scholarly journals Reactive sulphur species: an in vitro investigation of the oxidation properties of disulphide S-oxides

2002 ◽  
Vol 364 (2) ◽  
pp. 579-585 ◽  
Author(s):  
Gregory I. GILES ◽  
Karen M. TASKER ◽  
Catriona COLLINS ◽  
Niroshini M. GILES ◽  
Elizabeth O'ROURKE ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Zinc Finger Protein ◽  
Oxidation Pathway ◽  
Species Formation ◽  
In Vitro Investigation ◽  
High Concentrations ◽  
Redox Buffer ◽  
Sulphur Species

We have recently proposed that disulphide S-monoxides (thiosulphinates) and disulphide S-dioxides (thiosulphonates) are formed from their parent disulphides and ‘reactive oxygen species’ during oxidative stress. These ‘reactive sulphur species’ are themselves strong oxidizing agents that preferably attack the thiol functionality. We now show that under conditions where disulphides show little effect, disulphide S-oxides rapidly modify metallothionein, alcohol and glyceraldehyde 3-phosphate dehydrogenases and a zinc finger-protein fragment in vitro. The known antioxidants ascorbate, NADH, trolox and melatonin are unable to inhibit this oxidation pathway and only an excess of the cellular redox-buffer glutathione quenches the disulphide S-oxide activity. These results suggest that, under conditions of oxidative stress, despite the presence of high concentrations of antioxidants, reactive sulphur species formation may occur and inhibit the function of thiol-dependent proteins. Such a characterization of the disulphide S-oxide-oxidation pathway might also account for some previously observed anomalies in protein oxidation.

Characterization of In Vitro Lysosomal and Peroxisomal Function in Oxidative Stress-Induced Cell Lines

2010 ◽  
Vol 150 ◽  
pp. 554-554
Author(s):  
Jihee Yoon ◽  
Seung Hyuck Bang ◽  
Yang-Hoon Kim ◽  
Jiho Min
Keyword(s):  
Oxidative Stress ◽  
Cell Lines ◽  
Peroxisomal Function

scholarly journals Synthesis and Characterization of New Amino Acid-Schiff Bases and Studies their Effects on the Activity of ACP, PAP and NPA Enzymes (In Vitro)

2012 ◽  
Vol 9 (2) ◽  
pp. 962-969 ◽  
Author(s):  
Zahraa Salim M. Al-Garawi ◽  
Ivan Hameed R. Tomi ◽  
Ali Hussein R. Al-Daraji
Keyword(s):  
Schiff Base ◽  
Condensation Reaction ◽  
Synthesis And Characterization ◽  
Activation Effect ◽  
Inhibition Effect ◽  
H Nmr ◽  
Ft Ir ◽  
High Concentrations

In this study, two new Schiff base compounds derived from the condensation reaction ofL-glycine andL-tryptophan with 4-methylbenzal-dehyde have been synthesized. The Schiff base compounds were characterized by FT-IR, UV and1H NMR spectroscopy. Their effects on the activity of total (ACP), prostatic (PAP) and non prostatic (NPA) acid phosphatase enzymes were studied. The Schiff base derived fromL-glycine (A) demonstrated inhibition effect on the ACP and NPA activities and activation effect on PAP activity. The Schiff base derived fromL-tryptophan (B) demonstrated semi fixed inhibition effects on the ACP and NPA activities at high concentrations (5.5×10-2, 5.5×10-3and 5.5×10-4M) and activator effect at low concentration (5.5×10-5M) while it was exhibits as activator on PAP activity.

scholarly journals Construction and Phenotypic Characterization of an Auxotrophic Mutant of Mycobacterium tuberculosis Defective in l-Arginine Biosynthesis

2002 ◽  
Vol 70 (6) ◽  
pp. 3080-3084 ◽  
Author(s):  
Bhavna G. Gordhan ◽  
Debbie A. Smith ◽  
Heidi Alderton ◽  
Ruth A. McAdam ◽  
Gregory J. Bancroft ◽  
...  
Keyword(s):  
Mycobacterium Tuberculosis ◽  
Mutant Strain ◽  
Auxotrophic Mutant ◽  
Phenotypic Characterization ◽  
Wild Type ◽  
Arginine Biosynthesis ◽  
High Concentrations

