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Flores PC, Ahmed T, Podgorski J, Ortiz HR, Langlais PR, Mythreye K, Lee NY. Phosphoproteomic profiling identifies DNMT1 as a key substrate of beta IV spectrin-dependent ERK/MAPK signaling in suppressing angiogenesis. Biochem Biophys Res Commun 2024; 711:149916. [PMID: 38613866 PMCID: PMC11089540 DOI: 10.1016/j.bbrc.2024.149916] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2024] [Revised: 04/03/2024] [Accepted: 04/06/2024] [Indexed: 04/15/2024]
Abstract
βIV-spectrin is a membrane-associated cytoskeletal protein that maintains the structural stability of cell membranes and integral proteins such as ion channels and transporters. Its biological functions are best characterized in the brain and heart, although recently we discovered a fundamental new role in the vascular system. Using cellular and genetic mouse models, we reported that βIV-spectrin acts as a critical regulator of developmental and tumor-associated angiogenesis. βIV-spectrin was shown to selectively express in proliferating endothelial cells (EC) and suppress VEGF/VEGFR2 signaling by enhancing receptor internalization and degradation. Here we examined how these events impact the downstream kinase signaling cascades and target substrates. Based on quantitative phosphoproteomics, we found that βIV-spectrin significantly affects the phosphorylation of epigenetic regulatory enzymes in the nucleus, among which DNA methyltransferase 1 (DNMT1) was determined as a top substrate. Biochemical and immunofluorescence results showed that βIV-spectrin inhibits DNMT1 function by activating ERK/MAPK, which in turn phosphorylates DNMT1 at S717 to impede its nuclear localization. Given that DNMT1 controls the DNA methylation patterns genome-wide, and is crucial for vascular development, our findings suggest that epigenetic regulation is a key mechanism by which βIV-spectrin suppresses angiogenesis.
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Affiliation(s)
- Paola Cruz Flores
- Department of Chemistry & Biochemistry, University of Arizona, Tucson, AZ, 85724, USA
| | - Tasmia Ahmed
- Department of Chemistry & Biochemistry, University of Arizona, Tucson, AZ, 85724, USA
| | - Julia Podgorski
- Department of Pharmacology, University of Arizona, Tucson, AZ, 85724, USA
| | - Hannah R Ortiz
- Department of Pharmacology, University of Arizona, Tucson, AZ, 85724, USA
| | - Paul R Langlais
- Department of Medicine, University of Arizona, Tucson, AZ, 85724, USA
| | | | - Nam Y Lee
- Department of Pharmacology, University of Arizona, Tucson, AZ, 85724, USA; Comprehensive Cancer Center, University of Arizona, Tucson, AZ, 85724, USA.
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2
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Park E, Yang CR, Raghuram V, Chen L, Chou CL, Knepper MA. Using CRISPR-Cas9/phosphoproteomics to identify substrates of calcium/calmodulin-dependent kinase 2δ. J Biol Chem 2023; 299:105371. [PMID: 37865316 PMCID: PMC10783575 DOI: 10.1016/j.jbc.2023.105371] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 09/30/2023] [Accepted: 10/10/2023] [Indexed: 10/23/2023] Open
Abstract
Ca2+/Calmodulin-dependent protein kinase 2 (CAMK2) family proteins are involved in the regulation of cellular processes in a variety of tissues including brain, heart, liver, and kidney. One member, CAMK2δ (CAMK2D), has been proposed to be involved in vasopressin signaling in the renal collecting duct, which controls water excretion through regulation of the water channel aquaporin-2 (AQP2). To identify CAMK2D target proteins in renal collecting duct cells (mpkCCD), we deleted Camk2d and carried out LC-MS/MS-based quantitative phosphoproteomics. Specifically, we used CRISPR/Cas9 with two different guide RNAs targeting the CAMK2D catalytic domain to create multiple CAMK2D KO cell lines. AQP2 protein abundance was lower in the CAMK2D KO cells than in CAMK2D-intact controls. AQP2 phosphorylation at Ser256 and Ser269 (normalized for total AQP2) was decreased. However, trafficking of AQP2 to and from the apical plasma membrane was sustained. Large-scale quantitative phosphoproteomic analysis (TMT-labeling) in the presence of the vasopressin analog dDAVP (0.1 nM, 30 min) allowed quantification of 11,570 phosphosites of which 169 were significantly decreased, while 206 were increased in abundance in CAMK2D KO clones. These data are available for browsing or download at https://esbl.nhlbi.nih.gov/Databases/CAMK2D-proteome/. Motif analysis of the decreased phosphorylation sites revealed a target preference of -(R/K)-X-X-p(S/T)-X-(D/E), matching the motif identified in previous in vitro phosphorylation studies using recombinant CAMK2D. Thirty five of the significantly downregulated phosphorylation sites in CAMK2D KO cells had exactly this motif and are judged to be likely direct CAMK2D targets. This adds to the list of known CAMK2D target proteins found in prior reductionist studies.
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Affiliation(s)
- Euijung Park
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
| | - Chin-Rang Yang
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
| | - Viswanathan Raghuram
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
| | - Lihe Chen
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
| | - Chung-Lin Chou
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA
| | - Mark A Knepper
- Epithelial Systems Biology Laboratory, Systems Biology Center, National Heart, Lung, and Blood Institute, NIH, Bethesda, Maryland, USA.
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Ahmed T, Ramonett A, Kwak EA, Kumar S, Flores PC, Ortiz HR, Langlais PR, Hund TJ, Mythreye K, Lee NY. Endothelial tip/stalk cell selection requires BMP9-induced β IV-spectrin expression during sprouting angiogenesis. Mol Biol Cell 2023; 34:ar72. [PMID: 37126382 PMCID: PMC10295478 DOI: 10.1091/mbc.e23-02-0064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 04/14/2023] [Accepted: 04/19/2023] [Indexed: 05/02/2023] Open
Abstract
βIV-Spectrin is a membrane cytoskeletal protein with specialized roles in the nervous system and heart. Recent evidence also indicates a fundamental role for βIV-spectrin in angiogenesis as its endothelial-specific gene deletion in mice enhances embryonic lethality due to hypervascularization and hemorrhagic defects. During early vascular sprouting, βIV-spectrin is believed to inhibit tip cell sprouting in favor of the stalk cell phenotype by mediating VEGFR2 internalization and degradation. Despite these essential roles, mechanisms governing βIV-spectrin expression remain unknown. Here we identify bone morphogenetic protein 9 (BMP9) as a major inducer of βIV-spectrin gene expression in the vascular system. We show that BMP9 signals through the ALK1/Smad1 pathway to induce βIV-spectrin expression, which then recruits CaMKII to the cell membrane to induce phosphorylation-dependent VEGFR2 turnover. Although BMP9 signaling promotes stalk cell behavior through activation of hallmark stalk cell genes ID-1/3 and Hes-1 and Notch signaling cross-talk, we find that βIV-spectrin acts upstream of these pathways as loss of βIV-spectrin in neonate mice leads to retinal hypervascularization due to excessive VEGFR2 levels, increased tip cell populations, and strong Notch inhibition irrespective of BMP9 treatment. These findings demonstrate βIV-spectrin as a BMP9 gene target critical for tip/stalk cell selection during nascent vessel sprouting.
