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Olson AC, Butt AM, Christie NTM, Shelar A, Koelle MR. Multiple Subthreshold GPCR Signals Combined by the G-Proteins Gα q and Gα s Activate the Caenorhabditis elegans Egg-Laying Muscles. J Neurosci 2023; 43:3789-3806. [PMID: 37055179 PMCID: PMC10219013 DOI: 10.1523/jneurosci.2301-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 03/21/2023] [Accepted: 04/07/2023] [Indexed: 04/15/2023] Open
Abstract
Individual neurons or muscle cells express many G-protein-coupled receptors (GPCRs) for neurotransmitters and neuropeptides, yet it remains unclear how cells integrate multiple GPCR signals that all must activate the same few G-proteins. We analyzed this issue in the Caenorhabditis elegans egg-laying system, where multiple GPCRs on muscle cells promote contraction and egg laying. We genetically manipulated individual GPCRs and G-proteins specifically in these muscle cells within intact animals and then measured egg laying and muscle calcium activity. Two serotonin GPCRs on the muscle cells, Gαq-coupled SER-1 and Gαs-coupled SER-7, together promote egg laying in response to serotonin. We found that signals produced by either SER-1/Gαq or SER-7/Gαs alone have little effect, but these two subthreshold signals combine to activate egg laying. We then transgenically expressed natural or designer GPCRs in the muscle cells and found that their subthreshold signals can also combine to induce muscle activity. However, artificially inducing strong signaling through just one of these GPCRs can be sufficient to induce egg laying. Knocking down Gαq and Gαs in the egg-laying muscle cells induced egg-laying defects that were stronger than those of a SER-1/SER-7 double knockout, indicating that additional endogenous GPCRs also activate the muscle cells. These results show that in the egg-laying muscles multiple GPCRs for serotonin and other signals each produce weak effects that individually do not result in strong behavioral outcomes. However, they combine to produce sufficient levels of Gαq and Gαs signaling to promote muscle activity and egg laying.SIGNIFICANCE STATEMENT How can neurons and other cells gather multiple independent pieces of information from the soup of chemical signals in their environment and compute an appropriate response? Most cells express >20 GPCRs that each receive one signal and transmit that information through three main types of G-proteins. We analyzed how this machinery generates responses by studying the egg-laying system of C. elegans, where serotonin and multiple other signals act through GPCRs on the egg-laying muscles to promote muscle activity and egg laying. We found that individual GPCRs within an intact animal each generate effects too weak to activate egg laying. However, combined signaling from multiple GPCR types reaches a threshold capable of activating the muscle cells.
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Affiliation(s)
- Andrew C Olson
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| | - Allison M Butt
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| | - Nakeirah T M Christie
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| | - Ashish Shelar
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
| | - Michael R Koelle
- Department of Molecular Biophysics and Biochemistry, Yale University, New Haven, Connecticut 06510
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2
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Gao F, Liang T, Lu YW, Fu X, Dong X, Pu L, Hong T, Zhou Y, Zhang Y, Liu N, Zhang F, Liu J, Malizia AP, Yu H, Zhu W, Cowan DB, Chen H, Hu X, Mably JD, Wang J, Wang DZ, Chen J. A defect in mitochondrial protein translation influences mitonuclear communication in the heart. Nat Commun 2023; 14:1595. [PMID: 36949106 PMCID: PMC10033703 DOI: 10.1038/s41467-023-37291-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2022] [Accepted: 03/10/2023] [Indexed: 03/24/2023] Open
Abstract
The regulation of the informational flow from the mitochondria to the nucleus (mitonuclear communication) is not fully characterized in the heart. We have determined that mitochondrial ribosomal protein S5 (MRPS5/uS5m) can regulate cardiac function and key pathways to coordinate this process during cardiac stress. We demonstrate that loss of Mrps5 in the developing heart leads to cardiac defects and embryonic lethality while postnatal loss induces cardiac hypertrophy and heart failure. The structure and function of mitochondria is disrupted in Mrps5 mutant cardiomyocytes, impairing mitochondrial protein translation and OXPHOS. We identify Klf15 as a Mrps5 downstream target and demonstrate that exogenous Klf15 is able to rescue the overt defects and re-balance the cardiac metabolome. We further show that Mrps5 represses Klf15 expression through c-myc, together with the metabolite L-phenylalanine. This critical role for Mrps5 in cardiac metabolism and mitonuclear communication highlights its potential as a target for heart failure therapies.
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Affiliation(s)
- Feng Gao
- Department of Cardiology, Provincial Key Lab of Cardiovascular Research, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310029, China
| | - Tian Liang
- Department of Cardiology, Provincial Key Lab of Cardiovascular Research, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310029, China
| | - Yao Wei Lu
- Department of Cardiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA, 02115, USA
- Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Xuyang Fu
- Department of Cardiology, Provincial Key Lab of Cardiovascular Research, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310029, China
| | - Xiaoxuan Dong
- Department of Cardiology, Provincial Key Lab of Cardiovascular Research, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310029, China
| | - Linbin Pu
- Department of Cardiology, Provincial Key Lab of Cardiovascular Research, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310029, China
| | - Tingting Hong
- Department of Cardiology, Provincial Key Lab of Cardiovascular Research, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
| | - Yuxia Zhou
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310029, China
| | - Yu Zhang
- Department of Clinical Pharmacy, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310003, China
| | - Ning Liu
- Department of Cardiology, Provincial Key Lab of Cardiovascular Research, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310029, China
| | - Feng Zhang
- Department of Cardiology, Provincial Key Lab of Cardiovascular Research, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310029, China
| | - Jianming Liu
- Department of Cardiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA, 02115, USA
- Vertex pharmaceuticals, VCGT, 316-318 Northern Ave, Boston, MA, 02210, USA
| | - Andrea P Malizia
- Department of Cardiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Hong Yu
- Department of Cardiology, Provincial Key Lab of Cardiovascular Research, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
| | - Wei Zhu
- Department of Cardiology, Provincial Key Lab of Cardiovascular Research, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
| | - Douglas B Cowan
- Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Hong Chen
- Vascular Biology Program, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA, 02115, USA
| | - Xinyang Hu
- Department of Cardiology, Provincial Key Lab of Cardiovascular Research, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China
| | - John D Mably
- Center for Regenerative Medicine, University of South Florida Health Heart Institute, Morsani School of Medicine, University of South Florida, Tampa, FL, 33602, USA
| | - Jian'an Wang
- Department of Cardiology, Provincial Key Lab of Cardiovascular Research, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China.
| | - Da-Zhi Wang
- Department of Cardiology, Boston Children's Hospital, Harvard Medical School, 300 Longwood Avenue, Boston, MA, 02115, USA.
- Center for Regenerative Medicine, University of South Florida Health Heart Institute, Morsani School of Medicine, University of South Florida, Tampa, FL, 33602, USA.
| | - Jinghai Chen
- Department of Cardiology, Provincial Key Lab of Cardiovascular Research, Second Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou, 310009, China.
- Institute of Translational Medicine, Zhejiang University School of Medicine, Hangzhou, 310029, China.
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3
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Perez DM. α 1-Adrenergic Receptors: Insights into Potential Therapeutic Opportunities for COVID-19, Heart Failure, and Alzheimer's Disease. Int J Mol Sci 2023; 24:4188. [PMID: 36835598 PMCID: PMC9963459 DOI: 10.3390/ijms24044188] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 02/06/2023] [Accepted: 02/08/2023] [Indexed: 02/22/2023] Open
Abstract
α1-Adrenergic receptors (ARs) are members of the G-Protein Coupled Receptor superfamily and with other related receptors (β and α2), they are involved in regulating the sympathetic nervous system through binding and activation by norepinephrine and epinephrine. Traditionally, α1-AR antagonists were first used as anti-hypertensives, as α1-AR activation increases vasoconstriction, but they are not a first-line use at present. The current usage of α1-AR antagonists increases urinary flow in benign prostatic hyperplasia. α1-AR agonists are used in septic shock, but the increased blood pressure response limits use for other conditions. However, with the advent of genetic-based animal models of the subtypes, drug design of highly selective ligands, scientists have discovered potentially newer uses for both agonists and antagonists of the α1-AR. In this review, we highlight newer treatment potential for α1A-AR agonists (heart failure, ischemia, and Alzheimer's disease) and non-selective α1-AR antagonists (COVID-19/SARS, Parkinson's disease, and posttraumatic stress disorder). While the studies reviewed here are still preclinical in cell lines and rodent disease models or have undergone initial clinical trials, potential therapeutics discussed here should not be used for non-approved conditions.
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Affiliation(s)
- Dianne M Perez
- The Lerner Research Institute, The Cleveland Clinic Foundation, 9500 Euclid Ave, Cleveland, OH 44195, USA
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4
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Kim JD, Kwon C, Nakamura K, Muromachi N, Mori H, Muroi SI, Yamada Y, Saito H, Nakagawa Y, Fukamizu A. Increased angiotensin II coupled with decreased Adra1a expression enhances cardiac hypertrophy in pregnancy-associated hypertensive mice. J Biol Chem 2023; 299:102964. [PMID: 36736425 PMCID: PMC10011504 DOI: 10.1016/j.jbc.2023.102964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 12/27/2022] [Accepted: 01/26/2023] [Indexed: 02/05/2023] Open
Abstract
Cardiac hypertrophy is a crucial risk factor for hypertensive disorders during pregnancy, but its progression during pregnancy remains unclear. We previously showed cardiac hypertrophy in a pregnancy-associated hypertensive (PAH) mouse model, in which an increase in angiotensin II (Ang II) levels was induced by human renin and human angiotensinogen, depending on pregnancy conditions. Here, to elucidate the factors involved in the progression of cardiac hypertrophy, we performed a comprehensive analysis of changes in gene expression in the hearts of PAH mice and compared them with those in control mice. We found that alpha-1A adrenergic receptor (Adra1a) mRNA levels in the heart were significantly reduced under PAH conditions, whereas the renin-angiotensin system was upregulated. Furthermore, we found that Adra1a-deficient PAH mice exhibited more severe cardiac hypertrophy than PAH mice. Our study suggests that Adra1a levels are regulated by renin-angiotensin system and that changes in Adra1a expression are involved in progressive cardiac hypertrophy in PAH mice.
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Affiliation(s)
- Jun-Dal Kim
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki, Japan; Division of Complex Bioscience Research, Department of Research and Development, Institute of National Medicine, University of Toyama, Toyama, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo, Japan.
| | - Chulwon Kwon
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Kanako Nakamura
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki, Japan; Graduate School of Sciences and Technology, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Naoto Muromachi
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki, Japan; Doctoral Program in Life and Agricultural Sciences, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Haruka Mori
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki, Japan; Graduate School of Sciences and Technology, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Shin-Ichi Muroi
- Division of Complex Bioscience Research, Department of Research and Development, Institute of National Medicine, University of Toyama, Toyama, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo, Japan
| | - Yasunari Yamada
- Division of Complex Bioscience Research, Department of Research and Development, Institute of National Medicine, University of Toyama, Toyama, Japan
| | - Hodaka Saito
- Division of Complex Bioscience Research, Department of Research and Development, Institute of National Medicine, University of Toyama, Toyama, Japan
| | - Yoshimi Nakagawa
- Division of Complex Bioscience Research, Department of Research and Development, Institute of National Medicine, University of Toyama, Toyama, Japan
| | - Akiyoshi Fukamizu
- Life Science Center for Survival Dynamics, Tsukuba Advanced Research Alliance, University of Tsukuba, Tsukuba, Ibaraki, Japan; AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo, Japan; International Institute for Integrative Sleep Medicine (WPI-IIIS), University of Tsukuba, Tsukuba, Ibaraki, Japan.
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5
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Lustyk K, Sałaciak K, Siwek A, Sapa J, Zaręba P, Gałuszka A, Pytka K. The Antiarrhythmic and Hypotensive Effects of S-61 and S-73, the Pyrrolidin-2-one Derivatives with α1-Adrenolytic Properties. Int J Mol Sci 2022; 23:10381. [PMID: 36142287 PMCID: PMC9499458 DOI: 10.3390/ijms231810381] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2022] [Revised: 08/31/2022] [Accepted: 09/02/2022] [Indexed: 12/02/2022] Open
Abstract
Heart rhythm abnormalities are a cause of many deaths worldwide. Unfortunately, the available antiarrhythmic drugs show limited efficacy and proarrhythmic potential. Thus, efforts should be made to search for new, more effective, and safer pharmacotherapies. Several studies suggested that blocking the α1-adrenoceptors could restore normal heart rhythm in arrhythmia. In this study, we aimed to assess the antiarrhythmic potential of S-61 and S-73, two novel pyrrolidin-2-one derivatives with high affinity for α1-adrenergic receptors. First, using radioligand binding studies, we demonstrated that S-61 and S-73 did not bind with β1-adrenoceptors. Next, we assessed whether S-61 and S-73 could protect rats against arrhythmia in adrenaline-, calcium chloride- and aconitine-induced arrhythmia models. Both compounds showed potent prophylactic antiarrhythmic properties in the adrenaline-induced arrhythmia model, but the effect of S-61 was more pronounced. None of the compounds displayed antiarrhythmic effects in calcium chloride- or aconitine-induced arrhythmia models. Interestingly, both derivatives revealed therapeutic antiarrhythmic activity in the adrenaline-induced arrhythmia, diminishing heart rhythm irregularities. Neither S-61 nor S-73 showed proarrhythmic potential in rats. Finally, the compounds decreased blood pressure in rodents. The hypotensive effects were not observed after coadministration with methoxamine, which suggests the α1-adrenolytic properties of both compounds. Our results confirm that pyrrolidin-2-one derivatives possess potent antiarrhythmic properties. Given the promising results of our experiments, further studies on pyrrolidin-2-one derivatives might result in the development of a new class of antiarrhythmic drugs.
