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Crofton AE, Kovacs SL, Stern JA. Subvalvular Aortic Stenosis: Learning From Human and Canine Clinical Research. Cardiol Res 2023; 14:319-333. [PMID: 37936623 PMCID: PMC10627371 DOI: 10.14740/cr1547] [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: 07/12/2023] [Accepted: 10/03/2023] [Indexed: 11/09/2023] Open
Abstract
Subvalvular aortic stenosis (SAS) is the most common congenital heart disease (CHD) in dogs and is also prevalent in human children. A fibrous ridge below the aortic valve narrows the left ventricular outflow tract (LVOT) and increases blood flow velocity, leading to devastating side effects in diseased patients. Due to the similarities in presentation, anatomy, pathophysiology, cardiac development, genomics, and environment between humans and dogs, canine SAS patients represent a critical translational model of human SAS. Potential adverse outcomes of SAS include arrhythmias, left-sided congestive heart failure, endocarditis, exercise intolerance, syncope, and sudden cardiac death. The greatest divergence between canine and human SAS clinical research has been the standard of care regarding treatment of these outcomes, with pharmacological intervention dominating best practices in veterinary medicine and surgical intervention comprising the standard practice for human SAS patients. Regardless of the species, the field has yet to identify a treatment option to prevent disease progression or permanently remove the fibrous ridge, but historical leaps in SAS research support a continued translational approach as the most promising method for achieving this goal.
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Affiliation(s)
- Amanda E. Crofton
- Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA
| | - Samantha L. Kovacs
- Veterinary Medical Teaching Hospital, School of Veterinary Medicine, University of California Davis, Davis, CA 95616, USA
| | - Joshua A. Stern
- Department of Clinical Sciences, College of Veterinary Medicine, North Carolina State University, Raleigh, NC 27607, USA
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2
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Yu X. Promising Therapeutic Treatments for Cardiac Fibrosis: Herbal Plants and Their Extracts. Cardiol Ther 2023; 12:415-443. [PMID: 37247171 PMCID: PMC10423196 DOI: 10.1007/s40119-023-00319-4] [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: 02/28/2023] [Accepted: 04/27/2023] [Indexed: 05/30/2023] Open
Abstract
Cardiac fibrosis is closely associated with multiple heart diseases, which are a prominent health issue in the global world. Neurohormones and cytokines play indispensable roles in cardiac fibrosis. Many signaling pathways participate in cardiac fibrosis as well. Cardiac fibrosis is due to impaired degradation of collagen and impaired fibroblast activation, and collagen accumulation results in increasing heart stiffness and inharmonious activity, leading to structure alterations and finally cardiac function decline. Herbal plants have been applied in traditional medicines for thousands of years. Because of their naturality, they have attracted much attention for use in resisting cardiac fibrosis in recent years. This review sheds light on several extracts from herbal plants, which are promising therapeutics for reversing cardiac fibrosis.
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Affiliation(s)
- Xuejing Yu
- Department of Internal Medicine, Division of Cardiology, The University of Texas Southwestern Medical Center, 5323 Harry Hines Boulevard, Dallas, TX, 75235, USA.
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3
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Cha BH, Jung M, Kim AS, Lepak VC, Colson BA, Bull DA, Won Y. AZD2014, a dual mTOR inhibitor, attenuates cardiac hypertrophy in vitro and in vivo. J Biol Eng 2021; 15:24. [PMID: 34674743 PMCID: PMC8529824 DOI: 10.1186/s13036-021-00276-3] [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: 03/10/2021] [Accepted: 10/04/2021] [Indexed: 11/17/2022] Open
Abstract
Cardiac hypertrophy is one of the most common genetic heart disorders and considered a risk factor for cardiac morbidity and mortality. The mammalian target of rapamycin (mTOR) pathway plays a key regulatory function in cardiovascular physiology and pathology in hypertrophy. AZD2014 is a small-molecule ATP competitive mTOR inhibitor working on both mTORC1 and mTORC2 complexes. Little is known about the therapeutic effects of AZD2014 in cardiac hypertrophy and its underlying mechanism. Here, AZD2014 is examined in in vitro model of phenylephrine (PE)-induced human cardiomyocyte hypertrophy and a myosin-binding protein-C (Mybpc3)-targeted knockout (KO) mouse model of cardiac hypertrophy. Our results demonstrate that cardiomyocytes treated with AZD2014 retain the normal phenotype and AZD2014 attenuates cardiac hypertrophy in the Mybpc3-KO mouse model through inhibition of dual mTORC1 and mTORC2, which in turn results in the down-regulation of the Akt/mTOR signaling pathway.
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Affiliation(s)
- Byung-Hyun Cha
- Division of Cardio-Thoracic Surgery, Department of Surgery, University of Arizona College of Medicine, Tucson, AZ, 85724, USA
| | - Minjin Jung
- Division of Cardio-Thoracic Surgery, Department of Surgery, University of Arizona College of Medicine, Tucson, AZ, 85724, USA
| | - Angela S Kim
- Division of Cardio-Thoracic Surgery, Department of Surgery, University of Arizona College of Medicine, Tucson, AZ, 85724, USA
| | - Victoria C Lepak
- Department of Cellular & Molecular Medicine, University of Arizona College of Medicine, Tucson, AZ, 85724, USA
| | - Brett A Colson
- Department of Cellular & Molecular Medicine, University of Arizona College of Medicine, Tucson, AZ, 85724, USA
| | - David A Bull
- Division of Cardio-Thoracic Surgery, Department of Surgery, University of Arizona College of Medicine, Tucson, AZ, 85724, USA
| | - Youngwook Won
- Division of Cardio-Thoracic Surgery, Department of Surgery, University of Arizona College of Medicine, Tucson, AZ, 85724, USA.
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4
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Oh Y, Yang S, Liu X, Jana S, Izaddoustdar F, Gao X, Debi R, Kim DK, Kim KH, Yang P, Kassiri Z, Lakin R, Backx PH. Transcriptomic Bioinformatic Analyses of Atria Uncover Involvement of Pathways Related to Strain and Post-translational Modification of Collagen in Increased Atrial Fibrillation Vulnerability in Intensely Exercised Mice. Front Physiol 2020; 11:605671. [PMID: 33424629 PMCID: PMC7793719 DOI: 10.3389/fphys.2020.605671] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Accepted: 11/26/2020] [Indexed: 02/06/2023] Open
Abstract
Atrial Fibrillation (AF) is the most common supraventricular tachyarrhythmia that is typically associated with cardiovascular disease (CVD) and poor cardiovascular health. Paradoxically, endurance athletes are also at risk for AF. While it is well-established that persistent AF is associated with atrial fibrosis, hypertrophy and inflammation, intensely exercised mice showed similar adverse atrial changes and increased AF vulnerability, which required tumor necrosis factor (TNF) signaling, even though ventricular structure and function improved. To identify some of the molecular factors underlying the chamber-specific and TNF-dependent atrial changes induced by exercise, we performed transcriptome analyses of hearts from wild-type and TNF-knockout mice following exercise for 2 days, 2 or 6 weeks of exercise. Consistent with the central role of atrial stretch arising from elevated venous pressure in AF promotion, all 3 time points were associated with differential regulation of genes in atria linked to mechanosensing (focal adhesion kinase, integrins and cell-cell communications), extracellular matrix (ECM) and TNF pathways, with TNF appearing to play a permissive, rather than causal, role in gene changes. Importantly, mechanosensing/ECM genes were only enriched, along with tubulin- and hypertrophy-related genes after 2 days of exercise while being downregulated at 2 and 6 weeks, suggesting that early reactive strain-dependent remodeling with exercise yields to compensatory adjustments. Moreover, at the later time points, there was also downregulation of both collagen genes and genes involved in collagen turnover, a pattern mirroring aging-related fibrosis. By comparison, twofold fewer genes were differentially regulated in ventricles vs. atria, independently of TNF. Our findings reveal that exercise promotes TNF-dependent atrial transcriptome remodeling of ECM/mechanosensing pathways, consistent with increased preload and atrial stretch seen with exercise. We propose that similar preload-dependent mechanisms are responsible for atrial changes and AF in both CVD patients and athletes.
