2
|
Marczewski K, Gospodarczyk N, Gospodarczyk A, Widuch M, Tkocz M. APELIN IN HEART FAILURE. WIADOMOSCI LEKARSKIE (WARSAW, POLAND : 1960) 2022; 75:2501-2506. [PMID: 36472288 DOI: 10.36740/wlek202210130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/17/2023]
Abstract
Apelin is a biologically active protein encoded by the APLN gene. It was first isolated in 1998 as a ligand for the APJ receptor. It exists in several isoforms differing in polypeptide chain length and biological activity. It is secreted by white adipose tissue, and its expression has been identified in many body tissues, including the cardiovascular system, kidneys, lungs, CNS (especially the hypothalamus, suprachiasmatic and ventricular nuclei), skeletal muscle, mammary glands, adrenal glands, ovaries, stomach, liver cells, placenta, and breast milk. However, the highest concentrations were observed in the endocardium and endothelium of vascular smooth muscle cells. In myocardial tissue, apelin has a positive inotropic effect and exerts an opposing effect to the RAA (renin-angiotensin-aldosterone) system, lowering blood pressure. Therefore, its positive role in early stages of heart failure, in patients with hypertension and ischemic heart disease is emphasized. The synthesis and secretion of apelin by adipocytes makes it possible to classify this peptide as an adipokine. Therefore, its production in adipose tissue is enhanced in obesity. Furthermore, apelin has been shown to increase cellular sensitivity to insulin and improve glucose tolerance in the onset of type 2 diabetes, and therefore appears to play a significant role in the pathogenesis of metabolic disease. An accurate assessment of the importance of apelin in cardiovascular disease requires further studies, which may contribute to the use of apelin in the treatment of heart failure.
Collapse
Affiliation(s)
- Kamil Marczewski
- DEPARTMENT OF EMERGENCY MEDICINE, MEDICAL UNIVERSITY OF SILESIA, POLAND
| | | | | | - Michał Widuch
- DEPARTMENT OF BIOCHEMISTRY, MEDICAL UNIVERSITY OF SILESIA, POLAND
| | - Michał Tkocz
- UROLOGICAL DEPARTMENT OF MUNICIPAL HOSPITAL, MEDICAL UNIVERSITY OF SILESIA, POLAND
| |
Collapse
|
4
|
Ashokan A, Harisankar HS, Kameswaran M, Aradhyam GK. Critical APJ receptor residues in extracellular domains that influence effector selectivity. FEBS J 2021; 288:6543-6562. [PMID: 34076959 DOI: 10.1111/febs.16048] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2020] [Revised: 04/14/2021] [Accepted: 05/01/2021] [Indexed: 11/29/2022]
Abstract
Human APJ receptor/apelin receptor (APJR), activated by apelin peptide isoforms, regulates a wide range of physiological processes. The role of extracellular loop (ECL) domain residues of APJR in ligand binding and receptor activation has not been established yet. Based on multiple sequence alignment of APJ receptor from various organisms, we identified conserved residues in the extracellular domains. Alanine substitutions of specific residues were characterized to evaluate their ligand binding efficiency and Gq -, Gi -, and β-arrestin-mediated signaling. Mutation-dependent variation in ligand binding and signaling was observed. W197 A in ECL2 and L276 L277 W279 -AAA in ECL3 were deficient in Gi and β-arrestin signaling pathways with relatively preserved Gq -mediated signaling. T169 T170 -AA, Y182 A, and T190 A mutants in ECL2 showed impaired β-arrestin-dependent cell signaling while maintaining G protein- mediated signaling. Structural comparison with angiotensin II type I receptor revealed the importance of ECL2 and ECL3 residues in APJR ligand binding and signaling. Our results unequivocally confirm the specific role of these ECL residues in ligand binding and in orchestrating receptor conformations that are involved in preferential/biased signaling functions.