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6
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Sandroni PB, Fisher-Wellman KH, Jensen BC. Adrenergic Receptor Regulation of Mitochondrial Function in Cardiomyocytes. J Cardiovasc Pharmacol 2022; 80:364-377. [PMID: 35170492 PMCID: PMC9365878 DOI: 10.1097/fjc.0000000000001241] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Accepted: 02/01/2022] [Indexed: 01/31/2023]
Abstract
ABSTRACT Adrenergic receptors (ARs) are G protein-coupled receptors that are stimulated by catecholamines to induce a wide array of physiological effects across tissue types. Both α1- and β-ARs are found on cardiomyocytes and regulate cardiac contractility and hypertrophy through diverse molecular pathways. Acute activation of cardiomyocyte β-ARs increases heart rate and contractility as an adaptive stress response. However, chronic β-AR stimulation contributes to the pathobiology of heart failure. By contrast, mounting evidence suggests that α1-ARs serve protective functions that may mitigate the deleterious effects of chronic β-AR activation. Here, we will review recent studies demonstrating that α1- and β-ARs differentially regulate mitochondrial biogenesis and dynamics, mitochondrial calcium handling, and oxidative phosphorylation in cardiomyocytes. We will identify potential mechanisms of these actions and focus on the implications of these findings for the modulation of contractile function in the uninjured and failing heart. Collectively, we hope to elucidate important physiological processes through which these well-studied and clinically relevant receptors stimulate and fuel cardiac contraction to contribute to myocardial health and disease.
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Affiliation(s)
- Peyton B. Sandroni
- University of North Carolina School of Medicine, Department of Pharmacology
- University of North Carolina School of Medicine, McAllister Heart Institute
| | - Kelsey H. Fisher-Wellman
- East Carolina University Brody School of Medicine, Department of Physiology
- East Carolina University Diabetes and Obesity Institute
| | - Brian C. Jensen
- University of North Carolina School of Medicine, Department of Pharmacology
- University of North Carolina School of Medicine, McAllister Heart Institute
- University of North Carolina School of Medicine, Department of Medicine, Division of Cardiology
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7
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Chen J, Campbell AP, Wakelin LPG, Finch AM. Characterisation of bis(4-aminoquinoline)s as α 1A adrenoceptor allosteric modulators. Eur J Pharmacol 2021; 916:174659. [PMID: 34871559 DOI: 10.1016/j.ejphar.2021.174659] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2021] [Revised: 11/19/2021] [Accepted: 11/29/2021] [Indexed: 11/30/2022]
Abstract
The development of sub-type selective α1 adrenoceptor ligands has been hampered by the high sequence similarity of the amino acids forming the orthosteric binding pocket of the three α1 adrenoceptor subtypes, along with other biogenic amine receptors. One possible approach to overcome this issue is to target allosteric sites on the α1 adrenoceptors. Previous docking studies suggested that one of the quinoline moieties of a bis(4-aminoquinoline), comprising a 9-carbon methylene linker attached via the amine groups, could interact with residues outside of the orthosteric binding site while, simultaneously, the other quinoline moiety bound within the orthosteric site. We therefore hypothesized that this compound could act in a bitopic manner, displaying both orthosteric and allosteric binding properties. To test this proposition, we investigated the allosteric activity of a series of bis(4-aminoquinoline)s with linker lengths ranging from 2 to 12 methylene units (designated C2-C12). A linear trend of increasing [3H]prazosin dissociation rate with increasing linker length between C7 and C11 was observed, confirming their action as allosteric modulators. These data suggest that the optimal linker length for the bis(4-aminoquinoline)s to occupy the allosteric site of the α1A adrenoceptor is between 7 and 11 methylene units. In addition, the ability of C9 bis(4-aminoquinoline) to modulate the activation of the α1A adrenoceptor by norepinephrine was subsequently examined, showing that C9 acted as a non-competitive antagonist. Our findings indicate that the bis(4-aminoquinolines) are acting as allosteric modulators of orthosteric ligand binding, but not efficacy, in a bitopic manner.
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Affiliation(s)
- Junli Chen
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, Sydney, NSW, 2052, Australia
| | - Adrian P Campbell
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, Sydney, NSW, 2052, Australia
| | - Laurence P G Wakelin
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, Sydney, NSW, 2052, Australia
| | - Angela M Finch
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, Sydney, NSW, 2052, Australia.
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8
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Lustyk K, Sałaciak K, Zaręba P, Siwek A, Sapa J, Pytka K. The Antiarrhythmic Activity of Novel Pyrrolidin-2-one Derivative S-75 in Adrenaline-Induced Arrhythmia. Pharmaceuticals (Basel) 2021; 14:1065. [PMID: 34832847 DOI: 10.3390/ph14111065] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2021] [Revised: 10/13/2021] [Accepted: 10/14/2021] [Indexed: 11/29/2022] Open
Abstract
Arrhythmia is a quivering or irregular heartbeat that can often lead to blood clots, stroke, heart failure, and other heart-related complications. The limited efficacy and safety of antiarrhythmic drugs require the design of new compounds. Previous research indicated that pyrrolidin-2-one derivatives possess an affinity for α1-adrenergic receptors. The blockade of α1-adrenoceptor may play a role in restoring normal sinus rhythm; therefore, we aimed to verify the antiarrhythmic activity of novel pyrrolidin-2-one derivative S-75. In this study, we assessed the influence on sodium, calcium, potassium channels, and β1-adrenergic receptors to investigate the mechanism of action of S-75. Lack of affinity for β1-adrenoceptors and weak effects on ion channels decreased the role of these adrenoceptors and channels in the pharmacological activity of S-75. Next, we evaluated the influence of S-75 on normal ECG in rats and isolated rat hearts, and the tested derivative did not prolong the QTc interval, which may confirm the lack of the proarrhythmic potential. We tested antiarrhythmic activity in adrenaline-, aconitine- and calcium chloride-induced arrhythmia models in rats. The studied compound showed prophylactic antiarrhythmic activity in the adrenaline-induced arrhythmia, but no significant activity in the model of aconitine- or calcium chloride-induced arrhythmia. In addition, S-75 was not active in the model of post-reperfusion arrhythmias of the isolated rat hearts. Conversely, the compound showed therapeutic antiarrhythmic properties in adrenaline-induced arrhythmia, reducing post-arrhythmogen heart rhythm disorders, and decreasing animal mortality. Thus, we suggest that the blockade of α1-adrenoceptor might be beneficial in restoring normal heart rhythm in adrenaline-induced arrhythmia.
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9
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Abstract
The sympathetic nervous system is activated in the setting of heart failure (HF) to compensate for hemodynamic instability. However, acute sympathetic surge or sustained high neuronal firing rates activates β-adrenergic receptor (βAR) signaling contributing to myocardial remodeling, dysfunction and electrical instability. Thus, sympatho-βAR activation is regarded as a hallmark of HF and forms pathophysiological basis for β-blocking therapy. Building upon earlier research findings, studies conducted in the recent decades have significantly advanced our understanding on the sympatho-adrenergic mechanism in HF, which forms the focus of this article. This review notes recent research progress regarding the roles of cardiac β2AR or α1AR in the failing heart, significance of β1AR-autoantibodies, and βAR signaling through G-protein independent signaling pathways. Sympatho-βAR regulation of immune cells or fibroblasts is specifically discussed. On the neuronal aspects, knowledge is assembled on the remodeling of sympathetic nerves of the failing heart, regulation by presynaptic α2AR of NE release, and findings on device-based neuromodulation of the sympathetic nervous system. The review ends with highlighting areas where significant knowledge gaps exist but hold promise for new breakthroughs.
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Affiliation(s)
- Xiaojun Du
- Faculty of Physiology and Pathophysiology, School of Basic Medical Sciences, Xi’an Jiaotong University Health Science Center, 76 West Yanta Road, Xi’an710061, Shaanxi, China
- Baker Heart and Diabetes Institute, 75 Commercial Road, Melbourne, VIC3004, Australia
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10
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Guitart-Mampel M, Urquiza P, Borges JI, Lymperopoulos A, Solesio ME. Impact of Aldosterone on the Failing Myocardium: Insights from Mitochondria and Adrenergic Receptors Signaling and Function. Cells 2021; 10:1552. [PMID: 34205363 DOI: 10.3390/cells10061552] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2021] [Revised: 06/08/2021] [Accepted: 06/16/2021] [Indexed: 02/06/2023] Open
Abstract
The mineralocorticoid aldosterone regulates electrolyte and blood volume homeostasis, but it also adversely modulates the structure and function of the chronically failing heart, through its elevated production in chronic human post-myocardial infarction (MI) heart failure (HF). By activating the mineralocorticoid receptor (MR), a ligand-regulated transcription factor, aldosterone promotes inflammation and fibrosis of the heart, while increasing oxidative stress, ultimately induding mitochondrial dysfunction in the failing myocardium. To reduce morbidity and mortality in advanced stage HF, MR antagonist drugs, such as spironolactone and eplerenone, are used. In addition to the MR, aldosterone can bind and stimulate other receptors, such as the plasma membrane-residing G protein-coupled estrogen receptor (GPER), further complicating it signaling properties in the myocardium. Given the salient role that adrenergic receptor (ARs)—particularly βARs—play in cardiac physiology and pathology, unsurprisingly, that part of the impact of aldosterone on the failing heart is mediated by its effects on the signaling and function of these receptors. Aldosterone can significantly precipitate the well-documented derangement of cardiac AR signaling and impairment of AR function, critically underlying chronic human HF. One of the main consequences of HF in mammalian models at the cellular level is the presence of mitochondrial dysfunction. As such, preventing mitochondrial dysfunction could be a valid pharmacological target in this condition. This review summarizes the current experimental evidence for this aldosterone/AR crosstalk in both the healthy and failing heart, and the impact of mitochondrial dysfunction in HF. Recent findings from signaling studies focusing on MR and AR crosstalk via non-conventional signaling of molecules that normally terminate the signaling of ARs in the heart, i.e., the G protein-coupled receptor-kinases (GRKs), are also highlighted.
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11
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Perez DM. Targeting Adrenergic Receptors in Metabolic Therapies for Heart Failure. Int J Mol Sci 2021; 22:5783. [PMID: 34071350 DOI: 10.3390/ijms22115783] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 05/20/2021] [Accepted: 05/22/2021] [Indexed: 12/14/2022] Open
Abstract
The heart has a reduced capacity to generate sufficient energy when failing, resulting in an energy-starved condition with diminished functions. Studies have identified numerous changes in metabolic pathways in the failing heart that result in reduced oxidation of both glucose and fatty acid substrates, defects in mitochondrial functions and oxidative phosphorylation, and inefficient substrate utilization for the ATP that is produced. Recent early-phase clinical studies indicate that inhibitors of fatty acid oxidation and antioxidants that target the mitochondria may improve heart function during failure by increasing compensatory glucose oxidation. Adrenergic receptors (α1 and β) are a key sympathetic nervous system regulator that controls cardiac function. β-AR blockers are an established treatment for heart failure and α1A-AR agonists have potential therapeutic benefit. Besides regulating inotropy and chronotropy, α1- and β-adrenergic receptors also regulate metabolic functions in the heart that underlie many cardiac benefits. This review will highlight recent studies that describe how adrenergic receptor-mediated metabolic pathways may be able to restore cardiac energetics to non-failing levels that may offer promising therapeutic strategies.
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Perez DM. Current Developments on the Role of α 1-Adrenergic Receptors in Cognition, Cardioprotection, and Metabolism. Front Cell Dev Biol 2021; 9:652152. [PMID: 34113612 PMCID: PMC8185284 DOI: 10.3389/fcell.2021.652152] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2021] [Accepted: 04/29/2021] [Indexed: 12/13/2022] Open
Abstract
The α1-adrenergic receptors (ARs) are G-protein coupled receptors that bind the endogenous catecholamines, norepinephrine, and epinephrine. They play a key role in the regulation of the sympathetic nervous system along with β and α2-AR family members. While all of the adrenergic receptors bind with similar affinity to the catecholamines, they can regulate different physiologies and pathophysiologies in the body because they couple to different G-proteins and signal transduction pathways, commonly in opposition to one another. While α1-AR subtypes (α1A, α1B, α1C) have long been known to be primary regulators of vascular smooth muscle contraction, blood pressure, and cardiac hypertrophy, their role in neurotransmission, improving cognition, protecting the heart during ischemia and failure, and regulating whole body and organ metabolism are not well known and are more recent developments. These advancements have been made possible through the development of transgenic and knockout mouse models and more selective ligands to advance their research. Here, we will review the recent literature to provide new insights into these physiological functions and possible use as a therapeutic target.
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Affiliation(s)
- Dianne M Perez
- The Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, OH, United States
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13
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Walsh SK, Lipina C, Ang SY, Sato M, Chia LY, Kocan M, Hutchinson DS, Summers RJ, Wainwright CL. GPR55 regulates the responsiveness to, but does not dimerise with, α 1A-adrenoceptors. Biochem Pharmacol 2021; 188:114560. [PMID: 33844984 DOI: 10.1016/j.bcp.2021.114560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 03/26/2021] [Accepted: 04/06/2021] [Indexed: 11/15/2022]
Abstract
Emerging evidence suggests that G protein coupled receptor 55 (GPR55) may influence adrenoceptor function/activity in the cardiovascular system. Whether this reflects direct interaction (dimerization) between receptors or signalling crosstalk has not been investigated. This study explored the interaction between GPR55 and the alpha 1A-adrenoceptor (α1A-AR) in the cardiovascular system and the potential to influence function/signalling activities. GPR55 and α1A-AR mediated changes in both cardiac and vascular function was assessed in male wild-type (WT) and GPR55 homozygous knockout (GPR55-/-) mice by pressure volume loop analysis and isolated vessel myography, respectively. Dimerization of GPR55 with the α1A-AR was examined in transfected Chinese hamster ovary-K1 (CHO-K1) cells via Bioluminescence Resonance Energy Transfer (BRET). GPR55 and α1A-AR mediated signalling (extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation) was investigated in neonatal rat ventricular cardiomyocytes using AlphaScreen proximity assays. GPR55-/- mice exhibited both enhanced pressor and inotropic responses to A61603 (α1A-AR agonist), while in isolated vessels, A61603 induced vasoconstriction was attenuated by a GPR55-dependent mechanism. Conversely, GPR55-mediated vasorelaxation was not altered by pharmacological blockade of α1A-ARs with tamsulosin. While cellular studies demonstrated that GPR55 and α1A-AR failed to dimerize, pharmacological blockade of GPR55 altered α1A-AR mediated signalling and reduced ERK1/2 phosphorylation. Taken together, this study provides evidence that GPR55 and α1A-AR do not dimerize to form heteromers, but do interact at the signalling level to modulate the function of α1A-AR in the cardiovascular system.
