1
|
Kim HJ, Hong JH. Multiple Regulatory Signals and Components in the Modulation of Bicarbonate Transporters. Pharmaceutics 2024; 16:78. [PMID: 38258089 PMCID: PMC10820580 DOI: 10.3390/pharmaceutics16010078] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2023] [Revised: 01/01/2024] [Accepted: 01/03/2024] [Indexed: 01/24/2024] Open
Abstract
Bicarbonate transporters are responsible for the appropriate flux of bicarbonate across the plasma membrane to perform various fundamental cellular functions. The functions of bicarbonate transporters, including pH regulation, cell migration, and inflammation, are highlighted in various cellular systems, encompassing their participation in both physiological and pathological processes. In this review, we focused on recently identified modulatory signaling components that regulate the expression and activity of bicarbonate transporters. Moreover, we addressed recent advances in our understanding of cooperative systems of bicarbonate transporters and channelopathies. This current review aims to provide a new, in-depth understanding of numerous human diseases associated with the dysfunction of bicarbonate transporters.
Collapse
Affiliation(s)
| | - Jeong Hee Hong
- Department of Physiology, Lee Gil Ya Cancer and Diabetes Institute, College of Medicine, Gachon University, 155 Getbeolro, Yeonsu-gu, Incheon 21999, Republic of Korea;
| |
Collapse
|
2
|
Ji MJ, Son KH, Hong JH. Addition of oh8dG to Cardioplegia Attenuated Myocardial Oxidative Injury through the Inhibition of Sodium Bicarbonate Cotransporter Activity. Antioxidants (Basel) 2022; 11:antiox11091641. [PMID: 36139714 PMCID: PMC9495749 DOI: 10.3390/antiox11091641] [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: 07/13/2022] [Revised: 08/19/2022] [Accepted: 08/23/2022] [Indexed: 11/28/2022] Open
Abstract
The biomarker 8-hydroxy-2′-deoxyguanosine (oh8dG) is derived from oxidized nucleic acids or products of oxidant-mediated DNA damage. Enhanced sodium bicarbonate cotransporter (NBC) activity is caused by reactive oxygen species (ROS) production in ventricular myocytes. Thus, we hypothesized that cardioplegia-solution-mediated ROS generation may be involved in the regulation of NBC activity in cardiomyocytes and that oh8dG treatment may modulate ROS and associated NBC activity. Langendorff-free cardioplegia-arrested cardiac strips and cardiomyocytes were isolated to determine the NBC activity and effects of oh8dG on oxidative-stress-mediated cardiac damage markers. We first determined the histidine-tryptophan-ketoglutarate (HTK) solution mediated NBC activity in cardiac strips and cells. The oh8dG treatment attenuated NBC activity in the electroneutral or electrogenic form of NBC. Additionally, exposure to HTK solution induced ROS, whereas co-administration of oh8dG attenuated ROS-mediated NBC activity, reduced ROS levels, and decreased the expression of apoptotic markers and fibrosis-associated proteins in cardiac cells. The oh8dG-administrated cardiac tissues were also protected from enhanced HTK-induced damage markers, heat shock protein 60 and polyADP-ribose. Our results show that oh8dG has a protective role against myocardial oxidative damage and provides a useful treatment strategy for restoring cardiac function.
Collapse
Affiliation(s)
- Min Jeong Ji
- Department of Health Sciences and Technology, Lee Gil Ya Cancer and Diabetes Institute, GAIHST, Gachon University, 155 Getbeolro, Yeonsu-gu, Incheon 21999, Korea
| | - Kuk Hui Son
- Department of Thoracic and Cardiovascular Surgery, Gachon University Gil Medical Center, Gachon University, Incheon 21565, Korea
- Correspondence: (K.H.S.); (J.H.H.); Tel.: +82-32-899-6682 (J.H.H.)
| | - Jeong Hee Hong
- Department of Health Sciences and Technology, Lee Gil Ya Cancer and Diabetes Institute, GAIHST, Gachon University, 155 Getbeolro, Yeonsu-gu, Incheon 21999, Korea
- Correspondence: (K.H.S.); (J.H.H.); Tel.: +82-32-899-6682 (J.H.H.)
| |
Collapse
|
3
|
The electrogenic sodium bicarbonate cotransporter and its roles in the myocardial ischemia-reperfusion induced cardiac diseases. Life Sci 2021; 270:119153. [PMID: 33539911 DOI: 10.1016/j.lfs.2021.119153] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Revised: 01/06/2021] [Accepted: 01/22/2021] [Indexed: 12/19/2022]
Abstract
Cardiac tissue ischemia/hypoxia increases glycolysis and lactic acid accumulation in cardiomyocytes, leading to intracellular metabolic acidosis. Sodium bicarbonate cotransporters (NBCs) play a vital role in modulating intracellular pH and maintaining sodium ion concentrations in cardiomyocytes. Cardiomyocytes mainly express electrogenic sodium bicarbonate cotransporter (NBCe1), which has been demonstrated to participate in myocardial ischemia/reperfusion (I/R) injury. This review outlines the structural and functional properties of NBCe1, summarizes the signaling pathways and factors that may regulate the activity of NBCe1, and reviews the roles of NBCe1 in the pathogenesis of I/R-induced cardiac diseases. Further studies revealing the regulatory mechanisms of NBCe1 activity should provide novel therapeutic targets for preventing I/R-induced cardiac diseases.
