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Uehling DE, Joseph B, Chung KC, Zhang AX, Ler S, Prakesch MA, Poda G, Grouleff J, Aman A, Kiyota T, Leung-Hagesteijn C, Konda JD, Marcellus R, Griffin C, Subramaniam R, Abibi A, Strathdee CA, Isaac MB, Al-Awar R, Tiedemann RE. Design, Synthesis, and Characterization of 4-Aminoquinazolines as Potent Inhibitors of the G Protein-Coupled Receptor Kinase 6 (GRK6) for the Treatment of Multiple Myeloma. J Med Chem 2021; 64:11129-11147. [PMID: 34291633 DOI: 10.1021/acs.jmedchem.1c00506] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Both previous and additional genetic knockdown studies reported herein implicate G protein-coupled receptor kinase 6 (GRK6) as a critical kinase required for the survival of multiple myeloma (MM) cells. Therefore, we sought to develop a small molecule GRK6 inhibitor as an MM therapeutic. From a focused library of known kinase inhibitors, we identified two hits with moderate biochemical potencies against GRK6. From these hits, we developed potent (IC50 < 10 nM) analogues with selectivity against off-target kinases. Further optimization led to the discovery of an analogue (18) with an IC50 value of 6 nM against GRK6 and selectivity against a panel of 85 kinases. Compound 18 has potent cellular target engagement and antiproliferative activity against MM cells and is synergistic with bortezomib. In summary, we demonstrate that targeting GRK6 with small molecule inhibitors represents a promising approach for MM and identify 18 as a novel, potent, and selective GRK6 inhibitor.
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Affiliation(s)
- David E Uehling
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada
| | - Babu Joseph
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada
| | - Kim Chan Chung
- Princess Margaret Cancer Centre, Toronto Medical Discovery Tower, 101 College Street, Room 12-306, Toronto, Ontario M5G 1L7, Canada
| | - Andrew X Zhang
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada
| | - Spencer Ler
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada
| | - Michael A Prakesch
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada
| | - Gennady Poda
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada.,Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S 3M2, Canada
| | - Julie Grouleff
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada
| | - Ahmed Aman
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada.,Leslie Dan Faculty of Pharmacy, University of Toronto, 144 College Street, Toronto, Ontario M5S 3M2, Canada
| | - Taira Kiyota
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada
| | - Chungyee Leung-Hagesteijn
- Princess Margaret Cancer Centre, Toronto Medical Discovery Tower, 101 College Street, Room 12-306, Toronto, Ontario M5G 1L7, Canada
| | - John David Konda
- Princess Margaret Cancer Centre, Toronto Medical Discovery Tower, 101 College Street, Room 12-306, Toronto, Ontario M5G 1L7, Canada
| | - Richard Marcellus
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada
| | - Carly Griffin
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada
| | - Ratheesh Subramaniam
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada
| | - Ayome Abibi
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada
| | - Craig A Strathdee
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada
| | - Methvin B Isaac
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada
| | - Rima Al-Awar
- Drug Discovery Program, Ontario Institute for Cancer Research, MaRS Centre, 661 University Avenue, Suite 510, Toronto, Ontario M5G 0A3, Canada.,Department of Pharmacology and Toxicology, University of Toronto, Medical Sciences Building, 1 King's College Circle, Toronto, Ontario M5S 1A8, Canada
| | - Rodger E Tiedemann
- Princess Margaret Cancer Centre, Toronto Medical Discovery Tower, 101 College Street, Room 12-306, Toronto, Ontario M5G 1L7, Canada
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Influence of GRK5 gene polymorphisms on ritodrine efficacy and adverse drug events in preterm labor treatment. Sci Rep 2020; 10:1351. [PMID: 31992805 PMCID: PMC6987149 DOI: 10.1038/s41598-020-58348-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2019] [Accepted: 01/14/2020] [Indexed: 11/09/2022] Open
Abstract
The present prospective follow-up study aimed to evaluate the effects of GRK5 polymorphisms on ritodrine efficacy and adverse drug events (ADEs) in pregnant women undergoing preterm labor. A total of 162 women undergoing preterm labor were included in the study. Seven single nucleotide polymorphisms (SNPs) in the GRK5 gene (rs915120, rs2230345, rs2230349, rs7923896, rs1020672, rs4752308, and rs4752292) were assessed. Homozygous variant carriers of rs4752292 and rs1020672 had 0.6 times the hazard of delivery compared to wild-type allele carriers (95% confidence interval [CI], 0.41~0.99 and 0.38~0.99, respectively). In addition, homozygous variant carriers of rs4752292 and rs1020672 had 2.4-fold more (95% CI, 1.10~4.98) and 2.3-fold more (95% CI, 1.04~5.06) ADEs compared to those with the wild-type homozygotes, respectively. Among demographic variables, gestational age and modified Bishop score were significant factors associated with time to delivery, while body weight and maximum ritodrine infusion rate were significant factors associated with ADEs. In silico analysis showed that both rs4752292 and rs1020672 had the potential to affect mRNA splicing by alteration of splicing motifs. The present study shows that ritodrine efficacy and ADEs are associated with GRK5 gene polymorphisms in pregnant women undergoing preterm labor.
