scholarly journals Nitric Oxide Enhances Cytotoxicity of Lead by Modulating the Generation of Reactive Oxygen Species and Is Involved in the Regulation of Pb2+ and Ca2+ Fluxes in Tobacco BY-2 Cells

Plants ◽  
2019 ◽  
Vol 8 (10) ◽  
pp. 403 ◽  
Author(s):  
Jiaye Wu ◽  
Yue Zhang ◽  
Ruizhi Hao ◽  
Yuan Cao ◽  
Xiaoyi Shan ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Heavy Metal ◽  
Cell Death ◽  
Calcium Homeostasis ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Plant Responses ◽  
Oxygen Species ◽  
In Cells

Lead is a heavy metal known to be toxic to both animals and plants. Nitric oxide (NO) was reported to participate in plant responses to different heavy metal stresses. In this study, we analyzed the function of exogenous and endogenous NO in Pb-induced toxicity in tobacco BY-2 cells, focusing on the role of NO in the generation of reactive oxygen species (ROS) as well as Pb2+ and Ca2+ fluxes using non-invasive micro-test technology (NMT). Pb treatment induced BY-2 cell death and rapid NO and ROS generation, while NO burst occurred earlier than ROS accumulation. The elimination of NO by 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) resulted in a decrease of ROS, and the supplementation of NO by sodium nitroprusside (SNP) caused an increased accumulation of ROS. Furthermore, the addition of exogenous NO stimulated Pb2+ influx, thus promoting Pb uptake in cells and aggravating Pb-induced toxicity in cells, whereas the removal of endogenous NO produced the opposite effect. Moreover, we also found that both exogenous and endogenous NO enhanced Pb-induced Ca2+ effluxes and calcium homeostasis disorder. These results suggest that exogenous and endogenous NO played a critical regulatory role in BY-2 cell death induced by Pb stress by promoting Pb2+ influx and accumulation and disturbing calcium homeostasis.

scholarly journals CBIO-07. CELL DEATH INDUCED BY AN OSCILLATING MAGNETIC FIELD IN PATIENT DERIVED GLIOBLASTOMA CELLS IS MEDIATED BY REACTIVE OXYGEN SPECIES

2020 ◽  
Vol 22 (Supplement_2) ◽  
pp. ii17-ii17
Author(s):  
Shashank Hambarde ◽  
Martyn Sharpe ◽  
David Baskin ◽  
Santosh Helekar
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Cell Viability ◽  
Cortical Neurons ◽  
Reactive Oxygen ◽  
Great Promise ◽  
Antioxidant Vitamin ◽  
Ros Generation ◽  
Oxygen Species ◽  
Novel Therapy

Abstract Noninvasive cancer therapy with minimal side effects would be ideal for improving patient outcome in the clinic. We have developed a novel therapy using strong rotating magnets mounted on a helmet. They generate oscillating magnetic fields (OMF) that penetrate through the skull and cover the entire brain. We have demonstrated that OMF can effectively kill patient derived glioblastoma (GBM) cells in cell culture without having cytotoxic effects on cortical neurons and normal human astrocytes (NHA). Exposure of GBM cells to OMF reduced the cell viability by 33% in comparison to sham-treated cells (p< 0.001), while not affecting NHA cell viability. Time lapse video-microscopy for 16 h after OMF exposure showed a marked elevation of mitochondrial reactive oxygen species (ROS), and rapid apoptosis of GBM cells due to activation of caspase 3. Addition of a potent antioxidant vitamin E analog Trolox effectively blocked OMF-induced GBM cell death. Furthermore, OMF significantly potentiated the cytotoxic effect of the pro-oxidant Benzylamine. The results of our studies demonstrate that OMF-induced cell death is mediated by ROS generation. These results demonstrate a potent oncolytic effect on GBM cells that is novel and unrelated to any previously described therapy, including a very different mechanism of action and different technology compared to Optune therapy. The effect is very powerful, and unlike Optune, can be seen within hours after initiation of treatment. We believe that this technology holds great promise for new, effective and nontoxic treatment of glioblastoma.

scholarly journals The role of reactive oxygen species and nitric oxide in programmed cell death associated with self-incompatibility

2015 ◽  
Vol 66 (10) ◽  
pp. 2869-2876 ◽  
Author(s):  
Irene Serrano ◽  
María C. Romero-Puertas ◽  
Luisa M. Sandalio ◽  
Adela Olmedilla
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Cell Death ◽  
Programmed Cell Death ◽  
Reactive Oxygen ◽  
Oxygen Species ◽  
Self Incompatibility

z-VAD-fmk augmentation of TNFα-stimulated neutrophil apoptosis is compound specific and does not involve the generation of reactive oxygen species

