Modulation of the Mitochondrial Permeability Transition Pore by Pyridine Nucleotides and Dithiol Oxidation at Two Separate Sites

Costantini, Paola; Chernyak, Boris V.; Petronilli, Valeria; Bernardi, Paolo

doi:10.1074/jbc.271.12.6746

Cited by 494 publications

(320 citation statements)

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“…SUDHL4 cells exhibited a relatively higher GSH concentration compared with HL60 cells and could account for the greater intensity of PK11195-induced CMH 2 DCF fluorescence in HL60 cells (approximately one log fold). Bcl-2 transfection was not found to attenuate the generation of ROS in K562 cells, nor modulate cellular GSH content; however, Bcl-2 could conceivably antagonize ROS-induced permeability transition via its well described stabilizing effect on the permeability transition pore complex, the gating of which is regulated by the redox state of critical vicinal thiols (Costantini et al, 1996(Costantini et al, , 2000Marzo et al, 1998). This would be consistent with our finding that PK11195 can induce mitochondrial swelling in HL60 mitochondria, but not in SUDHL4 mitochondria which hyperexpress Bcl-2 due to t(14;18).…”

Section: Discussionmentioning

confidence: 91%

Bcl-2 resistant mitochondrial toxicity mediated by the isoquinoline carboxamide PK11195 involves de novo generation of reactive oxygen species

et al. 2001

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SummaryResistance to apoptosis is a major obstacle preventing effective therapy for malignancy. Mitochondria localized anti-death proteins of the Bcl-2 family play a central role in inhibiting apoptosis and therefore present valid targets for novel therapy. The peripheral benzodiazepine receptor (PBR) shares a close physical association with the permeability transition pore complex (PTPC), a pivotal regulator of cell death located at mitochondrial contact sites. In this study we investigated the cytotoxicity of the PBR ligand, PK11195, in the micromolar concentration range. PK11195 induced antioxidant inhibitable collapse of the inner mitochondrial membrane potential (∆Ψ m ) and mitochondrial swelling in HL60 human leukaemia cells, but not in SUDHL4 lymphoma cells (which exhibited a higher level of reduced glutathione and relative tolerance to chemotherapy or pro-oxidant induced ∆Ψ m dissipation). PK11195 induced the production of hydrogen peroxide that was not inhibited by Bcl-2 transfection, nor depletion of mitochondrial DNA. ROS production was however blocked by protonophore, implicating a requirement for ∆Ψ m . Our findings suggest that PK11195-induced cytotoxicity relies upon Bcl-2 resistant generation of oxidative stress; a process only observed at concentrations several orders of magnitude higher that required to saturate its receptor. 1397-1404 © 2001 Cancer Research Campaign doi: 10.1054/ bjoc.2001.1788, available online at http://www.idealibrary.com on http://www.bjcancer.com methyl-N-methyl-N-(1-methylpropyl)-isoquinoline carboxamide (PK11195), carbonylcyanide m-chlorophenylhdrazone (CCCP), propidium iodide and all cell culture reagents were purchased from Sigma-Aldrich Ltd, UK. FITC-conjugated mouse antihuman Bcl-2 monoclonal antibody, and the Dako intrastain fixation/permeabilization kit were purchased from Dako, UK. Cell culture and treatmentsHL60, KG1A, K652 cells stably transfected with the Bcl-2 gene (K562 B4) or vector only (K562 N2) (kindly provided by Dr DE Banker and Dr F Applebaum, The Fred Hutchinson Cancer Research Center, USA), and SUDHL4 lymphoma cell lines, were maintained in exponential suspension cultures in RPMI 1640 medium supplemented with 10% fetal calf serum, 5 mM glutamine, 100 µg ml -1 streptomycin and 100 U ml -1 penicillin. Cells were grown in a humidified atmosphere of 5% CO 2 /95% air at 37˚C. PK11195 was dissolved in ethanol at a stock concentration of 8.7 mg ml -1 , and added to cells at a 75 µM final concentration for 4 hours; vehicle alone was also used in medium. To test the effect of an antioxidant on PK11195 activity, cells were treated with 10 mM N-acetylcysteine for 45 minutes prior to treatment with PK11195.Cells were incubated with VP16, or ara-C at 10 µM final concentration for 24 hours, or with the thiol crosslinking prooxidant, diamide, at 100 µM concentration for 24 hours. The protonophore CCCP was used to dissipate ∆Ψ m by treating cells at a concentration of 10 µM for 15 minutes prior to treatment with PK11195. Depletion of mitochondrial DNAKG1A cells ...

