1
|
Shanmugam SK, Kanner SA, Zou X, Amarh E, Choudhury P, Soni R, Kass RS, Colecraft HM. Decoding polyubiquitin regulation of K V7. 1 functional expression with engineered linkage-selective deubiquitinases. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.09.17.613539. [PMID: 39345403 PMCID: PMC11429900 DOI: 10.1101/2024.09.17.613539] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Indexed: 10/01/2024]
Abstract
Protein posttranslational modification with distinct polyubiquitin linkage chains is a critical component of the 'ubiquitin code' that universally regulates protein expression and function to control biology. Functional consequences of diverse polyubiquitin linkages on proteins are mostly unknown, with progress hindered by a lack of methods to specifically tune polyubiquitin linkages on individual proteins in live cells. Here, we bridge this gap by exploiting deubiquitinases (DUBs) with preferences for hydrolyzing different polyubiquitin linkages: OTUD1 - K63; OTUD4 - K48; Cezanne - K11; TRABID - K29/K33; and USP21 - non-specific. We developed a suite of engineered deubiquitinases (enDUBs) comprised of DUB catalytic domains fused to a GFP-targeted nanobody and used them to investigate polyubiquitin linkage regulation of an ion channel, YFP-KCNQ1. Mass spectrometry of YFP-KCNQ1 expressed in HEK293 cells indicated channel polyubiquitination with K48 (72%) and K63 (24%) linkages being dominant. NEDD4-2 and ITCH both decreased KCNQ1 functional expression but with distinctive polyubiquitination signatures. All enDUBs reduced KCNQ1 ubiquitination but yielded unique effects on channel expression, surface density, ionic currents, and subcellular localization. The pattern of outcomes indicates K11, K29/K33, and K63 chains mediate net KCNQ1-YFP intracellular retention, but achieved in different ways: K11 promotes ER retention/degradation, enhances endocytosis, and reduces recycling; K29/K33 promotes ER retention/degradation; K63 enhances endocytosis and reduces recycling. The pattern of enDUB effects on KCNQ1-YFP differed in cardiomyocytes, emphasizing ubiquitin code mutability. Surprisingly, enDUB-O4 decreased KCNQ1-YFP surface density suggesting a role for K48 in forward trafficking. Lastly, linkage-selective enDUBs displayed varying capabilities to rescue distinct trafficking-deficient long QT syndrome type 1 mutations. The results reveal distinct polyubiquitin chains control different aspects of KCNQ1 functional expression, demonstrate ubiquitin code plasticity, and introduce linkage-selective enDUBs as a potent tool to help demystify the polyubiquitin code.
Collapse
Affiliation(s)
| | | | - Xinle Zou
- Department of Molecular Pharmacology and Therapeutics
| | - Enoch Amarh
- Department of Physiology and Cellular Biophysics
| | | | - Rajesh Soni
- Proteomics and Macromolecular crystallography, Columbia University Irving Medical Center, New York, NY
| | | | - Henry M. Colecraft
- Department of Physiology and Cellular Biophysics
- Department of Molecular Pharmacology and Therapeutics
| |
Collapse
|
2
|
Zhou D, Cheng M. Brugada syndrome in a patient with AKAP9 mutation: Case report and review of the literature. J Electrocardiol 2024; 86:153763. [PMID: 39079367 DOI: 10.1016/j.jelectrocard.2024.153763] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2024] [Revised: 07/03/2024] [Accepted: 07/19/2024] [Indexed: 09/15/2024]
Abstract
Brugada syndrome (BrS) is a rare autosomal dominant inherited channel disorder characterized by a specific electrocardiographic pattern of right precordial ST-segment elevation. Clinically, patients may experience polymorphic ventricular tachycardia and ventricular fibrillation, leading to recurrent syncope and sudden cardiac death (SCD) in the absence of structural cardiomyopathy. The A-kinase anchor protein 9 (AKAP9) gene, located on chromosome 7, encodes the AKAP9 protein, which plays a crucial role in regulating the phosphorylation of slowly activating delayed rectifier potassium channels (IKs). Here, we present a rare case of BrS associated with an insertion mutation in AKAP9, resulting in a frameshift mutation.
Collapse
Affiliation(s)
- Dongli Zhou
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, PR China; Hubei Key Laboratory of Biological Targeted Therapy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, PR China; Hubei Provincial Engineering Research Center of Immunological Diagnosis and Therapy for Cardiovascular Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, PR China
| | - Min Cheng
- Department of Cardiology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, PR China; Hubei Key Laboratory of Biological Targeted Therapy, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, PR China; Hubei Provincial Engineering Research Center of Immunological Diagnosis and Therapy for Cardiovascular Diseases, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, PR China.
| |
Collapse
|
3
|
Li B, Karlova M, Zhang H, Pustovit OB, Mai L, Novoseletsky V, Podolyak D, Zaklyazminskaya EV, Abramochkin DV, Sokolova OS. A mutation in the cardiac KV7.1 channel possibly disrupts interaction with Yotiao protein. Biochem Biophys Res Commun 2024; 714:149947. [PMID: 38657442 DOI: 10.1016/j.bbrc.2024.149947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 04/08/2024] [Accepted: 04/15/2024] [Indexed: 04/26/2024]
Abstract
Here, we characterized the p.Arg583His (R583H) Kv7.1 mutation, identified in two unrelated families suffered from LQT syndrome. This mutation is located in the HС-HD linker of the cytoplasmic portion of the Kv7.1 channel. This linker, together with HD helix are responsible for binding the A-kinase anchoring protein 9 (AKAP9), Yotiao. We studied the electrophysiological characteristics of the mutated channel expressed in CHO-K1 along with KCNE1 subunit and Yotiao protein, using the whole-cell patch-clamp technique. We found that R583H mutation, even at the heterozygous state, impedes IKs activation. Molecular modeling showed that HС and HD helixes of the C-terminal part of Kv7.1 channel are swapped along the C-terminus length of the channel and that R583 position is exposed to the outer surface of HC-HD tandem coiled-coil. Interestingly, the adenylate cyclase activator, forskolin had a smaller effect on the mutant channel comparing with the WT protein, suggesting that R583H mutation may disrupt the interaction of the channel with the adaptor protein Yotiao and, therefore, may impair phosphorylation of the KCNQ1 channel.
Collapse
Affiliation(s)
- Bowen Li
- Department of Biology, MSU-BIT University, Shenzhen, Guangdong Province, China
| | - Maria Karlova
- Department of Biology, Moscow Lomonosov University, Moscow, Russia
| | - Han Zhang
- Department of Biology, MSU-BIT University, Shenzhen, Guangdong Province, China
| | | | - Lisha Mai
- Department of Biology, MSU-BIT University, Shenzhen, Guangdong Province, China
| | - Valery Novoseletsky
- Department of Biology, MSU-BIT University, Shenzhen, Guangdong Province, China
| | - Dmitry Podolyak
- Petrovsky Russian Scientific Center for Surgery, Moscow, Russia
| | | | | | - Olga S Sokolova
- Department of Biology, MSU-BIT University, Shenzhen, Guangdong Province, China; Department of Biology, Moscow Lomonosov University, Moscow, Russia.
| |
Collapse
|
4
|
Fu Q, Wang Y, Yan C, Xiang YK. Phosphodiesterase in heart and vessels: from physiology to diseases. Physiol Rev 2024; 104:765-834. [PMID: 37971403 PMCID: PMC11281825 DOI: 10.1152/physrev.00015.2023] [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: 04/03/2023] [Revised: 10/17/2023] [Accepted: 11/08/2023] [Indexed: 11/19/2023] Open
Abstract
Phosphodiesterases (PDEs) are a superfamily of enzymes that hydrolyze cyclic nucleotides, including cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP). Both cyclic nucleotides are critical secondary messengers in the neurohormonal regulation in the cardiovascular system. PDEs precisely control spatiotemporal subcellular distribution of cyclic nucleotides in a cell- and tissue-specific manner, playing critical roles in physiological responses to hormone stimulation in the heart and vessels. Dysregulation of PDEs has been linked to the development of several cardiovascular diseases, such as hypertension, aneurysm, atherosclerosis, arrhythmia, and heart failure. Targeting these enzymes has been proven effective in treating cardiovascular diseases and is an attractive and promising strategy for the development of new drugs. In this review, we discuss the current understanding of the complex regulation of PDE isoforms in cardiovascular function, highlighting the divergent and even opposing roles of PDE isoforms in different pathogenesis.
Collapse
Affiliation(s)
- Qin Fu
- Department of Pharmacology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
- The Key Laboratory for Drug Target Research and Pharmacodynamic Evaluation of Hubei Province, Wuhan, China
| | - Ying Wang
- Department of Pharmacology, School of Medicine, Southern University of Science and Technology, Shenzhen, China
| | - Chen Yan
- Aab Cardiovascular Research Institute, University of Rochester Medical Center, Rochester, New York, United States
| | - Yang K Xiang
- Department of Pharmacology, University of California at Davis, Davis, California, United States
- Department of Veterans Affairs Northern California Healthcare System, Mather, California, United States
| |
Collapse
|
5
|
Zou X, Shanmugam SK, Kanner SA, Sampson KJ, Kass RS, Colecraft HM. Divergent regulation of KCNQ1/E1 by targeted recruitment of protein kinase A to distinct sites on the channel complex. eLife 2023; 12:e83466. [PMID: 37650513 PMCID: PMC10499372 DOI: 10.7554/elife.83466] [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: 09/16/2022] [Accepted: 08/30/2023] [Indexed: 09/01/2023] Open
Abstract
The slow delayed rectifier potassium current, IKs, conducted through pore-forming Q1 and auxiliary E1 ion channel complexes is important for human cardiac action potential repolarization. During exercise or fright, IKs is up-regulated by protein kinase A (PKA)-mediated Q1 phosphorylation to maintain heart rhythm and optimum cardiac performance. Sympathetic up-regulation of IKs requires recruitment of PKA holoenzyme (two regulatory - RI or RII - and two catalytic Cα subunits) to Q1 C-terminus by an A kinase anchoring protein (AKAP9). Mutations in Q1 or AKAP9 that abolish their functional interaction result in long QT syndrome type 1 and 11, respectively, which increases the risk of sudden cardiac death during exercise. Here, we investigated the utility of a targeted protein phosphorylation (TPP) approach to reconstitute PKA regulation of IKs in the absence of AKAP9. Targeted recruitment of endogenous Cα to E1-YFP using a GFP/YFP nanobody (nano) fused to RIIα enabled acute cAMP-mediated enhancement of IKs, reconstituting physiological regulation of the channel complex. By contrast, nano-mediated tethering of RIIα or Cα to Q1-YFP constitutively inhibited IKs by retaining the channel intracellularly in the endoplasmic reticulum and Golgi. Proteomic analysis revealed that distinct phosphorylation sites are modified by Cα targeted to Q1-YFP compared to free Cα. Thus, functional outcomes of synthetically recruited PKA on IKs regulation is critically dependent on the site of recruitment within the channel complex. The results reveal insights into divergent regulation of IKs by phosphorylation across different spatial and time scales, and suggest a TPP approach to develop new drugs to prevent exercise-induced sudden cardiac death.
