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Chowdhury MAR, An J, Jeong S. The Pleiotropic Face of CREB Family Transcription Factors. Mol Cells 2023; 46:399-413. [PMID: 37013623 PMCID: PMC10336275 DOI: 10.14348/molcells.2023.2193] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 02/03/2023] [Accepted: 02/07/2023] [Indexed: 04/05/2023] Open
Abstract
cAMP responsive element-binding protein (CREB) is one of the most intensively studied phosphorylation-dependent transcription factors that provide evolutionarily conserved mechanisms of differential gene expression in vertebrates and invertebrates. Many cellular protein kinases that function downstream of distinct cell surface receptors are responsible for the activation of CREB. Upon functional dimerization of the activated CREB to cis-acting cAMP responsive elements within the promoters of target genes, it facilitates signal-dependent gene expression. From the discovery of CREB, which is ubiquitously expressed, it has been proven to be involved in a variety of cellular processes that include cell proliferation, adaptation, survival, differentiation, and physiology, through the control of target gene expression. In this review, we highlight the essential roles of CREB proteins in the nervous system, the immune system, cancer development, hepatic physiology, and cardiovascular function and further discuss a wide range of CREB-associated diseases and molecular mechanisms underlying the pathogenesis of these diseases.
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Affiliation(s)
- Md. Arifur Rahman Chowdhury
- Division of Life Sciences (Molecular Biology Major), Department of Bioactive Material Sciences, and Research Center of Bioactive Materials, Jeonbuk National University, Jeonju 54896, Korea
| | - Jungeun An
- Division of Life Sciences (Life Sciences Major), Jeonbuk National University, Jeonju 54896, Korea
| | - Sangyun Jeong
- Division of Life Sciences (Molecular Biology Major), Department of Bioactive Material Sciences, and Research Center of Bioactive Materials, Jeonbuk National University, Jeonju 54896, Korea
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2
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Regulation of cardiac function by cAMP nanodomains. Biosci Rep 2023; 43:232544. [PMID: 36749130 PMCID: PMC9970827 DOI: 10.1042/bsr20220953] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/29/2023] [Accepted: 02/07/2023] [Indexed: 02/08/2023] Open
Abstract
Cyclic adenosine monophosphate (cAMP) is a diffusible intracellular second messenger that plays a key role in the regulation of cardiac function. In response to the release of catecholamines from sympathetic terminals, cAMP modulates heart rate and the strength of contraction and ease of relaxation of each heartbeat. At the same time, cAMP is involved in the response to a multitude of other hormones and neurotransmitters. A sophisticated network of regulatory mechanisms controls the temporal and spatial propagation of cAMP, resulting in the generation of signaling nanodomains that enable the second messenger to match each extracellular stimulus with the appropriate cellular response. Multiple proteins contribute to this spatiotemporal regulation, including the cAMP-hydrolyzing phosphodiesterases (PDEs). By breaking down cAMP to a different extent at different locations, these enzymes generate subcellular cAMP gradients. As a result, only a subset of the downstream effectors is activated and a specific response is executed. Dysregulation of cAMP compartmentalization has been observed in cardiovascular diseases, highlighting the importance of appropriate control of local cAMP signaling. Current research is unveiling the molecular organization underpinning cAMP compartmentalization, providing original insight into the physiology of cardiac myocytes and the alteration associated with disease, with the potential to uncover novel therapeutic targets. Here, we present an overview of the mechanisms that are currently understood to be involved in generating cAMP nanodomains and we highlight the questions that remain to be answered.
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Guo KM, Li W, Wang ZH, He LC, Feng Y, Liu HS. Low-dose aspirin inhibits trophoblast cell apoptosis by activating the CREB/Bcl-2 pathway in pre-eclampsia. Cell Cycle 2022; 21:2223-2238. [PMID: 35792905 PMCID: PMC9586659 DOI: 10.1080/15384101.2022.2092814] [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: 12/24/2021] [Revised: 05/06/2022] [Accepted: 05/31/2022] [Indexed: 11/03/2022] Open
Abstract
Excessive apoptosis of placental trophoblast cells is considered a major cause of pre-eclampsia (PE) pathogenesis. Phosphorylation of the widely expressed cAMP response element binding protein (CREB) regulates apoptosis and may be involved in PE incidence. Low-dose aspirin (LDA) is an effective approach for preventing PE with unclear mechanisms. Thus we examined whether LDA protects against PE by inhibiting trophoblast cell apoptosis through CREB. The effects of LDA on human PE placenta, PE model rat placenta, and hydrogen peroxide (H2O2)-induced HTR-8/SVneo cell apoptosis were analyzed. TUNEL assay, immunohistochemistry, Cell Counting Assay Kit-8 (CCK-8) assay, western blot, and flow cytometry assay were performed. In the placenta of human PE and rat PE models, the TUNEL index increased and was partially corrected with LDA pre-treatment. Meanwhile, decreased Bcl-2 and increased Bax expression were significantly reversed by LDA pre-treatment. In HTR-8/SVneo cells, H2O2 decreased cell viability, promoted apoptosis, reduced the Bcl-2/Bax ratio, aggravated loss of mitochondrial membrane potential (MMP), increased cytoplasmic cytochrome c release, and simultaneously activated caspase-9 and caspase-3. These effects were effectively restored by LDA pre-treatment in the cells. Moreover, LDA promoted CREB phosphorylation in trophoblast cells. CREB interference further promoted apoptosis, reduced the Bcl-2/Bax ratio, and increased MMP loss. CREB interference also reversed the inhibitory effect of LDA on H2O2-induced apoptosis in HTR-8/SVneo cells. Thus, LDA was shown to inhibit trophoblast cell mitochondrial apoptosis by activating the CREB/Bcl-2 pathway, providing novel evidence for the protective mechanism of LDA in PE.Abbreviations; PE: Pre-eclampsia; LDA: low-dose aspirin; CREB: cAMP response element binding protein; ROS: reactive oxygen species; H2O2: hydrogen peroxide; PBS: Phosphate-buffered saline; Bcl-2: B-cell lymphoma-2; MMP: Mitochondrial membrane potential; Cyt-c: CytochromeC.
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Affiliation(s)
- Kai-Min Guo
- Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Wei Li
- Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
- Department of Obstetrics and Gynecology, The First Affiliated Hospital of Xi’an Medical University, Xi’an, China
| | - Zhao-Hua Wang
- Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
- Department of Histology and Embryology, Guangzhou Medical University, Guangzhou, China
| | - Lang-Chi He
- Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Yan Feng
- Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
| | - Hui-Shu Liu
- Department of Obstetrics and Gynecology, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, China
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Crespo-García T, Cámara-Checa A, Dago M, Rubio-Alarcón M, Rapún J, Tamargo J, Delpón E, Caballero R. Regulation of cardiac ion channels by transcription factors: Looking for new opportunities of druggable targets for the treatment of arrhythmias. Biochem Pharmacol 2022; 204:115206. [PMID: 35963339 DOI: 10.1016/j.bcp.2022.115206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 08/04/2022] [Accepted: 08/05/2022] [Indexed: 11/29/2022]
Abstract
Cardiac electrical activity is governed by different ion channels that generate action potentials. Acquired or inherited abnormalities in the expression and/or function of ion channels usually result in electrophysiological changes that can cause cardiac arrhythmias. Transcription factors (TFs) control gene transcription by binding to specific DNA sequences adjacent to target genes. Linkage analysis, candidate-gene screening within families, and genome-wide association studies have linked rare and common genetic variants in the genes encoding TFs with genetically-determined cardiac arrhythmias. Besides its critical role in cardiac development, recent data demonstrated that they control cardiac electrical activity through the direct regulation of the expression and function of cardiac ion channels in adult hearts. This narrative review summarizes some studies showing functional data on regulation of the main human atrial and ventricular Na+, Ca2+, and K+ channels by cardiac TFs such as Pitx2c, Tbx20, Tbx5, Zfhx3, among others. The results have improved our understanding of the mechanisms regulating cardiac electrical activity and may open new avenues for therapeutic interventions in cardiac acquired or inherited arrhythmias through the identification of TFs as potential drug targets. Even though TFs have for a long time been considered as 'undruggable' targets, advances in structural biology have led to the identification of unique pockets in TFs amenable to be targeted with small-molecule drugs or peptides that are emerging as novel therapeutic drugs.
