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Perez-Quintero LA, Abidin BM, Tremblay ML. Immunotherapeutic implications of negative regulation by protein tyrosine phosphatases in T cells: the emerging cases of PTP1B and TCPTP. Front Med (Lausanne) 2024; 11:1364778. [PMID: 38707187 PMCID: PMC11066278 DOI: 10.3389/fmed.2024.1364778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Accepted: 03/27/2024] [Indexed: 05/07/2024] Open
Abstract
In the context of inflammation, T cell activation occurs by the concerted signals of the T cell receptor (TCR), co-stimulatory receptors ligation, and a pro-inflammatory cytokine microenvironment. Fine-tuning these signals is crucial to maintain T cell homeostasis and prevent self-reactivity while offering protection against infectious diseases and cancer. Recent developments in understanding the complex crosstalk between the molecular events controlling T cell activation and the balancing regulatory cues offer novel approaches for the development of T cell-based immunotherapies. Among the complex regulatory processes, the balance between protein tyrosine kinases (PTK) and the protein tyrosine phosphatases (PTPs) controls the transcriptional and metabolic programs that determine T cell function, fate decision, and activation. In those, PTPs are de facto regulators of signaling in T cells acting for the most part as negative regulators of the canonical TCR pathway, costimulatory molecules such as CD28, and cytokine signaling. In this review, we examine the function of two close PTP homologs, PTP1B (PTPN1) and T-cell PTP (TCPTP; PTPN2), which have been recently identified as promising candidates for novel T-cell immunotherapeutic approaches. Herein, we focus on recent studies that examine the known contributions of these PTPs to T-cell development, homeostasis, and T-cell-mediated immunity. Additionally, we describe the signaling networks that underscored the ability of TCPTP and PTP1B, either individually and notably in combination, to attenuate TCR and JAK/STAT signals affecting T cell responses. Thus, we anticipate that uncovering the role of these two PTPs in T-cell biology may lead to new treatment strategies in the field of cancer immunotherapy. This review concludes by exploring the impacts and risks that pharmacological inhibition of these PTP enzymes offers as a therapeutic approach in T-cell-based immunotherapies.
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Affiliation(s)
- Luis Alberto Perez-Quintero
- Rosalind and Morris Goodman Cancer Institute, Faculty of Medicine, McGill University, Montreal, QC, Canada
- Department of Biochemistry, McGill University, Montreal, QC, Canada
| | - Belma Melda Abidin
- Rosalind and Morris Goodman Cancer Institute, Faculty of Medicine, McGill University, Montreal, QC, Canada
- Department of Biochemistry, McGill University, Montreal, QC, Canada
| | - Michel L. Tremblay
- Rosalind and Morris Goodman Cancer Institute, Faculty of Medicine, McGill University, Montreal, QC, Canada
- Department of Biochemistry, McGill University, Montreal, QC, Canada
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2
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Verma S, Pandey A, Pandey AK, Butler J, Lee JS, Teoh H, Mazer CD, Kosiborod MN, Cosentino F, Anker SD, Connelly KA, Bhatt DL. Aldosterone and aldosterone synthase inhibitors in cardiorenal disease. Am J Physiol Heart Circ Physiol 2024; 326:H670-H688. [PMID: 38133623 DOI: 10.1152/ajpheart.00419.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 12/11/2023] [Accepted: 12/15/2023] [Indexed: 12/23/2023]
Abstract
Modulation of the renin-angiotensin-aldosterone system is a foundation of therapy for cardiovascular and kidney diseases. Excess aldosterone plays an important role in cardiovascular disease, contributing to inflammation, fibrosis, and dysfunction in the heart, kidneys, and vasculature through both genomic and mineralocorticoid receptor (MR)-mediated as well as nongenomic mechanisms. MR antagonists have been a key therapy for attenuating the pathologic effects of aldosterone but are associated with some side effects and may not always adequately attenuate the nongenomic effects of aldosterone. Aldosterone is primarily synthesized by the CYP11B2 aldosterone synthase enzyme, which is very similar in structure to other enzymes involved in steroid biosynthesis including CYP11B1, a key enzyme involved in glucocorticoid production. Lack of specificity for CYP11B2, off-target effects on the hypothalamic-pituitary-adrenal axis, and counterproductive increased levels of bioactive steroid intermediates such as 11-deoxycorticosterone have posed challenges in the development of early aldosterone synthase inhibitors such as osilodrostat. In early-phase clinical trials, newer aldosterone synthase inhibitors demonstrated promise in lowering blood pressure in patients with treatment-resistant and uncontrolled hypertension. It is therefore plausible that these agents offer protection in other disease states including heart failure or chronic kidney disease. Further clinical evaluation will be needed to clarify the role of aldosterone synthase inhibitors, a promising class of agents that represent a potentially major therapeutic advance.
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Affiliation(s)
- Subodh Verma
- Division of Cardiac Surgery, St. Michael's Hospital-Unity Health Toronto, Toronto, Ontario, Canada
- Department of Surgery, University of Toronto, Toronto, Ontario, Canada
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Avinash Pandey
- Department of Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Arjun K Pandey
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Javed Butler
- Baylor Scott and White Research Institute, Dallas, Texas, United States
- University of Mississippi, Jackson, Mississippi, United States
| | - John S Lee
- LJ Biosciences, LLC, Rockville, Maryland, United States
- PhaseBio Pharmaceuticals, Malvern, Pennsylvania, United States
| | - Hwee Teoh
- Division of Cardiac Surgery, St. Michael's Hospital-Unity Health Toronto, Toronto, Ontario, Canada
- Division of Endocrinology and Metabolism, St. Michael's Hospital-Unity Health Toronto, Toronto, Ontario, Canada
| | - C David Mazer
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
- Department of Anesthesia, St. Michael's Hospital-Unity Health Toronto, Toronto, Ontario, Canada
- Department of Anesthesiology and Pain Medicine, University of Toronto, Toronto, Ontario, Canada
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
| | - Mikhail N Kosiborod
- Saint Luke's Mid America Heart Institute, Kansas City, Missouri, United States
- University of Missouri-Kansas City, Kansas City, Missouri, United States
| | | | - Stefan D Anker
- Department of Cardiology and Berlin Institute of Health Center for Regenerative Therapies, German Centre for Cardiovascular Research partner site Berlin, Charité Universitätsmedizin Berlin, Berlin, Germany
| | - Kim A Connelly
- Department of Physiology, University of Toronto, Toronto, Ontario, Canada
- Division of Cardiology, St. Michael's Hospital-Unity Health Toronto, Toronto, Ontario, Canada
- Department of Medicine, University of Toronto, Toronto, Ontario, Canada
| | - Deepak L Bhatt
- Mount Sinai Fuster Heart, Icahn School of Medicine at Mount Sinai Health System, New York, New York, United States
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3
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Kinnear C, Agrawal R, Loo C, Pahnke A, Rodrigues DC, Thompson T, Akinrinade O, Ahadian S, Keeley F, Radisic M, Mital S, Ellis J. Everolimus Rescues the Phenotype of Elastin Insufficiency in Patient Induced Pluripotent Stem Cell-Derived Vascular Smooth Muscle Cells. Arterioscler Thromb Vasc Biol 2020; 40:1325-1339. [PMID: 32212852 PMCID: PMC7176340 DOI: 10.1161/atvbaha.119.313936] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Supplemental Digital Content is available in the text. Objective: Elastin gene deletion or mutation leads to arterial stenoses due to vascular smooth muscle cell (SMC) proliferation. Human induced pluripotent stem cells–derived SMCs can model the elastin insufficiency phenotype in vitro but show only partial rescue with rapamycin. Our objective was to identify drug candidates with superior efficacy in rescuing the SMC phenotype in elastin insufficiency patients. Approach and Results: SMCs generated from induced pluripotent stem cells from 5 elastin insufficiency patients with severe recurrent vascular stenoses (3 Williams syndrome and 2 elastin mutations) were phenotypically immature, hyperproliferative, poorly responsive to endothelin, and exerted reduced tension in 3-dimensional smooth muscle biowires. Elastin mRNA and protein were reduced in SMCs from patients compared to healthy control SMCs. Fourteen drug candidates were tested on patient SMCs. Of the mammalian target of rapamycin inhibitors studied, everolimus restored differentiation, rescued proliferation, and improved endothelin-induced calcium flux in all patient SMCs except one Williams syndrome. Of the calcium channel blockers, verapamil increased SMC differentiation and reduced proliferation in Williams syndrome patient cells but not in elastin mutation patients and had no effect on endothelin response. Combination treatment with everolimus and verapamil was not superior to everolimus alone. Other drug candidates had limited efficacy. Conclusions: Everolimus caused the most consistent improvement in SMC differentiation, proliferation and in SMC function in patients with both syndromic and nonsyndromic elastin insufficiency, and offers the best candidate for drug repurposing for treatment of elastin insufficiency associated vasculopathy.
