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Hulsurkar MM, Lahiri SK, Karch J, Wang MC, Wehrens XH. Targeting calcium-mediated inter-organellar crosstalk in cardiac diseases. Expert Opin Ther Targets 2022; 26:303-317. [PMID: 35426759 PMCID: PMC9081256 DOI: 10.1080/14728222.2022.2067479] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
INTRODUCTION Abnormal calcium signaling between organelles such as the sarcoplasmic reticulum (SR), mitochondria and lysosomes is a key feature of heart diseases. Calcium serves as a secondary messenger mediating inter-organellar crosstalk, essential for maintaining the cardiomyocyte function. AREAS COVERED This article examines the available literature related to calcium channels and transporters involved in inter-organellar calcium signaling. The SR calcium-release channels ryanodine receptor type-2 (RyR2) and inositol 1,4,5-trisphosphate receptor (IP3R), and calcium-transporter SR/ER-ATPase 2a (SERCA2a) are illuminated. The roles of mitochondrial voltage-dependent anion channels (VDAC), the mitochondria Ca2+ uniporter complex (MCUC), and the lysosomal H+/Ca2+ exchanger, two pore channels (TPC), and transient receptor potential mucolipin (TRPML) are discussed. Furthermore, recent studies showing calcium-mediated crosstalk between the SR, mitochondria, and lysosomes as well as how this crosstalk is dysregulated in cardiac diseases are placed under the spotlight. EXPERT OPINION Enhanced SR calcium release via RyR2 and reduced SR reuptake via SERCA2a, increased VDAC and MCUC-mediated calcium uptake into mitochondria, and enhanced lysosomal calcium-release via lysosomal TPC and TRPML may all contribute to aberrant calcium homeostasis causing heart disease. While mechanisms of this crosstalk need to be studied further, interventions targeting these calcium channels or combinations thereof might represent a promising therapeutic strategy.
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Affiliation(s)
- Mohit M. Hulsurkar
- Cardiovascular Research Institute
- Department of Molecular Physiology & Biophysics
| | - Satadru K. Lahiri
- Cardiovascular Research Institute
- Department of Molecular Physiology & Biophysics
| | - Jason Karch
- Cardiovascular Research Institute
- Department of Molecular Physiology & Biophysics
| | - Meng C. Wang
- Cardiovascular Research Institute
- Huffington Center on Aging
- Department of Molecular and Human Genetics
- Howard Hughes Medical Institute
| | - Xander H.T. Wehrens
- Cardiovascular Research Institute
- Department of Molecular Physiology & Biophysics
- Dept. of Medicine (Cardiology)
- Dept. of Neuroscience
- Dept. of Pediatrics (Cardiology)
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2
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Tammineni ER, Hurtado-Monzón AM, García MC, Carrillo ED, Hernández A, María Del Ángel R, Sánchez JA. Dantrolene hinders dengue virus-induced upregulation and translocation of calmodulin to cardiac cell nuclei. Virology 2020; 553:81-93. [PMID: 33249258 DOI: 10.1016/j.virol.2020.11.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Revised: 11/14/2020] [Accepted: 11/15/2020] [Indexed: 11/19/2022]
Abstract
Dengue virus (DENV) infection elevates intracellular Ca2+ concentration ([Ca2+]i), but it is unknown whether Ca2+ and calmodulin (CaM) are involved in DENV infection. We conducted immunofluorescence and western blot experiments and measured [Ca2+]i examining the effects of DENV infection and drugs that alter Ca2+/CaM functions on CaM translocation, DENV2 infection, protein expression, virus-inducible STAT2 protein abundance, and CREB phosphorylation in H9c2 cells. DENV infection increased CaM expression, its nuclear translocation and NS3 and E viral proteins expression and colocalization in a manner that could be blocked by the ryanodine receptor antagonist dantrolene. DENV infection also increased CREB phosphorylation, an effect inhibited by either dantrolene or the CaM inhibitor W7. Dantrolene substantially hindered infection as assessed by focus assays in Vero cells. These results suggest that Ca2+ and CaM play an important role in DENV infection of cardiac cells and that dantrolene may protect against severe DENV cardiac morbidity.