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Affiliation(s)
- Sarah K Walsh
- Cardiometabolic Health Research, School of Pharmacy and Life Sciences, Robert Gordon University, Sir Ian Wood Building, Aberdeen AB10 7GJ, UK.
| | - Christopher Lipina
- Division of Cell Signalling and Immunology, Sir James Black Centre, School of Life Sciences, University of Dundee, Dundee DD1 5EH, UK
| | - Sheng Y Ang
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Masaaki Sato
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Ling Yeong Chia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Martina Kocan
- The Florey Institute of Neuroscience and Mental Health and School of Biosciences, University of Melbourne, Parkville, VIC, Australia
| | - Dana S Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Roger J Summers
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Parkville, VIC, Australia
| | - Cherry L Wainwright
- Cardiometabolic Health Research, School of Pharmacy and Life Sciences, Robert Gordon University, Sir Ian Wood Building, Aberdeen AB10 7GJ, UK
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14
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Kaidonis X, Niu W, Chan AY, Kesteven S, Wu J, Iismaa SE, Vatner S, Feneley M, Graham RM. Adaptation to exercise-induced stress is not dependent on cardiomyocyte α 1A-adrenergic receptors. J Mol Cell Cardiol 2021; 155:78-87. [PMID: 33647309 DOI: 10.1016/j.yjmcc.2021.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 01/20/2021] [Accepted: 02/21/2021] [Indexed: 12/31/2022]
Abstract
The 'fight or flight' response to physiological stress involves sympathetic nervous system activation, catecholamine release and adrenergic receptor stimulation. In the heart, this induces positive inotropy, previously attributed to the β1-adrenergic receptor subtype. However, the role of the α1A-adrenergic receptor, which has been suggested to be protective in cardiac pathology, has not been investigated in the setting of physiological stress. To explore this, we developed a tamoxifen-inducible, cardiomyocyte-specific α1A-adrenergic receptor knock-down mouse model, challenged mice to four weeks of endurance swim training and assessed cardiac outcomes. With 4-OH tamoxifen treatment, expression of the α1A-adrenergic receptor was knocked down by 80-89%, without any compensatory changes in the expression of other adrenergic receptors, or changes to baseline cardiac structure and function. Swim training caused eccentric hypertrophy, regardless of genotype, demonstrated by an increase in heart weight/tibia length ratio (30% and 22% in vehicle- and tamoxifen-treated animals, respectively) and an increase in left ventricular end diastolic volume (30% and 24% in vehicle- and tamoxifen-treated animals, respectively) without any change in the wall thickness/chamber radius ratio. Consistent with physiological hypertrophy, there was no increase in fetal gene program (Myh7, Nppa, Nppb or Acta1) expression. In response to exercise-induced volume overload, stroke volume (39% and 30% in vehicle- and tamoxifen-treated animals, respectively), cardiac output/tibia length ratio (41% in vehicle-treated animals) and stroke work (61% and 33% in vehicle- and tamoxifen-treated animals, respectively) increased, regardless of genotype. These findings demonstrate that cardiomyocyte α1A-adrenergic receptors are not necessary for cardiac adaptation to endurance exercise stress and their acute ablation is not deleterious.
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Affiliation(s)
- Xenia Kaidonis
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia
| | - Wenxing Niu
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; School of Medical Sciences, University of NSW, Kensington, NSW 2052, Australia
| | - Andrea Y Chan
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Scott Kesteven
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia
| | - Jianxin Wu
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Siiri E Iismaa
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia
| | - Stephen Vatner
- Cardiovascular Research Institute, Dept. of Cell Biology and Molecular Medicine, Rutgers, New Jersey Medical School, Newark, NJ 07103, USA
| | - Michael Feneley
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia
| | - Robert M Graham
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia.
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15
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Carbajal-García A, Reyes-García J, Montaño LM. Androgen Effects on the Adrenergic System of the Vascular, Airway, and Cardiac Myocytes and Their Relevance in Pathological Processes. Int J Endocrinol 2020; 2020:8849641. [PMID: 33273918 PMCID: PMC7676939 DOI: 10.1155/2020/8849641] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 09/17/2020] [Accepted: 10/20/2020] [Indexed: 02/06/2023] Open
Abstract
INTRODUCTION Androgen signaling comprises nongenomic and genomic pathways. Nongenomic actions are not related to the binding of the androgen receptor (AR) and occur rapidly. The genomic effects implicate the binding to a cytosolic AR, leading to protein synthesis. Both events are independent of each other. Genomic effects have been associated with different pathologies such as vascular ischemia, hypertension, asthma, and cardiovascular diseases. Catecholamines play a crucial role in regulating vascular smooth muscle (VSM), airway smooth muscle (ASM), and cardiac muscle (CM) function and tone. OBJECTIVE The aim of this review is an updated analysis of the role of androgens in the adrenergic system of vascular, airway, and cardiac myocytes. Body. Testosterone (T) favors vasoconstriction, and its concentration fluctuation during life stages can affect the vascular tone and might contribute to the development of hypertension. In the VSM, T increases α1-adrenergic receptors (α 1-ARs) and decreases adenylyl cyclase expression, favoring high blood pressure and hypertension. Androgens have also been associated with asthma. During puberty, girls are more susceptible to present asthma symptoms than boys because of the increment in the plasmatic concentrations of T in young men. In the ASM, β 2-ARs are responsible for the bronchodilator effect, and T augments the expression of β 2-ARs evoking an increase in the relaxing response to salbutamol. The levels of T are also associated with an increment in atherosclerosis and cardiovascular risk. In the CM, activation of α 1A-ARs and β 2-ARs increases the ionotropic activity, leading to the development of contraction, and T upregulates the expression of both receptors and improves the myocardial performance. CONCLUSIONS Androgens play an essential role in the adrenergic system of vascular, airway, and cardiac myocytes, favoring either a state of health or disease. While the use of androgens as a therapeutic tool for treating asthma symptoms or heart disease is proposed, the vascular system is warmly affected.
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Affiliation(s)
- Abril Carbajal-García
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, CDMX, Mexico
| | - Jorge Reyes-García
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, CDMX, Mexico
| | - Luis M. Montaño
- Departamento de Farmacología, Facultad de Medicina, Universidad Nacional Autónoma de México, CDMX, Mexico
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16
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Abstract
Recent studies report that a single subtype of α1-adrenergic receptor (α1-AR), the α1A-subtype, mediates robust cardioprotective effects in multiple experimental models of heart failure, suggesting that the α1A-subtype is a potential therapeutic target for an agonist to treat heart failure. Moreover, we recently found that the α1A-subtype is present in human heart. The goal of this study was to assess the inotropic response mediated by the α1A-subtype in human myocardium, and to determine whether the response is downregulated in myocardium from failing human heart. We measured in vitro contractile responses of cardiac muscle preparations (trabeculae) isolated from the right ventricle from nonfailing and failing human hearts. Addition of the α1A-subtype agonist A61603 (100 nM) resulted in a large positive inotropic response (force increased ≈ 2-fold). This response represented ≈70% of the response mediated by the β-adrenergic receptor agonist isoproterenol (1 μM). Moreover, in myocardium from failing hearts, α1A-subtype responses remained robust, and only slightly reduced relative to nonfailing hearts. We conclude that α1A-subtype-mediated inotropy could represent a significant source of inotropic support in the human heart. Furthermore, the α1A-subtype remains functional in myocardium from failing human hearts and thus, might be a therapeutic target to support cardioprotective effects in patients with heart failure.
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17
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Chia LY, Evans BA, Mukaida S, Bengtsson T, Hutchinson DS, Sato M. Adrenoceptor regulation of the mechanistic target of rapamycin in muscle and adipose tissue. Br J Pharmacol 2019; 176:2433-2448. [PMID: 30740664 DOI: 10.1111/bph.14616] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 01/08/2019] [Accepted: 01/21/2019] [Indexed: 12/16/2022] Open
Abstract
A vital role of adrenoceptors in metabolism and energy balance has been well documented in the heart, skeletal muscle, and adipose tissue. It has been only recently demonstrated, however, that activation of the mechanistic target of rapamycin (mTOR) makes a significant contribution to various metabolic and physiological responses to adrenoceptor agonists. mTOR exists as two distinct complexes named mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2) and has been shown to play a critical role in protein synthesis, cell proliferation, hypertrophy, mitochondrial function, and glucose uptake. This review will describe the physiological significance of mTORC1 and 2 as a novel paradigm of adrenoceptor signalling in the heart, skeletal muscle, and adipose tissue. Understanding the detailed signalling cascades of adrenoceptors and how they regulate physiological responses is important for identifying new therapeutic targets and identifying novel therapeutic interventions. LINKED ARTICLES: This article is part of a themed section on Adrenoceptors-New Roles for Old Players. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.14/issuetoc.
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Affiliation(s)
- Ling Yeong Chia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia
| | - Bronwyn A Evans
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia
| | - Saori Mukaida
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, Stockholm, Sweden
| | - Dana S Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia
| | - Masaaki Sato
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, Melbourne, Victoria, Australia
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18
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Grisanti LA, Schumacher SM, Tilley DG, Koch WJ. Designer Approaches for G Protein-Coupled Receptor Modulation for Cardiovascular Disease. JACC Basic Transl Sci 2018; 3:550-562. [PMID: 30175279 PMCID: PMC6115700 DOI: 10.1016/j.jacbts.2017.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/08/2017] [Accepted: 12/14/2017] [Indexed: 12/17/2022]
Abstract
The new horizon for cardiac therapy may lie beneath the surface, with the downstream mediators of G protein–coupled receptor (GPCR) activity. Targeted approaches have shown that receptor activation may be biased toward signaling through G proteins or through GPCR kinases (GRKs) and β-arrestins, with divergent functional outcomes. In addition to these canonical roles, numerous noncanonical activities of GRKs and β-arrestins have been demonstrated to modulate GPCR signaling at all levels of receptor activation and regulation. Further, research continues to identify novel GRK/effector and β-arrestin/effector complexes with distinct impacts on cardiac function in the normal heart and the diseased heart. Coupled with the identification of once orphan receptors and endogenous ligands with beneficial cardiovascular effects, this expands the repertoire of GPCR targets. Together, this research highlights the potential for focused therapeutic activation of beneficial pathways, with simultaneous exclusion or inhibition of detrimental signaling, and represents a new wave of therapeutic development.
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Key Words
- AR, adrenergic receptor
- AT1R, angiotensin II type 1A receptor
- CRF, corticotropin-releasing factor
- EGFR, epidermal growth factor receptor
- ERK1/2, extracellular signal-regulated kinase
- G protein–coupled receptor kinases
- G protein–coupled receptors
- GPCR, G protein–coupled receptor
- GRK, G protein–coupled receptor kinase
- HF, heart failure
- ICL, intracellular loop
- PI3K, phosphoinositide 3-kinase
- SERCA2a, sarco(endo)plasmic reticulum Ca2+-ATPase
- SII, [Sar(1), Ile (4), Ile(8)]-angiotensin II
- biased ligands
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Affiliation(s)
- Laurel A Grisanti
- Center for Translational Medicine and Department of Pharmacology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania.,Department of Biomedical Sciences, University of Missouri, Columbia, Missouri
| | - Sarah M Schumacher
- Center for Translational Medicine and Department of Pharmacology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania.,Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio
| | - Douglas G Tilley
- Center for Translational Medicine and Department of Pharmacology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
| | - Walter J Koch
- Center for Translational Medicine and Department of Pharmacology, Lewis Katz School of Medicine, Temple University, Philadelphia, Pennsylvania
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19
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Abstract
G protein-coupled receptor kinases (GRKs) are classically known for their role in regulating the activity of the largest known class of membrane receptors, which influence diverse biological processes in every cell type in the human body. As researchers have tried to uncover how this family of kinases, containing only 7 members, achieves selective and coordinated control of receptors, they have uncovered a growing number of noncanonical activities for these kinases. These activities include phosphorylation of nonreceptor targets and kinase-independent molecular interactions. In particular, GRK2, GRK3, and GRK5 are the predominant members expressed in the heart. Their canonical and noncanonical actions within cardiac and other tissues have significant implications for cardiovascular function in healthy animals and for the development and progression of disease. This review summarizes what is currently known regarding the activity of these kinases, and particularly the role of GRK2 and GRK5 in the molecular alterations that occur during heart failure. This review further highlights areas of GRK regulation that remain poorly understood and how they may represent novel targets for therapeutic development.
