scholarly journals Hyperoxidation of Peroxiredoxins and Effects on Physiology of Drosophila

Antioxidants ◽  
2021 ◽  
Vol 10 (4) ◽  
pp. 606
Author(s):  
Austin McGinnis ◽  
Vladimir I. Klichko ◽  
William C. Orr ◽  
Svetlana N. Radyuk
Keyword(s):  
Oxidative Stress ◽  
Drosophila Melanogaster ◽  
Catalytic Activity ◽  
Oxidation State ◽  
Adaptive Response ◽  
Physiological Activity ◽  
Sulfenic Acid ◽  
Daily Variations ◽  
Positive Effect ◽  
Oxidative Load

The catalytic activity of peroxiredoxins (Prx) is determined by the conserved peroxidatic cysteine (CysP), which reacts with peroxides to form sulfenic acid (Cys-SOH). Under conditions of oxidative stress, CysP is oxidized to catalytically inactive sulfinic (Cys-SO2) and sulfonic (Cys-SO3) forms. The Cys-SO2 form can be reduced in a reaction catalyzed by sulfiredoxin (Srx). To explore the physiological significance of peroxiredoxin overoxidation, we investigated daily variations in the oxidation state of 2-Cys peroxiredoxins in flies of different ages, or under conditions when the pro-oxidative load is high. We found no statistically significant changes in the 2-Cys Prxs monomer:dimer ratio, which indirectly reflects changes in the Prx catalytic activity. However, we found daily variations in Prx-SO2/3 that were more pronounced in older flies as well as in flies lacking Srx. Unexpectedly, the srx mutant flies did not exhibit a diminished survivorship under normal or oxidative stress conditions. Moreover, the srx mutant was characterized by a higher physiological activity. In conclusion, catalytically inactive forms of Prx-SO2/3 serve not only as a marker of cellular oxidative burden, but may also play a role in an adaptive response, leading to a positive effect on the physiology of Drosophila melanogaster.

Metathesis Polymerization of Phenylacetylene by Tungsten Aryloxo Complexes

1995 ◽  
Vol 60 (3) ◽  
pp. 489-497 ◽  
Author(s):  
Hynek Balcar ◽  
Jan Sedláček ◽  
Marta Pacovská ◽  
Vratislav Blechta
Keyword(s):  
Molecular Weight ◽  
Catalytic Activity ◽  
Induction Period ◽  
Average Molecular Weight ◽  
Molar Fraction ◽  
Molar Ratio ◽  
Weight Average Molecular Weight ◽  
Polymer Yield ◽  
Positive Effect ◽  
Ligand Addition

Catalytic activity of the tungsten aryloxo complexes WCl5(OAr) and WOCl3(OAr), where Ar = 4-t-C4H9C6H4, 2,6-(t-C4H9)2C6H3, 2,6-Cl2C6H3, 2,4,6-Cl3C6H2, and 2,4,6-Br3C6H2 in polymerization of phenylacetylene (20 °C, monomer to catalyst molar ratio = 1 000) was studied. The activity of WCl5(OAr) as unicomponent catalysts increases with increasing electron withdrawing character of the -OAr ligand. Addition of two equivalents of organotin cocatalysts (Me4Sn, Bu4Sn, Ph4Sn, Bu3SnH) to WCl5(O-C6H2Cl3-2,4 ,6) has only slight positive effect (slightly higher polymer yield and/or molecular weight of poly(phenylacetylene)s was achieved). However, in the case of WOCl3(O-C6H3Cl2-2, 6) catalyst, it enhances the activity considerably by eliminating the induction period. Poly(phenylacetylene)s prepared with the catalysts studied have weight-average molecular weight ranging from 100 000 to 200 000. They are trans-prevailing and have relatively low molar fraction of monomer units comprised in cyclohexadiene sequences (about 6%).

scholarly journals Zone-specific damage of the olfactory epithelium under protein restriction

