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Westhoff M, Del Villar SG, Voelker TL, Thai PN, Spooner HC, Costa AD, Sirish P, Chiamvimonvat N, Dickson EJ, Dixon RE. BIN1 knockdown rescues systolic dysfunction in aging male mouse hearts. Nat Commun 2024; 15:3528. [PMID: 38664444 PMCID: PMC11045846 DOI: 10.1038/s41467-024-47847-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2023] [Accepted: 04/15/2024] [Indexed: 04/28/2024] Open
Abstract
Cardiac dysfunction is a hallmark of aging in humans and mice. Here we report that a two-week treatment to restore youthful Bridging Integrator 1 (BIN1) levels in the hearts of 24-month-old mice rejuvenates cardiac function and substantially reverses the aging phenotype. Our data indicate that age-associated overexpression of BIN1 occurs alongside dysregulated endosomal recycling and disrupted trafficking of cardiac CaV1.2 and type 2 ryanodine receptors. These deficiencies affect channel function at rest and their upregulation during acute stress. In vivo echocardiography reveals reduced systolic function in old mice. BIN1 knockdown using an adeno-associated virus serotype 9 packaged shRNA-mBIN1 restores the nanoscale distribution and clustering plasticity of ryanodine receptors and recovers Ca2+ transient amplitudes and cardiac systolic function toward youthful levels. Enhanced systolic function correlates with increased phosphorylation of the myofilament protein cardiac myosin binding protein-C. These results reveal BIN1 knockdown as a novel therapeutic strategy to rejuvenate the aging myocardium.
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Affiliation(s)
- Maartje Westhoff
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Silvia G Del Villar
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Taylor L Voelker
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Phung N Thai
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Davis, CA, USA
| | - Heather C Spooner
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Alexandre D Costa
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Padmini Sirish
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Davis, CA, USA
| | - Nipavan Chiamvimonvat
- Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis, Davis, CA, USA
- Department of Veterans Affairs, Northern California Health Care System, Mather, CA, USA
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Eamonn J Dickson
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA
| | - Rose E Dixon
- Department of Physiology and Membrane Biology, University of California Davis, Davis, CA, USA.
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Voelker TL, Del Villar SG, Westhoff M, Costa AD, Coleman AM, Hell JW, Horne MC, Dickson EJ, Dixon RE. Acute phosphatidylinositol 4,5 bisphosphate depletion destabilizes sarcolemmal expression of cardiac L-type Ca 2+ channel Ca V1.2. Proc Natl Acad Sci U S A 2023; 120:e2221242120. [PMID: 36976770 PMCID: PMC10083594 DOI: 10.1073/pnas.2221242120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/29/2023] Open
Abstract
CaV1.2 channels are critical players in cardiac excitation-contraction coupling, yet we do not understand how they are affected by an important therapeutic target of heart failure drugs and regulator of blood pressure, angiotensin II. Signaling through Gq-coupled AT1 receptors, angiotensin II triggers a decrease in PIP2, a phosphoinositide component of the plasma membrane (PM) and known regulator of many ion channels. PIP2 depletion suppresses CaV1.2 currents in heterologous expression systems but the mechanism of this regulation and whether a similar phenomenon occurs in cardiomyocytes is unknown. Previous studies have shown that CaV1.2 currents are also suppressed by angiotensin II. We hypothesized that these two observations are linked and that PIP2 stabilizes CaV1.2 expression at the PM and angiotensin II depresses cardiac excitability by stimulating PIP2 depletion and destabilization of CaV1.2 expression. We tested this hypothesis and report that CaV1.2 channels in tsA201 cells are destabilized after AT1 receptor-triggered PIP2 depletion, leading to their dynamin-dependent endocytosis. Likewise, in cardiomyocytes, angiotensin II decreased t-tubular CaV1.2 expression and cluster size by inducing their dynamic removal from the sarcolemma. These effects were abrogated by PIP2 supplementation. Functional data revealed acute angiotensin II reduced CaV1.2 currents and Ca2+ transient amplitudes thus diminishing excitation-contraction coupling. Finally, mass spectrometry results indicated whole-heart levels of PIP2 are decreased by acute angiotensin II treatment. Based on these observations, we propose a model wherein PIP2 stabilizes CaV1.2 membrane lifetimes, and angiotensin II-induced PIP2 depletion destabilizes sarcolemmal CaV1.2, triggering their removal, and the acute reduction of CaV1.2 currents and contractility.
