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1.
Comparative effects of acute-methionine loading on the plasma sulfur-amino acids in NAC-supplemented HIV+ patients and healthy controls.
Burini, RC, Borges-Santos, MD, Moreto, F, Yu, YM
Amino acids. 2018;(5):569-576
Abstract
In this study, an acute overloading of methionine (MetLo) was used to investigate the trassulfuration pathway response comparing healthy controls and HIV+ patients under their usual diet and dietary N-acetyl-L-cysteine (NAC) supplementation. MetLo (0.1 g Met/kg mass weight) was given after overnight fasting to 20 non-HIV+ control subjects (Co) and 12 HIV+ HAART-treated patients. Blood samples were taken before and after the MetLo in two different 7-day dietary situations, with NAC (1 g/day) or with their usual diet (UD). The amino acids (Met, Hcy, Cys, Tau, Ser, Glu and Gln) and GSH were determined by HPLC and their inflow rate into circulation (plasma) was estimated by the area under the curve (AUC). Under UD, the HIV+ had lower plasma GSH and amino acids (excepting Hcy) and higher oxidative stress (GSSG/GSH ratio), similar remethylation (RM: Me/Hcy + Ser ratio), transmethylation (TM; Hcy/Met ratio) and glutaminogenesis (Glu/Gln ratio), lower transsulfuration (TS: Cys/Hcy + Ser ratio) and Cys/Met ratio and, higher synthetic rates of glutathione (GG: GSH/Cys ratio) and Tau (TG: Tau/Cys ratio). NAC supplementation changed the HIV pattern by increasing RM above control, normalizing plasma Met and TS and, increasing plasma GSH and GG above controls. However, plasma Cys was kept always below controls probably, associatively to its higher consumption in GG (more GSSG than GSH) and TG. The failure of restoring normal Cys by MetLo, in addition to NAC, in HIV+ patients seems to be related to increased flux of Cys into GSH and Tau pathways, probably strengthening the cell-antioxidant capacity against the HIV progression (registered at http://www.clinicaltrials.gov , NCT00910442).
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Reliability of 7T (1) H-MRS measured human prefrontal cortex glutamate, glutamine, and glutathione signals using an adapted echo time optimized PRESS sequence: A between- and within-sessions investigation.
Lally, N, An, L, Banerjee, D, Niciu, MJ, Luckenbaugh, DA, Richards, EM, Roiser, JP, Shen, J, Zarate, CA, Nugent, AC
Journal of magnetic resonance imaging : JMRI. 2016;(1):88-98
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Abstract
PURPOSE To ascertain the mechanisms of neuropsychiatric illnesses and their treatment, accurate and reliable imaging techniques are required; proton magnetic resonance spectroscopy ((1) H-MRS) can noninvasively measure glutamatergic function. Evidence suggests that aberrant glutamatergic signaling plays a role in numerous psychopathologies. Until recently, overlapping glutamatergic signals (glutamate, glutamine, and glutathione) could not easily be separated. However, the advent of novel pulse sequences and higher field magnetic resonance imaging (MRI) allows more precise resolution of overlapping glutamatergic signals, although the question of signal reliability remains undetermined. MATERIALS AND METHODS At 7T MR, we acquired (1) H-MRS data from the medial pregenual anterior cingulate cortex of healthy volunteers (n = 26) twice on two separate days. An adapted echo time optimized point-resolved spectroscopy sequence, modified with the addition of a J-suppression pulse to attenuate N-acetyl-aspartate multiplet signals at 2.49 ppm, was used to excite and acquire the spectra. In-house software was used to model glutamate, glutamine, and glutathione, among other metabolites, referenced to creatine. Intraclass correlation coefficients (ICCs) were computed for within- and between-session measurements. RESULTS Within-session measurements of glutamate, glutamine, and glutathione were on average reliable (ICCs ≥0.7). As anticipated, ICCs for between-session values of glutamate, glutamine, and glutathione were slightly lower but nevertheless reliable (ICC >0.62). A negative correlation was observed between glutathione concentration and age (r(24) = -0.37; P < 0.05), and a gender effect was noted on glutamine and glutathione. CONCLUSION The adapted sequence provides good reliability to measure glutamate, glutamine, and glutathione signals.
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[Production effect comparison of SEPP and GPx between HepG2 and Hela cells with different selenocompounds].