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Affiliation(s)
- Caroline Kinnear
- From the Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.K., R.A., O.A., S.M.)
| | - Rahul Agrawal
- From the Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.K., R.A., O.A., S.M.)
| | - Caitlin Loo
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.L., D.C.R., T.T., J.E.).,Department of Molecular Genetics (C.L., J.E.), University of Toronto, Ontario, Canada
| | - Aric Pahnke
- Institute of Biomaterials and Biomedical Engineering (A.P., S.A., M.R.), University of Toronto, Ontario, Canada.,Department of Chemical Engineering and Applied Chemistry (A.P., S.A., M.R.), University of Toronto, Ontario, Canada
| | - Deivid Carvalho Rodrigues
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.L., D.C.R., T.T., J.E.)
| | - Tadeo Thompson
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.L., D.C.R., T.T., J.E.)
| | - Oyediran Akinrinade
- From the Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.K., R.A., O.A., S.M.)
| | - Samad Ahadian
- Institute of Biomaterials and Biomedical Engineering (A.P., S.A., M.R.), University of Toronto, Ontario, Canada.,Department of Chemical Engineering and Applied Chemistry (A.P., S.A., M.R.), University of Toronto, Ontario, Canada
| | - Fred Keeley
- Department of Biochemistry (F.K.), University of Toronto, Ontario, Canada.,Program in Molecular Medicine, The Hospital for Sick Children, Toronto, Ontario, Canada (F.K.)
| | - Milica Radisic
- Institute of Biomaterials and Biomedical Engineering (A.P., S.A., M.R.), University of Toronto, Ontario, Canada.,Department of Chemical Engineering and Applied Chemistry (A.P., S.A., M.R.), University of Toronto, Ontario, Canada
| | - Seema Mital
- From the Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.K., R.A., O.A., S.M.).,Department of Pediatrics, The Hospital for Sick Children (S.M.), University of Toronto, Ontario, Canada
| | - James Ellis
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, Toronto, Ontario, Canada (C.L., D.C.R., T.T., J.E.).,Department of Molecular Genetics (C.L., J.E.), University of Toronto, Ontario, Canada
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4
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Hasan HF, Radwan RR, Galal SM. Bradykinin‐potentiating factor isolated from
Leiurus quinquestriatus
scorpion venom alleviates cardiomyopathy in irradiated rats
via
remodelling of the RAAS pathway. Clin Exp Pharmacol Physiol 2019; 47:263-273. [DOI: 10.1111/1440-1681.13202] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2019] [Revised: 10/25/2019] [Accepted: 10/27/2019] [Indexed: 11/29/2022]
Affiliation(s)
- Hesham Farouk Hasan
- Radiation Biology Department National Center for Radiation Research and Technology (NCRRT) Atomic Energy Authority Cairo Egypt
| | - Rasha R. Radwan
- Drug Radiation Research Department National Center for Radiation Research and Technology Atomic Energy Authority Cairo Egypt
| | - Shereen Mohamed Galal
- Health Radiation Research Department National Center for Radiation Research and Technology Atomic Energy Authority Cairo Egypt
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5
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Pickup L, Radhakrishnan A, Townend JN, Ferro CJ. Arterial stiffness in chronic kidney disease. Curr Opin Nephrol Hypertens 2019; 28:527-536. [DOI: 10.1097/mnh.0000000000000535] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
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6
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Bae H, Choi J, Kim YW, Lee D, Kim JH, Ko JH, Bang H, Kim T, Lim I. Effects of Nitric Oxide on Voltage-Gated K⁺ Currents in Human Cardiac Fibroblasts through the Protein Kinase G and Protein Kinase A Pathways but Not through S-Nitrosylation. Int J Mol Sci 2018. [PMID: 29534509 PMCID: PMC5877675 DOI: 10.3390/ijms19030814] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
This study investigated the expression of voltage-gated K+ (KV) channels in human cardiac fibroblasts (HCFs), and the effect of nitric oxide (NO) on the KV currents, and the underlying phosphorylation mechanisms. In reverse transcription polymerase chain reaction, two types of KV channels were detected in HCFs: delayed rectifier K+ channel and transient outward K+ channel. In whole-cell patch-clamp technique, delayed rectifier K+ current (IK) exhibited fast activation and slow inactivation, while transient outward K+ current (Ito) showed fast activation and inactivation kinetics. Both currents were blocked by 4-aminopyridine. An NO donor, S-nitroso-N-acetylpenicillamine (SNAP), increased the amplitude of IK in a concentration-dependent manner with an EC50 value of 26.4 µM, but did not affect Ito. The stimulating effect of SNAP on IK was blocked by pretreatment with 1H-(1,2,4)oxadiazolo[4,3-a]quinoxalin-1-one (ODQ) or by KT5823. 8-bromo-cyclic GMP stimulated the IK. The stimulating effect of SNAP on IK was also blocked by pretreatment with KT5720 or by SQ22536. Forskolin and 8-bromo-cyclic AMP each stimulated IK. On the other hand, the stimulating effect of SNAP on IK was not blocked by pretreatment of N-ethylmaleimide or by DL-dithiothreitol. Our data suggest that NO enhances IK, but not Ito, among KV currents of HCFs, and the stimulating effect of NO on IK is through the PKG and PKA pathways, not through S-nitrosylation.
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Affiliation(s)
- Hyemi Bae
- Department of Physiology, College of Medicine, Chung-Ang University, 84 Heukseok-ro, Seoul 06974, Korea.
| | - Jeongyoon Choi
- Department of Physiology, College of Medicine, Chung-Ang University, 84 Heukseok-ro, Seoul 06974, Korea.
| | - Young-Won Kim
- Department of Physiology, College of Medicine, Chung-Ang University, 84 Heukseok-ro, Seoul 06974, Korea.
| | - Donghee Lee
- Department of Physiology, College of Medicine, Chung-Ang University, 84 Heukseok-ro, Seoul 06974, Korea.
| | - Jung-Ha Kim
- Department of Family Medicine, College of Medicine, Chung-Ang University Hospital, 102 Heukseok-ro, Seoul 06973, Korea.
| | - Jae-Hong Ko
- Department of Physiology, College of Medicine, Chung-Ang University, 84 Heukseok-ro, Seoul 06974, Korea.
| | - Hyoweon Bang
- Department of Physiology, College of Medicine, Chung-Ang University, 84 Heukseok-ro, Seoul 06974, Korea.
| | - Taeho Kim
- Department of Internal Medicine, College of Medicine, Chung-Ang University Hospital, 102 Heukseok-ro, Seoul 06973, Korea.
| | - Inja Lim
- Department of Physiology, College of Medicine, Chung-Ang University, 84 Heukseok-ro, Seoul 06974, Korea.
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7
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Ruhs S, Nolze A, Hübschmann R, Grossmann C. 30 YEARS OF THE MINERALOCORTICOID RECEPTOR: Nongenomic effects via the mineralocorticoid receptor. J Endocrinol 2017; 234:T107-T124. [PMID: 28348113 DOI: 10.1530/joe-16-0659] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2017] [Accepted: 03/27/2017] [Indexed: 12/12/2022]
Abstract
The mineralocorticoid receptor (MR) belongs to the steroid hormone receptor family and classically functions as a ligand-dependent transcription factor. It is involved in water-electrolyte homeostasis and blood pressure regulation but independent from these effects also furthers inflammation, fibrosis, hypertrophy and remodeling in cardiovascular tissues. Next to genomic effects, aldosterone elicits very rapid actions within minutes that do not require transcription or translation and that occur not only in classical MR epithelial target organs like kidney and colon but also in nonepithelial tissues like heart, vasculature and adipose tissue. Most of these effects can be mediated by classical MR and its crosstalk with different signaling cascades. Near the plasma membrane, the MR seems to be associated with caveolin and striatin as well as with receptor tyrosine kinases like EGFR, PDGFR and IGF1R and G protein-coupled receptors like AT1 and GPER1, which then mediate nongenomic aldosterone effects. GPER1 has also been named a putative novel MR. There is a close interaction and functional synergism between the genomic and the nongenomic signaling so that nongenomic signaling can lead to long-term effects and support genomic actions. Therefore, understanding nongenomic aldosterone/MR effects is of potential relevance for modulating genomic aldosterone effects and may provide additional targets for intervention.
