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Chaklader M, Rothermel BA. Calcineurin in the heart: New horizons for an old friend. Cell Signal 2021; 87:110134. [PMID: 34454008 PMCID: PMC8908812 DOI: 10.1016/j.cellsig.2021.110134] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2021] [Revised: 08/10/2021] [Accepted: 08/23/2021] [Indexed: 01/20/2023]
Abstract
Calcineurin, also known as PP2B or PPP3, is a member of the PPP family of protein phosphatases that also includes PP1 and PP2A. Together these three phosphatases carryout the majority of dephosphorylation events in the heart. Calcineurin is distinct in that it is activated by the binding of calcium/calmodulin (Ca2+/CaM) and therefore acts as a node for integrating Ca2+ signals with changes in phosphorylation, two fundamental intracellular signaling cascades. In the heart, calcineurin is primarily thought of in the context of pathological cardiac remodeling, acting through the Nuclear Factor of Activated T-cell (NFAT) family of transcription factors. However, calcineurin activity is also essential for normal heart development and homeostasis in the adult heart. Furthermore, it is clear that NFAT-driven changes in transcription are not the only relevant processes initiated by calcineurin in the setting of pathological remodeling. There is a growing appreciation for the diversity of calcineurin substrates that can impact cardiac function as well as the diversity of mechanisms for targeting calcineurin to specific sub-cellular domains in cardiomyocytes and other cardiac cell types. Here, we will review the basics of calcineurin structure, regulation, and function in the context of cardiac biology. Particular attention will be given to: the development of improved tools to identify and validate new calcineurin substrates; recent studies identifying new calcineurin isoforms with unique properties and targeting mechanisms; and the role of calcineurin in cardiac development and regeneration.
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Affiliation(s)
- Malay Chaklader
- Departments of Internal Medicine (Division of Cardiology) and Molecular Biology, University of Texas Southwestern Medical Centre, Dallas, TX, USA
| | - Beverly A Rothermel
- Departments of Internal Medicine (Division of Cardiology) and Molecular Biology, University of Texas Southwestern Medical Centre, Dallas, TX, USA.
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Seidlmayer LK, Mages C, Berbner A, Eder-Negrin P, Arias-Loza PA, Kaspar M, Song M, Dorn GW, Kohlhaas M, Frantz S, Maack C, Gerull B, Dedkova EN. Mitofusin 2 Is Essential for IP 3-Mediated SR/Mitochondria Metabolic Feedback in Ventricular Myocytes. Front Physiol 2019; 10:733. [PMID: 31379586 PMCID: PMC6658196 DOI: 10.3389/fphys.2019.00733] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 05/27/2019] [Indexed: 12/19/2022] Open
Abstract
Aim: Endothelin-1 (ET-1) and angiotensin II (Ang II) are multifunctional peptide hormones that regulate the function of the cardiovascular and renal systems. Both hormones increase the intracellular production of inositol-1,4,5-trisphosphate (IP3) by activating their membrane-bound receptors. We have previously demonstrated that IP3-mediated sarcoplasmic reticulum (SR) Ca2+ release results in mitochondrial Ca2+ uptake and activation of ATP production. In this study, we tested the hypothesis that intact SR/mitochondria microdomains are required for metabolic IP3-mediated SR/mitochondrial feedback in ventricular myocytes. Methods: As a model for disrupted mitochondrial/SR microdomains, cardio-specific tamoxifen-inducible mitofusin 2 (Mfn2) knock out (KO) mice were used. Mitochondrial Ca2+ uptake, membrane potential, redox state, and ATP generation were monitored in freshly isolated ventricular myocytes from Mfn2 KO mice and their control wild-type (WT) littermates. Results: Stimulation of ET-1 receptors in healthy control myocytes increases mitochondrial Ca2+ uptake, maintains mitochondrial membrane potential and redox balance leading to the enhanced ATP generation. Mitochondrial Ca2+ uptake upon ET-1 stimulation was significantly higher in interfibrillar (IFM) and perinuclear (PNM) mitochondria compared to subsarcolemmal mitochondria (SSM) in WT myocytes. Mfn2 KO completely abolished mitochondrial Ca2+ uptake in IFM and PNM mitochondria but not in SSM. However, mitochondrial Ca2+ uptake induced by beta-adrenergic receptors activation with isoproterenol (ISO) was highest in SSM, intermediate in IFM, and smallest in PNM regions. Furthermore, Mfn2 KO did not affect ISO-induced mitochondrial Ca2+ uptake in SSM and IFM mitochondria; however, enhanced mitochondrial Ca2+ uptake in PNM. In contrast to ET-1, ISO induced a decrease in ATP levels in WT myocytes. Mfn2 KO abolished ATP generation upon ET-1 stimulation but increased ATP levels upon ISO application with highest levels observed in PNM regions. Conclusion: When the physical link between SR and mitochondria by Mfn2 was disrupted, the SR/mitochondrial metabolic feedback mechanism was impaired resulting in the inability of the IP3-mediated SR Ca2+ release to induce ATP production in ventricular myocytes from Mfn2 KO mice. Furthermore, we revealed the difference in Mfn2-mediated SR-mitochondrial communication depending on mitochondrial location and type of communication (IP3R-mRyR1 vs. ryanodine receptor type 2-mitochondrial calcium uniporter).
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Affiliation(s)
- Lea K Seidlmayer
- Department of Internal Medicine, Cardiology, University Hospital Würzburg, Würzburg, Germany.,Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany
| | - Christine Mages
- Department of Internal Medicine, Cardiology, University Hospital Würzburg, Würzburg, Germany.,Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany
| | - Annette Berbner
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany
| | - Petra Eder-Negrin
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany
| | | | - Mathias Kaspar
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany
| | - Moshi Song
- Department of Internal Medicine, Center for Pharmacogenomics, Washington University School of Medicine, St. Louis, MO, United States
| | - Gerald W Dorn
- Department of Internal Medicine, Center for Pharmacogenomics, Washington University School of Medicine, St. Louis, MO, United States
| | - Michael Kohlhaas
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany
| | - Stefan Frantz
- Department of Internal Medicine, Cardiology, University Hospital Würzburg, Würzburg, Germany.,Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany
| | - Christoph Maack
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany
| | - Brenda Gerull
- Comprehensive Heart Failure Center, University of Würzburg, Würzburg, Germany
| | - Elena N Dedkova
- Department of Pharmacology, School of Medicine, University of California, Davis, Davis, CA, United States.,Department of Molecular Biosciences, School of Veterinary Medicine, University of California, Davis, Davis, CA, United States
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Yan X, Jiao K, Song X. Shen’ge powder decreases the cardiomyocyte hypertrophy in chronic heart failure by activating the Rho protein/Rho‐associated coiledcoil forming protein kinase signaling pathway. J Cell Biochem 2018; 120:3038-3045. [PMID: 30474257 DOI: 10.1002/jcb.27386] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2018] [Accepted: 07/09/2018] [Indexed: 12/15/2022]
Affiliation(s)
- Xinpeng Yan
- Department of Traditional Chinese Medicine Shengli Oilfield Central Hospital Dongying Shandong PR China
| | - Kai Jiao
- Department of Cardiology Shengli Oilfield Central Hospital Dongying Shandong PR China
| | - Xiaozheng Song
- Department of Cardiology Shengli Oilfield Central Hospital Dongying Shandong PR China
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A feed-forward regulation of endothelin receptors by c-Jun in human non-pigmented ciliary epithelial cells and retinal ganglion cells. PLoS One 2017; 12:e0185390. [PMID: 28938016 PMCID: PMC5609771 DOI: 10.1371/journal.pone.0185390] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Accepted: 09/12/2017] [Indexed: 12/21/2022] Open
Abstract
c-Jun, c-Jun N-terminal kinase(JNK) and endothelin B (ETB) receptor have been shown to contribute to the pathogenesis of glaucoma. Previously, we reported that an increase of c-Jun and CCAAT/enhancer binding protein β (C/EBPβ) immunohistostaining is associated with upregulation of the ETB receptor within the ganglion cell layer of rats with elevated intraocular pressure (IOP). In addition, both transcription factors regulate the expression of the ETB receptor in human non-pigmented ciliary epithelial cells (HNPE). The current study addressed the mechanisms by which ET-1 produced upregulation of ET receptors in primary rat retinal ganglion cells (RGCs) and HNPE cells. Treatment of ET-1 and ET-3 increased the immunocytochemical staining of c-Jun and C/EBPβ in primary rat RGCs and co-localization of both transcription factors was observed. A marked increase in DNA binding activity of AP-1 and C/EBPβ as well as elevated protein levels of c-Jun and c-Jun-N-terminal kinase (JNK) were detected following ET-1 treatment in HNPE cells. Overexpression of ETA or ETB receptor promoted the upregulation of c-Jun and also elevated its promoter activity. In addition, upregulation of C/EBPβ augmented DNA binding and mRNA expression of c-Jun, and furthermore, the interaction of c-Jun and C/EBPβ was confirmed using co-immunoprecipitation. Apoptosis of HNPE cells was identified following ET-1 treatment, and overexpression of the ETA or ETB receptor produced enhanced apoptosis. ET-1 mediated upregulation of c-Jun and C/EBPβ and their interaction may represent a novel mechanism contributing to the regulation of endothelin receptor expression. Reciprocally, c-Jun was also found to regulate the ET receptors and C/EBPβ appeared to play a regulatory role in promoting expression of c-Jun. Taken together, the data suggests that ET-1 triggers the upregulation of c-Jun through both ETA and ETB receptors, and conversely c-Jun also upregulates endothelin receptor expression, thereby generating a positive feed-forward loop of endothelin receptor activation and expression. This feed-forward regulation may contribute to RGC death and astrocyte proliferation following ET-1 treatment.
