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Shen S, Tiwari N, Madar J, Mehta P, Qiao LY. Beta 2-adrenergic receptor mediates noradrenergic action to induce cyclic adenosine monophosphate response element-binding protein phosphorylation in satellite glial cells of dorsal root ganglia to regulate visceral hypersensitivity. Pain 2022; 163:180-192. [PMID: 33941754 PMCID: PMC8556417 DOI: 10.1097/j.pain.0000000000002330] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2021] [Accepted: 04/28/2021] [Indexed: 01/03/2023]
Abstract
ABSTRACT Sympathoneuronal outflow into dorsal root ganglia (DRG) is suggested to be involved in sympathetically maintained chronic pain, which is mediated by norepinephrine (NE) action on DRG cells. This study combined in vitro and in vivo approaches to identify the cell types of DRG that received NE action and examined cell type-specific expression of adrenergic receptors (ARs) in DRG. Using DRG explants, we identified that NE acted on satellite glial cells (SGCs) to induce the phosphorylation of cAMP response element-binding protein (CREB). Using primarily cultured SGCs, we identified that beta (β)2-adrenergic receptor but not alpha (α)adrenergic receptor nor other βAR isoforms mediated NE-induced CREB phosphorylation and CRE-promoted luciferase transcriptional activity. Using fluorescence in situ hybridization and affinity purification of mRNA from specific cell types, we identified that β2AR was expressed by SGCs but not DRG neurons. We further examined β2AR expression and CREB phosphorylation in vivo in a model of colitis in which sympathetic nerve sprouting in DRG was observed. We found that β2AR expression and CREB phosphorylation were increased in SGCs of thoracolumbar DRG on day 7 after colitis induction. Inhibition but not augmentation of β2AR reduced colitis-induced calcitonin gene-related peptide release into the spinal cord dorsal horn and colonic pain responses to colorectal distention. Prolonged activation of β2AR in naive DRG increased calcitonin gene-related peptide expression in DRG neurons. These findings provide molecular basis of sympathetic modulation of sensory activity and chronic pain that involves β2AR-mediated signaling in SGCs of DRG.
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Affiliation(s)
- Shanwei Shen
- Department of Physiology and Biophysics, School of Medicine, Virginia Commonwealth University, Richmond, VA, United States
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2
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Rambacher KM, Moniri NH. Cysteine redox state regulates human β2-adrenergic receptor binding and function. Sci Rep 2020; 10:2934. [PMID: 32076070 PMCID: PMC7031529 DOI: 10.1038/s41598-020-59983-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 02/05/2020] [Indexed: 01/08/2023] Open
Abstract
Bronchoconstrictive airway disorders such as asthma are characterized by inflammation and increases in reactive oxygen species (ROS), which produce a highly oxidative environment. β2-adrenergic receptor (β2AR) agonists are a mainstay of clinical therapy for asthma and provide bronchorelaxation upon inhalation. We have previously shown that β2AR agonism generates intracellular ROS, an effect that is required for receptor function, and which post-translationally oxidizes β2AR cysteine thiols to Cys-S-sulfenic acids (Cys-S-OH). Furthermore, highly oxidative environments can irreversibly oxidize Cys-S-OH to Cys-S-sulfinic (Cys-SO2H) or S-sulfonic (Cys-SO3H) acids, which are incapable of further participating in homeostatic redox reactions (i.e., redox-deficient). The aim of this study was to examine the vitality of β2AR-ROS interplay and the resultant functional consequences of β2AR Cys-redox in the receptors native, oxidized, and redox-deficient states. Here, we show for the first time that β2AR can be oxidized to Cys-S-OH in situ, moreover, using both clonal cells and a human airway epithelial cell line endogenously expressing β2AR, we show that receptor redox state profoundly influences β2AR orthosteric ligand binding and downstream function. Specifically, homeostatic β2AR redox states are vital toward agonist-induced cAMP formation and subsequent CREB and G-protein-dependent ERK1/2 phosphorylation, in addition to β-arrestin-2 recruitment and downstream arrestin-dependent ERK1/2 phosphorylation and internalization. On the contrary, redox-deficient β2AR states exhibit decreased ability to signal via either Gαs or β-arrestin. Together, our results demonstrate a β2AR-ROS redox axis, which if disturbed, interferes with proper receptor function.
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Affiliation(s)
- Kalyn M Rambacher
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, GA30341, United States
| | - Nader H Moniri
- Department of Pharmaceutical Sciences, College of Pharmacy, Mercer University Health Sciences Center, Mercer University, Atlanta, GA30341, United States.
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3
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Chikazawa M, Sato R. Identification of a Novel Function of Resveratrol and Genistein as a Regulator of β 2 -Adrenergic Receptor Expression in Skeletal Muscle Cells and Characterization of Promoter Elements Required for Promoter Activation. Mol Nutr Food Res 2018; 62:e1800530. [PMID: 30184338 DOI: 10.1002/mnfr.201800530] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 08/22/2018] [Indexed: 11/09/2022]
Abstract
SCOPE Modulating β2 -adrenergic receptor (β2 -AR) expression and activation is important for maintaining skeletal muscle function. In this study, two food factors, resveratrol (RSV) and genistein (GEN), that are able to regulate β2 -AR promoter activity and may improve skeletal muscle function are identified. METHODS AND RESULTS Using luciferase reporter assay, 357 functional food factors as candidates for β2 -AR promoter activity have been screened and subsequently RSV and GEN increase β2 -AR promoter activity and β2 -AR mRNA expression. Using promoter sequence analysis, it is shown that the CCAAT box and the GC box on the β2 -AR promoter are required for the regulation of β2 -AR expression by RSV or GEN. It is also ascertained that transcription factor NF-YA binds to the CCAAT box on the β2 -AR promoter and that the amount of NF-YA bound to the CCAAT box is unchanged by RSV or GEN treatment. Finally, it is confirmed that a GEN-containing diet increases β2 -AR expression in mouse skeletal muscle and increased skeletal muscle mass. CONCLUSIONS The findings show that food-derived molecules have the potential to influence skeletal muscle mass and function by regulating G protein-coupled receptor expression.
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Affiliation(s)
- Miho Chikazawa
- Food Biochemistry Laboratory, Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan
| | - Ryuichiro Sato
- Food Biochemistry Laboratory, Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,Nutri-Life Science Laboratory, Department of Applied Biological Chemistry, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Tokyo, Japan.,AMED-CREST, Japan Agency for Medical Research and Development, Chiyoda-ku, Tokyo, Japan
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4
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Das M, Das S. Docosahexaenoic Acid (DHA) Induced Morphological Differentiation of Astrocytes Is Associated with Transcriptional Upregulation and Endocytosis of β 2-AR. Mol Neurobiol 2018; 56:2685-2702. [PMID: 30054857 DOI: 10.1007/s12035-018-1260-0] [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: 05/17/2018] [Accepted: 07/17/2018] [Indexed: 12/24/2022]
Abstract
Docosahexaenoic acid (DHA), an important ω-3 fatty acid, is abundantly present in the central nervous system and is important in every step of brain development. Much of this knowledge has been based on studies of the role of DHA in the function of the neurons, and reports on its effect on the glial cells are few and far between. We have previously reported that DHA facilitates astrocyte differentiation in primary culture. We have further explored the signaling mechanism associated with this event. It was observed that a sustained activation of the extracellular signal-regulated kinase (ERK) appeared to be critical for DHA-induced differentiation of the cultured astrocytes. Prior exposure to different endocytic inhibitors blocked both ERK activation and differentiation of the astrocytes during DHA treatment suggesting that the observed induction of ERK-2 was purely endosomal. Unlike the β1-adrenergic receptor (β1-AR) antagonist, atenolol, pre-treatment of the cells with the β2-adrenergic receptor (β2-AR) antagonist, ICI-118,551 inhibited the DHA-induced differentiation process, indicating a downstream involvement of β2-AR in the differentiation process. qRT-PCR and western blot analysis demonstrated a significant induction in the mRNA and protein expression of β2-AR at 18-24 h of DHA treatment, suggesting that the induction of β2-AR may be due to transcriptional upregulation. Moreover, DHA caused activation of PKA at 6 h, followed by activation of downstream cAMP response element-binding protein, a known transcription factor for β2-AR. Altogether, the observations suggest that DHA upregulates β2-AR in astrocytes, which undergo endocytosis and signals for sustained endosomal ERK activation to drive the differentiation process.
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Affiliation(s)
- Moitreyi Das
- Neurobiology Division, Cell Biology & Physiology Department, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Jadavpur, Kolkata, 700032, India
| | - Sumantra Das
- Neurobiology Division, Cell Biology & Physiology Department, CSIR-Indian Institute of Chemical Biology, 4 Raja S. C. Mullick Road, Jadavpur, Kolkata, 700032, India.
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5
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Cao H, Kou X, Yang R, Liu D, Wang X, Song Y, Feng L, He D, Gan Y, Zhou Y. Force-induced Adrb2 in periodontal ligament cells promotes tooth movement. J Dent Res 2014; 93:1163-9. [PMID: 25252876 DOI: 10.1177/0022034514551769] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The sympathetic nervous system (SNS) regulates bone resorption through β-2 adrenergic receptor (Adrb2). In orthodontic tooth movement (OTM), mechanical force induces and regulates alveolar bone remodeling. Compressive force-associated osteoclast differentiation and alveolar bone resorption are the rate-limiting steps of tooth movement. However, whether mechanical force can activate Adrb2 and thus contribute to OTM remains unknown. In this study, orthodontic nickel-titanium springs were applied to the upper first molars of rats and Adrb1/2(-/-) mice to confirm the role of SNS and Adrb2 in OTM. The results showed that blockage of SNS activity in the jawbones of rats by means of superior cervical ganglion ectomy reduced OTM distance from 860 to 540 μm after 14 d of force application. In addition, the injection of nonselective Adrb2 agonist isoproterenol activated the downstream signaling of SNS to accelerate OTM from 300 to 540 μm after 7 d of force application. Adrb1/2(-/-) mice showed significantly reduced OTM distance (19.5 μm) compared with the wild-type mice (107.6 μm) after 7 d of force application. Histopathologic analysis showed that the number of Adrb2-positive cells increased in the compressive region of periodontal ligament after orthodontic force was applied on rats. Mechanistically, mechanical compressive force upregulated Adrb2 expression in primary-cultured human periodontal ligament cells (PDLCs) through the elevation of intracellular Ca(2+) concentration. Activation of Adrb2 in PDLCs increased the RANKL/OPG ratio and promoted the peripheral blood mononuclear cell differentiation to osteoclasts in the cocultured system. Upregulation of Adrb2 in PDLCs promoted osteoclastogenesis, which accelerated OTM through Adrb2-enhanced bone resorption. In summary, this study suggests that mechanical force-induced Adrb2 activation in PDLCs contributes to SNS-regulated OTM.