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Differential regulation of β2-adrenoceptor and adenosine A2B receptor signalling by GRK and arrestin proteins in arterial smooth muscle. Cell Signal 2018; 51:86-98. [DOI: 10.1016/j.cellsig.2018.07.013] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 07/13/2018] [Accepted: 07/29/2018] [Indexed: 10/28/2022]
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Yang J, Villar VAM, Armando I, Jose PA, Zeng C. G Protein-Coupled Receptor Kinases: Crucial Regulators of Blood Pressure. J Am Heart Assoc 2016; 5:JAHA.116.003519. [PMID: 27390269 PMCID: PMC5015388 DOI: 10.1161/jaha.116.003519] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Jian Yang
- Department of Nutrition, Daping Hospital, The Third Military Medical University, Chongqing, China Department of Cardiology, Chongqing Key Laboratory for Hypertension, Chongqing Institute of Cardiology, Chongqing Cardiovascular Clinical Research Center, Daping Hospital, The Third Military Medical University, Chongqing, China
| | - Van Anthony M Villar
- Division of Renal Diseases & Hypertension, Department of Medicine, The George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Ines Armando
- Division of Renal Diseases & Hypertension, Department of Medicine, The George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Pedro A Jose
- Division of Renal Diseases & Hypertension, Department of Medicine, The George Washington University School of Medicine and Health Sciences, Washington, DC Department of Pharmacology and Physiology, The George Washington University School of Medicine and Health Sciences, Washington, DC
| | - Chunyu Zeng
- Department of Cardiology, Chongqing Key Laboratory for Hypertension, Chongqing Institute of Cardiology, Chongqing Cardiovascular Clinical Research Center, Daping Hospital, The Third Military Medical University, Chongqing, China
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“Barcode” and Differential Effects of GPCR Phosphorylation by Different GRKs. METHODS IN PHARMACOLOGY AND TOXICOLOGY 2016. [DOI: 10.1007/978-1-4939-3798-1_5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Lovasz N, Koncz A, Domokos D, Gaspar R, Falkay G. ATP-sensitive potassium channels modulate in vitro tocolytic effects of β₂-adrenergic receptor agonists on uterine muscle rings in rats in early but not in late pregnancy. Croat Med J 2015; 56:114-8. [PMID: 25891870 PMCID: PMC4410172 DOI: 10.3325/cmj.2015.56.114] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
Aim To investigate whether ATP-sensitive potassium (KATP) channels modulate the tocolytic effect of β2-AR agonists (ritodrine and salmeterol) in early-pregnant (day 6) and late-pregnant (day 22) rat uterus in vitro, in order to examine the relation between the KATP channel sulphonylurea-binding regulatory subunit (SUR) expression and pharmacological reactivity of β2-AR agonists. Methods The tocolytic effects of ritodrine and salmeterol (10-10-10-5 M) on spontaneous rhythmic contractions were investigated cumulatively, alone, or in the presence of the KATP channel blocker glibenclamide (10-6 M) and the KATP channel opener pinacidil (10-9-10-7 M) after 5-min preincubation. Results β2-AR agonist induced myometrial relaxation was inhibited by glibenclamide and enhanced by pinacidil on day 6, when SUR1 expression levels were high. Neither glibenclamide nor pinacidil mediated tocolytic effect was measured on day 22. Conclusion Low expression of the KATP channels at the end of gestation may facilitate enhanced excitability and contractility in the rat myometrium. The combination of a betamimetic and a KATP channel opener will therefore not be of therapeutic relevance in the treatment of preterm delivery.