Blood ◽  
2005 ◽  
Vol 105 (7) ◽  
pp. 2970-2972 ◽  
Author(s):  
Andrew S. Cowburn ◽  
Jessica F. White ◽  
John Deighton ◽  
Sarah R. Walmsley ◽  
Edwin R. Chilvers
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Broad Spectrum ◽  
Reactive Oxygen ◽  
Cell Types ◽  
Ros Generation ◽  
Neutrophil Apoptosis ◽  
Oxygen Species ◽  
Caspase Inhibitor ◽  
Induced Apoptosis

Abstract In most cell types constitutive and ligand-induced apoptosis is a caspase-dependent process. In neutrophils, however, the broad-spectrum caspase inhibitor z-VAD-fmk enhances tumor necrosis factor-α (TNFα)-induced cell death, and this has been interpreted as evidence for caspase-dependent and -independent cell death pathways. Our aim was to determine the specificity of the effect of z-VAD-fmk in neutrophils and define the potential mechanism of action. While confirming that z-VAD-fmk (> 100 μM) enhances TNFα-induced neutrophil apoptosis, lower concentrations (1-30 μM) completely blocked TNFα-stimulated apoptosis. Boc-D-fmk, a similar broad-spectrum caspase inhibitor, and z-IETD-fmk, a selective caspase-8 inhibitor, caused a concentration-dependent inhibition of only TNFα-stimulated apoptosis. Moreover, the caspase-9 inhibitor, Ac-LEHD-cmk, had no effect on TNFα-induced apoptosis, and z-VAD-fmk and Boc-D-fmk inhibited TNFα-stimulated reactive oxygen species (ROS) generation. These data suggest that TNFα-induced apoptosis in neutrophils is fully caspase dependent and uses a mitochondrial-independent pathway and that the proapoptotic effects of z-VAD-fmk are compound specific and ROS independent.

Mechanical traumatic injury without circulatory shock causes cardiomyocyte apoptosis: role of reactive nitrogen and reactive oxygen species

2005 ◽  
Vol 288 (6) ◽  
pp. H2811-H2818 ◽  
Author(s):  
Ling Tao ◽  
Hui-Rong Liu ◽  
Feng Gao ◽  
Yan Qu ◽  
Theodore A. Christopher ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Reactive Oxygen Species ◽  
Cell Death ◽  
Cardiac Dysfunction ◽  
Traumatic Injury ◽  
Reactive Oxygen ◽  
Cardiomyocyte Apoptosis ◽  
Reactive Nitrogen ◽  
Oxygen Species ◽  
Nitrogen Species

Apoptotic cell death plays a critical role in tissue injury and organ dysfunction under a variety of pathological conditions. The present study was designed to determine whether apoptosis may contribute to posttraumatic cardiac dysfunction, and if so, to investigate the mechanisms involved. Male adult mice were subjected to nonlethal traumatic injury, and cardiomyocyte apoptosis, cardiac function, and cardiac production of reactive oxygen/nitrogen species were determined. Modified Noble-Collip drum trauma did not result in circulatory shock, and the 24-h survival rate was 100%. No direct mechanical traumatic injury was observed in the heart immediately after trauma. However, cardiomyocyte apoptosis gradually increased and reached a maximal level 12 h after trauma. Significantly, cardiac dysfunction was observed 24 h after trauma in the isolated perfused heart. This was completely reversed when apoptosis was blocked by administration of a nonselective caspase inhibitor immediately after trauma. In the traumatized hearts, reactive nitrogen species (e.g., nitric oxide) and reactive oxygen species (e.g., superoxide) were both significantly increased, and maximal nitric oxide production preceded maximal apoptosis. Moreover, a highly cytotoxic reactive species, peroxynitrite, was markedly increased in the traumatic heart, and there was a significant positive correlation between cardiac nitrotyrosine content and caspase 3 activity. Our present study demonstrated for the first time that nonlethal traumatic injury caused delayed cell death and that apoptotic cardiomyocyte death contributes to posttrauma organ dysfunction. Antiapoptotic treatments, such as blockade of reactive nitrogen oxygen species generation, may be novel strategies in reducing posttrauma multiple organ failure.

