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The Joint Influence of Tl+ and Thiol-Modifying Agents on Rat Liver Mitochondrial Parameters In Vitro. Int J Mol Sci 2022; 23:ijms23168964. [PMID: 36012228 PMCID: PMC9409397 DOI: 10.3390/ijms23168964] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Revised: 08/02/2022] [Accepted: 08/03/2022] [Indexed: 11/17/2022] Open
Abstract
Recent data have shown that the mitochondrial permeability transition pore (MPTP) is the complex of the Ca2+-modified adenine nucleotide translocase (ANT) and the Ca2+-modified ATP synthase. We found in a previous study that ANT conformational changes may be involved in Tl+-induced MPTP opening in the inner membrane of Ca2+-loaded rat liver mitochondria. In this study, the effects of thiol-modifying agents (eosin-5-maleimide (EMA), fluorescein isothiocyanate (FITC), Cu(o-phenanthroline)2 (Cu(OP)2), and embelin (Emb)), and MPTP inhibitors (ADP, cyclosporine A (CsA), n-ethylmaleimide (NEM), and trifluoperazine (TFP)) on MPTP opening were tested simultaneously with increases in swelling, membrane potential (ΔΨmito) decline, decreases in state 3, 4, and 3UDNP (2,4-dinitrophenol-uncoupled) respiration, and changes in the inner membrane free thiol group content. The effects of these thiol-modifying agents on the studied mitochondrial characteristics were multidirectional and showed a clear dependence on their concentration. This research suggests that Tl+-induced MPTP opening in the inner membrane of calcium-loaded mitochondria may be caused by the interaction of used reagents (EMA, FITC, Emb, Cu(OP)2) with active groups of ANT, the mitochondrial phosphate carrier (PiC) and the mitochondrial respiratory chain complexes. This study provides further insight into the causes of thallium toxicity and may be useful in the development of new treatments for thallium poisoning.
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Porubský M, Gurská S, Stanková J, Hajdúch M, Džubák P, Hlaváč J. AminoBODIPY Conjugates for Targeted Drug Delivery Systems and Real-Time Monitoring of Drug Release. Mol Pharm 2021; 18:2385-2396. [PMID: 33961440 DOI: 10.1021/acs.molpharmaceut.1c00219] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
In this work, we report two concepts of drug delivery based on small-molecule drug conjugates with the ability of specific targeting and drug release monitoring via ratiometric fluorescence. The functionality of these concepts has been verified by two model systems consisting of three parts: (i) fluorescent aminoBODIPY for real-time detection of conjugate cleavage, (ii) a c(RGDfK) peptide specific for αvβ3 integrin receptors targeting angiogenesis in most solid tumors or redBODIPY for conjugate cleavage monitoring via FRET, and (iii) pegylated-2-phenyl-3-hydroxy-4(1H)-quinolinone (3HQ) as a model drug. The model drug release is based on a self-immolative disulfide linker sensitive to environments containing thiols, especially glutathione, which is overexpressed in cancer cells. The results show effective thiol-mediated cleavage of the fluorescent reporter and the subsequent liberation of the drug in a tube. The conjugate with c(RGDfK) was confirmed to penetrate the cells via interaction with integrin receptors. Drug release from this conjugate is possible to monitor inside the cells. Further, the synthetic approach to the conjugates and the method of fluorescence monitoring of the drug release have also been described.
