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Wrzosek A, Augustynek B, Żochowska M, Szewczyk A. Mitochondrial Potassium Channels as Druggable Targets. Biomolecules 2020; 10:E1200. [PMID: 32824877 PMCID: PMC7466137 DOI: 10.3390/biom10081200] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 08/03/2020] [Accepted: 08/13/2020] [Indexed: 12/16/2022] Open
Abstract
Mitochondrial potassium channels have been described as important factors in cell pro-life and death phenomena. The activation of mitochondrial potassium channels, such as ATP-regulated or calcium-activated large conductance potassium channels, may have cytoprotective effects in cardiac or neuronal tissue. It has also been shown that inhibition of the mitochondrial Kv1.3 channel may lead to cancer cell death. Hence, in this paper, we examine the concept of the druggability of mitochondrial potassium channels. To what extent are mitochondrial potassium channels an important, novel, and promising drug target in various organs and tissues? The druggability of mitochondrial potassium channels will be discussed within the context of channel molecular identity, the specificity of potassium channel openers and inhibitors, and the unique regulatory properties of mitochondrial potassium channels. Future prospects of the druggability concept of mitochondrial potassium channels will be evaluated in this paper.
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Affiliation(s)
| | | | | | - Adam Szewczyk
- Laboratory of Intracellular Ion Channels, Nencki Institute of Experimental Biology, Polish Academy of Sciences, 02-093 Warsaw, Poland; (A.W.); (B.A.); (M.Ż.)
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Cuccioloni M, Mozzicafreddo M, Ali I, Bonfili L, Cecarini V, Eleuteri AM, Angeletti M. Interaction between wheat alpha-amylase/trypsin bi-functional inhibitor and mammalian digestive enzymes: Kinetic, equilibrium and structural characterization of binding. Food Chem 2016; 213:571-578. [PMID: 27451220 DOI: 10.1016/j.foodchem.2016.07.020] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 05/05/2016] [Accepted: 07/05/2016] [Indexed: 12/25/2022]
Abstract
Alpha-amylase/trypsin bi-functional inhibitors (ATIs) are non-gluten protein components of wheat and other cereals that can hypersensitise the human gastrointestinal tract, eventually causing enteropathies in predisposed individuals. These inhibitory proteins can act both directly by targeting specific pro-inflammatory receptors, and indirectly by impairing the activity of digestive enzymes, the latter event causing the accumulation of undigested peptides with potential immunogenic properties. Herein, according to a concerted approach based on in vitro and in silico methods we characterized kinetics, equilibrium parameters and modes of binding of the complexes formed between wheat ATI and two representative mammalian digestive enzymes, namely trypsin and alpha-amylase. Interestingly, we demonstrated ATI to target both enzymes with independent binding sites and with moderately high affinity.
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Affiliation(s)
- Massimiliano Cuccioloni
- School of Biosciences and Veterinary Medicine, Via Gentile III da Varano, 62032 Camerino (MC), Italy.
