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Riis-Vestergaard MJ, Richelsen B, Bruun JM, Li W, Hansen JB, Pedersen SB. Beta-1 and Not Beta-3 Adrenergic Receptors May Be the Primary Regulator of Human Brown Adipocyte Metabolism. J Clin Endocrinol Metab 2020; 105:5684994. [PMID: 31867674 DOI: 10.1210/clinem/dgz298] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 12/19/2019] [Indexed: 11/19/2022]
Abstract
PURPOSE Brown adipose tissue (BAT) activation in humans has gained interest as a potential target for treatment of obesity and insulin resistance. In rodents, BAT is primarily induced through beta-3 adrenergic receptor (ADRB3) stimulation, whereas the primary beta adrenergic receptors (ADRBs) involved in human BAT activation are debated. We evaluated the importance of different ADRB subtypes for uncoupling protein 1 (UCP1) induction in human brown adipocytes. METHODS A human BAT cell model (TERT-hBA) was investigated for subtype-specific ADRB agonists and receptor knockdown on UCP1 mRNA levels and lipolysis (glycerol release). In addition, fresh human BAT biopsies and TERT-hBA were evaluated for expression of ADRB1, ADRB2, and ADRB3 using RT-qPCR. RESULTS The predominant ADRB subtype in TERT-hBA adipocytes and BAT biopsies was ADRB1. In TERT-hBA, UCP1 mRNA expression was stimulated 11.0-fold by dibutyryl cAMP (dbcAMP), 8.0-fold to 8.4-fold by isoproterenol (ISO; a pan-ADRB agonist), and 6.1-fold to 12.7-fold by dobutamine (ADRB1 agonist), whereas neither procaterol (ADRB2 agonist), CL314.432, or Mirabegron (ADRB3 agonists) affected UCP1. Similarly, dbcAMP, ISO, and dobutamine stimulated glycerol release, whereas lipolysis was unaffected by ADRB2 and ADRB3 agonists. Selective knockdown of ADRB1 significantly attenuated ISO-induced UCP1 expression. CONCLUSION The adrenergic stimulation of UCP1 and lipolysis may mainly be mediated through ADRB1. Moreover, ADRB1 is the predominant ADRB in both TERT-hBA and human BAT biopsies. Thus, UCP1 expression in human BAT may, unlike in rodents, primarily be regulated by ADRB1. These findings may have implications for ADRB agonists as future therapeutic compounds for human BAT activation.
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MESH Headings
- Adipocytes, Brown/cytology
- Adipocytes, Brown/metabolism
- Adult
- Aged
- Aged, 80 and over
- Cells, Cultured
- Cross-Sectional Studies
- Female
- Follow-Up Studies
- Gene Expression Regulation
- Humans
- Lipolysis
- Male
- Middle Aged
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-3/genetics
- Receptors, Adrenergic, beta-3/metabolism
- Young Adult
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Martyniuk CJ, Martínez R, Kostyniuk DJ, Mennigen JA, Zubcevic J. Genetic ablation of bone marrow beta-adrenergic receptors in mice modulates miRNA-transcriptome networks of neuroinflammation in the paraventricular nucleus. Physiol Genomics 2020; 52:169-177. [PMID: 32089076 PMCID: PMC7191424 DOI: 10.1152/physiolgenomics.00001.2020] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2020] [Revised: 02/07/2020] [Accepted: 02/16/2020] [Indexed: 12/21/2022] Open
Abstract
Elucidating molecular pathways regulating neuroimmune communication is critical for therapeutic interventions in conditions characterized by overactive immune responses and dysfunctional autonomic nervous system. We generated a bone marrow-specific adrenergic beta 1 and beta 2 knockout mouse chimera (AdrB1.B2 KO) to determine how sympathetic drive to the bone affects transcripts and miRNAs in the hypothalamic paraventricular nucleus (PVN). This model has previously exhibited a dampened systemic immune response and decreased blood pressure compared with control animals. Reduced sympathetic responsiveness of the bone marrow hematopoietic cells of AdrB1.B2 KO chimera led to suppression of transcriptional networks that included leukocyte cell adhesion and migration and T cell-activation and recruitment. Transcriptome responses related to IL-17a signaling and the renin-angiotensin system were also suppressed in the PVN. Based on the transcriptome response, we next computationally predicted miRNAs in the PVN that may underscore the reduced sympathetic responsiveness of the bone marrow cells. These included miR-27b-3p, miR-150, miR-223-3p, and miR-326. Using real-time PCR, we measured a downregulation in the expression of miR-150-5p, miR-205-5p, miR-223-3p, miR-375-5p, miR-499a-5p, miR-27b-3p, let-7a-5p, and miR-21a-5p in the PVN of AdrB1.B2 KO chimera, confirming computational predictions that these miRNAs are associated with reduced neuro-immune responses and the loss of sympathetic responsiveness in the bone marrow. Intriguingly, directional responses of the miRNA corresponded to mRNAs, suggesting complex temporal or circuit-dependent posttranscriptional control of gene expression in the PVN. This study identifies molecular pathways involved in neural-immune interactions that may act as targets of therapeutic intervention for a dysfunctional autonomic nervous system.
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Jaghoori A, Lamin V, Jacobczak R, Worthington M, Edwards J, Viana F, Stuklis R, Wilson DP, Beltrame JF. Sex differences in vascular reactivity of coronary artery bypass graft conduits. Heart Vessels 2020; 35:422-431. [PMID: 31576420 DOI: 10.1007/s00380-019-01508-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 09/20/2019] [Indexed: 11/29/2022]
Abstract
Females have increase in-hospital mortality and poorer outcomes following coronary artery bypass grafting (CABG). Biological differences in the reactivity of the graft conduits to circulating catecholamine may contribute to this sex difference. This study examined sex differences in the vasoconstrictor responses of internal mammary artery (IMA) and saphenous vein (SV) conduits to phenylephrine (PE) and endothelin-1 (ET-1). Functional IMA and SV were obtained from 78 male and 50 female patients undergoing CABG (67.7 ± 11 and 69 ± 10 years, respectively) and subjected to the following experimental conditions. (1) Concentration response curves for PE and ET-1 were generated in an intact IMA and SV and endothelium denuded IMA segments, (2) in the presence of the nitric oxide synthase inhibitor (L-NAME) or the cyclooxygenase inhibitor (indomethacin) in an endothelium-intact IMA and (3) the activity state (abundance and phosphorylation) of the α1-adrenergic receptor was investigated using Phos-tag™ western blot analysis. (1) Compared to male, female IMA and SV were hypersensitive to PE but not ET-1 (p < 0.05). The female IMA hypersensitivity response to PE was abolished following endothelial denudation, (2) persisted in the presence of L-NAME but was abolished in the presence of indomethacin and (3) there was no sex differences in the abundance and phosphorylation of the α1-adrenergic receptor in IMA. Female IMA and SV graft conduits are hypersensitive to α1-adrenergic stimuli. This endothelial cyclooxygenase pathway-mediated hypersensitivity may produce excessive IMA and SV graft constriction in females administered catecholamines and could contribute to their poorer CABG outcomes.