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Affiliation(s)
- Martin Porubský
- Department of Organic Chemistry, Faculty of Science, Palacký University, Tr. 17. Listopadu 12, 771 46 Olomouc, Czech Republic
| | - Soňa Gurská
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 5, 779 00 Olomouc, Czech Republic
| | - Jarmila Stanková
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 5, 779 00 Olomouc, Czech Republic
| | - Marián Hajdúch
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 5, 779 00 Olomouc, Czech Republic
| | - Petr Džubák
- Institute of Molecular and Translational Medicine, Faculty of Medicine and Dentistry, Palacký University, Hněvotínská 5, 779 00 Olomouc, Czech Republic
| | - Jan Hlaváč
- Department of Organic Chemistry, Faculty of Science, Palacký University, Tr. 17. Listopadu 12, 771 46 Olomouc, Czech Republic
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Interaction of Agaric Acid with the Adenine Nucleotide Translocase Induces Mitochondrial Oxidative Stress. Biochem Res Int 2021; 2020:5253108. [PMID: 33489376 PMCID: PMC7803168 DOI: 10.1155/2020/5253108] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Accepted: 12/05/2020] [Indexed: 12/05/2022] Open
Abstract
Mitochondrial permeability transition is characterized by the opening of a transmembranal pore that switches membrane permeability from specific to nonspecific. This structure allows the free traffic of ions, metabolites, and water across the mitochondrial inner membrane. The opening of the permeability transition pore is triggered by oxidative stress along with calcium overload. In this work, we explored if oxidative stress is a consequence, rather than an effector of the pore opening, by evaluating the interaction of agaric acid with the adenine nucleotide translocase, a structural component of the permeability transition pore. We found that agaric acid induces transition pore opening, increases the generation of oxygen-derived reactive species, augments the oxidation of unsaturated fatty acids in the membrane, and promotes the detachment of cytochrome c from the inner membrane. The effect of agaric acid was inhibited by the antioxidant tamoxifen in association with decreased binding of the thiol reagent eosin-3 maleimide to the adenine nucleotide translocase. We conclude that agaric acid promotes the opening of the pore, increasing ROS production that exerts oxidative modification of critical thiols in the adenine nucleotide translocase.
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A systematic review of post-translational modifications in the mitochondrial permeability transition pore complex associated with cardiac diseases. Biochim Biophys Acta Mol Basis Dis 2020; 1867:165992. [PMID: 33091565 DOI: 10.1016/j.bbadis.2020.165992] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/23/2020] [Accepted: 10/08/2020] [Indexed: 12/28/2022]
Abstract
The mitochondrial permeability transition pore (mPTP) opening is involved in the pathophysiology of multiple cardiac diseases, such as ischemia/reperfusion injury and heart failure. A growing number of evidence provided by proteomic screening techniques has demonstrated the role of post-translational modifications (PTMs) in several key components of the pore in response to changes in the extra/intracellular environment and bioenergetic demand. This could lead to a fine, complex regulatory mechanism that, under pathological conditions, can shift the state of mitochondrial functions and, thus, the cell's fate. Understanding the complex relationship between these PTMs is still under investigation and can provide new, promising therapeutic targets and treatment approaches. This review, using a systematic review of the literature, presents the current knowledge on PTMs of the mPTP and their role in health and cardiac disease.
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Gudkova OI, Demchenko AG, Shvets AV, Kuryakov VN, Sedyakina NE, Lyundup AV, Feldman NB, Gromovykh TI, Lutsenko SV. Biological Activity of Agaricinic Acid Nanoparticles against Human Hepatoma HepG2 Cells. Bull Exp Biol Med 2020; 169:508-511. [PMID: 32910380 DOI: 10.1007/s10517-020-04919-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2019] [Indexed: 11/25/2022]
Abstract
A stable preparation of agaricinic acid nanoparticles was obtained. The mean hydrodynamic size of nanoparticles according to photon correlation spectroscopy was 200 nm and zeta potential was -57 mV. Cytotoxic activity of agaricinic acid nanoparticles against human HepG2 hepatoma cells was evaluated. Nanoparticles with a low concentration of agaricinic acid stimulated and with high concentration - suppressed metabolic activity and viability of hepatoma cells. The EC50 for the stimulating effect was 32.8 μg/ml, and the IC50=602.1 mg/ml. The preparation of agaricinic acid nanoparticles can be used in medicine as a potential antitumor agent.