| | - Matteo Mozzicafreddo
- School of Biosciences and Veterinary Medicine, Via Gentile III da Varano, 62032 Camerino (MC), Italy
| | - Ishtiaq Ali
- School of Biosciences and Veterinary Medicine, Via Gentile III da Varano, 62032 Camerino (MC), Italy
| | - Laura Bonfili
- School of Biosciences and Veterinary Medicine, Via Gentile III da Varano, 62032 Camerino (MC), Italy
| | - Valentina Cecarini
- School of Biosciences and Veterinary Medicine, Via Gentile III da Varano, 62032 Camerino (MC), Italy
| | - Anna Maria Eleuteri
- School of Biosciences and Veterinary Medicine, Via Gentile III da Varano, 62032 Camerino (MC), Italy
| | - Mauro Angeletti
- School of Biosciences and Veterinary Medicine, Via Gentile III da Varano, 62032 Camerino (MC), Italy
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Godat E, Lecaille F, Desmazes C, Duchêne S, Weidauer E, Saftig P, Brömme D, Vandier C, Lalmanach G. Cathepsin K: a cysteine protease with unique kinin-degrading properties. Biochem J 2005; 383:501-6. [PMID: 15265002 PMCID: PMC1133743 DOI: 10.1042/bj20040864] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Taking into account a previous report of an unidentified enzyme from macrophages acting as a kininase, the ability of cysteine proteases to degrade kinins has been investigated. Wild-type fibroblast lysates from mice, by contrast with cathepsin K-deficient lysates, hydrolysed BK (bradykinin), and released two metabolites, BK-(1-4) and BK-(5-9). Cathepsin K, but not cathepsins B, H, L and S, cleaved kinins at the Gly4-Phe5 bond and the bradykinin-mimicking substrate Abz (o-aminobenzoic acid)-RPPGFSPFR-3-NO2-Tyr (3-nitrotyrosine) more efficiently (pH 6.0: kcat/K(m)=12500 mM(-1) x s(-1); pH 7.4: kcat/K(m)=6930 mM(-1) x s(-1)) than angiotensin-converting enzyme hydrolysed BK. Conversely Abz-RPPGFSPFR-3-NO2-Tyr was not cleaved by the Y67L (Tyr67-->Leu)/L205A (Leu205-->Ala) cathepsin K mutant, indicating that kinin degradation mostly depends on the S2 substrate specificity. Kininase activity was further evaluated on bronchial smooth muscles. BK, but not its metabolites BK(1-4) and BK(5-9), induced a dose-dependent contraction, which was abolished by Hoe140, a B2-type receptor antagonist. Cathepsin K impaired BK-dependent contraction of normal and chronic hypoxic rats, whereas cathepsins B and L did not. Taking together vasoactive properties of kinins and the potency of cathepsin K to modulate BK-dependent contraction of smooth muscles, the present data support the notion that cathepsin K may act as a kininase, a unique property among mammalian cysteine proteases.
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Affiliation(s)
- Emmanuel Godat
- *INSERM U618, Protéases et Vectorisation Pulmonaires/IFR 135 ‘Imagerie Fonctionnelle’, Université François Rabelais, Faculté de Médecine, 2 bis, Boulevard Tonnellé, F-37032 Tours Cédex, France
| | - Fabien Lecaille
- *INSERM U618, Protéases et Vectorisation Pulmonaires/IFR 135 ‘Imagerie Fonctionnelle’, Université François Rabelais, Faculté de Médecine, 2 bis, Boulevard Tonnellé, F-37032 Tours Cédex, France
| | - Claire Desmazes
- *INSERM U618, Protéases et Vectorisation Pulmonaires/IFR 135 ‘Imagerie Fonctionnelle’, Université François Rabelais, Faculté de Médecine, 2 bis, Boulevard Tonnellé, F-37032 Tours Cédex, France
| | - Sophie Duchêne
- *INSERM U618, Protéases et Vectorisation Pulmonaires/IFR 135 ‘Imagerie Fonctionnelle’, Université François Rabelais, Faculté de Médecine, 2 bis, Boulevard Tonnellé, F-37032 Tours Cédex, France
- †Laboratoire de Physiopathologie de la Paroi Artérielle, Université François Rabelais, Faculté de Médecine, 2 bis, Boulevard Tonnellé, F-37032 Tours Cédex, France
| | - Enrico Weidauer
- ‡Department of Human Genetics, Mount Sinai School of Medicine, New York, NY 10029, U.S.A
| | - Paul Saftig
- §Biochemisches Institut, Christian-Albrechts-Universität, Eduard-Buchner-Haus, Olshausenstrasse 40, D-24098 Kiel, Germany
| | - Dieter Brömme
- ‡Department of Human Genetics, Mount Sinai School of Medicine, New York, NY 10029, U.S.A