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20
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Martin RD, Sun Y, Bourque K, Audet N, Inoue A, Tanny JC, Hébert TE. Receptor- and cellular compartment-specific activation of the cAMP/PKA pathway by α 1-adrenergic and ETA endothelin receptors. Cell Signal 2018; 44:43-50. [PMID: 29329779 DOI: 10.1016/j.cellsig.2018.01.002] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2017] [Revised: 12/11/2017] [Accepted: 01/07/2018] [Indexed: 10/18/2022]
Abstract
The signalling functions of many G protein-coupled receptors (GPCRs) expressed in the myocardium are incompletely understood. Among these are the endothelin receptor (ETR) family and α1-adrenergic receptor (α1-AR), which are thought to couple to the G protein Gαq. In this study, we used transcriptome analysis to compare the signalling networks downstream of these receptors in primary neonatal rat cardiomyocytes. This analysis indicated increased expression of target genes of cAMP responsive element modulator (CREM) after 24 h treatment with the α1-AR agonist phenylephrine, but not the ETR agonist endothelin-1, suggesting a specific role for the α1-AR in promoting cAMP production in cardiomyocytes. To validate the difference observed between these two GPCRs, we used heterologous expression of the receptors and genetically encoded biosensors in HEK 293 cell lines. We validated that both α1A- and α1B-AR subtypes were able to lead to the accumulation of cAMP in response to phenylephrine in both the nucleus and cytoplasm in a Gαs-dependent manner. However, the ETR subtype ETA did not affect cAMP levels in either compartment. All three receptors were coupled to Gαq signalling as expected. Further, we showed that activation of PKA in different compartments was α1-AR subtype specific, with α1B-AR able to activate PKA in the cytoplasm and nucleus and α1A-AR only able to in the nucleus. We provide evidence for a pathway downstream of the α1-AR, and show that distinct pools of a receptor lead to differential activation of downstream effector proteins dependent on their cellular compartment.
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Affiliation(s)
- Ryan D Martin
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Yalin Sun
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Kyla Bourque
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Nicolas Audet
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi, Japan
| | - Jason C Tanny
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
| | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, Québec, Canada.
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21
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Sato M, Evans BA, Sandström AL, Chia LY, Mukaida S, Thai BS, Nguyen A, Lim L, Tan CYR, Baltos JA, White PJ, May LT, Hutchinson DS, Summers RJ, Bengtsson T. α 1A-Adrenoceptors activate mTOR signalling and glucose uptake in cardiomyocytes. Biochem Pharmacol 2017; 148:27-40. [PMID: 29175420 DOI: 10.1016/j.bcp.2017.11.016] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Accepted: 11/22/2017] [Indexed: 12/20/2022]
Abstract
The capacity of G protein-coupled receptors to modulate mechanistic target of rapamycin (mTOR) activity is a newly emerging paradigm with the potential to link cell surface receptors with cell survival. Cardiomyocyte viability is linked to signalling pathways involving Akt and mTOR, as well as increased glucose uptake and utilization. Our aim was to determine whether the α1A-adrenoceptor (AR) couples to these protective pathways, and increased glucose uptake. We characterised α1A-AR signalling in CHO-K1 cells co-expressing the human α1A-AR and GLUT4 (CHOα1AGLUT4myc) and in neonatal rat ventricular cardiomyocytes (NRVM), and measured glucose uptake, intracellular Ca2+ mobilization, and phosphorylation of mTOR, Akt, 5' adenosine monophosphate-activated kinase (AMPK) and S6 ribosomal protein (S6rp). In both systems, noradrenaline and the α1A-AR selective agonist A61603 stimulated glucose uptake by parallel pathways involving mTOR and AMPK, whereas another α1-AR agonist oxymetazoline increased glucose uptake predominantly by mTOR. All agonists promoted phosphorylation of mTOR at Ser2448 and Ser2481, indicating activation of both mTORC1 and mTORC2, but did not increase Akt phosphorylation. In CHOα1AGLUT4myc cells, siRNA directed against rictor but not raptor suppressed α1A-AR mediated glucose uptake. We have thus identified mTORC2 as a key component in glucose uptake stimulated by α1A-AR agonists. Our findings identify a novel link between the α1A-AR, mTORC2 and glucose uptake, that have been implicated separately in cardiomyocyte survival. Our studies provide an improved framework for examining the utility of α1A-AR selective agonists as tools in the treatment of cardiac dysfunction.
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Affiliation(s)
- Masaaki Sato
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden; Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Bronwyn A Evans
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Anna L Sandström
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden
| | - Ling Yeong Chia
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Saori Mukaida
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Bui San Thai
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Anh Nguyen
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Linzi Lim
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Christina Y R Tan
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Jo-Anne Baltos
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Paul J White
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Lauren T May
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Dana S Hutchinson
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Roger J Summers
- Drug Discovery Biology, Monash Institute of Pharmaceutical Sciences, Monash University, 399 Royal Parade, Parkville, Victoria 3052, Australia
| | - Tore Bengtsson
- Department of Molecular Biosciences, The Wenner-Gren Institute, Stockholm University, SE-106 91 Stockholm, Sweden.
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22
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Lynch JJ, Van Vleet TR, Mittelstadt SW, Blomme EAG. Potential functional and pathological side effects related to off-target pharmacological activity. J Pharmacol Toxicol Methods 2017; 87:108-126. [PMID: 28216264 DOI: 10.1016/j.vascn.2017.02.020] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2016] [Revised: 01/24/2017] [Accepted: 02/15/2017] [Indexed: 12/22/2022]
Abstract
Most pharmaceutical companies test their discovery-stage proprietary molecules in a battery of in vitro pharmacology assays to try to determine off-target interactions. During all phases of drug discovery and development, various questions arise regarding potential side effects associated with such off-target pharmacological activity. Here we present a scientific literature curation effort undertaken to determine and summarize the most likely functional and pathological outcomes associated with interactions at 70 receptors, enzymes, ion channels and transporters with established links to adverse effects. To that end, the scientific literature was reviewed using an on-line database, and the most commonly reported effects were summarized in tabular format. The resultant table should serve as a practical guide for research scientists and clinical investigators for the prediction and interpretation of adverse side effects associated with molecules interacting with components of this screening battery.
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Affiliation(s)
- James J Lynch
- AbbVie Inc., 1 North Waukegan Road, North Chicago, IL 60064, USA.
| | | | | | - Eric A G Blomme
- AbbVie Inc., 1 North Waukegan Road, North Chicago, IL 60064, USA
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23
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Beak J, Huang W, Parker JS, Hicks ST, Patterson C, Simpson PC, Ma A, Jin J, Jensen BC. An Oral Selective Alpha-1A Adrenergic Receptor Agonist Prevents Doxorubicin Cardiotoxicity. JACC Basic Transl Sci 2017; 2:39-53. [PMID: 28286875 DOI: 10.1016/j.jacbts.2016.10.006] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
There are 2 α1-ARs on cardiac myocytes: α1A and α1B. α1A adrenergic receptors serve important cardioprotective roles and do not mediate cardiac hypertrophy. Dabuzalgron, an oral α1A-AR agonist developed for the treatment of urinary incontinence and tolerated well in Phase 2 clinical trials, protects against doxorubicin-induced cardiotoxicity in vivo. Dabuzalgron enhances contractile function, regulates transcription of genes related to energy production and mitochondrial function, and preserves myocardial ATP content after doxorubicin. Activation of α1A-ARs on cardiomyocytes protects against doxorubicin cytotoxicity and enhances mitochondrial function in vitro. These cytoprotective effects likely are mediated by activation of ERK 1/2. Future studies will explore whether dabuzalgron, a well-tolerated oral α1A-AR agonist, might be repurposed to treat heart failure.
Alpha-1 adrenergic receptors (α1-ARs) play adaptive and protective roles in the heart. Dabuzalgron is an oral selective α1A-AR agonist that was well tolerated in multiple clinical trials of treatment for urinary incontinence, but has never been used to treat heart disease in humans or animal models. In this study, the authors administered dabuzalgron to mice treated with doxorubicin (DOX), a widely used chemotherapeutic agent with dose-limiting cardiotoxicity that can lead to heart failure (HF). Dabuzalgron protected against DOX-induced cardiotoxicity, likely by preserving mitochondrial function. These results suggest that activating cardiac α1A-ARs with dabuzalgron, a well-tolerated oral agent, might represent a novel approach to treating HF.
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Montgomery MD, Chan T, Swigart PM, Myagmar BE, Dash R, Simpson PC. An Alpha-1A Adrenergic Receptor Agonist Prevents Acute Doxorubicin Cardiomyopathy in Male Mice. PLoS One 2017; 12:e0168409. [PMID: 28081170 PMCID: PMC5231318 DOI: 10.1371/journal.pone.0168409] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2016] [Accepted: 11/29/2016] [Indexed: 01/12/2023] Open
Abstract
Alpha-1 adrenergic receptors mediate adaptive effects in the heart and cardiac myocytes, and a myocyte survival pathway involving the alpha-1A receptor subtype and ERK activation exists in vitro. However, data in vivo are limited. Here we tested A61603 (N-[5-(4,5-dihydro-1H-imidazol-2-yl)-2-hydroxy-5,6,7,8-tetrahydronaphthalen-1-yl]methanesulfonamide), a selective imidazoline agonist for the alpha-1A. A61603 was the most potent alpha-1-agonist in activating ERK in neonatal rat ventricular myocytes. A61603 activated ERK in adult mouse ventricular myocytes and protected the cells from death caused by the anthracycline doxorubicin. A low dose of A61603 (10 ng/kg/d) activated ERK in the mouse heart in vivo, but did not change blood pressure. In male mice, concurrent subcutaneous A61603 infusion at 10 ng/kg/d for 7 days after a single intraperitoneal dose of doxorubicin (25 mg/kg) increased survival, improved cardiac function, heart rate, and cardiac output by echocardiography, and reduced cardiac cell necrosis and apoptosis and myocardial fibrosis. All protective effects were lost in alpha-1A-knockout mice. In female mice, doxorubicin at doses higher than in males (35-40 mg/kg) caused less cardiac toxicity than in males. We conclude that the alpha-1A-selective agonist A61603, via the alpha-1A adrenergic receptor, prevents doxorubicin cardiomyopathy in male mice, supporting the theory that alpha-1A adrenergic receptor agonists have potential as novel heart failure therapies.
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Affiliation(s)
- Megan D. Montgomery
- Department of Medicine, Cardiology Division, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States of America
| | - Trevor Chan
- Department of Medicine, Cardiology Division, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States of America
| | - Philip M. Swigart
- Department of Medicine, Cardiology Division, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States of America
| | - Bat-erdene Myagmar
- Department of Medicine, Cardiology Division, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States of America
| | - Rajesh Dash
- Department of Medicine, Cardiology Division, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States of America
| | - Paul C. Simpson
- Department of Medicine, Cardiology Division, VA Medical Center, San Francisco, CA, United States of America
- Department of Medicine and Cardiovascular Research Institute, University of California, San Francisco, San Francisco, CA, United States of America
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Eiby YA, Shrimpton NY, Wright IM, Lumbers ER, Colditz PB, Duncombe GJ, Lingwood BE. Inotropes do not increase cardiac output or cerebral blood flow in preterm piglets. Pediatr Res 2016; 80:870-9. [PMID: 27490740 DOI: 10.1038/pr.2016.156] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2016] [Accepted: 06/10/2016] [Indexed: 01/26/2023]
Abstract
BACKGROUND The preterm newborn is at high risk of developing cardiovascular compromise during the first day of life and this is associated with increased risk of brain injury. Standard treatments are volume expansion and administration of inotropes, typically dopamine and/or dobutamine, but there is limited evidence that inotropes improve clinical outcomes. This study investigated the efficacy of dopamine and dobutamine for the treatment of cardiovascular compromise in the preterm newborn using a piglet model. METHODS Preterm and term piglets were assigned to either dopamine, dobutamine or control infusions. Heart rate, left ventricular contractility, cardiac output, blood pressure, and cerebral and regional blood flows were measured during baseline, low (10 µg/kg/h), and high (20 µg/kg/h) dose infusions. RESULTS At baseline, preterm piglets had lower cardiac contractility, cardiac output, blood pressure, and cerebral blood flow compared to term piglets. The response of preterm piglets to either dopamine or dobutamine administration was less than in term piglets. In both preterm and term piglets, cardiac output and cerebral blood flow were unaltered by either inotrope. CONCLUSION In order to provide better cardiovascular support, it may be necessary to develop treatments that target receptors with a more mature profile than adrenoceptors in the preterm newborn.
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Campbell AP, Wakelin LPG, Denny WA, Finch AM. Homobivalent Conjugation Increases the Allosteric Effect of 9-aminoacridine at the α1-Adrenergic Receptors. Mol Pharmacol 2016; 91:135-144. [PMID: 27903755 DOI: 10.1124/mol.116.105874] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2016] [Accepted: 11/28/2016] [Indexed: 12/14/2022] Open
Abstract
The α1-adrenergic receptors are targets for a number of cardiovascular and central nervous system conditions, but the current drugs for these receptors lack specificity to be of optimal clinical value. Allosteric modulators offer an alternative mechanism of action to traditional α1-adrenergic ligands, yet there is little information describing this drug class at the α1-adrenergic receptors. We have identified a series of 9-aminoacridine compounds that demonstrate allosteric modulation of the α1A- and α1B-adrenergic receptors. The 9-aminoacridines increase the rate of [3H]prazosin dissociation from the α1A- and α1B-adrenergic receptors and noncompetitively inhibit receptor activation by the endogenous agonist norepinephrine. The structurally similar compound, tacrine, which is a known allosteric modulator of the muscarinic receptors, is also shown to be a modulator of the α1-adrenergic receptors, which suggests a general lack of selectivity for allosteric binding sites across aminergic G protein-coupled receptor. Conjugation of two 9-aminoacridine pharmacophores, using linkers of varying length, increases the potency and efficacy of the allosteric effects of this ligand, likely through optimization of bitopic engagement of the allosteric and orthosteric binding sites of the receptor. Such a bivalent approach may provide a mechanism for fine tuning the efficacy of allosteric compounds in future drug design efforts.