Collapse
|
4
|
Medina AJ, Ibáñez AM, Diaz-Zegarra LA, Portiansky EL, Blanco PG, Pereyra EV, de Giusti VC, Aiello EA, Yeves AM, Ennis IL. Cardiac up-regulation of NBCe1 emerges as a beneficial consequence of voluntary wheel running in mice. Arch Biochem Biophys 2020; 694:108600. [PMID: 33007282 DOI: 10.1016/j.abb.2020.108600] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 09/17/2020] [Accepted: 09/23/2020] [Indexed: 11/30/2022]
Abstract
Physical training stimulates the development of physiologic cardiac hypertrophy (CH), being a key event in this process the inhibition of the Na+/H+ exchanger. However, the role of the sodium bicarbonate cotransporter (NBC) has not been explored yet under this circumstance. C57/Bl6 mice were allowed to voluntary exercise (wheel running) for five weeks. Cardiac mass was evaluated by echocardiography and histomorphometry detecting that training promoted the development of physiological CH (heart weight/tibia length ratio, mg/mm: 6.54 ± 0.20 vs 8.81 ± 0.24; interstitial collagen content, %: 3.14 ± 0.63 vs. 1.57 ± 0.27; and cross-sectional area of cardiomyocytes, μm2: 200.6 ± 8.92 vs. 281.9 ± 24.05; sedentary (Sed) and exercised (Ex) mice, respectively). The activity of the electrogenic isoform of the cardiac NBC (NBCe1) was estimated by recording intracellular pH under high potassium concentration and by measuring action potential duration (APD). NBCe1 activity was significantly increased in isolated cardiomyocytes of trained mice. Additionally, the APD was shorter and the alkalization due to high extracellular potassium-induced depolarization was greater in this group, indicating that the NBCe1 was hyperactive. These results are online with the observed myocardial up-regulation of the NBCe1 (Western Blot, %: 100 ± 13.86 vs. 202 ± 29.98; Sed vs. Ex, n = 6 each group). In addition, we detected a reduction in H2O2 production in the myocardium of trained mice. These results support that voluntary training induces the development of physiologic CH with up-regulation of the cardiac NBCe1 in mice. Furthermore, the improvement in the antioxidant capacity contributes to the beneficial cardiovascular consequences of physical training.
Collapse
Affiliation(s)
- Andrés J Medina
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E, Cingolani" Facultad de Ciencias Médicas UNLP-CONICET, Argentina
| | - Alejandro M Ibáñez
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E, Cingolani" Facultad de Ciencias Médicas UNLP-CONICET, Argentina
| | - Leandro A Diaz-Zegarra
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E, Cingolani" Facultad de Ciencias Médicas UNLP-CONICET, Argentina
| | - Enrique L Portiansky
- Laboratorio de Análisis de Imágenes, Facultad de Ciencias Veterinarias UNLP-CONICET, Argentina
| | - Paula G Blanco
- Servicio de Cardiología, Facultad de Ciencias Veterinarias, UNLP-CONICET, Argentina
| | - Erica V Pereyra
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E, Cingolani" Facultad de Ciencias Médicas UNLP-CONICET, Argentina
| | - Verónica C de Giusti
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E, Cingolani" Facultad de Ciencias Médicas UNLP-CONICET, Argentina
| | - Ernesto A Aiello
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E, Cingolani" Facultad de Ciencias Médicas UNLP-CONICET, Argentina
| | - Alejandra M Yeves
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E, Cingolani" Facultad de Ciencias Médicas UNLP-CONICET, Argentina
| | - Irene L Ennis
- Centro de Investigaciones Cardiovasculares "Dr. Horacio E, Cingolani" Facultad de Ciencias Médicas UNLP-CONICET, Argentina.
| |
Collapse
|
5
|
Portal L, Morin D, Motterlini R, Ghaleh B, Pons S. The CO-releasing molecule CORM-3 protects adult cardiomyocytes against hypoxia-reoxygenation by modulating pH restoration. Eur J Pharmacol 2019; 862:172636. [PMID: 31491405 DOI: 10.1016/j.ejphar.2019.172636] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 08/26/2019] [Accepted: 09/02/2019] [Indexed: 01/18/2023]
Abstract
Several studies have reported that CORM-3, a water-soluble carbon monoxide releasing molecule, elicits cardioprotection against myocardial infarction but the mechanism remains to be investigated. Numerous reports indicate that inhibition of pH regulators, the Na+/H+ exchanger (NHE) and Na+/HCO3- symporter (NBC), protect cardiomyocytes from hypoxia/reoxygenation injury by delaying the intracellular pH (pHi) recovery at reperfusion. Our goal was to explore whether CORM-3-mediated cytoprotection involves the modulation of pH regulation. When added at reoxygenation, CORM-3 (50 μM) reduced the mortality of cardiomyocytes exposed to 3 h of hypoxia and 2 h of reoxygenation in HCO3--buffered solution. This effect was lost when using inactive iCORM-3, which is depleted of CO and used as control, thus implicating CO as the mediator of this cardioprotection. Interestingly, the cardioprotective effect of CORM-3 was abolished by switching to a bicarbonate-free medium. This effect of CORM-3 was also inhibited by 5-hydroxydecanoate, a mitochondrial ATP-dependent K+ (mKATP) channel inhibitor (500 μM) or PD098059, a MEK1/2 inhibitor (10 μM). In additional experiments and in the absence of hypoxia-reoxygenation, intracellular pH was monitored in cardiomyocytes exposed to cariporide to block NHE activity. CORM-3 inhibited alkalinisation and this effect was blocked by PD098059 and 5-HD. In conclusion, CORM-3 protects the cardiomyocyte against hypoxia-reoxygenation injury by inhibiting a bicarbonate transporter at reoxygenation, probably the Na+/HCO3- symporter. This cardioprotective effect of CORM-3 requires the activation of mKATP channels and the activation of MEK1/2.