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Affiliation(s)
- Yena Oh
- Department of Biology, York University, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada.,Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Sibao Yang
- Department of Biology, York University, Toronto, ON, Canada.,Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Xueyan Liu
- Department of Biology, York University, Toronto, ON, Canada.,Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Sayantan Jana
- Department of Physiology, Cardiovascular Research Center, University of Alberta, Edmonton, AB, Canada
| | | | - Xiaodong Gao
- Department of Biology, York University, Toronto, ON, Canada
| | - Ryan Debi
- Department of Biology, York University, Toronto, ON, Canada
| | - Dae-Kyum Kim
- Donnelly Centre, University of Toronto, Toronto, ON, Canada.,Lunenfeld-Tanenbaum Research Institute, Sinai Health System, Toronto, ON, Canada
| | - Kyoung-Han Kim
- Department of Cellular and Molecular Medicine, Faculty of Medicine, University of Ottawa, Ottawa, ON, Canada.,University of Ottawa Heart Institute, Ottawa, ON, Canada
| | - Ping Yang
- Department of Cardiology, China-Japan Union Hospital of Jilin University, Changchun, China
| | - Zamaneh Kassiri
- Department of Physiology, Cardiovascular Research Center, University of Alberta, Edmonton, AB, Canada
| | - Robert Lakin
- Department of Biology, York University, Toronto, ON, Canada
| | - Peter H Backx
- Department of Biology, York University, Toronto, ON, Canada.,Department of Physiology, University of Toronto, Toronto, ON, Canada
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5
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Brooks DL, Garza AE, Katayama IA, Romero JR, Adler GK, Pojoga LH, Williams GH. Aldosterone Modulates the Mechanistic Target of Rapamycin Signaling in Male Mice. Endocrinology 2019; 160:716-728. [PMID: 30726893 PMCID: PMC6397424 DOI: 10.1210/en.2018-00989] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 01/31/2019] [Indexed: 12/12/2022]
Abstract
Both mechanistic target of rapamycin (mTOR) pathway and aldosterone are implicated in the development of cardiovascular and renal disease. However, the interaction between aldosterone and the mTOR pathway is unknown. We hypothesized the following: that (i) increased aldosterone will modulate the activity of the mTORC1 and mTORC2 molecular pathways in the heart and kidney; (ii) a physiologic increase in aldosterone will affect these pathways differently than a pathophysiologic one; and (iii) the changes in the mTOR level/activity will differ between the heart and kidney. In both kidney and heart tissues, phosphorylation of mTOR is significantly decreased when aldosterone levels are physiologically increased (by dietary sodium restriction), followed by a decrease in phosphorylated p70S6K1 in cardiac, but not renal, tissue. Sirtuin 1, an epigenetic modulator, is decreased in the heart but increased in the kidney. Conversely, pathophysiologic aldosterone levels (an infusion for 3 weeks) had divergent effects on phosphorylated mTOR and the downstream substrates of mTORC1 and mTORC2 in cardiac and renal tissues. Increased aldosterone levels significantly alter mTOR activity in the heart and kidney. In the kidney, substantial differences were noted if the increase was produced physiologically vs pathophysiologically, suggesting that mTOR activity, in part, may mediate aldosterone-induced renal damage. Thus, modulating mTOR activity may reduce aldosterone-dependent renal damage similar to mineralocorticoid receptor blockade but potentially with less adverse side effects.
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Affiliation(s)
- Danielle L Brooks
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
- Correspondence: Danielle L. Brooks, PhD, Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, 221 Longwood Avenue, Boston, Massachusetts 02115. E-mail:
| | - Amanda E Garza
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Isis A Katayama
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Jose R Romero
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Gail K Adler
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Luminita H Pojoga
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
| | - Gordon H Williams
- Division of Endocrinology, Diabetes and Hypertension, Brigham and Women’s Hospital, Boston, Massachusetts
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6
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Suhara T, Baba Y, Shimada BK, Higa JK, Matsui T. The mTOR Signaling Pathway in Myocardial Dysfunction in Type 2 Diabetes Mellitus. Curr Diab Rep 2017; 17:38. [PMID: 28434143 PMCID: PMC8219468 DOI: 10.1007/s11892-017-0865-4] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
PURPOSE OF REVIEW T2DM (type 2 diabetes mellitus) is a risk factor for heart failure. The mTOR (mechanistic target of rapamycin) is a key mediator of the insulin signaling pathway. We will discuss the role of mTOR in myocardial dysfunction in T2DM. RECENT FINDINGS In T2DM, chronically activated mTOR induces multiple pathological events, including a negative feedback loop that suppresses IRS (insulin receptor substrate)-1. While short-term treatment with rapamycin, an mTOR inhibitor, is a promising strategy for cardiac diseases such as acute myocardial infarction and cardiac hypertrophy in T2DM, there are many concerns about chronic usage of rapamycin. Two mTOR complexes, mTORC1 and mTORC2, affect many molecules and processes via distinct signaling pathways that regulate cardiomyocyte function and survival. Understanding mechanisms underlying mTOR-mediated pathophysiological features in the heart is essential for developing effective therapies for cardiac diseases in the context of T2DM.
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Affiliation(s)
- Tomohiro Suhara
- Department of Anatomy, Biochemistry & Physiology, John A. Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo St., BSB no. 110, Honolulu, HI, 96813, USA
- Department of Anesthesiology, Keio University School of Medicine, Tokyo, Japan
| | - Yuichi Baba
- Department of Anatomy, Biochemistry & Physiology, John A. Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo St., BSB no. 110, Honolulu, HI, 96813, USA
- Department of Cardiology and Geriatrics, Kochi Medical School, Kochi University, Kochi, Japan
| | - Briana K Shimada
- Department of Anatomy, Biochemistry & Physiology, John A. Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo St., BSB no. 110, Honolulu, HI, 96813, USA
| | - Jason K Higa
- Department of Anatomy, Biochemistry & Physiology, John A. Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo St., BSB no. 110, Honolulu, HI, 96813, USA
| | - Takashi Matsui
- Department of Anatomy, Biochemistry & Physiology, John A. Burns School of Medicine, University of Hawaii at Manoa, 651 Ilalo St., BSB no. 110, Honolulu, HI, 96813, USA.
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7
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Kaur A, Sharma S. Mammalian target of rapamycin (mTOR) as a potential therapeutic target in various diseases. Inflammopharmacology 2017; 25:293-312. [PMID: 28417246 DOI: 10.1007/s10787-017-0336-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 03/02/2017] [Indexed: 12/28/2022]
Abstract
Mammalian target of rapamycin (mTOR) is a serine/threonine protein kinase that belongs to Phosphatidylinositol-3-kinase related kinase superfamily. The signaling pathways of mTOR are integrated through the protein complexes of mTORC1 and mTORC2. mTORC1 controls protein synthesis, cell growth, proliferation, autophagy, cell metabolism, and stress responses, whereas mTORC2 seems to regulate cell survival and polarity. Dysregulation of the mTOR pathway has been implicated in the pathophysiology of a number of disease conditions, including cancer, cardiovascular, neurodegenerative, and various renal diseases. The hyperactivation of the mTOR pathway leads to increase in cell growth and proliferation and also has been documented to stimulate tumor growth. Therefore, investigation of the involvement of mTOR and its downstream pathways in various diseases intensively preoccupied scientific community. The present review is focussed on recent advances in the understanding of the mTOR signaling pathway and its role in health and various diseases.
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Affiliation(s)
- Avileen Kaur
- Cardiovascular Division, Department of Pharmacology, I. S. F. College of Pharmacy, Moga, Punjab, 142001, India
| | - Saurabh Sharma
- Cardiovascular Division, Department of Pharmacology, I. S. F. College of Pharmacy, Moga, Punjab, 142001, India.
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8
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Cardiac-targeting magnetic lipoplex delivery of SH-IGF1R plasmid attenuate norepinephrine-induced cardiac hypertrophy in murine heart. Biosci Rep 2014; 34:BSR20130107. [PMID: 24965872 PMCID: PMC4182904 DOI: 10.1042/bsr20130107] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Recent studies have demonstrated a number of molecular mechanisms contributing to the initiation of cardiac hypertrophy response to pressure overload. IGF1R (insulin-like growth factor-1 receptor), an important oncogene, is overexpressed in hypertrophic heart and mediates the hypertrophic pathology process. In this study, we applied with liposomal magnetofection that potentiated gene transfection by applying an external magnetic field to enhance its transfection efficiency. Liposomal magnetofection provided high efficiency in transgene expression in vivo. In vivo, IGF1R-specific-shRNA (small-hairpin RNA) by magnetofection inhibited IGF1R protein expression by 72.2 ± 6.8, 80.7 ± 9.6 and 84.5 ± 5.6%, at 24, 48 and 72 h, respectively, after pGFPshIGF1R injection, indicating that liposomal magnetofection is a promising method that allows the targeting of gene therapy for heart failure. Furthermore, we found that the treated animals (liposomal magnetofection with shIGF1R) showed reduced septal and posterior wall thickness, reduced HW:BWs (heart weight-to-body weights) compared with controls. Moreover, we also found that liposomal magnetofection-based shIGF1R transfection decreased the expression level of p-ERK (phosphorylated extracellular-signal-regulated kinase)1/2, p-AKT1 (phosphorylated protein kinase B1) compared with untreated hearts. These results suggested that liposomal magnetofection-mediated IGF1R-specific-shRNA may be a promising method, and suppression the IGF1R expression inhibited norepinephrine-induced cardiac hypertrophic process via inhibiting PI3K (phosphoinositide 3-kinase)/AKT pathway.
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9
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Abstract
The protein kinase mammalian or mechanistic target of rapamycin (mTOR) is an atypical serine/threonine kinase that exerts its main cellular functions by interacting with specific adaptor proteins to form 2 different multiprotein complexes, mTOR complex 1 (mTORC1) and mTOR complex 2 (mTORC2). mTORC1 regulates protein synthesis, cell growth and proliferation, autophagy, cell metabolism, and stress responses, whereas mTORC2 seems to regulate cell survival and polarity. The mTOR pathway plays a key regulatory function in cardiovascular physiology and pathology. However, the majority of information available about mTOR function in the cardiovascular system is related to the role of mTORC1 in the unstressed and stressed heart. mTORC1 is required for embryonic cardiovascular development and for postnatal maintenance of cardiac structure and function. In addition, mTORC1 is necessary for cardiac adaptation to pressure overload and development of compensatory hypertrophy. However, partial and selective pharmacological and genetic inhibition of mTORC1 was shown to extend life span in mammals, reduce pathological hypertrophy and heart failure caused by increased load or genetic cardiomyopathies, reduce myocardial damage after acute and chronic myocardial infarction, and reduce cardiac derangements caused by metabolic disorders. The optimal therapeutic strategy to target mTORC1 and increase cardioprotection is under intense investigation. This article reviews the information available regarding the effects exerted by mTOR signaling in cardiovascular physiology and pathological states.