Collapse
Affiliation(s)
- Xinle Zou
- Department of Molecular Pharmacology and Therapeutics, Columbia UniversityNew YorkUnited States
| | - Sri Karthika Shanmugam
- Department of Physiology and Cellular Biophysics, Columbia UniversityNew YorkUnited States
| | - Scott A Kanner
- Doctoral Program in Neurobiology and Behavior, Columbia UniversityNew YorkUnited States
| | - Kevin J Sampson
- Department of Molecular Pharmacology and Therapeutics, Columbia UniversityNew YorkUnited States
| | - Robert S Kass
- Department of Molecular Pharmacology and Therapeutics, Columbia UniversityNew YorkUnited States
| | - Henry M Colecraft
- Department of Molecular Pharmacology and Therapeutics, Columbia UniversityNew YorkUnited States
- Doctoral Program in Neurobiology and Behavior, Columbia UniversityNew YorkUnited States
| |
Collapse
|
6
|
Cyclic nucleotide phosphodiesterases as therapeutic targets in cardiac hypertrophy and heart failure. Nat Rev Cardiol 2023; 20:90-108. [PMID: 36050457 DOI: 10.1038/s41569-022-00756-z] [Citation(s) in RCA: 34] [Impact Index Per Article: 34.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/11/2022] [Indexed: 01/21/2023]
Abstract
Cyclic nucleotide phosphodiesterases (PDEs) modulate the neurohormonal regulation of cardiac function by degrading cAMP and cGMP. In cardiomyocytes, multiple PDE isozymes with different enzymatic properties and subcellular localization regulate local pools of cyclic nucleotides and specific functions. This organization is heavily perturbed during cardiac hypertrophy and heart failure (HF), which can contribute to disease progression. Clinically, PDE inhibition has been considered a promising approach to compensate for the catecholamine desensitization that accompanies HF. Although PDE3 inhibitors, such as milrinone or enoximone, have been used clinically to improve systolic function and alleviate the symptoms of acute HF, their chronic use has proved to be detrimental. Other PDEs, such as PDE1, PDE2, PDE4, PDE5, PDE9 and PDE10, have emerged as new potential targets to treat HF, each having a unique role in local cyclic nucleotide signalling pathways. In this Review, we describe cAMP and cGMP signalling in cardiomyocytes and present the various PDE families expressed in the heart as well as their modifications in pathological cardiac hypertrophy and HF. We also appraise the evidence from preclinical models as well as clinical data pointing to the use of inhibitors or activators of specific PDEs that could have therapeutic potential in HF.
Collapse
|
7
|
Davies A, Tomas A. Appreciating the potential for GPCR crosstalk with ion channels. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2023; 195:101-120. [PMID: 36707150 DOI: 10.1016/bs.pmbts.2022.06.013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
G protein-coupled receptors (GPCRs) are expressed by most tissues in the body and are exploited pharmacologically in a variety of pathological conditions including diabetes, cardiovascular disease, neurological diseases, and cancers. Numerous cell signaling pathways can be regulated by GPCR activation, depending on the specific GPCR, ligand and cell type. Ion channels are among the many effector proteins downstream of these signaling pathways. Saliently, ion channels are also recognized as druggable targets, and there is evidence that their activity may regulate GPCR function via membrane potential and cytoplasmic ion concentration. Overall, there appears to be a large potential for crosstalk between ion channels and GPCRs. This might have implications not only for targeting GPCRs for drug development, but also opens the possibility of co-targeting them with ion channels to achieve improved therapeutic outcomes. In this review, we highlight the large variety of possible GPCR-ion channel crosstalk modes.
Collapse
Affiliation(s)
- Amy Davies
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom
| | - Alejandra Tomas
- Section of Cell Biology and Functional Genomics, Department of Metabolism, Digestion and Reproduction, Imperial College London, London, United Kingdom.
| |
Collapse
|
8
|
Zou X, Wu X, Sampson KJ, Colecraft HM, Larsson HP, Kass RS. Pharmacological rescue of specific long QT variants of KCNQ1/KCNE1 channels. Front Physiol 2022; 13:902224. [PMID: 36505078 PMCID: PMC9726718 DOI: 10.3389/fphys.2022.902224] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Accepted: 11/02/2022] [Indexed: 11/24/2022] Open
Abstract
The congenital Long QT Syndrome (LQTS) is an inherited disorder in which cardiac ventricular repolarization is delayed and predisposes patients to cardiac arrhythmias and sudden cardiac death. LQT1 and LQT5 are LQTS variants caused by mutations in KCNQ1 or KCNE1 genes respectively. KCNQ1 and KCNE1 co-assemble to form critical IKS potassium channels. Beta-blockers are the standard of care for the treatment of LQT1, however, doing so based on mechanisms other than correcting the loss-of-function of K+ channels. ML277 and R-L3 are compounds that enhance IKS channels and slow channel deactivation in a manner that is dependent on the stoichiometry of KCNE1 subunits in the assembled channels. In this paper, we used expression of IKS channels in Chinese hamster ovary (CHO) cells and Xenopus oocytes to study the potential of these two drugs (ML277 and R-L3) for the rescue of LQT1 and LQT5 mutant channels. We focused on the LQT1 mutation KCNQ1-S546L, and two LQT5 mutations, KCNE1-L51H and KCNE1-G52R. We found ML277 and R-L3 potentiated homozygote LQTS mutations in the IKS complexes-KCNE1-G52R and KCNE1-L51H and in heterogeneous IKS channel complexes which mimic heterogeneous expression of mutations in patients. ML277 and R-L3 increased the mutant IKS current amplitude and slowed current deactivation, but not in wild type (WT) IKS. We obtained similar results in the LQT1 mutant (KCNQ1 S546L/KCNE1) with ML277 and R-L3. ML277 and R-L3 had a similar effect on the LQT1 and LQT5 mutants, however, ML277 was more effective than R-L3 in this modulation. Importantly we found that not all LQT5 mutants expressed with KCNQ1 resulted in channels that are potentiated by these drugs as the KCNE1 mutant D76N inhibited drug action when expressed with KCNQ1. Thus, our work shows that by directly studying the treatment of LQT1 and LQT5 mutations with ML277 and R-L3, we will understand the potential utility of these activators as options in specific LQTS therapeutics.
Collapse
Affiliation(s)
- Xinle Zou
- Department of Molecular Pharmacology & Therapeutics, Vagelos College of Physicians & Surgeons of Columbia University Irving Medical Center, New York, NY, United States
| | - Xiaoan Wu
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Kevin J. Sampson
- Department of Molecular Pharmacology & Therapeutics, Vagelos College of Physicians & Surgeons of Columbia University Irving Medical Center, New York, NY, United States
| | - Henry M. Colecraft
- Department of Molecular Pharmacology & Therapeutics, Vagelos College of Physicians & Surgeons of Columbia University Irving Medical Center, New York, NY, United States
| | - H. Peter Larsson
- Department of Physiology and Biophysics, Miller School of Medicine, University of Miami, Miami, FL, United States
| | - Robert S. Kass
- Department of Molecular Pharmacology & Therapeutics, Vagelos College of Physicians & Surgeons of Columbia University Irving Medical Center, New York, NY, United States,*Correspondence: Robert S. Kass,
| |
Collapse
|
9
|
Herrmann FE, Hesslinger C, Wollin L, Nickolaus P. BI 1015550 is a PDE4B Inhibitor and a Clinical Drug Candidate for the Oral Treatment of Idiopathic Pulmonary Fibrosis. Front Pharmacol 2022; 13:838449. [PMID: 35517783 PMCID: PMC9065678 DOI: 10.3389/fphar.2022.838449] [Citation(s) in RCA: 38] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2021] [Accepted: 02/21/2022] [Indexed: 11/30/2022] Open
Abstract
The anti-inflammatory and immunomodulatory abilities of oral selective phosphodiesterase 4 (PDE4) inhibitors enabled the approval of roflumilast and apremilast for use in chronic obstructive pulmonary disease and psoriasis/psoriatic arthritis, respectively. However, the antifibrotic potential of PDE4 inhibitors has not yet been explored clinically. BI 1015550 is a novel PDE4 inhibitor showing a preferential enzymatic inhibition of PDE4B. In vitro, BI 1015550 inhibits lipopolysaccharide (LPS)-induced tumor necrosis factor-α (TNF-α) and phytohemagglutinin-induced interleukin-2 synthesis in human peripheral blood mononuclear cells, as well as LPS-induced TNF-α synthesis in human and rat whole blood. In vivo, oral BI 1015550 shows potent anti-inflammatory activity in mice by inhibiting LPS-induced TNF-α synthesis ex vivo and in Suncus murinus by inhibiting neutrophil influx into bronchoalveolar lavage fluid stimulated by nebulized LPS. In Suncus murinus, PDE4 inhibitors induce emesis, a well-known gastrointestinal side effect limiting the use of PDE4 inhibitors in humans, and the therapeutic ratio of BI 1015550 appeared to be substantially improved compared with roflumilast. Oral BI 1015550 was also tested in two well-known mouse models of lung fibrosis (induced by either bleomycin or silica) under therapeutic conditions, and appeared to be effective by modulating various model-specific parameters. To better understand the antifibrotic potential of BI 1015550 in vivo, its direct effect on human fibroblasts from patients with idiopathic pulmonary fibrosis (IPF) was investigated in vitro. BI 1015550 inhibited transforming growth factor-β-stimulated myofibroblast transformation and the mRNA expression of various extracellular matrix proteins, as well as basic fibroblast growth factor plus interleukin-1β-induced cell proliferation. Nintedanib overall was unremarkable in these assays, but interestingly, the inhibition of proliferation was synergistic when it was combined with BI 1015550, leading to a roughly 10-fold shift of the concentration–response curve to the left. In summary, the unique preferential inhibition of PDE4B by BI 1015550 and its anticipated improved tolerability in humans, plus its anti-inflammatory and antifibrotic potential, suggest BI 1015550 to be a promising oral clinical candidate for the treatment of IPF and other fibro-proliferative diseases.
Collapse
Affiliation(s)
| | | | - Lutz Wollin
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| | - Peter Nickolaus
- Boehringer Ingelheim Pharma GmbH & Co. KG, Biberach an der Riss, Germany
| |
Collapse
|
10
|
Sanguinetti MC, Seebohm G. Physiological Functions, Biophysical Properties, and Regulation of KCNQ1 (K V7.1) Potassium Channels. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2022; 1349:335-353. [PMID: 35138621 DOI: 10.1007/978-981-16-4254-8_15] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
KCNQ1 (KV7.1) K+ channels are expressed in multiple tissues, including the heart, pancreas, colon, and inner ear. The gene encoding the KCNQ1 protein was discovered by a positional cloning effort to determine the genetic basis of long QT syndrome, an inherited ventricular arrhythmia that can cause sudden death. Mutations in KCNQ1 can also cause other types of arrhythmia (i.e., short QT syndrome, atrial fibrillation) and the gene may also have a role in diabetes and certain cancers. KCNQ1 α-subunits can partner with accessory β-subunits (KCNE1-KCNE5) to form K+-selective channels that have divergent biophysical properties. In the heart, KCNQ1 α-subunits coassemble with KCNE1 β-subunits to form channels that conduct IKs, a very slowly activating delayed rectifier K+ current. KV7.1 channels are highly regulated by PIP2, calmodulin, and phosphorylation, and rich pharmacology includes blockers and gating modulators. Recent biophysical studies and a cryo-EM structure of the KCNQ1-calmodulin complex have provided new insights into KV7.1 channel function, and how interactions between KCNQ1 and KCNE subunits alter the gating properties of heteromultimeric channels.
Collapse
Affiliation(s)
| | - Guiscard Seebohm
- Cellular Electrophysiology and Molecular Biology, Institute for Genetics of Heart Diseases, University Hospital Münster, Münster, Germany
| |
Collapse
|
11
|
Chaklader M, Rothermel BA. Calcineurin in the heart: New horizons for an old friend. Cell Signal 2021; 87:110134. [PMID: 34454008 PMCID: PMC8908812 DOI: 10.1016/j.cellsig.2021.110134] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/10/2021] [Accepted: 08/23/2021] [Indexed: 01/20/2023]
Abstract
Calcineurin, also known as PP2B or PPP3, is a member of the PPP family of protein phosphatases that also includes PP1 and PP2A. Together these three phosphatases carryout the majority of dephosphorylation events in the heart. Calcineurin is distinct in that it is activated by the binding of calcium/calmodulin (Ca2+/CaM) and therefore acts as a node for integrating Ca2+ signals with changes in phosphorylation, two fundamental intracellular signaling cascades. In the heart, calcineurin is primarily thought of in the context of pathological cardiac remodeling, acting through the Nuclear Factor of Activated T-cell (NFAT) family of transcription factors. However, calcineurin activity is also essential for normal heart development and homeostasis in the adult heart. Furthermore, it is clear that NFAT-driven changes in transcription are not the only relevant processes initiated by calcineurin in the setting of pathological remodeling. There is a growing appreciation for the diversity of calcineurin substrates that can impact cardiac function as well as the diversity of mechanisms for targeting calcineurin to specific sub-cellular domains in cardiomyocytes and other cardiac cell types. Here, we will review the basics of calcineurin structure, regulation, and function in the context of cardiac biology. Particular attention will be given to: the development of improved tools to identify and validate new calcineurin substrates; recent studies identifying new calcineurin isoforms with unique properties and targeting mechanisms; and the role of calcineurin in cardiac development and regeneration.