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Wang J, Zhang P, Liu N, Wang Q, Luo J, Wang L. Cadmium Induces Apoptosis in Freshwater Crab Sinopotamon henanense through Activating Calcium Signal Transduction Pathway. PLoS One 2015; 10:e0144392. [PMID: 26714174 PMCID: PMC4694652 DOI: 10.1371/journal.pone.0144392] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2015] [Accepted: 11/17/2015] [Indexed: 12/21/2022] Open
Abstract
Calcium ion (Ca2+) is one of the key intracellular signals, which is implicated in the regulation of cell functions such as impregnation, cell proliferation, differentiation and death. Cadmium (Cd) is a toxic environmental pollutant that can disturb cell functions and even lead to cell death. Recently, we have found that Cd induced apoptosis in gill cells of the freshwater crab Sinopotamon henanense via caspase activation. In the present study, we further investigated the role of calcium signaling in the Cd-induced apoptosis in the animals. Our data showed that Cd triggered gill cell apoptosis which is evidenced by apoptotic DNA fragmentation, activations of caspases-3, -8 and -9 and the presence of apoptotic morphological features. Moreover, Cd elevated the intracellular concentration of Ca2+, the protein concentration of calmodulin (CaM) and the activity of Ca2+-ATPase in the gill cells of the crabs. Pretreatment of the animals with ethylene glycol-bis-(b-aminoethyl ether)-N,N,N’,N’-tetraacetic acid (EGTA), Ca2+ chelator, inhibited Cd-induced activation of caspases-3, -8 and -9 as well as blocked the Cd-triggered apoptotic DNA fragmentation. The apoptotic morphological features were no longer observed in gill cells pretreated with the Ca2+ signaling inhibitors before Cd treatment. Our results indicate that Cd evokes gill cell apoptosis through activating Ca2+-CaM signaling transduction pathway.
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Affiliation(s)
- Jinxiang Wang
- School of Life Science, Shanxi University, Taiyuan, 030006, China
- School of Life Science, Shanxi Datong University, Datong, 037009, China
| | - Pingping Zhang
- School of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Na Liu
- School of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Qian Wang
- School of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Jixian Luo
- School of Life Science, Shanxi University, Taiyuan, 030006, China
| | - Lan Wang
- School of Life Science, Shanxi University, Taiyuan, 030006, China
- * E-mail:
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He S, Park YH, Yorio T, Krishnamoorthy RR. Endothelin-Mediated Changes in Gene Expression in Isolated Purified Rat Retinal Ganglion Cells. Invest Ophthalmol Vis Sci 2015; 56:6144-61. [PMID: 26397462 DOI: 10.1167/iovs.15-16569] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
PURPOSE A growing body of evidence suggests that the vasoactive peptides endothelins (ETs) and their receptors (primarily the ETB receptor) are contributors to neurodegeneration in glaucoma. However, actions of ETs in retinal ganglion cells (RGCs) are not fully understood. The purpose of this study was to determine the effects of ETs on gene expression in primary RGCs. METHODS Primary RGCs isolated from rat pups were treated with 100 nM of ET-1, ET-2, or ET-3 for 24 hours. Total RNA was extracted followed by cDNA synthesis. Changes in gene expression in RGCs were detected using Affymetrix Rat Genome 230 2.0 microarray and categorized by DAVID analysis. Real-time PCR was used to validate gene expression, and immunocytochemistry and immunoblotting to confirm the protein expression of regulated genes. RESULTS There was more than 2-fold upregulation of 328, 378, or 372 genes, and downregulation of 48, 33, or 28 genes with ET-1, ET-2, or ET-3 treatment, respectively, compared to untreated controls. The Bcl-2 family, S100 family, matrix metalloproteinases, c-Jun, and ET receptors were the major genes or proteins that were regulated by endothelin treatment. Immunocytochemical staining revealed a significant increase in ETA receptor, ETB receptor, growth associated protein 43 (GAP-43), phosphorylated c-Jun, c-Jun, and Bax with ET-1 treatment. Protein levels of GAP-43 and c-Jun were confirmed by immunoblotting. CONCLUSIONS Expression of key proteins having regulatory roles in apoptosis, calcium homeostasis, cell signaling, and matrix remodeling were altered by treatment with endothelins. The elucidation of molecular mechanisms underlying endothelins' actions in RGCs will help understand endothelin-mediated neurodegenerative changes during ocular hypertension.
