scholarly journals Increased Uptake of Zinc in Malignant Cells is Associated with Enhanced Activation of MAPK Signalling and P53-Dependent Cell Injury

2008 ◽  
Vol 51 (1) ◽  
pp. 43-49 ◽  
Author(s):  
Emil Rudolf
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Cell Injury ◽  
Cell Damage ◽  
Zinc Homeostasis ◽  
Malignant Cells ◽  
Intracellular Zinc ◽  
Free Zinc ◽  
Dependent Cell ◽  
Zinc Levels

Excess intracellular zinc has been demonstrated to be responsible for cell injury and cell death in various experimental as well as clinical models. While the cells possess a system of mechanisms regulating intracellular zinc homeostasis, their saturation by acutely increased zinc levels or by a sustained exposure to elevated zinc levels results in liberation of free zinc stores within the cells and ultimate cell damage and cell death. Here we report that in Hep-2 malignant cells enhanced uptake of zinc causes activation of mitogen-activated protein kinase (MAPK) signaling with resulting p53-dependent cell injury which can be significantly prevented by specific p53 inhibition and by prevention of oxidative stress. Our observations are consistent with the view that subacutely increased intracellular free zinc levels stimulate via oxidative stress p53-dependent pathways which are responsible for the final cell damage in tumor cells.

scholarly journals Alterations in ZnT1 expression and function lead to impaired intracellular zinc homeostasis in cancer

2019 ◽  
Vol 5 (1) ◽  
Author(s):  
Adrian Israel Lehvy ◽  
Guy Horev ◽  
Yarden Golan ◽  
Fabian Glaser ◽  
Yael Shammai ◽  
...  
Keyword(s):  
Malignant Tumors ◽  
Zinc Homeostasis ◽  
Healthy Population ◽  
Missense Mutations ◽  
Protein Alignment ◽  
Loss Of Function ◽  
Intracellular Zinc ◽  
Dismal Prognosis ◽  
Zinc Levels ◽  
And Function

Abstract Zinc is vital for the structure and function of ~3000 human proteins and hence plays key physiological roles. Consequently, impaired zinc homeostasis is associated with various human diseases including cancer. Intracellular zinc levels are tightly regulated by two families of zinc transporters: ZIPs and ZnTs; ZIPs import zinc into the cytosol from the extracellular milieu, or from the lumen of organelles into the cytoplasm. In contrast, the vast majority of ZnTs compartmentalize zinc within organelles, whereas the ubiquitously expressed ZnT1 is the sole zinc exporter. Herein, we explored the hypothesis that qualitative and quantitative alterations in ZnT1 activity impair cellular zinc homeostasis in cancer. Towards this end, we first used bioinformatics to analyze inactivating mutations in ZIPs and ZNTs, catalogued in the COSMIC and gnomAD databases, representing tumor specimens and healthy population controls, respectively. ZnT1, ZnT10, ZIP8, and ZIP10 showed extremely high rates of loss of function mutations in cancer as compared to healthy controls. Analysis of the putative functional impact of missense mutations in ZnT1-ZnT10 and ZIP1-ZIP14, using homologous protein alignment and structural predictions, revealed that ZnT1 displays a markedly increased frequency of predicted functionally deleterious mutations in malignant tumors, as compared to a healthy population. Furthermore, examination of ZnT1 expression in 30 cancer types in the TCGA database revealed five tumor types with significant ZnT1 overexpression, which predicted dismal prognosis for cancer patient survival. Novel functional zinc transport assays, which allowed for the indirect measurement of cytosolic zinc levels, established that wild type ZnT1 overexpression results in low intracellular zinc levels. In contrast, overexpression of predicted deleterious ZnT1 missense mutations did not reduce intracellular zinc levels, validating eight missense mutations as loss of function (LoF) mutations. Thus, alterations in ZnT1 expression and LoF mutations in ZnT1 provide a molecular mechanism for impaired zinc homeostasis in cancer formation and/or progression.