Collapse
Affiliation(s)
- Malay Chaklader
- Departments of Internal Medicine (Division of Cardiology) and Molecular Biology, University of Texas Southwestern Medical Centre, Dallas, TX, USA
| | - Beverly A Rothermel
- Departments of Internal Medicine (Division of Cardiology) and Molecular Biology, University of Texas Southwestern Medical Centre, Dallas, TX, USA.
| |
Collapse
|
12
|
Harvey RD, Clancy CE. Mechanisms of cAMP compartmentation in cardiac myocytes: experimental and computational approaches to understanding. J Physiol 2021; 599:4527-4544. [PMID: 34510451 DOI: 10.1113/jp280801] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2021] [Accepted: 09/07/2021] [Indexed: 01/04/2023] Open
Abstract
The small diffusible second messenger 3',5'-cyclic adenosine monophosphate (cAMP) is found in virtually every cell in our bodies, where it mediates responses to a variety of different G protein coupled receptors (GPCRs). In the heart, cAMP plays a critical role in regulating many different aspects of cardiac myocyte function, including gene transcription, cell metabolism, and excitation-contraction coupling. Yet, not all GPCRs that stimulate cAMP production elicit the same responses. Subcellular compartmentation of cAMP is essential to explain how different receptors can utilize the same diffusible second messenger to elicit unique functional responses. However, the mechanisms contributing to this behaviour and its significance in producing physiological and pathological responses are incompletely understood. Mathematical modelling has played an essential role in gaining insight into these questions. This review discusses what we currently know about cAMP compartmentation in cardiac myocytes and questions that are yet to be answered.
Collapse
Affiliation(s)
- Robert D Harvey
- Department of Pharmacology, University of Nevada, Reno, NV, 89557, USA
| | - Colleen E Clancy
- Department of Physiology and Membrane Biology, University of California-Davis, Davis, CA, 95616, USA
| |
Collapse
|
13
|
Crotti L, Odening KE, Sanguinetti MC. Heritable arrhythmias associated with abnormal function of cardiac potassium channels. Cardiovasc Res 2021; 116:1542-1556. [PMID: 32227190 DOI: 10.1093/cvr/cvaa068] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/20/2019] [Revised: 02/24/2020] [Accepted: 03/26/2020] [Indexed: 12/16/2022] Open
Abstract
Cardiomyocytes express a surprisingly large number of potassium channel types. The primary physiological functions of the currents conducted by these channels are to maintain the resting membrane potential and mediate action potential repolarization under basal conditions and in response to changes in the concentrations of intracellular sodium, calcium, and ATP/ADP. Here, we review the diversity and functional roles of cardiac potassium channels under normal conditions and how heritable mutations in the genes encoding these channels can lead to distinct arrhythmias. We briefly review atrial fibrillation and J-wave syndromes. For long and short QT syndromes, we describe their genetic basis, clinical manifestation, risk stratification, traditional and novel therapeutic approaches, as well as insights into disease mechanisms provided by animal and cellular models.
Collapse
Affiliation(s)
- Lia Crotti
- Center for Cardiac Arrhythmias of Genetic Origin, Istituto Auxologico Italiano, IRCCS, Milan, Italy.,Laboratory of Cardiovascular Genetics, Istituto Auxologico Italiano, IRCCS, Milan, Italy.,Department of Cardiovascular, Neural and Metabolic Sciences, Istituto Auxologico Italiano, IRCCS, San Luca Hospital, Milan, Italy.,Department of Medicine and Surgery, University of Milano-Bicocca, Milan, Italy
| | - Katja E Odening
- Department of Cardiology and Angiology I, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany.,Institute of Experimental Cardiovascular Medicine, Heart Center University of Freiburg, Medical Faculty, Freiburg, Germany.,Department of Cardiology, Translational Cardiology, Inselspital, Bern University Hospital, and Institute of Physiology, University of Bern, Bern, Switzerland
| | - Michael C Sanguinetti
- Department of Internal Medicine, Nora Eccles Harrison Cardiovascular Research and Training Institute, University of Utah, Salt Lake City, UT, USA
| |
Collapse
|
14
|
Abou Ziki MD, Bhat N, Neogi A, Driscoll TP, Ugwu N, Liu Y, Smith E, Abboud JM, Chouairi S, Schwartz MA, Akar JG, Mani A. Epistatic interaction of PDE4DIP and DES mutations in familial atrial fibrillation with slow conduction. Hum Mutat 2021; 42:1279-1293. [PMID: 34289528 DOI: 10.1002/humu.24265] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Revised: 06/29/2021] [Accepted: 07/06/2021] [Indexed: 11/09/2022]
Abstract
The genetic causes of atrial fibrillation (AF) with slow conduction are unknown. Eight kindreds with familial AF and slow conduction, including a family affected by early-onset AF, heart block, and incompletely penetrant nonischemic dilated cardiomyopathy (DCM) underwent whole exome sequencing. A known pathogenic mutation in the desmin (DES) gene resulting in p.S13F substitution (NM_001927.3:c.38C>T) at a PKC phosphorylation site was identified in all four members of the kindred with early-onset AF and heart block, while only two developed DCM. Higher penetrance for AF and heart block prompted a genetic screening for DES modifier(s). A deleterious mutation in the phosphodiesterase-4D-interacting-protein (PDE4DIP) gene resulting in p.A123T substitution (NM_001002811:c.367G>A) was identified that segregated with early-onset AF, heart block, and the DES mutation. Three additional novel deleterious PDE4DIP mutations were identified in four other unrelated kindreds. Characterization of PDE4DIPA123T in vitro suggested impaired compartmentalization of PKA and PDE4D characterized by reduced colocalization with PDE4D, increased cAMP activation leading to higher PKA phosphorylation of the β2-adrenergic-receptor, and decreased PKA phosphorylation of desmin after isoproterenol stimulation. Our findings identify PDE4DIP as a novel gene for slow AF and unravel its epistatic interaction with DES mutations in development of conduction disease and arrhythmia.
Collapse
Affiliation(s)
- Maen D Abou Ziki
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Neha Bhat
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Arpita Neogi
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Tristan P Driscoll
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.,Chemical and Biomedical Engineering, Florida A&M University-Florida State University College of Engineering, Tallahassee, Florida, USA
| | - Nelson Ugwu
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Ya Liu
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Emily Smith
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Johny M Abboud
- Saint George Hospital University Medical Center, Beirut, Lebanon
| | - Salah Chouairi
- Saint George Hospital University Medical Center, Beirut, Lebanon
| | - Martin A Schwartz
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Joseph G Akar
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA
| | - Arya Mani
- Section of Cardiovascular Medicine, Department of Internal Medicine, Yale University School of Medicine, New Haven, Connecticut, USA.,Department of Genetics, Yale University School of Medicine, New Haven, Connecticut, USA
| |
Collapse
|
15
|
Paes D, Schepers M, Rombaut B, van den Hove D, Vanmierlo T, Prickaerts J. The Molecular Biology of Phosphodiesterase 4 Enzymes as Pharmacological Targets: An Interplay of Isoforms, Conformational States, and Inhibitors. Pharmacol Rev 2021; 73:1016-1049. [PMID: 34233947 DOI: 10.1124/pharmrev.120.000273] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The phosphodiesterase 4 (PDE4) enzyme family plays a pivotal role in regulating levels of the second messenger cAMP. Consequently, PDE4 inhibitors have been investigated as a therapeutic strategy to enhance cAMP signaling in a broad range of diseases, including several types of cancers, as well as in various neurologic, dermatological, and inflammatory diseases. Despite their widespread therapeutic potential, the progression of PDE4 inhibitors into the clinic has been hampered because of their related relatively small therapeutic window, which increases the chance of producing adverse side effects. Interestingly, the PDE4 enzyme family consists of several subtypes and isoforms that can be modified post-translationally or can engage in specific protein-protein interactions to yield a variety of conformational states. Inhibition of specific PDE4 subtypes, isoforms, or conformational states may lead to more precise effects and hence improve the safety profile of PDE4 inhibition. In this review, we provide an overview of the variety of PDE4 isoforms and how their activity and inhibition is influenced by post-translational modifications and interactions with partner proteins. Furthermore, we describe the importance of screening potential PDE4 inhibitors in view of different PDE4 subtypes, isoforms, and conformational states rather than testing compounds directed toward a specific PDE4 catalytic domain. Lastly, potential mechanisms underlying PDE4-mediated adverse effects are outlined. In this review, we illustrate that PDE4 inhibitors retain their therapeutic potential in myriad diseases, but target identification should be more precise to establish selective inhibition of disease-affected PDE4 isoforms while avoiding isoforms involved in adverse effects. SIGNIFICANCE STATEMENT: Although the PDE4 enzyme family is a therapeutic target in an extensive range of disorders, clinical use of PDE4 inhibitors has been hindered because of the adverse side effects. This review elaborately shows that safer and more effective PDE4 targeting is possible by characterizing 1) which PDE4 subtypes and isoforms exist, 2) how PDE4 isoforms can adopt specific conformations upon post-translational modifications and protein-protein interactions, and 3) which PDE4 inhibitors can selectively bind specific PDE4 subtypes, isoforms, and/or conformations.
Collapse
Affiliation(s)
- Dean Paes
- Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, EURON, Maastricht University, Maastricht, The Netherlands (D.P, M.S., B.R., D.v.d.H., T.V., J.P.); Department of Neuroscience, Neuro-Immune Connect and Repair laboratory, Biomedical Research Institute, Hasselt University, Hasselt, Belgium (D.P., M.S., B.R., T.V.); and Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg, Germany (D.v.d.H.)
| | - Melissa Schepers
- Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, EURON, Maastricht University, Maastricht, The Netherlands (D.P, M.S., B.R., D.v.d.H., T.V., J.P.); Department of Neuroscience, Neuro-Immune Connect and Repair laboratory, Biomedical Research Institute, Hasselt University, Hasselt, Belgium (D.P., M.S., B.R., T.V.); and Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg, Germany (D.v.d.H.)
| | - Ben Rombaut
- Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, EURON, Maastricht University, Maastricht, The Netherlands (D.P, M.S., B.R., D.v.d.H., T.V., J.P.); Department of Neuroscience, Neuro-Immune Connect and Repair laboratory, Biomedical Research Institute, Hasselt University, Hasselt, Belgium (D.P., M.S., B.R., T.V.); and Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg, Germany (D.v.d.H.)
| | - Daniel van den Hove
- Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, EURON, Maastricht University, Maastricht, The Netherlands (D.P, M.S., B.R., D.v.d.H., T.V., J.P.); Department of Neuroscience, Neuro-Immune Connect and Repair laboratory, Biomedical Research Institute, Hasselt University, Hasselt, Belgium (D.P., M.S., B.R., T.V.); and Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg, Germany (D.v.d.H.)
| | - Tim Vanmierlo
- Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, EURON, Maastricht University, Maastricht, The Netherlands (D.P, M.S., B.R., D.v.d.H., T.V., J.P.); Department of Neuroscience, Neuro-Immune Connect and Repair laboratory, Biomedical Research Institute, Hasselt University, Hasselt, Belgium (D.P., M.S., B.R., T.V.); and Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg, Germany (D.v.d.H.)
| | - Jos Prickaerts
- Department of Psychiatry & Neuropsychology, School for Mental Health and Neuroscience, EURON, Maastricht University, Maastricht, The Netherlands (D.P, M.S., B.R., D.v.d.H., T.V., J.P.); Department of Neuroscience, Neuro-Immune Connect and Repair laboratory, Biomedical Research Institute, Hasselt University, Hasselt, Belgium (D.P., M.S., B.R., T.V.); and Department of Psychiatry, Psychosomatics and Psychotherapy, University of Würzburg, Würzburg, Germany (D.v.d.H.)
| |
Collapse
|
16
|
Colombe AS, Pidoux G. Cardiac cAMP-PKA Signaling Compartmentalization in Myocardial Infarction. Cells 2021; 10:cells10040922. [PMID: 33923648 PMCID: PMC8073060 DOI: 10.3390/cells10040922] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2021] [Revised: 04/02/2021] [Accepted: 04/13/2021] [Indexed: 02/07/2023] Open
Abstract
Under physiological conditions, cAMP signaling plays a key role in the regulation of cardiac function. Activation of this intracellular signaling pathway mirrors cardiomyocyte adaptation to various extracellular stimuli. Extracellular ligand binding to seven-transmembrane receptors (also known as GPCRs) with G proteins and adenylyl cyclases (ACs) modulate the intracellular cAMP content. Subsequently, this second messenger triggers activation of specific intracellular downstream effectors that ensure a proper cellular response. Therefore, it is essential for the cell to keep the cAMP signaling highly regulated in space and time. The temporal regulation depends on the activity of ACs and phosphodiesterases. By scaffolding key components of the cAMP signaling machinery, A-kinase anchoring proteins (AKAPs) coordinate both the spatial and temporal regulation. Myocardial infarction is one of the major causes of death in industrialized countries and is characterized by a prolonged cardiac ischemia. This leads to irreversible cardiomyocyte death and impairs cardiac function. Regardless of its causes, a chronic activation of cardiac cAMP signaling is established to compensate this loss. While this adaptation is primarily beneficial for contractile function, it turns out, in the long run, to be deleterious. This review compiles current knowledge about cardiac cAMP compartmentalization under physiological conditions and post-myocardial infarction when it appears to be profoundly impaired.