scholarly journals Insulin-Induced Generation of Reactive Oxygen Species and Uncoupling of Nitric Oxide Synthase Underlie the Cerebrovascular Insulin Resistance in Obese Rats

2012 ◽  
Vol 32 (5) ◽  
pp. 792-804 ◽  
Author(s):  
Prasad VG Katakam ◽  
James A Snipes ◽  
Mesia M Steed ◽  
David W Busija
Keyword(s):  
Nitric Oxide ◽  
Insulin Resistance ◽  
Reactive Oxygen Species ◽  
Nitric Oxide Synthase ◽  
Cerebral Arteries ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Oxygen Species ◽  
Fluorescence Studies ◽  
Oxide Synthase

Hyperinsulinemia accompanying insulin resistance (IR) is an independent risk factor for stroke. The objective is to examine the cerebrovascular actions of insulin in Zucker obese (ZO) rats with IR and Zucker lean (ZL) control rats. Diameter measurements of cerebral arteries showed diminished insulin-induced vasodilation in ZO compared with ZL. Endothelial denudation revealed vasoconstriction to insulin that was greater in ZO compared with ZL. Nonspecific inhibition of nitric oxide synthase (NOS) paradoxically improved vasodilation in ZO. Scavenging of reactive oxygen species (ROS), supplementation of tetrahydrobiopterin (BH4) precursor, and inhibition of neuronal NOS or NADPH oxidase or cyclooxygenase (COX) improved insulin-induced vasodilation in ZO. Immunoblot experiments revealed that insulin-induced phosphorylation of Akt, endothelial NOS, and expression of GTP cyclohydrolase-I (GTP-CH) were diminished, but phosphorylation of PKC and ERK was enhanced in ZO arteries. Fluorescence studies showed increased ROS in ZO arteries in response to insulin that was sensitive to NOS inhibition and BH4 supplementation. Thus, a vicious cycle of abnormal insulin-induced ROS generation instigating NOS uncoupling leading to further ROS production underlies the cerebrovascular IR in ZO rats. In addition, decreased bioavailability and impaired synthesis of BH4 by GTP-CH induced by insulin promoted NOS uncoupling.

scholarly journals The Neuro-Protective Effects of the TSPO Ligands CB86 and CB204 on 6-OHDA-Induced PC12 Cell Death as an In Vitro Model for Parkinson’s Disease

Biology ◽  
2021 ◽  
Vol 10 (11) ◽  
pp. 1183
Author(s):  
Sheelu Monga ◽  
Nunzio Denora ◽  
Valentino Laquintana ◽  
Rami Yashaev ◽  
Abraham Weizman ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Parkinson’S Disease ◽  
Parkinson's Disease ◽  
Cell Death ◽  
Neurodegenerative Disorder ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Oxygen Species ◽  
The Impact

Parkinson’s disease (PD) is a progressive neurodegenerative disorder which is characterized by the degeneration of dopaminergic neurons in substantia nigra (SN). Oxidative stress or reactive oxygen species (ROS) generation was suggested to play a role in this specific type of neurodegeneration. Therapeutic options which can target and counteract ROS generation may be of benefit. TSPO ligands are known to counteract with neuro-inflammation, ROS generation, apoptosis, and necrosis. In the current study, we investigated an in vitro cellular PD model by the assessment of 6-hydroxydopamine (6-OHDA, 80 µM)-induced PC12 neurotoxicity. Simultaneously to the exposure of the cells to 6-OHDA, we added the TSPO ligands CB86 and CB204 (25 µM each) and assessed the impact on several markers of cell death. The two ligands normalized significantly (57% and 52% respectively, from 44%; whereas the control was 68%) cell proliferation at different time points from 0–24 h. Additionally, we evaluated the effect of these two TSPO ligands on necrosis using propidium iodide (PI) staining and found that the ligands inhibited significantly the 6-OHDA-induced necrosis. As compared to control, the red count was increased up to 57-fold whereas CB86 and CB204 inhibited to 2.7-fold and 3.2-fold respectively. Necrosis was also analyzed by LDH assay which showed significant effect. Both assays demonstrated similar potent anti-necrotic effect of the two TSPO ligands. Reactive oxygen species (ROS) generation induced by 6-OHDA was also inhibited by the two TSPO ligand up to 1.3 and 1.5-fold respectively, as compared to 6-OHDA group. CB86 and CB204 inhibited also normalized the cell viability up to 1.8-fold after the exposure to 6-OHDA, as assessed by XTT assay. The two TSPO ligands also inhibited apoptosis significantly (1.3-fold for both) as assessed by apopxin green staining. In summary, it appears that the two TSPO ligands CB86 and CB204 can suppress cell death of PC12 induced by 6-OHDA. The results may be relevant to the use of these two TSPO ligands as therapeutic option neurodegenerative diseases like PD.