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Affiliation(s)
- H Cao
- Department of Orthodontics Center for Craniofacial Stem Cell Research and Regeneration
| | - X Kou
- Department of Orthodontics Center for Craniofacial Stem Cell Research and Regeneration
| | - R Yang
- Department of Orthodontics Center for Craniofacial Stem Cell Research and Regeneration
| | - D Liu
- Department of Orthodontics Center for Craniofacial Stem Cell Research and Regeneration
| | - X Wang
- Department of Orthodontics Center for Craniofacial Stem Cell Research and Regeneration
| | - Y Song
- Department of Orthodontics Center for Craniofacial Stem Cell Research and Regeneration
| | - L Feng
- Department of Orthodontics Center for Craniofacial Stem Cell Research and Regeneration
| | - D He
- Department of Orthodontics Center for Craniofacial Stem Cell Research and Regeneration
| | - Y Gan
- Center for Temporomandibular Disorders and Orofacial Pain, Peking University School and Hospital of Stomatology, Beijing, China
| | - Y Zhou
- Department of Orthodontics Center for Craniofacial Stem Cell Research and Regeneration
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6
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Kämpfer N, Lamyel F, Schütz I, Warnken M, Hoffmann K, von Kügelgen I, Racké K. Dual regulation of β2-adrenoceptor messenger RNA expression in human lung fibroblasts by β2-cAMP signaling; delayed upregulated inhibitors oppose a rapid in onset, direct stimulation of gene expression. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2014; 387:649-57. [PMID: 24705868 PMCID: PMC4065340 DOI: 10.1007/s00210-014-0971-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/08/2013] [Accepted: 03/04/2014] [Indexed: 11/26/2022]
Abstract
Based on their bronchodilatory effect, β2-adrenoceptor agonists constitute essential elements in the treatment of bronchial asthma and COPD. As treatment with β2-adrenoceptor agonists has been associated with worsening of airway hyper-reactivity, possibly because of loss of β-adrenoceptor function, molecular mechanism of the regulation of β2-adrenoceptor expression were studied. MRC-5 human lung fibroblasts were cultured in absence or presence of test substances followed by β2-adrenoceptor messenger RNA (mRNA) determination by qPCR. After inhibition of mRNA synthesis by actinomycin D, β2-adrenoceptor mRNA decreased with a half-life of 23 min, whereas inhibition of protein synthesis by cycloheximide caused an about 5- and 6-fold increase within 1.5 and 4 h, respectively. β2-Adrenoceptor mRNA was increased by about 100 % after 1 h exposure to formoterol or olodaterol but decreased by about 60 % after 4 h agonist exposure. Both effects of β2-adrenoceptor agonists were mimicked by forskolin, a direct activator of adenylyl cyclase and cholera toxin, which stimulates adenylyl cyclase by permanent activation of Gs. β2-Adrenoceptor agonist-induced upregulation of β2-adrenoceptor mRNA was blocked by the β2-adrenoceptor antagonist ICI 118551 and prevented by actinomycin D, but not by cycloheximide. Moreover, in presence of cycloheximide, β2-adrenoceptor agonist-induced reduction in β2-adrenoceptor mRNA was converted into stimulation, resulting in a more than 10-fold increase. In conclusion, expression of β2-adrenoceptors in human lung fibroblasts is highly regulated at transcriptional level. The β2-adrenoceptor gene is under strong inhibitory control of short-living suppressor proteins. β2-Adrenoceptor activation induces via adenylyl cyclase - cyclic adenosine monophosphate (cAMP) signaling a rapid in onset direct stimulation of the β2-adrenoceptor gene transcription, an effect opposed by a delayed upregulation of inhibitory factors.
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Affiliation(s)
- N. Kämpfer
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - F. Lamyel
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - I. Schütz
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - M. Warnken
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - K. Hoffmann
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - I. von Kügelgen
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
| | - Kurt Racké
- Institute of Pharmacology & Toxicology, University of Bonn, Biomedical Center, Sigmund-Freud-Str. 25, D-53105 Bonn, Germany
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7
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Dekkers BGJ, Racké K, Schmidt M. Distinct PKA and Epac compartmentalization in airway function and plasticity. Pharmacol Ther 2012; 137:248-65. [PMID: 23089371 DOI: 10.1016/j.pharmthera.2012.10.006] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Accepted: 10/09/2012] [Indexed: 12/15/2022]
Abstract
Asthma and chronic obstructive pulmonary disease (COPD) are obstructive lung diseases characterized by airway obstruction, airway inflammation and airway remodelling. Next to inflammatory cells and airway epithelial cells, airway mesenchymal cells, including airway smooth muscle cells and (myo)fibroblasts, substantially contribute to disease features by the release of inflammatory mediators, smooth muscle contraction, extracellular matrix deposition and structural changes in the airways. Current pharmacological treatment of both diseases intends to target the dynamic features of the endogenous intracellular suppressor cyclic AMP (cAMP). This review will summarize our current knowledge on cAMP and will emphasize on key discoveries and paradigm shifts reflecting the complex spatio-temporal nature of compartmentalized cAMP signalling networks in health and disease. As airway fibroblasts and airway smooth muscle cells are recognized as central players in the development and progression of asthma and COPD, we will focus on the role of cAMP signalling in their function in relation to airway function and plasticity. We will recapture on the recent identification of cAMP-sensing multi-protein complexes maintained by cAMP effectors, including A-kinase anchoring proteins (AKAPs), proteins kinase A (PKA), exchange protein directly activated by cAMP (Epac), cAMP-elevating seven-transmembrane (7TM) receptors and phosphodiesterases (PDEs) and we will report on findings indicating that the pertubation of compartmentalized cAMP signalling correlates with the pathopysiology of obstructive lung diseases. Future challenges include studies on cAMP dynamics and compartmentalization in the lung and the development of novel drugs targeting these systems for therapeutic interventions in chronic obstructive inflammatory diseases.
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Affiliation(s)
- Bart G J Dekkers
- Department of Molecular Pharmacology, University Center of Pharmacy, University of Groningen, The Netherlands.
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8
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Thomsen M, Dahl M, Tybjaerg-Hansen A, Nordestgaard BG. β2 -adrenergic receptor Thr164IIe polymorphism, blood pressure and ischaemic heart disease in 66 750 individuals. J Intern Med 2012; 271:305-14. [PMID: 21883537 DOI: 10.1111/j.1365-2796.2011.02447.x] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
OBJECTIVES The β(2) -adrenergic receptor (ADRB2) is located on smooth muscle cells and is an important regulator of smooth muscle tone. The Thr164Ile polymorphism (rs1800888) in the ADRB2 gene is rare but has profound functional consequences on receptor function and could cause lifelong elevated smooth muscle tone. We tested the hypothesis that Thr164Ile is associated with increased blood pressure, increased frequency of hypertension and increased risk of cardiovascular disease (CVD). SUBJECTS A total of 66 750 individuals from two large Danish general population studies were genotyped, and 1943 Thr164Ile heterozygotes and 16 homozygotes were identified. RESULTS Thr164Ile genotype was associated with increased systolic and diastolic blood pressure in women (trend: P = 0.04 and 0.02): systolic and diastolic blood pressure increased by 5% and 2%, respectively, in female homozygotes compared with female noncarriers. All female Thr164Ile homozygotes had hypertension compared with 58% of female heterozygotes and 54% of female noncarriers (chi-square: P = 0.001). Female Thr164Ile homozygotes and heterozygotes had odds ratios for ischaemic heart disease (IHD) of 2.93 (0.56-15.5) and 1.28 (1.03-1.61), respectively, compared with female noncarriers (trend: P = 0.007). These differences were not observed in men. Furthermore, Gly16Arg (rs1042713) and Gln27Glu (rs1042714) in the ADRB2 gene were not associated with blood pressure, hypertension or CVD either in the population overall or in women and men separately. CONCLUSIONS ADRB2 Thr164Ile is associated with increased blood pressure, increased frequency of hypertension and increased risk of IHD amongst women in the general population. These findings, particularly for homozygotes, are novel.
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Affiliation(s)
- M Thomsen
- Department of Clinical Biochemistry, Herlev Hospital, Copenhagen University Hospital, Copenhagen, Denmark
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9
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Cellular signals underlying β-adrenergic receptor mediated salivary gland enlargement. Differentiation 2012; 83:68-76. [DOI: 10.1016/j.diff.2011.09.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2011] [Revised: 08/25/2011] [Accepted: 09/10/2011] [Indexed: 01/01/2023]
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10
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Muscle plasticity and β₂-adrenergic receptors: adaptive responses of β₂-adrenergic receptor expression to muscle hypertrophy and atrophy. J Biomed Biotechnol 2011; 2011:729598. [PMID: 22190857 PMCID: PMC3228688 DOI: 10.1155/2011/729598] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2011] [Accepted: 08/23/2011] [Indexed: 02/04/2023] Open
Abstract
We discuss the functional roles of β2-adrenergic receptors in skeletal
muscle hypertrophy and atrophy as well as
the adaptive responses of β2-adrenergic receptor expression to anabolic and catabolic conditions. β2-Adrenergic receptor stimulation using
anabolic drugs increases muscle mass by promoting
muscle protein synthesis and/or attenuating
protein degradation. These effects are prevented
by the downregulation of the receptor. Endurance
training improves oxidative performance partly
by increasing β2-adrenergic receptor density in
exercise-recruited slow-twitch muscles. However,
excessive stimulation of β2-adrenergic receptors negates their beneficial effects. Although the preventive effects of β2-adrenergic receptor stimulation on
atrophy induced by muscle disuse and catabolic
hormones or drugs are observed, these catabolic
conditions decrease β2-adrenergic receptor expression in
slow-twitch muscles. These findings present
evidence against the use of β2-adrenergic agonists in therapy for muscle wasting and weakness. Thus, β2-adrenergic receptors in the skeletal
muscles play an important physiological role in
the regulation of protein and energy balance.
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11
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Murray DR, Mummidi S, Valente AJ, Yoshida T, Somanna NK, Delafontaine P, Dinarello CA, Chandrasekar B. β2 adrenergic activation induces the expression of IL-18 binding protein, a potent inhibitor of isoproterenol induced cardiomyocyte hypertrophy in vitro and myocardial hypertrophy in vivo. J Mol Cell Cardiol 2011; 52:206-18. [PMID: 22004899 DOI: 10.1016/j.yjmcc.2011.09.022] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2011] [Revised: 09/03/2011] [Accepted: 09/25/2011] [Indexed: 11/25/2022]
Abstract
Both the sympathetic nervous system and the proinflammatory cytokine interleukin-18 (IL-18) play key roles in the pathophysiology of the hypertrophied failing heart. IL-18 binding protein (IL-18BP), a natural inhibitor of IL-18, counters its biological effects. β-AR stimulation induces IL-18 expression, but whether it also regulates IL-18BP is not known. Here we demonstrate that the β-AR agonist isoproterenol (ISO) increases steady state IL-18BP mRNA and protein levels in adult mouse cardiomyocytes in a β(2)-AR-dependent manner. We cloned mouse Il18bp 5'cis-regulatory region, and identified putative CREB and C/EBPβ transcription factor-binding sites. Forced expression of mutant CREB or C/EBPβ knockdown markedly attenuated ISO-induced Il18bp transcription and deletion or mutation of CREB and C/EBP motifs in the Il18bp promoter reduced ISO-induced promoter-reporter gene activity. ISO induced CREB and C/EBPβ activation in cardiomyocytes via PI3K/Akt and ERK1/2. Importantly, ISO-induced hypertrophy in vitro was dependent on IL-18 induction as it was blunted by IL-18 neutralizing antibodies and forced expression of IL-18BP. Moreover, ISO-induced hypertrophy was markedly attenuated in IL-18 null and IL-18BP transgenic mice. These data support the novel concept that β-AR activation, in addition to inducing cardiomyocyte hypertrophy via IL-18, concomitantly induces a countering effect by stimulating IL-18BP expression, and that ISO-induced cardiomyocyte hypertrophy may result from a net effect of IL-18 and IL-18BP induction.