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Affiliation(s)
- Taylor L Voelker
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Silvia G Del Villar
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Maartje Westhoff
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Alexandre D Costa
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Andrea M Coleman
- Department of Pharmacology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Johannes W Hell
- Department of Pharmacology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Mary C Horne
- Department of Pharmacology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Eamonn J Dickson
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA 95616
| | - Rose E Dixon
- Department of Physiology and Membrane Biology, School of Medicine, University of California Davis, Davis, CA 95616
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Roman-Campos D, Sales-Junior P, Costa AD, Souza DS, Santos-Miranda A, Joviano-Santos JV, Ropert C, Cruz JS. Impact of IFN-γ Deficiency on the Cardiomyocyte Function in the First Stage of Experimental Chagas Disease. Microorganisms 2022; 10:microorganisms10020271. [PMID: 35208732 PMCID: PMC8874532 DOI: 10.3390/microorganisms10020271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2021] [Revised: 01/10/2022] [Accepted: 01/23/2022] [Indexed: 12/10/2022] Open
Abstract
Chagas disease (CD) is caused by the parasitic protozoan T. cruzi. The progression of CD in ~30% of patients results in Chagasic Cardiomyopathy (CCM). Currently, it is known that the inflammatory system plays a significant role in the CCM. Interferon-gamma (IFN-γ) is the major cytokine involved in parasitemia control but has also been linked to CCM. The L-type calcium current (ICa,L) is crucial in the excitation/contraction coupling in cardiomyocytes. Thus, we compared ICa,L and the mechanical properties of cardiomyocytes isolated from infected wild type (WT) and IFN-γ(−/−) mice in the first stage of T. cruzi infection. Using the patch clamp technique, we demonstrated that the infection attenuated ICa,L in isolated cardiomyocytes from the right and left ventricles of WT mice at 15 days post-infection (dpi), which was not observed in the IFN-γ(−/−) cardiomyocytes. However, ICa,L was attenuated between 26 and 30 dpi in both experimental groups. Interestingly, the same profile was observed in the context of the mechanical properties of isolated cardiomyocytes from both experimental groups. Simultaneously, we tracked the mortality and MCP-1, TNF-α, IL-12, IL-6, and IL-10 serum levels in the infected groups. Importantly, the IFN-γ(−/−) and WT mice presented similar parasitemia and serum inflammatory markers at 10 dpi, indicating that the modifications in the cardiomyocyte functions observed at 15 dpi were directly associated with IFN-γ(−/−) deficiency. Thus, we showed that IFN-γ plays a crucial role in the electromechanical remodeling of cardiomyocytes during experimental T. cruzi infection in mice.
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Affiliation(s)
- Danilo Roman-Campos
- Laboratório de Cardiobiologia, Department of Biophysics, Federal University of São Paulo, São Paulo 04021, Brazil; (D.S.S.); (A.S.-M.); (J.V.J.-S.)
- Correspondence: (D.R.-C.); (J.S.C.)
| | | | - Alexandre D. Costa
- Laboratório de Membranas Excitáveis e de Biologia Cardíaca, Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte 31270, Brazil; (A.D.C.); (C.R.)
| | - Diego Santos Souza
- Laboratório de Cardiobiologia, Department of Biophysics, Federal University of São Paulo, São Paulo 04021, Brazil; (D.S.S.); (A.S.-M.); (J.V.J.-S.)
| | - Artur Santos-Miranda
- Laboratório de Cardiobiologia, Department of Biophysics, Federal University of São Paulo, São Paulo 04021, Brazil; (D.S.S.); (A.S.-M.); (J.V.J.-S.)
