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Tennakoon M, Senarath K, Kankanamge D, Ratnayake K, Wijayaratna D, Olupothage K, Ubeysinghe S, Martins-Cannavino K, Hébert TE, Karunarathne A. Subtype-dependent regulation of Gβγ signalling. Cell Signal 2021; 82:109947. [PMID: 33582184 PMCID: PMC8026654 DOI: 10.1016/j.cellsig.2021.109947] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/01/2021] [Accepted: 02/02/2021] [Indexed: 01/04/2023]
Abstract
G protein-coupled receptors (GPCRs) transmit information to the cell interior by transducing external signals to heterotrimeric G protein subunits, Gα and Gβγ subunits, localized on the inner leaflet of the plasma membrane. Though the initial focus was mainly on Gα-mediated events, Gβγ subunits were later identified as major contributors to GPCR-G protein signalling. A broad functional array of Gβγ signalling has recently been attributed to Gβ and Gγ subtype diversity, comprising 5 Gβ and 12 Gγ subtypes, respectively. In addition to displaying selectivity towards each other to form the Gβγ dimer, numerous studies have identified preferences of distinct Gβγ combinations for specific GPCRs, Gα subtypes and effector molecules. Importantly, Gβ and Gγ subtype-dependent regulation of downstream effectors, representing a diverse range of signalling pathways and physiological functions have been found. Here, we review the literature on the repercussions of Gβ and Gγ subtype diversity on direct and indirect regulation of GPCR/G protein signalling events and their physiological outcomes. Our discussion additionally provides perspective in understanding the intricacies underlying molecular regulation of subtype-specific roles of Gβγ signalling and associated diseases.
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Affiliation(s)
- Mithila Tennakoon
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | - Kanishka Senarath
- Genetics and Molecular Biology Unit, University of Sri Jayewardenepura, Nugegoda, Sri Lanka
| | - Dinesh Kankanamge
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | - Kasun Ratnayake
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA; Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Dhanushan Wijayaratna
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | - Koshala Olupothage
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | - Sithurandi Ubeysinghe
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA
| | | | - Terence E Hébert
- Department of Pharmacology and Therapeutics, McGill University, Montréal, QC H3G 1Y6, Canada.
| | - Ajith Karunarathne
- Department of Chemistry and Biochemistry, The University of Toledo, Toledo, OH 43606, USA.
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Abstract
BACKGROUND Cluster headache is the most severe primary headache disorder. A genetic basis has long been suggested by family and twin studies; however, little is understood about the genetic variants that contribute to cluster headache susceptibility. METHODS We conducted a literature search of the MEDLINE database using the PubMed search engine to identify all human genetic studies for cluster headache. In this article we provide a review of those genetic studies, along with an overview of the pathophysiology of cluster headache and a brief review of migraine genetics, which have both been significant drivers of cluster headache candidate gene selection. RESULTS The investigation of cluster headache genetic etiology has been dominated by candidate gene studies. Candidate selection has largely been driven by the pathophysiology, such as the striking rhythmic nature of the attacks, which spurred close examination of the circadian rhythm genes CLOCK and HCRTR2. More recently, unbiased genetic approaches such as genome-wide association studies (GWAS) have yielded new genetic avenues of interest including ADCYAP1R1 and MME. CONCLUSIONS The majority of candidate genes studied for cluster headache suffer from poor reproducibility. Broader genetic interrogation through larger unbiased GWAS, exome, and whole genome studies may provide more robust candidates, and in turn provide a clearer understanding of the causes of cluster headache.