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Affiliation(s)
| | | | | | | | - György Falkay
- György Falkay, Department of Pharmacodynamics and Biopharmacy, Faculty of Pharmacy, University of Szeged, H-6701, P.O. Box 121, Hungary,
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GRK6 deficiency in mice causes autoimmune disease due to impaired apoptotic cell clearance. Nat Commun 2013; 4:1532. [PMID: 23443560 PMCID: PMC3586722 DOI: 10.1038/ncomms2540] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 01/24/2013] [Indexed: 12/24/2022] Open
Abstract
Efficient engulfment of apoptotic cells is critical for maintaining tissue homoeostasis. When phagocytes recognize ‘eat me’ signals presented on the surface of apoptotic cells, this subsequently induces cytoskeletal rearrangement of phagocytes for the engulfment through Rac1 activation. However, the intracellular signalling cascades that result in Rac1 activation remain largely unknown. Here we show that G-protein-coupled receptor kinase 6 (GRK6) is involved in apoptotic cell clearance. GRK6 cooperates with GIT1 to activate Rac1, which promotes apoptotic engulfment independently from the two known DOCK180/ELMO/Rac1 and GULP1/Rac1 engulfment pathways. As a consequence, GRK6-deficient mice develop an autoimmune disease. GRK6-deficient mice also have increased iron stores in splenic red pulp in which F4/80+ macrophages are responsible for senescent red blood cell clearance. Our results reveal previously unrecognized roles for GRK6 in regulating apoptotic engulfment and its fundamental importance in immune and iron homoeostasis. The clearance of apoptotic cells by macrophages is important for tissue homoeostasis. Here Nakaya et al. reveal a role for GRK6 in the regulation of apoptotic engulfment and show that GRK6 deficiency in mice leads to autoimmune disease and iron accumulation in the spleen.
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Brighton PJ, Rana S, Challiss RJ, Konje JC, Willets JM. Arrestins differentially regulate histamine- and oxytocin-evoked phospholipase C and mitogen-activated protein kinase signalling in myometrial cells. Br J Pharmacol 2011; 162:1603-17. [PMID: 21175586 DOI: 10.1111/j.1476-5381.2010.01173.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
BACKGROUND AND PURPOSE The uterotonins oxytocin and histamine, mediate contractile signals through specific G protein-coupled receptors, a process which is tightly controlled during gestation to prevent preterm labour. We previously identified G protein-coupled receptor kinase (GRK)2 and GRK6 as respective cardinal negative regulators of histamine H(1) and oxytocin receptor signalling. GRK-mediated phosphorylation promotes arrestin recruitment, not only desensitizing receptors but activating an increasing number of diverse signalling pathways. Here we investigate potential roles that arrestins play in the regulation of myometrial oxytocin/histamine H(1) receptor signalling. EXPERIMENTAL APPROACH Endogenous arrestins2 and 3 were specifically depleted using RNA-interference in a human myometrial cell line and the consequences of this for G protein-coupled receptor-mediated signalling were assessed using Ca(2+) /inositol 1,4,5-trisphophate imaging and standard mitogen-activated protein kinase (MAPK) assays. KEY RESULTS Depletion of arrestin3, but not arrestin2 enhanced and prolonged H(1) receptor-stimulated Ca(2+) responses, whilst depletion of either arrestin increased oxytocin receptor responses. Arrestin3 depletion decreased H(1) receptor desensitization, whilst removal of either arrestin isoform was equally effective in preventing oxytocin receptor desensitization. Following arrestin3 depletion oxytocin-induced phospho-extracellular signal-regulated kinase1/2 signals were diminished and histamine-stimulated signals virtually absent, whereas depletion of arrestin2 augmented extracellular signal-regulated kinase1/2 responses to each agonist. Conversely, depletion of arrestin3 enhanced p38 signals to each agonist, whilst arrestin2 suppression increased oxytocin-, but not histamine-induced p38 MAPK responses. CONCLUSIONS AND IMPLICATIONS Arrestin proteins are key regulators of H(1) and oxytocin receptor desensitization, and play integral roles mediating uterotonin-stimulated MAPK-signalling. These data provide insights into the in situ regulation of these receptor subtypes and may inform pathophysiological functioning in preterm labour.
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Affiliation(s)
- Paul J Brighton
- Endocannabinoid Research Group, Reproductive Sciences Section, Department of Cancer Studies and Molecular Medicine, University of Leicester, Leicester Royal Infirmary, Leicester, UK
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Abstract
Dopamine is an important regulator of systemic blood pressure via multiple mechanisms. It affects fluid and electrolyte balance by its actions on renal hemodynamics and epithelial ion and water transport and by regulation of hormones and humoral agents. The kidney synthesizes dopamine from circulating or filtered L-DOPA independently from innervation. The major determinants of the renal tubular synthesis/release of dopamine are probably sodium intake and intracellular sodium. Dopamine exerts its actions via two families of cell surface receptors, D1-like receptors comprising D1R and D5R, and D2-like receptors comprising D2R, D3R, and D4R, and by interactions with other G protein-coupled receptors. D1-like receptors are linked to vasodilation, while the effect of D2-like receptors on the vasculature is variable and probably dependent upon the state of nerve activity. Dopamine secreted into the tubular lumen acts mainly via D1-like receptors in an autocrine/paracrine manner to regulate ion transport in the proximal and distal nephron. These effects are mediated mainly by tubular mechanisms and augmented by hemodynamic mechanisms. The natriuretic effect of D1-like receptors is caused by inhibition of ion transport in the apical and basolateral membranes. D2-like receptors participate in the inhibition of ion transport during conditions of euvolemia and moderate volume expansion. Dopamine also controls ion transport and blood pressure by regulating the production of reactive oxygen species and the inflammatory response. Essential hypertension is associated with abnormalities in dopamine production, receptor number, and/or posttranslational modification.
