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Yoldaş O, Nogueira AVB, Kantar PM, Ziskoven PC, Deschner J, Buduneli N. Gingival crevicular fluid levels of apelin correlates with clinical periodontal diagnosis. Clin Oral Investig 2023; 28:50. [PMID: 38153555 DOI: 10.1007/s00784-023-05461-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2023] [Accepted: 12/18/2023] [Indexed: 12/29/2023]
Abstract
OBJECTIVES Limitations of clinical periodontal measurements have led to the search for reliable biomarkers that can be used in diagnosis and monitoring of periodontal diseases. Considering the relationship of adipokines with periodontal disease, diabetes, and obesity, apelin may be a biomarker for periodontal diseases due to its modulating effects on inflammation. The present study was conducted to determine gingival crevicular fluid (GCF) apelin levels in systemically healthy individuals and to evaluate the potential of apelin as a biomarker for periodontal diagnosis. MATERIALS AND METHODS Ten individuals with clinically healthy periodontal tissues, 10 patients diagnosed with gingivitis, and 10 patients with periodontitis were included in the present study. Whole mouth clinical periodontal measurements were recorded and GCF samples were obtained from the buccal approximal regions of single-rooted teeth with features that would represent clinical periodontal diagnosis. Apelin level in the samples was determined by ELISA. Clinical and biochemical findings were statistically analyzed. Possible relationship between the variables was evaluated with Pearson correlation analysis. RESULTS Apelin level in the gingivitis group was higher than that in the clinically healthy group (p = 0.000) and lower than that in the periodontitis group (p = 0.000). A positive correlation was found between GCF apelin concentration and plaque score, bleeding on probing, and probing depth (p = 0.000). CONCLUSIONS Within the limits of this study, it can be suggested that GCF apelin concentration may be a biomarker that can distinguish between healthy periodontal tissues, gingivitis, and periodontitis patients. CLINICAL RELEVANCE Apelin concentration in the gingival crevicular fluid may aid in the diagnosis of periodontal disease.
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Affiliation(s)
- Onur Yoldaş
- Department of Periodontology, School of Dentistry, Ege University, 35100, Bornova, İzmir, Turkey
| | - Andressa V B Nogueira
- Department of Periodontology and Operative Dentistry, University Medical Center of the Johannes Gutenberg University, 55131, Mainz, Germany
| | - Pınar Meriç Kantar
- Department of Periodontology, School of Dentistry, Ege University, 35100, Bornova, İzmir, Turkey
| | - Pablo Cores Ziskoven
- Department of Periodontology and Operative Dentistry, University Medical Center of the Johannes Gutenberg University, 55131, Mainz, Germany
| | - James Deschner
- Department of Periodontology and Operative Dentistry, University Medical Center of the Johannes Gutenberg University, 55131, Mainz, Germany
| | - Nurcan Buduneli
- Department of Periodontology, School of Dentistry, Ege University, 35100, Bornova, İzmir, Turkey.
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2
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Wyderka R, Diakowska D, Łoboz-Rudnicka M, Mercik J, Borger M, Osuch Ł, Brzezińska B, Leśków A, Krzystek-Korpacka M, Jaroch J. Influence of the Apelinergic System on Conduction Disorders in Patients after Myocardial Infarction. J Clin Med 2023; 12:7603. [PMID: 38137673 PMCID: PMC10744328 DOI: 10.3390/jcm12247603] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 11/28/2023] [Accepted: 11/30/2023] [Indexed: 12/24/2023] Open
Abstract
BACKGROUND There is a growing body of evidence for an important role of the apelinergic system in the modulation of cardiovascular homeostasis. The aim of our study was to (1) examine the relationship between apelin serum concentration at index myocardial infarction (MI) and atrioventricular conduction disorders (AVCDs) at 12-month follow-up, and (2) investigate the association between initial apelin concentration and the novel marker of post-MI scar (Q/QRS ratio) at follow-up. METHODS In 84 patients with MI with complete revascularization, apelin peptide serum concentrations for apelin-13, apelin-17, elabela (ELA) and apelin receptor (APJ) were measured on day one of hospitalization; at 12-month follow-up, 54 of them underwent thorough examination that included 12-lead electrocardiography (ECG), Holter ECG monitoring and echocardiography. RESULTS The mean age was 58.9 years. At 12-month follow-up, AVCDs were diagnosed in 21.4% of subjects, with AV first-degree block in 16.7% and sinoatrial arrest in 3.7%. ELA serum concentration at index MI correlated positively with the occurrence of AVCD (p = 0.003) and heart rate (p = 0.005) at 12-month follow-up. The apelin-13 serum concentration at index MI correlated negatively with the Q/QRS ratio. CONCLUSIONS The apelin peptide concentration during an acute phase of MI impacts the development of AVCD and the value of Q/QRS ratio in MI survivors.
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Affiliation(s)
- Rafał Wyderka
- Department of Cardiology, Tadeusz Marciniak Lower Silesia Specialist Hospital-Emergency Medicine Center, Fieldorf 2, 54-049 Wroclaw, Poland (J.M.); (M.B.)
- Faculty of Medicine, Wrocław University of Science and Technology, 50-370 Wroclaw, Poland
| | - Dorota Diakowska
- Department of Basic Sciences, Faculty of Health Science, Wroclaw Medical University, Bartla 5, 51-618 Wroclaw, Poland
| | - Maria Łoboz-Rudnicka
- Department of Cardiology, Tadeusz Marciniak Lower Silesia Specialist Hospital-Emergency Medicine Center, Fieldorf 2, 54-049 Wroclaw, Poland (J.M.); (M.B.)
| | - Jakub Mercik
- Department of Cardiology, Tadeusz Marciniak Lower Silesia Specialist Hospital-Emergency Medicine Center, Fieldorf 2, 54-049 Wroclaw, Poland (J.M.); (M.B.)
| | - Michał Borger
- Department of Cardiology, Tadeusz Marciniak Lower Silesia Specialist Hospital-Emergency Medicine Center, Fieldorf 2, 54-049 Wroclaw, Poland (J.M.); (M.B.)
- Department of Internal Nursing, Faculty of Health Science, Wroclaw Medical University, Bartla 5, 51-618 Wroclaw, Poland
| | - Łukasz Osuch
- Department of Cardiology, Tadeusz Marciniak Lower Silesia Specialist Hospital-Emergency Medicine Center, Fieldorf 2, 54-049 Wroclaw, Poland (J.M.); (M.B.)
| | - Barbara Brzezińska
- Department of Cardiology, Tadeusz Marciniak Lower Silesia Specialist Hospital-Emergency Medicine Center, Fieldorf 2, 54-049 Wroclaw, Poland (J.M.); (M.B.)
| | - Anna Leśków
- Department of Basic Sciences, Faculty of Health Science, Wroclaw Medical University, Bartla 5, 51-618 Wroclaw, Poland
| | | | - Joanna Jaroch
- Department of Cardiology, Tadeusz Marciniak Lower Silesia Specialist Hospital-Emergency Medicine Center, Fieldorf 2, 54-049 Wroclaw, Poland (J.M.); (M.B.)
- Faculty of Medicine, Wrocław University of Science and Technology, 50-370 Wroclaw, Poland
- Department of Internal Nursing, Faculty of Health Science, Wroclaw Medical University, Bartla 5, 51-618 Wroclaw, Poland
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3
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Xu C. Cardiovascular aspects of ELABELA: A potential diagnostic biomarker and therapeutic target. Vascul Pharmacol 2023; 151:107193. [PMID: 37433415 DOI: 10.1016/j.vph.2023.107193] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/17/2023] [Revised: 06/19/2023] [Accepted: 07/05/2023] [Indexed: 07/13/2023]
Abstract
ELABELA, an early endogenous ligand for the G protein-coupled receptor APJ (apelin peptide jejunum, apelin receptor), has been known as an important regulator in cardiovascular homeostasis and may be a novel therapeutic target for multiple cardiovascular diseases (CVDs). At the physiological level, ELABELA exhibits angiogenic and vasorelaxant effects and is essential for heart development. At the pathological level, circulating ELABELA levels may be a novel diagnostic biomarker for various CVDs. ELABELA peripherally displays antihypertensive, vascular-protective, and cardioprotective effects, whereas central administration of ELABELA elevated BP and caused cardiovascular remodeling. This review highlights the physiological and pathological roles of ELABELA in the cardiovascular system. Enhancement of the peripheral ELABELA may be a promising pharmacological therapeutic strategy for CVDs.
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Affiliation(s)
- Chuanming Xu
- Translational Medicine Centre, Jiangxi University of Chinese Medicine, Nanchang 330002, Jiangxi, China.
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4
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Li A, Zhao Q, Chen L, Li Z. Apelin/APJ system: an emerging therapeutic target for neurological diseases. Mol Biol Rep 2023; 50:1639-1653. [PMID: 36378421 PMCID: PMC9665010 DOI: 10.1007/s11033-022-08075-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2022] [Accepted: 11/01/2022] [Indexed: 11/16/2022]
Abstract
Apelin, an endogenous ligand for the G protein-coupled receptor APJ, is extensively expressed in various systems, especially the nervous system. This article reviews the role of apelin/APJ system in neurological diseases. In detail, apelin/APJ system can relieve acute brain injury including subarachnoid hemorrhage, traumatic brain injury, and ischemic stroke. Also, apelin/APJ system has therapeutic effects on chronic neurodegenerative disease models, involving the regulation of neurotrophic factors, neuroendocrine, oxidative stress, neuroinflammation, neuronal apoptosis, and autophagy. In addition, through different routes of administration, apelin/APJ system has a biphasic effect on depression, epilepsy, and pain. However, apelin/APJ system exacerbates the proliferation and invasion of glioblastoma. Thus, apelin/APJ system is expected to be a therapeutic target for the treatment of nervous system diseases.
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Affiliation(s)
- Ao Li
- Institute of Pharmacy and Pharmacology, Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China
| | - Qun Zhao
- Health Management Center, The Third Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Linxi Chen
- Institute of Pharmacy and Pharmacology, Hunan Provincial Key Laboratory of Tumor Microenvironment Responsive Drug Research, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, Hengyang Medical School, University of South China, Hengyang, 421001, Hunan, China.
| | - Zhiyue Li
- Department of Orthopedics, Third Xiangya Hospital of Central South University, Changsha, Hunan, China.