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Affiliation(s)
- Eshwar Reddy Tammineni
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico
| | - Arianna Mahely Hurtado-Monzón
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico
| | - María Carmen García
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico
| | - Elba Dolores Carrillo
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico
| | - Ascención Hernández
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico
| | - Rosa María Del Ángel
- Departamento de Infectómica y Patogénesis Molecular, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico
| | - Jorge Alberto Sánchez
- Departamento de Farmacología, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Mexico.
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Walsh KB, Li H, Koley G. Graphene alters the properties of voltage-gated Ca
2+
channels in rat cardiomyocytes. Biomed Phys Eng Express 2018. [DOI: 10.1088/2057-1976/aad0cd] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Fernandes VFL, Macaspac C, Lu L, Yoshizawa M. Evolution of the developmental plasticity and a coupling between left mechanosensory neuromasts and an adaptive foraging behavior. Dev Biol 2018; 441:262-271. [PMID: 29782817 DOI: 10.1016/j.ydbio.2018.05.012] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2018] [Revised: 05/10/2018] [Accepted: 05/15/2018] [Indexed: 11/30/2022]
Abstract
Many animal species exhibit laterality in sensation and behavioral responses, namely, the preference for using either the left or right side of the sensory system. For example, some fish use their left eye when observing social stimuli, whereas they use their right eye to observe novel objects. However, it is largely unknown whether such laterality in sensory-behavior coupling evolves during rapid adaptation processes. Here, in the Mexican tetra, Astyanax mexicanus, we investigate the laterality in the relationship between an evolved adaptive behavior, vibration attraction behavior (VAB), and its main sensors, mechanosensory neuromasts. A. mexicanus has a surface-dwelling form and cave-dwelling forms (cavefish), whereby a surface fish ancestor colonized the new environment of a cave, eventually evolving cave-type morphologies such as increased numbers of neuromasts at the cranium. These neuromasts are known to regulate VAB, and it is known that, in teleosts, the budding (increasing) process of neuromasts is accompanied with dermal bone formation. This bone formation is largely regulated by endothelin signaling. To assess the evolutionary relationship between bone formation, neuromast budding, and VAB, we treated 1-3 month old juvenile fish with endothelin receptor antagonists. This treatment significantly increased cranial neuromasts in both surface and cavefish, and the effect was significantly more pronounced in cavefish. Antagonist treatment also increased the size of dermal bones in cavefish, but neuromast enhancement was observed earlier than dermal bone formation, suggesting that endothelin signaling may independently regulate neuromast development and bone formation. In addition, although we did not detect a major change in VAB level under this antagonist treatment, cavefish did show a positive correlation of VAB with the number of neuromasts on their left side but not their right. This laterality in correlation was observed when VAB emerged during cavefish development, but it was not seen in surface fish under any conditions tested, suggesting this laterality emerged through an evolutionary process. Above all, cavefish showed higher developmental plasticity in neuromast number and bone formation, and they showed an asymmetric correlation between the number of left-right neuromasts and VAB.
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Affiliation(s)
| | - Christian Macaspac
- Department of Biology, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - Louise Lu
- Department of Biology, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA
| | - Masato Yoshizawa
- Department of Biology, University of Hawai'i at Mānoa, Honolulu, HI 96822, USA.