Collapse
Affiliation(s)
- Lolita Portal
- U955-IMRB, Equipe 03, Inserm, UPEC, Ecole Nationale Vétérinaire d'Alfort, Créteil, France
| | - Didier Morin
- U955-IMRB, Equipe 03, Inserm, UPEC, Ecole Nationale Vétérinaire d'Alfort, Créteil, France
| | | | - Bijan Ghaleh
- U955-IMRB, Equipe 03, Inserm, UPEC, Ecole Nationale Vétérinaire d'Alfort, Créteil, France.
| | - Sandrine Pons
- U955-IMRB, Equipe 03, Inserm, UPEC, Ecole Nationale Vétérinaire d'Alfort, Créteil, France
| |
Collapse
|
6
|
Hoffmann M, Chen X, Hirano M, Arimitsu K, Kimura H, Higuchi T, Decker M. 18
F‐Labeled Derivatives of Irbesartan for Angiotensin II Receptor PET Imaging. ChemMedChem 2018; 13:2546-2557. [DOI: 10.1002/cmdc.201800638] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Indexed: 12/31/2022]
Affiliation(s)
- Matthias Hoffmann
- Pharmaceutical and Medicinal ChemistryInstitute of Pharmacy and Food ChemistryJulius Maximilian University Würzburg Am Hubland 97074 Würzburg Germany
| | - Xinyu Chen
- Department of Nuclear Medicine and Comprehensive Heart Failure Centre (CHFC)University Hospital of Würzburg Oberdürrbacherstr. 6 97080 Würzburg Germany
| | - Mitsuru Hirano
- Department of Bio-Medical ImagingNational Cerebral and Cardiovascular Centre, 5–7-1 Fujishiro-dai Suita Osaka 565-8565 Japan
| | - Kenji Arimitsu
- Department of Analytical and Bioinorganic ChemistryKyoto Pharmaceutical University 5 Nakauchi-Cho, Misasagi Yamashina-ku Kyoto 607–8414 Japan
| | - Hiroyuki Kimura
- Department of Analytical and Bioinorganic ChemistryKyoto Pharmaceutical University 5 Nakauchi-Cho, Misasagi Yamashina-ku Kyoto 607–8414 Japan
| | - Takahiro Higuchi
- Department of Nuclear Medicine and Comprehensive Heart Failure Centre (CHFC)University Hospital of Würzburg Oberdürrbacherstr. 6 97080 Würzburg Germany
- Department of Bio-Medical ImagingNational Cerebral and Cardiovascular Centre, 5–7-1 Fujishiro-dai Suita Osaka 565-8565 Japan
| | - Michael Decker
- Pharmaceutical and Medicinal ChemistryInstitute of Pharmacy and Food ChemistryJulius Maximilian University Würzburg Am Hubland 97074 Würzburg Germany
| |
Collapse
|
7
|
Orlowski A, De Giusti VC, Ciancio MC, Espejo MS, Aiello EA. The cardiac electrogenic sodium/bicarbonate cotransporter (NBCe1) is activated by aldosterone through the G protein-coupled receptor 30 (GPR 30). Channels (Austin) 2016; 10:428-434. [PMID: 27249584 DOI: 10.1080/19336950.2016.1195533] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The sodium/bicarbonate cotransporter (NBC) transports extracellular Na+ and HCO3- into the cytoplasm upon intracellular acidosis, restoring the acidic pHi to near neutral values. Two different NBC isoforms have been described in the heart, the electroneutral NBCn1 (1Na+:1HCO3-) and the electrogenic NBCe1 (1Na+:2HCO3-). Certain non-genomic effects of aldosterone (Ald) were due to an orphan G protein-couple receptor 30 (GPR30). We have recently demonstrated that Ald activates GPR30 in adult rat ventricular myocytes, which transactivates the epidermal growth factor receptor (EGFR) and in turn triggers a reactive oxygen species (ROS)- and PI3K/AKT-dependent pathway, leading to the stimulation of NBC. The aim of this study was to investigate the NBC isoform involved in the Ald/GPR30-induced NBC activation. Using specific NBCe1 inhibitory antibodies (a-L3) we demonstrated that Ald does not affect NBCn1 activity. Ald was able to increase NBCe1 activity recorded in isolation. Using immunofluorescence and confocal microscopy analysis we showed in this work that both NBCe1 and GPR30 are localized in t-tubules. In conclusion, we have demonstrated that NBCe1 is the NBC isoform activated by Ald in the heart.