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Targeting the elabela/apelin-apelin receptor axis as a novel therapeutic approach for hypertension. Chin Med J (Engl) 2021; 135:1019-1026. [PMID: 34608073 PMCID: PMC9276310 DOI: 10.1097/cm9.0000000000001766] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
ABSTRACT Hypertension is the leading risk factor for global mortality and morbidity and those with hypertension are more likely to develop severe symptoms in cardiovascular and cerebrovascular system, which is closely related to abnormal renin-angiotensin system and elabela/apelin-apelin receptor (APJ) axis. The elabela/apelin-APJ axis exerts essential roles in regulating blood pressure levels, vascular tone, and cardiovascular dysfunction in hypertension by counterbalancing the action of the angiotensin II/angiotensin II type 1 receptor axis and enhancing the endothelial nitric oxide (NO) synthase/NO signaling. Furthermore, the elabela/apelin-APJ axis demonstrates beneficial effects in cardiovascular physiology and pathophysiology, including angiogenesis, cellular proliferation, fibrosis, apoptosis, oxidative stress, and cardiovascular remodeling and dysfunction during hypertension. More importantly, effects of the elabela/apelin-APJ axis on vascular tone may depend upon blood vessel type or various pathological conditions. Intriguingly, the broad distribution of elabela/apelin and alternative isoforms implicated its distinct functions in diverse cardiac and vascular cells and tissue types. Finally, both loss-of-function and gain-of-function approaches have defined critical roles of the elabela/apelin-APJ axis in reducing the development and severity of hypertensive diseases. Thus, targeting the elabela/apelin-APJ axis has emerged as a pre-warning biomarker and a novel therapeutic approach against progression of hypertension, and an increased understanding of cardiovascular actions of the elabela/apelin-APJ axis will help to develop effective interventions for hypertension. In this review, we focus on the physiology and biochemistry, diverse actions, and underlying mechanisms of the elabela/apelin-APJ axis, highlighting its role in hypertension and hypertensive cardiovascular injury and dysfunction, with a view to provide a prospective strategy for hypertensive disease therapy.
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6
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Griffiths PR, Lolait SJ, Paton JFR, O'Carroll AM. Circumventricular Organ Apelin Receptor Knockdown Decreases Blood Pressure and Sympathetic Drive Responses in the Spontaneously Hypertensive Rat. Front Physiol 2021; 12:711041. [PMID: 34421653 PMCID: PMC8373520 DOI: 10.3389/fphys.2021.711041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2021] [Accepted: 07/12/2021] [Indexed: 11/18/2022] Open
Abstract
The central site(s) mediating the cardiovascular actions of the apelin-apelin receptor (APJ) system remains a major question. We hypothesized that the sensory circumventricular organs (CVOs), interfacing between the circulation and deeper brain structures, are sites where circulating apelin acts as a signal in the central nervous system to decrease blood pressure (BP). We show that APJ gene (aplnr) expression was elevated in the CVOs of spontaneously hypertensive rats (SHRs) compared to normotensive Wistar Kyoto (WKY) controls, and that there was a greater mean arterial BP (MABP) decrease following microinjection of [Pyr1]apelin-13 to the CVOs of SHRs compared to WKY rats. Lentiviral APJ-specific-shRNA (LV-APJ-shRNA) was used to knockdown aplnr expression, both collectively in three CVOs and discretely in individual CVOs, of rats implanted with radiotelemeters to measure arterial pressure. LV-APJ-shRNA-injection decreased aplnr expression in the CVOs and abolished MABP responses to microinjection of [Pyr1]apelin-13. Chronic knockdown of aplnr in any of the CVOs, collectively or individually, did not affect basal MABP in SHR or WKY rats. Moreover, knockdown of aplnr in any of the CVOs individually did not affect the depressor response to systemic [Pyr1]apelin-13. By contrast, multiple knockdown of aplnr in the three CVOs reduced acute cardiovascular responses to peripheral [Pyr1]apelin-13 administration in SHR but not WKY rats. These results suggest that endogenous APJ activity in the CVOs has no effect on basal BP but that functional APJ in the CVOs is required for an intact cardiovascular response to peripherally administered apelin in the SHR.
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Affiliation(s)
- Philip R Griffiths
- Faculty of Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Stephen J Lolait
- Faculty of Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Julian F R Paton
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,Faculty of Biomedical Sciences, School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Anne-Marie O'Carroll
- Faculty of Health Sciences, Bristol Medical School, University of Bristol, Bristol, United Kingdom
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7
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Ji M, Wang Q, Zhao Y, Shi L, Zhou Z, Li Y. Targeting Hypertension: Superoxide Anions are Involved in Apelininduced Long-term High Blood Pressure and Sympathetic Activity in the Paraventricular Nucleus. Curr Neurovasc Res 2020; 16:455-464. [PMID: 31657686 DOI: 10.2174/1567202616666191023111839] [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: 08/19/2019] [Revised: 09/27/2019] [Accepted: 10/03/2019] [Indexed: 12/31/2022]
Abstract
AIM To determine whether apelin in paraventricular nucleus (PVN) can be a therapeutic target for hypertension. BACKGROUND Apelin is a specific endogenous ligand of orphan G protein-coupled receptor APJ. OBJECTIVE This study was designed to determine how apelin chronically regulates sympathetic nerve activity and blood pressure in PVN of rats. METHODS Apelin and APJ antagonist F13A were infused into PVN with osmotic minipumps. The NAD(P)H oxidase activity and superoxide anions levels in PVN of rats were determined by chemiluminescence. RESULTS Infusion of apelin into PVN of Wistar-Kyoto (WKY) rats induced chronic increases in systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), plasma norepinephrine (NE) level, maximal depressor response to hexamethonium (Hex), NAD(P)H oxidase activity, superoxide anions levels, and Nox4 expression. Infusion of F13A into PVN of spontaneously hypertensive rats (SHRs) caused chronic decreases in SBP, DBP, MAP, plasma NE level, maximal depressor response to Hex, NAD(P)H oxidase activity, and superoxide anions levels. Hex, a sympathetic ganglion blocker, inhibited apelin-induced increases in SBP, DBP and MAP. SOD overexpression in PVN of SHRs inhibited the apelin-induced increase in SBP, DBP, MAP, plasma NE level, and maximal depressor response to Hex. PVN Nox4 knockdown also attenuated the apelin-induced increase in SBP, DBP, MAP, plasma NE level, and maximal depressor response to Hex. Chronic injection of F13A into PVN reduced fibrosis of renal artery, thoracic aorta, and heart in SHRs. CONCLUSION These results demonstrated that in PVN apelin induced long-term high blood pressure and sympathetic activity via increasing oxidative stress.
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Affiliation(s)
- Mingyue Ji
- Department of Cardiology, Lianshui County People's Hospital, Huaian, China.,Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Qian Wang
- Pediatric Department, Shanghai General Hospital, Shanghai, China.,Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yuewu Zhao
- Department of Cardiology, Xuzhou No. 1 People's Hospital, Xuzhou, China
| | - Lu Shi
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Zihao Zhou
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
| | - Yong Li
- Department of Cardiology, The First Affiliated Hospital of Nanjing Medical University, Nanjing, China
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8
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Yan J, Wang A, Cao J, Chen L. Apelin/APJ system: an emerging therapeutic target for respiratory diseases. Cell Mol Life Sci 2020; 77:2919-2930. [PMID: 32128601 PMCID: PMC11105096 DOI: 10.1007/s00018-020-03461-7] [Citation(s) in RCA: 49] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 12/20/2019] [Accepted: 01/10/2020] [Indexed: 12/14/2022]
Abstract
Apelin is an endogenous ligand of G protein-coupled receptor APJ. It is extensively expressed in many tissues such as heart, liver, and kidney, especially in lung tissue. A growing body of evidence suggests that apelin/APJ system is closely related to the development of respiratory diseases. Therefore, in this review, we focus on the role of apelin/APJ system in respiratory diseases, including pulmonary arterial hypertension (PAH), pulmonary embolism (PE), acute lung injury (ALI)/acute respiratory distress syndrome (ARDS), obstructive sleep apnoea syndrome (OSAS), non-small cell lung cancer (NSCLC), pulmonary edema, asthma, and chronic obstructive pulmonary diseases. In detail, apelin/APJ system attenuates PAH by activating AMPK-KLF2-eNOS-NO signaling and miR424/503-FGF axis. Also, apelin protects against ALI/ARDS by reducing mitochondrial ROS-triggered oxidative damage, mitochondria apoptosis, and inflammatory responses induced by the activation of NF-κB and NLRP3 inflammasome. Apelin/APJ system also prevents the occurrence of pulmonary edema via activating AKT-NOS3-NO pathway. Moreover, apelin/APJ system accelerates NSCLC cells' proliferation and migration via triggering ERK1/2-cyclin D1 and PAK1-cofilin signaling, respectively. Additionally, apelin/APJ system may act as a predictor in the development of OSAS and PE. Considering the pleiotropic actions of apelin/APJ system, targeting apelin/APJ system may be a potent therapeutic avenue for respiratory diseases.
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Affiliation(s)
- Jialong Yan
- Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, 421001, People's Republic of China
| | - Aiping Wang
- Institute of Clinical Research, Affiliated Nanhua Hospital, University of South China, Hengyang, 421002, Hunan, People's Republic of China
| | - Jiangang Cao
- Institute of Clinical Research, Affiliated Nanhua Hospital, University of South China, Hengyang, 421002, Hunan, People's Republic of China.
| | - Linxi Chen
- Institute of Pharmacy and Pharmacology, Learning Key Laboratory for Pharmacoproteomics, Hunan Province Cooperative Innovation Center for Molecular Target New Drug Study, University of South China, Hengyang, 421001, People's Republic of China.
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9
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Griffiths PR, Lolait SJ, Bijabhai A, O’Carroll-Lolait A, Paton JFR, O’Carroll AM. Increased apelin receptor gene expression in the subfornical organ of spontaneously hypertensive rats. PLoS One 2020; 15:e0231844. [PMID: 32315363 PMCID: PMC7173921 DOI: 10.1371/journal.pone.0231844] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2020] [Accepted: 04/01/2020] [Indexed: 02/06/2023] Open
Abstract
The vascular organ of the lamina terminalis, subfornical organ (SFO), and area postrema comprise the sensory circumventricular organs (CVO) which are central structures that lie outside the blood brain barrier and are thought to provide an interface between peripherally circulating signals and the brain through their projections to central autonomic structures. The SFO expresses mRNA for the G protein-coupled apelin receptor (APJ, gene name aplnr) and exogenous microinjection of the neuropeptide apelin (apln) to the SFO elicits a depressor effect. Here we investigated the expression and cellular distribution of aplnr, apln and the recently described ligand apela (apela) in the CVOs and investigated whether differences in the levels of expression of apelinergic gene transcripts in these regions might underlie the chronic elevated blood pressure seen in hypertension. We carried out multiplex in situ hybridization histochemistry on CVO tissue sections from spontaneously hypertensive rats (SHR) and normotensive Wistar Kyoto (WKY) controls. Confocal immunofluorescent images indicated strong aplnr expression, with lower levels of apln and modest apela expression, in the CVOs of both WKY rats and SHRs, in both neurons and glia. The expression level of aplnr transcripts was increased in the SFO of SHRs compared to WKY rats. Our data may highlight a potential dysfunction in the communication between CVOs and downstream signalling pathways in SHRs, which may contribute to its different phenotype/s.