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Affiliation(s)
- Stefanie Ruhs
- Julius Bernstein Institute of PhysiologyMartin Luther University Halle-Wittenberg, Halle, Germany
| | - Alexander Nolze
- Julius Bernstein Institute of PhysiologyMartin Luther University Halle-Wittenberg, Halle, Germany
| | - Ralf Hübschmann
- Julius Bernstein Institute of PhysiologyMartin Luther University Halle-Wittenberg, Halle, Germany
| | - Claudia Grossmann
- Julius Bernstein Institute of PhysiologyMartin Luther University Halle-Wittenberg, Halle, Germany
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8
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Dierickx P, Vermunt MW, Muraro MJ, Creyghton MP, Doevendans PA, van Oudenaarden A, Geijsen N, Van Laake LW. Circadian networks in human embryonic stem cell-derived cardiomyocytes. EMBO Rep 2017; 18:1199-1212. [PMID: 28536247 PMCID: PMC5494509 DOI: 10.15252/embr.201743897] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2017] [Revised: 03/29/2017] [Accepted: 04/10/2017] [Indexed: 11/09/2022] Open
Abstract
Cell-autonomous circadian oscillations strongly influence tissue physiology and pathophysiology of peripheral organs including the heart, in which the circadian clock is known to determine cardiac metabolism and the outcome of for instance ischemic stress. Human pluripotent stem cells represent a powerful tool to study developmental processes in vitro, but the extent to which human embryonic stem (ES) cell-derived cardiomyocytes establish circadian rhythmicity in the absence of a systemic context is unknown. Here we demonstrate that while undifferentiated human ES cells do not possess an intrinsic functional clock, oscillatory expression of known core clock genes emerges spontaneously during directed cardiac differentiation. We identify a set of clock-controlled output genes that contain an oscillatory network of stress-related transcripts. Furthermore, we demonstrate that this network results in a time-dependent functional response to doxorubicin, a frequently used anti-cancer drug with known cardiotoxic side effects. Taken together, our data provide a framework from which the effect of oscillatory gene expression on cardiomyocyte physiology can be modeled in vitro, and demonstrate the influence of a functional clock on experimental outcome.
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Affiliation(s)
- Pieterjan Dierickx
- Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, The Netherlands .,Division of Heart and Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands.,Regenerative Medicine Center Utrecht, University Medical Center Utrecht, Utrecht, The Netherlands
| | - Marit W Vermunt
- Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, The Netherlands
| | - Mauro J Muraro
- Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, The Netherlands
| | - Menno P Creyghton
- Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, The Netherlands
| | - Pieter A Doevendans
- Division of Heart and Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands.,Netherlands Heart Institute, Utrecht, The Netherlands
| | | | - Niels Geijsen
- Hubrecht Institute-KNAW and University Medical Center Utrecht, Utrecht, The Netherlands
| | - Linda W Van Laake
- Division of Heart and Lungs, Department of Cardiology, University Medical Center Utrecht, Utrecht, The Netherlands .,Regenerative Medicine Center Utrecht, University Medical Center Utrecht, Utrecht, The Netherlands
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9
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Ong GSY, Young MJ. Mineralocorticoid regulation of cell function: the role of rapid signalling and gene transcription pathways. J Mol Endocrinol 2017; 58:R33-R57. [PMID: 27821439 DOI: 10.1530/jme-15-0318] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2016] [Accepted: 11/06/2016] [Indexed: 12/22/2022]
Abstract
The mineralocorticoid receptor (MR) and mineralocorticoids regulate epithelial handling of electrolytes, and induces diverse effects on other tissues. Traditionally, the effects of MR were ascribed to ligand-receptor binding and activation of gene transcription. However, the MR also utilises a number of intracellular signalling cascades, often by transactivating unrelated receptors, to change cell function more rapidly. Although aldosterone is the physiological mineralocorticoid, it is not the sole ligand for MR. Tissue-selective and mineralocorticoid-specific effects are conferred through the enzyme 11β-hydroxysteroid dehydrogenase 2, cellular redox status and properties of the MR itself. Furthermore, not all aldosterone effects are mediated via MR, with implication of the involvement of other membrane-bound receptors such as GPER. This review will describe the ligands, receptors and intracellular mechanisms available for mineralocorticoid hormone and receptor signalling and illustrate their complex interactions in physiology and disease.
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Affiliation(s)
- Gregory S Y Ong
- Cardiovascular Endocrinology LaboratoryCentre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of MedicineSchool of Clinical Sciences, Monash University, Clayton, Victoria, Australia
| | - Morag J Young
- Cardiovascular Endocrinology LaboratoryCentre for Endocrinology and Metabolism, Hudson Institute of Medical Research, Clayton, Victoria, Australia
- Department of PhysiologySchool of Biomedical Sciences, Monash University, Clayton, Victoria, Australia
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10
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Aziz J, Shezali H, Radzi Z, Yahya NA, Abu Kassim NH, Czernuszka J, Rahman MT. Molecular Mechanisms of Stress-Responsive Changes in Collagen and Elastin Networks in Skin. Skin Pharmacol Physiol 2016; 29:190-203. [PMID: 27434176 DOI: 10.1159/000447017] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2016] [Accepted: 05/19/2016] [Indexed: 11/19/2022]
Abstract
Collagen and elastin networks make up the majority of the extracellular matrix in many organs, such as the skin. The mechanisms which are involved in the maintenance of homeostatic equilibrium of these networks are numerous, involving the regulation of genetic expression, growth factor secretion, signalling pathways, secondary messaging systems, and ion channel activity. However, many factors are capable of disrupting these pathways, which leads to an imbalance of homeostatic equilibrium. Ultimately, this leads to changes in the physical nature of skin, both functionally and cosmetically. Although various factors have been identified, including carcinogenesis, ultraviolet exposure, and mechanical stretching of skin, it was discovered that many of them affect similar components of regulatory pathways, such as fibroblasts, lysyl oxidase, and fibronectin. Additionally, it was discovered that the various regulatory pathways intersect with each other at various stages instead of working independently of each other. This review paper proposes a model which elucidates how these molecular pathways intersect with one another, and how various internal and external factors can disrupt these pathways, ultimately leading to a disruption in collagen and elastin networks.
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Affiliation(s)
- Jazli Aziz
- Faculty of Dentistry, University of Malaya, Kuala Lumpur, Malaysia
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11
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Qa'aty N, Vincent M, Wang Y, Wang A, Mitts TF, Hinek A. Synthetic ligands of the elastin receptor induce elastogenesis in human dermal fibroblasts via activation of their IGF-1 receptors. J Dermatol Sci 2015; 80:175-85. [PMID: 26475432 DOI: 10.1016/j.jdermsci.2015.10.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2015] [Revised: 08/19/2015] [Accepted: 10/01/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND We have previously reported that a mixture of peptides obtained after chemical or enzymatic degradation of bovine elastin, induced new elastogenesis in human skin. OBJECTIVE Now, we investigated the elastogenic potential of synthetic peptides mimicking the elastin-derived, VGVAPG sequence, IGVAPG sequence that we found in the rice bran, and a similar peptide, VGVTAG that we identified in the IGF-1-binding protein-1 (IGFBP-1). RESULTS We now demonstrate that treatment with each of these xGVxxG peptides (recognizable by the anti-elastin antibody), up-regulated the levels of elastin-encoding mRNA, tropoelastin protein, and the deposition of new elastic fibers in cultures of human dermal fibroblasts and in cultured explants of human skin. Importantly, we found that such induction of new elastogenesis may involve two parallel signaling pathways triggered after activation of IGF-1 receptor. In the first one, the xGVxxG peptides interact with the cell surface elastin receptor, thereby causing the downstream activation of the c-Src kinase and a consequent cross-activation of the adjacent IGF-1R, even in the absence of its principal ligand. In the second pathway their hydrophobic association with the N-terminal domain (VGVTAG) of the serum-derived IGFBP-1 induces conformational changes of this IGF-1 chaperone allowing for the release of its cargo and a consequent ligand-specific phosphorylation of IGF-1R. CONCLUSION We present a novel, clinically relevant mechanism in which products of partial degradation of dermal elastin may stimulate production of new elastic fibers by dermal fibroblasts. Our findings particularly encourage the use of biologically safe synthetic xGVxxG peptides for regeneration of the injured or aged human skin.