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Affiliation(s)
- Sebastiano Sciarretta
- From the Cardiovascular Research Institute, Department of Cell Biology and Molecular Medicine, Rutgers New Jersey Medical School, Newark, NJ (S.S., J.S.); IRCCS Neuromed, Pozzilli, Italy (S.S., M.V.); and Division of Cardiology, Department of Clinical and Molecular Medicine, Faculty of Medicine and Psychology, University Sapienza, Rome, Italy (M.V.)
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10
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Troncoso R, Ibarra C, Vicencio JM, Jaimovich E, Lavandero S. New insights into IGF-1 signaling in the heart. Trends Endocrinol Metab 2014; 25:128-37. [PMID: 24380833 DOI: 10.1016/j.tem.2013.12.002] [Citation(s) in RCA: 165] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Revised: 11/16/2013] [Accepted: 12/02/2013] [Indexed: 01/15/2023]
Abstract
Insulin-like growth factor 1 (IGF-1) signaling regulates contractility, metabolism, hypertrophy, autophagy, senescence, and apoptosis in the heart. IGF-1 deficiency is associated with an increased risk of cardiovascular disease, whereas cardiac activation of IGF-1 receptor (IGF-1R) protects from the detrimental effects of a high-fat diet and myocardial infarction. IGF-1R activates multiple pathways through its intrinsic tyrosine kinase activity and through coupling to heterotrimeric G protein. These pathways involve classic second messengers, phosphorylation cascades, lipid signaling, Ca(2+) transients, and gene expression. In addition, IGF-1R triggers signaling in different subcellular locations including the plasma membrane, perinuclear T tubules, and also in internalized vesicles. In this review, we provide a fresh and updated view of the complex IGF-1 scenario in the heart, including a critical focus on therapeutic strategies.
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Affiliation(s)
- Rodrigo Troncoso
- Facultad de Ciencias Quimicas y Farmaceuticas & Facultad Medicina, Universidad de Chile, Santiago 838049, Chile; Centro de Estudios Moleculares de la Célula, Facultad de Ciencias Quimicas y Farmaceuticas & Facultad de Medicina, Universidad de Chile, Santiago 838049, Chile
| | - Cristián Ibarra
- Department of Medical Biochemistry and Biophysics, Karolinska Institutet, Stockholm 17177, Sweden
| | | | - Enrique Jaimovich
- Centro de Estudios Moleculares de la Célula, Facultad de Ciencias Quimicas y Farmaceuticas & Facultad de Medicina, Universidad de Chile, Santiago 838049, Chile
| | - Sergio Lavandero
- Facultad de Ciencias Quimicas y Farmaceuticas & Facultad Medicina, Universidad de Chile, Santiago 838049, Chile; Centro de Estudios Moleculares de la Célula, Facultad de Ciencias Quimicas y Farmaceuticas & Facultad de Medicina, Universidad de Chile, Santiago 838049, Chile; Department of Internal Medicine (Cardiology Division), University of Texas Southwestern Medical Center, Dallas, TX, 75390-8573, USA.
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11
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Carrasco L, Cea P, Rocco P, Peña-Oyarzún D, Rivera-Mejias P, Sotomayor-Flores C, Quiroga C, Criollo A, Ibarra C, Chiong M, Lavandero S. Role of Heterotrimeric G Protein and Calcium in Cardiomyocyte Hypertrophy Induced by IGF-1. J Cell Biochem 2014; 115:712-20. [DOI: 10.1002/jcb.24712] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2013] [Accepted: 11/05/2013] [Indexed: 01/09/2023]
Affiliation(s)
- Loreto Carrasco
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Paola Cea
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Paola Rocco
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Daniel Peña-Oyarzún
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Pablo Rivera-Mejias
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Cristian Sotomayor-Flores
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Clara Quiroga
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Alfredo Criollo
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Departamento Ciencias Básicas y Comunitarias; Facultad Odontología; Universidad de Chile; Santiago Chile
| | - Cristian Ibarra
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Department of Medical Biochemistry and Biophysics; Karolinska Institutet; Stockholm Sweden
| | - Mario Chiong
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
| | - Sergio Lavandero
- Advanced Center for Chronic Diseases; Universidad de Chile; Santiago Chile
- Centro Estudios Moleculares de la Celula; Facultad de Ciencias y Farmacéuticas; Universidad de Chile; Santiago Chile
- Instituto de Ciencias Biomédicas; Facultad Medicina; Universidad de Chile; Santiago Chile
- Cardiology Division; Department of Internal Medicine; University of Texas Southwestern Medical Center; Dallas Texas
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12
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Wang KCW, Botting KJ, Padhee M, Zhang S, McMillen IC, Suter CM, Brooks DA, Morrison JL. Early origins of heart disease: Low birth weight and the role of the insulin-like growth factor system in cardiac hypertrophy. Clin Exp Pharmacol Physiol 2012; 39:958-64. [DOI: 10.1111/j.1440-1681.2012.05743.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Affiliation(s)
- Kimberley CW Wang
- Early Origins of Adult Health Research Group; Sansom Institute for Health Research; School of Pharmacy and Medical Sciences; University of Adelaide; Adelaide; South Australia; Australia
| | | | - Monalisa Padhee
- Early Origins of Adult Health Research Group; Sansom Institute for Health Research; School of Pharmacy and Medical Sciences; University of Adelaide; Adelaide; South Australia; Australia
| | - Song Zhang
- Early Origins of Adult Health Research Group; Sansom Institute for Health Research; School of Pharmacy and Medical Sciences; University of Adelaide; Adelaide; South Australia; Australia
| | - I Caroline McMillen
- Early Origins of Adult Health Research Group; Sansom Institute for Health Research; School of Pharmacy and Medical Sciences; University of Adelaide; Adelaide; South Australia; Australia
| | - Catherine M Suter
- Victor Chang Cardiac Research Institute; Darlinghurst; New South Wales; Australia
| | - Doug A Brooks
- Cell Biology of Diseases Research Group; Sansom Institute for Health Research; School of Pharmacy and Medical Sciences; University of Adelaide; Adelaide; South Australia; Australia
| | - Janna L Morrison
- Early Origins of Adult Health Research Group; Sansom Institute for Health Research; School of Pharmacy and Medical Sciences; University of Adelaide; Adelaide; South Australia; Australia
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13
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Wang KCW, Brooks DA, Thornburg KL, Morrison JL. Activation of IGF-2R stimulates cardiomyocyte hypertrophy in the late gestation sheep fetus. J Physiol 2012; 590:5425-37. [PMID: 22930271 DOI: 10.1113/jphysiol.2012.238410] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023] Open
Abstract
In vitro studies using rat and fetal sheep cardiomyocytes indicate that, in addition to its role as a clearance receptor, the insulin-like growth factor 2 receptor (IGF-2R) can induce cardiomyocyte hypertrophy. In the present study, we have determined the effect of specific activation of the IGF-2R in the heart of the late gestation fetus on cardiomyocyte development. Leu(27)IGF-2, an IGF-2R agonist, was infused into the fetal left circumflex coronary artery for 4 days beginning at 128.1 ± 0.4 days gestation. Ewes were humanely killed at 132.2 ± 1.2 days gestation (term, 150 days). Fetuses were delivered and hearts dissected to isolate the cardiomyocytes and to collect and snap-freeze tissue. Leu(27)IGF-2 infusion into the left circumflex coronary artery of fetal sheep increased the area of binucleated cardiomyocytes in the left, but not the right, ventricle. However, this infusion of Leu(27)IGF-2 did not change fetal weight, heart weight, blood pressure, blood gases or cardiomyocyte proliferation/binucleation. The increase in cardiomyocyte size in the Leu(27)IGF-2-infused group was associated with increased expression of proteins in the Gαs, but not the Gαq, signalling pathway. We concluded that infusion of Leu(27)IGF-2 into the left circumflex coronary artery causes cardiac IGF-2R activation in the left ventricle of the heart, and this stimulates cardiomyocyte hypertrophy in a Gαs-dependent manner.
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Affiliation(s)
- Kimberley C W Wang
- Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, GPO Box 2471, Adelaide, SA, Australia 5001
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Wang KC, Brooks DA, Botting KJ, Morrison JL. IGF-2R-Mediated Signaling Results in Hypertrophy of Cultured Cardiomyocytes from Fetal Sheep1. Biol Reprod 2012; 86:183. [DOI: 10.1095/biolreprod.112.100388] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/01/2022] Open
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15
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Ye Y, Hu SJ, Li L. Inhibition of farnesylpyrophosphate synthase prevents angiotensin II-induced hypertrophic responses in rat neonatal cardiomyocytes: involvement of the RhoA/Rho kinase pathway. FEBS Lett 2009; 583:2997-3003. [PMID: 19716825 DOI: 10.1016/j.febslet.2009.08.034] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2009] [Revised: 07/22/2009] [Accepted: 08/22/2009] [Indexed: 01/10/2023]
Abstract
The RhoA/Rho-kinase (ROCK) pathway is involved in angiotensin (Ang) II-induced cardiac hypertrophy. However, it is still unclear whether inhibition of farnesylpyrophosphate (FPP) synthase can attenuate Ang II-induced hypertrophic responses, and whether it involves the RhoA/ROCK pathway. The anti-hypertrophic effects of inhibition of FPP synthase with alendronate in Ang II-cultured neonatal cardiomyocytes were partially reversed by geranylgeranyol (GGOH) and were mimicked by GGTI-286, a geranylgeranyl transferase-I inhibitor, C3 exoenzyme, an inhibitor of Rho, or Y-27632, an inhibitor of ROCK. Pull-down assay showed alendronate reduced-active RhoA by Ang II was also partially antagonized by GGOH. This study revealed that the inhibition of FPP synthase by alendronate reduces RhoA activation by diminishing geranylgeranylation which prevents Ang II-induced hypertrophic responses in neonatal cardiomyocytes.
