Zinc Induces Apoptosis That Can Be Suppressed by Lanthanum in C6 Rat Glioma Cells

Abstract Zinc ions have both essential and toxic effects on mammalian cells. Here we report the ability of zinc to act as an inducer of apoptosis in C6 rat glioma cells. Incubation with 150 to 300 M ZnCl2 caused cell death that was characterized as apoptotic by internucleosomal DNA fragmentation, formation of apoptotic bodies, nuclear fragmentation and breakdown of the mitochondrial membrane potential. On the other hand, zinc deprivation by the membrane permeable chelator TPEN [N,N,N,N,tetrakis (2-pyridylmethyl)ethylenediamine] also induced programmed death in this cell line, indicating the existence of intracellular zinc levels below and above which apoptosis is induced. Zincinduced apoptosis in C6 cells was independent of major signaling pathways (protein kinase C, mitogen activated protein kinase and guanylate cyclase) and protein synthesis, but was increased by facilitating zinc uptake with the ionophore pyrithione. Lanthanum(III)chloride was also able to increase the net zinc uptake, but nevertheless apoptotic features and zinc toxicity were reduced. Remarkably, lanthanum suppressed the zincinduced breakdown of the mitochondrial membrane potential. We conclude that in C6 cells lanthanum acts in two different ways, as a promoter of net zinc uptake and as a suppressor of zincinduced apoptosis.

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Review of T-2307, an Investigational Agent That Causes Collapse of Fungal Mitochondrial Membrane Potential

Journal of Fungi ◽

10.3390/jof7020130 ◽

2021 ◽

Vol 7 (2) ◽

pp. 130

Author(s):

Nathan P. Wiederhold

Keyword(s):

Membrane Potential ◽

Mitochondrial Membrane Potential ◽

Candida Species ◽

Mammalian Cells ◽

Mitochondrial Membrane ◽

Fungal Infections ◽

Published Data ◽

Candida Auris

Invasive infections caused by Candida that are resistant to clinically available antifungals are of increasing concern. Increasing rates of fluconazole resistance in non-albicans Candida species have been documented in multiple countries on several continents. This situation has been further exacerbated over the last several years by Candida auris, as isolates of this emerging pathogen that are often resistant to multiple antifungals. T-2307 is an aromatic diamidine currently in development for the treatment of invasive fungal infections. This agent has been shown to selectively cause the collapse of the mitochondrial membrane potential in yeasts when compared to mammalian cells. In vitro activity has been demonstrated against Candida species, including C. albicans, C. glabrata, and C. auris strains, which are resistant to azole and echinocandin antifungals. Activity has also been reported against Cryptococcus species, and this has translated into in vivo efficacy in experimental models of invasive candidiasis and cryptococcosis. However, little is known regarding the clinical efficacy and safety of this agent, as published data from studies involving humans are not currently available.

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Glyoxal Damages Human Aortic Endothelial Cells by Perturbing the Glutathione, Mitochondrial Membrane Potential, and Mitogen-Activated Protein Kinase Pathways

10.21203/rs.3.rs-270505/v1 ◽

2021 ◽

Author(s):

Ming-Zhang Xie ◽

Chun Guo ◽

Jia-Qi Dong. BA ◽

Jie Zhang ◽

Ke-Tao Sun ◽

...

Keyword(s):

Endothelial Cells ◽

Membrane Potential ◽

Protein Kinase ◽

Mitochondrial Membrane Potential ◽

Mitochondrial Membrane ◽

Mitogen Activated Protein Kinase ◽

Aortic Endothelial Cells ◽

Mitogen Activated Protein ◽

Human Aortic Endothelial Cells ◽

Quantitative Fluorescence

Abstract Background: Exposure to glyoxal, the smallest dialdehyde, is associated with several diseases; humans are routinely exposed to glyoxal because of its ubiquitous presence in foods and the environment. The aim of this study was to examine the damage caused by glyoxal in human aortic endothelial cells. Methods: Cell survival assays and quantitative fluorescence assays were performed to measure DNA damage; oxidative stress was detected by colorimetric assays and quantitative fluorescence, and the mitogen-activated protein kinase pathways were assessed using western blotting. Results: Exposure to glyoxal was found to be linked to abnormal glutathione activity, the collapse of mitochondrial membrane potential, and the activation of mitogen-activated protein kinase pathways. However, DNA damage and thioredoxin oxidation were not induced by dialdehydes. Conclusions: Intracellular glutathione, members of the mitogen-activated protein kinase pathways, and the mitochondrial membrane potential are all critical targets of glyoxal. These findings provide novel insights into the molecular mechanisms perturbed by glyoxal and may facilitate the development of new therapeutics and diagnostic markers for cardiovascular diseases.

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MITOCHONDRIAL MEMBRANE POTENTIAL, MORPHOLOGY AND ATP PRODUCTION IN MAMMALIAN CELLS EXPOSED TO X-RAYS

Radiation Protection Dosimetry ◽

10.1093/rpd/ncy254 ◽

2018 ◽

Vol 183 (1-2) ◽

pp. 98-101

Author(s):

R Hamada ◽

K Kaminaga ◽

K Suzuki ◽

A Yokoya

Keyword(s):

Membrane Potential ◽

Mitochondrial Membrane Potential ◽

Mammalian Cells ◽

Mitochondrial Membrane ◽

X Rays ◽

Atp Production

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Visualization of mitochondrial membrane potential in mammalian cells

Methods in Cell Biology - Mitochondria, 3rd Edition ◽

10.1016/bs.mcb.2019.10.003 ◽

2020 ◽

pp. 221-245

Author(s):