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Affiliation(s)
| | | | - Nunu Lund
- 2 Danish Headache Center, Department of Neurology, University of Copenhagen, Denmark
| | - Rigmor Jensen
- 2 Danish Headache Center, Department of Neurology, University of Copenhagen, Denmark
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Costa B, Pini S, Baldwin DS, Silove D, Manicavasagar V, Abelli M, Coppedè F, Martini C. Oxytocin receptor and G-protein polymorphisms in patients with depression and separation anxiety. J Affect Disord 2017; 218:365-373. [PMID: 28499211 DOI: 10.1016/j.jad.2017.03.056] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/06/2016] [Revised: 03/16/2017] [Accepted: 03/26/2017] [Indexed: 10/19/2022]
Abstract
BACKGROUND The impact of combined variants of Oxytocin Receptor (OXTR) and G protein β3 subunit genes was investigated in relation to retrospective reports of childhood as well as contemporary adult separation anxiety (SA), based on evidence of a β/γ dimer-mediated signaling for OXTR. METHODS A case-control association study (225 healthy adults and 188 outpatients with depression) was performed to establish Risk-Combined Genotype (RCG) of the studied variants (OXTR rs53576 and the functional Gβ3 subunit rs5443). Current SA was evaluated by the ASA-27 and retrospective childhood symptoms by the SASI. GG genotype of OXTR rs53576 combined with T-carrier genotype of Gβ3 rs5443 represented the RCG. RESULTS Compared to non-RCG, those with RCG had significantly higher levels of childhood and adult SA. The RCG was significantly associated with childhood SA threshold score (OR=2.85, 90%CI: 1.08-7.50). Childhood SA was, in turn, strongly associated with a threshold SA score in adulthood (OR=15.58; 95% CI: 4.62-52.59). LIMITATIONS Although the overall sample size is sizable, comparisons among subgroups with specific combination of alleles are based on relatively small numbers. CONCLUSIONS Our study indicates that variations in OXTR and Gβ3 genes are specifically associated with presence and severity of SA in childhood and adulthood, but not with depression or anxiety in general. Because there is increasing interest in oxytocin in social behavior, the gene-SA associations identified have potential translational and clinical relevance.
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Affiliation(s)
- Barbara Costa
- Department of Pharmacy, University of Pisa, Pisa, Italy
| | - Stefano Pini
- Department of Clinical and Experimental Medicine, Section of Psychiatry, University of Pisa, Pisa, Italy.
| | - David S Baldwin
- Clinical and Experimental Sciences, University of Southampton Faculty of Medicine, Academic Centre, College Keep, 4-12 Terminus Terrace, Southampton SO14 3DT, United Kingdom
| | - Derrick Silove
- Psychiatry Research and Teaching Unit, School of Psychiatry, University of New South Wales, Sydney, Australia
| | | | - Marianna Abelli
- Department of Clinical and Experimental Medicine, Section of Psychiatry, University of Pisa, Pisa, Italy
| | - Fabio Coppedè
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
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Eto M, Takeshima T, Harada M, Fujiwara S, Kumada M, Kamesaki T, Takamura K, Kenzaka T, Nakamura Y, Aonuma T, Okayama M, Kajii E. Association between G-protein β3 subunit gene and isolated systolic blood pressure elevation of greater than 130 mmHg: A large-scale cross-sectional study in the Japanese population. World J Hypertens 2017; 7:24-31. [DOI: 10.5494/wjh.v7.i2.24] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2016] [Revised: 12/22/2016] [Accepted: 02/13/2017] [Indexed: 02/06/2023] Open
Abstract
AIM To investigate whether GNB3 C825T single nucleotide polymorphism (SNP) contributes to systolic blood pressure (SBP) ≥ 130 mmHg in a large-scale cross-sectional study among the Japanese population with diastolic blood pressure (DBP) < 85 mmHg.
METHODS We analyzed 11008 Japanese subjects, including 2797 cases (SBP ≥ 130 and DBP < 85 mmHg) who were not taking anti-hypertensive medication and 8211 controls (SBP < 130 and DBP < 85 mmHg), all of whom enrolled in the genome banking project of the 21st Century COE (Center of Excellence) Program at Jichi Medical University. Subjects were divided into four groups according to gender (male and female) and age (≤ 49 years and ≥ 50 years). GNB3 gene polymorphism was determined using the TaqMan probe method. We compared the frequencies of alleles and genotypes between cases and controls by chi-squared test. The strength of the associations was estimated by odds ratios (ORs) and 95%CI by using logistic regression analysis. The ORs were adjusted for age and body mass index.
RESULTS Allele and genotype distributions significantly differed between cases and controls only in males aged ≤ 49 years. Compared to the CC genotype, a significant OR was obtained in the TT genotype among males aged ≤ 49 years.
CONCLUSION This study indicates that the TT genotype of the GNB3 C825T SNP may contribute to SBP elevation of greater than 130 mmHg compared to the CC genotype in Japanese males aged ≤ 49 years.