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Affiliation(s)
- Yang Ye
- Institute of Cardiology, The First Affiliated Hospital, College of Medicine, Zhejiang University, #79 Qing-Chun Road, Hangzhou 310003, PR China.
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16
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Lumbers ER, Kim MY, Burrell JH, Kumarasamy V, Boyce AC, Gibson KJ, Gatford KL, Owens JA. Effects of intrafetal IGF-I on growth of cardiac myocytes in late-gestation fetal sheep. Am J Physiol Endocrinol Metab 2009; 296:E513-9. [PMID: 19126787 DOI: 10.1152/ajpendo.90497.2008] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Intrafetal insulin-like growth factor (IGF)-I promotes cardiac hypertrophy in the late-gestation fetal sheep; whether these effects are sustained is unknown. IGF-I was infused for 4 days at 80 microg/h from 121 to 125 days of gestation, and its effects at 128 days, 3 days after the infusion stopped, were determined by comparison with untreated fetal sheep. After IGF-I treatment, fetal weights were similar to those in control fetuses but kidney weights were bigger (P < 0.05), as were spleen weights of male fetuses (P < 0.05). Cardiac myocytes were larger in female than male fetal sheep (P < 0.001). IGF-I increased male (P < 0.001) but not female myocyte volumes. IGF-I did not alter the proportions of uni- or binucleated right or left ventricular myocytes. Female fetal sheep had a greater proportion of binucleated cardiac myocytes than males (P < 0.05). IGF-I-treated fetuses had a slightly greater proportion of right ventricular nuclei in cell cycle phase G(2)/M and a reduced proportion of G(0)/G(1) phase nuclei (P < 0.1). Therefore, evidence for IGF-I-stimulated cardiac cell hyperplasia in fetal sheep in late gestation was limited. In conclusion, the greater sizes and larger proportion of binucleated cardiac myocytes in female fetal sheep suggest that myocyte maturation may occur earlier in females than in males. This may explain in part the male sex-specific responsiveness of cardiac hypertrophy to IGF-I in late gestation. If IGF-I-stimulated cardiomyocyte growth is accompanied by maturation of contractile function, IGF-I may be a potential therapeutic agent for maintaining cardiac output in preterm males.
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Affiliation(s)
- Eugenie R Lumbers
- Department of Physiology, University of New South Wales, Sydney, Australia.
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17
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Peivandi AA, Loffelholz K, Vahl CF. Die Signaltransduktion der konzentrischen Myokardhypertrophie. ZEITSCHRIFT FUR HERZ THORAX UND GEFASSCHIRURGIE 2009. [DOI: 10.1007/s00398-009-0680-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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18
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Teos LY, Zhao A, Alvin Z, Laurence GG, Li C, Haddad GE. Basal and IGF-I-dependent regulation of potassium channels by MAP kinases and PI3-kinase during eccentric cardiac hypertrophy. Am J Physiol Heart Circ Physiol 2008; 295:H1834-45. [PMID: 18757484 DOI: 10.1152/ajpheart.321.2008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The potassium channels I(K) and I(K1), responsible for the action potential repolarization and resting potential respectively, are altered during cardiac hypertrophy. The activation of insulin-like growth factor-I (IGF-I) during hypertrophy may affect channel activity. The aim was to examine the modulatory effects of IGF-I on I(K) and I(K1) through mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3-kinase (PI3K) pathways during hypertrophy. With the use of specific inhibitors for ERK1/2 (PD98059), p38 MAPK (SB203580) and PI3K/Akt (LY294002), Western blot and whole cell patch-clamp were conducted on sham and aorto-caval shunt-induced hypertrophy adult rat myocytes. Basal activation levels of MAPKs and Akt were increased during hypertrophy. Acute IGF-I (10(-8) M) enhanced basal activation levels of these kinases in normal hearts but only those of Akt in hypertrophied ones. I(K) and I(K1) activities were lowered by IGF-I. Inhibition of ERK1/2, p38 MAPK, or Akt reduced basal I(K) activity by 70, 32, or 50%, respectively, in normal cardiomyocytes vs. 53, 34, or 52% in hypertrophied ones. However, basal activity of I(K1) was reduced by 45, 48, or 45% in the former vs. 63, 43, or 24% in the latter. The inhibition of either MAPKs or Akt alleviated IGF-I effects on I(K) and I(K1). We conclude that basal I(K) and I(K1) are positively maintained by steady-state Akt and ERK activities. K+ channels seem to be regulated in a dichotomic manner by acutely stimulated MAPKs and Akt. Eccentric cardiac hypertrophy may be associated with a change in the regulation of the steady-state basal activities of K+ channels towards MAPKs, while that of the acute IGF-I-stimulated ones toward Akt.
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Affiliation(s)
- Leyla Y Teos
- Department of Physiology and Biophysics, College of Medicine, Howard University, Washington, DC 20059, USA
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19
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Chabowski A, Coort SLM, Calles-Escandon J, Tandon NN, Glatz JFC, Luiken JJFP, Bonen A. Insulin stimulates fatty acid transport by regulating expression of FAT/CD36 but not FABPpm. Am J Physiol Endocrinol Metab 2004; 287:E781-9. [PMID: 15166001 DOI: 10.1152/ajpendo.00573.2003] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Because insulin has been shown to stimulate long-chain fatty acid (LCFA) esterification in skeletal muscle and cardiac myocytes, we investigated whether insulin increased the rate of LCFA transport by altering the expression and the subcellular distribution of the fatty acid transporters FAT/CD36 and FABPpm. In cardiac myocytes, insulin very rapidly increased the expression of FAT/CD36 protein in a time- and dose-dependent manner. During a 2-h period, insulin (10 nM) increased cardiac myocyte FAT/CD36 protein by 25% after 60 min and attained a maximum after 90-120 min (+40-50%). There was a dose-dependent relationship between insulin (10(-12) to 10(-7) M) and FAT/CD36 expression. The half-maximal increase in FAT/CD36 protein occurred at 0.5 x 10(-9) M insulin, and the maximal increase occurred at 10(-9) to 10(-8) M insulin (+40-50%). There were similar insulin-induced increments in FAT/CD36 protein in cardiac myocytes (+43%) and in Langendorff-perfused hearts (+32%). In contrast to FAT/CD36, insulin did not alter the expression of FABPpm protein in either cardiac myocytes or the perfused heart. By use of specific inhibitors of insulin-signaling pathways, it was shown that insulin-induced expression of FAT/CD36 occurred via the PI 3-kinase/Akt insulin-signaling pathway. Subcellular fractionation of cardiac myocytes revealed that insulin not only increased the expression of FAT/CD36, but this hormone also targeted some of the FAT/CD36 to the plasma membrane while concomitantly lowering the intracellular depot of FAT/CD36. At the functional level, the insulin-induced increase in FAT/CD36 protein resulted in an increased rate of palmitate transport into giant vesicles (+34%), which paralleled the increase in plasmalemmal FAT/CD36 (+29%). The present studies have shown that insulin regulates protein expression of FAT/CD36, but not FABPpm, via the PI 3-kinase/Akt insulin-signaling pathway.
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Affiliation(s)
- Adrian Chabowski
- Department of Human Biology and Nutritional Sciences, University of Guelph, ON N1G 2W1, Canada
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20
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Zhang D, Bar-Eli M, Meloche S, Brodt P. Dual Regulation of MMP-2 Expression by the Type 1 Insulin-like Growth Factor Receptor. J Biol Chem 2004; 279:19683-90. [PMID: 14993222 DOI: 10.1074/jbc.m313145200] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The matrix metalloproteinase (MMP)-2 has been recognized as a major mediator of basement membrane degradation, angiogenesis, tumor invasion, and metastasis. The factors that regulate its expression have not, however, been fully elucidated. We previously identified the type I insulin-like growth factor (IGF-I) receptor as a regulator of MMP-2 synthesis. The objective of the present study was to investigate the signal transduction pathway(s) mediating this regulation. We show here that in Lewis lung carcinoma subline H-59 cells treated with IGF-I (10 ng/ml), the PI 3-kinase (phosphatidylinositol 3'-kinase) /protein kinase B (Akt) and C-Raf/ERK pathways were activated, and MMP-2 promoter activity, mRNA, and protein synthesis were induced. MMP-2 induction was blocked by the PI 3-kinase inhibitors LY294002 and wortmannin, by overexpression of a dominant-negative Akt or wild-type PTEN (phosphatase and tensin homologue deleted on chromosome 10), and by rapamycin. In contrast, a MEK inhibitor PD98059 failed to reduce MMP-2 promoter activation and actually increased MMP-2 mRNA and protein synthesis by up to 30%. Interestingly, suppression of PI 3-kinase signaling by a dominant-negative Akt enhanced ERK activity in cells stimulated with 10 ng/ml but not with 100 ng/ml IGF-I. Furthermore, at the higher (100 ng/ml) IGF-I concentration, C-Raf and ERK, but not PI 3-kinase activation, was enhanced, and this resulted in down-regulation of MMP-2 synthesis. This effect was reversed in cells expressing a dominant-negative ERK mutant. The results suggest that IGF-I can up-regulate MMP-2 synthesis via PI 3-kinase/Akt/mTOR (the mammalian target of rapamycin) signaling while concomitantly transmitting a negative regulatory signal via the Raf/ERK pathway. The outcome of IGF-IR (the receptor for IGF-I) activation may ultimately depend on factors, such as ligand bioavailability, that can shift the balance preferentially toward one pathway or the other.
