scholarly journals Nitric oxides mediates a shift from early necrosis to late apoptosis in cytokine-treated β-cells that is associated with irreversible DNA damage

2009 ◽  
Vol 297 (5) ◽  
pp. E1187-E1196 ◽  
Author(s):  
Katherine J. Hughes ◽  
Kari T. Chambers ◽  
Gordon P. Meares ◽  
John A. Corbett
Keyword(s):  
Nitric Oxide ◽  
Dna Damage ◽  
Cell Death ◽  
Caspase 3 ◽  
Cell Types ◽  
Caspase Activity ◽  
Nitric Oxides ◽  
Β Cells ◽  
Caspase Cleavage ◽  
Endogenous Nitric Oxide

For many cell types, including pancreatic β-cells, nitric oxide is a mediator of cell death; however, it is paradoxical that for a given cell type nitric oxide can induce both necrosis and apoptosis. This report tests the hypothesis that cell death mediated by nitric oxide shifts from an early necrotic to a late apoptotic event. Central to this transition is the ability of β-cells to respond and repair nitric oxide-mediated damage. β-Cells have the ability to repair DNA that is damaged following 24-h incubation with IL-1; however, cytokine-induced DNA damage becomes irreversible following 36-h incubation. This irreversible DNA damage following 36-h incubation with IL-1 correlates with the activation of caspase-3 (cleavage and activity). The increase in caspase activity correlates with reductions in endogenous nitric oxide production, as nitric oxide is an inhibitor of caspase activity. In contrast, caspase cleavage or activation is not observed under conditions in which β-cells are capable of repairing damaged DNA (24-h incubation with cytokines). These findings provide evidence that β-cell death in response to cytokines shifts from an early necrotic process to apoptosis and that this shift is associated with irreversible DNA damage and caspase-3 activation.

scholarly journals Nitric Oxide Inhibits Caspase Activation and Apoptotic Morphology but Does Not Rescue Neuronal Death

2005 ◽  
Vol 25 (3) ◽  
pp. 348-357 ◽  
Author(s):  
Ping Zhou ◽  
Liping Qian ◽  
Costantino Iadecola
Keyword(s):  
Nitric Oxide ◽  
Cell Death ◽  
Cell Viability ◽  
Cell Survival ◽  
Caspase 3 ◽  
Apoptotic Cell ◽  
Cysteine Residue ◽  
Caspase Activity ◽  
No Donors ◽  
Apoptotic Morphology

Nitric oxide (NO) has been shown to inhibit apoptotic cell death by S-nitrosylation of the catalytic-site cysteine residue of caspases. However, it is not clear whether in neurons NO-mediated caspase inactivation leads to improved cell survival. To address this issue, we studied the effect of NO donors on caspase activity and cell survival in cortical neuronal culture treated with the apoptosis inducer staurosporine (STS) and camptothecin. In parallel, cell viability was assessed by the MTS assay and MAP2 staining. We found that NO donors ((±)- S-nitroso- N-acetylpenicillamine, S-nitrosoglutathione, and NONOates) dose-dependently inhibited caspase-3 and -9 activity induced by STS and camptothecin. The reduction in caspase-3 activity was, in large part, because of the blockage of the proteolytic conversion of pro-caspase-3 to active caspase-3. NO donors also inhibited the appearance of the classical apoptotic nuclear morphology. However, inhibition of both caspase activity and apoptotic morphology was not associated with enhancement of cell viability. Thus, inhibition of caspase and apoptotic morphology by NO donors does not improve neuronal survival. The data suggest that inhibition of caspase by NO unmasks a caspase-independent form of cell death. A better understanding of this form of cell death may provide new strategies for neuroprotection in neuropathologies, such as ischemic brain injury, associated with apoptosis.

scholarly journals Differential responses of pancreatic β-cells to ROS and RNS

2013 ◽  
Vol 304 (6) ◽  
pp. E614-E622 ◽  
Author(s):  
Gordon P. Meares ◽  
Dominique Fontanilla ◽  
Katarzyna A. Broniowska ◽  
Teresa Andreone ◽  
Jack R. Lancaster ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Dna Damage ◽  
Cell Death ◽  
Cell Viability ◽  
Cell Fate ◽  
Β Cells ◽  
Pancreatic Β Cells ◽  
Unfolded Protein ◽  
Heat Shock Responses ◽  
Reduce Cell Viability