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Affiliation(s)
- Philip R. Griffiths
- Bristol Medical School, Faculty of Health Sciences, University of Bristol, Bristol, United Kingdom
| | - Stephen J. Lolait
- Bristol Medical School, Faculty of Health Sciences, University of Bristol, Bristol, United Kingdom
| | - Aarifah Bijabhai
- Bristol Medical School, Faculty of Health Sciences, University of Bristol, Bristol, United Kingdom
| | - Aoife O’Carroll-Lolait
- School of Medical Sciences, Faculty of Biology, Medicine and Health, University of Manchester, Manchester, United Kingdom
| | - Julian F. R. Paton
- Department of Physiology, Faculty of Medical & Health Sciences, University of Auckland, Auckland, New Zealand
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol, Bristol, United Kingdom
| | - Anne-Marie O’Carroll
- Bristol Medical School, Faculty of Health Sciences, University of Bristol, Bristol, United Kingdom
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10
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Griffiths PR, Lolait SJ, Pearce LE, McBryde FD, Paton JFR, O'Carroll AM. Blockade of Rostral Ventrolateral Medulla Apelin Receptors Does Not Attenuate Arterial Pressure in SHR and L-NAME-Induced Hypertensive Rats. Front Physiol 2018; 9:1488. [PMID: 30459635 PMCID: PMC6232890 DOI: 10.3389/fphys.2018.01488] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 10/02/2018] [Indexed: 01/02/2023] Open
Abstract
Dysfunction of the apelinergic system, comprised of the neuropeptide apelin mediating its effects via the G protein-coupled apelin receptor (APJ), may underlie the onset of cardiovascular disease such as hypertension. Apelin expression is increased in the rostral ventrolateral medulla (RVLM) in spontaneously hypertensive rats (SHRs) compared to Wistar-Kyoto (WKY) normotensive rats, however, evidence that the apelinergic system chronically influences mean arterial blood pressure (MABP) under pathophysiological conditions remains to be established. In this study we investigated, in conscious unrestrained rats, whether APJ contributes to MABP and sympathetic vasomotor tone in the progression of two models of hypertension - SHR and L-NAME-treated rats - and whether APJ contributes to the development of hypertension in pre-hypertensive SHR. In SHR we showed that APJ gene (aplnr) expression was elevated in the RVLM, and there was a greater MABP increase following microinjection of [Pyr1]apelin-13 to the RVLM of SHR compared to WKY rats. Bilateral microinjection of a lentiviral APJ-specific-shRNA construct into the RVLM of WKY, SHR, and L-NAME-treated rats, chronically implanted with radiotelemeters to measure MABP, decreased aplnr expression in the RVLM and abolished acute [Pyr1]apelin-13-induced increases in MABP. However, chronic knockdown of aplnr in the RVLM did not affect MABP in either SHR or L-NAME-treated rats. Moreover, knockdown of aplnr in the RVLM of prehypertensive SHR did not protect against the development of hypertension. These results show that endogenous apelin, acting via APJ, is not involved in the genesis or maintenance of hypertension in either animal model used in this study.
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Affiliation(s)
- Philip R Griffiths
- Laboratories for Integrative Neuroscience and Endocrinology, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Stephen J Lolait
- Laboratories for Integrative Neuroscience and Endocrinology, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Louise E Pearce
- Laboratories for Integrative Neuroscience and Endocrinology, Bristol Medical School, University of Bristol, Bristol, United Kingdom
| | - Fiona D McBryde
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand
| | - Julian F R Paton
- Department of Physiology, Faculty of Medical and Health Sciences, University of Auckland, Auckland, New Zealand.,School of Physiology, Pharmacology and Neuroscience, University of Bristol, Bristol, United Kingdom
| | - Anne-Marie O'Carroll
- Laboratories for Integrative Neuroscience and Endocrinology, Bristol Medical School, University of Bristol, Bristol, United Kingdom
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11
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Dual autonomic inhibitory action of central Apelin on gastric motor functions in rats. Auton Neurosci 2018; 212:17-22. [DOI: 10.1016/j.autneu.2018.03.005] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2018] [Revised: 03/15/2018] [Accepted: 03/27/2018] [Indexed: 11/15/2022]
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12
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Bülbül M, Travagli RA. Novel transmitters in brain stem vagal neurocircuitry: new players on the pitch. Am J Physiol Gastrointest Liver Physiol 2018; 315:G20-G26. [PMID: 29597355 PMCID: PMC6109706 DOI: 10.1152/ajpgi.00059.2018] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The last few decades have seen a major increase in the number of neurotransmitters and neuropeptides recognized as playing a role in brain stem neurocircuits, including those involved in homeostatic functions such as stress responsiveness, gastrointestinal motility, feeding, and/or arousal/wakefulness. This minireview will focus on the known physiological role of three of these novel neuropeptides, i.e., apelin, nesfatin-1, and neuropeptide-S, with a special emphasis on their hypothetical roles in vagal signaling related to gastrointestinal motor functions.
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Affiliation(s)
- Mehmet Bülbül
- 1Faculty of Medicine, Department of Physiology, Akdeniz UniversityAntalya, Turkey
| | - R. Alberto Travagli
- 2Department of Neural and Behavioral Neurosciences, Pennsylvania State University College of Medicine, Hershey, Pennsylvania
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13
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Abstract
Apelin is a vasoactive peptide and is an endogenous ligand for APJ receptors, which are widely expressed in blood vessels, heart, and cardiovascular regulatory regions of the brain. A growing body of evidence now demonstrates a regulatory role for the apelin/APJ receptor system in cardiovascular physiology and pathophysiology, thus making it a potential target for cardiovascular drug discovery and development. Indeed, ongoing studies are investigating the potential benefits of apelin and apelin-mimetics for disorders such as heart failure and pulmonary arterial hypertension. Apelin causes relaxation of isolated arteries, and systemic administration of apelin typically results in a reduction in systolic and diastolic blood pressure and an increase in blood flow. Nonetheless, vasopressor responses and contraction of vascular smooth muscle in response to apelin have also been observed under certain conditions. The goal of the current review is to summarize major findings regarding the apelin/APJ receptor system in blood vessels, with an emphasis on regulation of vascular tone, and to identify areas of investigation that may provide guidance for the development of novel therapeutic agents that target this system.
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Affiliation(s)
- Amreen Mughal
- Department of Pharmaceutical Sciences, North Dakota State University Fargo, ND, USA
| | - Stephen T O'Rourke
- Department of Pharmaceutical Sciences, North Dakota State University Fargo, ND, USA.
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Cano Martínez LJ, Coral Vázquez RM, Méndez JP, Trejo S, Pérez Razo JC, Canto P. Serum concentrations of apelin-17 isoform vary in accordance to blood pressure categories in individuals with obesity class 3. Clin Exp Hypertens 2018; 41:168-173. [DOI: 10.1080/10641963.2018.1462374] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Luis Javier Cano Martínez
- Obesity Research Unit, Faculty of Medicine, National Autonomous University of Mexico, México City, México
| | - Ramón Mauricio Coral Vázquez
- Section of Postgraduate Studies and Research, Higher School of Medicine, National Polytechnic Institute, México City, México
- Subdirection of Teaching and Research, National Medical Center “20 de November”, Institute of Security and Social Services of State Workers, México City, México
| | - Juan Pablo Méndez
- Obesity Research Unit, Faculty of Medicine, National Autonomous University of Mexico, México City, México
- Obesity Clinic, National Institute of Medical Sciences and Nutrition “Salvador Zubirán”, México City, México
| | - Silvia Trejo
- Integral Clinic of Surgery for Obesity and Metabolic Diseases, General Hospital “Dr. Rubén Leñero”, CDMX, México City, México
| | - Juan Carlos Pérez Razo
- Division of Genomic Medicine, Subdirection of Teaching and Research, National Medical Center “20 de November”, Institute of Security and Social Services of State Workers, México City, México
| | - Patricia Canto
- Obesity Research Unit, Faculty of Medicine, National Autonomous University of Mexico, México City, México
- Obesity Clinic, National Institute of Medical Sciences and Nutrition “Salvador Zubirán”, México City, México
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15
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Bülbül M, Sinen O, Gök M, Travagli RA. Apelin-13 inhibits gastric motility through vagal cholinergic pathway in rats. Am J Physiol Gastrointest Liver Physiol 2018; 314:G201-G210. [PMID: 29025730 PMCID: PMC5866420 DOI: 10.1152/ajpgi.00223.2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
Abstract
The expression of apelin and its receptors (APJ) in central autonomic networks suggests that apelin may regulate gastrointestinal motor functions. In rodents, central administration of apelin-13 has been shown to inhibit gastric emptying; however, the mechanisms involved remain to be determined. Using male adult Sprague-Dawley rats, the aims of the present study were 1) to determine the expression of APJ receptor in the dorsal vagal complex (DVC), 2) to assess the effects of central application of apelin-13 into the DVC on gastric tone and motility, and 3) to investigate the neuronal pathways responsible for apelin-induced alterations. APJ receptor immunoreactivity was detected in gastric-projecting and choline acetyltransferase-positive neurons of the DVC. Microinjection of apelin-13 into the DVC significantly decreased gastric tone and motility in both corpus and antrum. The apelin-induced reduction in gastric tone and motility was prevented by surgical vagotomy or fourth ventricular application of the APJ receptor antagonist, [Ala13]apelin-13 (F13A). Systemic administration of the muscarinic receptor antagonist atropine, but not the nitric oxide synthase inhibitor nitro-l-arginine methyl ester (l-NAME), abolished the apelin-induced inhibitory responses. The present results indicate a central modulatory role of apelin in the vagal neurocircuitry that controls gastric motor functions via withdrawal of the tonically active cholinergic pathway. NEW & NOTEWORTHY This is the first study investigating the effects induced by brain stem application of apelin-13 while monitoring gastric tone and motility in rats. We have found that gastric-projecting neurons of the dorsal vagal complex express apelin receptors (APJ), which mediate the inhibitory actions of apelin-13. The inhibitory effects of apelin were abolished by systemic preadministration of atropine, but not nitro-l-arginine methyl ester (l-NAME). Apelin seems to modulate gastric motility via withdrawal of the tonically active vagal cholinergic pathway.
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Affiliation(s)
- Mehmet Bülbül
- 1Department of Neural and Behavioral Neurosciences, Penn State University College of Medicine, Hershey, Pennsylvania,2Department of Physiology, Akdeniz University, Faculty of Medicine, Antalya, Turkey
| | - Osman Sinen
- 2Department of Physiology, Akdeniz University, Faculty of Medicine, Antalya, Turkey
| | - Melahat Gök
- 2Department of Physiology, Akdeniz University, Faculty of Medicine, Antalya, Turkey
| | - R. Alberto Travagli
- 1Department of Neural and Behavioral Neurosciences, Penn State University College of Medicine, Hershey, Pennsylvania
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16
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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.
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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
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Peyronnet R, Bollensdorff C, Capel RA, Rog-Zielinska EA, Woods CE, Charo DN, Lookin O, Fajardo G, Ho M, Quertermous T, Ashley EA, Kohl P. Load-dependent effects of apelin on murine cardiomyocytes. PROGRESS IN BIOPHYSICS AND MOLECULAR BIOLOGY 2017; 130:333-343. [PMID: 28935153 PMCID: PMC5726609 DOI: 10.1016/j.pbiomolbio.2017.09.013] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/13/2017] [Revised: 09/07/2017] [Accepted: 09/08/2017] [Indexed: 01/26/2023]
Abstract
The apelin peptide is described as one of the most potent inotropic agents, produced endogenously in a wide range of cells, including cardiomyocytes. Despite positive effects on cardiac contractility in multicellular preparations, as well as indications of cardio-protective actions in several diseases, its effects and mechanisms of action at the cellular level are incompletely understood. Here, we report apelin effects on dynamic mechanical characteristics of single ventricular cardiomyocytes, isolated from mouse models (control, apelin-deficient [Apelin-KO], apelin-receptor KO mouse [APJ-KO]), and rat. Dynamic changes in maximal velocity of cell shortening and relaxation were monitored. In addition, more traditional indicators of inotropic effects, such as maximum shortening (in mechanically unloaded cells) or peak force development (in auxotonic contracting cells, preloaded using the carbon fibre technique) were studied. The key finding is that, using Apelin-KO cardiomyocytes exposed to different preloads with the 2-carbon fibre technique, we observe a lowering of the slope of the end-diastolic stress-length relation in response to 10 nM apelin, an effect that is preload-dependent. This suggests a positive lusitropic effect of apelin, which could explain earlier counter-intuitive findings on an apelin-induced increase in contractility occurring without matching rise in oxygen consumption.