| | - Julliane V. Joviano-Santos
- Laboratório de Cardiobiologia, Department of Biophysics, Federal University of São Paulo, São Paulo 04021, Brazil; (D.S.S.); (A.S.-M.); (J.V.J.-S.)
| | - Catherine Ropert
- Laboratório de Membranas Excitáveis e de Biologia Cardíaca, Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte 31270, Brazil; (A.D.C.); (C.R.)
| | - Jader S. Cruz
- Laboratório de Membranas Excitáveis e de Biologia Cardíaca, Department of Biochemistry and Immunology, Federal University of Minas Gerais, Belo Horizonte 31270, Brazil; (A.D.C.); (C.R.)
- Correspondence: (D.R.-C.); (J.S.C.)
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Santos-Miranda A, Costa AD, Joviano-Santos JV, Rhana P, Bruno AS, Rocha P, Cau SB, Vieira LQ, Cruz JS, Roman-Campos D. Inhibition of calcium/calmodulin (Ca 2+ /CaM)-Calcium/calmodulin-dependent protein kinase II (CaMKII) axis reduces in vitro and ex vivo arrhythmias in experimental Chagas disease. FASEB J 2021; 35:e21901. [PMID: 34569665 DOI: 10.1096/fj.202101060r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2021] [Revised: 08/18/2021] [Accepted: 08/19/2021] [Indexed: 11/11/2022]
Abstract
Chagasic cardiomyopathy (CCC) is one of the main causes of heart failure and sudden death in Latin America. To date, there is no available medication to prevent or reverse the onset of cardiac symptoms. CCC occurs in a scenario of disrupted calcium dynamics and enhanced oxidative stress, which combined, may favor the hyper activation of calcium/calmodulin (Ca2+ /CaM)-calcium/calmodulin-dependent protein kinase II (CaMKII) (Ca2+ /CaM-CaMKII) pathway, which is fundamental for heart physiology and it is implicated in other cardiac diseases. Here, we evaluated the association between Ca2+ /CaM-CaMKII in the electro-mechanical (dys)function of the heart in the early stage of chronic experimental Trypanosoma cruzi infection. We observed that in vitro and ex vivo inhibition of Ca2+ /CaM-CaMKII reversed the arrhythmic profile of isolated hearts and isolated left-ventricles cardiomyocytes. The benefits of the limited Ca2+ /CaM-CaMKII activation to cardiomyocytes' electrical properties are partially related to the restoration of Ca2+ dynamics in a damaged cellular environment created after T. cruzi infection. Moreover, Ca2+ /CaM-CaMKII inhibition prevented the onset of arrhythmic contractions on isolated heart preparations of chagasic mice and restored the responsiveness to the increase in the left-ventricle pre-load. Taken together, our data provide the first experimental evidence for the potential of targeting Ca2+ /CaM-CaMKII pathway as a novel therapeutic target to treat CCC.
