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Zieziulewicz TJ, Mondal TK, Gao D, Lawrence DA. Stress-induced effects, which inhibit host defenses, alter leukocyte trafficking. Cell Stress Chaperones 2013; 18:279-91. [PMID: 23111563 PMCID: PMC3631090 DOI: 10.1007/s12192-012-0380-0] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Revised: 10/08/2012] [Accepted: 10/09/2012] [Indexed: 12/24/2022] Open
Abstract
Acute cold restraint stress (ACRS) has been reported to suppress host defenses against Listeria monocytogenes, and this suppression was mediated by beta1-adrenoceptors (β1-ARs). Although ACRS appears to inhibit mainly early innate immune defenses, interference with leukocyte chemotaxis and the involvement of β1-AR (or β2-AR) signaling had not been assessed. Thus, the link between sympathetic nerve stimulation, release of neurotransmitters, and changes in blood leukocyte profiles, including oxidative changes, following ACRS was evaluated. The numbers of leukocyte subsets in the blood were differentially affected by β1-ARs and β2-ARs following ACRS; CD3(+) (CD4 and CD8) T-cells were shown to be decreased following ACRS, and the T cell lymphopenia was mediated mainly through a β2-AR mechanism, while the decrease in CD19(+) B-cells was influenced through both β1- and β2-ARs, as assessed by pharmacological and genetic manipulations. In contrast to the ACRS-induced loss of circulating lymphocytes, the number of circulating neutrophils was increased (i.e., neutrophilia), and this neutrophilia was mediated through β1-ARs. The increase in circulating neutrophils was not due to an increase in serum chemokines promoting neutrophil emigration from the bone marrow; rather it was due to neutrophil release from the bone marrow through activation of a β1-AR pathway. There was no loss of glutathione in any of the leukocyte subsets suggesting that there was minimal oxidative stress; however, there was early production of nitric oxide and generation of some protein radicals. Premature egress of neutrophils from bone marrow is suggested to be due to norepinephrine induction of nitric oxide, which affects the early release of neutrophils from bone marrow and lessens host defenses.
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MESH Headings
- Animals
- Bone Marrow/drug effects
- Bone Marrow/metabolism
- Chemokine CXCL12/pharmacology
- Chemotactic Factors/blood
- Chemotaxis, Leukocyte/drug effects
- Chemotaxis, Leukocyte/immunology
- Cold Temperature
- Gene Expression Regulation/drug effects
- Glutathione/metabolism
- Leukocytes/drug effects
- Leukocytes/metabolism
- Leukocytes/pathology
- Lymphocytes/drug effects
- Lymphocytes/metabolism
- Lymphopenia/blood
- Lymphopenia/immunology
- Lymphopenia/pathology
- Male
- Mice
- Mice, Inbred BALB C
- Mice, Knockout
- Neutrophils/drug effects
- Neutrophils/metabolism
- Nitric Oxide/biosynthesis
- Oxidative Stress/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Adrenergic, beta-1/deficiency
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/metabolism
- Restraint, Physical
- Stress, Physiological/drug effects
- Stress, Physiological/immunology
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Barman PP, Cheng H, Hancox JC, James AF. Nickel inhibits β-1 adrenoceptor mediated activation of cardiac CFTR chloride channels. Biochem Biophys Res Commun 2013; 432:46-51. [PMID: 23376720 PMCID: PMC3686155 DOI: 10.1016/j.bbrc.2013.01.087] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2013] [Accepted: 01/25/2013] [Indexed: 11/24/2022]
Abstract
Cardiac ventricular myocytes exhibit a protein kinase A-dependent Cl(-) current (ICl.PKA) mediated by the cystic fibrosis transmembrane conductance regulator (CFTR). There is conflicting evidence regarding the ability of the divalent cation nickel (Ni(2+)), which has been used widely in vitro in the study of other cardiac ionic conductances, to inhibit ICl.PKA. Here the action of Ni(2+) on ICl.PKA activated by β-adrenergic stimulation has been elucidated. Whole-cell patch-clamp recordings were made from rabbit isolated ventricular myocytes. Externally applied Ni(2+) blocked ICl.PKA activated by 1 μM isoprenaline with a log IC50 (M) of -4.107 ± 0.075 (IC50=78.1 μM) at +100 mV and -4.322 ± 0.107 (IC50=47.6 μM) at -100 mV. Thus, the block of ICl.PKA by Ni(2+) was not strongly voltage dependent. Ni(2+) applied internally via the patch-pipette was ineffective at inhibiting isoprenaline-activated ICl,PKA, but in the same experiments the current was suppressed by external Ni(2+) application, indicative of an external site of Ni(2+) action. In the presence of 1 μM atenolol isoprenaline was ineffective at activating ICl.PKA, but in the presence of the β2-adrenoceptor inhibitor ICI 118,551 isoprenaline still activated Ni(2+)-sensitive ICl.PKA. Collectively, these data demonstrate that Ni(2+) ions produce marked inhibition of β1-adrenoceptor activated ventricular ICl.PKA at submillimolar [Ni(2+)]: an action that is likely to involve an interaction between Ni(2+) and β1-adrenoceptors. The concentration-dependence for ICl.PKA inhibition seen here indicates the potential for confounding effects on ICl,PKA to occur even at comparatively low Ni(2+) concentrations, when Ni(2+) is used to study other cardiac ionic currents under conditions of β-adrenergic agonism.
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78
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Cotarlan V, Brofferio A, Gerhard GS, Chu X, Shirani J. Impact of β(1)- and β(2)-adrenergic receptor gene single nucleotide polymorphisms on heart rate response to metoprolol prior to coronary computed tomographic angiography. Am J Cardiol 2013; 111:661-6. [PMID: 23261005 DOI: 10.1016/j.amjcard.2012.11.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 11/14/2012] [Accepted: 11/14/2012] [Indexed: 11/18/2022]
Abstract
A slow, steady heart rate (HR) is necessary for optimal image quality during coronary computed tomographic angiography. Beta blockers are often used, but the goal HR is not achieved in some patients. The aim of this study was to examine the influence of single-nucleotide polymorphisms (SNPs) of the β(1) (codons 49 and 389) and β(2) (codons 16, 27, and 164) adrenergic receptor (AR) genes on HR response to metoprolol in 200 adults (mean age 56 ± 11 years) referred for coronary computed tomographic angiography (using a 64-slice scanner). Oral and intravenous (IV) metoprolol was given to achieve a goal HR of <60 beats/min. Overall, 37 patients (18.5%) did not reach the goal HR despite the administration of oral (181 ± 116 mg) and IV (4.2 ± 9.4 mg) metoprolol. Patients with the β(1)-AR Ser49Gly or Gly49Gly genotype (n = 49) more often failed to reach an optimal HR compared to those with the Ser49Ser genotype (n = 151) (29% vs 15%, p = 0.04), despite receiving higher doses of oral (210 ± 115 vs 172 ± 115 mg, p = 0.048) and IV (7 ± 13 vs 3 ± 8 mg, p = 0.02) metoprolol. Similarly, patients with the β(1)-AR Gly389Gly genotype (n = 11) more often failed to reach an optimal HR compared to those with the Arg389Arg and Arg389Gly genotypes (n = 189) (45% vs 17%, p = 0.02), despite receiving higher doses of IV (13 ± 15 vs 4 ± 9 mg, p = 0.002) but not oral (162 ± 105 vs 182 ± 117 mg, p = 0.50) metoprolol. Multivariate analysis identified β(1)-AR SNPs at codons 49 and 389 and β(2)-AR SNP at codon 27 as independent predictors of suboptimal HR response. In conclusion, these data indicate that the selected SNPs of β(1)-AR and β(2)-AR genes influence HR response to metoprolol in patients who undergo coronary computed tomographic angiography.