Collapse
Affiliation(s)
- Alejandro Orlowski
- a Centro de Investigaciones Cardiovasculares "Dr. Horacio Cingolani" , Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET , La Plata , Buenos Aires , Argentina
| | - Verónica C De Giusti
- a Centro de Investigaciones Cardiovasculares "Dr. Horacio Cingolani" , Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET , La Plata , Buenos Aires , Argentina
| | - María C Ciancio
- a Centro de Investigaciones Cardiovasculares "Dr. Horacio Cingolani" , Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET , La Plata , Buenos Aires , Argentina
| | - María S Espejo
- a Centro de Investigaciones Cardiovasculares "Dr. Horacio Cingolani" , Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET , La Plata , Buenos Aires , Argentina
| | - Ernesto A Aiello
- a Centro de Investigaciones Cardiovasculares "Dr. Horacio Cingolani" , Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET , La Plata , Buenos Aires , Argentina
| |
Collapse
|
8
|
De Giusti VC, Orlowski A, Ciancio MC, Espejo MS, Gonano LA, Caldiz CI, Vila Petroff MG, Villa-Abrille MC, Aiello EA. Aldosterone stimulates the cardiac sodium/bicarbonate cotransporter via activation of the g protein-coupled receptor gpr30. J Mol Cell Cardiol 2015; 89:260-7. [PMID: 26497404 DOI: 10.1016/j.yjmcc.2015.10.024] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/21/2015] [Revised: 10/07/2015] [Accepted: 10/20/2015] [Indexed: 12/22/2022]
Abstract
Some cardiac non-genomic effects of aldosterone (Ald) are reported to be mediated through activation of the classic mineralocorticoid receptor (MR). However, in the last years, it was proposed that activation of the novel G protein-coupled receptor GPR30 mediates certain non-genomic effects of Ald. The aim of this study was to elucidate if the sodium/bicarbonate cotransporter (NBC) is stimulated by Ald and if the activation of GPR30 mediates this effect. NBC activity was evaluated in rat cardiomyocytes perfused with HCO3(-)/CO2 solution in the continuous presence of HOE642 (sodium/hydrogen exchanger blocker) during recovery from acidosis using intracellular fluorescence measurements. Ald enhanced NBC activity (% of ΔJHCO3(-); control: 100±5.82%, n=7 vs Ald: 151.88±11.02%, n=5; P<0.05), which was prevented by G15 (GPR30 blocker, 90.53±7.81%, n=7). Further evidence for the involvement of GPR30 was provided by G1 (GPR30 agonist), which stimulated NBC (185.13±18.28%, n=6; P<0.05) and this effect was abrogated by G15 (124.19±10.96%, n=5). Ald- and G1-induced NBC stimulation was abolished by the reactive oxygen species (ROS) scavenger MPG and by the NADPH oxidase inhibitor apocynin. In addition, G15 prevented Ald- and G1-induced ROS production. Pre-incubation of myocytes with wortmannin (PI3K-AKT pathway blocker) prevented Ald- or G1-induced NBC stimulation. In summary, Ald stimulates NBC by GPR30 activation, ROS production and AKT stimulation.
Collapse
Affiliation(s)
- Verónica C De Giusti
- Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET, La Plata, Argentina
| | - Alejandro Orlowski
- Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET, La Plata, Argentina
| | - María C Ciancio
- Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET, La Plata, Argentina
| | - María S Espejo
- Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET, La Plata, Argentina
| | - Luis A Gonano
- Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET, La Plata, Argentina
| | - Claudia I Caldiz
- Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET, La Plata, Argentina
| | - Martín G Vila Petroff
- Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET, La Plata, Argentina
| | - María C Villa-Abrille
- Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET, La Plata, Argentina
| | - Ernesto A Aiello
- Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET, La Plata, Argentina
| |
Collapse
|
9
|
Steinkamp AD, Seling N, Lee S, Boedtkjer E, Bolm C. Synthesis of N-cyano-substituted sulfilimine and sulfoximine derivatives of S0859 and their biological evaluation as sodium bicarbonate co-transport inhibitors. MEDCHEMCOMM 2015. [DOI: 10.1039/c5md00367a] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Two analogs of S0859 have been synthesized and their effects on Na+,HCO3− co-transport activity have been evaluated.