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Affiliation(s)
- T Crespo-García
- Department of Pharmacology and Toxicology. School of Medicine. Universidad Complutense de Madrid, Instituto de Investigación Sanitaria Gregorio Marañón. CIBERCV, 28040 Madrid, Spain
| | - A Cámara-Checa
- Department of Pharmacology and Toxicology. School of Medicine. Universidad Complutense de Madrid, Instituto de Investigación Sanitaria Gregorio Marañón. CIBERCV, 28040 Madrid, Spain
| | - M Dago
- Department of Pharmacology and Toxicology. School of Medicine. Universidad Complutense de Madrid, Instituto de Investigación Sanitaria Gregorio Marañón. CIBERCV, 28040 Madrid, Spain
| | - M Rubio-Alarcón
- Department of Pharmacology and Toxicology. School of Medicine. Universidad Complutense de Madrid, Instituto de Investigación Sanitaria Gregorio Marañón. CIBERCV, 28040 Madrid, Spain
| | - J Rapún
- Department of Pharmacology and Toxicology. School of Medicine. Universidad Complutense de Madrid, Instituto de Investigación Sanitaria Gregorio Marañón. CIBERCV, 28040 Madrid, Spain
| | - J Tamargo
- Department of Pharmacology and Toxicology. School of Medicine. Universidad Complutense de Madrid, Instituto de Investigación Sanitaria Gregorio Marañón. CIBERCV, 28040 Madrid, Spain
| | - E Delpón
- Department of Pharmacology and Toxicology. School of Medicine. Universidad Complutense de Madrid, Instituto de Investigación Sanitaria Gregorio Marañón. CIBERCV, 28040 Madrid, Spain.
| | - R Caballero
- Department of Pharmacology and Toxicology. School of Medicine. Universidad Complutense de Madrid, Instituto de Investigación Sanitaria Gregorio Marañón. CIBERCV, 28040 Madrid, Spain
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- Department of Pharmacology and Toxicology. School of Medicine. Universidad Complutense de Madrid, Instituto de Investigación Sanitaria Gregorio Marañón. CIBERCV, 28040 Madrid, Spain
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Hall EJ, Pal S, Glennon MS, Shridhar P, Satterfield SL, Weber B, Zhang Q, Salama G, Lal H, Becker JR. Cardiac natriuretic peptide deficiency sensitizes the heart to stress induced ventricular arrhythmias via impaired CREB signaling. Cardiovasc Res 2021; 118:2124-2138. [PMID: 34329394 DOI: 10.1093/cvr/cvab257] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 07/28/2021] [Indexed: 11/14/2022] Open
Abstract
AIMS The cardiac natriuretic peptides (atrial natriuretic peptide [ANP] and B-type natriuretic peptide [BNP]) are important regulators of cardiovascular physiology, with reduced natriuretic peptide (NP) activity linked to multiple human cardiovascular diseases. We hypothesized that deficiency of either ANP or BNP would lead to similar changes in left ventricular structure and function given their shared receptor affinities. METHODS AND RESULTS We directly compared murine models deficient of ANP or BNP in the same genetic backgrounds (C57BL6/J) and environments. We evaluated control, ANP deficient (Nppa-/-) or BNP deficient (Nppb-/-) mice under unstressed conditions and multiple forms of pathological myocardial stress. Survival, myocardial structure, function and electrophysiology, tissue histology, and biochemical analyses were evaluated in the groups. In vitro validation of our findings was performed using human derived induced pluripotent stem cell cardiomyocytes (iPS-CM). In the unstressed state, both ANP and BNP deficient mice displayed mild ventricular hypertrophy which did not increase up to 1 year of life. NP-deficient mice exposed to acute myocardial stress secondary to thoracic aortic constriction (TAC) had similar pathological myocardial remodeling but a significant increase in sudden death. We discovered that the NP-deficient mice are more susceptible to stress induced ventricular arrhythmias using both in vivo and ex vivo models. Mechanistically, deficiency of either ANP or BNP led to reduced myocardial cGMP levels and reduced phosphorylation of the cAMP response element-binding protein (CREBS133) transcriptional regulator. Selective CREB inhibition sensitized wild type hearts to stress induced ventricular arrhythmias. ANP and BNP regulate cardiomyocyte CREBS133 phosphorylation through a cGMP-dependent protein kinase 1 (PKG1) and p38 mitogen activated protein kinase (p38 MAPK) signaling cascade. CONCLUSIONS Our data show that ANP and BNP act in a non-redundant fashion to maintain myocardial cGMP levels to regulate cardiomyocyte p38 MAPK and CREB activity. Cardiac natriuretic peptide deficiency leads to a reduction in CREB signaling which sensitizes the heart to stress induced ventricular arrhythmias. TRANSLATIONAL PERSPECTIVE Our study found that ANP or BNP deficiency leads to increased sudden death and ventricular arrhythmias after acute myocardial stress in murine models. We discovered that ANP and BNP act in a non-redundant fashion to maintain myocardial cGMP levels and uncovered a unique role for these peptides in regulating cardiomyocyte p38 MAPK and CREB signaling through a cGMP-PKG1 pathway. Importantly, this signaling pathway was conserved in human cardiomyocytes. This study provides mechanistic insight into how modulating natriuretic peptide levels in human heart failure patients reduces sudden death and mortality.
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Affiliation(s)
- Eric J Hall
- Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, USA
| | - Soumojit Pal
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute and Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Michael S Glennon
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute and Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Puneeth Shridhar
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute and Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Sidney L Satterfield
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute and Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Beth Weber
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute and Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Qinkun Zhang
- Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham Medical Center, Birmingham, AL, USA
| | - Guy Salama
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute and Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA, USA
| | - Hind Lal
- Division of Cardiovascular Disease, Department of Medicine, University of Alabama at Birmingham Medical Center, Birmingham, AL, USA
| | - Jason R Becker
- Pittsburgh Heart, Lung, Blood, and Vascular Medicine Institute and Division of Cardiology, Department of Medicine, University of Pittsburgh School of Medicine and University of Pittsburgh Medical Center, Pittsburgh, PA, USA
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Alyu F, Olgar Y, Degirmenci S, Turan B, Ozturk Y. Interrelated In Vitro Mechanisms of Sibutramine-Induced Cardiotoxicity. Cardiovasc Toxicol 2021; 21:322-335. [PMID: 33389602 DOI: 10.1007/s12012-020-09622-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 11/24/2020] [Indexed: 11/26/2022]
Abstract
Consumption of illicit pharmaceutical products containing sibutramine has been reported to cause cardiovascular toxicity problems. This study aimed to demonstrate the toxicity profile of sibutramine, and thereby provide important implications for the development of more effective strategies in both clinical approaches and drug design studies. Action potentials (APs) were determined from freshly isolated ventricular cardiomyocytes with whole-cell configuration of current clamp as online. The maximum amplitude of APs (MAPs), the resting membrane potential (RMP), and AP duration from the repolarization phases were calculated from original records. The voltage-dependent K+-channel currents (IK) were recorded in the presence of external Cd2+ and both inward and outward parts of the current were calculated, while their expression levels were determined with qPCR. The levels of intracellular free Ca2+ and H+ (pHi) as well as reactive oxygen species (ROS) were measured using either a ratiometric micro-spectrofluorometer or confocal microscope. The mechanical activity of isolated hearts was observed with Langendorff-perfusion system. Acute sibutramine applications (10-8-10-5 M) induced significant alterations in both MAPs and RMP as well as the repolarization phases of APs and IK in a concentration-dependent manner. Sibutramine (10 μM) induced Ca2+-release from the sarcoplasmic reticulum under either electrical or caffeine stimulation, whereas it depressed left ventricular developed pressure with a marked decrease in the end-diastolic pressure. pHi inhibition by sibutramine supports the observed negative alterations in contractility. Changes in mRNA levels of different IK subunits are consistent with the acute inhibition of the repolarizing IK, affecting AP parameters, and provoke the cardiotoxicity.
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Affiliation(s)
- Feyza Alyu
- Department of Pharmacology, Faculty of Pharmacy, Anadolu University, Yunus Emre Campus, 26470, Eskisehir, Turkey
| | - Yusuf Olgar
- Department of Biophysics, Faculty of Medicine, Ankara University, 06230, Ankara, Turkey
| | - Sinan Degirmenci
- Department of Biophysics, Faculty of Medicine, Ankara University, 06230, Ankara, Turkey
| | - Belma Turan
- Department of Biophysics, Faculty of Medicine, Ankara University, 06230, Ankara, Turkey
- Department of Biophysics, Faculty of Medicine, Lokman Hekim University, 06230, Ankara, Turkey
| | - Yusuf Ozturk
- Department of Pharmacology, Faculty of Pharmacy, Anadolu University, Yunus Emre Campus, 26470, Eskisehir, Turkey.