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Affiliation(s)
- Tasmia Ahmed
- Department of Chemistry & Biochemistry, University of Arizona, Tucson, AZ 85724
| | - Aaron Ramonett
- Department of Pharmacology, University of Arizona, Tucson, AZ 85724
| | - Eun-A Kwak
- Department of Pharmacology, University of Arizona, Tucson, AZ 85724
| | - Sanjay Kumar
- Division of Biology, Indian Institute of Science Education and Research, Tirupati 517507, India
| | - Paola Cruz Flores
- Department of Chemistry & Biochemistry, University of Arizona, Tucson, AZ 85724
| | - Hannah R. Ortiz
- Department of Pharmacology, University of Arizona, Tucson, AZ 85724
| | | | - Thomas J. Hund
- Department of Biomedical Engineering, Ohio State University, Columbus, OH 43210
| | - Karthikeyan Mythreye
- Department of Pathology, University of Alabama at Birmingham, Birmingham, AL 35294
| | - Nam Y. Lee
- Department of Chemistry & Biochemistry, University of Arizona, Tucson, AZ 85724
- Department of Pharmacology, University of Arizona, Tucson, AZ 85724
- Comprehensive Cancer Center, University of Arizona, Tucson, AZ 85724
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Crespo-García T, Rubio-Alarcón M, Cámara-Checa A, Dago M, Rapún J, Nieto-Marín P, Marín M, Cebrián J, Tamargo J, Delpón E, Caballero R. A Cantú syndrome mutation produces dual effects on KATP channels by disrupting ankyrin B regulation. J Gen Physiol 2022; 155:213613. [PMID: 36287534 PMCID: PMC9614705 DOI: 10.1085/jgp.202112995] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 09/09/2022] [Accepted: 10/04/2022] [Indexed: 02/01/2023] Open
Abstract
ATP-sensitive potassium (KATP) channels composed of Kir6.x and sulfonylurea receptor (SURs) subunits couple cellular metabolism to electrical activity. Cantú syndrome (CS) is a rare disease caused by mutations in the genes encoding Kir6.1 (KCNJ8) and SUR2A (ABCC9) that produce KATP channel hyperactivity due to a reduced channel block by physiological ATP concentrations. We functionally characterized the p.S1054Y SUR2A mutation identified in two CS carriers, who exhibited a mild phenotype although the mutation was predicted as highly pathogenic. We recorded macroscopic and single-channel currents in CHO and HEK-293 cells and measured the membrane expression of the channel subunits by biotinylation assays in HEK-293 cells. The mutation increased basal whole-cell current density and at the single-channel level, it augmented opening frequency, slope conductance, and open probability (Po), and promoted the appearance of multiple conductance levels. p.S1054Y also reduced Kir6.2 and SUR2A expression specifically at the membrane. Overexpression of ankyrin B (AnkB) prevented these gain- and loss-of-function effects, as well as the p.S1054Y-induced reduction of ATP inhibition of currents measured in inside-out macropatches. Yeast two-hybrid assays suggested that SUR2A WT and AnkB interact, while p.S1054Y interaction with AnkB is decreased. The p.E322K Kir6.2 mutation, which prevents AnkB binding to Kir6.2, produced similar biophysical alterations than p.S1054Y. Our results are the first demonstration of a CS mutation whose functional consequences involve the disruption of AnkB effects on KATP channels providing a novel mechanism by which CS mutations can reduce ATP block. Furthermore, they may help explain the mild phenotype associated with this mutation.
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Affiliation(s)
- Teresa Crespo-García
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Madrid, Spain,Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares, Madrid, Spain
| | - Marcos Rubio-Alarcón
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Madrid, Spain,Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares, Madrid, Spain
| | - Anabel Cámara-Checa
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Madrid, Spain,Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares, Madrid, Spain
| | - María Dago
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Madrid, Spain,Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares, Madrid, Spain
| | - Josu Rapún
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Madrid, Spain,Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares, Madrid, Spain
| | - Paloma Nieto-Marín
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Madrid, Spain,Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares, Madrid, Spain
| | - María Marín
- Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares, Madrid, Spain
| | - Jorge Cebrián
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Madrid, Spain,Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares, Madrid, Spain
| | - Juan Tamargo
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Madrid, Spain,Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares, Madrid, Spain
| | - Eva Delpón
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Madrid, Spain,Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares, Madrid, Spain,Correspondence to Eva Delpón:
| | - Ricardo Caballero
- Department of Pharmacology and Toxicology, School of Medicine, Universidad Complutense de Madrid, Instituto de Investigación Gregorio Marañón, Madrid, Spain,Centro de Investigación Biomédica en Red Enfermedades Cardiovasculares, Madrid, Spain
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5
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βIV-spectrin as a stalk cell-intrinsic regulator of VEGF signaling. Nat Commun 2022; 13:1326. [PMID: 35288568 PMCID: PMC8921520 DOI: 10.1038/s41467-022-28933-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Accepted: 02/14/2022] [Indexed: 11/25/2022] Open
Abstract
Defective angiogenesis underlies over 50 malignant, ischemic and inflammatory disorders yet long-term therapeutic applications inevitably fail, thus highlighting the need for greater understanding of the vast crosstalk and compensatory mechanisms. Based on proteomic profiling of angiogenic endothelial components, here we report βIV-spectrin, a non-erythrocytic cytoskeletal protein, as a critical regulator of sprouting angiogenesis. Early loss of endothelial-specific βIV-spectrin promotes embryonic lethality in mice due to hypervascularization and hemorrhagic defects whereas neonatal depletion yields higher vascular density and tip cell populations in developing retina. During sprouting, βIV-spectrin expresses in stalk cells to inhibit their tip cell potential by enhancing VEGFR2 turnover in a manner independent of most cell-fate determining mechanisms. Rather, βIV-spectrin recruits CaMKII to the plasma membrane to directly phosphorylate VEGFR2 at Ser984, a previously undefined phosphoregulatory site that strongly induces VEGFR2 internalization and degradation. These findings support a distinct spectrin-based mechanism of tip-stalk cell specification during vascular development. Defective angiogenesis remains a high source of morbidity in multiple disorders. Here they show that βIV-spectrin, a membrane-associated cytoskeletal protein, is essential for regulation of endothelial tip cell populations and VEGF signaling during sprouting angiogenesis.
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6
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蒋 文, 吴 俊, 曽 佳, 景 光, 汤 礼, 孙 红. [Role of CaMK II in pancreatic injury in mice with severe acute pancreatitis]. NAN FANG YI KE DA XUE XUE BAO = JOURNAL OF SOUTHERN MEDICAL UNIVERSITY 2022; 42:286-292. [PMID: 35365455 PMCID: PMC8983368 DOI: 10.12122/j.issn.1673-4254.2022.02.17] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 11/13/2021] [Indexed: 06/14/2023]
Abstract
OBJECTIVE To investigate the expression of Ca2+/calmodulin-dependent protein kinase II (CaMK Ⅱ) in pancreatic tissues of mice with severe acute pancreatitis (SAP) and explore the protective effect of KN93, a CaMK Ⅱ inhibitor, against pancreatic injury in SAP and the possible mechanism. METHODS Thirty-six healthy male C57 mice were randomly divided into sham operation group, SAP group, KN93 group and SAP + KN93 group (n=9). Serum and pancreatic tissue samples were collected 24 h after modeling. The pathological changes in the pancreatic tissues were observed using HE staining. Serum lipase and amylase activities and the levels of inflammatory factors were detected using ELISA. Western blotting was used to detect the expressions of CaMK Ⅱ, p-CaMK Ⅱ, p-NF-κB, MAPK and p-MAPK in mouse pancreas. RESULTS Compared with those in sham operation group, the expressions of p-CaMK Ⅱ, p-NF-κB and p-MAPK were significantly increased in SAP group (P < 0.05). KN93 treatment obviously alleviated pathological injuries of the pancreas in SAP mice, and significantly lowered serum levels of lipase, amylase and inflammatory factors (TNF-α and IL-6) and phosphorylation levels of NF-κB, ERK and MAPK proteins (P < 0.05). CONCLUSION The activity of CaMK Ⅱ is significantly increased in the pancreatic tissue of SAP mice. KN93 can alleviate pancreatic injury and inflammation in SAP mice possibly through the ERK/MAPK signaling pathway.