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Rowe G, Kelm NQ, Beare JE, Tracy E, Yuan F, LeBlanc AJ. Enhanced beta-1 adrenergic receptor responsiveness in coronary arterioles following intravenous stromal vascular fraction therapy in aged rats. Aging (Albany NY) 2019; 11:4561-4578. [PMID: 31296794 PMCID: PMC6660031 DOI: 10.18632/aging.102069] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Accepted: 06/25/2019] [Indexed: 04/30/2023]
Abstract
Our past study showed that a single tail vein injection of adipose-derived stromal vascular fraction (SVF) into old rats was associated with improved dobutamine-mediated coronary flow reserve. We hypothesize that i.v. injection of SVF improves coronary microvascular function in aged rats via alterations in beta adrenergic microvascular signaling. Female Fischer-344 rats aged young (3 months, n=32) and old (24 months, n=30) were utilized, along with two cell therapies intravenously injected in old rats four weeks prior to sacrifice: 1x107 green fluorescent protein (GFP+) SVF cells (O+SVF, n=21), and 5x106 GFP+ bone-marrow mesenchymal stromal cells (O+BM, n=6), both harvested from young donors. Cardiac ultrasound and pressure-volume measurements were obtained, and coronary arterioles were isolated from each group for microvessel reactivity studies and immunofluorescence staining. Coronary flow reserve decreased with advancing age, but this effect was rescued by the SVF treatment in the O+SVF group. Echocardiography showed an age-related diastolic dysfunction that was improved with SVF to a greater extent than with BM treatment. Coronary arterioles isolated from SVF-treated rats showed amelioration of the age-related decrease in vasodilation to a non-selective β-AR agonist. I.v. injected SVF cells improved β-adrenergic receptor-dependent coronary flow and microvascular function in a model of advanced age.
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Chen Y, Guo B, Zhang H, Hu L, Wang J. Higenamine, a Dual Agonist for β 1- and β 2-Adrenergic Receptors Identified by Screening a Traditional Chinese Medicine Library. PLANTA MEDICA 2019; 85:738-744. [PMID: 31185502 DOI: 10.1055/a-0942-4502] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Chronic heart failure is the terminal stage of various cardiovascular diseases. Despite the availability of several classes of drugs, there is still an unmet need for effective treatment. Based on bench work during the past two decades, we have proposed that enhancement of β 2-adrenergic receptor signaling in combination with the presently preferred β 1-adrenergic receptor blockade would be a promising strategy. Chinese herbal medicines have been shown to be effective in the treatment of heart failure, although the mechanisms largely remain unknown. In the present study, we screened an herbal medicine compound/extract library for β-adrenergic receptor ligands to determine the target of certain effective botanical remedies and seek a leading compound(s) for chronic heart failure treatment. Using a high-throughput screening assay, we identified higenamine, which has a long history in chronic heart failure treatment in traditional Chinese medicine, to be a potent β-adrenergic receptor agonist. Further experiments using specific inhibitors showed that higenamine activated both β 1-adrenergic receptor and β 2-adrenergic receptor. Inhibition of its action by pertussis toxin (a Gi inhibitor) indicated that it is a β 2-adrenergic receptor Gs/Gi dual agonist. Contractility experiments demonstrated a positive inotropic effect of higenamine. In conclusion, we found an herbal compound, higenamine, to be a dual agonist for β 1/β 2-adrenergic receptors with no preference in stimulating the Gs and Gi pathways in β 2-adrenergic receptor signaling. Our results elucidated not only the target of higenamine to explain its pharmacological effect in treating chronic heart failure, but also the mechanisms of its cardiac toxicity.
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MESH Headings
- Adrenergic beta-1 Receptor Agonists/pharmacology
- Adrenergic beta-2 Receptor Agonists/pharmacology
- Alkaloids/chemistry
- Alkaloids/pharmacology
- Animals
- Cell Line
- Dose-Response Relationship, Drug
- Drugs, Chinese Herbal/chemistry
- Drugs, Chinese Herbal/pharmacology
- High-Throughput Screening Assays/methods
- Humans
- Molecular Docking Simulation
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/physiology
- Rats, Sprague-Dawley
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Tetrahydroisoquinolines/chemistry
- Tetrahydroisoquinolines/pharmacology
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Ito A, Ohnuki Y, Suita K, Ishikawa M, Mototani Y, Shiozawa K, Kawamura N, Yagisawa Y, Nariyama M, Umeki D, Nakamura Y, Okumura S. Role of β-adrenergic signaling in masseter muscle. PLoS One 2019; 14:e0215539. [PMID: 30986276 PMCID: PMC6464212 DOI: 10.1371/journal.pone.0215539] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2018] [Accepted: 04/03/2019] [Indexed: 02/07/2023] Open
Abstract
In skeletal muscle, the major isoform of β-adrenergic receptor (β-AR) is β2-AR and the minor isoform is β1-AR, which is opposite to the situation in cardiac muscle. Despite extensive studies in cardiac muscle, the physiological roles of the β-AR subtypes in skeletal muscle are not fully understood. Therefore, in this work, we compared the effects of chronic β1- or β2-AR activation with a specific β1-AR agonist, dobutamine (DOB), or a specific β2-AR agonist, clenbuterol (CB), on masseter and cardiac muscles in mice. In cardiac muscle, chronic β1-AR stimulation induced cardiac hypertrophy, fibrosis and myocyte apoptosis, whereas chronic β2-AR stimulation induced cardiac hypertrophy without histological abnormalities. In masseter muscle, however, chronic β1-AR stimulation did not induce muscle hypertrophy, but did induce fibrosis and apoptosis concomitantly with increased levels of p44/42 MAPK (ERK1/2) (Thr-202/Tyr-204), calmodulin kinase II (Thr-286) and mammalian target of rapamycin (mTOR) (Ser-2481) phosphorylation. On the other hand, chronic β2-AR stimulation in masseter muscle induced muscle hypertrophy without histological abnormalities, as in the case of cardiac muscle, concomitantly with phosphorylation of Akt (Ser-473) and mTOR (Ser-2448) and increased expression of microtubule-associated protein light chain 3-II, an autophagosome marker. These results suggest that the β1-AR pathway is deleterious and the β2-AR is protective in masseter muscle. These data should be helpful in developing pharmacological approaches for the treatment of skeletal muscle wasting and weakness.
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Keksel N, Bussmann H, Unger M, Drewe J, Boonen G, Häberlein H, Franken S. St John's wort extract influences membrane fluidity and composition of phosphatidylcholine and phosphatidylethanolamine in rat C6 glioblastoma cells. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2019; 54:66-76. [PMID: 30668384 DOI: 10.1016/j.phymed.2018.06.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/23/2018] [Revised: 04/27/2018] [Accepted: 06/18/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND Chronic stress, an important factor in the development of depressive disorders, leads to an increased formation of cortisol, which causes a hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. In addition, cortisol mediates an adaptive effect on plasma membrane fluidity which may affect signal transduction of membrane-bound receptors and contribute to pathophysiological changes. METHODS Membrane fluidity was measured by fluorescence anisotropy using DPH (1,6-diphenyl-1,3,5-hexatriene) and TMA-DPH (1-(4-(trimethylamino)phenyl)-6-phenylhexa-1,3,5-triene). Changes in cellular content of phosphatidylcholine species was determined by pulse-chase experiments using deuterated choline and mass spectrometry. Single molecule tracking was used to examine the lateral mobility of β1-adrenoceptors and changes in cAMP formation were measured by ELISA. RESULTS Chronic exposure (6 - 8 days) of C6 cells to cortisol dose-dependently decreased DPH and TMA-DPH fluorescence anisotropy, reflecting increased membrane fluidity. In contrast, cells pretreated with St. John's wort extract Ze117 showed increased DPH and TMA-DPH fluorescence anisotropy values, indicating a membrane rigidification effect which was mediated at least by the constituents hypericin, hyperforin, quercetin, amentoflavone and biapigenin. The observed membrane fluidizing effect of cortisol could be reversed by cotreatment with Ze117. The membrane rigidification of Ze117 was in line with the in parallel observed decrease in the phosphatidylcholine/phosphatidylethanolamine ratio determined in whole cell lipid extracts. Interestingly, pulse-chase experiments demonstrated, that Ze117 inhibited the incorporation of choline-D9 in phosphatidylcholine species with saturated or monounsaturated fatty acids compared to control cells, while the synthesis of phosphatidylcholine species with polyunsaturated fatty acids was not affected. C6 cells whose membranes have become more rigid by Ze117 showed altered lateral mobility of β1-adrenoceptors as well as reduced cAMP formation after stimulation with the β1-adrenoceptor agonist dobutamine. CONCLUSION Obviously, the signaling of β1-adrenoceptors depends on the nature of the membrane environment. It can therefore be assumed that Ze117 has a normalizing effect not only on the membrane fluidity of "stressed" cells, but also on lateral mobility and subsequently on the signal transduction of membrane-associated receptors.