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Oxytocin Downregulates the Ca V1.2 L-Type Ca 2+ Channel via Gi/cAMP/PKA/CREB Signaling Pathway in Cardiomyocytes. MEMBRANES 2021; 11:membranes11040234. [PMID: 33806201 PMCID: PMC8066716 DOI: 10.3390/membranes11040234] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 03/17/2021] [Accepted: 03/24/2021] [Indexed: 12/13/2022]
Abstract
Oxytocin (OT) and its receptor (OTR) are expressed in the heart and are involved in the physiological cardiovascular functional system. Although it is known that OT/OTR signaling is cardioprotective by reducing the inflammatory response and improving cardiovascular function, the role of OT in the cardiac electrical excitation modulation has not been clarified. This study investigates the molecular mechanism of the action of OT on cardiomyocyte membrane excitation focusing on the L-type Ca2+ channel. Our methodology uses molecular biological methods and a patch-clamp technique on rat cardiomyocytes with OT, combined with several signal inhibitors and/or activators. Our results show that long-term treatment of OT significantly decreases the expression of Cav1.2 mRNA, and reduces the L-type Ca2+ channel current (ICa.L) in cardiomyocytes. OT downregulates the phosphorylated component of a transcription factor adenosine-3′,5′-cyclic monophosphate (cAMP) response element binding protein (CREB), whose action is blocked by OTR antagonist and pertussis toxin, a specific inhibitor of the inhibitory GTP-binding regulators of adenylate cyclase, Gi. On the other hand, the upregulation of Cav1.2 mRNA expression by isoproterenol is halted by OT. Furthermore, inhibition of phospholipase C (PLC) was without effect on the OT action to downregulate Cav1.2 mRNA—which suggests a signal pathway of Gi/protein kinase A (PKA)/CREB mediated by OT/OTR. These findings indicate novel signaling pathways of OT contributing to a downregulation of the Cav1.2-L-type Ca2+ channel in cardiomyocytes.
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8
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Pluteanu F, Seidl MD, Hamer S, Scholz B, Müller FU. Inward Rectifier K + Currents Contribute to the Proarrhythmic Electrical Phenotype of Atria Overexpressing Cyclic Adenosine Monophosphate Response Element Modulator Isoform CREM-IbΔC-X. J Am Heart Assoc 2020; 9:e016144. [PMID: 33191843 PMCID: PMC7763782 DOI: 10.1161/jaha.119.016144] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND Transgenic mice (TG) with heart-directed overexpresion of the isoform of the transcription factor cyclic adenosine monophosphate response element modulator (CREM), CREM-IbΔC-X, display spontaneous atrial fibrillation (AF) and action potential prolongation. The remodeling of the underlying ionic currents remains unknown. Here, we investigated the regulatory role of CREM-IbΔC-X on the expression of K+ channel subunits and the corresponding K+ currents in relation to AF onset in TG atrial myocytes. METHODS AND RESULTS ECG recordings documented the absence or presence of AF in 6-week-old (before AF onset) and 12-week-old TG (after AF onset) and wild-type littermate mice before atria removal to perform patch clamp, contractility, and biochemical experiments. In TG atrial myocytes, we found reduced repolarization reserve K+ currents attributed to a decrease of transiently outward current and inward rectifier K+ current with phenotype progression, and of acetylcholine-activated K+ current, age independent. The molecular determinants of these changes were lower mRNA levels of Kcnd2/3, Kcnip2, Kcnj2/4, and Kcnj3/5 and decreased protein levels of K+ channel interacting protein 2 (KChIP2 ), Kir2.1/3, and Kir3.1/4, respectively. After AF onset, inward rectifier K+ current contributed less to action potential repolarization, in line with the absence of outward current component, whereas the acetylcholine-induced action potential shortening before AF onset (6-week-old TG mice) was smaller than in wild-type and 12-week-old TG mice. Atrial force of contraction measured under combined vagal-sympathetic stimulation revealed increased sensitivity to isoprenaline irrespective of AF onset in TG. Moreover, we identified Kcnd2, Kcnd3, Kcnj3, and Kcnh2 as novel CREM-target genes. CONCLUSIONS Our study links the activation of cyclic adenosine monophosphate response element-mediated transcription to the proarrhythmogenic electrical remodeling of atrial inward rectifier K+ currents with a role in action potential duration, resting membrane stability, and vagal control of the electrical activity.
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Affiliation(s)
| | - Matthias D. Seidl
- Institute of Pharmacology and ToxicologyUniversity of MünsterMünsterGermany
| | - Sabine Hamer
- Institute of Pharmacology and ToxicologyUniversity of MünsterMünsterGermany
| | - Beatrix Scholz
- Institute of Pharmacology and ToxicologyUniversity of MünsterMünsterGermany
| | - Frank U. Müller
- Institute of Pharmacology and ToxicologyUniversity of MünsterMünsterGermany
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9
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Gowen BH, Reyes MV, Joseph LC, Morrow JP. Mechanisms of Chronic Metabolic Stress in Arrhythmias. Antioxidants (Basel) 2020; 9:antiox9101012. [PMID: 33086602 PMCID: PMC7603089 DOI: 10.3390/antiox9101012] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 10/07/2020] [Accepted: 10/13/2020] [Indexed: 02/06/2023] Open
Abstract
Cardiac arrhythmias are responsible for many cardiovascular disease-related deaths worldwide. While arrhythmia pathogenesis is complex, there is increasing evidence for metabolic causes. Obesity, diabetes, and chronically consuming high-fat foods significantly increase the likelihood of developing arrhythmias. Although these correlations are well established, mechanistic explanations connecting a high-fat diet (HFD) to arrhythmogenesis are incomplete, although oxidative stress appears to be critical. This review investigates the metabolic changes that occur in obesity and after HFD. Potential therapies to prevent or treat arrhythmias are discussed, including antioxidants.
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Affiliation(s)
| | | | | | - John P. Morrow
- Correspondence: ; Tel.: +1-212-305-5553; Fax: +1-212-305-4648
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10
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Heinick A, Pluteanu F, Hermes C, Klemme A, Domnik M, Husser X, Gerke V, Schmitz W, Müller FU. Annexin A4 N-terminal peptide inhibits adenylyl cyclase 5 and limits β-adrenoceptor-mediated prolongation of cardiac action potential. FASEB J 2020; 34:10489-10504. [PMID: 32579290 DOI: 10.1096/fj.201902094rr] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 05/08/2020] [Accepted: 05/26/2020] [Indexed: 11/11/2022]
Abstract
Adenylyl cyclases (AC) are essential for the normal and pathophysiological response of many cells. In cardiomyocytes, the predominant AC isoforms are AC5 and AC6. Specific AC5 inhibition was suggested as an option for the treatment of heart failure potentially advantageous over β-blockers. We previously reported an interaction between the calcium-binding protein annexin A4 (ANXA4) and AC5 in human embryonic kidney 293 (HEK293) cells and an inhibition of cyclic adenosine monophosphate (cAMP) production in cardiomyocytes. Here, we investigated whether ANXA4 is able to differentiate between AC5 and AC6. In transfected HEK293 cells, ANXA4 specifically co-immunoprecipitated with AC5 and not with AC6, via its N-terminal domain. Both ANXA4 and a peptide comprising the ANXA4 N-terminal sequence (A4N1-22 ) decreased the cAMP production in AC5 and not in AC6 expressing cells. In line with ACs inhibition, in myocytes from ANXA4-deficient mice, β-adrenoceptor (βAR) stimulation led to a higher increase of the L-type calcium current (ICaL ) and to an excessive action potential duration (APD) prolongation as compared to wild-type cardiomyocytes. This enhanced response was reversed in the presence of A4N1-22 peptide likely via specific AC5 inhibition. We conclude that via the N-terminal domain ANXA4 inhibits AC5 not AC6, and that A4N1-22 as a specific AC5 inhibitor could serve as a novel therapeutic tool for the treatment of AC5-linked diseases.
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Affiliation(s)
- Alexander Heinick
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Florentina Pluteanu
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Christina Hermes
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Andre Klemme
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Manuel Domnik
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Xenia Husser
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Volker Gerke
- Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany.,Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany
| | - Wilhelm Schmitz
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
| | - Frank U Müller
- Institute of Pharmacology and Toxicology, University of Münster, Münster, Germany
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Ionic mechanisms underlying atrial electrical remodeling after a fontan-style operation in a canine model. Heart Vessels 2020; 35:731-741. [PMID: 31912231 PMCID: PMC7136189 DOI: 10.1007/s00380-019-01544-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 12/13/2019] [Indexed: 11/05/2022]
Abstract
Atrial arrhythmia is an important cause of late death in patients after the Fontan-Style operation. However, the detailed electrophysiological characteristics of the post-Fontan atrium and its underlying mechanisms are largely unknown. In this study, we investigated electrophysiological characteristics and the ionic remodeling in the right atrium (RA) of a canine model after the Fontan operation. We performed the operation of RA to pulmonary artery connection to mimic the Fontan operation. We undertook hemodynamic measurements, cardiac electrophysiological studies, and ion current measurements. The expression of ionic channels was analyzed by PCR and western-blotting. Our Fontan model induced RA hypertension, enlarged the size of RA, and increased atrial fibrosis, representing the classic characteristic of Fontan patients. In the Fontan group, the atrial effective refractory period and the active potential duration were reduced, and the atrial tachycardia has been more often to be induced. The electrical conduction mapping showed that the Fontan group reduced the conduction velocity. The Fontan operation significantly down-regulated the expression of KCND3/Kv4.3, CACNA1C/Cav1.2 and SCN5A, but up-regulated the expression of KCNJ2/Kir2.1. Correspondingly, The Fontan operation reduced transient-outward (Ito) and L-type Ca2 (ICa,L) and INa currents, while increasing the inward-rectifier current (IK1). Thus, the net shortening of the action potential in the post-Fontan atrium is associated with the altered expression of ionic channels which disturbed the balance between inward and outward currents. Taken together, the Fontan operation induces the ionic remodeling, and thus altered electrophysiological characteristics of the right atrium, improving our understanding on the pathophysiology of atrial arrhythmias in Fontan patients.