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Affiliation(s)
- David R Murray
- William S. Middleton Memorial Veterans Hospital, Madison, WI 53705, United States
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12
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Sato S, Shirato K, Tachiyashiki K, Imaizumi K. Synthesized glucocorticoid, dexamethasone regulates the expressions of .BETA.2-adrenoceptor and glucocorticoid receptor mRNAs but not proteins in slow-twitch soleus muscle of rats. J Toxicol Sci 2011; 36:479-86. [DOI: 10.2131/jts.36.479] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Shogo Sato
- Laboratory of Physiological Sciences, Faculty of Human Sciences, Waseda University
- Japan Society for the Promotion of Science
| | - Ken Shirato
- Laboratory of Physiological Sciences, Faculty of Human Sciences, Waseda University
| | - Kaoru Tachiyashiki
- Department of Natural and Living Sciences, Graduate School of Education, Joetsu University of Education
| | - Kazuhiko Imaizumi
- Laboratory of Physiological Sciences, Faculty of Human Sciences, Waseda University
- Global COE Doctoral Program, Graduate School of Sport Sciences, Waseda University
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13
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Sato S, Nomura S, Kawano F, Tanihata J, Tachiyashiki K, Imaizumi K. Adaptive effects of the beta2-agonist clenbuterol on expression of beta2-adrenoceptor mRNA in rat fast-twitch fiber-rich muscles. J Physiol Sci 2010; 60:119-27. [PMID: 20033361 PMCID: PMC10716947 DOI: 10.1007/s12576-009-0075-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2009] [Accepted: 11/23/2009] [Indexed: 10/20/2022]
Abstract
Administration of the beta(2)-agonist clenbuterol has been shown to reduce the expression of beta(2)-adrenoceptor (AR) mRNA in fast-twitch fiber-rich (extensor digitorum longus, EDL) muscle without changing that in slow-twitch fiber-rich (soleus, SOL) muscle in rats. However, the regulatory mechanism for muscle fiber type-dependent down-regulation of the expression of beta(2)-AR mRNA induced by clenbuterol is still unclear. Therefore, mRNA expression of transcriptional and post-transcriptional regulatory factors for beta(2)-AR mRNA levels in fast-twitch fiber-rich (EDL and plantaris, PLA) and slow-twitch fiber-rich (SOL) muscles in clenbuterol-administered (1.0 mg/kg body weight/day for 10 days, subcutaneous) rats was studied by real-time reverse transcription-polymerase chain reaction. Administration of clenbuterol significantly reduced expression of beta(2)-AR mRNA in EDL and PLA muscles without changing that in SOL muscle. Administration of clenbuterol also significantly reduced the mRNA expression of transcriptional regulatory factor (glucocorticoid receptor) and mRNA stabilizing factor (Hu antigen R) in EDL and PLA muscles without changing those in SOL muscle. These results suggest that muscle fiber type-dependent effects of clenbuterol on expression of beta(2)-AR mRNA are closely related to the down-regulation of mRNA expression of transcriptional and post-transcriptional regulatory factors for beta(2)-AR mRNA levels.
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MESH Headings
- Adaptation, Physiological/drug effects
- Adaptation, Physiological/physiology
- Adrenergic beta-Agonists/pharmacology
- Animals
- Cells, Cultured
- Clenbuterol/pharmacology
- Gene Expression Regulation/drug effects
- Gene Expression Regulation/physiology
- Male
- Muscle Fibers, Fast-Twitch/drug effects
- Muscle Fibers, Fast-Twitch/physiology
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptors, Adrenergic, beta-3/genetics
- Receptors, Adrenergic, beta-3/metabolism
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Affiliation(s)
- Shogo Sato
- Laboratory of Physiological Sciences, Faculty of Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 359-1192 Japan
| | - Sachiko Nomura
- Graduate School of Medicine, Osaka University, 1-17 Machikaneyama, Toyonaka, Osaka 560-0043 Japan
| | - Fuuun Kawano
- Graduate School of Arts and Sciences, The University of Tokyo, 3-8-1 Komaba, Meguro-ku, Tokyo, 153-8902 Japan
| | - Jun Tanihata
- Laboratory of Rehabilitation Biomedical Sciences, Faculty of Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 359-1192 Japan
| | - Kaoru Tachiyashiki
- Department of Living and Health Sciences, Graduate School of Joetsu University of Education, 1 Yamayashiki, Joetsu, Niigata 943-8512 Japan
| | - Kazuhiko Imaizumi
- Laboratory of Physiological Sciences, Faculty of Human Sciences, Waseda University, 2-579-15 Mikajima, Tokorozawa, Saitama 359-1192 Japan
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14
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Jajoo S, Mukherjea D, Kumar S, Sheth S, Kaur T, Rybak LP, Ramkumar V. Role of beta-arrestin1/ERK MAP kinase pathway in regulating adenosine A1 receptor desensitization and recovery. Am J Physiol Cell Physiol 2009; 298:C56-65. [PMID: 19828838 DOI: 10.1152/ajpcell.00190.2009] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Exposure of cells to adenosine receptor (AR) agonists leads to receptor uncoupling from G proteins and downregulation of the A(1)AR. The receptor levels on the cell surface generally recover on withdrawal of the agonist, because of either translocation of the sequestered A(1)AR back to plasma membrane or de novo synthesis of A(1)AR. To examine the mechanism(s) underlying A(1)AR downregulation and recovery, we treated ductus deferens tumor (DDT(1) MF-2) cells with the agonist R-phenylisopropyladenosine (R-PIA) and showed a decrease in membrane A(1)AR levels by 24 h, which was associated with an unexpected 11-fold increase in A(1)AR mRNA. Acute exposure of these cells to R-PIA resulted in a rapid translocation of beta-arrestin1 to the plasma membrane. Knockdown of beta-arrestin1 by short interfering RNA (siRNA) blocked R-PIA-mediated downregulation of the A(1)AR, suppressed R-PIA-dependent ERK1/2 and activator protein-1 (AP-1) activity, and reduced the induction of A(1)AR mRNA. Withdrawal of the agonist after a 24-h exposure resulted in rapid recovery of plasma membrane A(1)AR. This was dependent on the de novo protein synthesis and on the activity of ERK1/2 but independent of beta-arrestin1 and nuclear factor-kappaB. Together, these data suggest that exposure to A(1)AR agonist stimulates ERK1/2 activity via beta-arrestin1, which subserves receptor uncoupling and downregulation, in addition to the induction of A(1)AR expression. We propose that such a pathway ensures both the termination of the agonist signal and recovery by priming the cell for rapid de novo synthesis of A(1)AR once the drug is terminated.
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Affiliation(s)
- Sarvesh Jajoo
- PO Box 19629, SIU School of Medicine, Springfield, IL 62794, USA.
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15
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Kabir SM, Mukherjee S, Rajaratnam V, Smith MG, Das SK. Desensitization of beta-adrenergic receptors in lung injury induced by 2-chloroethyl ethyl sulfide, a mustard analog. J Biochem Mol Toxicol 2009; 23:59-70. [PMID: 19202564 DOI: 10.1002/jbt.20265] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
2-Choloroethyl Ethyl Sulfide (CEES) exposure causes inflammatory lung diseases, including acute respiratory distress syndrome (ARDS) and pulmonary fibrosis. This may be associated with oxidative stress, which has been implicated in the desensitization of beta-adrenergic receptors (beta-ARs). The objective of this study was to investigate whether lung injury induced by intratracheal CEES exposure (2 mg/kg body weight) causes desensitization of beta-ARs. The animals were sacrificed after 7 days and lungs were removed. Lung injury was established by measuring the leakage of iodinated-bovine serum albumin ([(125)I]-BSA) into lung tissue. Receptor-binding characteristics were determined by measuring the binding of [(3)H] dihydroalprenolol ([(3)H] DHA) (0.5-24 nM) to membrane fraction in the presence and absence of DLDL-propranolol (10 micro M). Both high- and low-affinity beta-ARs were identified in the lung. Binding capacity was significantly higher in low-affinity site in both control and experimental groups. Although CEES exposure did not change K(D) and B(max) at the high-affinity site, it significantly decreased both K(D) and B(max) at low affinity sites. A 20% decrease in beta(2)-AR mRNA level and a 60% decrease in membrane protein levels were observed in the experimental group. Furthermore, there was significantly less stimulation of adenylate cyclase activity by both cholera toxin and isoproterenol in the experimental group in comparison to the control group. Treatment of lungs with 3-isobutyl-1-methylxanthine (IBMX), an inhibitor of phosphodiesterase (PDE) could not abolish the difference between the control group and the experimental group on the stimulation of the adenylate cyclase activity. Thus, our study indicates that CEES-induced lung injury is associated with desensitization of beta(2)-AR.
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Affiliation(s)
- Syeda M Kabir
- Department of Cancer Biology, Meharry Medical College, 1005 David Todd Blvd., Nashville, TN 37208, USA
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16
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Zebrafish beta-adrenergic receptor mRNA expression and control of pigmentation. Gene 2009; 446:18-27. [PMID: 19540320 DOI: 10.1016/j.gene.2009.06.005] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2009] [Revised: 06/12/2009] [Accepted: 06/15/2009] [Indexed: 01/08/2023]
Abstract
Beta adrenergic receptors (beta-ARs) are members of the G-protein-coupled receptor superfamily and mediate various physiological processes in many species. The expression patterns and functions of beta-ARs in zebrafish are, however, largely unknown. We have identified zebrafish beta-AR orthologs, which we have designated as adrb1, adrb2a, adrb2b, adrb3a and adrb3b. adrb1 was found to be expressed in the heart and brain. Expression of adrb2a predominated in the brain and skin, whereas adrb2b was found to be highly expressed in muscle, pancreas and liver. Both adrb3a and adrb3b were exclusively expressed in blood. Knock-down of these beta-ARs by morpholino oligonucleotides revealed a functional importance of adrb2a in pigmentation. Expression of atp5a1 and atp5b, genes that encode subunits of F1F0-ATPase, which is known to be involved in pigmentation, was significantly increased by knock-down of adrb2a. Our data suggest that adrb2a may regulate pigmentation, partly by modulating F1F0-ATPase.
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17
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Meyer KD, Zhang L. Short- and long-term adverse effects of cocaine abuse during pregnancy on the heart development. Ther Adv Cardiovasc Dis 2009; 3:7-16. [PMID: 19144667 DOI: 10.1177/1753944708099877] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
The effect of cocaine on the developing fetus is a topic of considerable interest and debate. One of the potential effects of fetal cocaine exposure is damage to the developing heart. This review provides an overview of the current understanding of the short- and long-term effects of fetal cocaine exposure on the heart in both humans and animal models. Human studies are still preliminary but have suggested that fetal cocaine exposure impacts on the developing heart. Studies in animal models provide strong evidence for a programming effect resulting in detrimental long-term changes to the heart induced by fetal cocaine exposure. In the rat model, fetal cocaine results in apoptosis in the term heart, left ventricular remodeling and myocyte hypertrophy, as well as increased sensitivity to ischemia/reperfusion injury in the adult male offspring. The rat model has also shown evidence of epigenetic modifications in response to intrauterine cocaine. Increased DNA methylation of promoter regions leads to a long-term decrease in the expression of the cardioprotective gene, PKCepsilon. The current data shows fetal cocaine exposure has significant immediate and long-term cardiac consequences in animal models and while human studies are still incomplete they suggest this phenomenon may also be significant in humans exposed to cocaine during development.
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Affiliation(s)
- Kurt D Meyer
- Center for Perinatal Biology, Department of Physiology/Pharmacology and Biochemistry, Loma Linda University, School of Medicine, Loma Linda, California 92350, USA.
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18
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Ben-Shlomo A, Zhou C, Pichurin O, Chesnokova V, Liu NA, Culler MD, Melmed S. Constitutive somatostatin receptor activity determines tonic pituitary cell response. Mol Endocrinol 2009; 23:337-48. [PMID: 19131507 DOI: 10.1210/me.2008-0361] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Somatostatin (SRIF) binds G protein-coupled SRIF receptor subtypes (SST1, -2, -3, -4, and -5) to regulate cell secretion and proliferation. Hypothalamic SRIF inhibits pituitary growth hormone, thyroid stimulating hormone, and ACTH secretion. We tested SRIF-independent constitutive SST activity in AtT20 mouse pituitary corticotroph cells in which ACTH secretion is highly sensitive to SRIF action. Stable transfectants expressing SST2 or SST5 were sensitized to selective agonist action, and constitutive SST receptor activity was demonstrated by forskolin and pertussis toxin cAMP cell responses. Persistent constitutive SST activity decreased cell ACTH responses to CRH through decreased expression of CRH receptor subtype 1. Decreased dopamine receptor type 1 expression was associated with attenuated dopamine agonist action, whereas responses to isoproterenol were enhanced through increased beta2-adrenoreceptor expression. Thus, integrated pituitary cell ACTH regulation is determined both by phasic SRIF action, as well as by tonic constitutive SST activity, independently of SRIF.