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ayinuer Tuerdi ◽  
Shu Kikuta ◽  
Makoto Kinoshita ◽  
Teru Kamogashira ◽  
Kenji Kondo ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Olfactory Epithelium ◽  
Control Diet ◽  
Intervention Strategy ◽  
Protein Restriction ◽  
Outer Hair Cells ◽  
Basal Cells ◽  
Cell Dynamics ◽  
Age Related ◽  
Positive Effect

AbstractOxidative stress causes tissue damage, affecting age-related pathologies. Protein restriction (PR) provides a powerful intervention strategy for reducing oxidative stress, which may have a positive effect on individual organs. However, it is unknown whether PR intervention influences the olfactory system. Here, we investigated how 10 months of PR could affect the cell dynamics of the olfactory epithelium (OE) in mice. We found that PR reduced age-related loss of outer hair cells in the cochlea, providing preventive effects against age-related hearing loss. In contrast, PR resulted in reduced mature olfactory sensory neurons (OSNs), increased proliferative basal cells, and increased apoptotic OSNs in zone 1 (the only area containing neurons expressing NQO1 [quinone dehydrogenase 1]) of the OE in comparison with animals given a control diet. Substantial oxidative stress occurred in NQO1-positive cells and induced apoptotic OSNs in zone 1. These results indicate that in contrast to the positive effect on the auditory system, PR induces oxidative stress and structurally and functionally negative effects on OSNs in zone 1, which is probably involved in the bioactivation of NQO1.

scholarly journals How N-Acetylcysteine Supplementation Affects Redox Regulation, Especially at Mitohormesis and Sarcohormesis Level: Current Perspective

Antioxidants ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 153
Author(s):  
Aslı Devrim-Lanpir ◽  
Lee Hill ◽  
Beat Knechtle
Keyword(s):  
Oxidative Stress ◽  
Oxidative Metabolism ◽  
Adaptive Response ◽  
Redox Regulation ◽  
Therapeutic Agent ◽  
Metabolic Effects ◽  
Metabolic Adaptations ◽  
Current Perspective ◽  
Exercise Induced ◽  
Response To Exercise

Exercise frequently alters the metabolic processes of oxidative metabolism in athletes, including exposure to extreme reactive oxygen species impairing exercise performance. Therefore, both researchers and athletes have been consistently investigating the possible strategies to improve metabolic adaptations to exercise-induced oxidative stress. N-acetylcysteine (NAC) has been applied as a therapeutic agent in treating many diseases in humans due to its precursory role in the production of hepatic glutathione, a natural antioxidant. Several studies have investigated NAC’s possible therapeutic role in oxidative metabolism and adaptive response to exercise in the athletic population. However, still conflicting questions regarding NAC supplementation need to be clarified. This narrative review aims to re-evaluate the metabolic effects of NAC on exercise-induced oxidative stress and adaptive response developed by athletes against the exercise, especially mitohormetic and sarcohormetic response.

scholarly journals Effects of sodium fluoride and Ocimum sanctum extract on the lifespan and climbing ability of Drosophila melanogaster

2021 ◽  
Vol 82 (1) ◽  
Author(s):  
Sidra Perveen ◽  
Shalu Kumari ◽  
Himali Raj ◽  
Shahla Yasmin
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Drosophila Melanogaster ◽  
Sodium Fluoride ◽  
Ocimum Sanctum ◽  
Activity Assay ◽  
Lipid Peroxidation Assay ◽  
Climbing Ability ◽  
The Impact ◽  
Sublethal Concentrations

Abstract Background Fluoride may induce oxidative stress and apoptosis. It may also lead to neurobehavioural defects including neuromuscular damage. The present study aimed to explore the effects of sub lethal concentrations of sodium fluoride (NaF) on the lifespan and climbing ability of Drosophila melanogaster. In total, 0.6 mg/L and 0.8 mg/L of NaF were selected as sublethal concentrations of NaF for the study. Lifespan was measured and climbing activity assay was performed. Results The study showed significant decrease in lifespan of flies treated with fluoride. With increasing age, significant reduction in climbing activity was observed in flies treated with sodium fluoride as compared to normal (control) flies. Flies treated with tulsi (Ocimum sanctum) and NaF showed increase in lifespan and climbing activity as compared to those treated with NaF only. Lipid peroxidation assay showed significant increase in malondialdehyde (MDA) values in the flies treated with NaF as compared to control. The MDA values decreased significantly in flies treated with tulsi mixed with NaF. Conclusions The results indicate that exposure to sub lethal concentration of NaF may cause oxidative stress and affect the lifespan and climbing activity of D. melanogaster. Tulsi extract may help in reducing the impact of oxidative stress and toxicity caused by NaF.