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Yen HY, Hoi KK, Liko I, Hedger G, Horrell MR, Song W, Wu D, Heine P, Warne T, Lee Y, Carpenter B, Plückthun A, Tate CG, Sansom MSP, Robinson CV. PtdIns(4,5)P 2 stabilizes active states of GPCRs and enhances selectivity of G-protein coupling. Nature 2018; 559:423-427. [PMID: 29995853 PMCID: PMC6059376 DOI: 10.1038/s41586-018-0325-6] [Citation(s) in RCA: 190] [Impact Index Per Article: 31.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2017] [Accepted: 05/14/2018] [Indexed: 11/21/2022]
Abstract
G-protein-coupled receptors (GPCRs) are involved in many physiological processes and are therefore key drug targets1. Although detailed structural information is available for GPCRs, the effects of lipids on the receptors, and on downstream coupling of GPCRs to G proteins are largely unknown. Here we use native mass spectrometry to identify endogenous lipids bound to three class A GPCRs. We observed preferential binding of phosphatidylinositol-4,5-bisphosphate (PtdIns(4,5)P2) over related lipids and confirm that the intracellular surface of the receptors contain hotspots for PtdIns(4,5)P2 binding. Endogenous lipids were also observed bound directly to the trimeric Gαsβγ protein complex of the adenosine A2A receptor (A2AR) in the gas phase. Using engineered Gα subunits (mini-Gαs, mini-Gαi and mini-Gα12)2, we demonstrate that the complex of mini-Gαs with the β1 adrenergic receptor (β1AR) is stabilized by the binding of two PtdIns(4,5)P2 molecules. By contrast, PtdIns(4,5)P2 does not stabilize coupling between β1AR and other Gα subunits (mini-Gαi or mini-Gα12) or a high-affinity nanobody. Other endogenous lipids that bind to these receptors have no effect on coupling, highlighting the specificity of PtdIns(4,5)P2. Calculations of potential of mean force and increased GTP turnover by the activated neurotensin receptor when coupled to trimeric Gαiβγ complex in the presence of PtdIns(4,5)P2 provide further evidence for a specific effect of PtdIns(4,5)P2 on coupling. We identify key residues on cognate Gα subunits through which PtdIns(4,5)P2 forms bridging interactions with basic residues on class A GPCRs. These modulating effects of lipids on receptors suggest consequences for understanding function, G-protein selectivity and drug targeting of class A GPCRs.
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MESH Headings
- Animals
- GTP-Binding Protein alpha Subunits, Gi-Go/metabolism
- GTP-Binding Protein alpha Subunits, Gs/metabolism
- Heterotrimeric GTP-Binding Proteins/metabolism
- Humans
- Molecular Dynamics Simulation
- Phosphatidylinositol 4,5-Diphosphate/metabolism
- Protein Stability
- Rats
- Receptors, Adrenergic, alpha-2/chemistry
- Receptors, Adrenergic, alpha-2/genetics
- Receptors, Adrenergic, alpha-2/metabolism
- Receptors, Adrenergic, beta-1/chemistry
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, G-Protein-Coupled/chemistry
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Neurotensin/chemistry
- Receptors, Neurotensin/genetics
- Receptors, Neurotensin/metabolism
- Single-Chain Antibodies/chemistry
- Single-Chain Antibodies/metabolism
- Substrate Specificity
- Turkeys
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Fedorowski A, Li H, Yu X, Koelsch KA, Harris VM, Liles C, Murphy TA, Quadri SMS, Scofield RH, Sutton R, Melander O, Kem DC. Antiadrenergic autoimmunity in postural tachycardia syndrome. Europace 2018; 19:1211-1219. [PMID: 27702852 PMCID: PMC5834103 DOI: 10.1093/europace/euw154] [Citation(s) in RCA: 95] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2016] [Accepted: 05/10/2016] [Indexed: 11/15/2022] Open
Abstract
Aims Postural tachycardia syndrome (POTS), a common and debilitating cardiovascular disorder, is characterized by an exaggerated heart rate increase during orthostasis and a wide spectrum of adrenergic-related symptoms. To determine the aetiology of POTS, we examined a possible pathophysiological role for autoantibodies against α1-adrenergic (α1AR) and β1/2-adrenergic receptors (β1/2AR). Methods and results Immunoglobulin G (IgG) derived from 17 POTS patients, 7 with recurrent vasovagal syncope (VVS), and 11 normal controls was analysed for its ability to modulate activity and ligand responsiveness of α1AR and β1/2AR in transfected cells and to alter contractility of isolated rat cremaster arterioles in vitro. Immunoglobulin G activation of α1AR and β1/2AR was significantly higher in POTS compared with VVS and controls in cell-based assays. Eight, 11, and 12 of the 17 POTS patients possessed autoantibodies that activated α1AR, β1AR and β2AR, respectively. Pharmacological blockade suppressed IgG-induced activation of α1AR and β1/2AR. Eight of 17 POTS IgG decreased the α1AR responsiveness to phenylephrine and 13 of 17 POTS IgG increased the β1AR responsiveness to isoproterenol irrespective of their ability to directly activate their receptors. Postural tachycardia syndrome IgG contracted rat cremaster arterioles, which was reversed by α1AR blockade. The upright heart rate correlated with IgG-mediated β1AR and α1AR activity but not with β2AR activity. Conclusion These data confirm a strong relationship between adrenergic autoantibodies and POTS. They support the concept that allosteric-mediated shifts in the α1AR and β1AR responsiveness are important in the pathophysiology of postural tachycardia.