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Affiliation(s)
- Anat Ben-Shlomo
- Cedars-Sinai Medical Center, 8700 Beverly Boulevard, Academic Affairs, Room 2015, Los Angeles, California 90048, USA
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19
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Sato S, Nomura S, Kawano F, Tanihata J, Tachiyashiki K, Imaizumi K. Effects of the beta2-agonist clenbuterol on beta1- and beta2-adrenoceptor mRNA expressions of rat skeletal and left ventricle muscles. J Pharmacol Sci 2008; 107:393-400. [PMID: 18678986 DOI: 10.1254/jphs.08097fp] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022] Open
Abstract
The beta2-agonist clenbuterol [4-amino-alpha(t-butyl-amino)methyl-3,5-dichlorobenzyl alcohol] is used as a non-steroidal anabolic drug for sports doping. The effects of clenbuterol on the transcriptional process and mRNA stability of beta-adrenoceptor (beta-AR) in skeletal and cardiac muscles are still unknown. Therefore, we investigated the effects of clenbuterol on beta1- and beta2-AR mRNA expressions of fast-twitch fiber-rich extensor digitorum longus (EDL), slow-twitch fiber-rich soleus (SOL), and left ventricle (LV) muscles by real-time RT-PCR. Adult male Sprague Dawley rats were divided into the clenbuterol-administered group and control group. The administration (dose = 1.0 mg/kg body weight/day, s.c.) of clenbuterol was maintained for 10 days. The administration of clenbuterol significantly increased the weight, RNA concentration, and total RNA content of EDL muscle. No effects of clenbuterol on those of SOL and LV muscles, however, were observed. The administration of clenbuterol significantly decreased beta1-AR mRNA expression of LV muscle. Furthermore, the administration of clenbuterol significantly decreased beta2-AR mRNA expression of EDL and LV muscles. No effect of clenbuterol on beta2-AR mRNA expression of SOL muscle, however, was observed. These results suggest that the effects of clenbuterol on beta1- and beta2-AR mRNA expressions and muscle hypertrophy depend on muscle fiber types.
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Affiliation(s)
- Shogo Sato
- Laboratory of Physiological Sciences, Faculty of Human Sciences, Waseda University, Tokorozawa, Saitama, Japan
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20
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Lynch GS, Ryall JG. Role of beta-adrenoceptor signaling in skeletal muscle: implications for muscle wasting and disease. Physiol Rev 2008; 88:729-67. [PMID: 18391178 DOI: 10.1152/physrev.00028.2007] [Citation(s) in RCA: 298] [Impact Index Per Article: 18.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
The importance of beta-adrenergic signaling in the heart has been well documented, but it is only more recently that we have begun to understand the importance of this signaling pathway in skeletal muscle. There is considerable evidence regarding the stimulation of the beta-adrenergic system with beta-adrenoceptor agonists (beta-agonists). Although traditionally used for treating bronchospasm, it became apparent that some beta-agonists could increase skeletal muscle mass and decrease body fat. These so-called "repartitioning effects" proved desirable for the livestock industry trying to improve feed efficiency and meat quality. Studying beta-agonist effects on skeletal muscle has identified potential therapeutic applications for muscle wasting conditions such as sarcopenia, cancer cachexia, denervation, and neuromuscular diseases, aiming to attenuate (or potentially reverse) the muscle wasting and associated muscle weakness, and to enhance muscle growth and repair after injury. Some undesirable cardiovascular side effects of beta-agonists have so far limited their therapeutic potential. This review describes the physiological significance of beta-adrenergic signaling in skeletal muscle and examines the effects of beta-agonists on skeletal muscle structure and function. In addition, we examine the proposed beneficial effects of beta-agonist administration on skeletal muscle along with some of the less desirable cardiovascular effects. Understanding beta-adrenergic signaling in skeletal muscle is important for identifying new therapeutic targets and identifying novel approaches to attenuate the muscle wasting concomitant with many diseases.
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Affiliation(s)
- Gordon S Lynch
- Basic and Clinical Myology Laboratory, Department of Physiology, The University of Melbourne, Victoria, Australia.
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21
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Harikai N, Shinnou R, Semma M, Tanaka S, Ichikawa A. EXPRESSION OF ADRENORECEPTOR AND MELANOCORTIN 2 RECEPTOR mRNA IN VARIOUS TISSUES FROM SHR.CG-LEPR CP/NDMCR RATS. Clin Exp Pharmacol Physiol 2007. [DOI: 10.1111/j.1440-1681.2007.04764.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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22
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Palmer TM, Stiles GL. The new biology of adenosine receptors. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 69:83-120. [PMID: 7817871 DOI: 10.1002/9780470123157.ch3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Affiliation(s)
- T M Palmer
- Department of Medicine, Duke University Medical Center, Durham, NC
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23
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Li B, Kaetzel MA, Dedman JR. Signaling pathways regulating murine cardiac CREB phosphorylation. Biochem Biophys Res Commun 2006; 350:179-84. [PMID: 16996475 DOI: 10.1016/j.bbrc.2006.09.016] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2006] [Accepted: 09/06/2006] [Indexed: 11/22/2022]
Abstract
Using the mouse Langendorff heart perfusion model, the signaling pathways that regulate cardiac CREB-S133 phosphorylation have been defined. In mouse hearts stimulated with isoproterenol (ISO) (10(-8) M), endothelin-1 (ET-1) (10(-8) M), and phorbol 12-myristate 13-acetate (TPA) (10(-7) M), CREB-S133 phosphorylation was attained only by TPA-treatment. Activation of protein kinase A (PKA) was achieved by ISO. ISO- and ET-1-stimulation activated Ca2+/calmodulin-dependent kinase II (CaMKII). Protein kinase C (PKC) and p90(RSK) were activated with all three stimuli. Inhibition of ERK1/2 with PD98059 (10(-5) M) completely inhibited the activation of p90(RSK), but did not block CREB-S133 phosphorylation in TPA-perfused heart, indicating that PKA, CaMKII, and p90(RSK) do not phosphorylate CREB-S133 in the murine heart. PKC activation is signal specific. Analyses of PKC isoforms suggest that CREB phosphorylation is mediated by PKC epsilon translocating into nucleus only with TPA stimulation. These results, unlike those reported in other tissues, demonstrate that cardiac CREB is not a multi-signal target.
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Affiliation(s)
- Bailing Li
- Department of Genome Science, University of Cincinnati Genome Research Institute, Cincinnati, OH 45237-0505, USA.
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24
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Commiskey S, Fan LW, Ho IK, Rockhold RW. Butorphanol: effects of a prototypical agonist-antagonist analgesic on kappa-opioid receptors. J Pharmacol Sci 2005; 98:109-16. [PMID: 15942128 DOI: 10.1254/jphs.crj05001x] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022] Open
Abstract
The opioid analgesic, butorphanol (17-cyclobutylmethyl-3,14-dihydroxymorphinan) tartrate is a prototypical agonist-antagonist opioid analgesic agent whose potential for abuse has been the cause of litigation in the United States. With a published affinity for opioid receptors in vitro of 1:4:25 (mu:delta:kappa), the relative contribution of actions at each of these receptors to the in vivo actions of the drug are an issue of active investigation. A body of evidence has been developed which indicates that a substantial selective action of butorphanol on the kappa-opioid receptor mediates the development of tolerance to butorphanol and cross-tolerance to other opioid agonists; to the production of dependence upon butorphanol, particularly in the rodent; and to compensatory alterations in brain opioid receptor-effector systems. This perspective will identify the current state of understanding of the effects produced by butorphanol on brain opioid receptors, particularly on the kappa-opioid receptor subtype, and on the expression of phosphotyrosyl proteins following chronic treatment with butorphanol.
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Affiliation(s)
- Stephen Commiskey
- Department of Pharmacology & Toxicology, University of Mississippi Medical Center, Jackson, USA
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25
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Srinivas SP, Satpathy M, Gallagher P, Larivière E, Van Driessche W. Adenosine induces dephosphorylation of myosin II regulatory light chain in cultured bovine corneal endothelial cells. Exp Eye Res 2004; 79:543-51. [PMID: 15381038 DOI: 10.1016/j.exer.2004.06.027] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2004] [Accepted: 06/25/2004] [Indexed: 10/26/2022]
Abstract
PURPOSE Dephosphorylation of the myosin II regulatory light chain (MLC) promotes barrier integrity of cellular monolayers through relaxation of the actin cytoskeleton. This study has investigated the influence of adenosine (ADO) on MLC phosphorylation in cultured bovine corneal endothelial cells (BCEC). METHODS MLC phosphorylation was assessed by urea-glycerol gel electrophoresis and immunoblotting. Elevation of cAMP in response to agonists of A2b receptors (subtype of P1 purinergic receptors) was confirmed by phosphorylation of the cAMP response element binding protein (CREB), which was determined by Western blotting. Activation of MAP kinases (i.e. activated ERK1 and ERK2) was assessed by Western blotting to examine their influence on MLC phosphorylation. Transepithelial electrical resistance (TER) of cells grown on porous filters was measured to assess the altered barrier integrity. RESULTS Exposure to ADO (200 microm; 30 min) and N-ethyl (carboxamido) adenosine (NECA; 50 microm; 30 min), known agonists of A2b receptors, induced phosphorylation of CREB similar to forskolin (FSK, 20 microm; 30 min), a direct activator of adenylate cyclase. Exposure to ADO, NECA, and FSK led to dephosphorylation of MLC by 51, 40, and 47%, respectively. ADO-induced dephosphorylation was dose-dependent with as much as 31% dephosphorylation at 1 microm ADO. CGS-21680, a selective A2a agonist, neither induced MLC dephosphorylation nor CREB phosphorylation. ADO phosphorylated MAP kinases which could be prevented by exposure to the MAP kinase-specific inhibitor, U0126 (10 microM). NECA and FSK also induced ERK1 and ERK2 activation similar to ADO. Exposure to U0126 inhibited MLC phosphorylation under basal conditions by 17%. ADO-induced MLC dephosphorylation was enhanced by a simultaneous exposure to U0126 (25% increase in dephosphorylation). Exposure to ADO caused an increase in TER from 17 to 22 ohms cm2. CONCLUSIONS (1) CREB phosphorylation in response to ADO and NECA, which indicates activation of the cAMP-PKA axis, suggests expression of A2b receptors in BCEC. (2) ERK1 and ERK2, activated by cAMP and A2b receptors, promote MLC phosphorylation. However, the net result of cAMP elevation is MLC dephosphorylation, presumably because the competing pathways involving inactivation of MLCK and/or ROCK are dominant (Rho-associated coiled coil-containing protein kinase or Rho kinase). (3) Consistent with MLC dephosphorylation, exposure to ADO increases TER, which suggests increased barrier integrity.
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Affiliation(s)
- S P Srinivas
- School of Optometry, Indiana University, 800 Atwater Ave, Bloomington, IN 47405, USA.