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Affiliation(s)
- Shaoqing He
- Department of Cell Biology and Immunology, University of North Texas Health Science Center, Fort Worth, Texas, United States 2North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Yong H Park
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States 3Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Thomas Yorio
- North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States 3Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, United States
| | - Raghu R Krishnamoorthy
- Department of Cell Biology and Immunology, University of North Texas Health Science Center, Fort Worth, Texas, United States 2North Texas Eye Research Institute, University of North Texas Health Science Center, Fort Worth, Texas, United States
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7
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Xiang L, Mittwede PN, Clemmer JS. Glucose Homeostasis and Cardiovascular Alterations in Diabetes. Compr Physiol 2015; 5:1815-39. [DOI: 10.1002/cphy.c150001] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Nakaoka M, Iwai-Kanai E, Katamura M, Okawa Y, Mita Y, Matoba S. An alpha-adrenergic agonist protects hearts by inducing Akt1-mediated autophagy. Biochem Biophys Res Commun 2014; 456:250-6. [PMID: 25446079 DOI: 10.1016/j.bbrc.2014.11.067] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2014] [Accepted: 11/17/2014] [Indexed: 01/07/2023]
Abstract
Alpha-adrenergic agonists is known to be protective in cardiac myocytes from apoptosis induced by beta-adrenergic stimulation. Although there has been a recent focus on the role of cardiac autophagy in heart failure, its role in heart failure with adrenergic overload has not yet been elucidated. In the present study, we investigated the contribution of autophagy to cardiac failure during adrenergic overload both in vitro and in vivo. Neonatal rat cardiac myocytes overexpressing GFP-tagged LC3 were prepared and stimulated with the alpha1-adrenergic agonist, phenylephrine (PE), the beta-adrenergic agonist, isoproterenol (ISO), or norepinephrine (NE) in order to track changes in the formation of autophagosomes in vitro. All adrenergic stimulators increased cardiac autophagy by stimulating autophagic flux. Blocking autophagy by the knockdown of autophagy-related 5 (ATG5) exacerbated ISO-induced apoptosis and negated the anti-apoptotic effects of PE, which indicated the cardioprotective role of autophagy during adrenergic overload. PE-induced cardiac autophagy was mediated by the PI3-kinase/Akt pathway, but not by MEK/ERK, whereas both pathways mediated the anti-apoptotic effects of PE. Knock down of Akt1 was the most essential among the three Akt family members examined for the induction of cardiac autophagy. The four-week administration of PE kept the high level of cardiac autophagy without heart failure in vivo, whereas autophagy levels in a myocardium impaired by four-week persistent administration of ISO or NE were the same with the control state. These present study indicated that cardiac autophagy played a protective role during adrenergic overload and also that the Akt pathway could mediate cardiac autophagy for the anti-apoptotic effects of the alpha-adrenergic pathway.
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Affiliation(s)
- Mikihiko Nakaoka
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Eri Iwai-Kanai
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan; Faculty of Health Care, Tenri Health Care University, 80-1 Bessho-cho, Tenri, Nara 632-0018, Japan.
| | - Maki Katamura
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Yoshifumi Okawa
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Yuichiro Mita
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan
| | - Satoaki Matoba
- Department of Cardiovascular Medicine, Graduate School of Medical Science, Kyoto Prefectural University of Medicine, 465 Kajii-cho, Kamigyo-ku, Kyoto 602-8566, Japan
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Role of soluble adenylyl cyclase in cell death and growth. Biochim Biophys Acta Mol Basis Dis 2014; 1842:2646-55. [PMID: 25010002 DOI: 10.1016/j.bbadis.2014.06.034] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2014] [Revised: 06/26/2014] [Accepted: 06/27/2014] [Indexed: 12/13/2022]
Abstract
cAMP signaling is an evolutionarily conserved intracellular communication system controlling numerous cellular functions. Until recently, transmembrane adenylyl cyclase (tmAC) was considered the major source for cAMP in the cell, and the role of cAMP signaling was therefore attributed exclusively to the activity of this family of enzymes. However, increasing evidence demonstrates the role of an alternative, intracellular source of cAMP produced by type 10 soluble adenylyl cyclase (sAC). In contrast to tmAC, sAC produces cAMP in various intracellular microdomains close to specific cAMP targets, e.g., in nucleus and mitochondria. Ongoing research demonstrates involvement of sAC in diverse physiological and pathological processes. The present review is focused on the role of cAMP signaling, particularly that of sAC, in cell death and growth. Although the contributions of sAC to the regulation of these cellular functions have only recently been discovered, current data suggest that sAC plays key roles in mitochondrial bioenergetics and the mitochondrial apoptosis pathway, as well as cell proliferation and development. Furthermore, recent reports suggest the importance of sAC in several pathologies associated with apoptosis as well as in oncogenesis. This article is part of a Special Issue entitled: The role of soluble adenylyl cyclase in health and disease.
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He S, Minton AZ, Ma HY, Stankowska DL, Sun X, Krishnamoorthy RR. Involvement of AP-1 and C/EBPβ in upregulation of endothelin B (ETB) receptor expression in a rodent model of glaucoma. PLoS One 2013; 8:e79183. [PMID: 24265756 PMCID: PMC3827153 DOI: 10.1371/journal.pone.0079183] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2013] [Accepted: 09/23/2013] [Indexed: 12/31/2022] Open
Abstract
Previous studies showed that the endothelin B receptor (ETB) expression was upregulated and played a key role in neurodegeneration in rodent models of glaucoma. However, the mechanisms underlying upregulation of ETB receptor expression remain largely unknown. Using promoter-reporter assays, the 1258 bp upstream the human ETB promoter region was found to be essential for constitutive expression of ETB receptor gene in human non-pigmented ciliary epithelial cells (HNPE). The −300 to −1 bp and −1258 to −600 bp upstream promoter regions of the ETB receptor appeared to be the key binding regions for transcription factors. In addition, the crucial AP-1 binding site located at −615 to −624 bp upstream promoter was confirmed by luciferase assays and CHIP assays which were performed following overexpression of c-Jun in HNPE cells. Overexpression of either c-Jun or C/EBPβ enhanced the ETB receptor promoter activity, which was reflected in increased mRNA and protein levels of ETB receptor. Furthermore, knock-down of either c-Jun or C/EBPβ in HNPE cells was significantly correlated to decreased mRNA levels of both ETB and ETA receptor. These observations suggest that c-Jun and C/EBPβ are important for regulated expression of the ETB receptor in HNPE cells. In separate experiments, intraocular pressure (IOP) was elevated in one eye of Brown Norway rats while the corresponding contralateral eye served as control. Two weeks of IOP elevation produced increased expression of c-Jun and C/EBPβ in the retinal ganglion cell (RGC) layer from IOP-elevated eyes. The mRNA levels of c-Jun, ETA and ETB receptor were upregulated by 2.2-, 3.1- and 4.4-fold in RGC layers obtained by laser capture microdissection from retinas of eyes with elevated IOP, compared to those from contralateral eyes. Taken together, these data suggest that transcription factor AP-1 plays a key role in elevation of ETB receptor in a rodent model of ocular hypertension.
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Affiliation(s)
- Shaoqing He
- Department of Cell Biology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States of America
- * E-mail:
| | - Alena Z. Minton
- Department of Cell Biology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States of America
| | - Hai-Ying Ma
- Department of Pharmacology and Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, United States of America
| | - Dorota L. Stankowska
- Department of Cell Biology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States of America
| | - Xiangle Sun
- Department of Molecular Biology and Immunology, University of North Texas Health Science Center, Fort Worth, Texas, United States of America
| | - Raghu R. Krishnamoorthy
- Department of Cell Biology and Anatomy, University of North Texas Health Science Center, Fort Worth, Texas, United States of America
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Trypanosoma cruzi infection and endothelin-1 cooperatively activate pathogenic inflammatory pathways in cardiomyocytes. PLoS Negl Trop Dis 2013; 7:e2034. [PMID: 23409199 PMCID: PMC3566987 DOI: 10.1371/journal.pntd.0002034] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2012] [Accepted: 12/12/2012] [Indexed: 12/15/2022] Open
Abstract
Trypanosoma cruzi, the causative agent of Chagas' disease, induces multiple responses in the heart, a critical organ of infection and pathology in the host. Among diverse factors, eicosanoids and the vasoactive peptide endothelin-1 (ET-1) have been implicated in the pathogenesis of chronic chagasic cardiomyopathy. In the present study, we found that T. cruzi infection in mice induces myocardial gene expression of cyclooxygenase-2 (Cox2) and thromboxane synthase (Tbxas1) as well as endothelin-1 (Edn1) and atrial natriuretic peptide (Nppa). T. cruzi infection and ET-1 cooperatively activated the Ca2+/calcineurin (Cn)/nuclear factor of activated T cells (NFAT) signaling pathway in atrial myocytes, leading to COX-2 protein expression and increased eicosanoid (prostaglandins E2 and F2α, thromboxane A2) release. Moreover, T. cruzi infection of ET-1-stimulated cardiomyocytes resulted in significantly enhanced production of atrial natriuretic peptide (ANP), a prognostic marker for impairment in cardiac function of chagasic patients. Our findings support an important role for the Ca2+/Cn/NFAT cascade in T. cruzi-mediated myocardial production of inflammatory mediators and may help define novel therapeutic targets. Chronic cardiomyopathy is the most common and severe manifestation of human Chagas' disease, caused by the protozoan parasite Trypanosoma cruzi. Among diverse inflammation-promoting moieties, eicosanoids and the vasoactive peptide endothelin-1 (ET-1) have been implicated in its pathogenesis. Nevertheless, the link between these two factors has not yet been identified. In the present study, we found that T. cruzi infection induces gene expression of ET-1 and eicosanoid-forming enzymes in the heart of infected mice. We also demonstrated that HL-1 atrial myocytes respond to ET-1 stimulus and T. cruzi infection by induction of cyclooxygenase-2 through activation of the Ca2+/calcineurin/NFAT intracellular signaling pathway. Moreover, the cooperation between T. cruzi and ET-1 leads to overproduction of eicosanoids (prostaglandins E2 and F2α, thromboxane A2) and the pro-hypertrophic atrial natriuretic peptide. Our results support an important role for NFAT in T. cruzi plus ET-1-dependent induction of key agents of pathogenesis in chronic chagasic cardiomyopathy. Identification of the Ca2+/calcineurin/NFAT cascade as mediator of cardiovascular pathology in Chagas' disease advances our understanding of host-parasite interrelationship and may help define novel potential targets for therapeutic interventions to ameliorate or prevent cardiomyopathy during chronic T. cruzi infection.