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Affiliation(s)
- Adrian P Campbell
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, Kensington, Australia (A.P.C., L.P.G.W., A.M.F.); Auckland Cancer Society Research Centre, Faculty of Medicine and Health Science, University of Auckland, Auckland, New Zealand (W.A.D.)
| | - Laurence P G Wakelin
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, Kensington, Australia (A.P.C., L.P.G.W., A.M.F.); Auckland Cancer Society Research Centre, Faculty of Medicine and Health Science, University of Auckland, Auckland, New Zealand (W.A.D.)
| | - William A Denny
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, Kensington, Australia (A.P.C., L.P.G.W., A.M.F.); Auckland Cancer Society Research Centre, Faculty of Medicine and Health Science, University of Auckland, Auckland, New Zealand (W.A.D.)
| | - Angela M Finch
- Department of Pharmacology, School of Medical Sciences, UNSW Australia, Kensington, Australia (A.P.C., L.P.G.W., A.M.F.); Auckland Cancer Society Research Centre, Faculty of Medicine and Health Science, University of Auckland, Auckland, New Zealand (W.A.D.)
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Abstract
Although convention dictates that G protein-coupled receptors localize to and signal at the plasma membrane, accumulating evidence suggests that G protein-coupled receptors localize to and signal at intracellular membranes, most notably the nucleus. In fact, there is now significant evidence indicating that endogenous alpha-1 adrenergic receptors (α1-ARs) localize to and signal at the nuclei in adult cardiac myocytes. Cumulatively, the data suggest that α1-ARs localize to the inner nuclear membrane, activate intranuclear signaling, and regulate physiologic function in adult cardiac myocytes. Although α1-ARs signal through Gαq, unlike other Gq-coupled receptors, α1-ARs mediate important cardioprotective functions including adaptive/physiologic hypertrophy, protection from cell death (survival signaling), positive inotropy, and preconditioning. Also unlike other Gq-coupled receptors, most, if not all, functional α1-ARs localize to the nuclei in adult cardiac myocytes, as opposed to the sarcolemma. Together, α1-AR nuclear localization and cardioprotection might suggest a novel model for compartmentalization of Gq-coupled receptor signaling in which nuclear Gq-coupled receptor signaling is cardioprotective.
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Dolatshad NF, Hellen N, Jabbour RJ, Harding SE, Földes G. G-protein Coupled Receptor Signaling in Pluripotent Stem Cell-derived Cardiovascular Cells: Implications for Disease Modeling. Front Cell Dev Biol 2015; 3:76. [PMID: 26697426 PMCID: PMC4673467 DOI: 10.3389/fcell.2015.00076] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2015] [Accepted: 11/09/2015] [Indexed: 12/13/2022] Open
Abstract
Human pluripotent stem cell derivatives show promise as an in vitro platform to study a range of human cardiovascular diseases. A better understanding of the biology of stem cells and their cardiovascular derivatives will help to understand the strengths and limitations of this new model system. G-protein coupled receptors (GPCRs) are key regulators of stem cell maintenance and differentiation and have an important role in cardiovascular cell signaling. In this review, we will therefore describe the state of knowledge concerning the regulatory role of GPCRs in both the generation and function of pluripotent stem cell derived-cardiomyocytes, -endothelial, and -vascular smooth muscle cells. We will consider how far the in vitro disease models recapitulate authentic GPCR signaling and provide a useful basis for discovery of disease mechanisms or design of therapeutic strategies.
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Affiliation(s)
- Nazanin F Dolatshad
- Myocardial Function, National Heart and Lung Institute, Imperial College London London, UK
| | - Nicola Hellen
- Myocardial Function, National Heart and Lung Institute, Imperial College London London, UK
| | - Richard J Jabbour
- Myocardial Function, National Heart and Lung Institute, Imperial College London London, UK
| | - Sian E Harding
- Myocardial Function, National Heart and Lung Institute, Imperial College London London, UK
| | - Gabor Földes
- Myocardial Function, National Heart and Lung Institute, Imperial College London London, UK ; The Heart and Vascular Center of Semmelweis University, Semmelweis University Budapest, Hungary
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Abstract
While α(1)-adrenergic receptors (ARs) have been previously shown to limit ischemic cardiac damage, the mechanisms remain unclear. Most previous studies utilized low oxygen conditions in addition to ischemic buffers with glucose deficiencies, but we discovered profound differences if the two conditions are separated. We assessed both mouse neonatal and adult myocytes and HL-1 cells in a series of assays assessing ischemic damage under hypoxic or low glucose conditions. We found that α(1)-AR stimulation protected against increased lactate dehydrogenase release or Annexin V(+) apoptosis under conditions that were due to low glucose concentration not to hypoxia. The α(1)-AR antagonist prazosin or nonselective protein kinase C (PKC) inhibitors blocked the protective effect. α(1)-AR stimulation increased (3)H-deoxyglucose uptake that was blocked with either an inhibitor to glucose transporter 1 or 4 (GLUT1 or GLUT4) or small interfering RNA (siRNA) against PKCδ. GLUT1/4 inhibition also blocked α(1)-AR-mediated protection from apoptosis. The PKC inhibitor rottlerin or siRNA against PKCδ blocked α(1)-AR stimulated GLUT1 or GLUT4 plasma membrane translocation. α(1)-AR stimulation increased plasma membrane concentration of either GLUT1 or GLUT4 in a time-dependent fashion. Transgenic mice overexpressing the α(1A)-AR but not α(1B)-AR mice displayed increased glucose uptake and increased GLUT1 and GLUT4 plasma membrane translocation in the adult heart while α(1A)-AR but not α(1B)-AR knockout mice displayed lowered glucose uptake and GLUT translocation. Our results suggest that α(1)-AR activation is anti-apoptotic and protective during cardiac ischemia due to glucose deprivation and not hypoxia by enhancing glucose uptake into the heart via PKCδ-mediated GLUT translocation that may be specific to the α(1A)-AR subtype.
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Affiliation(s)
- Ting Shi
- a Department of Molecular Cardiology , Lerner Research Institute, Cleveland Clinic Foundation , Cleveland , OH , USA
| | - Robert S Papay
- a Department of Molecular Cardiology , Lerner Research Institute, Cleveland Clinic Foundation , Cleveland , OH , USA
| | - Dianne M Perez
- a Department of Molecular Cardiology , Lerner Research Institute, Cleveland Clinic Foundation , Cleveland , OH , USA
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Cotecchia S, Del Vescovo CD, Colella M, Caso S, Diviani D. The alpha1-adrenergic receptors in cardiac hypertrophy: signaling mechanisms and functional implications. Cell Signal 2015; 27:1984-93. [PMID: 26169957 DOI: 10.1016/j.cellsig.2015.06.009] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Revised: 06/22/2015] [Accepted: 06/30/2015] [Indexed: 01/05/2023]
Abstract
Cardiac hypertrophy is a complex remodeling process of the heart induced by physiological or pathological stimuli resulting in increased cardiomyocyte size and myocardial mass. Whereas cardiac hypertrophy can be an adaptive mechanism to stressful conditions of the heart, prolonged hypertrophy can lead to heart failure which represents the primary cause of human morbidity and mortality. Among G protein-coupled receptors, the α1-adrenergic receptors (α1-ARs) play an important role in the development of cardiac hypertrophy as demonstrated by numerous studies in the past decades, both in primary cardiomyocyte cultures and genetically modified mice. The results of these studies have provided evidence of a large variety of α1-AR-induced signaling events contributing to the defining molecular and cellular features of cardiac hypertrophy. Recently, novel signaling mechanisms have been identified and new hypotheses have emerged concerning the functional role of the α1-adrenergic receptors in the heart. This review will summarize the main signaling pathways activated by the α1-AR in the heart and their functional implications in cardiac hypertrophy.
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Affiliation(s)
- Susanna Cotecchia
- Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università di Bari, Via Orabona 4, 70125 Bari, Italy.
| | - Cosmo Damiano Del Vescovo
- Department de Pharmacologie et de de Toxicologie, Université de Lausanne, Rue du Bugnon 27, 1005, Lausanne, Switzerland
| | - Matilde Colella
- Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università di Bari, Via Orabona 4, 70125 Bari, Italy
| | - Stefania Caso
- Dipartimento di Bioscienze, Biotecnologie e Biofarmaceutica, Università di Bari, Via Orabona 4, 70125 Bari, Italy; Department de Pharmacologie et de de Toxicologie, Université de Lausanne, Rue du Bugnon 27, 1005, Lausanne, Switzerland
| | - Dario Diviani
- Department de Pharmacologie et de de Toxicologie, Université de Lausanne, Rue du Bugnon 27, 1005, Lausanne, Switzerland
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Cowley PM, Wang G, Chang AN, Makwana O, Swigart PM, Lovett DH, Stull JT, Simpson PC, Baker AJ. The α1A-adrenergic receptor subtype mediates increased contraction of failing right ventricular myocardium. Am J Physiol Heart Circ Physiol 2015; 309:H888-96. [PMID: 26116709 DOI: 10.1152/ajpheart.00042.2015] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 06/24/2015] [Indexed: 12/23/2022]
Abstract
Dysfunction of the right ventricle (RV) is closely related to prognosis for patients with RV failure. Therefore, strategies to improve failing RV function are significant. In a mouse RV failure model, we previously reported that α1-adrenergic receptor (α1-AR) inotropic responses are increased. The present study determined the roles of both predominant cardiac α1-AR subtypes (α1A and α1B) in upregulated inotropy in failing RV. We used the mouse model of bleomycin-induced pulmonary fibrosis, pulmonary hypertension, and RV failure. We assessed the myocardial contractile response in vitro to stimulation of the α1A-subtype (using α1A-subtype-selective agonist A61603) and α1B-subtype [using α1A-subtype knockout mice and nonsubtype selective α1-AR agonist phenylephrine (PE)]. In wild-type nonfailing RV, a negative inotropic effect of α1-AR stimulation with PE (force decreased ≈50%) was switched to a positive inotropic effect (PIE) with bleomycin-induced RV injury. Upregulated inotropy in failing RV occurred with α1A-subtype stimulation (force increased ≈200%), but not with α1B-subtype stimulation (force decreased ≈50%). Upregulated inotropy mediated by the α1A-subtype involved increased activator Ca(2+) transients and increased phosphorylation of myosin regulatory light chain (a mediator of increased myofilament Ca(2+) sensitivity). In failing RV, the PIE elicited by the α1A-subtype was appreciably less when the α1A-subtype was stimulated in combination with the α1B-subtype, suggesting functional antagonism between α1A- and α1B-subtypes. In conclusion, upregulation of α1-AR inotropy in failing RV myocardium requires the α1A-subtype and is opposed by the α1B-subtype. The α1A subtype might be a therapeutic target to improve the function of the failing RV.
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Affiliation(s)
- Patrick M Cowley
- Veterans Affairs Medical Center, San Francisco, and Department of Medicine, University California San Francisco, San Francisco, California; and
| | - Guanying Wang
- Veterans Affairs Medical Center, San Francisco, and Department of Medicine, University California San Francisco, San Francisco, California; and
| | - Audrey N Chang
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Om Makwana
- Veterans Affairs Medical Center, San Francisco, and Department of Medicine, University California San Francisco, San Francisco, California; and
| | - Philip M Swigart
- Veterans Affairs Medical Center, San Francisco, and Department of Medicine, University California San Francisco, San Francisco, California; and
| | - David H Lovett
- Veterans Affairs Medical Center, San Francisco, and Department of Medicine, University California San Francisco, San Francisco, California; and
| | - James T Stull
- Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas
| | - Paul C Simpson
- Veterans Affairs Medical Center, San Francisco, and Department of Medicine, University California San Francisco, San Francisco, California; and
| | - Anthony J Baker
- Veterans Affairs Medical Center, San Francisco, and Department of Medicine, University California San Francisco, San Francisco, California; and
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32
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Del Olmo-Turrubiarte A, Calzada-Torres A, Díaz-Rosas G, Palma-Lara I, Sánchez-Urbina R, Balderrábano-Saucedo NA, González-Márquez H, Garcia-Alonso P, Contreras-Ramos A. Mouse models for the study of postnatal cardiac hypertrophy. Int J Cardiol Heart Vasc 2015; 7:131-140. [PMID: 28785661 PMCID: PMC5497247 DOI: 10.1016/j.ijcha.2015.02.005] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2014] [Revised: 01/19/2015] [Accepted: 02/01/2015] [Indexed: 12/16/2022]
Abstract
The main objective of this study was to create a postnatal model for cardiac hypertrophy (CH), in order to explain the mechanisms that are present in childhood cardiac hypertrophy. Five days after implantation, intraperitoneal (IP) isoproterenol (ISO) was injected for 7 days to pregnant female mice. The fetuses were obtained at 15, 17 and 19 dpc from both groups, also newborns (NB), neonates (7-15 days) and young adults (6 weeks of age). Histopathological exams were done on the hearts. Immunohistochemistry and western blot demonstrated GATA4 and PCNA protein expression, qPCR real time the mRNA of adrenergic receptors (α-AR and β-AR), alpha and beta myosins (α-MHC, β-MHC) and GATA4. After the administration of ISO, there was no change in the number of offsprings. We observed significant structural changes in the size of the offspring hearts. Morphometric analysis revealed an increase in the size of the left ventricular wall and interventricular septum (IVS). Histopathological analysis demonstrated loss of cellular compaction and presence of left ventricular small fibrous foci after birth. Adrenergic receptors might be responsible for changing a physiological into a pathological hypertrophy. However GATA4 seemed to be the determining factor in the pathology. A new animal model was established for the study of pathologic CH in early postnatal stages.
