Expressão fenotípica da homozigose para hemoglobina S em relação aos haplótipos da beta globina, polimorfismos da glutationa S-transferase e enzimas de detoxificação

A anemia falciforme (AF) apresenta fisiopatologia que envolve múltiplas alterações nos eritrócitos falcêmicos, episódios vasoclusivos, hemólise, ativação de mediadores inflamatórios, disfunção das células endoteliais e estresse oxidativo. Estes eventos dificultam o tratamento e culminam no desenvolvimento de manifestações como anemia, crises de dor e insuficiência de múltiplos órgãos. Portanto, o presente estudo objetivou, em portadores da AF, avaliar marcadores do estresse oxidativo e da capacidade antioxidante, correlacionando-os ao tratamento com hidroxiureia (HU), aos haplótipos da β-globina e aos polimorfismos da glutationa S-transferase (GSTT1, GSTM1 e GSTP1), em comparação com os resultados do grupo controle (GC). Os grupos estudados se compuseram de 48 indivíduos sem hemoglobinopatias (GC), pacientes com AF tratados com HU [AF (+HU), n=13] e pacientes não tratados [AF (-HU); n=15], após consentimento informado. Para a composição dos grupos utilizamos métodos citológicos, eletroforéticos, cromatográficos, moleculares e informações de prontuários. A pesquisa dos polimorfismos de GSTM1 e GSTT1 foi realizada por meio de PCR-MULTIPLEX, enquanto o polimorfismo GSTP1 por PCR-RFLP. Os parâmetros bioquímicos foram avaliados por meio de métodos espectrofotométricos [TBARS, TEAC, atividade das enzimas catalase (CAT) e GST] e cromatográficos [glutationa (GSH)]. Os níveis de Hb Fetal (Hb F) verificados no grupo AF (+HU) (10,9%) confirmaram seu já bem descrito efeito farmacológico da HU, porém, o grupo AF (-HU) também apresentou níveis elevados de Hb F (6,1%) que podem ter sido influenciados por fatores genéticos não considerados neste estudo. Encontramos maior frequência do haplótipo Bantu (48,2%), seguido pelo Benin (32,1%) e, também, haplótipo Camarões...Sickle cell anemia (SCA) shows a pathophysiology that involves multiple changes in the sickle cell erythrocytes, vaso-occlusive episodes, hemolysis, activation of inflammatory mediators, endothelial cell dysfunction and oxidative stress. These events complicate the treatment and culminate in the manifestations development such as anemia, pain crises and multiorgan dysfunction. Therefore, the aim of this study was to evaluate, in SCA patients, oxidative stress and antioxidant capacity markers, correlating them to treatment with hydroxyurea (HU), the β-globin haplotypes and glutathione S-transferase polymorphisms (GSTT1, GSTM1 and GSTP1) in comparison to a control group (CG). The groups were composed of 48 individuals without hemoglobinopathies (CG), SCA patients treated with HU [AF (+ HU), n = 13] and untreated patients [AF (-HU), n = 15], after informed consent . For the groups composition we used cytological, electrophoretic, chromatographic and molecular methods and information from medical records. The GSTM1 and GSTT1 polymorphisms study was performed by multiplex PCR, while the GSTP1 polymorphism by PCR-RFLP. Biochemical parameters were measured using spectrophotometric methods [TBARS, TEAC and catalase (CAT) and GST activities] and chromatographic method [glutathione (GSH)]. The Fetal Hb (Hb F) levels observed in the SCA (+HU) group (10.9%) confirmed their already welldescribed pharmacological effect of HU, however, the SCA (-HU) group also had high Hb F levels (6.1%) that may have been influenced by genetic factors not targeted in this study. We found a higher frequency of Bantu haplotype (48.2%), followed by Benin (32.1%) and also Cameroon haplotype, rare in our population and 19.7% of atypical haplotypes. The Bantu haplotype presence was related to higher lipid peroxidation levels in patients, but also, it confered the differential response to HU treatment... (Complete abstract click electronic access below

Hemoglobin D-Punjab: origin, distribution and laboratory diagnosis

This review discusses hemoglobin D-Punjab, also known as hemoglobin D-Los Angeles, one of the most common hemoglobin variants worldwide. It is derived from a point mutation in the beta-globin gene (HBB: c.364G>C; rs33946267) prevalent in the Punjab region, North-western Indian. Hemoglobin D-Punjab can be inherited in heterozygosis with hemoglobin A causing no clinical or hematological alterations, or in homozygosis, the rarest form of inheritance, a condition that is commonly not related to clinical symptomatology. Moreover, this variant can exist in association with other hemoglobinopathies, such as thalassemias; the most noticeable clinical alterations occur when hemoglobin D-Punjab is associated to hemoglobin S. The clinical manifestations of this association can be similar to homozygosis for hemoglobin S. Although hemoglobin D-Punjab is a common variant globally with clinical importance especially in cases of double heterozygosis, hemoglobin S/D-Punjab is still understudied. In Brazil, for example, hemoglobin D-Punjab is the third most common hemoglobin variant. Thus, this paper summarizes information about the origin, geographic distribution, characterization and occurrence of hemoglobin D-Punjab haplotypes to try to improve our knowledge of this variant. Moreover, a list of the main techniques used in its identification is provided emphasizing the importance of complementary molecular analysis for accurate diagnosis