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Abstract
Improved understanding of the pathophysiology of salt and water homeostasis has provided a foundation for explaining the renal mechanisms of emerging therapies for heart failure, as well as why renal function might potentially be improved or harmed. These aspects are reviewed in this article for a number of newer therapies including adenosine, endothelin, and vasopressin receptor antagonists, as well as extracorporeal ultrafiltration. An appreciation of the complexity and sometimes opposing pathways of these approaches may explain their limited efficacy in early trials, in which there has not been a substantial improvement in patient or renal outcomes. In that there is often a balance between beneficial and maladaptive receptor actions and neurohumoral responses, this physiologic approach also provides insight into the rationale for combining therapies. Multi-agent strategies may thus maximize their effectiveness while minimizing adverse effects and tolerance. In this paper, the theoretical impact of the emerging agents based on their mechanism of action and pathophysiology of the disease is initially addressed. Then, the available clinical evidence for each class of drugs is reviewed with special emphasis on their effect on kidney-related parameters. Finally, a general overview of the complexity of the interpretation of trials is offered along with a number of potential explanations for the observed results.
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Endothelin and endothelin receptors in the renal and cardiovascular systems. Life Sci 2012; 91:490-500. [PMID: 22480517 DOI: 10.1016/j.lfs.2012.03.026] [Citation(s) in RCA: 73] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2011] [Revised: 03/12/2012] [Accepted: 03/16/2012] [Indexed: 01/08/2023]
Abstract
Endothelin-1 (ET-1) is a multifunctional hormone which regulates the physiology of the cardiovascular and renal systems. ET-1 modulates cardiac contractility, systemic and renal vascular resistance, salt and water renal reabsorption, and glomerular function. ET-1 is responsible for a variety of cellular events: contraction, proliferation, apoptosis, etc. These effects take place after the activation of the two endothelin receptors ET(A) and ET(B), which are present - among others - on cardiomyocytes, fibroblasts, smooth muscle and endothelial cells, glomerular and tubular cells of the kidney. The complex and numerous intracellular pathways, which can be contradictory in term of functional response depending on the receptor type, cell type and physiological situation, are described in this review. Many diseases share an enhanced ET-1 expression as part of the pathophysiology. However, the use of endothelin blockers is currently restricted to pulmonary arterial hypertension, and more recently to digital ulcer. The complexity of the endothelin system does not facilitate the translation of the molecular knowledge to clinical applications. Endothelin antagonists can prevent disease development but secondary undesirable effects limit their usage. Nevertheless, the increasing understanding of the effects of ET-1 on the cardiac and renal physiology maintains the endothelin system as a promising therapeutic target.
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Insel PA, Zhang L, Murray F, Yokouchi H, Zambon AC. Cyclic AMP is both a pro-apoptotic and anti-apoptotic second messenger. Acta Physiol (Oxf) 2012; 204:277-87. [PMID: 21385327 DOI: 10.1111/j.1748-1716.2011.02273.x] [Citation(s) in RCA: 165] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The second messenger cyclic AMP (cAMP) can either stimulate or inhibit programmed cell death (apoptosis). Here, we review examples of cell types that show pro-apoptotic or anti-apoptotic responses to increases in cAMP. We also show that cells can have both such responses, although predominantly having one or the other. Protein kinase A (PKA)-promoted changes in phosphorylation and gene expression can mediate pro-apoptotic responses, such as in murine S49 lymphoma cells, based on evidence that mutants lacking PKA fail to undergo cAMP-promoted, mitochondria-dependent apoptosis. Mechanisms for the anti-apoptotic response to cAMP likely involve Epac (Exchange protein activated by cAMP), a cAMP-regulated effector that is a guanine nucleotide exchange factor (GEF) for the low molecular weight G-protein, Rap1. Therapeutic approaches that activate PKA-mediated pro-apoptosis or block Epac-mediated anti-apoptotisis may provide a means to enhance cell killing, such as in certain cancers. In contrast, efforts to block PKA or stimulate Epac have the potential to be useful in diseases settings (such as heart failure) associated with cAMP-promoted apoptosis.
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Affiliation(s)
- P A Insel
- Department of Pharmacology, University of California, San Diego, La Jolla, 92093-0636, USA.
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15
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Somvanshi RK, Chaudhari N, Qiu X, Kumar U. Heterodimerization of β2 adrenergic receptor and somatostatin receptor 5: Implications in modulation of signaling pathway. J Mol Signal 2011; 6:9. [PMID: 21838893 PMCID: PMC3166894 DOI: 10.1186/1750-2187-6-9] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Accepted: 08/12/2011] [Indexed: 12/17/2022] Open
Abstract
Background In the present study, we describe heterodimerization between human-Somatostatin Receptor 5 (hSSTR5) and β2-Adrenergic Receptor (β2AR) and its impact on the receptor trafficking, coupling to adenylyl cyclase and signaling including mitogen activated protein kinases and calcineurin-NFAT pathways. Methods We used co-immunoprecipitation, photobleaching- fluorescence resonance energy transfer and Fluorescence assisted cell sorting analysis to characterize heterodimerization between SSTR5 and β2AR. Results Our results indicate that hSSTR5/β2AR exist as preformed heterodimers in the basal condition which is enhanced upon co-activation of both receptors. In contrast, the activation of individual receptors leads to the dissociation of heterodimers. Receptor coupling to adenylyl cyclase displayed predominant effect of β2AR, however, somatostatin mediated inhibition of cAMP was enhanced upon blocking β2AR. Our results indicate hSSTR5 mediated significant activation of ERK1/2 and inhibition of phospho-p38. The phospho-NFAT level was enhanced in cotransfected cells indicating the blockade of calcineurin mediated dephosphorylation of NFAT upon receptor heterodimerization. Conclusion These data for the first time unveil a novel insight for the role of hSSTR5/β2AR in the modulation of signaling pathways which has not been addressed earlier.
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Affiliation(s)
- Rishi K Somvanshi
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, BC, Canada.
