scholarly journals Oxidative stress inducing agents’ copper and alloxan accelerate cell cycle re-entering of somatic plant cells in the presence of suboptimal exogenous auxin

2020 ◽  
Author(s):  
Taras Pasternak
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Cellular Response ◽  
Plant Cells ◽  
Cellular Reprogramming ◽  
Physiological Status ◽  
Ros Scavenging ◽  
Exogenous Auxin ◽  
Cell State ◽  
Auxin Concentration

AbstractThe physiological status of differentiated somatic plant cells and kinetics of re-entering in cell cycle were investigated in the case of Medicago sativa leaf protoplasts after the application of oxidative stress-inducing agents. Excess copper (30 μM) and alloxan (0.5 mM) accelerated cell cycle re-entry at an exogenous auxin concentration that alone was insufficient to induce cell activation. Application of stress-inducing agents accelerated changes in the nuclei landscape with further faster re-entry in DNA replication and cytokinesis. This acceleration was accompanied by a lower level of reactive oxygen species (ROS) accumulations. At later stages, stress-agents treated cells resemble stem cells in planta with a smaller size, higher cell viability, lower ROS level, and lower activities of major ROS scavenging enzymes. A similar cellular response could be achieved by increasing the exogenous auxin concentration. Based on these experimental results, it is suggested that sub-lethal stress treatments evoke a transient cell state that accelerates cellular reprogramming. We also speculate that this transient cell state serves as an effective mechanism for protection against oxidative stress.

scholarly journals NRF2 preserves genomic integrity by facilitating ATR activation and G2 cell cycle arrest

2020 ◽  
Vol 48 (16) ◽  
pp. 9109-9123 ◽  
Author(s):  
Xiaohui Sun ◽  
Yan Wang ◽  
Kaihua Ji ◽  
Yang Liu ◽  
Yangyang Kong ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Dna Damage ◽  
Cell Cycle Arrest ◽  
Cellular Response ◽  
Genome Stability ◽  
Related Factor ◽  
Dna Double Strand Breaks ◽  
Ros Scavenging ◽  
Cycle Arrest ◽  
G2 Cell Cycle Arrest

Abstract Nuclear factor erythroid 2-related factor 2 (NRF2) is a well-characterized transcription factor that protects cells against oxidative and electrophilic stresses. Emerging evidence has suggested that NRF2 protects cells against DNA damage by mechanisms other than antioxidation, yet the mechanism remains poorly understood. Here, we demonstrate that knockout of NRF2 in cells results in hypersensitivity to ionizing radiation (IR) in the presence or absence of reactive oxygen species (ROS). Under ROS scavenging conditions, induction of DNA double-strand breaks (DSBs) increases the NRF2 protein level and recruits NRF2 to DNA damage sites where it interacts with ATR, resulting in activation of the ATR–CHK1–CDC2 signaling pathway. In turn, this leads to G2 cell cycle arrest and the promotion of homologous recombination repair of DSBs, thereby preserving genome stability. The inhibition of NRF2 by brusatol increased the radiosensitivity of tumor cells in xenografts by perturbing ATR and CHK1 activation. Collectively, our results reveal a novel function of NRF2 as an ATR activator in the regulation of the cellular response to DSBs. This shift in perspective should help furnish a more complete understanding of the function of NRF2 and the DNA damage response.

Known Hepatoprotectors Act as Antioxidants and Immune Stimulators in Stressed Mice: Perspectives in Animal Health Care

2019 ◽  
Vol 24 (40) ◽  
pp. 4825-4837 ◽  
Author(s):  
Gustavo Alberto de la Riva ◽  
Francisco Javier López Mendoza ◽  
Guillermin Agüero-Chapin
Keyword(s):  
Oxidative Stress ◽  
Animal Health ◽  
Cellular Damage ◽  
Farm Animals ◽  
Physiological Status ◽  
Stress Markers ◽  
Glutathione Peroxidases ◽  
Transport Chain ◽  
Exogenous Compounds ◽  
Relationship Of