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Affiliation(s)
- Ines Armando
- Children’s National Medical Center—Center for Molecular Physiology Research, Washington, District of Columbia
| | - Van Anthony M. Villar
- Children’s National Medical Center—Center for Molecular Physiology Research, Washington, District of Columbia
| | - Pedro A. Jose
- Children’s National Medical Center—Center for Molecular Physiology Research, Washington, District of Columbia
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Abstract
The ability to assess whether individual proteins are involved in the signalling or regulation of G -protein-coupled receptor signalling is highly dependent on the pharmacological tools available. In the absence of appropriate pharmacological agents, alternative molecular approaches have been developed to alter either protein function or expression. This has included the use of mutants, for example catalytically inactive (kinase-dead) enzymes, which when overexpressed function as dominant negatives to inhibit endogenous enzyme function, and more latterly small (21-23 bp) interfering RNA dsRNA oligos, whose antisense strand is designed complementary to the target protein mRNA and which can be used to deplete target protein expression. Critically, the success of these approaches depends on the transfection efficiency, and the chosen experimental assay in the cell type studied. Therefore, three transfection techniques and their merits and drawbacks are described. In addition, one method of examining G protein-coupled receptor (GPCR) regulation, combining siRNA-mediated GRK depletion and imaging of fluorescent GPCR -signalling reporter biosensors in difficult-to-transfect cells is briefly described.
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Affiliation(s)
- Jonathon M Willets
- Department of Cancer Studies and Molecular Medicine, University of Leicester, Leicester, UK.
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Jose PA, Soares-da-Silva P, Eisner GM, Felder RA. Dopamine and G protein-coupled receptor kinase 4 in the kidney: role in blood pressure regulation. Biochim Biophys Acta Mol Basis Dis 2010; 1802:1259-67. [PMID: 20153824 DOI: 10.1016/j.bbadis.2010.02.004] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2009] [Revised: 02/05/2010] [Accepted: 02/07/2010] [Indexed: 12/11/2022]
Abstract
Complex interactions between genes and environment result in a sodium-induced elevation in blood pressure (salt sensitivity) and/or hypertension that lead to significant morbidity and mortality affecting up to 25% of the middle-aged adult population worldwide. Determining the etiology of genetic and/or environmentally-induced high blood pressure has been difficult because of the many interacting systems involved. Two main pathways have been implicated as principal determinants of blood pressure since they are located in the kidney (the key organ responsible for blood pressure regulation), and have profound effects on sodium balance: the dopaminergic and renin-angiotensin systems. These systems counteract or modulate each other, in concert with a host of intracellular second messenger pathways to regulate sodium and water balance. In particular, the G protein-coupled receptor kinase type 4 (GRK4) appears to play a key role in regulating dopaminergic-mediated natriuresis. Constitutively activated GRK4 gene variants (R65L, A142V, and A486V), by themselves or by their interaction with other genes involved in blood pressure regulation, are associated with essential hypertension and/or salt-sensitive hypertension in several ethnic groups. GRK4γ 142Vtransgenic mice are hypertensive on normal salt intake while GRK4γ 486V transgenic mice develop hypertension only with an increase in salt intake. GRK4 gene variants have been shown to hyperphosphorylate, desensitize, and internalize two members of the dopamine receptor family, the D(1) (D(1)R) and D(3) (D(3)R) dopamine receptors, but also increase the expression of a key receptor of the renin-angiotensin system, the angiotensin type 1 receptor (AT(1)R). Knowledge of the numerous blood pressure regulatory pathways involving angiotensin and dopamine may provide new therapeutic approaches to the pharmacological regulation of sodium excretion and ultimately blood pressure control.
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Affiliation(s)
- Pedro A Jose
- Children's National Medical Center, George Washington University for the Health Sciences, Washington, DC, USA.