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MESH Headings
- Adrenergic beta-Antagonists/administration & dosage
- Adult
- Aged
- Aged, 80 and over
- Coronary Angiography/methods
- Coronary Artery Disease/diagnostic imaging
- Coronary Artery Disease/drug therapy
- Coronary Artery Disease/genetics
- DNA/genetics
- Female
- Genotype
- Heart Rate/genetics
- Humans
- Male
- Metoprolol/administration & dosage
- Middle Aged
- Polymorphism, Single Nucleotide
- Prospective Studies
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Tomography, X-Ray Computed
- Young Adult
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79
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Leonard AP, Appleton KM, Luttrell LM, Peterson YK. A high-content, live-cell, and real-time approach to the quantitation of ligand-induced β-Arrestin2 and Class A/Class B GPCR mobilization. MICROSCOPY AND MICROANALYSIS : THE OFFICIAL JOURNAL OF MICROSCOPY SOCIETY OF AMERICA, MICROBEAM ANALYSIS SOCIETY, MICROSCOPICAL SOCIETY OF CANADA 2013; 19:150-170. [PMID: 23351552 PMCID: PMC4169994 DOI: 10.1017/s1431927612014067] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
We report the development of a method to analyze receptor and β-arrestin2 mobilization between Class A and B GPCRs via time-resolved fluorescent microscopy coupled with semiautomated high-content multiparametric analysis. Using transiently expressed, tagged β2-adrenergic receptor (β₂-AR) or parathyroid hormone receptor type 1 (PTH₁R), we quantified trafficking of the receptors along with the mobilization and colocalization of coexpressed tagged β-arrestin2. This classification system allows for exclusion of cells with nonoptimal characteristics and calculation of multiple morphological and spatial parameters including receptor endosome formation, β-arrestin mobilization, colocalization, areas, and shape. Stimulated Class A and B receptors demonstrate dramatically different patterns with regard to β-arrestin interactions. The method provides high kinetic resolution measurement of receptor translocation, which allows for the identification of the fleeting β-arrestin interaction found with β₂-AR agonist stimulation, in contrast to stronger mobilization and receptor colocalization with agonist stimulation of the PTH₁R. Though especially appropriate for receptor kinetic studies, this method is generalizable to any dual fluorescence probe system in which quantification of object formation and movement is desired. These methodologies allow for quantitative, unbiased measurement of microscopy data and are further enhanced by providing real-time kinetics.
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80
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Du Y, Yan L, Wang J, Zhan W, Song K, Han X, Li X, Cao J, Liu H. β1-Adrenoceptor autoantibodies from DCM patients enhance the proliferation of T lymphocytes through the β1-AR/cAMP/PKA and p38 MAPK pathways. PLoS One 2012; 7:e52911. [PMID: 23300817 PMCID: PMC3534136 DOI: 10.1371/journal.pone.0052911] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2012] [Accepted: 11/21/2012] [Indexed: 11/21/2022] Open
Abstract
Background Autoantibodies against the second extracellular loop of the β1-adrenergic receptor (β1-AA) not only contribute to increased susceptibility to heart failure, but also play a causative role in myocardial remodeling through their sympathomimetic-like effects that are induced upon binding to the β1-adrenergic receptor. However, their role in the function of T lymphocytes has never been previously investigated. Our present study was designed to determine whether β1-AA isolated from the sera of dilated cardiomyopathy (DCM) patients caused the proliferation of T cells and the secretion of cytokines. Methods Blood samples were collected from 95 DCM patients as well as 95 healthy subjects, and β1-AA was detected using ELISA. The CD3+T lymphocytes were selected separately through flow cytometry and the effect of β1-AA on T lymphocyte proliferation was examined by CCK-8 kits and CFSE assay. Western blotting was used to analyze the expressions of phospho-VASP and phospho-p38 MAPK. Results β1-AA enhanced the proliferation of T lymphocytes. This effect could be blocked by the selective β1-adrenergic receptor antagonist metoprolol, PKA inhibitor H89, and p38 MAPK inhibitor SB203580. Furthermore, the expression of the phosphorylated forms of phospho-VASP and phospho-p38 MAPK were markedly increased in the presence of β1-AA. β1-AA also inhibited the secretion of interferon-γ (IFN-γ) while promoting an increase in interleukin-4 (IL-4) levels. Conclusions These results demonstrate that β1-AA isolated from DCM patients binds to β1-AR on the surface of T cells, causing changes in T-cell proliferation and secretion through the β1-AR/cAMP/PKA and p38 MAPK pathways.
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81
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Berthouze-Duquesnes M, Lucas A, Saulière A, Sin YY, Laurent AC, Galés C, Baillie G, Lezoualc'h F. Specific interactions between Epac1, β-arrestin2 and PDE4D5 regulate β-adrenergic receptor subtype differential effects on cardiac hypertrophic signaling. Cell Signal 2012; 25:970-80. [PMID: 23266473 DOI: 10.1016/j.cellsig.2012.12.007] [Citation(s) in RCA: 44] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2012] [Accepted: 12/17/2012] [Indexed: 12/24/2022]
Abstract
β1 and β2 adrenergic receptors (βARs) are highly homologous but fulfill distinct physiological and pathophysiological roles. Here we show that both βAR subtypes activate the cAMP-binding protein Epac1, but they differentially affect its signaling. The distinct effects of βARs on Epac1 downstream effectors, the small G proteins Rap1 and H-Ras, involve different modes of interaction of Epac1 with the scaffolding protein β-arrestin2 and the cAMP-specific phosphodiesterase (PDE) variant PDE4D5. We found that β-arrestin2 acts as a scaffold for Epac1 and is necessary for Epac1 coupling to H-Ras. Accordingly, knockdown of β-arrestin2 prevented Epac1-induced histone deacetylase 4 (HDAC4) nuclear export and cardiac myocyte hypertrophy upon β1AR activation. Moreover, Epac1 competed with PDE4D5 for interaction with β-arrestin2 following β2AR activation. Dissociation of the PDE4D5-β-arrestin2 complex allowed the recruitment of Epac1 to β2AR and induced a switch from β2AR non-hypertrophic signaling to a β1AR-like pro-hypertrophic signaling cascade. These findings have implications for understanding the molecular basis of cardiac myocyte remodeling and other cellular processes in which βAR subtypes exert opposing effects.
