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Duan HY, Barajas-Martinez H, Antzelevitch C, Hu D. The potential anti-arrhythmic effect of SGLT2 inhibitors. Cardiovasc Diabetol 2024; 23:252. [PMID: 39010053 PMCID: PMC11251349 DOI: 10.1186/s12933-024-02312-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Accepted: 06/16/2024] [Indexed: 07/17/2024] Open
Abstract
Sodium-glucose cotransporter type 2 inhibitors (SGLT2i) were initially recommended as oral anti-diabetic drugs to treat type 2 diabetes (T2D), by inhibiting SGLT2 in proximal tubule and reduce renal reabsorption of sodium and glucose. While many clinical trials demonstrated the tremendous potential of SGLT2i for cardiovascular diseases. 2022 AHA/ACC/HFSA guideline first emphasized that SGLT2i were the only drug class that can cover the entire management of heart failure (HF) from prevention to treatment. Subsequently, the antiarrhythmic properties of SGLT2i have also attracted attention. Although there are currently no prospective studies specifically on the anti-arrhythmic effects of SGLT2i. We provide clues from clinical and fundamental researches to identify its antiarrhythmic effects, reviewing the evidences and mechanism for the SGLT2i antiarrhythmic effects and establishing a novel paradigm involving intracellular sodium, metabolism and autophagy to investigate the potential mechanisms of SGLT2i in mitigating arrhythmias.
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Affiliation(s)
- Hong-Yi Duan
- Department of Cardiology and Cardiovascular Research Institute, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, 430060, Hubei, China
- Hubei Key Laboratory of Cardiology, Wuhan, 430060, Hubei, China
| | - Hector Barajas-Martinez
- Lankenau Institute for Medical Research, Lankenau Heart Institute, Wynnewood, PA, 19096, USA
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, 19107, USA
| | - Charles Antzelevitch
- Lankenau Institute for Medical Research, Lankenau Heart Institute, Wynnewood, PA, 19096, USA
- Sidney Kimmel Medical College, Thomas Jefferson University, Philadelphia, 19107, USA
| | - Dan Hu
- Department of Cardiology and Cardiovascular Research Institute, Renmin Hospital of Wuhan University, 238 Jiefang Road, Wuhan, 430060, Hubei, China.
- Hubei Key Laboratory of Cardiology, Wuhan, 430060, Hubei, China.
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2
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He Y, Dong N, Wang X, Lv RJ, Yu Q, Yue HM. Obstructive sleep apnea affects cognition: dual effects of intermittent hypoxia on neurons. Sleep Breath 2024; 28:1051-1065. [PMID: 38308748 DOI: 10.1007/s11325-024-03001-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2023] [Revised: 01/10/2024] [Accepted: 01/12/2024] [Indexed: 02/05/2024]
Abstract
Obstructive sleep apnea (OSA) is a common respiratory disorder. Multiple organs, especially the central nervous system (CNS), are damaged, and dysfunctional when intermittent hypoxia (IH) occurs during sleep for a long time. The quality of life of individuals with OSA is significantly impacted by cognitive decline, which also escalates the financial strain on their families. Consequently, the development of novel therapies becomes imperative. IH induces oxidative stress, endoplasmic reticulum stress, iron deposition, and neuroinflammation in neurons. Synaptic dysfunction, reactive gliosis, apoptosis, neuroinflammation, and inhibition of neurogenesis can lead to learning and long-term memory impairment. In addition to nerve injury, the role of IH in neuroprotection was also explored. While causing neuron damage, IH activates the neuronal self-repairing mechanism by regulating antioxidant capacity and preventing toxic protein deposition. By stimulating the proliferation and differentiation of neural stem cells (NSCs), IH has the potential to enhance the ratio of neonatal neurons and counteract the decline in neuron numbers. This review emphasizes the perspectives and opportunities for the neuroprotective effects of IH and informs novel insights and therapeutic strategies in OSA.
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Affiliation(s)
- Yao He
- The First Clinical Medical College of Lanzhou University, Lanzhou, China
| | - Na Dong
- The First Clinical Medical College of Lanzhou University, Lanzhou, China
| | - Xiao Wang
- The First Clinical Medical College of Lanzhou University, Lanzhou, China
| | - Ren-Jun Lv
- The First Clinical Medical College of Lanzhou University, Lanzhou, China
| | - Qin Yu
- Department of Respiratory and Critical Care Medicine, The First Hospital of Lanzhou University, Lanzhou, China
| | - Hong-Mei Yue
- Department of Respiratory and Critical Care Medicine, The First Hospital of Lanzhou University, Lanzhou, China.
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3
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Zhong J, Dong J, Ruan W, Duan X. Potential Theranostic Roles of SLC4 Molecules in Human Diseases. Int J Mol Sci 2023; 24:15166. [PMID: 37894847 PMCID: PMC10606849 DOI: 10.3390/ijms242015166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 09/28/2023] [Accepted: 10/03/2023] [Indexed: 10/29/2023] Open
Abstract
The solute carrier family 4 (SLC4) is an important protein responsible for the transport of various ions across the cell membrane and mediating diverse physiological functions, such as the ion transporting function, protein-to-protein interactions, and molecular transduction. The deficiencies in SLC4 molecules may cause multisystem disease involving, particularly, the respiratory system, digestive, urinary, endocrine, hematopoietic, and central nervous systems. Currently, there are no effective strategies to treat these diseases. SLC4 proteins are also found to contribute to tumorigenesis and development, and some of them are regarded as therapeutic targets in quite a few clinical trials. This indicates that SLC4 proteins have potential clinical prospects. In view of their functional characteristics, there is a critical need to review the specific functions of bicarbonate transporters, their related diseases, and the involved pathological mechanisms. We summarize the diseases caused by the mutations in SLC4 family genes and briefly introduce the clinical manifestations of these diseases as well as the current treatment strategies. Additionally, we illustrate their roles in terms of the physiology and pathogenesis that has been currently researched, which might be the future therapeutic and diagnostic targets of diseases and a new direction for drug research and development.
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Affiliation(s)
| | | | | | - Xiaohong Duan
- State Key Laboratory of Oral & Maxillofacial Reconstruction and Regeneration, National Clinical Research Center for Oral Disease, Shaanxi Key Laboratory of Stomatology, Department of Oral Biology & Clinic of Oral Rare Diseases and Genetic Diseases, School of Stomatology, The Fourth Military Medical University, Xi’an 710032, China; (J.Z.); (J.D.); (W.R.)
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Zhu ML, Yu YN, Song YT, Wang CY, Miao Z, Chen BL, Guo S, Shen MM, Zhang MX, Zhan HQ, Yang PF, Wang QQ, Yin YL, Li P. Cardioprotective role of A-cycloglycosylated derivative of Rubiadin in diabetic cardiomyopathy in rats. Int Immunopharmacol 2023; 118:110008. [PMID: 36989899 DOI: 10.1016/j.intimp.2023.110008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 02/24/2023] [Accepted: 03/06/2023] [Indexed: 03/30/2023]
Abstract
Diabetic cardiomyopathy (DCM) is a kind of idiopathic heart disease, which is one of the main complications of diabetes and seriously threatens the life of diabetic patients. Rubiadin, an anthraquinone compound extracted from the stems and roots of rubiaceae, has been widely discussed for its anti-diabetes, anti-oxidation and other pharmacological effects. However, Rubiadin can cause drug-induced liver injury. Therefore, A-cycloglycosylated derivative of Rubiadin (ACDR) was obtained by modifying its structure. The purpose of this study was to investigate the effect of ACDR on DCM cardiac injury and its mechanism. The DCM animal model was established by streptozotocin, and the success of DCM was verified by blood glucose level, echocardiographic evidence of impaired myocardial functions along with enhanced myocardial fibrosis. We performed liver function tests, morphological staining of the heart and tests for oxidative stress to evaluate cardiac functional and structural changes. Finally, the expression of Na+/H+ exchanger (NHE1) protein was analyzed by immunohistochemistry and western bolt, and the expression of hairy/enhancer-of-split related with YRPW motif 1 (Hey1) and P-p38 protein was detected by immunofluorescence chemistry and western blotting. The results showed that ACDR can improve cardiac dysfunction, reduce myocardial injury, reduce oxidative stress, and protect the liver in DCM rats. Interestingly, all variations were countered by LiCl. Our study suggests that, along with controlling hyperglycemia, ACDR may improve DCM by reducing NHE1 expression, further inhibiting P-p38 activity and increasing Hey1 expression to reduce oxidative stress.
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Pérez-Carrillo L, Aragón-Herrera A, Giménez-Escamilla I, Delgado-Arija M, García-Manzanares M, Anido-Varela L, Lago F, Martínez-Dolz L, Portolés M, Tarazón E, Roselló-Lletí E. Cardiac Sodium/Hydrogen Exchanger (NHE11) as a Novel Potential Target for SGLT2i in Heart Failure: A Preliminary Study. Pharmaceutics 2022; 14:pharmaceutics14101996. [PMID: 36297433 PMCID: PMC9608584 DOI: 10.3390/pharmaceutics14101996] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 09/08/2022] [Accepted: 09/19/2022] [Indexed: 11/29/2022] Open
Abstract
Despite the reduction of cardiovascular events, including the risk of death, associated with sodium/glucose cotransporter 2 inhibitors (SGLT2i), their basic action remains unclear. Sodium/hydrogen exchanger (NHE) has been proposed as the mechanism of action, but there are controversies related to its function and expression in heart failure (HF). We hypothesized that sodium transported-related molecules could be altered in HF and modulated through SGLT2i. Transcriptome alterations in genes involved in sodium transport in HF were investigated in human heart samples by RNA-sequencing. NHE11 and NHE1 protein levels were determined by ELISA; the effect of empagliflozin on NHE11 and NHE1 mRNA levels in rats’ left ventricular tissues was studied through RT-qPCR. We highlighted the overexpression of SLC9C2 and SCL9A1 sodium transport genes and the increase of the proteins that encode them (NHE11 and NHE1). NHE11 levels were correlated with left ventricular diameters, so we studied the effect of SGLT2i on its expression, observing that NHE11 mRNA levels were reduced in treated rats. We showed alterations in several sodium transports and reinforced the importance of these channels in HF progression. We described upregulation in NHE11 and NHE1, but only NHE11 correlated with human cardiac dysfunction, and its levels were reduced after treatment with empagliflozin. These results propose NHE11 as a potential target of SGLT2i in cardiac tissue.