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Affiliation(s)
- 文 蒋
- 西南交通大学医学院,四川 成都 610063College of Medicine Southwest Jiaotong University, Chengdu 610063, China
- 西部战区总医院全军普通外科中心//四川省胰腺损伤与修复重点实验室,四川 成都 610083PLA Center of General Surgery, Pancreatic Injury and Repair Key Laboratory of Sichuan Province, General Hospital of Western Theater Command, Chengdu 610083, China
| | - 俊 吴
- 西南交通大学医学院,四川 成都 610063College of Medicine Southwest Jiaotong University, Chengdu 610063, China
- 西部战区总医院全军普通外科中心//四川省胰腺损伤与修复重点实验室,四川 成都 610083PLA Center of General Surgery, Pancreatic Injury and Repair Key Laboratory of Sichuan Province, General Hospital of Western Theater Command, Chengdu 610083, China
| | - 佳容 曽
- 西南交通大学医学院,四川 成都 610063College of Medicine Southwest Jiaotong University, Chengdu 610063, China
- 西部战区总医院全军普通外科中心//四川省胰腺损伤与修复重点实验室,四川 成都 610083PLA Center of General Surgery, Pancreatic Injury and Repair Key Laboratory of Sichuan Province, General Hospital of Western Theater Command, Chengdu 610083, China
| | - 光旭 景
- 西南交通大学医学院,四川 成都 610063College of Medicine Southwest Jiaotong University, Chengdu 610063, China
- 西部战区总医院全军普通外科中心//四川省胰腺损伤与修复重点实验室,四川 成都 610083PLA Center of General Surgery, Pancreatic Injury and Repair Key Laboratory of Sichuan Province, General Hospital of Western Theater Command, Chengdu 610083, China
| | - 礼军 汤
- 西南交通大学医学院,四川 成都 610063College of Medicine Southwest Jiaotong University, Chengdu 610063, China
- 西部战区总医院全军普通外科中心//四川省胰腺损伤与修复重点实验室,四川 成都 610083PLA Center of General Surgery, Pancreatic Injury and Repair Key Laboratory of Sichuan Province, General Hospital of Western Theater Command, Chengdu 610083, China
| | - 红玉 孙
- 西南交通大学医学院,四川 成都 610063College of Medicine Southwest Jiaotong University, Chengdu 610063, China
- 西部战区总医院全军普通外科中心//四川省胰腺损伤与修复重点实验室,四川 成都 610083PLA Center of General Surgery, Pancreatic Injury and Repair Key Laboratory of Sichuan Province, General Hospital of Western Theater Command, Chengdu 610083, China
- 西部战区总医院基础医学实验室,四川 成都 610083Basic Medical Laboratory, General Hospital of Western Theater Command, Chengdu 610083, China
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Lavilla CJ, Billacura MP, Hanna K, Boocock DJ, Coveney C, Miles AK, Foulds GA, Murphy A, Tan A, Jackisch L, Sayers SR, Caton PW, Doig CL, McTernan PG, Colombo SL, Sale C, Turner MD. Carnosine protects stimulus-secretion coupling through prevention of protein carbonyl adduction events in cells under metabolic stress. Free Radic Biol Med 2021; 175:65-79. [PMID: 34455039 DOI: 10.1016/j.freeradbiomed.2021.08.233] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/05/2021] [Revised: 07/23/2021] [Accepted: 08/25/2021] [Indexed: 12/17/2022]
Abstract
Type 2 diabetes is characterised by failure to control glucose homeostasis, with numerous diabetic complications attributable to the resulting exposure of cells and tissues to chronic elevated concentrations of glucose and fatty acids. This, in part, results from formation of advanced glycation and advanced lipidation end-products that are able to modify protein, lipid, or DNA structure, and disrupt normal cellular function. Herein we used mass spectrometry to identify proteins modified by two such adduction events in serum of individuals with obesity, type 2 diabetes, and gestational diabetes, along with similar analyses of human and mouse skeletal muscle cells and mouse pancreatic islets exposed to glucolipotoxic stress. We also report that carnosine, a histidine containing dipeptide, prevented 65-90% of 4-hydroxynonenal and 3-nitrotyrosine adduction events, and that this in turn preserved mitochondrial function and protected stimulus-secretion coupling in cells exposed to metabolic stress. Carnosine therefore offers significant therapeutic potential against metabolic diseases.
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Affiliation(s)
- Charlie Jr Lavilla
- Centre for Diabetes, Chronic Diseases and Ageing, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK
| | - Merell P Billacura
- Centre for Diabetes, Chronic Diseases and Ageing, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK
| | - Katie Hanna
- Centre for Diabetes, Chronic Diseases and Ageing, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK
| | - David J Boocock
- John van Geest Cancer Research Centre, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK
| | - Clare Coveney
- John van Geest Cancer Research Centre, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK
| | - Amanda K Miles
- John van Geest Cancer Research Centre, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK
| | - Gemma A Foulds
- John van Geest Cancer Research Centre, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK
| | - Alice Murphy
- Centre for Diabetes, Chronic Diseases and Ageing, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK
| | - Arnold Tan
- Centre for Diabetes, Chronic Diseases and Ageing, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK
| | - Laura Jackisch
- Department of Physiology, Maastricht University, 6229 ER, Maastricht, the Netherlands
| | - Sophie R Sayers
- Diabetes and Nutritional Sciences Division, King's College London, London, SE1 1UL, UK
| | - Paul W Caton
- Diabetes and Nutritional Sciences Division, King's College London, London, SE1 1UL, UK
| | - Craig L Doig
- Centre for Diabetes, Chronic Diseases and Ageing, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK
| | - Philip G McTernan
- Centre for Diabetes, Chronic Diseases and Ageing, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK
| | - Sergio L Colombo
- Centre for Diabetes, Chronic Diseases and Ageing, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK
| | - Craig Sale
- Sport, Health and Performance Enhancement Research Centre, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK
| | - Mark D Turner
- Centre for Diabetes, Chronic Diseases and Ageing, School of Science and Technology, Nottingham Trent University, Clifton, Nottingham, NG11 8NS, UK.
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8
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Regulation of Cardiac Conduction and Arrhythmias by Ankyrin/Spectrin-Based Macromolecular Complexes. J Cardiovasc Dev Dis 2021; 8:jcdd8050048. [PMID: 33946725 PMCID: PMC8146975 DOI: 10.3390/jcdd8050048] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2021] [Revised: 04/15/2021] [Accepted: 04/19/2021] [Indexed: 12/19/2022] Open
Abstract
The cardiac conduction system is an extended network of excitable tissue tasked with generation and propagation of electrical impulses to signal coordinated contraction of the heart. The fidelity of this system depends on the proper spatio-temporal regulation of ion channels in myocytes throughout the conduction system. Importantly, inherited or acquired defects in a wide class of ion channels has been linked to dysfunction at various stages of the conduction system resulting in life-threatening cardiac arrhythmia. There is growing appreciation of the role that adapter and cytoskeletal proteins play in organizing ion channel macromolecular complexes critical for proper function of the cardiac conduction system. In particular, members of the ankyrin and spectrin families have emerged as important nodes for normal expression and regulation of ion channels in myocytes throughout the conduction system. Human variants impacting ankyrin/spectrin function give rise to a broad constellation of cardiac arrhythmias. Furthermore, chronic neurohumoral and biomechanical stress promotes ankyrin/spectrin loss of function that likely contributes to conduction disturbances in the setting of acquired cardiac disease. Collectively, this review seeks to bring attention to the significance of these cytoskeletal players and emphasize the potential therapeutic role they represent in a myriad of cardiac disease states.
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9
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Yang Y, Sun K, Liu W, Li X, Tian W, Shuai P, Zhu X. The phosphatidylserine flippase β-subunit Tmem30a is essential for normal insulin maturation and secretion. Mol Ther 2021; 29:2854-2872. [PMID: 33895325 PMCID: PMC8417432 DOI: 10.1016/j.ymthe.2021.04.026] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2020] [Revised: 03/17/2021] [Accepted: 04/19/2021] [Indexed: 12/12/2022] Open
Abstract
The processing, maturation, and secretion of insulin are under precise regulation, and dysregulation causes profound defects in glucose handling, leading to diabetes. Tmem30a is the β subunit of the phosphatidylserine (PS) flippase, which maintains the membrane asymmetric distribution of PS. Tmem30a regulates cell survival and the localization of subcellular structures and is thus critical to the normal function of multiple physiological systems. Here, we show that conditional knockout of Tmem30a specifically in pancreatic islet β cells leads to obesity, hyperglycemia, glucose intolerance, hyperinsulinemia, and insulin resistance in mice, due to insufficient insulin release. Moreover, we reveal that Tmem30a plays an essential role in clathrin-mediated vesicle transport between the trans Golgi network (TGN) and the plasma membrane (PM), which comprises immature secretory granule (ISG) budding at the TGN. We also find that Tmem30a deficiency impairs clathrin-mediated vesicle budding and thus blocks both insulin maturation in ISGs and the transport of glucose-sensing Glut2 to the PM. Collectively, these disruptions compromise both insulin secretion and glucose sensitivity, thus contributing to impairments in glucose-stimulated insulin secretion. Taken together, our data demonstrate an important role of Tmem30a in insulin maturation and glucose metabolic homeostasis and suggest the importance of membrane phospholipid distribution in metabolic disorders.