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12
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Scholz B, Schulte JS, Hamer S, Himmler K, Pluteanu F, Seidl MD, Stein J, Wardelmann E, Hammer E, Völker U, Müller FU. HDAC (Histone Deacetylase) Inhibitor Valproic Acid Attenuates Atrial Remodeling and Delays the Onset of Atrial Fibrillation in Mice. Circ Arrhythm Electrophysiol 2019; 12:e007071. [PMID: 30879335 PMCID: PMC6426346 DOI: 10.1161/circep.118.007071] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Supplemental Digital Content is available in the text. Background: A structural, electrical and metabolic atrial remodeling is central in the development of atrial fibrillation (AF) contributing to its initiation and perpetuation. In the heart, HDACs (histone deacetylases) control remodeling associated processes like hypertrophy, fibrosis, and energy metabolism. Here, we analyzed, whether the HDAC class I/IIa inhibitor valproic acid (VPA) is able to attenuate atrial remodeling in CREM-IbΔC-X (cAMP responsive element modulator isoform IbΔC-X) transgenic mice, a mouse model of extensive atrial remodeling with age-dependent progression from spontaneous atrial ectopy to paroxysmal and finally long-lasting AF. Methods: VPA was administered for 7 or 25 weeks to transgenic and control mice. Atria were analyzed macroscopically and using widefield and electron microscopy. Action potentials were recorded from atrial cardiomyocytes using patch-clamp technique. ECG recordings documented the onset of AF. A proteome analysis with consecutive pathway mapping identified VPA-mediated proteomic changes and related pathways. Results: VPA attenuated many components of atrial remodeling that are present in transgenic mice, animal AF models, and human AF. VPA significantly (P<0.05) reduced atrial dilatation, cardiomyocyte enlargement, atrial fibrosis, and the disorganization of myocyte’s ultrastructure. It significantly reduced the occurrence of atrial thrombi, reversed action potential alterations, and finally delayed the onset of AF by 4 to 8 weeks. Increased histone H4-acetylation in atria from VPA-treated transgenic mice verified effective in vivo HDAC inhibition. Cardiomyocyte-specific genetic inactivation of HDAC2 in transgenic mice attenuated the ultrastructural disorganization of myocytes comparable to VPA. Finally, VPA restrained dysregulation of proteins in transgenic mice that are involved in a multitude of AF relevant pathways like oxidative phosphorylation or RhoA (Ras homolog gene family, member A) signaling and disease functions like cardiac fibrosis and apoptosis of muscle cells. Conclusions: Our results suggest that VPA, clinically available, well-tolerated, and prescribed to many patients for years, has the therapeutic potential to delay the development of atrial remodeling and the onset of AF in patients at risk.
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Affiliation(s)
- Beatrix Scholz
- Institute of Pharmacology and Toxicology, University of Münster, Germany (B.S., J.S.S., S.H., K.H., F.P., M.D.S., J.S., F.U.M.)
| | - Jan Sebastian Schulte
- Institute of Pharmacology and Toxicology, University of Münster, Germany (B.S., J.S.S., S.H., K.H., F.P., M.D.S., J.S., F.U.M.)
| | - Sabine Hamer
- Institute of Pharmacology and Toxicology, University of Münster, Germany (B.S., J.S.S., S.H., K.H., F.P., M.D.S., J.S., F.U.M.)
| | - Kirsten Himmler
- Institute of Pharmacology and Toxicology, University of Münster, Germany (B.S., J.S.S., S.H., K.H., F.P., M.D.S., J.S., F.U.M.)
| | - Florentina Pluteanu
- Institute of Pharmacology and Toxicology, University of Münster, Germany (B.S., J.S.S., S.H., K.H., F.P., M.D.S., J.S., F.U.M.)
| | - Matthias Dodo Seidl
- Institute of Pharmacology and Toxicology, University of Münster, Germany (B.S., J.S.S., S.H., K.H., F.P., M.D.S., J.S., F.U.M.)
| | - Juliane Stein
- Institute of Pharmacology and Toxicology, University of Münster, Germany (B.S., J.S.S., S.H., K.H., F.P., M.D.S., J.S., F.U.M.)
| | - Eva Wardelmann
- Gerhard-Domagk-Institute of Pathology, University Hospital Münster, Germany (E.W.)
| | - Elke Hammer
- Interfaculty Institute of Genetics und Functional Genomics, University Medicine Greifswald, Germany (E.H., U.V.).,DZHK (German Centre for Cardiovascular Research), partner site Greifswald, Germany (E.H., U.V.)
| | - Uwe Völker
- Interfaculty Institute of Genetics und Functional Genomics, University Medicine Greifswald, Germany (E.H., U.V.).,DZHK (German Centre for Cardiovascular Research), partner site Greifswald, Germany (E.H., U.V.)
| | - Frank Ulrich Müller
- Institute of Pharmacology and Toxicology, University of Münster, Germany (B.S., J.S.S., S.H., K.H., F.P., M.D.S., J.S., F.U.M.)
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13
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Li MCH, O'Brien TJ, Todaro M, Powell KL. Acquired cardiac channelopathies in epilepsy: Evidence, mechanisms, and clinical significance. Epilepsia 2019; 60:1753-1767. [PMID: 31353444 DOI: 10.1111/epi.16301] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2019] [Revised: 07/07/2019] [Accepted: 07/07/2019] [Indexed: 12/13/2022]
Abstract
There is growing evidence that cardiac dysfunction in patients with chronic epilepsy could play a pathogenic role in sudden unexpected death in epilepsy (SUDEP). Recent animal studies have revealed that epilepsy secondarily alters the expression of cardiac ion channels alongside abnormal cardiac electrophysiology and remodeling. These molecular findings represent novel evidence for an acquired cardiac channelopathy in epilepsy, distinct from inherited ion channels mutations associated with cardiocerebral phenotypes. Specifically, seizure activity has been shown to alter the messenger RNA (mRNA) and protein expression of voltage-gated sodium channels (Nav 1.1, Nav 1.5), voltage-gated potassium channels (Kv 4.2, Kv 4.3), sodium-calcium exchangers (NCX1), and nonspecific cation-conducting channels (HCN2, HCN4). The pathophysiology may involve autonomic dysfunction and structural cardiac disease, as both are independently associated with epilepsy and ion channel dysregulation. Indeed, in vivo and in vitro studies of cardiac pathology reveal a complex network of signaling pathways and transcription factors regulating ion channel expression in the setting of sympathetic overactivity, cardiac failure, and hypertrophy. Other mechanisms such as circulating inflammatory mediators or exogenous effects of antiepileptic medications lack evidence. Moreover, an acquired cardiac channelopathy may underlie the electrophysiologic cardiac abnormalities seen in chronic epilepsy, potentially contributing to the increased risk of malignant arrhythmias and sudden death. Therefore, further investigation is necessary to establish whether cardiac ion channel dysregulation similarly occurs in patients with epilepsy, and to characterize any pathogenic relationship with SUDEP.
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Affiliation(s)
- Michael C H Li
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
| | - Terence J O'Brien
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia
| | - Marian Todaro
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia.,Department of Medicine, Royal Melbourne Hospital, University of Melbourne, Parkville, Victoria, Australia.,Department of Neurology, Royal Melbourne Hospital, Parkville, Victoria, Australia
| | - Kim L Powell
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, Victoria, Australia
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14
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Masuda K, Takanari H, Morishima M, Ma F, Wang Y, Takahashi N, Ono K. Testosterone-mediated upregulation of delayed rectifier potassium channel in cardiomyocytes causes abbreviation of QT intervals in rats. J Physiol Sci 2018; 68:759-767. [PMID: 29332211 PMCID: PMC10717990 DOI: 10.1007/s12576-017-0590-4] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2017] [Accepted: 12/26/2017] [Indexed: 12/01/2022]
Abstract
Men have shorter rate-corrected QT intervals (QTc) than women, especially at the period of adolescence or later. The aim of this study was to elucidate the long-term effects of testosterone on cardiac excitability parameters including electrocardiogram (ECG) and potassium channel current. Testosterone shortened QT intervals in ECG in castrated male rats, not immediately after, but on day 2 or later. Expression of Kv7.1 (KCNQ1) mRNA was significantly upregulated by testosterone in cardiomyocytes of male and female rats. Short-term application of testosterone was without effect on delayed rectifier potassium channel current (IKs), whereas IKs was significantly increased in cardiomyocytes treated with dihydrotestosterone for 24 h, which was mimicked by isoproterenol (24 h). Gene-selective inhibitors of a transcription factor SP1, mithramycin, abolished the effects of testosterone on Kv7.1. Testosterone increases Kv7.1-IKs possibly through a pathway related to a transcription factor SP1, suggesting a genomic effect of testosterone as an active factor for cardiac excitability.