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5
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Fabbri C, Crisafulli C, Calabrò M, Spina E, Serretti A. Progress and prospects in pharmacogenetics of antidepressant drugs. Expert Opin Drug Metab Toxicol 2016; 12:1157-68. [DOI: 10.1080/17425255.2016.1202237] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Affiliation(s)
- Chiara Fabbri
- Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna, Italy
| | - Concetta Crisafulli
- Department of Biomedical Science, Odontoiatric and Morphological and Functional Images, University of Messina, Messina, Italy
| | - Marco Calabrò
- Department of Biomedical Science, Odontoiatric and Morphological and Functional Images, University of Messina, Messina, Italy
| | - Edoardo Spina
- Department of Biomedical Science, Odontoiatric and Morphological and Functional Images, University of Messina, Messina, Italy
| | - Alessandro Serretti
- Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna, Italy
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Martinucci I, Blandizzi C, de Bortoli N, Bellini M, Antonioli L, Tuccori M, Fornai M, Marchi S, Colucci R. Genetics and pharmacogenetics of aminergic transmitter pathways in functional gastrointestinal disorders. Pharmacogenomics 2016; 16:523-39. [PMID: 25916523 DOI: 10.2217/pgs.15.12] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Functional gastrointestinal disorders (FGIDs) are highly prevalent syndromes, without evident underlying organic causes. Their pathogenesis is multifactorial in nature, with a combination of environmental and genetic factors contributing to their clinical manifestations, for which most of current treatments are not satisfactory. It is acknowledged that amine mediators (noradrenaline, dopamine and serotonin) play pivotal regulatory actions on gut functions and visceral sensation. In addition, drugs of therapeutic interest for FGIDs act on these transmitter pathways. The present article reviews current knowledge on the impact of genetics and pharmacogenetics of aminergic pathways on FGID pathophysiology, clinical presentations, symptom severity and medical management, in an attempt of highlighting the most relevant evidence and point out issues that should be addressed in future investigations.
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Affiliation(s)
- Irene Martinucci
- Gastroenterology Unit, Department of Translational Research & New Technologies in Medicine, University of Pisa, Via Paradisa 2, I-56124 Pisa, Italy
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Fabbri C, Serretti A. Pharmacogenetics of major depressive disorder: top genes and pathways toward clinical applications. Curr Psychiatry Rep 2015; 17:50. [PMID: 25980509 DOI: 10.1007/s11920-015-0594-9] [Citation(s) in RCA: 49] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
The pharmacogenetics of antidepressants has been not only a challenging but also frustrating research field since its birth in the 1990s. Indeed, great expectations followed the first evidence of familiar aggregation of antidepressant response. Despite the progress from candidate gene studies to genome-wide association studies (GWAS), results fell out the expectations and they were often inconsistent. Anyway, the cumulative evidence supports the involvement of some genes and molecular pathways in antidepressant efficacy. The best single genes are SLC6A4, HTR2A, BDNF, GNB3, FKBP5, ABCB1, and cytochrome P450 genes (CYP2D6 and CYP2C19). Molecular pathways involved in inflammation and neuroplasticity show the greatest support. The first studies evaluating benefits of genotype-guided antidepressant treatments provided encouraging results and confirmed the relevance of SLC6A4, HTR2A, ABCB1, and cytochrome P450 genes. Further progress in genotyping and data analysis would allow to move forward and complete the understanding of antidepressant pharmacogenetics and its translation into clinical applications.
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Affiliation(s)
- Chiara Fabbri
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Viale Carlo Pepoli 5, 40123, Bologna, Italy,
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8
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Ye Y, Sun Z, Guo A, Song LS, Grobe JL, Chen S. Ablation of the GNB3 gene in mice does not affect body weight, metabolism or blood pressure, but causes bradycardia. Cell Signal 2014; 26:2514-20. [PMID: 25093805 DOI: 10.1016/j.cellsig.2014.07.030] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 06/26/2014] [Accepted: 07/28/2014] [Indexed: 11/18/2022]
Abstract
G protein β3 (Gβ3) is an isoform of heterotrimeric G protein β subunits involved in transducing G protein coupled receptor (GPCR) signaling. Polymorphisms in Gβ3 (GNB3) are associated with many human disorders (e.g. hypertension, diabetes and obesity) but the role of GNB3 in these pathogeneses remains unclear. Here, Gβ3-null mice (GNB3(-/-)) were characterized to determine how Gβ3 functions to regulate blood pressure, body weight and metabolism. We found Gβ3 expression restricted to limited types of tissues, including the retina, several regions of the brain and heart ventricles. Gβ3-deficient mice were normal as judged by body weight gain by age or by feeding with high-fat diet (HFD); glucose tolerance and insulin sensitivity; baseline blood pressure and angiotensin II infusion-induced hypertension. During tail-cuff blood pressure measurements, however, Gβ3-null mice had slower heart rates (~450 vs ~500 beats/min). This bradycardia was not observed in isolated and perfused Gβ3-null mouse hearts. Moreover, mouse hearts isolated from GNB3(-/-) and controls responded equivalently to muscarinic receptor- and β-adrenergic receptor-stimulated bradycardia and tachycardia, respectively. Since no difference was seen in isolated hearts, Gβ3 is unlikely to be involved directly in the GPCR signaling activity that controls heart pacemaker activity. These results demonstrate that although Gβ3 appears dispensable in mice for the regulation of blood pressure, body weight and metabolic features associated with obesity and diabetes, Gβ3 may regulate heart rate.