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Affiliation(s)
- O I Gudkova
- I. M. Sechenov First Moscow State Medical University, Ministry of Health of the Russian Federation (Sechenov University), Moscow, Russia
| | - A G Demchenko
- I. M. Sechenov First Moscow State Medical University, Ministry of Health of the Russian Federation (Sechenov University), Moscow, Russia
| | - A V Shvets
- I. M. Sechenov First Moscow State Medical University, Ministry of Health of the Russian Federation (Sechenov University), Moscow, Russia
| | - V N Kuryakov
- Oil and Gas Research Institute, Russian Academy of Sciences, Moscow, Russia
| | - N E Sedyakina
- I. M. Sechenov First Moscow State Medical University, Ministry of Health of the Russian Federation (Sechenov University), Moscow, Russia
| | - A V Lyundup
- I. M. Sechenov First Moscow State Medical University, Ministry of Health of the Russian Federation (Sechenov University), Moscow, Russia
| | - N B Feldman
- I. M. Sechenov First Moscow State Medical University, Ministry of Health of the Russian Federation (Sechenov University), Moscow, Russia.
| | - T I Gromovykh
- I. M. Sechenov First Moscow State Medical University, Ministry of Health of the Russian Federation (Sechenov University), Moscow, Russia
| | - S V Lutsenko
- I. M. Sechenov First Moscow State Medical University, Ministry of Health of the Russian Federation (Sechenov University), Moscow, Russia
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Correa F, Pavón N, Buelna-Chontal M, Chiquete-Félix N, Hernández-Esquivel L, Chávez E. Calcium Induces Mitochondrial Oxidative Stress Because of its Binding to Adenine Nucleotide Translocase. Cell Biochem Biophys 2018; 76:445-450. [PMID: 30159781 DOI: 10.1007/s12013-018-0856-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2018] [Accepted: 08/21/2018] [Indexed: 12/22/2022]
Abstract
Several studies have demonstrated that the mitochondrial membrane switches from selective to non-selective permeability because of its improved matrix Ca2+ accumulation and oxidative stress. This process, known as permeability transition, evokes severe dysfunction in mitochondria through the opening of a non-specific pore, whose chemical nature is still under discussion. There are some proposals regarding the components of the pore structure, e.g., the adenine nucleotide translocase and dimers of the F1 Fo-ATP synthase. Our results reveal that Ca2+ induces oxidative stress, which not only increases lipid peroxidation and ROS generation but also brings about both the collapse of the transmembrane potential and the membrane release of cytochrome c. Additionally, it is shown that Ca2+ increases the binding of the probe eosin-5-maleimide to adenine nucleotide translocase. Interestingly, these effects are diminished after the addition of ADP. It is suggested that pore opening is caused by the binding of Ca2+ to the adenine nucleotide translocase.
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Affiliation(s)
- Francisco Correa
- Departamento de Biomedicina Cardiovascular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Natalia Pavón
- Departamento de Farmacología, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Mabel Buelna-Chontal
- Departamento de Biomedicina Cardiovascular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Natalia Chiquete-Félix
- Departamento de Genética Molecular, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, Ciudad de México, Mexico
| | - Luz Hernández-Esquivel
- Departamento de Bioquímica, . Instituto Nacional de Cardiología, Ignacio Chávez. Tlalpan, Cd. de México, Mexico
| | - Edmundo Chávez
- Departamento de Bioquímica, . Instituto Nacional de Cardiología, Ignacio Chávez. Tlalpan, Cd. de México, Mexico.