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Tyson EK, Smith R, Read M. Evidence that corticotropin-releasing hormone modulates myometrial contractility during human pregnancy. Endocrinology 2009; 150:5617-25. [PMID: 19846610 DOI: 10.1210/en.2009-0348] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
As human pregnancy advances, CRH increases exponentially and is hypothesized to trigger the transition from myometrial quiescence to active contractions at labor. Paradoxically, CRH stimulates cAMP production, suggesting it should cause relaxation. To evaluate CRH as a mediator of quiescence, the effect of CRH on contractions in preterm and term myometria with concurrent progesterone (P4) was determined. In late gestation, we hypothesized that high concentrations of CRH down-regulate agonist-activated-cAMP relaxatory pathways and that increased phosphodiesterase (PDE) activity induces heterologous down-regulation of agonist-activated-cAMP pathways. CRH caused dose-dependent relaxation of spontaneously contracting myometrial strips of 31 +/- 8% (mean +/- sem; n = 12) and 35 +/- 20% (n = 3) in term and preterm samples, respectively. CRH with P4 pretreatment caused a 40 +/- 13% (n = 4) reduction in contractility, whereas in matched samples, CRH alone exerted a 26 +/- 6% (n = 4) reduction, with a shift of CRH dose-response curves (P < 0.01, ANOVA). Pretreatment of strips with 10(-7) m CRH did not attenuate relaxation induced by subsequent CRH (n = 3) or salbutamol (beta(2)-agonist) treatment (n = 9). PDE inhibition by rolipram showed a 2.2- and 1.5-fold increase in maximal relaxation induced by CRH and salbutamol, respectively, with a shift of both dose-response curves (P < 0.05 and P < 0.01, ANOVA). In conclusion, CRH at physiological concentrations acts synergistically with P4 contributing to myometrial quiescence. P4 withdrawal may reduce CRH-mediated relaxation. Our functional model does not support homologous or heterologous down-regulation of agonist-stimulated-cAMP pathways by high CRH concentrations. PDE inhibition potentiates CRH and salbutamol-induced relaxation. Up-regulation of PDEs, through chronic cAMP elevation by CRH, could provide a mechanism for down-regulation of agonist-stimulated-cAMP pathways at term.
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Affiliation(s)
- Elisa K Tyson
- Department of Endocrinology, Mothers and Babies Research Centre, John Hunter Hospital, New Lambton Heights, Newcastle 2305, Australia.
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Willets JM, Brighton PJ, Mistry R, Morris GE, Konje JC, Challiss RAJ. Regulation of oxytocin receptor responsiveness by G protein-coupled receptor kinase 6 in human myometrial smooth muscle. Mol Endocrinol 2009; 23:1272-80. [PMID: 19423652 PMCID: PMC5419184 DOI: 10.1210/me.2009-0047] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2009] [Accepted: 04/29/2009] [Indexed: 11/19/2022] Open
Abstract
Oxytocin plays an important role in the progression, timing, and modulation of uterine contraction during labor and is widely used as an uterotonic agent. We investigated the mechanisms regulating oxytocin receptor (OTR) signaling in human primary myometrial smooth muscle cells and the ULTR cell-line. Oxytocin produced concentration-dependent increases in both total [(3)H]inositol phosphate accumulation and intracellular Ca(2+) concentration ([Ca(2+)](i)); however, responses were greater and more reproducible in the ULTR cell line. Assessment of phospholipase C activity in single cells revealed that the OTR desensitizes rapidly (within 5 min) in the presence of oxytocin (100 nm). To characterize OTR desensitization further, cells were stimulated with a maximally effective concentration of oxytocin (100 nm, 30 sec) followed by a variable washout period and a second identical application of oxytocin. This brief exposure to oxytocin caused a marked decrease (>70%) in OTR responsiveness to rechallenge and was fully reversed by increasing the time period between agonist challenges. To assess involvement of G protein-coupled receptor kinases (GRKs) in OTR desensitization, cells were transfected with small interfering RNAs to cause specific > or =75% knockdown of GRKs 2, 3, 5, or 6. In both primary myometrial and ULTR cells, knockdown of GRK6 largely prevented oxytocin-induced OTR desensitization; in contrast, selective depletion of GRKs 2, 3, or 5 was without effect. These data indicate that GRK6 recruitment is a cardinal effector of OTR responsiveness and provide mechanistic insight into the likely in vivo regulation of OTR signaling in uterine smooth muscle.
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Affiliation(s)
- Jonathon M Willets
- Reproductive Sciences Section, Department of Cancer Studies and Molecular Medicine, University of Leicester, Clinical Sciences Building, Leicester Royal Infirmary, Leicester LE2 7LX, United Kingdom.