Collapse
Affiliation(s)
- Anisha Ashokan
- Signal Transduction Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
| | - Harikumar Sheela Harisankar
- Signal Transduction Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
| | - Mythili Kameswaran
- Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai, India
| | - Gopala Krishna Aradhyam
- Signal Transduction Laboratory, Department of Biotechnology, Bhupat and Jyoti Mehta School of Biosciences, Indian Institute of Technology Madras, Chennai, India
| |
Collapse
|
5
|
Chen P, Wang Y, Chen L, Song N, Xie J. Apelin-13 Protects Dopaminergic Neurons against Rotenone-Induced Neurotoxicity through the AMPK/mTOR/ULK-1 Mediated Autophagy Activation. Int J Mol Sci 2020; 21:ijms21218376. [PMID: 33171641 PMCID: PMC7664695 DOI: 10.3390/ijms21218376] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2020] [Revised: 10/29/2020] [Accepted: 11/02/2020] [Indexed: 02/07/2023] Open
Abstract
Parkinson’s disease (PD) is characterized by the progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Several brain–gut peptides are able to exert neuroprotective effects on the nigrostriatal dopaminergic system. Apelin-13 is a neuropeptide, conveying potential neuroprotective activities. However, whether, and how, apelin-13 could antagonize rotenone-induced neurotoxicity has not yet been elucidated. In the present study, rotenone-treated SH-SY5Y cells and rats were used to clarify whether apelin-13 has protective effects on dopaminergic neurons, both in vivo and in vitro. The results showed that apelin-13 could protect SH-SY5Y cells from rotenone-induced injury and apoptosis. Apelin-13 was able to activate autophagy, and restore rotenone induced autophagy impairment in SH-SY5Y cells, which could be blocked by the autophagy inhibitor 3-Methyladenine. Apelin-13 activated AMPK/mTOR/ULK-1 signaling, AMPKα inhibitor compound C, as well as apelin receptor blockage via siRNA, which could block apelin-13-induced signaling activation, autophagy activation, and protective effects, in rotenone-treated SH-SY5Y cells. These results indicated that apelin-13 exerted neuroprotective properties against rotenone by stimulating AMPK/mTOR/ULK-1 signaling-mediated autophagy via the apelin receptor. We also observed that intracerebroventricular injection of apelin-13 could alleviate nigrostriatal dopaminergic neuron degeneration in rotenone-treated rats. Our findings provide new insights into the mechanism by which apelin-13 might attenuate neurotoxicity in PD.
Collapse
Affiliation(s)
- Peng Chen
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Qingdao University, Qingdao 266071, China; (P.C.); (Y.W.); (L.C.)
- Department of Physiology, College of Basic Medicine, Shandong First Medical University & Shandong Academy of Medical Sciences, Jinan 250000, China
| | - Youcui Wang
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Qingdao University, Qingdao 266071, China; (P.C.); (Y.W.); (L.C.)
| | - Leilei Chen
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Qingdao University, Qingdao 266071, China; (P.C.); (Y.W.); (L.C.)
| | - Ning Song
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Qingdao University, Qingdao 266071, China; (P.C.); (Y.W.); (L.C.)
- Correspondence: (N.S.); or (J.X.)
| | - Junxia Xie
- Institute of Brain Science and Disease, Shandong Provincial Key Laboratory of Pathogenesis and Prevention of Neurological Disorders, Shandong Provincial Collaborative Innovation Center for Neurodegenerative Disorders, Qingdao University, Qingdao 266071, China; (P.C.); (Y.W.); (L.C.)
- Correspondence: (N.S.); or (J.X.)
| |
Collapse
|
6
|
Read C, Nyimanu D, Williams TL, Huggins DJ, Sulentic P, Macrae RGC, Yang P, Glen RC, Maguire JJ, Davenport AP. International Union of Basic and Clinical Pharmacology. CVII. Structure and Pharmacology of the Apelin Receptor with a Recommendation that Elabela/Toddler Is a Second Endogenous Peptide Ligand. Pharmacol Rev 2019; 71:467-502. [PMID: 31492821 PMCID: PMC6731456 DOI: 10.1124/pr.119.017533] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The predicted protein encoded by the APJ gene discovered in 1993 was originally classified as a class A G protein-coupled orphan receptor but was subsequently paired with a novel peptide ligand, apelin-36 in 1998. Substantial research identified a family of shorter peptides activating the apelin receptor, including apelin-17, apelin-13, and [Pyr1]apelin-13, with the latter peptide predominating in human plasma and cardiovascular system. A range of pharmacological tools have been developed, including radiolabeled ligands, analogs with improved plasma stability, peptides, and small molecules including biased agonists and antagonists, leading to the recommendation that the APJ gene be renamed APLNR and encode the apelin receptor protein. Recently, a second endogenous ligand has been identified and called Elabela/Toddler, a 54-amino acid peptide originally identified in the genomes of fish and humans but misclassified as noncoding. This precursor is also able to be cleaved to shorter sequences (32, 21, and 11 amino acids), and all are able to activate the apelin receptor and are blocked by apelin receptor antagonists. This review summarizes the pharmacology of these ligands and the apelin receptor, highlights the emerging physiologic and pathophysiological roles in a number of diseases, and recommends that Elabela/Toddler is a second endogenous peptide ligand of the apelin receptor protein.
