have not been studied yet. Our aim was to determine the mechanisms underlying costunolide-induced eryptosis and to reverse this process. Phosphatidylserine exposure was estimated from annexin-V-binding, cell volume from forward scatter in flow cytometry, and intracellular glutathione [GSH
Pharmacological targeting of glucose-6-phosphate dehydrogenase in human erythrocytes by Bay 11-7082, parthenolide and dimethyl fumarate
In mature erythrocytes, glucose-6-phosphate dehydrogenase (G6PDH) and 6-phosphogluconate dehydrogenase (6PGDH) yield NADPH, a crucial cofactor of the enzyme glutathione reductase (GR) converting glutathione disulfide (GSSG) into its reduced state (GSH). GSH is essential for detoxification processes in and survival of erythrocytes. We explored whether the anti-inflammatory compounds Bay 11-7082, parthenolide and dimethyl fumarate (DMF) were able to completely deplete a common target (GSH), and to impair the function of upstream enzymes of GSH recycling and replenishment. Treatment of erythrocytes with Bay 11-7082, parthenolide or DMF led to concentration-dependent eryptosis resulting from complete depletion of GSH. GSH depletion was due to strong inhibition of G6PDH activity. Bay 11-7082 and DMF, but not parthenolide, were able to inhibit the GR activity. This approach "Inhibitors, Detection of their common target that is completely depleted or inactivated when pharmacologically relevant concentrations of each single inhibitor are applied, Subsequent functional analysis of upstream enzymes for this target" (IDS), can be applied to a broad range of inhibitors and cell types according to the selected target. The specific G6PDH inhibitory effect of these compounds may be exploited for the treatment of human diseases with high NADPH and GSH consumption rates, including malaria, trypanosomiasis, cancer or obesity
Molecular Characterization of <b>β</b>-Thalassemia in the Czech and Slovak Populations: Mediterranean, Asian and Unique Mutations
<p>β-Thalassemia (β-thal) is considered rare in Central Europe. As in other malaria-free regions, the presence of β-thal in Central Europe reflects historical and recent immigration, and demographic changes that have influenced the genetic variability of the current populations living in this area. This study assesses the frequency and spectrum of mutations on the β-globin gene in Czech and Slovak subjects with clinical symptoms of thalassemia. The results of the initial part of this research were published more than two decades ago; the aim of this study was to update these original reports. During the period from 2002 to 2015, 400 cases from Czech and Slovak hematological centers were analyzed. Twenty-nine β-thal mutations, identified in 356 heterozygotes from 218 unrelated families, involve five unique mutations including a recently described insertion of a transposable L1 element into the β-globin gene. One mutation described here is reported for the first time. Most of the mutations were of Mediterranean origin and accounted for 82.0% of cases. All but one case studied were heterozygous carriers, manifesting β-thal minor, with rare exceptions represented by the rare (β<sup>0</sup>) codons 46/47 (+G) (<i>HBB</i>: c.142_142dupG) mutation associated with an α-globin gene quadruplication and by dominantly inherited β-thal with a more severe phenotype. One double heterozygous β-thal patient was a recent immigrant from Moldavia. The list of δβ-thal alleles (26 carriers, 16 families) contains Hb Lepore and two types of δβ<sup>0</sup>-thal deletions. In the past, genetic drift and migration as well as recent immigrations were responsible for the introduction of Mediterranean alleles, while several mutations described in single families were of local origin.</p