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Larivière S, Garrel-Lazayres G, Simon V, Shintani N, Baba A, Counis R, Cohen-Tannoudji J. Gonadotropin-releasing hormone inhibits pituitary adenylyl cyclase-activating polypeptide coupling to 3',5'-cyclic adenosine-5'-monophosphate pathway in LbetaT2 gonadotrope cells through novel protein kinase C isoforms and phosphorylation of pituitary adenylyl cyclase-activating polypeptide type I receptor. Endocrinology 2008; 149:6389-98. [PMID: 18755795 DOI: 10.1210/en.2008-0504] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Gonadotrope cells are primarily regulated by GnRH but are also targets of the pituitary adenylyl cyclase-activating polypeptide (PACAP). Although it has been reported that reciprocal interactions between both neuropeptides contribute to regulation of gonadotrope function, the underlying mechanisms remain poorly understood. In this study, we reevaluated PACAP coupling to the cAMP pathway in LbetaT2 gonadotrope cells and analyzed GnRH effect on PACAP signaling. We established that PACAP38 markedly increases intracellular cAMP levels (EC50 of 4.7 +/- 1.3 nm) through the PACAP type 1 receptor (PAC1-R), as evidenced by pharmacological and RT-PCR studies. Interestingly, although GnRH couples to cAMP pathway in LbetaT2 cells, the effects of both neuropeptides were not synergistic. Instead, the GnRH agonist (GnRHa) triptorelin rapidly and strongly inhibited (70% inhibition as early as 5 min) PACAP38-induced cAMP production. Inhibition was calcium independent, mimicked by the phorbol ester phorbol 12-myristate 13-acetate, and blocked by the protein kinase C (PKC) inhibitor bisindoylmaleimide, indicating that GnRHa inhibitory action relies on PKC. Selective down-regulation of both conventional and novel PKC prevented a GnRHa effect, whereas pharmacological inhibition of conventional PKC only was ineffective, strongly suggesting the involvement of novel PKC isoforms. GnRHa did not inhibit forskolin- or cholera toxin-stimulated cAMP accumulation, suggesting that PAC1-R is the predominant target of GnRH. Accordingly, we demonstrated for the first time that GnRH increases PAC1-R phosphorylation through PKC, providing a potential molecular mechanism which may account for GnRH inhibitory effect.
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Affiliation(s)
- Sigolène Larivière
- Unité Mixte de Recherche-Centre National de la Recherche Scientifique 7079 Physiologie and Physiopathologie, Université Pierre and Marie Curie-Paris 6, Case 256, 4 Place Jussieu, 75252 Paris cedex 05, France
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Gáspár R, Ducza E, Mihályi A, Márki A, Kolarovszki-Sipiczki Z, Páldy E, Benyhe S, Borsodi A, Földesi I, Falkay G. Pregnancy-induced decrease in the relaxant effect of terbutaline in the late-pregnant rat myometrium: role of G-protein activation and progesterone. Reproduction 2005; 130:113-22. [PMID: 15985637 DOI: 10.1530/rep.1.00490] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
The effectiveness of beta2-agonists in preterm delivery is reduced by several factors. The aim of this study was to determine the influence of late pregnancy in the uterus-relaxing effect of terbutaline in the rat in vitro. Rat uterine tissues from late pregnancy (days 15, 18, 20 and 22) were used. In vitro electrical field-stimulation (EFS) was used to evoke contractions. The radioligand-binding technique, reverse transcription-polymerase chain reaction and radioimmunoassay technique were used to determine the beta-adrenergic receptor density and mRNA level and the plasma sex hormone level, respectively. The activated G-protein level of the beta-adrenergic receptors was investigated by a radiolabelled GTP binding assay.EFS-induced contractions were inhibited by terbutaline. This effect decreased towards term with respect to both the EC50 and maximal inhibition values. A drop in plasma progesterone level was also detected. Binding studies revealed an increase in beta-adrenergic receptor number on the last day of pregnancy, which correlated with the change in receptor mRNA level. The G-protein-activating effect of terbutaline decreased continuously between days 15 and 20. Surprisingly, terbutaline decreased the G-protein activation to below the basal level on day 22. However, progesterone pretreatment set back the uterine action of terbutaline, increased the density of the beta2-adrenergic receptors and their mRNA level and increased the G-protein-activating property of terbutaline. These data provide evidence of a pregnancy-induced decrease in activated G-protein level after beta2-agonist stimulation. The decrease in plasma progesterone level has a crucial role in this process. The effects of beta2-adrenergic receptor agonists in tocolytic therapy may possibly be potentiated with progesterone.