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Affiliation(s)
- Kimiko Masuda
- Department of Cardiology and Clinical Examination, Oita University School of Medicine, Yufu, Oita, 879-5593, Japan
- Department of Pathophysiology, Oita University School of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita, 879-5593, Japan
| | - Hiroki Takanari
- Department of Pathophysiology, Oita University School of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita, 879-5593, Japan
| | - Masaki Morishima
- Department of Pathophysiology, Oita University School of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita, 879-5593, Japan
| | - FangFang Ma
- Department of Pathophysiology, Oita University School of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita, 879-5593, Japan
| | - Yan Wang
- Department of Cardiology and Clinical Examination, Oita University School of Medicine, Yufu, Oita, 879-5593, Japan
- Department of Pathophysiology, Oita University School of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita, 879-5593, Japan
| | - Naohiko Takahashi
- Department of Cardiology and Clinical Examination, Oita University School of Medicine, Yufu, Oita, 879-5593, Japan
| | - Katsushige Ono
- Department of Pathophysiology, Oita University School of Medicine, 1-1 Idaigaoka, Hasama, Yufu, Oita, 879-5593, Japan.
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15
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Bögeholz N, Schulte JS, Kaese S, Bauer BK, Pauls P, Dechering DG, Frommeyer G, Goldhaber JI, Kirchhefer U, Eckardt L, Pott C, Müller FU. The Effects of SEA0400 on Ca 2+ Transient Amplitude and Proarrhythmia Depend on the Na +/Ca 2+ Exchanger Expression Level in Murine Models. Front Pharmacol 2017; 8:649. [PMID: 28983248 PMCID: PMC5613119 DOI: 10.3389/fphar.2017.00649] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2017] [Accepted: 09/01/2017] [Indexed: 11/13/2022] Open
Abstract
Background/Objective: The cardiac Na+/Ca2+ exchanger (NCX) has been identified as a promising target to counter arrhythmia in previous studies investigating the benefit of NCX inhibition. However, the consequences of NCX inhibition have not been investigated in the setting of altered NCX expression and function, which is essential, since major cardiac diseases (heart failure/atrial fibrillation) exhibit NCX upregulation. Thus, we here investigated the effects of the NCX inhibitor SEA0400 on the Ca2+ transient amplitude and on proarrhythmia in homozygous NCX overexpressor (OE) and heterozygous NCX knockout (hetKO) mice compared to corresponding wild-types (WTOE/WThetKO). Methods/Results: Ca2+ transients of field-stimulated isolated ventricular cardiomyocytes were recorded with fluo-4-AM or indo-1-AM. SEA0400 (1 μM) significantly reduced NCX forward mode function in all mouse lines. SEA0400 (1 μM) significantly increased the amplitude of field-stimulated Ca2+ transients in WTOE, WThetKO, and hetKO, but not in OE (% of basal; OE = 98.7 ± 5.0; WTOE = 137.8 ± 5.2*; WThetKO = 126.3 ± 6.0*; hetKO = 140.6 ± 12.8*; *p < 0.05 vs. basal). SEA0400 (1 μM) significantly reduced the number of proarrhythmic spontaneous Ca2+ transients (sCR) in OE, but increased it in WTOE, WThetKO and hetKO (sCR per cell; basal/+SEA0400; OE = 12.5/3.7; WTOE = 0.2/2.4; WThetKO = 1.3/8.8; hetKO = 0.2/5.5) and induced Ca2+ overload with subsequent cell death in hetKO. Conclusion: The effects of SEA0400 on Ca2+ transient amplitude and the occurrence of spontaneous Ca2+ transients as a proxy measure for inotropy and cellular proarrhythmia depend on the NCX expression level. The antiarrhythmic effect of SEA0400 in conditions of increased NCX expression promotes the therapeutic concept of NCX inhibition in heart failure/atrial fibrillation. Conversely, in conditions of reduced NCX expression, SEA0400 suppressed the NCX function below a critical level leading to adverse Ca2+ accumulation as reflected by an increase in Ca2+ transient amplitude, proarrhythmia and cell death. Thus, the remaining NCX function under inhibition may be a critical factor determining the inotropic and antiarrhythmic efficacy of SEA0400.
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Affiliation(s)
- Nils Bögeholz
- Division of Electrophysiology, Department of Cardiovascular Medicine, University Hospital MünsterMünster, Germany
| | - Jan S Schulte
- Institute of Pharmacology and Toxicology, University of MünsterMünster, Germany
| | - Sven Kaese
- Division of Electrophysiology, Department of Cardiovascular Medicine, University Hospital MünsterMünster, Germany
| | - B Klemens Bauer
- Division of Electrophysiology, Department of Cardiovascular Medicine, University Hospital MünsterMünster, Germany.,Institute of Pharmacology and Toxicology, University of MünsterMünster, Germany
| | - Paul Pauls
- Division of Electrophysiology, Department of Cardiovascular Medicine, University Hospital MünsterMünster, Germany.,Institute of Pharmacology and Toxicology, University of MünsterMünster, Germany
| | - Dirk G Dechering
- Division of Electrophysiology, Department of Cardiovascular Medicine, University Hospital MünsterMünster, Germany
| | - Gerrit Frommeyer
- Division of Electrophysiology, Department of Cardiovascular Medicine, University Hospital MünsterMünster, Germany
| | - Joshua I Goldhaber
- Cedars-Sinai Medical Center, Heart InstituteLos Angeles, CA, United States
| | - Uwe Kirchhefer
- Institute of Pharmacology and Toxicology, University of MünsterMünster, Germany
| | - Lars Eckardt
- Division of Electrophysiology, Department of Cardiovascular Medicine, University Hospital MünsterMünster, Germany
| | - Christian Pott
- Division of Electrophysiology, Department of Cardiovascular Medicine, University Hospital MünsterMünster, Germany
| | - Frank U Müller
- Institute of Pharmacology and Toxicology, University of MünsterMünster, Germany
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16
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Zhang M, Schulte JS, Heinick A, Piccini I, Rao J, Quaranta R, Zeuschner D, Malan D, Kim KP, Röpke A, Sasse P, Araúzo-Bravo M, Seebohm G, Schöler H, Fabritz L, Kirchhof P, Müller FU, Greber B. Universal cardiac induction of human pluripotent stem cells in two and three-dimensional formats: implications for in vitro maturation. Stem Cells 2016; 33:1456-69. [PMID: 25639979 DOI: 10.1002/stem.1964] [Citation(s) in RCA: 68] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 12/26/2014] [Indexed: 12/13/2022]
Abstract
Directed cardiac differentiation of human pluripotent stem cells (hPSCs) enables disease modeling, investigation of human cardiogenesis, as well as large-scale production of cardiomyocytes (CMs) for translational purposes. Multiple CM differentiation protocols have been developed to individually address specific requirements of these diverse applications, such as enhanced purity at a small scale or mass production at a larger scale. However, there is no universal high-efficiency procedure for generating CMs both in two-dimensional (2D) and three-dimensional (3D) culture formats, and undefined or complex media additives compromise functional analysis or cost-efficient upscaling. Using systematic combinatorial optimization, we have narrowed down the key requirements for efficient cardiac induction of hPSCs. This implied differentiation in simple serum and serum albumin-free basal media, mediated by a minimal set of signaling pathway manipulations at moderate factor concentrations. The method was applicable both to 2D and 3D culture formats as well as to independent hPSC lines. Global time-course gene expression analyses over extended time periods and in comparison with human heart tissue were used to monitor culture-induced maturation of the resulting CMs. This suggested that hPSC-CMs obtained with our procedure reach a rather stable transcriptomic state after approximately 4 weeks of culture. The underlying gene expression changes correlated well with a decline of immature characteristics as well as with a gain of structural and physiological maturation features within this time frame. These data link gene expression patterns of hPSC-CMs to functional readouts and thus define the cornerstones of culture-induced maturation.