Collapse
Affiliation(s)
| | - Nico Seling
- Institute of Organic Chemistry
- RWTH Aachen University
- 52056 Aachen
- Germany
| | - Soojung Lee
- Department of Biomedicine
- Aarhus University
- DK-8000 Aarhus C
- Denmark
| | - Ebbe Boedtkjer
- Department of Biomedicine
- Aarhus University
- DK-8000 Aarhus C
- Denmark
| | - Carsten Bolm
- Institute of Organic Chemistry
- RWTH Aachen University
- 52056 Aachen
- Germany
| |
Collapse
|
10
|
Wang HS, Chen Y, Vairamani K, Shull GE. Critical role of bicarbonate and bicarbonate transporters in cardiac function. World J Biol Chem 2014; 5:334-345. [PMID: 25225601 PMCID: PMC4160527 DOI: 10.4331/wjbc.v5.i3.334] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/01/2014] [Revised: 03/06/2014] [Accepted: 05/19/2014] [Indexed: 02/05/2023] Open
Abstract
Bicarbonate is one of the major anions in mammalian tissues and extracellular fluids. Along with accompanying H+, HCO3- is generated from CO2 and H2O, either spontaneously or via the catalytic activity of carbonic anhydrase. It serves as a component of the major buffer system, thereby playing a critical role in pH homeostasis. Bicarbonate can also be utilized by a variety of ion transporters, often working in coupled systems, to transport other ions and organic substrates across cell membranes. The functions of HCO3- and HCO3--transporters in epithelial tissues have been studied extensively, but their functions in heart are less well understood. Here we review studies of the identities and physiological functions of Cl-/HCO3- exchangers and Na+/HCO3- cotransporters of the SLC4A and SLC26A families in heart. We also present RNA Seq analysis of their cardiac mRNA expression levels. These studies indicate that slc4a3 (AE3) is the major Cl-/HCO3- exchanger and plays a protective role in heart failure, and that Slc4a4 (NBCe1) is the major Na+/HCO3- cotransporter and affects action potential duration. In addition, previous studies show that HCO3- has a positive inotropic effect in the perfused heart that is largely independent of effects on intracellular Ca2+. The importance of HCO3- in the regulation of contractility is supported by experiments showing that isolated cardiomyocytes exhibit sharply enhanced contractility, with no change in Ca2+ transients, when switched from Hepes-buffered to HCO3-- buffered solutions. These studies demonstrate that HCO3- and HCO3--handling proteins play important roles in the regulation of cardiac function.
Collapse
|
11
|
Li M, Ma G, Han L, Li J. Regulating Effect of Tea Polyphenols on Endothelin, Intracellular Calcium Concentration, and Mitochondrial Membrane Potential in Vascular Endothelial Cells Injured by Angiotensin II. Ann Vasc Surg 2014; 28:1016-22. [DOI: 10.1016/j.avsg.2013.11.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 10/24/2013] [Accepted: 11/25/2013] [Indexed: 01/12/2023]
|
12
|
De Giusti VC, Ciancio MC, Orlowski A, Aiello EA. Modulation of the cardiac sodium/bicarbonate cotransporter by the renin angiotensin aldosterone system: pathophysiological consequences. Front Physiol 2014; 4:411. [PMID: 24478712 PMCID: PMC3894460 DOI: 10.3389/fphys.2013.00411] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2013] [Accepted: 12/27/2013] [Indexed: 12/22/2022] Open
Abstract
The sodium/bicarbonate cotransporter (NBC) is one of the major alkalinizing mechanisms in the cardiomyocytes. It has been demonstrated the existence of at least two functional isoforms, one that promotes the co-influx of 1 molecule of Na+ per 1 molecule of HCO−3 (electroneutral isoform; NBCn1) and the other one that generates the co-influx of 1 molecule of Na+ per 2 molecules of HCO−3 (electrogenic isoform; NBCe1). Both isoforms are important to maintain intracellular pH (pHi) and sodium concentration ([Na+]i). In addition, NBCe1 generates an anionic repolarizing current that modulates the action potential duration (APD). The renin-angiotensin-aldosterone system (RAAS) is implicated in the modulation of almost all physiological cardiac functions and is also involved in the development and progression of cardiac diseases. It was reported that angiotensin II (Ang II) exhibits an opposite effect on NBC isoforms: it activates NBCn1 and inhibits NBCe1. The activation of NBCn1 leads to an increase in pHi and [Na+]i, which indirectly, due to the stimulation of reverse mode of the Na+/Ca2+ exchanger (NCX), conduces to an increase in the intracellular Ca2+ concentration. On the other hand, the inhibition of NBCe1 generates an APD prolongation, potentially representing a risk of arrhythmias. In the last years, the potentially altered NBC function in pathological scenarios, as cardiac hypertrophy and ischemia-reperfusion, has raised increasing interest among investigators. This review attempts to draw the attention on the relevant regulation of NBC activity by RAAS, since it modulates pHi and [Na+]i, which are involved in the development of cardiac hypertrophy, the damage produced by ischemia-reperfusion and the generation of arrhythmic events, suggesting a potential role of NBC in cardiac diseases.