ABSTRACT A mutant of Mycobacterium tuberculosis defective in the metabolism of l-arginine was constructed by allelic exchange mutagenesis. The argF mutant strain required exogenous l-arginine for growth in vitro, and in the presence of 0.96 mM l-arginine, it achieved a growth rate and cell density in stationary phase comparable to those of the wild type. The mutant strain was also able to grow in the presence of high concentrations of argininosuccinate, but its auxotrophic phenotype could not be rescued by l-citrulline, suggesting that the ΔargF::hyg mutation exerted a polar effect on the downstream argG gene but not on argH. The mutant strain displayed reduced virulence in immunodeficient SCID mice and was highly attenuated in immunocompetent DBA/2 mice, suggesting that l-arginine availability is restricted in vivo.

scholarly journals Characterization of the secretory profile and exosomes of limbal stem cells in the canine species

PLoS ONE ◽  
2020 ◽  
Vol 15 (12) ◽  
pp. e0244327
Author(s):  
Antonio J. Villatoro ◽  
Cristina Alcoholado ◽  
María del Carmen Martín-Astorga ◽  
Gustavo Rico ◽  
Viviana Fernández ◽  
...  
Keyword(s):  
Stem Cells ◽  
Ocular Surface ◽  
Inhibitory Effect ◽  
Proteomic Profile ◽  
Limbal Stem Cells ◽  
High Concentrations ◽  
First Time

Limbal stem cells (LSCs) are a quiescent cell population responsible for the renewal of the corneal epithelium. Their deficiency is responsible for the conjunctivization of the cornea that is seen in different ocular pathologies, both in humans and in the canine species. The canine species represents an interesting preclinical animal model in ocular surface pathologies. However, the role of LSCs in physiological and pathological conditions in canine species is not well understood. Our objective was to characterize for the first time the soluble factors and the proteomic profile of the secretome and exosomes of canine LSCs (cLSCs). In addition, given the important role that fibroblasts play in the repair of the ocular surface, we evaluated the influence of the secretome and exosomes of cLSCs on their proliferation in vitro. Our results demonstrated a secretory profile of cLSCs with high concentrations of MCP-1, IL-8, VEGF-A, and IL-10, as well as significant production of exosomes. Regarding the proteomic profile, 646 total proteins in the secretome and 356 in exosomes were involved in different biological processes. Functionally, the cLSC secretome showed an inhibitory effect on the proliferation of fibroblasts in vitro, which the exosomes did not. These results open the door to new studies on the possible use of the cLSC secretome or some of its components to treat certain pathologies of the ocular surface in canine species.

scholarly journals Overexpression of Trypanosoma rangeli trypanothione reductase increases parasite survival under oxidative stress

2016 ◽  
Vol 2 ◽  
Author(s):  
I.T. BELTRAME-BOTELHO ◽  
P.H. STOCO ◽  
M. STEINDEL ◽  
B. ANDERSSON ◽  
E.F. PELOSO ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Functional Characterization ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Single Copy ◽  
Trypanothione Reductase ◽  
Trypanosoma Rangeli ◽  
Reading Frame ◽  
Key Enzyme

SUMMARYThe infectivity and virulence of pathogenic trypanosomatids are directly associated with the efficacy of their antioxidant system. Among the molecules involved in the trypanosomatid response to reactive oxygen or nitrogen species, trypanothione reductase (TRed) is a key enzyme. In this study, we performed a molecular and functional characterization of the TRed enzyme fromTrypanosoma rangeli(TrTRed), an avirulent trypanosome of mammals. TheTrTRed gene has an open reading frame (ORF) of 1473 bp (~490 aa, 53 kDa) and occurs as a single-copy gene in the haploid genome. The predicted protein contains two oxidoreductase domains, which are equally expressed in the cytosol of epimastigotes and trypomastigotes. Nicotinamide adenine dinucleotide phosphate (NADPH) generation is reduced and endogenous H2O2production is elevated inT. rangeliChoachí strain compared withT. cruziY strain epimastigotes. Oxidative stress induced by H2O2does not induce significant alterations inTrTRed expression. Overexpression ofTrTRed did not influencein vitrogrowth or differentiation into trypomastigotes, but mutant parasites showed increased resistance to H2O2-induced stress. Our results indicate thatT. rangeliconstitutively expresses TRed during the entire life cycle, with reduced levels during infective and non-replicative trypomastigote stages.