Collapse
|
17
|
Turner MJ, Abbott-Banner K, Thomas DY, Hanrahan JW. Cyclic nucleotide phosphodiesterase inhibitors as therapeutic interventions for cystic fibrosis. Pharmacol Ther 2021; 224:107826. [PMID: 33662448 DOI: 10.1016/j.pharmthera.2021.107826] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2020] [Revised: 01/05/2021] [Accepted: 02/22/2021] [Indexed: 12/13/2022]
Abstract
Cystic Fibrosis (CF) lung disease results from mutations in the CFTR anion channel that reduce anion and fluid secretion by airway epithelia. Impaired secretion compromises airway innate defence mechanisms and leads to bacterial colonization, excessive inflammation and tissue damage; thus, restoration of CFTR function is the goal of many CF therapies. CFTR channels are activated by cyclic nucleotide-dependent protein kinases. The second messengers 3'5'-cAMP and 3'5'-cGMP are hydrolysed by a large family of cyclic nucleotide phosphodiesterases that provide subcellular spatial and temporal control of cyclic nucleotide-dependent signalling. Selective inhibition of these enzymes elevates cyclic nucleotide levels, leading to activation of CFTR and other downstream effectors. Here we examine members of the PDE family that are likely to regulate CFTR-dependent ion and fluid secretion in the airways and discuss other actions of PDE inhibitors that can influence cyclic nucleotide-regulated mucociliary transport, inflammation and bronchodilation. Finally, we review PDE inhibitors and the potential benefits they could provide as CF therapeutics.
Collapse
Affiliation(s)
- Mark J Turner
- Department of Physiology, McGill University, Montreal, QC, Canada; Cystic Fibrosis Translational Research Centre, McGill University, Montreal, QC, Canada.
| | | | - David Y Thomas
- Cystic Fibrosis Translational Research Centre, McGill University, Montreal, QC, Canada; Department of Biochemistry, McGill University, Montreal, QC, Canada
| | - John W Hanrahan
- Department of Physiology, McGill University, Montreal, QC, Canada; Cystic Fibrosis Translational Research Centre, McGill University, Montreal, QC, Canada
| |
Collapse
|
18
|
Abstract
Long QT syndrome (LQTS) is a cardiovascular disorder characterized by an abnormality in cardiac repolarization leading to a prolonged QT interval and T-wave irregularities on the surface electrocardiogram. It is commonly associated with syncope, seizures, susceptibility to torsades de pointes, and risk for sudden death. LQTS is a rare genetic disorder and a major preventable cause of sudden cardiac death in the young. The availability of therapy for this lethal disease emphasizes the importance of early and accurate diagnosis. Additionally, understanding of the molecular mechanisms underlying LQTS could help to optimize genotype-specific treatments to prevent deaths in LQTS patients. In this review, we briefly summarize current knowledge regarding molecular underpinning of LQTS, in particular focusing on LQT1, LQT2, and LQT3, and discuss novel strategies to study ion channel dysfunction and drug-specific therapies in LQT1, LQT2, and LQT3 syndromes.
Collapse
Affiliation(s)
| | - Isabelle Deschênes
- Department of Physiology and Cell Biology, The Ohio State University, Columbus, Ohio
| |
Collapse
|
19
|
Abstract
The field of cAMP signaling is witnessing exciting developments with the recognition that cAMP is compartmentalized and that spatial regulation of cAMP is critical for faithful signal coding. This realization has changed our understanding of cAMP signaling from a model in which cAMP connects a receptor at the plasma membrane to an intracellular effector in a linear pathway to a model in which cAMP signals propagate within a complex network of alternative branches and the specific functional outcome strictly depends on local regulation of cAMP levels and on selective activation of a limited number of branches within the network. In this review, we cover some of the early studies and summarize more recent evidence supporting the model of compartmentalized cAMP signaling, and we discuss how this knowledge is starting to provide original mechanistic insight into cell physiology and a novel framework for the identification of disease mechanisms that potentially opens new avenues for therapeutic interventions. SIGNIFICANCE STATEMENT: cAMP mediates the intracellular response to multiple hormones and neurotransmitters. Signal fidelity and accurate coordination of a plethora of different cellular functions is achieved via organization of multiprotein signalosomes and cAMP compartmentalization in subcellular nanodomains. Defining the organization and regulation of subcellular cAMP nanocompartments is necessary if we want to understand the complex functional ramifications of pharmacological treatments that target G protein-coupled receptors and for generating a blueprint that can be used to develop precision medicine interventions.
Collapse
Affiliation(s)
- Manuela Zaccolo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Anna Zerio
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Miguel J Lobo
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| |
Collapse
|
20
|
Sadek MS, Cachorro E, El-Armouche A, Kämmerer S. Therapeutic Implications for PDE2 and cGMP/cAMP Mediated Crosstalk in Cardiovascular Diseases. Int J Mol Sci 2020; 21:E7462. [PMID: 33050419 PMCID: PMC7590001 DOI: 10.3390/ijms21207462] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2020] [Revised: 10/07/2020] [Accepted: 10/08/2020] [Indexed: 12/11/2022] Open
Abstract
Phosphodiesterases (PDEs) are the principal superfamily of enzymes responsible for degrading the secondary messengers 3',5'-cyclic nucleotides cAMP and cGMP. Their refined subcellular localization and substrate specificity contribute to finely regulate cAMP/cGMP gradients in various cellular microdomains. Redistribution of multiple signal compartmentalization components is often perceived under pathological conditions. Thereby PDEs have long been pursued as therapeutic targets in diverse disease conditions including neurological, metabolic, cancer and autoimmune disorders in addition to numerous cardiovascular diseases (CVDs). PDE2 is a unique member of the broad family of PDEs. In addition to its capability to hydrolyze both cAMP and cGMP, PDE2 is the sole isoform that may be allosterically activated by cGMP increasing its cAMP hydrolyzing activity. Within the cardiovascular system, PDE2 serves as an integral regulator for the crosstalk between cAMP/cGMP pathways and thereby may couple chronically adverse augmented cAMP signaling with cardioprotective cGMP signaling. This review provides a comprehensive overview of PDE2 regulatory functions in multiple cellular components within the cardiovascular system and also within various subcellular microdomains. Implications for PDE2- mediated crosstalk mechanisms in diverse cardiovascular pathologies are discussed highlighting the prospective use of PDE2 as a potential therapeutic target in cardiovascular disorders.
Collapse
Affiliation(s)
| | | | - Ali El-Armouche
- Department of Pharmacology and Toxicology, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany; (M.S.S.); (E.C.)
| | - Susanne Kämmerer
- Department of Pharmacology and Toxicology, Carl Gustav Carus Faculty of Medicine, Technische Universität Dresden, Fetscherstraße 74, 01307 Dresden, Germany; (M.S.S.); (E.C.)
| |
Collapse
|
21
|
Increased isoform-specific phosphodiesterase 4D expression is associated with pathology and cognitive impairment in Alzheimer's disease. Neurobiol Aging 2020; 97:56-64. [PMID: 33157432 DOI: 10.1016/j.neurobiolaging.2020.10.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 09/16/2020] [Accepted: 10/04/2020] [Indexed: 02/07/2023]
Abstract
Pharmacological phosphodiesterase 4D (PDE4D) inhibition shows therapeutic potential to restore memory function in Alzheimer's disease (AD), but will likely evoke adverse side effects. As PDE4D encodes multiple isoforms, targeting specific isoforms may improve treatment efficacy and safety. Here, we investigated whether PDE4D isoform expression and PDE4D DNA methylation is affected in AD and whether expression changes are associated with severity of pathology and cognitive impairment. In post-mortem temporal lobe brain material from AD patients (n = 42) and age-matched controls (n = 40), we measured PDE4D isoform expression and PDE4D DNA (hydroxy)methylation using quantitative polymerase chain reaction and Illumina 450k Beadarrays, respectively. Linear regression revealed increased PDE4D1, -D3, -D5, and -D8 expression in AD with concurrent (hydroxy)methylation changes in associated promoter regions. Moreover, increased PDE4D1 and -D3 expression was associated with higherplaque and tau pathology levels, higher Braak stages, and progressed cognitive impairment. Future studies should indicate functional roles of specific PDE4D isoforms and the efficacy and safety of their selective inhibition to restore memory function in AD.
Collapse
|
22
|
Abstract
Kv7 channels (Kv7.1-7.5) are voltage-gated K+ channels that can be modulated by five β-subunits (KCNE1-5). Kv7.1-KCNE1 channels produce the slow-delayed rectifying K+ current, IKs, which is important during the repolarization phase of the cardiac action potential. Kv7.2-7.5 are predominantly neuronally expressed and constitute the muscarinic M-current and control the resting membrane potential in neurons. Kv7.1 produces drastically different currents as a result of modulation by KCNE subunits. This flexibility allows the Kv7.1 channel to have many roles depending on location and assembly partners. The pharmacological sensitivity of Kv7.1 channels differs from that of Kv7.2-7.5 and is largely dependent upon the number of β-subunits present in the channel complex. As a result, the development of pharmaceuticals targeting Kv7.1 is problematic. This review discusses the roles and the mechanisms by which different signaling pathways affect Kv7.1 and KCNE channels and could potentially provide different ways of targeting the channel.
Collapse
Affiliation(s)
- Emely Thompson
- Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada;
| | - Jodene Eldstrom
- Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada;
| | - David Fedida
- Department of Anesthesiology, Pharmacology, and Therapeutics, University of British Columbia, Vancouver, British Columbia V6T 1Z3, Canada;
| |
Collapse
|
23
|
van der Horst J, Greenwood IA, Jepps TA. Cyclic AMP-Dependent Regulation of Kv7 Voltage-Gated Potassium Channels. Front Physiol 2020; 11:727. [PMID: 32695022 PMCID: PMC7338754 DOI: 10.3389/fphys.2020.00727] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Accepted: 06/04/2020] [Indexed: 01/08/2023] Open
Abstract
Voltage-gated Kv7 potassium channels, encoded by KCNQ genes, have major physiological impacts cardiac myocytes, neurons, epithelial cells, and smooth muscle cells. Cyclic adenosine monophosphate (cAMP), a well-known intracellular secondary messenger, can activate numerous downstream effector proteins, generating downstream signaling pathways that regulate many functions in cells. A role for cAMP in ion channel regulation has been established, and recent findings show that cAMP signaling plays a role in Kv7 channel regulation. Although cAMP signaling is recognized to regulate Kv7 channels, the precise molecular mechanism behind the cAMP-dependent regulation of Kv7 channels is complex. This review will summarize recent research findings that support the mechanisms of cAMP-dependent regulation of Kv7 channels.