Background: Oxygen is involved in a variety of physiological reactions in aerobic organisms, such as those produced in the electron transport chain, hydroxylation, and oxygenation. Reactive oxygen species (ROS) are naturally formed as byproducts from these previously reactions involving the O2 molecule; they are made up of superoxide anion (O2−), hydroxyl radical (HO−), hydrogen peroxide (H2O2), nitric oxide (NO), peroxyl (ROO−), and reactive aldehyde (ROCH). Under certain environmental stress conditions, ROS are accumulated causing cellular damage but also triggering the overexpression of several enzyme classes such as superoxide dismutases (SOD), catalases (CAT) and glutathione peroxidases (GPx), which represent an important intrinsic antioxidant defence line. Liver is a key organ in vertebrates including farm animals and human. The oxidative stress plays an important role in systemic malfunctions including hepatic, renal and immunological, disorders. Methods: This review presents a brief update about the relationship of oxidative stress with hepatic, renal and immunological malfunctions in stressed organisms. Cellular and exogenous hepatoprotective compounds share also the ability to scavenge ROS acting as antioxidants and in many cases as stimulators of immune response in stressed organisms. We present the effect of some hepatoprotectors on the hepatic, renal and immunological function in stressed mice by the jointed evaluation of biological and oxidative stress markers. Conclusion: Hepatoprotective effect of several exogenous compounds is very associated with their antioxidant capacity. This fact is relevant for keeping oxidant/antioxidant balance in the respective organs, but also for maintaining the physiological status of the whole organism.

Hydrogen peroxide and quercetin induced changes on cell viability, apoptosis and oxidative stress in HepG2 cells

2020 ◽  
Vol 01 ◽  
Author(s):  
Ayşe Mine Yılmaz ◽  
Gökhan Biçim ◽  
Kübra Toprak ◽  
Betül Karademir Yılmaz ◽  
Irina Milisav ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Hydrogen Peroxide ◽  
Cell Viability ◽  
Hepg2 Cells ◽  
Proteasome Activity ◽  
Cell Cycle Phases ◽  
Induced Changes ◽  
And Oxidative Stress ◽  
Quercetin Treatment

Background: Different cellular responses influence the progress of cancer. In this study, we have investigated the effect of hydrogen peroxide and quercetin induced changes on cell viability, apoptosis and oxidative stress in human hepatocellular carcinoma (HepG2) cells. Methods: The effects of hydrogen peroxide and quercetin on cell viability, cell cycle phases and oxidative stress related cellular changes were investigated. Cell viability was assessed by WST-1 assay. Apoptosis rate, cell cycle phase changes and oxidative stress were measured by flow cytometry. Protein expressions of p21, p27, p53, NF-Kβ-p50 and proteasome activity were determined by Western blot and fluorometry, respectively. Results: Hydrogen peroxide and quercetin treatment resulted in decreased cell viability and increased apoptosis in HepG2 cells. Proteasome activity was increased by hydrogen peroxide but decreased by quercetin treatment. Conclusion: Both agents resulted in decreased p53 protein expression and increased cell death by different mechanisms regarding proteostasis and cell cycle phases.

Dual effect of oxidized LDL on cell cycle in human endothelial cells through oxidative stress

2001 ◽  
Vol 59 (s78) ◽  
pp. 120-123 ◽  
Author(s):  
Jan Galle ◽  
Alexandra Heinloth ◽  
Christoph Wanner ◽  
Kathrin Heermeier
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Endothelial Cells ◽  
Oxidized Ldl ◽  
Human Endothelial Cells ◽  
Dual Effect

scholarly journals Genetic variants and cognitive functions in patients with brain tumors

2019 ◽  
Vol 21 (10) ◽  
pp. 1297-1309 ◽  
Author(s):  
Denise D Correa ◽  
Jaya Satagopan ◽  
Axel Martin ◽  
Erica Braun ◽  
Maria Kryza-Lacombe ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Dna Repair ◽  
Brain Tumor ◽  
Brain Tumors ◽  
Cell Cycle Regulation ◽  
Cognitive Outcome ◽  
Cholesterol Transport ◽  
Tumor Patients ◽  
Cycle Regulation