Biochemical responses in armored catfish (Pterygoplichthys anisitsi) after short-term exposure to diesel oil, pure biodiesel and biodiesel blends

Biodiesel fuel is gradually replacing petroleum-based diesel oil use. Despite the biodiesel being considered friendlier to the environment, little is known about its effects in aquatic organisms. In this work we evaluated whether biodiesel exposure can affect oxidative stress parameters and biotransformation enzymes in armored catfish (Pterygoplichthys anisitsi, Loricariidae), a South American endemic species. Thus, fish were exposed for 2 and 7d to 0.01mLL-1 and 0.1mLL-1 of pure diesel, pure biodiesel (B100) and blends of diesel with 5% (B5) and 20% (B20) biodiesel. Lipid peroxidation (malondialdehyde) levels and the activities of the enzymes glutathione S-transferase, superoxide dismutase, catalase and glutathione peroxidase were measured in liver and gills. Also, DNA damage (8-oxo-7, 8-dihydro-2'-deoxyguanosine) levels in gills and 7-ethoxyresorufin-O-deethylase activity in liver were assessed. Pure diesel, B5 and B20 blends changed most of the enzymes tested and in some cases, B5 and B20 induced a higher enzyme activity than pure diesel. Antioxidant system activation in P. anisitsi was effective to counteract reactive oxygen species effects, since DNA damage and lipid peroxidation levels were maintained at basal levels after all treatments. However, fish gills exposed to B20 and B100 presented increased lipid peroxidation. Despite biodiesel being more biodegradable fuel that emits less greenhouse gases, the increased lipid peroxidation showed that biofuel and its blends also represent hazards to aquatic biota. © 2013 Elsevier Ltd

Influence of Melatonin Treatment on Cellular Mechanisms of Redox Adaptation in K562 Erythroleukemic Cells

Melatonin (MEL) presents well-documented pleiotropic actions against oxidative stress (OS), acting indirectly through activation of transcription factors, e.g., FoxO3 and Nrf2. Thus, this study aimed to investigate the possible modulating effects of MEL on the redox signaling pathways PI3K/AKT/FoxO3 and Keap1/Nrf2/ARE in K562 erythroleukemic cells subjected to OS induction. For this, the viability, and transcript levels of genes involved in redox adaptation were evaluated in K562 cells in different periods of erythroid differentiation: under OS induction by hydrogen peroxide (100 µM H2O2); treated with 1 nM (C1) and 1 mM (C2) MEL; and associated or not with stress induction. We observed a restoration of physiological levels of Nrf2 in both MEL concentrations under OS. The C1 was related to enhanced expression of antioxidant and proteasome genes through the Nrf2-ARE pathway, while C2 to the induction of FOXO3 expression, suggesting an involvement with apoptotic pathway, according to BIM transcript levels. The effects of MEL administration in these cells showed a period and dose-dependent pattern against induced-OS, with direct and indirect actions through different pathways of cellular adaptation, reinforcing the importance of this indolamine in the regulation of cellular homeostasis, being a promising therapeutic alternative for diseases that present an exacerbated OS

Potential Cytoprotective and Regulatory Effects of Ergothioneine on Gene Expression of Proteins Involved in Erythroid Adaptation Mechanisms and Redox Pathways in K562 Cells

This study aimed to establish the importance of ergothioneine (ERT) in the erythroid adaptation mechanisms by appraising the expression levels of redox-related genes associated with the PI3K/AKT/FoxO3 and Nrf2-ARE pathways using K562 cells induced to erythroid differentiation and H2O2-oxidative stress. Cell viability and gene expression were evaluated. Two concentrations of ERT were assessed, 1 nM (C1) and 100 µM (C2), with and without stress induction (100 µM H2O2). Assessments were made in three periods of the cellular differentiation process (D0, D2, and D4). The C1 treatment promoted the induction of FOXO3 (D0 and 2), PSMB5, and 6 expressions (D4); C1 + H2O2 treatment showed the highest levels of NRF2 transcripts, KEAP1 (D0), YWHAQ (D2 and 4), PSMB5 (D2) and PSMB6 (D4); and C2 + H2O2 (D2) an increase in FOXO3 and MST1 expression, with a decrease of YWHAQ and NRF2 was observed. in C2 + H2O2 (D2) an increase in FOXO3 and MST1, with a decrease in YWHAQ and NRF2 was observed All ERT treatments increased gamma-globin expression. Statistical multivariate analyzes highlighted that the Nrf2-ARE pathway presented a greater contribution in the production of PRDX1, SOD1, CAT, and PSBM5 mRNAs, whereas the PI3K/AKT/FoxO3 pathway was associated with the PRDX2 and TRX transcripts. In conclusion, ERT presented a cytoprotective action through Nrf2 and FoxO3, with the latter seeming to contribute to erythroid proliferation/differentiation