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Affiliation(s)
- Yeming Yang
- Health Management Center, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China; The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
| | - Kuanxiang Sun
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
| | - Wenjing Liu
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
| | - Xiao Li
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
| | - Wanli Tian
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China
| | - Ping Shuai
- Health Management Center, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China; The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China; Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072 China.
| | - Xianjun Zhu
- Health Management Center, Sichuan Provincial People's Hospital, School of Medicine, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China; The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Center for Medical Genetics, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan 610072, China; Key Laboratory of Tibetan Medicine Research, Chinese Academy of Sciences and Qinghai Provincial Key Laboratory of Tibetan Medicine Research, Northwest Institute of Plateau Biology, Xining, Qinghai 810008, China; Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan 610072 China; Natural Products Research Center, Institute of Chengdu Biology, Sichuan Translational Medicine Hospital, Chinese Academy of Sciences, Chengdu, Sichuan 610072, China; Department of Ophthalmology, First People's Hospital of Shangqiu, Shangqiu, Hennan 476100, China.
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10
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Ježek P, Holendová B, Jabůrek M, Tauber J, Dlasková A, Plecitá-Hlavatá L. The Pancreatic β-Cell: The Perfect Redox System. Antioxidants (Basel) 2021; 10:antiox10020197. [PMID: 33572903 PMCID: PMC7912581 DOI: 10.3390/antiox10020197] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2020] [Revised: 01/20/2021] [Accepted: 01/25/2021] [Indexed: 12/12/2022] Open
Abstract
Pancreatic β-cell insulin secretion, which responds to various secretagogues and hormonal regulations, is reviewed here, emphasizing the fundamental redox signaling by NADPH oxidase 4- (NOX4-) mediated H2O2 production for glucose-stimulated insulin secretion (GSIS). There is a logical summation that integrates both metabolic plus redox homeostasis because the ATP-sensitive K+ channel (KATP) can only be closed when both ATP and H2O2 are elevated. Otherwise ATP would block KATP, while H2O2 would activate any of the redox-sensitive nonspecific calcium channels (NSCCs), such as TRPM2. Notably, a 100%-closed KATP ensemble is insufficient to reach the -50 mV threshold plasma membrane depolarization required for the activation of voltage-dependent Ca2+ channels. Open synergic NSCCs or Cl- channels have to act simultaneously to reach this threshold. The resulting intermittent cytosolic Ca2+-increases lead to the pulsatile exocytosis of insulin granule vesicles (IGVs). The incretin (e.g., GLP-1) amplification of GSIS stems from receptor signaling leading to activating the phosphorylation of TRPM channels and effects on other channels to intensify integral Ca2+-influx (fortified by endoplasmic reticulum Ca2+). ATP plus H2O2 are also required for branched-chain ketoacids (BCKAs); and partly for fatty acids (FAs) to secrete insulin, while BCKA or FA β-oxidation provide redox signaling from mitochondria, which proceeds by H2O2 diffusion or hypothetical SH relay via peroxiredoxin "redox kiss" to target proteins.
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11
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Morrow JS, Stankewich MC. The Spread of Spectrin in Ataxia and Neurodegenerative Disease. JOURNAL OF EXPERIMENTAL NEUROLOGY 2021; 2:131-139. [PMID: 34528024 PMCID: PMC8439443] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Experimental and hereditary defects in the ubiquitous scaffolding proteins of the spectrin gene family cause an array of neuropathologies. Most recognized are ataxias caused by missense, deletions, or truncations in the SPTBN2 gene that encodes beta III spectrin. Such mutations disrupt the organization of post-synaptic receptors, their active transport through the secretory pathway, and the organization and dynamics of the actin-based neuronal skeleton. Similar mutations in SPTAN1 that encodes alpha II spectrin cause severe and usually lethal neurodevelopmental defects including one form of early infantile epileptic encephalopathy type 5 (West syndrome). Defects in these and other spectrins are implicated in degenerative and psychiatric conditions. In recent published work, we describe in mice a novel variant of alpha II spectrin that results in a progressive ataxia with widespread neurodegenerative change. The action of this variant is distinct, in that rather than disrupting a constitutive ligand-binding function of spectrin, the mutation alters its response to calcium and calmodulin-regulated signaling pathways including its response to calpain activation. As such, it represents a novel spectrinopathy that targets a key regulatory pathway where calcium and tyrosine kinase signals converge. Here we briefly discuss the various roles of spectrin in neuronal processes and calcium activated regulatory inputs that control its participation in neuronal growth, organization, and remodeling. We hypothesize that damage to the neuronal spectrin scaffold may be a common final pathway in many neurodegenerative disorders. Targeting the pathways that regulate spectrin function may thus offer novel avenues for therapeutic intervention.
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Affiliation(s)
- Jon S. Morrow
- Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA,Molecular & Cellular Developmental Biology, Yale University, New Haven, CT 06520, USA,Correspondence should be addressed to Jon S. Morrow; , Michael Stankewich;
| | - Michael C. Stankewich
- Department of Pathology, Yale School of Medicine, New Haven, CT 06520, USA,Correspondence should be addressed to Jon S. Morrow; , Michael Stankewich;
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12
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Patel NJ, Nassal DM, Greer-Short AD, Unudurthi SD, Scandling BW, Gratz D, Xu X, Kalyanasundaram A, Fedorov VV, Accornero F, Mohler PJ, Gooch KJ, Hund TJ. βIV-Spectrin/STAT3 complex regulates fibroblast phenotype, fibrosis, and cardiac function. JCI Insight 2019; 4:131046. [PMID: 31550236 DOI: 10.1172/jci.insight.131046] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 09/18/2019] [Indexed: 01/30/2023] Open
Abstract
Increased fibrosis is a characteristic remodeling response to biomechanical and neurohumoral stress and a determinant of cardiac mechanical and electrical dysfunction in disease. Stress-induced activation of cardiac fibroblasts (CFs) is a critical step in the fibrotic response, although the precise sequence of events underlying activation of these critical cells in vivo remain unclear. Here, we tested the hypothesis that a βIV-spectrin/STAT3 complex is essential for maintenance of a quiescent phenotype (basal nonactivated state) in CFs. We reported increased fibrosis, decreased cardiac function, and electrical impulse conduction defects in genetic and acquired mouse models of βIV-spectrin deficiency. Loss of βIV-spectrin function promoted STAT3 nuclear accumulation and transcriptional activity, and it altered gene expression and CF activation. Furthermore, we demonstrate that a quiescent phenotype may be restored in βIV-spectrin-deficient fibroblasts by expressing a βIV-spectrin fragment including the STAT3-binding domain or through pharmacological STAT3 inhibition. We found that in vivo STAT3 inhibition abrogates fibrosis and cardiac dysfunction in the setting of global βIV-spectrin deficiency. Finally, we demonstrate that fibroblast-specific deletion of βIV-spectrin is sufficient to induce fibrosis and decreased cardiac function. We propose that the βIV-spectrin/STAT3 complex is a determinant of fibroblast phenotype and fibrosis, with implications for remodeling response in cardiovascular disease (CVD).