Wang, Q, Gao, L, Han, F, Lu, J, Liu, Y, Sun, L, Huang, Z
Wei sheng yan jiu = Journal of hygiene research. 2016;(2):259-62
Abstract
OBJECTIVE To compare the effect of several selenocompounds on the productions of SEPP and GPx in HepG2 and Hela cells. METHODS The cultured HepG2 and Hela cells were divided into the control, Na2SeO3, SeMet and MeSeCys groups. After adding the selected selenocompounds (with the respective concentration 0.01 and 0.1 μmol/L), the experimental groups were then incubated for 48 h and 72 h. Finally, the cell culture supernatants and homogenates were collected for the SEPP and GPx concentrations detection by a double-antibody sandwich enyme-linked immuno-sorbent-assay (ELISA). RESULTS The SEPP and GPx concentrations in Hela cells treated with 0.1 μmol/L SeMet and MeSeCys were significantly higher than that in the control group (P < 0.05). The SEPP and GPx concentrations in HepG2 cell treated with 0.1 μmol/L selenocompounds were significantly higher than that in Hela cells (P < 0.05). CONCLUSION HepG2 cells are more beneficial to the production of selenoproteins than Hela cells.
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Study of linkage between glutathione pathway and the antibiotic resistance of Escherichia coli from patients' swabs.
Kominkova, M, Michalek, P, Cihalova, K, Guran, R, Cernei, N, Nejdl, L, Smerkova, K, Dostalova, S, Chudobova, D, Heger, Z, et al
International journal of molecular sciences. 2015;(4):7210-29
Abstract
In this work, we focused on the differences between bacterial cultures of E. coli obtained from swabs of infectious wounds of patients compared to laboratory E. coli. In addition, blocking of the protein responsible for the synthesis of glutathione (γ-glutamylcysteine synthase-GCL) using 10 mM buthionine sulfoximine was investigated. Each E. coli showed significant differences in resistance to antibiotics. According to the determined resistance, E. coli were divided into experimental groups based on a statistical evaluation of their properties as more resistant and more sensitive. These groups were also used for finding the differences in a dependence of the glutathione pathway on resistance to antibiotics. More sensitive E. coli showed the same kinetics of glutathione synthesis while blocking GCL (Km 0.1 µM), as compared to non-blocking. In addition, the most frequent mutations in genes of glutathione synthetase, glutathione peroxidase and glutathione reductase were observed in this group compared to laboratory E.coli. The group of "more resistant" E. coli exhibited differences in Km between 0.3 and 0.8 µM. The number of mutations compared to the laboratory E. coli was substantially lower compared to the other group.
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Time-course evaluation of oxidative stress-related biomarkers after renal transplantation.
Vostálová, J, Galandáková, A, Svobodová, AR, Orolinová, E, Kajabová, M, Schneiderka, P, Zapletalová, J, Strebl, P, Zadražil, J
Renal failure. 2012;(4):413-9
Abstract
Patients with chronic renal disease have a high prevalence of oxidative stress (OS), which is associated with the cardiovascular complications occurring in this population. The restoration of kidney function after kidney transplantation (KT) can lead to reduction in the metabolic abnormalities and elimination of the OS. Time-dependent changes in OS-related markers and specific kidney function and metabolic parameters were evaluated in patients (N = 39; 23 males; 16 females; mean age = 57 ± 10 years) before (day 0) and after KT (day 1, 7, 30, 90, and 180) to monitor the graft. In particular, total antioxidant capacity (TAC), levels of advanced oxidation protein products (AOPP), lipid peroxidation as thiobarbituric acid-reactive substances (TBARS) and reduced glutathione (GSH); activities of glutathione peroxidase, catalase, and superoxide dismutase; and kidney function markers were measured. AOPP, TAC, and TBARS were significantly decreased, whereas GSH was significantly increased after KT. Antioxidant enzyme activities were not significantly changed during the monitored period after KT. Apropos specific kidney function markers and glomerular filtration significantly increased and creatinine level significantly decreased after transplantation. Changes in high-density lipoprotein cholesterol were also found. Our results show that successful KT results in normalization of the antioxidant status and lipid metabolism that is connected with both improved renal function and reduced cardiovascular complications.