Biochemical biomarkers in Nile tilapia (Oreochromis niloticus) after short-term exposure to diesel oil, pure biodiesel and biodiesel blends

Fossil fuels such as diesel are being gradually replaced by biodiesel, a renewable energy source, cheaper and less polluting. However, little is known about the toxic effects of this new energy source on aquatic organisms. Thus, we evaluated biochemical biomarkers related to oxidative stress in Nile tilapia (Oreochromis niloticus) after two and seven exposure days to diesel and pure biodiesel (B100) and blends B5 and B20 at concentrations of 0.01 and 0.1mLL -1. The hepatic ethoxyresorufin-O-deethylase activity was highly induced in all groups, except for those animals exposed to B100. There was an increase in lipid peroxidation in liver and gills in the group exposed to the higher concentration of B5. All treatments caused a significant increase in the levels of 1-hydroxypyrene excreted in the bile after 2 and 7d, except for those fish exposed to B100. The hepatic glutathione-S-transferase increased after 7d in animals exposed to the higher concentration of diesel and in the gill of fish exposed to the higher concentration of pure diesel and B5, but decreased for the two tested concentrations of B100. Superoxide dismutase, catalase and glutathione peroxidase also presented significant changes according to the treatments for all groups, including B100. Biodiesel B20 in the conditions tested had fewer adverse effects than diesel and B5 for the Nile tilapia, and can be suggested as a less harmful fuel in substitution to diesel. However, even B100 could activate biochemical responses in fish, at the experimental conditions tested, indicating that this fuel can also represent a risk to the aquatic biota. © 2011 Elsevier Ltd

The influence of hydroxyurea on oxidative stress in sickle cell anemia

OBJECTIVE: The oxidative stress in 20 sickle cell anemia patients taking hydroxyurea and 13 sickle cell anemia patients who did not take hydroxyurea was compared with a control group of 96 individuals without any hemoglobinopathy. METHODS: Oxidative stress was assessed by thiobarbituric acid reactive species production, the Trolox-equivalent antioxidant capacity and plasma glutathione levels. RESULTS: Thiobarbituric acid reactive species values were higher in patients without specific medication, followed by patients taking hydroxyurea and the Control Group (p < 0.0001). The antioxidant capacity was higher in patients taking hydroxyurea and lower in the Control Group (p = 0.0002 for Trolox-equivalent antioxidant capacity and p < 0.0292 for plasma glutathione). Thiobarbituric acid reactive species levels were correlated with higher hemoglobin S levels (r = 0.55; p = 0.0040) and lower hemoglobin F concentrations(r = -0.52; p = 0.0067). On the other hand, plasma glutathione levels were negatively correlated with hemoglobin S levels (r = -0.49; p = 0.0111) and positively associated with hemoglobin F values (r = 0.56; p = 0.0031). CONCLUSION: Sickle cell anemia patients have high oxidative stress and, conversely, increased antioxidant activity. The increase in hemoglobin F levels provided by hydroxyurea and its antioxidant action may explain the reduction in lipid peroxidation and increased antioxidant defenses in these individuals

Serum levels of oxidative stress biomarkers is changed in pharmacoresistant mesial temporal lobe epilepsy patients with or without psychiatric disorders

The objective of the present study was to assess the levels of oxidative stress biomarkers (OSB) in patients with pharmacoresistant temporal lobe epilepsy and mesial temporal sclerosis (TLE-MTS) in order to investigate a possible role of oxidative stress (OS) in the pathophysiology of such disease. Ninety-eight participants were included and distributed in three groups: group 1 (G1) - 25 patients with pharmacoresistant TLE-MTS, without comorbid PD; Group 2 (G2) - 21 patients with pharmacoresistant TLE-MTS with PD; Group 3 (G3) - 52 healthy control subjects. Serum levels of catalase (CAT), glutathione peroxidase (GPx), glutathione reductase (GR), reduced glutathione plus oxidated glutathione (total GSH), glucose-6-phosphate dehydrogenase (G6PD), Trolox-equivalent antioxidant capacity (TEAC), and thiobarbituric acid reactive substances (TBARS) were analyzed through spectrometry. The significance level was set at P0.05). A family history of epilepsy was more frequent among G1 and G2 groups when compared to G3 (P = 0.0002). Compared to controls, G1 and G2 presented higher CAT (P0.05). The lower levels of GPx, G6PD, and total GSH, as well as the higher CAT and TBARS levels observed in pharmaco-resistant TLE-MTS patients can indicate an imbalance between oxidizing agent production and elimination, supporting the hypothesis of a possible role of OS in the pathogenesis of this condition