Dual effect of spermine on mitochondrial Ca2+ transport

Lenzen, Sigurd; Münster, Wilfried; Rustenbeck, Ingo

doi:10.1042/bj2860597

Cited by 35 publications

(20 citation statements)

References 33 publications

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“…Spermine, a polyamine, has been shown to influence the MPT in rat liver mitochondria, as well as Ca 2+ accumulation in the mitochondrial matrix (Lapidus and Sokolove, 1994; Lenzen et al ., 1992). In the absence of added Ca 2+ , µ m spermine also induced rapid swelling of A23187‐pretreated mitochondria (Figure 1b), reaching saturation at 50 µ m spermine.…”

Section: Resultsmentioning

confidence: 99%

The oat mitochondrial permeability transition and its implication in victorin binding and induced cell death

Curtis

Wolpert

2002

The Plant Journal

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SummaryThe mitochondrion has emerged as a key regulator of apoptosis, a form of animal programmed cell death (PCD). The mitochondrial permeability transition (MPT), facilitated by a pore-mediated, rapid permeability increase in the inner membrane, has been implicated as an early and critical step of apoptosis. Victorin, the host-selective toxin produced by Cochliobolus victoriae, the causal agent of victoria blight of oats, has been demonstrated to bind to the mitochondrial P-protein and also induces a form of PCD. Previous results suggest that a MPT may facilitate victorin's access to the mitochondrial matrix and binding to the P-protein: (i) victorin-induced cell death displays features similar to apoptosis; (ii) in vivo, victorin binds to the mitochondrial P-protein only in toxin-sensitive genotypes whereas victorin binds equally well to P-protein isolated from toxin-sensitive and insensitive oats; (iii) isolated, untreated mitochondria are impermeable to victorin. The data implicate an in vivo change in mitochondrial permeability in response to victorin. This study focused on whether oat mitochondria can undergo a MPT. Isolated oat mitochondria demonstrated high-amplitude swelling when treated with spermine or Ca 2+ in the presence of the Ca 2+ -ionophore A23187, and when treated with mastoparan, an inducer of the MPT in rat liver mitochondria. In all cases, swelling demonstrated size exclusion in the range 0.9±1.7 kDa, similar to that found in animal mitochondria. Further, MPT-inducing conditions permitted victorin access to the mitochondrial matrix and binding to the P-protein. In vivo, victorin treatment induced the collapse of mitochondrial transmembrane potential within 2 h, indicating a MPT. Also, the victorin-induced collapse of membrane potential was clearly distinct from that induced by uncoupling respiration, as the latter event prevented the victorin-induced PCD response and binding to P-protein. These results demonstrate that a MPT can occur in oat mitochondria in vitro, and are consistent with the hypothesis that an MPT, which allows victorin access to the mitochondrial matrix and binding to the P-protein, occurs in vivo during victorin-induced PCD.

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Section: Resultsmentioning

confidence: 99%

The oat mitochondrial permeability transition and its implication in victorin binding and induced cell death

Curtis

Wolpert

2002

The Plant Journal

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“…The concentration of free mitochondrial Mg 2+ ions in hepatic mitochondria has been estimated to be between 400 µM and 1000 µM [6,7]. The concentration of Mg 2+ ions can alter ALDH activity by altering the rate limiting steps of enzyme catalysis.…”

