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Zizi V, Becatti M, Bani D, Nistri S. Serelaxin Protects H9c2 Cardiac Myoblasts against Hypoxia and Reoxygenation-Induced Damage through Activation of AMP Kinase/Sirtuin1: Further Insight into the Molecular Mechanisms of the Cardioprotection of This Hormone. Antioxidants (Basel) 2024; 13:163. [PMID: 38397761 PMCID: PMC10886064 DOI: 10.3390/antiox13020163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2023] [Revised: 01/16/2024] [Accepted: 01/24/2024] [Indexed: 02/25/2024] Open
Abstract
Serelaxin (RLX), namely the human recombinant Relaxin-2 hormone, protects the heart from ischemia/reperfusion (I/R)-induced damage due to its anti-inflammatory, anti-apoptotic and antioxidant properties. RLX acts by binding to its specific RXFP1 receptor whereby it regulates multiple transduction pathways. In this in vitro study, we offer the first evidence for the involvement of the AMP kinase/Sirtuin1 (AMPK/SIRT1) pathway in the protection by RLX against hypoxia/reoxygenation (H/R)-induced damage in H9c2 cells. The treatment of the H/R-exposed cells with RLX (17 nmol L-1) enhanced SIRT1 expression and activity. The inhibition of SIRT1 signaling with EX527 (10 µmol L-1) reduced the beneficial effect of the hormone on mitochondrial efficiency and cell apoptosis. Moreover, RLX upregulated the AMPK pathway, as shown by the increase in the expression of phospho-AMPK-activated protein. Finally, AMPK pathway inhibition by Compound C (10 and 20 μmol L-1) abrogated the increase in SIRT1 expression induced by RLX, thus suggesting the involvement of the AMPK pathway in this effect of RLX. These results strengthen the concept that RLX exerts its cardioprotective effects against H/R-induced injury through multiple pathways which also include AMPK/SIRT1. These new findings support the use of RLX or RLX-derived molecules as a promising therapeutic for those diseases in which I/R and oxidative stress play a pathogenic role.
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Affiliation(s)
- Virginia Zizi
- Department of Experimental & Clinical Medicine, Research Unit of Histology & Embryology, University of Florence, Viale G. Pieraccini 6, 50139 Florence, Italy; (V.Z.); (D.B.)
| | - Matteo Becatti
- Department of Experimental & Clinical Biomedical Sciences “Mario Serio”, Section of Biochemical Sciences, University of Florence, Viale G.B. Morgagni 50, 50134 Florence, Italy;
| | - Daniele Bani
- Department of Experimental & Clinical Medicine, Research Unit of Histology & Embryology, University of Florence, Viale G. Pieraccini 6, 50139 Florence, Italy; (V.Z.); (D.B.)
| | - Silvia Nistri
- Department of Experimental & Clinical Medicine, Research Unit of Histology & Embryology, University of Florence, Viale G. Pieraccini 6, 50139 Florence, Italy; (V.Z.); (D.B.)
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2
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Zhao BH, Ruze A, Zhao L, Li QL, Tang J, Xiefukaiti N, Gai MT, Deng AX, Shan XF, Gao XM. The role and mechanisms of microvascular damage in the ischemic myocardium. Cell Mol Life Sci 2023; 80:341. [PMID: 37898977 PMCID: PMC11073328 DOI: 10.1007/s00018-023-04998-z] [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: 05/22/2023] [Revised: 09/08/2023] [Accepted: 10/02/2023] [Indexed: 10/31/2023]
Abstract
Following myocardial ischemic injury, the most effective clinical intervention is timely restoration of blood perfusion to ischemic but viable myocardium to reduce irreversible myocardial necrosis, limit infarct size, and prevent cardiac insufficiency. However, reperfusion itself may exacerbate cell death and myocardial injury, a process commonly referred to as ischemia/reperfusion (I/R) injury, which primarily involves cardiomyocytes and cardiac microvascular endothelial cells (CMECs) and is characterized by myocardial stunning, microvascular damage (MVD), reperfusion arrhythmia, and lethal reperfusion injury. MVD caused by I/R has been a neglected problem compared to myocardial injury. Clinically, the incidence of microvascular angina and/or no-reflow due to ineffective coronary perfusion accounts for 5-50% in patients after acute revascularization. MVD limiting drug diffusion into injured myocardium, is strongly associated with the development of heart failure. CMECs account for > 60% of the cardiac cellular components, and their role in myocardial I/R injury cannot be ignored. There are many studies on microvascular obstruction, but few studies on microvascular leakage, which may be mainly due to the lack of corresponding detection methods. In this review, we summarize the clinical manifestations, related mechanisms of MVD during myocardial I/R, laboratory and clinical examination means, as well as the research progress on potential therapies for MVD in recent years. Better understanding the characteristics and risk factors of MVD in patients after hemodynamic reconstruction is of great significance for managing MVD, preventing heart failure and improving patient prognosis.
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Affiliation(s)
- Bang-Hao Zhao
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Amanguli Ruze
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Ling Zhao
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Qiu-Lin Li
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Jing Tang
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Nilupaer Xiefukaiti
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Min-Tao Gai
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - An-Xia Deng
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Xue-Feng Shan
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China
| | - Xiao-Ming Gao
- State Key Laboratory of Pathogenesis, Prevention and Treatment of High Incidence Diseases in Central Asian, Department of Cardiology, the First Affiliated Hospital of Xinjiang Medical University, Clinical Medical Research Institute of Xinjiang Medical University, 137 Liyushan South Road, Urumqi, 830054, China.
- Xinjiang Key Laboratory of Medical Animal Model Research, Urumqi, China.
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Hossain MA, Praveen P, Noorzi NA, Wu H, Harrison IP, Handley T, Selemidis S, Samuel CS, Bathgate RAD. Development of Novel High-Affinity Antagonists for the Relaxin Family Peptide Receptor 1. ACS Pharmacol Transl Sci 2023; 6:842-853. [PMID: 37200817 PMCID: PMC10186362 DOI: 10.1021/acsptsci.3c00053] [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: 03/13/2023] [Indexed: 05/20/2023]
Abstract
H2 relaxin is a peptide hormone that exerts its biological actions through the G protein-coupled receptor, RXFP1. The numerous important biological functions of H2 relaxin, including potent renal, vasodilatory, cardioprotective, and anti-fibrotic actions, have resulted in considerable interest in its use as a therapeutic for various cardiovascular diseases and other fibrotic indications. Interestingly though, H2 relaxin and RXFP1 have been shown to be overexpressed in prostate cancer, allowing for the downregulation or blocking of relaxin/RXFP1 to decrease prostate tumor growth. These findings suggest the application of an RXFP1 antagonist for the treatment of prostate cancer. However, these therapeutically relevant actions are still poorly understood and have been hindered by the lack of a high-affinity antagonist. In this study, we chemically synthesized three novel H2 relaxin analogues that have complex insulin-like structures with two chains (A and B) and three disulfide bridges. We report here the structure-activity relationship studies on H2 relaxin that resulted in the development of a novel high-affinity RXFP1 antagonist, H2 B-R13HR (∼40 nM), that has only one extra methylene group in the side chain of arginine 13 in the B-chain (ArgB13) of H2 relaxin. Most notably, the synthetic peptide was shown to be active in a mouse model of prostate tumor growth in vivo where it inhibited relaxin-mediated tumor growth. Our compound H2 B-R13HR will be an important research tool to understand relaxin actions through RXFP1 and may be a potential lead compound for the treatment of prostate cancer.
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Affiliation(s)
- Mohammed Akhter Hossain
- Florey
Institute of Neuroscience and Mental Health, University of Melbourne, Parkville 3010, Victoria, Australia
- School
of Chemistry, University of Melbourne, Parkville 3010, Victoria, Australia
- Department
of Biochemistry and Pharmacology, University
of Melbourne, Parkville 3010, Victoria, Australia
| | - Praveen Praveen
- Florey
Institute of Neuroscience and Mental Health, University of Melbourne, Parkville 3010, Victoria, Australia
| | - Nurhayati Ahmad Noorzi
- Cardiovascular
Disease Program, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia
- Department
of Pharmacology, Monash University, Clayton 3800, Victoria, Australia
| | - Hongkang Wu
- Florey
Institute of Neuroscience and Mental Health, University of Melbourne, Parkville 3010, Victoria, Australia
- Department
of Biochemistry and Pharmacology, University
of Melbourne, Parkville 3010, Victoria, Australia
| | - Ian P. Harrison
- Cardiovascular
Disease Program, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia
- Department
of Pharmacology, Monash University, Clayton 3800, Victoria, Australia
| | - Thomas Handley
- Florey
Institute of Neuroscience and Mental Health, University of Melbourne, Parkville 3010, Victoria, Australia
| | - Stavros Selemidis
- School
of
Health and Biomedical Sciences, RMIT University, Bundoora 3083, Victoria, Australia
| | - Chrishan S. Samuel
- Cardiovascular
Disease Program, Monash Biomedicine Discovery Institute, Monash University, Clayton 3800, Victoria, Australia
- Department
of Pharmacology, Monash University, Clayton 3800, Victoria, Australia
| | - Ross A. D. Bathgate
- Florey
Institute of Neuroscience and Mental Health, University of Melbourne, Parkville 3010, Victoria, Australia
- Department
of Biochemistry and Pharmacology, University
of Melbourne, Parkville 3010, Victoria, Australia
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4
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Relaxin does not prevent development of hypoxia-induced pulmonary edema in rats. Pflugers Arch 2022; 474:1053-1067. [PMID: 35778581 PMCID: PMC9492557 DOI: 10.1007/s00424-022-02720-9] [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: 02/17/2022] [Revised: 06/06/2022] [Accepted: 06/15/2022] [Indexed: 11/29/2022]
Abstract
Acute hypoxia impairs left ventricular (LV) inotropic function and induces development of pulmonary edema (PE). Enhanced and uneven hypoxic pulmonary vasoconstriction is an important pathogenic factor of hypoxic PE. We hypothesized that the potent vasodilator relaxin might reduce hypoxic pulmonary vasoconstriction and prevent PE formation. Furthermore, as relaxin has shown beneficial effects in acute heart failure, we expected that relaxin might also improve LV inotropic function in hypoxia. Forty-two rats were exposed over 24 h to normoxia or hypoxia (10% N2 in O2). They were infused with either 0.9% NaCl solution (normoxic/hypoxic controls) or relaxin at two doses (15 and 75 μg kg−1 day−1). After 24 h, hemodynamic measurements and bronchoalveolar lavage were performed. Lung tissue was obtained for histological and immunohistochemical analyses. Hypoxic control rats presented significant depression of LV systolic pressure by 19% and of left and right ventricular contractility by about 40%. Relaxin did not prevent the hypoxic decrease in LV inotropic function, but re-increased right ventricular contractility. Moreover, hypoxia induced moderate interstitial PE and inflammation in the lung. Contrasting to our hypothesis, relaxin did not prevent hypoxia-induced pulmonary edema and inflammation. In hypoxic control rats, PE was similarly distributed in the apical and basal lung lobes. In relaxin-treated rats, PE index was 35–40% higher in the apical than in the basal lobe, which is probably due to gravity effects. We suggest that relaxin induced exaggerated vasodilation, and hence pulmonary overperfusion. In conclusion, the results show that relaxin does not prevent but rather may aggravate PE formation.