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26
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Farias-Silva E, dos Santos IN, Corezola do Amaral ME, Grassi-Kassisse DM, Spadari-Bratfisch RC. Glucocorticoid receptor and Beta-adrenoceptor expression in epididymal adipose tissue from stressed rats. Ann N Y Acad Sci 2004; 1018:328-32. [PMID: 15240386 DOI: 10.1196/annals.1296.040] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Adipocytes isolated from epididymal adipose tissue of foot-shock stressed rats are supersensitive to isoprenaline and subsensitive to norepinephrine. These alterations are probably mediated by a stress-induced increase in plasma corticosterone levels. We investigated whether foot-shock stress modifies the expression of glucocorticoid receptors (GRs) and beta-adrenergic protein receptors (beta-ARs) in epididymal adipose tissue from rats submitted to one daily foot-shock session on three consecutive days. This stress protocol caused decreases in GR, beta(1)-AR, and beta(3)-AR protein levels, but caused an increase in beta(2)-AR. These results confirm and support previous functional studies. The alterations in protein expression may be modulated by the high corticosterone levels that downregulate the glucocorticoid receptor.
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Affiliation(s)
- Elisangela Farias-Silva
- Laboratório do Estudo do Estresse (LABEEST), Departamento de Fisiologia e Biofísica, Instituto de Biologia, Universidade Estadual de Campinas (UNICAMP), CP 6109, CEP: 13089-970, Campinas, SP, Brasil.
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27
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Cao W, Daniel KW, Robidoux J, Puigserver P, Medvedev AV, Bai X, Floering LM, Spiegelman BM, Collins S. p38 mitogen-activated protein kinase is the central regulator of cyclic AMP-dependent transcription of the brown fat uncoupling protein 1 gene. Mol Cell Biol 2004; 24:3057-67. [PMID: 15024092 PMCID: PMC371122 DOI: 10.1128/mcb.24.7.3057-3067.2004] [Citation(s) in RCA: 447] [Impact Index Per Article: 22.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
It is well established that catecholamine-stimulated thermogenesis in brown fat requires beta-adrenergic elevations in cyclic AMP (cAMP) to increase expression of the uncoupling protein 1 (UCP1) gene. However, little is known about the downstream components of the signaling cascade or the relevant transcription factor targets thereof. Here we demonstrate that cAMP- and protein kinase A-dependent activation of p38 mitogen-activated protein kinase (MAPK) in brown adipocytes is an indispensable step in the transcription of the UCP1 gene in mice. By phosphorylating activating transcription factor 2 (ATF-2) and peroxisome proliferator-activated receptor gamma (PPARgamma) coativator 1alpha (PGC-1alpha), members of two distinct nuclear factor families, p38 MAPK controls the expression of the UCP1 gene through their respective interactions with a cAMP response element and a PPAR response element that both reside within a critical enhancer motif of the UCP1 gene. Activation of ATF-2 by p38 MAPK additionally serves as the cAMP sensor that increases expression of the PGC-1alpha gene itself in brown adipose tissue. In conclusion, our findings illustrate that by orchestrating the activity of multiple transcription factors, p38 MAPK is a central mediator of the cAMP signaling mechanism of brown fat that promotes thermogenesis.
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Affiliation(s)
- Wenhong Cao
- Department of Psychiatry, Duke University Medical Center, Durham, North Carolina 27710, USA
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28
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Srinivas SP, Maertens C, Goon LH, Goon L, Satpathy M, Yue BYJT, Droogmans G, Nilius B. Cell volume response to hyposmotic shock and elevated cAMP in bovine trabecular meshwork cells. Exp Eye Res 2004; 78:15-26. [PMID: 14667824 DOI: 10.1016/j.exer.2003.10.001] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
PURPOSE Hyposmolar perfusion of intact trabecular meshwork (TM) induces a decrease in its hydraulic conductivity (Lp). However, exposure to agents that elevate intracellular cAMP in TM cells increases Lp. Since volume of TM cells could directly influence porosity of the TM and hence Lp, this study has investigated changes in volume in response to acute hyposmotic shock (i.e. regulatory volume decrease or RVD) and elevated cAMP in cultured TM cells. METHODS Bovine trabecular meshwork cells (BTMC), grown on glass coverslips and loaded with the fluorescent dye MQAE, were used to measure rapid changes in cell volume using the principle of dynamic fluorescence quenching. Activation of volume-regulated anion channels (VRAC) was assessed by measuring volume-sensitive Cl(-) currents (I(Cl,swell)) in the whole cell configuration of the patch clamp technique and by determining the swelling-induced enhancement in I(-) permeability using the halide-sensitivity of MQAE. Expressions of ClC (chloride channels of the ClC gene family), P-glycoprotein (Pgp), and cystic fibrosis transmembrane regulator (CFTR) Cl(-) channels were examined by RT-PCR. Elevation of cAMP in response to forskolin was confirmed by determining the phosphorylation of cAMP response element-binding protein and activating transcription factor-1 (CREB, ATF-1), which form the downstream targets of protein kinase A. RESULTS As a response to hyposmotic shock, there was an acute increase in cell volume but there was no robust RVD. Patch clamp experiments showed activation of a characteristic Cl(-) current in response to cell swelling. This Cl(-) current was inhibited by NPPB (100microM) and fluoxetine (50microM), both of which are known blockers of VRAC. Experiments, which used the halide-sensitivity of MQAE, also indicated a 9-fold increase in I(-) influx upon cell swelling (8.9+/-4.6; n=9), consistent with activation of a VRAC-like Cl(-) current. To examine whether RVD is limited by K(+) conductance, the swollen cells were exposed to gramicidin, which is known to induce cation channel activity. Such a maneuver led to secondary swelling with [Na(+)](o)=140mM but a rapid shrinkage [Na(+)](o)=8mM indicating that the RVD is limited by cationic conductance necessary for K(+) efflux. Exposure to forskolin, which resulted in CREB and ATF-1 phosphorylation, caused a reversible decrease in cell volume (14.5+/-5%; n=20) under isosmotic and hyposmotic conditions. RT-PCR analysis confirmed expression of ClC-2, ClC-5, and Pgp Cl(-) channels in bovine TM cells. However, ClC-3 and CFTR were not expressed. CONCLUSIONS TM cells respond to acute hyposmotic shock in an osmometric manner, but their RVD is limited by K(+) conductance. The lack of CFTR expression and decrease in cell volume in response to forskolin concomitant with hyposmolarity suggest that elevated cAMP activates a K(+) conductance. Thus, the altered resistance to aqueous outflow in response to hyposmotic perfusion of the TM and elevated cAMP may be attributed to persistent cell swelling and cell shrinkage, respectively.
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Affiliation(s)
- S P Srinivas
- School of Optometry, Indiana University, 800 East Atwater Avenue, Bloomington, IN 47405, USA.
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Patberg KW, Plotnikov AN, Quamina A, Gainullin RZ, Rybin A, Danilo P, Sun LS, Rosen MR. Cardiac memory is associated with decreased levels of the transcriptional factor CREB modulated by angiotensin II and calcium. Circ Res 2003; 93:472-8. [PMID: 12893738 DOI: 10.1161/01.res.0000088785.24381.2f] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cardiac memory (CM) has short- (STCM) and long-term (LTCM) components modulated by calcium and angiotensin II. LTCM is associated with reduced Ito and Kv4.3 mRNA levels. Because the cAMP response element binding protein, CREB, contributes to CNS memory transcription, we hypothesized that it might be a transcriptional factor in CM, influenced by calcium and angiotensin II. We studied STCM in dogs that were AV sequentially paced (AVP) for 2 hours or sham-operated. STCM was evaluated with ECG and vectorcardiogram (VCG), and subepicardial biopsies were taken at 5 to 120 minutes and investigated for CREB. LTCM was studied in dogs paced for 3 weeks and in sham controls. At 3 weeks the heart was excised, biopsies obtained, and CRE binding tested. STCM induction occurred in AVP dogs but not in sham or AVP dogs treated with saralasin or nifedipine. Nuclear CREB was significantly decreased at 2 hours in the AVP no-drug group only. LTCM dogs manifested reduced binding of nuclear proteins to CRE, and CRE binding activity in the promoter region of Kv4.3. In conclusion, there is an association between STCM induction and decreased nuclear CREB that is angiotensin-modulated and calcium-dependent. Moreover, the decreased CRE binding after 3 weeks of AVP combined with CRE binding activity in the Kv4.3 promoter can explain the Kv4.3 mRNA and Ito downregulation that characterize LTCM.
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Affiliation(s)
- Kornelis W Patberg
- Department of Pharmacology, Center for Molecular Therapeutics, College of Physicians and Surgeons of Columbia University, New York, NY 10032, USA
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30
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Wadhawan R, Tseng YT, Stabila J, McGonnigal B, Sarkar S, Padbury J. Regulation of cardiac beta 1-adrenergic receptor transcription during the developmental transition. Am J Physiol Heart Circ Physiol 2003; 284:H2146-52. [PMID: 12742828 DOI: 10.1152/ajpheart.00929.2002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The beta(1)-adrenergic receptor (beta(1)AR) gene contains binding sites for myc/max proteins within a glucocorticoid response element. Transcriptional activation of the beta(1)AR is the result of cooperative binding between c-myc and the glucocorticoid receptor on the beta(1)AR promoter. The transcriptional regulation of both beta(1)AR and c-myc are developmentally regulated. We used transcription rate assays of nuclei isolated from fetal hearts to demonstrate a fivefold increase in the transcription rate of beta(1)AR vs. postnatal hearts (P < 0.01). This was associated with a fourfold increase in c-myc transcription. Transcription rate assays performed in a rat fibroblast cell line that overexpresses c-myc (myc(+/+)) showed similarly increased beta(1)AR expression compared with the wild-type cell line. Transient transfection experiments in the myc(+/+) cells demonstrated robust expression of beta(1)AR promoter constructs, which was abrogated by mutation of the myc/max binding site or by cotransfection with a c-myc antisense expression vector. These results suggest that the regulation of cardiac beta(1)AR transcription and the expression of c-myc are tightly integrated.
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MESH Headings
- Animals
- Animals, Newborn/metabolism
- Cell Nucleus/metabolism
- Cells, Cultured
- Female
- Gene Expression Regulation, Developmental/physiology
- Heart/embryology
- Kinetics
- Muscle Cells/metabolism
- Myocardium/metabolism
- Oligodeoxyribonucleotides, Antisense
- Pregnancy
- Proto-Oncogene Proteins c-myc/biosynthesis
- Rats
- Rats, Sprague-Dawley
- Receptors, Adrenergic, beta-1/biosynthesis
- Receptors, Adrenergic, beta-1/genetics
- Sheep
- Transcription, Genetic/drug effects
- Transcription, Genetic/physiology
- Transfection
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Affiliation(s)
- Rajan Wadhawan
- Women and Infants' Hospital of Rhode Island, Brown University School of Medicine, Providence 02905-2499, USA
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31
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Lo HW, Ali-Osman F. Cyclic AMP mediated GSTP1 gene activation in tumor cells involves the interaction of activated CREB-1 with the GSTP1 CRE: a novel mechanism of cellular GSTP1 gene regulation. J Cell Biochem 2003; 87:103-16. [PMID: 12210727 DOI: 10.1002/jcb.10275] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The human GSTP1 gene is frequently over-expressed in many human cancers and the expression increases with tumor progression and is associated with a more aggressive biology, poor patient survival, and resistance to therapy. The molecular regulation of the human GSTP1 gene during malignancy is, however, still not well understood. Recently, we reported the presence of a cAMP response element (CRE) in the 5'-region of the human GSTP1 gene, raising the possibility that the cAMP signaling pathway, frequently aberrant in human cancers, may play an important role in the transcriptional activation of the GSTP1 gene in human tumors. In this study, we report that the GSTP1 gene is an early cAMP response gene. Treatment of cells of the human lung carcinoma cell line, Calu-6, with 25 microM forskolin to activate the cAMP pathway resulted in a rapid and significant (sevenfold after 30 min) increase in GSTP1 gene transcripts, which peaked at 12-fold after 4 h. The forskolin-activated GSTP1 transcription in Calu-6 cells was suppressed dose-dependently by a 2-h pre-treatment with 0.1, 1.0, and 10 microM of the adenylate cyclase inhibitor, 2', 5'-dideoxyadenosine. Western blot analysis showed a rapid, fivefold increase, in GSTP1 protein levels after treatment with 25 microM forskolin, with a peak at 2 h post-treatment. The levels of phosphorylated CRE (Ser133) binding protein-1 (CREB-1) increased rapidly, sevenfold at 30 min, and reached 10-fold at 4 h following forskolin treatment. Intracellular cAMP levels also increased rapidly reaching 12-fold at 30 min. Gel mobility shift and supershift assays and DNase/footprinting analyses demonstrated that CREB-1 bZIP and CREB-containing nuclear extracts recognized the GSTP1 CRE with high affinity and specificity. Binding of CREB-1 bZIP to the GSTP1 CRE was abolished when the GSTP1 CRE sequence 5'-CGTCA-3', was mutated at the core nucleotides. Finally, transfection studies using luciferase plasmid constructs showed the GSTP1 CRE to be required for the cAMP-activated gene expression. Together, these findings describe a novel cAMP- and CREB-1-mediated mechanism of transcriptional regulation of the GSTP1 gene and suggest that this may be an important mechanism underlying the increased GSTP1 expression observed in tumors with an aberrant cAMP signaling pathway and in normal cells under conditions of stress, associated with increased intracellular cAMP.