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Affiliation(s)
- Donglei Zhang
- Department of Surgery, McGill University Health Center, the Royal Victoria Hospital, Room H6.25, 687 Pine Avenue West, Montreal, Quebec, Canada H3A 1A1
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21
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Ibarra C, Estrada M, Carrasco L, Chiong M, Liberona JL, Cardenas C, Díaz-Araya G, Jaimovich E, Lavandero S. Insulin-like growth factor-1 induces an inositol 1,4,5-trisphosphate-dependent increase in nuclear and cytosolic calcium in cultured rat cardiac myocytes. J Biol Chem 2003; 279:7554-65. [PMID: 14660553 DOI: 10.1074/jbc.m311604200] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
In the heart, insulin-like growth factor-1 (IGF-1) is a pro-hypertrophic and anti-apoptotic peptide. In cultured rat cardiomyocytes, IGF-1 induced a fast and transient increase in Ca(2+)(i) levels apparent both in the nucleus and cytosol, releasing this ion from intracellular stores through an inositol 1,4,5-trisphosphate (IP(3))-dependent signaling pathway. Intracellular IP(3) levels increased after IGF-1 stimulation in both the presence and absence of extracellular Ca(2+). A different spatial distribution of IP(3) receptor isoforms in cardiomyocytes was found. Ryanodine did not prevent the IGF-1-induced increase of Ca(2+)(i) levels but inhibited the basal and spontaneous Ca(2+)(i) oscillations observed when cardiac myocytes were incubated in Ca(2+)-containing resting media. Spatial analysis of fluorescence images of IGF-1-stimulated cardiomyocytes incubated in Ca(2+)-containing resting media showed an early increase in Ca(2+)(i), initially localized in the nucleus. Calcium imaging suggested that part of the Ca(2+) released by stimulation with IGF-1 was initially contained in the perinuclear region. The IGF-1-induced increase on Ca(2+)(i) levels was prevented by 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid-AM, thapsigargin, xestospongin C, 2-aminoethoxy diphenyl borate, U-73122, pertussis toxin, and betaARKct (a peptide inhibitor of Gbetagamma signaling). Pertussis toxin also prevented the IGF-1-dependent IP(3) mass increase. Genistein treatment largely decreased the IGF-1-induced changes in both Ca(2+)(i) and IP(3). LY29402 (but not PD98059) also prevented the IGF-1-dependent Ca(2+)(i) increase. Both pertussis toxin and U73122 prevented the IGF-1-dependent induction of both ERKs and protein kinase B. We conclude that IGF-1 increases Ca(2+)(i) levels in cultured cardiac myocytes through a Gbetagamma subunit of a pertussis toxin-sensitive G protein-PI3K-phospholipase C signaling pathway that involves participation of IP(3).
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Affiliation(s)
- Cristian Ibarra
- Departament de Bioquímica y Biología Molecular, Facultad de Ciencias Químicas y Farmacéuticas, Universidad de Chile, Santiago
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22
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Sundgren NC, Giraud GD, Schultz JM, Lasarev MR, Stork PJS, Thornburg KL. Extracellular signal-regulated kinase and phosphoinositol-3 kinase mediate IGF-1 induced proliferation of fetal sheep cardiomyocytes. Am J Physiol Regul Integr Comp Physiol 2003; 285:R1481-9. [PMID: 12947030 DOI: 10.1152/ajpregu.00232.2003] [Citation(s) in RCA: 92] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Growth of the fetal heart involves cardiomyocyte enlargement, division, and maturation. Insulin-like growth factor-1 (IGF-1) is implicated in many aspects of growth and is likely to be important in developmental heart growth. IGF-1 stimulates the IGF-1 receptor (IGF1R) and downstream signaling pathways, including extracellular signal-regulated kinase (ERK) and phosphoinositol-3 kinase (PI3K). We hypothesized that IGF-1 stimulates cardiomyocyte proliferation and enlargement through stimulation of the ERK cascade and stimulates cardiomyocyte differentiation through the PI3K cascade. In vivo administration of Long R3 IGF-1 (LR3 IGF-1) did not stimulate cardiomyocyte hypertrophy but led to a decreased percentage of cells that were binucleated in vivo. In culture, LR3 IGF-1 increased myocyte bromodeoxyuridine (BrdU) uptake by three- to five-fold. The blockade of either ERK or PI3K signaling (by UO-126 or LY-294002, respectively) completely abolished BrdU uptake stimulated by LR3 IGF-1. LR3 IGF-1 did not increase footprint area, but as expected, phenylephrine stimulated an increase in binucleated cardiomyocyte size. We conclude that 1) IGF-1 through IGF1R stimulates cardiomyocyte division in vivo; hyperplastic growth is the most likely explanation of IGF-1 stimulated heart growth in vivo; 2) IGF-1 through IGF1R does not stimulate binucleation in vitro or in vivo; 3) IGF-1 through IGF1R does not stimulate hypertrophy either in vivo or in vitro; and 4) IGF-1 through IGF1R requires both ERK and PI3K signaling for proliferation of near-term fetal sheep cardiomyocytes in vitro.
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Affiliation(s)
- Nathan C Sundgren
- Department of Physiology and Pharmacology, Oregon Health and Science University, Portland, Oregon 97239, USA
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23
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Zhang D, Brodt P. Type 1 insulin-like growth factor regulates MT1-MMP synthesis and tumor invasion via PI 3-kinase/Akt signaling. Oncogene 2003; 22:974-82. [PMID: 12592384 DOI: 10.1038/sj.onc.1206197] [Citation(s) in RCA: 125] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The membrane type 1 matrix metalloproteinase (MT1-MMP) has been identified as a major activator of MMP-2 - a process involving the formation of a trimolecular complex with TIMP-2. We previously identified the IGF-I receptor as a positive regulator of MMP-2 synthesis. Here, we investigated the role of IGF-IR in the regulation of MT1-MMP. Highly invasive Lewis lung carcinoma subline H-59 cells express MT1-MMP and utilize it to activate their major extracellular matrix degrading proteinase-MMP-2. These cells were transiently transfected with a plasmid vector expressing a luciferase reporter gene downstream of the mouse MT1-MMP promoter. IGF-I treatment increased luciferase activity in the transfected cells by up to 10-fold and augmented endogenous MT1-MMP mRNA and protein synthesis by up to 2-3-fold, relative to controls. MT1-MMP induction and invasion were blocked by the PI 3-kinase inhibitors LY294002 and wortmannin and by rapamycin, but not by the MEK inhibitor PD98059. Overexpression of a dominant negative Akt mutant or of the tumor suppressor phosphatase and tensin homologue, PTEN, in these cells also caused a significant reduction in MT1-MMP expression and invasion. The results demonstrate that IGF-IR controls tumor cell invasion by coordinately regulating MMP-2 expression and its MT1-MMP-mediated activation and identify PI 3-kinase/Akt/mTOR signaling as critical to this regulation.
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MESH Headings
- Amino Acid Substitution
- Androstadienes/pharmacology
- Animals
- Carcinoma, Lewis Lung/metabolism
- Carcinoma, Lewis Lung/pathology
- Chromones/pharmacology
- Collagen
- Drug Combinations
- Enzyme Induction/drug effects
- Enzyme Inhibitors/pharmacology
- Flavonoids/pharmacology
- Gene Expression Regulation, Neoplastic/drug effects
- Insulin-Like Growth Factor I/pharmacology
- Insulin-Like Growth Factor I/physiology
- Laminin
- Matrix Metalloproteinase 14
- Matrix Metalloproteinase 2/physiology
- Matrix Metalloproteinases, Membrane-Associated
- Metalloendopeptidases/biosynthesis
- Metalloendopeptidases/genetics
- Mice
- Morpholines/pharmacology
- Neoplasm Invasiveness/physiopathology
- Neoplasm Proteins/antagonists & inhibitors
- Neoplasm Proteins/biosynthesis
- Neoplasm Proteins/genetics
- Neoplasm Proteins/physiology
- PTEN Phosphohydrolase
- Phosphatidylinositol 3-Kinases/physiology
- Phosphoinositide-3 Kinase Inhibitors
- Phosphoric Monoester Hydrolases/genetics
- Phosphoric Monoester Hydrolases/physiology
- Phosphorylation/drug effects
- Point Mutation
- Promoter Regions, Genetic
- Protein Kinases/physiology
- Protein Processing, Post-Translational/drug effects
- Protein Serine-Threonine Kinases/genetics
- Protein Serine-Threonine Kinases/physiology
- Proteoglycans
- Proto-Oncogene Proteins
- Proto-Oncogene Proteins c-akt
- RNA, Messenger/biosynthesis
- RNA, Neoplasm/biosynthesis
- Receptor, IGF Type 1/drug effects
- Receptor, IGF Type 1/physiology
- Recombinant Fusion Proteins/physiology
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Sirolimus/pharmacology
- TOR Serine-Threonine Kinases
- Tumor Cells, Cultured/metabolism
- Tumor Cells, Cultured/pathology
- Tumor Suppressor Proteins/genetics
- Tumor Suppressor Proteins/physiology
- Wortmannin
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Affiliation(s)
- Donglei Zhang
- Department of Surgery, McGill University Health Center, The Royal Victoria Hospital, Montreal, Quebec, Canada
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Li M, Li C, Parkhouse WS. Differential effects of des IGF-1 on Erks, AKT-1 and P70 S6K activation in mouse skeletal and cardiac muscle. Mol Cell Biochem 2002; 236:115-22. [PMID: 12190109 DOI: 10.1023/a:1016164601887] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Alterations in the degree of the phosphorylation of ERKI/2, Akt-1 and p70 S6K in mouse skeletal and cardiac muscle was examined in vivo following an intraperitoneal injection of des IGF-I. Plasma levels of insulin, IGF-I and glucose were measured. The administration of des IGF-I had no effect on plasma levels of insulin, or IGF-I, but plasma glucose levels were decreased about 50% (p < 0.01). In both skeletal and cardiac muscle, des IGF-I increased the phosphorylation of Akt-1 at Ser 473 (p < 0.01) with no change in the phosphorylation of p44 and p42 MAP kinases at Thr202/Tyr204. The phosphorylation of p70 S6K at Thr421/Ser424 was increased in skeletal muscle (p < 0.01), but not in cardiac muscle. The phosphorylation of the nuclear transcription factor CREB phosphorylation at Ser 133 was not significantly changed in either skeletal or cardiac muscle. Des IGF-I increased the phosphorylation of the transcription factor FKHR in cardiac muscle only (p < 0.05). These data demonstrate that the administration of des IGF-I had differential effects on the activation of the MAP kinase and PI 3-kinase pathways in mouse skeletal and cardiac muscle.