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MESH Headings
- Animals
- Arrestins/antagonists & inhibitors
- Arrestins/genetics
- Arrestins/metabolism
- Cardiomegaly/metabolism
- Cardiomegaly/pathology
- Cells, Cultured
- Cyclic Nucleotide Phosphodiesterases, Type 3/metabolism
- Cyclic Nucleotide Phosphodiesterases, Type 4
- Fluorescence Resonance Energy Transfer
- Guanine Nucleotide Exchange Factors/metabolism
- HEK293 Cells
- Humans
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/metabolism
- Protein Interaction Maps
- Proto-Oncogene Proteins p21(ras)/metabolism
- RNA Interference
- RNA, Small Interfering/metabolism
- Rats
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/metabolism
- Signal Transduction
- beta-Arrestins
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82
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Benes J, Varejkova E, Farar V, Novakova M, Myslivecek J. Decrease in heart adrenoceptor gene expression and receptor number as compensatory tool for preserved heart function and biological rhythm in M(2) KO animals. Naunyn Schmiedebergs Arch Pharmacol 2012; 385:1161-73. [PMID: 23093370 DOI: 10.1007/s00210-012-0800-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 10/05/2012] [Indexed: 11/26/2022]
Abstract
Muscarinic receptors (MR) are main cardioinhibitory receptors. We investigated the changes in gene expression, receptor number, echocardiography, muscarinic/adrenergic agonist/antagonist changes in heart rate (HR) and HR biorhythm in M(2) KO mice (mice lacking the main cardioinhibitory receptors) in the left ventricle (LV) and right ventricle (RV). We hypothesize that the disruption of M(2) MR, key players in parasympathetic bradycardia, would change the number of receptors with antagonistic effects on the heart (β(1)- and β(2)-adrenoceptors, BAR), while the function of the heart would be changed only marginally. We have found changes in LV, but not in RV: decrease in M(3) MR, β(1)- and β(2)-adrenoceptor gene expressions that were accompanied by a decrease in MR and BAR receptor binding. No changes were found both in LV systolic and diastolic function as assessed by echocardiography (e.g., similar LV end-systolic and end-diastolic diameter, fractional shortening, mitral flow characteristics, and maximal velocity in LV outflow tract). We have found only marginal changes in specific HR biorhythm parameters. The effects of isoprenaline and propranolol on HR were similar in WT and KO (but with lesser extent). Atropine was not able to increase HR in KO animals. Carbachol decreased the HR in WT but increased HR in KO, suggesting the presence of cardiostimulatory MR. Therefore, we can conclude that although the main cardioinhibitory receptors are not present in the heart, the function is not much affected. As possible mechanisms of almost normal cardiac function, the decreases of both β(1)- and β(2)-adrenoceptor gene expression and receptor binding should be considered.
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83
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Chang CC, Lee PP, Cheng W. Norepinephrine regulates prophenoloxidase system-related parameters and gene expressions via α- and β-adrenergic receptors in Litopenaeus vannamei. FISH & SHELLFISH IMMUNOLOGY 2012; 33:962-968. [PMID: 22971348 DOI: 10.1016/j.fsi.2012.08.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2012] [Revised: 08/06/2012] [Accepted: 08/08/2012] [Indexed: 06/01/2023]
Abstract
The total (THC) and differential haemocyte counts (DHC), phenoloxidase (PO) activity, and prophenoloxidase (proPO) system-related genes were investigated in haemocytes of Litopenaeus vannamei that received saline, norepinephrine (NE), and NE co-treated with various adrenergic receptor (AR) antagonists both in vivo and in vitro. Results showed that semi-granular and granular cells of shrimp which received NE, NE + phentolamine (Phe), NE + prazosin (Pra), NE + propanolol (Pro) and NE + metoprolol (Met) significantly decreased, while the PO activity of the shrimp received NE + Phe in vivo was significant higher than all the other treatments. PO activities of haemocytes exposed to saline, Pra + NE, and Met + NE were significantly higher than those of haemocytes exposed to NE, Phe + NE, and Pro + NE in vitro. Similar phenomena in lipopolysaccharide- and β-1,3-glucan-binding protein (LGBP), proPO-I, proPO-II, serine proteinases (SP), and peroxinectin (PE) messenger (m)RNA expressions of haemocytes exposed to saline, NE, and NE co-treated with various AR antagonists were observed both in vivo and in vitro. No significant differences were observed for LGBP and proPO-II mRNA expressions between haemocytes treated with saline and Pra + NE, for proPO-I mRNA expression between haemocytes treated with saline and Met + NE; or for SP and PE mRNA expressions among haemocytes treated with saline, Pra + NE, and Met + NE. These results suggest that stress-induced NE may promote the migration of circulating granulocytes to the site of the injection and the existing proPO mRNA translation which had been stored in granulocytes. NE downregulated the LGBP, proPO-I, proPO-II, SP, and PE gene transcription by haemocytes via α1-, β1-, α1-, α1- and β1-, and α1- and β1-ARs, respectively, which subsequently decreased the PO activity by α1- and β1-ARs in haemocytes of L. vannamei.
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84
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McLean RC, Baird SW, Becker LC, Townsend SN, Gerstenblith G, Kass DA, Tomaselli GF, Schulman SP. Response to catecholamine stimulation of polymorphisms of the beta-1 and beta-2 adrenergic receptors. Am J Cardiol 2012; 110:1001-7. [PMID: 22742717 DOI: 10.1016/j.amjcard.2012.05.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 05/23/2012] [Accepted: 05/23/2012] [Indexed: 11/18/2022]
Abstract
Previous studies have demonstrated that β-adrenergic receptor polymorphisms affect outcomes in patients with heart failure or after an acute coronary syndrome. Whether β-adrenergic polymorphisms influence catecholamine responses in patients with cardiovascular disease is not known. Cardiovascular responses to the β1-receptor agonist dobutamine and the β2-receptor agonist terbutaline were studied using gated blood pool scintigraphy in 21 patients on long-term β-blocker therapy. Heart rate (HR), stroke volume (SV), and cardiac output (CO) increased, and end-systolic volume decreased with dobutamine and terbutaline. Changes in HR and CO with dobutamine were higher for those with ≥1 β1 Arg389 allele than those homozygous for the Gly389 allele (change in HR 15 vs 1 beat/min, p = 0.02; change in CO 2.4 vs 1.0 L/min, p = 0.02). Increases in HR, CO, and SV with terbutaline were greater for those homozygous for the β2 Glu27 allele than those with ≥1 Gln27 allele (change in HR 13.7 vs 4.8 beats/min, p = 0.048; change in CO 3.1 vs 1.6 L/min, p = 0.034; change in SV 28.3 vs 14.8 ml, p = 0.045). Changes in CO and volume with terbutaline were greater in those with an ejection fraction <40% than in those with an ejection fraction ≥40%. In conclusion, β-receptor gene variants significantly influence inotropic and chronotropic responses to β-agonist exposure in patients on β-blocker therapy.
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MESH Headings
- Acute Coronary Syndrome/complications
- Acute Coronary Syndrome/drug therapy
- Acute Coronary Syndrome/genetics
- Alleles
- Catecholamines/pharmacology
- DNA/genetics
- Female
- Gene Frequency
- Heart Failure/drug therapy
- Heart Failure/etiology
- Heart Failure/genetics
- Humans
- Male
- Middle Aged
- Myocardial Contraction/drug effects
- Myocardial Contraction/genetics
- Polymorphism, Genetic/drug effects
- Prognosis
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Stroke Volume/drug effects
- Ventricular Function, Left/drug effects
- Ventricular Function, Left/genetics
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85
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Li MP, Sun GJ, You XH. [Effects of electroacupuncture stimulation of scalp-point on cardiac sympathetic discharges, myocardial beta1-adrenoceptor protein expression and plasma norepinephrine concentration in myocardial ischemia-reperfusion injury rats]. ZHEN CI YAN JIU = ACUPUNCTURE RESEARCH 2012; 37:385-389. [PMID: 23342778] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
OBJECTIVE To explore the mechanism of electroacupuncture (EA) of scalp-point in the management of myocardial ischemia-reperfusion injury (MI/RI) by examining its effects on left cardiac sympathetic nerve activity, myocardial beta1-adrenaline receptor (AR) protein expression and plasma norepinephrine (NE) concentration in MI/RI rats. METHODS Eighteen Wistar rats were randomly divided into sham, model and EA groups (n = 6). MI/RI model was induced by ligation of the left anterior descending coronary artery for 30 min, followed by release of the ligation for 15 min. EA was applied to bilateral Epangxian I (MS 2) for 15 min. The left cardiac sympathetic nerve activity was recorded with BL-420 E+ biological signal acquisition system. Myocardial beta1-AR protein expression was examined by western blot and plasma NE level detected by enzyme-labeled immunosorbent assay. RESULTS Compared with the sham group, the left cardiac sympathetic discharges and plasma NE levels and myocardial beta1-AR protein expression were markedly increased in the model group (P < 0.01), whereas in comparison with the model group, the sympathetic discharges, plasma NE level and myocardial beta1-AR protein expression in the EA group were down-regulated significantly (P < 0.05). CONCLUSION Scalp-point EA intervention can suppress MI/RI induced increase of sympathetic nerve activity and plasma NE level, and beta1-AR protein expression, which may contribute to its effect in relieving myocardial ischemia.