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Affiliation(s)
- Nehal J Patel
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Drew M Nassal
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Amara D Greer-Short
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Sathya D Unudurthi
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Benjamin W Scandling
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Daniel Gratz
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Xianyao Xu
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Anuradha Kalyanasundaram
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Physiology and Cell Biology, and
| | - Vadim V Fedorov
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Physiology and Cell Biology, and
| | - Federica Accornero
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Physiology and Cell Biology, and
| | - Peter J Mohler
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Physiology and Cell Biology, and.,Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
| | - Keith J Gooch
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA
| | - Thomas J Hund
- The Frick Center for Heart Failure and Arrhythmia, Dorothy M. Davis Heart and Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, Ohio, USA.,Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio, USA
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13
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Myocardial death and dysfunction after ischemia-reperfusion injury require CaMKIIδ oxidation. Sci Rep 2019; 9:9291. [PMID: 31243295 PMCID: PMC6595001 DOI: 10.1038/s41598-019-45743-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Accepted: 06/11/2019] [Indexed: 02/08/2023] Open
Abstract
Reactive oxygen species (ROS) contribute to myocardial death during ischemia-reperfusion (I/R) injury, but detailed knowledge of molecular pathways connecting ROS to cardiac injury is lacking. Activation of the Ca2+/calmodulin-dependent protein kinase II (CaMKIIδ) is implicated in myocardial death, and CaMKII can be activated by ROS (ox-CaMKII) through oxidation of regulatory domain methionines (Met281/282). We examined I/R injury in mice where CaMKIIδ was made resistant to ROS activation by knock-in replacement of regulatory domain methionines with valines (MMVV). We found reduced myocardial death, and improved left ventricular function 24 hours after I/R injury in MMVV in vivo and in vitro compared to WT controls. Loss of ATP sensitive K+ channel (KATP) current contributes to I/R injury, and CaMKII promotes sequestration of KATP from myocardial cell membranes. KATP current density was significantly reduced by H2O2 in WT ventricular myocytes, but not in MMVV, showing ox-CaMKII decreases KATP availability. Taken together, these findings support a view that ox-CaMKII and KATP are components of a signaling axis promoting I/R injury by ROS.
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14
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Hegyi B, Bers DM, Bossuyt J. CaMKII signaling in heart diseases: Emerging role in diabetic cardiomyopathy. J Mol Cell Cardiol 2019; 127:246-259. [PMID: 30633874 DOI: 10.1016/j.yjmcc.2019.01.001] [Citation(s) in RCA: 75] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Accepted: 01/04/2019] [Indexed: 02/07/2023]
Abstract
Calcium/calmodulin-dependent protein kinase II (CaMKII) is upregulated in diabetes and significantly contributes to cardiac remodeling with increased risk of cardiac arrhythmias. Diabetes is frequently associated with atrial fibrillation, coronary artery disease, and heart failure, which may further enhance CaMKII. Activation of CaMKII occurs downstream of neurohormonal stimulation (e.g. via G-protein coupled receptors) and involve various posttranslational modifications including autophosphorylation, oxidation, S-nitrosylation and O-GlcNAcylation. CaMKII signaling regulates diverse cellular processes in a spatiotemporal manner including excitation-contraction and excitation-transcription coupling, mechanics and energetics in cardiac myocytes. Chronic activation of CaMKII results in cellular remodeling and ultimately arrhythmogenic alterations in Ca2+ handling, ion channels, cell-to-cell coupling and metabolism. This review addresses the detrimental effects of the upregulated CaMKII signaling to enhance the arrhythmogenic substrate and trigger mechanisms in the heart. We also briefly summarize preclinical studies using kinase inhibitors and genetically modified mice targeting CaMKII in diabetes. The mechanistic understanding of CaMKII signaling, cardiac remodeling and arrhythmia mechanisms may reveal new therapeutic targets and ultimately better treatment in diabetes and heart disease in general.
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Affiliation(s)
- Bence Hegyi
- Department of Pharmacology, University of California Davis, Davis, CA, USA
| | - Donald M Bers
- Department of Pharmacology, University of California Davis, Davis, CA, USA.
| | - Julie Bossuyt
- Department of Pharmacology, University of California Davis, Davis, CA, USA
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15
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Hulsurkar M, Quick AP, Wehrens XH. STAT3: a link between CaMKII-βIV-spectrin and maladaptive remodeling? J Clin Invest 2018; 128:5219-5221. [PMID: 30418170 PMCID: PMC6264720 DOI: 10.1172/jci124778] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
βIV-Spectrin, along with ankyrin and Ca2+/calmodulin-dependent kinase II (CaMKII), has been shown to form local signaling domains at the intercalated disc, while playing a key role in the regulation of Na+ and K+ channels in cardiomyocytes. In this issue of the JCI, Unudurthi et al. show that under chronic pressure overload conditions, CaMKII activation leads to βIV-spectrin degradation, resulting in the release of sequestered STAT3 from the intercalated discs. This in turn leads to dysregulation of STAT3-mediated gene transcription, maladaptive remodeling, fibrosis, and decreased cardiac function. Overall, this study presents interesting findings regarding the role of CaMKII and βIV-spectrin under physiological as well as pathological conditions.
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Affiliation(s)
- Mohit Hulsurkar
- Cardiovascular Research Institute
- Department of Molecular Physiology and Biophysics
| | - Ann P. Quick
- Cardiovascular Research Institute
- Department of Molecular Physiology and Biophysics
| | - Xander H.T. Wehrens
- Cardiovascular Research Institute
- Department of Molecular Physiology and Biophysics
- Department of Medicine
- Department of Pediatrics
- Department of Neuroscience, and
- Center for Space Medicine, Baylor College of Medicine, Houston, Texas, USA
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16
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Moriguchi S, Ishizuka T, Yabuki Y, Shioda N, Sasaki Y, Tagashira H, Yawo H, Yeh JZ, Sakagami H, Narahashi T, Fukunaga K. Blockade of the K ATP channel Kir6.2 by memantine represents a novel mechanism relevant to Alzheimer's disease therapy. Mol Psychiatry 2018; 23:211-221. [PMID: 27777420 DOI: 10.1038/mp.2016.187] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/24/2015] [Revised: 08/11/2016] [Accepted: 08/22/2016] [Indexed: 01/09/2023]
Abstract
Here, we report a novel target of the drug memantine, ATP-sensitive K+ (KATP) channels, potentially relevant to memory improvement. We confirmed that memantine antagonizes memory impairment in Alzheimer's model APP23 mice. Memantine increased CaMKII activity in the APP23 mouse hippocampus, and memantine-induced enhancement of hippocampal long-term potentiation (LTP) and CaMKII activity was totally abolished by treatment with pinacidil, a specific opener of KATP channels. Memantine also inhibited Kir6.1 and Kir6.2 KATP channels and elevated intracellular Ca2+ concentrations in neuro2A cells overexpressing Kir6.1 or Kir6.2. Kir6.2 was preferentially expressed at postsynaptic regions of hippocampal neurons, whereas Kir6.1 was predominant in dendrites and cell bodies of pyramidal neurons. Finally, we confirmed that Kir6.2 mutant mice exhibit severe memory deficits and impaired hippocampal LTP, impairments that cannot be rescued by memantine administration. Altogether, our studies show that memantine modulates Kir6.2 activity, and that the Kir6.2 channel is a novel target for therapeutics to improve memory impairment in Alzheimer disease patients.
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Affiliation(s)
- S Moriguchi
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - T Ishizuka
- Department of Developmental Biology and Neuroscience, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - Y Yabuki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - N Shioda
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - Y Sasaki
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - H Tagashira
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
| | - H Yawo
- Department of Developmental Biology and Neuroscience, Graduate School of Life Sciences, Tohoku University, Sendai, Japan
| | - J Z Yeh
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - H Sakagami
- Department of Anatomy, Kitasato University School of Medicine, Sagamihara, Japan
| | - T Narahashi
- Department of Molecular Pharmacology and Biological Chemistry, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - K Fukunaga
- Department of Pharmacology, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Japan
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17
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Abstract
KATP channels are integral to the functions of many cells and tissues. The use of electrophysiological methods has allowed for a detailed characterization of KATP channels in terms of their biophysical properties, nucleotide sensitivities, and modification by pharmacological compounds. However, even though they were first described almost 25 years ago (Noma 1983, Trube and Hescheler 1984), the physiological and pathophysiological roles of these channels, and their regulation by complex biological systems, are only now emerging for many tissues. Even in tissues where their roles have been best defined, there are still many unanswered questions. This review aims to summarize the properties, molecular composition, and pharmacology of KATP channels in various cardiovascular components (atria, specialized conduction system, ventricles, smooth muscle, endothelium, and mitochondria). We will summarize the lessons learned from available genetic mouse models and address the known roles of KATP channels in cardiovascular pathologies and how genetic variation in KATP channel genes contribute to human disease.