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Affiliation(s)
- Róbert Gáspár
- Department of Pharmacodynamics and Biopharmacy, Faculty of Pharmacy, University of Szeged, H-6720 Szeged, Eötvös u. 6, Hungary
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16
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Luo X, Ding L, Xu J, Williams RS, Chegini N. Leiomyoma and myometrial gene expression profiles and their responses to gonadotropin-releasing hormone analog therapy. Endocrinology 2005; 146:1074-96. [PMID: 15604208 DOI: 10.1210/en.2004-1384] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
Abstract
Gene microarray was used to characterize the molecular environment of leiomyoma and matched myometrium during growth and in response to GnRH analog (GnRHa) therapy as well as GnRHa direct action on primary cultures of leiomyoma and myometrial smooth muscle cells (LSMC and MSMC). Unsupervised and supervised analysis of gene expression values and statistical analysis in R programming with a false discovery rate of P < or = 0.02 resulted in identification of 153 and 122 differentially expressed genes in leiomyoma and myometrium in untreated and GnRHa-treated cohorts, respectively. The expression of 170 and 164 genes was affected by GnRHa therapy in these tissues compared with their respective untreated group. GnRHa (0.1 microm), in a time-dependent manner (2, 6, and 12 h), targeted the expression of 281 genes (P < or = 0.005) in LSMC and MSMC, 48 of which genes were found in common with GnRHa-treated tissues. Functional annotations assigned these genes as key regulators of processes involving transcription, translational, signal transduction, structural activities, and apoptosis. We validated the expression of IL-11, early growth response 3, TGF-beta-induced factor, TGF-beta-inducible early gene response, CITED2 (cAMP response element binding protein-binding protein/p300-interacting transactivator with ED-rich tail), Nur77, growth arrest-specific 1, p27, p57, and G protein-coupled receptor kinase 5, representing cytokine, common transcription factors, cell cycle regulators, and signal transduction, at tissue levels and in LSMC and MSMC in response to GnRHa time-dependent action using real-time PCR, Western blotting, and immunohistochemistry. In conclusion, using different, complementary approaches, we characterized leiomyoma and myometrium molecular fingerprints and identified several previously unrecognized genes as targets of GnRHa action, implying that local expression and activation of these genes may represent features differentiating leiomyoma and myometrial environments during growth and GnRHa-induced regression.
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MESH Headings
- Active Transport, Cell Nucleus
- Blotting, Western
- Cluster Analysis
- Cohort Studies
- DNA, Complementary/metabolism
- DNA-Binding Proteins/metabolism
- Down-Regulation
- Female
- Gene Expression Regulation
- Gene Expression Regulation, Neoplastic
- Gonadotropin-Releasing Hormone/analogs & derivatives
- Humans
- Immunohistochemistry
- Leiomyoma/metabolism
- Models, Biological
- Myocytes, Smooth Muscle/cytology
- Myometrium/metabolism
- Nuclear Receptor Subfamily 4, Group A, Member 1
- Oligonucleotide Array Sequence Analysis
- Premenopause
- Protein Processing, Post-Translational
- RNA, Messenger/metabolism
- Receptors, Cytoplasmic and Nuclear
- Receptors, Steroid
- Repressor Proteins/metabolism
- Reverse Transcriptase Polymerase Chain Reaction
- Time Factors
- Trans-Activators/metabolism
- Transcription Factors/metabolism
- Up-Regulation
- Uterine Neoplasms/metabolism
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Affiliation(s)
- Xiaoping Luo
- Department of Obstetrics and Gynecology, University of Florida, Box 100294, Gainesville, Florida 32610, USA
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17
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Métayé T, Gibelin H, Perdrisot R, Kraimps JL. Pathophysiological roles of G-protein-coupled receptor kinases. Cell Signal 2005; 17:917-28. [PMID: 15894165 DOI: 10.1016/j.cellsig.2005.01.002] [Citation(s) in RCA: 102] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2004] [Accepted: 01/11/2005] [Indexed: 12/19/2022]
Abstract
G-protein-coupled receptor kinases (GRKs) interact with the agonist-activated form of G-protein-coupled receptors (GPCRs) to effect receptor phosphorylation and to initiate profound impairment of receptor signalling, or desensitization. GPCRs form the largest family of cell surface receptors known and defects in GRK function have the potential consequence to affect GPCR-stimulated biological responses in many pathological situations. This review focuses on the physiological role of GRKs revealed by genetically modified animals but also develops the involvement of GRKs in human diseases as, Oguchi disease, heart failure, hypertension or rhumatoid arthritis. Furthermore, the regulation of GRK levels in opiate addiction, cancers, psychiatric diseases, cystic fibrosis and cardiac diseases is discussed. Both transgenic mice and human pathologies have demonstrated the importance of GRKs in the signalling pathways of rhodopsin, beta-adrenergic and dopamine-1 receptors. The modulation of GRK activity in animal models of cardiac diseases can be effective to restore cardiac function in heart failure and opens a novel therapeutic strategy in diseases with GPCR dysregulation.
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Affiliation(s)
- Thierry Métayé
- Department of Nuclear Medicine and Biophysics, Groupe de Recherche en Endocrinologie Expérimentale et Clinique, CHU de Poitiers, France.