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86
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Wang H, Chen Y, Zhu H, Wang S, Zhang X, Xu D, Cao K, Zou J. Increased response to β₂-adrenoreceptor stimulation augments inhibition of IKr in heart failure ventricular myocytes. PLoS One 2012; 7:e46186. [PMID: 23029432 PMCID: PMC3460863 DOI: 10.1371/journal.pone.0046186] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2012] [Accepted: 08/28/2012] [Indexed: 11/26/2022] Open
Abstract
Background Increasing evidence indicates that the rapid component of delayed rectifier potassium current (IKr) is modulated by α- and β-adrenergic stimulation. However, the role and mechanism regulating IKr through β2-adrenoreceptor (β-AR) stimulation in heart failure (HF) are unclear. Methodology/Principal Findings In the present study, we investigated the effects of fenoterol, a highly selective β2-AR agonist, on IKr in left ventricular myocytes obtained from control and guinea pigs with HF induced by descending aortic banding. IKr was measured by using whole cell patch clamp technique. In control myocytes, superfusion of fenoterol (10 µM) caused a 17% decrease in IKr. In HF myocytes, the same concentration of fenoterol produced a significantly greater decrease (33%) in IKr. These effects were not modified by the incubation of myocytes with CGP-20712A, a β1-AR antagonist, but were abolished by pretreatment of myocytes with ICI-118551, a β2-AR antagonist. An inhibitory cAMP analog, Rp-cAMPS and PKA inhibitor significantly attenuated fenoterol-induced inhibition of IKr in HF myocytes. Moreover, fenoterol markedly prolonged action potential durations at 90% (APD90) repolarization in HF ventricular myocytes. Conclusions The results indicate that inhibition of IKr induced by β2-AR stimulation is increased in HF. The inhibitory effect is likely to be mediated through a cAMP/PKA pathway in HF ventricular myocytes.
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87
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Ueta CB, Fernandes GW, Capelo LP, Fonseca TL, Maculan FD, Gouveia CHA, Brum PC, Christoffolete MA, Aoki MS, Lancellotti CL, Kim B, Bianco AC, Ribeiro MO. β(1) Adrenergic receptor is key to cold- and diet-induced thermogenesis in mice. J Endocrinol 2012; 214:359-65. [PMID: 22728333 PMCID: PMC4977996 DOI: 10.1530/joe-12-0155] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Brown adipose tissue (BAT) is predominantly regulated by the sympathetic nervous system (SNS) and the adrenergic receptor signaling pathway. Knowing that a mouse with triple β-receptor knockout (KO) is cold intolerant and obese, we evaluated the independent role played by the β(1) isoform in energy homeostasis. First, the 30 min i.v. infusion of norepinephrine (NE) or the β(1) selective agonist dobutamine (DB) resulted in similar interscapular BAT (iBAT) thermal response in WT mice. Secondly, mice with targeted disruption of the β(1) gene (KO of β(1) adrenergic receptor (β(1)KO)) developed hypothermia during cold exposure and exhibited decreased iBAT thermal response to NE or DB infusion. Thirdly, when placed on a high-fat diet (HFD; 40% fat) for 5 weeks, β(1)KO mice were more susceptible to obesity than WT controls and failed to develop diet-induced thermogenesis as assessed by BAT Ucp1 mRNA levels and oxygen consumption. Furthermore, β(1)KO mice exhibited fasting hyperglycemia and more intense glucose intolerance, hypercholesterolemia, and hypertriglyceridemia when placed on the HFD, developing marked non-alcoholic steatohepatitis. In conclusion, the β(1) signaling pathway mediates most of the SNS stimulation of adaptive thermogenesis.
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MESH Headings
- Adaptation, Physiological/drug effects
- Adaptation, Physiological/physiology
- Adipose Tissue, Brown/innervation
- Adipose Tissue, Brown/physiology
- Adrenergic alpha-Agonists/pharmacology
- Adrenergic beta-1 Receptor Agonists/pharmacology
- Animals
- Blood Glucose/metabolism
- Body Temperature Regulation/drug effects
- Body Temperature Regulation/physiology
- Cold Temperature
- Dietary Fats/pharmacology
- Dobutamine/pharmacology
- Energy Metabolism/drug effects
- Energy Metabolism/physiology
- Fatty Liver/metabolism
- Fatty Liver/physiopathology
- Hyperglycemia/metabolism
- Hyperglycemia/physiopathology
- Hypothermia/metabolism
- Hypothermia/physiopathology
- Ion Channels/genetics
- Ion Channels/metabolism
- Lipids/blood
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mitochondrial Proteins/genetics
- Mitochondrial Proteins/metabolism
- Non-alcoholic Fatty Liver Disease
- Norepinephrine/pharmacology
- Obesity/metabolism
- Obesity/physiopathology
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Signal Transduction/drug effects
- Signal Transduction/physiology
- Sympathetic Nervous System/physiology
- Uncoupling Protein 1
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88
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González S, Moreno-Delgado D, Moreno E, Pérez-Capote K, Franco R, Mallol J, Cortés A, Casadó V, Lluís C, Ortiz J, Ferré S, Canela E, McCormick PJ. Circadian-related heteromerization of adrenergic and dopamine D₄ receptors modulates melatonin synthesis and release in the pineal gland. PLoS Biol 2012; 10:e1001347. [PMID: 22723743 PMCID: PMC3378626 DOI: 10.1371/journal.pbio.1001347] [Citation(s) in RCA: 117] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2011] [Accepted: 05/10/2012] [Indexed: 11/18/2022] Open
Abstract
Dopamine and adrenergic receptor complexes form under a circadian-regulated cycle and directly modulate melatonin synthesis and release from the pineal gland. The role of the pineal gland is to translate the rhythmic cycles of night and day encoded by the retina into hormonal signals that are transmitted to the rest of the neuronal system in the form of serotonin and melatonin synthesis and release. Here we describe that the production of both melatonin and serotonin by the pineal gland is regulated by a circadian-related heteromerization of adrenergic and dopamine D4 receptors. Through α1B-D4 and β1-D4 receptor heteromers dopamine inhibits adrenergic receptor signaling and blocks the synthesis of melatonin induced by adrenergic receptor ligands. This inhibition was not observed at hours of the day when D4 was not expressed. These data provide a new perspective on dopamine function and constitute the first example of a circadian-controlled receptor heteromer. The unanticipated heteromerization between adrenergic and dopamine D4 receptors provides a feedback mechanism for the neuronal hormone system in the form of dopamine to control circadian inputs. Animals respond to cycles of light and dark with patterns in sleeping, feeding, body temperature alterations, and other biological functions. The pineal gland translates these light signals received from the retina into a language understandable to the rest of the body through the rhythmic synthesis and release of melatonin in response to the light and dark cycle. This process is controlled by adrenergic receptors. One impressive and mysterious aspect of the system is the rapid ability of rhythmic melatonin production and/or degradation to respond to changes in the cycle. In this study, we demonstrate that part of this response is due to the formation of receptor-receptor complexes (heteromers) between the adrenergic receptors α1B or β1 and the D4 dopamine receptor. Using both biochemical and biophysical methods in transfected cells and in ex vivo tissue we show that dopamine, a neurotransmitter, inhibits adrenergic receptor signaling through these heteromers. This inhibition causes a dramatic decrease in melatonin production of the pineal gland. We postulate that these heteromers provide a rapid feedback mechanism for the neuronal hormone system to modulate circadian-controlled outputs.