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Affiliation(s)
- Miao Zhang
- Human Stem Cell Pluripotency Group; Chemical Genomics Centre of the Max Planck Society, Dortmund, Germany
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17
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Schulte JS, Fehrmann E, Tekook MA, Kranick D, Fels B, Li N, Wehrens XHT, Heinick A, Seidl MD, Schmitz W, Müller FU. Cardiac expression of the CREM repressor isoform CREM-IbΔC-X in mice leads to arrhythmogenic alterations in ventricular cardiomyocytes. Basic Res Cardiol 2016; 111:15. [PMID: 26818679 PMCID: PMC4729809 DOI: 10.1007/s00395-016-0532-y] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 01/08/2016] [Indexed: 12/19/2022]
Abstract
Chronic β-adrenergic stimulation is regarded as a pivotal step in the progression of heart failure which is associated with a high risk for arrhythmia. The cAMP-dependent transcription factors cAMP-responsive element binding protein (CREB) and cAMP-responsive element modulator (CREM) mediate transcriptional regulation in response to β-adrenergic stimulation and CREM repressor isoforms are induced after stimulation of the β-adrenoceptor. Here, we investigate whether CREM repressors contribute to the arrhythmogenic remodeling in the heart by analyzing arrhythmogenic alterations in ventricular cardiomyocytes (VCMs) from mice with transgenic expression of the CREM repressor isoform CREM-IbΔC-X (TG). Patch clamp analyses, calcium imaging, immunoblotting and real-time quantitative RT-PCR were conducted to study proarrhythmic alterations in TG VCMs vs. wild-type controls. The percentage of VCMs displaying spontaneous supra-threshold transient-like Ca(2+) releases was increased in TG accompanied by an enhanced transduction rate of sub-threshold Ca(2+) waves into these supra-threshold events. As a likely cause we discovered enhanced NCX-mediated Ca(2+) transport and NCX1 protein level in TG. An increase in I NCX and decrease in I to and its accessory channel subunit KChIP2 was associated with action potential prolongation and an increased proportion of TG VCMs showing early afterdepolarizations. Finally, ventricular extrasystoles were augmented in TG mice underlining the in vivo relevance of our findings. Transgenic expression of CREM-IbΔC-X in mouse VCMs leads to distinct arrhythmogenic alterations. Since CREM repressors are inducible by chronic β-adrenergic stimulation our results suggest that the inhibition of CRE-dependent transcription contributes to the formation of an arrhythmogenic substrate in chronic heart disease.
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Affiliation(s)
- J S Schulte
- Institute of Pharmacology and Toxicology, University of Münster, Domagkstr. 12, 48149, Münster, Germany.
| | - E Fehrmann
- Institute of Pharmacology and Toxicology, University of Münster, Domagkstr. 12, 48149, Münster, Germany
| | - M A Tekook
- Institute of Pharmacology and Toxicology, University of Münster, Domagkstr. 12, 48149, Münster, Germany
| | - D Kranick
- Institute of Pharmacology and Toxicology, University of Münster, Domagkstr. 12, 48149, Münster, Germany
| | - B Fels
- Institute of Pharmacology and Toxicology, University of Münster, Domagkstr. 12, 48149, Münster, Germany
| | - N Li
- Department of Molecular Physiology and Biophysics, Medicine (Cardiology), and Pediatrics, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - X H T Wehrens
- Department of Molecular Physiology and Biophysics, Medicine (Cardiology), and Pediatrics, Cardiovascular Research Institute, Baylor College of Medicine, Houston, TX, USA
| | - A Heinick
- Institute of Pharmacology and Toxicology, University of Münster, Domagkstr. 12, 48149, Münster, Germany
| | - M D Seidl
- Institute of Pharmacology and Toxicology, University of Münster, Domagkstr. 12, 48149, Münster, Germany
| | - W Schmitz
- Institute of Pharmacology and Toxicology, University of Münster, Domagkstr. 12, 48149, Münster, Germany
| | - F U Müller
- Institute of Pharmacology and Toxicology, University of Münster, Domagkstr. 12, 48149, Münster, Germany
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18
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Heinick A, Husser X, Himmler K, Kirchhefer U, Nunes F, Schulte JS, Seidl MD, Rolfes C, Dedman JR, Kaetzel MA, Gerke V, Schmitz W, Müller FU. Annexin A4 is a novel direct regulator of adenylyl cyclase type 5. FASEB J 2015; 29:3773-87. [PMID: 26023182 DOI: 10.1096/fj.14-269837] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2015] [Accepted: 05/12/2015] [Indexed: 12/14/2022]
Abstract
Annexin A4 (AnxA4), a Ca(2+)- and phospholipid-binding protein, is up-regulated in the human failing heart. In this study, we examined the impact of AnxA4 on β-adrenoceptor (β-AR)/cAMP-dependent signal transduction. Expression of murine AnxA4 in human embryonic kidney (HEK)293 cells dose-dependently inhibited cAMP levels after direct stimulation of adenylyl cyclases (ACs) with forskolin (FSK), as determined with an exchange protein activated by cAMP-Förster resonance energy transfer (EPAC-FRET) sensor and an ELISA (control vs. +AnxA4: 1956 ± 162 vs. 1304 ± 185 fmol/µg protein; n = 8). Disruption of the anxA4 gene led to a consistent increase in intracellular cAMP levels in isolated adult mouse cardiomyocytes, with heart-directed expression of the EPAC-FRET sensor, stimulated with FSK, and as determined by ELISA, also in mouse cardiomyocytes stimulated with the β-AR agonist isoproterenol (ISO) (anxA4a(+/+) vs. anxA4a(-/-): 5.1 ± 0.3 vs. 6.7 ± 0.6 fmol/µg protein) or FSK (anxA4a(+/+) vs. anxA4a(-/-): 1891 ± 238 vs. 2796 ± 343 fmol/µg protein; n = 9-10). Coimmunoprecipitation experiments in HEK293 cells revealed a direct interaction of murine AnxA4 with human membrane-bound AC type 5 (AC5). As a functional consequence of AnxA4-mediated AC inhibition, AnxA4 inhibited the FSK-induced transcriptional activation mediated by the cAMP response element (CRE) in reporter gene studies (10-fold vs. control; n = 4 transfections) and reduced the FSK-induced phosphorylation of the CRE-binding protein (CREB) measured on Western blots (control vs. +AnxA4: 150 ± 17% vs. 105 ± 10%; n = 6) and by the use of the indicator of CREB activation caused by phosphorylation (ICAP)-FRET sensor, indicating CREB phosphorylation. Inactivation of AnxA4 in anxA4a(-/-) mice was associated with an increased cardiac response to β-AR stimulation. Together, these results suggest that AnxA4 is a novel direct negative regulator of AC5, adding a new facet to the functions of annexins.
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Affiliation(s)
- Alexander Heinick
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Xenia Husser
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Kirsten Himmler
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Uwe Kirchhefer
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Frank Nunes
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Jan S Schulte
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Matthias D Seidl
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Christina Rolfes
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - John R Dedman
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Marcia A Kaetzel
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Volker Gerke
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Wilhelm Schmitz
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
| | - Frank U Müller
- *Institute of Pharmacology and Toxicology, Institute of Medical Biochemistry, Center for Molecular Biology of Inflammation, and Interdisciplinary Clinical Research Center, University of Münster, Münster, Germany; and Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, Ohio, USA
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19
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Cardiac gene expression data and in silico analysis provide novel insights into human and mouse taste receptor gene regulation. Naunyn Schmiedebergs Arch Pharmacol 2015; 388:1009-27. [PMID: 25986534 DOI: 10.1007/s00210-015-1118-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2015] [Accepted: 03/24/2015] [Indexed: 12/21/2022]
Abstract
G protein-coupled receptors are the principal mediators of the sweet, umami, bitter, and fat taste qualities in mammals. Intriguingly, the taste receptors are also expressed outside of the oral cavity, including in the gut, airways, brain, and heart, where they have additional functions and contribute to disease. However, there is little known about the mechanisms governing the transcriptional regulation of taste receptor genes. Following our recent delineation of taste receptors in the heart, we investigated the genomic loci encoding for taste receptors to gain insight into the regulatory mechanisms that drive their expression in the heart. Gene expression analyses of healthy and diseased human and mouse hearts showed coordinated expression for a subset of chromosomally clustered taste receptors. This chromosomal clustering mirrored the cardiac expression profile, suggesting that a common gene regulatory block may control the taste receptor locus. We identified unique domains with strong regulatory potential in the vicinity of taste receptor genes. We also performed de novo motif enrichment in the proximal promoter regions and found several overrepresented DNA motifs in cardiac taste receptor gene promoters corresponding to ubiquitous and cardiac-specific transcription factor binding sites. Thus, combining cardiac gene expression data with bioinformatic analyses, this study has provided insights into the noncoding regulatory landscape for taste GPCRs. These findings also have broader relevance for the study of taste GPCRs outside of the classical gustatory system, where understanding the mechanisms controlling the expression of these receptors may have implications for future therapeutic development.