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Affiliation(s)
- Rémi Peyronnet
- Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg · Bad Krozingen, Medical School of the University of Freiburg, Germany; Imperial College London, NHLI, Heart Science Centre, UK.
| | - Christian Bollensdorff
- Imperial College London, NHLI, Heart Science Centre, UK; Sidra Medical and Research Center, Qatar Foundation, Qatar
| | | | - Eva A Rog-Zielinska
- Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg · Bad Krozingen, Medical School of the University of Freiburg, Germany; Imperial College London, NHLI, Heart Science Centre, UK
| | - Christopher E Woods
- Stanford University Division of Cardiovascular Medicine, Stanford, USA; Palo Alto Medical Foundation, Burlingame, CA, USA
| | - David N Charo
- Stanford University Division of Cardiovascular Medicine, Stanford, USA
| | - Oleg Lookin
- Ural Branch of the Russian Academy of Sciences, Ekaterinburg, Russian Federation
| | - Giovanni Fajardo
- Stanford University Division of Cardiovascular Medicine, Stanford, USA
| | - Michael Ho
- Stanford University Division of Cardiovascular Medicine, Stanford, USA
| | | | - Euan A Ashley
- Stanford University Division of Cardiovascular Medicine, Stanford, USA
| | - Peter Kohl
- Institute for Experimental Cardiovascular Medicine, University Heart Centre Freiburg · Bad Krozingen, Medical School of the University of Freiburg, Germany; Imperial College London, NHLI, Heart Science Centre, UK
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Griffiths PR, Lolait SJ, Harris LE, Paton JFR, O'Carroll AM. Vasopressin V1a receptors mediate the hypertensive effects of [Pyr 1 ]apelin-13 in the rat rostral ventrolateral medulla. J Physiol 2017; 595:3303-3318. [PMID: 28255983 PMCID: PMC5451710 DOI: 10.1113/jp274178] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2017] [Accepted: 02/27/2017] [Indexed: 11/22/2022] Open
Abstract
Key points Dysfunctions in CNS regulation of arterial blood pressure lead to an increase in sympathetic nerve activity that participates in the pathogenesis of hypertension. The apelin‐apelin receptor system affects arterial blood pressure homeostasis; however, the central mechanisms underlying apelin‐mediated changes in sympathetic nerve activity and blood pressure have not been clarified. We explored the mechanisms involved in the regulation of [Pyr1]apelin‐13‐mediated cardiovascular control within the rostral ventrolateral medulla (RVLM) using selective receptor antagonists. We show that [Pyr1]apelin‐13 acts as a modulating neurotransmitter in the normotensive RVLM to affect vascular tone through interaction with the vasopressin V1a receptor but that [Pyr1]apelin‐13‐induced sympathoexcitation is independent of angiotensin II receptor type 1, oxytocin, ionotropic glutamate and GABAA receptors. Our data confirm a role for the apelin peptide system in cardiovascular regulation at the level of the RVLM and highlight that this system is a possible potential therapeutic target for the treatment of hypertension.
Abstract Apelin is a ubiquitous peptide that can elevate arterial blood pressure (ABP) yet understanding of the mechanisms involved remain incomplete. Bilateral microinjection of [Pyr1]apelin‐13 into the rostral ventrolateral medulla (RVLM), a major source of sympathoexcitatory neurones, increases ABP and sympathetic nerve activity. We aimed to investigate the potential involvement of neurotransmitter systems through which the apelin pressor response may occur within the RVLM. Adult male Wistar rats were anaesthetized and ABP was monitored via a femoral arterial catheter. Bilateral RVLM microinjection of [Pyr1]apelin‐13 significantly increased ABP (9 ± 1 mmHg) compared to saline (−1 ± 2mmHg; P < 0.001), which was blocked by pretreatment with the apelin receptor antagonist, F13A (0 ± 1 mmHg; P < 0.01). The rise in ABP was associated with an increase in the low frequency spectra of systolic BP (13.9 ± 4.3% total power; P < 0.001), indicative of sympathetic vasomotor activation. The [Pyr1]apelin‐13‐mediated pressor response and the increased low frequency spectra of systolic BP response were fully maintained despite RVLM pretreatment with the angiotensin II type 1 receptor antagonist losartan, the oxytocin receptor antagonist desGly‐NH2, d(CH2)5[D‐Tyr2,Thr4]OVT, the ionotropic glutamate receptor antagonist kynurenate or the GABAA antagonist bicuculline (P > 0.05). By contrast, the [Pyr1]apelin‐13 induced pressor and sympathoexcitatory effects were abolished by pretreatment of the RVLM with the vasopressin V1a receptor antagonist, SR 49059 (−1 ± 1 mmHg; 1.1 ± 1.1% total power, respectively; P < 0.001). These findings suggest that the pressor action of [Pyr1]apelin‐13 in the RVLM of normotensive rats is not mediated via angiotensin II type 1 receptor, oxytocin, ionotropic glutamate or GABAA receptors but instead involves a close relationship with the neuropeptide modulator vasopressin. Dysfunctions in CNS regulation of arterial blood pressure lead to an increase in sympathetic nerve activity that participates in the pathogenesis of hypertension. The apelin‐apelin receptor system affects arterial blood pressure homeostasis; however, the central mechanisms underlying apelin‐mediated changes in sympathetic nerve activity and blood pressure have not been clarified. We explored the mechanisms involved in the regulation of [Pyr1]apelin‐13‐mediated cardiovascular control within the rostral ventrolateral medulla (RVLM) using selective receptor antagonists. We show that [Pyr1]apelin‐13 acts as a modulating neurotransmitter in the normotensive RVLM to affect vascular tone through interaction with the vasopressin V1a receptor but that [Pyr1]apelin‐13‐induced sympathoexcitation is independent of angiotensin II receptor type 1, oxytocin, ionotropic glutamate and GABAA receptors. Our data confirm a role for the apelin peptide system in cardiovascular regulation at the level of the RVLM and highlight that this system is a possible potential therapeutic target for the treatment of hypertension.
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Affiliation(s)
| | | | - Louise E Harris
- School of Clinical Sciences, University of Bristol, Bristol, UK
| | - Julian F R Paton
- School of Physiology, Pharmacology and Neuroscience, Biomedical Sciences, University of Bristol, Bristol, UK
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Baysal SS, Pirat B, Okyay K, Bal UA, Uluçam MZ, Öztuna D, Müderrisoğlu H. Treatment-associated change in apelin concentration in patients with hypertension and its relationship with left ventricular diastolic function. Anatol J Cardiol 2017; 17:125-131. [PMID: 27599667 PMCID: PMC5336750 DOI: 10.14744/anatoljcardiol.2016.7035] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/06/2016] [Indexed: 12/31/2022] Open
Abstract
OBJECTIVE We examined the change in apelin concentration and its relationship with left ventricular diastolic function in patients treated for hypertension. METHODS Ninety treatment-naive patients with newly diagnosed hypertension and 33 age- and sex-matched control subjects were prospectively enrolled. Patients with hypertension were randomized to treatment either with telmisartan 80 mg or amlodipine 10 mg. Apelin concentration was measured and echocardiography was performed at baseline and after 1 month of treatment. RESULTS The data of 77 patients and 33 controls were analyzed. Mean age, gender, baseline blood pressure, apelin levels, and echocardiographic measurements were similar between the treatment groups (p>0.05 for all). Apelin concentration was significantly lower in patients with hypertension than in controls. There was a significant increase in apelin level after 1 month of treatment in both groups (0.32±0.17 vs. 0.38±0.17 ng/dL in telmisartan group, p=0.009, and 0.27±0.13 vs. 0.34±0.18 ng/dL in amlodipine group, p=0.013). Diastolic function improved significantly in both groups (p<0.05) but was not significantly associated with change in apelin concentration. CONCLUSION Apelin concentration increased significantly after 1 month of effective treatment with telmisartan or amlodipine to a similar extent. Change in apelin concentration was not associated with improvement in diastolic function.
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Affiliation(s)
| | - Bahar Pirat
- Department of Cardiology, Faculty of Medicine, Başkent University; Ankara-Turkey
| | - Kaan Okyay
- Department of Cardiology, Faculty of Medicine, Başkent University; Ankara-Turkey
| | - Uğur Abbas Bal
- Department of Cardiology, Faculty of Medicine, Başkent University; Ankara-Turkey
| | - Melek Zekiye Uluçam
- Department of Cardiology, Faculty of Medicine, Başkent University; Ankara-Turkey
| | - Derya Öztuna
- Department of Biostatistics, Faculty of Medicine, Ankara University; Ankara-Turkey
| | - Haldun Müderrisoğlu
- Department of Cardiology, Faculty of Medicine, Başkent University; Ankara-Turkey
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21
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Czarzasta K, Cudnoch-Jedrzejewska A, Szczepanska-Sadowska E, Fus L, Puchalska L, Gondek A, Dobruch J, Gomolka R, Wrzesien R, Zera T, Gornicka B, Kuch M. The role of apelin in central cardiovascular regulation in rats with post-infarct heart failure maintained on a normal fat or high fat diet. Clin Exp Pharmacol Physiol 2016; 43:983-94. [DOI: 10.1111/1440-1681.12617] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 05/31/2016] [Accepted: 06/30/2016] [Indexed: 01/18/2023]
Affiliation(s)
- Katarzyna Czarzasta
- Department of Experimental and Clinical Physiology; Laboratory of Centre for Preclinical Research; Medical University of Warsaw; Warsaw Poland
| | - Agnieszka Cudnoch-Jedrzejewska
- Department of Experimental and Clinical Physiology; Laboratory of Centre for Preclinical Research; Medical University of Warsaw; Warsaw Poland
| | - Ewa Szczepanska-Sadowska
- Department of Experimental and Clinical Physiology; Laboratory of Centre for Preclinical Research; Medical University of Warsaw; Warsaw Poland
| | - Lukasz Fus
- Department of Pathology; Medical University of Warsaw; Warsaw Poland
| | - Liana Puchalska
- Department of Experimental and Clinical Physiology; Laboratory of Centre for Preclinical Research; Medical University of Warsaw; Warsaw Poland
| | - Agata Gondek
- Department of Experimental and Clinical Physiology; Laboratory of Centre for Preclinical Research; Medical University of Warsaw; Warsaw Poland
| | - Jakub Dobruch
- Department of Urology; Centre of Postgraduate Medical Education; Warsaw Poland
| | - Ryszard Gomolka
- Faculty of Electronics and Information Technology; Warsaw University of Technology; Warsaw Poland
| | - Robert Wrzesien
- Central Laboratory of Experimental Animals; Medical University of Warsaw; Warsaw Poland
| | - Tymoteusz Zera
- Department of Experimental and Clinical Physiology; Laboratory of Centre for Preclinical Research; Medical University of Warsaw; Warsaw Poland
| | - Barbara Gornicka
- Department of Pathology; Medical University of Warsaw; Warsaw Poland
| | - Marek Kuch
- Chair and Department of Cardiology, Hypertension and Internal Medicine; Medical University of Warsaw; Warsaw Poland
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22
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Han L, Luo H, Huang F, Tian S, Qin X. Apelin-13 Impaires Acquisition but Not Consolidation or Expression of Contextual Fear in Rats. Neurochem Res 2016; 41:2345-51. [PMID: 27216619 DOI: 10.1007/s11064-016-1948-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2016] [Revised: 05/04/2016] [Accepted: 05/05/2016] [Indexed: 12/17/2022]
Abstract
Apelin-13, as an endogenous neuropeptide, is the ligand for the G-protein-coupled receptor, APJ, which has recently been demonstrated to be involved in the process that contributes to learning and memory. Previous studies showed that apelin may be required for certain forms of learning and memory. Up to date, the role of apelin in fear memory has not been explored. In the present study, we tested the effects of apelin-13 (1.0, 2.0 and 4.0 µg/rat) on contextual fear conditioning (experiment 1), consolidation (experiment 2) and expression (experiment 3) in rats. A well established fear conditioning protocol was used, which contained three training phases: habituation, fear conditioning and test. Apelin-13 was i.c.v injected 10 min before conditioning (experiment 1), immediately after conditioning (experiment 2) or 10 min before testing (experiment 3). The values of percent freezing were used to measure fear. We found that only 2.0 µg apelin-13 administrations produced a decrease freezing in experiment 1. The most effective dose of apelin-13 (2.0 µg) was selected, but it had no effect on freezing in experiment 2 and 3. Furthermore, the decreased freezing in experiment 1 was not attributed to the deficits of locomotor activity and foot-shock sensitivity. These results, for the first time, indicated that apelin-13 impaired fear acquisition but not fear consolidation or expression.