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Affiliation(s)
- Monique N Foster
- Departments of Pediatrics, Physiology & Neuroscience, and Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York
| | - William A Coetzee
- Departments of Pediatrics, Physiology & Neuroscience, and Biochemistry and Molecular Pharmacology, NYU School of Medicine, New York, New York
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18
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Sturm AC, Kline CF, Glynn P, Johnson BL, Curran J, Kilic A, Higgins RSD, Binkley PF, Janssen PML, Weiss R, Raman SV, Fowler SJ, Priori SG, Hund TJ, Carnes CA, Mohler PJ. Use of whole exome sequencing for the identification of Ito-based arrhythmia mechanism and therapy. J Am Heart Assoc 2015; 4:JAHA.114.001762. [PMID: 26015324 PMCID: PMC4599408 DOI: 10.1161/jaha.114.001762] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [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
BACKGROUND Identified genetic variants are insufficient to explain all cases of inherited arrhythmia. We tested whether the integration of whole exome sequencing with well-established clinical, translational, and basic science platforms could provide rapid and novel insight into human arrhythmia pathophysiology and disease treatment. METHODS AND RESULTS We report a proband with recurrent ventricular fibrillation, resistant to standard therapeutic interventions. Using whole-exome sequencing, we identified a variant in a previously unidentified exon of the dipeptidyl aminopeptidase-like protein-6 (DPP6) gene. This variant is the first identified coding mutation in DPP6 and augments cardiac repolarizing current (Ito) causing pathological changes in Ito and action potential morphology. We designed a therapeutic regimen incorporating dalfampridine to target Ito. Dalfampridine, approved for multiple sclerosis, normalized the ECG and reduced arrhythmia burden in the proband by >90-fold. This was combined with cilostazol to accelerate the heart rate to minimize the reverse-rate dependence of augmented Ito. CONCLUSIONS We describe a novel arrhythmia mechanism and therapeutic approach to ameliorate the disease. Specifically, we identify the first coding variant of DPP6 in human ventricular fibrillation. These findings illustrate the power of genetic approaches for the elucidation and treatment of disease when carefully integrated with clinical and basic/translational research teams.
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Affiliation(s)
- Amy C Sturm
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.) Department of Internal Medicine, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., P.F.B., R.W., S.V.R., T.J.H., P.J.M.)
| | - Crystal F Kline
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.) Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (C.F.K., J.C., P.L.J., P.J.M.)
| | - Patric Glynn
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.) Department of Surgery, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (P.G., A.K., R.D.H.)
| | - Benjamin L Johnson
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.)
| | - Jerry Curran
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.) Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (C.F.K., J.C., P.L.J., P.J.M.)
| | - Ahmet Kilic
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.) Department of Surgery, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (P.G., A.K., R.D.H.)
| | - Robert S D Higgins
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.) Department of Surgery, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (P.G., A.K., R.D.H.)
| | - Philip F Binkley
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.) Department of Internal Medicine, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., P.F.B., R.W., S.V.R., T.J.H., P.J.M.)
| | - Paul M L Janssen
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.) Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (C.F.K., J.C., P.L.J., P.J.M.)
| | - Raul Weiss
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.) Department of Internal Medicine, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., P.F.B., R.W., S.V.R., T.J.H., P.J.M.)
| | - Subha V Raman
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.) Department of Internal Medicine, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., P.F.B., R.W., S.V.R., T.J.H., P.J.M.)
| | - Steven J Fowler
- Cardiovascular Genetics Program, Clinical Cardiac Electrophysiology, New York University Langone Medical Center, New York, NY (S.J.F., S.G.P.) Leon H. Charney Division of Cardiology, New York University Langone Medical Center, New York, NY (S.J.F.)
| | - Silvia G Priori
- Cardiovascular Genetics Program, Clinical Cardiac Electrophysiology, New York University Langone Medical Center, New York, NY (S.J.F., S.G.P.) Molecular Cardiology, IRCCS Fondazione Salvatore Maugeri, University of Pavia, Italy (S.G.P.) Department of Cardiology, University of Pavia, Italy (S.G.P.)
| | - Thomas J Hund
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.) Department of Internal Medicine, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., P.F.B., R.W., S.V.R., T.J.H., P.J.M.) Department of Biomedical Engineering, The Ohio State University, Columbus, OH (T.J.H.)
| | - Cynthia A Carnes
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.) College of Pharmacy, Columbus, OH (C.A.C.)
| | - Peter J Mohler
- The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., C.F.K., P.G., B.L.J., J.C., A.K., R.D.H., P.F.B., P.L.J., R.W., S.V.R., T.J.H., C.A.C., P.J.M.) Department of Internal Medicine, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (A.C.S., P.F.B., R.W., S.V.R., T.J.H., P.J.M.) Department of Physiology and Cell Biology, The Ohio State University Wexner Medical Center, The Ohio State University College of Engineering, Columbus, OH (C.F.K., J.C., P.L.J., P.J.M.)
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Curran J, Mohler PJ. Alternative Paradigms for Ion Channelopathies: Disorders of Ion Channel Membrane Trafficking and Posttranslational Modification. Annu Rev Physiol 2015; 77:505-24. [DOI: 10.1146/annurev-physiol-021014-071838] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Jerry Curran
- The Dorothy M. Davis Heart & Lung Research Institute,
- Department of Physiology and Cell Biology, and
| | - Peter J. Mohler
- The Dorothy M. Davis Heart & Lung Research Institute,
- Department of Physiology and Cell Biology, and
- Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, Ohio 43210;
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Hund TJ, Mohler PJ. Role of CaMKII in cardiac arrhythmias. Trends Cardiovasc Med 2014; 25:392-7. [PMID: 25577293 DOI: 10.1016/j.tcm.2014.12.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/03/2014] [Revised: 12/01/2014] [Accepted: 12/01/2014] [Indexed: 11/30/2022]
Abstract
Protein phosphorylation is a central mechanism in vertebrates for the regulation of signaling. With regard to the cardiovascular system, phosphorylation of myocyte targets is critical for the regulation of excitation contraction coupling, metabolism, intracellular calcium regulation, mitochondrial activity, transcriptional regulation, and cytoskeletal dynamics. In fact, pathways that tune protein kinase signaling have been a mainstay for cardiovascular therapies for the past 60 years. The calcium/calmodulin-dependent protein kinase II (CaMKII) is a multifunctional serine/threonine kinase with numerous roles in human physiology. Dysfunction in CaMKII-based signaling has been linked with a host of cardiovascular phenotypes including heart failure and arrhythmia, and CaMKII levels are elevated in human and animal disease models of heart disease. While nearly a decade has been invested in targeting CaMKII for the treatment of heart failure and arrhythmia phenotypes, to date, approaches to target the molecule for antiarrhythmic benefit have been unsuccessful for reasons that are still not entirely clear, although (1) lack of compound specificity and (2) the multitude of downstream targets are likely contributing factors. This review will provide an update on current pathways regulated by CaMKII with the goal of illustrating potential upstream regulatory mechanisms and downstream targets that may be modulated for the prevention of cardiac electrical defects. While the review will cover multiple aspects of CaMKII dysfunction in cardiovascular disease, we have given special attention to the potential of CaMKII-associated late Na(+) current as a novel therapeutic target for cardiac arrhythmia.