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Affiliation(s)
- Nour Qa'aty
- Physiology & Experimental Medicine Program, Hospital for Sick Children, ON, Canada; Institute of Medical Science, University of Toronto, ON, Canada
| | - Matthew Vincent
- Physiology & Experimental Medicine Program, Hospital for Sick Children, ON, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, ON, Canada
| | - Yanting Wang
- Physiology & Experimental Medicine Program, Hospital for Sick Children, ON, Canada
| | - Andrew Wang
- Physiology & Experimental Medicine Program, Hospital for Sick Children, ON, Canada
| | | | - Aleksander Hinek
- Physiology & Experimental Medicine Program, Hospital for Sick Children, ON, Canada; Institute of Medical Science, University of Toronto, ON, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, ON, Canada.
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12
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Hinek A, Kim HJ, Wang Y, Wang A, Mitts TF. Sodium L-ascorbate enhances elastic fibers deposition by fibroblasts from normal and pathologic human skin. J Dermatol Sci 2014; 75:173-82. [PMID: 25015208 DOI: 10.1016/j.jdermsci.2014.05.011] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2014] [Revised: 04/30/2014] [Accepted: 05/27/2014] [Indexed: 12/23/2022]
Abstract
BACKGROUND Vitamin C (L-ascorbic acid), a known enhancer of collagen deposition, has also been identified as an inhibitor of elastogenesis. OBJECTIVE Present studies explored whether and how the L-ascorbic acid derivative (+) sodium L-ascorbate (SA) would affect production of collagen and elastic fibers in cultures of fibroblasts derived from normal human skin and dermal fat, as well as in explants of normal human skin, stretch-marked skin and keloids. METHODS Effects of SA on the extracellular matrix production were assessed quantitatively by PCR analyses, western blots, biochemical assay of insoluble elastin and by immuno-histochemistry. We also evaluated effects of SA on production of the reactive oxygen species (ROS) and phosphorylation of IGF-I and insulin receptors. RESULTS SA, applied in 50-200 μM concentrations, stimulates production of both collagen and elastic fibers in all tested cultures. Moreover, combination of SA with a proline hydroxylase inhibitor induces a beneficial remodelling in explants of dermal scars, resulting in the inhibition of collagen deposition and induction of new elastogenesis. Importantly, we revealed that SA stimulates elastogenesis only after intracellular influx of non-oxidized ascorbate anions (facilitated by the sodium-dependent ascorbate transporter), that causes reduction of intracellular ROS, activation of c-Src tyrosine kinase and the enhancement of IGF-1-induced phosphorylation of the IGF-1 receptor that ultimately triggers elastogenic signalling pathway. CONCLUSION Our results endorse the use of this potent stimulator of collagen and elastin production in the treatment of wrinkled and stretch-marked skin. They also encourage inclusion of SA into therapeutic combinations with collagenogenesis inhibitors to prevent formation of dermal scars and keloids.
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Affiliation(s)
- Aleksander Hinek
- The Hospital for Sick Children, PGCRL, 686 Bay Street, Toronto, ON M5G 0A4, Canada; Department of Laboratory Medicine and Pathobiology, University of Toronto, Canada; Human Matrix Sciences, LLC, Visalia, CA, USA.
| | - Hyunjun J Kim
- The Hospital for Sick Children, PGCRL, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Yanting Wang
- The Hospital for Sick Children, PGCRL, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Andrew Wang
- The Hospital for Sick Children, PGCRL, 686 Bay Street, Toronto, ON M5G 0A4, Canada
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Mao S, Wang Y, Zhang M, Hinek A. Phytoestrogen, tanshinone IIA diminishes collagen deposition and stimulates new elastogenesis in cultures of human cardiac fibroblasts. Exp Cell Res 2014; 323:189-197. [PMID: 24525372 DOI: 10.1016/j.yexcr.2014.02.001] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2013] [Revised: 01/30/2014] [Accepted: 02/03/2014] [Indexed: 12/16/2022]
Abstract
It has been previously reported that oral or intra-peritoneal administration of tanshinone IIA can alleviate the ventricular hypertrophy and fibrosis that develops in rats after experimental cardiac infarction. Our present studies, performed on cultures of human cardiac fibroblasts, investigated the mechanism by which tanshinone IIA produces these beneficial effects. We found that treatment of cardiac fibroblasts with 0.1-10µM tanshinone IIA significantly inhibited their deposition of collagen I, while enhancing production of new elastic fibers. Moreover, both anti-collagenogenic and pro-elastogenic effects of tanshinone IIA occurred only after selective activation of the G protein-coupled estrogen receptor (GPER). This subsequently leads to initiation of the PKA/CREB phosphorylation pathway that inversely modulated transcription of collagen I and elastin genes. Interestingly, treatment of human cardiac fibroblasts with tanshinone IIA additionally up-regulated the production of the 67-kDa elastin binding protein, which facilitates tropoelastin secretion, and increased synthesis of lysyl oxidase, catalyzing cross-linkings of tropoelastin. Moreover, tanshinone IIA also caused up-regulation in the synthesis of collagenolytic MMP-1, but down-regulated levels of elastolytic MMP-2 and MMP-9. In summary, our data validate a novel mechanism in which tanshinone IIA, interacting with a non-classic estrogen receptor, maintains the proper balance between the net deposition of collagen and elastin, allowing for optimal durability and resiliency of the newly deposited matrix.
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Affiliation(s)
- Shuai Mao
- Physiology & Experimental Medicine Program, Heart Center, Hospital for Sick Children, 555 University Avenue, Ontario, Toronto, QJ;Canada M5G 1X8; Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada; Second Clinical Medical College, Guangzhou University of Traditional Chinese Medicine, Guangzhou, China; Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou, China
| | - Yanting Wang
- Physiology & Experimental Medicine Program, Heart Center, Hospital for Sick Children, 555 University Avenue, Ontario, Toronto, QJ;Canada M5G 1X8
| | - Minzhou Zhang
- Second Clinical Medical College, Guangzhou University of Traditional Chinese Medicine, Guangzhou, China; Guangdong Provincial Hospital of Traditional Chinese Medicine, Guangzhou, China
| | - Aleksander Hinek
- Physiology & Experimental Medicine Program, Heart Center, Hospital for Sick Children, 555 University Avenue, Ontario, Toronto, QJ;Canada M5G 1X8; Department of Laboratory Medicine and Pathobiology, University of Toronto, Ontario, Canada.
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14
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Liu S, Xie Z, Daugherty A, Cassis LA, Pearson KJ, Gong MC, Guo Z. Mineralocorticoid receptor agonists induce mouse aortic aneurysm formation and rupture in the presence of high salt. Arterioscler Thromb Vasc Biol 2013; 33:1568-79. [PMID: 23661677 PMCID: PMC3707291 DOI: 10.1161/atvbaha.112.300820] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2012] [Accepted: 04/24/2013] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Elevated plasma aldosterone concentrations in patients have been linked to a spectrum of cardiovascular diseases. Mineralocorticoid receptor antagonists provide additional benefits in patients with heart failure. However, whether aldosterone and the mineralocorticoid receptor are involved in aortic aneurysm is unknown. APPROACH AND RESULTS We report that administration of deoxycorticosterone acetate (DOCA) and salt or aldosterone and salt, but not DOCA or salt alone, to C57BL/6 male mice induced abdominal and thoracic aortic aneurysm formation and rupture in an age-dependent manner. DOCA and salt- or aldosterone and salt-induced aortic aneurysm mimicked human aortic aneurysm with respect to elastin degradation, inflammatory cell infiltration, smooth muscle cell degeneration and apoptosis, and oxidative stress. Aortic aneurysm formation did not correlate with the increase in blood pressure induced by DOCA and salt. Systemic administration of the angiotensin-converting enzyme inhibitor, enalapril, or angiotensin type 1 receptor antagonist, losartan, did not affect DOCA and salt-induced aortic aneurysm. In contrast, the mineralocorticoid receptor antagonists, spironolactone or eplerenone, significantly attenuated DOCA and salt- or aldosterone and salt-induced aortic aneurysm. CONCLUSIONS The current study describes a novel aortic aneurysm animal model induced by mineralocorticoid receptor agonist and high salt, and reveals a previously unrecognized but potentially significant role of aldosterone in the pathogenesis of aortic aneurysm. These findings imply that mineralocorticoid receptor antagonists may be effective in the treatment of some aortic aneurysms.
