scholarly journals Precipitation at Room Temperature as a Fast and Versatile Method for Calcium Phosphate/TiO2 Nanocomposites Synthesis

Nanomaterials ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 1523
Author(s):  
Ina Erceg ◽  
Atiđa Selmani ◽  
Andreja Gajović ◽  
Borna Radatović ◽  
Suzana Šegota ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Calcium Phosphates ◽  
Reactive Oxygen ◽  
Fine Tuning ◽  
Fast Method ◽  
Oxygen Species ◽  
Precipitation System ◽  
Significant Difference ◽  
Tio2 Nanomaterials ◽  
Metal Oxide Nanomaterials

The constantly growing need for advanced bone regeneration materials has motivated the development of calcium phosphates (CaPs) composites with a different metal or metal-oxide nanomaterials and their economical and environmentally friendly production. Here, two procedures for the synthesis of CaPs composites with TiO2 nanoplates (TiNPl) and nanowires (TiNWs) were tested, with the immersion of TiO2 nanomaterials (TiNMs) in corrected simulated body fluid (c-SBF) and precipitation of CaP in the presence of TiNMs. The materials obtained were analyzed by powder X-ray diffraction, spectroscopic and microscopic techniques, Brunauer–Emmett–Teller surface area analysis, thermogravimetric analysis, dynamic and electrophoretic light scattering, and their hemocompatibility and ability to induce reactive oxygen species were evaluated. After 28 days of immersion in c-SBF, no significant CaP coating was formed on TiNMs. However, the composites with calcium-deficient apatite (CaDHA) were obtained after one hour in the spontaneous precipitation system. In the absence of TiNMs, CaDHA was also formed, indicating that control of the CaP phase formed can be accomplished by fine-tuning conditions in the precipitation system. Although the morphology and size of crystalline domains of CaDHA obtained on the different nanomaterials differed, no significant difference was detected in their local structure. Composites showed low reactive oxygen species (ROS) production and did not induce hemolysis. The results obtained indicate that precipitation is a suitable and fast method for the preparation of CaPs/TiNMs nanocomposites which shows great potential for biomedical applications.

scholarly journals PRDX1 is essential for the viability and maintenance of reactive oxygen species in chicken DT40

2021 ◽  
Vol 43 (1) ◽  
Author(s):  
Takahito Moriwaki ◽  
Akari Yoshimura ◽  
Yuki Tamari ◽  
Hiroyuki Sasanuma ◽  
Shunichi Takeda ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Intracellular Signaling ◽  
Reactive Oxygen ◽  
Fine Tuning ◽  
Oxygen Species ◽  
Ros Homeostasis ◽  
Intracellular Ros ◽  
Chromosomal Breaks ◽  
Dt40 Cells

Abstract Background Peroxiredoxin 1 (PRDX1) is a member of a ubiquitous family of thiol peroxidases that catalyze the reduction of peroxides, including hydrogen peroxide. It functions as an antioxidant enzyme, similar to catalase and glutathione peroxidase. PRDX1 was recently shown act as a sensor of reactive oxygen species (ROS) and play a role in ROS-dependent intracellular signaling pathways. To investigate its physiological functions, PRDX1 was conditionally disrupted in chicken DT40 cells in the present study. Results The depletion of PRDX1 resulted in cell death with increased levels of intracellular ROS. PRDX1-depleted cells did not show the accumulation of chromosomal breaks or sister chromatid exchange (SCE). These results suggest that cell death in PRDX1-depleted cells was not due to DNA damage. 2-Mercaptoethanol protected against cell death in PRDX1-depleted cells and also suppressed elevations in ROS. Conclusions PRDX1 is essential in chicken DT40 cells and plays an important role in maintaining intracellular ROS homeostasis (or in the fine-tuning of cellular ROS levels). Cells deficient in PRDX1 may be used as an endogenously deregulated ROS model to elucidate the physiological roles of ROS in maintaining proper cell growth.

scholarly journals Reactive oxygen species formation during tetanic contractions in single isolated Xenopus myofibers

2011 ◽  
Vol 111 (3) ◽  
pp. 898-904 ◽  
Author(s):  
Li Zuo ◽  
Leonardo Nogueira ◽  
Michael C. Hogan
Keyword(s):  
Reactive Oxygen Species ◽  
Skeletal Muscle ◽  
Real Time ◽  
Contractile Activity ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Oxygen Species ◽  
Fatigue Development ◽  
Species Formation ◽  
Significant Difference

