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Prag HA, Aksentijevic D, Dannhorn A, Giles AV, Mulvey JF, Sauchanka O, Du L, Bates G, Reinhold J, Kula-Alwar D, Xu Z, Pellerin L, Goodwin RJA, Murphy MP, Krieg T. Ischemia-Selective Cardioprotection by Malonate for Ischemia/Reperfusion Injury. Circ Res 2022; 131:528-541. [PMID: 35959683 PMCID: PMC9426742 DOI: 10.1161/circresaha.121.320717] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
BACKGROUND Inhibiting SDH (succinate dehydrogenase), with the competitive inhibitor malonate, has shown promise in ameliorating ischemia/reperfusion injury. However, key for translation to the clinic is understanding the mechanism of malonate entry into cells to enable inhibition of SDH, its mitochondrial target, as malonate itself poorly permeates cellular membranes. The possibility of malonate selectively entering the at-risk heart tissue on reperfusion, however, remains unexplored. METHODS C57BL/6J mice, C2C12 and H9c2 myoblasts, and HeLa cells were used to elucidate the mechanism of selective malonate uptake into the ischemic heart upon reperfusion. Cells were treated with malonate while varying pH or together with transport inhibitors. Mouse hearts were either perfused ex vivo (Langendorff) or subjected to in vivo left anterior descending coronary artery ligation as models of ischemia/reperfusion injury. Succinate and malonate levels were assessed by liquid chromatography-tandem mass spectrometry LC-MS/MS, in vivo by mass spectrometry imaging, and infarct size by TTC (2,3,5-triphenyl-2H-tetrazolium chloride) staining. RESULTS Malonate was robustly protective against cardiac ischemia/reperfusion injury, but only if administered at reperfusion and not when infused before ischemia. The extent of malonate uptake into the heart was proportional to the duration of ischemia. Malonate entry into cardiomyocytes in vivo and in vitro was dramatically increased at the low pH (≈6.5) associated with ischemia. This increased uptake of malonate was blocked by selective inhibition of MCT1 (monocarboxylate transporter 1). Reperfusion of the ischemic heart region with malonate led to selective SDH inhibition in the at-risk region. Acid-formulation greatly enhances the cardioprotective potency of malonate. CONCLUSIONS Cardioprotection by malonate is dependent on its entry into cardiomyocytes. This is facilitated by the local decrease in pH that occurs during ischemia, leading to its selective uptake upon reperfusion into the at-risk tissue, via MCT1. Thus, malonate's preferential uptake in reperfused tissue means it is an at-risk tissue-selective drug that protects against cardiac ischemia/reperfusion injury.
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Affiliation(s)
- Hiran A. Prag
- Department of Medicine (H.A.P., A.V.G., J.F.M., O.S., D.K.-A., M.P.M., T.K.), University of Cambridge, United Kingdom.,MRC Mitochondrial Biology Unit (H.A.P., A.V.G., G.B., J.R., M.M.P.), University of Cambridge, United Kingdom
| | - Dunja Aksentijevic
- Centre for Biochemical Pharmacology, William Harvey Research Institute, Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom (D.A.)
| | - Andreas Dannhorn
- Imaging and Data Analytics, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Cambridge, United Kingdom (A.D., R.J.A.G.)
| | - Abigail V. Giles
- Department of Medicine (H.A.P., A.V.G., J.F.M., O.S., D.K.-A., M.P.M., T.K.), University of Cambridge, United Kingdom.,MRC Mitochondrial Biology Unit (H.A.P., A.V.G., G.B., J.R., M.M.P.), University of Cambridge, United Kingdom.,Laboratory of Cardiac Energetics, National Heart, Lung and Blood Institute, Bethesda, MD (A.V.G.)
| | - John F. Mulvey
- Department of Medicine (H.A.P., A.V.G., J.F.M., O.S., D.K.-A., M.P.M., T.K.), University of Cambridge, United Kingdom
| | - Olga Sauchanka
- Department of Medicine (H.A.P., A.V.G., J.F.M., O.S., D.K.-A., M.P.M., T.K.), University of Cambridge, United Kingdom
| | - Luping Du
- Department of Physiology and Pathophysiology, Tianjin Medical University, China (L.D., Z.X.)