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5
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Garcia MI, Boehning D. Cardiac inositol 1,4,5-trisphosphate receptors. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2016; 1864:907-914. [PMID: 27884701 DOI: 10.1016/j.bbamcr.2016.11.017] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 11/16/2016] [Accepted: 11/16/2016] [Indexed: 10/20/2022]
Abstract
Calcium is a second messenger that regulates almost all cellular functions. In cardiomyocytes, calcium plays an integral role in many functions including muscle contraction, gene expression, and cell death. Inositol 1,4,5-trisphosphate receptors (IP3Rs) are a family of calcium channels that are ubiquitously expressed in all tissues. In the heart, IP3Rs have been associated with regulation of cardiomyocyte function in response to a variety of neurohormonal agonists, including those implicated in cardiac disease. Notably, IP3R activity is thought to be essential for mediating the hypertrophic response to multiple stimuli including endothelin-1 and angiotensin II. In this review, we will explore the functional implications of IP3R activity in the heart in health and disease.
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Affiliation(s)
- M Iveth Garcia
- Cell Biology Graduate Program, University of Texas Medical Branch, Galveston, TX 77555, United States; Department of Biochemistry and Molecular Biology, McGovern Medical School at UTHealth, Houston, TX 77030, United States
| | - Darren Boehning
- Department of Biochemistry and Molecular Biology, McGovern Medical School at UTHealth, Houston, TX 77030, United States.
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Paradis A, Xiao D, Zhou J, Zhang L. Endothelin-1 promotes cardiomyocyte terminal differentiation in the developing heart via heightened DNA methylation. Int J Med Sci 2014; 11:373-80. [PMID: 24578615 PMCID: PMC3936032 DOI: 10.7150/ijms.7802] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/03/2013] [Accepted: 12/17/2013] [Indexed: 01/08/2023] Open
Abstract
AIMS Hypoxia is a major stress on fetal development and leads to induction of endothelin-1 (ET-1) expression. We tested the hypothesis that ET-1 stimulates the terminal differentiation of cardiomyocytes from mononucleate to binucleate in the developing heart. METHODS AND RESULTS Hypoxia (10.5% O2) treatment of pregnant rats from day 15 to day 21 resulted in a significant increase in prepro-ET-1 mRNA expression in fetal hearts. ET-1 ex vivo treatment of fetal rat cardiomyocytes increased percent binucleate cells and decreased Ki-67 expression, a marker for proliferation, under both control and hypoxic conditions. Hypoxia alone decreased Ki-67 expression and in conjunction with ET-1 treatment decreased cardiomyocyte size. PD145065, a non-selective ET-receptor antagonist, blocked the changes in binucleation and proliferation caused by ET-1. DNA methylation in fetal cardiomyocytes was significantly increased with ET-1 treatment, which was blocked by 5-aza-2'-deoxycytidine, a DNA methylation inhibitor. In addition, 5-aza-2'-deoxycytidine treatment abrogated the increase in binucleation and decrease in proliferation induced by ET-1. CONCLUSIONS Hypoxic stress and synthesis of ET-1 increases DNA methylation and promotes terminal differentiation of cardiomyocytes in the developing heart. This premature exit of the cell cycle may lead to a reduced cardiomyocyte endowment in the heart and have a negative impact on cardiac function.