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18
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Yono M, Foster HE, Shin D, Mane S, Latifpour J. Molecular classification of doxazosin-induced alterations in the rat prostate using gene expression profiling. Life Sci 2005; 77:470-9. [PMID: 15894016 DOI: 10.1016/j.lfs.2005.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2004] [Accepted: 01/06/2005] [Indexed: 11/29/2022]
Abstract
We investigated molecular changes that occurred during chronic administration of doxazosin, an alpha1-adrenoceptor (AR) antagonist, using Affymetrix GeneChip analysis of gene expression. Rats were treated with doxazosin (4 mg/kg/day subcutaneously, supplemented with 4 mg/kg/day orally) for 12 weeks. Labeled cRNA was prepared and the subsequent hybridization to rat 230A arrays was performed. The alterations in gene expression levels of candidate genes identified by microarray analysis with potential biological relevance were verified by real-time reverse transcription polymerase chain reaction (RT-PCR) using SYBR Green I. Doxazosin treated rats had significantly heavier prostates compared to control rats. Microarray analysis revealed that chronic doxazosin treatment caused changes in the expression levels of 625 genes, of which 39 were related to cell death, necrosis, growth, proliferation and G-protein signalling pathways in the rat prostate. Furthermore, RT-PCR experiments, in accord with the microarray analysis, indicated that chronic doxazosin treatment caused an up-regulation in the mRNA expression level of clusterin, an antiapoptotic mediator, and epiregulin, a mitogen, in the ventral and dorsolateral prostate, respectively. These findings, that demonstrate chronic doxazosin administration causes significant changes in the expression of several hundred genes in the rat prostate, may provide insight into the long-term efficacy of alpha1-AR antagonists in the treatment of benign prostatic hyperplasia.
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Affiliation(s)
- Makoto Yono
- Section of Urology, Yale University School of Medicine, P.O. Box 208041, New Haven, CT 06520, USA
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19
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Teli T, Markovic D, Levine MA, Hillhouse EW, Grammatopoulos DK. Regulation of corticotropin-releasing hormone receptor type 1alpha signaling: structural determinants for G protein-coupled receptor kinase-mediated phosphorylation and agonist-mediated desensitization. Mol Endocrinol 2004; 19:474-90. [PMID: 15498832 DOI: 10.1210/me.2004-0275] [Citation(s) in RCA: 61] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Attenuation of CRH receptor type 1 (CRH-R1) signaling activity might involve desensitization and uncoupling of CRH-R1 from intracellular effectors. We investigated the desensitization of native CRH-R in human myometrial cells from pregnant women and recombinant CRH-R1alpha stably overexpressed in human embryonic kidney (HEK) 293 cells. In both cell types, CRH-R1-mediated adenylyl cyclase activation was susceptible to homologous desensitization induced by pretreatment with high concentrations of CRH. Time course studies showed half-maximal desensitization occurring after approximately 40 min of pretreatment and full recovery of CRH-R1alpha functional response within 2 h of removal of CRH pretreatment. In HEK 293 cells, desensitization of CRH-R1alpha was associated with receptor phosphorylation and subsequent endocytosis. To analyze the mechanism leading to CRH-R1alpha desensitization, we overexpressed a truncated beta-arrestin (319-418) and performed coimmunoprecipitation and G protein-coupled receptor kinase (GRK) translocation studies. We found that GRK3 and GRK6 are the main isoforms that interact with CRH-R1alpha, and that recruitment of GRK3 requires Gbetagamma-subunits as well as beta-arrestin. Site-directed mutagenesis of Ser and Thr residues in the CRH-R1alpha C terminus, identified Thr399 as important for GRK-induced receptor phosphorylation and desensitization.We conclude that homologous desensitization of CRH-R1alpha involves the coordinated action of multiple GRK isoforms, Gbeta gamma dimers and beta-arrestin. Based on our identification of key amino acid(s) for GRK-dependent phosphorylation, we demonstrate the importance of the CRH-R1alpha carboxyl tail for regulation of receptor activity.
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Affiliation(s)
- Thalia Teli
- Sir Quinton Hazell Molecular Medicine Research Centre, Department of Biological Sciences, The University of Warwick, Gibbet Hill Road, Coventry CV4 7AL, United Kingdom
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20
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Abstract
G-protein-coupled receptor kinases (GRKs) comprise a family of seven mammalian serine/threonine protein kinases that phosphorylate and regulate agonist-occupied or constitutively active G-protein-coupled receptors (GPCRs). Studies of the details and consequences of these mechanisms have focused heavily on the original beta-adrenoceptor kinase (beta-ARK) family (GRK2 and GRK3) and, in particular, on phosphorylation-dependent recruitment of adaptor proteins such as the beta-arrestins. However, recent work has indicated roles for the other, non-visual GRKs (GRK4, GRK5 and GRK6) and has revealed potential phosphorylation-independent regulation of GPCRs by GRK2 and GRK3. In this article, we review this newer information and attempt to put it into context with GRKs as physiological regulators that could be appropriate targets for future pharmacological intervention.
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Affiliation(s)
- Jonathon M Willets
- Department of Cell Physiology & Pharmacology, University of Leicester, Maurice Shock Medical Sciences Building, University Road, LE1 9HN, Leicester, UK
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