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5
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Lan S, Zhou L, Wang Y, Fang L, Yang L, Zheng S, Zhou X, Tang B, Duan J, Wu X, Yang C, Hong T. miRNA Profiling of Circulating Small Extracellular Vesicles From Subarachnoid Hemorrhage Rats Using Next-Generation Sequencing. Front Cell Neurosci 2020; 14:242. [PMID: 32903819 PMCID: PMC7439219 DOI: 10.3389/fncel.2020.00242] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2020] [Accepted: 07/13/2020] [Indexed: 12/31/2022] Open
Abstract
Background Extracellular vesicles (EVs) are produced during abnormal and normal physiological conditions. Understanding the expression profile of microRNA (miRNA) in plasma-derived small extracellular vesicles (sEVs) and their roles in subarachnoid hemorrhage (SAH) that cause cerebral vasospasm (CVS) is imperative. Methods Sprague Dawley rats (250–300 g) were allocated to sham or SAH groups established using endovascular perforation method. miRNA expression profiles of plasma sEVs in both groups (each n = 4) were evaluated using next-generation sequencing (NGS). Results There were 142 microRNAs (miRNAs) significantly expressed differently between the two groups, of which 73 were up-regulated while 69 were down-regulated in SAH sEVs compared with those of sham (p < 0.05; fold change ≥ 2). The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway and Gene Ontology (GO) analyses of differently expressed (DE) miRNAs revealed signaling pathways and target genes (TGs) in the SAH group. rno-miR-185-5p, rno-miR-103-3p, rno-miR-15b-3p, rno-miR-93-5p, and rno-miR-98-5p were the top five most up-regulated sEVs miRNAs. Conclusion Our results suggest that miRNA can be selectively packaged into sEVs under SAH, and this could help develop potential targets for the prevention, diagnosis, and treatment of CVS after this condition.
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Affiliation(s)
- Shihai Lan
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Lin Zhou
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Yimei Wang
- Department of Plastic Surgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Linchun Fang
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Le Yang
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Suyue Zheng
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - XinHui Zhou
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Bin Tang
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Jian Duan
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Xiao Wu
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Chengxing Yang
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
| | - Tao Hong
- Department of Neurosurgery, The First Affiliated Hospital of Nanchang University, Nanchang, China
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Punjani N, Lamb DJ. Male infertility and genitourinary birth defects: there is more than meets the eye. Fertil Steril 2020; 114:209-218. [PMID: 32741459 PMCID: PMC10590568 DOI: 10.1016/j.fertnstert.2020.06.042] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2020] [Revised: 06/24/2020] [Accepted: 06/24/2020] [Indexed: 12/17/2022]
Abstract
Male factor infertility is a significant problem present in up to 50% of infertile couples. The relationship between male infertility and systemic disease is of significant interest, and emerging evidence suggests a relationship between male infertility and male genitourinary (GU) birth defects (cryptorchidism, hypospadias, ambiguous genitalia, and congenital anomalies of the kidney and urinary tract). Many of these birth defects are treated in isolation by busy urologists without acknowledgment that these may be related to more global syndromic conditions. Conversely, geneticists and nonurologists who treat variable systemic phenotypes may overlook GU defects, which are indeed related conditions. Many of these defects are attributed to copy number variants dosage-sensitive genes due to chromosome microdeletions or microduplications. These variants are responsible for disease phenotypes seen in the general population. The copy number variants described in this review are syndromic in some cases and responsible for both GU birth defects as well as other systemic phenotypes. This review highlights the emerging evidence between these birth defects, male infertility, and other systemic conditions.
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Affiliation(s)
- Nahid Punjani
- James Buchanan Brady Foundation Institute of Urology, Weill Cornell Medical College, New York, New York
| | - Dolores J Lamb
- James Buchanan Brady Foundation Institute of Urology, Weill Cornell Medical College, New York, New York; Englander Institute for Precision Medicine, Weill Cornell Medical College, New York, New York; Center for Reproductive Genomics, Weill Cornell Medical College, New York, New York.
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7
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Cabiati M, Botta L, Caselli C, Del Ry S. Transcriptional evaluation of relaxin and endothelin-1 axis in heart failure patients: First evidence of its involvement during left ventricular assist device support. Int J Cardiol 2020; 306:109-115. [PMID: 32143920 DOI: 10.1016/j.ijcard.2020.02.058] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2019] [Revised: 02/18/2020] [Accepted: 02/23/2020] [Indexed: 12/29/2022]
Abstract
BACKGROUND Left ventricular assist devices (LVAD) are implanted in patients with end-stage heart failure (ESHF) as a mechanical support for the failing myocardium, which is characterized by an activation of the neuro-hormonal system, with release of vasoactive mediators, such as endothelin (ET)-1 and relaxin (RLX)-2. The aim of this study was to evaluate whether LVAD is able to modulate the RLX-2 and ET-1 system expression in ESHF patients. METHODS Cardiac tissue was collected from ESHF patients before LVAD implantation (pre-LVAD group, n = 22), at the time of cardiac transplantation with concomitant LVAD removal (post-LVAD group, n = 6), and from stable HF patients on medical therapy at the time of cardiac transplantation (HTx group, n = 7). The expression of RLX-2, ET-1 system and inflammatory markers (IL-8, IL-6, TNF-α) were evaluated by Real-Time PCR. RESULTS RLX-2 mRNA resulted similar in pre-LVAD and HTx, but it was significantly increased in post-LVAD (p = 0.02/p = 0.01 respectively). A similar trend was observed for ET-1 and ET-converting enzyme (ECE)-1 while no significant difference was observed for ET-receptors. A positive correlation was found between ET-1 and ET-A (p = 0.031) and ECE-1 (p < 0.0001). The inflammatory markers resulted activated in all the three groups. A significant correlation between RLX-2 and ET-1 in pre-LVAD, as well as between RLX-2 and IL-8/IL-6, was found. CONCLUSIONS Our research investigates for the first time the involvement of RLX-2 and ET-1 system in ESHF patients supported by LVAD, demonstrating their potential ability to partially recover the failing myocardium, indicating their possible clinical role as biomarkers or pharmacological agents in LVAD patients. TRANSLATIONAL ASPECT The study of novel biomarkers in patients supported by continuous axial flow devices may be a starting point analysis applicable to patients with centrifugal flow devices.
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Affiliation(s)
| | - Luca Botta
- Department of Cardiac Surgery, Niguarda Ca' Granda Hospital, Milan, Italy; Department of Cardiac Surgery, AOU Bologna, S. Orsola Hospital, Italy
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8
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Wang C, Pinar AA, Widdop RE, Hossain MA, Bathgate RAD, Denton KM, Kemp-Harper BK, Samuel CS. The anti-fibrotic actions of relaxin are mediated through AT 2 R-associated protein phosphatases via RXFP1-AT 2 R functional crosstalk in human cardiac myofibroblasts. FASEB J 2020; 34:8217-8233. [PMID: 32297670 DOI: 10.1096/fj.201902506r] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 04/02/2020] [Accepted: 04/06/2020] [Indexed: 12/19/2022]
Abstract
Fibrosis is a hallmark of several cardiovascular diseases. The relaxin family peptide receptor 1 (RXFP1) agonist, relaxin, has rapidly occurring anti-fibrotic actions which are mediated through RXFP1 and angiotensin II receptor crosstalk on renal and cardiac myofibroblasts. Here, we investigated whether this would allow relaxin to indirectly activate angiotensin II type 2 receptor (AT2 R)-specific signal transduction in primary human cardiac myofibroblasts (HCMFs). The anti-fibrotic effects of recombinant human relaxin (RLX; 16.8 nM) or the AT2 R-agonist, Compound 21 (C21; 1 μM), were evaluated in TGF-β1-stimulated HCMFs, in the absence or presence of an RXFP1 antagonist (1 μM) or AT2 R antagonist (0.1 μM) to confirm RXFP1-AT2 R crosstalk. Competition binding for RXFP1 was determined. Western blotting was performed to determine which AT2 R-specific protein phosphatases were expressed by HCMFs; then, the anti-fibrotic effects of RLX and/or C21 were evaluated in the absence or presence of pharmacological inhibition (NSC95397 (1 μM) for MKP-1; okadaic acid (10 nM) for PP2A) or siRNA-knockdown of these phosphatases after 72 hours. The RLX- or C21-induced increase in ERK1/2 and nNOS phosphorylation, and decrease in α-SMA (myofibroblast differentiation) and collagen-I expression by HCMFs was abrogated by pharmacological blockade of RXFP1 or the AT2 R, confirming RXFP1-AT2 R crosstalk in these cells. HCMFs were found to express AT2 R-dependent MKP-1 and PP2A phosphatases, while pharmacological blockade or siRNA-knockdown of either phosphatase also abolished RLX and/or C21 signal transduction in HCMFs (all P < .05 vs RLX or C21 alone). These findings demonstrated that RLX can indirectly activate AT2 R-dependent phosphatase activity in HCMFs by signaling through RXFP1-AT2 R crosstalk, which have important therapeutic implications for its anti-fibrotic actions.