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Myers R, Timofeyev V, Li N, Kim C, Ledford HA, Sirish P, Lau V, Zhang Y, Fayyaz K, Singapuri A, Lopez JE, Knowlton AA, Zhang XD, Chiamvimonvat N. Feedback mechanisms for cardiac-specific microRNAs and cAMP signaling in electrical remodeling. Circ Arrhythm Electrophysiol 2015; 8:942-50. [PMID: 25995211 DOI: 10.1161/circep.114.002162] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 05/08/2015] [Indexed: 12/25/2022]
Abstract
BACKGROUND Loss of transient outward K(+) current (Ito) is well documented in cardiac hypertrophy and failure both in animal models and in humans. Electrical remodeling contributes to prolonged action potential duration and increased incidence of arrhythmias. Furthermore, there is a growing body of evidence linking microRNA (miR) dysregulation to the progression of both conditions. In this study, we examined the mechanistic basis underlying miR dysregulation in electrical remodeling and revealed a novel interaction with the adrenergic signaling pathway. METHODS AND RESULTS We first used a tissue-specific knockout model of Dicer1 in cardiomyocytes to reveal the overall regulatory effect of miRs on the ionic currents and action potentials. We then validated the inducible cAMP early repressor as a target of miR-1 and took advantage of a clinically relevant model of post myocardial infarction and miR delivery to probe the mechanistic basis of miR dysregulation in electrical remodeling. These experiments revealed the role of inducible cAMP early repressor as a repressor of miR-1 and Ito, leading to prolonged action potential duration post myocardial infarction. In addition, delivery of miR-1 and miR-133a suppressed inducible cAMP early repressor expression and prevented both electrical remodeling and hypertrophy. CONCLUSIONS Taken together, our results illuminate the mechanistic links between miRs, adrenergic signaling, and electrical remodeling. They also serve as a proof-of-concept for the therapeutic potential of miR delivery post myocardial infarction.
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Affiliation(s)
- Richard Myers
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.)
| | - Valeriy Timofeyev
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.)
| | - Ning Li
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.)
| | - Catherine Kim
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.)
| | - Hannah A Ledford
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.)
| | - Padmini Sirish
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.)
| | - Victor Lau
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.)
| | - Yinuo Zhang
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.)
| | - Kiran Fayyaz
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.)
| | - Anil Singapuri
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.)
| | - Javier E Lopez
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.)
| | - Anne A Knowlton
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.)
| | - Xiao-Dong Zhang
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.).
| | - Nipavan Chiamvimonvat
- From the Division of Cardiovascular Medicine, Department of Internal Medicine, University of California, Davis (R.M., V.T.,N.L., C.K., H.A.L., P.S., V.L., Y.Z., K.F., A.S., J.E.L., A.A.K., X.-D.Z., N.C.); and Department of Veterans Affairs, Northern California Health Care System, Mather (A.A.K., N.C.).
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21
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Weber K, Rostert N, Bauersachs S, Wess G. Serum microRNA profiles in cats with hypertrophic cardiomyopathy. Mol Cell Biochem 2015; 402:171-80. [PMID: 25573325 DOI: 10.1007/s11010-014-2324-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2014] [Accepted: 12/23/2014] [Indexed: 12/22/2022]
Abstract
The role of microRNAs (miRNAs) in the pathogenesis of heart diseases of humans and rodents, as well as their diagnostic potential, has recently received much attention, but comparable studies for spontaneous disease models in the domestic cat are missing. Hypertrophic cardiomyopathy (HCM) is the most common heart disease in cats. The pathology is largely unknown, but is suspected to be influenced by genetic background. In this study, we examined the miRNA profiles in the serum of cats with stable congestive heart failure caused by HCM (n = 11) and healthy control cats (n = 12) using miRNA arrays. 965 out of 2026 miRNAs could be detected in at least six samples of either of the groups. Eleven mammalian miRNAs were differentially expressed between the groups with a fold change ≥ 1.6. Hierarchical cluster analysis resulted in distinct separation of the two groups. After correction for multiple testing (adjusted p < 0.05), a higher expression of miR-381-3p, miR-486-3p, miR-4751, miR-476c-3p, miR-5700, miR-513a-3p, and miR-320e in the HCM group was confirmed. Additionally, miR-1246 was found to be upregulated 3-fold in the HCM group using quantitative RT-PCR. Software analysis of the significantly regulated miRNAs revealed 49 mRNA targets involved in cardiac hypertrophy. Cats with primary HCM show a distinct miRNA profile that includes miRNAs that have already been shown to be differentially regulated in human patients and rodent models for cardiac disease. Studying HCM as a spontaneous cardiac disease of the cat may help to reveal additional pathophysiologic pathways.
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Affiliation(s)
- K Weber
- Faculty of Veterinary Medicine, Clinic of Small Animal Medicine, Centre for Clinical Veterinary Medicine, LMU Munich, Veterinaerstr. 13, 80539, Munich, Germany,
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22
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Kirchhof P, Tal T, Fabritz L, Klimas J, Nesher N, Schulte JS, Ehling P, Kanyshkova T, Budde T, Nikol S, Fortmueller L, Stallmeyer B, Müller FU, Schulze-Bahr E, Schmitz W, Zlotkin E, Kirchhefer U. First report on an inotropic peptide activating tetrodotoxin-sensitive, "neuronal" sodium currents in the heart. Circ Heart Fail 2014; 8:79-88. [PMID: 25424392 DOI: 10.1161/circheartfailure.113.001066] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
BACKGROUND New therapeutic approaches to improve cardiac contractility without severe risk would improve the management of acute heart failure. Increasing systolic sodium influx can increase cardiac contractility, but most sodium channel activators have proarrhythmic effects that limit their clinical use. Here, we report the cardiac effects of a novel positive inotropic peptide isolated from the toxin of the Black Judean scorpion that activates neuronal tetrodotoxin-sensitive sodium channels. METHODS AND RESULTS All venoms and peptides were isolated from Black Judean Scorpions (Buthotus Hottentotta) caught in the Judean Desert. The full scorpion venom increased left ventricular function in sedated mice in vivo, prolonged ventricular repolarization, and provoked ventricular arrhythmias. An inotropic peptide (BjIP) isolated from the full venom by chromatography increased cardiac contractility but did neither provoke ventricular arrhythmias nor prolong cardiac repolarization. BjIP increased intracellular calcium in ventricular cardiomyocytes and prolonged inactivation of the cardiac sodium current. Low concentrations of tetrodotoxin (200 nmol/L) abolished the effect of BjIP on calcium transients and sodium current. BjIP did not alter the function of Nav1.5, but selectively activated the brain-type sodium channels Nav1.6 or Nav1.3 in cellular electrophysiological recordings obtained from rodent thalamic slices. Nav1.3 (SCN3A) mRNA was detected in human and mouse heart tissue. CONCLUSIONS Our pilot experiments suggest that selective activation of tetrodotoxin-sensitive neuronal sodium channels can safely increase cardiac contractility. As such, the peptide described here may become a lead compound for a new class of positive inotropic agents.
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Affiliation(s)
- Paulus Kirchhof
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.).
| | - Tzachy Tal
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Larissa Fabritz
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Jan Klimas
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Nir Nesher
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Jan S Schulte
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Petra Ehling
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Tatayana Kanyshkova
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Thomas Budde
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Sigrid Nikol
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Lisa Fortmueller
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Birgit Stallmeyer
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Frank U Müller
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Eric Schulze-Bahr
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Wilhelm Schmitz
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Eliahu Zlotkin
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
| | - Uwe Kirchhefer
- From the Department of Cardiovascular Medicine (P.K., L.F., S.N., L.F.), Department of Pharmacology and Toxicology (J.K., J.S.S., F.U.M., W.S., U.K.), and Department of Cardiovascular Medicine, Institute for Genetics of Heart Disease (IfGH) (B.S., E.S.-B.), Hospital of the University of Muenster, Muenster, Germany; Center for Cardiovascular Sciences, School of Clinical and Experimental Medicine, and SWBH NHS Trust, University of Birmingham, Birmingham, United Kingdom (P.K., L.F.); Technion Israel Institute of Technology, Haifa, Israel (T.T.); Department of Animal and Cell Biology, Institute of Life Sciences, The Hebrew University of Jerusalem, Jerusalem, Israel (T.T., N.N., E.Z.); Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University in Bratislava, Bratislava, Slovak Republic (J.K.); Department of Neurology, and Division of Neuropathophysiology, Institute of Physiology I (P.E.) and Institute of Physiology I (T.K., T.B.), University of Muenster, Muenster, Germany; and Department of Clinical and Interventional Angiology, Asklepios Clinic St. Georg, Hamburg, Germany (S.N.)