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Affiliation(s)
- Li Han
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, 410007, Hunan, People's Republic of China
| | - Huaiqing Luo
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, 410007, Hunan, People's Republic of China.,Department of Anatomy, Histology and Embryology, Changsha Medical University, Changsha, 410219, Hunan, People's Republic of China
| | - Fulian Huang
- Department of Anatomy and Neurobiology, School of Basic Medical Sciences, Central South University, Changsha, 410013, Hunan, People's Republic of China
| | - Shaowen Tian
- Department of Physiology, College of Medicine, University of South China, Hengyang, 421001, Hunan, People's Republic of China.
| | - Xiaoqun Qin
- Department of Physiology, School of Basic Medical Science, Central South University, Changsha, 410007, Hunan, People's Republic of China.
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Cudnoch-Jedrzejewska A, Gomolka R, Szczepanska-Sadowska E, Czarzasta K, Wrzesien R, Koperski L, Puchalska L, Wsol A. High-fat diet and chronic stress reduce central pressor and tachycardic effects of apelin in Sprague-Dawley rats. Clin Exp Pharmacol Physiol 2015; 42:52-62. [PMID: 25311903 DOI: 10.1111/1440-1681.12324] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2014] [Revised: 09/26/2014] [Accepted: 10/02/2014] [Indexed: 12/17/2022]
Abstract
Central application of apelin elevates blood pressure and influences neuroendocrine responses to stress and food consumption. However, it is not known whether the central cardiovascular effects of apelin depend also on caloric intake or chronic stress. The purpose of the present study was to determine the effects of intracerebroventricular administration of apelin on blood pressure (mean arterial blood pressure) and heart rate in conscious Sprague-Dawley rats consuming either a normal-fat diet (NFD) or high-fat diet (HFD) for 12 weeks. During the last 4 weeks of the food regime, the rats were exposed (NFDS and HFDS groups) or not exposed (NFDNS and HFDNS groups) to chronic stress. Each group was divided into two subgroups receiving intracerebroventricular infusions of either vehicle or apelin. Apelin elicited significant increase of mean arterial blood pressure and heart rate in the NFDNS rats. This effect was abolished in the HFDNS, HFDS and NFDS groups. HFD resulted in a significant elevation of blood concentrations of total cholesterol, triglycerides glucose and insulin. Chronic stress reduced plasma concentration of total and high-density lipoprotein cholesterol, and increased plasma corticosterone concentration and APJ receptor mRNA expression in the hypothalamus, whereas a combination of a HFD with chronic stress resulted in the elevation of plasma triglycerides, total cholesterol and low-density lipoprotein cholesterol, and in increased plasma corticosterone concentration, apelin concentration and APJ receptor mRNA expression in the hypothalamus. It is concluded that a HFD and chronic stress result in significant suppression of the central pressor action of apelin, and cause significant though not unidirectional changes of metabolic and endocrine parameters.
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Affiliation(s)
- Agnieszka Cudnoch-Jedrzejewska
- Department of Experimental and Clinical Physiology, Laboratory of Centre for Preclinical Research, Medical University of Warsaw, Warsaw, Poland
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Maresca F, Palma VD, Bevilacqua M, Uccello G, Taglialatela V, Giaquinto A, Esposito G, Trimarco B, Cirillo P. Adipokines, Vascular Wall, and Cardiovascular Disease. Angiology 2015; 66:8-24. [DOI: 10.1177/0003319713520463] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/29/2023]
Abstract
Epidemiological evidence has shown that abdominal obesity is closely associated with the development of cardiovascular (CV) disease, suggesting that it might be considered as an independent CV risk factor. However, the pathophysiological mechanisms responsible for the association between these 2 clinical entities remain largely unknown. Adipocytes are considered able to produce and secrete chemical mediators known as “adipokines” that may exert several biological actions, including those on heart and vessels. Of interest, a different adipokine profile can be observed in the plasma of patients with obesity or metabolic syndrome compared with healthy controls. We consider the main adipokines, focusing on their effects on the vascular wall and analyzing their role in CV pathophysiology.
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Affiliation(s)
- Fabio Maresca
- Department of Advanced Biomedical Sciences, Division of Cardiology, University of Naples, Naples, Italy
| | - Vito Di Palma
- Department of Advanced Biomedical Sciences, Division of Cardiology, University of Naples, Naples, Italy
| | - Michele Bevilacqua
- Department of Advanced Biomedical Sciences, Division of Cardiology, University of Naples, Naples, Italy
| | - Giuseppe Uccello
- Department of Advanced Biomedical Sciences, Division of Cardiology, University of Naples, Naples, Italy
| | - Vittorio Taglialatela
- Department of Advanced Biomedical Sciences, Division of Cardiology, University of Naples, Naples, Italy
| | - Alessandro Giaquinto
- Department of Advanced Biomedical Sciences, Division of Cardiology, University of Naples, Naples, Italy
| | - Giovanni Esposito
- Department of Advanced Biomedical Sciences, Division of Cardiology, University of Naples, Naples, Italy
| | - Bruno Trimarco
- Department of Advanced Biomedical Sciences, Division of Cardiology, University of Naples, Naples, Italy
| | - Plinio Cirillo
- Department of Advanced Biomedical Sciences, Division of Cardiology, University of Naples, Naples, Italy
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25
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Topsakal S, Akin F, Turgut S, Yaylali GF, Herek D, Ayada C. Relationship of apelin, procalcitonin, and fetuin-A concentrations with carotid intima-media thickness in acromegaly. Ann Clin Biochem 2014; 52:456-61. [DOI: 10.1177/0004563214562431] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 11/06/2014] [Indexed: 12/31/2022]
Abstract
Background Acromegaly is characterized by excess growth hormone and insulin-like growth factor-1 concentrations. There is conflicting evidence as to whether acromegaly is associated with an increased risk of atherosclerosis. Apelin is an adipose tissue-derived peptide that may be associated with hyperinsulinemia. Fetuin-A is a hepatocyte produced plasma glycoprotein that has an important role as a calcification inhibitor. The aim of this study was to examine apelin, fetuin-A, and procalcitonin concentrations and to assess their relationship with carotid intima medial thickness (cIMT) in subjects with acromegaly. Methods Apelin, fetuin-A, and procalcitonin serum concentrations were measured in 37 (20 inactive and 17 active) subjects with acromegaly and 30 control subjects, along with carotid intima medial thickness. Results The concentrations of apelin, fetuin-A, and procalcitonin were increased in subjects with acromegaly. There were significant correlations between apelin, fetuin-A, and procalcitonin in subjects with acromegaly. Carotid intima medial thickness values were similar between control subjects and subjects with acromegaly. Conclusions Carotid intima medial thickness was not increased in subjects with acromegaly. It is possible that the increased apelin and fetuin-A concentrations observed play a protective role against the development of atherosclerosis in subjects with acromegaly.
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Affiliation(s)
- S Topsakal
- Department of Endocrinology and Metabolism, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - F Akin
- Department of Endocrinology and Metabolism, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - S Turgut
- Department of Physiology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - GF Yaylali
- Department of Endocrinology and Metabolism, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - D Herek
- Department of Radiology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
| | - C Ayada
- Department of Physiology, Faculty of Medicine, Pamukkale University, Denizli, Turkey
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Zhu P, Lin F, Huang F, Huang Q, Li Q, Gao Z, Chen F. Apelin andAPLNsingle nucleotide polymorphisms and combined hypertension and central retinal artery stenosis in a Chinese population. Clin Exp Hypertens 2014; 37:280-7. [DOI: 10.3109/10641963.2014.960970] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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Zhang F, Sun HJ, Xiong XQ, Chen Q, Li YH, Kang YM, Wang JJ, Gao XY, Zhu GQ. Apelin-13 and APJ in paraventricular nucleus contribute to hypertension via sympathetic activation and vasopressin release in spontaneously hypertensive rats. Acta Physiol (Oxf) 2014; 212:17-27. [PMID: 24995933 DOI: 10.1111/apha.12342] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2014] [Revised: 04/23/2014] [Accepted: 07/01/2014] [Indexed: 12/13/2022]
Abstract
AIMS Apelin is a specific endogenous ligand of orphan G protein-coupled receptor APJ. This study was designed to determine the roles and mechanisms of apelin-13 and APJ in paraventricular nucleus (PVN) in renal sympathetic nerve activity (RSNA), arginine vasopressin (AVP) release and mean arterial pressure (MAP) in spontaneously hypertensive rats (SHR). METHOD Acute experiment was carried out in 13-week-old male SHR and Wistar-Kyoto rats (WKY) under anaesthesia. RSNA and MAP responses to the PVN microinjection were determined. Apelin and APJ expressions were examined with quantitative real-time PCR and Western blot. AVP and noradrenaline were determined with ELISA. Osmotic minipumps were used for chronic PVN infusion in conscious WKY. RESULTS Apelin and APJ in the PVN were up-regulated in SHR. The PVN microinjection of apelin-13 increased, but APJ antagonist F13A decreased the RSNA, MAP, plasma noradrenaline and AVP levels in SHR. N-methyl-D-aspartate receptor (NMDAR) antagonist plus non-NMDAR antagonist abolished the apelin-13-induced sympathetic activation rather than AVP release. NMDAR antagonist or non-NMDAR antagonist alone attenuated the apelin-13-induced sympathetic activation. Chronic infusion of apelin-13 into the PVN in normotensive rats induced hypertension, increased plasma noradrenaline and AVP levels and promoted myocardial atrial natriuretic peptide and beta-myosin heavy chain mRNA expressions, two indicative markers of cardiac hypertrophy. CONCLUSION Apelin-13 and APJ in the PVN contribute to hypertension via sympathetic activation and AVP release in SHR. The sympatho-excitatory effect of apeline-13 is mediated by both NMDAR and non-NMDAR in the PVN. Persistent activation of APJ in the PVN induces hypertension.