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Affiliation(s)
- Chao Wang
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia.,Department of Pharmacology, Monash University, Clayton, VIC, Australia
| | - Anita A Pinar
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia.,Department of Pharmacology, Monash University, Clayton, VIC, Australia
| | - Robert E Widdop
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia.,Department of Pharmacology, Monash University, Clayton, VIC, Australia
| | - Mohammed A Hossain
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia
| | - Ross A D Bathgate
- Florey Institute of Neuroscience and Mental Health, Parkville, VIC, Australia.,Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, VIC, Australia
| | - Kate M Denton
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia.,Department of Physiology, Monash University, Clayton, VIC, Australia
| | - Barbara K Kemp-Harper
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia.,Department of Pharmacology, Monash University, Clayton, VIC, Australia
| | - Chrishan S Samuel
- Cardiovascular Disease Program, Monash Biomedicine Discovery Institute, Clayton, VIC, Australia.,Department of Pharmacology, Monash University, Clayton, VIC, Australia.,Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, VIC, Australia
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9
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Hoare BL, Bruell S, Sethi A, Gooley PR, Lew MJ, Hossain MA, Inoue A, Scott DJ, Bathgate RAD. Multi-Component Mechanism of H2 Relaxin Binding to RXFP1 through NanoBRET Kinetic Analysis. iScience 2018; 11:93-113. [PMID: 30594862 PMCID: PMC6309025 DOI: 10.1016/j.isci.2018.12.004] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2018] [Revised: 11/20/2018] [Accepted: 12/05/2018] [Indexed: 12/27/2022] Open
Abstract
The peptide hormone H2 relaxin has demonstrated promise as a therapeutic, but mimetic development has been hindered by the poorly understood relaxin receptor RXFP1 activation mechanism. H2 relaxin is hypothesized to bind to two distinct ECD sites, which reorientates the N-terminal LDLa module to activate the transmembrane domain. Here we provide evidence for this model in live cells by measuring bioluminescence resonance energy transfer (BRET) between nanoluciferase-tagged RXFP1 constructs and fluorescently labeled H2 relaxin (NanoBRET). Additionally, we validate these results using the related RXFP2 receptor and chimeras with an inserted RXFP1-binding domain utilizing NanoBRET and nuclear magnetic resonance studies on recombinant proteins. We therefore provide evidence for the multi-component molecular mechanism of H2 relaxin binding to RXFP1 on the full-length receptor in cells. Also, we show the utility of NanoBRET real-time binding kinetics to reveal subtle binding complexities, which may be overlooked in traditional equilibrium binding assays. NanoBRET was used to assess relaxin binding kinetics to its receptor RXFP1 Binding on wild-type and mutant RXFP1 demonstrated a multi-component mechanism This binding mode was validated using RXFP2/RXFP1 chimeras and protein NMR studies NanoBRET binding can reveal subtle GPCR binding modes to aid drug development
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Affiliation(s)
- Bradley L Hoare
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC 3052, Australia
| | - Shoni Bruell
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC 3052, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, VIC, Australia
| | - Ashish Sethi
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, VIC, Australia; Bio21 Molecular and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Paul R Gooley
- Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, VIC, Australia; Bio21 Molecular and Biotechnology Institute, The University of Melbourne, Parkville, VIC, Australia
| | - Michael J Lew
- Department of Pharmacology and Therapeutics, The University of Melbourne, Parkville, VIC 3052, Australia
| | - Mohammed A Hossain
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC 3052, Australia; Department of Chemistry, The University of Melbourne, Parkville, VIC 3052, Australia
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3, Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Daniel J Scott
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC 3052, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, VIC, Australia.
| | - Ross A D Bathgate
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC 3052, Australia; Department of Biochemistry and Molecular Biology, The University of Melbourne, Parkville, VIC, Australia.
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10
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Lian X, Beer-Hammer S, König GM, Kostenis E, Nürnberg B, Gollasch M. RXFP1 Receptor Activation by Relaxin-2 Induces Vascular Relaxation in Mice via a Gα i2-Protein/PI3Kß/γ/Nitric Oxide-Coupled Pathway. Front Physiol 2018; 9:1234. [PMID: 30233409 PMCID: PMC6131674 DOI: 10.3389/fphys.2018.01234] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2018] [Accepted: 08/15/2018] [Indexed: 01/10/2023] Open
Abstract
Background: Relaxins are small peptide hormones, which are novel candidate molecules that play important roles in cardiometablic syndrome. Relaxins are structurally related to the insulin hormone superfamily, which provide vasodilatory effects by activation of G-protein-coupled relaxin receptors (RXFPs) and stimulation of endogenous nitric oxide (NO) generation. Recently, relaxin could be demonstrated to activate Gi proteins and phosphoinositide 3-kinase (PI3K) pathways in cultured endothelial cells in vitro. However, the contribution of the Gi-PI3K pathway and their individual components in relaxin-dependent relaxation of intact arteries remains elusive. Methods: We used Gαi2- (Gnai2-/-) and Gαi3-deficient (Gnai3-/-) mice, pharmacological tools and wire myography to study G-protein-coupled signaling pathways involved in relaxation of mouse isolated mesenteric arteries by relaxins. Human relaxin-1, relaxin-2, and relaxin-3 were tested. Results: Relaxin-2 (∼50% relaxation at 10-11 M) was the most potent vasodilatory relaxin in mouse mesenteric arteries, compared to relaxin-1 and relaxin-3. The vasodilatory effects of relaxin-2 were inhibited by removal of the endothelium or treatment of the vessels with N (G)-nitro-L-arginine methyl ester (L-NAME, endothelial nitric oxide synthase (eNOS) inhibitor) or simazine (RXFP1 inhibitor). The vasodilatory effects of relaxin-2 were absent in arteries of mice treated with pertussis toxin (PTX). They were also absent in arteries isolated from Gnai2-/- mice, but not from Gnai3-/- mice. The effects were not affected by FR900359 (Gαq protein inhibitor) or PI-103 (PI3Kα inhibitor), but inhibited by TGX-221 (PI3Kβ inhibitor) or AS-252424 (PI3Kγ inhibitor). Simazine did not influence the anti-contractile effect of perivascular adipose tissue. Conclusion: Our data indicate that relaxin-2 produces endothelium- and NO-dependent relaxation of mouse mesenteric arteries by activation of RXFP1 coupled to Gi2-PI3K-eNOS pathway. Targeting vasodilatory Gi-protein-coupled RXFP1 pathways may provide promising opportunities for drug discovery in endothelial dysfunction and cardiometabolic disease.
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Affiliation(s)
- Xiaoming Lian
- Experimental and Clinical Research Center (ECRC), Charité - University Medicine Berlin and Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Sandra Beer-Hammer
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research (ICePhA), Tübingen, Germany
| | - Gabriele M König
- Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Evi Kostenis
- Institute for Pharmaceutical Biology, University of Bonn, Bonn, Germany
| | - Bernd Nürnberg
- Department of Pharmacology and Experimental Therapy, Institute of Experimental and Clinical Pharmacology and Toxicology, Eberhard Karls University Hospitals and Clinics, and Interfaculty Center of Pharmacogenomics and Drug Research (ICePhA), Tübingen, Germany
| | - Maik Gollasch
- Experimental and Clinical Research Center (ECRC), Charité - University Medicine Berlin and Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany.,Medical Clinic for Nephrology and Internal Intensive Care, Charité Campus Virchow Klinikum, Berlin, Germany
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11
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Strassheim D, Karoor V, Stenmark K, Verin A, Gerasimovskaya E. A current view of G protein-coupled receptor - mediated signaling in pulmonary hypertension: finding opportunities for therapeutic intervention. ACTA ACUST UNITED AC 2018; 2. [PMID: 31380505 PMCID: PMC6677404 DOI: 10.20517/2574-1209.2018.44] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Pathological vascular remodeling is observed in various cardiovascular diseases including pulmonary hypertension (PH), a disease of unknown etiology that has been characterized by pulmonary artery vasoconstriction, right ventricular hypertrophy, vascular inflammation, and abnormal angiogenesis in pulmonary circulation. G protein-coupled receptors (GPCRs) are the largest family in the genome and widely expressed in cardiovascular system. They regulate all aspects of PH pathophysiology and represent therapeutic targets. We overview GPCRs function in vasoconstriction, vasodilation, vascular inflammation-driven remodeling and describe signaling cross talk between GPCR, inflammatory cytokines, and growth factors. Overall, the goal of this review is to emphasize the importance of GPCRs as critical signal transducers and targets for drug development in PH.
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Affiliation(s)
- Derek Strassheim
- Departments of Medicine, University of Colorado Denver, Aurora, CO 80045, USA
| | - Vijaya Karoor
- Departments of Medicine, University of Colorado Denver, Aurora, CO 80045, USA.,Cardiovascular and Pulmonary Research laboratories, University of Colorado Denver, Aurora, CO 80045, USA
| | - Kurt Stenmark
- Cardiovascular and Pulmonary Research laboratories, University of Colorado Denver, Aurora, CO 80045, USA.,Department of Pediatrics, Pulmonary and Critical Care Medicine, University of Colorado Denver, Aurora, CO 80045, USA
| | - Alexander Verin
- Vascular Biology Center, Augusta University, Augusta, GA 30912, USA
| | - Evgenia Gerasimovskaya
- Cardiovascular and Pulmonary Research laboratories, University of Colorado Denver, Aurora, CO 80045, USA.,Department of Pediatrics, Pulmonary and Critical Care Medicine, University of Colorado Denver, Aurora, CO 80045, USA
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12
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You X, Guo ZF, Cheng F, Yi B, Yang F, Liu X, Zhu N, Zhao X, Yan G, Ma XL, Sun J. Transcriptional up-regulation of relaxin-3 by Nur77 attenuates β-adrenergic agonist-induced apoptosis in cardiomyocytes. J Biol Chem 2018; 293:14001-14011. [PMID: 30006349 DOI: 10.1074/jbc.ra118.003099] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2018] [Revised: 07/12/2018] [Indexed: 12/28/2022] Open
Abstract
The relaxin family peptides have been shown to exert several beneficial effects on the heart, including anti-apoptosis, anti-fibrosis, and anti-hypertrophy activity. Understanding their regulation might provide new opportunities for therapeutic interventions, but the molecular mechanism(s) coordinating relaxin expression in the heart remain largely obscured. Previous work demonstrated a role for the orphan nuclear receptor Nur77 in regulating cardiomyocyte apoptosis. We therefore investigated Nur77 in the hopes of identifying novel relaxin regulators. Quantitative real-time PCR (qRT-PCR) and enzyme-linked immunosorbent assay (ELISA) data indicated that ectopic expression of orphan nuclear receptor Nur77 markedly increased the expression of latexin-3 (RLN3), but not relaxin-1 (RLN1), in neonatal rat ventricular cardiomyocytes (NRVMs). Furthermore, we found that the β-adrenergic agonist isoproterenol (ISO) markedly stimulated RLN3 expression, and this stimulation was significantly attenuated in Nur77 knockdown cardiomyocytes and Nur77 knockout hearts. We showed that Nur77 significantly increased RLN3 promoter activity via specific binding to the RLN3 promoter, as demonstrated by electrophoretic mobility shift assay (EMSA) and chromatin immunoprecipitation (ChIP) assays. Furthermore, we found that Nur77 overexpression potently inhibited ISO-induced cardiomyocyte apoptosis, whereas this protective effect was significantly attenuated in RLN3 knockdown cardiomyocytes, suggesting that Nur77-induced RLN3 expression is an important mediator for the suppression of cardiomyocyte apoptosis. These findings show that Nur77 regulates RLN3 expression, therefore suppressing apoptosis in the heart, and suggest that activation of Nur77 may represent a useful therapeutic strategy for inhibition of cardiac fibrosis and heart failure.