Collapse
Affiliation(s)
- Verónica C De Giusti
- Facultad de Ciencias Médicas, Centro de Investigaciones Cardiovasculares, Universidad Nacional de La Plata, CONICET-La Plata La Plata, Argentina
| | - María C Ciancio
- Facultad de Ciencias Médicas, Centro de Investigaciones Cardiovasculares, Universidad Nacional de La Plata, CONICET-La Plata La Plata, Argentina
| | - Alejandro Orlowski
- Facultad de Ciencias Médicas, Centro de Investigaciones Cardiovasculares, Universidad Nacional de La Plata, CONICET-La Plata La Plata, Argentina
| | - Ernesto A Aiello
- Facultad de Ciencias Médicas, Centro de Investigaciones Cardiovasculares, Universidad Nacional de La Plata, CONICET-La Plata La Plata, Argentina
| |
Collapse
|
13
|
Orlowski A, Ciancio MC, Caldiz CI, De Giusti VC, Aiello EA. Reduced sarcolemmal expression and function of the NBCe1 isoform of the Na⁺-HCO₃⁻ cotransporter in hypertrophied cardiomyocytes of spontaneously hypertensive rats: role of the renin-angiotensin system. Cardiovasc Res 2013; 101:211-9. [PMID: 24253522 DOI: 10.1093/cvr/cvt255] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
AIMS Electroneutral (NBCn1) and electrogenic (NBCe1) isoforms of the Na(+)-HCO3(-) cotransporter (NBC) coexist in the heart. We studied the expression and function of these isoforms in hearts of Wistar and spontaneously hypertensive rats (SHR), elucidating the direct implication of the renin-angiotensin system in the NBC regulation. METHODS AND RESULTS We used myocytes from Wistar, SHR, losartan-treated SHR (Los-SHR), and Angiotensin II (Ang II)-induced cardiac hypertrophy. We found an overexpression of NBCe1 and NBCn1 proteins in SHR that was prevented in Los-SHR. Hyperkalaemic-induced pHi alkalization was used to study selective activation of NBCe1. Despite the increase in NBCe1 expression, its activity was lower in SHR than in Wistar or Los-SHR. Similar results were found in Ang II-induced hypertrophy. A specific inhibitory antibody against NBCe1 allowed the discrimination between NBCe1 and NBCn1 activity. Whereas in SHR most of the pHi recovery was due to NBCn1 stimulation, in Wistar and Los-SHR the activity of both isoforms was equitable, suggesting that the deteriorated cardiac NBCe1 function observed in SHR is compensated by an enhanced activity of NBCn1. Using the biotin method, we observed greater level of internalized NBCe1 protein in SHR than in the non-hypertophic groups, while with immunofluorescence we localized the protein in endosomes near the nucleus only in SHR. CONCLUSIONS We conclude that Ang II is responsible for the impairment of the NBCe1 in hypertrophied hearts. This is due to retained transporter protein units in early endosomes. Moreover, NBCn1 activity seems to be increased in the hypertrophic myocardium of SHR, compensating impaired function of NBCe1.
Collapse
Affiliation(s)
- Alejandro Orlowski
- Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata-CONICET, Calle 60 y 120, 1900 La Plata, Argentina
| | | | | | | | | |
Collapse
|
14
|
Gholami K, Muniandy S, Salleh N. Modulation of sodium-bicarbonate co-transporter (SLC4A4/NBCe1) protein and mRNA expression in rat's uteri by sex-steroids and at different phases of the oestrous cycle. Res Vet Sci 2013; 96:164-70. [PMID: 24295739 DOI: 10.1016/j.rvsc.2013.11.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2013] [Revised: 08/16/2013] [Accepted: 11/10/2013] [Indexed: 01/25/2023]
Abstract
UNLABELLED Oestrogen-induced uterine fluid sodium (Na(+)) and bicarbonate (HCO3(-)) secretion may involve SLC4A4. We hypothesized that uterine SLC4A4 expression changes under different sex-steroid influence, therefore may account for the fluctuation in uterine fluid Na(+) and HCO3(-) content throughout the oestrous cycle. The aim of this study is to investigate the differential effects of sex-steroids and oestrous cycle phases on uterine SLC4A4 expression. METHODS Adult female WKY rats were ovariectomised and treated with different doses of 17β-oestradiol (E2) (0.2, 2, 20 and 50 μg/ml/day) or progesterone (P4) (4 mg/ml/day) for three consecutive days and 3 days treatment with 0.2 μg/ml/day E2 followed by another 3 days with P4 to mimic the hormonal changes in early pregnancy. Oestrous cycle phases in intact, non-ovariectomised rats were determined by vaginal smear. The animals were then sacrificed and uteri were removed for protein and mRNA expression analyses by Western blotting and Real Time PCR, respectively. SLC4A4 distribution was observed by immunohistochemistry. RESULTS Treatment with increasing E2 doses resulted in a dose-dependent increase in SLC4A4 protein expression. High SLC4A4 protein and mRNA expression can be seen at estrus. SLC4A4 is distributed mainly at the apical as well as basolateral membranes of the luminal and glandular epithelia following E2 treatment and at Es. Meanwhile, SLC4A4 expression was reduced following P4 treatment and was low at diestrus. CONCLUSION High SLC4A4 expression under estrogen dominance may contribute to the increase in uterine fluid Na(+) and HCO3(-) content, while its low expression under P4 dominance may result in vice versa.