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Early enteral nutrition with whey protein or casein in elderly patients with acute ischemic stroke: a double-blind randomized trial.
de Aguilar-Nascimento, JE, Prado Silveira, BR, Dock-Nascimento, DB
Nutrition (Burbank, Los Angeles County, Calif.). 2011;(4):440-4
Abstract
OBJECTIVE The aim of this study was to investigate the effects of an early enteral formula containing whey protein, in comparison to a standard enteral formula containing casein as the protein source, on the levels of glutathione and inflammatory markers in aged patients with acute ischemic stroke. METHODS Thirty-one elderly patients (12 males and 19 females; median age = 74 [range,65-90] y old) with ischemic stroke were randomized to receive early nasogastric feeding (35 kcal/kg/d and 1.2 g of protein/kg/d) with either a formula containing polymeric [corrected] casein (casein group, n =16) or another isocaloric and isonitrogenous formula containing hydrolyzed whey protein (WP group, n = 15) for 5 d. The primary endpoints of the study were the changes in the serum levels of glutathione peroxidase, C-reactive protein (CRP), and interleukin 6 (IL-6). RESULTS Twenty-five patients completed the study (10 in the WP group and 15 in the casein group). Mortality was similar between groups (33%; P = 1.00) and was associated with higher serum IL-6 (73.7 ± 24.7 versus 16.6 ± 2.4 pg/dL; P = 0.04) and CRP (82.0 ± 35.6 versus 48.3 ± 14.5 mg/L; P = 0.02) levels. Albumin levels dropped from the first to the fifth feeding day only in the casein group (P < 0.01). Serum IL-6 decreased (62.7 ± 47.2 to 20.6 ± 10.3 pg/dL; P = 0.02) and glutathione increased (32.2 ± 2.1 to 39.9 ± 6.8 U/G Hb; P = 0.03) only in the WP group. Serum IL-6 was lower (P = 0.03) and glutathione was higher (P = 0.03) in whey protein-fed patients than in the casein group. CONCLUSION Enteral formula containing whey protein may decrease inflammation and increase antioxidant defenses in elderly patients with ischemic stroke, compared to casein-containing formula.
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Antioxidants in Erica andevalensis: a comparative study between wild plants and cadmium-exposed plants under controlled conditions.
Márquez-García, B, Horemans, N, Cuypers, A, Guisez, Y, Córdoba, F
Plant physiology and biochemistry : PPB. 2011;(1):110-5
Abstract
Erica andevalensis is an endemic species from SW Iberian Peninsula, always growing in metal-enriched and acid soils. In the present study, a comparison was made between wild E. andevalensis plants collected from the field and cultivated ones exposed to different cadmium levels (0, 0.5, 5 and 50 μM). Wild plants contain higher levels of ascorbic acid (around 8000 nmol g(-1) FW) than lab-cultivated control plants (around 3000 nmol g(-1) FW). Glutathione levels follow an opposite trend being smaller in wild plants than lab-cultivated ones. Moreover, the total antioxidant capacity of wild plants is 90 times higher than in cultivated plants non-exposed to cadmium. Cadmium treatment of lab-cultivated plants did not affect the growth of E. andevalensis or the glutathione levels. However, the total antioxidative capacity increased in plants exposed to 50 μM of cadmium. Cadmium was added to the soil and it was transported into leaves reaching levels of 3.299 ± 0.781 μg Cd/g DW in plants exposed to 50 μM. These results underline a possible importance of antioxidants in the metal tolerance show by the high antioxidant capacity detected in both wild and lab-cultivated plants exposed to high cadmium levels.
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Intracellular GSH depletion triggered mitochondrial Bax translocation to accomplish resveratrol-induced apoptosis in the U937 cell line.
Guha, P, Dey, A, Sen, R, Chatterjee, M, Chattopadhyay, S, Bandyopadhyay, SK
The Journal of pharmacology and experimental therapeutics. 2011;(1):206-14
Abstract
We have previously demonstrated that resveratrol (Resv)-induced cellular apoptosis occurs after formation of reactive oxygen species (ROS) but the role of GSH has not been well defined. Our experimental data enumerated that Resv treatment (50 μm) induced apoptosis in human leukemic monocyte lymphoma cells, which was preceded by cellular GSH efflux. High concentration of extracellular thiol (GSH, N-acetyl cysteine) and two specific inhibitors of carrier-mediated GSH extrusion, methionine or cystathionine, prevented the process of oxidative burst and cell death. This proved that GSH efflux could be a major molecular switch to modulate Resv-induced ROS generation. Spectrofluorometric data depicted that after 6 h of Resv treatment, ROS generation was evident. Pretreatment of cells with intracellular ROS scavenger (polyethylene glycol-superoxide dismutase and polyethylene glycol-catalase) efficiently reduced ROS generation but failed to prevent intracellular GSH depletion. Thus, it suggested that intracellular GSH depletion was independent of ROS production but dependent on GSH extrusion. Furthermore, to bridge the link between GSH efflux and ROS generation, we carried out confocal microscopy of the localization of Bax protein. Microscopic analysis and small interfering RNA treatment emphasized that cellular GSH efflux triggered Bax translocation to mitochondria, which resulted in the loss of mitochondrial membrane potential, ROS generation, and caspase 3 activation and thus triggered apoptosis.