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Affiliation(s)
- Xiaohua You
- From the Department of Cardiology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China.,the Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, and
| | - Zhi-Fu Guo
- From the Department of Cardiology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China.,the Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, and
| | - Fang Cheng
- the Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, and
| | - Bing Yi
- the Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, and
| | - Fan Yang
- the Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, and
| | - Xinzhu Liu
- the Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, and
| | - Ni Zhu
- From the Department of Cardiology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
| | - Xianxian Zhao
- From the Department of Cardiology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China
| | - Guijun Yan
- the Reproductive Medicine Center, Affiliated Drum Tower Hospital of Nanjing University Medical School, Nanjing 211166, China
| | - Xin-Liang Ma
- the Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, and
| | - Jianxin Sun
- From the Department of Cardiology, Changhai Hospital, Second Military Medical University, Shanghai 200433, China, .,the Center for Translational Medicine, Thomas Jefferson University, Philadelphia, Pennsylvania 19107, and
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13
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Idrizaj E, Garella R, Francini F, Squecco R, Baccari MC. Relaxin influences ileal muscular activity through a dual signaling pathway in mice. World J Gastroenterol 2018; 24:882-893. [PMID: 29491682 PMCID: PMC5829152 DOI: 10.3748/wjg.v24.i8.882] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/14/2017] [Accepted: 11/27/2017] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate the signaling pathways involved in the relaxin (RLX) effects on ileal preparations from mice through mechanical and electrophysiological experiments.
METHODS For mechanical experiments, ileal preparations from female mice were mounted in organ baths containing Krebs-Henseleit solution. The mechanical activity was recorded via force-displacement transducers, which were coupled to a polygraph for continuous recording of isometric tension. Electrophysiological measurements were performed in current- and voltage-clamp conditions by a microelectrode inserted in a single smooth muscle cell (SMC) of the ileal longitudinal layer. Both the membrane passive properties and inward voltage-dependent L-type Ca2+ currents were recorded using suitable solutions and voltage stimulation protocols.
RESULTS Mechanical experiments showed that RLX induced a decay of the basal tension and a reduction in amplitude of the spontaneous contractions. The effects of RLX were partially reduced by 1H-[1,2,4]oxadiazolo[4,3-a]-quinoxalin-1-one (ODQ) or 9-cyclopentyladenine mesylate (9CPA), inhibitors of guanylate cyclase (GC) and adenylate cyclase (AC), respectively, and were abolished in the concomitant presence of both drugs. Electrophysiological experiments demonstrated that RLX directly influenced the biophysical properties of ileal SMCs, decreasing the membrane conductance, hyperpolarizing the resting membrane potential, reducing the L-type calcium current amplitude and affecting its kinetics. The voltage dependence of the current activation and inactivation time constant was significantly speeded by RLX. Each electrophysiological effect of RLX was reduced by ODQ or 9CPA, and abolished in the concomitant presence of both drugs as observed in mechanical experiments.
CONCLUSION Our new findings demonstrate that RLX influences ileal muscle through a dual mechanism involving both GC and AC.
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Affiliation(s)
- Eglantina Idrizaj
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
| | - Rachele Garella
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
| | - Fabio Francini
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
| | - Roberta Squecco
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
| | - Maria Caterina Baccari
- Department of Experimental and Clinical Medicine, Section of Physiological Sciences, University of Florence, Florence 50134, Italy
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14
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Zhang X, Pan L, Yang K, Fu Y, Liu Y, Chen W, Ma X, Yin X. Alterations of relaxin and its receptor system components in experimental diabetic cardiomyopathy rats. Cell Tissue Res 2017; 370:297-304. [PMID: 28776188 DOI: 10.1007/s00441-017-2662-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2017] [Accepted: 06/21/2017] [Indexed: 10/19/2022]
Abstract
High glucose induces apoptosis of cardiomyocytes and fibrosis of cardiac fibroblasts, contributing to diabetic cardiomyopathy. In this work, we explore the production of relaxin alterations and the significance of their receptor system components in the hearts of experimental diabetic cardiomyopathy rats. We measured rat relaxin-1 (equivalent to human relaxin-2), relaxin-3, RXFP1 and RXFP3 mRNA expression in the hearts of experimental diabetic cardiomyopathy rats. Neonatal rat ventricular myocytes (NRVMs) and cardiac fibroblasts were treated with 5.5 mmol/l normal glucose (NG) and 33 mmol/l high glucose (HG) for 0, 6, 12, 24, 48 and 72 h. Rat relaxin-1, relaxin-3, RXFP1 and RXFP3 mRNA expression were determined by real-time PCR. In the present study, we offer the first evidence that Relaxin-1 mRNA significantly increased and Relaxin-3 mRNA expression decreased at 4 and 8 weeks after STZ in the hearts of diabetic rats. In addition, significant down regulation of the mRNA expression of RXFP1 and RXFP3 was observed at 4 w after STZ; however, the mRNA expression levels of RXFP1 and RXFP3 were increased at 8 weeks after STZ. Apoptotic NRVMs induced by high glucose generate a decreased level of relaxin-1 and RXFP1. In HG-administered cardiac fibroblasts, Relaxin-1 mRNA was significantly increased and relaxin-3 mRNA was significantly decreased. Additionally, the mRNA expression of RXFP1 was decreased, and the mRNA expression of RXFP3 was increased. This results showed that an important role of relaxin-2, relaxin-3 and their receptors system in the regulation of diabetic cardiomyopathy.
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Affiliation(s)
- Xiaohui Zhang
- The Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, No. 23, YouZheng Road, NanGang District, Harbin, Heilongjiang Province, 150001, China
| | - Liya Pan
- The Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, No. 23, YouZheng Road, NanGang District, Harbin, Heilongjiang Province, 150001, China
| | - Kelaier Yang
- The Department of Endocrinology, The First Affiliated Hospital of Harbin Medical University, Harbin, China
| | - Yu Fu
- The Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, No. 23, YouZheng Road, NanGang District, Harbin, Heilongjiang Province, 150001, China
| | - Yue Liu
- The Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, No. 23, YouZheng Road, NanGang District, Harbin, Heilongjiang Province, 150001, China
| | - Wenjia Chen
- The Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, No. 23, YouZheng Road, NanGang District, Harbin, Heilongjiang Province, 150001, China
| | - Xiao Ma
- The Department of Gastroenterology, The Second Affiliated Hospital of Harbin Medical University, 246 Xue-Fu Road, Nan-Gang District, Harbin, Heilongjiang, 150086, China.
| | - Xinhua Yin
- The Department of Cardiology, The First Affiliated Hospital of Harbin Medical University, No. 23, YouZheng Road, NanGang District, Harbin, Heilongjiang Province, 150001, China.
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15
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Abstract
Myocardial injury, mechanical stress, neurohormonal activation, inflammation, and/or aging all lead to cardiac remodeling, which is responsible for cardiac dysfunction and arrhythmogenesis. Of the key histological components of cardiac remodeling, fibrosis either in the form of interstitial, patchy, or dense scars, constitutes a key histological substrate of arrhythmias. Here we discuss current research findings focusing on the role of fibrosis, in arrhythmogenesis. Numerous studies have convincingly shown that patchy or interstitial fibrosis interferes with myocardial electrophysiology by slowing down action potential propagation, initiating reentry, promoting after-depolarizations, and increasing ectopic automaticity. Meanwhile, there has been increasing appreciation of direct involvement of myofibroblasts, the activated form of fibroblasts, in arrhythmogenesis. Myofibroblasts undergo phenotypic changes with expression of gap-junctions and ion channels thereby forming direct electrical coupling with cardiomyocytes, which potentially results in profound disturbances of electrophysiology. There is strong evidence that systemic and regional inflammatory processes contribute to fibrogenesis (i.e., structural remodeling) and dysfunction of ion channels and Ca2+ homeostasis (i.e., electrical remodeling). Recognizing the pivotal role of fibrosis in the arrhythmogenesis has promoted clinical research on characterizing fibrosis by means of cardiac imaging or fibrosis biomarkers for clinical stratification of patients at higher risk of lethal arrhythmia, as well as preclinical research on the development of antifibrotic therapies. At the end of this review, we discuss remaining key questions in this area and propose new research approaches. © 2017 American Physiological Society. Compr Physiol 7:1009-1049, 2017.
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Affiliation(s)
- My-Nhan Nguyen
- Baker Heart and Diabetes Institute, Melbourne, Australia.,Central Clinical School, Monash University, Melbourne, Australia
| | - Helen Kiriazis
- Baker Heart and Diabetes Institute, Melbourne, Australia
| | - Xiao-Ming Gao
- Baker Heart and Diabetes Institute, Melbourne, Australia.,Central Clinical School, Monash University, Melbourne, Australia
| | - Xiao-Jun Du
- Baker Heart and Diabetes Institute, Melbourne, Australia.,Central Clinical School, Monash University, Melbourne, Australia
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16
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Fernández-Solà J, Planavila Porta A. New Treatment Strategies for Alcohol-Induced Heart Damage. Int J Mol Sci 2016; 17:E1651. [PMID: 27690014 PMCID: PMC5085684 DOI: 10.3390/ijms17101651] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2016] [Revised: 09/15/2016] [Accepted: 09/16/2016] [Indexed: 02/07/2023] Open
Abstract
High-dose alcohol misuse induces multiple noxious cardiac effects, including myocyte hypertrophy and necrosis, interstitial fibrosis, decreased ventricular contraction and ventricle enlargement. These effects produce diastolic and systolic ventricular dysfunction leading to congestive heart failure, arrhythmias and an increased death rate. There are multiple, dose-dependent, synchronic and synergistic mechanisms of alcohol-induced cardiac damage. Ethanol alters membrane permeability and composition, interferes with receptors and intracellular transients, induces oxidative, metabolic and energy damage, decreases protein synthesis, excitation-contraction coupling and increases cell apoptosis. In addition, ethanol decreases myocyte protective and repair mechanisms and their regeneration. Although there are diverse different strategies to directly target alcohol-induced heart damage, they are partially effective, and can only be used as support medication in a multidisciplinary approach. Alcohol abstinence is the preferred goal, but control drinking is useful in alcohol-addicted subjects not able to abstain. Correction of nutrition, ionic and vitamin deficiencies and control of alcohol-related systemic organ damage are compulsory. Recently, several growth factors (myostatin, IGF-1, leptin, ghrelin, miRNA, and ROCK inhibitors) and new cardiomyokines such as FGF21 have been described to regulate cardiac plasticity and decrease cardiac damage, improving cardiac repair mechanisms, and they are promising agents in this field. New potential therapeutic targets aim to control oxidative damage, myocyte hypertrophy, interstitial fibrosis and persistent apoptosis In addition, stem-cell therapy may improve myocyte regeneration. However, these strategies are not yet approved for clinical use.