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) direct the activation of distinct signaling pathways that determine cell fate. In this study, the pathways activated and the mechanisms by which ROS and RNS control the viability of pancreatic β-cells were examined. Although both nitric oxide and hydrogen peroxide (H2O2) induce DNA damage, reduce cell viability, and activate AMPK, the mechanisms of AMPK activation and cell death induction differ between each reactive species. Nitric oxide activates the unfolded protein and heat shock responses and MAPK kinase signaling, whereas H2O2 stimulates p53 stabilization and poly(ADP-ribose) polymerase (PARP) activation but fails to induce the unfolded protein or heat shock responses or MAPK activation. The control of cell fate decisions is selective for the form of stress. H2O2-mediated reduction in β-cell viability is controlled by PARP, whereas cell death in response to nitric oxide is PARP independent but associated with the nuclear localization of GAPDH. These findings show that both ROS and RNS activate AMPK, induce DNA damage, and reduce cell viability; however, the pathways controlling the responses of β-cells are selective for the type of reactive species.

The regulation of oxidative metabolism by nitric oxide protects β-cells from DNA damage-induced cell death

2018 ◽  
Vol 128 ◽  
pp. S96
Author(s):  
Chay Teng Yeo ◽  
Bryndon Oleson ◽  
Katarzyna Broniowska ◽  
Aaron Naatz ◽  
Jamie Schnuck ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Dna Damage ◽  
Cell Death ◽  
Oxidative Metabolism ◽  
Β Cells

DNA damage-induced neural precursor cell apoptosis requires p53 and caspase 9 but neither Bax nor caspase 3

Development ◽  
2001 ◽  
Vol 128 (1) ◽  
pp. 137-146
Author(s):  
C. D'Sa-Eipper ◽  
J.R. Leonard ◽  
G. Putcha ◽  
T.S. Zheng ◽  
R.A. Flavell ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Cell Apoptosis ◽  
Neuronal Apoptosis ◽  
Caspase 3 ◽  
Precursor Cell ◽  
Neural Precursor ◽  
Normal Brain ◽  
Neural Precursor Cell ◽  
Caspase 9

Programmed cell death (apoptosis) is critical for normal brain morphogenesis and may be triggered by neurotrophic factor deprivation or irreparable DNA damage. Members of the Bcl2 and caspase families regulate neuronal responsiveness to trophic factor withdrawal; however, their involvement in DNA damage-induced neuronal apoptosis is less clear. To define the molecular pathway regulating DNA damage-induced neural precursor cell apoptosis, we have examined the effects of drug and gamma-irradiation-induced DNA damage on telencephalic neural precursor cells derived from wild-type embryos and mice with targeted disruptions of apoptosis-associated genes. We found that DNA damage-induced neural precursor cell apoptosis, both in vitro and in vivo, was critically dependent on p53 and caspase 9, but neither Bax nor caspase 3 expression. Neural precursor cell apoptosis was also unaffected by targeted disruptions of Bclx and Bcl2, and unlike neurotrophic factor-deprivation-induced neuronal apoptosis, was not associated with a detectable loss of cytochrome c from mitochondria. The apoptotic pathway regulating DNA damage-induced neural precursor cell death is different from that required for normal brain morphogenesis, which involves both caspase 9 and caspase 3 but not p53, indicating that additional apoptotic stimuli regulate neural precursor cell numbers during telencephalic development.

Honokiol Induces Autophagic Apoptosis in Neuroblastoma Cells through a P53-Dependent Pathway

2019 ◽  
Vol 47 (04) ◽  
pp. 895-912 ◽  
Author(s):  
Ming-Chung Lin ◽  
Yuan-Wen Lee ◽  
Yuan-Yun Tseng ◽  
Yung-Wei Lin ◽  
Jui-Tai Chen ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Cell Apoptosis ◽  
Caspase 3 ◽  
Therapeutic Option ◽  
Neuroblastoma Cells ◽  
Cytochrome C Release ◽  
Dependent Pathway ◽  
Dependent Mechanism ◽  
Stimulation Of