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Affiliation(s)
| | - Alexandre D Costa
- Department of Physiology and Biophysics, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | | | - Paula Rhana
- Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Alexandre Santos Bruno
- Department of Pharmacology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Peter Rocha
- Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Stefany Bruno Cau
- Department of Pharmacology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Leda Q Vieira
- Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Jader S Cruz
- Department of Biochemistry and Immunology, Universidade Federal de Minas Gerais, Belo Horizonte, Brazil
| | - Danilo Roman-Campos
- Department of Biophysics, Universidade Federal de São Paulo, São Paulo, Brazil
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Riess ML, Costa AD, Carlson R, Garlid KD, Heinen A, Stowe DF. Differential increase of mitochondrial matrix volume by sevoflurane in isolated cardiac mitochondria. Anesth Analg 2008; 106:1049-55, table of contents. [PMID: 18349172 DOI: 10.1213/ane.0b013e318167875e] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
BACKGROUND Mitochondrial (m) adenosine triphosphate sensitive potassium (K(ATP)) channel opening has been reported to trigger and/or mediate cardioprotection by volatile anesthetics. However, the effects of volatile anesthetics on mitochondrial function are not well understood. Prevention of mitochondrial matrix volume (MMV) contraction during ischemia may contribute to cardioprotection against ischemia/reperfusion injury. We investigated whether sevoflurane increases MMV and if this increase is mediated by mK(ATP) channel opening. METHODS Mitochondria from fresh guinea pig hearts were isolated and diluted in buffer that included oligomycin and ATP to inhibit ATP synthesis. Changes in MMV by diazoxide, a known mK(ATP) channel opener, and by different sevoflurane concentrations, were measured by light absorption at 520 nm in the absence or presence of the mK(ATP) channel blocker, 5-hydroxydecanoate. RESULTS Compared with control, 30-300 microM sevoflurane (approximately 0.2-2.1 vol %) increased MMV by 30%-55%, which was similar to the effect of diazoxide. These increases were blocked by 5-hydroxydecanoate. Higher sevoflurane concentration (1000 microM; 7.1 vol %), however, had no effect on MMV. CONCLUSIONS In clinically relevant concentrations, sevoflurane increases MMV via mK(ATP) channel opening. Preservation of mitochondrial integrity may contribute to the cardioprotective effects of sevoflurane against ischemia/reperfusion injury. Impaired mitochondrial function at supraclinical anesthetic concentrations may explain the observed biphasic response. These findings add to our understanding of the intracellular mechanisms of volatile anesthetics as cardioprotective drugs.
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Affiliation(s)
- Matthias L Riess
- Department of Anesthesiology, Medical College of Wisconsin, 8701 Watertown Plank Rd., Milwaukee, WI 53226, USA.
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Costa AD, Garlid KD. MitoKATP, H2O2, and PKCε – completing the cycle. J Mol Cell Cardiol 2007. [DOI: 10.1016/j.yjmcc.2007.03.126] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Abstract
Opening the mitochondrial ATP-sensitive K(+) channel (mitoK(ATP)) increases levels of reactive oxygen species (ROS) in cardiomyocytes. This increase in ROS is necessary for cardioprotection against ischemia-reperfusion injury; however, the mechanism of mitoK(ATP)-dependent stimulation of ROS production is unknown. We examined ROS production in suspensions of isolated rat heart and liver mitochondria, using fluorescent probes that are sensitive to hydrogen peroxide. When mitochondria were treated with the K(ATP) channel openers diazoxide or cromakalim, their ROS production increased by 40-50%, and this effect was blocked by 5-hydroxydecanoate. ROS production exhibited a biphasic dependence on valinomycin concentration, with peak production occurring at valinomycin concentrations that catalyze about the same K(+) influx as K(ATP) channel openers. ROS production decreased with higher concentrations of valinomycin and with all concentrations of a classical protonophoretic uncoupler. Our studies show that the increase in ROS is due specifically to K(+) influx into the matrix and is mediated by the attendant matrix alkalinization. Myxothiazol stimulated mitoK(ATP)-dependent ROS production, whereas rotenone had no effect. This indicates that the superoxide originates in complex I (NADH:ubiquinone oxidoreductase) of the electron transport chain.
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Vieira S, Costa A, Rieder M. Crit Care 2003; 7:P176. [DOI: 10.1186/cc2065] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Borecký J, Maia IG, Costa AD, Jezek P, Chaimovich H, de Andrade PB, Vercesi AE, Arruda P. Functional reconstitution of Arabidopsis thaliana plant uncoupling mitochondrial protein (AtPUMP1) expressed in Escherichia coli. FEBS Lett 2001; 505:240-4. [PMID: 11566183 DOI: 10.1016/s0014-5793(01)02835-6] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Arabidopsis thaliana uncoupling protein (UCP) gene was expressed in Escherichia coli and isolated protein reconstituted into liposomes. Linoleic acid-induced H+ fluxes were sensitive to purine nucleotide inhibition with an apparent K(i) (in mM) of 0.8 (GDP), 0.85 (ATP), 0.98 (GTP), and 1.41 (ADP); the inhibition was pH-dependent. Kinetics of AtPUMP1-mediated H+ fluxes were determined for lauric, myristic, palmitic, oleic, linoleic, and linolenic acids. Properties of recombinant AtPUMP1 indicate that it represents a plant counterpart of animal UCP2 or UCP3. This work brings the functional and genetic approaches together for the first time, providing strong support that AtPUMP1 is truly an UCP.