Insights into flibanserin oxidative stress degradation pathway: in silico – in vitro toxicity assessment of its degradates

2021 ◽  
Vol 45 (5) ◽  
pp. 2620-2630
Author(s):  
Mohammed F. El-Behairy ◽  
Rasha M. Ahmed ◽  
Marwa A. A. Fayed ◽  
Samar Mowafy ◽  
Inas A. Abdallah
Keyword(s):  
Oxidative Stress ◽  
Degradation Products ◽  
Degradation Pathway ◽  
Toxicity Assessment ◽  
In Vitro Toxicity ◽  
Pharmaceutical Drugs ◽  
Stress Degradation ◽  
In Vitro Toxicity Assessment

Characterization of the degradation products of pharmaceutical drugs is essential to assess their safety.

scholarly journals The Effect of Hydrogen Sulfide on Different Parameters of Human Plasma in the Presence or Absence of Exogenous Reactive Oxygen Species

Antioxidants ◽  
2019 ◽  
Vol 8 (12) ◽  
pp. 610 ◽  
Author(s):  
Beata Olas ◽  
Paulina Brodek ◽  
Bogdan Kontek
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Hydrogen Sulfide ◽  
Human Plasma ◽  
Maximum Velocity ◽  
Thiobarbituric Acid Reactive Substance ◽  
Thrombin Time ◽  
Sodium Hydrosulfide ◽  
High Concentrations

The main aim of the study is to examine the effect of sodium hydrosulfide (NaHS), an H2S donor, on the oxidative stress in human plasma in vitro. It also examined the effects of very high concentrations of exogenous hydrogen sulfide on the hemostatic parameters (coagulation and fibrinolytic activity) of human plasma. Plasma was incubated for 5–30 min with different concentrations of NaHS from 0.01 to 10 mM. Following this, lipid peroxidation was measured as a thiobarbituric acid reactive substance (TBARS) concentration and the oxidation of amino acid residues in proteins was measured by determining the amounts of thiol groups and carbonyl groups. Hydrogen peroxide (H2O2) and the hydroxyl radical generating oxidation system (Fe/H2O2) were used as oxidative stress inducers. Hemostatic factors, such as the maximum velocity of clot formation, fibrin lysis half-time, the activated partial thromboplastin time (APTT), thrombin time (TT), and international normalized ratio (INR), were estimated. Changes in lipid peroxidation, carbonyl group formation, and thiol group oxidation were detected at high concentrations of H2S (0.1–10 mM), and these results indicate that NaHS (as the precursor of H2S) may have pro-oxidative effects in human plasma in vitro. Moreover, considering the data presented in this study, we suggest that the oxidative stress stimulated by NaHS (at high concentrations: 1–10 mM) is not involved in changes of the hemostatic activity of plasma.

scholarly journals Hormetic-Like Effects of L-Homocysteine on Synaptic Structure, Function, and Aβ Aggregation

2020 ◽  
Vol 13 (2) ◽  
pp. 24 ◽  
Author(s):  
Carla Montecinos-Oliva ◽  
Macarena S. Arrázola ◽  
Claudia Jara ◽  
Cheril Tapia-Rojas ◽  
Nibaldo C. Inestrosa
Keyword(s):  
Oxidative Stress ◽  
Risk Factor ◽  
Hippocampal Slices ◽  
The Elderly ◽  
Long Term Potentiation ◽  
Synaptic Activity ◽  
Synaptic Proteins ◽  
Protein Levels ◽  
High Concentrations

Alzheimer’s Disease (AD) is the primary cause of dementia among the elderly population. Elevated plasma levels of homocysteine (HCy), an amino acid derived from methionine metabolism, are considered a risk factor and biomarker of AD and other types of dementia. An increase in HCy is mostly a consequence of high methionine and/or low vitamin B intake in the diet. Here, we studied the effects of physiological and pathophysiological HCy concentrations on oxidative stress, synaptic protein levels, and synaptic activity in mice hippocampal slices. We also studied the in vitro effects of HCy on the aggregation kinetics of Aβ40. We found that physiological cerebrospinal concentrations of HCy (0.5 µM) induce an increase in synaptic proteins, whereas higher doses of HCy (30–100 µM) decrease their levels, thereby increasing oxidative stress and causing excitatory transmission hyperactivity, which are all considered to be neurotoxic effects. We also observed that normal cerebrospinal concentrations of HCy slow the aggregation kinetic of Aβ40, whereas high concentrations accelerate its aggregation. Finally, we studied the effects of HCy and HCy + Aβ42 over long-term potentiation. Altogether, by studying an ample range of effects under different HCy concentrations, we report, for the first time, that HCy can exert beneficial or toxic effects over neurons, evidencing a hormetic-like effect. Therefore, we further encourage the use of HCy as a biomarker and modifiable risk factor with therapeutic use against AD and other types of dementia.

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