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MESH Headings
- Animals
- CHO Cells
- Circadian Rhythm/physiology
- Cricetinae
- Dopamine/metabolism
- HEK293 Cells
- Humans
- Male
- Melatonin/biosynthesis
- Pineal Gland/metabolism
- Rats
- Receptors, Adrenergic, alpha-1/genetics
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Dopamine D4/genetics
- Receptors, Dopamine D4/metabolism
- Serotonin/biosynthesis
- Transfection
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89
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Weaver J. Novel Melatonin-Blocking Complex Helps Control Body Rhythms. PLoS Biol 2012; 10:e1001348. [PMID: 22723744 PMCID: PMC3378613 DOI: 10.1371/journal.pbio.1001348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Dopamine and adrenergic receptor complexes form under a circadian-regulated cycle and directly modulate melatonin synthesis and release from the pineal gland.
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90
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Ghosh PM, Shu ZJ, Zhu B, Lu Z, Ikeno Y, Barnes JL, Yeh CK, Zhang BX, Katz MS, Kamat A. Role of β-adrenergic receptors in regulation of hepatic fat accumulation during aging. J Endocrinol 2012; 213:251-61. [PMID: 22457517 PMCID: PMC3539306 DOI: 10.1530/joe-11-0406] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Excessive fat accumulation in liver (hepatic steatosis) predisposes to hepatic functional and structural impairment and overall metabolic risk. Previous studies noted an association between hepatic steatosis and age in humans and rodents. However, the mechanisms leading to age-associated hepatic fat accumulation remain unknown. Earlier work from our group showed that β-adrenergic receptor (β-AR) levels and β-AR-stimulated adenylyl cyclase activity increase in rat liver during aging. Here we investigated whether age-associated increases in β-AR signaling play a role in augmenting hepatic lipid accumulation. We demonstrate an increase in hepatic lipid content during senescence and a significant correlation between hepatic fat content and stimulation of adenylyl cyclase activity by the β-AR agonist isoproterenol in rat liver. Isoproterenol administration to young and old rodents in vivo increased hepatic lipid accumulation. Furthermore, in vitro overexpression of β1- and β2-AR subtypes in hepatocytes from young rodents increased cellular lipid content, whereas inhibition of β-ARs by receptor subtype-specific inhibitors reduced lipid levels in hepatocytes from senescent animals. Isoproterenol-induced hepatic lipid accumulation in vivo was prevented by the β-AR nonselective blocker propranolol, suggesting a novel therapeutic effect of this class of drugs in hepatic steatosis. Acipimox, which inhibits adipose tissue lipolysis, did not alter isoproterenol-mediated hepatic fat accumulation; thus β-AR responsive hepatic lipid accumulation does not appear to be related primarily to altered lipolysis. These findings suggest that augmented hepatic β-AR signaling during aging may increase lipid accumulation in liver and advocate a possible role for β-adrenergic blockers in preventing or retarding the development of hepatic steatosis.
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MESH Headings
- Adenylyl Cyclases/metabolism
- Adrenergic beta-Agonists/pharmacology
- Adrenergic beta-Antagonists/pharmacology
- Aging
- Animals
- Cells, Cultured
- Enzyme Activation/drug effects
- Fats/metabolism
- Hepatocytes/drug effects
- Hepatocytes/metabolism
- Imidazoles/pharmacology
- Isoproterenol/pharmacology
- Lipids/analysis
- Liver/metabolism
- Male
- Mice
- Mice, Inbred C57BL
- Propanolamines/pharmacology
- Propranolol/pharmacology
- Rats
- Rats, Inbred F344
- Receptors, Adrenergic, beta/genetics
- Receptors, Adrenergic, beta/metabolism
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Signal Transduction/drug effects
- Time Factors
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91
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Seqqat R, Guo X, Rafiq K, Kolpakov MA, Guo J, Koch WJ, Houser SR, Dell'italia LJ, Sabri A. Beta1-adrenergic receptors promote focal adhesion signaling downregulation and myocyte apoptosis in acute volume overload. J Mol Cell Cardiol 2012; 53:240-9. [PMID: 22609523 DOI: 10.1016/j.yjmcc.2012.05.004] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/14/2012] [Revised: 05/05/2012] [Accepted: 05/07/2012] [Indexed: 11/19/2022]
Abstract
Numerous studies demonstrated increased expression of extracellular matrix (ECM) proteins and activation of focal adhesion (FA) signaling pathways in models of pressure overload-induced cardiac hypertrophy. However, little is known about FA signaling in response to volume overload where cardiac hypertrophy is associated with ECM loss. This study examines the role of beta1-adrenergic receptors (β(1)-ARs) in FA signaling changes and myocyte apoptosis induced during acute hemodynamic stress of volume overload. Rats with eccentric cardiac hypertrophy induced after aorto-caval fistula (ACF) develop reduced interstitial collagen content and decreased tyrosine phosphorylation of key FA signaling molecules FAK, Pyk(2) and paxillin along with an increase in cardiac myocyte apoptosis. ACF also increased activation of PTEN, a dual lipid and protein phosphatase, and its interaction with FA proteins. β(1)-AR blockade (extended-release of metoprolol succinate, 100mg QD) markedly attenuated PTEN activation, restored FA signaling and reduced myocyte apoptosis induced by ACF at 2days, but failed to reduce interstitial collagen loss and left ventricular dilatation. Treating cultured myocytes with β(1)-AR agonists or adenoviral expression of β(1)-ARs caused PTEN activation and interaction with FA proteins, thus leading to FA signaling downregulation and myocyte apoptosis. Adenoviral-mediated expression of a catalytically inactive PTEN mutant or wild-type FAK restored FA signaling downregulation and attenuated myocyte apoptosis induced by β(1)-ARs. Collectively, these data show that β(1)-AR stimulation in response to ACF induces FA signaling downregulation through an ECM-independent mechanism. This effect involves PTEN activation and may contribute to adverse cardiac remodeling and function in the course of volume overload.