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Affiliation(s)
- M Li
- Metabolic Biochemistry Laboratory, School of Kinesiology, Simon Fraser University, Burnaby, British Columbia, Canada
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25
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Herrmann BL, Bruch C, Saller B, Bartel T, Ferdin S, Erbel R, Mann K. Acromegaly: evidence for a direct relation between disease activity and cardiac dysfunction in patients without ventricular hypertrophy. Clin Endocrinol (Oxf) 2002; 56:595-602. [PMID: 12030909 DOI: 10.1046/j.1365-2265.2002.01528.x] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
BACKGROUND AND AIMS Cardiac abnormalities, such as cardiomegaly and congestive heart failure, occur frequently in advanced acromegaly. Abnormalities of systolic and diastolic function, mostly associated with left ventricular (LV) hypertrophy, have been reported. The impact of disease activity on LV performance in patients with normal or slightly elevated LV muscle mass has not been demonstrated. PATIENTS AND METHODS Conventional two-dimensional/Doppler echocardiography and tissue Doppler imaging (TDI) of the mitral annulus were performed in 13 patients with active acromegaly (AA) and normal or slightly elevated LV muscle mass (< 140 g/m2) and in 19 cured/well-controlled patients (CA). A group of 21 volunteers without symptoms or signs of cardiac disease served as controls (CON). The combined myocardial performance index (Tei-Index) was determined in all patients and controls. RESULTS Muscle mass index of the left ventricle, ejection fraction, fractional shorting, E/ET-ratio, systolic (ST) and late diastolic (AT) annular velocities did not differ significantly between the three groups. In the AA group, the early diastolic annular velocity ET[7.13 +/- 2.11 (AA); 9.83 +/- 3.29 (CA); 10.10 +/- 1.70 m/s (CON); P < 0.05 AA vs. CA, P < 0.005 AA vs. CON] and the ET/AT-ratio [0.71 +/- 0.26 (AA); 0.95 +/- 0.33 (CA); 1.00 +/- 0.15 m/s (CON); P < 0.05 AA vs. CA, P < 0.005 AA vs. CON] were significantly reduced. Patients with AA had a longer deceleration time [209 +/- 19 (AA); 179 +/- 22 (CA); 185 +/- 26 ms (CON); P < 0.05]. The Tei-Index was significantly higher in AA in comparison with CON [0.50 +/- 0.15 (AA); 0.48 +/- 0.12 (CA); 0.41 +/- 0.10 (CON); P < 0.05 AA vs. CON]. Subjects with CA did not differ significantly from controls with respect to 2-D/Doppler echo- and TDI-derived parameters. CONCLUSION The data demonstrate that diastolic dysfunction can be verified by tissue Doppler imaging in patients with active acromegaly with normal or slightly elevated muscle mass of the left ventricle and seems to be related to disease activity. The Tei-Index as a sensitive combined myocardial performance index can be used to complete the assessment of systolic and diastolic LV performance in acromegalic patients.
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Affiliation(s)
- Burkhard L Herrmann
- Department of Internal Medicine, Division of Endocrinology, University of Essen, Hufelandstrasse 55, D-45122 Essen, Germany.
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26
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Huang CY, Hao LY, Buetow DE. Hypertrophy of cultured adult rat ventricular cardiomyocytes induced by antibodies against the insulin-like growth factor (IGF)-I or the IGF-I receptor is IGF-II-dependent. Mol Cell Biochem 2002; 233:65-72. [PMID: 12083381 DOI: 10.1023/a:1015514324328] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Antibodies against the insulin-like growth factor-I (IGF-I) or the IGF-I receptor (IGF-IR) directly initiate a rapid (within 6 h) hypertrophy of isolated adult rat ventricular cardiomyocytes cultured in the absence of serum. Further, cardiomyocytes treated with either of these agonistic antibodies upregulate the expression of their genes for insulin-like growth factor-II (IGF-II) and the IGF-II receptor (IGF-IIR). Genistein, an inhibitor of the tyrosine kinase IGF-IR, also induces the cardiomyocytes to hypertrophy. Anti-IGF-II antibody inhibits the cardiomyocyte hypertrophy induced by anti-IGF-I and anti-IGF-IR antibodies or by genistein. Results are consistent with a model in which local production of IGF-II is upregulated when the IGF-IR signaling pathway is blocked and in which an IGF-II-mediated pathway, likely involving the IGF-IIR, then stimulates hypertrophy of the cardiomyocytes.
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Affiliation(s)
- Chih-Yang Huang
- Department of Molecular and Integrative Physiology, University of Illinois, Urbana 61801, USA
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Huang CY, Hao LY, Buetow DE. Insulin-like growth factor-induced hypertrophy of cultured adult rat cardiomyocytes is L-type calcium-channel-dependent. Mol Cell Biochem 2002; 231:51-9. [PMID: 11952165 DOI: 10.1023/a:1014432923220] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The insulin-like growth factors-I and -II are potent growth stimulators in vivo and for many different cultured cells in vitro. Here IGF-I and -II are shown to directly induce hypertrophy of adult rat ventricular cardiomyocytes in serum-free medium as demonstrated by their increased size, total protein synthesis, and transcription of muscle-specific genes. The cells hypertrophied within 1 day when exposed to as little as 10(-11) M IGF-I or 10(-10) M IGF-II. With 10(-8) M IGF-I, cell size was significantly increased 34% by 1 day of culture and 57% by 2 days. With 10(-8) M IGF-II, cell size was similarly increased 32% by day 1 and 57% by 2 days. During hypertrophy, total protein synthesis was increased 2.3-fold with IGF-I and 2-fold with IGF-II. Gene expression for myosin light chain 2 and troponin I was upregulated with either growth factor. Hypertrophy induced by IGF-I was blocked by IGF binding protein-3, which binds IGF-I, while that induced by IGF-II was blocked by antibodies against IGF-II. Nicardipine, an inhibitor of L-type Ca2+-channels, completely blocked the hypertrophy induced by either IGF showing for the first time that such voltage-dependent channels are necessary for the hypertrophic effects of the IGFs on adult cardiomyocytes.
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Affiliation(s)
- Chih-Yang Huang
- Department of Molecular and Integrative Physiology, University of Illinois, Urbana 61801, USA
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28
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Pritchard J, Horst N, Cruikshank W, Smith TJ. Igs from patients with Graves' disease induce the expression of T cell chemoattractants in their fibroblasts. JOURNAL OF IMMUNOLOGY (BALTIMORE, MD. : 1950) 2002; 168:942-50. [PMID: 11777993 DOI: 10.4049/jimmunol.168.2.942] [Citation(s) in RCA: 115] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Thyroid-associated ophthalmopathy and dermopathy are connective tissue manifestations of Graves' disease (GD). Tissue remodeling is a prominent feature of both and is apparently driven by recruited T cells. In this study, we report that IgG isolated from patients with GD (GD-IgG) up-regulates T lymphocyte chemoattractant activity in GD-derived fibroblasts from orbit, thyroid, and several regions of skin. This chemoattractant activity, absent in fibroblasts from donors without known thyroid disease, is partially susceptible to neutralization by anti-IL-16 and anti-RANTES Abs. IL-16 is a CD4(+)-specific chemoattractant and RANTES is a C-C-type chemokine. IL-16 and RANTES protein levels, as determined by specific ELISAs, are substantially increased by GD-IgG in GD fibroblasts. Addition of the macrolide, rapamycin, to fibroblast culture medium blocked the up-regulation by GD-IgG of IL-16, implicating the FRAP/mTOR/p70(s6k) pathway in the induction of IL-16 expression. These findings suggest a specific mechanism for activation of fibroblasts in GD resulting in the recruitment of T cells. They may provide insight into a missing link between the glandular and extrathyroidal manifestations of GD.