Collapse
Affiliation(s)
- Jennifer van der Horst
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Iain A Greenwood
- Molecular and Clinical Sciences Institute, St. George's University of London, London, United Kingdom
| | - Thomas A Jepps
- Vascular Biology Group, Department of Biomedical Sciences, University of Copenhagen, Copenhagen, Denmark
| |
Collapse
|
24
|
Nanometric targeting of type 9 adenylyl cyclase in heart. Biochem Soc Trans 2020; 47:1749-1756. [PMID: 31769471 DOI: 10.1042/bst20190227] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 11/11/2019] [Accepted: 11/12/2019] [Indexed: 12/15/2022]
Abstract
Adenylyl cyclases (ACs) convert ATP into the classical second messenger cyclic adenosine monophosphate (cAMP). Cardiac ACs, specifically AC5, AC6, and AC9, regulate cAMP signaling controlling functional outcomes such as heart rate, contractility and relaxation, gene regulation, stress responses, and glucose and lipid metabolism. With so many distinct functional outcomes for a single second messenger, the cell creates local domains of cAMP signaling to correctly relay signals. Targeting of ACs to A-kinase anchoring proteins (AKAPs) not only localizes ACs, but also places them within signaling nanodomains, where cAMP levels and effects can be highly regulated. Here we will discuss the recent work on the structure, regulation and physiological functions of AC9 in the heart, where it accounts for <3% of total AC activity. Despite the small contribution of AC9 to total cardiac cAMP production, AC9 binds and regulates local PKA phosphorylation of Yotiao-IKs and Hsp20, demonstrating a role for nanometric targeting of AC9.
Collapse
|
25
|
Li Y, Hof T, Baldwin TA, Chen L, Kass RS, Dessauer CW. Regulation of I Ks Potassium Current by Isoproterenol in Adult Cardiomyocytes Requires Type 9 Adenylyl Cyclase. Cells 2019; 8:cells8090981. [PMID: 31461851 PMCID: PMC6770663 DOI: 10.3390/cells8090981] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/20/2019] [Accepted: 08/23/2019] [Indexed: 02/06/2023] Open
Abstract
The subunits KCNQ1 and KCNE1 generate the slowly activating, delayed rectifier potassium current, IKs, that responds to sympathetic stimulation and is critical for human cardiac repolarization. The A-kinase anchoring protein Yotiao facilitates macromolecular complex formation between IKs and protein kinase A (PKA) to regulate phosphorylation of KCNQ1 and IKs currents following beta-adrenergic stimulation. We have previously shown that adenylyl cyclase Type 9 (AC9) is associated with a KCNQ1-Yotiao-PKA complex and facilitates isoproterenol-stimulated phosphorylation of KCNQ1 in an immortalized cell line. However, requirement for AC9 in sympathetic control of IKs in the heart was unknown. Using a transgenic mouse strain expressing the KCNQ1-KCNE1 subunits of IKs, we show that AC9 is the only adenylyl cyclase (AC) isoform associated with the KCNQ1-KCNE1-Yotiao complex in the heart. Deletion of AC9 resulted in the loss of isoproterenol-stimulated KCNQ1 phosphorylation in vivo, even though AC9 represents less than 3% of total cardiac AC activity. Importantly, a significant reduction of isoproterenol-stimulated IKs currents was also observed in adult cardiomyocytes from IKs-expressing AC9KO mice. AC9 and Yotiao co-localize with N-cadherin, a marker of intercalated disks and cell–cell junctions, in neonatal and adult cardiomyocytes, respectively. In conclusion, AC9 is necessary for sympathetic regulation of PKA phosphorylation of KCNQ1 in vivo and for functional regulation of IKs in adult cardiomyocytes.
Collapse
Affiliation(s)
- Yong Li
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Thomas Hof
- Department of Pharmacology, Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
| | - Tanya A Baldwin
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA
| | - Lei Chen
- Department of Pharmacology, Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
| | - Robert S Kass
- Department of Pharmacology, Department of Medicine, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
| | - Carmen W Dessauer
- Department of Integrative Biology and Pharmacology, McGovern Medical School, University of Texas Health Science Center, Houston, TX 77030, USA.
| |
Collapse
|
26
|
Huang H, Xie M, Gao L, Zhang W, Zhu X, Wang Y, Li W, Wang R, Chen K, Boutjdir M, Chen L. Rolipram, a PDE4 Inhibitor, Enhances the Inotropic Effect of Rat Heart by Activating SERCA2a. Front Pharmacol 2019; 10:221. [PMID: 30967774 PMCID: PMC6439224 DOI: 10.3389/fphar.2019.00221] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 02/22/2019] [Indexed: 12/25/2022] Open
Abstract
This study was designed to investigate the hemodynamic effect of rolipram, a phosphodiesterase type 4 (PDE4) inhibitor, in normal rat hearts both in vivo and in vitro and its underlying mechanism. The pressure-volume loop, isolated heart, and Ca2+ transients triggered by field stimulation or caffeine were used to analyze the hemodynamic mechanism of rolipram. The results demonstrated that rolipram (3 mg/kg, ip) significantly increased the in vivo rat heart contractility by enhancing stroke work, cardiac output, stroke volume, end-systolic volume, end-diastolic volume, end-systolic pressure, heart rate, ejection fraction, peak rate of rise of left pressure (+dp/dtmax), the slopes of end-systolic pressure-volume relationship (slope of ESPVR) named as left ventricular end-systolic elastance, and reduced the slopes of end-diastolic pressure-volume relationship (slope of EDPVR). Meanwhile, the systolic blood pressure, diastolic blood pressure, and pulse pressure were significantly enhanced by rolipram. Also, rolipram deviated normal ventricular-arterial coupling without changing the arterial elastance. Furthermore, rolipram (0.1, 1, 10 μM) also exerted positive inotropic effect in isolated rat hearts by increasing the left ventricular development pressure, and +dp/dtmax in non-paced and paced modes. Rolipram (10 μM) increased the SERCA2a activity, Ca2+ content, and Ca2+ leak rate without changing diastolic Ca2+ level. Rolipram had significant positive inotropic effect with less effect on peripheral vascular elastance and its underlying mechanism was mediated by increasing SERCA2a activity. PDE4 inhibition by rolipram resulted in a positive inotropic effect and might serve as a target for developing agents for the treatment of heart failure in clinical settings.
Collapse
Affiliation(s)
- Huili Huang
- National Standard Laboratory of Pharmacology for Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Ming Xie
- National Standard Laboratory of Pharmacology for Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Li Gao
- National Standard Laboratory of Pharmacology for Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Wenhui Zhang
- National Standard Laboratory of Pharmacology for Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Xiaojia Zhu
- National Standard Laboratory of Pharmacology for Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Yuwei Wang
- National Standard Laboratory of Pharmacology for Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Wei Li
- National Standard Laboratory of Pharmacology for Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China
| | - Rongrong Wang
- Dalian Institute of Chemical Physics, Dalian, China.,Chinese Academy of Sciences Biomedical Innovation Institute of China Medical City, Taizhou, China
| | - Kesu Chen
- Department of Respiratory, Inpatient Wards for Senior Cadres, Nanjing General Hospital of Nanjing Military Command Region, Nanjing, China
| | - Mohamed Boutjdir
- VA New York Harbor Healthcare System, New York, NY, United States.,State University of New York Downstate Medical Center, New York, NY, United States.,NYU School of Medicine, New York, NY, United States
| | - Long Chen
- National Standard Laboratory of Pharmacology for Chinese Materia Medica, School of Pharmacy, Nanjing University of Chinese Medicine, Nanjing, China.,Institute of Chinese Medicine of Taizhou China Medical City, Taizhou, China
| |
Collapse
|
27
|
Gildart M, Kapiloff MS, Dodge-Kafka KL. Calcineurin-AKAP interactions: therapeutic targeting of a pleiotropic enzyme with a little help from its friends. J Physiol 2018; 598:3029-3042. [PMID: 30488951 PMCID: PMC7586300 DOI: 10.1113/jp276756] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2018] [Accepted: 11/14/2018] [Indexed: 01/14/2023] Open
Abstract
The ubiquitous Ca2+ /calmodulin-dependent phosphatase calcineurin is a key regulator of pathological cardiac hypertrophy whose therapeutic targeting in heart disease has been elusive due to its role in other essential biological processes. Calcineurin is targeted to diverse intracellular compartments by association with scaffold proteins, including by multivalent A-kinase anchoring proteins (AKAPs) that bind protein kinase A and other important signalling enzymes determining cardiac myocyte function and phenotype. Calcineurin anchoring by AKAPs confers specificity to calcineurin function in the cardiac myocyte. Targeting of calcineurin 'signalosomes' may provide a rationale for inhibiting the phosphatase in disease.
Collapse
Affiliation(s)
- Moriah Gildart
- Calhoun Center for Cardiology, University of Connecticut Health Center, Farmington, CT, USA
| | - Michael S Kapiloff
- Departments of Ophthalmology and Cardiovascular Medicine, Byers Eye Institute and Spencer Center for Vision Research, Stanford Cardiovascular Institute, Stanford University, Palo Alto, CA, USA
| | - Kimberly L Dodge-Kafka
- Calhoun Center for Cardiology, University of Connecticut Health Center, Farmington, CT, USA
| |
Collapse
|
28
|
Démares F, Coquerel Q, Richoux G, Linthicum K, Bloomquist J. Fatty Acid and Related Potassium Kv2 Channel Blockers: Toxicity and Physiological Actions on Mosquitoes. INSECTS 2018; 9:E155. [PMID: 30388752 PMCID: PMC6315728 DOI: 10.3390/insects9040155] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/27/2018] [Revised: 10/19/2018] [Accepted: 10/30/2018] [Indexed: 11/17/2022]
Abstract
Potassium channels constitute a very diverse group involved in neural signaling, neuronal activity, membrane potential maintenance, and action potential generation. Here, we tested the mammalian potassium channel blockers TRAM-34 and 5-hydroxydecanoate (5-HDC), as well as certain fatty acids (FA) that might fit in the lumen of the pore and block channel activity by obstructing K⁺ ion passage. Kv channel blockers could be leads for a novel pesticide type. Insecticidal activity was assessed by topical application to Anopheles gambiae adult mosquitoes, paralysis in a headless larval assay, at the cellular level with patch-clamp recordings of engineered HEK cells expressing AgKv2.1 channels, as well as central nervous system recordings from larval Drosophila melanogaster. With only one hydroxyl group difference, decanoic acid had a consistently greater effect than 5-HDC in blocking Kv channels, paralyzing larvae, and killing mosquitoes. The 11-dansylamino undecanoic acid (DAUDA) blockage of eukaryotic Kv channels is demonstrated for the first time, but it failed to kill adult mosquitoes. We synthesized alkyl esters from DAUDA and decanoic acid in an effort to improve cuticular penetration, but it had little impact upon adult toxicity. TRAM-34 and rolipram did not show activity on Kv channels nor potent insecticidal effect on adult mosquitoes. Furthermore, co-application of test compounds with permethrin did not increase mortality in adults. In conclusion, the compounds tested had modest insecticidal and synergistic activity.
Collapse
Affiliation(s)
- Fabien Démares
- Neurotoxicology Laboratory, Department of Entomology and Nematology, Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA.
| | - Quentin Coquerel
- Neurotoxicology Laboratory, Department of Entomology and Nematology, Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA.
| | - Gary Richoux
- Neurotoxicology Laboratory, Department of Entomology and Nematology, Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA.
| | - Kenneth Linthicum
- USDA, ARS, Center for Medical, Agricultural and Veterinary Entomology, Gainesville, FL 32608, USA.
| | - Jeffrey Bloomquist
- Neurotoxicology Laboratory, Department of Entomology and Nematology, Emerging Pathogens Institute, University of Florida, Gainesville, FL 32610, USA.
| |
Collapse
|
29
|
Johnstone TB, Agarwal SR, Harvey RD, Ostrom RS. cAMP Signaling Compartmentation: Adenylyl Cyclases as Anchors of Dynamic Signaling Complexes. Mol Pharmacol 2018; 93:270-276. [PMID: 29217670 PMCID: PMC5820540 DOI: 10.1124/mol.117.110825] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 12/04/2017] [Indexed: 11/22/2022] Open
Abstract
It is widely accepted that cAMP signaling is compartmentalized within cells. However, our knowledge of how receptors, cAMP signaling enzymes, effectors, and other key proteins form specific signaling complexes to regulate specific cell responses is limited. The multicomponent nature of these systems and the spatiotemporal dynamics involved as proteins interact and move within a cell make cAMP responses highly complex. Adenylyl cyclases, the enzymatic source of cAMP production, are key starting points for understanding cAMP compartments and defining the functional signaling complexes. Three basic elements are required to form a signaling compartment. First, a localized signal is generated by a G protein-coupled receptor paired to one or more of the nine different transmembrane adenylyl cyclase isoforms that generate the cAMP signal in the cytosol. The diffusion of cAMP is subsequently limited by several factors, including expression of any number of phosphodiesterases (of which there are 24 genes plus spice variants). Finally, signal response elements are differentially localized to respond to cAMP produced within each locale. A-kinase-anchoring proteins, of which there are 43 different isoforms, facilitate this by targeting protein kinase A to specific substrates. Thousands of potential combinations of these three elements are possible in any given cell type, making the characterization of cAMP signaling compartments daunting. This review will focus on what is known about how cells organize cAMP signaling components as well as identify the unknowns. We make an argument for adenylyl cyclases being central to the formation and maintenance of these signaling complexes.