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Affiliation(s)
- Lorena Pérez-Carrillo
- Clinical and Translational Research in Cardiology Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain
| | - Alana Aragón-Herrera
- Cellular and Molecular Cardiology Research Unit, Department of Cardiology and Institute of Biomedical Research, University Clinical Hospital, 15706 Santiago de Compostela, Spain
- Cardiovascular Biomedical Research Center Network (CIBERCV), 28029 Madrid, Spain
| | - Isaac Giménez-Escamilla
- Clinical and Translational Research in Cardiology Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain
| | - Marta Delgado-Arija
- Clinical and Translational Research in Cardiology Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain
| | - María García-Manzanares
- Department of Animal Medicine and Surgery, Veterinary Faculty, CEU Cardenal Herrera Unversity, 46115 Valencia, Spain
| | - Laura Anido-Varela
- Cellular and Molecular Cardiology Research Unit, Department of Cardiology and Institute of Biomedical Research, University Clinical Hospital, 15706 Santiago de Compostela, Spain
- Cardiovascular Biomedical Research Center Network (CIBERCV), 28029 Madrid, Spain
| | - Francisca Lago
- Cellular and Molecular Cardiology Research Unit, Department of Cardiology and Institute of Biomedical Research, University Clinical Hospital, 15706 Santiago de Compostela, Spain
- Cardiovascular Biomedical Research Center Network (CIBERCV), 28029 Madrid, Spain
| | - Luis Martínez-Dolz
- Clinical and Translational Research in Cardiology Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain
- Cardiovascular Biomedical Research Center Network (CIBERCV), 28029 Madrid, Spain
| | - Manuel Portolés
- Clinical and Translational Research in Cardiology Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain
- Cardiovascular Biomedical Research Center Network (CIBERCV), 28029 Madrid, Spain
| | - Estefanía Tarazón
- Clinical and Translational Research in Cardiology Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain
- Cardiovascular Biomedical Research Center Network (CIBERCV), 28029 Madrid, Spain
- Correspondence: (E.T.); (E.R.-L.); Tel.: +34-9-6124-6644 (E.T. & E.R.-L.)
| | - Esther Roselló-Lletí
- Clinical and Translational Research in Cardiology Unit, Health Research Institute Hospital La Fe (IIS La Fe), 46026 Valencia, Spain
- Cardiovascular Biomedical Research Center Network (CIBERCV), 28029 Madrid, Spain
- Correspondence: (E.T.); (E.R.-L.); Tel.: +34-9-6124-6644 (E.T. & E.R.-L.)
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Ma J, Gao X, Li Y, DeCoursey TE, Shull GE, Wang HS. The HVCN1 voltage-gated proton channel contributes to pH regulation in canine ventricular myocytes. J Physiol 2022; 600:2089-2103. [PMID: 35244217 PMCID: PMC9058222 DOI: 10.1113/jp282126] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2021] [Accepted: 02/24/2022] [Indexed: 11/09/2022] Open
Abstract
KEY POINTS Intracellular pH (pHi ) regulation is crucial for cardiac function, as acidification depresses contractility and causes arrhythmias. H+ ions are generated in cardiomyocytes from metabolic processes and particularly from CO2 hydration, which has been shown to facilitate CO2 -venting from mitochondria. Currently, the NHE1 Na+ /H+ exchanger is viewed as the dominant H+ -extrusion mechanism in cardiac muscle. We show that the HVCN1 voltage-gated proton channel is present and functional in canine ventricular myocytes, and that HVCN1 and NHE1 both contribute to pHi regulation. HVCN1 provides an energetically-efficient mechanism of H+ -extrusion that would not cause Na+ -loading, which can cause pathology, and that could contribute to transport-mediated CO2 disposal. These results provide a major advance in our understanding of pHi regulation in cardiac muscle. ABSTRACT Regulation of intracellular pH (pHi ) in cardiomyocytes is crucial for cardiac function; however, currently known mechanisms for direct or indirect extrusion of acid from cardiomyocytes seem insufficient for energetically-efficient extrusion of the massive H+ loads generated under in vivo conditions. In cardiomyocytes, voltage-sensitive H+ channel activity mediated by the HVCN1 proton channel would be a highly efficient means of disposing of H+ , while avoiding Na+ -loading, as occurs during direct acid extrusion via Na+ /H+ exchange or indirect acid extrusion via Na+ -HCO3 - cotransport. PCR and immunoblotting demonstrated expression of HVCN1 mRNA and protein in canine heart. Patch clamp analysis of canine ventricular myocytes revealed a voltage-gated H+ current that was highly H+ -selective. The current was blocked by external Zn2+ and the HVCN1 blocker 5-chloro-2-guanidinobenzimidazole (ClGBI). Both the gating and Zn2+ blockade of the current were strongly influenced by the pH gradient across the membrane. All characteristics of the observed current were consistent with the known hallmarks of HVCN1-mediated H+ current. Inhibition of HVCN1 and the NHE1 Na+ /H+ exchanger, singly and in combination, showed that either mechanism is largely sufficient to maintain pHi in beating cardiomyocytes, but that inhibition of both activities causes rapid acidification. These results show that HVCN1 is expressed in canine ventricular myocytes and provides a major H+ -extrusion activity, with a capacity similar to that of NHE1. In the beating heart in vivo, this activity would allow Na+ -independent extrusion of H+ during each action potential and, when functionally coupled with anion transport mechanisms, could facilitate transport-mediated CO2 disposal. Abstract figure legend The HVCN1 proton channel is expressed in canine ventricular myocytes and contributes to H+ extrusion. This article is protected by copyright. All rights reserved.
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Affiliation(s)
- Jianyong Ma
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, 45267, USA
| | - Xiaoqian Gao
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, 45267, USA
| | - Yutian Li
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, 45267, USA
| | - Thomas E DeCoursey
- Department of Physiology & Biophysics, Rush University, Chicago, Illinois, 60612, USA
| | - Gary E Shull
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, 45267, USA
| | - Hong-Sheng Wang
- Department of Pharmacology and Systems Physiology, University of Cincinnati College of Medicine, Cincinnati, Ohio, 45267, USA
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Yang J, Zhang Y, Jiang L, Li C, Sun Z, Zhang Y, Lin T, Jiang Y, Liu B. A triple combination strategy of UHPLC-MS n, hypolipidemic activity and transcriptome sequencing to unveil the hypolipidemic mechanism of Nelumbo nucifera alkaloids. JOURNAL OF ETHNOPHARMACOLOGY 2022; 282:114608. [PMID: 34517059 DOI: 10.1016/j.jep.2021.114608] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/05/2021] [Revised: 08/31/2021] [Accepted: 09/04/2021] [Indexed: 06/13/2023]
Abstract
ETHNOPHARMACOLOGICAL RELEVANCE Nelumbo nucifera (N. nucifera), a kind of edible Chinese herbal, has been studied in treating hyperlipidemia. However, the hypolipidemic mechanism of N. nucifera remains unknown. Aims of this review: We aimed to screen the effective constituent of N. nucifera alkaloids and elucidated the potential mechanism for treating hyperlipidemia. A triple combination strategy of UHPLC-MSn, hypolipidemic activity and transcriptome sequencing was built to unveil the hypolipidemic mechanism of Nelumbo nucifera alkaloid. MATERIALS AND METHODS We comprehensively investigated the characterization of N. nucifera alkaloids by using UHPLC-LTQ-Orbitrap MSn. And the hypolipidemic activity of candidate active ingredients were evaluated on sodium oleate-induced HepG2 cell. Finally, O-nornuciferine and N. nucifera alkaloid extraction were analyzed by RNA sequence (RNA-seq) to decipher the underlying hypolipidemic mechanism and were verified by qRT-PCR. RESULTS 35 compounds were identified from N. nucifera alkaloid extraction by UHPLC-LTQ-Orbitrap MSn. Among them, O-nornuciferine and N. nucifera alkaloid extraction which showed significant hypolipidemic activity were analyzed by transcriptome sequencing. After the intervention of O-nornuciferine and N. nucifera alkaloid extraction, 1 and 158 differentially expressed genes (DEGs) were identified, severally. The enrichment analysis indicated that the hypolipidemic effect was adjusted by the expression of numerous key DEGs involved in bile secretion, glycerolipid and sphingolipid metabolism, PPAR signaling pathway. CONCLUSIONS O-nornuciferine and N. nucifera alkaloids had exibited significant effects in hyperlipidemia. The candidate genes were LDLR, LPL and ANGPTL4, etc. It was most likely that they adjusted lipid metabolism by modulating expression levels of various key factors which were involved in bile secretion, glycerolipid metabolism, sphingolipid metabolism and PPAR signaling pathway, and so on. This study clarified the hypolipidemic mechanism of the alkaloids in N. nucifera, and laid a foundation for the subsequent development of clinical application and better quality of N. nucifera.
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Affiliation(s)
- Jiaying Yang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Yu Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Lijuan Jiang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Caixia Li
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Zhenxiao Sun
- School of Life Science, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Yan Zhang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Tianfeng Lin
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China
| | - Yanyan Jiang
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China.
| | - Bin Liu
- School of Chinese Materia Medica, Beijing University of Chinese Medicine, Beijing 102488, China.
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Liu J, Tian J, Sodhi K, Shapiro JI. The Na/K-ATPase Signaling and SGLT2 Inhibitor-Mediated Cardiorenal Protection: A Crossed Road? J Membr Biol 2021; 254:513-529. [PMID: 34297135 PMCID: PMC8595165 DOI: 10.1007/s00232-021-00192-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2021] [Accepted: 07/06/2021] [Indexed: 12/17/2022]
Abstract
In different large-scale clinic outcome trials, sodium (Na+)/glucose co-transporter 2 (SGLT2) inhibitors showed profound cardiac- and renal-protective effects, making them revolutionary treatments for heart failure and kidney disease. Different theories are proposed according to the emerging protective effects other than the original purpose of glucose-lowering in diabetic patients. As the ATP-dependent primary ion transporter providing the Na+ gradient to drive other Na+-dependent transporters, the possible role of the sodium–potassium adenosine triphosphatase (Na/K-ATPase) as the primary ion transporter and its signaling function is not explored.