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92
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Laukova M, Vargovic P, Csaderova L, Chovanova L, Vlcek M, Imrich R, Krizanova O, Kvetnansky R. Acute stress differently modulates β1, β2 and β3 adrenoceptors in T cells, but not in B cells, from the rat spleen. Neuroimmunomodulation 2012; 19:69-78. [PMID: 22248722 DOI: 10.1159/000329002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/18/2011] [Accepted: 04/29/2011] [Indexed: 11/19/2022] Open
Abstract
OBJECTIVES Stress-induced rise in circulating catecholamines (CAs), followed by modulation of β-adrenergic receptors (adrenoceptors, ARs), is one of the pathways involved in the stress-mediated effects of immune functions. The spleen is an organ with a high number of lymphocytes and provides a unique microenvironment in which they reside. Thus, lymphocytes may respond differently to CAs in the spleen than in the circulation. No reports exist concerning the involvement of β-ARs in stress-mediated effects on T and B cells isolated from the spleen. Therefore, our aim was to investigate the effect of single stress exposure on gene expression and cellular localization of β-adrenoceptor subtypes in splenic T and B cells. We tried to correlate changes in adrenoceptors with the expression of apoptotic proteins. METHODS Immobilization (IMMO) was used as a stress model. T and B cells were isolated from rat spleen using magnetically labeled antibodies. The gene expression of individual adrenoceptors and apoptotic proteins was evaluated by real-time PCR. Immunofluorescence was used to evaluate localization and adrenoceptor expression. RESULTS We have found T cells to be more vulnerable to stress compared to B cells, because of increased β₁-, β₂- and β₃-ARs after a single IMMO. Moreover, β₂-ARs translocated from the nucleus to the plasma membrane in T cells after IMMO. The rise in β-ARs most probably led to the rise of Bax mRNA and Bax to Bcl-2 mRNA ratio. This might suggest the induction of an apoptotic process in T cells. CONCLUSION Higher susceptibility of T cells to stress via modulation of β-ARs and apoptotic proteins might shift the immune responsiveness in the spleen.
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93
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Mattsson CL, Csikasz RI, Chernogubova E, Yamamoto DL, Hogberg HT, Amri EZ, Hutchinson DS, Bengtsson T. β₁-Adrenergic receptors increase UCP1 in human MADS brown adipocytes and rescue cold-acclimated β₃-adrenergic receptor-knockout mice via nonshivering thermogenesis. Am J Physiol Endocrinol Metab 2011; 301:E1108-18. [PMID: 21878665 DOI: 10.1152/ajpendo.00085.2011] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
With the finding that brown adipose tissue is present and negatively correlated to obesity in adult man, finding the mechanism(s) of how to activate brown adipose tissue in humans could be important in combating obesity, type 2 diabetes, and their complications. In mice, the main regulator of nonshivering thermogenesis in brown adipose tissue is norepinephrine acting predominantly via β(3)-adrenergic receptors. However, vast majorities of β(3)-adrenergic agonists have so far not been able to stimulate human β(3)-adrenergic receptors or brown adipose tissue activity, and it was postulated that human brown adipose tissue could be regulated instead by β(1)-adrenergic receptors. Therefore, we have investigated the signaling pathways, specifically pathways to nonshivering thermogenesis, in mice lacking β(3)-adrenergic receptors. Wild-type and β(3)-knockout mice were either exposed to acute cold (up to 12 h) or acclimated for 7 wk to cold, and parameters related to metabolism and brown adipose tissue function were investigated. β(3)-knockout mice were able to survive both acute and prolonged cold exposure due to activation of β(1)-adrenergic receptors. Thus, in the absence of β(3)-adrenergic receptors, β(1)-adrenergic receptors are effectively able to signal via cAMP to elicit cAMP-mediated responses and to recruit and activate brown adipose tissue. In addition, we found that in human multipotent adipose-derived stem cells differentiated into functional brown adipocytes, activation of either β(1)-adrenergic receptors or β(3)-adrenergic receptors was able to increase UCP1 mRNA and protein levels. Thus, in humans, β(1)-adrenergic receptors could play an important role in regulating nonshivering thermogenesis.
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MESH Headings
- Acclimatization/genetics
- Acclimatization/physiology
- Adipocytes, Brown/cytology
- Adipocytes, Brown/metabolism
- Animals
- Cell Differentiation/genetics
- Cell Differentiation/physiology
- Cells, Cultured
- Cold Temperature
- Down-Regulation/genetics
- Epistasis, Genetic/physiology
- Female
- Humans
- Ion Channels/genetics
- Ion Channels/metabolism
- Male
- Mice
- Mice, Knockout
- Mitochondrial Proteins/genetics
- Mitochondrial Proteins/metabolism
- Multipotent Stem Cells/cytology
- Multipotent Stem Cells/metabolism
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-1/physiology
- Receptors, Adrenergic, beta-3/genetics
- Shivering/genetics
- Shivering/physiology
- Thermogenesis/genetics
- Thermogenesis/physiology
- Uncoupling Protein 1
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94
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Branco AF, Pereira SL, Moreira AC, Holy J, Sardão VA, Oliveira PJ. Isoproterenol cytotoxicity is dependent on the differentiation state of the cardiomyoblast H9c2 cell line. Cardiovasc Toxicol 2011; 11:191-203. [PMID: 21455642 DOI: 10.1007/s12012-011-9111-5] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
H9c2 cells are used as a surrogate for cardiac cells in several toxicological studies, which are usually performed with cells in their undifferentiated state, raising questions on the applicability of the results to adult cardiomyocytes. Since H9c2 myoblasts have the capacity to differentiate into skeletal and cardiac muscle cells under different conditions, the hypothesis of the present work was that cells in different differentiation states differ in their susceptibility to toxicants. In order to test the hypothesis, the effects of the cardiotoxicant isoproterenol (ISO) were investigated. The present work demonstrates that differentiated H9c2 cells are more susceptible to ISO toxicity. Cellular content of beta(1)-adrenergic receptors (AR), beta(3)-AR, and calcineurin is decreased as cells differentiate, as opposed to the content on the mitochondrial voltage-dependent anion channel (VDAC) and phosphorylated p38-MAPK, which increase. After ISO treatment, the pro-apoptotic protein Bax increases in all experimental groups, although only undifferentiated myoblasts up-regulate the anti-apoptotic Bcl-2. Calcineurin is decreased in differentiated H9c2 cells, which suggests an important role against ISO-induced cell death. The results indicate that the differentiation state of H9c2 myoblasts influence ISO toxicity, which may involve calcineurin, p38-MAPK, and Bax/Bcl-2 alterations. The data also provide new insights into cardiovascular toxicology during early development.