AbstractBackgroundPatients with brain tumors treated with radiotherapy (RT) and chemotherapy (CT) often experience cognitive dysfunction. We reported that single nucleotide polymorphisms (SNPs) in the APOE, COMT, and BDNF genes may influence cognition in brain tumor patients. In this study, we assessed whether genes associated with late-onset Alzheimer’s disease (LOAD), inflammation, cholesterol transport, dopamine and myelin regulation, and DNA repair may influence cognitive outcome in this population.MethodsOne hundred and fifty brain tumor patients treated with RT ± CT or CT alone completed a neurocognitive assessment and provided a blood sample for genotyping. We genotyped genes/SNPs in these pathways: (i) LOAD risk/inflammation/cholesterol transport, (ii) dopamine regulation, (iii) myelin regulation, (iv) DNA repair, (v) blood–brain barrier disruption, (vi) cell cycle regulation, and (vii) response to oxidative stress. White matter (WM) abnormalities were rated on brain MRIs.ResultsMultivariable linear regression analysis with Bayesian shrinkage estimation of SNP effects, adjusting for relevant demographic, disease, and treatment variables, indicated strong associations (posterior association summary [PAS] ≥ 0.95) among tests of attention, executive functions, and memory and 33 SNPs in genes involved in: LOAD/inflammation/cholesterol transport (eg, PDE7A, IL-6), dopamine regulation (eg, DRD1, COMT), myelin repair (eg, TCF4), DNA repair (eg, RAD51), cell cycle regulation (eg, SESN1), and response to oxidative stress (eg, GSTP1). The SNPs were not significantly associated with WM abnormalities.ConclusionThis novel study suggests that polymorphisms in genes involved in aging and inflammation, dopamine, myelin and cell cycle regulation, and DNA repair and response to oxidative stress may be associated with cognitive outcome in patients with brain tumors.

scholarly journals Cellular Response against Oxidative Stress, a Novel Insight into Lupus Nephritis Pathogenesis

2021 ◽  
Vol 11 (8) ◽  
pp. 693
Author(s):  
Corina Daniela Ene ◽  
Simona Roxana Georgescu ◽  
Mircea Tampa ◽  
Clara Matei ◽  
Cristina Iulia Mitran ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lupus Nephritis ◽  
Cellular Response ◽  
Molecular Mechanisms ◽  
Control Group ◽  
Dna Repair Mechanisms ◽  
Glycation End Products ◽  
Repair Mechanisms ◽  
Low Levels ◽  
Defective Dna Repair

The interaction of reactive oxygen species (ROS) with lipids, proteins, nucleic acids and hydrocarbonates promotes acute and chronic tissue damage, mediates immunomodulation and triggers autoimmunity in systemic lupus erythematous (SLE) patients. The aim of the study was to determine the pathophysiological mechanisms of the oxidative stress-related damage and molecular mechanisms to counteract oxidative stimuli in lupus nephritis. Our study included 38 SLE patients with lupus nephritis (LN group), 44 SLE patients without renal impairment (non-LN group) and 40 healthy volunteers as control group. In the present paper, we evaluated serum lipid peroxidation, DNA oxidation, oxidized proteins, carbohydrate oxidation, and endogenous protective systems. We detected defective DNA repair mechanisms via 8-oxoguanine-DNA-glycosylase (OGG1), the reduced regulatory effect of soluble receptor for advanced glycation end products (sRAGE) in the activation of AGE-RAGE axis, low levels of thiols, disulphide bonds formation and high nitrotyrosination in lupus nephritis. All these data help us to identify more molecular mechanisms to counteract oxidative stress in LN that could permit a more precise assessment of disease prognosis, as well as developing new therapeutic targets.

scholarly journals THU0495 NOVEL UNDERSTANDING OF THE PATHOGENESIS OF JUVENILE IDIOPATHIC ARTHRITIS: FOCUS ON MESENCHYMAL STEM CELLS IMPAIRMENT, SENESCENCE AND IMMUNOREGULATORY FUNCTION