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Affiliation(s)
- Alexandra Paradis
- 1. Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California 92350
| | - Daliao Xiao
- 1. Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California 92350
| | - Jianjun Zhou
- 1. Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California 92350 ; 2. Department of Obstetrics and Gynecology, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing 210008, China
| | - Lubo Zhang
- 1. Center for Perinatal Biology, Division of Pharmacology, Department of Basic Sciences, Loma Linda University School of Medicine, Loma Linda, California 92350
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Meng FJ, Hou ZW, Li Y, Yang Y, Yu B. The protective effect of picroside II against hypoxia/reoxygenation injury in neonatal rat cardiomyocytes. PHARMACEUTICAL BIOLOGY 2012; 50:1226-1232. [PMID: 22880952 DOI: 10.3109/13880209.2012.664555] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
CONTEXT Picroside II, an iridoid glucoside found in the root of Picrorhiza scrophulariiflora Pennell (Scrophulariaceae), has been demonstrated to possess potent antioxidant activity. However, whether picroside II has a protective effect against hypoxia/reoxygenation (H/R)-induced cardiomyocyte injury is poorly understood. OBJECTIVE To explore the cardioprotective role of picroside II against oxidative stress induced by H/R injury in neonatal rat cardiacmyocytes. MATERIALS AND METHODS The viability and cellular damage of cardiomyocytes were assessed by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolim bromide (MTT) and lactate dehydrogenase (LDH) assays, respectively. The activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px), the levels of reduced (GSH) and oxidized glutathione (GSSG), and the contents of malondialdehyde (MDA) were determined by a colorimetric method. The levels of intracellular reactive oxygen species (ROS) and calcium were evaluated by flow cytometric analysis. RESULTS We analyzed the effective half-maximal concentration for protection from the dose-response curves and obtained the concentration of 50 µg/mL as EC(50). Pretreated cardiomyocytes with picroside II (50-200 µg/mL), prior to H/R exposure, inhibited LDH activity in culture media and increased cell viability in a dose-dependent manner. This protective effect was accompanied by significantly increasing reduced GSH contents and the activities of SOD and GSH-Px and attenuating MDA and GSSG contents in response to H/R injury. Furthermore, treatment with picroside II also inhibited ROS production and calcium accumulation in cardiomyocytes. DISCUSSION AND CONCLUSION The present study demonstrates that picroside II protects cardiomyocytes against oxidative-stress injury induced by H/R through reduction of ROS production and calcium accumulation and enhancement of the activity of antioxidant defense.
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Affiliation(s)
- Fan-Ji Meng
- Department of Cardiology, The First Affiliated Hospital of China Medical University, Shenyang, P.R. China.
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8
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Porchia F, Papucci M, Gargini C, Asta A, De Marco G, Agretti P, Tonacchera M, Mazzoni MR. Endothelin-1 up-regulates p115RhoGEF in embryonic rat cardiomyocytes during the hypertrophic response. J Recept Signal Transduct Res 2008; 28:265-83. [PMID: 18569527 DOI: 10.1080/10799890802084515] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
In cardiomyocytes, certain extracellular stimuli that activate heterotrimeric G protein-coupled receptors (GPCRs) can induce hypertrophy by regulating gene expression and increasing protein synthesis. We investigated if rat embryonic cardiomyocytes (H9c2) underwent variations in the expression levels and subcellular distribution of key components of GPCR-activated signaling pathways during endothelin-1 (ET-1)-induced hypertrophic response. A significant increase of p115RhoGEF protein level was evident in ET-1-treated cells. Real-time quantitative PCR showed RhoGEF mRNA levels were significantly increased. Inhibition of the Rho-associated kinase (ROCK) caused a significant decrease of p115RhoGEF protein in the nuclear fraction, whereas an inhibitor of PKC induced a redistribution of the protein between membrane/organelle and nuclear fractions. The ROCK inhibitor also decreased H9c2 cell hypertrophic response. These results indicate that ROCK and its downstream target molecules, which are involved in inducing the hypertrophic response, are also implicated in signaling the up-regulation of the p115RhoGEF protein.