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MESH Headings
- Abdominal Muscles/blood supply
- Adolescent
- Adrenergic alpha-1 Receptor Agonists/pharmacology
- Adrenergic beta-1 Receptor Agonists/pharmacology
- Adrenergic beta-2 Receptor Agonists/pharmacology
- Adult
- Animals
- Arterioles/drug effects
- Arterioles/metabolism
- Autoantibodies/blood
- Autoimmunity
- CHO Cells
- Case-Control Studies
- Cricetulus
- Dose-Response Relationship, Drug
- Female
- Humans
- Immunoglobulin G/blood
- In Vitro Techniques
- Male
- Postural Orthostatic Tachycardia Syndrome/blood
- Postural Orthostatic Tachycardia Syndrome/diagnosis
- Postural Orthostatic Tachycardia Syndrome/immunology
- Rats
- Receptors, Adrenergic, alpha-1/drug effects
- Receptors, Adrenergic, alpha-1/genetics
- Receptors, Adrenergic, alpha-1/immunology
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/immunology
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/drug effects
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/immunology
- Receptors, Adrenergic, beta-2/metabolism
- Transfection
- Vasoconstriction/drug effects
- Young Adult
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Nooh MM, Bahouth SW. Visualization and quantification of GPCR trafficking in mammalian cells by confocal microscopy. Methods Cell Biol 2017; 142:67-78. [PMID: 28964341 DOI: 10.1016/bs.mcb.2017.07.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
G protein-coupled receptors (GPCRs) are recognized as one of the most fruitful group of therapeutic targets, accounting for more than 40% of all approved pharmaceuticals on the market. Therefore, the search for selective agents that affect GPCR function is of major interest to the pharmaceutical industry. This chapter describes methods for measuring agonist-promoted GPCR trafficking, which involves the internalization of the GPCR and its subsequent recycling back to the plasma membrane or retention and eventual degradation. These pathways will be analyzed by confocal cellular imaging, using the β1-adrenergic receptor (β1-AR) as a primary model. A major problem encountered in studying GPCR trafficking is the unavailability of antibodies that would recognize the native receptor in cells or tissues. Therefore, wild-type, point mutants, and β1-AR chimeras are generated as epitope-tagged proteins, which are stably- or transiently expressed in mammalian cells. GPCR are labeled with a fluorophore-conjugated antibody directed against the N-terminal epitope tag. The trafficking of the fluorophore-tagged GPCR between divergent trafficking pathways that result in retention and eventual degradation or recycling and reinsertion into the plasma membrane can be followed by confocal immunofluorescence microscopy techniques outlined in this review.
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Yi B, Jahangir A, Evans AK, Briggs D, Ravina K, Ernest J, Farimani AB, Sun W, Rajadas J, Green M, Feinberg EN, Pande VS, Shamloo M. Discovery of novel brain permeable and G protein-biased beta-1 adrenergic receptor partial agonists for the treatment of neurocognitive disorders. PLoS One 2017; 12:e0180319. [PMID: 28746336 PMCID: PMC5529018 DOI: 10.1371/journal.pone.0180319] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 06/14/2017] [Indexed: 01/09/2023] Open
Abstract
The beta-1 adrenergic receptor (ADRB1) is a promising therapeutic target intrinsically involved in the cognitive deficits and pathological features associated with Alzheimer's disease (AD). Evidence indicates that ADRB1 plays an important role in regulating neuroinflammatory processes, and activation of ADRB1 may produce neuroprotective effects in neuroinflammatory diseases. Novel small molecule modulators of ADRB1, engineered to be highly brain permeable and functionally selective for the G protein with partial agonistic activity, could have tremendous value both as pharmacological tools and potential lead molecules for further preclinical development. The present study describes our ongoing efforts toward the discovery of functionally selective partial agonists of ADRB1 that have potential therapeutic value for AD and neuroinflammatory disorders, which has led to the identification of the molecule STD-101-D1. As a functionally selective agonist of ADRB1, STD-101-D1 produces partial agonistic activity on G protein signaling with an EC50 value in the low nanomolar range, but engages very little beta-arrestin recruitment compared to the unbiased agonist isoproterenol. STD-101-D1 also inhibits the tumor necrosis factor α (TNFα) response induced by lipopolysaccharide (LPS) both in vitro and in vivo, and shows high brain penetration. Other than the therapeutic role, this newly identified, functionally selective, partial agonist of ADRB1 is an invaluable research tool to study mechanisms of G protein-coupled receptor signal transduction.
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MESH Headings
- Adrenergic beta-1 Receptor Agonists/chemistry
- Adrenergic beta-1 Receptor Agonists/pharmacokinetics
- Adrenergic beta-1 Receptor Agonists/therapeutic use
- Alzheimer Disease/drug therapy
- Alzheimer Disease/metabolism
- Animals
- Brain/metabolism
- CHO Cells
- Cell Line, Tumor
- Cells, Cultured
- Cricetinae
- Cricetulus
- Crystallography, X-Ray
- Drug Discovery
- GTP-Binding Proteins/metabolism
- Humans
- Magnetic Resonance Spectroscopy
- Male
- Mice, Inbred C57BL
- Models, Chemical
- Models, Molecular
- Molecular Structure
- Neurocognitive Disorders/drug therapy
- Neurocognitive Disorders/metabolism
- Permeability
- Phenyl Ethers/chemistry
- Phenyl Ethers/pharmacokinetics
- Phenyl Ethers/therapeutic use
- Propanolamines/chemistry
- Propanolamines/pharmacokinetics
- Propanolamines/therapeutic use
- Protein Binding
- Rats, Sprague-Dawley
- Receptors, Adrenergic, beta-1/chemistry
- Receptors, Adrenergic, beta-1/metabolism
- Structure-Activity Relationship
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de Jong JMA, Wouters RTF, Boulet N, Cannon B, Nedergaard J, Petrovic N. The β 3-adrenergic receptor is dispensable for browning of adipose tissues. Am J Physiol Endocrinol Metab 2017; 312:E508-E518. [PMID: 28223294 DOI: 10.1152/ajpendo.00437.2016] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/06/2017] [Accepted: 02/16/2017] [Indexed: 12/30/2022]
Abstract
Brown and brite/beige adipocytes are attractive therapeutic targets to treat metabolic diseases. To maximally utilize their functional potential, further understanding is required about their identities and their functional differences. Recent studies with β3-adrenergic receptor knockout mice reported that brite/beige adipocytes, but not classical brown adipocytes, require the β3-adrenergic receptor for cold-induced transcriptional activation of thermogenic genes. We aimed to further characterize this requirement of the β3-adrenergic receptor as a functional distinction between classical brown and brite/beige adipocytes. However, when comparing wild-type and β3-adrenergic receptor knockout mice, we observed no differences in cold-induced thermogenic gene expression (Ucp1, Pgc1a, Dio2, and Cidea) in brown or white (brite/beige) adipose tissues. Irrespective of the duration of the cold exposure or the sex of the mice, we observed no effect of the absence of the β3-adrenergic receptor. Experiments with the β3-adrenergic receptor agonist CL-316,243 verified the functional absence of β3-adrenergic signaling in these knockout mice. The β3-adrenergic receptor knockout model in the present study was maintained on a FVB/N background, whereas earlier reports used C57BL/6 and 129Sv mice. Thus our data imply background-dependent differences in adrenergic signaling mechanisms in response to cold exposure. Nonetheless, the present data indicate that the β3-adrenergic receptor is dispensable for cold-induced transcriptional activation in both classical brown and, as opposed to earlier studies, brite/beige cells.