2020 ◽  
Vol 79 (Suppl 1) ◽  
pp. 483.2-484
Author(s):  
L. Zaripova ◽  
A. Midgley ◽  
S. Christmas ◽  
E. Baildam ◽  
R. Oldershaw
Keyword(s):  
Oxidative Stress ◽  
Cell Cycle ◽  
Stem Cells ◽  
Cell Proliferation ◽  
Mesenchymal Stem Cells ◽  
Juvenile Idiopathic Arthritis ◽  
Metabolic Activity ◽  
Healthy Controls ◽  
High Level ◽  
Pro Inflammatory Cytokines

Background:Juvenile idiopathic arthritis (JIA) is a well-known chronic rheumatic disease of childhood characterised by progressive joint destruction and severe systemic complications.Immune cells are known to trigger the pathophysiological cascade in JIA, but there is little information regarding the contribution made by Mesenchymal stem cells (MSCs). These cells are able to modulate the immune response and decrease the level of pro-inflammatory cytokines. With addition of regenerative property it makes MSCs potential candidates for clinical application as immunosuppressants in treatment of autoimmune diseases.Objectives:To investigate MSCs proliferation, viability and immunomodulatory function in JIA and healthy children.Methods:MSCs were separated from peripheral blood (PB) and synovial fluid (SF) of JIA patients and healthy controls. Cell proliferation rate was counted by Population doublings per day (PDD) during 9 days, in the last of which alamarBlue™ assays were performed to assess cell viability. Due to measure senescence MSCs were stained with SA-β-galactosidase. Immunofluorescence was used to examine the expression of p16, p21, p53. Oxidative stress was measured with DCFH-DA. Cell cycle analysis was evaluated with Propidium Iodide and analysed by Accuri® C6 Flow Cytometer.Commercially-available bone marrow mesenchymal stem cells (BM-MSCs) were treated with graded concentrations of pro-inflammatory cytokines (0.1-100 ng/ml) with following examination of cell viability. Mixed lymphocyte reactions (MLR) were performed to measure MSC immunomodulatory abilityin vitro.Results:The growth kinetics of JIA-MSCs were different from healthy controls. JIA-MSCs divided slowly and appeared disorganised with large cytoplasm and loads of outgrowth. They demonstrated a decrease in cell proliferation (negative PDD) and metabolic activity. Difference in growth kinetics and metabolic activity were found inside the JIA PB group with some evidence of response following biological treatment. Thus, PB-MSCs from patients treated with TNFi and anti-IL6 medications had notably higher cell proliferation and metabolic activity against JIA patients received other therapy. Considering this difference, it was hypothesised that cytokines obtained in a high amount in PB and SF of JIA patients may influence MSCs viability. To prove this BM-MSCs were treated with cytokines and demonstrated a dose-dependent decrease in metabolic activity significantly after TNFα and IL1, no significantly after treatment with IL6. Both BM-MSCs treated with cytokines and JIA-MSCs displayed high level of reactive oxygen species.Cell cycle analysis revealed that JIA-MSCs were arrested in G0/G1 phase with low number of mitotic cells. In addition, the number of senescence-associated SA-β-gal-positive cells was notably higher in JIA-MSCs. Furthermore, JIA-MSCs expressed high level of immunofluorescence for p16, p21 and p53 which played an important role in regulating the senescence progress of MSCs.Results of MLR showed the ability of BM-MSCs to decrease the percentage of activated T-helpers, T-suppressors, B-cells and natural killers proliferation, while JIA-MSCs lost this property.Conclusion:Taken together current research has demonstrated that under the influence of proinflammatory cytokines JIA-MSCs suffered from oxidative stress and disruption of metabolic activity acquire senescent morphology, shorten of telomere length, arrest in G0 phase of cell cycle and finally loss of immune regulation. We are continuing our research to determine the mechanisms that are responsible for the impaired phenotype with the aim of identifying new therapeutic strategies for the treatment of JIA.Disclosure of Interests: :None declared

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