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Section: Discussionmentioning

confidence: 91%

Bcl-2 resistant mitochondrial toxicity mediated by the isoquinoline carboxamide PK11195 involves de novo generation of reactive oxygen species

et al. 2001

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“…conversion of ADP to ATP at the expense of the electrochemical gradient during oxidative phosphorylation) [22]. Mitochondrial membrane integrity is dependent on the oxidationreduction equilibrium of ROI, pyridine nucleotides (NADH/NAD + NADPH/NADP) and reduced glutathione (GSH) levels [68]. Regeneration of GSH by glutathione reductase from its oxidized form, GSSG, depends on NADPH produced by the pentose phosphate pathway (PPP) [43].…”

Section: Box 1 Regulation Of the Mitochondrial Transmembrane Potentimentioning

confidence: 99%

Mitochondrial hyperpolarization: a checkpoint of T-cell life, death and autoimmunity

Perl

Gergely

Nagy

et al. 2004

Trends in Immunology

220

142

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T-cell activation, proliferation and selection of the cell death pathway depend on the production of reactive oxygen intermediates (ROIs) and ATP synthesis, which are tightly regulated by the mitochondrial transmembrane potential (ΔΨ m ). Mitochondrial hyperpolarization (MHP) and ATP depletion represent early and reversible steps in T-cell activation and apoptosis. By contrast, T cells of patients with systemic lupus erythematosus (SLE) exhibit persistent MHP, cytoplasmic alkalinization, increased ROI production and depleted ATP, which mediate enhanced spontaneous and diminished activation-induced apoptosis and sensitize lupus T cells to necrosis. Necrotic, but not apoptotic, cell lysates activate dendritic cells and might account for increased interferon a production and inflammation in lupus patients. MHP is proposed as a key mechanism of SLE pathogenesis and is therefore a target for pharmacological intervention.Innate and adaptive immune responses depend on controlled production of ATP and reactive oxygen intermediates (ROIs) in mitochondria. In response to antigenic stimulation, clonal expansion of T and B cells are continuously downsized and potentially autoreactive cells are eliminated by apoptosis. An array of signals through the T-cell receptor (TCR), costimulatory molecules, cell death receptors, lymphokines, and other circulating metabolites, such as ATP, NAD, cADPR, glucose, glutathione, nitric oxide (NO) and ROIs, determine the fate of T cells [1]. T-cell activation and death pathway selection depend on the production of ROIs and ATP synthesis, which are tightly regulated by the mitochondrial transmembrane potential (ΔΨ m ) (Box 1). Disruption of ΔΨ m has been proposed as the point of no return in apoptotic signaling [2] T-cell activation is regulated by mitochondrial ROI productionROIs modulate T-cell activation, cytokine production and proliferation at multiple levels [12]. The antigen-binding αβ or γδTCR is associated with a multimeric receptor module comprising the CD3γδε and TCRζ chains. The cytoplasmic domains of the CD3 and ζ chains contain a common motif, termed the immunoreceptor tyrosinebased activation motif (ITAM), which is crucial for the coupling of intracellular tyrosine kinases [13]. . Thus, expression of cytokines can be selectively regulated by oxidative stress depending on the relative expression level of transcription factors involved (e.g. IL-2 is expressed through a promoter that has AP-1 and NFAT motifs, and IL-4 is expressed through an AP-1-less NFAT enhancer; Figure 1). Redox control of apoptosis signal processingProgrammed cell death (PCD) or apoptosis is a physiological mechanism for elimination of autoreactive lymphocytes during development. Signaling through the Fas or structurally related TNF family of cell-surface death receptors has emerged as a major pathway in the elimination of unwanted cells under physiological and disease conditions [18]. Fas and TNF receptors mediate cell death through cytoplasmic death domains (DDs) shared by both receptors [19]. They ...

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“…The electrochemical gradient across the inner mitochondrial membrane is maintained by the electron transport chain (ETC) and Δψ m (negative inside and positive outside) [3]. The Δψ m is subject to regulation by an oxidation-reduction equilibrium of ROI, pyridine nucleotides (NADH/NAD + NADPH/NADP) and GSH levels [4]. Controlled levels of ROI modulate various aspects of cellular function and are necessary for signal transduction pathways, including those mediating T-cell activation and apoptosis [5] (Fig.…”

Section: Introductionmentioning

confidence: 99%

Nitric oxide, mitochondrial hyperpolarization, and T cell activation☆

Nagy

Koncz

Fernández

et al. 2007

Free Radical Biology and Medicine

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T lymphocyte activation is associated with nitric oxide (NO) production that plays an essential role in multiple T cell functions. NO acts as a messenger, activating soluble guanyl cyclase and participating in the transduction signaling pathways involving cyclic GMP. NO modulates mitochondrial events that are involved in apoptosis and regulates mitochondrial membrane potential and mitochondrial biogenesis in many cell types, including lymphocytes. Mitochondrial hyperpolarization (MHP), an early and reversible event during both T lymphocyte activation and apoptosis, is regulated by NO. Here, we discuss recent evidence that NO-induced MHP represents a molecular switch in multiple T cell signaling pathways. Overproduction of NO in systemic lupus erythematosus (SLE) induces mitochondrial biogenesis and alters Ca 2+ signaling. Thus, while NO plays a physiological role in lymphocyte cell signaling, its overproduction may disturb normal T cell function, contributing to the pathogenesis of autoimmunity.

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Modulation of the Mitochondrial Permeability Transition Pore by Pyridine Nucleotides and Dithiol Oxidation at Two Separate Sites

Cited by 494 publications

References 53 publications

Bcl-2 resistant mitochondrial toxicity mediated by the isoquinoline carboxamide PK11195 involves de novo generation of reactive oxygen species

Bcl-2 resistant mitochondrial toxicity mediated by the isoquinoline carboxamide PK11195 involves de novo generation of reactive oxygen species

Mitochondrial hyperpolarization: a checkpoint of T-cell life, death and autoimmunity

Nitric oxide, mitochondrial hyperpolarization, and T cell activation☆

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