| | - Georgina Bates
- MRC Mitochondrial Biology Unit (H.A.P., A.V.G., G.B., J.R., M.M.P.), University of Cambridge, United Kingdom
| | - Johannes Reinhold
- MRC Mitochondrial Biology Unit (H.A.P., A.V.G., G.B., J.R., M.M.P.), University of Cambridge, United Kingdom.,Faculty of Medicine and Health Sciences, University of East Anglia, Norwich Research Park (J.R.)
| | - Duvaraka Kula-Alwar
- Department of Medicine (H.A.P., A.V.G., J.F.M., O.S., D.K.-A., M.P.M., T.K.), University of Cambridge, United Kingdom
| | - Zhelong Xu
- Department of Physiology and Pathophysiology, Tianjin Medical University, China (L.D., Z.X.)
| | - Luc Pellerin
- Département de Physiologie, Université de Lausanne, Switzerland (L.P.).,Centre de Résonance Magnétique des Systèmes Biologiques, UMR5536 CNRS, LabEx TRAIL-IBIO, Université de Bordeaux, France (L.P.).,Inserm U1313, Université et CHU de Poitiers, France (L.P.)
| | - Richard J. A. Goodwin
- Imaging and Data Analytics, Clinical Pharmacology and Safety Sciences, R&D, AstraZeneca, Cambridge, United Kingdom (A.D., R.J.A.G.).,Institute of Infection, Immunity and Inflammation, College of Medical, Veterinary and Life Sciences, University of Glasgow, United Kingdom (R.J.A.G.)
| | - Michael P. Murphy
- Department of Medicine (H.A.P., A.V.G., J.F.M., O.S., D.K.-A., M.P.M., T.K.), University of Cambridge, United Kingdom.,MRC Mitochondrial Biology Unit (H.A.P., A.V.G., G.B., J.R., M.M.P.), University of Cambridge, United Kingdom
| | - Thomas Krieg
- Department of Medicine (H.A.P., A.V.G., J.F.M., O.S., D.K.-A., M.P.M., T.K.), University of Cambridge, United Kingdom
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Jennings ML. Cell Physiology and Molecular Mechanism of Anion Transport by Erythrocyte Band 3/AE1. Am J Physiol Cell Physiol 2021; 321:C1028-C1059. [PMID: 34669510 PMCID: PMC8714990 DOI: 10.1152/ajpcell.00275.2021] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The major transmembrane protein of the red blood cell, known as band 3, AE1, and SLC4A1, has two main functions: 1) catalysis of Cl-/HCO3- exchange, one of the steps in CO2 excretion; 2) anchoring the membrane skeleton. This review summarizes the 150 year history of research on red cell anion transport and band 3 as an experimental system for studying membrane protein structure and ion transport mechanisms. Important early findings were that red cell Cl- transport is a tightly coupled 1:1 exchange and band 3 is labeled by stilbenesulfonate derivatives that inhibit anion transport. Biochemical studies showed that the protein is dimeric or tetrameric (paired dimers) and that there is one stilbenedisulfonate binding site per subunit of the dimer. Transport kinetics and inhibitor characteristics supported the idea that the transporter acts by an alternating access mechanism with intrinsic asymmetry. The sequence of band 3 cDNA provided a framework for detailed study of protein topology and amino acid residues important for transport. The identification of genetic variants produced insights into the roles of band 3 in red cell abnormalities and distal renal tubular acidosis. The publication of the membrane domain crystal structure made it possible to propose concrete molecular models of transport. Future research directions include improving our understanding of the transport mechanism at the molecular level and of the integrative relationships among band 3, hemoglobin, carbonic anhydrase, and gradients (both transmembrane and subcellular) of HCO3-, Cl-, O2, CO2, pH, and NO metabolites during pulmonary and systemic capillary gas exchange.
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Affiliation(s)
- Michael L Jennings
- Department of Physiology and Cell Biology, University of Arkansas for Medical Sciences, Little Rock, Arkansas, United States
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