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Affiliation(s)
- F. Zhang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
| | - H.-J. Sun
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
| | - X.-Q. Xiong
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
| | - Q. Chen
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
| | - Y.-H. Li
- Department of Pathophysiology; Nanjing Medical University; Nanjing Jiangsu China
| | - Y.-M. Kang
- Department of Physiology and Pathophysiology; Cardiovascular Research Center; Xi'an Jiaotong University School of Medicine; Xi'an China
| | - J.-J. Wang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
| | - X.-Y. Gao
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
| | - G.-Q. Zhu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention; Department of Physiology; Nanjing Medical University; Nanjing Jiangsu China
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Wu D, He L, Chen L. Apelin/APJ system: a promising therapy target for hypertension. Mol Biol Rep 2014; 41:6691-703. [DOI: 10.1007/s11033-014-3552-4] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2014] [Accepted: 06/20/2014] [Indexed: 10/25/2022]
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Telegdy G, Jászberényi M. Transmitter mediation of the anxiolytic action of apelin-13 in male mice. Behav Brain Res 2014; 263:198-202. [DOI: 10.1016/j.bbr.2014.01.009] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2013] [Revised: 01/09/2014] [Accepted: 01/15/2014] [Indexed: 12/11/2022]
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O'Carroll AM, Lolait SJ, Harris LE, Pope GR. The apelin receptor APJ: journey from an orphan to a multifaceted regulator of homeostasis. J Endocrinol 2013; 219:R13-35. [PMID: 23943882 DOI: 10.1530/joe-13-0227] [Citation(s) in RCA: 246] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
The apelin receptor (APJ; gene symbol APLNR) is a member of the G protein-coupled receptor gene family. Neural gene expression patterns of APJ, and its cognate ligand apelin, in the brain implicate the apelinergic system in the regulation of a number of physiological processes. APJ and apelin are highly expressed in the hypothalamo-neurohypophysial system, which regulates fluid homeostasis, in the hypothalamic-pituitary-adrenal axis, which controls the neuroendocrine response to stress, and in the forebrain and lower brainstem regions, which are involved in cardiovascular function. Recently, apelin, synthesised and secreted by adipocytes, has been described as a beneficial adipokine related to obesity, and there is growing awareness of a potential role for apelin and APJ in glucose and energy metabolism. In this review we provide a comprehensive overview of the structure, expression pattern and regulation of apelin and its receptor, as well as the main second messengers and signalling proteins activated by apelin. We also highlight the physiological and pathological roles that support this system as a novel therapeutic target for pharmacological intervention in treating conditions related to altered water balance, stress-induced disorders such as anxiety and depression, and cardiovascular and metabolic disorders.
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Affiliation(s)
- Anne-Marie O'Carroll
- Henry Wellcome Laboratories for Integrative Neuroscience and Endocrinology, School of Clinical Sciences, University of Bristol, Dorothy Hodgkin Building, Whitson Street, Bristol BS1 3NY, UK
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Repeated electroacupuncture attenuating of apelin expression and function in the rostral ventrolateral medulla in stress-induced hypertensive rats. Brain Res Bull 2013; 97:53-62. [DOI: 10.1016/j.brainresbull.2013.05.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2013] [Revised: 05/24/2013] [Accepted: 05/28/2013] [Indexed: 02/06/2023]
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Dai L, Smith PM, Kuksis M, Ferguson AV. Apelin acts in the subfornical organ to influence neuronal excitability and cardiovascular function. J Physiol 2013; 591:3421-32. [PMID: 23629509 DOI: 10.1113/jphysiol.2013.254144] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Apelin is an adipocyte-derived hormone involved in the regulation of water balance, food intake and the cardiovascular system partially through actions in the CNS. The subfornical organ (SFO) is a circumventricular organ with identified roles in body fluid homeostasis, cardiovascular control and energy balance. The SFO lacks a normal blood-brain barrier, and is thus able to detect circulating signalling molecules such as angiotensin II and leptin. In this study, we investigated actions of apelin-13, the predominant apelin isoform in brain and circulatory system, on the excitability of dissociated SFO neurons using electrophysiological approaches, and determined the cardiovascular consequences of direct administration into the SFO of anaesthetized rats. Whole cell current clamp recording revealed that bath-applied 100 nm apelin-13 directly influences the excitability of the majority of SFO neurons by eliciting either depolarizing (31.8%, mean 7.0 ± 0.8 mV) or hyperpolarizing (28.6%, mean -10.4 ± 1.8 mV) responses. Using voltage-clamp techniques, we also identified modulatory actions of apelin-13 on specific ion channels, demonstrating that apelin-13 activates a non-selective cationic conductance to depolarize SFO neurons while activation of the delayed rectifier potassium conductance underlies hyperpolarizing effects. In anaesthetized rats, microinjection of apelin into SFO decreased both blood pressure (BP) (mean area under the curve -1492.3 ± 357.1 mmHg.s, n = 5) and heart rate (HR) (-32.4 ± 10.39 beats, n = 5). Our data suggest that circulating apelin can directly affect BP and HR as a consequence of the ability of this peptide to modulate the excitability of SFO neurons.
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Affiliation(s)
- Li Dai
- Biomedical and Molecular Sciences, Department of Physiology, Queen's University, Kingston, ON K7L 3N6, Canada
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Telegdy G, Adamik A, Jászberényi M. Involvement of neurotransmitters in the action of apelin-13 on passive avoidance learning in mice. Peptides 2013; 39:171-4. [PMID: 23131543 DOI: 10.1016/j.peptides.2012.10.011] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/11/2012] [Revised: 10/28/2012] [Accepted: 10/28/2012] [Indexed: 12/12/2022]
Abstract
The widespread distribution of apelin-13 and apelin receptors in the brain suggests an important function of this neuropeptide in the brain that has not been explored extensively so far. In the present work, apelin-13 was found to facilitate the consolidation of passive avoidance learning in mice. In order to assess the possible involvement of transmitters in this action, the animals were pretreated with the following receptor blockers in doses which themselves did not influence the behavioral paradigm: phenoxybenzamine (a nonselective α-adrenergic receptor antagonist), propranolol (a β-adrenergic receptor antagonist), cyproheptadine (a nonselective 5-HT2 serotonergic receptor antagonist), atropine (a nonselective muscarinic acetylcholine receptor antagonist), haloperidol (a D2, D3 and D4 dopamine receptor antagonist), bicuculline (a γ-aminobutyric acid subunit A (GABA-A) receptor antagonist), naloxone (a nonselective opioid receptor antagonist), and nitro-L-arginine (a nitric oxide synthase inhibitor). Phenoxybenzamine, cyproheptadine, atropine, haloperidol, bicuculline and nitro-L-arginine prevented the action of apelin-13. Propranolol and naloxone were ineffective. The data suggest that apelin-13 elicits its action on the consolidation of passive avoidance learning via α-adrenergic, 5-HT2 serotonergic, cholinergic, dopaminergic, GABA-A-ergic and nitric oxide mediations.
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Affiliation(s)
- Gyula Telegdy
- Department of Pathophysiology, University of Szeged, Szeged, Hungary.
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Najafipour H, Soltani Hekmat A, Nekooian AA, Esmaeili-Mahani S. Apelin receptor expression in ischemic and non- ischemic kidneys and cardiovascular responses to apelin in chronic two‐kidney–one‐clip hypertension in rats. ACTA ACUST UNITED AC 2012; 178:43-50. [DOI: 10.1016/j.regpep.2012.06.006] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2011] [Revised: 03/27/2012] [Accepted: 06/22/2012] [Indexed: 12/15/2022]
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Masaki T, Yasuda T, Yoshimatsu H. Apelin-13 microinjection into the paraventricular nucleus increased sympathetic nerve activity innervating brown adipose tissue in rats. Brain Res Bull 2012; 87:540-3. [DOI: 10.1016/j.brainresbull.2012.02.004] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 02/13/2012] [Accepted: 02/14/2012] [Indexed: 10/28/2022]
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Wang LY, Zhang DL, Zheng JF, Zhang Y, Zhang QD, Liu WH. Apelin-13 passes through the ADMA-damaged endothelial barrier and acts on vascular smooth muscle cells. Peptides 2011; 32:2436-43. [PMID: 22001227 DOI: 10.1016/j.peptides.2011.10.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 10/01/2011] [Accepted: 10/02/2011] [Indexed: 12/26/2022]
Abstract
Asymmetric dimethylarginine (ADMA), an endogenous nitric oxide synthase inhibitor, is associated with vascular dysfunction. The polypeptide apelin mediates two major actions on blood vessels. However, their combined effects on vascular function are not fully understood. The present study aimed to determine the effect of apelin-13 on myosin light chain (MLC) phosphorylation in vascular smooth muscle cells (VSMCs) under ADMA-induced endothelial leakage conditions. To assess the increased permeability induced by ADMA, human umbilical vein endothelium cells (HUVECs) were plated in transwell dishes. The FITC-dextran flux and FITC-apelin-13 flux through the endothelial monolayer were measured. To examine the effect of leakage of apelin-13 on MLC phosphorylation in HUVSMCs, transwell dishes were used to establish a coculture system with HUVECs in upper chambers and HUVSMCs in lower chambers. Western blot was performed to assess the phospho-MLC levels. ADMA increased endothelial permeability in a concentration- and time-dependent manner, accompanied by actin stress fiber assembly and intercellular gap formation. When HUVECs were treated with ADMA, the permeability to both macromolecular dextran and micromolecular apelin-13 increased significantly. Both p38 MAPK inhibitor and NADPH oxidase inhibitor could prevent HUVECs from the increased permeability, and the changes of cytoskeleton and intercellular junction, which were induced by ADMA. Apelin-13 passed through the ADMA-stimulated endothelial monolayer and increased the expression of phospho-MLC in VSMCs. These results suggest that ADMA increases endothelial permeability, which may involve the p38 MAPK and NADPH oxidase pathway. Apelin-13 can pass through the damaged endothelial barrier, and acts directly on VSMCs to increase MLC phosphorylation.