scholarly journals Autophagy impairment as a key feature for acetaminophen-induced ototoxicity

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Tong Zhao ◽  
Tihua Zheng ◽  
Huining Yu ◽  
Bo Hua Hu ◽  
Bing Hu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Lysosomal Enzymes ◽  
Apoptotic Cell ◽  
Cell Damage ◽  
Treatment Strategies ◽  
Explant Culture ◽  
Apoptotic Cell Death ◽  
Lysosomal Dysfunction ◽  
Autophagic Degradation

AbstractMacroautophagy/autophagy is a highly conserved self-digestion pathway that plays an important role in cytoprotection under stress conditions. Autophagy is involved in hepatotoxicity induced by acetaminophen (APAP) in experimental animals and in humans. APAP also causes ototoxicity. However, the role of autophagy in APAP-induced auditory hair cell damage is unclear. In the present study, we investigated autophagy mechanisms during APAP-induced cell death in a mouse auditory cell line (HEI-OC1) and mouse cochlear explant culture. We found that the expression of LC3-II protein and autophagic structures was increased in APAP-treated HEI-OC1 cells; however, the degradation of SQSTM1/p62 protein, the yellow puncta of mRFP-GFP-LC3 fluorescence, and the activity of lysosomal enzymes decreased in APAP-treated HEI-OC1 cells. The degradation of p62 protein and the expression of lysosomal enzymes also decreased in APAP-treated mouse cochlear explants. These data indicate that APAP treatment compromises autophagic degradation and causes lysosomal dysfunction. We suggest that lysosomal dysfunction may be directly responsible for APAP-induced autophagy impairment. Treatment with antioxidant N-acetylcysteine (NAC) partially alleviated APAP-induced autophagy impairment and apoptotic cell death, suggesting the involvement of oxidative stress in APAP-induced autophagy impairment. Inhibition of autophagy by knocking down of Atg5 and Atg7 aggravated APAP-induced ER and oxidative stress and increased apoptotic cell death. This study provides a better understanding of the mechanism responsible for APAP ototoxicity, which is important for future exploration of treatment strategies for the prevention of hearing loss caused by ototoxic medications.

ATP depletion rather than mitochondrial depolarization mediates hepatocyte killing after metabolic inhibition

1994 ◽  
Vol 267 (1) ◽  
pp. C67-C74 ◽  
Author(s):  
A. L. Nieminen ◽  
A. K. Saylor ◽  
B. Herman ◽  
J. J. Lemasters
Keyword(s):  
Cell Death ◽  
Cell Injury ◽  
Rat Hepatocytes ◽  
Cell Killing ◽  
Atp Depletion ◽  
Mitochondrial Depolarization ◽  
Minimum Concentration ◽  
Atp Formation ◽  
Mitochondrial Atp Synthase ◽  
Dependent Cell

The importance of ATP depletion and mitochondrial depolarization in the toxicity of cyanide, oligomycin, and carbonyl cyanide m-cholorophenylhydrazone (CCCP), an uncoupler, was evaluated in rat hepatocytes. Oligomycin, an inhibitor of the reversible mitochondrial ATP synthase (F1F0-adenosinetriphosphatase), caused dose-dependent cell killing with 0.1 microgram/ml being the minimum concentration causing the maximum cell killing. Oligomycin also caused rapid ATP depletion without causing mitochondrial depolarization. Fructose (20 mM), a potent glycolytic substrate in liver, protected completely against oligomycin toxicity. CCCP (5 microM) also caused rapid killing of hepatocytes. Fructose retarded cell death caused by CCCP but failed to prevent lethal cell injury. Although oligomycin (1.0 microgram/ml) was lethally toxic by itself, in the presence of fructose it protected completely against CCCP-induced cell killing. Cyanide (2.5 mM), an inhibitor of mitochondrial respiration, caused rapid cell killing that was reversed by fructose. CCCP completely blocked fructose protection against cyanide, causing mitochondrial depolarization and rapid ATP depletion. In the presence of fructose and cyanide, oligomycin protected cells against CCCP-induced ATP depletion and cell death but did not prevent mitochondrial depolarization. In every instance, cell killing was associated with ATP depletion, whereas protection against lethal cell injury was associated with preservation of ATP. In conclusion, protection by fructose against toxicity of cyanide, oligomycin, and CCCP was mediated by glycolytic ATP formation rather than by preservation of the mitochondrial membrane potential. These findings support the hypothesis that inhibition of cellular ATP formation is a crucial event in the progression of irreversible cell injury.