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Affiliation(s)
- Joaquim Fernández-Solà
- Alcohol Unit, Department of Internal Medicine, Hospital Clinic, University of Barcelona, Villarroel 170, 08036 Barcelona, Spain.
| | - Ana Planavila Porta
- Departament of Biochemistry and Molecular Biomedicine, Faculty of Biology, Avda Diagonal 643, Universitat de Barcelona, 08028 Barcelona, Spain.
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17
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Marshall SA, Senadheera SN, Parry LJ, Girling JE. The Role of Relaxin in Normal and Abnormal Uterine Function During the Menstrual Cycle and Early Pregnancy. Reprod Sci 2016; 24:342-354. [DOI: 10.1177/1933719116657189] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Sarah A. Marshall
- School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
| | | | - Laura J. Parry
- School of Biosciences, University of Melbourne, Melbourne, Victoria, Australia
| | - Jane E. Girling
- Department of Obstetrics and Gynaecology, Gynaecology Research Centre, The University of Melbourne and Royal Women’s Hospital, Melbourne, Victoria, Australia
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18
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Lee YS, Choi JW, Oh JE, Yun CO, Kim SW. Human relaxin gene expression delivered by bioreducible dendrimer polymer for post-infarct cardiac remodeling in rats. Biomaterials 2016; 97:164-75. [PMID: 27174688 PMCID: PMC5448559 DOI: 10.1016/j.biomaterials.2016.04.025] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2016] [Revised: 04/12/2016] [Accepted: 04/21/2016] [Indexed: 02/06/2023]
Abstract
In consensus, myocardial infarction (MI) is defined as irreversible cell death secondary to prolonged ischemia in heart. The aim of our study was to evaluate the therapeutic potential of anti-fibrotic human Relaxin-expressing plasmid DNA with hypoxia response element (HRE) 12 copies (HR1) delivered by a dendrimer type PAM-ABP polymer G0 (HR1/G0) after MI on functional, hemodynamic, geometric, and cardiac extracellular matrix (ECM) remodeling in rats. HR1/G0 demonstrated significantly improved LV systolic function, hemodynamic parameters, and geometry on 1 wk and 4 wks after MI in rats, compared with I/R group. The resolution of regional wall motional abnormalities and the increased blood flow of infarct-related coronary artery supported functional improvements of HR1/G0. Furthermore, HR1/G0 polyplex showed favorable post-infarct cardiac ECM remodeling reflected on the favorable cardiac ECM compositions. Overall, this is the first study, which presented an advanced platform for the gene therapy that reverses adverse cardiac remodeling after MI with a HR1 gene delivered by a bioreducible dendrimer polymer in the cardiac ECM.
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Affiliation(s)
- Young Sook Lee
- Center for Controlled Chemical Delivery, Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT, 84112, USA
| | - Joung-Woo Choi
- Center for Controlled Chemical Delivery, Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT, 84112, USA
| | - Jung-Eun Oh
- Department of Bioengineering, College of Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, Republic of Korea
| | - Chae-Ok Yun
- Department of Bioengineering, College of Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, Republic of Korea.
| | - Sung Wan Kim
- Center for Controlled Chemical Delivery, Department of Pharmaceutics and Pharmaceutical Chemistry, University of Utah, Salt Lake City, UT, 84112, USA; Department of Bioengineering, College of Engineering, Hanyang University, 222 Wangsimni-ro, Seongdong-gu, Seoul, 133-791, Republic of Korea
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19
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Serelaxin: A Novel Therapeutic for Vascular Diseases. Trends Pharmacol Sci 2016; 37:498-507. [PMID: 27130518 DOI: 10.1016/j.tips.2016.04.001] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2016] [Revised: 03/31/2016] [Accepted: 04/04/2016] [Indexed: 12/19/2022]
Abstract
Vascular dysfunction is an important hallmark of cardiovascular disease. It is characterized by increased sensitivity to vasoconstrictors, decreases in the endothelium-derived vasodilators nitric oxide (NO) and prostacyclin (PGI2), and endothelium-derived hyperpolarization (EDH). Serelaxin (recombinant human relaxin) has gained considerable attention as a new vasoactive drug, largely through its beneficial therapeutic effects in acute heart failure. In this review we first describe the contribution of endogenous relaxin to vascular homeostasis. We then provide a comprehensive overview of the novel mechanisms of serelaxin action in blood vessels that differentiate it from other vasodilator drugs and explain how this peptide could be used more widely as a therapeutic to alleviate vascular dysfunction in several cardiovascular diseases.
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20
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Abstract
With the total cases and economic burden of heart failure continuing to rise, there is an overwhelming need for novel therapies. Several drugs for heart failure have succeeded in preclinical and early-phase clinical trials, but most of them failed to show the real benefit in pivotal clinical trials. Meanwhile, the US Food and Drug Administration recently approved two promising new drugs to treat heart failure: ivabradine and sacubitril/valsartan. Furthermore, some of the newer agents in testing offer the potential for significant progress in addition to these drugs. Patiromer and zirconium cyclosilicate are attractive agents that are expected to prevent hyperkalemia during renin-angiotensin-aldosterone system inhibition, and serelaxin and urodilatin are promising drugs in the treatment of acute heart failure. Future clinical trials with more appropriate study designs, optimal clinical endpoints, and proper patient selection are mandatory to assess the true efficacy of these attractive compounds in clinical practice.
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Affiliation(s)
- Takeshi Kitai
- Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Wh Wilson Tang
- Department of Cardiovascular Medicine, Heart and Vascular Institute, Cleveland Clinic, Cleveland, OH, USA; Center for Clinical Genomics, Cleveland Clinic, Cleveland, OH, USA
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21
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Squecco R, Garella R, Idrizaj E, Nistri S, Francini F, Baccari MC. Relaxin Affects Smooth Muscle Biophysical Properties and Mechanical Activity of the Female Mouse Colon. Endocrinology 2015; 156:4398-410. [PMID: 26360621 DOI: 10.1210/en.2015-1428] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The hormone relaxin (RLX) has been reported to influence gastrointestinal motility in mice. However, at present, nothing is known about the effects of RLX on the biophysical properties of the gastrointestinal smooth muscle cells (SMCs). Other than extending previous knowledge of RLX on colonic motility, the purpose of this study was to investigate the ability of the hormone to induce changes in resting membrane potential (RMP) and on sarcolemmal ion channels of colonic SMCs of mice that are related to its mechanical activity. To this aim, we used a combined mechanical and electrophysiological approach. In the mechanical experiments, we observed that RLX caused a decay of the basal tone coupled to an increase of the spontaneous contractions, completely abolished by the guanylate cyclase inhibitor 1H-[1,2,4]oxadiazolo[4,3-a]-quinoxalin-1-one (ODQ). The electrophysiological results indicate for the first time that RLX directly affects the SMC biophysical properties inducing hyperpolarization of RMP and cycles of slow hyperpolarization/depolarization oscillations. The effects of RLX on RMP were abolished by ODQ as well as by a specific inhibitor of the cGMP-dependent protein kinase, KT5823. RLX reduced Ca(2+) entry through the voltage-dependent L-type channels and modulated either voltage- or ATP-dependent K(+) channels. These effects were abolished by ODQ, suggesting the involvement of the nitric oxide/guanylate cyclase pathway in the effects of RLX on RMP and ion channel modulation. These actions of RLX on membrane properties may contribute to the regulation of the proximal colon motility by the nitric oxide/cGMP/cGMP-dependent protein kinase pathway.
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MESH Headings
- Animals
- Biophysical Phenomena/drug effects
- Calcium/metabolism
- Calcium Channels, L-Type/drug effects
- Calcium Channels, L-Type/metabolism
- Carbazoles/pharmacology
- Colon/cytology
- Colon/drug effects
- Colon/metabolism
- Cyclic GMP-Dependent Protein Kinases/antagonists & inhibitors
- Female
- Gastrointestinal Motility
- Guanylate Cyclase/antagonists & inhibitors
- KATP Channels/drug effects
- KATP Channels/metabolism
- Membrane Potentials/drug effects
- Mice
- Muscle Contraction/drug effects
- Muscle, Smooth/drug effects
- Myenteric Plexus/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/metabolism
- Oxadiazoles/pharmacology
- Patch-Clamp Techniques
- Potassium Channels, Voltage-Gated/drug effects
- Potassium Channels, Voltage-Gated/metabolism
- Quinoxalines/pharmacology
- RNA, Messenger/metabolism
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Relaxin/pharmacology
- Reverse Transcriptase Polymerase Chain Reaction
- Sarcolemma/drug effects
- Sarcolemma/metabolism
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Affiliation(s)
- Roberta Squecco
- Sections of Physiology (R.S., R.G., E.I., F.F., M.C.B.) and Anatomy and Histology (S.N.), Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Rachele Garella
- Sections of Physiology (R.S., R.G., E.I., F.F., M.C.B.) and Anatomy and Histology (S.N.), Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Eglantina Idrizaj
- Sections of Physiology (R.S., R.G., E.I., F.F., M.C.B.) and Anatomy and Histology (S.N.), Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Silvia Nistri
- Sections of Physiology (R.S., R.G., E.I., F.F., M.C.B.) and Anatomy and Histology (S.N.), Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Fabio Francini
- Sections of Physiology (R.S., R.G., E.I., F.F., M.C.B.) and Anatomy and Histology (S.N.), Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
| | - Maria Caterina Baccari
- Sections of Physiology (R.S., R.G., E.I., F.F., M.C.B.) and Anatomy and Histology (S.N.), Department of Experimental and Clinical Medicine, University of Florence, 50134 Florence, Italy
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22
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Tailhades J, Sethi A, Petrie EJ, Gooley PR, Bathgate RA, Wade JD, Hossain MA. Native Chemical Ligation to Minimize Aspartimide Formation during Chemical Synthesis of Small LDLa Protein. Chemistry 2015; 22:1146-51. [PMID: 26612092 DOI: 10.1002/chem.201503599] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2015] [Indexed: 12/21/2022]
Abstract
The inhibition of the G protein-coupled receptor, relaxin family peptide receptor 1 (RXFP1), by a small LDLa protein may be a potential approach for prostate cancer treatment. However, it is a significant challenge to chemically produce the 41-residue and three-disulfide cross-bridged LDLa module which is highly prone to aspartimide formation due to the presence of several aspartic acid residues. Known palliative measures, including addition of HOBt to piperidine for N(α) -deprotection, failed to completely overcome this side reaction. For this reason, an elegant native chemical ligation approach was employed in which two segments were assembled for generating the linear LDLa protein. Acquisition of correct folding was achieved by using either a regioselective disulfide bond formation or global oxidation strategies. The final synthetic LDLa protein obtained was characterized by NMR spectroscopic structural analysis after chelation with a Ca(2+) ion and confirmed to be equivalent to the same protein obtained by recombinant DNA production.