Contracting skeletal muscle produces reactive oxygen species (ROS) that have been shown to affect muscle function and adaptation. However, real-time measurement of ROS in contracting myofibers has proven to be difficult. We used amphibian ( Xenopus laevis) muscle to test the hypothesis that ROS are formed during contractile activity in isolated single skeletal muscle fibers and that this contraction-induced ROS formation affects fatigue development. Single myofibers were loaded with 5 μM dihydrofluorescein-DA (Hfluor-DA), a fluorescent probe that reacts with ROS and results in the formation of fluorescein (Fluor) to precisely monitor ROS generation within single myofibers in real time using confocal miscroscopy. Three identical periods of maximal tetanic contractions (1 contraction/3 s for 2 min, separated by 60 min of rest) were conducted by each myofiber ( n = 6) at 20°C. Ebselen (an antioxidant) was present in the perfusate (10 μM) during the second contractile period. Force was reduced by ∼30% during each of the three contraction periods, with no significant difference in fatigue development among the three periods. The Fluor signal, indicative of ROS generation, increased significantly above baseline in both the first (42 ± 14%) and third periods (39 ± 10%), with no significant difference in the increase in fluorescence between the first and third periods. There was no increase of Fluor in the presence of ebselen during the second contractile period. These results demonstrated that, in isolated intact Xenopus myofibers, 1) ROS can be measured in real time during tetanic contractions, 2) contractile activity induced a significant increase above resting levels of ROS production, and 3) ebselen treatment reduced ROS generation to baseline levels but had no effect on myofiber contractility and fatigue development.

84 PTEROSTILBENE CAN REDUCE THE PERCENTAGE OF LIPIDS AND REACTIVE OXYGEN SPECIES IN IN VITRO-PRODUCED BOVINE EMBRYOS

2017 ◽  
Vol 29 (1) ◽  
pp. 149
Author(s):  
F. Sosa ◽  
J. Fernando de la Torre ◽  
H. Álvarez ◽  
S. Pérez ◽  
M. E. Kjelland ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Culture Medium ◽  
Statistical Significance ◽  
Cell Mass ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Embryo Production ◽  
Cell Counts ◽  
Significant Difference ◽  
And Control

The actual challenge for the majority of research centers involves the embryo culture medium, since it is known that the culture medium plays a large role in determining embryo quality. Pterostilbene (PT) is a natural analogue of Resveratrol, an antioxidant that can reduce lipids in embryos, but no reports exist of PT being used with IVF-produced embryos or gametes. The objective of the present research was to evaluate the effect of PT in culture media CDM1 and CDM2 on embryo production, cell count, lipid accumulation, and reactive oxygen species (ROS). A total of 4 concentrations of PT and a control were evaluated, i.e. 3, 1, 0.33, 0.11, and 0 μM, in 2 separate experiments. The first experiment was performed using 6 replicates (n = 204) to evaluate blastocyst production (n = 201) and determine the percentage of lipids using the stain Sudan-Black, (n = 100). Hoechst 33258 and propidium iodide were used for determining cell counts. The second experiment was performed using 7 replicates, the effect of using PT (0.33 μM) was compared with a control with 2 O2 concentrations (5 and 20%) for evaluating ROS production (n = 124). Blastocysts without zona pellucida were incubated 48 h at 38.5°C in PBS (without polyvinyl alcohol) with 60 μL of ro-green fluorescent protein. After incubation, 25 μL of 4′,6-diamidino-2-phenylindole (1 mg mL−1) was added and incubated for 5 min. A fluorescence microscope was used and positive ROS particles digitized using Photoshop CS6 and quantified using the program ImageJ®. The data were transformed to arcsin values for subsequent analysis. In the first experiment, ANOVA and least significant difference tests were used to determine statistical significance (Statgraphics). No significant differences were found among treatments (P > 0.05) for the internal cell mass: 3, 1, 0.33, 0.11 μM PT (29.2 ± 5.2; 28.9 ± 3.8; 22.2 ± 3.2; 29.0 ± 1.7, respectively) and the control (27.0 ± 1.7). The cells of the trophectoderm did not differ (P > 0.05) between treatments (31.7 ± 4.8; 31.3 ± 3.9; 38.6 ± 3.5; 30.8 ± 1.8) and control (33.4 ± 2.1). Total cells did not differ (P > 0.05) between treatments (72.0 ± 9.8; 82.6 ± 4.3; 94.8 ± 12.8; 73.2 ± 9.2) and control (83.8 ± 7.7). Embryo production (Day 8) was greater for control (33.5 ± 3.0) versus treatments (14.1 ± 1.7; 19.4 ± 1.9; 21.1 ± 2.6; 20.8 ± 2.1) (P < 0.05); however, PT reduced the percentage of lipids (11.0 ± 0.8; 10.7 ± 0.9; 11.6 ± 1.3; 11.3 ± 1.1) within the cytoplasm of the embryos (P < 0.05) versus control (17.01 ± 1.20). In the second experiment, a factorial 2 × 2 matrix demonstrated that the O2 concentration did not have an effect on ROS (P > 0.05); however, the PT had a significant effect on the reduction of ROS (P < 0.05), i.e. a negative correlation, r = −0.835. In summary, we determined that PT did not improve the production of blastocysts but resulted in a significant reduction of ROS and lipids.