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MESH Headings
- Aldosterone/blood
- Angiotensin II Type 1 Receptor Blockers/administration & dosage
- Angiotensin-Converting Enzyme Inhibitors/administration & dosage
- Animals
- Aorta/drug effects
- Aorta/metabolism
- Aorta/pathology
- Aortic Aneurysm, Abdominal/chemically induced
- Aortic Aneurysm, Abdominal/drug therapy
- Aortic Aneurysm, Abdominal/etiology
- Aortic Aneurysm, Abdominal/metabolism
- Aortic Aneurysm, Abdominal/pathology
- Aortic Aneurysm, Abdominal/physiopathology
- Aortic Aneurysm, Thoracic/chemically induced
- Aortic Aneurysm, Thoracic/drug therapy
- Aortic Aneurysm, Thoracic/etiology
- Aortic Aneurysm, Thoracic/metabolism
- Aortic Aneurysm, Thoracic/pathology
- Aortic Aneurysm, Thoracic/physiopathology
- Aortic Rupture/chemically induced
- Aortic Rupture/drug therapy
- Aortic Rupture/etiology
- Aortic Rupture/metabolism
- Aortic Rupture/pathology
- Aortic Rupture/physiopathology
- Apoptosis
- Blood Pressure
- Desoxycorticosterone
- Disease Models, Animal
- Elastin/metabolism
- Enalapril/administration & dosage
- Eplerenone
- Losartan/administration & dosage
- Male
- Mice
- Mice, Inbred C57BL
- Mineralocorticoid Receptor Antagonists/administration & dosage
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Oxidative Stress
- Receptors, Mineralocorticoid/agonists
- Receptors, Mineralocorticoid/metabolism
- Sodium Chloride, Dietary
- Spironolactone/administration & dosage
- Spironolactone/analogs & derivatives
- Time Factors
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Affiliation(s)
- Shu Liu
- Department of Internal Medicine, University of Kentucky, Lexington, KY 40536
| | - Zhongwen Xie
- Department of Physiology, University of Kentucky, Lexington, KY 40536
| | - Alan Daugherty
- Department of Internal Medicine, University of Kentucky, Lexington, KY 40536
- The Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY 40536
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY 40536
| | - Lisa A. Cassis
- The Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY 40536
- Department of Molecular and Biomedical Pharmacology, University of Kentucky, Lexington, KY 40536
| | - Kevin J. Pearson
- The Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY 40536
| | - Ming C. Gong
- Department of Physiology, University of Kentucky, Lexington, KY 40536
- The Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY 40536
| | - Zhenheng Guo
- Department of Internal Medicine, University of Kentucky, Lexington, KY 40536
- The Graduate Center for Nutritional Sciences, University of Kentucky, Lexington, KY 40536
- Saha Cardiovascular Research Center, University of Kentucky, Lexington, KY 40536
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Affiliation(s)
- R. Thomas Collins
- From the Arkansas Children’s Hospital and University of Arkansas for Medical Sciences, Little Rock, AR
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16
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Abstract
Underlying the dynamic regulation of tropoelastin expression and elastin formation in development and disease are transcriptional and post-transcriptional mechanisms that have been the focus of much research. Of particular importance is the cytokine-governed elastin regulatory axis in which the pro-elastogenic activities of transforming growth factor β-1 (TGFβ1) and insulin-like growth factor-I (IGF-I) are opposed by anti-elastogenic activities of basic fibroblast growth factor (bFGF/FGF-2), heparin-binding epidermal growth factor-like growth factor (HB-EGF), EGF, PDGF-BB, TGFα, tumor necrosis factor-alpha (TNF-α), interleukin (IL)-1β and noncanonical TGFβ1 signaling. A key mechanistic feature of the regulatory axis is that cytokines influence elastin formation through effects on the cell cycle involving control of cyclin-cyclin dependent kinase complexes and activation of the Ras/MEK/ERK signaling pathway. In this article we provide an overview of the major cytokines/growth factors that modulate elastogenesis and describe the underlying molecular mechanisms for their action on elastin production.
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Affiliation(s)
- Erin P Sproul
- Department of Regenerative Medicine and Cell Biology, Medical University of South Carolina, Charleston, SC 29425, USA.
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17
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Li X, Qi Y, Li Y, Zhang S, Guo S, Chu S, Gao P, Zhu D, Wu Z, Lu L, Shen W, Jia N, Niu W. Impact of mineralocorticoid receptor antagonists on changes in cardiac structure and function of left ventricular dysfunction: a meta-analysis of randomized controlled trials. Circ Heart Fail 2013; 6:156-65. [PMID: 23400891 DOI: 10.1161/circheartfailure.112.000074] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
BACKGROUND A comprehensive evaluation of the benefits of mineralocorticoid receptor antagonists on cardiac remodeling is lacking. We aimed to evaluate the impact of mineralocorticoid receptor antagonists on changes in cardiac structure and function of left ventricular dysfunction. METHODS AND RESULTS Articles were identified by online searches in PubMed, EMBASE, Cochrane, and ClinicalTrials.gov databases before June 2012, by hand searches of reviews and relevant journals, and by contact with the authors. Qualified articles were restricted to randomized controlled trials. There were, respectively, 12, 4, and 3 qualified trials that randomized 572, 647, and 407 patients to spironolactone, canrenoate, and eplerenone, and 531, 655, and 395 patients to placebo or active treatment, respectively. Overall, under mineralocorticoid receptor antagonist treatment there was improvement in left ventricular ejection fraction (weighted mean difference, 2.97; 95% confidence interval [95% CI], 2.26-3.67; P<0.0005), left ventricular end-systolic and end-diastolic volume index (weighted mean difference, -5.64; 95% CI, -7.94 to -3.34; P<0.0005 and weighted mean difference, -7.46; 95% CI, -11.63 to -3.3; P<0.0005), serum amino-terminal peptide of procollagen type-III (weighted mean difference, -1.12; 95% CI, -1.49 to -0.74; P<0.0005), B-type natriuretic peptide (weighted mean difference, -67.06; 95% CI, -91.24 to -42.88; P<0.0005), peak velocities of early mitral inflow (E; weighted mean difference, -9.57; 95% CI, -12.98 to -6.17; P<0.0005), and E wave deceleration time (weighted mean difference, 7.08; 95% CI, 4.07-10.09; P<0.0005). There was low probability of heterogeneity and publication bias. CONCLUSIONS Our findings demonstrate that mineralocorticoid receptor antagonist treatment may exert beneficial effects on the reversal of cardiac remodeling and improvement of left ventricular function.
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Affiliation(s)
- Xiaobo Li
- State Key Laboratory of Medical Genomics, Ruijin Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
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Hypertension caused by primary hyperaldosteronism: increased heart damage and cardiovascular risk. Rev Esp Cardiol 2012; 66:47-52. [PMID: 23153688 DOI: 10.1016/j.recesp.2012.07.025] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2012] [Accepted: 07/15/2012] [Indexed: 01/07/2023]
Abstract
INTRODUCTION AND OBJECTIVES Primary hyperaldosteronism is the most common cause of secondary hypertension. Elevated aldosterone levels cause heart damage and increase cardiovascular morbidity and mortality. Early diagnosis could change the course of this entity. The objective of this report was to study the clinical characteristics, cardiac damage and cardiovascular risk associated with primary hyperaldosteronism. METHODS We studied 157 patients with this diagnosis. We analyzed the reason for etiological investigation, and the routinely performed tests, including echocardiography. We used a cohort of 720 essential hypertensive patients followed in our unit for comparison. RESULTS Compared with essential hypertensive patients, those with hyperaldosteronism were younger (56.9 [11.7] years vs 60 [14.4] years; P<.001), had higher blood pressure prior to the etiological diagnosis (136 [20.6] mmHg vs 156 [23.2] mmHg), more frequently had a family history of early cardiovascular disease (25.5% vs 2.2%; P<.001), and had a higher prevalence of concentric left ventricular hypertrophy (69% vs 25.7%) and higher cardiovascular risk. Specific treatment resulted in optimal control of systolic and diastolic blood pressures (from 150.7 [23.0] mmHg and 86.15 [14.07] mmHg to 12.69 [15.3] mmHg and 76.34 [9.7] mmHg, respectively). We suspected the presence of hyperaldosteronism because of resistant hypertension (33.1%), hypokalemia (38.2%), and hypertensive crises (12.7%). Only 4.6% of these patients had been referred from primary care with a suspected diagnosis of hyperaldosteronism. CONCLUSIONS Hyperaldosteronism should be suspected in cases of resistant hypertension, hypokalemia and hypertensive crises. The diagnosis of hyperaldosteronism allows better blood pressure control. The most prevalent target organ damage is left ventricular hypertrophy.