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Affiliation(s)
- Hui-Wen Lo
- Section of Molecular Therapeutics, Department of Neurosurgery, Brain Tumor Center, University of Texas M.D. Anderson Cancer Center, Houston, Texas 77030, USA
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32
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Abstract
cAMP response binding protein (CREB) is a transcriptional factor known to regulate gene expression. Phosphorylation of CREB at serine 133 is necessary for CREB activation, and quantification of phospho-CREB (p-CREB) expression is an index of CREB activation. Because CREB expression and activation in specific brain regions are modified after chronic cocaine administration, we sought to determine whether chronic perinatal cocaine exposure affects the expression of CREB and p-CREB in the postnatal rat heart. Pregnant rats were treated daily with saline (control) or cocaine at 20 mg/kg (C20) or 60 mg/kg (C60) by intragastric administration throughout gestation. The expression of total CREB and p-CREB was quantified in nuclear extracts isolated from 1- and 7-d-old neonatal rat hearts. Cardiac nuclear p-CREB was increased in the C20 and C60 groups on d 1 and 7 of age compared with their respective age-matched control groups. The increase in p-CREB expression corresponded to an increase in cAMP response element binding activity. We also assayed nuclear protein kinase A activity, which was up-regulated in d 1 animals with prenatal cocaine exposure, but was comparable in all groups at d 7. Our results suggest that perinatal cocaine exposure stimulates CREB activation in the neonatal heart, and it may be mediated by different mechanisms at d 1 and d 7. The changes in myocardial CREB activation induced by perinatal cocaine exposure are likely to result in modified gene expression in the neonatal heart that may account for the cardiac dysfunction reported in human neonates born to cocaine-abusing mothers.
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Affiliation(s)
- Lena S Sun
- Department of Anesthesiology, College of Physicians and Surgeons, Columbia University, New York, New York 10032, USA.
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33
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Fan LW, Tanaka S, Park Y, Sasaki K, Ma T, Tien LT, Rockhold RW, Ho IK. Butorphanol dependence and withdrawal decrease hippocampal kappa 2-opioid receptor binding. Brain Res 2002; 958:277-90. [PMID: 12470863 DOI: 10.1016/s0006-8993(02)03572-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The present study examines the degree and distribution of alterations in the expression of kappa-opioid receptor subtypes using a model of chronic intracerebroventricular (i.c.v.) infusion of butorphanol. Autoradiographic characterization of binding for brain kappa(1) ([3H]CI-977)-, kappa(2) ([3H]bremazocine in the presence of DAMGO, DPDPE, and U-69,593)- and total kappa ([3H]bremazocine in the presence of only DAMGO and DPDPE)-opioid receptors was performed. Dependence was induced by a 72 h i.c.v. infusion with butorphanol (26 nmol/microl per hour) (butorphanol-dependent). Butorphanol withdrawal was produced by terminating the infusion of butorphanol in dependent animals. Responses were studied 7 h following termination (butorphanol-withdrawal). During both dependence and withdrawal phases, the binding signals for both kappa(1)- and kappa(2)-opioid receptors were significantly increased in certain regions, with especially marked increases in the frontal cortex, nucleus accumbens, parietal cortex, dorsomedial hypothalamus, ventral tegmental area and locus coeruleus. In contrast, a highly specific decrease in kappa(2)-, but increase in kappa(1)-, opioid receptor binding was noted in the hippocampus of rats in both butorphanol-dependent and-withdrawal groups. Therefore, alterations in kappa(1)- and kappa(2)-opioid receptors in the hippocampus may be differently involved in both adaptation to and recovery from chronic exposure to a mixed agonist/antagonist opioid analgesic. These results further illustrate the regional distribution of changes in binding characteristics of rat brain kappa(1)- and kappa(2)-opioid receptor subtypes in an established model of butorphanol dependence and withdrawal.
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Affiliation(s)
- Lir-Wan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, 2500 North State Street, Jackson, MS 39216, USA
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34
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Adcock IM, Maneechotesuwan K, Usmani O. Molecular interactions between glucocorticoids and long-acting beta2-agonists. J Allergy Clin Immunol 2002; 110:S261-8. [PMID: 12464934 DOI: 10.1067/mai.2002.129705] [Citation(s) in RCA: 64] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
beta(2)-Adrenergic receptor agonists and glucocorticoids are the two most effective treatments for asthma, and used in combination they are more effective than either alone. Glucocorticoids mediate their anti-inflammatory effects through the action of activated glucocorticoid receptors (GRs), with the level of activity being related to the number of nuclear receptors. Glucocorticoids can upregulate the synthesis of several genes in human lung cells through interaction with specific DNA binding regions (glucocorticoid response elements) within the promoter region of glucocorticoid-responsive genes. Many of the down-regulating effects of GRs on the synthesis of cytokines and other inflammatory mediators are due to repression of other transcription factors, such as activator protein-1 and nuclear factor kappaB. GR functions such as nuclear localization and gene activation can be regulated by phosphorylation status. Long-acting beta(2)-agonists may affect GR nuclear localization through modulation of GR phosphorylation and furthermore through priming of GR functions within the nucleus by modifying GR or GR-associated protein phosphorylation. Glucocorticoids in turn may regulate beta(2)-adrenergic receptor function by increasing its expression, acting through glucocorticoid response elements, and, importantly, by restoring G-protein-beta(2)-receptor coupling and inhibiting beta(2)-receptor downregulation, thereby preventing desensitization.
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Affiliation(s)
- Ian M Adcock
- Department of Thoracic Medicine, National Heart and Lung Institute, Imperial College of Science, Technology and Medicine, London, UK
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35
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Rovin BH, Lu L, Zhang X. A novel interleukin-8 polymorphism is associated with severe systemic lupus erythematosus nephritis. Kidney Int 2002; 62:261-5. [PMID: 12081586 DOI: 10.1046/j.1523-1755.2002.00438.x] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
BACKGROUND Interleukin-8 (IL-8) is a potent neutrophil chemokine that has been implicated in the pathogenesis of renal inflammation in human glomerulonephritis. To explain inter-patient variations in renal inflammation during diseases such as systemic lupus erythematosus (SLE), it was postulated that the promoter region of the IL-8 gene contains polymorphic residues that influence the level of IL-8 expression in response to immune-complex deposition, and thereby affect the severity of renal injury. This study was undertaken to identify polymorphisms in the 5'-flanking region of the IL-8 gene that correlate with the severity of SLE nephritis. METHODS A 1526 base pair segment of the IL-8 5'-flanking region was PCR amplified from the genomic DNA of 100 individuals and sequenced on an automated capillary electrophoresis system. Sequence data were compared with the published IL-8 sequence to identify polymorphisms. Allelic variations were verified by cloning and re-sequencing, and also by restriction enzyme analysis. Patients with SLE nephritis were genotyped for IL-8 polymorphisms, and associations between specific alleles and severity of SLE nephritis [based on the World Health Organization (WHO) classification] were determined. RESULTS Three single nucleotide polymorphisms were identified in the IL-8 flanking region. Labeled relative to the IL-8 translational start site, these are T-845C, T-738A, and A-353T. T-845C and T-738A are novel, and found primarily in African Americans. The C for T change at position -845 was found to be 3.6 to 7.5 times more frequent in African Americans with severe (WHO Class IV) SLE nephritis, than in African American controls, or patients with less severe forms of SLE nephritis, respectively. CONCLUSIONS IL-8-845C might predispose African Americans with SLE nephritis to more severe renal injury, perhaps by influencing IL-8 expression. Genotyping patients with glomerulonephritis for IL-8 polymorphisms may be useful in predicting disease outcome and individualizing immunosuppressive therapy.
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Affiliation(s)
- Brad H Rovin
- Nephrology Division, The Ohio State University School of Medicine and Public Health, N210 Means Hall, 1654 Upham Drive, Columbus, OH 43210, USA.
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36
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Fan LW, Tanaka S, Tien LT, Ma T, Rockhold RW, Ho IK. Withdrawal from dependence upon butorphanol uniquely increases kappa(1)-opioid receptor binding in the rat brain. Brain Res Bull 2002; 58:149-60. [PMID: 12127012 DOI: 10.1016/s0361-9230(02)00760-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Changes in kappa(1)-opioid receptor binding have been implicated in the development of dependence upon and withdrawal from butorphanol. Autoradiographic characterization of binding for brain kappa(1)-([3H]CI-977), mu-([3H]DAMGO), and delta-([3H]DPDPE) opioid receptors was performed in rats undergoing naloxone-precipitated withdrawal from dependence upon butorphanol or morphine. Dependence was induced by a 72h i.c.v. infusion with either butorphanol or morphine (26nmol/microl/h). Withdrawal was subsequently precipitated by i.c.v. challenge with naloxone (48 nmol/5 microl/rat), administered 2h following cessation of butorphanol or morphine infusion. During withdrawal from butorphanol, but not morphine, kappa(1)-opioid receptor binding was increased significantly in the frontal cortex, posterior basolateral amygdaloid nucleus, dorsomedial hypothalamus, hippocampus, posterior paraventricular thalamic nucleus, ventral tegmental area and locus coeruleus. In contrast, mu-opioid receptor binding decreased in these brain regions in naloxone-precipitated withdrawal from morphine, but not butorphanol, while binding for delta-opioid receptors was altered in both withdrawal groups. The brain kappa(1)-opioid receptor appears to be more directly involved in the development of physical dependence upon, and the expression of withdrawal from, butorphanol, as opposed to the prototypical opioid analgesic, morphine.