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Affiliation(s)
- A Del Olmo-Turrubiarte
- Laboratorio de Investigación de Biología del Desarrollo y Teratogénesis Experimental, Hospital Infantil de México Federico Gómez (HIMFG), Mexico.,Posgrado en Biología Experimental, Universidad Autónoma Metropolitana, Mexico
| | - A Calzada-Torres
- Laboratorio de Investigación de Biología del Desarrollo y Teratogénesis Experimental, Hospital Infantil de México Federico Gómez (HIMFG), Mexico
| | - G Díaz-Rosas
- Laboratorio de Investigación de Biología del Desarrollo y Teratogénesis Experimental, Hospital Infantil de México Federico Gómez (HIMFG), Mexico
| | | | - R Sánchez-Urbina
- Laboratorio de Investigación de Biología del Desarrollo y Teratogénesis Experimental, Hospital Infantil de México Federico Gómez (HIMFG), Mexico
| | | | - H González-Márquez
- Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana, Mexico
| | | | - A Contreras-Ramos
- Laboratorio de Investigación de Biología del Desarrollo y Teratogénesis Experimental, Hospital Infantil de México Federico Gómez (HIMFG), Mexico
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Moore XL, Su Y, Fan Y, Zhang YY, Woodcock EA, Dart AM, Du XJ. Diverse regulation of cardiac expression of relaxin receptor by α1- and β1-adrenoceptors. Cardiovasc Drugs Ther 2014; 28:221-8. [PMID: 24852484 DOI: 10.1007/s10557-014-6525-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE Relaxin, a new drug for heart failure therapy, exerts its cardiac actions through relaxin family peptide receptor 1 (RXFP1). Factors regulating RXFP1 expression remain unknown. We have investigated effects of activation of adrenoceptors (AR), an important modulator in the development and prognosis of heart failure, on expression of RXFP1 in rat cardiomyocytes and mouse left ventricles (LV). METHODS Expression of RXFP1 at mRNA (real-time PCR) and protein levels (immunoblotting) was measured in cardiomyocytes treated with α- and β-AR agonists or antagonists. RXFP1 expression was also determined in the LV of transgenic mouse strains with cardiac-restricted overexpression of α1A-, α1B- or β2-AR. Specific inhibitors were used to explore signal pathways involved in α1-AR mediated regulation of RXFP1 in cardiomyocytes. RESULTS In cultured cardiomyocytes, α1-AR stimulation resulted in 2-3 fold increase in RXFP1 mRNA (P < 0.001), which was blocked by specific inhibitors for protein kinase C (PKC) or mitogen-activated protein kinases/extracellular signal-regulated kinases (MAPK/ERK). Activation of β1-, but not β2-AR, significantly inhibited RXFP1 expression (P < 0.001). Relative to respective wild-type controls, RXFP1 mRNA levels in the LV of mice overexpressing α1A- or α1B-AR were increased by 3- or 10-fold, respectively, but unchanged in β2-AR transgenic hearts. Upregulation by α1-AR stimulation RXFP1 expression was confirmed at protein levels both in vitro and in vivo. CONCLUSIONS Expression of RXFP1 was up-regulated by α1-AR but suppressed by β-AR, mainly β1-AR subtype, in cardiomyocytes. Future studies are warranted to characterize the functional significance of such regulation, especially in the setting of heart failure.
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Jensen BC, OʼConnell TD, Simpson PC. Alpha-1-adrenergic receptors in heart failure: the adaptive arm of the cardiac response to chronic catecholamine stimulation. J Cardiovasc Pharmacol 2014; 63:291-301. [PMID: 24145181 DOI: 10.1097/FJC.0000000000000032] [Citation(s) in RCA: 56] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Alpha-1-adrenergic receptors (ARs) are G protein-coupled receptors activated by catecholamines. The alpha-1A and alpha-1B subtypes are expressed in mouse and human myocardium, whereas the alpha-1D protein is found only in coronary arteries. There are far fewer alpha-1-ARs than beta-ARs in the nonfailing heart, but their abundance is maintained or increased in the setting of heart failure, which is characterized by pronounced chronic elevation of catecholamines and beta-AR dysfunction. Decades of evidence from gain and loss-of-function studies in isolated cardiac myocytes and numerous animal models demonstrate important adaptive functions for cardiac alpha-1-ARs to include physiological hypertrophy, positive inotropy, ischemic preconditioning, and protection from cell death. Clinical trial data indicate that blocking alpha-1-ARs is associated with incident heart failure in patients with hypertension. Collectively, these findings suggest that alpha-1-AR activation might mitigate the well-recognized toxic effects of beta-ARs in the hyperadrenergic setting of chronic heart failure. Thus, exogenous cardioselective activation of alpha-1-ARs might represent a novel and viable approach to the treatment of heart failure.
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35
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Wu SC, Dahl EF, Wright CD, Cypher AL, Healy CL, O'Connell TD. Nuclear localization of a1A-adrenergic receptors is required for signaling in cardiac myocytes: an “inside-out” a1-AR signaling pathway. J Am Heart Assoc 2014; 3:e000145. [PMID: 24772522 PMCID: PMC4187477 DOI: 10.1161/jaha.113.000145] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Background Recent studies indicate that α1‐adrenergic receptors (α1‐ARs) are cardioprotective by preventing cardiac myocyte death and augmenting contractility in heart failure. Although G‐protein‐coupled receptors are assumed to localize to and signal at the plasma membrane, we previously demonstrated that endogenous α1‐ARs localize to the nuclei in adult cardiac myocytes. However, the functional consequence of this nuclear localization remains unclear. Here, we attempted to reconcile nuclear localization of α1‐ARs with their physiologic function by examining α1‐AR‐induced contractility in adult cardiac myocytes. Methods and Results By measuring shortening in unloaded, cultured adult cardiac myocytes, we found that the α1A‐subtype regulated contractility through phosphorylation of cardiac troponin I (cTnI) at the protein kinase C (PKC) site, threonine 144. Reconstitution of an α1A‐subtype nuclear localization mutant in cardiac myocytes lacking α1‐ARs failed to rescue nuclear α1A‐mediated phosphorylation of cTnI and myocyte contractility. Leptomycin B, the nuclear export inhibitor, also blocked α1A‐mediated phosphorylation of cTnI. These data indicate that α1‐AR signaling originates in the nucleus. Consistent with these observations, we localized the α1A‐subtype to the inner nuclear membrane, identified PKCα, δ, and ε in the nucleus, and found that α1‐ARs activate PKCδ in nuclei isolated from adult cardiac myocytes. Finally, we found that a PKCδ nuclear localization mutant blunted α1‐induced phosphorylation of cTnI. Conclusions Together, our data identify a novel, “inside‐out” nuclear α1A‐subtype/PKCδ/cTnI‐signaling pathway that regulates contractile function in adult cardiac myocytes. Importantly, these data help resolve the discrepancy between nuclear localization of α1‐ARs and α1‐AR‐mediated physiologic function.
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Affiliation(s)
- Steven C. Wu
- Department of Integrative Biology and Physiology, The University of Minnesota, Minneapolis, MN (S.C.W., E.F.D., C.D.W., A.L.C., C.L.H., T.D.C.)
| | - Erika F. Dahl
- Department of Integrative Biology and Physiology, The University of Minnesota, Minneapolis, MN (S.C.W., E.F.D., C.D.W., A.L.C., C.L.H., T.D.C.)
| | - Casey D. Wright
- Department of Integrative Biology and Physiology, The University of Minnesota, Minneapolis, MN (S.C.W., E.F.D., C.D.W., A.L.C., C.L.H., T.D.C.)
- Novartis Animal Health US, Inc, 1447140th St, Larchwood, IA 51241
| | - Andrew L. Cypher
- Department of Integrative Biology and Physiology, The University of Minnesota, Minneapolis, MN (S.C.W., E.F.D., C.D.W., A.L.C., C.L.H., T.D.C.)
- Novartis Animal Health US, Inc, 1447140th St, Larchwood, IA 51241
| | - Chastity L. Healy
- Department of Integrative Biology and Physiology, The University of Minnesota, Minneapolis, MN (S.C.W., E.F.D., C.D.W., A.L.C., C.L.H., T.D.C.)
| | - Timothy D. O'Connell
- Department of Integrative Biology and Physiology, The University of Minnesota, Minneapolis, MN (S.C.W., E.F.D., C.D.W., A.L.C., C.L.H., T.D.C.)
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Walsh SK, Hector EE, Andréasson AC, Jönsson-Rylander AC, Wainwright CL. GPR55 deletion in mice leads to age-related ventricular dysfunction and impaired adrenoceptor-mediated inotropic responses. PLoS One 2014; 9:e108999. [PMID: 25275556 PMCID: PMC4183508 DOI: 10.1371/journal.pone.0108999] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 09/05/2014] [Indexed: 01/25/2023] Open
Abstract
G protein coupled receptor 55 (GPR55) is expressed throughout the body, and although its exact physiological function is unknown, studies have suggested a role in the cardiovascular system. In particular, GPR55 has been proposed as mediating the haemodynamic effects of a number of atypical cannabinoid ligands; however this data is conflicting. Thus, given the incongruous nature of our understanding of the GPR55 receptor and the relative paucity of literature regarding its role in cardiovascular physiology, this study was carried out to examine the influence of GPR55 on cardiac function. Cardiac function was assessed via pressure volume loop analysis, and cardiac morphology/composition assessed via histological staining, in both wild-type (WT) and GPR55 knockout (GPR55−/−) mice. Pressure volume loop analysis revealed that basal cardiac function was similar in young WT and GPR55−/− mice. In contrast, mature GPR55−/− mice were characterised by both significant ventricular remodelling (reduced left ventricular wall thickness and increased collagen deposition) and systolic dysfunction when compared to age-matched WT mice. In particular, the load-dependent parameter, ejection fraction, and the load-independent indices, end-systolic pressure-volume relationship (ESPVR) and Emax, were all significantly (P<0.05) attenuated in mature GPR55−/− mice. Furthermore, GPR55−/− mice at all ages were characterised by a reduced contractile reserve. Our findings demonstrate that mice deficient in GPR55 exhibit maladaptive adrenergic signalling, as evidenced by the reduced contractile reserve. Furthermore, with age these mice are characterised by both significant adverse ventricular remodelling and systolic dysfunction. Taken together, this may suggest a role for GPR55 in the control of adrenergic signalling in the heart and potentially a role for this receptor in the pathogenesis of heart failure.
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Affiliation(s)
- Sarah K. Walsh
- Institute for Health & Wellbeing Research, Robert Gordon University, Riverside East, Aberdeen, United Kingdom
| | - Emma E. Hector
- Institute for Health & Wellbeing Research, Robert Gordon University, Riverside East, Aberdeen, United Kingdom
| | | | | | - Cherry L. Wainwright
- Institute for Health & Wellbeing Research, Robert Gordon University, Riverside East, Aberdeen, United Kingdom
- * E-mail:
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Yu ZY, Tan JC, McMahon AC, Iismaa SE, Xiao XH, Kesteven SH, Reichelt ME, Mohl MC, Smith NJ, Fatkin D, Allen D, Head SI, Graham RM, Feneley MP. RhoA/ROCK signaling and pleiotropic α1A-adrenergic receptor regulation of cardiac contractility. PLoS One 2014; 9:e99024. [PMID: 24919197 PMCID: PMC4053326 DOI: 10.1371/journal.pone.0099024] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2014] [Accepted: 05/09/2014] [Indexed: 11/18/2022] Open
Abstract
Aims To determine the mechanisms by which the α1A-adrenergic receptor (AR) regulates cardiac contractility. Background We reported previously that transgenic mice with cardiac-restricted α1A-AR overexpression (α1A-TG) exhibit enhanced contractility but not hypertrophy, despite evidence implicating this Gαq/11-coupled receptor in hypertrophy. Methods Contractility, calcium (Ca2+) kinetics and sensitivity, and contractile proteins were examined in cardiomyocytes, isolated hearts and skinned fibers from α1A-TG mice (170-fold overexpression) and their non-TG littermates (NTL) before and after α1A-AR agonist stimulation and blockade, angiotensin II (AngII), and Rho kinase (ROCK) inhibition. Results Hypercontractility without hypertrophy with α1A-AR overexpression is shown to result from increased intracellular Ca2+ release in response to agonist, augmenting the systolic amplitude of the intracellular Ca2+ concentration [Ca2+]i transient without changing resting [Ca2+]i. In the absence of agonist, however, α1A-AR overexpression reduced contractility despite unchanged [Ca2+]i. This hypocontractility is not due to heterologous desensitization: the contractile response to AngII, acting via its Gαq/11-coupled receptor, was unaltered. Rather, the hypocontractility is a pleiotropic signaling effect of the α1A-AR in the absence of agonist, inhibiting RhoA/ROCK activity, resulting in hypophosphorylation of both myosin phosphatase targeting subunit 1 (MYPT1) and cardiac myosin light chain 2 (cMLC2), reducing the Ca2+ sensitivity of the contractile machinery: all these effects were rapidly reversed by selective α1A-AR blockade. Critically, ROCK inhibition in normal hearts of NTLs without α1A-AR overexpression caused hypophosphorylation of both MYPT1 and cMLC2, and rapidly reduced basal contractility. Conclusions We report for the first time pleiotropic α1A-AR signaling and the physiological role of RhoA/ROCK signaling in maintaining contractility in the normal heart.