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16
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Baarine M, Thandapilly SJ, Louis XL, Mazué F, Yu L, Delmas D, Netticadan T, Lizard G, Latruffe N. Pro-apoptotic versus anti-apoptotic properties of dietary resveratrol on tumoral and normal cardiac cells. GENES AND NUTRITION 2011; 6:161-9. [PMID: 21541654 DOI: 10.1007/s12263-011-0232-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/08/2010] [Accepted: 04/21/2011] [Indexed: 12/20/2022]
Abstract
Resveratrol is a natural dietary polyphenol found in grape skin, red wine, and various other food products. Resveratrol has proved to be an effective chemopreventive agent for different malignant tumors. It has also been shown to prevent vascular alterations such as atherosclerosis and inflammatory-associated events. In view of these observations, we investigated the anti-proliferative and pro-apoptotic activities of resveratrol on a tumoral cardiac cell line (HL-1 NB) derived from mouse tumoral atrial cardiac myocytes. These effects were compared with those found on normal neonatal mouse cardiomyocytes. HL-1 NB cells and neonatal cardiomyocytes were treated with resveratrol (5, 30, and/or 100 μM) for different times of culture (24, 48, and/or 72 h). Resveratrol effects were determined by various microscopical and flow cytometric methods. After resveratrol treatment, a strong inhibition of tumoral cardiac HL1-NB cell growth associated with a loss of cell adhesion was observed. This cell proliferation arrest was associated with an apoptotic process revealed by an increased percentage of cells with fragmented and/or condensed nuclei (characteristic of apoptotic cells) identified after staining with Hoechst 33342 and by the presence of cells in subG1. At the opposite, on normal cardiomyocytes, no cytotoxic effects of resveratrol were observed, and a protective effect of resveratrol against norepinephrine-induced apoptosis was found on normal cardiomyocytes. Altogether, the present data demonstrate that resveratrol (1) induces apoptosis of tumoral cardiac HL1-NB cells, (2) does not induce cell death on normal cardiomyocytes, and (3) prevents norepinephrine-induced apoptosis on normal cardiomyocytes.
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Affiliation(s)
- Mauhamad Baarine
- Centre de Recherche Inserm UMR 866 (Lipides, Nutrition, Cancer), Université de Bourgogne, Equipe Biochimie Métabolique et Nutritionnelle-6, Bd Gabriel, Dijon, France
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17
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Rehsia NS, Dhalla NS. Potential of endothelin-1 and vasopressin antagonists for the treatment of congestive heart failure. Heart Fail Rev 2009; 15:85-101. [DOI: 10.1007/s10741-009-9152-z] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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18
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Cardioprotective signaling by endothelin. Trends Cardiovasc Med 2009; 18:233-9. [PMID: 19232951 DOI: 10.1016/j.tcm.2008.11.005] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/08/2008] [Revised: 11/18/2008] [Accepted: 11/20/2008] [Indexed: 02/08/2023]
Abstract
The endothelin axis promotes vasoconstriction, suggesting that antagonists of endothelin signaling might be useful in treatment of heart failure. However, promising results from animal trials have not been recapitulated in heart failure patients. Here we review the role of major signaling pathways in the heart that are involved in cell survival initiated by ET-1. These pathways include mitogen-activated protein kinase, phosphatidyl inositol-1,4,5-triphosphate kinase (PI3K-AKT), nuclear factor-kappaB (NF-kappaB), and calcineurin signaling. A better understanding of endothelin-mediated signaling in cardiac cell survival may allow a reevaluation of endothelin receptor antagonists (ETRAs) in the treatment of heart failure.
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Rodriguez-Collazo P, Snyder SK, Chiffer RC, Bressler EA, Voss TC, Anderson EP, Genieser HG, Smith CL. cAMP signaling regulates histone H3 phosphorylation and mitotic entry through a disruption of G2 progression. Exp Cell Res 2008; 314:2855-69. [PMID: 18644368 DOI: 10.1016/j.yexcr.2008.06.022] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2008] [Revised: 06/28/2008] [Accepted: 06/30/2008] [Indexed: 01/06/2023]
Abstract
cAMP signaling is known to have significant effects on cell growth, either inhibitory or stimulatory depending on the cell type. Study of cAMP-induced growth inhibition in mammalian somatic cells has focused mainly on the combined role of protein kinase A (PKA) and mitogen-activated protein (MAP) kinases in regulation of progression through the G1 phase of the cell cycle. Here we show that cAMP signaling regulates histone H3 phosphorylation in a cell cycle-dependent fashion, increasing it in quiescent cells but dramatically reducing it in cycling cells. The latter is due to a rapid and dramatic loss of mitotic histone H3 phosphorylation caused by a disruption in G2 progression, as evidenced by the inhibition of mitotic entry and decreased activity of the CyclinB/Cdk1 kinase. The inhibition of G2 progression induced through cAMP signaling is dependent on expression of the catalytic subunit of PKA and is highly sensitive to intracellular cAMP concentration. The mechanism by which G2 progression is inhibited is independent of both DNA damage and MAP kinase signaling. Our results suggest that cAMP signaling activates a G2 checkpoint by a unique mechanism and provide new insight into normal cellular regulation of G2 progression.
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Affiliation(s)
- Pedro Rodriguez-Collazo
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, MD 20892, USA
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20
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Deschamps AM, Zavadzkas J, Murphy RL, Koval CN, McLean JE, Jeffords L, Saunders SM, Sheats NJ, Stroud RE, Spinale FG. Interruption of endothelin signaling modifies membrane type 1 matrix metalloproteinase activity during ischemia and reperfusion. Am J Physiol Heart Circ Physiol 2007; 294:H875-83. [PMID: 18065523 DOI: 10.1152/ajpheart.00918.2007] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The matrix metalloproteinases (MMPs), in particular, membrane type 1 MMP (MT1-MMP), are increased in the context of myocardial ischemia and reperfusion (I/R) and likely contribute to myocardial dysfunction. One potential upstream induction mechanism for MT1-MMP is endothelin (ET) release and subsequent protein kinase C (PKC) activation. Modulation of ET and PKC signaling with respect to MT1-MMP activity with I/R has yet to be explored. Accordingly, this study examined in vivo MT1-MMP activation during I/R following modification of ET signaling and PKC activation. With the use of a novel fluorogenic microdialysis system, myocardial interstitial MT1-MMP activity was measured in pigs (30 kg; n = 9) during I/R (90 min I/120 min R). Local ET(A) receptor antagonism (BQ-123, 1 microM) and PKC inhibition (chelerythrine, 1 microM) were performed in parallel microdialysis probes. MT1-MMP activity was increased during I/R by 122 +/- 10% (P < 0.05) and was unchanged from baseline with ET antagonism and/or PKC inhibition. Selective PKC isoform induction occurred such that PKC-betaII increased by 198 +/- 31% (P < 0.05). MT1-MMP phosphothreonine, a putative PKC phosphorylation site, was increased by 121 +/- 8% (P < 0.05) in the I/R region. These studies demonstrate for the first time that increased interstitial MT1-MMP activity during I/R is a result of the ET/PKC pathway and may be due to enhanced phosphorylation of MT1-MMP. These findings identify multiple potential targets for modulating a local proteolytic pathway operative during I/R.