Epicatechin and its in vivo metabolite, 3′-O-methyl epicatechin, protect human fibroblasts from oxidative-stress-induced cell death involving caspase-3 activation

2001 ◽  
Vol 354 (3) ◽  
pp. 493-500 ◽  
Author(s):  
Jeremy P. E. SPENCER ◽  
Hagen SCHROETER ◽  
Gunter KUHNLE ◽  
S. Kaila S. SRAI ◽  
Rex M. TYRRELL ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Hydrogen Peroxide ◽  
Cell Death ◽  
Caspase 3 ◽  
Cell Damage ◽  
Protective Action ◽  
Human Fibroblasts ◽  
Membrane Damage ◽  
Antioxidant Properties

There is considerable current interest in the cytoprotective effects of natural antioxidants against oxidative stress. In particular, epicatechin, a major member of the flavanol family of polyphenols with powerful antioxidant properties in vitro, has been investigated to determine its ability to attenuate oxidative-stress-induced cell damage and to understand the mechanism of its protective action. We have induced oxidative stress in cultured human fibroblasts using hydrogen peroxide and examined the cellular responses in the form of mitochondrial function, cell-membrane damage, annexin-V binding and caspase-3 activation. Since one of the major metabolites of epicatechin in vivo is 3′-O-methyl epicatechin, we have compared its protective effects with that of epicatechin. The results provide the first evidence that 3′-O-methyl epicatechin inhibits cell death induced by hydrogen peroxide and that the mechanism involves suppression of caspase-3 activity as a marker for apoptosis. Furthermore, the protection elicited by 3′-O-methyl epicatechin is not significantly different from that of epicatechin, suggesting that hydrogen-donating antioxidant activity is not the primary mechanism of protection.

scholarly journals Curcumin Protects Human Umbilical Vein Endothelial Cells against H2O2-Induced Cell Injury

2019 ◽  
Vol 2019 ◽  
pp. 1-7 ◽  
Author(s):  
Jipeng Ouyang ◽  
Rong Li ◽  
Haiqin Shi ◽  
Jianping Zhong
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Cell Death ◽  
Cell Injury ◽  
Umbilical Vein ◽  
Therapeutic Drug ◽  
Human Umbilical Vein ◽  
Antioxidative Enzyme Activities ◽  
Apoptosis Related Protein ◽  
Umbilical Vein Endothelial Cells

Migraine is a prevalent neurological disorder which causes a huge economic burden on society. It is thought to be a neurovascular disease with oxidative stress might be involved. Curcumin, one of the major ingredients of turmeric, has potent antioxidative and anti-inflammatory properties, but whether it could be used as a potential treatment for migraine remains to be explored. In the present study, human umbilical vein endothelial cells (HUVECs) were pretreated with various concentrations of curcumin (0 μM, 10 μM, 20 μM, 30 μM, 40 μM, and 50 μM) for 12 h, thereby exposed to H2O2 (100 μM) for another 12 h. The viability of HUVECs was tested by the CCK-8 assay, and the activities of antioxidant enzymes including superoxide dismutase (SOD) and glutathione (GSH) were also examined. Intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) were assayed to determine H2O2-induced oxidative stress. In addition, several cell death-related genes (p53, p21, Bax, and Bcl-2) were detected by PCR, and an apoptosis-related protein (caspase3) was evaluated by western blotting. Our results showed that curcumin improved the H2O2-induced decrease of cell viability and antioxidative enzyme activities and decreased the level of oxidative stress. As a conclusion, curcumin could mitigate H2O2-induced oxidative stress and cell death in HUVECs and may be a potential therapeutic drug for migraine.