In children, neuroblastomas are the most common and deadly solid tumor. Our previous studies showed that honokiol can cross the blood–brain barrier and kill neuroblastoma cells. In this study, we further evaluated if exposure to honokiol for short periods could induce autophagy and subsequent apoptosis of neuroblastoma cells and possible mechanisms. Exposure of neuroblastoma neuro-2a cells to honokiol for 24[Formula: see text]h induced morphological shrinkage and cell death. As to the mechanisms, honokiol consecutively induced cytochrome c release from mitochondria, caspase-3 activation, DNA fragmentation and cell apoptosis. Separately, honokiol time-dependently augmented the proportion of autophagic cells and the ratio of light chain 3 (LC3)-II/LC3-I. Pretreatment of neuro-2a cells with 3-methyladenine, an inhibitor of autophagy, attenuated honokiol-induced cell autophagy, caspase-3 activation, DNA damage and cell apoptosis. In contrast, stimulation of autophagy by rapamycin, an inducer of autophagy, significantly enhanced honokiol-induced cell apoptosis. Furthermore, honokiol-induced autophagic apoptosis was confirmed in neuroblastoma NB41A3 cells. Knocking down translation of p53 using RNA interference attenuated honokiol-induced autophagy and apoptosis in neuro-2a and NB41A3 cells. Taken together, this study showed that at early periods, honokiol can induce autophagic apoptosis of neuroblastoma cells through activating a p53-dependent mechanism. Consequently, honokiol has the potential to be a therapeutic option for neuroblastomas.

PGJ2-stimulated β-cell apoptosis is associated with prolonged UPR activation

2007 ◽  
Vol 292 (4) ◽  
pp. E1052-E1061 ◽  
Author(s):  
Kari T. Chambers ◽  
Sarah M. Weber ◽  
John A. Corbett
Keyword(s):  
Cell Death ◽  
Cell Survival ◽  
Cellular Response ◽  
Caspase 3 ◽  
Initiation Factor ◽  
Cytokine Signaling ◽  
Peroxisome Proliferator ◽  
Β Cells ◽  
Β Cell ◽  
Cell Death Pathway

Peroxisome proliferator-activated receptor-γ (PPARγ) ligands have been shown to possess anti-inflammatory properties that include the inhibition of transcription factor activation and the expression of inflammatory genes. Using pancreatic β-cells, we have shown that PPARγ ligands such as 15-deoxy-Δ12,14-prostaglandin J2 (PGJ2) attenuate interferon-γ-induced signal transducer and activator of transcription 1 activation and interleukin (IL)-1β-induced nuclear factor-κB activation by a pathway that correlates with endoplasmic reticulum stress and the induction of the unfolded protein response (UPR). The UPR is a conserved cellular response activated by a number of cell stressors and is believed to alleviate the stress and promote cell survival. However, prolonged activation of the UPR results in cellular death by apoptosis. In this report, we have examined the effects of PGJ2 on UPR activation and the consequences of this activation on cell survival. Consistent with induction of a cell death pathway, treatment of rat islets and RINm5F cells for 24 h with PGJ2 results in caspase-3 activation and caspase-dependent β-cell death. The actions of these ligands do not appear to be selective for β-cells, because PGJ2 stimulates macrophage apoptosis in a similar fashion. Associated with cell death is the enhanced phosphorylation of eukaryotic initiation factor 2α (eIF2α), and in cells expressing a mutant of eIF2α that cannot be phosphorylated, the stimulatory actions of PGJ2 on caspase-3 activation are augmented. These findings suggest that, whereas PGJ2-induced UPR activation is associated with an inhibition of cytokine signaling, prolonged UPR activation results in cell death, and that eIF2α phosphorylation may function in a protective manner to attenuate cell death.

scholarly journals Activation of Phosphatidylinositol 3-Kinase Contributes to Insulin-Like Growth Factor I-Mediated Inhibition of Pancreatic β-Cell Death

Endocrinology ◽  
2002 ◽  
Vol 143 (10) ◽  
pp. 3802-3812 ◽  
Author(s):  
Wenli Liu ◽  
Catherine Chin-Chance ◽  
Eun-Jig Lee ◽  
William L. Lowe
Keyword(s):  
Cell Death ◽  
Fetal Calf Serum ◽  
Calf Serum ◽  
Cell Types ◽  
Phosphatidylinositol 3 Kinase ◽  
Β Cells ◽  
Β Cell ◽  
Creb Phosphorylation ◽  
Lactate Dehydrogenase Release ◽  
Igf I