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Affiliation(s)
- Jiang Liu
- Department of Biomedical Sciences, JCE School of Medicine, Marshall University, Huntington, WV, USA.
| | - Jiang Tian
- Department of Biomedical Sciences, JCE School of Medicine, Marshall University, Huntington, WV, USA
| | - Komal Sodhi
- Department of Surgery, JCE School of Medicine, Marshall University, Huntington, WV, USA
| | - Joseph I Shapiro
- Departments of Medicine, JCE School of Medicine, Marshall University, Huntington, WV, USA
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9
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Nikolaou PE, Efentakis P, Abu Qourah F, Femminò S, Makridakis M, Kanaki Z, Varela A, Tsoumani M, Davos CH, Dimitriou CA, Tasouli A, Dimitriadis G, Kostomitsopoulos N, Zuurbier CJ, Vlahou A, Klinakis A, Brizzi MF, Iliodromitis EK, Andreadou I. Chronic Empagliflozin Treatment Reduces Myocardial Infarct Size in Nondiabetic Mice Through STAT-3-Mediated Protection on Microvascular Endothelial Cells and Reduction of Oxidative Stress. Antioxid Redox Signal 2021; 34:551-571. [PMID: 32295413 DOI: 10.1089/ars.2019.7923] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Aims: Empagliflozin (EMPA) demonstrates cardioprotective effects on diabetic myocardium but its infarct-sparing effects in normoglycemia remain unspecified. We investigated the acute and chronic effect of EMPA on infarct size after ischemia-reperfusion (I/R) injury and the mechanisms of cardioprotection in nondiabetic mice. Results: Chronic oral administration of EMPA (6 weeks) reduced myocardial infarct size after 30 min/2 h I/R (26.5% ± 3.9% vs 45.8% ± 3.3% in the control group, p < 0.01). Body weight, blood pressure, glucose levels, and cardiac function remained unchanged between groups. Acute administration of EMPA 24 or 4 h before I/R did not affect infarct size. Chronic EMPA treatment led to a significant reduction of oxidative stress biomarkers. STAT-3 (signal transducer and activator of transcription 3) was activated by Y(705) phosphorylation at the 10th minute of R, but it remained unchanged at 2 h of R and in the acute administration protocols. Proteomic analysis was employed to investigate signaling intermediates and revealed that chronic EMPA treatment regulates several pathways at reperfusion, including oxidative stress and integrin-related proteins that were further evaluated. Superoxide dismutase and vascular endothelial growth factor were increased throughout reperfusion. EMPA pretreatment (24 h) increased the viability of human microvascular endothelial cells in normoxia and on 3 h hypoxia/1 h reoxygenation and reduced reactive oxygen species production. In EMPA-treated murine hearts, CD31-/VEGFR2-positive endothelial cells and the pSTAT-3(Y705) signal derived from endothelial cells were boosted at early reperfusion. Innovation: Chronic EMPA administration reduces infarct size in healthy mice via the STAT-3 pathway and increases the survival of endothelial cells. Conclusion: Chronic but not acute administration of EMPA reduces infarct size through STAT-3 activation independently of diabetes mellitus.
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Affiliation(s)
| | - Panagiotis Efentakis
- Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece
| | - Fairouz Abu Qourah
- Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece
| | - Saveria Femminò
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Manousos Makridakis
- Biotechnology Laboratory, Centre of Basic Research, Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens, Greece
| | - Zoi Kanaki
- Biomedical Research Foundation Academy of Athens, Athens, Greece
| | - Aimilia Varela
- Cardiovascular Research Laboratory, Biomedical Research Foundation Academy of Athens, Athens, Greece
| | - Maria Tsoumani
- Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece
| | - Constantinos H Davos
- Cardiovascular Research Laboratory, Biomedical Research Foundation Academy of Athens, Athens, Greece
| | - Constantinos A Dimitriou
- Cardiovascular Research Laboratory, Biomedical Research Foundation Academy of Athens, Athens, Greece
| | | | - George Dimitriadis
- 2nd Department of Internal Medicine, Research Institute and Diabetes Center, National and Kapodistrian University of Athens, "Attikon" University Hospital, Athens, Greece
| | - Nikolaos Kostomitsopoulos
- Academy of Athens Biomedical Research Foundation, Centre of Clinical Experimental Surgery and Translational Research, Athens, Greece
| | - Coert J Zuurbier
- Amsterdam UMC, University of Amsterdam, Laboratory of Experimental Intensive Care and Anesthesiology, Department of Anesthesiology, Amsterdam Cardiovascular Sciences, Amsterdam Infection & Immunity, Amsterdam, The Netherlands
| | - Antonia Vlahou
- Biotechnology Laboratory, Centre of Basic Research, Biomedical Research Foundation of the Academy of Athens (BRFAA), Athens, Greece
| | | | - Maria F Brizzi
- Department of Medical Sciences, University of Turin, Turin, Italy
| | - Efstathios K Iliodromitis
- 2nd University Department of Cardiology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Ioanna Andreadou
- Laboratory of Pharmacology, Faculty of Pharmacy, National and Kapodistrian University of Athens, Athens, Greece
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10
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Mustroph J, Hupf J, Hanses F, Evert K, Baier MJ, Evert M, Meindl C, Wagner S, Hubauer U, Pietrzyk G, Leininger S, Staudner S, Vogel M, Wallner S, Zimmermann M, Sossalla S, Maier LS, Jungbauer C. Decreased GLUT1/NHE1 RNA expression in whole blood predicts disease severity in patients with COVID-19. ESC Heart Fail 2021; 8:309-316. [PMID: 33215884 PMCID: PMC7835506 DOI: 10.1002/ehf2.13063] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2020] [Revised: 09/09/2020] [Accepted: 09/25/2020] [Indexed: 02/06/2023] Open
Abstract
AIMS We aimed to assess whether expression of whole-blood RNA of sodium proton exchanger 1 (NHE1) and glucose transporter 1 (GLUT1) is associated with COVID-19 infection and outcome in patients presenting to the emergency department with respiratory infections. Furthermore, we investigated NHE1 and GLUT1 expression in the myocardium of deceased COVID-19 patients. METHODS AND RESULTS Whole-blood quantitative assessment of NHE1 and GLUT1 RNA was performed using quantitative PCR in patients with respiratory infection upon first contact in the emergency department and subsequently stratified by SARS-CoV-2 infection status. Assessment of NHE1 and GLUT1 RNA using PCR was also performed in left ventricular myocardium of deceased COVID-19 patients. NHE1 expression is up-regulated in whole blood of patients with COVID-19 compared with other respiratory infections at first medical contact in the emergency department (control: 0.0021 ± 0.0002, COVID-19: 0.0031 ± 0.0003, P = 0.01). The ratio of GLUT1 to NHE1 is significantly decreased in the blood of COVID-19 patients who are subsequently intubated and/or die (severe disease) compared with patients with moderate disease (moderate disease: 0.497 ± 0.083 vs. severe disease: 0.294 ± 0.0336, P = 0.036). This ratio is even further decreased in the myocardium of patients who deceased from COVID-19 in comparison with the myocardium of non-infected donors. CONCLUSIONS NHE1 and GLUT1 may be critically involved in the disease progression of SARS-CoV-2 infection. We show here that SARS-CoV-2 infection critically disturbs ion channel expression in the heart. A decreased ratio of GLUT1/NHE1 could potentially serve as a biomarker for disease severity in patients with COVID-19.
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Affiliation(s)
- Julian Mustroph
- Department of Internal Medicine II (Cardiology)University Hospital RegensburgFranz‐Josef‐Strauß‐Allee 11Regensburg93053Germany
| | - Julian Hupf
- Emergency DepartmentUniversity Hospital RegensburgRegensburgGermany
| | - Frank Hanses
- Emergency DepartmentUniversity Hospital RegensburgRegensburgGermany
- Department of Infection Prevention and Infectious DiseasesUniversity Hospital RegensburgRegensburgGermany
| | - Katja Evert
- Institute of PathologyUniversity Hospital RegensburgRegensburgGermany
| | - Maria J. Baier
- Department of Internal Medicine II (Cardiology)University Hospital RegensburgFranz‐Josef‐Strauß‐Allee 11Regensburg93053Germany
| | - Matthias Evert
- Institute of PathologyUniversity Hospital RegensburgRegensburgGermany
| | - Christine Meindl
- Department of Internal Medicine II (Cardiology)University Hospital RegensburgFranz‐Josef‐Strauß‐Allee 11Regensburg93053Germany
| | - Stefan Wagner
- Department of Internal Medicine II (Cardiology)University Hospital RegensburgFranz‐Josef‐Strauß‐Allee 11Regensburg93053Germany
| | - Ute Hubauer
- Department of Internal Medicine II (Cardiology)University Hospital RegensburgFranz‐Josef‐Strauß‐Allee 11Regensburg93053Germany
| | - Gabriela Pietrzyk
- Department of Internal Medicine II (Cardiology)University Hospital RegensburgFranz‐Josef‐Strauß‐Allee 11Regensburg93053Germany
| | - Simon Leininger
- Department of Internal Medicine II (Cardiology)University Hospital RegensburgFranz‐Josef‐Strauß‐Allee 11Regensburg93053Germany
| | - Stephan Staudner
- Department of Internal Medicine II (Cardiology)University Hospital RegensburgFranz‐Josef‐Strauß‐Allee 11Regensburg93053Germany
| | - Manuel Vogel
- Department of Internal Medicine II (Cardiology)University Hospital RegensburgFranz‐Josef‐Strauß‐Allee 11Regensburg93053Germany
| | - Stefan Wallner
- Department of Clinical Chemistry and Laboratory MedicineUniversity Hospital RegensburgRegensburgGermany
| | | | - Samuel Sossalla
- Department of Internal Medicine II (Cardiology)University Hospital RegensburgFranz‐Josef‐Strauß‐Allee 11Regensburg93053Germany
| | - Lars S. Maier
- Department of Internal Medicine II (Cardiology)University Hospital RegensburgFranz‐Josef‐Strauß‐Allee 11Regensburg93053Germany
| | - Carsten Jungbauer
- Department of Internal Medicine II (Cardiology)University Hospital RegensburgFranz‐Josef‐Strauß‐Allee 11Regensburg93053Germany
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11
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Vasquez-Rios G, Nadkarni GN. SGLT2 Inhibitors: Emerging Roles in the Protection Against Cardiovascular and Kidney Disease Among Diabetic Patients. Int J Nephrol Renovasc Dis 2020; 13:281-296. [PMID: 33149657 PMCID: PMC7604253 DOI: 10.2147/ijnrd.s268811] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2020] [Accepted: 09/30/2020] [Indexed: 12/15/2022] Open
Abstract
PURPOSE OF REVIEW Type 2 diabetes mellitus (T2DM) is a prevalent disease with the severe clinical implications including myocardial infarction, stroke, and kidney disease. Therapies focusing on glycemic control in T2DM such as biguanides, sulfonylureas, thiazolidinediones, and insulin-based regimens have largely failed to substantially improve cardiovascular and kidney outcomes. We review the recent findings on sodium-glucose co-transporter type 2 (SGLT2) inhibitors which have shown to have beneficial cardiovascular and kidney-related effects. RECENT FINDINGS SGLT2 inhibitors are a new class of diabetic medications that reduce the absorption of glucose in the kidney, decrease proteinuria, control blood pressure, and are associated with weight loss. SGLT2 inhibitors provide complementary therapy independent of insulin secretion or action with proved glucose-lowering effects. Recent placebo-controlled clinical trials have demonstrated that these medications can decrease cardiovascular death, progression of kidney disease, and all-cause mortality in diabetic and non-diabetic patients. Interestingly, SGT2 inhibitors such as dapagliflozin have also proven to decrease heart failure admissions and cardiovascular endpoints in non-diabetic patients, suggesting pleiotropic effects. The exact mechanisms responsible for reductions in atherosclerotic heart disease, need for kidney replacement therapy, and progressive kidney disease remain unknown. While regulation of glomerular hyperfiltration, albuminuria, and natriuresis may be part of the explanation, it is possible that complex cellular effects including energy balance optimization, downregulation of oxidative stress, and modulation of pro-inflammatory signaling pathways are associated with favorable outcomes observed in large clinical studies. CONCLUSION SGLT2 inhibitors are novel antidiabetic medications with immense utility in the management of patients with T2DM. Furthermore, SGLT2 inhibitors have demonstrated to reduce the progression to advanced forms of kidney disease and its associated complications. These medications should be front and center in the management of patients with diabetic kidney disease with and without chronic kidney disease as they confer protection against cardiovascular/renal death and improve all-cause mortality. Future studies should evaluate the benefits and implications of early initiation of SGLT2 inhibitors, as well as the long-term effects of this therapy.