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Affiliation(s)
- J Borecký
- Department of Membrane Transport Biophysics, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague, Czech Republic
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Abstract
Evidence has been provided that the plant uncoupling proteins (pUCP) play basic physiological roles similar to the other uncoupling protein subfamily members (mammalian UCP1,2,3,4 and BMCP) and are effective in the situations of slight uncoupling that leads to: (1) accelerated respiration and metabolic rates that are beneficial to plant growth and development; (2) decreased formation of reactive oxygen species in mitochondria; and, (3) mild thermogenesis, inevitably accompanying the previous two phenomena. Hypothetically, specific physiological roles of pUCP such as cut off of ATP synthesis could be manifested in connection with climacteric respiratory rise during fruit ripening, seed dormancy, and plant senescence. pUCP might also facilitate growth under low temperatures, e.g., during seed germination or in roots. The existence of these specific roles is suggested by the immunochemical and functional localization of pUCP in mitochondria of fruits, seeds and roots of various plant species.
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Affiliation(s)
- P Jezek
- Department of Membrane Transport Biophysics, Institute of Physiology, Academy of Sciences of the Czech Republic, Prague
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Costa A, Moritz R, Matos J, Machado F. Crit Care 2001; 5:P82. [DOI: 10.1186/cc1415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
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Abstract
Chemical modifications were used to identify some of the functionally important amino acid residues of the potato plant uncoupling protein (StUCP). The proton-dependent swelling of potato mitochondria in K(+)-acetate in the presence of linoleic acid and valinomycin was inhibited by mersalyl (K(i) = 5 microM) and other hydrophilic SH reagents such as Thiolyte MB, iodoacetate and 5, 5'-dithio-bis-(2-nitrobenzoate), but not by hydrophobic N-ethylmaleimide. This pattern of inhibition by SH reagents was similar to that of brown adipose tissue uncoupling protein (UCP1). As with UCP1, the arginine reagent 2,3-butadione, but not N-ethylmaleimide or other hydrophobic SH reagents, prevented the inhibition of StUCP-mediated transport by ATP in isolated potato mitochondria or with reconstituted StUCP. The results indicate that the most reactive amino acid residues in UCP1 and StUCP are similar, with the exception of N-ethylmaleimide-reactive cysteines in the purine nucleotide-binding site.
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Affiliation(s)
- P Jezek
- Department of Membrane Transport Biophysics, Institute of Physiology, Academy of Science, Prague, Czech Republic
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Costa AD, Nantes IL, Jezek P, Leite A, Arruda P, Vercesi AE. Plant uncoupling mitochondrial protein activity in mitochondria isolated from tomatoes at different stages of ripening. J Bioenerg Biomembr 1999; 31:527-33. [PMID: 10653480 DOI: 10.1023/a:1005408809619] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
In the present study we have observed a higher state of coupling in respiring mitochondria isolated from green as compared to red tomatoes (Lycopersicon esculentum, Mill.). Green tomato mitochondria produced a membrane potential (deltapsi) high enough to phosphorylate ADP, whereas in red tomato mitochondria, BSA and ATP were required to restore deltapsi to the level of that obtained with green tomato mitochondria. This supports the notion that such uncoupling in red tomato mitochondria is mediated by a plant uncoupling mitochondrial protein (PUMP; cf. Vercesi et al., 1995). Nevertheless, mitochondria from both green and red tomatoes exhibited an ATP-sensitive linoleic acid (LA)-induced deltapsi decrease providing evidence that PUMP is also present in green tomatoes. Indeed, proteoliposomes containing reconstituted green or red tomato PUMP showed LA uniport and LA-induced H+ transport. It is suggested that the higher concentration of free fatty acids (PUMP substrates) in red tomatoes could explain the lower coupling state in mitochondria isolated from these fruits.