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Affiliation(s)
- Julien Tailhades
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, 3010, Australia.
| | - Ashish Sethi
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
| | - Emma J Petrie
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
| | - Paul R Gooley
- Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
| | - Ross A Bathgate
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, 3010, Australia.,Department of Biochemistry and Molecular Biology, Bio21 Molecular Science and Biotechnology Institute, The University of Melbourne, Victoria, 3010, Australia
| | - John D Wade
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, 3010, Australia. .,The School of Chemistry, The University of Melbourne, Victoria, 3010, Australia.
| | - Mohammed A Hossain
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Victoria, 3010, Australia. .,The School of Chemistry, The University of Melbourne, Victoria, 3010, Australia.
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23
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Haugaard-Kedström LM, Hossain MA, Daly NL, Bathgate RAD, Rinderknecht E, Wade JD, Craik DJ, Rosengren KJ. Solution structure, aggregation behavior, and flexibility of human relaxin-2. ACS Chem Biol 2015; 10:891-900. [PMID: 25547165 DOI: 10.1021/cb500918v] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Relaxin is a member of the relaxin/insulin peptide hormone superfamily and is characterized by a two-chain structure constrained by three disulfide bonds. Relaxin is a pleiotropic hormone and involved in a number of physiological and pathogenic processes, including collagen and cardiovascular regulation and tissue remodelling during pregnancy and cancer. Crystallographic and ultracentrifugation experiments have revealed that the human form of relaxin, H2 relaxin, self-associates into dimers, but the significance of this is poorly understood. Here, we present the NMR structure of a monomeric, amidated form of H2 relaxin and compare its features and behavior in solution to those of native H2 relaxin. The overall structure of H2 relaxin is retained in the monomeric form. H2 relaxin amide is fully active at the relaxin receptor RXFP1 and thus dimerization is not required for biological activity. Analysis of NMR chemical shifts and relaxation parameters identified internal motion in H2 relaxin at the pico-nanosecond and milli-microsecond time scales, which is commonly seen in other relaxin and insulin peptides and might be related to function.
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Affiliation(s)
| | | | - Norelle L. Daly
- Centre for
Biodiscovery and Molecular Development of Therapeutics, AITHM, James Cook University, Cairns, Queensland 4878, Australia
| | | | - Ernst Rinderknecht
- Corthera, c/o
Novartis Corporation, San Carlos, California 94070, United States
| | | | | | - K. Johan Rosengren
- School
of Natural Sciences, Linnaeus University, SE-391 82 Kalmar, Sweden
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24
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Wilson SS, Ayaz SI, Levy PD. Relaxin: A Novel Agent for the Treatment of Acute Heart Failure. Pharmacotherapy 2015; 35:315-27. [DOI: 10.1002/phar.1548] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Affiliation(s)
- Suprat S. Wilson
- Department of Pharmacy; Detroit Receiving Hospital; Detroit Michigan
| | - Syed I. Ayaz
- Department of Emergency Medicine; Wayne State University School of Medicine; Detroit Michigan
| | - Phillip D. Levy
- Department of Emergency Medicine; Cardiovascular Research Institute; Wayne State University School of Medicine; Detroit Michigan
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Abstract
PURPOSE Relaxin, a new drug for heart failure therapy, exerts its cardiac actions through relaxin family peptide receptor 1 (RXFP1). Factors regulating RXFP1 expression remain unknown. We have investigated effects of activation of adrenoceptors (AR), an important modulator in the development and prognosis of heart failure, on expression of RXFP1 in rat cardiomyocytes and mouse left ventricles (LV). METHODS Expression of RXFP1 at mRNA (real-time PCR) and protein levels (immunoblotting) was measured in cardiomyocytes treated with α- and β-AR agonists or antagonists. RXFP1 expression was also determined in the LV of transgenic mouse strains with cardiac-restricted overexpression of α1A-, α1B- or β2-AR. Specific inhibitors were used to explore signal pathways involved in α1-AR mediated regulation of RXFP1 in cardiomyocytes. RESULTS In cultured cardiomyocytes, α1-AR stimulation resulted in 2-3 fold increase in RXFP1 mRNA (P < 0.001), which was blocked by specific inhibitors for protein kinase C (PKC) or mitogen-activated protein kinases/extracellular signal-regulated kinases (MAPK/ERK). Activation of β1-, but not β2-AR, significantly inhibited RXFP1 expression (P < 0.001). Relative to respective wild-type controls, RXFP1 mRNA levels in the LV of mice overexpressing α1A- or α1B-AR were increased by 3- or 10-fold, respectively, but unchanged in β2-AR transgenic hearts. Upregulation by α1-AR stimulation RXFP1 expression was confirmed at protein levels both in vitro and in vivo. CONCLUSIONS Expression of RXFP1 was up-regulated by α1-AR but suppressed by β-AR, mainly β1-AR subtype, in cardiomyocytes. Future studies are warranted to characterize the functional significance of such regulation, especially in the setting of heart failure.
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26
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Upregulation of relaxin after experimental subarachnoid hemorrhage in rabbits. BIOMED RESEARCH INTERNATIONAL 2014; 2014:836397. [PMID: 25133183 PMCID: PMC4123578 DOI: 10.1155/2014/836397] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/09/2014] [Accepted: 06/24/2014] [Indexed: 12/16/2022]
Abstract
BACKGROUND Although relaxin causes vasodilatation in systemic arteries, little is known about its role in cerebral arteries. We investigated the expression and role of relaxin in basilar arteries after subarachnoid hemorrhage (SAH) in rabbits. METHODS Microarray analysis with rabbit basilar artery RNA was performed. Messenger RNA expression of relaxin-1 and relaxin/insulin-like family peptide receptor 1 (RXFP1) was investigated with quantitative RT-PCR. RXFP1 expression in the basilar artery was investigated with immunohistochemistry. Relaxin concentrations in cerebrospinal fluid (CSF) and serum were investigated with an enzyme-linked immunosorbent assay. Using human brain vascular smooth muscle cells (HBVSMC) preincubated with relaxin, myosin light chain phosphorylation (MLC) was investigated with immunoblotting after endothelin-1 stimulation. RESULTS After SAH, RXFP1 mRNA and protein were significantly downregulated on day 3, whereas relaxin-1 mRNA was significantly upregulated on day 7. The relaxin concentration in CSF was significantly elevated on days 5 and 7. Pretreatment with relaxin reduced sustained MLC phosphorylation induced by endothelin-1 in HBVSMC. CONCLUSION Upregulation of relaxin and downregulation of RXFP1 after SAH may participate in development of cerebral vasospasm. Downregulation of RXFP1 may induce a functional decrease in relaxin activity during vasospasm. Understanding the role of relaxin may provide further insight into the mechanisms of cerebral vasospasm.
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Abstract
Over the past few decades, research on the peptide hormone, relaxin, has significantly improved our understanding of its biological actions under physiological and diseased conditions. This has facilitated the conducting of clinical trials to explore the use of serelaxin (human recombinant relaxin). Acute heart failure (AHF) is a very difficult to treat clinical entity, with limited success so far in developing new drugs to combat it. A recent phase-III RELAX-AHF trial using serelaxin therapy given during hospitalization revealed acute (ameliorated dyspnea) and chronic (improved 180-day survival) effects. Although these findings support a substantial improvement by serelaxin therapy over currently available therapies for AHF, they also raise key questions and stimulate new hypotheses. To facilitate the development of serelaxin as a new drug for heart disease, joint efforts of clinicians, research scientists and pharmacological industries are necessary to study these questions and hypotheses. In this review, after providing a brief summary of clinical findings and the pathophysiology of AHF, we present a working hypothesis of the mechanisms responsible for the observed efficacy of serelaxin in AHF patients. The existing clinical and preclinical data supporting our hypotheses are summarized and discussed. The development of serelaxin as a drug provides an excellent example of the bilateral nature of translational research.
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Affiliation(s)
- Xiao-Jun Du
- Baker IDI Heart and Diabetes Institute, Monash University
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28
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Violin JD, Soergel DG, Boerrigter G, Burnett JC, Lark MW. GPCR biased ligands as novel heart failure therapeutics. Trends Cardiovasc Med 2013; 23:242-9. [DOI: 10.1016/j.tcm.2013.01.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 01/22/2013] [Accepted: 01/23/2013] [Indexed: 01/14/2023]
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29
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Abstract
Heart failure is an important public health problem that is increasing in prevalence throughout the world. Not only is this condition common, but it is associated with significant morbidity and mortality as well as high costs to medical care systems. Vasodilator drugs help unload the heart and may have other effects that could benefit heart failure patients. Consequently, they have emerged as an important therapeutic approach for patients with this condition. Novel vasodilator therapies that are currently in development target new pathways, potentially giving clinicians alternate options for improving outcomes in this vulnerable population. This review focuses on investigational drugs that have the ability to dilate blood vessels amongst their therapeutic properties. These drugs include the natriuretic peptides that activate particulate guanylate cyclase, the novel agent cinaciguat that activates the soluble guanylate cyclase system, and finally a recombinant form of the naturally occurring vasodilating agent relaxin, a hormone that mediates many of the changes that allows the cardiovascular system to successfully adapt to pregnancy.
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30
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Lin F, Tailhades J, Chan LJ, Bathgate RA, Hossain MA, Wade JD. Preparation of canine relaxin by Fmoc-solid phase synthesis and regioselective disulfide bond formation within the A- and B-chains. ACTA ACUST UNITED AC 2013. [DOI: 10.7243/2052-9341-1-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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31
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Baccari MC, Traini C, Garella R, Cipriani G, Vannucchi MG. Relaxin exerts two opposite effects on mechanical activity and nitric oxide synthase expression in the mouse colon. Am J Physiol Endocrinol Metab 2012; 303:E1142-50. [PMID: 22932783 DOI: 10.1152/ajpendo.00260.2012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The hormone relaxin exerts a variety of functions on the smooth muscle of reproductive and nonreproductive organs, most of which occur through a nitric oxide (NO)-mediated mechanism. In the stomach and ileum, relaxin causes muscle relaxation by modulating the activity and expression of different nitric oxide synthase (NOS) isoforms region-dependently. Nothing is known on the effects of relaxin in the colon, the gut region expressing the highest number of neuronal (n) NOSβ-immunoreactive neurons and mainly involved in motor symptoms of pregnancy and menstrual cycle. Therefore, we studied the effects of relaxin exposure in the mouse proximal colon in vitro evaluating muscle mechanical activity and NOS isoform expression. The functional experiments showed that relaxin decreases muscle tone and increases amplitude of spontaneous contractions; the immunohistochemical results showed that relaxin increases nNOSβ and endothelial (e) NOS expression in the neurons and decreases nNOSα and eNOS expression in the smooth muscle cells (SMC). We hypothesized that, in the colon, relaxin primarily increases the activity and expression of nNOSβ and eNOS in the neurons, causing a reduction of the muscle tone. The downregulation of nNOSα and eNOS expression in the SMC associated with increased muscle contractility could be the consequence of continuous exposue of these cells to the NO of neuronal origin. These findings may help to better understand the physiology of NO in the gastrointestinal tract and the role that the "relaxin-NO" system plays in motor disorders such as functional bowel disease.