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MESH Headings
- Adipogenesis/drug effects
- Adipose Tissue, Beige/cytology
- Adipose Tissue, Beige/drug effects
- Adipose Tissue, Beige/metabolism
- Adipose Tissue, Brown/cytology
- Adipose Tissue, Brown/drug effects
- Adipose Tissue, Brown/metabolism
- Adrenergic beta-3 Receptor Agonists/pharmacology
- Animals
- Cold-Shock Response/drug effects
- Dioxoles/pharmacology
- Female
- Gene Expression Regulation/drug effects
- Intra-Abdominal Fat/cytology
- Intra-Abdominal Fat/drug effects
- Intra-Abdominal Fat/metabolism
- Male
- Mice
- Mice, Knockout
- RNA, Messenger/metabolism
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-3/chemistry
- Receptors, Adrenergic, beta-3/genetics
- Receptors, Adrenergic, beta-3/metabolism
- Reproducibility of Results
- Signal Transduction/drug effects
- Species Specificity
- Time Factors
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38
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Shimamoto S, Ijiri D, Kawaguchi M, Nakashima K, Tada O, Inoue H, Ohtsuka A. β 1- and β 2-adrenergic receptor stimulation differ in their effects on PGC-1α and atrogin-1/MAFbx gene expression in chick skeletal muscle. Comp Biochem Physiol A Mol Integr Physiol 2017; 211:1-6. [PMID: 28578076 DOI: 10.1016/j.cbpa.2017.05.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2016] [Revised: 05/24/2017] [Accepted: 05/26/2017] [Indexed: 11/18/2022]
Abstract
Adrenaline changes expression of the genes encoding peroxisome proliferator-activated receptor-gamma coactivator-1 alpha (PGC-1α), which is known as a regulator of muscle size, and atrogin-1/muscle atrophy F-box (MAFbx), which is a muscle-specific ubiquitin ligase. However, the subtype of β-adrenergic receptor (β-AR) involved in regulating these genes in skeletal muscle is not yet well defined. In this study, the effects of intraperitoneal injection of adrenaline and three β1-3-AR selective agonists on chick skeletal muscle metabolism were examined, to evaluate the functions of β-AR subtypes. Adrenaline decreased atrogin-1/MAFbx mRNA levels accompanied by an increase in PGC-1α mRNA and protein levels. However, among the three selective agonists, only the β1-AR agonist, dobutamine, increased PGC-1α mRNA and protein levels, while the β2-AR agonist, clenbuterol, suppressed atrogin-1/MAFbx mRNA levels. In addition, preinjection of the β1-AR antagonist, acebutolol, and the β2-AR antagonist, butoxamine, inhibited the adrenaline-induced increase in PGC-1α mRNA levels and the decrease in atrogin-1/MAFbx mRNA levels, respectively. Compared with adrenaline administration, the β3-AR agonist, BRL37344, decreased PGC-1α mRNA levels and increased atrogin-1/MAFbx mRNA levels. These results suggest that, in chick skeletal muscle, PGC-1α is induced via the β1-AR, while atrogin-1/MAFbx is suppressed via the β2-AR.
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39
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Hayashi K, Gotou M, Matsui T, Imahashi K, Nishimoto T, Kobayashi H. Identification of phosphorylation sites on β1-adrenergic receptor in the mouse heart. Biochem Biophys Res Commun 2017; 488:362-367. [PMID: 28501616 DOI: 10.1016/j.bbrc.2017.05.054] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 05/08/2017] [Indexed: 11/17/2022]
Abstract
β1-adrenergic receptor (Adrb1) belongs to the superfamily of G-protein-coupled receptors (GPCRs) and plays a critical role in the regulation of heart rate and myocardial contraction force. GPCRs are phosphorylated at multiple sites to regulate distinct signal transduction pathways in different tissues. However, little is known about the location and function of distinct phosphorylation sites of Adrb1 in vivo. To clarify the mechanisms underlying functional regulation associated with Adrb1 phosphorylation in vivo, we aimed to identify Adrb1 phosphorylation sites in the mouse heart using phosphoproteomics techniques with nano-flow liquid chromatography/tandem mass spectrometry (LC-MS/MS). We revealed the phosphorylation residues of Adrb1 to be Ser274 and Ser280 in the third intracellular loop and Ser412, Ser417, Ser450, Ser451, and Ser462 at the C-terminus. We also found that phosphorylation at Ser274, Ser280, and Ser462 was enhanced in response to stimulation with an Adrb1 agonist. This is the first study to identify Adrb1 phosphorylation sites in vivo. These findings will provide novel insights into the regulatory mechanisms mediated by Adrb1 phosphorylation.
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40
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Hinz L, Ahles A, Ruprecht B, Küster B, Engelhardt S. Two serines in the distal C-terminus of the human ß1-adrenoceptor determine ß-arrestin2 recruitment. PLoS One 2017; 12:e0176450. [PMID: 28472170 PMCID: PMC5417508 DOI: 10.1371/journal.pone.0176450] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Accepted: 04/11/2017] [Indexed: 01/14/2023] Open
Abstract
G protein-coupled receptors (GPCRs) undergo phosphorylation at several intracellular residues by G protein-coupled receptor kinases. The resulting phosphorylation pattern triggers arrestin recruitment and receptor desensitization. The exact sites of phosphorylation and their function remained largely unknown for the human β1-adrenoceptor (ADRB1), a key GPCR in adrenergic signal transduction and the target of widely used drugs such as β-blockers. The present study aimed to identify the intracellular phosphorylation sites in the ADRB1 and to delineate their function. The human ADRB1 was expressed in HEK293 cells and its phosphorylation pattern was determined by mass spectrometric analysis before and after stimulation with a receptor agonist. We identified a total of eight phosphorylation sites in the receptor's third intracellular loop and C-terminus. Analyzing the functional relevance of individual sites using phosphosite-deficient receptor mutants we found phosphorylation of the ADRB1 at Ser461/Ser462 in the distal part of the C-terminus to determine β-arrestin2 recruitment and receptor internalization. Our data reveal the phosphorylation pattern of the human ADRB1 and the site that mediates recruitment of β-arrestin2.
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41
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Shi Q, Li M, Mika D, Fu Q, Kim S, Phan J, Shen A, Vandecasteele G, Xiang YK. Heterologous desensitization of cardiac β-adrenergic signal via hormone-induced βAR/arrestin/PDE4 complexes. Cardiovasc Res 2017; 113:656-670. [PMID: 28339772 PMCID: PMC5852637 DOI: 10.1093/cvr/cvx036] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/02/2016] [Revised: 10/20/2017] [Accepted: 02/17/2017] [Indexed: 12/22/2022] Open
Abstract
AIMS Cardiac β-adrenergic receptor (βAR) signalling is susceptible to heterologous desensitization by different neurohormonal stimuli in clinical conditions associated with heart failure. We aim to examine the underlying mechanism of cross talk between βARs and a set of G-protein coupled receptors (GPCRs) activated by hormones/agonists. METHODS AND RESULTS Rat ventricular cardiomyocytes were used to determine heterologous phosphorylation of βARs under a series of GPCR agonists. Activation of Gs-coupled dopamine receptor, adenosine receptor, relaxin receptor and prostaglandin E2 receptor, and Gq-coupled α1 adrenergic receptor and angiotensin II type 1 receptor promotes phosphorylation of β1AR and β2AR at putative protein kinase A (PKA) phosphorylation sites; but activation of Gi-coupled α2 adrenergic receptor and activation of protease-activated receptor does not. The GPCR agonists that promote β2AR phosphorylation effectively inhibit βAR agonist isoproterenol-induced PKA phosphorylation of phospholamban and contractile function in ventricular cardiomyocytes. Heterologous GPCR stimuli have minimal to small effect on isoproterenol-induced β2AR activation and G-protein coupling for cyclic adenosine monophosphate (cAMP) production. However, these GPCR stimuli significantly promote phosphorylation of phosphodiesterase 4D (PDE4D), and recruit PDE4D to the phosphorylated β2AR in a β-arrestin 2 dependent manner without promoting β2AR endocytosis. The increased binding between β2AR and PDE4D effectively hydrolyzes cAMP signal generated by subsequent stimulation with isoproterenol. Mutation of PKA phosphorylation sites in β2AR, inhibition of PDE4, or genetic ablation of PDE4D or β-arrestin 2 abolishes this heterologous inhibitory effect. Ablation of β-arrestin 2 or PDE4D gene also rescues β-adrenergic stimuli-induced myocyte contractile function. CONCLUSIONS These data reveal essential roles of β-arrestin 2 and PDE4D in a common mechanism for heterologous desensitization of cardiac βARs under hormonal stimulation, which is associated with impaired cardiac function during the development of pathophysiological conditions.