Collapse
Affiliation(s)
- Khadijeh Gholami
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Sekaran Muniandy
- Department of Molecular Medicine, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia
| | - Naguib Salleh
- Department of Physiology, Faculty of Medicine, University of Malaya, 50603 Kuala Lumpur, Malaysia.
| |
Collapse
|
15
|
Aiello EA, De Giusti VC. Regulation of the cardiac sodium/bicarbonate cotransporter by angiotensin II: potential Contribution to structural, ionic and electrophysiological myocardial remodelling. Curr Cardiol Rev 2013; 9:24-32. [PMID: 23116057 PMCID: PMC3584305 DOI: 10.2174/157340313805076340] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/27/2012] [Revised: 08/15/2012] [Accepted: 09/13/2012] [Indexed: 12/15/2022] Open
Abstract
The sodium/ bicarbonate cotransporter (NBC) is, with the Na+/H+ exchanger (NHE), an important alkalinizing mechanism that maintains cellular intracellular pH (pHi). In the heart exists at least three isoforms of NBC, one that promotes the co-influx of 1 molecule of Na+ per 1molecule of HCO3-(electroneutral isoform; nNBC) and two others that generates the co-influx of 1 molecule of Na+ per 2 molecules of HCO3- (electrogenic isoforms; eNBC). In addition, the eNBC generates an anionic repolarizing current that modulate the cardiac action potential (CAP), adding to such isoforms the relevance to modulate the electrophysiological function of the heart. Angiotensin II (Ang II) is one of the main hormones that regulate cardiac physiology. The alkalinizing mechanisms (NHE and NBC) are stimulated by Ang II, increasing pHi and intracellular Na+ concentration, which indirectly, due to the stimulation of the Na+/Ca2+ exchanger (NCX) operating in the reverse form, leads to an increase in the intracellular Ca2+ concentration. Interestingly, it has been shown that Ang II exhibits an opposite effect on NBC isoforms: it activates the nNBC and inhibits the eNBC. This inhibition generates a CAP prolongation, which could directly increase the intracellular Ca2+ concentration. The regulation of the intracellular Na+ and Ca2+ concentrations is crucial for the cardiac cellular physiology, but these ions are also involved in the development of cardiac hypertrophy and the damage produced by ischemia-reperfusion, suggesting a potential role of NBC in cardiac diseases.
Collapse
Affiliation(s)
- Ernesto Alejandro Aiello
- Centro de Investigaciones Cardiovasculares, Facultad de Ciencias Médicas, Universidad Nacional de La Plata, Calle 60 y 120, 1900, La Plata, Argentina.
| | | |
Collapse
|
16
|
Garciarena CD, Youm JB, Swietach P, Vaughan-Jones RD. H⁺-activated Na⁺ influx in the ventricular myocyte couples Ca²⁺-signalling to intracellular pH. J Mol Cell Cardiol 2013; 61:51-9. [PMID: 23602948 DOI: 10.1016/j.yjmcc.2013.04.008] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 04/02/2013] [Accepted: 04/03/2013] [Indexed: 12/23/2022]
Abstract
Acid extrusion on Na(+)-coupled pH-regulatory proteins (pH-transporters), Na(+)/H(+) exchange (NHE1) and Na(+)-HCO3(-) co-transport (NBC), drives Na(+) influx into the ventricular myocyte. This H(+)-activated Na(+)-influx is acutely up-regulated at pHi<7.2, greatly exceeding Na(+)-efflux on the Na(+)/K(+) ATPase. It is spatially heterogeneous, due to the co-localisation of NHE1 protein (the dominant pH-transporter) with gap-junctions at intercalated discs. Overall Na(+)-influx via NBC is considerably lower, but much is co-localised with L-type Ca(2+)-channels in transverse-tubules. Through a functional coupling with Na(+)/Ca(2+) exchange (NCX), H(+)-activated Na(+)-influx increases sarcoplasmic-reticular Ca(2+)-loading and release during intracellular acidosis. This raises Ca(2+)-transient amplitude, rescuing it from direct H(+)-inhibition. Functional coupling is biochemically regulated and linked to membrane receptors, through effects on NHE1 and NBC. It requires adequate cytoplasmic Na(+)-mobility, as NHE1 and NCX are spatially separated (up to 60μm). The relevant functional NCX activity must be close to dyads, as it exerts no effect on bulk diastolic Ca(2+). H(+)-activated Na(+)-influx is up-regulated during ischaemia-reperfusion and some forms of maladaptive hypertrophy and heart failure. It is thus an attractive system for therapeutic manipulation. This article is part of a Special Issue entitled "Na(+) Regulation in Cardiac Myocytes".
Collapse
Affiliation(s)
- Carolina D Garciarena
- Burdon Sanderson Cardiac Science Centre, Department of Physiology Anatomy & Genetics, Oxford, UK
| | | | | | | |
Collapse
|
17
|
Parker MD, Boron WF. The divergence, actions, roles, and relatives of sodium-coupled bicarbonate transporters. Physiol Rev 2013; 93:803-959. [PMID: 23589833 PMCID: PMC3768104 DOI: 10.1152/physrev.00023.2012] [Citation(s) in RCA: 197] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
The mammalian Slc4 (Solute carrier 4) family of transporters is a functionally diverse group of 10 multi-spanning membrane proteins that includes three Cl-HCO3 exchangers (AE1-3), five Na(+)-coupled HCO3(-) transporters (NCBTs), and two other unusual members (AE4, BTR1). In this review, we mainly focus on the five mammalian NCBTs-NBCe1, NBCe2, NBCn1, NDCBE, and NBCn2. Each plays a specialized role in maintaining intracellular pH and, by contributing to the movement of HCO3(-) across epithelia, in maintaining whole-body pH and otherwise contributing to epithelial transport. Disruptions involving NCBT genes are linked to blindness, deafness, proximal renal tubular acidosis, mental retardation, and epilepsy. We also review AE1-3, AE4, and BTR1, addressing their relevance to the study of NCBTs. This review draws together recent advances in our understanding of the phylogenetic origins and physiological relevance of NCBTs and their progenitors. Underlying these advances is progress in such diverse disciplines as physiology, molecular biology, genetics, immunocytochemistry, proteomics, and structural biology. This review highlights the key similarities and differences between individual NCBTs and the genes that encode them and also clarifies the sometimes confusing NCBT nomenclature.