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Affiliation(s)
- Lir-Wan Fan
- Department of Pharmacology and Toxicology, University of Mississippi Medical Center, Jackson, MS 39216, USA
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37
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Tseng YT, Stabila JP, Nguyen TT, McGonnigal BG, Waschek JA, Padbury JF. A novel glucocorticoid regulatory unit mediates the hormone responsiveness of the beta1-adrenergic receptor gene. Mol Cell Endocrinol 2001; 181:165-78. [PMID: 11476950 DOI: 10.1016/s0303-7207(01)00490-7] [Citation(s) in RCA: 21] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
The effects of glucocorticoids on expression of the beta1-adrenergic receptor (beta1AR) gene have been varied. To study the mechanism underling hormonal regulation of the beta1AR, transient transfection of progressively deleted ovine beta1AR promoter fragments was used to identify a 43-bp region (-1274 to -1232 from the translation start site) that contains a novel glucocorticoid regulatory unit (GRU) and confers glucocorticoid responsiveness. Using DNase I footprinting and electrophoretic mobility shift assays (EMSA), we demonstrated the GRU was composed of a palindrome, 5'-TAATTA-3', which is a core binding motif for the homeodomain proteins, an E-box (5'-CACGTG-3'), binding site for the Myc/Max family proteins, and an overlapping glucocorticoid response element (GRE) half-site (5'-TGTTCT-3'). EMSA demonstrated that the GRE half-site is critical for GRU-protein interactions, which also require binding of proteins to the E-box and the homeodomain region. Co-transfection of a plasmid expressing a c-myc antisense construct significantly reduced glucocorticoid responsiveness of the ovine beta1AR promoter. Furthermore, expression of proteins binding to the GRU was shown to be developmentally regulated, being high in embryonic, reduced in newborn and not detectable in adult heart. We conclude that the ovine beta1AR promoter contains a novel, functional GRU and that glucocorticoid receptor (GR) and the Myc/Max family proteins are involved in the cell-specific nuclear factor binding and transactivation via this element. The results suggest an alternative pathway through which glucocorticoids may exert their effects on genes lacking a full consensus GRE.
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Affiliation(s)
- Y T Tseng
- Department of Pediatrics, Women and Infants Hospital of Rhode Island, Brown Medical School, Providence, RI 02905-2401, USA.
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38
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Port JD, Bristow MR. Altered beta-adrenergic receptor gene regulation and signaling in chronic heart failure. J Mol Cell Cardiol 2001; 33:887-905. [PMID: 11343413 DOI: 10.1006/jmcc.2001.1358] [Citation(s) in RCA: 189] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
J. D. Port and M. R. Bristow. Altered Beta-adrenergic Receptor Gene Regulation and Signaling in Chronic Heart Failure. Journal of Molecular and Cellular Cardiology (2001) 33, 887-905. Beta adrenergic receptors (beta -ARs) are critical regulators of cardiac function in both normal and pathophysiological states. Under normal conditions, beta -ARs and their signaling pathways modulate both the rate and force of myocardial contraction and relaxation, allowing individuals to respond appropriately to physiological stress or exercise. However, in chronic heart failure, sustained activation of the beta -AR signaling pathways can have overtly negative biological consequences. This notion is reinforced by the positive outcomes of a number of clinical trials demonstrating the usefulness of beta-blocker therapy in chronic congestive heart failure. During the last few years, significant progress has been made in understanding the molecular biological basis of beta -AR function, both at the biochemical and genetic levels. In this review, the biological basis of adrenergic signaling and how this changes in heart failure is discussed. Aspects of adrenergic receptor pharmacology relevant to heart failure are reviewed, including the recently emerging differences described for beta(1)- v beta(2)-AR signaling pathways. Highlighting these differences is recent evidence that over-stimulation of the beta(1)-AR pathway in cardiac myocytes appears to be pro-apoptotic, whereas stimulation of the beta(2)-AR pathway may be anti-apoptotic. Overview of beta -AR gene regulation, transgenic models of beta -AR overexpression, and beta -AR polymorphisms as they relate to heart failure progression are also discussed.
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Affiliation(s)
- J D Port
- Department of Medicine, Division of Cardiology, University of Colorado Health Sciences Center, 4200 East Ninth Ave., Denver, CO 80262, USA.
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Souazé F. Maintaining cell sensitivity to G-protein coupled receptor agonists: neurotensin and the role of receptor gene activation. J Neuroendocrinol 2001; 13:473-9. [PMID: 11328459 DOI: 10.1046/j.1365-2826.2001.00658.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
In the last few years, a number of studies have brought new insights into the fundamental mechanisms of cell desensitization and internalization of G-protein coupled receptors. Such studies have demonstrated that cells remain desensitized from a few minutes to several hours, after exposure to high concentrations of agonist. However, in vivo, agonists such as hormones are always present, even in small amounts, and such long desensitization is not conceivable, since constant stimulation of cells is required for physiological responses. Under such circumstances, cells would require a means to permanently maintain sensitivity to various internal or external stimuli. In the present review, we have taken as an example the expression of the high affinity neurotensin receptor, a seven transmembrane G-protein coupled receptor, upon prolonged exposure to its agonist, and observed that cells remained sensitive only if the receptor gene was activated by the agonist. Consequently, new receptors were synthesized, and either delivered to the cell surface or accumulated in submembrane pools. This regulation takes place only after prolonged and intense agonist stimulation. Under these conditions, it is proposed that receptor turnover is accelerated in proportion to the agonist concentration in order to allow the cells to produce an adapted cellular response to external stimuli. Such mechanisms thus play a key role in cell sensitivity to hormones.
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Affiliation(s)
- F Souazé
- INSERM U339, Hôpital St Antoine, Paris, France.
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40
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Flügge G. Regulation of monoamine receptors in the brain: dynamic changes during stress. INTERNATIONAL REVIEW OF CYTOLOGY 1999; 195:145-213. [PMID: 10603576 DOI: 10.1016/s0074-7696(08)62705-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/30/2023]
Abstract
Monoamine receptors are membrane-bound receptors that are coupled to G-proteins. Upon stimulation by agonists, they initiate a cascade of intracellular events that guide biochemical reactions of the cell. In the central nervous system, they undergo diverse regulatory processes, among which are receptor desensitization, internalization into the cell, and downregulation. These processes vary among different types of monoamine receptors. alpha 2-Adrenoceptors are often downregulated by agonists, and beta-adrenoceptors are internalized rapidly. Others, such as serotonin1A-receptors, are controlled tightly by steroid hormones. Expression of these receptors is reduced by the "stress hormones" glucocorticoids, whereas gonadal hormones such as testosterone can counterbalance the glucocorticoid effects. Because of this, the pattern of monoamine receptors in certain brain regions undergoes dynamic changes when there are elevated concentrations of agonists or when the hormonal milieu changes. Stress is a physiological situation accompanied by the high activity of brain monoaminergic systems and dramatic changes in peripheral hormones. Resulting alterations in monoamine receptors are considered to be in part responsible for changes in the behavior of an individual.
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Affiliation(s)
- G Flügge
- German Primate Center, Göttingen, Germany
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41
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Abstract
It has been proposed that behavioural changes induced by chronic psychosocial stress in male tree shrews might be related to alterations in the central nervous alpha2-adrenoceptor system. In the noradrenergic centres of the brain, alpha2-adrenoceptors function as autoreceptors regulating noradrenaline release. Chronic stress downregulates these receptors in several brain regions. Since during stress, the activity of the hypothalamus-pituitary-adrenal axis is increased leading to high concentrations of plasma glucocorticoids, we investigated whether the effects of chronic stress can be mimicked by cortisol treatments. Two experiments were performed: a short-term treatment (males were injected i.v. with 1.5 mg cortisol and brains were dissected 2 h later) and a long-term treatment (animals received the hormone in their drinking water for 5 days; daily uptake 3-7 mg). The short-term treatment (injection), similar to the stress effects, downregulated alpha2-adrenoceptors in several brain regions. In contrast, the long-term oral treatment induced regional receptor upregulation. These data show: (i) that glucocorticoids regulate alpha2-adrenoceptors in the brain; (ii) that the duration and/or the route of cortisol application determines the results: and (iii) that chronic stress effects are not only due to the long-term glucocorticoid exposure, but also to other elements of the stress response.
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Affiliation(s)
- G Flügge
- German Primate Centre, Göttingen, Germany.
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42
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Gaiddon C, Larmet Y, Trinh E, Boutillier AL, Sommer B, Loeffler JP. Brain-derived neurotrophic factor exerts opposing effects on beta2-adrenergic receptor according to depolarization status of cerebellar neurons. J Neurochem 1999; 73:1467-76. [PMID: 10501191 DOI: 10.1046/j.1471-4159.1999.0731467.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
To investigate the molecular mechanisms underlying brain-derived neurotrophic factor (BDNF)-controlled synaptic plasticity, we studied beta2-adrenergic receptor (beta2-AR) expression in cultured cerebellar granule cells. We show that, depending on the state of depolarization, BDNF exerts opposite effects on beta2-AR expression. In neurons maintained in low K+ medium (5 mM K+) that will enter apoptosis, BDNF increases beta2-AR and beta2-AR transcripts. In contrast, in depolarized neurons (high K+ medium, 25 mM K+) BDNF represses beta2-AR expression. The use of reporter genes (driven by the beta2-AR promoter or restricted regulatory elements) revealed that BDNF exerts its opposite effects at the transcriptional level by recruiting a cyclic AMP response element (CRE) and the trans-acting factor CRE binding protein. These results provide the first evidence that a neurotrophin, e.g., BDNF, may exert an opposite effect on receptor expression and function (beta2-AR) according to the depolarization status of the neuron. Based on this finding, we propose that BDNF not only mediates neuronal survival, but is also involved in the modulation of the general sensitivity of the neuron to external signals, thus maintaining its optimal functional integration within the neuronal network.
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Affiliation(s)
- C Gaiddon
- UMR 7519 CNRS, Institut de Physiologie et de Chimie Biologique, Université Louis Pasteur, Strasbourg, France
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43
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Scott MGH, Swan C, Jobson TM, Rees S, Hall IP. Effects of a range of beta2 adrenoceptor agonists on changes in intracellular cyclic AMP and on cyclic AMP driven gene expression in cultured human airway smooth muscle cells. Br J Pharmacol 1999; 128:721-9. [PMID: 10516654 PMCID: PMC1571671 DOI: 10.1038/sj.bjp.0702829] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
1. The effects of the selective beta2 adrenoceptor agonists salbutamol, terbutaline and salmeterol and the non-selective beta adrenoceptor agonist isoprenaline on [3H]-cyclic AMP formation and cyclic AMP response element (CRE) driven luciferase expression, assessed using the construct p6CRE/luc, were studied in primary cultures of human airway smooth muscle (HASM) cells. 2. Optimal transfection conditions for transient expression of pGL3 Control were 4 microg DNA/well71 in a 6 well plate and 1.8 microl Transfectam/microg DNA. Expression was maximal at 48 - 72 h. 3. Salbutamol (maximum response 19%, EC50 0.6 microM), terbutaline (maximum response 38%, EC50 2.3 microM) and salmeterol (maximum response 18%, EC50 0.0012 microM) were all partial agonists for cyclic AMP formation compared with isoprenaline (EC50 0.08 microM). However, all of the beta2 adrenoceptor agonists produced increases in CRE-driven luciferase activity, in cultured HASM transfected with the vector p6CRE/luc, which were equivalent or greater (salmeterol) than those seen with isoprenaline. 4. Both salbutamol and salmeterol were more potent at increasing luciferase expression than in elevating cyclic AMP levels in these cells. The potency ratios (EC50 (cyclic AMP)/EC50 (LUC)) for the agents studied were isoprenaline: 0. 2 fold, terbutaline: 3 fold, salbutamol: 24 fold, salmeterol: 38 fold. 5. These data suggest that important quantitative differences exist in the ability of beta2 adrenoceptor agonists to increase whole cell cyclic AMP levels in airway smooth muscle and to drive gene expression via a CRE-driven mechanism.