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Calvier L, Miana M, Reboul P, Cachofeiro V, Martinez-Martinez E, de Boer RA, Poirier F, Lacolley P, Zannad F, Rossignol P, López-Andrés N. Galectin-3 mediates aldosterone-induced vascular fibrosis. Arterioscler Thromb Vasc Biol 2012; 33:67-75. [PMID: 23117656 DOI: 10.1161/atvbaha.112.300569] [Citation(s) in RCA: 259] [Impact Index Per Article: 21.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Aldosterone (Aldo) is involved in arterial stiffness and heart failure, but the mechanisms have remained unclear. Galectin-3 (Gal-3), a β-galactoside-binding lectin, plays an important role in inflammation, fibrosis, and heart failure. We investigated here whether Gal-3 is involved in Aldo-induced vascular fibrosis. METHODS AND RESULTS In rat vascular smooth muscle cells Gal-3 overexpression enhanced specifically collagen type I synthesis. Moreover Gal-3 inhibition by modified citrus pectin or small interfering RNA blocked Aldo-induced collagen type I synthesis. Rats were treated with Aldo-salt combined with spironolactone or modified citrus pectin for 3 weeks. Hypertensive Aldo-treated rats presented vascular hypertrophy, inflammation, fibrosis, and increased aortic Gal-3 expression. Spironolactone or modified citrus pectin treatment reversed all the above effects. Wild-type and Gal-3 knock-out mice were treated with Aldo for 6 hours or 3 weeks. Aldo increased aortic Gal-3 expression, inflammation, and collagen type I in wild-type mice at both the short- and the long-term, whereas no changes occurred in Gal-3 knock-out mice. CONCLUSIONS Our data indicate that Gal-3 is required for inflammatory and fibrotic responses to Aldo in vascular smooth muscle cells in vitro and in vivo, suggesting a key role for Gal-3 in vascular fibrosis.
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Affiliation(s)
- Laurent Calvier
- Inserm, U961, Faculty of Medicine, Université de Lorraine, Vandoeuvre-lès-Nancy, France
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20
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Lin S, Mequanint K. The role of Ras-ERK-IL-1β signaling pathway in upregulation of elastin expression by human coronary artery smooth muscle cells cultured in 3D scaffolds. Biomaterials 2012; 33:7047-56. [PMID: 22796164 DOI: 10.1016/j.biomaterials.2012.06.044] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2012] [Accepted: 06/22/2012] [Indexed: 12/27/2022]
Abstract
Incorporation of endogenous elastin, a key structural component of the vascular extracellular matrix (ECM), is an important requirement for engineered vascular tissues. In addition to providing elastic recoil of the tissue, elastin influences cell function and promotes cell signaling by interacting with specific cell surface receptors. Although progress has been made in understanding the mechanisms of in vivo elastin expression and incorporation into fibers, it is notably absent from engineered vessels. Recently we showed that the three-dimensional (3D) scaffold topography was able to upregulate elastin synthesis by human coronary artery smooth muscle cells (HCASMC). The present study was undertaken to explore the molecular mechanisms responsible for 3D scaffold-induced elastin gene transcription. Here, we show several lines of evidence that signal transduction pathway leading to elastin gene expression by HCASMC cultured in synthetic 3D scaffolds to be strikingly different from two-dimensional (2D) surfaces. In 3D scaffolds, α5β1 integrin engagement by HCASMC was significantly reduced and the putative focal adhesion kinase (FAK) was poorly phosphorylated concomitant with FAK and protein tyrosine kinase Pyk2 downregulation. FAK-associated adhesion proteins vinculin and paxillin were also significantly downregulated by the 3D scaffold topography. Furthermore, contrary to 2D cultures, HCASMC cultured on 3D scaffolds had no Rho activation suggesting pliability of the elastomeric synthetic scaffold. Elastin expression in 3D cultures followed Ras-ERK1/2 signal transduction pathway and was further dependent on endogenously expressed interleukin-1β (IL-1β). Blocking of ERK1/2 activation using a pharmacologic inhibitor reduced both elastin and IL-1β gene expressions in 3D cultures. Transient transfection of IL-1β using siRNA, however, did not affect ERK1/2 activation but downregulated elastin gene expression suggesting that endogenous IL-1β acts downstream from ERK1/2. Taken together, results of the present study provide evidence that endogenous IL-1β play a role in elastin gene upregulation and, that this upregulation is mediated by the Ras-ERK1/2 pathway in 3D cultures.
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Affiliation(s)
- Shigang Lin
- Department of Chemical and Biochemical Engineering, Faculty of Engineering, The University of Western Ontario, London, Ontario, Canada
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Lehman A, Mattman A, Sin D, Pare P, Zong Z, d'Azzo A, Campos Y, Sirrs S, Hinek A. Emphysema in an adult with galactosialidosis linked to a defect in primary elastic fiber assembly. Mol Genet Metab 2012; 106:99-103. [PMID: 22386972 DOI: 10.1016/j.ymgme.2012.02.004] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/06/2012] [Revised: 02/02/2012] [Accepted: 02/02/2012] [Indexed: 01/04/2023]
Abstract
Galactosialidosis is a lysosomal storage disorder caused by loss of function of protective protein cathepsin A, which leads to secondary deficiencies of β-galactosidase and neuraminidase-1. Emphysema has not been previously reported as a possible complication of this disorder, but we now describe this condition in a 41-year-old, non-smoking male. Our patient did not display deficiency in α-1-antitrypsin, the most common cause of emphysema in non-smokers, which brings about disseminated elastolysis. We therefore hypothesized that loss of cathepsin A activity was responsible because of previously published evidence showing it is prerequisite for normal elastogenesis. We now present experimental evidence to support this theory by demonstrating impaired primary elastogenesis in cultures of dermal fibroblasts from our patient. The obtained data further endorse our previous finding that functional integrity of the cell surface-targeted molecular complex of cathepsin A, neuraminidase-1 and the elastin-binding protein (spliced variant of β-galactosidase) is prerequisite for the normal assembly of elastic fibers. Importantly, we also found that elastic fiber production was increased after exposure either to losartan, spironolactone, or dexamethasone. Of immediate clinical relevance, our data suggest that surviving patients with galactosialidosis should have periodic assessment of their pulmonary function. We also encourage further experimental exploration of therapeutic potential of the afore-mentioned elastogenesis-stimulating drugs for the alleviation of pathological processes in galactosialidosis that could be mechanistically linked to impaired deposition of elastic fibers.
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Affiliation(s)
- Anna Lehman
- Department of Medical Genetics and the Child and Family Research Institute, University of British Columbia, Vancouver, Canada.
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Insulin induces production of new elastin in cultures of human aortic smooth muscle cells. THE AMERICAN JOURNAL OF PATHOLOGY 2012; 180:715-26. [PMID: 22236491 DOI: 10.1016/j.ajpath.2011.10.022] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Revised: 09/27/2011] [Accepted: 10/23/2011] [Indexed: 11/23/2022]
Abstract
Diabetes mellitus accelerates atherosclerotic progression, peripheral angiopathy development, and arterial hypertension, all of which are associated with elastic fiber disease. However, the potential mechanistic links between insulin deficiency and impaired elastogenesis in diabetes have not been explored. Results of the present study reveal that insulin administered in therapeutically relevant concentrations (0.5 to 10 nmol/L) selectively stimulates formation of new elastic fibers in cultures of human aortic smooth muscle cells. These concentrations of insulin neither up-regulate collagen type I and fibronectin deposition nor stimulate cellular proliferation. Further, the elastogenic effect of insulin occurs after insulin receptor activation, which triggers the PI3K downstream signaling pathway and activates elastin gene transcription. In addition, the promoter region of the human elastin gene contains the CAAATAA sequence, consistent with the FoxO-recognized element, and the genomic effects of insulin occur after removal of the FoxO1 transcriptional inhibitor from the FoxO-recognized element in the elastin gene promoter. In addition, insulin signaling facilitates the association of tropoelastin with its specific 67-kDa elastin-binding protein/spliced form of β-galactosidase chaperone, enhancing secretion. These results are crucial to understanding of the molecular and cellular mechanisms of diabetes-associated vascular disease, and, in particular, endorse use of insulin therapy for treatment of atherosclerotic lesions in patients with type 1 diabetes, in which induction of new elastic fibers would mechanically stabilize the developing plaques and prevent arterial occlusions.