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Affiliation(s)
- Jane Pritchard
- Department of Medicine, Division of Molecular Medicine, Harbor-University of California, Los Angeles Medical Center, Torrance, CA 90502, USA
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29
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Jäger D, Müller-Werdan U, Pönicke K, Holtz J, Werdan K, Müller SP. The impact of insulin-like growth factor-1 on the pattern of cardiac elongation factor-2 variants in a model of overload. Mol Cell Biochem 2002; 229:25-34. [PMID: 11936844 DOI: 10.1023/a:1017982724938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Because of its key role in proteosynthesis, the total content of elongation factor-2 (EF-2) and the distribution of six main EF-2 variants were investigated after Pseudomonas Exotoxin A catalyzed [37P]ADP-ribosylation using 1D-PAGE and isoelectric focusing (IEF) in a rat model of hemodynamic overload with variable degrees of cardiac hypertrophy: Chronic NO-synthase inhibition by L-NAME (N-omega-nitro-L-arginine-methyl-ester; 0.75 mg/ml drinking water) induced arterial hypertension without hypertrophy but myocardial apoptosis; additional treatment with IGF-1 (osmotic micropumps) did not modify hypertension but reduced apoptosis allowing moderate hypertrophy of the left ventricles. Total EF-2 did not significantly increase in rats with hemodynamic overload with or without IGF-1 supplementation. A positive correlation was found between an acidic EF-2 variant and apoptosis (p = 0.01). Hypertrophy under additional IGF-1 was combined with a shift of the EF-2 variants to basic subtypes (p < 0.01). This finding may be indicative of the trophic potency of IGF-1.
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Affiliation(s)
- Doris Jäger
- Department of Mediicne III, Martin-Luther-University, Halle-Wittenberg, Germany.
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30
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Miyashita T, Takeishi Y, Takahashi H, Kato S, Kubota I, Tomoike H. Role of calcineurin in insulin-like growth factor-1-induced hypertrophy of cultured adult rat ventricular myocytes. JAPANESE CIRCULATION JOURNAL 2001; 65:815-9. [PMID: 11548882 DOI: 10.1253/jcj.65.815] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The present study examined the role of calcineurin in insulin-like growth factor (IGF)-1-induced hypertrophy in primary cultures of adult rat ventricular myocytes (ARVM), prepared from the ventricles of 14-16-week-old male Sprague-Dawley rats. The effects of several humoral factors, including phenylephrine, angiotensin II, endothelin-1, IGF-1 and interleukin-6, on the morphology of ARVM were studied. Myocyte surface area was significantly increased by IGF-1 (2,268 +/- 571 to 3,018 +/- 836 microm2, p < 0.01), but not by other humoral factors. This hypertrophic effect of IGF-1 was blocked by genistein (tyrosine kinase inhibitor), PD98059 (MEK inhibitor). These findings suggest that IGF-1 produces ARVM hypertrophy by a tyrosine kinase-MEK mediated pathway as has been reported in neonatal cardiomyocytes. IGF-1-mediated ARVM hypertrophy was also attenuated by cyclosporine A (calcineurin inhibitor), and staurosporine and chelerythrine (protein kinase C inhibitors). IGF-1 markedly increased calcineurin activity (8.7 +/- 1.2 to 98.0 +/- 54.3 pmol x h(-1) mg(-1), p < 0.01), and this activation was completely blocked by pre-treatment with cyclosporine A (8.5 +/- 11.4pmol x h(-1) x mg(-1), p < 0.01) and chelerythrine (2.3 +/- 2.7 pmol x h(-1) mg(-1), p < 0.01). It appears that IGF-1 activates calcineurin by a protein kinase C-dependent pathway. Increased mRNA expression of atrial natriuretic factor by IGF-1 was inhibited by cyclosporine A (p < 0.01). The findings indicate that IGF-1 induces ARVM hypertrophy by protein kinase C and calcineurin-related mechanisms. The fact that elevated calcineurin activity and induced atrial natriuretic factor mRNA expression by IGF-1 were blocked by cyclosporine A further supports the hypothesis that calcineurin is critically involved in IGF-1-induced ARVM hypertrophy.
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Affiliation(s)
- T Miyashita
- The First Department of Internal Medicine, Yamagata University School of Medicine, Japan
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31
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Foncea R, Gálvez A, Pérez V, Morales MP, Calixto A, Meléndez J, González-Jara F, Díaz-Araya G, Sapag-Hagar M, Sugden PH, LeRoith D, Lavandero S. Extracellular regulated kinase, but not protein kinase C, is an antiapoptotic signal of insulin-like growth factor-1 on cultured cardiac myocytes. Biochem Biophys Res Commun 2000; 273:736-44. [PMID: 10873673 DOI: 10.1006/bbrc.2000.3008] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study aims to elucidate the signaling pathway for insulin-like growth factor-1 (IGF-1) in cultured neonatal rat cardiomyocytes and particularly the role of IGF-1 in cardiac apoptosis. IGF-1 stimulated polyphosphoinositide turnover, translocation of protein kinase C (PKC) isoforms (alpha, epsilon, and delta) from the soluble to the particulate fraction, activation of phospholipid-dependent and Ca(2+)-, phospholipid-dependent PKC, and activation of the extracellular-regulated kinase (ERK). IGF-1 attenuated sorbitol-induced cardiomyocyte viability and nuclear DNA fragmentation. These antiapoptotic effects of IGF-1 were blocked by PD-098059 (an MEK inhibitor) but not by bisindolylmaleimide I (BIM, a specific PKC inhibitor). The ERK pathway may therefore be an important component in the mechanism whereby IGF-1 exerts its antiapoptotic effect on the cardiomyocyte.
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Affiliation(s)
- R Foncea
- Departamento de Bioquímica y Biología Molecular, Universidad de Chile, Santiago, 664 0750, Chile
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32
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Quevedo C, Alcázar A, Salinas M. Two different signal transduction pathways are implicated in the regulation of initiation factor 2B activity in insulin-like growth factor-1-stimulated neuronal cells. J Biol Chem 2000; 275:19192-7. [PMID: 10764740 DOI: 10.1074/jbc.m000238200] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Eukaryotic initiation factor eIF-2B plays an important role in translation regulation and has been suggested to be implicated in the increased protein synthesis promoted in response to growth factors. We have used primary cultured neurons to delineate the signaling pathways by which insulin-like growth factor-1 (IGF-1), which plays a critical role in the survival of neuronal cells, promotes eIF-2B and protein synthesis activation. Treatment of cortical neurons with IGF-1 (100 ng/ml) for 30 min stimulates [(3)H]methionine incorporation, and a parallel increase in eIF-2B activity was observed. Wortmannin and LY294002 reversed both effects, indicating that phosphatidylinositol 3-kinase mediates IGF-1-induced protein synthesis and eIF-2B activation. IGF-1 induced glycogen synthase kinase-3 (GSK-3) inactivation in a phosphatidylinositol 3-kinase-dependent fashion because it is inhibited by wortmannin and LY294002. By using GSK-3 immunoprecipitated from untreated and IGF-1-treated cells, we demonstrate the phosphorylation of eIF-2B coincident with its inactivation. The treatment of cortical neurons with IGF-1 also promoted the activation of mitogen-activated protein kinase (MAPK). The MAPK-activating kinase (MEK) inhibitor PD98059 inhibited MAPK activation and reversed IGF-1-induced protein synthesis and eIF-2B activation. These findings suggest that IGF-1-induced eIF-2B activation on neurons is promoted through phosphatidylinositol 3-kinase and GSK-3 kinase, and we report an IGF-1-induced MEK/MAPK activation pathway implicated in eIF-2B activation.
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Affiliation(s)
- C Quevedo
- Servicio de Bioquimica-Investigación, Hospital Ramón y Cajal, 28034 Madrid, Spain
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33
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Ruwhof C, van Wamel AE, Egas JM, van der Laarse A. Cyclic stretch induces the release of growth promoting factors from cultured neonatal cardiomyocytes and cardiac fibroblasts. Mol Cell Biochem 2000; 208:89-98. [PMID: 10939632 DOI: 10.1023/a:1007046105745] [Citation(s) in RCA: 84] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Growth factors and hormones may play an autocrine/paracrine role in mechanical stress-induced cardiac hypertrophy. Using an in vitro model of mechanical stress, i.e. stretch of cardiomyocytes and cardiac fibroblasts, we tested the involvement of growth factors and hormones in this process. We found that conditioned medium (CM) derived from 4 h cyclicly (1 Hz) stretched cardiomyocytes increased the rate of protein synthesis in static cardiomyocytes by 8 +/- 3%. Moreover, CM derived from 2 h stretched fibroblasts increased the rate of protein synthesis in static fibroblasts as well as in static cardiomyocytes by 8 +/- 2 and 6 +/- 2%, respectively. Analysis of CM using size-exclusion HPLC showed that cardiomyocytes and fibroblasts released at least three factors with MW < or = 10 kD, their quantities being time-dependently increased by stretch. Subsequent analyses using immunoassays revealed that cardiomyocytes released atrial natriuretic peptide (ANP) and transforming growth factor-beta1 (TGFbeta1) being increased by 45 +/- 17 and 21 +/- 4% upon 4 h of stretch, respectively. Fibroblasts released TGFbeta1 and very low quantity of endothelin-1 (ET-1). The release of TGFbeta1 was significantly increased by 18 +/- 4% after 24 h of stretch in fibroblasts. Both cell types released no detectable amount of angiotensin II (Ang II). In conclusion, upon cyclic stretch cardiomyocytes and fibroblasts secrete growth factors and hormones which induce growth responses in cardiomyocytes and fibroblasts in an autocrine/paracrine way. TGFbeta secreted by cardiomyocytes and fibroblasts, and ANP secreted by cardiomyocytes are likely candidates. We found no evidence for the involvement of Ang II and ET-1 in autocrine/paracrine mechanisms between cardiac cell types.