scholarly journals Blockage of NOX2/MAPK/NF-κB Pathway Protects Photoreceptors against Glucose Deprivation-Induced Cell Death

2017 ◽  
Vol 2017 ◽  
pp. 1-14 ◽  
Author(s):  
Bin Fan ◽  
Bei-Fen Wang ◽  
Lin Che ◽  
Ying-Jian Sun ◽  
Shu-Yan Liu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Western Blot ◽  
Glucose Deprivation ◽  
Photoreceptor Cells ◽  
Retinal Neurons ◽  
Dependent Cell ◽  
Ischemic Diseases ◽  
Cell Death Cascade ◽  
Energy Failure

Acute energy failure is one of the critical factors contributing to the pathogenic mechanisms of retinal ischemia. Our previous study demonstrated that glucose deprivation can lead to a caspase-dependent cell death of photoreceptors. The aim of this study was to decipher the upstream signal pathway in glucose deprivation- (GD-) induced cell death. We mimicked acute energy failure by using glucose deprivation in photoreceptor cells (661W cells). GD-induced oxidative stress was evaluated by measuring ROS with the DCFH-DA assay and HO-1 expression by Western blot analysis. The activation of NOX2/MAPK/NF-κB signal was assessed by Western blot and immunohistochemical assays. The roles of these signals in GD-induced cell death were measured by using their specific inhibitors. Inhibition of Rac-1 and NOX2 suppressed GD-induced oxidative stress and protected photoreceptors against GD-induced cell death. NOX2 was an upstream signal in the caspase-dependent cell death cascade, yet the downstream MAPK pathways were activated and blocking MAPK signals rescued 661W cells from GD-induced death. In addition, GD caused the activation of NF-κB signal and inhibiting NF-κB significantly protected 661W cells. These observations may provide insights for treating retinal ischemic diseases and protecting retinal neurons from ischemia-induced cell death.

scholarly journals Icaritin protects SH-SY5Y cells transfected with TDP-43 by alleviating mitochondrial damage and oxidative stress

PeerJ ◽  
2021 ◽  
Vol 9 ◽  
pp. e11978
Author(s):  
Yongjian Zhou ◽  
Nanqu Huang ◽  
Yuanyuan Li ◽  
Zhisheng Ba ◽  
Yanjun Zhou ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Cell Injury ◽  
Cell Damage ◽  
Mitochondrial Damage ◽  
Atp Content ◽  
Sod Activity ◽  
Mda Content ◽  
Copper Zinc ◽  
Total Antioxidative Capacity ◽  
Underlying Mechanisms

Background The aim of this study was to investigate the effect of icaritin (ICT) on TAR DNA-binding protein 43 (TDP-43)-induced neuroblastoma (SH-SY5Y) cell damage and to further explore its underlying mechanisms. Methods To investigate the possible mechanism, TDP-43 was used to induce SH-SY5Y cell injury. Cell viability was evaluated by the CCK-8 assay. The mitochondrial membrane potential (MMP) was determined with JC-1. The expression levels of TDP-43 and cytochrome C (CytC) were measuring by Western blotting. Changes in adenosine 5′-triphosphate (ATP) content, total antioxidative capacity (T-AOC), glutathione peroxidase (GSH-Px) activity, superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were detected with specific kits. Results The results showed that ICT reduced the cell damage induced by TDP-43. ICT reduced the expression level of TDP-43; increased ATP content and the MMP; decreased CytC expression; increased T-AOC and GSH-Px, total SOD (T-SOD), copper/zinc SOD (CuZn-SOD), and manganese SOD (Mn-SOD) activity; and decreased MDA content. Conclusions The results suggest that ICT has a protective effect on TDP-43-transfected SH-SY5Y cells that is related to reductions in TDP-43 expression and mitochondrial damage and alleviation of oxidative stress.