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MESH Headings
- Animals
- Cells, Cultured
- Cyclic AMP-Dependent Protein Kinases/metabolism
- Cyclic Nucleotide Phosphodiesterases, Type 4/genetics
- Cyclic Nucleotide Phosphodiesterases, Type 4/metabolism
- Hormones/pharmacology
- Male
- Mice, Knockout
- Myocardial Contraction/drug effects
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Phosphorylation
- Protein Kinase C/metabolism
- Rats
- Receptor Cross-Talk
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/drug effects
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Signal Transduction/drug effects
- Time Factors
- beta-Arrestin 1/genetics
- beta-Arrestin 1/metabolism
- beta-Arrestin 2/genetics
- beta-Arrestin 2/metabolism
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42
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Goth CK, Tuhkanen HE, Khan H, Lackman JJ, Wang S, Narimatsu Y, Hansen LH, Overall CM, Clausen H, Schjoldager KT, Petäjä-Repo UE. Site-specific O-Glycosylation by Polypeptide N-Acetylgalactosaminyltransferase 2 (GalNAc-transferase T2) Co-regulates β 1-Adrenergic Receptor N-terminal Cleavage. J Biol Chem 2017; 292:4714-4726. [PMID: 28167537 PMCID: PMC5377785 DOI: 10.1074/jbc.m116.730614] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2016] [Revised: 01/29/2017] [Indexed: 01/08/2023] Open
Abstract
The β1-adrenergic receptor (β1AR) is a G protein-coupled receptor (GPCR) and the predominant adrenergic receptor subtype in the heart, where it mediates cardiac contractility and the force of contraction. Although it is the most important target for β-adrenergic antagonists, such as β-blockers, relatively little is yet known about its regulation. We have shown previously that β1AR undergoes constitutive and regulated N-terminal cleavage participating in receptor down-regulation and, moreover, that the receptor is modified by O-glycosylation. Here we demonstrate that the polypeptide GalNAc-transferase 2 (GalNAc-T2) specifically O-glycosylates β1AR at five residues in the extracellular N terminus, including the Ser-49 residue at the location of the common S49G single-nucleotide polymorphism. Using in vitro O-glycosylation and proteolytic cleavage assays, a cell line deficient in O-glycosylation, GalNAc-T-edited cell line model systems, and a GalNAc-T2 knock-out rat model, we show that GalNAc-T2 co-regulates the metalloproteinase-mediated limited proteolysis of β1AR. Furthermore, we demonstrate that impaired O-glycosylation and enhanced proteolysis lead to attenuated receptor signaling, because the maximal response elicited by the βAR agonist isoproterenol and its potency in a cAMP accumulation assay were decreased in HEK293 cells lacking GalNAc-T2. Our findings reveal, for the first time, a GPCR as a target for co-regulatory functions of site-specific O-glycosylation mediated by a unique GalNAc-T isoform. The results provide a new level of β1AR regulation that may open up possibilities for new therapeutic strategies for cardiovascular diseases.
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43
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Xie AX, Lee JJ, McCarthy KD. Ganglionic GFAP + glial Gq-GPCR signaling enhances heart functions in vivo. JCI Insight 2017; 2:e90565. [PMID: 28138563 DOI: 10.1172/jci.insight.90565] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
The sympathetic nervous system (SNS) accelerates heart rate, increases cardiac contractility, and constricts resistance vessels. The activity of SNS efferent nerves is generated by a complex neural network containing neurons and glia. Gq G protein-coupled receptor (Gq-GPCR) signaling in glial fibrillary acidic protein-expressing (GFAP+) glia in the central nervous system supports neuronal function and regulates neuronal activity. It is unclear how Gq-GPCR signaling in GFAP+ glia affects the activity of sympathetic neurons or contributes to SNS-regulated cardiovascular functions. In this study, we investigated whether Gq-GPCR activation in GFAP+ glia modulates the regulatory effect of the SNS on the heart; transgenic mice expressing Gq-coupled DREADD (designer receptors exclusively activated by designer drugs) (hM3Dq) selectively in GFAP+ glia were used to address this question in vivo. We found that acute Gq-GPCR activation in peripheral GFAP+ glia significantly accelerated heart rate and increased left ventricle contraction. Pharmacological experiments suggest that the glial-induced cardiac changes were due to Gq-GPCR activation in satellite glial cells within the sympathetic ganglion; this activation led to increased norepinephrine (NE) release and beta-1 adrenergic receptor activation within the heart. Chronic glial Gq-GPCR activation led to hypotension in female Gfap-hM3Dq mice. This study provides direct evidence that Gq-GPCR activation in peripheral GFAP+ glia regulates cardiovascular functions in vivo.
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44
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Shi L, Gao JH, Zhao JP, Zhu B, Yu XC, Rong PJ. [Development of Researches on Mechanisms of Acupuncture Intervention in Improving Myocar-dial Ischemia by Balancing Interaction between β-adrenergic Receptor and Acetylcholinergic Receptor Signal Transduction Pathway of Myocardiocytes]. ZHEN CI YAN JIU = ACUPUNCTURE RESEARCH 2016; 41:270-275. [PMID: 29071918] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
The imbalance of autonomic nervous function after myocardial ischemia (MI) accelerates the development of ischemic myocardial injury. The beta-adrenergic receptor (β-AR) and muscarinic acetylcholine receptor (M-AChR) are the main receptor types of the cardiomyocyte and the binding sites of the cardiac sympathetic and parasympathetic transmitters. In the present paper, the authors review recent progress of experimental researches on the mechanisms of acupuncture therapy in the prevention and treatment of MI, mainly focusing on the signaling of β1-AR and M2-AChR subtypes. Results showed that acupuncture could attenuate the injury of myocardial ischemia via down-regulating the over expression of β1-AR and up-regulating the expression of M2-AChR protein. Correspondingly, acupuncture intervention could reverse the abnormal expression of the intracellular stimulatory G protein and inhibitory G protein caused by MI, and suppress the activity of cellular adenylate cyclase. In addition, acupuncture could also enhance the activity of nitric oxide synthase and the level of nitric oxide in the ischemic cardiomyocytes, and increase the synthesis of cyclic guanosine monophosphate, ultimately reducing the level of cyclic adenosine 3', 5'monophosphate, and lowering the activity of protein kinase A and the inward flow of Ca2+ in cardiomyocytes. In this way, the ischemic myocardial injury is improved at last. However, some results of acupuncture intervention are not identical and need being confirmed further by more approaches.