Section: Introductionmentioning

confidence: 99%

NADH fluorescence lifetime analysis of the effect of magnesium ions on ALDH2

Gonnella

Leedahl

Karlstad

et al. 2011

Chemico-Biological Interactions

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Aldehyde dehydrogenase 2 (ALDH2) catalyzes oxidation of toxic aldehydes to carboxylic acids. Physiologic levels of Mg2+ ions influence ALDH2 activity in part by increasing NADH binding affinity. Traditional fluorescence measurements monitor the blue shift of the NADH fluorescence spectrum to study ALDH2-NADH interactions. By using time-resolved fluorescence spectroscopy, we have resolved the fluorescent lifetimes (τ) of free NADH (τ = 0.4 ns) and bound NADH (τ = 6.0 ns). We used this technique to investigate the effects of Mg2+ on the ALDH2-NADH binding characteristics and enzyme catalysis. From the resolved free and bound NADH fluorescence signatures, the KD for NADH with ALDH2 ranged from 468 µM to 12 µM for Mg2+ ion concentrations of 20 µM to 6000 µM, respectively. The rate constant for dissociation of the enzyme-NADH complex ranged from 0.4 s−1 (6000 µM Mg2+) to 8.3 s−1 (0 µM Mg2+) as determined by addition of excess NAD+ to prevent re-association of NADH and resolving the real-time NADH fluorescence signal. The apparent NADH association/re-association rate constants were approximately 0.04 µM−1s−1 over the entire Mg2+ ion concentration range and demonstrate that Mg 2+ ions slow the release of NADH from the enzyme rather than promoting its re-association. We applied NADH fluorescence lifetime analysis to the study of NADH binding during enzyme catalysis. Our fluorescence lifetime analysis confirmed complex behavior of the enzyme activity as a function of Mg2+ concentration. Importantly, we observed no pre-steady state burst of NADH formation. Furthermore, we observed distinct fluorescence signatures from multiple ALDH2-NADH complexes corresponding to free NADH, enzyme-bound NADH, and, potentially, an abortive NADH-enzyme-propanal complex (τ = 11.2 ns).

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“…Spermine obtained from ornithine decarboxylation increases calcium uptake elevating its cytosolic levels. Quercetin is reported to inhibit ornithine decarboxylase and hence inhibits polyamine release [19] . Calcium mediated signals have been associated with mitotic progression in fi broblasts [20] .…”

Section: Discussionmentioning

confidence: 99%

Regulation of Intracellular Calcium Levels and Urokinase Activity in MDA MB 231 Cells by Quercetin

et al. 2006

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Background: The common plant bioflavonoid, quercetin, is cytotoxic to various tumor cell lines, particularly breast cancer, by affecting the protein-kinase-C-dependent signal pathways and by cell cycle regulation. However, its role in breast cancer metastasis has not been studied so far. Increased uPA activity is evident in highly metastatic breast cancer, which is calcium dependent. Methods: MDA MB 231 cells were treated with various concentrations of quercetin (15–45 µg/ml). The cytotoxic effect of quercetin was assessed by MTT assay and DNA fragmentation analysis. Intracellular calcium levels were measured using Fura-2, a specific Ca²⁺ fluorescence indicator. Calcium uptake and release in cells treated with quercetin were measured using radioactive ⁴⁵Ca²⁺. Urokinase enzyme activity was assayed by a casein zymogram. Results: Quercetin elicited dose- and time-dependent cytotoxicity as evidenced by the MTT assay. The maximum effect was observed at 48 h with a quercetin concentration of (45 µg/ml). DNA agarose gel electrophoresis showed dose-dependent DNA fragmentation on quercetin treatment. Quercetin caused significant depletion of cytosolic calcium levels and decreased calcium uptake from the intracellular stores. Casein zymogram showed a marked reduction of urokinase activity as evident by clear lysis bands on a dark background on treatment with quercetin. Conclusion: Quercetin was found to exhibit cytotoxicity in the highly invasive breast cancer cell line MDA MB 231 in a dose- and time-dependent manner. Quercetin inhibited calcium dependent urokinase activity and hence may prove to be an effective antimetastatic agent.

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Dual effect of spermine on mitochondrial Ca2+ transport

Cited by 35 publications

References 33 publications

The oat mitochondrial permeability transition and its implication in victorin binding and induced cell death

The oat mitochondrial permeability transition and its implication in victorin binding and induced cell death

NADH fluorescence lifetime analysis of the effect of magnesium ions on ALDH2

Regulation of Intracellular Calcium Levels and Urokinase Activity in MDA MB 231 Cells by Quercetin

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