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Affiliation(s)
- George Vasquez-Rios
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
| | - Girish N Nadkarni
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
- The Charles Bronfman Institute of Personalized Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, USA
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12
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Islam M, Diwan A, Mani K. Come Together: Protein Assemblies, Aggregates and the Sarcostat at the Heart of Cardiac Myocyte Homeostasis. Front Physiol 2020; 11:586. [PMID: 32581848 PMCID: PMC7287178 DOI: 10.3389/fphys.2020.00586] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2020] [Accepted: 05/11/2020] [Indexed: 12/13/2022] Open
Abstract
Homeostasis in vertebrate systems is contingent on normal cardiac function. This, in turn, depends on intricate protein-based cellular machinery, both for contractile function, as well as, durability of cardiac myocytes. The cardiac small heat shock protein (csHsp) chaperone system, highlighted by αB-crystallin (CRYAB), a small heat shock protein (sHsp) that forms ∼3–5% of total cardiac mass, plays critical roles in maintaining proteostatic function via formation of self-assembled multimeric chaperones. In this work, we review these ancient proteins, from the evolutionarily preserved role of homologs in protists, fungi and invertebrate systems, as well as, the role of sHsps and chaperones in maintaining cardiac myocyte structure and function. We propose the concept of the “sarcostat” as a protein quality control mechanism in the sarcomere. The roles of the proteasomal and lysosomal proteostatic network, as well as, the roles of the aggresome, self-assembling protein complexes and protein aggregation are discussed in the context of cardiac myocyte homeostasis. Finally, we will review the potential for targeting the csHsp system as a novel therapeutic approach to prevent and treat cardiomyopathy and heart failure.
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Affiliation(s)
- Moydul Islam
- Division of Cardiology, Washington University School of Medicine, St. Louis, MO, United States.,Center for Cardiovascular Research, Washington University School of Medicine, St. Louis, MO, United States.,Department of Chemistry, Washington University in St. Louis, St. Louis, MO, United States
| | - Abhinav Diwan
- Division of Cardiology, Washington University School of Medicine, St. Louis, MO, United States.,Center for Cardiovascular Research, Washington University School of Medicine, St. Louis, MO, United States.,John Cochran Veterans Affairs Medical Center, St. Louis, MO, United States
| | - Kartik Mani
- Division of Cardiology, Washington University School of Medicine, St. Louis, MO, United States.,Center for Cardiovascular Research, Washington University School of Medicine, St. Louis, MO, United States.,John Cochran Veterans Affairs Medical Center, St. Louis, MO, United States
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13
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Packer M. Role of Impaired Nutrient and Oxygen Deprivation Signaling and Deficient Autophagic Flux in Diabetic CKD Development: Implications for Understanding the Effects of Sodium-Glucose Cotransporter 2-Inhibitors. J Am Soc Nephrol 2020; 31:907-919. [PMID: 32276962 DOI: 10.1681/asn.2020010010] [Citation(s) in RCA: 77] [Impact Index Per Article: 19.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Growing evidence indicates that oxidative and endoplasmic reticular stress, which trigger changes in ion channels and inflammatory pathways that may undermine cellular homeostasis and survival, are critical determinants of injury in the diabetic kidney. Cells are normally able to mitigate these cellular stresses by maintaining high levels of autophagy, an intracellular lysosome-dependent degradative pathway that clears the cytoplasm of dysfunctional organelles. However, the capacity for autophagy in both podocytes and renal tubular cells is markedly impaired in type 2 diabetes, and this deficiency contributes importantly to the intensity of renal injury. The primary drivers of autophagy in states of nutrient and oxygen deprivation-sirtuin-1 (SIRT1), AMP-activated protein kinase (AMPK), and hypoxia-inducible factors (HIF-1α and HIF-2α)-can exert renoprotective effects by promoting autophagic flux and by exerting direct effects on sodium transport and inflammasome activation. Type 2 diabetes is characterized by marked suppression of SIRT1 and AMPK, leading to a diminution in autophagic flux in glomerular podocytes and renal tubules and markedly increasing their susceptibility to renal injury. Importantly, because insulin acts to depress autophagic flux, these derangements in nutrient deprivation signaling are not ameliorated by antihyperglycemic drugs that enhance insulin secretion or signaling. Metformin is an established AMPK agonist that can promote autophagy, but its effects on the course of CKD have been demonstrated only in the experimental setting. In contrast, the effects of sodium-glucose cotransporter-2 (SGLT2) inhibitors may be related primarily to enhanced SIRT1 and HIF-2α signaling; this can explain the effects of SGLT2 inhibitors to promote ketonemia and erythrocytosis and potentially underlies their actions to increase autophagy and mute inflammation in the diabetic kidney. These distinctions may contribute importantly to the consistent benefit of SGLT2 inhibitors to slow the deterioration in glomerular function and reduce the risk of ESKD in large-scale randomized clinical trials of patients with type 2 diabetes.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, Texas .,Imperial College, London, United Kingdom
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14
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Packer M. Autophagy stimulation and intracellular sodium reduction as mediators of the cardioprotective effect of sodium-glucose cotransporter 2 inhibitors. Eur J Heart Fail 2020; 22:618-628. [PMID: 32037659 DOI: 10.1002/ejhf.1732] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2019] [Revised: 11/26/2019] [Accepted: 11/28/2019] [Indexed: 12/17/2022] Open
Abstract
In five large-scale trials involving >40 000 patients, sodium-glucose cotransporter 2 (SGLT2) inhibitors decreased the risk of serious heart failure events by 25-40%. This effect cannot be explained by control of hyperglycaemia, since it is not observed with antidiabetic drugs with greater glucose-lowering effects. It cannot be attributed to ketogenesis, since it is not causally linked to ketone body production, and the benefit is not enhanced in patients with diabetes. The effect cannot be ascribed to a natriuretic action, since SGLT2 inhibitors decrease natriuretic peptides only modestly, and they reduce cardiovascular death, a benefit that diuretics do not possess. Although SGLT2 inhibitors increase red blood cell mass, enhanced erythropoiesis does not favourably influence the course of heart failure. By contrast, experimental studies suggest that SGLT2 inhibitors may reduce intracellular sodium, thereby preventing oxidative stress and cardiomyocyte death. Additionally, SGLT2 inhibitors induce a transcriptional paradigm that mimics nutrient and oxygen deprivation, which includes activation of adenosine monophosphate-activated protein kinase, sirtuin-1, and/or hypoxia-inducible factors-1α/2α. The interplay of these mediators stimulates autophagy, a lysosomally-mediated degradative pathway that maintains cellular homeostasis. Autophagy-mediated clearance of damaged organelles reduces inflammasome activation, thus mitigating cardiomyocyte dysfunction and coronary microvascular injury. Interestingly, the action of hypoxia-inducible factors-1α/2α to both stimulate erythropoietin and induce autophagy may explain why erythrocytosis is strongly correlated with the reduction in heart failure events. Therefore, the benefits of SGLT2 inhibitors on heart failure may be mediated by a direct cardioprotective action related to modulation of pathways responsible for cardiomyocyte homeostasis.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute, Baylor University Medical Center, Dallas, TX, USA.,Imperial College, London, UK
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15
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Cao L, Yuan Z, Liu M, Stock C. (Patho-)Physiology of Na +/H + Exchangers (NHEs) in the Digestive System. Front Physiol 2020; 10:1566. [PMID: 32009977 PMCID: PMC6974801 DOI: 10.3389/fphys.2019.01566] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2019] [Accepted: 12/12/2019] [Indexed: 02/06/2023] Open
Abstract
Na+/H+ exchangers (NHEs) are expressed in virtually all human tissues and organs. Two major tasks of those NHE isoforms that are located in plasma membranes are cell volume control by Na+-uptake and cellular pH regulation by H+-extrusion. Several NHEs, particularly NHE 1–4 and 8, are involved in the pathogenesis of diseases of the digestive system such as inflammatory bowel disease (ulcerative colitis, Crohn’s disease) and gastric and colorectal tumorigenesis. In the present review, we describe the physiological purposes, possible malfunctions and pathophysiological effects of the different NHE isoforms along the alimentary canal from esophagus to colon, including pancreas, liver and gallbladder. Particular attention is paid to the functions of NHEs in injury repair and to the role of NHE1 in Barrett’s esophagus. The impact of NHEs on gut microbiota and intestinal mucosal integrity is also dealt with. As the hitherto existing findings are not always consistent, sometimes even controversial, they are compared and critically discussed.