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MESH Headings
- Adrenergic beta-Agonists/toxicity
- Animals
- Calcineurin/metabolism
- Cell Differentiation
- Cell Line
- Dose-Response Relationship, Drug
- Isoproterenol/toxicity
- Myoblasts, Cardiac/drug effects
- Myoblasts, Cardiac/metabolism
- Myoblasts, Cardiac/pathology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Phosphorylation
- Proto-Oncogene Proteins c-bcl-2/metabolism
- Rats
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-3/drug effects
- Receptors, Adrenergic, beta-3/metabolism
- Voltage-Dependent Anion Channels/metabolism
- bcl-2-Associated X Protein/metabolism
- p38 Mitogen-Activated Protein Kinases/metabolism
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95
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Pizarro JC, Boulot G, Bentley GA, Gómez KA, Hoebeke J, Hontebeyrie M, Levin MJ, Smulski CR. Crystal structure of the complex mAb 17.2 and the C-terminal region of Trypanosoma cruzi P2β protein: implications in cross-reactivity. PLoS Negl Trop Dis 2011; 5:e1375. [PMID: 22069505 PMCID: PMC3206007 DOI: 10.1371/journal.pntd.0001375] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2011] [Accepted: 09/11/2011] [Indexed: 01/07/2023] Open
Abstract
Patients with Chronic Chagas' Heart Disease possess high levels of antibodies against the carboxyl-terminal end of the ribosomal P2ß protein of Trypanosoma cruzi (TcP2ß). These antibodies, as well as the murine monoclonal antibody (mAb) 17.2, recognize the last 13 amino acids of TcP2ß (called the R13 epitope: EEEDDDMGFGLFD) and are able to cross-react with, and stimulate, the ß1 adrenergic receptor (ß1-AR). Indeed, the mAb 17.2 was able to specifically detect human β1-AR, stably transfected into HEK cells, by flow cytometry and to induce repolarisation abnormalities and first degree atrioventricular conduction block after passive transfer to naïve mice. To study the structural basis of this cross-reactivity, we determined the crystal structure of the Fab region of the mAb 17.2 alone at 2.31 Å resolution and in complex with the R13 peptide at 1.89 Å resolution. We identified as key contact residues on R13 peptide Glu3, Asp6 and Phe9 as was previously shown by alanine scanning. Additionally, we generated a model of human β1-AR to elucidate the interaction with anti-R13 antibodies. These data provide an understanding of the molecular basis of cross-reactive antibodies induced by chronic infection with Trypanosoma cruzi.
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MESH Headings
- Animals
- Antibodies, Monoclonal/chemistry
- Antibodies, Monoclonal/immunology
- Antibodies, Monoclonal/metabolism
- Antibodies, Protozoan/chemistry
- Antibodies, Protozoan/immunology
- Antibodies, Protozoan/metabolism
- Cross Reactions
- Crystallography, X-Ray
- Female
- Humans
- Immunoglobulin Fab Fragments/chemistry
- Immunoglobulin Fab Fragments/immunology
- Immunoglobulin Fab Fragments/metabolism
- Mice
- Mice, Inbred BALB C
- Models, Molecular
- Phosphoproteins/chemistry
- Phosphoproteins/immunology
- Phosphoproteins/metabolism
- Protein Binding
- Protein Structure, Quaternary
- Receptors, Adrenergic, beta-1/immunology
- Receptors, Adrenergic, beta-1/metabolism
- Ribosomal Proteins/chemistry
- Ribosomal Proteins/immunology
- Ribosomal Proteins/metabolism
- Trypanosoma cruzi/chemistry
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96
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Zhang W, Yano N, Deng M, Mao Q, Shaw SK, Tseng YT. β-Adrenergic receptor-PI3K signaling crosstalk in mouse heart: elucidation of immediate downstream signaling cascades. PLoS One 2011; 6:e26581. [PMID: 22028912 PMCID: PMC3197531 DOI: 10.1371/journal.pone.0026581] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2011] [Accepted: 09/29/2011] [Indexed: 01/21/2023] Open
Abstract
Sustained β-adrenergic receptors (βAR) activation leads to cardiac hypertrophy and prevents left ventricular (LV) atrophy during LV unloading. The immediate signaling pathways downstream from βAR stimulation, however, have not been well investigated. The current study was to examine the early cardiac signaling mechanism(s) following βAR stimulation. In adult C57BL/6 mice, acute βAR stimulation induced significant increases in PI3K activity and activation of Akt and ERK1/2 in the heart, but not in lungs or livers. In contrast, the same treatment did not elicit these changes in β1/β2AR double knockout mice. We further showed the specificity of β2AR in this crosstalk as treatment with formoterol, a β2AR-selective agonist, but not dobutamine, a predominantly β1AR agonist, activated cardiac Akt and ERK1/2. Acute βAR stimulation also significantly increased the phosphorylation of mTOR (the mammalian target of rapamycin), P70S6K, ribosomal protein S6, GSK-3α/β (glycogen synthase kinase-3α/β), and FOXO1/3a (the forkhead box family of transcription factors 1 and 3a). Moreover, acute βAR stimulation time-dependently decreased the mRNA levels of the muscle-specific E3 ligases atrogin-1 and muscle ring finger protein-1 (MuRF1) in mouse heart. Our results indicate that acute βAR stimulation in vivo affects multiple cardiac signaling cascades, including the PI3K signaling pathway, ERK1/2, atrogin-1 and MuRF1. These data 1) provide convincing evidence for the crosstalk between βAR and PI3K signaling pathways; 2) confirm the β2AR specificity in this crosstalk in vivo; and 3) identify novel signaling factors involved in cardiac hypertrophy and LV unloading. Understanding of the intricate interplay between β2AR activation and these signaling cascades should provide critical clues to the pathogenesis of cardiac hypertrophy and enable identification of targets for early clinical interaction of cardiac lesions.
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MESH Headings
- Adrenergic beta-Agonists/pharmacology
- Animals
- Forkhead Transcription Factors/metabolism
- Gene Knockout Techniques
- Glycogen Synthase Kinase 3/metabolism
- Glycogen Synthase Kinase 3 beta
- Male
- Mice
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3/metabolism
- Muscle Proteins/genetics
- Myocardium/cytology
- Myocardium/metabolism
- Organ Specificity
- Phosphatidylinositol 3-Kinases/metabolism
- Phosphorylation/drug effects
- Proto-Oncogene Proteins c-akt/metabolism
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Receptors, Adrenergic, beta-1/deficiency
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/deficiency
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Ribosomal Protein S6 Kinases, 70-kDa/metabolism
- SKP Cullin F-Box Protein Ligases/genetics
- Signal Transduction/drug effects
- TOR Serine-Threonine Kinases/metabolism
- Tripartite Motif Proteins
- Ubiquitin-Protein Ligases/genetics
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97
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Jiang Q, Yuan H, Xing X, Liu J, Huang Z, Du X. Methylation of adrenergic β1 receptor is a potential epigenetic mechanism controlling antihypertensive response to metoprolol. INDIAN JOURNAL OF BIOCHEMISTRY & BIOPHYSICS 2011; 48:301-307. [PMID: 22165287] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Although metoprolol is used to treat hypertension, clinical responses are variable and unpredictable. Evidence suggests that adrenergic beta1 receptor (ADRB1, designated Adrb1 in rodents) gene polymorphisms influence the level of blood pressure response to this drug therapy, but their presence can not predict the response of the individual patient. The question exists whether epigenetic modifications, such as DNA methylation could cause changes in the gene's expression that are a determining factor in metoprolol's efficacy. The aim of this study was to verify whether DNA methylation could change the expression of the ADRB1 gene, and epigenetic modification could explain why individuals with identical ADRB1 gene polymorphisms have different antihypertensive responses to metoprolol. H9c2 rat myocardial cells in vitro were randomly divided into 5-aza-2'-deoxycytidine (decitabine)-treated (0.5 to 10.0 microM) and control groups. For the in vivo experiments, 45 spontaneously hypertensive rats (SHRs) were divided into metoprolol-treated and control groups, and after a 4-week intervention myocardia were harvested. Genomic methylation-sensitive PCR was used to assess the methylation status of the Adrb1 promoter after DNA extraction from H9c2 cells and SHR myocardia. Real-time fluorescent quantitative RT-PCR was used to determine levels ofAdrb1 mRNA. In H9c2 cells, the least degree of methylation was observed in the 5.0 microM decitabine treated group. Prolonged exposure of cells to 5.0 microM decitabine resulted in downregulating methylation of the Adrb1 promoter. Increased levels of Adrb1 mRNA of the 5.0 microM group demonstrated that this concentration resulted in the highest expression. Accordingly, DNA methylation resulted in the downregulation of Adrb1 transcription. In vivo, the lower level of methylation of the Adrb1 promoter from SHR myocardial samples demonstrated a better antihypertensive effect by metoprolol. The expression of Adrb1 mRNA in the effective group of SHRs was significantly upregulated. In conclusion, as shown in both H9c2 cells and SHRs, downregulated methylation of the Adrb1 promoter is likely to improve the antihypertensive efficacy of metoprolol.