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MESH Headings
- Anesthetics, Local/pharmacology
- Animals
- Colon/blood supply
- Colon/cytology
- Colon/innervation
- Colon/metabolism
- Colon, Ascending/cytology
- Colon, Ascending/drug effects
- Colon, Ascending/innervation
- Colon, Ascending/metabolism
- Colon, Transverse/cytology
- Colon, Transverse/drug effects
- Colon, Transverse/innervation
- Colon, Transverse/metabolism
- Enzyme Inhibitors/pharmacology
- Female
- Guanylate Cyclase/antagonists & inhibitors
- In Vitro Techniques
- Interstitial Cells of Cajal/cytology
- Interstitial Cells of Cajal/drug effects
- Interstitial Cells of Cajal/metabolism
- Mechanical Phenomena
- Mice
- Mice, Inbred Strains
- Muscle Contraction/drug effects
- Muscle, Smooth/blood supply
- Muscle, Smooth/cytology
- Muscle, Smooth/innervation
- Muscle, Smooth/metabolism
- Nerve Tissue Proteins/antagonists & inhibitors
- Nerve Tissue Proteins/metabolism
- Neurons/cytology
- Neurons/drug effects
- Neurons/metabolism
- Nitric Oxide Donors/pharmacology
- Nitric Oxide Synthase Type I/antagonists & inhibitors
- Nitric Oxide Synthase Type I/metabolism
- Nitric Oxide Synthase Type III/antagonists & inhibitors
- Nitric Oxide Synthase Type III/metabolism
- Osmolar Concentration
- Relaxin/metabolism
- Submucous Plexus/cytology
- Submucous Plexus/drug effects
- Submucous Plexus/metabolism
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Affiliation(s)
- M C Baccari
- Department of Physiological Sciences, University of Florence, Florence, Italy
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32
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Kwok WH, Ho ENM, Leung GNW, Wong ASY, Yue SK, Wan TSM. Identification of recombinant human relaxin-2 in equine plasma by liquid chromatography-high resolution mass spectrometry. Drug Test Anal 2012; 5:627-33. [PMID: 23081913 DOI: 10.1002/dta.1427] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2012] [Revised: 08/16/2012] [Accepted: 09/13/2012] [Indexed: 11/07/2022]
Affiliation(s)
- Wai Him Kwok
- Racing Laboratory, The Hong Kong Jockey Club, Sha Tin Racecourse, Sha Tin, N.T., Hong Kong, China.
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33
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Human relaxin-2: historical perspectives and role in cancer biology. Amino Acids 2012; 43:1131-40. [DOI: 10.1007/s00726-012-1375-y] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Accepted: 07/20/2012] [Indexed: 12/30/2022]
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34
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Royce SG, Cheng V, Samuel CS, Tang MLK. The regulation of fibrosis in airway remodeling in asthma. Mol Cell Endocrinol 2012; 351:167-75. [PMID: 22266540 DOI: 10.1016/j.mce.2012.01.007] [Citation(s) in RCA: 86] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Accepted: 01/04/2012] [Indexed: 01/12/2023]
Abstract
Fibrosis is one of the key pathological features of airway remodeling in asthma. In the normal airway the amount of collagen and other extracellular matrix components is kept in equilibrium by regulation of synthesis and degradation. In asthma this homeostasis is disrupted due to genetic and environmental factors. In the airways of patients with the disease there is increased extracellular matrix deposition, particularly in the reticular basement membrane region, lamina propria and submucosa. Fibrosis is important as it can occur early in the pathogenesis of asthma, be associated with severity and resistant to therapy. In this review we will discuss current knowledge of relaxin and other key regulators of fibrosis in the airway including TGFβ, Smad2/3 and matrix metalloproteinases. As fibrosis is not directly targeted or effectively treated by current asthma drugs including corticosteroids, characterization of airway fibrosis and how it is regulated will be essential for the development of novel therapies for asthma.
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Affiliation(s)
- Simon G Royce
- Department of Allergy and Immunology, Murdoch Children's Research Institute, The Royal Children's Hospital, Melbourne 3052, Australia
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35
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Abstract
Administering relaxin to conscious rats and humans elicits systemic and renal vasodilation. The molecular mechanisms vary according to the duration of relaxin exposure-so-called "rapid" (within minutes) or "sustained" (hours to days) vasodilatory responses-both being endothelium-dependent. Rapid responses are mediated by G(αi/o) protein coupling to phosphoinositol-3 kinase/Akt (protein kinase B)-dependent phosphorylation and activation of nitric oxide synthase. Sustained responses are mediated by vascular endothelial and placental growth factors, as well as increases in arterial gelatinase activity. Thus, after hours or days of relaxin treatment, respectively, arterial MMP-9 or MMP-2 hydrolyze "big" endothelin (ET) at a gly-leu bond to form ET(1-32), which in turn activates the endothelial ET(B) receptor/nitric oxide vasodilatory pathway. Administration of relaxin to conscious rats also increases global systemic arterial compliance and passive compliance of select isolated blood vessels such as small renal arteries (SRA). The increase in SRA passive compliance is mediated by both geometric remodeling (outward) and compositional remodeling (decreased collagen). Relaxin-induced geometric remodeling has also been observed in brain parenchymal arteries, and this remodeling appears to be via the activation of peroxisome proliferator-activated receptor-γ. Given the vasodilatory and arterial remodeling properties of relaxin, the hormone may have therapeutic potential in the settings of abnormal pregnancies, heart failure, and pathologies associated with stiffening of arteries.
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36
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Arroyo JI, Hoffmann FG, Opazo JC. Gene Duplication and Positive Selection Explains Unusual Physiological Roles of the Relaxin Gene in the European Rabbit. J Mol Evol 2012; 74:52-60. [DOI: 10.1007/s00239-012-9487-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2011] [Accepted: 01/25/2012] [Indexed: 10/28/2022]
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37
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Hewitson TD, Zhao C, Wigg B, Lee SW, Simpson ER, Boon WC, Samuel CS. Relaxin and castration in male mice protect from, but testosterone exacerbates, age-related cardiac and renal fibrosis, whereas estrogens are an independent determinant of organ size. Endocrinology 2012; 153:188-99. [PMID: 22028442 DOI: 10.1210/en.2011-1311] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
This study determined the effects of castration and hormone replacement therapy on the age-related cardiac and renal pathology of male relaxin gene-knockout (RlnKO) and age-matched wild-type (RlnWT) mice and that of aged male aromatase knockout (ArKO) mice, which lack estrogens and have 5-10 times the androgen levels of male wild-type mice. One-month-old RlnWT and RlnKO mice were bilaterally gonadectomized or sham operated and maintained until 12 months. Subgroups of castrated animals received testosterone or 17β-estradiol treatment from 9 to 12 months. Male ArKO mice and aromatase wild-type mice were aged to 12 months. Collected heart and kidney tissues were assessed for changes in organ size and fibrosis. Castration reduced body, heart, left ventricle, and kidney weights in both RlnKO and RlnWT mice, and the cardiac/renal fibrosis that was seen in sham RlnKO animals (all P < 0.05 vs. respective sham). Testosterone normalized organ weights and organ weight to body weight ratio of castrated animals and increased cardiac/renal collagen concentration to levels measured in or beyond that of sham RlnKO mice (all P < 0.05 vs. respective castrated mice). Furthermore, expression of TGF-β1, mothers against decapentaplegic homolog 2 (Smad2), and myofibroblast differentiation paralleled the above changes (all P < 0.05 vs. respective castrated mice), whereas matrix metalloproteinase-13 was decreased in testosterone-treated RlnKO mice. Conversely, 17β-estradiol only restored changes in organ size. Consistent with these findings, intact ArKO mice demonstrated increased cardiac/renal fibrosis in the absence of changes in organ size. These findings suggest that relaxin and castration protect, whereas androgens exacerbate, cardiac and renal fibrosis during ageing, whereas estrogens, in synergy with relaxin, regulates age-related changes in organ size.
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Affiliation(s)
- Tim D Hewitson
- Howard Florey Institute, University of Melbourne, Parkville, Victoria 3010, Australia
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38
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Samuel CS, Cendrawan S, Gao XM, Ming Z, Zhao C, Kiriazis H, Xu Q, Tregear GW, Bathgate RAD, Du XJ. Relaxin remodels fibrotic healing following myocardial infarction. J Transl Med 2011; 91:675-90. [PMID: 21221074 DOI: 10.1038/labinvest.2010.198] [Citation(s) in RCA: 84] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
In the setting of myocardial infarction (MI), implanted stem cell viability is low and scar formation limits stem cell homing, viability, and integration. Thus, interventions that favorably remodel fibrotic healing may benefit stem cell therapies. However, it remains unclear whether it is feasible and safe to remodel fibrotic healing post-MI without compromising ventricular remodeling and dysfunction. This study, therefore, determined the anti-fibrotic and other effects of the hormone, relaxin in a mouse model of MI. Adult male mice underwent left coronary artery ligation-induced MI and were immediately treated with recombinant human relaxin (MI+RLX) or vehicle (MI+VEH) over 7 or 30 days, representing time points of early and mature fibrotic healing. Cardiac function was assessed by echocardiography and catheterization, while comprehensive immunohistochemistry, morphometry, and western blotting were performed to explore the relaxin-induced mechanisms of action post-MI. RLX significantly inhibited the MI-induced progression of cardiac fibrosis over 7 and 30 days, which was associated with a reduction in TGF-β1 expression, myofibroblast differentiation, and cardiomyocyte apoptosis in addition to a promotion of matrix metalloproteinase-13 levels and de novo blood vessel growth (all P<0.05 vs respective measurements from MI+VEH mice). Despite the evident fibrotic healing post-MI, relaxin did not adversely affect the incidence of ventricular free-wall rupture or the extent of LV remodeling and dysfunction. These combined findings demonstrate that RLX favorably remodels the process of fibrotic healing post-infarction by lowering the density of mature scar tissue in the infarcted myocardium, border zone, and non-infarcted myocardium, and may, therefore, facilitate cell-based therapies in the setting of ischemic heart disease.
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Affiliation(s)
- Chrishan S Samuel
- Howard Florey Institute, University of Melbourne, Parkville, Victoria, Australia.