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Affiliation(s)
- Thomas J Hund
- The Dorothy M. Davis Heart & Lung Research Institute, OH; Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus, OH
| | - Peter J Mohler
- The Dorothy M. Davis Heart & Lung Research Institute, OH; Department of Internal Medicine, The Ohio State University Wexner Medical Center, Columbus, OH; Department of Physiology & Cell Biology, The Ohio State University Wexner Medical Center, Columbus, OH.
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Makara MA, Curran J, Little SC, Musa H, Polina I, Smith SA, Wright PJ, Unudurthi SD, Snyder J, Bennett V, Hund TJ, Mohler PJ. Ankyrin-G coordinates intercalated disc signaling platform to regulate cardiac excitability in vivo. Circ Res 2014; 115:929-38. [PMID: 25239140 DOI: 10.1161/circresaha.115.305154] [Citation(s) in RCA: 91] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
RATIONALE Nav1.5 (SCN5A) is the primary cardiac voltage-gated Nav channel. Nav1.5 is critical for cardiac excitability and conduction, and human SCN5A mutations cause sinus node dysfunction, atrial fibrillation, conductional abnormalities, and ventricular arrhythmias. Further, defects in Nav1.5 regulation are linked with malignant arrhythmias associated with human heart failure. Consequently, therapies to target select Nav1.5 properties have remained at the forefront of cardiovascular medicine. However, despite years of investigation, the fundamental pathways governing Nav1.5 membrane targeting, assembly, and regulation are still largely undefined. OBJECTIVE Define the in vivo mechanisms underlying Nav1.5 membrane regulation. METHODS AND RESULTS Here, we define the molecular basis of an Nav channel regulatory platform in heart. Using new cardiac-selective ankyrin-G(-/-) mice (conditional knock-out mouse), we report that ankyrin-G targets Nav1.5 and its regulatory protein calcium/calmodulin-dependent kinase II to the intercalated disc. Mechanistically, βIV-spectrin is requisite for ankyrin-dependent targeting of calcium/calmodulin-dependent kinase II-δ; however, βIV-spectrin is not essential for ankyrin-G expression. Ankyrin-G conditional knock-out mouse myocytes display decreased Nav1.5 expression/membrane localization and reduced INa associated with pronounced bradycardia, conduction abnormalities, and ventricular arrhythmia in response to Nav channel antagonists. Moreover, we report that ankyrin-G links Nav channels with broader intercalated disc signaling/structural nodes, as ankyrin-G loss results in reorganization of plakophilin-2 and lethal arrhythmias in response to β-adrenergic stimulation. CONCLUSIONS Our findings provide the first in vivo data for the molecular pathway required for intercalated disc Nav1.5 targeting/regulation in heart. Further, these new data identify the basis of an in vivo cellular platform critical for membrane recruitment and regulation of Nav1.5.
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Affiliation(s)
- Michael A Makara
- From The Dorothy M. Davis Heart & Lung Research Institute (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., S.D.U., J.S., T.J.H., P.J.M. ), Departments of Internal Medicine (S.A.S., P.J.M.), and Physiology and Cell Biology (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., P.J.M.), The Ohio State University Wexner Medical Center, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (S.D.U., J.S., T.J.H.); and Howard Hughes Medical Institute, Department of Biochemistry, Duke University Medical Center, Durham, NC (V.B.)
| | - Jerry Curran
- From The Dorothy M. Davis Heart & Lung Research Institute (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., S.D.U., J.S., T.J.H., P.J.M. ), Departments of Internal Medicine (S.A.S., P.J.M.), and Physiology and Cell Biology (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., P.J.M.), The Ohio State University Wexner Medical Center, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (S.D.U., J.S., T.J.H.); and Howard Hughes Medical Institute, Department of Biochemistry, Duke University Medical Center, Durham, NC (V.B.)
| | - Sean C Little
- From The Dorothy M. Davis Heart & Lung Research Institute (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., S.D.U., J.S., T.J.H., P.J.M. ), Departments of Internal Medicine (S.A.S., P.J.M.), and Physiology and Cell Biology (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., P.J.M.), The Ohio State University Wexner Medical Center, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (S.D.U., J.S., T.J.H.); and Howard Hughes Medical Institute, Department of Biochemistry, Duke University Medical Center, Durham, NC (V.B.)
| | - Hassan Musa
- From The Dorothy M. Davis Heart & Lung Research Institute (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., S.D.U., J.S., T.J.H., P.J.M. ), Departments of Internal Medicine (S.A.S., P.J.M.), and Physiology and Cell Biology (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., P.J.M.), The Ohio State University Wexner Medical Center, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (S.D.U., J.S., T.J.H.); and Howard Hughes Medical Institute, Department of Biochemistry, Duke University Medical Center, Durham, NC (V.B.)
| | - Iuliia Polina
- From The Dorothy M. Davis Heart & Lung Research Institute (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., S.D.U., J.S., T.J.H., P.J.M. ), Departments of Internal Medicine (S.A.S., P.J.M.), and Physiology and Cell Biology (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., P.J.M.), The Ohio State University Wexner Medical Center, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (S.D.U., J.S., T.J.H.); and Howard Hughes Medical Institute, Department of Biochemistry, Duke University Medical Center, Durham, NC (V.B.)
| | - Sakima A Smith
- From The Dorothy M. Davis Heart & Lung Research Institute (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., S.D.U., J.S., T.J.H., P.J.M. ), Departments of Internal Medicine (S.A.S., P.J.M.), and Physiology and Cell Biology (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., P.J.M.), The Ohio State University Wexner Medical Center, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (S.D.U., J.S., T.J.H.); and Howard Hughes Medical Institute, Department of Biochemistry, Duke University Medical Center, Durham, NC (V.B.)
| | - Patrick J Wright
- From The Dorothy M. Davis Heart & Lung Research Institute (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., S.D.U., J.S., T.J.H., P.J.M. ), Departments of Internal Medicine (S.A.S., P.J.M.), and Physiology and Cell Biology (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., P.J.M.), The Ohio State University Wexner Medical Center, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (S.D.U., J.S., T.J.H.); and Howard Hughes Medical Institute, Department of Biochemistry, Duke University Medical Center, Durham, NC (V.B.)
| | - Sathya D Unudurthi
- From The Dorothy M. Davis Heart & Lung Research Institute (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., S.D.U., J.S., T.J.H., P.J.M. ), Departments of Internal Medicine (S.A.S., P.J.M.), and Physiology and Cell Biology (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., P.J.M.), The Ohio State University Wexner Medical Center, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (S.D.U., J.S., T.J.H.); and Howard Hughes Medical Institute, Department of Biochemistry, Duke University Medical Center, Durham, NC (V.B.)
| | - Jed Snyder
- From The Dorothy M. Davis Heart & Lung Research Institute (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., S.D.U., J.S., T.J.H., P.J.M. ), Departments of Internal Medicine (S.A.S., P.J.M.), and Physiology and Cell Biology (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., P.J.M.), The Ohio State University Wexner Medical Center, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (S.D.U., J.S., T.J.H.); and Howard Hughes Medical Institute, Department of Biochemistry, Duke University Medical Center, Durham, NC (V.B.)
| | - Vann Bennett
- From The Dorothy M. Davis Heart & Lung Research Institute (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., S.D.U., J.S., T.J.H., P.J.M. ), Departments of Internal Medicine (S.A.S., P.J.M.), and Physiology and Cell Biology (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., P.J.M.), The Ohio State University Wexner Medical Center, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (S.D.U., J.S., T.J.H.); and Howard Hughes Medical Institute, Department of Biochemistry, Duke University Medical Center, Durham, NC (V.B.)
| | - Thomas J Hund
- From The Dorothy M. Davis Heart & Lung Research Institute (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., S.D.U., J.S., T.J.H., P.J.M. ), Departments of Internal Medicine (S.A.S., P.J.M.), and Physiology and Cell Biology (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., P.J.M.), The Ohio State University Wexner Medical Center, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (S.D.U., J.S., T.J.H.); and Howard Hughes Medical Institute, Department of Biochemistry, Duke University Medical Center, Durham, NC (V.B.)
| | - Peter J Mohler
- From The Dorothy M. Davis Heart & Lung Research Institute (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., S.D.U., J.S., T.J.H., P.J.M. ), Departments of Internal Medicine (S.A.S., P.J.M.), and Physiology and Cell Biology (M.A.M., J.C., S.C.L., H.M., I.P., S.A.S., P.J.W., P.J.M.), The Ohio State University Wexner Medical Center, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (S.D.U., J.S., T.J.H.); and Howard Hughes Medical Institute, Department of Biochemistry, Duke University Medical Center, Durham, NC (V.B.).