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98
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Jensen MK, Pers TH, Dworzynski P, Girman CJ, Brunak S, Rimm EB. Protein interaction-based genome-wide analysis of incident coronary heart disease. CIRCULATION. CARDIOVASCULAR GENETICS 2011; 4:549-56. [PMID: 21880673 PMCID: PMC3197770 DOI: 10.1161/circgenetics.111.960393] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
BACKGROUND Network-based approaches may leverage genome-wide association (GWA) analysis by testing for the aggregate association across several pathway members. We aimed to examine if networks of genes that represent experimentally determined protein-protein interactions (PPIs) are enriched in genes associated with risk of coronary heart disease (CHD). METHODS AND RESULTS Genome-wide association analyses of approximately ≈700,000 single-nucleotide polymorphisms in 899 incident CHD cases and 1823 age- and sex-matched controls within the Nurses' Health and the Health Professionals Follow-up Studies were used to assign genewise P values. A large database of PPIs was used to assemble 8351 unbiased protein complexes and corresponding gene sets. Superimposed genewise P values were used to rank gene sets based on their enrichment in genes associated with CHD. After correcting for the number of complexes tested, 1 gene set was overrepresented in CHD-associated genes (P=0.002). Centered on the β1-adrenergic receptor gene (ADRB1), this complex included 18 protein interaction partners that have not been identified as candidate loci for CHD. Of the 19 genes in the top complex, 5 are involved in abnormal cardiovascular system physiological features based on knockout mice (4-fold enrichment; Fisher exact test, P=0.006). Ingenuity pathway analysis revealed that canonical pathways, especially related to blood pressure regulation, were significantly enriched in the genes from the top complex. CONCLUSIONS The integration of a GWA study with PPI data successfully identifies a set of candidate susceptibility genes for incident CHD that would have been missed in single-marker GWA analysis.
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99
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Turdi S, Yuan M, Leedy GM, Wu Z, Ren J. Chronic social stress induces cardiomyocyte contractile dysfunction and intracellular Ca2+ derangement in rats. Physiol Behav 2011; 105:498-509. [PMID: 21952229 DOI: 10.1016/j.physbeh.2011.09.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2011] [Revised: 09/06/2011] [Accepted: 09/11/2011] [Indexed: 12/29/2022]
Abstract
Chronic psychosocial stress triggers cardiovascular diseases although underlying mechanisms are still elusive. This study examined the effect of social stress on cardiomyocyte contractile function and pathological changes in myocardium using the visible burrow system (VBS) model. Chronic social stress was induced using a mixed-sex VBS housing in adult Sprague-Dawley (SD) rats. Contractile and intracellular Ca(2+) properties were evaluated in isolated cardiomyocytes including peak shortening (PS), time-to-PS (TPS), time-to-90% relengthening (TR(90)), maximal velocity of shortening/relengthening (± dL/dt), Fura-2 fluorescence intensity, and intracellular Ca(2+) decay. Myocardial histology was evaluated using Masson trichrome staining. Social stress led to depressed PS, ± dL/dt, shortened TPS and prolonged TR(90) compared with the unstressed controls. Baseline and electrically-stimulated rise in Ca(2+) were reduced whereas intracellular Ca(2+) decay was delayed in stressed rats. Histological analyses exhibited overt interstitial fibrosis and cardiomyocyte hypertrophy in stressed rats. The GSH/GSSG ratio (indicative of oxidative stress status) was reduced whereas oxidative protein carbonyl formation was elevated in stressed rats. Western blot analysis showed unchanged expression of superoxide dismutase 1 (SOD1), β(1)-adrenoceptor (β(1)-AR) levels, reduced sarco(endo)plasmic reticulum Ca(2+)-ATPase (SERCA2a) levels, and elevated phosphorylation of the stress signaling protein kinase JNK but not ERK in myocardium from stressed rats. Short-term in vitro treatment of cardiomyocytes with the stress inducer phenylephrine mimicked cell damage and intracellular Ca(2+) mishandling, the effects of which were mitigated by antioxidant, JNK inhibition, carvedilol and SERCA2a adenovirus. These findings indicate that chronic social stress is detrimental to cardiac structure and function possibly via mechanisms associated with oxidative injury and intracellular Ca(2+) mishandling.
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Giltrow E, Eccles PD, Hutchinson TH, Sumpter JP, Rand-Weaver M. Characterisation and expression of β1-, β2- and β3-adrenergic receptors in the fathead minnow (Pimephales promelas). Gen Comp Endocrinol 2011; 173:483-90. [PMID: 21827763 DOI: 10.1016/j.ygcen.2011.07.006] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/09/2010] [Revised: 07/22/2011] [Accepted: 07/25/2011] [Indexed: 01/18/2023]
Abstract
Complimentary DNAs for three beta-adrenergic receptors (βARs) were isolated and characterised in the fathead minnow. The encoded proteins of 402 (β(1)AR), 397 (β(2)AR) and 434 (β(3)AR) amino acids were homologous to other vertebrate βARs, and displayed the characteristic seven transmembrane helices of G Protein-coupled receptors. Motifs and amino acids shown to be important for ligand binding were conserved in the fathead minnow receptors. Quantitative RT-PCR revealed the expression of all receptors to be highest in the heart and lowest in the ovary. However, the β(1)AR was the predominant subtype in the heart (70%), and β(3)AR the predominant subtype in the ovary (53%). In the brain, β(1)AR expression was about 200-fold higher than that of β(2)- and β(3)AR, whereas in the liver, β(2)AR expression was about 20-fold and 100-fold higher than β(3)- and β(1)AR expression, respectively. Receptor gene expression was modulated by exposure to propranolol (0.001-1mg/L) for 21 days, but not in a consistent, concentration-related manner. These results show that the fathead minnow has a beta-adrenergic receptor repertoire similar to that of mammals, with the molecular signatures required for ligand binding. An exogenous ligand, the beta-blocker propranolol, is able to alter the expression profile of these receptors, although the functional relevance of such changes remains to be determined. Characterisation of the molecular targets for beta-blockers in fish will aid informed environmental risk assessments of these drugs, which are known to be present in the aquatic environment.
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MESH Headings
- Amino Acid Motifs
- Animals
- Binding Sites
- Cyprinidae/metabolism
- DNA, Complementary/chemistry
- Female
- Phylogeny
- Protein Structure, Tertiary
- RNA, Messenger/metabolism
- Receptors, Adrenergic, beta-1/chemistry
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-1/physiology
- Receptors, Adrenergic, beta-2/chemistry
- Receptors, Adrenergic, beta-2/metabolism
- Receptors, Adrenergic, beta-2/physiology
- Receptors, Adrenergic, beta-3/chemistry
- Receptors, Adrenergic, beta-3/metabolism
- Receptors, Adrenergic, beta-3/physiology
- Sequence Alignment
- Sequence Analysis, Protein
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