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Kirchhefer U, Brekle C, Eskandar J, Isensee G, Kučerová D, Müller FU, Pinet F, Schulte JS, Seidl MD, Boknik P. Cardiac function is regulated by B56α-mediated targeting of protein phosphatase 2A (PP2A) to contractile relevant substrates. J Biol Chem 2014; 289:33862-73. [PMID: 25320082 DOI: 10.1074/jbc.m114.598938] [Citation(s) in RCA: 37] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Dephosphorylation of important myocardial proteins is regulated by protein phosphatase 2A (PP2A), representing a heterotrimer that is comprised of catalytic, scaffolding, and regulatory (B) subunits. There is a multitude of B subunit family members directing the PP2A holoenzyme to different myocellular compartments. To gain a better understanding of how these B subunits contribute to the regulation of cardiac performance, we generated transgenic (TG) mice with cardiomyocyte-directed overexpression of B56α, a phosphoprotein of the PP2A-B56 family. The 2-fold overexpression of B56α was associated with an enhanced PP2A activity that was localized mainly in the cytoplasm and myofilament fraction. Contractility was enhanced both at the whole heart level and in isolated cardiomyocytes of TG compared with WT mice. However, peak amplitude of [Ca]i did not differ between TG and WT cardiomyocytes. The basal phosphorylation of cardiac troponin inhibitor (cTnI) and the myosin-binding protein C was reduced by 26 and 35%, respectively, in TG compared with WT hearts. The stimulation of β-adrenergic receptors by isoproterenol (ISO) resulted in an impaired contractile response of TG hearts. At a depolarizing potential of -5 mV, the ICa,L current density was decreased by 28% after administration of ISO in TG cardiomyocytes. In addition, the ISO-stimulated phosphorylation of phospholamban at Ser(16) was reduced by 27% in TG hearts. Thus, the increased PP2A-B56α activity in TG hearts is localized to specific subcellular sites leading to the dephosphorylation of important contractile proteins. This may result in higher myofilament Ca(2+) sensitivity and increased basal contractility in TG hearts. These effects were reversed by β-adrenergic stimulation.
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Affiliation(s)
- Uwe Kirchhefer
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Christiane Brekle
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - John Eskandar
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Gunnar Isensee
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Dana Kučerová
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Frank U Müller
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Florence Pinet
- INSERM, U744, Institut Pasteur de Lille, 59019 Lille, France
| | - Jan S Schulte
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Matthias D Seidl
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
| | - Peter Boknik
- From the Institut für Pharmakologie und Toxikologie, Universitätsklinikum Münster, D-48149 Münster, Germany and
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24
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Barnes J, Pat B, Chen YW, Powell PC, Bradley WE, Zheng J, Karki A, Cui X, Guichard J, Wei CC, Collawn J, Dell'Italia LJ. Whole-genome profiling highlights the molecular complexity underlying eccentric cardiac hypertrophy. Ther Adv Cardiovasc Dis 2014; 8:97-118. [PMID: 24692245 DOI: 10.1177/1753944714527490] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
OBJECTIVES Heart failure is typically preceded by myocardial hypertrophy and remodeling, which can be concentric due to pressure overload (PO), or eccentric because of volume overload (VO). The molecular mechanisms that underlie these differing patterns of hypertrophy are distinct and have yet to be fully elucidated. Thus, the goal of this work is to identify novel therapeutic targets for cardiovascular conditions marked by hypertrophy that have previously been resistant to medical treatment, such as a pure VO. METHODS Concentric or eccentric hypertrophy was induced in rats for 2 weeks with transverse aortic constriction (TAC) or aortocaval fistula (ACF), respectively. Hemodynamic and echocardiographic analysis were used to assess the development of left ventricular (LV) hypertrophy and functional differences between groups. Changes in gene expression were determined by microarray and further characterized with Ingenuity Pathway Analysis. RESULTS Both models of hypertrophy increased LV mass. Rats with TAC demonstrated concentric LV remodeling while rats with ACF exhibited eccentric LV remodeling. Microarray analysis associated eccentric remodeling with a more extensive alteration of gene expression compared with concentric remodeling. Rats with VO had a marked activation of extracellular matrix genes, promotion of cell cycle genes, downregulation of genes associated with oxidative metabolism, and dysregulation of genes critical to cardiac contractile function. Rats with PO demonstrated similar categorical changes, but with the involvement of fewer individual genes. CONCLUSIONS Our results indicate that eccentric remodeling is a far more complex process than concentric remodeling. This study highlights the importance of several key biological functions early in the course of VO, including regulation of matrix, metabolism, cell proliferation, and contractile function. Thus, the results of this analysis will inform the ongoing search for new treatments to prevent the progression to heart failure in VO.
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Affiliation(s)
- Justin Barnes
- Department of Pathology, Division of Molecular and Cellular Pathology, University of Alabama at Birmingham, Birmingham, Alabama, USADepartment of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Betty Pat
- Department of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Yuan-Wen Chen
- Department of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Pamela C Powell
- Department of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Wayne E Bradley
- Department of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Junying Zheng
- Department of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Amrit Karki
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Xiangqin Cui
- Department of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jason Guichard
- Department of Medicine, Division of Cardiology, University of Alabama at Birmingham, Birmingham, Alabama, USADepartment of Biostatistics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Chih-Chang Wei
- Birmingham Department of Veteran Affairs, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - James Collawn
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, Alabama, USA
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25
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Seidl MD, Nunes F, Fels B, Hildebrandt I, Schmitz W, Schulze-Osthoff K, Müller FU. A novel intronic promoter of the Crem gene induces small ICER (smICER) isoforms. FASEB J 2013; 28:143-52. [PMID: 24022402 DOI: 10.1096/fj.13-231977] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The transcription factors cAMP-responsive element binding protein (CREB) and cAMP-responsive element modulator (CREM) regulate gene transcription in response to elevated cAMP levels. The Crem isoform inducible cAMP early repressor (Icer) is transcribed by the internal promoter P2 as a critical regulator of multiple cellular processes. Here, we describe a novel inducible Crem isoform, small Icer (smIcer), regulated by a newly identified promoter (P6). ChIP revealed binding of CREB to P6 in human and mouse myocardium. P6 activity was induced by constitutively active CREB or stimulation of adenylyl cyclase. In mice, smIcer mRNA was ubiquitously expressed and transiently induced by β-adrenoceptor stimulation e.g., in heart and lung. SmICER repressed both basal and cAMP-induced activities of P6 and P2 promoters. Stimulation of adenylyl cyclase induced P2 and P6 in cell type-specific manner. Alternative translational start sites resulted in three different smICER proteins, linked to increased apoptosis sensitivity. In conclusion, the Crem gene provides two distinct and mutually controlled mechanisms of a cAMP-dependent induction of transcriptional repressors. Our results suggest not only that smICER is a novel regulator of cAMP-mediated gene regulation, but also emphasize that biological effects that have been ascribed solely to ICER, should be revised with regard to smICER.
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Affiliation(s)
- Matthias D Seidl
- 2Institute of Pharmacology and Toxicology, University of Münster, Domagkstr. 12, 48149 Münster, Germany.
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26
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Huang H, Amin V, Gurin M, Wan E, Thorp E, Homma S, Morrow JP. Diet-induced obesity causes long QT and reduces transcription of voltage-gated potassium channels. J Mol Cell Cardiol 2013; 59:151-8. [PMID: 23517696 DOI: 10.1016/j.yjmcc.2013.03.007] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/04/2013] [Revised: 02/24/2013] [Accepted: 03/11/2013] [Indexed: 12/18/2022]
Abstract
In humans, obesity is associated with long QT, increased frequency of premature ventricular complexes, and sudden cardiac death. The mechanisms of the pro-arrhythmic electrophysiologic remodeling of obesity are poorly understood. We tested the hypothesis that there is decreased expression of voltage-gated potassium channels in the obese heart, leading to long QT. Using implanted telemeters, we found that diet-induced obese (DIO) wild-type mice have impaired cardiac repolarization, demonstrated by long QT, as well as more frequent ventricular ectopy, similar to obese humans. DIO mice have reduced protein and mRNA levels of the potassium channel Kv1.5 caused by a reduction of the transcription factor cyclic AMP response element binding protein (CREB) in DIO hearts. We found that CREB knock-down by siRNA reduces Kv1.5, CREB binds to the Kv1.5 promoter in the heart, and CREB increases transcription of mouse and human Kv1.5 promoters. The reduction in CREB protein during lipotoxicity can be rescued by inhibiting protein kinase D (PKD). Our results identify a mechanism for obesity-induced electrophysiologic remodeling in the heart, namely PKD-induced reduction of CREB, which in turn decreases expression of the potassium channel Kv1.5.
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Affiliation(s)
- Haiyan Huang
- Department of Medicine, Division of Cardiology, College of Physicians and Surgeons of Columbia University, New York, NY, USA
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