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Affiliation(s)
- C Ruwhof
- Department of Cardiology, Leiden University Medical Center, The Netherlands
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34
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Morales MP, Gálvez A, Eltit JM, Ocaranza P, Díaz-Araya G, Lavandero S. IGF-1 regulates apoptosis of cardiac myocyte induced by osmotic-stress. Biochem Biophys Res Commun 2000; 270:1029-35. [PMID: 10772945 DOI: 10.1006/bbrc.2000.2550] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Insulin-like growth factor-1 (IGF-1) is a natural protectant of cardiac myocytes that has been shown to improve cardiac function. The role of IGF-1 in attenuating apoptosis induced by osmotic stress (sorbitol, SOR) or by other known apoptotic stimuli (doxorubicin, angiotensin II, and serum withdrawal) was determined in cultured cardiac myocytes. After 6 h of exposure to SOR, apoptosis was initiated, concomitant with a decrease in cell survival and increases in poly-[ADP-ribose] polymerase (PARP) degradation and DNA fragmentation. These effects were maximal after 24 h. IGF-1 partially attenuated apoptosis induced by sorbitol but not that induced by angiotensin II, doxorubicin, or serum withdrawal. In cells preincubated with IGF-1 before the addition of SOR, we detected an increase in the number of viable cells, a decrease in the generation of DNA fragments on agarose gel electrophoresis and in the percentage of positive TUNEL cells, and a reduction on PARP levels. These results suggest that IGF-1 prevents apoptosis induced by osmotic stress in cardiac myocytes but not apoptosis induced by doxorubicin and angiotensin II.
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Affiliation(s)
- M P Morales
- Department of Biochemistry and Molecular Biology, University of Chile, Santiago, 6640750, Chile
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35
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Wang L, Wang X, Proud CG. Activation of mRNA translation in rat cardiac myocytes by insulin involves multiple rapamycin-sensitive steps. Am J Physiol Heart Circ Physiol 2000; 278:H1056-68. [PMID: 10749698 DOI: 10.1152/ajpheart.2000.278.4.h1056] [Citation(s) in RCA: 95] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Insulin acutely activates protein synthesis in ventricular cardiomyocytes from adult rats. In this study, we have established the methodology for studying the regulation of the signaling pathways and translation factors that may be involved in this response and have examined the effects of acute insulin treatment on them. Insulin rapidly activated the 70-kDa ribosomal S6 kinase (p70 S6k), and this effect was inhibited both by rapamycin and by inhibitors of phosphatidylinositol 3-kinase. The activation of p70 S6k is mediated by a signaling pathway involving the mammalian target of rapamycin (mTOR), which also modulates other translation factors. These include the eukaryotic initiation factor (eIF) 4E binding proteins (4E-BPs) and eukaryotic elongation factor 2 (eEF2). Insulin caused phosphorylation of 4E-BP1 and induced its dissociation from eIF4E, and these effects were also blocked by rapamycin. Concomitant with this, insulin increased the binding of eIF4E to eIF4G. Insulin also activated protein kinase B (PKB), which may lie upstream of p70 S6k and 4E-BP1, with the activation of the different isoforms being in the order alpha>beta>gamma. Insulin also caused inhibition of glycogen synthase kinase 3, which lies downstream of PKB, and of eEF2 kinase. The phosphorylation of eEF2 itself was also decreased by insulin, and this effect and the inactivation of eEF2 kinase were attenuated by rapamycin. The activation of overall protein synthesis by insulin in cardiomyocytes was substantially inhibited by rapamycin (but not by inhibitors of other specific signaling pathways, e.g., mitogen-activated protein kinase), showing that signaling events linked to mTOR play a major role in the control of translation by insulin in this cell type.
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Affiliation(s)
- L Wang
- Department of Anatomy and Physiology, Medical Sciences Institute, University of Dundee, Dundee DD1 5EH, United Kingdom
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36
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Affiliation(s)
- W J Brickman
- Children's Memorial Hospital, Department of Pediatrics, Northwestern University Medical School, Chicago, IL 60614, USA
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37
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Takahashi T, Fukuda K, Pan J, Kodama H, Sano M, Makino S, Kato T, Manabe T, Ogawa S. Characterization of insulin-like growth factor-1-induced activation of the JAK/STAT pathway in rat cardiomyocytes. Circ Res 1999; 85:884-91. [PMID: 10559134 DOI: 10.1161/01.res.85.10.884] [Citation(s) in RCA: 46] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
This study was designed to investigate whether insulin-like growth factor-1 (IGF-1) transduces signaling through the Janus kinase (JAK)/signal transducers and activators of transcription (STAT) pathway in cardiomyocytes and to assess the upstream signals of serine and tyrosine phosphorylation of STAT family proteins. Primary cultured neonatal rat cardiomyocytes were stimulated with IGF-1 (10(-8) mol/L). JAK1, but not JAK2 or Tyk2, was phosphorylated by IGF-1 as early as 2 minutes and peaked at 5 minutes. IGF-1 induced both tyrosine and serine phosphorylation of STAT1 and STAT3. Tyrosine phosphorylation of STAT1 peaked at 15 minutes and correlated with that of JAK1, whereas that of STAT3 was sustained up to 120 minutes and was dissociated from the activation of JAK1. Tyrosine phosphorylation of STAT3 was unaffected by the preincubation with CV11974 (AT(1) blocker), TAK044 (endothelin-1 receptor blocker), RX435 (anti-gp130 blocking antibody), PD98058, wortmannin, EDTA, or KN62 but was significantly attenuated by BAPTA-AM and chelerythrine. The time course of a gel mobility shift of SIE (sis-inducing element) coincided with the phosphorylation of STAT3. Serine phosphorylation of STAT1 peaked at 30 minutes and that of STAT3 was observed from 5 to 60 minutes. These results indicated that (1) IGF-1 activated JAK1 but not JAK2 or Tyk2 in rat cardiomyocytes; (2) IGF-1 induced both tyrosine and serine phosphorylation of STAT1 and STAT3; and (3) the tyrosine phosphorylation of STAT3 was not caused by JAK1 alone, and protein kinase C and intracellular Ca(2+) were required for phosphorylation.
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Affiliation(s)
- T Takahashi
- Cardiopulmonary Division, Department of Internal Medicine, Keio University, Tokyo, Japan
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38
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Jalil JE, Ebensperger R, Meléndez J, Acevedo E, Sapag-Hagar M, González-Jara F, Gálvez A, Pérez-Montes V, Lavandero S. Effects of antihypertensive treatment on cardiac IGF-1 during prevention of ventricular hypertrophy in the rat. Life Sci 1999; 64:1603-12. [PMID: 10328520 DOI: 10.1016/s0024-3205(99)00097-1] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
There is some evidence that cardiac rather than circulating insulin-like growth factor-1 (IGF-1) levels contribute to the development of renovascular hypertensive left ventricular hypertrophy (LVH), remaining unknown the effects of antihypertensive drugs on IGF-1 levels. We have assessed here the preventive effects of enalapril, losartan, propanolol and alpha-methyldopa on left ventricle (LV) and circulating IGF-1 levels in a rat model of hypertension and LVH (Goldblatt, GB). Our results show that relative LV mass and the LV content of IGF-1 were significantly lower with all antihypertensive drugs in GB rats (p<0.001). Serum concentrations of IGF-1 were lower in GB rats treated with enalapril, alpha-methyldopa and propanolol (p<0.01), but not in those treated with losartan. These results support the hypothesis that local rather than seric IGF-1 contributes to the development of left ventricular hypertrophy induced by pressure overload in the rat.
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Affiliation(s)
- J E Jalil
- Department of Cardiovascular Diseases, School of Medicine, P. Catholic University of Chile, Santiago
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39
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Ritchie RH, Marsh JD, Schiebinger RJ. Bradykinin-stimulated protein synthesis by myocytes is dependent on the MAP kinase pathway and p70(S6K). THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 276:H1393-8. [PMID: 10199867 DOI: 10.1152/ajpheart.1999.276.4.h1393] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Bradykinin (BK) has a direct hypertrophic effect on rat ventricular cardiomyocytes (VCM) as defined by an increase in protein synthesis and an increase in atrial natriuretic peptide mRNA and secretion. In the current study, we have examined the dependence of BK-induced protein synthesis on activation of 90-kDa ribosomal S6 kinase (p90(rsk)) and 70-kDa S6 kinase (p70(S6K)). Both of these kinases possess the ability to phosphorylate the ribosomal protein S6, which plays an important role in initiating mRNA translation. Stimulation of adult VCM with 10 microM BK increased p90(rsk) activity by 2.5 +/- 0.3-fold and increased p70(S6K) activity by 2.0 +/- 0.3-fold. p90(rsk) is a terminal kinase in the mitogen-activated protein (MAP) kinase pathway. Inhibition of MAP kinase kinase activation by Raf in the MAP kinase pathway with PD-098059 (25 microM) blocked BK-stimulated activation of p90(rsk) by 70% and unexpectedly blocked p70(S6K) by 72%. Rapamycin inhibited BK-stimulated p70(S6K) activity by 93% but had no effect on p90(rsk) activation by BK. Inhibition of the MAP kinase pathway and p70(S6K) with PD-098059 was paralleled by changes in protein synthesis. BK (10 microM) increased [3H]phenylalanine incorporation by 27 +/- 3 and 39 +/- 6% in cultured adult and neonatal VCM, respectively. Treatment with PD-098059 or rapamycin abolished the increase in protein synthesis stimulated by BK. These results suggest that 1) BK activates p70(S6K) and p90(rsk); 2) although both p70(S6K) and p90(rsk) have the potential to phosphorylate the ribosomal S6 protein, p70(S6K) and not p90(rsk) is the predominant kinase involved in increasing protein synthesis by BK; and 3) p70(S6K) activation is dependent on stimulation of the MAP kinase pathway at a point distal to Raf.
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Affiliation(s)
- R H Ritchie
- Program in Molecular and Cellular Cardiology, Department of Internal Medicine, Wayne State University, Detroit, Michigan 48201, USA
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