Collapse
Affiliation(s)
- Timothy B Johnstone
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (T.B.J., R.S.O.); and Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno Nevada (S.R.A., R.D.H.)
| | - Shailesh R Agarwal
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (T.B.J., R.S.O.); and Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno Nevada (S.R.A., R.D.H.)
| | - Robert D Harvey
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (T.B.J., R.S.O.); and Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno Nevada (S.R.A., R.D.H.)
| | - Rennolds S Ostrom
- Department of Biomedical and Pharmaceutical Sciences, Chapman University School of Pharmacy, Irvine, California (T.B.J., R.S.O.); and Department of Pharmacology, University of Nevada, Reno School of Medicine, Reno Nevada (S.R.A., R.D.H.)
| |
Collapse
|
30
|
Leroy J, Vandecasteele G, Fischmeister R. Cyclic AMP signaling in cardiac myocytes. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2017.11.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
|
31
|
Fertig BA, Baillie GS. PDE4-Mediated cAMP Signalling. J Cardiovasc Dev Dis 2018; 5:jcdd5010008. [PMID: 29385021 PMCID: PMC5872356 DOI: 10.3390/jcdd5010008] [Citation(s) in RCA: 51] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/18/2018] [Accepted: 01/23/2018] [Indexed: 12/20/2022] Open
Abstract
cAMP is the archetypal and ubiquitous second messenger utilised for the fine control of many cardiovascular cell signalling systems. The ability of cAMP to elicit cell surface receptor-specific responses relies on its compartmentalisation by cAMP hydrolysing enzymes known as phosphodiesterases. One family of these enzymes, PDE4, is particularly important in the cardiovascular system, where it has been extensively studied and shown to orchestrate complex, localised signalling that underpins many crucial functions of the heart. In the cardiac myocyte, cAMP activates PKA, which phosphorylates a small subset of mostly sarcoplasmic substrate proteins that drive β-adrenergic enhancement of cardiac function. The phosphorylation of these substrates, many of which are involved in cardiac excitation-contraction coupling, has been shown to be tightly regulated by highly localised pools of individual PDE4 isoforms. The spatial and temporal regulation of cardiac signalling is made possible by the formation of macromolecular “signalosomes”, which often include a cAMP effector, such as PKA, its substrate, PDE4 and an anchoring protein such as an AKAP. Studies described in the present review highlight the importance of this relationship for individual cardiac PKA substrates and we provide an overview of how this signalling paradigm is coordinated to promote efficient adrenergic enhancement of cardiac function. The role of PDE4 also extends to the vascular endothelium, where it regulates vascular permeability and barrier function. In this distinct location, PDE4 interacts with adherens junctions to regulate their stability. These highly specific, non-redundant roles for PDE4 isoforms have far reaching therapeutic potential. PDE inhibitors in the clinic have been plagued with problems due to the active site-directed nature of the compounds which concomitantly attenuate PDE activity in all highly localised “signalosomes”.
Collapse
|
32
|
Phosphodiesterase Diversity and Signal Processing Within cAMP Signaling Networks. ADVANCES IN NEUROBIOLOGY 2018; 17:3-14. [PMID: 28956327 DOI: 10.1007/978-3-319-58811-7_1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
A large number of neuromodulators activate G-protein coupled receptors (GPCRs) and mediate their cellular actions via the regulation of intracellular cAMP, the small highly diffusible second messenger. In fact, in the same neuron several different GPCRs can regulate cAMP with seemingly identical timecourses that give rise to distinct signaling outcomes, suggesting that cAMP does not have equivalent access to all its downstream effectors and may exist within defined intracellular pools or domains. cAMP compartmentalization is the process that allows the neuron to differentially interpret these various intracellular cAMP signals into cellular response. The molecular mechanisms that give rise to cAMP compartmentalization are not fully understood, but it is thought that phosphodiesterases (PDEs), the enzymes that degrade cAMP, significantly contribute to this process. PDEs, as the sole mechanism of signal termination for cAMP, hold great promise as therapeutic targets for pathologies that are due to the dysregulation of intracellular cAMP signaling. Due to their diverse catalytic activity, regulation and localization each PDE subtype expressed in a given neuron may have a distinct role on downstream signaling.
Collapse
|
33
|
Function of Adenylyl Cyclase in Heart: the AKAP Connection. J Cardiovasc Dev Dis 2018; 5:jcdd5010002. [PMID: 29367580 PMCID: PMC5872350 DOI: 10.3390/jcdd5010002] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Revised: 01/09/2018] [Accepted: 01/11/2018] [Indexed: 12/13/2022] Open
Abstract
Cyclic adenosine monophosphate (cAMP), synthesized by adenylyl cyclase (AC), is a universal second messenger that regulates various aspects of cardiac physiology from contraction rate to the initiation of cardioprotective stress response pathways. Local pools of cAMP are maintained by macromolecular complexes formed by A-kinase anchoring proteins (AKAPs). AKAPs facilitate control by bringing together regulators of the cAMP pathway including G-protein-coupled receptors, ACs, and downstream effectors of cAMP to finely tune signaling. This review will summarize the distinct roles of AC isoforms in cardiac function and how interactions with AKAPs facilitate AC function, highlighting newly appreciated roles for lesser abundant AC isoforms.
Collapse
|
34
|
Wu YS, Chen CC, Chien CL, Lai HL, Jiang ST, Chen YC, Lai LP, Hsiao WF, Chen WP, Chern Y. The type VI adenylyl cyclase protects cardiomyocytes from β-adrenergic stress by a PKA/STAT3-dependent pathway. J Biomed Sci 2017; 24:68. [PMID: 28870220 PMCID: PMC5584049 DOI: 10.1186/s12929-017-0367-3] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2017] [Accepted: 08/11/2017] [Indexed: 01/14/2023] Open
Abstract
BACKGROUND The type VI adenylyl cyclase (AC6) is a main contributor of cAMP production in the heart. The amino acid (aa) sequence of AC6 is highly homologous to that of another major cardiac adenylyl cyclase, AC5, except for its N-terminus (AC6-N, aa 1-86). Activation of AC6, rather than AC5, produces cardioprotective effects against heart failure, while the underlying mechanism remains to be unveiled. Using an AC6-null (AC6-/-) mouse and a knockin mouse with AC6-N deletion (AC6 ΔN/ΔN), we aimed to investigate the cardioprotective mechanism of AC6 in the heart. METHODS Western blot analysis and immunofluorescence staining were performed to determine the intracellular distribution of AC6, AC6-ΔN (a truncated AC6 lacking the first 86 amino acids), and STAT3 activation. Activities of AC6 and AC6-ΔN in the heart were assessed by cAMP assay. Apoptosis of cardiomyocytes were evaluated by the TUNEL assay and a propidium iodine-based survival assay. Fibrosis was examined by collagen staining. RESULTS Immunofluorescence staining revealed that cardiac AC6 was mainly anchored on the sarcolemmal membranes, while AC6-ΔN was redistributed to the sarcoplasmic reticulum. AC6ΔN/ΔN and AC6-/- mice had more apoptotic myocytes and cardiac remodeling than WT mice in experimental models of isoproterenol (ISO)-induced myocardial injury. Adult cardiomyocytes isolated from AC6ΔN/ΔN or AC6-/- mice survived poorly after exposure to ISO, which produced no effect on WT cardiomyocytes under the condition tested. Importantly, ISO treatment induced cardiac STAT3 phosphorylation/activation in WT mice, but not in AC6ΔN/ΔN and AC6-/- mice. Pharmacological blockage of PKA-, Src-, or STAT3- pathway markedly reduced the survival of WT myocytes in the presence of ISO, but did not affect those of AC6ΔN/ΔN and AC6-/- myocytes, suggesting an important role of AC6 in mediating cardioprotective action through the activation of PKA-Src-STAT3-signaling. CONCLUSIONS Collectively, AC6-N controls the anchorage of cardiac AC6 on the sarcolemmal membrane, which enables the coupling of AC6 with the pro-survival PKA-STAT3 pathway. Our findings may facilitate the development of novel therapies for heart failure.
Collapse
Affiliation(s)
- Yu-Shuo Wu
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, 115, Taiwan
| | - Chien-Chang Chen
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, 115, Taiwan
| | - Chen-Li Chien
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan.,Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, 115, Taiwan
| | - Hsing-Lin Lai
- Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, 115, Taiwan
| | - Si-Tse Jiang
- National Laboratory Animal Center, National Applied Research Laboratories, Tainan, Taiwan
| | - Yong-Cyuan Chen
- Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, 115, Taiwan
| | - Lin-Ping Lai
- Institute of Internal Medicine, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Wei-Fan Hsiao
- Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
| | - Wen-Pin Chen
- Institute of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan.
| | - Yijuang Chern
- Graduate Institute of Life Sciences, National Defense Medical Center, Taipei, Taiwan. .,Institute of Biomedical Sciences, Academia Sinica, Nankang, Taipei, 115, Taiwan.
| |
Collapse
|
35
|
Harmer SC, Tinker A. The impact of recent advances in genetics in understanding disease mechanisms underlying the long QT syndromes. Biol Chem 2017; 397:679-93. [PMID: 26910742 DOI: 10.1515/hsz-2015-0306] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 02/18/2016] [Indexed: 11/15/2022]
Abstract
Long QT syndrome refers to a characteristic abnormality of the electrocardiogram and it is associated with a form of ventricular tachycardia known as torsade-de-pointes and sudden arrhythmic death. It can occur as part of a hereditary syndrome or can be acquired usually because of drug administration. Here we review recent genetic, molecular and cellular discoveries and outline how they have furthered our understanding of this disease. Specifically we focus on compound mutations, genome wide association studies of QT interval, modifier genes and the therapeutic implications of this recent work.
Collapse
|
36
|
Motte E, Le Stunff C, Briet C, Dumaz N, Silve C. Modulation of signaling through GPCR-cAMP-PKA pathways by PDE4 depends on stimulus intensity: Possible implications for the pathogenesis of acrodysostosis without hormone resistance. Mol Cell Endocrinol 2017; 442:1-11. [PMID: 27908835 DOI: 10.1016/j.mce.2016.11.026] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/30/2016] [Revised: 11/25/2016] [Accepted: 11/26/2016] [Indexed: 12/30/2022]
Abstract
In acrodysostosis without hormone resistance, a disease caused by phosphodiesterase (PDE)-4D mutations, increased PDE activity leads to bone developmental defects but with normal renal responses to PTH. To identify potential mechanisms for these disparate responses, we compared the effect of PDE activity on hormone signaling through the GPCR-Gsα-cAMP-PKA pathway in cells from two lineages, HEK-293 cells stably overexpressing PTH1R (HEKpthr) and human dermal fibroblasts, including studies evaluating cAMP levels using an Epac-based BRET-sensor for cAMP (CAMYEL). For ligand-induced responses inducing strong cAMP accumulation, the inhibition of PDE4 activity resulted in relatively small further increases. In contrast, when ligand-induced cAMP accumulation was of lesser intensity, the inhibition of PDE4 had a more pronounced effect. Similar results were obtained evaluating downstream events (cellular CREB phosphorylation and CRE-luciferase activity). Thus, the ability of PDE4 to modulate signaling through GPCR-cAMP-PKA pathways can depend on the cell type and stimulus intensity.