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Affiliation(s)
- Li Cao
- Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zhenglin Yuan
- Department of Stomatology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Mei Liu
- Department of Gastroenterology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Christian Stock
- Department of Gastroenterology, Hepatology and Endocrinology, Hannover Medical School, Hanover, Germany
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16
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Affiliation(s)
- Seungho Jun
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
| | - Miguel A. Aon
- Laboratory of Cardiovascular Science, National Institute on Aging, National Institutes of Health, Baltimore, Maryland
- Translational Gerontology Branch, National Institute on Aging, National Institutes of Health, Baltimore, Maryland
| | - Nazareno Paolocci
- Division of Cardiology, Department of Medicine, Johns Hopkins School of Medicine, Baltimore, Maryland
- Department of Biomedical Sciences, University of Padova, Padova, Italy
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17
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Pedersen SF, Counillon L. The SLC9A-C Mammalian Na +/H + Exchanger Family: Molecules, Mechanisms, and Physiology. Physiol Rev 2019; 99:2015-2113. [PMID: 31507243 DOI: 10.1152/physrev.00028.2018] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Na+/H+ exchangers play pivotal roles in the control of cell and tissue pH by mediating the electroneutral exchange of Na+ and H+ across cellular membranes. They belong to an ancient family of highly evolutionarily conserved proteins, and they play essential physiological roles in all phyla. In this review, we focus on the mammalian Na+/H+ exchangers (NHEs), the solute carrier (SLC) 9 family. This family of electroneutral transporters constitutes three branches: SLC9A, -B, and -C. Within these, each isoform exhibits distinct tissue expression profiles, regulation, and physiological roles. Some of these transporters are highly studied, with hundreds of original articles, and some are still only rudimentarily understood. In this review, we present and discuss the pioneering original work as well as the current state-of-the-art research on mammalian NHEs. We aim to provide the reader with a comprehensive view of core knowledge and recent insights into each family member, from gene organization over protein structure and regulation to physiological and pathophysiological roles. Particular attention is given to the integrated physiology of NHEs in the main organ systems. We provide several novel analyses and useful overviews, and we pinpoint main remaining enigmas, which we hope will inspire novel research on these highly versatile proteins.
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Affiliation(s)
- S F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
| | - L Counillon
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
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18
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García-Ropero Á, Vargas-Delgado AP, Santos-Gallego CG, Badimon JJ. Inhibition of Sodium Glucose Cotransporters Improves Cardiac Performance. Int J Mol Sci 2019; 20:E3289. [PMID: 31277431 PMCID: PMC6651487 DOI: 10.3390/ijms20133289] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2019] [Revised: 07/01/2019] [Accepted: 07/02/2019] [Indexed: 02/06/2023] Open
Abstract
The sodium-glucose cotransporter (SGLT) inhibitors represent a new alternative for treating patients with diabetes mellitus. They act primarily by inhibiting glucose reabsorption in the renal tubule and therefore, decreasing blood glucose levels. While little is yet known about SGLT subtype 1, SGLT2 inhibitors have demonstrated to significantly reduce cardiovascular mortality and heart failure hospitalizations. This cardioprotective benefit seems to be independent of their glucose-lowering properties; however, the underlying mechanism(s) remains still unclear and numerous hypotheses have been postulated to date. Moreover, preclinical research has suggested an important role of SGLT1 receptors on myocardial ischemia. Following acute phase of cardiac injury there is an increased activity of SGLT1 cotransport that ensures adequate energy supply to the cardiac cells. Nonetheless, a long-term upregulation of this receptor may not be that beneficial and whether its inhibition is positive or not should be further addressed. This review aims to present the most cutting-edge insights into SGLT receptors.
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Affiliation(s)
- Álvaro García-Ropero
- Atherothrombosis Research Unit, Mount Sinai Heart, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Cardiology Department, Imperial College London, The Royal Brompton and Harefield Hospital, London 6W3 6NP, UK
| | - Ariana P Vargas-Delgado
- Atherothrombosis Research Unit, Mount Sinai Heart, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
- Instituto Ecuatoriano del Corazón IECOR, Guayaquil 090513, Ecuador
| | - Carlos G Santos-Gallego
- Atherothrombosis Research Unit, Mount Sinai Heart, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA
| | - Juan J Badimon
- Atherothrombosis Research Unit, Mount Sinai Heart, Icahn School of Medicine at Mount Sinai, New York, NY 10029, USA.
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19
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Zhang-James Y, Vaudel M, Mjaavatten O, Berven FS, Haavik J, Faraone SV. Effect of disease-associated SLC9A9 mutations on protein-protein interaction networks: implications for molecular mechanisms for ADHD and autism. ACTA ACUST UNITED AC 2019; 11:91-105. [PMID: 30927234 DOI: 10.1007/s12402-018-0281-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Accepted: 11/27/2018] [Indexed: 12/20/2022]
Abstract
Na+/H+ Exchanger 9 (NHE9) is an endosomal membrane protein encoded by the Solute Carrier 9A, member 9 gene (SLC9A9). SLC9A9 has been implicated in attention deficit hyperactivity disorder (ADHD), autism spectrum disorders (ASDs), epilepsy, multiple sclerosis and cancers. To better understand the function of NHE9 and the effects of disease-associated variants on protein-protein interactions, we conducted a quantitative analysis of the NHE9 interactome using co-immunoprecipitation and isobaric labeling-based quantitative mass spectrometry. We identified 100 proteins that interact with NHE9. These proteins were enriched in known functional pathways for NHE9: the endocytosis, protein ubiquitination and phagosome pathways, as well as some novel pathways including oxidative stress, mitochondrial dysfunction, mTOR signaling, cell death and RNA processing pathways. An ADHD-associated mutation (A409P) significantly altered NHE9's interactions with a subset of proteins involved in caveolae-mediated endocytosis and MAP2K2-mediated downstream signaling. An ASD nonsense mutation in SLC9A9, R423X, produced no-detectable amount of NHE9, suggesting the overall loss of NHE9 functional networks. In addition, seven of the NHE9 interactors are products of known autism candidate genes (Simons Foundation Autism Research Initiative, SFARI Gene) and 90% of the NHE9 interactome overlap with SFARI protein interaction network PIN (p < 0.0001), supporting the role of NHE9 interactome in ASDs molecular mechanisms. Our results provide a detailed understanding of the functions of protein NHE9 and its disrupted interactions, possibly underlying ADHD and ASDs. Furthermore, our methodological framework proved useful for functional characterization of disease-associated genetic variants and suggestion of druggable targets.
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Affiliation(s)
- Yanli Zhang-James
- Departments of Psychiatry, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY, 13210, USA
| | - Marc Vaudel
- Department of Clinical Science, University of Bergen, Bergen, Norway
| | - Olav Mjaavatten
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Frode S Berven
- Department of Biomedicine, University of Bergen, Bergen, Norway
| | - Jan Haavik
- Department of Biomedicine, University of Bergen, Bergen, Norway.,K.G. Jebsen Centre for Research on Neuropsychiatric Disorders, University of Bergen, Bergen, Norway.,Division of Psychiatry, Haukeland University Hospital, Bergen, Norway
| | - Stephen V Faraone
- Departments of Psychiatry, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY, 13210, USA. .,Neuroscience and Physiology, SUNY Upstate Medical University, 750 East Adams St., Syracuse, NY, 13210, USA.
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20
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Garcia-Ropero A, Santos-Gallego CG, Zafar MU, Badimon JJ. Metabolism of the failing heart and the impact of SGLT2 inhibitors. Expert Opin Drug Metab Toxicol 2019; 15:275-285. [DOI: 10.1080/17425255.2019.1588886] [Citation(s) in RCA: 32] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Affiliation(s)
- Alvaro Garcia-Ropero
- Atherothrombosis Research Unit, Mount Sinai Heart, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Carlos G. Santos-Gallego
- Atherothrombosis Research Unit, Mount Sinai Heart, Icahn School of Medicine at Mount Sinai, New York, USA
| | - M. Urooj Zafar
- Atherothrombosis Research Unit, Mount Sinai Heart, Icahn School of Medicine at Mount Sinai, New York, USA
| | - Juan J. Badimon
- Atherothrombosis Research Unit, Mount Sinai Heart, Icahn School of Medicine at Mount Sinai, New York, USA
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21
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Vairamani K, Prasad V, Wang Y, Huang W, Chen Y, Medvedovic M, Lorenz JN, Shull GE. NBCe1 Na +-HCO3 - cotransporter ablation causes reduced apoptosis following cardiac ischemia-reperfusion injury in vivo. World J Cardiol 2018; 10:97-109. [PMID: 30344957 PMCID: PMC6189072 DOI: 10.4330/wjc.v10.i9.97] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 07/05/2018] [Accepted: 07/16/2018] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the hypothesis that cardiomyocyte-specific loss of the electrogenic NBCe1 Na+-HCO3- cotransporter is cardioprotective during in vivo ischemia-reperfusion (IR) injury.
METHODS An NBCe1 (Slc4a4 gene) conditional knockout mouse (KO) model was prepared by gene targeting. Cardiovascular performance of wildtype (WT) and cardiac-specific NBCe1 KO mice was analyzed by intraventricular pressure measurements, and changes in cardiac gene expression were determined by RNA Seq analysis. Response to in vivo IR injury was analyzed after 30 min occlusion of the left anterior descending artery followed by 3 h of reperfusion.
RESULTS Loss of NBCe1 in cardiac myocytes did not impair cardiac contractility or relaxation under basal conditions or in response to β-adrenergic stimulation, and caused only limited changes in gene expression patterns, such as those for electrical excitability. However, following ischemia and reperfusion, KO heart sections exhibited significantly fewer apoptotic nuclei than WT sections.
CONCLUSION These studies indicate that cardiac-specific loss of NBCe1 does not impair cardiovascular performance, causes only minimal changes in gene expression patterns, and protects against IR injury in vivo .
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Affiliation(s)
- Kanimozhi Vairamani
- Division of Oncology, Cancer and Blood Diseases Institute, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229-3026, United States
| | - Vikram Prasad
- Department of Pediatrics, Cincinnati Children’s Hospital Medical Center, University of Cincinnati, Cincinnati, OH 45229-3039, United States
| | - Yigang Wang
- Department of Pathology, University of Cincinnati, College of Medicine, Cincinnati, OH 45267-0529, United States
| | - Wei Huang
- Department of Pathology, University of Cincinnati, College of Medicine, Cincinnati, OH 45267-0529, United States
| | - Yinhua Chen
- Division of Developmental Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229-3039, United States
| | - Mario Medvedovic
- Department of Environmental Health, University of Cincinnati, College of Medicine, Cincinnati, OH 45267-0056, United States
| | - John N Lorenz
- Department of Pharmacology and Systems Physiology, University of Cincinnati, College of Medicine, Cincinnati, OH 45267-0575, United States
| | - Gary E Shull
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, College of Medicine, Cincinnati, OH 45267-0524, United States
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22
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Xu H, Ghishan FK, Kiela PR. SLC9 Gene Family: Function, Expression, and Regulation. Compr Physiol 2018; 8:555-583. [PMID: 29687889 DOI: 10.1002/cphy.c170027] [Citation(s) in RCA: 38] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
The Slc9 family of Na+ /H+ exchangers (NHEs) plays a critical role in electroneutral exchange of Na+ and H+ in the mammalian intestine as well as other absorptive and secretory epithelia of digestive organs. These transport proteins contribute to the transepithelial Na+ and water absorption, intracellular pH and cellular volume regulation as well as the electrolyte, acid-base, and fluid volume homeostasis at the systemic level. They also influence the function of other membrane transport mechanisms, affect cellular proliferation and apoptosis as well as cell migration, adherence to the extracellular matrix, and tissue repair. Additionally, they modulate the extracellular milieu to facilitate other nutrient absorption and to regulate the intestinal microbial microenvironment. Na+ /H+ exchange is inhibited in selected gastrointestinal diseases, either by intrinsic factors (e.g., bile acids, inflammatory mediators) or infectious agents and associated bacterial toxins. Disrupted NHE activity may contribute not only to local and systemic electrolyte imbalance but also to the disease severity via multiple mechanisms. In this review, we describe the cation proton antiporter superfamily of Na+ /H+ exchangers with a particular emphasis on the eight SLC9A isoforms found in the digestive tract, followed by a more integrative description in their roles in each of the digestive organs. We discuss regulatory mechanisms that determine the function of Na+ /H+ exchangers as pertinent to the digestive tract, their regulation in pathological states of the digestive organs, and reciprocally, the contribution of dysregulated Na+ /H+ exchange to the disease pathogenesis and progression. © 2018 American Physiological Society. Compr Physiol 8:555-583, 2018.