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45
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Hergenreder JE, Legako JF, Dinh TTN, Spivey KS, Baggerman JO, Broadway PR, Beckett JL, Branine ME, Johnson BJ. Zinc Methionine Supplementation Impacts Gene and Protein Expression in Calf-Fed Holstein Steers with Minimal Impact on Feedlot Performance. Biol Trace Elem Res 2016; 171:315-327. [PMID: 26446862 PMCID: PMC4856723 DOI: 10.1007/s12011-015-0521-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2015] [Accepted: 09/24/2015] [Indexed: 11/09/2022]
Abstract
Providing cattle a more bioavailable zinc (Zn) source prior to administering a beta adrenergic agonist (βAA) may enhance the metabolic pool of primary nutrients that will influence the magnitude of the βAA response. Calf-fed Holstein steers were supplemented with a Zn methionine supplement (ZnMet; ZINPRO(®); Zinpro Corporation, Eden Prairie, MN) for 115 ± 5 days prior to harvest along with zilpaterol hydrochloride (ZH; Zilmax(®); Merck Animal Health, Summit, NJ) for the last 20 days with a 3-day withdrawal to evaluate the effects on growth and carcass performance together with gene and protein expression of skeletal muscle, adipose tissue, and fatty acid composition of polar and neutral lipid depots. Steers (n = 1296; initial weight = 468.5 ± 0.5 kg) were sorted by weight, blocked by harvest date, and randomly assigned to pens (n = 12) and treatments: control (90 ppm Zn from ZnSO4) and ZnMet (Control plus 720 mg Zn from ZnMet/hd/d). There were no differences (P > 0.05) in growth performance or carcass characteristics. The ZnMet-fed cattle had reduced (P < 0.05) abundance of myosin heavy chain (MHC)-IIX, β1-adrenergic receptor (βAR), peroxisome proliferator-activated receptor gamma, and stearoyl-CoA desaturase mRNA in skeletal muscle tissue. The ZnMet cattle had greater (P < 0.05) abundance of MHC-II protein, increased MHC-IIA and IIX cross-sectional areas (P < 0.05), an increased percentage of MHC-I fibers (P < 0.05), and a decreased percentage of MHC-IIX fibers (P < 0.05). The combination of ZnMet and ZH had positive biological effects on musculoskeletal tissue; however, these molecular effects were not significant enough to impact overall feedlot and carcass performance.
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46
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Feldman AM, Gordon J, Wang J, Song J, Zhang XQ, Myers VD, Tilley DG, Gao E, Hoffman NE, Tomar D, Madesh M, Rabinowitz J, Koch WJ, Su F, Khalili K, Cheung JY. BAG3 regulates contractility and Ca(2+) homeostasis in adult mouse ventricular myocytes. J Mol Cell Cardiol 2016; 92:10-20. [PMID: 26796036 PMCID: PMC4789075 DOI: 10.1016/j.yjmcc.2016.01.015] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 01/14/2016] [Accepted: 01/17/2016] [Indexed: 12/22/2022]
Abstract
Bcl2-associated athanogene 3 (BAG3) is a 575 amino acid anti-apoptotic protein that is constitutively expressed in the heart. BAG3 mutations, including mutations leading to loss of protein, are associated with familial cardiomyopathy. Furthermore, BAG3 levels have been found to be reduced in end-stage non-familial failing myocardium. In contrast to neonatal myocytes in which BAG3 is found in the cytoplasm and involved in protein quality control and apoptosis, in adult mouse left ventricular (LV) myocytes BAG3 co-localized with Na(+)-K(+)-ATPase and L-type Ca(2+) channels in the sarcolemma and t-tubules. BAG3 co-immunoprecipitated with β1-adrenergic receptor, L-type Ca(2+) channels and phospholemman. To simulate decreased BAG3 protein levels observed in human heart failure, we targeted BAG3 by shRNA (shBAG3) in adult LV myocytes. Reducing BAG3 by 55% resulted in reduced contraction and [Ca(2+)]i transient amplitudes in LV myocytes stimulated with isoproterenol. L-type Ca(2+) current (ICa) and sarcoplasmic reticulum (SR) Ca(2+) content but not Na(+)/Ca(2+) exchange current (INaCa) or SR Ca(2+) uptake were reduced in isoproterenol-treated shBAG3 myocytes. Forskolin or dibutyryl cAMP restored ICa amplitude in shBAG3 myocytes to that observed in WT myocytes, consistent with BAG3 having effects upstream and at the level of the receptor. Resting membrane potential and action potential amplitude were unaffected but APD50 and APD90 were prolonged in shBAG3 myocytes. Protein levels of Ca(2+) entry molecules and other important excitation-contraction proteins were unchanged in myocytes with lower BAG3. Our findings that BAG3 is localized at the sarcolemma and t-tubules while modulating myocyte contraction and action potential duration through specific interaction with the β1-adrenergic receptor and L-type Ca(2+) channel provide novel insight into the role of BAG3 in cardiomyopathies and increased arrhythmia risks in heart failure.
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MESH Headings
- Action Potentials/drug effects
- Adaptor Proteins, Signal Transducing/biosynthesis
- Adaptor Proteins, Signal Transducing/genetics
- Animals
- Apoptosis Regulatory Proteins/biosynthesis
- Apoptosis Regulatory Proteins/genetics
- Arrhythmias, Cardiac/genetics
- Arrhythmias, Cardiac/metabolism
- Arrhythmias, Cardiac/pathology
- Calcium/metabolism
- Calcium Channels, L-Type/metabolism
- Cardiomyopathy, Dilated/genetics
- Cardiomyopathy, Dilated/metabolism
- Cardiomyopathy, Dilated/pathology
- Excitation Contraction Coupling
- Heart Failure/genetics
- Heart Failure/metabolism
- Heart Failure/pathology
- Heart Ventricles/metabolism
- Heart Ventricles/pathology
- Homeostasis
- Humans
- Isoproterenol/administration & dosage
- Membrane Proteins/metabolism
- Mice
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Phosphoproteins/metabolism
- RNA, Small Interfering/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Sarcolemma/metabolism
- Sodium-Potassium-Exchanging ATPase/metabolism
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47
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Koyama H, Iwakura H, Dote K, Bando M, Hosoda H, Ariyasu H, Kusakabe T, Son C, Hosoda K, Akamizu T, Kangawa K, Nakao K. Comprehensive Profiling of GPCR Expression in Ghrelin-Producing Cells. Endocrinology 2016; 157:692-704. [PMID: 26671185 DOI: 10.1210/en.2015-1784] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
To determine the comprehensive G protein-coupled receptor (GPCR) expression profile in ghrelin-producing cells and to elucidate the role of GPCR-mediated signaling in the regulation of ghrelin secretion, we determined GPCR expression profiles by RNA sequencing in the ghrelin-producing cell line MGN3-1 and analyzed the effects of ligands for highly expressed receptors on intracellular signaling and ghrelin secretion. Expression of selected GPCRs was confirmed in fluorescence-activated cell-sorted fluorescently tagged ghrelin-producing cells from ghrelin-promoter CreERT2/Rosa-CAG-LSL-ZsGreen1 mice. Expression levels of GPCRs previously suggested to regulate ghrelin secretion including adrenergic-β1 receptor, GPR81, oxytocin receptor, GPR120, and somatostatin receptor 2 were high in MGN3-1 cells. Consistent with previous reports, isoproterenol and oxytocin stimulated the Gs and Gq pathways, respectively, whereas lactate, palmitate, and somatostatin stimulated the Gi pathway, confirming the reliability of current assays. Among other highly expressed GPCRs, prostaglandin E receptor 4 agonist prostaglandin E2 significantly stimulated the Gs pathway and ghrelin secretion. Muscarine, the canonical agonist of cholinergic receptor muscarinic 4, stimulated both the Gq and Gi pathways. Although muscarine treatment alone did not affect ghrelin secretion, it did suppress forskolin-induced ghrelin secretion, suggesting that the cholinergic pathway may play a role in counterbalancing the stimulation of ghrelin by Gs (eg, by adrenaline). In addition, GPR142 ligand tryptophan stimulated ghrelin secretion. In conclusion, we determined the comprehensive expression profile of GPCRs in ghrelin-producing cells and identified two novel ghrelin regulators, prostaglandin E2 and tryptophan. These results will lead to a greater understanding of the physiology of ghrelin and facilitate the development of ghrelin-modulating drugs.