Collapse
Affiliation(s)
- Emmanuelle Motte
- INSERM U1169, Université Paris Sud, Hôpital Bicêtre, Le Kremlin Bicêtre, France
| | - Catherine Le Stunff
- INSERM U1169, Université Paris Sud, Hôpital Bicêtre, Le Kremlin Bicêtre, France
| | - Claire Briet
- INSERM U1169, Université Paris Sud, Hôpital Bicêtre, Le Kremlin Bicêtre, France
| | - Nicolas Dumaz
- INSERM U976, Institut de Recherche sur la Peau, Hôpital Saint Louis, Paris, France
| | - Caroline Silve
- INSERM U1169, Université Paris Sud, Hôpital Bicêtre, Le Kremlin Bicêtre, France; Centre de Référence des Maladies Rares du Métabolisme du Phosphore et du Calcium, Assistance Publique Hôpitaux de Paris, Paris, France; Service de Biochimie et Génétique Moléculaires, Assistance Publique Hôpitaux de Paris, Hôpital Cochin, Paris, France.
| |
Collapse
|
37
|
Finlay M, Harmer SC, Tinker A. The control of cardiac ventricular excitability by autonomic pathways. Pharmacol Ther 2017; 174:97-111. [PMID: 28223225 DOI: 10.1016/j.pharmthera.2017.02.023] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Central to the genesis of ventricular cardiac arrhythmia are variations in determinants of excitability. These involve individual ionic channels and transporters in cardiac myocytes but also tissue factors such as variable conduction of the excitation wave, fibrosis and source-sink mismatch. It is also known that in certain diseases and particularly the channelopathies critical events occur with specific stressors. For example, in hereditary long QT syndrome due to mutations in KCNQ1 arrhythmic episodes are provoked by exercise and in particular swimming. Thus not only is the static substrate important but also how this is modified by dynamic signalling events associated with common physiological responses. In this review, we examine the regulation of ventricular excitability by signalling pathways from a cellular and tissue perspective in an effort to identify key processes, effectors and potential therapeutic approaches. We specifically focus on the autonomic nervous system and related signalling pathways.
Collapse
Affiliation(s)
- Malcolm Finlay
- The Heart Centre, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Charterhouse Square, London EC1M6BQ, UK
| | - Stephen C Harmer
- The Heart Centre, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Charterhouse Square, London EC1M6BQ, UK
| | - Andrew Tinker
- The Heart Centre, William Harvey Research Institute, Barts and the London School of Medicine and Dentistry, Charterhouse Square, London EC1M6BQ, UK.
| |
Collapse
|
38
|
Bedioune I, Bobin P, Leroy J, Fischmeister R, Vandecasteele G. Cyclic Nucleotide Phosphodiesterases and Compartmentation in Normal and Diseased Heart. MICRODOMAINS IN THE CARDIOVASCULAR SYSTEM 2017. [DOI: 10.1007/978-3-319-54579-0_6] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
|
39
|
Subcellular Targeting of PDE4 in Cardiac Myocytes and Generation of Signaling Compartments. MICRODOMAINS IN THE CARDIOVASCULAR SYSTEM 2017. [DOI: 10.1007/978-3-319-54579-0_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
40
|
Bohnen MS, Peng G, Robey SH, Terrenoire C, Iyer V, Sampson KJ, Kass RS. Molecular Pathophysiology of Congenital Long QT Syndrome. Physiol Rev 2017; 97:89-134. [PMID: 27807201 PMCID: PMC5539372 DOI: 10.1152/physrev.00008.2016] [Citation(s) in RCA: 114] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Ion channels represent the molecular entities that give rise to the cardiac action potential, the fundamental cellular electrical event in the heart. The concerted function of these channels leads to normal cyclical excitation and resultant contraction of cardiac muscle. Research into cardiac ion channel regulation and mutations that underlie disease pathogenesis has greatly enhanced our knowledge of the causes and clinical management of cardiac arrhythmia. Here we review the molecular determinants, pathogenesis, and pharmacology of congenital Long QT Syndrome. We examine mechanisms of dysfunction associated with three critical cardiac currents that comprise the majority of congenital Long QT Syndrome cases: 1) IKs, the slow delayed rectifier current; 2) IKr, the rapid delayed rectifier current; and 3) INa, the voltage-dependent sodium current. Less common subtypes of congenital Long QT Syndrome affect other cardiac ionic currents that contribute to the dynamic nature of cardiac electrophysiology. Through the study of mutations that cause congenital Long QT Syndrome, the scientific community has advanced understanding of ion channel structure-function relationships, physiology, and pharmacological response to clinically employed and experimental pharmacological agents. Our understanding of congenital Long QT Syndrome continues to evolve rapidly and with great benefits: genotype-driven clinical management of the disease has improved patient care as precision medicine becomes even more a reality.
Collapse
Affiliation(s)
- M S Bohnen
- Department of Pharmacology, Columbia University Medical Center, New York, New York; and The New York Stem Cell Foundation Research Institute, New York, New York
| | - G Peng
- Department of Pharmacology, Columbia University Medical Center, New York, New York; and The New York Stem Cell Foundation Research Institute, New York, New York
| | - S H Robey
- Department of Pharmacology, Columbia University Medical Center, New York, New York; and The New York Stem Cell Foundation Research Institute, New York, New York
| | - C Terrenoire
- Department of Pharmacology, Columbia University Medical Center, New York, New York; and The New York Stem Cell Foundation Research Institute, New York, New York
| | - V Iyer
- Department of Pharmacology, Columbia University Medical Center, New York, New York; and The New York Stem Cell Foundation Research Institute, New York, New York
| | - K J Sampson
- Department of Pharmacology, Columbia University Medical Center, New York, New York; and The New York Stem Cell Foundation Research Institute, New York, New York
| | - R S Kass
- Department of Pharmacology, Columbia University Medical Center, New York, New York; and The New York Stem Cell Foundation Research Institute, New York, New York
| |
Collapse
|
41
|
Bobin P, Belacel-Ouari M, Bedioune I, Zhang L, Leroy J, Leblais V, Fischmeister R, Vandecasteele G. Cyclic nucleotide phosphodiesterases in heart and vessels: A therapeutic perspective. Arch Cardiovasc Dis 2016; 109:431-43. [PMID: 27184830 DOI: 10.1016/j.acvd.2016.02.004] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/03/2015] [Revised: 01/28/2016] [Accepted: 02/02/2016] [Indexed: 01/21/2023]
Abstract
Cyclic nucleotide phosphodiesterases (PDEs) degrade the second messengers cyclic adenosine monophosphate (cAMP) and cyclic guanosine monophosphate (cGMP), thereby regulating multiple aspects of cardiac and vascular muscle functions. This highly diverse class of enzymes encoded by 21 genes encompasses 11 families that are not only responsible for the termination of cyclic nucleotide signalling, but are also involved in the generation of dynamic microdomains of cAMP and cGMP, controlling specific cell functions in response to various neurohormonal stimuli. In the myocardium and vascular smooth muscle, the PDE3 and PDE4 families predominate, degrading cAMP and thereby regulating cardiac excitation-contraction coupling and smooth muscle contractile tone. PDE3 inhibitors are positive inotropes and vasodilators in humans, but their use is limited to acute heart failure and intermittent claudication. PDE5 is particularly important for the degradation of cGMP in vascular smooth muscle, and PDE5 inhibitors are used to treat erectile dysfunction and pulmonary hypertension. There is experimental evidence that these PDEs, as well as other PDE families, including PDE1, PDE2 and PDE9, may play important roles in cardiac diseases, such as hypertrophy and heart failure, as well as several vascular diseases. After a brief presentation of the cyclic nucleotide pathways in cardiac and vascular cells, and the major characteristics of the PDE superfamily, this review will focus on the current use of PDE inhibitors in cardiovascular diseases, and the recent research developments that could lead to better exploitation of the therapeutic potential of these enzymes in the future.
Collapse
Affiliation(s)
- Pierre Bobin
- UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Milia Belacel-Ouari
- UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Ibrahim Bedioune
- UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Liang Zhang
- UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Jérôme Leroy
- UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Véronique Leblais
- UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France
| | - Rodolphe Fischmeister
- UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France.
| | - Grégoire Vandecasteele
- UMR-S 1180, INSERM, Université Paris-Sud, Université Paris-Saclay, Châtenay-Malabry, France.
| |
Collapse
|
42
|
Abstract
Cardiac delayed rectifier potassium channels conduct outward potassium currents during the plateau phase of action potentials and play pivotal roles in cardiac repolarization. These include IKs, IKr and the atrial specific IKur channels. In this article, we will review their molecular identities and biophysical properties. Mutations in the genes encoding delayed rectifiers lead to loss- or gain-of-function phenotypes, disrupt normal cardiac repolarization and result in various cardiac rhythm disorders, including congenital Long QT Syndrome, Short QT Syndrome and familial atrial fibrillation. We will also discuss the prospect of using delayed rectifier channels as therapeutic targets to manage cardiac arrhythmia.
Collapse
Affiliation(s)
- Lei Chen
- Department of Pharmacology, College of Physicians & Surgeons of Columbia University, 630 West 168th Street, New York, NY 10032, USA
| | - Kevin J Sampson
- Department of Pharmacology, College of Physicians & Surgeons of Columbia University, 630 West 168th Street, New York, NY 10032, USA
| | - Robert S Kass
- Department of Pharmacology, College of Physicians & Surgeons of Columbia University, 630 West 168th Street, New York, NY 10032, USA.
| |
Collapse
|
43
|
Tomson TT, Arora R. Modulation of Cardiac Potassium Current by Neural Tone and Ischemia. Card Electrophysiol Clin 2016; 8:349-60. [PMID: 27261826 DOI: 10.1016/j.ccep.2016.01.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The cardiac action potential is generated by intricate flows of ions across myocyte cell membranes in a coordinated fashion to control myocardial contraction and the heart rhythm. Modulation of the flow of these ions in response to a variety of stimuli results in changes to the action potential. Abnormal or altered ion currents can result in cardiac arrhythmias. Abnormalities of autonomic regulation of potassium current play a role in the genesis of cardiac arrhythmias, and alterations in acetylcholine-activated potassium channels may play a key role in atrial fibrillation. Ischemia is another important modulator of cardiac cellular electrophysiology.
Collapse
Affiliation(s)
- Todd T Tomson
- Bluhm Cardiovascular Institute, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Rishi Arora
- Bluhm Cardiovascular Institute, Northwestern University Feinberg School of Medicine, Chicago, IL, USA.
| |
Collapse
|
44
|
Zhang Y, Chu X, Liu L, Zhang N, Guo H, Yang F, Liu Z, Dong Y, Bao Y, Zhang X, Zhang J. Tannic acid activates the Kv7.4 and Kv7.3/7.5 K+ channels expressed in HEK293 cells and reduces tension in the rat mesenteric arteries. J Pharm Pharmacol 2016; 68:494-502. [PMID: 26969140 DOI: 10.1111/jphp.12527] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2015] [Accepted: 01/14/2016] [Indexed: 12/13/2022]
Abstract
Abstract
Objectives
This study investigated the effect of tannic acid (TA), a plant-derived hydrolyzable polyphenol, on Kv7.4 and Kv7.5 K+ channels and rat mesenteric artery.
Methods
Whole-cell patch clamp experiments were used to record the Kv7.4 and Kv7.3/7.5 K+ currents expressed in HEK293 cells; and the tension changes of mesenteric arteries isolated from rats were recorded using small vessel myography apparatus.
Key findings
Tannic acid increases the Kv7.4 and Kv7.3/7.5 K+ currents in a concentration-dependent manner (median effective concentration (EC50) = 27.3 ± 3.6 μm and EC50 = 23.1 ± 3.9 μm, respectively). In addition, 30 μm TA shifts the G–V curve of Kv7.4 and Kv7.3/7.5 K+ currents to the left by 14.18 and 25.24 mV, respectively, and prolongs the deactivation time constants by 184.44 and 154.77 ms, respectively. Moreover, TA relaxes the vascular tension of rat mesenteric arteries in a concentration-dependent manner (half inhibitory concentration (IC50) = 148.7 ± 13.4 μm).
Conclusion
These results confirms the vasodilatory effects of TA on rat mesenteric artery and the activating effects on the Kv7.4 and Kv7.3/7.5 K+ channels, which may be a mechanism to explain the vasodilatory effect and this mechanism can be used in the research of antihypertension.