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Baines CP, Gutiérrez-Aguilar M. The still uncertain identity of the channel-forming unit(s) of the mitochondrial permeability transition pore. Cell Calcium 2018; 73:121-130. [PMID: 29793100 PMCID: PMC5993635 DOI: 10.1016/j.ceca.2018.05.003] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2018] [Revised: 05/07/2018] [Accepted: 05/12/2018] [Indexed: 10/16/2022]
Abstract
Mitochondria from different organisms can undergo a sudden process of inner membrane unselective leakiness to molecules known as the mitochondrial permeability transition (MPT). This process has been studied for nearly four decades and several proteins have been claimed to constitute, or at least regulate the usually inactive pore responsible for this transition. However, no protein candidate proposed as the actual pore-forming unit has passed rigorous gain- or loss-of-function genetic tests. Here we review evidence for -and against- putative channel-forming components of the MPT pore. We conclude that the structure of the MPT pore still remains largely undefined and suggest that future studies should follow established technical considerations to unambiguously consolidate the channel forming constituent(s) of the MPT pore.
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Affiliation(s)
- Christopher P Baines
- Dalton Cardiovascular Research Center, University of Missouri-Columbia, Columbia, MO 65211, USA; Department of Biomedical Sciences, University of Missouri-Columbia, Columbia, MO 65211, USA; Department of Medical Pharmacology and Physiology, University of Missouri-Columbia, Columbia, MO 65211, USA.
| | - Manuel Gutiérrez-Aguilar
- Departamento de Bioquímica, Facultad de Química, Universidad Nacional Autónoma de México, Ciudad Universitaria, 04510 Ciudad de México, Mexico.
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Ex Vivo Cardiotoxicity of Antineoplastic Casiopeinas Is Mediated through Energetic Dysfunction and Triggered Mitochondrial-Dependent Apoptosis. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2018; 2018:8949450. [PMID: 29765507 PMCID: PMC5889877 DOI: 10.1155/2018/8949450] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/31/2017] [Revised: 12/23/2017] [Accepted: 01/23/2018] [Indexed: 01/24/2023]
Abstract
Casiopeinas are a group of copper-based antineoplastic molecules designed as a less toxic and more therapeutic alternative to cisplatin or Doxorubicin; however, there is scarce evidence about their toxic effects on the whole heart and cardiomyocytes. Given this, rat hearts were perfused with Casiopeinas or Doxorubicin and the effects on mechanical performance, energetics, and mitochondrial function were measured. As well, the effects of Casiopeinas-triggered cell death were explored in isolated cardiomyocytes. Casiopeinas III-Ea, II-gly, and III-ia induced a progressive and sustained inhibition of heart contractile function that was dose- and time-dependent with an IC50 of 1.3 ± 0.2, 5.5 ± 0.5, and 10 ± 0.7 μM, correspondingly. Myocardial oxygen consumption was not modified at their respective IC50, although ATP levels were significantly reduced, indicating energy impairment. Isolated mitochondria from Casiopeinas-treated hearts showed a significant loss of membrane potential and reduction of mitochondrial Ca2+ retention capacity. Interestingly, Cyclosporine A inhibited Casiopeinas-induced mitochondrial Ca2+ release, which suggests the involvement of the mitochondrial permeability transition pore opening. In addition, Casiopeinas reduced the viability of cardiomyocytes and stimulated the activation of caspases 3, 7, and 9, demonstrating a cell death mitochondrial-dependent mechanism. Finally, the early perfusion of Cyclosporine A in isolated hearts decreased Casiopeinas-induced dysfunction with reduction of their toxic effect. Our results suggest that heart cardiotoxicity of Casiopeinas is similar to that of Doxorubicin, involving heart mitochondrial dysfunction, loss of membrane potential, changes in energetic metabolites, and apoptosis triggered by mitochondrial permeability.