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Affiliation(s)
- A D Costa
- Departamento de Patologia Clínica (NMCE), Faculdade de Ciências Médicas, Universidade Estadual de Campinas, SP, Brazil
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Jezek P, Engstová H, Zácková M, Vercesi AE, Costa AD, Arruda P, Garlid KD. Fatty acid cycling mechanism and mitochondrial uncoupling proteins. Biochim Biophys Acta 1998; 1365:319-27. [PMID: 9693744 DOI: 10.1016/s0005-2728(98)00084-x] [Citation(s) in RCA: 144] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
We hypothesize that fatty acid-induced uncoupling serves in bioenergetic systems to set the optimum efficiency and tune the degree of coupling of oxidative phosphorylation. Uncoupling results from fatty acid cycling, enabled by several phylogenetically specialized proteins and, to a lesser extent, by other mitochondrial carriers. It is suggested that the regulated uncoupling in mammalian mitochondria is provided by uncoupling proteins UCP-1, UCP-2 and UCP-3, whereas in plant mitochondria by PUMP and StUCP, all belonging to the gene family of mitochondrial carriers. UCP-1, and hypothetically UCP-3, serve mostly to provide nonshivering thermogenesis in brown adipose tissue and skeletal muscle, respectively. Fatty acid cycling was documented for UCP-1, PUMP and ADP/ATP carrier, and is predicted also for UCP-2 and UCP-3. UCP-1 mediates a purine nucleotide-sensitive uniport of monovalent unipolar anions, including anionic fatty acids. The return of protonated fatty acid leads to H+ uniport and uncoupling. UCP-2 is probably involved in the regulation of body weight and energy balance, in fever, and defense against generation of reactive oxygen species. PUMP has been discovered in potato tubers and immunologically detected in fruits and corn, whereas StUCP has been cloned and sequenced froma a potato gene library. PUMP is supposed to act in the termination of synthetic processes in mature fruits and during the climacteric respiratory rise.
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Affiliation(s)
- P Jezek
- Department of Membrane Transport Biophysics, Academy of Sciences of the Czech Republic, Prague.
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Kowaltowski AJ, Costa AD, Vercesi AE. Activation of the potato plant uncoupling mitochondrial protein inhibits reactive oxygen species generation by the respiratory chain. FEBS Lett 1998; 425:213-6. [PMID: 9559650 DOI: 10.1016/s0014-5793(98)00231-2] [Citation(s) in RCA: 127] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
A variety of plant tissues contain an uncoupling mitochondrial protein (PUMP), recently described and characterized by our group. In this study we show that the inhibition of PUMP activity in potato tuber mitochondria significantly increases mitochondrial H2O2 generation, while PUMP substrates, such as linoleic acid, reduce mitochondrial H2O2 generation. This H2O2 generation occurred mainly by the dismutation of superoxide radicals formed through monoelectronic reduction of O2 by semiquinone forms of coenzyme Q. The results presented suggest that protection against mitochondrial oxidative stress may be a physiological role of PUMP.