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Affiliation(s)
- Anne M Deschamps
- Division of Cardiothoracic Surgery, Medical University of South Carolina, Charleston, SC 29403, USA
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21
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Lirussi F, Rakotoniaina Z, Madani S, Goirand F, Breuiller-Fouché M, Leroy MJ, Sagot P, Morrison JJ, Dumas M, Bardou M. ADRB3 adrenergic receptor is a key regulator of human myometrial apoptosis and inflammation during chorioamnionitis. Biol Reprod 2007; 78:497-505. [PMID: 17989355 DOI: 10.1095/biolreprod.107.064444] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
The pathophysiology underlying preterm labor triggered by inflammatory conditions such as chorioamnionitis remains largely unclear. It has already been suggested that beta-3 adrenergic (ADRB3) agonists might be of interest in the pharmacological management of preterm labor. Although there is evidence implicating ADRB receptors in the control of inflammation, there are minimal data relating specifically to ADRB3. To explore the cellular consequences of chorioamnionitis and detect apoptosis, we first performed immunostaining and Western blot experiments on human myometrial samples obtained from women with confirmed chorioamnionitis. We then developed an in vitro model of chorioamnionitis by incubating the myometrial samples obtained from uncomplicated pregnancies with Escherichia coli lipopolysaccharide (LPS). We observed that chorioamnionitis was associated with a significant increase in cleaved CASP3 protein expression, as well as chromatin condensation, which were reproduced experimentally by LPS stimulation (10 microg/ml, 48 h). Lipopolysaccharide stimulation of normal human myometrium also induced CASP3 transcripts, increased the proapoptotic marker BAX, and decreased the antiapoptotic marker BCL2. Lipopolysaccharide-induced apoptosis was antagonized by neutralization of secreted tumor necrosis factor by a specific antibody. Furthermore, LPS stimulation increased medium culture levels of proinflammatory cytokines interleukin 6 (IL6) and IL8. Lipopolysaccharide-induced apoptosis and cytokine production were prevented by the new and potent ADRB3 agonist SAR150640 in a concentration-dependent manner. SAR150640 by itself did not exhibit any effect on apoptosis or cytokine production in control tissues. This study shows that chorioamnionitis is associated with apoptosis of human myometrial cells. It emphasizes the potential therapeutic interest of ADRB3 agonists in the field of preterm labor and other inflammatory conditions.
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Affiliation(s)
- Fréderic Lirussi
- Laboratoire de Physiologie et Pharmacologie Cardiovasculaires Expérimentales (LPPCE, EA279, IFR Santé-STIC), Faculté de Médecine, Université de Bourgogne, Dijon, France
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22
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Zecchin KG, Seidinger ALO, Chiaratti MR, Degasperi GR, Meirelles FV, Castilho RF, Vercesi AE. High Bcl-2/Bax ratio in Walker tumor cells protects mitochondria but does not prevent H2O2-induced apoptosis via calcineurin pathways. J Bioenerg Biomembr 2007; 39:186-94. [PMID: 17431754 DOI: 10.1007/s10863-007-9076-z] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2007] [Accepted: 03/08/2007] [Indexed: 12/18/2022]
Abstract
It has been previously shown that Walker 256 tumor cells express a high content of the anti-apoptotic protein Bcl-2 which protects mitochondria against the damaging effects of Ca(2+). In the present study, we analyze H(2)O(2)-induced apoptotic death in two different types of tumor cells: Walker 256 and SCC-25. Treatment with H(2)O(2) (4mM) increased reactive oxygen species generation and the concentration of cytosolic free Ca(2+). These alterations preceded apoptosis in both cell lines. In Walker cells, which show a high Bcl-2/Bax ratio, apoptosis was dependent on calcineurin activation and independent of changes in mitochondrial membrane potential (DeltaPsi(m)), as well as cytochrome c release. In contrast, in SCC-25 cells, which show a lower Bcl-2/Bax ratio, apoptosis was preceded by a decrease in DeltaPsi(m), mitochondrial permeability transition, and cytochrome c release. Caspase-3 activation occurred in both cell lines. The data suggest that although the high Bcl-2/Bax ratio protected the mitochondria of Walker cells from oxidative stress, it was not sufficient to prevent apoptosis through calcineurin pathways.
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Affiliation(s)
- Karina G Zecchin
- Departamento de Patologia Clínica, Faculdade de Ciências Médicas, Universidade Estadual de Campinas (UNICAMP), Campinas, SP 13083-887, Brazil
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23
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Abstract
Because the number of transplants is still fewer than the number of patients waiting for a donor organ, new concepts of therapy are needed that allow patients to bridge the time gap until heart transplantation or even to improve symptoms while on treatment. Ca(2+)-sensitisers are agents that directly influence myofilaments and/or the cross-bridge-cycle. Depending on the molecular mechanisms underlying their action, Ca(2+)-sensitisers have been divided into three classes. While, a number of Ca(2+)-sensitising drugs have been described, currently only the Ca(2+)-sensitisers pimobendan and levosimendan are in clinical use. This review provides a survey on the molecular mechanisms and the therapeutic effectiveness of Ca(2+)-sensitisers for the treatment of human heart failure.
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Affiliation(s)
- Klara Brixius
- Laboratory of Muscle Research and Molecular Cardiology, Department of Internal Medicine III, University of Cologne, Cologne
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24
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Johnson-Anuna LN, Eckert GP, Franke C, Igbavboa U, Müller WE, Wood WG. Simvastatin protects neurons from cytotoxicity by up-regulating Bcl-2 mRNA and protein. J Neurochem 2007; 101:77-86. [PMID: 17241114 DOI: 10.1111/j.1471-4159.2006.04375.x] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Statins are most commonly prescribed to reduce hypercholesterolemia; however, recent studies have shown that statins have additional benefits, including neuroprotection. Until now, the mechanism underlying statin-induced neuroprotection has been poorly understood. Recent in vivo studies from our lab reported the novel finding that simvastatin increased expression levels of a gene encoding for a major cell survival protein, bcl-2 [Johnson-Anuna et al., J. Pharmacol. Exp. Ther.312 (2005) 786]. The purpose of the present experiments was to determine if simvastatin could protect neurons from excitotoxicity by altering Bcl-2 levels. Neurons were pre-treated with simvastatin and challenged with a compound known to reduce Bcl-2 levels and induce cell death. Simvastatin pre-treatment resulted in a significant reduction in cytotoxicity (lactate dehydrogenase release and caspase 3 activation) following challenge compared with unchallenged neurons. In addition, chronic simvastatin treatment significantly increased Bcl-2 mRNA and protein levels while challenge resulted in a significant reduction in Bcl-2 protein abundance. G3139, an antisense oligonucleotide directed against Bcl-2, abolished the protective effects of simvastatin and eliminated simvastatin-induced up-regulation of Bcl-2 protein. These findings suggest that neuroprotection by simvastatin is dependent on the drug's previously unexplored and important effect of up-regulating Bcl-2.
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Affiliation(s)
- Leslie N Johnson-Anuna
- Department of Pharmacology, University of Minnesota School of Medicine, Geriatric Research, Education and Clinical Center, VA Medical Center, Minneapolis, Minnesota 55417, USA
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25
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Raymond MN, Bole-Feysot C, Banno Y, Tanfin Z, Robin P. Endothelin-1 inhibits apoptosis through a sphingosine kinase 1-dependent mechanism in uterine leiomyoma ELT3 cells. Endocrinology 2006; 147:5873-82. [PMID: 16959847 DOI: 10.1210/en.2006-0291] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Uterine leiomyomas, or fibroids, are the most common tumors of the myometrium. The ELT3 cell line, derived from Eker rat leiomyoma, has been successfully used as a model for the study of leiomyomas. We have demonstrated previously the potent mitogenic properties of the peptidic hormone endothelin (ET)-1 in this cell line. Here we investigated the antiapoptotic effect of ET-1 in ELT3 cells. We found that 1) serum starvation of ELT3 cells induced an apoptotic process characterized by cytochrome c release from mitochondria, caspase-3/7 activation, nuclei condensation and DNA fragmentation; 2) ET-1 prevented the apoptotic process; and 3) this effect of ET-1 was fully reproduced by ETB agonists. In contrast, no antiapoptotic effect of ET-1 was observed in normal myometrial cells. A pharmacological approach showed that the effect of ET-1 on caspase-3/7 activation in ELT3 cells was not dependent on phosphatidylinositol 3-kinase, ERK1/2, or phospholipase D activities. However, inhibitors of sphingosine kinase-1 (SphK1), dimethylsphingosine and threo-dihydrosphingosine, reduced the effect of ET-1 by about 50%. Identical results were obtained when SphK1 expression was down-regulated in ELT3 cells transfected with SphK1 small interfering RNA. Furthermore, serum starvation induced a decrease in SphK1 activity that was prevented by ET-1 without affecting the level of SphK1 protein expression. Finally, sphingosine 1-phosphate, the product of SphK activity, was as efficient as ET-1 in inhibiting serum starvation-induced caspase-3/7 activation. Together, these results demonstrate that ET-1 possesses a potent antiapoptotic effect in ELT3 cells that involves sphingolipid metabolism through the activation of SphK1.