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Buelna-Chontal M, Hernández-Esquivel L, Correa F, Díaz-Ruiz JL, Chávez E. Tamoxifen inhibits mitochondrial oxidative stress damage induced by copper orthophenanthroline. Cell Biol Int 2016; 40:1349-1356. [PMID: 27730705 DOI: 10.1002/cbin.10690] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 10/05/2016] [Indexed: 11/11/2022]
Abstract
In this work, we studied the effect of tamoxifen and cyclosporin A on mitochondrial permeability transition caused by addition of the thiol-oxidizing pair Cu2+ -orthophenanthroline. The findings indicate that tamoxifen and cyclosporin A circumvent the oxidative membrane damage manifested by matrix Ca2+ release, mitochondrial swelling, and transmembrane electrical gradient collapse. Furthermore, it was found that tamoxifen and cyclosporin A prevent the generation of TBARs promoted by Cu2+ -orthophenanthroline, as well as the inactivation of the mitochondrial enzyme aconitase and disruption of mDNA. Electrophoretic analysis was unable to demonstrate a cross-linking reaction between membrane proteins. Yet, it was found that Cu2+ -orthophenanthroline induced the generation of reactive oxygen species. It is thus plausible that membrane leakiness is due to an oxidative stress injury.
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Affiliation(s)
- Mabel Buelna-Chontal
- Departamento de Biomedicina Cardiovascular, Instituto Nacional de Cardiología, Ignacio Chávez, D.F. México, México
| | - Luz Hernández-Esquivel
- Departamento de Bioquímica, Instituto Nacional de Cardiología, Ignacio Chávez, D.F. México, 14080, México
| | - Francisco Correa
- Departamento de Biomedicina Cardiovascular, Instituto Nacional de Cardiología, Ignacio Chávez, D.F. México, México
| | - Jorge Luis Díaz-Ruiz
- Departamento de Biomedicina Cardiovascular, Instituto Nacional de Cardiología, Ignacio Chávez, D.F. México, México
| | - Edmundo Chávez
- Departamento de Bioquímica, Instituto Nacional de Cardiología, Ignacio Chávez, D.F. México, 14080, México
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Antineoplastic copper coordinated complexes (Casiopeinas) uncouple oxidative phosphorylation and induce mitochondrial permeability transition in cardiac mitochondria and cardiomyocytes. J Bioenerg Biomembr 2016; 48:43-54. [PMID: 26739598 DOI: 10.1007/s10863-015-9640-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2015] [Accepted: 12/27/2015] [Indexed: 01/10/2023]
Abstract
Copper-based drugs, Casiopeinas (Cas), exhibit antiproliferative and antineoplastic activities in vitro and in vivo, respectively. Unfortunately, the clinical use of these novel chemotherapeutics could be limited by the development of dose-dependent cardiotoxicity. In addition, the molecular mechanisms underlying Cas cardiotoxicity and anticancer activity are not completely understood. Here, we explore the potential impact of Cas on the cardiac mitochondria energetics as the molecular mechanisms underlying Cas-induced cardiotoxicity. To explore the properties on mitochondrial metabolism, we determined Cas effects on respiration, membrane potential, membrane permeability, and redox state in isolated cardiac mitochondria. The effect of Cas on the mitochondrial membrane potential (Δψm) was also evaluated in isolated cardiomyocytes by confocal microscopy and flow cytometry. Cas IIIEa, IIgly, and IIIia predominately inhibited maximal NADH- and succinate-linked mitochondrial respiration, increased the state-4 respiration rate and reduced membrane potential, suggesting that Cas also act as mitochondrial uncouplers. Interestingly, cyclosporine A inhibited Cas-induced mitochondrial depolarization, suggesting the involvement of mitochondrial permeability transition pore (mPTP). Similarly to isolated mitochondria, in isolated cardiomyocytes, Cas treatment decreased the Δψm and cyclosporine A treatment prevented mitochondrial depolarization. The production of H2O2 increased in Cas-treated mitochondria, which might also increase the oxidation of mitochondrial proteins such as adenine nucleotide translocase. In accordance, an antioxidant scavenger (Tiron) significantly diminished Cas IIIia mitochondrial depolarization. Cas induces a prominent loss of membrane potential, associated with alterations in redox state, which increases mPTP opening, potentially due to thiol-dependent modifications of the pore, suggesting that direct or indirect inhibition of mPTP opening might reduce Cas-induced cardiotoxicity.