scholarly journals Bufalin Induces Reactive Oxygen Species Dependent Bax Translocation and Apoptosis in ASTC-a-1 Cells

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Lei Sun ◽  
Tongsheng Chen ◽  
Xiaoping Wang ◽  
Yun Chen ◽  
Xunbin Wei
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
Molecular Mechanisms ◽  
Caspase 3 ◽  
Temporal Dynamics ◽  
Reactive Oxygen ◽  
Ros Generation ◽  
Ros Production ◽  
Oxygen Species ◽  
Induced Apoptosis

Bufalin has been shown to induce cancer cell death through apoptotic pathways. However, the molecular mechanisms are not well understood. In this study, we used the confocal fluorescence microscopy (CFM) to monitor the spatio-temporal dynamics of reactive oxygen species (ROS) production, Bax translocation and caspase-3 activation during bufalin-induced apoptosis in living human lung adenocarcinoma (ASTC-a-1) cells. Bufalin induced ROS production and apoptotic cell death, demonstrated by Hoechst 33258 staining as well as flow cytometry analysis. Bax redistributed from cytosol to mitochondria from 12 to 48 h after bufalin treatment in living cells expressed with green fluorescent protein Bax. Treatment with the antioxidantN-acetyl-cysteine (NAC), a ROS scavenger, inhibited ROS generation and Bax translocation and led to a significant protection against bufalin-induced apoptosis. Our results also revealed that bufalin induced a prominent increase of caspase-3 activation blocked potently by NAC. Taken together, bufalin induced ROS-mediated Bax translocation, mitochondrial permeability transition and caspase-3 activation, implying that bufalin induced apoptosis via ROS-dependent mitochondrial death pathway in ASTC-a-1 cells.

Complement-mediated cell death induced by rituximab in B-cell lymphoproliferative disorders is mediated in vitro by a caspase-independent mechanism involving the generation of reactive oxygen species

Blood ◽  
2001 ◽  
Vol 98 (9) ◽  
pp. 2771-2777 ◽  
Author(s):  
Beatriz Bellosillo ◽  
Neus Villamor ◽  
Armando López-Guillermo ◽  
Silvia Marcé ◽  
Jordi Esteve ◽  
...  
Keyword(s):  
Reactive Oxygen Species ◽  
Cell Death ◽  
B Cell ◽  
Cytotoxic Effect ◽  
Reactive Oxygen ◽  
Lymphoproliferative Disorders ◽  
Oxygen Species ◽  
Independent Mechanism ◽  
In Cells

Abstract Mechanisms involving the in vitro effect of rituximab in cells from 55 patients with B-cell lymphoproliferative disorders were investigated. No cytotoxic effect was observed when cells were incubated with rituximab alone, but in the presence of human AB serum rituximab induced complement-dependent cell death (R-CDC). A cytotoxic effect was observed in cells from 9 of 33 patients with B-cell chronic lymphocytic leukemia, 16 of 16 patients with mantle-cell lymphoma, 4 of 4 patients with follicular lymphoma, and 2 of 2 patients with hairy-cell leukemia. R-CDC was observed in cells from patients expressing more than 50 × 103 CD20 molecules per cell, and directly correlated with the number of CD20 molecules per cell. Preincubation with anti-CD59 increased the cytotoxic effect of rituximab and sensitized cells from nonsensitive cases. Neither cleavage of poly-ADP ribose polymerase (PARP) nor activation of caspase-3 was observed in R-CDC. In addition, no cells with a hypodiploid DNA content were detected and R-CDC was not prevented by a broad-spectrum caspase inhibitor, suggesting a caspase-independent mechanism. Incubation with rituximab in the presence of AB serum induced a rapid and intense production of reactive oxygen species (ROS). R-CDC was blocked by the incubation of cells with N-acetyl-L-cysteine (NAC) or Tiron, 2 ROS scavengers, indicating that the cytotoxic effect was due to the generation of superoxide (O2−) radicals. In conclusion, the results of the present study suggest that CD20, CD59, and complement have a role in the in vitro cytotoxic effect of rituximab, which is mediated by a caspase-independent process that involves ROS generation.

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