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Affiliation(s)
- Francesca Porchia
- Dipartimento di Psichiatria, Neurobiologia, Farmacologia e Biotecnologie, University of Pisa, Pisa, Italy
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9
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Chen HP, He M, Huang QR, Liu D, Huang M. Sasanquasaponin protects rat cardiomyocytes against oxidative stress induced by anoxia-reoxygenation injury. Eur J Pharmacol 2007; 575:21-7. [PMID: 17761161 DOI: 10.1016/j.ejphar.2007.07.043] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2007] [Revised: 07/18/2007] [Accepted: 07/23/2007] [Indexed: 11/21/2022]
Abstract
Reactive oxygen species can play an important role in the pathogenesis of anoxia-reoxygenation injury. Sasanquasaponin (SQS) is a biologically active ingredient extracted from the Chinese medicinal plant Camellia oleifera Abel. Some studies have shown that SQS possesses potent antioxidant activities. However, it has not been elucidated whether SQS diminishes reactive oxygen species stress induced by anoxia-reoxygenation injury in cardiomyocytes. In this work, neonatal rat cardiomyocytes pretreated with the test compound were subjected to anoxia-reoxygenation. The extent of cellular damage was accessed by cell viability and the amount of released lactate dehydrogenase (LDH). Superoxide dismutase, catalase and glutathione peroxidase activities, reduced (GSH) and oxidized glutathione (GSSG) levels, and malondialdehyde contents were measured by a colorimetric method. The levels of intracellular reactive oxygen species and calcium were determined by flow cytometry. The results showed that SQS reduced LDH release and increased cell viability in a dose-dependent manner up to 10 microM and concomitantly decreased malondialdehyde and GSSG contents, while significantly increased GSH contents and the activities of superoxide dismutase, catalase and glutathione peroxidase. Moreover, treatment with SQS decreased intracellular reactive oxygen species levels and alleviated calcium accumulation in cardiomyocytes undergoing anoxia-reoxygenation. It is suggested that SQS could protect cardiomyocytes against oxidative stress induced by anoxia-reoxygenation by attenuating reactive oxygen species generation and increasing activities of endogenous antioxidants.
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Affiliation(s)
- He-Ping Chen
- Institute of Clinical Pharmacology, School of Pharmaceutical Sciences, Sun Yat-Sen University, Guangzhou, PR China
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Hofgaard JP, Sigurdardottir KS, Treiman M. Protection by 6-aminonicotinamide against oxidative stress in cardiac cells. Pharmacol Res 2006; 54:303-10. [PMID: 16879976 DOI: 10.1016/j.phrs.2006.06.007] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/22/2005] [Revised: 05/18/2006] [Accepted: 06/13/2006] [Indexed: 11/18/2022]
Abstract
Oxidative stress at the time of reperfusion is a major aspect of ischemia-reperfusion injury in heart as well as in other organs. There is a continuing interest in development of pharmacological approaches to alleviate this injury. 6-Aminonicotinamide (6AN) has been shown to diminish myocardial necrosis following global ischemia in an isolated rat heart, apparently by limiting the oxidative injury component. We therefore explored the antioxidative potential of 6AN in a model using H9C2(2-1) rat cardiac myoblasts exposed to H2O2 stress. Dependent on the specific protocol, 6AN pretreatment for 6-23 h resulted in a strongly increased cell survival: from 11% to 16% in untreated cells to 56-75% following 6AN treatment. This 6AN-mediated protection was associated with a modest increase (up to 55%) of the cytosolic free Ca2+, and was blocked by ryanodine, but not by verapamil or nifedipine. The protective effect of 6AN was associated with a decrease in total cell content of the reduced glutathione (GSH) by 15-44%, indicative of an oxidative shift in the GSH/GSSG system redox potential. We propose that this redox shift caused an increased Ca2+ leak through ryanodine receptors, reflecting their known sensitivity to redox modulation. In turn, this Ca2+ redistribution appeared to trigger a state of an enhanced antioxidative resistance, somewhat analogous to the phenomenon of Ca2+ preconditioning. Similar to some of the cases of Ca2+ preconditioning, this protected state involved the activity of Ca2+ -independent, but not of Ca2+ -dependent, isoform(s) of protein kinase C.