Collapse
Affiliation(s)
- Cai Read
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, United Kingdom (C.R., D.N., T.L.W., D.J.H., P.S., R.G.C.M., P.Y., J.J.M., A.P.D.); The Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, Cambridge, United Kingdom (D.J.H., R.C.G.); and Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom (R.C.G.)
| | - Duuamene Nyimanu
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, United Kingdom (C.R., D.N., T.L.W., D.J.H., P.S., R.G.C.M., P.Y., J.J.M., A.P.D.); The Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, Cambridge, United Kingdom (D.J.H., R.C.G.); and Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom (R.C.G.)
| | - Thomas L Williams
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, United Kingdom (C.R., D.N., T.L.W., D.J.H., P.S., R.G.C.M., P.Y., J.J.M., A.P.D.); The Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, Cambridge, United Kingdom (D.J.H., R.C.G.); and Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom (R.C.G.)
| | - David J Huggins
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, United Kingdom (C.R., D.N., T.L.W., D.J.H., P.S., R.G.C.M., P.Y., J.J.M., A.P.D.); The Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, Cambridge, United Kingdom (D.J.H., R.C.G.); and Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom (R.C.G.)
| | - Petra Sulentic
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, United Kingdom (C.R., D.N., T.L.W., D.J.H., P.S., R.G.C.M., P.Y., J.J.M., A.P.D.); The Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, Cambridge, United Kingdom (D.J.H., R.C.G.); and Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom (R.C.G.)
| | - Robyn G C Macrae
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, United Kingdom (C.R., D.N., T.L.W., D.J.H., P.S., R.G.C.M., P.Y., J.J.M., A.P.D.); The Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, Cambridge, United Kingdom (D.J.H., R.C.G.); and Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom (R.C.G.)
| | - Peiran Yang
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, United Kingdom (C.R., D.N., T.L.W., D.J.H., P.S., R.G.C.M., P.Y., J.J.M., A.P.D.); The Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, Cambridge, United Kingdom (D.J.H., R.C.G.); and Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom (R.C.G.)
| | - Robert C Glen
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, United Kingdom (C.R., D.N., T.L.W., D.J.H., P.S., R.G.C.M., P.Y., J.J.M., A.P.D.); The Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, Cambridge, United Kingdom (D.J.H., R.C.G.); and Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom (R.C.G.)
| | - Janet J Maguire
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, United Kingdom (C.R., D.N., T.L.W., D.J.H., P.S., R.G.C.M., P.Y., J.J.M., A.P.D.); The Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, Cambridge, United Kingdom (D.J.H., R.C.G.); and Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom (R.C.G.)
| | - Anthony P Davenport
- Experimental Medicine and Immunotherapeutics, University of Cambridge, Centre for Clinical Investigation, Addenbrooke's Hospital, Cambridge, United Kingdom (C.R., D.N., T.L.W., D.J.H., P.S., R.G.C.M., P.Y., J.J.M., A.P.D.); The Centre for Molecular Informatics, Department of Chemistry, University of Cambridge, Cambridge, United Kingdom (D.J.H., R.C.G.); and Computational and Systems Medicine, Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London, United Kingdom (R.C.G.)
| |
Collapse
|
8
|
Abstract
Apelin and apela (ELABELA/ELA/Toddler) are two peptide ligands for a class A G-protein-coupled receptor named the apelin receptor (AR/APJ/APLNR). Ligand-AR interactions have been implicated in regulation of the adipoinsular axis, cardiovascular system, and central nervous system alongside pathological processes. Each ligand may be processed into a variety of bioactive isoforms endogenously, with apelin ranging from 13 to 55 amino acids and apela from 11 to 32, typically being cleaved C-terminal to dibasic proprotein convertase cleavage sites. The C-terminal region of the respective precursor protein is retained and is responsible for receptor binding and subsequent activation. Interestingly, both apelin and apela exhibit isoform-dependent variability in potency and efficacy under various physiological and pathological conditions, but most studies focus on a single isoform. Biophysical behavior and structural properties of apelin and apela isoforms show strong correlations with functional studies, with key motifs now well determined for apelin. Unlike its ligands, the AR has been relatively difficult to characterize by biophysical techniques, with most characterization to date being focused on effects of mutagenesis. This situation may improve following a recently reported AR crystal structure, but there are still barriers to overcome in terms of comprehensive biophysical study. In this review, we summarize the three components of the apelinergic system in terms of structure-function correlation, with a particular focus on isoform-dependent properties, underlining the potential for regulation of the system through multiple endogenous ligands and isoforms, isoform-dependent pharmacological properties, and biological membrane-mediated receptor interaction. © 2018 American Physiological Society. Compr Physiol 8:407-450, 2018.
Collapse
Affiliation(s)
- Kyungsoo Shin
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Calem Kenward
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Jan K Rainey
- Department of Biochemistry & Molecular Biology, Dalhousie University, Halifax, Nova Scotia, Canada
- Department of Chemistry, Dalhousie University, Halifax, Nova Scotia, Canada
| |
Collapse
|