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Riojas-Hernández A, Bernal-Ramírez J, Rodríguez-Mier D, Morales-Marroquín FE, Domínguez-Barragán EM, Borja-Villa C, Rivera-Álvarez I, García-Rivas G, Altamirano J, García N. Enhanced oxidative stress sensitizes the mitochondrial permeability transition pore to opening in heart from Zucker Fa/fa rats with type 2 diabetes. Life Sci 2015; 141:32-43. [DOI: 10.1016/j.lfs.2015.09.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2015] [Revised: 08/18/2015] [Accepted: 09/22/2015] [Indexed: 12/13/2022]
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Buelna-Chontal M, Pavón N, Correa F, Hernández-Esquivel L, Chávez E. Titration of lysine residues on adenine nucleotide translocase by fluorescamine induces permeability transition. Cell Biol Int 2013; 38:287-95. [PMID: 23765583 DOI: 10.1002/cbin.10142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2013] [Accepted: 05/27/2013] [Indexed: 11/11/2022]
Abstract
Chemical modification of primary amino groups of mitochondrial membrane proteins by the fluorescent probe fluorescamine induces non-specific membrane permeabilisation. Titration of the lysine ϵ-amino group promoted efflux of accumulated Ca(2+), collapse of transmembrane potential and mitochondrial swelling. Ca(2+) release was inhibited by cyclosporin A. Considering the latter, we assumed that fluorescamine induces permeability transition. Carboxyatractyloside also inhibited the reaction. Using a polyclonal antibody for adenine nucleotide translocase, Western blot analysis showed that the carrier appeared labelled with the fluorescent probe. The results point out the importance of the ϵ-amino group of lysine residues, located in the adenine nucleotide carrier, on the modulation of membrane permeability, since its blockage suffices to promote opening of the non-specific nanopore.
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Affiliation(s)
- Mabel Buelna-Chontal
- Departamento de Bioquímica Instituto Nacional de Cardiología Ignacio Chávez, Mexico, D.F., 014080, Mexico
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García N, Zazueta C, El-Hafidi M, Pavón N, Martínez-Abundis E, Hernández-Esquivel L, Chávez E. Cyclosporin A inhibits UV-radiation-induced membrane damage but is unable to inhibit carboxyatractyloside-induced permeability transition. Radiat Res 2009; 172:575-83. [PMID: 19883225 DOI: 10.1667/rr1799.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
This work was undertaken to gain further information on the chemical characteristics of the membrane entity involved in the formation of the nonspecific pore. Mitochondria were subjected to oxidative stress by exposure to UV radiation. The results indicate that ultraviolet C radiation induces structural modifications in the adenine nucleotide translocase that lead to membrane permeability transition. Membrane leakage was assessed by measuring mitochondrial Ca2+ transport, the transmembrane electric gradient, and mitochondrial swelling. UV-irradiated mitochondria were unable to retain matrix Ca2+ or to maintain a high level of membrane potential when Ca2+ was added; furthermore, UV-irradiated mitochondria underwent large amplitude swelling. Release of cytochrome c and formation of malondialdehyde, owing to lipid peroxidation, were also seen. Structural modifications of the translocase were revealed by an increase in the binding of the fluorescent probe eosin-5-maleimide to thiol residues of the ADP/ATP carrier. These modifications, taken together with findings indicating that cyclosporin resulted unable to inhibit carboxyatractyloside-induced permeability transition, prompted us to conclude that the translocase could constitute the nonspecific pore or at least be an important modulator of it.
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Affiliation(s)
- Noemí García
- Departamento de Bioquímica, Instituto Nacional de Cardiología, Ignacio Chávez, Mexico, D.F. 014080, Mexico
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Garcia N, Hernandez-Esquivel L, Zazueta C, Martinez-Abundis E, Pavon N, Chavez E. Induction of Mitochondrial Permeability Transition by the DNA-intercalating Cationic Dye Ethidium Bromide. J Biochem 2009; 146:887-94. [DOI: 10.1093/jb/mvp137] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
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