Abstract To begin to determine whether IGF-I treatment represents a potential means of enhancing the survival of islet cell grafts after transplantation, the present studies established a model of β-cell death secondary to loss of trophic support and examined the ability of IGF-I to prevent cell death. The studies were performed using the rat pancreatic β-cell line, INS-1. Incubating INS-1 cells in RPMI 1640 and 0.25% BSA for 48 h increased cell death, as determined by lactate dehydrogenase release, compared with that of cells maintained in RPMI and 10% fetal calf serum. Addition of 100 ng/ml IGF-I to the serum-free medium decreased lactate dehydrogenase release to a level comparable to that found in cells maintained in fetal calf serum. Similar results were seen using a mouse β-cell line, MIN6, infected with an adenovirus expressing IGF-I. Examination of IGF-I-stimulated signaling demonstrated that IGF-I increased the phosphorylation of protein kinase B in both cell lines, whereas IGF-I-induced phosphorylation of the MAPKs, ERK1 and -2, was observed only in INS-1 cells. The effect of IGF-I on phosphorylation of substrates of phosphatidylinositol 3-kinase (PI 3-kinase) or protein kinase B was also examined in INS-1 cells. IGF-I increased the phosphorylation of glycogen synthase kinase 3β, BAD, FKHR, and p70S6 kinase. Another pathway that has been shown to mediate the protective of IGF-I in some cell types is activation of cAMP response element-binding protein (CREB). IGF-I increased CREB phosphorylation at a concentration as low as 10 ng/ml, and this effect was inhibited by H89, a PKA inhibitor, and PD98059, a MAPK kinase inhibitor. Consistent with the effect of IGF-I on CREB phosphorylation, IGF-I increased the transcriptional activity of CREB, although it had no effect on CREB binding to DNA. Use of inhibitors of the PI 3-kinase (LY 294002) or ERK (PD98059) pathways or CREB phosphorylation (H89) in the cell death assay demonstrated partial abrogation of the protective effect of IGF-I with LY 294002. These data demonstrate that IGF-I protects pancreatic β-cells from cell death secondary to loss of trophic support and that, although IGF-I activates several signaling pathways that contribute to its protective effect in other cell types, only activation of PI 3-kinase contributes to this effect in β-cells.

scholarly journals The Role of Metabolic Flexibility in the Regulation of the DNA Damage Response by Nitric Oxide

2019 ◽  
Vol 39 (18) ◽  
Author(s):  
Bryndon J. Oleson ◽  
Katarzyna A. Broniowska ◽  
Chay Teng Yeo ◽  
Michael Flancher ◽  
Aaron Naatz ◽  
...  
Keyword(s):  
Nitric Oxide ◽  
Dna Damage ◽  
Dna Damage Response ◽  
Oxidative Metabolism ◽  
Protective Mechanism ◽  
Metabolic Flexibility ◽  
Β Cells ◽  
Β Cell ◽  
Damage Response ◽  
Mitochondrial Toxins

ABSTRACTIn this report, we show that nitric oxide suppresses DNA damage response (DDR) signaling in the pancreatic β-cell line INS 832/13 and rat islets by inhibiting intermediary metabolism. Nitric oxide is known to inhibit complex IV of the electron transport chain and aconitase of the Krebs cycle. Non-β cells compensate by increasing glycolytic metabolism to maintain ATP levels; however, β cells lack this metabolic flexibility, resulting in a nitric oxide-dependent decrease in ATP and NAD+. Like nitric oxide, mitochondrial toxins inhibit DDR signaling in β cells by a mechanism that is associated with a decrease in ATP. Non-β cells compensate for the effects of mitochondrial toxins with an adaptive shift to glycolytic ATP generation that allows for DDR signaling. Forcing non-β cells to derive ATP via mitochondrial respiration (replacing glucose with galactose in the medium) and glucose deprivation sensitizes these cells to nitric oxide-mediated inhibition of DDR signaling. These findings indicate that metabolic flexibility is necessary to maintain DDR signaling under conditions in which mitochondrial oxidative metabolism is inhibited and support the inhibition of oxidative metabolism (decreased ATP) as one protective mechanism by which nitric oxide attenuates DDR-dependent β-cell apoptosis.