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Affiliation(s)
- Li-Yan Wang
- Department of Nephrology, Affiliated Beijing Friendship Hospital, Faculty of Kidney Diseases, Capital Medical University, No. 95 Yong An Road, Xi Cheng District, Beijing 100050, China
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Nakagaki T, Hirooka Y, Ito K, Kishi T, Hoka S, Sunagawa K. Role of angiotensin-(1-7) in rostral ventrolateral medulla in blood pressure regulation via sympathetic nerve activity in Wistar-Kyoto and spontaneous hypertensive rats. Clin Exp Hypertens 2011; 33:223-30. [PMID: 21699448 DOI: 10.3109/10641963.2011.583967] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Angiotensin (Ang)-(1-7) Ang-(1-7) is formed from angiotensin II by angiotensin-converting enzyme 2 (ACE2) and modulates the renin-angiotensin system. We evaluated whether the Ang-(1-7)-Mas axis in the rostral ventrolateral medulla (RVLM) contributes to neural mechanisms of blood pressure (BP) regulation. We microinjected Ang-(1-7), Ang-(1-7)-Mas receptor antagonist A-779, and ACE2 inhibitor DX600 into the RVLM of anesthetized Wistar-Kyoto rats (WKY) and spontaneously hypertensive rats (SHRs). Unilateral Ang-(1-7) microinjection induced a significantly greater increase in AP (arterial blood pressure) in SHR than in WKY. Bilateral A-779 microinjection induced a significantly greater decrease in AP and renal sympathetic nerve activity in SHR than in WKY. Bilateral DX600 microinjection induced a significantly greater decrease in AP in SHR than in WKY. Our results suggest that endogenous Ang-(1-7) in the RVLM contributes to maintain AP and renal sympathetic nerve activity both in SHR and WKY and that its activity might be enhanced in SHR.
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Affiliation(s)
- Toshiaki Nakagaki
- Department of Cardiovascular Medicine, Kyushu University Graduate School of Medical Sciences, Fukuoka, Japan
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Soltani Hekmat A, Najafipour H, Nekooian AA, Esmaeli-Mahani S, Javanmardi K. Cardiovascular responses to apelin in two-kidney-one-clip hypertensive rats and its receptor expression in ischemic and non-ischemic kidneys. ACTA ACUST UNITED AC 2011; 172:62-8. [PMID: 21911011 DOI: 10.1016/j.regpep.2011.08.010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2011] [Revised: 08/15/2011] [Accepted: 08/23/2011] [Indexed: 11/17/2022]
Abstract
BACKGROUND Apelin and its receptor APJ have been shown to have beneficial effects on cardiovascular function. Apelin was shown to elicit hypotensive effects and also a positive inotropic effect on failing hearts. In this study, we investigated the effect of apelin on blood pressure and cardiac contractility in a two-kidney-one-clip (2K1C) hypertension model. We also assessed the changes in the level of apelin and some other hemodynamically effective hormones in serum and apelin receptor gene expression in nonischemic and ischemic kidneys. METHODS 2K1C was produced by placing a Plexiglas clip around the left renal artery. Four weeks later, blood pressure (BP) and cardiac indices of contractility were measured by power lab system. The sample venous blood was drawn from the jugular vein for biochemical variable measurements. The mRNA and protein level of APJ were determined in the kidneys by RT-PCR and Western blot methods respectively. RESULTS The findings showed that, 2K1C increased BP from 116/75 in sham group to 200/140 mmHg in test group. Furthermore, intravenous administration of apelin-13 to hypertensive rats significantly decreased systolic (SBP) and diastolic (DBP) blood pressures in dose of 20 μg/kg with maximal responses within 2 min of injection. This reduction was long lasting and prominent in dose of 40 μg/kg. Apelin at dose of 20 μg/kg increased +LVdp/dt max and -LVdp/dt max. However at dose of 40 μg/kg SBP, DBP, +LVdp/dt max and -LVdp/dt max strongly decreased. All of the observed effects were completely blocked by apelin antagonist F13A. 2K1C did not change serum apelin, aldosterone and arginine-vasopressin levels but significantly increased angiotensin II level. 2K1C hypertension decreased apelin receptor mRNA and protein expression in contra lateral (nonischemic) kidney, but these were not affected in clipped kidney. CONCLUSION Apelin induces hypotensive and positive inotropic effects in medium doses. However, in higher doses it elicits hypotensive and negative inotropic effects in 2K1C rats. Down regulation of apelin receptor in nonischemic kidney of hypertensive rats may play a role in pathophysiology of renovascular hypertension. Apelin together with renin-angiotensin antagonism may play a useful role in treatment of this type of hypertension.
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Affiliation(s)
- Ava Soltani Hekmat
- Physiology Research Center, Kerman University of Medical Sciences, Kerman, Iran.
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Reduced circulating apelin in essential hypertension and its association with cardiac dysfunction. J Hypertens 2011; 29:971-9. [PMID: 21346619 DOI: 10.1097/hjh.0b013e328344da76] [Citation(s) in RCA: 56] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
OBJECTIVE Apelin--a novel multifunction peptide implicated in regulation of the cardiovascular system, including blood pressure and cardiac function control - has been postulated to be involved in the pathophysiology of hypertension and hypertensive heart disease. We investigated the circulating apelin level and its relationship to left ventricular function in patients with essential hypertension. METHODS We enrolled 232 hypertensive patients without concomitant diseases affecting cardiovascular functions and 76 healthy controls. Each patient underwent plasma apelin measurement and echocardiographic assessment of left ventricular systolic and diastolic function using myocardial velocities and deformation parameters, and myocardial reflectivity using calibrated integrated backscatter. RESULTS Hypertensive patients demonstrated lower plasma apelin than the controls (265 ± 127 vs. 330 ± 159 pg/ml; P<0.001). Patients with the lowest plasma apelin, that is, from the first tertile, exhibited more severe left ventricular systolic and diastolic function abnormalities than their peers from the other two tertiles. In multivariable regression analysis, apelin was, in addition to patient age, BMI, blood pressure, left ventricular mass index and calibrated integrated backscatter in the basal septum, an independent correlate of left ventricular systolic function parameters (β=0.18; P<0.001 for strain and β=0.12; P<0.03 for systolic strain rate) and diastolic function parameters (β=0.13; P<0.01 for early diastolic strain rate, β=0.11; P<0.04 for early diastolic myocardial velocity, and β=-0.11; P<0.04 for the ratio of mitral inflow to mitral annular early diastolic velocity). CONCLUSION In patients with essential hypertension, circulating apelin levels are reduced, and lower plasma apelin is independently associated with more profound left ventricular systolic and diastolic function impairment.
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Validation of genetic association in apelin-AGTRL1 system with hypertension in a larger Han Chinese population. J Hypertens 2010; 28:1854-61. [PMID: 20485192 DOI: 10.1097/hjh.0b013e32833b1fad] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
BACKGROUND AND OBJECTIVE We have recently resequenced apelin and AGTRL1 genes to identify candidate polymorphisms in family-based association with hypertension and related phenotypes. In this study, we aimed to determine and replicate these polymorphisms via a larger, independent case-control study in Shanghai Han Chinese. METHODS Two polymorphisms [rs3761581 (A/C) and T-1860C] in apelin gene and two [rs7119375 (G/A), rs10501367 (G/A)] in AGTRL1 gene were genotyped using the TaqMan assay among 969 patients diagnosed with essential hypertension and 980 age and sex-matched controls. Data were analyzed using Haplo.stats program. RESULTS In single-locus analysis, significant differences were observed in allele distribution of rs3761581 (P = 0.0156) in men and in rs7119375 (P = 0.0488) genotype distribution in women between patients and controls. Haplotype analysis indicated that haplotypes C-C-G-G (in order of T-1860C, rs3761581, rs7119375 and rs10501367) [adjusted odds ratio (ORadjusted) = 1.67, P = 0.0061] and T-A-A-A (ORadjusted = 1.62, P = 0.0008) conferred an increased risk for hypertension after adjustment for age, onset age, body mass index (BMI) and waist-to-hip ratio, whereas haplotype C-C-A-A (ORadjusted = 0.33, P = 0.0048) conferred a protective effect. In women, increased risk for hypertension was seen for haplotypes T-A-G-G (ORadjusted = 1.30, P = 0.0051), C-C-G-G (ORadjusted = 2.86, P < 0.0001), T-A-A-A (ORadjusted = 1.66, P = 0.0003) and C-C-A-A (ORadjusted = 2.65, P < 0.0001), whereas decreased risk was seen for haplotypes C-A-G-G (ORadjusted = 0.48, P < 0.0001) and T-C-G-G (ORadjusted = 0.40, P < 0.0001). Further haplotype-phenotype analyses indicated the robustness of these associations. For example, haplotype T-A-A-A was significantly associated with obesity index (BMI and waist-to-hip ratio) in both sexes and blood pressures in men (P-sim < 0.05). CONCLUSION In this exploratory pilot case-control study, we found robust haplotype-based and haplotype-phenotype associations of four well characterized polymorphisms in apelin-AGTRL1 system with hypertension and related phenotypes.
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Yang YJ, Lv SY, Xiu MH, Xu N, Chen Q. Intracerebroventricular administration of apelin-13 inhibits distal colonic transit in mice. Peptides 2010; 31:2241-6. [PMID: 20849897 DOI: 10.1016/j.peptides.2010.09.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/17/2010] [Revised: 09/04/2010] [Accepted: 09/04/2010] [Indexed: 01/17/2023]
Abstract
Apelin is a novel bioactive peptide as the endogenous ligand for the orphan G-protein-coupled receptor (GPCR), APJ, a receptor distributed in various tissues such as the hypothalamus and the gastrointestinal tract. Recent reports showed that apelin regulated many biological functions, including blood pressure, neuroendocrine, drinking behavior and food intake. However, the role of apelin in regulating gastrointestinal motility remains unknown. The present study aimed to investigate the actions of intracerebroventricularly administered apelin-13 on colonic transit as well as the actions of apelin-13 on the contraction of isolated distal colon in vitro. Intracerebroventricular (i.c.v.) injection of apelin-13 (0.3, 0.5, 1 and 3 μg/mouse) dose-dependently inhibited fecal pellet output and bead expulsion. This effect was significantly antagonized by the APJ receptor antagonist apelin-13(F13A), indicating an APJ receptor-mediated mechanism. Furthermore, naloxone could also reverse the inhibitory effect of apelin-13 on fecal pellet output and bead expulsion, suggesting the involvement of opioid receptors in the suppressive effect of apelin-13 on distal colon transit. However, apelin-13 (10⁻⁸-10⁻⁶ M) did not affect distal colonic contractions in vitro.