scholarly journals Correlative Microscopy to Localize and Characterize Iron Deposition in Alzheimer’s Disease

2020 ◽  
Vol 4 (1) ◽  
pp. 525-536
Author(s):  
Steven J. Madsen ◽  
Phillip S. DiGiacomo ◽  
Yitian Zeng ◽  
Maged Goubran ◽  
Yuanxin Chen ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Electron Microscope ◽  
Oxidation State ◽  
Transmission Electron Microscope ◽  
Iron Deposition ◽  
Direct Link ◽  
Transmission Electron ◽  
And Oxidative Stress

Background: Recent evidence suggests that the accumulation of iron, specifically ferrous Fe2+, may play a role in the development and progression of neurodegeneration in Alzheimer’s disease (AD) through the production of oxidative stress. Objective: To localize and characterize iron deposition and oxidation state in AD, we analyzed human hippocampal autopsy samples from four subjects with advanced AD that have been previously characterized with correlative MRI-histology. Methods: We perform scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), and electron energy loss spectroscopy (EELS) in the higher resolution transmission electron microscope on the surface and cross-sections of specific iron-rich regions of interest. Results: Specific previously analyzed regions were visualized using SEM and confirmed to be iron-rich deposits using EDS. Subsequent analysis using focused ion beam cross-sectioning and SEM characterized the iron deposition throughout the 3-D volumes, confirming the presence of iron throughout the deposits, and in two out of four specimens demonstrating colocalization with zinc. Analysis of traditional histology slides showed the analyzed deposits overlapped both with amyloid and tau deposition. Following higher resolution analysis of a single iron deposit using scanning transmission electron microscope (STEM), we demonstrated the potential of monochromated STEM-EELS to discern the relative oxidation state of iron within a deposit. Conclusion: These findings suggest that iron is present in the AD hippocampus and can be visualized and characterized using combined MRI and EM techniques. An altered relative oxidation state may suggest a direct link between iron and oxidative stress in AD. These methods thus could potentially measure an altered relative oxidation state that could suggest a direct link between iron and oxidative stress in AD. Furthermore, we have demonstrated the ability to analyze metal deposition alongside commonly used histological markers of AD pathology, paving the way for future insights into the molecular interactions between Aβ, tau, iron, and other putative metals, such as zinc.

Oxidative stress and decreased dopamine levels induced by imidacloprid exposure cause behavioral changes in a neurodevelopmental disorder model in Drosophila melanogaster

2021 ◽  
Author(s):  
Dieniffer Espinosa Janner ◽  
Nathalie Savedra Gomes ◽  
Márcia Rósula Poetini ◽  
Kétnne Hanna Poleto ◽  
Elize Aparecida Santos Musachio ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Drosophila Melanogaster ◽  
Neurodevelopmental Disorder ◽  
Behavioral Changes

scholarly journals Vitamin C Recycling Is Enhanced in the Adaptive Response to Leptin-Induced Oxidative Stress in Keratinocytes

2003 ◽  
Vol 121 (4) ◽  
pp. 786-793 ◽  
Author(s):  
Isabella Savini ◽  
Maria Valeria Catani ◽  
Antonello Rossi ◽  
Guglielmo Duranti ◽  
Marco Ranalli ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Vitamin C ◽  
Adaptive Response

AROS-29 is involved in adaptive response to oxidative stress

2006 ◽  
Vol 40 (5) ◽  
pp. 467-476 ◽  
Author(s):  
Nicola Montesano Gesualdi ◽  
Giuseppa Chirico ◽  
Maria Teresa Catanese ◽  
Giuseppe Pirozzi ◽  
Franca Esposito
Keyword(s):  
Oxidative Stress ◽  
Adaptive Response
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