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Affiliation(s)
- A J Kowaltowski
- Departamento de Patologia Clinica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas, SP, Brazil
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Jezek P, Costa AD, Vercesi AE. Reconstituted plant uncoupling mitochondrial protein allows for proton translocation via fatty acid cycling mechanism. J Biol Chem 1997; 272:24272-8. [PMID: 9305881 DOI: 10.1074/jbc.272.39.24272] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Potato and tomato plant uncoupling mitochondrial protein (PUMP) was reconstituted into liposomes, and K+ or H+ fluxes associated with fatty acid (FA)-induced ion movement were measured using fluorescent ion indicators potassium binding benzofuraneisophthalate and 6-methoxy-N-(3-sulfopropyl)-quinolinium. We suggest that PUMP, like its mammalian counterpart, the uncoupling protein of brown adipose tissue mitochondria (Garlid, K. D., Orosz, D. E., Modrianský, M., Vassanelli, S., and Jeek, P. (1996), J. Biol. Chem. 271, 2615-2702), allows for H+ translocation via a FA cycling mechanism. Reconstituted PUMP translocated anionic linoleic and heptylbenzoic acids, undecanesulfonate, and hexanesulfonate, but not phenylvaleric and abscisic acids or Cl-. Transport was inhibited by ATP and GDP. Internal acidification of protein-free liposomes by linoleic or heptylbenzoic acid indicated that H+ translocation occurs by FA flip-flopping across the lipid bilayer. However, addition of valinomycin after FA-initiated GDP-sensitive H+ efflux solely in proteoliposomes, indicating that influx of anionic FA via PUMP precedes a return of protonated FA carrying H+. Phenylvaleric acid, unable to flip-flop, was without effect. Kinetics of FA and undecanesulfonate uniport suggested the existence of an internal anion binding site. Exponential flux-voltage characteristics were also studied. We suggest that regulated uncoupling in plant mitochondria may be important during fruit ripening, senescence, and seed dormancy.
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Affiliation(s)
- P Jezek
- Department of Membrane Transport Biophysics, Institute of Physiology, Academy of Sciences, 14220 Prague 4, Czech Republic.
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Gadelha FR, Thomson L, Fagian MM, Costa AD, Radi R, Vercesi AE. Ca2+-independent permeabilization of the inner mitochondrial membrane by peroxynitrite is mediated by membrane protein thiol cross-linking and lipid peroxidation. Arch Biochem Biophys 1997; 345:243-50. [PMID: 9308896 DOI: 10.1006/abbi.1997.0259] [Citation(s) in RCA: 94] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Peroxynitrite anion, the reaction product of superoxide and nitric oxide, is a potent biological oxidant, which inactivates mammalian heart mitochondrial NADH-coenzyme Q reductase (complex I), succinate dehydrogenase (complex II), and ATPase, without affecting cytochrome c oxidase (complex IV). In this paper, we evaluated the effect of peroxynitrite on mitochondrial membrane integrity and permeability under low calcium concentration. Phosphate buffer was used in most of our experiments since Hepes, Tris, mannitol, and sucrose were found to inhibit the oxidative chemistry of peroxynitrite. Peroxynitrite (0.1-1.0 mM) caused a dose-dependent decrease in the ability of mitochondria to build up a membrane potential when N,N,N',N'-tetramethyl-p-phenylenediamine/ascorbate were used as substrate. Elimination of the membrane potential was accompanied by penetration of the osmotic support (KCl/NaCl) into the matrix as judged by the parallel occurrence of mitochondrial swelling. This swelling was partially inhibited by dithiothreitol (DTT) or butylated hydroxytoluene (BHT) and was insensitive to ethylene glycol-bis(beta-aminoethyl ether)-N,N,N',N'-tetraacetic acid, ADP, and cyclosporin A. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis of solubilized membrane proteins indicated that alterations in membrane permeability were associated with the production of protein aggregates due to membrane protein thiol cross-linking. The protective effect of DTT on both mitochondrial swelling and protein polymerization suggests the involvement of disulfide bonds in the membrane permeabilization process. In addition, the increase in thiobarbituric acid-reactive substances and the partial inhibitory effect of BHT indicate the occurrence of lipid peroxidation. These results support the idea that under our experimental conditions peroxynitrite causes mitochondrial structural and functional alterations by Ca2+-independent mechanisms through lipid peroxidation and protein sulfhydryl oxidation.