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Affiliation(s)
- Johannes P Hofgaard
- Department of Medical Physiology, The Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, The Panum Institute 12.5, Blegdamsvej 3, Copenhagen N, Denmark
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D'Ursi AM, Giusti L, Albrizio S, Porchia F, Esposito C, Caliendo G, Gargini C, Novellino E, Lucacchini A, Rovero P, Mazzoni MR. A membrane-permeable peptide containing the last 21 residues of the G alpha(s) carboxyl terminus inhibits G(s)-coupled receptor signaling in intact cells: correlations between peptide structure and biological activity. Mol Pharmacol 2005; 69:727-36. [PMID: 16332984 DOI: 10.1124/mol.105.017715] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Cell-penetrating peptides are able to transport covalently attached cargoes such as peptide or polypeptide fragments of endogenous proteins across cell membranes. Taking advantage of the cell-penetrating properties of the 16-residue fragment penetratin, we synthesized a chimeric peptide that possesses an N-terminal sequence with membrane-penetrating activity and a C-terminal sequence corresponding to the last 21 residues of G alpha(s). This G alpha(s) peptide was an effective inhibitor of 5'-N-ethylcarboxamidoadenosine (NECA) and isoproterenol-stimulated production of cAMP in rat PC12 and human microvascular endothelial (HMEC-1) cells, whereas the carrier peptide had no effect. The maximal efficacy of NECA was substantially reduced when PC12 cells were treated with the chimeric peptide, suggesting that it competes with G alpha(s) for interaction with receptors. The peptide inhibited neither G(q)- nor G(i)-coupled receptor signaling. The use of a carboxy-fluorescein derivative of the peptide proved its ability to cross the plasma membrane of live cells. NMR analysis of the chimeric peptide structure in a membrane-mimicking environment showed that the G alpha(s) fragment assumed an amphipathic alpha-helical conformation tailored to make contact with key residues on the intracellular side of the receptor. The N-terminal penetratin portion of the molecule also showed an alpha-helical structure, but hydrophobic and hydrophilic residues formed clustered surfaces at the N terminus and center of the fragment, suggesting their involvement in the mechanism of penetratin internalization by endocytosis. Our biological data supported by NMR analysis indicate that the membrane-permeable G alpha(s) peptide is a valuable, nontoxic research tool to modulate G(s)-coupled receptor signal transduction in cell culture models.
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Affiliation(s)
- Anna Maria D'Ursi
- Dip. di Psichiatria, Neurobiologia, Farmacologia e Biotecnologie, Università di Pisa, Italy
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Giusti L, Gargini C, Ceccarelli F, Bacci M, Italiani P, Mazzoni MR. Modulation of Endothelin-A Receptor, Gα Subunit, and RGS2 Expression during H9c2 Cardiomyoblast Differentiation. J Recept Signal Transduct Res 2004; 24:297-317. [PMID: 15648448 DOI: 10.1081/rrs-200040331] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
In cardiac myocytes, growth responses depend on activation of G protein-coupled receptors interacting with Gq/11 protein subfamily members. Endothelin receptors of the ETA subtype belong to this receptor group inducing hypertrophic responses. To understand the role of ETA receptors and signal transduction proteins in modulating cell growth, we analyzed the pharmacological profile of this receptor, its level of expression together with those of Galpha subunits and the RGS2 protein in cardiomyoblasts differentiating into the cardiac phenotype. H9c2 rat cardiomyoblasts were grown in the presence of 10% fetal bovine serum (FBS) or 1% FBS plus all-trans-retinoic acid to induce the cardiac phenotype. The pharmacological properties of ETA receptors were investigated by competition-binding experiments, whereas the protein expression profile was analyzed by immunoblot and immunocytochemistry. The pharmacological profile of ETA receptors changed during differentiation of cardiomyoblasts into cardiomyocytes, and the amount of expressed receptor appeared to increase. Immunocytochemistry also showed a marked increase of receptor expression on cell membranes of differentiated cardiomyocytes. Among the other signaling proteins examined, both Galphaq/11 and RGS2 expression decreased in cells with the cardiac phenotype. Our results demonstrate that the expression of key proteins (ETA receptor, Galphaq/11, and RGS2) involved in signal transduction of hypertrophic stimuli is modulated during cell differentiation and correlates with the cardiac phenotype.
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Affiliation(s)
- Laura Giusti
- Dipartimento di Psichiatria, Neurobiologia, Farmacologia e Biotecnologie, Università di Pisa, Pisa, Italy
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