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Photoprotective effect of yellow-tinted intraocular lenses.
Mukai, K, Matsushima, H, Sawano, M, Nobori, H, Obara, Y
Japanese journal of ophthalmology. 2009;(1):47-51
Abstract
PURPOSE The aim of this study was to experimentally investigate changes in visible light-induced photo-oxidation and to evaluate the inhibitory effect of various acrylic tinted intraocular lenses (IOLs) on photooxidation. METHODS Three types of nontinted (VA-60BB, HOYA; SA60AT, Alcon; AU-6, Menicon) and tinted (YA-60BB, HOYA; SN60AT, Alcon; AN-6, Menicon) IOLs were used. In the first experiment, we investigated oxidation related to ultraviolet rays by using a mixed solution of reduced glutathione, nicotinamide adenine dinucleotide phosphate (NADPH), and glutathione reductase. The mixed glutathione solution was irradiated for 30, 60, or 90 min with direct artificial sunlight or artificial sunlight that had been passed through various IOLs. Oxidation was detected at 340 nm. In the second experiment, human retinal pigment epithelium (RPE) cells were prepared and cultured in a 96-well dish until confluent. After light exposure for 30 min or 48 h, lactate dehydrogenase (LDH) levels of the culture supernatant were measured to assess the amount of cell damage. RESULTS Visible light-induced glutathione oxidation progressed over time. Intraocular lenses inhibited photooxidation, with the inhibitory effect shown to increase when tinted IOLs were used. LDH levels in RPE cells increased as a result of exposure to visible light. There was a higher increase in LDH with nontinted than with tinted IOLs. CONCLUSION Visible light causes photooxidation, which damages intraocular tissue in vitro. These results suggest that tinted IOLs effectively inhibit tissue damage from visible light.
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Effects on skeletal muscle glutathione status of ischemia and reperfusion following abdominal aortic aneurysm surgery.
Westman, B, Johansson, G, Luo, JL, Söderlund, K, Wernerman, J, Hammarqvist, F
Annals of vascular surgery. 2006;(1):99-105
Abstract
Glutathione (GSH) is an important endogenous scavenger against reactive oxygen species. Elective abdominal surgery without ischemia and reperfusion leads to decreased muscle GSH concentrations 4-72 hr postoperatively without altering GSH redox status. In the present study, we investigated to what extent muscle GSH status was affected during and following elective abdominal aortic aneurysm repair. From patients (n = 10) undergoing abdominal aortic repair, thigh muscle specimens were taken preoperatively, at maximal ischemia, and at 10 min and 4, 24, and 48 hr of reperfusion. Specimens were analyzed for GSH, amino acids, and energy-rich compounds. At maximal ischemia, phosphocreatine decreased by 37% (p < 0.05) and lactate and creatine increased by 274% and 57% (p < 0.001 and 0.05), respectively, indicating ischemia during the clamping of aorta. Adenosine triphosphate, on the other hand, remained unaltered during the entire study period. Total GSH (tGSH) decreased by 46% at 24 hr and by 43% at 48 hr of reperfusion (p < 0.001), while reduced GSH decreased by 48% at 24 hr and by 44% at 48 hr (p < 0.001). The redox status (GSH/tGSH) of GSH and oxidized GSH remained unaltered. Among the constituent amino acids of GSH, glycine and cysteine remained unaltered while glutamine and glutamate decreased by 55% and 55%, respectively (p < 0.001). Abdominal aortic aneurysm repair induces metabolic alterations characteristic for ischemia. The antioxidative capacity in terms of muscle levels of GSH was decreased. However, the oxidative stress during reperfusion did not change GSH status more than what has been reported following abdominal surgery without ischemia and reperfusion. The results indicate that the oxidative stress elicited by elective abdominal aortic aneurysm repair is outbalanced by a compensated GSH metabolism not giving rise to an increased amount of oxidized GSH or an altered GSH redox status.