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Abstract
High plasmatic levels of aldosterone cause hypertension and contribute to progressive organ damage to the heart, vasculature, and kidneys. Recent studies have demonstrated a role for the immune system in these pathological processes. Aldosterone promotes an inflammatory state characterized by vascular infiltration of immune cells, reactive oxidative stress, and proinflammatory cytokine production. Further, cells of the adaptive immune system, such as T cells, seem to participate in the genesis of mineralocorticoid hormone-induced hypertension. In addition, the observation that aldosterone can promote CD4⁺ T-cell activation and Th17 polarization suggests that this hormone could contribute to the onset of autoimmunity. Here we discuss recent evidence supporting a significant involvement of the immune system, especially adaptive immunity, in the genesis of hypertension and organ damage induced by primary aldosteronism. In addition, possible new therapeutic approaches consisting of immunomodulator drugs to control exacerbated immune responses triggered by elevated aldosterone concentrations will be described.
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Diastolic heart failure: progress, treatment challenges, and prevention. Can J Cardiol 2011; 27:302-10. [PMID: 21601770 DOI: 10.1016/j.cjca.2011.02.008] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2011] [Accepted: 02/13/2011] [Indexed: 01/27/2023] Open
Abstract
Diastolic heart failure (DHF) is an important entity, the significance of which is increasingly recognized. This report examines the available evidence regarding the role, significance, and mechanisms of DHF. Epidemiologic studies have documented the rising burden of DHF, and experimental data are revealing the unique mechanisms distinguishing it from systolic heart failure. Despite controversies on the definition of DHF, or heart failure with preserved ejection fraction, standardized clinical criteria with supplementary imaging and structural data have identified DHF as a distinct pathophysiological entity. The mechanisms underlying DHF include abnormal matrix dynamics, altered myocyte cytoskeleton, and impaired active relaxation. The commonly held belief that survival of patients with DHF is better than that of patients with systolic heart failure has been challenged by updated data. The heterogeneous etiologies or risk factors for the condition include aging, diabetes, hypertension, and ischemia, making a common diagnostic or treatment pathway difficult. Novel therapeutic targets that address the pathophysiology of this disease are under consideration, although there are no proven therapies for DHF to date. Exacerbating factors include volume and sodium indiscretion, arrhythmias, ischemia, and comorbidities. Strategies to ameliorate or to obviate these precipitating factors are most effective in preventing DHF and its exacerbations. Meanwhile, prevention of DHF through appropriate and aggressive risk factor identification and management must remain the cornerstone of clinical intervention.
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Aldosterone induces arterial stiffness in absence of oxidative stress and endothelial dysfunction. J Hypertens 2010; 27:2192-200. [PMID: 19654560 DOI: 10.1097/hjh.0b013e328330a963] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
AIMS Monocyte/macrophages participate in inflammatory responses that may play an important role in mineralocorticoid-induced vascular damage. We hypothesized that monocyte/macrophages modulate aldosterone effects on oxidative stress, endothelial function, and ultimately vascular stiffness. METHODS Adult heterozygous osteopetrotic (Op/+) and wild-type mice were infused with aldosterone (600 microg/kg per day s.c. with Alzet osmotic minipumps) and received 1% NaCl in drinking water or were infused with vehicle for 14 days. Blood pressure was measured by the tail-cuff method. Endothelial function was determined in mesenteric arteries on a pressurized myograph by the response to acetylcholine following norepinephrine preconstriction. Extracellular matrix was quantified by immunohistochemistry, reactive oxygen species by image analysis of dihydroethidium staining, and reduced nicotinamide adenine dinucleotide phosphate oxidase activity by chemiluminescence. RESULTS Body weight and blood pressure did not change following aldosterone treatment. Aldosterone induced stiffening of resistance arteries among all treated animals, as reflected by decreased sum of squares of strain from 2.07 +/- 0.15 to 1.54 +/- 0.29 in wild type, and from 2.68 +/- 0.28 to 2.04 +/- 0.15 in Op/+, and increased fibronectin-to-elastin ratio from 1.12 +/- 0.40 to 4.52 +/- 0.47 and 0.92 +/- 0.47 to 5.26 +/- 0.88, respectively. Endothelial function was impaired and reactive oxygen species increased only in aldosterone-treated wild-type mice. Reduced nicotinamide adenine dinucleotide phosphate oxidase activity was unaffected. CONCLUSION Monocyte/macrophage deficiency in Op/+ mice results in absence of aldosterone-induced oxidative stress and endothelial dysfunction, but does not play a role in aldosterone-induced arterial stiffness. Thus, although monocyte/macrophage-mediated inflammatory responses play a role in oxidative stress and endothelial dysfunction, vascular stiffening in response to aldosterone may be independent of inflammation.
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Cascella T, Radhakrishnan Y, Maile LA, Busby WH, Gollahon K, Colao A, Clemmons DR. Aldosterone enhances IGF-I-mediated signaling and biological function in vascular smooth muscle cells. Endocrinology 2010; 151:5851-64. [PMID: 20881255 PMCID: PMC2999491 DOI: 10.1210/en.2010-0350] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
The IGF-I pathway and renin-angiotensin-aldosterone axis are both involved in the pathogenesis of hypertension and atherosclerosis, but no information is available about IGF-I and aldosterone interaction or their potential synergistic effects in vascular smooth muscle cells (VSMCs). The aims of this study were to investigate whether aldosterone influences IGF-I signaling and to determine the mechanism(s) by which aldosterone affects IGF-I function. Aldosterone resulted in significant increases in the Akt (1.87 ± 0.24, P < 0.001), MAPK (1.78 ± 0.13, P < 0.001), p70S6kinase (1.92 ± 0.15, P < 0.001), IGF-I receptor (1.69 ± 0.05, P < 0.01), and insulin receptor substrate-1 (1.7 ± 0.04, P < 0.01) (fold increase, mean ± SEM, n = 3) phosphorylation responses to IGF-I compared with IGF-I treatment alone. There were also significant increases in VSMC proliferation, migration, and protein synthesis (1.63 ± 0.03-, 1.56 ± 0.08-, and 1.51 ± 0.04-fold increases compared with IGF-I alone, respectively, n = 3, P < 0.001). Aldosterone induced osteopontin (OPN) mRNA expression and activation of αVβ3-integrin as well as an increase in the synthesis of IGF-I receptor. The enhancing effects of aldosterone were inhibited by eplerenone (10 μmol/liter), actinomycin-D (20 nmol/liter), and an anti-αVβ3-integrin antibody that blocks OPN binding. The antioxidant N-acetylcysteine (2 mmol/liter) completely inhibited the ability of aldosterone to induce any of these changes. In conclusion, our results show that aldosterone enhances IGF-I signaling and biological actions in VSMCs through induction of OPN followed by its subsequent activation of the αVβ3-integrin and by increasing IGF-I receptor. These changes are mediated in part through increased oxidative stress. The findings suggest a new mechanism by which aldosterone could accelerate the development of atherosclerosis.
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Affiliation(s)
- Teresa Cascella
- Department of Medicine, University of North Carolina, Chapel Hill, North Carolina 27599, USA
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27
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Aldosterone and mineralocorticoid receptor antagonists modulate elastin and collagen deposition in human skin. J Invest Dermatol 2010; 130:2396-406. [PMID: 20535129 DOI: 10.1038/jid.2010.155] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
We have shown that the steroid hormone aldosterone, recognized for its action on the kidney and the cardiovascular system, also modulates deposition of extracellular matrix in human skin. We have shown that treatment of primary cultures of normal skin fibroblasts with aldosterone (10 n-1 μM), in addition to stimulation of collagen type I expression, induces elastin gene expression and elastic fiber deposition. We have further shown that the elastogenic effect of aldosterone, which can be enhanced in the presence of mineralocorticoid receptor (MR) antagonists spironolactone and eplerenone, is executed in a MR-independent manner via amplification of IGF-I receptor-mediated signaling. Because aldosterone applied alone stimulates both collagen and elastin deposition in cultures of fibroblasts and in cultures of skin explants derived from dermal stretch marks, we postulate that this steroid should be used in the treatment of damaged skin that loses its volume and elasticity. Moreover, aldosterone applied in conjunction with spironolactone or eplerenone induces matrix remodeling and exclusively enhances elastogenesis in cultures of fibroblasts and explants derived from dermal scars and keloids. We therefore propose that intra-lesional injection of these factors should be considered in therapy for disfiguring dermal lesions and especially in prevention of their recurrence after surgical excision.