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Affiliation(s)
- Yan-Jie Yang
- Institute of Biochemistry and Molecular Biology, School of Life Science, Lanzhou University, 222 Tian Shui South Road, Lanzhou 730000, PR China
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Yao F, Modgil A, Zhang Q, Pingili A, Singh N, O'Rourke ST, Sun C. Pressor effect of apelin-13 in the rostral ventrolateral medulla: role of NAD(P)H oxidase-derived superoxide. J Pharmacol Exp Ther 2010; 336:372-80. [PMID: 21047952 DOI: 10.1124/jpet.110.174102] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Microinjection of apelin-13 into the rostral ventrolateral medulla (RVLM) in the brainstem increases blood pressure in rats. In the present study, we tested the hypotheses that apelin-13 directly stimulates neuronal activity in neurons cultured from the brainstem and that NAD(P)H oxidase-derived reactive oxygen species are involved in this action of apelin-13. Microinjection of apelin-13 into the RVLM resulted in increases in arterial pressure and in renal sympathetic nerve activity in Sprague-Dawley rats. The pressor effect of apelin-13 was attenuated by the specific NAD(P)H-oxidase inhibitor gp91ds-tat. In neurons cultured from the ventral brainstem, spontaneous action potentials were recorded using current-clamp recording. Superfusion of neurons with apelin-13 (100 nM) increased the neuronal firing rate from 0.79 ± 0.14 to 1.45 ± 0.26 Hz (n = 7, P < 0.01) in angiotensin II receptor-like 1-positive neurons, identified with single-cell reverse transcriptase-polymerase chain reaction. Neither the angiotensin II type 1 receptor antagonist losartan nor the angiotensin II type 2 receptor antagonist 1-[[4-(dimethylamino)-3-methylphenyl[methyl]-5-(diphenylacetyl)-4,5,6,7-tetrahydro-1H-imidazo[4,5-c]pyridine-6-carboxylic acid ditrifluoroacetate (PD123319) altered the positive chronotropic effect of apelin-13. Pretreatment of cells with either the reactive oxygen species scavenger superoxide dismutase [polyethylene glycol-superoxide dismutase (PEG-SOD), 25 U/ml] or with gp91ds-tat significantly attenuated the chronotropic action of apelin-13. PEG-SOD and gp91ds-tat alone had no effect on basal neuronal firing. In addition, apelin-13 significantly increased NAD(P)H oxidase activity and elevated intracellular superoxide levels in neuronal cultures. The superoxide generator xanthine-xanthine oxidase also increased neuronal activity in neurons, mimicking the neuronal response to apelin-13. These observations provide the first evidence that apelin-13 directly increases neuronal activity via stimulation of NAD(P)H oxidase-derived superoxide, a cellular signaling mechanism that may be involved in the pressor effect of apelin-13 in the RVLM.
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Affiliation(s)
- Fanrong Yao
- Department of Pharmaceutical Sciences, North Dakota State University, Fargo, North Dakota 58108-6050, USA
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Vlasova M, Purhonen AK, Jarvelin MR, Rodilla E, Pascual J, Herzig KH. Role of adipokines in obesity-associated hypertension. Acta Physiol (Oxf) 2010; 200:107-27. [PMID: 20653609 DOI: 10.1111/j.1748-1716.2010.02171.x] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
It has been well documented that obesity is a major risk factor for the development of the hypertensive state. The correlation between body mass index and blood pressure level is well established. Nevertheless, the exact mechanisms which contribute to obesity-related hypertension remain poorly understood. In the last years, we have realized that the white adipose tissue is not just an inert organ for nutrient storage and isolation but rather depending on the body mass index the biggest endocrinological organ. Thus, the possible contribution of adipokines to the blood pressure elevation becomes an attractive hypothesis to explain the hypertensive state that often occurs in obesity. In this review, we consider direct and indirect effects of main adipokines on structural and functional changes in the cardiovascular system.
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Affiliation(s)
- M Vlasova
- Department of Pharmaceutics, University of Kuopio, Kuopio, Finland
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44
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Pilowsky PM, Lung MSY, Spirovski D, McMullan S. Differential regulation of the central neural cardiorespiratory system by metabotropic neurotransmitters. Philos Trans R Soc Lond B Biol Sci 2009; 364:2537-52. [PMID: 19651655 DOI: 10.1098/rstb.2009.0092] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Central neurons in the brainstem and spinal cord are essential for the maintenance of sympathetic tone, the integration of responses to the activation of reflexes and central commands, and the generation of an appropriate respiratory motor output. Here, we will discuss work that aims to understand the role that metabotropic neurotransmitter systems play in central cardiorespiratory mechanisms. It is well known that blockade of glutamatergic, gamma-aminobutyric acidergic and glycinergic pathways causes major or even complete disruption of cardiorespiratory systems, whereas antagonism of other neurotransmitter systems barely affects circulation or ventilation. Despite the lack of an 'all-or-none' role for metabotropic neurotransmitters, they are nevertheless significant in modulating the effects of central command and peripheral adaptive reflexes. Finally, we propose that a likely explanation for the plethora of neurotransmitters and their receptors on cardiorespiratory neurons is to enable differential regulation of outputs in response to reflex inputs, while at the same time maintaining a tonic level of sympathetic activity that supports those organs that significantly autoregulate their blood supply, such as the heart, brain, retina and kidney. Such an explanation of the data now available enables the generation of many new testable hypotheses.
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Affiliation(s)
- Paul M Pilowsky
- Australian School of Advanced Medicine, Dow-Corning Building, Level 1, 3 Innovation Road, Macquarie University, 2109 NSW, Australia.
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Xu N, Wang H, Fan L, Chen Q. Supraspinal administration of apelin-13 induces antinociception via the opioid receptor in mice. Peptides 2009; 30:1153-7. [PMID: 19463749 DOI: 10.1016/j.peptides.2009.02.011] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2008] [Revised: 02/12/2009] [Accepted: 02/12/2009] [Indexed: 11/28/2022]
Abstract
The effect of apelin-13 on pain modulation at the supraspinal level was investigated in mice using the tail immersion test. Intracerebroventricular (i.c.v.) administration of apelin-13 (0.3, 0.5, 0.8 and 3 microg/mouse) produced a dose- and time-related antinociceptive effect. This effect was significantly antagonized by the APJ receptor antagonist apelin-13(F13A), indicating an APJ receptor-mediated mechanism. Furthermore, naloxone, beta-funaltrexamine and naloxonazine, could reverse the analgesic effect. However, naltrindole or nor-binaltorphimine could not reverse the effect, suggesting that mu opioid receptor (primarily mu(1) opioid receptor subtype) is involved in the analgesic response evoked by apelin-13. Moreover, i.c.v. administration of apelin-13 potentiated the analgesic effect induced by morphine (i.c.v., 5 microg/kg) and this potentiated effect can be also reversed by naloxone.
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Affiliation(s)
- Ning Xu
- Department of Biochemistry and Molecular Biology, Lanzhou University, Lanzhou, PR China
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46
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Pilowsky PM, Goodchild AK. Neuropeptides and the Central Neural Regulation of the Cardiorespiratory System. Tzu Chi Med J 2009. [DOI: 10.1016/s1016-3190(09)60019-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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47
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Family-based analysis of apelin and AGTRL1 gene polymorphisms with hypertension in Han Chinese. J Hypertens 2009; 27:1194-201. [DOI: 10.1097/hjh.0b013e32832a3eb1] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
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48
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Zhang Q, Yao F, Raizada MK, O'Rourke ST, Sun C. Apelin gene transfer into the rostral ventrolateral medulla induces chronic blood pressure elevation in normotensive rats. Circ Res 2009; 104:1421-8. [PMID: 19443838 DOI: 10.1161/circresaha.108.192302] [Citation(s) in RCA: 65] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The peripheral apelin system plays a significant role in cardiovascular homeostasis and in the pathophysiology of cardiovascular diseases. However, the central effect of this neurohormonal system in neural control of cardiovascular function remains poorly understood. Thus, this study was undertaken to evaluate the effect of apelin in the rostral ventrolateral medulla (RVLM) on blood pressure, cardiac function, and sympathetic nerve activity. Apelin mRNA and protein levels were detected with real-time RT-PCR and Western blots, respectively. Expression of apelin was significantly enhanced in the RVLM of spontaneously hypertensive rat (SHR) compared with normotensive Wistar-Kyoto (WKY) rats. To study the functional consequence of upregulated apelin expression, apelin was overexpressed by bilateral microinjection of the AAV2-apelin viral vector into the RVLM of WKY rats. Immunofluorescence staining and Western blots demonstrated that microinjection of AAV2-apelin into the RVLM resulted in a significant increase in apelin expression, which was associated with a chronic elevation in blood pressure and cardiac hypertrophy. In addition, direct microinjection of exogenous apelin-13 (200 pmol in 50 nL) into the RVLM caused a 20 mm Hg elevation in blood pressure and a 24% increase in sympathetic nerve activity. The present study is the first to show that apelin expression is enhanced in the RVLM of SHR versus WKY rats and that overexpression of this gene in the RVLM results in chronic blood pressure elevation and cardiac hypertrophy in normotensive rats. Thus, the apelin system in the RVLM may play a very important role in central blood pressure regulation and in the pathogenesis of hypertension.
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Affiliation(s)
- Qi Zhang
- Department of Pharmaceutical Sciences, North Dakota State University, 1401 Albrecht Blvd, Fargo, ND 58105, USA
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Xia H, Lazartigues E. Angiotensin-converting enzyme 2 in the brain: properties and future directions. J Neurochem 2008; 107:1482-94. [PMID: 19014390 PMCID: PMC2667944 DOI: 10.1111/j.1471-4159.2008.05723.x] [Citation(s) in RCA: 252] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Angiotensin (Ang)-converting enzyme (ACE) 2 cleaves Ang-II into the vasodilator peptide Ang-(1-7), thus acting as a pivotal element in balancing the local effects of these peptides. ACE2 has been identified in various tissues and is supposed to be a modulator of cardiovascular function. Decreases in ACE2 expression and activity have been reported in models of hypertension, heart failure, atherosclerosis, diabetic nephropathy and others. In addition, the expression level and/or activity are affected by other renin-angiotensin system components (e.g., ACE and AT1 receptors). Local inhibition or global deletion of brain ACE2 induces a reduction in baroreflex sensitivity. Moreover, ACE2-null mice have been shown to exhibit either blood pressure or cardiac dysfunction phenotypes. On the other hand, over-expression of ACE2 exerts protective effects in local tissues, including the brain. In this review, we will first summarize the major findings linking ACE2 to cardiovascular function in the periphery then focus on recent discoveries related to ACE2 in the CNS. Finally, we will unveil new tools designed to address the importance of central ACE2 in various diseases, and discuss the potential for this carboxypeptidase as a new target in the treatment of hypertension and other cardiovascular diseases.
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Affiliation(s)
- Huijing Xia
- Department of Pharmacology and Experimental Therapeutics and Cardiovascular Center of Excellence, Louisiana State University Health Sciences Center, New Orleans, LA 70112, USA
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Chandrasekaran B, Dar O, McDonagh T. The role of apelin in cardiovascular function and heart failure. Eur J Heart Fail 2008; 10:725-32. [PMID: 18583184 DOI: 10.1016/j.ejheart.2008.06.002] [Citation(s) in RCA: 113] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 04/21/2008] [Accepted: 06/04/2008] [Indexed: 12/11/2022] Open
Abstract
Apelin is a novel peptide that acts through the APJ receptor, sharing similarities with the angiotensin II-angiotensin II type 1 receptor pathway. It is a peripheral vasodilator, powerful inotrope and may affect central fluid homeostasis. Animal and human studies suggest that it may play a role in the pathogenesis of heart failure by modulating the harmful effects of angiotensin II. Apelin is reduced in patients with heart failure and up regulated following favourable left ventricular remodelling. It is widely distributed in a number of tissues, mainly restricted to vascular endothelium. This comprehensive review of the literature highlights the important studies that have led to the discovery of apelin and its role in cardiovascular function and heart failure.
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