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MESH Headings
- Adrenergic beta-Agonists/pharmacology
- Animals
- Cell Line, Tumor
- Colforsin/pharmacology
- Dinoprostone/pharmacology
- Gastric Mucosa/cytology
- Gastric Mucosa/drug effects
- Gastric Mucosa/metabolism
- Gene Expression Profiling
- Ghrelin/drug effects
- Ghrelin/metabolism
- Hormones/pharmacology
- Immunohistochemistry
- Isoproterenol/pharmacology
- Lactic Acid/pharmacology
- Mice
- Mice, Transgenic
- Muscarine/pharmacology
- Muscarinic Agonists/pharmacology
- Oxytocics/pharmacology
- Oxytocin/pharmacology
- Palmitates/pharmacology
- RNA, Messenger/metabolism
- Receptor, Muscarinic M4/agonists
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, G-Protein-Coupled/drug effects
- Receptors, G-Protein-Coupled/genetics
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Oxytocin/drug effects
- Receptors, Oxytocin/genetics
- Receptors, Oxytocin/metabolism
- Receptors, Prostaglandin E, EP4 Subtype/agonists
- Receptors, Somatostatin/drug effects
- Receptors, Somatostatin/genetics
- Receptors, Somatostatin/metabolism
- Sequence Analysis, RNA
- Somatostatin/pharmacology
- Tryptophan/pharmacology
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48
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Khor KH, Moore TA, Shiels IA, Greer RM, Arumugam TV, Mills PC. A Potential Link between the C5a Receptor 1 and the β1-Adrenoreceptor in the Mouse Heart. PLoS One 2016; 11:e0146022. [PMID: 26727203 PMCID: PMC4699762 DOI: 10.1371/journal.pone.0146022] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 12/11/2015] [Indexed: 12/17/2022] Open
Abstract
Purpose Inflammation may contribute to the pathogenesis of specific cardiovascular diseases, but it is uncertain if mediators released during the inflammatory process will affect the continued efficacy of drugs used to treat clinical signs of the cardiac disease. We investigated the role of the complement 5a receptor 1 (C5aR1/CD88) in the cardiac response to inflammation or atenolol, and the effect of C5aR1 deletion in control of baseline heart rate in an anesthetized mouse model. Methods An initial study showed that PMX53, an antagonist of C5aR1 in normal C57BL6/J (wild type, WT) mice reduced heart rate (HR) and appeared to have a protective effect on the heart following induced sepsis. C5aR1 knockout (CD88-/-) mice had a lower HR than wild type mice, even during sham surgery. A model to assess heart rate variability (HRV) in anesthetized mice was developed to assess the effects of inhibiting the β1-adrenoreceptor (β1-AR) in a randomized crossover study design. Results HR and LF Norm were constitutively lower and SDNN and HF Norm constitutively higher in the CD88-/- compared with WT mice (P< 0.001 for all outcomes). Administration of atenolol (2.5 mg/kg) reduced the HR and increased HRV (P< 0.05, respectively) in the wild type but not in the CD88-/- mice. There was no shift of the sympathovagal balance post-atenolol in either strains of mice (P> 0.05), except for the reduced LF/HF (Lower frequency/High frequency) ratio (P< 0.05) at 60 min post-atenolol, suggesting increased parasympathetic tone of the heart due to the effect of atenolol administration. The HR of the WT mice were lower post atenolol compared to the CD88-/- mice (P = 0.001) but the HRV of CD88-/- mice were significantly increased (P< 0.05), compared with WT mice. Conclusion Knockout of the C5aR1 attenuated the effect of β1-AR in the heart, suggesting an association between the β1-AR and C5aR1, although further investigation is required to determine if this is a direct or causal association.
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Drugs targeting beta-adrenergic receptors: total "selectivity" is elusive. PRESCRIRE INTERNATIONAL 2016; 25:9. [PMID: 26942250] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
MESH Headings
- Adrenergic beta-Agonists/pharmacology
- Humans
- Molecular Targeted Therapy
- Receptors, Adrenergic, beta-1/drug effects
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/drug effects
- Receptors, Adrenergic, beta-2/metabolism
- Receptors, Adrenergic, beta-3/drug effects
- Receptors, Adrenergic, beta-3/metabolism
- Sympathomimetics/pharmacology
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Fan X, Gu X, Zhao R, Zheng Q, Li L, Yang W, Ding L, Xue F, Fan J, Gong Y, Wang Y. Cardiac β2-Adrenergic Receptor Phosphorylation at Ser355/356 Regulates Receptor Internalization and Functional Resensitization. PLoS One 2016; 11:e0161373. [PMID: 27541735 PMCID: PMC4991819 DOI: 10.1371/journal.pone.0161373] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2016] [Accepted: 08/04/2016] [Indexed: 02/05/2023] Open
Abstract
Previous studies have demonstrated that β2-adrenergic receptors (β2ARs) can be phosphorylated by G protein-coupled receptor kinases (GRKs) and protein kinase A (PKA), affecting β2AR internalization and desensitization. However, the exact physiological function of β2ARs in cardiomyocytes is unknown. In this study, we showed that neonatal mouse cardiomyocytes had different contraction and internalization responses to sustained or repeated, transient agonist stimulation. Specifically, short-time stimulation (10 min) with epinephrine or norepinephrine increased the cardiomyocyte contraction rate, reaching a maximum at 5 min, followed by a slow decline. When the agonist was re-added after a 60-min wash-out period, the increase in the cardiomyocyte contraction rate was similar to the initial response. In contrast, when cardiomyocytes were exposed continuously to epinephrine or norepinephrine for 60 min, the second agonist stimulation did not increase the contraction response. These results indicated that continuous β2AR stimulation caused functional desensitization. Phosphorylation of β2ARs at serine (Ser)355/356 GRK phosphorylation sites, but not at Ser345/346 PKA phosphorylation sites increased with continuous epinephrine stimulation for 60 min. Accordingly, β2AR internalization increased. Interestingly, β2AR internalization was blocked by mutations at the GRK phosphorylation sites, but not by mutations at the PKA phosphorylation sites. Furthermore, inhibition of β2AR dephosphorylation by okadaic acid, a phosphatase 2A inhibitor, impaired the recovery of internalized β2ARs and reduced the cardiomyocyte contraction rate in response to epinephrine. Finally, epinephrine treatment induced the physical interaction of β-arrestin with internalized β2ARs in cardiomyocytes. Together, these data revealed the essential role of the Ser355/356 phosphorylation status of β2ARs in regulating receptor internalization and physiological resensitization in neonatal cardiomyocytes to contraction functions.
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MESH Headings
- Animals
- Animals, Newborn
- Cells, Cultured
- Epinephrine/pharmacology
- Female
- Kinetics
- Male
- Mice
- Mice, Inbred C57BL
- Mice, Inbred DBA
- Mice, Knockout
- Mutagenesis, Site-Directed
- Mutation/genetics
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Norepinephrine/pharmacology
- Phosphorylation/drug effects
- Receptors, Adrenergic, beta-1/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Receptors, Adrenergic, beta-2/genetics
- Receptors, Adrenergic, beta-2/metabolism
- Serine/metabolism
- Signal Transduction/drug effects
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