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Affiliation(s)
- Hua Xu
- Department of Pediatrics, Steele Children's Research Center, University of Arizona, Tucson, Arizona, USA
| | - Fayez K Ghishan
- Department of Pediatrics, Steele Children's Research Center, University of Arizona, Tucson, Arizona, USA
| | - Pawel R Kiela
- Department of Pediatrics, Steele Children's Research Center, University of Arizona, Tucson, Arizona, USA.,Department of Immunobiology, University of Arizona, Tucson, Arizona, USA
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23
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Zhou Y, Shi X, Chen H, Zhang S, Salker MS, Mack AF, Föller M, Mak TW, Singh Y, Lang F. DJ-1/Park7 Sensitive Na + /H + Exchanger 1 (NHE1) in CD4 + T Cells. J Cell Physiol 2017; 232:3050-3059. [PMID: 27509531 DOI: 10.1002/jcp.25516] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 08/09/2016] [Indexed: 01/03/2023]
Abstract
DJ-1/Park7 is a redox-sensitive chaperone protein counteracting oxidation and presumably contributing to the control of oxidative stress responses and thus inflammation. DJ-1 gene deletion exacerbates the progression of Parkinson's disease presumably by augmenting oxidative stress. Formation of reactive oxygen species (ROS) is paralleled by activation of the Na+ /H+ exchanger 1 (NHE1). ROS formation in CD4+ T cells plays a decisive role in regulating inflammatory responses. In the present study, we explored whether DJ-1 is expressed in CD4+ T cells, and affects ROS production as well as NHE1 in those cells. To this end, DJ-1 and NHE1 transcript, and protein levels were quantified by qRT-PCR and Western blotting, respectively, intracellular pH (pHi ) utilizing bis-(2-carboxyethyl)-5-(and-6)-carboxyfluorescein (BCECF) fluorescence, NHE activity from realkalinization after an ammonium pulse, and ROS production utilizing 2',7' -dichlorofluorescin diacetate (DCFDA) fluorescence. As a result DJ-1 was expressed in CD4+ T cells. ROS formation, NHE1 transcript levels, NHE1 protein, and NHE activity were higher in CD4+ T cells from DJ-1 deficient mice than in CD4+ T cells from wild type mice. Antioxidant N-acetyl-cysteine (NAC) and protein tyrosine kinase (PTK) inhibitor staurosporine decreased the NHE activity in DJ-1 deficient CD4+ T cells, and blunted the difference between DJ-1-/- and DJ-1+/+ CD4+ T cells, an observation pointing to a role of ROS in the up-regulation of NHE1 in DJ-1-/- CD4+ T cells. In conclusion, DJ-1 is a powerful regulator of ROS production as well as NHE1 expression and activity in CD4+ T cells. J. Cell. Physiol. 232: 3050-3059, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Yuetao Zhou
- Department of Cardiology, Vascular Medicine and Physiology, Eberhard-Karls-University, Tübingen, Germany
| | - Xiaolong Shi
- Department of Cardiology, Vascular Medicine and Physiology, Eberhard-Karls-University, Tübingen, Germany
| | - Hong Chen
- Department of Cardiology, Vascular Medicine and Physiology, Eberhard-Karls-University, Tübingen, Germany
| | - Shaqiu Zhang
- Department of Cardiology, Vascular Medicine and Physiology, Eberhard-Karls-University, Tübingen, Germany.,Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Wenjiang, Chengdu City, Sichuan, China
| | - Madhuri S Salker
- Department of Cardiology, Vascular Medicine and Physiology, Eberhard-Karls-University, Tübingen, Germany
| | - Andreas F Mack
- Institute of Clinical Anatomy and Cell Analysis, Eberhard-Karls-University, Tübingen, Germany
| | - Michael Föller
- Department of Cardiology, Vascular Medicine and Physiology, Eberhard-Karls-University, Tübingen, Germany.,Campbell Family Institute for Breast Cancer Research, Ontario Cancer Institute, UHN, Toronto, Canada.,Institute of Agricultural and Nutritional Sciences, Martin Luther University Halle-Wittenberg, Halle (Saale), Germany
| | - Tak W Mak
- Campbell Family Institute for Breast Cancer Research, Ontario Cancer Institute, UHN, Toronto, Canada
| | - Yogesh Singh
- Department of Cardiology, Vascular Medicine and Physiology, Eberhard-Karls-University, Tübingen, Germany
| | - Florian Lang
- Department of Cardiology, Vascular Medicine and Physiology, Eberhard-Karls-University, Tübingen, Germany
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24
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Duanmu Y, Cong R, Tao S, Tian J, Dong H, Zhang Y, Ni Y, Zhao R. Comparative proteomic analysis of the effects of high-concentrate diet on the hepatic metabolism and inflammatory response in lactating dairy goats. J Anim Sci Biotechnol 2016; 7:5. [PMID: 26855776 PMCID: PMC4744397 DOI: 10.1186/s40104-016-0065-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2015] [Accepted: 01/25/2016] [Indexed: 12/26/2022] Open
Abstract
Background To understand the impact of feeding a high-concentrate diet to mid-lactating goats for a long time on liver metabolism and inflammatory response, two dimensional polyacrylamide gel electrophoresis (2-DE) and real-time PCR method were employed to detect proteins differentially expressed in liver and their mRNAs expression in goats fed high concentrate diet (HC) or low concentrate diet (LC). Twelve lactating dairy goats were randomly assigned to either a HC diet group (65 % concentrate of dry matter; n = 6) or a LC diet group (35 % concentrate of dry matter; n = 6) for 10 wk. Results Twenty differentially expressed spots (≥2.0-fold changes) in the hepatic tissues were excised and successfully identified using MALDI TOF/TOF. Of these, 8 proteins were up-regulated, while the rest 12 proteins were down-regulated in HC goats compared to LC. Differential expressed proteins including alpha enolase 1 (ENO1), glutamate dehydrogenase 1 (GLUD1), glutathione S-transferase A1 (GSTA1), ATP synthase subunit 5β (ATP5β), superoxide dismutase [Cu-Zn] (SOD1), cytochrom c oxidase subunit Via (COX6A1) and heat shock protein 60 (HSP60) were further verified by real-time PCR and/or western blot at mRNA or protein expression level. Consistent with the 2-DE results, a significant decrease of β-actin protein expression and SOD enzyme activity was observed in liver of HC goats (P < 0.05), while ENO1 protein expression was significantly up-regulated in HC compared to LC goats (P < 0.05) . However, western blot analysis did not show a significant difference of hepatic HSP60 protein between HC and LC group, which did not match the decrease of HSP60 content detected by 2-DE analysis. Real-time PCR showed that glutathione S-transferase P1 (GSTP1) and SOD1 mRNA expression was significantly decreased in liver of HC goats, while cytochrom c oxidase (COX3) and ATPase 8 (ATP8) mRNAs expression were markedly increased compared to LC (P < 0.05). Gene Ontology (GO) analysis revealed that HC diet resulted in altered expression of proteins related to catalytic and mitochondrial metabolism in the liver, and may increase the stress response with up-regulating the expression of differentiation 14 (CD14) cluster and serum amyloid A (SAA) as well as C-reactive protein (CRP) in the liver. Conclusions These results suggest that feeding high concentrate diet to lactating goats for 10 wk leads to the activation of the inflammatory response, and decreases the anti-oxidant capacity, and subsequently impairs the mitochondrial function in the liver. Electronic supplementary material The online version of this article (doi:10.1186/s40104-016-0065-0) contains supplementary material, which is available to authorized users.
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Affiliation(s)
- Yongqian Duanmu
- Key Laboratory of Animal Physiology & Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu China
| | - Rihua Cong
- College of Veterinary Medicine, Northwest A & F University, Yangling, Shannxi China
| | - Shiyu Tao
- Key Laboratory of Animal Physiology & Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu China
| | - Jing Tian
- Key Laboratory of Animal Physiology & Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu China
| | - Haibo Dong
- Key Laboratory of Animal Physiology & Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu China
| | - Yuanshu Zhang
- Key Laboratory of Animal Physiology & Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu China
| | - Yingdong Ni
- Key Laboratory of Animal Physiology & Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu China
| | - Ruqian Zhao
- Key Laboratory of Animal Physiology & Biochemistry, Ministry of Agriculture, Nanjing Agricultural University, Nanjing, Jiangsu China
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25
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Li P, Chen GR, Wang F, Xu P, Liu LY, Yin YL, Wang SX. Inhibition of NA(+)/H(+) Exchanger 1 Attenuates Renal Dysfunction Induced by Advanced Glycation End Products in Rats. J Diabetes Res 2016; 2016:1802036. [PMID: 26697498 PMCID: PMC4677205 DOI: 10.1155/2016/1802036] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 06/24/2015] [Indexed: 11/20/2022] Open
Abstract
It has been recognized that sodium hydrogen exchanger 1 (NHE1) is involved in the development of diabetic nephropathy. The role of NHE1 in kidney dysfunction induced by advanced glycation end products (AGEs) remains unknown. Renal damage was induced by AGEs via tail vein injections in rats. Function and morphology of kidney were determined. Compared to vehicle- or BSA-treated rats, AGEs caused abnormalities of kidney structures and functions in rats, accompanied with higher MDA level and lower GSH content. Gene expressions of NHE1 gene and TGF-β1 in the renal cortex and urine were also increased in AGEs-injected rats. Importantly, all these detrimental effects induced by AGEs were reversed by inhibition of NHE1 or suppression of oxidative stress. These pieces of data demonstrated that AGEs may activate NHE1 to induce renal damage, which is related to TGF-β1.