Collapse
Affiliation(s)
- Mark D Parker
- Dept. of Physiology and Biophysics, Case Western Reserve University School of Medicine, 10900 Euclid Ave., Cleveland, OH 44106-4970, USA.
| | | |
Collapse
|
18
|
Björkman E, Edebo A, Casselbrant A, Helander HF, Bratlie SO, Vieth M, Fändriks L. The renin-angiotensin system in the esophageal mucosa of healthy subjects and patients with reflux disease. Scand J Gastroenterol 2013; 48:147-59. [PMID: 23270416 DOI: 10.3109/00365521.2012.749510] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
OBJECTIVE Components of the renin-angiotensin system (RAS) were recently discovered in the esophagus, which could be of interest in relation to gastroesophageal reflux disease (GERD). The present study was undertaken to confirm and further investigate the expression of RAS in healthy and refluxed exposed human esophageal mucosae. METHODS Esophageal biopsies were obtained from healthy subjects (n = 34) and individuals with erosive reflux disease (ERD, n = 28). Evaluation of general morphology and histological signs of reflux as well as investigation of gene transcript, protein expression and localization of various RAS components using RT-PCR, ELISA, western blot and immunohistochemistry were performed. Physiological effects of the AT2R were investigated in Ussing chamber experiments. RESULTS The study confirmed histological signs of reflux in ERD and expression of ACE, AT1R, AT2R and CatD in all examined specimens. In addition, the main effector peptide AngII, the pro-hormone AGT, the Mas receptor and the angiotensin-forming enzymes renin, CMA, CatG and NEP were present. Individuals with reflux disease had higher transcription activity of ACE and AT1R, increased protein levels of AT2R and lower levels of MasR. AT2R stimulation increased the ion currents in healthy epithelium, whereas epithelium from individuals with reflux disease exhibited no significant response. CONCLUSIONS The study demonstrated that a local RAS is present in the human esophageal epithelium. Some RAS components were significantly altered in individuals diagnosed with ERD suggesting involvement in the pathophysiology of GERD.
Collapse
Affiliation(s)
- Eleonora Björkman
- Department of Gastrosurgical Research and Education, Institute of Clinical Sciences, The Sahlgrenska Academy, University of Gothenburg, Gothenburg, Sweden.
| | | | | | | | | | | | | |
Collapse
|
19
|
Chen LM, Qin X, Moss FJ, Liu Y, Boron WF. Effect of simultaneously replacing putative TM6 and TM12 of human NBCe1-A with those from NBCn1 on surface abundance in Xenopus oocytes. J Membr Biol 2012; 245:131-40. [PMID: 22383045 DOI: 10.1007/s00232-012-9421-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2011] [Accepted: 02/04/2012] [Indexed: 01/20/2023]
Abstract
HCO₃⁻ translocation across the plasma membrane via the electrogenic Na/HCO₃⁻ cotransporter NBCe1 plays an important role in intracellular pH regulation and transepithelial HCO₃⁻ transport. However, the structural determinants of transporter function remain largely unknown. A previous study showed that the putative fourth extracellular loop (EL4) plays an essential role in determining the electrogenicity of NBCe1. In the present study, we generated eight new chimeras of human NBCe1-A and NBCn1-A. All possess the putative NBCe1 EL4 and are electrogenic. Chimera O, in which the putative sixth transmembrane segment (TM6) and EL5 through the C terminus (Ct) of NBCe1 was replaced by corresponding NBCn1 sequence, produces the smallest hyperpolarization (1-2 mV) when CO₂/HCO₃⁻ is added to the extracellular solution. Biotinylation experiments show that O has a very low abundance at the plasma membrane. However, chimeras in which we simultaneously replaced the putative TM6 and smaller subdomains of the EL5-Ct region for the NBCn1 sequence were strongly electrogenic except for chimera T, in which we replaced TM6 and TM12 of NBCe1 with the corresponding regions of NBCn1. T exhibited greatly reduced transporter surface expression compared to wild-type NBCe1-A, while retaining at least some electrogenic character. We hypothesize that putative TM6 and TM12 are part of a functional unit and that if the two TMs are replaced by those of the same transporter type, high surface expression would require that the surrounding TMs are also from the same transporter type.
Collapse
Affiliation(s)
- Li-Ming Chen
- Department of Biological Sciences, Key Laboratory of Molecular Biophysics of the Ministry of Education, College of Life Science and Technology, Huazhong University of Science & Technology, Wuhan 430074, Hubei Province, China.
| | | | | | | | | |
Collapse
|