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Affiliation(s)
- Ze-Yan Yu
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Cardiology Department, St Vincent’s Hospital, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Ju-Chiat Tan
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
| | - Aisling C. McMahon
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Cardiology Department, St Vincent’s Hospital, Darlinghurst, Australia
| | - Siiri E. Iismaa
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Xiao-Hui Xiao
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
| | | | | | - Marion C. Mohl
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
| | - Nicola J. Smith
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Diane Fatkin
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Cardiology Department, St Vincent’s Hospital, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - David Allen
- Physiology Department, University of Sydney, Sydney, Australia
| | - Stewart I. Head
- Physiology Department, University of New South Wales, Sydney, Australia
| | - Robert M. Graham
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Cardiology Department, St Vincent’s Hospital, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
| | - Michael P. Feneley
- Victor Chang Cardiac Research Institute, Darlinghurst, Australia
- Cardiology Department, St Vincent’s Hospital, Darlinghurst, Australia
- Faculty of Medicine, University of New South Wales, Sydney, Australia
- * E-mail:
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38
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Kim MY, Finch AM, Lumbers ER, Boyce AC, Gibson KJ, Eiby YA, Lingwood BE. Expression of adrenoceptor subtypes in preterm piglet heart is different to term heart. PLoS One 2014; 9:e92167. [PMID: 24670668 PMCID: PMC3966759 DOI: 10.1371/journal.pone.0092167] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 02/19/2014] [Indexed: 11/18/2022] Open
Abstract
Preterm delivery increases the risk of inadequate systemic blood flow and hypotension, and many preterm infants fail to respond to conventional inotrope treatments. If the profile of cardiac adrenoceptor subtypes in the preterm neonate is different to that at term this may contribute to these clinical problems. This study measured mRNA expression of β1, β2, α1A, α2A and α2B-adrenoceptor subtypes by real time PCR in term (113d), preterm (91d) and preterm piglets (91d) exposed to maternal glucocorticoid treatment. Abundance of β-adrenoceptor binding sites in the left ventricle was measured using saturation binding assays. Relative abundance of β1-adrenoceptor mRNA in untreated preterm hearts was ∼50% of term abundance in both left and right ventricles (P<0.001). Trends in receptor binding site density measurements supported this observation (P = 0.07). Glucocorticoid exposure increased β1-adrenoceptor mRNA levels in the right ventricle of preterm hearts (P = 0.008) but did not alter expression in the left ventricle (P>0.1). Relative abundance of α1A-adrenoceptor mRNA was the same in preterm and term piglet hearts (P = >0.1) but was reduced by maternal glucocorticoid treatment (P<0.01); α2A-adrenoceptor mRNA abundance was higher in untreated and glucocorticoid exposed preterm piglet hearts than in term piglets (P<0.001). There was no difference between male and female piglets in mRNA abundance of any of the genes studied. In conclusion, there is reduced mRNA abundance of β1-adrenoceptors in the preterm pig heart. If this lower expression of β-adrenoceptors occurs in human preterm infants, it could explain their poor cardiovascular function and their frequent failure to respond to commonly used inotropes.
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MESH Headings
- Animals
- Binding Sites
- Female
- Gene Expression Regulation, Developmental
- Heart/embryology
- Male
- Myocardium/metabolism
- Premature Birth/metabolism
- Receptors, Adrenergic/genetics
- Receptors, Adrenergic/metabolism
- Receptors, Adrenergic, alpha/genetics
- Receptors, Adrenergic, alpha/metabolism
- Receptors, Adrenergic, beta/genetics
- Receptors, Adrenergic, beta/metabolism
- Sus scrofa/embryology
- Term Birth/metabolism
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Affiliation(s)
- Min Young Kim
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
| | - Angela M. Finch
- Department of Pharmacology, School of Medical Sciences, The University of New South Wales, Sydney, Australia
| | - Eugenie R. Lumbers
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
- Department of Physiology, School of Medical Sciences, The University of New South Wales, Sydney, Australia
- School of Biomedical Sciences and Pharmacy, University of Newcastle, Newcastle, Australia
| | - Amanda C. Boyce
- Department of Physiology, School of Medical Sciences, The University of New South Wales, Sydney, Australia
| | - Karen J. Gibson
- Department of Physiology, School of Medical Sciences, The University of New South Wales, Sydney, Australia
| | - Yvonne A. Eiby
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
| | - Barbara E. Lingwood
- The University of Queensland, UQ Centre for Clinical Research, Brisbane, Australia
- * E-mail:
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Baker AJ. Adrenergic signaling in heart failure: a balance of toxic and protective effects. Pflugers Arch 2014; 466:1139-50. [PMID: 24623099 DOI: 10.1007/s00424-014-1491-5] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2014] [Revised: 02/24/2014] [Accepted: 02/26/2014] [Indexed: 10/25/2022]
Abstract
Heart failure with reduced ejection fraction involves activation of the sympathetic nervous system and chronic hyperactivation of the sympatho-adrenergic receptors (ARs) β-ARs and α1-ARs, which are thought to be cardiotoxic and worsen pathological remodeling and function. Concurrently, the failing heart manifests significant decreases in sympathetic nerve terminal density, decreased cardiac norepinephrine levels, and marked downregulation of β-AR abundance and signaling. Thus, a state of both feast and famine coexist with respect to the adrenergic state in heart failure. For the failing heart, the hyperadrenergic state is toxic. However, the role of hypoadrenergic mechanisms in the pathophysiology of heart failure is less clear. Cardiotoxic effects are known to arise from the β1-AR subtype, and use of β-AR blockers is a cornerstone of current heart failure therapy. However, cardioprotective effects arise from the β2-AR subtype that counteract hyperactive β1-AR signaling, but unfortunately, β2-AR cardioprotective signaling in heart failure is inhibited by β-AR blocker therapy. In contrast to current dogma, recent research shows β1-AR signaling can also be cardioprotective. Moreover, for some forms of heart failure, β2-AR signaling is cardiotoxic. Thus for both β-AR subtypes, there is a balance between cardiotoxic versus cardioprotective effects. In heart failure, stimulation of α1-ARs is widely thought to be cardiotoxic. However, also contrary to current dogma, recent research shows that α1-AR signaling is cardioprotective. Taken together, recent research identifies cardioprotective signaling arising from β1-AR, β2-AR, and α1-ARs. A goal for future therapies will to harness the protective effects of AR signaling while minimizing cardiotoxic effects. The trajectory of heart failure therapy changed radically from the previous and intuitive use of sympathetic agonists, which unfortunately resulted in greater mortality, to the current use of β-AR blockers, which initially seemed counterintuitive. As a cautionary note, if the slow adoption of beta-blocker therapy in heart failure is any guide, then new treatment strategies, especially counterintuitive therapies involving stimulating β-AR and α1-AR signaling, may take considerable time to develop and gain acceptance.
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Affiliation(s)
- Anthony J Baker
- Veterans Affairs Medical Center, San Francisco and Department of Medicine, University of California, Cardiology Division (111C), 4150 Clement St, San Francisco, CA, 94121, USA,
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40
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Bondarenko VE. A compartmentalized mathematical model of the β1-adrenergic signaling system in mouse ventricular myocytes. PLoS One 2014; 9:e89113. [PMID: 24586529 PMCID: PMC3931689 DOI: 10.1371/journal.pone.0089113] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2013] [Accepted: 01/14/2014] [Indexed: 01/08/2023] Open
Abstract
The β1-adrenergic signaling system plays an important role in the functioning of cardiac cells. Experimental data shows that the activation of this system produces inotropy, lusitropy, and chronotropy in the heart, such as increased magnitude and relaxation rates of [Ca2+]i transients and contraction force, and increased heart rhythm. However, excessive stimulation of β1-adrenergic receptors leads to heart dysfunction and heart failure. In this paper, a comprehensive, experimentally based mathematical model of the β1-adrenergic signaling system for mouse ventricular myocytes is developed, which includes major subcellular functional compartments (caveolae, extracaveolae, and cytosol). The model describes biochemical reactions that occur during stimulation of β1-adrenoceptors, changes in ionic currents, and modifications of Ca2+ handling system. Simulations describe the dynamics of major signaling molecules, such as cyclic AMP and protein kinase A, in different subcellular compartments; the effects of inhibition of phosphodiesterases on cAMP production; kinetics and magnitudes of phosphorylation of ion channels, transporters, and Ca2+ handling proteins; modifications of action potential shape and duration; magnitudes and relaxation rates of [Ca2+]i transients; changes in intracellular and transmembrane Ca2+ fluxes; and [Na+]i fluxes and dynamics. The model elucidates complex interactions of ionic currents upon activation of β1-adrenoceptors at different stimulation frequencies, which ultimately lead to a relatively modest increase in action potential duration and significant increase in [Ca2+]i transients. In particular, the model includes two subpopulations of the L-type Ca2+ channels, in caveolae and extracaveolae compartments, and their effects on the action potential and [Ca2+]i transients are investigated. The presented model can be used by researchers for the interpretation of experimental data and for the developments of mathematical models for other species or for pathological conditions.
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Affiliation(s)
- Vladimir E. Bondarenko
- Department of Mathematics and Statistics and Neuroscience Institute, Georgia State University, Atlanta, Georgia, United States of America
- * E-mail:
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41
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O'Connell TD, Jensen BC, Baker AJ, Simpson PC. Cardiac alpha1-adrenergic receptors: novel aspects of expression, signaling mechanisms, physiologic function, and clinical importance. Pharmacol Rev 2013; 66:308-33. [PMID: 24368739 DOI: 10.1124/pr.112.007203] [Citation(s) in RCA: 126] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Adrenergic receptors (AR) are G-protein-coupled receptors (GPCRs) that have a crucial role in cardiac physiology in health and disease. Alpha1-ARs signal through Gαq, and signaling through Gq, for example, by endothelin and angiotensin receptors, is thought to be detrimental to the heart. In contrast, cardiac alpha1-ARs mediate important protective and adaptive functions in the heart, although alpha1-ARs are only a minor fraction of total cardiac ARs. Cardiac alpha1-ARs activate pleiotropic downstream signaling to prevent pathologic remodeling in heart failure. Mechanisms defined in animal and cell models include activation of adaptive hypertrophy, prevention of cardiac myocyte death, augmentation of contractility, and induction of ischemic preconditioning. Surprisingly, at the molecular level, alpha1-ARs localize to and signal at the nucleus in cardiac myocytes, and, unlike most GPCRs, activate "inside-out" signaling to cause cardioprotection. Contrary to past opinion, human cardiac alpha1-AR expression is similar to that in the mouse, where alpha1-AR effects are seen most convincingly in knockout models. Human clinical studies show that alpha1-blockade worsens heart failure in hypertension and does not improve outcomes in heart failure, implying a cardioprotective role for human alpha1-ARs. In summary, these findings identify novel functional and mechanistic aspects of cardiac alpha1-AR function and suggest that activation of cardiac alpha1-AR might be a viable therapeutic strategy in heart failure.
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Affiliation(s)
- Timothy D O'Connell
- VA Medical Center (111-C-8), 4150 Clement St., San Francisco, CA 94121. ; or Dr. Timothy D. O'Connell, E-mail:
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Papay RS, Shi T, Piascik MT, Naga Prasad SV, Perez DM. α₁A-adrenergic receptors regulate cardiac hypertrophy in vivo through interleukin-6 secretion. Mol Pharmacol 2013; 83:939-48. [PMID: 23404509 DOI: 10.1124/mol.112.084483] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
The role of α₁-adrenergic receptors (ARs) in the regulation of cardiac hypertrophy is still unclear, because transgenic mice demonstrated hypertrophy or the lack of it despite high receptor overexpression. To further address the role of the α₁-ARs in cardiac hypertrophy, we analyzed unique transgenic mice that overexpress constitutively active mutation (CAM) α₁A-ARs or CAM α₁B-ARs under the regulation of large fragments of their native promoters. These constitutively active receptors are expressed in all tissues that endogenously express their wild-type counterparts as opposed to only myocyte-targeted transgenic mice. In this study, we discovered that CAM α₁A-AR mice in vivo have cardiac hypertrophy independent of changes in blood pressure, corroborating earlier studies, but in contrast to myocyte-targeted α₁A-AR mice. We also found cardiac hypertrophy in CAM α₁B-AR mice, in agreement with previous studies, but hypertrophy only developed in older mice. We also discovered unique α₁-AR-mediated hypertrophic signaling that was AR subtype-specific with CAM α₁A-AR mice secreting atrial naturietic factor and interleukin-6 (IL-6), whereas CAM α₁B-AR mice expressed activated nuclear factor-κB (NF-κB). These particular hypertrophic signals were blocked when the other AR subtype was coactivated. We also discovered that crossbreeding the two CAM models (double CAM α₁A/B-AR) inhibited the development of hypertrophy and was reversible with single receptor activation, suggesting that coactivation of the receptors can lead to novel antagonistic signal transduction. This was confirmed by demonstrating antagonistic signals that were even lower than normal controls in the double CAM α₁A/B-AR mice for p38, NF-κB, and the IL-6/glycoprotein 130/signal transducer and activator of transcription 3 pathway. Because α₁A/B double knockout mice fail to develop hypertrophy in response to IL-6, our results suggest that IL-6 is a major mediator of α₁A-AR cardiac hypertrophy.
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Affiliation(s)
- Robert S Papay
- Department of Molecular Cardiology, Lerner Research Institute, Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA
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Chu C, Thai K, Park KW, Wang P, Makwana O, Lovett DH, Simpson PC, Baker AJ. Intraventricular and interventricular cellular heterogeneity of inotropic responses to α(1)-adrenergic stimulation. Am J Physiol Heart Circ Physiol 2013; 304:H946-53. [PMID: 23355341 DOI: 10.1152/ajpheart.00822.2012] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
α1-Adrenergic receptors (α1-ARs) elicit a negative inotropic effect (NIE) in the mouse right ventricular (RV) myocardium but a positive inotropic effect (PIE) in the left ventricular (LV) myocardium. Effects on myofilament Ca(2+) sensitivity play a role, but effects on Ca(2+) handling could also contribute. We monitored the effects of α1-AR stimulation on contraction and Ca(2+) transients using single myocytes isolated from the RV or LV. Interestingly, for both the RV and LV, we found heterogeneous myocyte inotropic responses. α1-ARs mediated either a PIE or NIE, although RV myocytes had a greater proportion of cells manifesting a NIE (68%) compared with LV myocytes (36%). Stimulation of a single α1-AR subtype (α1A-ARs) with a subtype-selective agonist also elicited heterogeneous inotropic responses, suggesting that the heterogeneity arose from events downstream of the α1A-AR subtype. For RV and LV myocytes, an α1-AR-mediated PIE was associated with an increased Ca(2+) transient and a NIE was associated with a decreased Ca(2+) transient, suggesting a key role for Ca(2+) handling. For RV and LV myocytes, α1-AR-mediated decreases in the Ca(2+) transient were associated with increased Ca(2+) export from the cell and decreased Ca(2+) content of the sarcoplasmic reticulum. In contrast, for myocytes with α1-AR-induced increased Ca(2+) transients, sarcoplasmic reticulum Ca(2+) content was not increased, suggesting that other mechanisms contributed to the increased Ca(2+) transients. This study demonstrates the marked heterogeneity of LV and RV cellular inotropic responses to stimulation of α1-ARs and reveals a new aspect of biological heterogeneity among myocytes in the regulation of contraction.