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Vinson GP, Coghlan JP. Expanding view of aldosterone action, with an emphasis on rapid action. Clin Exp Pharmacol Physiol 2010; 37:410-6. [PMID: 20409082 DOI: 10.1111/j.1440-1681.2010.05352.x] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Affiliation(s)
- Gavin P Vinson
- School of Biological and Chemical Sciences, Queen Mary University of London, London, UK
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Bunda S, Wang Y, Mitts TF, Liu P, Arab S, Arabkhari M, Hinek A. Aldosterone stimulates elastogenesis in cardiac fibroblasts via mineralocorticoid receptor-independent action involving the consecutive activation of Galpha13, c-Src, the insulin-like growth factor-I receptor, and phosphatidylinositol 3-kinase/Akt. J Biol Chem 2009; 284:16633-16647. [PMID: 19372600 PMCID: PMC2713569 DOI: 10.1074/jbc.m109.008748] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2009] [Revised: 04/15/2009] [Indexed: 11/06/2022] Open
Abstract
We previously demonstrated that aldosterone, which stimulates collagen production through the mineralocorticoid receptor (MR)-dependent pathway, also induces elastogenesis via a parallel MR-independent mechanism involving insulin-like growth factor-I receptor (IGF-IR) signaling. The present study provides a more detailed explanation of this signaling pathway. Our data demonstrate that small interfering RNA-driven elimination of MR in cardiac fibroblasts does not inhibit aldosterone-induced IGF-IR phosphorylation and subsequent increase in elastin production. These results exclude the involvement of the MR in aldosterone-induced increases in elastin production. Results of further experiments aimed at identifying the upstream signaling component(s) that might be activated by aldosterone also eliminate the putative involvement of pertussis toxin-sensitive Galphai proteins, which have previously been shown to be responsible for some MR-independent effects of aldosterone. Instead, we found that small interfering RNA-dependent elimination of another heterotrimeric G protein, Galpha13, eliminates aldosterone-induced elastogenesis. We further demonstrate that aldosterone first engages Galpha13 and then promotes its transient interaction with c-Src, which constitutes a prerequisite step for aldosterone-dependent activation of the IGF-IR and propagation of consecutive downstream elastogenic signaling involving phosphatidylinositol 3-kinase/Akt. In summary, the data we present reveal new details of an MR-independent cellular signaling pathway through which aldosterone stimulates elastogenesis in human cardiac fibroblasts.
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Affiliation(s)
- Severa Bunda
- From the Physiology and Experimental Medicine Program, The Hospital for Sick Children, Department of Laboratory Medicine and Pathobiology, Toronto, Ontario M5G 1X8, Canada
| | - Yanting Wang
- From the Physiology and Experimental Medicine Program, The Hospital for Sick Children, Department of Laboratory Medicine and Pathobiology, Toronto, Ontario M5G 1X8, Canada
| | - Thomas F Mitts
- From the Physiology and Experimental Medicine Program, The Hospital for Sick Children, Department of Laboratory Medicine and Pathobiology, Toronto, Ontario M5G 1X8, Canada
| | - Peter Liu
- Heart and Stroke/Richard Lewar Centre for Excellence, University of Toronto, Toronto, Ontario M5G 1X8, Canada; Toronto General Hospital/University Health Network, Toronto, Ontario M5G 1X8, Canada
| | - Sara Arab
- Toronto General Hospital/University Health Network, Toronto, Ontario M5G 1X8, Canada
| | - Majid Arabkhari
- From the Physiology and Experimental Medicine Program, The Hospital for Sick Children, Department of Laboratory Medicine and Pathobiology, Toronto, Ontario M5G 1X8, Canada
| | - Aleksander Hinek
- From the Physiology and Experimental Medicine Program, The Hospital for Sick Children, Department of Laboratory Medicine and Pathobiology, Toronto, Ontario M5G 1X8, Canada; Heart and Stroke/Richard Lewar Centre for Excellence, University of Toronto, Toronto, Ontario M5G 1X8, Canada.
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Lee S, Chanoit G, McIntosh R, Zvara DA, Xu Z. Molecular mechanism underlying Akt activation in zinc-induced cardioprotection. Am J Physiol Heart Circ Physiol 2009; 297:H569-75. [PMID: 19525380 DOI: 10.1152/ajpheart.00293.2009] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Our previous study demonstrated that zinc prevents cardiac reperfusion injury by targeting the mitochondrial permeability transition pore (mPTP) via Akt and glycogen synthetase kinase 3beta (GSK-3beta). We aimed to address the mechanism by which zinc activates Akt. Treatment of H9c2 cells with ZnCl(2) (10 microM) in the presence of the zinc ionophore pyrithione (4 microM) for 20 min enhanced Akt phosphorylation (Ser(473)), indicating that zinc can rapidly activate Akt. Zinc did not alter either phosphatase and tensin homolog deleted on chromosome 10 (PTEN) phosphorylation and total PTEN protein levels or PTEN oxidation, implying that PTEN may not play a role in the action of zinc. However, zinc-induced Akt phosphorylation was blocked by both the nonselective receptor tyrosine kinase (RTK) inhibitor genistein and the selective insulin-like growth factor-1 RTK (IGF-1RTK) inhibitor AG1024, indicating that zinc activates Akt via IGF-1RTK. Zinc-induced phosphorylation of protein tyrosine and Ser/Thr was also abolished by AG1024. In addition, zinc markedly enhanced phosphorylation of IGF-1 receptor (IGF-1R), which was again reversed by genistein and AG1024. A confocal imaging study revealed that AG1024 abolished the preventive effect of zinc on oxidant-induced mPTP opening, confirming that IGF-1RTK plays a role in zinc-induced cardioprotection. Furthermore, zinc decreased the activity of protein phosphatase 2A (PP2A), a major protein Ser/Thr phosphatase, implying that protein Ser/Thr phosphatases may also play a role in the action of zinc on Akt activity. Taken together, these findings demonstrate that exogenous zinc activates Akt via IGF-1RTK and prevents the mPTP opening in cardiac cells. Inactivation of Ser/Thr protein phosphatases may also contribute to zinc-induced Akt activation.
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Affiliation(s)
- Sungryul Lee
- Department of Anesthesiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina 27599, USA
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Tsugita M, Iwasaki Y, Nishiyama M, Taguchi T, Shinahara M, Taniguchi Y, Kambayashi M, Nishiyama A, Gomez-Sanchez CE, Terada Y, Hashimoto K. Glucocorticoid receptor plays an indispensable role in mineralocorticoid receptor-dependent transcription in GR-deficient BE(2)C and T84 cells in vitro. Mol Cell Endocrinol 2009; 302:18-25. [PMID: 19146914 DOI: 10.1016/j.mce.2008.12.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/26/2008] [Revised: 10/26/2008] [Accepted: 12/04/2008] [Indexed: 10/21/2022]
Abstract
The mineralocorticoid receptor (MR) plays an important functional role in the central nervous system; however, the molecular mechanism of MR-dependent gene expression is not entirely clear. In this study, we examined the MR-dependent transcriptional regulation using a human neuronal cell line BE(2)C and an MR/GR-dependent reporter gene (HRE-luciferase) in vitro. Western blot analysis revealed that the cell line expresses MR but not glucocorticoid receptor (GR). In this experimental condition, unexpectedly, the MR-specific ligand aldosterone did not induce HRE-dependent transcription in a native or MR-overexpressed condition, whereas significant transcriptional induction by aldosterone was observed when the GR was co-expressed. The effect of aldosterone was completely inhibited by the MR antagonist spironolactone, indicating an MR-dependent effect. We found similar results in T84 colonic cells expressing neither MR nor GR, such that the aldosterone effect was obtained only when both receptors were co-expressed. The co-operative effect of GR was not obvious with the dimer-deficient mutant GR. Finally, the above findings were reproducible with different promoters containing HRE such as ENaC and MMTV. These results suggest that GR plays an indispensable role in MR-dependent transcription, possibly by forming a MR/GR heterodimer or by acting as a co-activator of MR/MR homodimer.
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Affiliation(s)
- Makoto Tsugita
- Department of Endocrinology, Metabolism, and Nephrology, Kochi Medical School, Kochi University, Kohasu, Oko-cho, Nankoku 783-8505, Japan
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Actions of aldosterone in the cardiovascular system: the good, the bad, and the ugly? Pflugers Arch 2008; 458:231-46. [DOI: 10.1007/s00424-008-0616-0] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Accepted: 10/30/2008] [Indexed: 01/11/2023]
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