FITNESS, a CCT domain-containing protein, deregulates reactive oxygen species levels and leads to fine-tuning trade-offs between reproductive success and defence responses in Arabidopsis

2018 ◽  
Vol 41 (10) ◽  
pp. 2328-2341 ◽  
Author(s):  
Ana Virginia Osella ◽  
Diego Alberto Mengarelli ◽  
Julieta Mateos ◽  
Shuchao Dong ◽  
Marcelo J. Yanovsky ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Reproductive Success ◽  
Reactive Oxygen ◽  
Fine Tuning ◽  
Oxygen Species ◽  
Trade Offs ◽  
Defence Responses

scholarly journals Oxidoreductases and Reactive Oxygen Species in Conversion of Lignocellulosic Biomass

2018 ◽  
Vol 82 (4) ◽  
Author(s):  
Bastien Bissaro ◽  
Anikó Várnai ◽  
Åsmund K. Røhr ◽  
Vincent G. H. Eijsink
Keyword(s):  
Reactive Oxygen Species ◽  
Plant Cell Wall ◽  
Biomass Conversion ◽  
Hydrolytic Enzymes ◽  
Reactive Oxygen ◽  
Industrial Applications ◽  
Fine Tuning ◽  
Oxygen Species ◽  
Redox Systems ◽  
Polysaccharide Monooxygenases

SUMMARYBiomass constitutes an appealing alternative to fossil resources for the production of materials and energy. The abundance and attractiveness of vegetal biomass come along with challenges pertaining to the intricacy of its structure, evolved during billions of years to face and resist abiotic and biotic attacks. To achieve the daunting goal of plant cell wall decomposition, microorganisms have developed many (enzymatic) strategies, from which we seek inspiration to develop biotechnological processes. A major breakthrough in the field has been the discovery of enzymes today known as lytic polysaccharide monooxygenases (LPMOs), which, by catalyzing the oxidative cleavage of recalcitrant polysaccharides, allow canonical hydrolytic enzymes to depolymerize the biomass more efficiently. Very recently, it has been shown that LPMOs are not classical monooxygenases in that they can also use hydrogen peroxide (H2O2) as an oxidant. This discovery calls for a revision of our understanding of how lignocellulolytic enzymes are connected since H2O2is produced and used by several of them. The first part of this review is dedicated to the LPMO paradigm, describing knowns, unknowns, and uncertainties. We then present different lignocellulolytic redox systems, enzymatic or not, that depend on fluxes of reactive oxygen species (ROS). Based on an assessment of these putatively interconnected systems, we suggest that fine-tuning of H2O2levels and proximity between sites of H2O2production and consumption are important for fungal biomass conversion. In the last part of this review, we discuss how our evolving understanding of redox processes involved in biomass depolymerization may translate into industrial applications.

scholarly journals Elevated Serum Reactive Oxygen Species Level Predicts Early Abortion