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Affiliation(s)
- Marie-Noëlle Raymond
- Signalisation et Régulations Cellulaires, Institut de Biochimie et Biophysique Moléculaire et Cellulaire, Centre National de la Recherche Scientifique, Unité Mixte de Recherche 8619, Bâtiment 430, Université Paris Sud, 91 S/R/C 405 Orsay Cedex, France
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26
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Leineweber K, Aker S, Beilfuß A, Rekasi H, Konietzka I, Martin C, Heusch G, Schulz R. Inhibition of Na+/H+-exchanger with sabiporide attenuates the downregulation and uncoupling of the myocardial beta-adrenoceptor system in failing rabbit hearts. Br J Pharmacol 2006; 148:137-46. [PMID: 16520740 PMCID: PMC1617059 DOI: 10.1038/sj.bjp.0706714] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
Abstract
Chronic heart failure (HF) is characterized by left ventricular (LV) structural remodeling, impaired function, increased circulating noradrenaline (NA) levels and impaired responsiveness of the myocardial beta-adrenoceptor (betaAR)-adenylyl cyclase (AC) system. In failing hearts, inhibition of the sodium/proton-exchanger (NHE)-1 attenuates LV remodeling and improves LV function. The mechanism(s) involved in these cardioprotective effects remain(s) unclear, but might involve effects on the impaired betaAR-AC system. Therefore, we investigated whether NHE-1 inhibition with sabiporide (SABI; 30 mg kg(-1) day(-1) p.o.) might affect myocardial betaAR density and AC activity in relation to changes in LV end-diastolic diameter (LVEDD) and LV systolic fractional shortening (LVS-FS) after 3 weeks of rapid LV pacing in rabbits. After 3 weeks of rapid LV pacing LVEDD was significantly increased (Shams 17+/-0.2 mm, n=9 vs 3 wksHF 20+/-0.5 mm, n=8; P<0.05) and LVS-FS decreased (Shams 31+/-1%, n=9 vs 3 wksHF 10+/-1%, n=8; P<0.05). SABI treatment significantly improved LV function independent of whether rabbits were treated after 1 week of pacing (3 wksHF+2 wksSABI (n=7): LVEDD 18+/-1 mm; LVS-FS 16+/-4%) or before pacing (3 wksHF+3wksSABI (n=9): LVEDD 18+/-1 mm; LVS-FS 18+/-6%). After 3 weeks of rapid LV pacing, SABI treatment significantly attenuated increases in serum NA content (Shams 0.83+/-0.19, 3 wksHF 2.68+/-0.38, 3 wksHF+2 wksSABI 1.22+/-0.32, 3 wksHF+3wksSABI 1.38+/-0.33 ng ml(-1)). Moreover, betaAR density (Shams 64+/-5, 3 wksHF 38+/-3, 3 wksHF+2 wksSABI 48+/-4, 3 wksHF+3 wksSABI 55+/-3 fmol mg(-1) protein) and responsiveness (isoprenaline-stimulated AC activity. (Shams 57.6+/-4.9, 3 wksHF 36.3+/-6.0, 3 wksHF+2 wksSABI 56.9+/-6.0, 3 wksHF+3 wksSABI 54.5+/-4.8 pmol cyclic AMP mg(-1) protein(-1) min(-1)) were significantly improved in SABI-treated rabbits. From the present data we cannot address whether the improved betaAR-AC system permitted improved LV function and/or whether the improved LV function resulted in less activation of the sympathetic nervous system and by this in a reduced stimulation of the betaAR-AC system. Accordingly, additional studies are needed to fully establish the cause-and-effect relationship between NHE-1 inhibition and the restoration of the myocardial betaAR system.
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Affiliation(s)
- Kirsten Leineweber
- Institute of Pathophysiology, University of Essen School of Medicine, D-45122 Essen, Germany
| | - Stephanie Aker
- Institute of Pathophysiology, University of Essen School of Medicine, D-45122 Essen, Germany
| | - Anja Beilfuß
- Institute of Pathophysiology, University of Essen School of Medicine, D-45122 Essen, Germany
| | - Heike Rekasi
- Institute of Pathophysiology, University of Essen School of Medicine, D-45122 Essen, Germany
| | - Ina Konietzka
- Institute of Pathophysiology, University of Essen School of Medicine, D-45122 Essen, Germany
| | - Claus Martin
- Institute of Pathophysiology, University of Essen School of Medicine, D-45122 Essen, Germany
| | - Gerd Heusch
- Institute of Pathophysiology, University of Essen School of Medicine, D-45122 Essen, Germany
| | - Rainer Schulz
- Institute of Pathophysiology, University of Essen School of Medicine, D-45122 Essen, Germany
- Author for correspondence:
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27
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Penna C, Rastaldo R, Mancardi D, Cappello S, Pagliaro P, Westerhof N, Losano G. Effect of endothelins on the cardiovascular system. J Cardiovasc Med (Hagerstown) 2006; 7:645-52. [PMID: 16932076 DOI: 10.2459/01.jcm.0000242996.19077.ba] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
Endothelins (ETs) exert a persistent constrictor effect on the vessels via an increase in intracellular Ca2+ concentration due to the activation of Na+/H+ and Na+/Ca2+ exchangers of the vascular smooth muscle fibres. They also produce a transient dilator effect via the activation of endothelial nitric oxide synthase mediated by protein kinase B/Akt. ETA and ETB2 receptors are involved in vasoconstriction, whereas transient vasodilatation depends on the activation of ETB1 receptors. Depending on animal species and experimental conditions, ETs can also play a role in cardiac muscle contraction and induce either an increase or a decrease in contractility. It is likely that only ETA, and not ETB, receptors are involved in the ET-induced increase in myocardial contractility. As in the case of vasoconstriction, this inotropic effect depends on an increase in intracellular Ca2+ concentration induced by Na+/H+ and Na+/Ca2+ exchangers. Activation of the Na+/H+ exchanger is stimulated by protein kinase C, which is activated by diacylglycerol released in response to ET activity. It has also been proposed that the positive inotropic effect can occur without the contribution of the Na+/Ca2+ exchanger, if the cell alkalinisation produced by the Na/H exchanger improves myofibrillar Ca2+ sensitivity. A reduction in contractility has been attributed to the involvement of the Gi protein/protein kinase G pathway or to the activation of protein kinase C without an increase in intracellular Ca2+ concentration or in myofibrillar Ca2+ sensitivity. The chronic effect of ETs on the myocardium results in hypertrophy and prevention of apoptosis, two processes that are together responsible for the contradictory effect of ETs in heart failure.