scholarly journals Screening for Lung Cancer with Low Dose Computed Tomography (LDCT)

2021 ◽  
pp. 794-832
Author(s):  
Elena Locci ◽  
Silvia Raymond
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Research Team ◽  
Low Dose ◽  
Small Cell ◽  
Small Cell Lung ◽  
Tumor Cell Death ◽  
Dependent Cell ◽  
Keywords Cancer ◽  
Low Dose Computed Tomography

Using samples of small cell lung tumors, a research team led by biologist Dr. Raymond discovered two new ways to induce tumor cell death. By activating ferroptosis, one of two subtypes of tumor cells can be targeted: first, iron-dependent cell death due to oxidative stress, and second, oxidative stress. Therefore, cell death can also be induced in a different way. Both types of cell death must be caused by drugs at the same time to eliminate the majority of the tumor mass. Keywords: Cancer; Cells; Tissues, Tumors; Prevention, Prognosis; Diagnosis; Imaging; Screening; Treatment; Management

scholarly journals Role of CNC1 gene in TDP-43 aggregation-induced oxidative stress-mediated cell death in S. cerevisiae model of ALS

2020 ◽  
Author(s):  
Vidhya Bharathi ◽  
Amandeep Girdhar ◽  
Basant K Patel
Keyword(s):  
Oxidative Stress ◽  
Cell Death ◽  
Stress Response ◽  
Molecular Mechanisms ◽  
Motor Neuron Diseases ◽  
C Protein ◽  
Cell Death Pathway ◽  
Cyclin C ◽  
Dependent Cell ◽  
Anti Oxidant

ABSTRACTTDP-43 is a multi-functional ribonucleoprotein that is also found deposited as hyper-phosphorylated and ubiquitinated TDP-43 inclusions in the brain and spinal cord of the patients of the motor neuron diseases, amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD). Till date, how the cell death ensues is not fully deciphered although several molecular mechanisms of the TDP-43 toxicity such as impairments of endocytosis and chromatin remodelling, mis-regulations of autophagy and proteasome function, mis-localization to the mitochondria and generation of oxidative stress etc., have been proposed. A predominantly nuclear protein, Cyclin C, can regulate the oxidative stress response by affecting the transcription of stress response genes and also by translocation to the cytoplasm for the activation of the mitochondrial fragmentation-dependent cell death pathway. Using the well-established yeast model of TDP-43 aggregation and toxicity, we examined here whether upon TDP-43 aggregation, the cell survival depends on the presence of the CNC1 gene that encodes Cyclin C protein or other genes that encode proteins that function in conjunction with Cyclin C, such as the DNM1, FIS1 and MED13 genes. We found that the TDP-43 toxicity is significantly reduced in the yeast deleted for the CNC1 or DNM1 genes. Importantly, the rescue of TDP-43 toxicity in these yeast deletion backgrounds required the presence of functional mitochondria. Also, the deletion of YBH3 gene, which encodes for a protein involved in the mitochondria-dependent apoptosis, also reduced the TDP-43 toxicity. Furthermore, Cyclin C-YFP was observed to localize from the nucleus to the cytoplasm in response to the TDP-43 co-expression. Also, this cytoplasmic localization of Cyclin C was prevented by the addition of an anti-oxidant molecule, N-acetyl-cysteine. Taken together, our data suggest that Cyclin C, Dnm1 and Ybh3 proteins are important in mediating the TDP-43-induced oxidative stress-mediated cell death in the S. cerevisiae model.

Sign in / Sign up

Export Citation Format

Share Document