| | - Christophe Vandier
- †Laboratoire de Physiopathologie de la Paroi Artérielle, Université François Rabelais, Faculté de Médecine, 2 bis, Boulevard Tonnellé, F-37032 Tours Cédex, France
| | - Gilles Lalmanach
- *INSERM U618, Protéases et Vectorisation Pulmonaires/IFR 135 ‘Imagerie Fonctionnelle’, Université François Rabelais, Faculté de Médecine, 2 bis, Boulevard Tonnellé, F-37032 Tours Cédex, France
- To whom correspondence should be addressed (email )
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Dubuis E, Kumar P, Gautier M, Girardin C, Vandier C. Acidosis abolishes the effect of repeated applications of ATP on pulmonary artery force and [Ca2+]i. Respir Physiol Neurobiol 2004; 141:157-66. [PMID: 15239966 DOI: 10.1016/j.resp.2004.04.011] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2004] [Indexed: 10/26/2022]
Abstract
The purine nucleotide, ATP, can cause receptor-mediated desensitizing contractions of smooth muscle that may be modulated by pH. We investigated in the rat the effect of acidosis upon the contractile and Ca2+ responses induced by ATP upon intrapulmonary artery (PA) smooth muscle. Four successive applications of ATP (300 microM) at pH 7.4 induced desensitising contractile responses that showed progressively decreasing peak amplitudes that correlated with decreases of [Ca2+]i. Acidosis significantly reduced the peak contractile response to the first application of ATP without modifying the rate or degree of desensitisation in response to ATP and without decreasing the [Ca2+]i. Successive applications of ATP did not further reduce contractile force nor [Ca2+]i. These results demonstrated that acidosis abolishes the effect of repeat applications of ATP on pulmonary artery force and [Ca2+]i via alteration in the desensitization-resensitisation characteristics of ATP receptor. This suggest a potentially important physiological role for changes in external pH in the regulation of ATP-mediated control of the pulmonary circulation.
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Affiliation(s)
- Eric Dubuis
- Laboratoire de Physiopathologie de la Paroi Artérielle, Faculté de Médecine, 2 bis Boulevard Tonnellé, 37032 Tours, France
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Dubuis E, Gautier M, Melin A, Rebocho M, Girardin C, Bonnet P, Vandier C. Chronic carbon monoxide exposure of hypoxic rats increases in vitro sensitivity of pulmonary artery smooth muscle. Can J Physiol Pharmacol 2003; 81:711-9. [PMID: 12897819 DOI: 10.1139/y03-070] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Exogenous carbon monoxide (CO) induces pulmonary vasodilation by acting directly on pulmonary artery (PA) smooth muscle cells. We investigated the contribution of K+ channels and soluble guanylyl cyclase to the regulation of PA tone by acute CO in chronic hypoxic rats (3 weeks at 0.5 atm (1 atm = 101.325 kPa); hypoxic) and in chronic hypoxic rats exposed to exogenous CO (3 weeks at 0.5 atm + 50 ppm CO; hypoxic-CO). Acute CO induced relaxation in PA rings from all animals. However, the amplitude of CO relaxation was significantly decreased in hypoxic rings and increased in hypoxic-CO rings. This different effect occurred with a decrease and an increase of pD2, respectively, in hypoxic and hypoxic-CO rings. We showed a positive relation between the percentage of inhibition of CO relaxation by a blocker of K+ channels and the increase of CO sensitivity. Thus, we showed for the first time that chronic hypoxia decreases acute CO sensitivity, which in contrast, increases in the presence of chronic CO. The present study provides initial evidence of a link between increased K(+)-channel activity and CO sensitivity.
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Affiliation(s)
- Eric Dubuis
- Laboratoire de physiopathologie de la paroi artérielle (LABPART), Institut Fédératif de Recherche no 120, Faculté de Médecine, 2 bis, boulevard Tonnellé, 37032 Tours, France
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