Role of airway endogenous nitric oxide on lung function during and after exercise in mild asthma

2002 ◽  
Vol 93 (6) ◽  
pp. 1932-1938 ◽  
Author(s):  
Oscar E. Suman ◽  
Kenneth C. Beck
Keyword(s):  
Nitric Oxide ◽  
Cell Types ◽  
Constant Load ◽  
Forced Expiratory Volume ◽  
Mild Asthma ◽  
Airway Function ◽  
Endogenous Nitric Oxide ◽  
Slow Rise ◽  
Exercise Induced ◽  
Synthase Inhibitor

We hypothesized that nitric oxide (NO), a known mild bronchodilator that can be released by several cell types within pulmonary airways, might protect airways during exercise in asthmatic subjects. We studied 17 individuals with documented exercise-induced asthma (screening exercise evaluation) on 2 study days: after treatment with inhaled NO synthase inhibitor N G-monomethyl-l-arginine (l-NMMA; 2 ml of 25 mg/ml mist) and after treatment with saline vehicle. Pulmonary resistance (Rl, esophageal manometry) rose and forced expiratory volume in 1 s fell more after l-NMMA compared with saline treatment, suggesting a bronchoprotective role for NO at baseline. The rise in Rlseen after l-NMMA treatment was nearly completely reversed early in exercise, suggesting a non-NO-mediated bronchodilation. A slow rise in Rl during constant-load exercise and dramatic increase in Rl after exercise were the same on the 2 treatment days, indicating little role for NO in regulating airway function during and after exercise. We conclude that endogenous NO plays little role in regulating airway function during and after exercise in subjects with mild asthma.

The Telomerase Inhibitor RHPS4 Induces Telomere Shortening, DNA-Damage and Cell Death in AML Cells and Chemosensitises Cells to Daunorubicin.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 2760-2760
Author(s):  
Monica Pallis ◽  
Dotun Ojo ◽  
Jaineeta Richardson ◽  
John Ronan ◽  
Malcolm Stevens ◽  
...  
Keyword(s):  
Dna Damage ◽  
Cell Death ◽  
Telomere Length ◽  
Progenitor Cells ◽  
Cell Lines ◽  
Dna Damage Response ◽  
Cell Types ◽  
Telomere Shortening ◽  
Damage Response

Abstract Abstract 2760 Poster Board II-736 The quadruplex ligand RHPS4 is the lead compound in a drug discovery program at the University of Nottingham. It has been shown to bind to telomeres and inhibit telomerase, and subsequently induces growth arrest in progenitor cells from cancer cell lines whilst sparing normal haematopoietic progenitor cells. We explored its in vitro effects in AML cells, which are reported generally to have considerably shorter telomeres than normal CD34+ cells. AML cell lines were grown for 21 days in suspension culture. Primary samples were cultured for 14 days in semi-solid medium. Telomere length was measured by Southern blotting. γH2A.X was used to identify a DNA damage response, and cell viability was measured flow cytometrically with 7-amino actinomycin D. As reported in other tumour cell types, sensitivity to RHPS4 was found to be greatest in those AML cells with the shortest telomeres. In the OCI-AML3 cell line 0.3 μM RHPS4 inhibited cell growth by 50% in a 21 day clonogenic assay, accompanied by shortening of telomeres from 2.6 Kb to <1 Kb. Molm 13 cells (initial telomere length 3.2kB) also underwent telomere shortening in the presence of 0.3 μM RHPS4 (2.8Kb), whereas TF1a and U937 (both with initial telomere lengths approximately 6.5 kB) were insensitive at that concentration. After 6 days at 0.3 μM, RHPS4 was cytostatic, but at higher concentrations (1 μM) the drug was found to induce a substantial DNA damage response and loss of viability to OCI-AML3 cells. Moreover 0.3 μM RHPS4 enhanced the γH2A.X expression and cell death induced by the chemotherapy drug daunorubicin in these cells. Using 14 day clonogenic assays in primary AML samples (n=6), we found that the IC50 for RHPS4 alone was 0.7 μM. However, in the presence of 0.3 μM RHPS4, the median IC50 to daunorubicin was reduced from 19 nM to 5.5 nM. In conclusion we have determined that RHPS4 has telomere-shortening, cytostatic, cytotoxic and chemosensitising properties in AML cells. Disclosures: Stevens: Pharminox Ltd: director and shareholder of Pharminox Ltd which has a financial interest in RHPS4.

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