2021 ◽  
Vol 5 (1) ◽  
pp. 37
Author(s):  
Joserizal Serudji ◽  
Nuzulia Irawati ◽  
Johanes Cornelius Mose ◽  
Hirowati Ali ◽  
Yusrawati Yusrawati
Keyword(s):  
Reactive Oxygen Species ◽  
Gestational Age ◽  
Elevated Serum ◽  
Reactive Oxygen ◽  
Normal Pregnancy ◽  
Trophoblast Invasion ◽  
Enzyme Linked Immunosorbent Assay ◽  
Oxygen Species ◽  
Significant Difference ◽  
Early Abortion

Background: Impaired trophoblast invasion is associated with early abortion. The calorie needed for the trophoblast cell (TC) invasion is mainly met by adenosine triphosphate (ATP) produced in the mitochondria. Reactive oxygen species (ROS), byproduct of ATP synthesis, plays an important role in cellular physiology, but a high level of ROS may result in deoxyribonucleic acid (DNA) damage or cell dysfunction, thereby impaired TC invasion leading to early abortion. The study aims to determine elevated serum ROS level to predicts early abortion.Materials and method: This was an observational study with a cross-sectional design. Fifty subjects with gestational age less than 12 weeks, consist of 25 early abortions and 25 normal pregnancies subjects, were included in this study. Clinical examination and diagnosis are carried out in 2 Hospitals and 5 Public Health Centers in Padang. Examination of ROS levels was carried out by enzyme-linked immunosorbent assay (ELISA) in the Biomedical Laboratory, Faculty of Medicine, Universitas Andalas. The Mann-Whitney test was used to analyze the difference of serum ROS levels, with a significance level of 0.05.Results: The subjects of the two study groups were equivalent in terms of age, gestational age, and gravidity (p=0.051, p=0.453, and p=1.000). The median ROS levels were found to be 1.36 (1.02-26.30) ng/mL in the early abortion and 1.20 (0.43-2.75) ng/mL in the normal pregnancy (p=0.003).Conclusion: There is a significant difference between ROS levels in early abortion and normal pregnancy.Keywords: ROS, early abortion, normal pregnancy

scholarly journals An Autoregulatory Loop ControllingCYP1A1 Gene Expression: Role of H2O2and NFI

1999 ◽  
Vol 19 (10) ◽  
pp. 6825-6832 ◽  
Author(s):  
Yannick Morel ◽  
Nicolas Mermod ◽  
Robert Barouki
Keyword(s):  
Oxidative Stress ◽  
Gene Expression ◽  
Reactive Oxygen Species ◽  
Gene Promoter ◽  
Reactive Oxygen ◽  
Fine Tuning ◽  
Expression Vectors ◽  
Oxygen Species ◽  
Cytochrome P450 1A1 ◽  
Down Regulation

ABSTRACT Cytochrome P450 1A1 (CYP1A1), like many monooxygenases, can produce reactive oxygen species during its catalytic cycle. Apart from the well-characterized xenobiotic-elicited induction, the regulatory mechanisms involved in the control of the steady-state activity of CYP1A1 have not been elucidated. We show here that reactive oxygen species generated from the activity of CYP1A1 limit the levels of induced CYP1A1 mRNAs. The mechanism involves the repression of theCYP1A1 gene promoter activity in a negative-feedback autoregulatory loop. Indeed, increasing the CYP1A1 activity by transfecting CYP1A1 expression vectors into hepatoma cells elicited an oxidative stress and led to the repression of a reporter gene driven by the CYP1A1 gene promoter. This negative autoregulation is abolished by ellipticine (an inhibitor of CYP1A1) and by catalase (which catalyzes H2O2 catabolism), thus implying that H2O2 is an intermediate. Down-regulation is also abolished by the mutation of the proximal nuclear factor I (NFI) site in the promoter. The transactivating domain of NFI/CTF was found to act in synergy with the arylhydrocarbon receptor pathway during the induction of CYP1A1 by 2,3,7,8-tetrachloro-p-dibenzodioxin. Using an NFI/CTF-Gal4 fusion, we show that NFI/CTF transactivating function is decreased by a high activity of CYP1A1. This regulation is also abolished by catalase or ellipticine. Consistently, the transactivating function of NFI/CTF is repressed in cells treated with H2O2, a novel finding indicating that the transactivating domain of a transcription factor can be targeted by oxidative stress. In conclusion, an autoregulatory loop leads to the fine tuning of theCYP1A1 gene expression through the down-regulation of NFI activity by CYP1A1-based H2O2 production. This mechanism allows a limitation of the potentially toxic CYP1A1 activity within the cell.

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