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Affiliation(s)
- Charles Chu
- Veterans Affairs Medical Center, San Francisco, CA 94121, USA
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Vettel C, Wittig K, Vogt A, Wuertz CM, El-Armouche A, Lutz S, Wieland T. A novel player in cellular hypertrophy: Giβγ/PI3K-dependent activation of the RacGEF TIAM-1 is required for α₁-adrenoceptor induced hypertrophy in neonatal rat cardiomyocytes. J Mol Cell Cardiol 2012; 53:165-75. [PMID: 22564263 DOI: 10.1016/j.yjmcc.2012.04.015] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/11/2011] [Revised: 04/25/2012] [Accepted: 04/26/2012] [Indexed: 01/08/2023]
Abstract
Activation of α(1)-adrenoceptors (α(1)-AR) by high catecholamine levels, e.g. in heart failure, is thought to be a driving force of cardiac hypertrophy. In this context several downstream mediators and cascades have been identified to potentially play a role in cardiomyocyte hypertrophy. One of these proteins is the monomeric G protein Rac1. However, until now it is unclear how this essential G protein is activated by α(1)-AR agonists and what are the downstream targets inducing cellular growth. By using protein-based as well as pharmacological inhibitors and the shRNA technique, we demonstrate that in neonatal rat cardiomyocytes (NRCM) Rac1 is activated via a cascade involving the α(1A)-AR subtype, G(i)βγ, the phosphoinositide-3'-kinase and the guanine nucleotide exchange factor Tiam1. We further demonstrate that this signaling induces an increase in protein synthesis, cell size and atrial natriuretic peptide expression. We identified the p21-activated kinase 2 (PAK2) as a downstream effector of Rac1 and were able to link this cascade to the activation of the pro-hypertrophic kinases ERK1/2 and p90RSK. Our data thus reveal a prominent role of the α(1A)-AR/G(i)βγ/Tiam1-mediated activation of Rac1 and its effector PAK2 in the induction of hypertrophy in NRCM.
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45
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von Lueder TG, Gravning J, How OJ, Vinge LE, Ahmed MS, Krobert KA, Levy FO, Larsen TS, Smiseth OA, Aasum E, Attramadal H. Cardiomyocyte-restricted inhibition of G protein-coupled receptor kinase-3 attenuates cardiac dysfunction after chronic pressure overload. Am J Physiol Heart Circ Physiol 2012; 303:H66-74. [PMID: 22542621 DOI: 10.1152/ajpheart.00724.2011] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Transgenic mice with cardiac-specific expression of a peptide inhibitor of G protein-coupled receptor kinase (GRK)3 [transgenic COOH-terminal GRK3 (GRK3ct) mice] display myocardial hypercontractility without hypertrophy and enhanced α(1)-adrenergic receptor signaling. A role for GRK3 in the pathogenesis of heart failure (HF) has not been investigated, but inhibition of its isozyme, GRK2, has been beneficial in several HF models. Here, we tested whether inhibition of GRK3 modulated evolving cardiac hypertrophy and dysfunction after pressure overload. Weight-matched male GRK3ct transgenic and nontransgenic littermate control (NLC) mice subjected to chronic pressure overload by abdominal aortic banding (AB) were compared with sham-operated (SH) mice. At 6 wk after AB, a significant increase of cardiac mass consistent with induction of hypertrophy was found, but no differences between GRK3ct-AB and NLC-AB mice were discerned. Simultaneous left ventricular (LV) pressure-volume analysis of electrically paced, ex vivo perfused working hearts revealed substantially reduced systolic and diastolic function in NLC-AB mice (n = 7), which was completely preserved in GRK3ct-AB mice (n = 7). An additional cohort was subjected to in vivo cardiac catheterization and LV pressure-volume analysis at 12 wk after AB. NLC-AB mice (n = 11) displayed elevated end-diastolic pressure (8.5 ± 3.1 vs. 2.9 ± 1.2 mmHg, P < 0.05), reduced cardiac output (3,448 ± 323 vs. 4,488 ± 342 μl/min, P < 0.05), and reduced dP/dt(max) and dP/dt(min) (both P < 0.05) compared with GRK3ct-AB mice (n = 16), corroborating the preserved cardiac structure and function observed in GRK3ct-AB hearts assessed ex vivo. Increased cardiac mass and myocardial mRNA expression of β-myosin heavy chain confirmed the similar induction of cardiac hypertrophy in both AB groups, but only NLC-AB hearts displayed significantly elevated mRNA levels of brain natriuretic peptide and myocardial collagen contents as well as reduced β(1)-adrenergic receptor responsiveness to isoproterenol, indicating increased LV wall stress and the transition to HF. Inhibition of cardiac GRK3 in mice does not alter the hypertrophic response but attenuates cardiac dysfunction and HF after chronic pressure overload.
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Affiliation(s)
- Thomas G von Lueder
- Institute for Surgical Research, Oslo University Hospital, Rikshospitalet, Norway
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Zhao X, Park J, Ho D, Gao S, Yan L, Ge H, Iismaa S, Lin L, Tian B, Vatner DE, Graham RM, Vatner SF. Cardiomyocyte overexpression of the α1A-adrenergic receptor in the rat phenocopies second but not first window preconditioning. Am J Physiol Heart Circ Physiol 2012; 302:H1614-24. [PMID: 22307672 DOI: 10.1152/ajpheart.01072.2011] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We examined α(1A)-adrenergic receptor (AR) mediation of preconditioning in a novel α(1A)-AR cardiac transgenic (TG) rat model (α(1A)-TG). Compared with nontransgenic littermates (NTLs), in conscious α(1A)-TG rats, heart rate was reduced, contractility [left ventricle (LV) +dP/dt, ejection fraction, end-systolic elastance] was significantly enhanced, and triple product (LV systolic wall stress × LV +dP/dt × heart rate) was unchanged. However, infarct size (IS)/area at risk (AAR) in response to ischemia-reperfusion (30 min coronary occlusion/3 h reperfusion) was reduced to 35 ± 4.6% in α(1A)-TGs vs. 52 ± 2.2% in NTLs (P < 0.05). Second window preconditioning reduced IS/AAR in NTLs to 29 ± 2.7% but did not afford further protection in α(1A)-TGs. In contrast, with first window preconditioning, IS/AAR was reduced to similar levels in both α(1A)-TGs (12 ± 1.4%) and NTLs (10 ± 1.1%). In untreated α(1A)-TGs, cardioprotection was associated with enhanced myocardial phosphorylated (p)-mitogen/extracellular signal-regulated kinase (MEK), p-extracellular signal-regulated kinase (ERK), and inducible nitric oxide synthase (iNOS) at the protein level, along with a 1.3-fold increase in total nitric oxide synthase activity like in second window preconditioning. Affymetrix microarrays revealed that few genes (4.6% of 3,172 upregulated; 8.8% of 3,498 downregulated) showed directionally similar changes in α(1A)-TGs vs. NTLs subjected to second window preconditioning. Thus, second, but not first, window cardioprotection is evident in α(1A)-TGs in the absence of ischemic preconditioning and is mediated by iNOS activation associated with MEK/ERK phosphorylation. Transcriptionally, however, second window preconditioning is considerably more complex than α(1A)-TG preconditioning, with the alteration of thousands of additional genes affording no further protection than that already available in α(1A)-TG rats.
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Affiliation(s)
- Xin Zhao
- Department of Cell Biology and Molecular Medicine, Cardiovascular Research Institute, University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, New Jersey 07103, USA
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Liu F, He K, Yang X, Xu N, Liang Z, Xu M, Zhao X, Han Q, Zhang Y. α1A-adrenergic receptor induces activation of extracellular signal-regulated kinase 1/2 through endocytic pathway. PLoS One 2011; 6:e21520. [PMID: 21738688 PMCID: PMC3125289 DOI: 10.1371/journal.pone.0021520] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Accepted: 05/30/2011] [Indexed: 11/22/2022] Open
Abstract
G protein-coupled receptors (GPCRs) activate mitogen-activated protein kinases through a number of distinct pathways in cells. Increasing evidence has suggested that endosomal signaling has an important role in receptor signal transduction. Here we investigated the involvement of endocytosis in α1A-adrenergic receptor (α1A-AR)-induced activation of extracellular signal-regulated kinase 1/2 (ERK1/2). Agonist-mediated endocytic traffic of α1A-AR was assessed by real-time imaging of living, stably transfected human embryonic kidney 293A cells (HEK-293A). α1A-AR was internalized dynamically in cells with agonist stimulation, and actin filaments regulated the initial trafficking of α1A-AR. α1A-AR-induced activation of ERK1/2 but not p38 MAPK was sensitive to disruption of endocytosis, as demonstrated by 4°C chilling, dynamin mutation and treatment with cytochalasin D (actin depolymerizing agent). Activation of protein kinase C (PKC) and C-Raf by α1A-AR was not affected by 4°C chilling or cytochalasin D treatment. U73122 (a phospholipase C [PLC] inhibitor) and Ro 31–8220 (a PKC inhibitor) inhibited α1B-AR- but not α1A-AR-induced ERK1/2 activation. These data suggest that the endocytic pathway is involved in α1A-AR-induced ERK1/2 activation, which is independent of Gq/PLC/PKC signaling.
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Affiliation(s)
- Fei Liu
- Institute of Vascular Medicine, Peking University Third Hospital, and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China
| | - Kangmin He
- Institute of Vascular Medicine, Peking University Third Hospital, and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China
| | - Xinxing Yang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Biodynamic Optical Imaging Center, Peking University, Beijing, China
| | - Ning Xu
- Institute of Vascular Medicine, Peking University Third Hospital, and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China
| | - Zhangyi Liang
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Biodynamic Optical Imaging Center, Peking University, Beijing, China
| | - Ming Xu
- Institute of Vascular Medicine, Peking University Third Hospital, and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China
| | - Xinsheng Zhao
- Beijing National Laboratory for Molecular Sciences, State Key Laboratory for Structural Chemistry of Unstable and Stable Species, Department of Chemical Biology, College of Chemistry and Molecular Engineering, Biodynamic Optical Imaging Center, Peking University, Beijing, China
| | - Qide Han
- Institute of Vascular Medicine, Peking University Third Hospital, and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China
| | - Youyi Zhang
- Institute of Vascular Medicine, Peking University Third Hospital, and Key Laboratory of Molecular Cardiovascular Sciences, Ministry of Education, Beijing, China
- * E-mail:
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Ho D, Yan L, Iwatsubo K, Vatner DE, Vatner SF. Modulation of beta-adrenergic receptor signaling in heart failure and longevity: targeting adenylyl cyclase type 5. Heart Fail Rev 2011; 15:495-512. [PMID: 20658186 DOI: 10.1007/s10741-010-9183-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
Despite remarkable advances in therapy, heart failure remains a leading cause of morbidity and mortality. Although enhanced beta-adrenergic receptor stimulation is part of normal physiologic adaptation to either the increase in physiologic demand or decrease in cardiac function, chronic beta-adrenergic stimulation has been associated with increased mortality and morbidity in both animal models and humans. For example, overexpression of cardiac Gsalpha or beta-adrenergic receptors in transgenic mice results in enhanced cardiac function in young animals, but with prolonged overstimulation of this pathway, cardiomyopathy develops in these mice as they age. Similarly, chronic sympathomimetic amine therapy increases morbidity and mortality in patients with heart failure. Conversely, the use of beta-blockade has proven to be of benefit and is currently part of the standard of care for heart failure. It is conceivable that interrupting distal mechanisms in the beta-adrenergic receptor-G protein-adenylyl cyclase pathway may also provide targets for future therapeutic modalities for heart failure. Interestingly, there are two major isoforms of adenylyl cyclase (AC) in the heart (type 5 and type 6), which may exert opposite effects on the heart, i.e., cardiac overexpression of AC6 appears to be protective, whereas disruption of type 5 AC prolongs longevity and protects against cardiac stress. The goal of this review is to summarize the paradigm shift in the treatment of heart failure over the past 50 years from administering sympathomimetic amine agonists to administering beta-adrenergic receptor antagonists, and to explore the basis for a novel therapy of inhibiting type 5 AC.
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Affiliation(s)
- David Ho
- Department of Cell Biology and Molecular Medicine and The Cardiovascular Research Institute, University of Medicine & Dentistry of New Jersey, New Jersey Medical School, 185 South Orange Avenue, MSB G609, Newark, NJ 07103, USA
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Mohl MC, Iismaa SE, Xiao XH, Friedrich O, Wagner S, Nikolova-Krstevski V, Wu J, Yu ZY, Feneley M, Fatkin D, Allen DG, Graham RM. Regulation of murine cardiac contractility by activation of α1A-adrenergic receptor-operated Ca2+ entry. Cardiovasc Res 2011; 91:310-9. [DOI: 10.1093/cvr/cvr081] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Abstract
Sympathetic nervous system regulation by the α(1)-adrenergic receptor (AR) subtypes (α(1A), α(1B), α(1D)) is complex, whereby chronic activity can be either detrimental or protective for both heart and brain function. This review will summarize the evidence that this dual regulation can be mediated through the different α(1)-AR subtypes in the context of cardiac hypertrophy, heart failure, apoptosis, ischemic preconditioning, neurogenesis, locomotion, neurodegeneration, cognition, neuroplasticity, depression, anxiety, epilepsy, and mental illness.
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Affiliation(s)
- Dianne M Perez
- Department of Molecular Cardiology, NB50, The Lerner Research Institute, The Cleveland Clinic Foundation, Cleveland, Ohio 44195, USA.
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