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Affiliation(s)
- Elise Balse
- Sorbonne Universités, UPMC, UMR_S 1166-ICAN, INSERM UMR_S 1166-ICAN, Institute of Cardiometabolism and Nutrition, ICAN, Pitié-Salpêtrière Hospital, Paris F-75013, France
| | - Stéphane N Hatem
- Sorbonne Universités, UPMC, UMR_S 1166-ICAN, INSERM UMR_S 1166-ICAN, Institute of Cardiometabolism and Nutrition, ICAN, Pitié-Salpêtrière Hospital, Paris F-75013, France Assistance Publique Hôpitaux de Paris, Heart and Metabolism Department, Pitié-Salpêtrière Hospital, Paris F-75013, France
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Curran J, Makara MA, Little SC, Musa H, Liu B, Wu X, Polina I, Alecusan JS, Wright P, Li J, Billman GE, Boyden PA, Gyorke S, Band H, Hund TJ, Mohler PJ. EHD3-dependent endosome pathway regulates cardiac membrane excitability and physiology. Circ Res 2014; 115:68-78. [PMID: 24759929 DOI: 10.1161/circresaha.115.304149] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
RATIONALE Cardiac function is dependent on the coordinate activities of membrane ion channels, transporters, pumps, and hormone receptors to tune the membrane electrochemical gradient dynamically in response to acute and chronic stress. Although our knowledge of membrane proteins has rapidly advanced during the past decade, our understanding of the subcellular pathways governing the trafficking and localization of integral membrane proteins is limited and essentially unstudied in vivo. In the heart, to our knowledge, there are no in vivo mechanistic studies that directly link endosome-based machinery with cardiac physiology. OBJECTIVE To define the in vivo roles of endosome-based cellular machinery for cardiac membrane protein trafficking, myocyte excitability, and cardiac physiology. METHODS AND RESULTS We identify the endosome-based Eps15 homology domain 3 (EHD3) pathway as essential for cardiac physiology. EHD3-deficient hearts display structural and functional defects including bradycardia and rate variability, conduction block, and blunted response to adrenergic stimulation. Mechanistically, EHD3 is critical for membrane protein trafficking, because EHD3-deficient myocytes display reduced expression/localization of Na/Ca exchanger and L-type Ca channel type 1.2 with a parallel reduction in Na/Ca exchanger-mediated membrane current and Cav1.2-mediated membrane current. Functionally, EHD3-deficient myocytes show increased sarcoplasmic reticulum [Ca], increased spark frequency, and reduced expression/localization of ankyrin-B, a binding partner for EHD3 and Na/Ca exchanger. Finally, we show that in vivo EHD3-deficient defects are attributable to cardiac-specific roles of EHD3 because mice with cardiac-selective EHD3 deficiency demonstrate both structural and electric phenotypes. CONCLUSIONS These data provide new insight into the critical role of endosome-based pathways in membrane protein targeting and cardiac physiology. EHD3 is a critical component of protein trafficking in heart and is essential for the proper membrane targeting of select cellular proteins that maintain excitability.
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Affiliation(s)
- Jerry Curran
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.).
| | - Michael A Makara
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - Sean C Little
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - Hassan Musa
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - Bin Liu
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - Xiangqiong Wu
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - Iuliia Polina
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - Joseph S Alecusan
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - Patrick Wright
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - Jingdong Li
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - George E Billman
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - Penelope A Boyden
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - Sandor Gyorke
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - Hamid Band
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - Thomas J Hund
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
| | - Peter J Mohler
- From The Dorothy M. Davis Heart & Lung Research Institute, The Ohio State University Wexner Medical Center, Columbus (J.C., M.A.M., S.C.L., H.M., B.L., X.W., I.P., J.S.A., P.W., J.L., G.E.B., S.G., T.J.H., P.J.M.); Departments of Internal Medicine (P.J.M.) and Physiology and Cell Biology (J.C., M.A.M., S.C.L., H.M., B.L., P.W., G.E.B., S.G., P.J.M.), The Ohio State University, Columbus; Department of Biomedical Engineering, The Ohio State University College of Engineering, Columbus (T.J.H.); Department of Pharmacology and Center for Molecular Therapeutics, Columbia University Medical Center, New York, NY (P.A.B.); and The Eppley Institute and UNMC-Eppley Cancer Center, University of Nebraska Medical Center, Omaha (H.B.)
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24
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Dadi PK, Vierra NC, Ustione A, Piston DW, Colbran RJ, Jacobson DA. Inhibition of pancreatic β-cell Ca2+/calmodulin-dependent protein kinase II reduces glucose-stimulated calcium influx and insulin secretion, impairing glucose tolerance. J Biol Chem 2014; 289:12435-45. [PMID: 24627477 DOI: 10.1074/jbc.m114.562587] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Glucose-stimulated insulin secretion (GSIS) from pancreatic β-cells is caused by Ca(2+) entry via voltage-dependent Ca(2+) channels. CaMKII is a key mediator and feedback regulator of Ca(2+) signaling in many tissues, but its role in β-cells is poorly understood, especially in vivo. Here, we report that mice with conditional inhibition of CaMKII in β-cells show significantly impaired glucose tolerance due to decreased GSIS. Moreover, β-cell CaMKII inhibition dramatically exacerbates glucose intolerance following exposure to a high fat diet. The impairment of islet GSIS by β-cell CaMKII inhibition is not accompanied by changes in either glucose metabolism or the activities of KATP and voltage-gated potassium channels. However, glucose-stimulated Ca(2+) entry via voltage-dependent Ca(2+) channels is reduced in islet β-cells with CaMKII inhibition, as well as in primary wild-type β-cells treated with a peptide inhibitor of CaMKII. The levels of basal β-cell cytoplasmic Ca(2+) and of endoplasmic reticulum Ca(2+) stores are also decreased by CaMKII inhibition. In addition, CaMKII inhibition suppresses glucose-stimulated action potential firing frequency. These results reveal that CaMKII is a Ca(2+) sensor with a key role as a feed-forward stimulator of β-cell Ca(2+) signals that enhance GSIS under physiological and pathological conditions.
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Affiliation(s)
- Prasanna K Dadi
- From the Department of Molecular Physiology and Biophysics, Vanderbilt University, Nashville, Tennessee 37232
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25
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Mustroph J, Maier LS, Wagner S. CaMKII regulation of cardiac K channels. Front Pharmacol 2014; 5:20. [PMID: 24600393 PMCID: PMC3930912 DOI: 10.3389/fphar.2014.00020] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2013] [Accepted: 01/31/2014] [Indexed: 11/23/2022] Open
Abstract
Cardiac K channels are critical determinants of cardiac excitability. In hypertrophied and failing myocardium, alterations in the expression and activity of voltage-gated K channels are frequently observed and contribute to the increased propensity for life-threatening arrhythmias. Thus, understanding the mechanisms of disturbed K channel regulation in heart failure (HF) is of critical importance. Amongst others, Ca/calmodulin-dependent protein kinase II (CaMKII) has been identified as an important regulator of K channel activity. In human HF but also various animal models, increased CaMKII expression and activity has been linked to deteriorated contractile function and arrhythmias. This review will discuss the current knowledge about CaMKII regulation of several K channels, its influence on action potential properties, dispersion of repolarization, and arrhythmias with special focus on HF.
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Affiliation(s)
- Julian Mustroph
- Department of Cardiology, University Medical Center Göttingen Göttingen, Germany
| | - Lars S Maier
- Department of Cardiology, University Medical Center Göttingen Göttingen, Germany
| | - Stefan Wagner
- Department of Cardiology, University Medical Center Göttingen Göttingen, Germany
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