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39
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Vannucchi MG, Garella R, Cipriani G, Baccari MC. Relaxin counteracts the altered gastric motility of dystrophic (mdx) mice: functional and immunohistochemical evidence for the involvement of nitric oxide. Am J Physiol Endocrinol Metab 2011; 300:E380-91. [PMID: 21081707 DOI: 10.1152/ajpendo.00375.2010] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Impaired gastric motility ascribable to a defective nitric oxide (NO) production has been reported in dystrophic (mdx) mice. Since relaxin upregulates NO biosynthesis, its effects on the motor responses and NO synthase (NOS) expression in the gastric fundus of mdx mice were investigated. Mechanical responses of gastric strips were recorded via force displacement transducers. Evaluation of the three NOS isoforms was performed by immunohistochemistry and Western blot. Wild-type (WT) and mdx mice were distributed into three groups: untreated, relaxin pretreated, and vehicle pretreated. In strips from both untreated and vehicle-pretreated animals, electrical field stimulation (EFS) elicited contractile responses that were greater in mdx than in WT mice. In carbachol-precontracted strips, EFS induced fast relaxant responses that had a lower amplitude in mdx than in WT mice. Only in the mdx mice did relaxin depress the amplitude of the neurally induced excitatory responses and increase that of the inhibitory ones. In the presence of L-NNA, relaxin was ineffective. In relaxin-pretreated mdx mice, the amplitude of the EFS-induced contractile responses was decreased and that of the fast relaxant ones was increased compared with untreated mdx animals. Responses to methacholine or papaverine did not differ among preparations and were not influenced by relaxin. Immunohistochemistry and Western blotting showed a significant decrease in neuronal NOS expression and content in mdx compared with WT mice, which was recovered in the relaxin-pretreated mdx mice. The results suggest that relaxin is able to counteract the altered contractile and relaxant responses in the gastric fundus of mdx mice by upregulating nNOS expression.
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40
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Hossain MA, Chow Suet Man B, Zhao C, Xu Q, Du XJ, Wade JD, Samuel CS. H3 Relaxin Demonstrates Antifibrotic Properties via the RXFP1 Receptor. Biochemistry 2011; 50:1368-75. [DOI: 10.1021/bi1013968] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
| | | | | | - Qi Xu
- Baker IDI Heart and Diabetes Institute, St. Kilda Road Central, Melbourne, Victoria 8008, Australia
| | - Xiao-Jun Du
- Baker IDI Heart and Diabetes Institute, St. Kilda Road Central, Melbourne, Victoria 8008, Australia
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41
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Brecht A, Bartsch C, Baumann G, Stangl K, Dschietzig T. Relaxin inhibits early steps in vascular inflammation. ACTA ACUST UNITED AC 2011; 166:76-82. [DOI: 10.1016/j.regpep.2010.09.001] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 08/22/2010] [Accepted: 09/13/2010] [Indexed: 12/14/2022]
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Halls ML, Cooper DMF. Sub-picomolar relaxin signalling by a pre-assembled RXFP1, AKAP79, AC2, beta-arrestin 2, PDE4D3 complex. EMBO J 2010; 29:2772-87. [PMID: 20664520 PMCID: PMC2924647 DOI: 10.1038/emboj.2010.168] [Citation(s) in RCA: 66] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2010] [Accepted: 07/01/2010] [Indexed: 12/17/2022] Open
Abstract
Biochemical studies suggest that G-protein-coupled receptors (GPCRs) achieve exquisite signalling specificity by forming selective complexes, termed signalosomes. Here, using cAMP biosensors in single cells, we uncover a pre-assembled, constitutively active GPCR signalosome, that couples the relaxin receptor, relaxin family peptide receptor 1 (RXFP1), to cAMP following receptor stimulation with sub-picomolar concentrations of peptide. The physiological effects of relaxin, a pleiotropic hormone with therapeutic potential in cancer metastasis and heart failure, are generally attributed to local production of the peptide, that occur in response to sub-micromolar concentrations. The highly sensitive signalosome identified here provides a regulatory mechanism for the extremely low levels of relaxin that circulate. The signalosome includes requisite Galpha(s), Gbetagamma and adenylyl cyclase 2 (AC2); AC2 is functionally coupled to RXFP1 through AKAP79 binding to helix 8 of the receptor; activation of AC2 is tonically opposed by protein kinase A (PKA)-activated PDE4D3, scaffolded through a beta-arrestin 2 interaction with Ser(704) of the receptor C-terminus. This elaborate, pre-assembled, ligand-independent GPCR signalosome represents a new paradigm in GPCR signalling and provides a mechanism for the distal actions of low circulating levels of relaxin.
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Affiliation(s)
- Michelle L Halls
- Department of Pharmacology, University of Cambridge, Cambridge, UK
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Abstract
Relaxin is a naturally occurring human peptide initially identified as a reproductive hormone. More recently, relaxin has been shown to play a key role in the maternal hemodynamic and renal adjustments that accommodate pregnancy. An understanding of these physiologic effects has led to the evaluation of relaxin as a pharmacologic agent for the treatment of patients with acute heart failure. Preliminary results have been encouraging. In addition, the other known biologic properties of relaxin, including anti-inflammatory effects, extracellular matrix remodeling effects, and angiogenic and anti-ischemic effects, all may play a role in potential benefits of relaxin therapy. Ongoing, large-scale clinical testing will provide additional insights into the potential role of relaxin in the treatment of heart failure.
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Affiliation(s)
- Sam L. Teichman
- Corthera, Inc, a subsidiary of Novartis Pharmaceuticals Corp., 1660 South Amphlett Boulevard, Suite 200, San Mateo, CA 94402 USA
| | - Elaine Unemori
- Corthera, Inc, a subsidiary of Novartis Pharmaceuticals Corp., 1660 South Amphlett Boulevard, Suite 200, San Mateo, CA 94402 USA
| | - John R. Teerlink
- Section of Cardiology, Veterans Affairs Medical Center, University of California, San Francisco VA Medical Center, Cardiology-111C, Building 203, Room 2A-49, 4150 Clement Street, San Francisco, CA 94121-1545 USA
| | - Gad Cotter
- Momentum Research, Inc, 3100 Tower Boulevard, Suite 802, Durham, NC 27707 USA
| | - Marco Metra
- Section of Cardiovascular Diseases, Department of Experimental and Applied Medicine, University of Brescia, Cardiology, University and Civil Hospital, Piazza Spedali Civili 1, 25123 Brescia, Italy
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Alexiou K, Matschke K, Westphal A, Stangl K, Dschietzig T. Relaxin is a candidate drug for lung preservation: Relaxin-induced protection of rat lungs from ischemia-reperfusion injury. J Heart Lung Transplant 2010; 29:454-60. [DOI: 10.1016/j.healun.2009.09.012] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2009] [Revised: 09/02/2009] [Accepted: 09/03/2009] [Indexed: 10/20/2022] Open
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Xu Q, Chakravorty A, Bathgate RAD, Dart AM, Du XJ. Relaxin therapy reverses large artery remodeling and improves arterial compliance in senescent spontaneously hypertensive rats. Hypertension 2010; 55:1260-6. [PMID: 20351343 DOI: 10.1161/hypertensionaha.109.149369] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Hypertension and aging are associated with large artery structural remodeling and stiffening, which are known to increase cardiovascular risk. Relaxin is a peptide hormone with potent antifibrotic action in multiple organs. Although relaxin is able to reduce peripheral vascular resistance and improve arterial compliance in rats, it remains unclear whether the improvement in compliance is indirectly attributed to a vasodilatory action or whether relaxin is able to reverse arterial remodeling and stiffening directly in aged hypertensive animals. Senescent spontaneously hypertensive rats (17 months old) were treated with relaxin for 2 weeks (0.5 mg/kg per day) followed by a 1-week washout period. We determined large artery compliance using in vivo and in vitro techniques and quantified arterial remodeling by morphological and chemical means. Relaxin therapy significantly reversed aortic remodeling (ie, increases in vessel size, wall thickness, and collagen content) and improved arterial compliance, effects independent of its vasodilatory action. In relaxin-treated spontaneously hypertensive rats, arterial collagen content showed a greater reduction (-31%; P<0.05) than that of elastin (-8%), resulting in an increased elastin:collagen ratio (0.63+/-0.03 versus 0.47+/-0.02; P<0.05). In conclusion, our results demonstrated that relaxin is potent in mediating reversal of arterial remodeling and improving arterial structural compliance in aged hypertensive rats.
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Affiliation(s)
- Qi Xu
- Baker IDI Heart and Diabetes Institute, St Kilda Road Central, Melbourne, PO Box 6492, Victoria 8008, Australia
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Barlos KK, Gatos D, Vasileiou Z, Barlos K. An optimized chemical synthesis of human relaxin-2. J Pept Sci 2010; 16:200-11. [DOI: 10.1002/psc.1221] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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Hossain MA, Samuel CS, Binder C, Hewitson TD, Tregear GW, Wade JD, Bathgate RAD. The chemically synthesized human relaxin-2 analog, B-R13/17K H2, is an RXFP1 antagonist. Amino Acids 2009; 39:409-16. [DOI: 10.1007/s00726-009-0454-1] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2009] [Accepted: 12/17/2009] [Indexed: 01/06/2023]
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Formigli L, Francini F, Nistri S, Margheri M, Luciani G, Naro F, Silvertown JD, Orlandini SZ, Meacci E, Bani D. Skeletal myoblasts overexpressing relaxin improve differentiation and communication of primary murine cardiomyocyte cell cultures. J Mol Cell Cardiol 2009; 47:335-45. [DOI: 10.1016/j.yjmcc.2009.05.008] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/20/2009] [Revised: 04/23/2009] [Accepted: 05/13/2009] [Indexed: 11/24/2022]
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Bani D, Nistri S, Formigli L, Meacci E, Francini F, Zecchi-Orlandini S. Prominent role of relaxin in improving postinfarction heart remodeling. Ann N Y Acad Sci 2009; 1160:269-77. [PMID: 19416202 DOI: 10.1111/j.1749-6632.2008.03781.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Stem cell transplantation is a promising approach for treatment of the postinfarcted heart and prevention of deleterious cardiac remodeling and heart failure. We explored this issue by transplanting mouse C2C12 myoblasts, genetically engineered to express enhanced green fluorescent protein (eGFP) or eGFP and relaxin (eGFP/RLX), into swine with chronic myocardial infarction. One month later, C2C12 myoblasts selectively settled in the ischemic scar around blood vessels, showing an activated endothelium (ICAM-1 and VCAM positive). Although unable to differentiate to a muscle phenotype, these cells induced extracellular matrix (ECM) remodeling by matrix metalloprotease secretion and increased microvessel density by vascular endothelial growth factor expression. C2C12/RLX myoblasts gave better results than C2C12/GFP. By echocardiography, C2C12-engrafted swine, especially those that received C2C12/RLX, showed better heart contractility than the untreated controls. Hence, the advantage afforded by the grafted myoblasts on cardiac function is primarily dependent on their paracrine effects on ECM remodeling and vascularization.
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Affiliation(s)
- Daniele Bani
- Department of Anatomy, University of Florence, Florence, Italy.
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