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Affiliation(s)
- Peng Li
- College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China
- Department of Pharmacology, Pharmaceutical College, Central South University, Changsha 410078, China
| | - Geng-Rong Chen
- Department of Pharmacology, Pharmaceutical College, Central South University, Changsha 410078, China
| | - Fu Wang
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital, School of Medicine, Shandong University, Jinan 250012, China
| | - Ping Xu
- College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China
| | - Li-Ying Liu
- Department of Pharmacology, Pharmaceutical College, Central South University, Changsha 410078, China
- Medical College of San-Quan, Xinxiang Medical University, Xinxiang 453003, China
| | - Ya-Ling Yin
- College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China
- School of Basic Medical Sciences, Xinxiang Medical University, Xinxiang 453003, China
| | - Shuang-Xi Wang
- College of Pharmacy, Xinxiang Medical University, Xinxiang 453003, China
- The Key Laboratory of Cardiovascular Remodeling and Function Research, Chinese Ministry of Education and Chinese Ministry of Health, Qilu Hospital, School of Medicine, Shandong University, Jinan 250012, China
- *Shuang-Xi Wang:
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26
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5-Aminolevulinic acid regulates the inflammatory response and alloimmune reaction. Int Immunopharmacol 2015; 37:71-78. [PMID: 26643355 DOI: 10.1016/j.intimp.2015.11.034] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2015] [Revised: 11/25/2015] [Accepted: 11/26/2015] [Indexed: 12/15/2022]
Abstract
5-Aminolevulinic acid (5-ALA) is a naturally occurring amino acid and precursor of heme and protoporphyrin IX (PpIX). Exogenously administrated 5-ALA increases the accumulation of PpIX in tumor cells specifically due to the compromised metabolism of 5-ALA to heme in mitochondria. PpIX emits red fluorescence by the irradiation of blue light and the formation of reactive oxygen species and singlet oxygen. Thus, performing a photodynamic diagnosis (PDD) and photodynamic therapy (PDT) using 5-ALA have given rise to a new strategy for tumor diagnosis and therapy. In addition to the field of tumor therapy, 5-ALA has been implicated in the treatment of inflammatory disease, autoimmune disease and transplantation due to the anti-inflammation and immunoregulation properties that are elicited with the expression of heme oxygenase (HO)-1, an inducible enzyme that catalyzes the rate-limiting step in the oxidative degradation of heme to free iron, biliverdin and carbon monoxide (CO), in combination with sodium ferrous citrate (SFC), because an inhibitor of HO-1 abolishes the effects of 5-ALA. Furthermore, NF-E2-related factor 2 (Nrf2), mitogen-activated protein kinase (MAPK), and heme are involved in the HO-1 expression. Biliverdin and CO are also known to have anti-apoptotic, anti-inflammatory and immunoregulatory functions. We herein review the current use of 5-ALA in inflammatory diseases, transplantation medicine, and tumor therapy.
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27
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Cao J, Xie H, Sun Y, Zhu J, Ying M, Qiao S, Shao Q, Wu H, Wang C. Sevoflurane post-conditioning reduces rat myocardial ischemia reperfusion injury through an increase in NOS and a decrease in phopshorylated NHE1 levels. Int J Mol Med 2015; 36:1529-37. [PMID: 26459736 PMCID: PMC4678156 DOI: 10.3892/ijmm.2015.2366] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 09/24/2015] [Indexed: 12/22/2022] Open
Abstract
The protective effects of sevoflurane post-conditioning against myocardial ischemia/reperfusion (I/R) injury (MIRI) have been previously reported. However, the mechanisms responsible for these protective effects remain elusive. In this study, in order to investigate the molecular mechanisms responsible for the protective effects of sevoflurane post-conditioning on isolated rat hearts subjected to MIRI, Sprague-Dawley rat hearts were randomly divided into the following 6 groups: i) the sham-operated control; ii) 2.5% sevoflurane; iii) ischemia/reperfusion (I/R); iv) 2.5% sevoflurane post-conditioning plus I/R; v) 2.5% sevoflurane post-conditioning + NG-nitro-L-arginine methyl ester (L-NAME) plus I/R; and vi) L-NAME plus I/R. The infarct size was measured using 2,3,5-triphenyl tetrazolium chloride (TTC) staining. Additionally, the myocardial nitric oxide (NO), NO synthase (NOS) and nicotinamide adenine dinucleotide (NAD+) levels were determined. Autophagosomes and apoptosomes in the myocardium were detected by transmission electron microscopy. The levels of Bcl-2, cleaved caspase-3, Beclin-1, microtubule-associated protein light chain 3 (LC3)-I/II, Na+/H+ exchanger 1 (NHE1) and phosphorylated NHE1 protein were measured by western blot analysis. NHE1 mRNA levels were measured by reverse transcription-quantitative polymerase chain reaction. Compared with the I/R group, 15 min of exposure to 2.5% sevoflurane during early reperfusion significantly decreased the myocardial infarct size, the autophagic vacuole numbers, the NHE1 mRNA and protein expression of cleaved caspase-3, Beclin-1 and LC3-I/II. Post-conditioning with 2.5% sevoflurane also increased the NO and NOS levels and Bcl-2 protein expression (P<0.05 or P<0.01). Notably, the cardioprotective effects of sevoflurane were partly abolished by the NOS inhibitor, L-NAME. The findings of the present study suggest that sevoflurane post-conditioning protects the myocardium against I/R injury and reduces the myocardial infarct size. The underlying protective mechanisms are associated with the inhibition of mitochondrial permeability transition pore opening, and with the attenuation of cardiomyoctye apoptosis and excessive autophagy. These effects are mediated through an increase in NOS and a decrease in phopshorylated NHE1 levels.
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Affiliation(s)
- Jianfang Cao
- Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Hong Xie
- Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Ying Sun
- Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Jiang Zhu
- Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Ming Ying
- Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Shigang Qiao
- Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Qin Shao
- Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Haorong Wu
- Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
| | - Chen Wang
- Department of Anesthesiology, The Second Affiliated Hospital of Soochow University, Suzhou, Jiangsu 215004, P.R. China
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28
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Yang D, Liu X, Liu M, Chi H, Liu J, Han H. Protective effects of quercetin and taraxasterol against H 2O 2-induced human umbilical vein endothelial cell injury in vitro. Exp Ther Med 2015; 10:1253-1260. [PMID: 26622474 PMCID: PMC4578013 DOI: 10.3892/etm.2015.2713] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2014] [Accepted: 11/28/2014] [Indexed: 12/22/2022] Open
Abstract
Due to the association between inflammation and endothelial dysfunction in atherosclerosis, the blockage of the inflammatory process that occurs on the endothelial cells may be a useful way of preventing atherosclerosis. In the present study, human umbilical vein endothelial cells (HUVECs) were used to investigate the protective effects of quercetin and taraxasterol against H2O2-induced oxidative damage and inflammation. HUVECs were pretreated with quercetin or taraxasterol at concentrations ranging between 0 and 210 µM for 12 h, prior to being administered different concentrations of H2O2 for 4 h. Cell viability and levels of apoptosis were assessed through cell counting kit-8 (CCK-8) and terminal deoxynucleotidyl transferase dUTP nick end labeling assays, respectively, to determine the injury to the HUVECs. The viability loss in the H2O2-induced HUVECs was markedly restored in a concentration-dependent manner by pretreatment with quercetin or taraxasterol. This effect was accompanied by significantly decreased expression of vascular cell adhesion molecule 1 (VCAM-1) and cluster of differentiation (CD)80 for taraxasterol and that of CD80 for quercetin. In conclusion, the present study showed the protective effects of quercetin and taraxasterol against cell injury and inflammation in HUVECs and indicated that the effects were mediated via the downregulation of VCAM-1 and CD80 expression. This study has therefore served as a preliminary investigation on the anti-atherosclerotic and cardiovascular protective effects of quercetin and taraxasterol as dietary supplements.
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Affiliation(s)
- Dongwei Yang
- Department of Cardiology, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450007, P.R. China
| | - Xinye Liu
- Department of Cardiology, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450007, P.R. China
| | - Min Liu
- Department of Cardiology, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450007, P.R. China
| | - Hao Chi
- Department of Cardiology, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450007, P.R. China
| | - Jirong Liu
- Department of Internal Medicine, North China Electric Power University Hospital, Beijing 102206, P.R. China
| | - Huamin Han
- Department of Cardiology, Zhengzhou Central Hospital Affiliated to Zhengzhou University, Zhengzhou, Henan 450007, P.R. China
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29
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Mohamed IA, Mraiche F. Targeting osteopontin, the silent partner of Na+/H+ exchanger isoform 1 in cardiac remodeling. J Cell Physiol 2015; 230:2006-18. [PMID: 25677682 DOI: 10.1002/jcp.24958] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2014] [Accepted: 02/06/2015] [Indexed: 12/11/2022]
Abstract
Cardiac hypertrophy (CH), characterized by the enlargement of cardiomyocytes, fibrosis and apoptosis, contributes to cardiac remodeling, which if left unresolved results in heart failure. Understanding the signaling pathways underlying CH is necessary to identify potential therapeutic targets. The Na(+) /H(+) -exchanger isoform I (NHE1), a ubiquitously expressed glycoprotein and cardiac specific isoform, regulates intracellular pH. Recent studies have demonstrated that enhanced expression/activity of NHE1 contributes to cardiac remodeling and CH. Inhibition of NHE1 in both in vitro and in vivo models have suggested that inhibition of NHE1 protects against hypertrophy. However, clinical trials using NHE1 inhibitors have proven to be unsuccessful, suggesting that additional factors maybe contributing to cardiac remodeling. Recent studies have indicated that the upregulation of NHE1 is associated with enhanced levels of osteopontin (OPN) in the setting of CH. OPN has been demonstrated to be upregulated in left ventricular hypertrophy, dilated cardiomyopathy and in diabetic cardiomyopathy. The cellular interplay between OPN and NHE1 in the setting of CH remains unknown. This review focuses on the role of NHE1 and OPN in cardiac remodeling and emphasizes the signaling pathways implicating OPN in the NHE1-induced hypertrophic response.