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Affiliation(s)
- Mark G H Scott
- Institute of Cell Signalling and School of Medical and Surgical Sciences, Division of Therapeutics, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Caroline Swan
- Institute of Cell Signalling and School of Medical and Surgical Sciences, Division of Therapeutics, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Timothy M Jobson
- Institute of Cell Signalling and School of Medical and Surgical Sciences, Division of Therapeutics, Queen's Medical Centre, Nottingham NG7 2UH, UK
| | - Steve Rees
- Receptor Systems, Glaxo-Wellcome Research & Development, Gunnels Wood Road, Stevenage, Hertfordshire SG1 2NY, UK
| | - Ian P Hall
- Institute of Cell Signalling and School of Medical and Surgical Sciences, Division of Therapeutics, Queen's Medical Centre, Nottingham NG7 2UH, UK
- Author for correspondence:
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Abstract
Heterotrimeric G proteins in vertebrates constitute a family molecular switches that transduce the activation of a populous group of cell-surface receptors to a group of diverse effector units. The receptors include the photopigments such as rhodopsin and prominent families such as the adrenergic, muscarinic acetylcholine, and chemokine receptors involved in regulating a broad spectrum of responses in humans. Signals from receptors are sensed by heterotrimeric G proteins and transduced to effectors such as adenylyl cyclases, phospholipases, and various ion channels. Physiological regulation of G protein-linked receptors allows for integration of signals that directly or indirectly effect the signaling from receptor-->G protein-->effector(s). Steroid hormones can regulate signaling via transcriptional control of the activities of the genes encoding members of G protein-linked pathways. Posttranscriptional mechanisms are under physiological control, altering the stability of preexisting mRNA and affording an additional level for regulation. Protein phosphorylation, protein prenylation, and proteolysis constitute major posttranslational mechanisms employed in the physiological regulation of G protein-linked signaling. Drawing upon mechanisms at all three levels, physiological regulation permits integration of demands placed on G protein-linked signaling.
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Affiliation(s)
- A J Morris
- Department of Molecular Pharmacology, Diabetes and Metabolic Diseases Research Center, University Medical Center, State University of New York/Stony Brook, Stony Brook, New York 11794-8651, USA
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Maya-Núñez G, Conn PM. Transcriptional regulation of the gonadotropin-releasing hormone receptor gene is mediated in part by a putative repressor element and by the cyclic adenosine 3',5'-monophosphate response element. Endocrinology 1999; 140:3452-8. [PMID: 10433200 DOI: 10.1210/endo.140.8.6945] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
The levels of the GnRH receptor (GnRHR) and its messenger RNA depend on the pattern of administration of GnRH. In this study, internal deletion mutants in a luciferase reporter gene vector (GnRHR-pXP2) containing a 1226-bp promoter fragment of mouse GnRHR gene were used to examine the regulation of GnRHR gene transcription in GGH3 cells. Our results indicate that the mouse GnRHR promoter contains one putative repressor element located at position -343/-335. When this sequence was deleted, the GnRHR promoter activity was significantly increased in both basal and GnRH agonist (Buserelin)-, phorbol ester-, and forskolin-stimulated cells. Gel mobility shift assay showed that the sequence -343/-335 is capable of binding GGH3 nuclear proteins. With deletion of the cAMP response element (-107/-100), basal and Buserelin-stimulated transcription was decreased. The same response was observed after stimulation with forskolin. Stimulation with (Bu)2cAMP did not alter transcription above basal levels. The stimulation with phorbol ester resulted in an attenuated increase in transcriptional activity, suggesting that this sequence of the GnRHR promoter is a cAMP response element. These results suggest that the transcriptional activity of the GnRHR gene is mediated in part by a putative repressor element and by the cAMP response element.
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Affiliation(s)
- G Maya-Núñez
- Oregon Regional Primate Research Center, Beaverton 97006, USA
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Yang J, Dong LW, Tang C, Liu MS. Transcriptional and posttranscriptional regulation of beta(2)-adrenergic receptor gene in rat liver during sepsis. THE AMERICAN JOURNAL OF PHYSIOLOGY 1999; 277:R132-9. [PMID: 10409266 DOI: 10.1152/ajpregu.1999.277.1.r132] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Changes in beta(2)-adrenergic receptor (beta(2)-AR) gene expression in the rat liver during different phases of sepsis were studied. Sepsis was induced by cecal ligation and puncture (CLP). Septic rats exhibit two metabolically distinct phases: an initial hyperglycemic (9 h after CLP; early sepsis) followed by a hypoglycemic phase (18 h after CLP; late sepsis). The [(3)H]dihydroalprenolol binding studies show that the density of beta(2)-AR was decreased by 12 and 35% during the early and late phases of sepsis, respectively. Western blot analyses depict that the beta(2)-AR protein level was reduced by 37 and 72% during early and late sepsis, respectively. The reverse transcription polymerase chain reaction and Southern blot analyses reveal that the steady-state level of beta(2)-AR mRNA was decreased by 37% during early phase and 77% during late phase of sepsis. Nuclear run-off assays show that the rate of transcription of beta(2)-AR mRNA was reduced by 36% during early sepsis and 64% during late sepsis. The stability assays indicate that the half-life of beta(2)-AR mRNA was shortened by 21 and 50% during the early and late phases of sepsis, respectively, indicating that the rate of degradation of beta(2)-AR mRNA was progressively enhanced during sepsis. These findings demonstrate that the beta(2)-AR gene was underexpressed in the liver during the progression of sepsis, and, furthermore, the underexpression of the beta(2)-AR gene was the result of a reduction in the rate of transcription coupled with an enhancement in the rate of degradation of beta(2)-AR gene transcripts. Thus our findings that the transcriptional and posttranscriptional regulation of beta(2)-AR gene associated with decreases in beta(2)-AR number and its protein expression may provide a molecular mechanistic explanation for the development of hypoglycemia during the late stage of sepsis.
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Affiliation(s)
- J Yang
- Department of Pharmacological and Physiological Science, St. Louis University School of Medicine, St. Louis, Missouri 63104, USA
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Danner S, Lohse MJ. Regulation of beta-adrenergic receptor responsiveness modulation of receptor gene expression. Rev Physiol Biochem Pharmacol 1999; 136:183-223. [PMID: 9932487 DOI: 10.1007/bfb0032325] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Affiliation(s)
- S Danner
- Institute of Pharmacology, University of Würzburg, Germany
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Lin RZ, Chen J, Hu ZW, Hoffman BB. Phosphorylation of the cAMP response element-binding protein and activation of transcription by alpha1 adrenergic receptors. J Biol Chem 1998; 273:30033-8. [PMID: 9792725 DOI: 10.1074/jbc.273.45.30033] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Activation of alpha1 adrenergic receptors not only stimulates smooth muscle contraction but also modifies gene expression. We wondered if alpha1 adrenergic receptors could activate transcription of genes regulated by the cAMP response element-binding protein (CREB). Using Rat1 cells stably transfected with each of the three cloned human alpha1 adrenergic receptor subtypes, norepinephrine strongly stimulated CREB phosphorylation in alpha1A and alpha1B but more weakly in alpha1D-transfected cells. Norepinephrine increased the activity of a somatostatin cAMP-regulated enhancer-chloramphenicol acetyltransferase reporter in these cells. alpha1 adrenergic receptors are known to activate protein kinase C (PKC) and increase [Ca2+ ]i. Nonetheless, neither GF109203X, a PKC inhibitor, nor BAPTA-AM, a calcium chelator, blocked phosphorylation of CREB induced by norepinephrine. In addition, alpha1 adrenergic receptor-induced CREB phosphorylation was not mediated via the mitogen-activated protein kinase pathway because norepinephrine did not stimulate mitogen-activated protein kinase activity in these cells. Activation of alpha1 adrenergic receptors increased cAMP accumulation in these cells. Norepinephrine-induced cAMP-regulated enhancer-chloramphenicol acetyltransferase activity was inhibited either by expression of the PKA inhibitory peptide or a dominant negative PKA regulatory subunit mutant. These results demonstrate that alpha1 adrenergic receptors activate the transcription factor CREB by a PKA-dependent pathway.
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Affiliation(s)
- R Z Lin
- Veterans Affairs Palo Alto Health Care System, Geriatrics, Research, Education, and Clinical Center, Palo Alto, California 94304, USA
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Tittelbach V, Volff JN, Giray J, Ratge D, Wisser H. Agonist-induced down-regulation of the beta2-adrenoceptor and its mRNA in human mononuclear leukocytes. Biochem Pharmacol 1998; 56:967-75. [PMID: 9776307 DOI: 10.1016/s0006-2952(98)00231-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Agonist-mediated regulation of beta2-adrenoceptors in mononuclear leukocytes has been examined at the protein but not at the mRNA level. In the present study, incubation of mononuclear leukocytes with the beta-agonist (-)-isoproterenol (10(-6) M) for up to 42 hr led to a maximum decrease in both beta2-adrenoceptor mRNA concentration and total receptor number of ca. 56 and 70%, respectively. The decrease in the mRNA level, however, was slower than for the protein level. After 4 hr of incubation with the beta-agonist, the protein level decreased to a minimum of 65% of the initial amount, while an incubation of 8 hr was necessary to reach a similar decrease in the level of mRNA (69% of the initial level). Measurements of mRNA stability revealed a reduction in the half-life of beta2-adrenoceptor mRNA from 2.7 to 1.1 hr following 4 hr of incubation with (-)-isoproterenol. Our data clearly demonstrate that treatment of human mononuclear leukocytes with (-)-isoproterenol induces a beta2-adrenoceptor down-regulation together with a slower time course of mRNA down-regulation which is partly due to a reduction of mRNA stability.
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Affiliation(s)
- V Tittelbach
- Department of Clinical Pathology, Robert Bosch Hospital, Stuttgart, Germany
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50
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Myslivecek J, Lisá V, Trojan S, Tucek S. Heterologous regulation of muscarinic and beta-adrenergic receptors in rat cardiomyocytes in culture. Life Sci 1998; 63:1169-82. [PMID: 9763212 DOI: 10.1016/s0024-3205(98)00378-6] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Previous work indicated that hyperstimulation of muscarinic receptors brings about profound changes not only in the density of the muscarinic receptors, but also of the beta-adrenoceptors in rat heart atria in vivo. We have now investigated whether a similar receptor cross-regulation occurs in cardiomyocytes in vitro. Cardiomyocytes from 3-4 day old rats were exposed to chemical agents on days 5-6 in culture. Densities of muscarinic and beta-adrenergic receptors were measured according to the binding of N-[3H]methylscopolamine and [ H]CGP 12177, respectively, to cell surface membranes and cell homogenates. Exposure of cells to the muscarinic agonist carbachol (1 mmol/l) brought about a profound decrease in the number of muscarinic receptors. The number of beta-adrenoceptors displayed biphasic changes, being augmented after 24 h (by 20-45% on the cell surface and by 29% in the homogenate) and diminished after 48 h and 72 h (after 48 h, decrease by 44-75% on the cell surface and by 36% in the homogenate). These effects of carbachol were not prevented by dimethylaminopropyl-bis-indolylmaleimide, the inhibitor of protein kinase C. Exposure of cells to the beta-adrenoceptor agonist isoprenaline (0.1 mmol/l) strongly diminished the number of beta-adrenoceptors on the cell surface and in the homogenate. The density of muscarinic receptors on the cell surface was diminished by 24-43% after 24 h exposure to isoprenaline and unchanged after 48 h, whereas the concentration of muscarinic receptors in the homogenate was unchanged after 24 h and increased by 20% after 48 h. The isoprenaline-induced decrease in the density of cell surface muscarinic receptors could not be simulated by forskolin and was not abolished by the protein kinase A inhibitors Rp-cAMPS and HA-1004. Dibutyryl cyclic AMP diminished the density of cell surface muscarinic receptors more than that of the beta-adrenergic receptors. Our data reveal a novel phenomenon of a biphasic change (an increase followed by a loss) in the density of beta-adrenoceptors during exposure of cardiocytes to carbachol. Activation of beta-adrenoceptors brings about less conspicuous changes in the density of muscarinic receptors. The observed phenomena of receptor cross-regulation cannot be explained by simple activations of protein kinases A and C.
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Affiliation(s)
- J Myslivecek
- Institute of Physiology, Academy of Sciences of the Czech Republic, Prague
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