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Affiliation(s)
- Claudia Penna
- Department of Clinical and Biological Sciences, University of Turin, Turin, Italy
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28
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Abstract
Zinc plays a vital role in various cellular functions. Zinc deprivation is associated with severe disorders related to growth, maturation, and stress responses. In the heart, zinc affects differentiation and regeneration of cardiac muscle, cardiac conductance, acute stress responses, and recovery of heart transplants. Recent discoveries of the molecular players in zinc homeostasis revealed that the amount of intracellular free zinc is tightly controlled on the level of uptake, intracellular sequestration, redistribution, storage, and elimination, consequently creating a narrow window of optimal zinc concentration in the cells. Most of intracellular zinc is bound to numerous structural and regulatory proteins, with metabolically active, labile zinc present in picoto nanomolar concentrations. The central position of zinc in the redox signaling network is built on its unique chemical nature. The redox inert zinc creates a redox active environment when it binds to a sulfur ligand. The reversible oxidation of the sulfur ligand is coupled to the reversible zinc release from the protein, thereby executing the task of so-called protein "redox zinc switch." Clearly, the impairment of zinc homeostasis will have far reaching physiological consequences.
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Affiliation(s)
- Irina Korichneva
- Department of Medicine, Division of Cardiovascular Diseases and Hypertension, UMDNJ-Robert Wood Johnson Medical School, New Brunswick, New Jersey 08903, USA.
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Buchholz M, Schatz A, Wagner M, Michl P, Linhart T, Adler G, Gress TM, Ellenrieder V. Overexpression of c-myc in pancreatic cancer caused by ectopic activation of NFATc1 and the Ca2+/calcineurin signaling pathway. EMBO J 2006; 25:3714-24. [PMID: 16874304 PMCID: PMC1538549 DOI: 10.1038/sj.emboj.7601246] [Citation(s) in RCA: 217] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2005] [Revised: 05/23/2006] [Accepted: 06/26/2006] [Indexed: 12/25/2022] Open
Abstract
The nuclear factor of activated T cell (NFAT) proteins are a family of Ca2+/calcineurin-responsive transcription factors primarily recognized for their central roles in T lymphocyte activation and cardiac valve development. We demonstrate that NFATc1 is commonly overexpressed in pancreatic carcinomas and enhances the malignant potential of tumor cells through transcriptional activation of the c-myc oncogene. Activated NFATc1 directly binds to a specific element within the proximal c-myc promoter and upregulates c-myc transcription, ultimately resulting in increased cell proliferation and enhanced anchorage-independent growth. Conversely, c-myc transcription and anchorage-dependent and -independent cell growth is significantly attenuated by inhibition of Ca2+/calcineurin signaling or siRNA-mediated knock down of NFATc1 expression. Together, these results demonstrate that ectopic activation of NFATc1 and the Ca2+/calcineurin signaling pathway is an important mechanism of oncogenic c-myc activation in pancreatic cancer.
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Affiliation(s)
- Malte Buchholz
- Translational Genome Research Group, Department of Internal Medicine I, University of Ulm, Ulm, Germany
- Department of Gastroenterology and Endocrinology, University of Marburg, Marburg, Germany
| | - Alexandra Schatz
- Signal Transduction Laboratory, Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Martin Wagner
- Clinical GI research, Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Patrick Michl
- Translational Genome Research Group, Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Thomas Linhart
- Signal Transduction Laboratory, Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Guido Adler
- Clinical GI research, Department of Internal Medicine I, University of Ulm, Ulm, Germany
| | - Thomas M Gress
- Translational Genome Research Group, Department of Internal Medicine I, University of Ulm, Ulm, Germany
- Department of Gastroenterology and Endocrinology, University of Marburg, Marburg, Germany
| | - Volker Ellenrieder
- Signal Transduction Laboratory, Department of Internal Medicine I, University of Ulm, Ulm, Germany
- Department of Gastroenterology and Endocrinology, University of Marburg, Marburg, Germany
- Innere Medizin, SP Gastroenterologie, Universitaet Marburg, Baldingerstraβe, 35043 Marburg, Germany. Tel.: +49 6421 286 2318; Fax: +49 6421 286 8922; E-mail:
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Shemarova IV, Nesterov VP. Role of Ca2+ and transmitters of the sympathetic nervous system in transduction of stress signal in cardiomyocytes. J EVOL BIOCHEM PHYS+ 2006. [DOI: 10.1134/s0022093006020013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Chagnon F, Metz CN, Bucala R, Lesur O. Endotoxin-induced myocardial dysfunction: effects of macrophage migration inhibitory factor neutralization. Circ Res 2005; 96:1095-102. [PMID: 15879312 DOI: 10.1161/01.res.0000168327.22888.4d] [Citation(s) in RCA: 97] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The pathophysiology of sepsis-induced myocardial dysfunction still remains controversial. Macrophage migration inhibitory factor (MIF) has recently been identified as a cardiac-derived myocardial depressant factor in septic shock. Putative mechanisms by which MIF affects cardiac function are unknown. In an investigation of possible mechanisms of action, a rat model of endotoxin toxicity was designed using intraperitoneal (I/P) injection of lipopolysaccharides (LPS) with or without coinfusion of neutralizing anti-MIF or isotypic-matched antibodies. Echocardiographic evaluation revealed that MIF neutralization reversed endotoxin-induced myocardial dysfunction at 24 hours after injection. RNase protection assay (RPA) and Western blot established that MIF neutralization prevented LPS-induced mRNA expression and production of heart-derived inflammatory paracrine and autocrine cytokines such as IL-1s and IL-6. Moreover, MIF immunoneutralization increased heart Bcl-2/Bax protein ratio and suppressed endotoxin-induced release of mitochondrial cytochrome-c, as demonstrated by Western blotting. Inhibition of mitochondrial loss of cytochrome-c decreased in heart caspase-3 activity at 6 and 24 hours after injection. MIF neutralization also restored the LPS-induced deficient nuclear translocation of phospho-Akt and consequently the expression of the heart survival nuclear factor GATA-4. The restoration of the translocation/expression of survival factors by MIF inhibition resulted in lowered endotoxin-induced DNA fragmentation at 24 hours, a hallmark of downstream cardiomyocyte apoptosis. Our data indicate that early inactivation of MIF significantly reverses the imbalance of proapoptotic to prosurvival pathways and reduces acute inflammation of the heart thereby improving myocardial dysfunction induced by endotoxin.
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Affiliation(s)
- Frederic Chagnon
- Groupe de Recherche en Physiopathologie Respiratoire, Centre de Recherche Clinique, Universite de Sherbrooke, PQ, Canada
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Suzuki YJ, Nagase H, Nie K, Park AM. Redox control of growth factor signaling: recent advances in cardiovascular medicine. Antioxid Redox Signal 2005; 7:829-34. [PMID: 15890031 DOI: 10.1089/ars.2005.7.829] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Growth factors play vital roles in the regulation of various biologic processes, including those in cardiovascular and respiratory systems. Accumulating evidence suggests that reactive oxygen species mediate growth factor signal transduction. The discovery of reactive oxygen species production by angiotensin II in vascular smooth muscle cells via the activation of NAD(P)H oxidase promoted studies of redox control of growth factor signaling. In the past few years, there have been further advances in this field. In addition to established roles of reactive oxygen species in vascular smooth muscle growth, these species have been demonstrated to serve as second messengers for cardiac hypertrophy induced by angiotensin II. NAD(P)H oxidase also produces reactive oxygen species in response to endothelin-1 in vascular smooth muscle and cardiac muscle cells. These results suggest that inhibiting NAD(P)H oxidase might be a useful therapeutic strategy. In fact, adenovirus-mediated gene transfer appears to be an effective approach to prevent vascular hypertrophy in rodent models. Growth factors also induce survival signaling in cardiac and smooth muscle cells, and redox control may play a role in such events. It is likely that studies reporting the mechanisms of redox control of growth factor signaling will rapidly emerge in the next several years, and understanding of such regulation should help in the development of therapeutic strategies against heart and lung diseases.
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Affiliation(s)
- Yuichiro J Suzuki
- Department of Pharmacology, Georgetown University Medical Center, Washington, DC 20057, USA.
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