Noemí Esteras ◽

Merel J.W. Adjobo-Hermans ◽

Andrey Y. Abramov ◽

Werner J.H. Koopman

Keyword(s):

Membrane Potential ◽

Mitochondrial Membrane Potential ◽

Mammalian Cells ◽

Mitochondrial Membrane

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Progesterone Maintains Basal Intracellular Adenosine Triphosphate Levels and Viability of Spontaneously Immortalized Granulosa Cells by Promoting an Interaction between 14-3-3σ and ATP Synthaseβ/Precursor through a Protein Kinase G-Dependent Mechanism

Endocrinology ◽

10.1210/en.2006-1603 ◽

2007 ◽

Vol 148 (5) ◽

pp. 2037-2044 ◽

Cited By ~ 13

Author(s):

John J. Peluso ◽

Xiufang Liu ◽

Jonathan Romak

Keyword(s):

Membrane Potential ◽

Protein Kinase ◽

Mitochondrial Membrane Potential ◽

Granulosa Cells ◽

Mitochondrial Membrane ◽

Apoptotic Cell ◽

Protein Kinase G ◽

Disulfonic Acid ◽

Causative Role ◽

Atp Content

The present studies were designed to 1) describe changes in both the mitochondrial membrane potential and ATP content of spontaneously immortalized granulosa cells as they undergo apoptosis, 2) identify some of the downstream events that are activated by progesterone (P4), and 3) relate these downstream events to changes in mitochondrial function and apoptotic cell death. These studies revealed that in response to serum deprivation, the mitochondrial membrane potential initially hyperpolarizes and ATP content increases. That this increase in ATP is required for apoptosis was demonstrated by the finding that oligomycin inhibited the increase in ATP and apoptosis. Piridoxalphosphate-6-azopeyl-2′-4′-disulfonic acid, an inhibitor of purinergic receptors, which are activated by ATP, also inhibited apoptosis due to serum withdrawal. This study provides additional support for ATP’s causative role in apoptosis. Moreover, 8-Br-cGMP, a protein kinase G (PKG) activator, mimicked P4’s action, whereas a PKG antagonist, DT-3, attenuated P4’s suppressive effect on ATP and apoptosis. Finally, DT-3 treatment was shown to attenuate P4-regulated phosphorylation of 14-3-3σ and its binding partner, ATP synthaseβ/precursor and the amount of ATP synthaseβ/precursor that bound to 14-3-3σ. Based on these data, it is proposed that P4 prevents apoptosis in part by activating PKG, which in turn maintains the interaction between ATP synthaseβ/precursor and 14-3-3σ. In the absence of P4-induced PKG activity, we further propose that some ATP synthaseβ precursor dissociates from 14-3-3σ, resulting in its activation and incorporation into the ATP synthase complex, which ultimately results in an increase in ATP and apoptosis.

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Protein Kinase Cδ Targets Mitochondria, Alters Mitochondrial Membrane Potential, and Induces Apoptosis in Normal and Neoplastic Keratinocytes When Overexpressed by an Adenoviral Vector

Molecular and Cellular Biology ◽

10.1128/mcb.19.12.8547 ◽

1999 ◽

Vol 19 (12) ◽

pp. 8547-8558 ◽

Cited By ~ 199

Author(s):

Luowei Li ◽

Patricia S. Lorenzo ◽

Krisztina Bogi ◽

Peter M. Blumberg ◽

Stuart H. Yuspa

Keyword(s):

Cell Death ◽

Membrane Potential ◽

Protein Kinase ◽

Mitochondrial Membrane Potential ◽

Mitochondrial Membrane ◽

Fluorescent Protein ◽

Protein Fusion ◽

Cell Death Pathway ◽

Morphological Criteria ◽

Protein Kinase Cδ

ABSTRACT Inactivation of protein kinase Cδ (PKCδ) is associated with resistance to terminal cell death in epidermal tumor cells, suggesting that activation of PKCδ in normal epidermis may be a component of a cell death pathway. To test this hypothesis, we constructed an adenovirus vector carrying an epitope-tagged PKCδ under a cytomegalovirus promoter to overexpress PKCδ in normal and neoplastic keratinocytes. While PKCδ overexpression was detected by immunoblotting in keratinocytes, the expression level of other PKC isozymes, including PKCα, PKCɛ, PKCζ, and PKCη, did not change. Calcium-independent PKC-specific kinase activity increased after infection of keratinocytes with the PKCδ adenovirus. Activation of PKCδ by 12-O-tetradecanoylphorbol-13-acetate (TPA) at a nanomolar concentration was lethal to normal and neoplastic mouse and human keratinocytes overexpressing PKCδ. Lethality was inhibited by PKC selective inhibitors, GF109203X and Ro-32-0432. TPA-induced cell death was apoptotic as evidenced by morphological criteria, TUNEL (terminal deoxynucleotidyltransferase-mediated dUTP-biotin nick end labeling) assay, DNA fragmentation, and increased caspase activity. Subcellular fractionation indicated that PKCδ translocated to a mitochondrial enriched fraction after TPA activation, and this finding was confirmed by confocal microscopy of cells expressing a transfected PKCδ-green fluorescent protein fusion protein. Furthermore, activation of PKCδ in keratinocytes altered mitochondrial membrane potential, as indicated by rhodamine-123 fluorescence. Mitochondrial inhibitors, rotenone and antimycin A, reduced TPA-induced cell death in PKCδ-overexpressing keratinocytes. These results indicate that PKCδ can initiate a death pathway in keratinocytes that involves direct interaction with mitochondria and alterations of mitochondrial function.

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