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30
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Mohamed IA, Gadeau AP, Fliegel L, Lopaschuk G, Mlih M, Abdulrahman N, Fillmore N, Mraiche F. Na+/H+ exchanger isoform 1-induced osteopontin expression facilitates cardiomyocyte hypertrophy. PLoS One 2015; 10:e0123318. [PMID: 25884410 PMCID: PMC4401699 DOI: 10.1371/journal.pone.0123318] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2014] [Accepted: 03/02/2015] [Indexed: 01/02/2023] Open
Abstract
Enhanced expression and activity of the Na+/H+ exchanger isoform 1 (NHE1) has been implicated in cardiomyocyte hypertrophy in various experimental models. The upregulation of NHE1 was correlated with an increase in osteopontin (OPN) expression in models of cardiac hypertrophy (CH), and the mechanism for this remains to be delineated. To determine whether the expression of active NHE1-induces OPN and contributes to the hypertrophic response in vitro, cardiomyocytes were infected with the active form of the NHE1 adenovirus or transfected with OPN silencing RNA (siRNA-OPN) and characterized for cardiomyocyte hypertrophy. Expression of NHE1 in cardiomyocytes resulted in a significant increase in cardiomyocyte hypertrophy markers: cell surface area, protein content, ANP mRNA and expression of phosphorylated-GATA4. NHE1 activity was also significantly increased in cardiomyocytes expressing active NHE1. Interestingly, transfection of cardiomyocytes with siRNA-OPN significantly abolished the NHE1-induced cardiomyocyte hypertrophy. siRNA-OPN also significantly reduced the activity of NHE1 in cardiomyocytes expressing NHE1 (68.5±0.24%; P<0.05), confirming the role of OPN in the NHE1-induced hypertrophic response. The hypertrophic response facilitated by NHE1-induced OPN occurred independent of the extracellular-signal-regulated kinases and Akt, but required p90-ribosomal S6 kinase (RSK). The ability of OPN to facilitate the NHE1-induced hypertrophic response identifies OPN as a potential therapeutic target to reverse the hypertrophic effect induced by the expression of active NHE1.
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Affiliation(s)
| | - Alain-Pierre Gadeau
- University of Bordeaux, Adaptation Cardiovasculaire à L'ischémie, UMR1034, Pessac, France
| | - Larry Fliegel
- Department of Biochemistry, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Gary Lopaschuk
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Mohamed Mlih
- College of Pharmacy, Qatar University, Doha, Qatar
| | | | - Natasha Fillmore
- Mazankowski Alberta Heart Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Fatima Mraiche
- College of Pharmacy, Qatar University, Doha, Qatar
- * E-mail:
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31
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Zhao M, Guo H, Chen J, Fujino M, Ito H, Takahashi K, Abe F, Nakajima M, Tanaka T, Wang J, Huang H, Zheng S, Hei M, Li J, Huang S, Li J, Ma X, Chen Y, Zhao L, Zhuang J, Zhu P, Li XK. 5-aminolevulinic acid combined with sodium ferrous citrate ameliorates H2O2-induced cardiomyocyte hypertrophy via activation of the MAPK/Nrf2/HO-1 pathway. Am J Physiol Cell Physiol 2015; 308:C665-72. [PMID: 25652453 DOI: 10.1152/ajpcell.00369.2014] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 02/02/2015] [Indexed: 11/22/2022]
Abstract
Hydrogen peroxide (H2O2) causes cell damage via oxidative stress. Heme oxygenase-1 (HO-1) is an antioxidant enzyme that can protect cardiomyocytes against oxidative stress. In this study, we investigated whether the heme precursor 5-aminolevulinic acid (5-ALA) with sodium ferrous citrate (SFC) could protect cardiomyocytes from H2O2-induced hypertrophy via modulation of HO-1 expression. HL-1 cells pretreated with/without 5-ALA and SFC were exposed to H2O2 to induce a cardiomyocyte hypertrophy model. Hypertrophy was evaluated by planar morphometry, (3)H-leucine incorporation, and RT-PCR analysis of hypertrophy-related gene expressions. Reactive oxygen species (ROS) production was assessed by 5/6-chloromethyl-2',7'-ichlorodihydrofluorescein diacetate acetylester. HO-1 and nuclear factor erythroid 2-related factor 2 (Nrf2) protein expressions were analyzed by Western blot. In our experiments, HL-1 cells were transfected with Nrf2 siRNA or treated with a signal pathway inhibitor. We found several results. 1) ROS production, cell surface area, protein synthesis, and expressions of hypertrophic marker genes, including atrial natriuretic peptide, brain natriuretic peptide, atrial natriuretic factor, and β-myosin heavy chain, were decreased in HL-1 cells pretreated with 5-ALA and SFC. 2) 5-ALA and SFC increased HO-1 expression in a dose- and time-dependent manner, associated with upregulation of Nrf2. Notably, Nrf2 siRNA dramatically reduced HO-1 expression in HL-1 cells. 3) ERK1/2, p38, and SAPK/JNK signaling pathways were activated and modulate 5-ALA- and SFC-enhanced HO-1 expression. SB203580 (p38 kinase), PD98059 (ERK), or SP600125 (JNK) inhibitors significantly reduced this effect. In conclusion, our data suggest that 5-ALA and SFC protect HL-1 cells from H2O2-induced cardiac hypertrophy via activation of the MAPK/Nrf2/HO-1 signaling pathway.
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Affiliation(s)
- Mingyi Zhao
- Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Huiming Guo
- Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Jimei Chen
- Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | | | | | | | | | | | | | - Jinju Wang
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio
| | - Huanlei Huang
- Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Shaoyi Zheng
- Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Mingyan Hei
- Department of Pediatrics, the Third Xiangya Hospital, Central South University, Changsha, China
| | - Jiaxin Li
- Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Shuai Huang
- Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Jiani Li
- Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Xiaotang Ma
- Guangdong Key Laboratory of Age-Related Cardiac and Cerebral Diseases, Affiliated Hospital of Guangdong Medical College, Zhanjiang, China
| | - Yanfang Chen
- Department of Pharmacology and Toxicology, Boonshoft School of Medicine, Wright State University, Dayton, Ohio
| | - Lingling Zhao
- Department of Pediatrics, the Third Xiangya Hospital, Central South University, Changsha, China
| | - Jian Zhuang
- Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China
| | - Ping Zhu
- Department of Cardiovascular Surgery, Guangdong Cardiovascular Institute, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, China;
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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.
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Prasad V, Chirra S, Kohli R, Shull GE. NHE1 deficiency in liver: implications for non-alcoholic fatty liver disease. Biochem Biophys Res Commun 2014; 450:1027-31. [PMID: 24976401 DOI: 10.1016/j.bbrc.2014.06.095] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Accepted: 06/20/2014] [Indexed: 12/23/2022]
Abstract
Non-alcoholic fatty liver disease NAFLD is closely associated with the dysregulation of lipid homeostasis. Diet-induced hepatic steatosis, which can initiate NAFLD progression, has been shown to be dramatically reduced in mice lacking the electroneutral Na(+)/H(+) exchanger NHE1 (Slc9a1). In this study, we investigated if NHE1 deficiency had effects in liver that could contribute to the apparent protection against aberrant lipid accumulation. RT-PCR and immunoblot analyses of wild-type and NHE1-null livers revealed an expression profile that strongly suggested attenuation of both de novo lipogenesis and hepatic stellate cell activation, which is implicated in liver fibrosis. This included upregulation of the farnesoid X receptor FXR, peroxisome proliferator-activated receptor PPARγ, its co-activator PGC1α, and sestrin 2, an antioxidant protein involved in hepatic metabolic homeostasis. Furthermore, expression levels of the pro-lipogenic liver X receptor LXRα, and acetyl CoA carboxylases 1 and 2 were downregulated. These changes were associated with evidence of reduced cellular stress, which persisted even upon exposure to a high-fat diet, and the better preservation of insulin signaling, as evidenced by protein kinase B/Akt phosphorylation (Ser473). These results indicate that NHE1 deficiency may protect against NAFLD pathogenesis, which is significant given the availability of highly specific NHE1 inhibitors.
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Affiliation(s)
- Vikram Prasad
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, United States.
| | - Shivani Chirra
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, United States
| | - Rohit Kohli
- Department of Gastroenterology, Hepatology, and Nutrition, Cincinnati Children's Hospital, University of Cincinnati, Cincinnati, OH 45267, United States
| | - Gary E Shull
- Department of Molecular Genetics, Biochemistry, and Microbiology, University of Cincinnati College of Medicine, United States
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Prasad V, Lorenz JN, Lasko VM, Nieman ML, Al Moamen NJ, Shull GE. Loss of the AE3 Cl(-)/HCO(-) 3 exchanger in mice affects rate-dependent inotropy and stress-related AKT signaling in heart. Front Physiol 2013; 4:399. [PMID: 24427143 PMCID: PMC3875869 DOI: 10.3389/fphys.2013.00399] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2013] [Accepted: 12/19/2013] [Indexed: 01/12/2023] Open
Abstract
Cl(-)/HCO(-) 3 exchangers are expressed abundantly in cardiac muscle, suggesting that HCO(-) 3 extrusion serves an important function in heart. Mice lacking Anion Exchanger Isoform 3 (AE3), a major cardiac Cl(-)/HCO(-) 3 exchanger, appear healthy, but loss of AE3 causes decompensation in a hypertrophic cardiomyopathy (HCM) model. Using intra-ventricular pressure analysis, in vivo pacing, and molecular studies we identified physiological and biochemical changes caused by loss of AE3 that may contribute to decompensation in HCM. AE3-null mice had normal cardiac contractility under basal conditions and after β-adrenergic stimulation, but pacing of hearts revealed that frequency-dependent inotropy was blunted, suggesting that AE3-mediated HCO(-) 3 extrusion is required for a robust force-frequency response (FFR) during acute biomechanical stress in vivo. Modest changes in expression of proteins that affect Ca(2+)-handling were observed, but Ca(2+)-transient analysis of AE3-null myocytes showed normal twitch-amplitude and Ca(2+)-clearance. Phosphorylation and expression of several proteins implicated in HCM and FFR, including phospholamban (PLN), myosin binding protein C, and troponin I were not altered in hearts of paced AE3-null mice; however, phosphorylation of Akt, which plays a central role in mechanosensory signaling, was significantly higher in paced AE3-null hearts than in wild-type controls and phosphorylation of AMPK, which is affected by Akt and is involved in energy metabolism and some cases of HCM, was reduced. These data show loss of AE3 leads to impaired rate-dependent inotropy, appears to affect mechanical stress-responsive signaling, and reduces activation of AMPK, which may contribute to decompensation in heart failure.
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Affiliation(s)
- Vikram Prasad
- Departments of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine Cincinnati, OH, USA
| | - John N Lorenz
- Departments of Cellular and Molecular Physiology, University of Cincinnati College of Medicine Cincinnati, OH, USA
| | - Valerie M Lasko
- Departments of Cellular and Molecular Physiology, University of Cincinnati College of Medicine Cincinnati, OH, USA
| | - Michelle L Nieman
- Departments of Cellular and Molecular Physiology, University of Cincinnati College of Medicine Cincinnati, OH, USA
| | - Nabeel J Al Moamen
- Genetic Laboratory, Department of Pathology, Salmaniya Medical Complex Manama, Bahrain
| | - Gary E Shull
- Departments of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati College of Medicine Cincinnati, OH, USA
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