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Affiliation(s)
- F R Gadelha
- Departamento de Bioquímica, Instituto de Biologia, Universidade Estadual de Campinas, SP, Brazil
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Abstract
Transport properties of plant mitochondria from potato tubers were investigated using the swelling technique and membrane potential measurements. Proton-dependent swelling of fatty acid-depleted mitochondria in potassium acetate with valinomycin was possible only in the presence of fatty acids (linoleic acid and 12-(4-azido-2-nitrophenylamino)dodecanoic acid) and was inhibited by various purine nucleotides including ATP, GDP, and GTP. Swelling representing uptake of hexanesulfonate was also inhibited by purine nucleotides. Also, the membrane potential of fatty acid-depleted potato mitochondria energized by succinate declined upon the addition of linoleic acid or 12-(4-azido-2-nitrophenylamino)dodecanoic acid, and this decrease was prevented by ATP and other purine nucleotides. These transport activities are identical to those reported for brown adipose tissue mitochondria and related to the uncoupling protein; therefore, we ascribed them to the plant mitochondrial uncoupling protein (PUMP). A major difference between plant and mammalian uncoupling protein is that PUMP transports small hydrophilic anions such as Cl- very slowly, if at all. We suggest that PUMP may play an important role in plant physiology, where a regulated uncoupling and thermogenesis can proceed during fruit and seed development.
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Affiliation(s)
- P Jezek
- Department of Membrane Transport Biophysics, Institute of Physiology, Academy of Sciences, 14220 Prague 4, Czech Republic
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Abstract
Ethical values of 171 college students at California State University, Chico, were measured, using a subset of the Rokeach (1968, 1971) Value Survey. Nonparametric statistical analysis, four value measures, and four different consistent tests of significance and probability showed, surprisingly, that the younger students were more ethical than the older students. College students under 21 scored significantly higher ethically on three out of the four measures. Younger college students valued equality, freedom, and honesty more than their older classmates did. Surprisingly also, the younger students were significantly more concerned with being helpful and intellectual and were less involved in pursuing an exciting life and in social recognition than were the older students.
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Affiliation(s)
- A Sikula
- Department of Management, California State University, Chico 95929-0031
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de Oliveira AT, Rabelo LM, Costa AD, Lessa I. [Characteristics of the demand for cranial computerized tomography: reasons and costs of the exam]. Arq Neuropsiquiatr 1992; 50:91-8. [PMID: 1307485 DOI: 10.1590/s0004-282x1992000100016] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
It was reviewed a series of 2860 cerebral computed tomography (CCT) in order to compare the main reasons at referral to investigation with the CCT results and the costs with normal and abnormal CCT. It was also studied the age and sex of the patients. Data were collected from one out of three diagnostic centers in Salvador, Brasil, for a three years period. The 2860 CCT exclude all investigation carried out for the follow-up of a previously diagnosed abnormality. CCT abnormalities were detected in 1152 (40.3%). The following reasons showed the highest proportion of abnormal CCT, for males and females respectively: demential syndrome (91.7 and 83.3%); cerebrovascular accidents (85.1 and 73.6%); infectious and parasitary diseases (76.5 and 78.6%); tumors (65.8 and 55.4%); and head injuries, 63.6% for males. In the female group, 65.0% of the CCT were normal, in a range of 65.0 to 80.0% for the age groups under 54 years old. In the male group, the highest proportion of normal CCT was found in the age groups: 25-34 (68.4%), < 15 (62.9%) and 35-44 (62.7%). The most common reasons for normal CCT for males and females were: headache (81.3 and 87.5%); dizziness/vertigo (79.3 and 78.6%); seizures (67.3 and 70.0%); psychomotor deficiency (72.0 and 67.7%) and "endocrine disorders", 75.0% for each sex. The highest proportion of normal CCT (65.3%) was requested by medical "convenios". The cost with normal CCT reached US$565,225 and with the abnormal ones, US$381,247. Costs with normal CCT were 2.2 higher for medical "convenios" as compared to those of the National Institute of Security requests and 2.8 more than those of private medicine.
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Costa AD, Anzai A, Neto JB, Ikeda J. [Use of calcium hydroxide in the treatment of teeth with periapical lesions: clinical observation of 13 cases]. Rev Assoc Paul Cir Dent 1981; 35:220-6. [PMID: 6943624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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