Collapse
Affiliation(s)
- Yuanyuan Zhang
- Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China
| | - Xi Chu
- Department of Pharmacy, The Fourth Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Ling Liu
- Department of Pharmacy, Maternal and Child Health Hospital, Tangshan, Hebei, China
| | - Nan Zhang
- Vascular Surgery, The East Branch of Second Hospital of Hebei Medical University, Shijiazhuang, Hebei, China
| | - Hui Guo
- Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China
| | - Fan Yang
- Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China
| | - Zhenyi Liu
- Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China
| | - Yongsheng Dong
- Intensive Care Unit, Air Force General Hospital, Beijing, Jiangsu, China
| | - Yifan Bao
- Key Laboratory of Drug Metabolism & Pharmacokinetics, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Xuan Zhang
- Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China
| | - Jianping Zhang
- Department of Pharmacology, Hebei University of Chinese Medicine, Shijiazhuang, Hebei, China
| |
Collapse
|
45
|
New pharmacologic interventions to increase cardiac contractility: challenges and opportunities. Curr Opin Cardiol 2015; 30:285-91. [PMID: 25807221 DOI: 10.1097/hco.0000000000000165] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
PURPOSE OF REVIEW The most extensively studied inotropic agents in patients with heart failure are phosphodiesterase (PDE) 3 inhibitors, which increase contractility by raising intracellular cyclic adenosine monophosphate content. In clinical trials, the inotropic benefits of these agents have been outweighed by an increase in sudden cardiac death. Here, I review recent findings that help explain what are likely to be distinct mechanisms involved in the beneficial and adverse effects of PDE3 inhibition. RECENT FINDINGS The proapoptotic consequences of PDE3 inhibition are becoming more apparent. Moreover, it has also become clear that individual PDE3 isoforms in cardiac myocytes are selectively regulated to interact with different proteins in different intracellular compartments. The beneficial and adverse effects of PDE3 inhibition may thus be attributable to the inhibition of different isoforms in different intracellular domains. In particular, PDE3A1 has been shown to interact directly with sarcoplasmic/endoplasmic reticulum Ca ATPase (SERCA2) in the sarcoplasmic reticulum through a phosphorylation of a site in its unique N-terminal domain, making it possible that this isoform can be selectively targeted to increase intracellular Ca cycling. SUMMARY Conventional PDE3 inhibitors target several functionally distinct isoforms of these enzymes. Isoform-selective and/or compartment-selective targeting of PDE3, through its protein-protein interactions, may produce the inotropic benefits of PDE3 inhibition without the adverse consequences.
Collapse
|
46
|
Weber S, Meyer-Roxlau S, Wagner M, Dobrev D, El-Armouche A. Counteracting Protein Kinase Activity in the Heart: The Multiple Roles of Protein Phosphatases. Front Pharmacol 2015; 6:270. [PMID: 26617522 PMCID: PMC4643138 DOI: 10.3389/fphar.2015.00270] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Accepted: 10/28/2015] [Indexed: 12/19/2022] Open
Abstract
Decades of cardiovascular research have shown that variable and flexible levels of protein phosphorylation are necessary to maintain cardiac function. A delicate balance between phosphorylated and dephosphorylated states of proteins is guaranteed by a complex interplay of protein kinases (PKs) and phosphatases. Serine/threonine phosphatases, in particular members of the protein phosphatase (PP) family govern dephosphorylation of the majority of these cardiac proteins. Recent findings have however shown that PPs do not only dephosphorylate previously phosphorylated proteins as a passive control mechanism but are capable to actively control PK activity via different direct and indirect signaling pathways. These control mechanisms can take place on (epi-)genetic, (post-)transcriptional, and (post-)translational levels. In addition PPs themselves are targets of a plethora of proteinaceous interaction partner regulating their endogenous activity, thus adding another level of complexity and feedback control toward this system. Finally, novel approaches are underway to achieve spatiotemporal pharmacologic control of PPs which in turn can be used to fine-tune misleaded PK activity in heart disease. Taken together, this review comprehensively summarizes the major aspects of PP-mediated PK regulation and discusses the subsequent consequences of deregulated PP activity for cardiovascular diseases in depth.
Collapse
Affiliation(s)
- Silvio Weber
- Department of Pharmacology and Toxicology, Dresden University of Technology , Dresden, Germany
| | - Stefanie Meyer-Roxlau
- Department of Pharmacology and Toxicology, Dresden University of Technology , Dresden, Germany
| | - Michael Wagner
- Department of Pharmacology and Toxicology, Dresden University of Technology , Dresden, Germany
| | - Dobromir Dobrev
- Institute of Pharmacology, Faculty of Medicine, West German Heart and Vascular Center , Essen, Germany
| | - Ali El-Armouche
- Department of Pharmacology and Toxicology, Dresden University of Technology , Dresden, Germany
| |
Collapse
|
47
|
Abbott GW. KCNE1 and KCNE3: The yin and yang of voltage-gated K(+) channel regulation. Gene 2015; 576:1-13. [PMID: 26410412 DOI: 10.1016/j.gene.2015.09.059] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2015] [Revised: 09/03/2015] [Accepted: 09/22/2015] [Indexed: 12/20/2022]
Abstract
The human KCNE gene family comprises five genes encoding single transmembrane-spanning ion channel regulatory subunits. The primary function of KCNE subunits appears to be regulation of voltage-gated potassium (Kv) channels, and the best-understood KCNE complexes are with the KCNQ1 Kv α subunit. Here, we review the often opposite effects of KCNE1 and KCNE3 on Kv channel biology, with an emphasis on regulation of KCNQ1. Slow-activating IKs channel complexes formed by KCNQ1 and KCNE1 are essential for human ventricular myocyte repolarization, while constitutively active KCNQ1-KCNE3 channels are important in the intestine. Inherited sequence variants in human KCNE1 and KCNE3 cause cardiac arrhythmias but by different mechanisms, and each is important for hearing in unique ways. Because of their contrasting effects on KCNQ1 function, KCNE1 and KCNE3 have proved invaluable tools in the mechanistic understanding of how channel gating can be manipulated, and each may also provide a window into novel insights and new therapeutic opportunities in K(+) channel pharmacology. Finally, findings from studies of Kcne1(-/-) and Kcne3(-/-) mouse lines serve to illustrate the complexity of KCNE biology and KCNE-linked disease states.
Collapse
Affiliation(s)
- Geoffrey W Abbott
- Bioelectricity Laboratory, Dept. of Pharmacology and Dept. of Physiology and Biophysics, School of Medicine, University of California, Irvine, CA, USA; 360 Medical Surge II, Dept. of Pharmacology, School of Medicine, University of California, Irvine, CA 92697, USA.
| |
Collapse
|
48
|
Dema A, Perets E, Schulz MS, Deák VA, Klussmann E. Pharmacological targeting of AKAP-directed compartmentalized cAMP signalling. Cell Signal 2015; 27:2474-87. [PMID: 26386412 DOI: 10.1016/j.cellsig.2015.09.008] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 09/08/2015] [Accepted: 09/14/2015] [Indexed: 01/26/2023]
Abstract
The second messenger cyclic adenosine monophosphate (cAMP) can bind and activate protein kinase A (PKA). The cAMP/PKA system is ubiquitous and involved in a wide array of biological processes and therefore requires tight spatial and temporal regulation. Important components of the safeguard system are the A-kinase anchoring proteins (AKAPs), a heterogeneous family of scaffolding proteins defined by its ability to directly bind PKA. AKAPs tether PKA to specific subcellular compartments, and they bind further interaction partners to create local signalling hubs. The recent discovery of new AKAPs and advances in the field that shed light on the relevance of these hubs for human disease highlight unique opportunities for pharmacological modulation. This review exemplifies how interference with signalling, particularly cAMP signalling, at such hubs can reshape signalling responses and discusses how this could lead to novel pharmacological concepts for the treatment of disease with an unmet medical need such as cardiovascular disease and cancer.
Collapse
Affiliation(s)
- Alessandro Dema
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Ekaterina Perets
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Maike Svenja Schulz
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Veronika Anita Deák
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Enno Klussmann
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany; DZHK, German Centre for Cardiovascular Research, Oudenarder Straße 16, 13347 Berlin, Germany.
| |
Collapse
|
49
|
Choudhary I, Lee H, Pyo MJ, Heo Y, Bae SK, Kwon YC, Yoon WD, Kang C, Kim E. Proteomics approach to examine the cardiotoxic effects of Nemopilema nomurai Jellyfish venom. J Proteomics 2015; 128:123-31. [PMID: 26193491 DOI: 10.1016/j.jprot.2015.07.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2015] [Revised: 07/07/2015] [Accepted: 07/13/2015] [Indexed: 01/19/2023]
Abstract
UNLABELLED Nemopilema nomurai is one of the largest species of jellyfish in the world. It blooms mainly offshore of Korea, China, and Japan. Increasing population numbers of N. nomurai is increasing the risk of sea bathers to the jellyfish stings and accompanying envenomations. Cardiovascular effects, and cytotoxicity and hemolytic activities have been previously reported in rodent models. To understand the mechanism of cardiac toxicity, we examined the effect of N. nomurai jellyfish venom (NnV) at the proteome level on rat cardiomyocytes cell line H9c2 using two-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF/MS). Cells treated with NnV displayed dose-dependent inhibition of viability. Cellular changes at proteome level were investigated after 6h and 12h of venom treatment. Electrophoretic examination revealed 72 protein spots displaying significant quantitative changes. These proteins were analyzed by MALDI-TOF/MS. Thirty four differentially expressed proteins were successfully identified; 24 proteins increased in quantity and 10 proteins decreased, compared to the respective controls. Proteins altered in content in Western blot analyses included myosin VII, annexin A2, aldose reductase, suppressor of cytokine signaling 1 (SOCS1), and calumenin, which are well-known marker proteins of cardiac dysfunctions. BIOLOGICAL SIGNIFICANCE This is the first report revealing the cardiac toxicity of NnV at the proteome level. NnV directly targeted proteins involved in cardiac dysfunction or maintenance. Suppressor of cytokine signaling 1 (SOCS1), which inhibits the Janus kinase/signal transducers and activators of transcription (JAK/STAT) pathway, was upregulated by NnV. Other proteins related to cardiac arrest that were over-expressed included aldose reductase and calumenin. These results clarify the underlying mechanism of cardiomyocyte damage caused by NnV. By inhibiting these particular targets and more precisely identifying the components of NnV-mediated cardiac toxicity, jellyfish venom-associated poisoning could be reduced or prevented.
Collapse
Affiliation(s)
- Indu Choudhary
- College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - Hyunkyoung Lee
- College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - Min-Jung Pyo
- College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - Yunwi Heo
- College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - Seong Kyeong Bae
- College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - Young Chul Kwon
- College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea
| | - Won Duk Yoon
- Headquarters for Marine Environment, National Fisheries Research & Development Institute, Shiran-ri, Gijang-eup, Gijang-gun, Busan 619-705, Republic of Korea
| | - Changkeun Kang
- College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea; Institutes of Agriculture and Life Science, Gyeongsang National University, Jinju, Republic of Korea
| | - Euikyung Kim
- College of Veterinary Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea; Institute of Animal Medicine, Gyeongsang National University, Jinju 660-701, Republic of Korea.
| |
Collapse
|
50
|
Soni S, Scholten A, Vos MA, van Veen TAB. Anchored protein kinase A signalling in cardiac cellular electrophysiology. J Cell Mol Med 2014; 18:2135-46. [PMID: 25216213 PMCID: PMC4224547 DOI: 10.1111/jcmm.12365] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2013] [Accepted: 06/10/2014] [Indexed: 01/13/2023] Open
Abstract
The cyclic adenosine monophosphate (cAMP)-dependent protein kinase (PKA) is an elementary molecule involved in both acute and chronic modulation of cardiac function. Substantial research in recent years has highlighted the importance of A-kinase anchoring proteins (AKAP) therein as they act as the backbones of major macromolecular signalling complexes of the β-adrenergic/cAMP/PKA pathway. This review discusses the role of AKAP-associated protein complexes in acute and chronic cardiac modulation by dissecting their role in altering the activity of different ion channels, which underlie cardiac action potential (AP) generation. In addition, we review the involvement of different AKAP complexes in mechanisms of cardiac remodelling and arrhythmias.
Collapse
Affiliation(s)
- Siddarth Soni
- Division of Heart & Lungs, Dept of Medical Physiology, University Medical Centre Utrecht, Utrecht, The Netherlands; Biomolecular Mass Spectrometry & Proteomics, Utrecht Institute for Pharmaceutical Sciences and Bijvoet Center for Biomolecular Research, Utrecht University, Utrecht, The Netherlands
| | | | | | | |
Collapse
|