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Affiliation(s)
- Yuanchao Ye
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Zhizeng Sun
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Ang Guo
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Long-Sheng Song
- Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Justin L Grobe
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
| | - Songhai Chen
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA; Department of Internal Medicine, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA.
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9
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Fabbri C, Porcelli S, Serretti A. From pharmacogenetics to pharmacogenomics: the way toward the personalization of antidepressant treatment. CANADIAN JOURNAL OF PSYCHIATRY. REVUE CANADIENNE DE PSYCHIATRIE 2014; 59:62-75. [PMID: 24881125 PMCID: PMC4079233 DOI: 10.1177/070674371405900202] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
OBJECTIVE Major depressive disorder is the most common psychiatric disorder, worldwide, yet response and remission rates are still unsatisfactory. The identification of genetic predictors of antidepressant (AD) response could provide a promising opportunity to improve current AD efficacy through the personalization of treatment. The major steps and findings along this path are reviewed together with their clinical implications and limitations. METHOD We systematically reviewed the literature through MEDLINE and Embase database searches, using any word combination of "antidepressant," "gene," "polymorphism," "pharmacogenetics," "genome-wide association study," "GWAS," "response," and "adverse drug reactions." Experimental works and reviews published until March 2012 were collected and compared. RESULTS Numerous genes pertaining to several functional systems were associated with AD response. The more robust findings were found for the following genes: solute carrier family 6 (neurotransmitter transporter), member 4; serotonin receptor 1A and 2A; brain-derived neurotrophic factor; and catechol-O-methyltransferase. Genome-wide association studies (GWASs) provided many top markers, even if none of them reached genome-wide significance. CONCLUSIONS AD pharmacogenetics have not produced any knowledge applicable to routine clinical practice yet, as results were mainly inconsistent across studies. Despite this, the rising awareness about methodological deficits of past studies could allow for the identication of more suitable strategies, such as the integration of the GWAS approach with the candidate gene approach, and innovative methodologies, such as pathway analysis and study of depressive endophenotypes.
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Affiliation(s)
- Chiara Fabbri
- Researcher, Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna, Italy
| | - Stefano Porcelli
- Researcher, Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna, Italy
| | - Alessandro Serretti
- Professor, Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna, Italy
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10
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Fabbri C, Di Girolamo G, Serretti A. Pharmacogenetics of antidepressant drugs: an update after almost 20 years of research. Am J Med Genet B Neuropsychiatr Genet 2013; 162B:487-520. [PMID: 23852853 DOI: 10.1002/ajmg.b.32184] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/04/2012] [Accepted: 06/19/2013] [Indexed: 12/12/2022]
Abstract
Major depressive disorder (MDD) is an emergent cause of personal and socio-economic burden, both for the high prevalence of the disorder and the unsatisfying response rate of the available antidepressant treatments. No reliable predictor of treatment efficacy and tolerance in the single patient is available, thus drug choice is based on a trial and error principle with poor clinical efficiency. Among modulators of treatment outcome, genetic polymorphisms are thought to explain a significant share of the inter-individual variability. The present review collected the main pharmacogenetic findings primarily about antidepressant response and secondly about antidepressant induced side effects, and discussed the main strengths and limits of both candidate and genome-wide association studies and the most promising methodological opportunities and challenges of the field. Despite clinical applications of antidepressant pharmacogenetics are not available yet, previous findings suggest that genotyping may be applied in the clinical practice. In order to reach this objective, further rigorous pharmacogenetic studies (adequate sample size, study of better defined clinical subtypes of MDD, adequate covering of the genetic variability), their combination with the results obtained through complementary methodologies (e.g., pathway analysis, epigenetics, transcriptomics, and proteomics), and finally cost-effectiveness trials are required.
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Affiliation(s)
- Chiara Fabbri
- Department of Biomedical and NeuroMotor Sciences, University of Bologna, Bologna, Italy
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11
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Khan SM, Sleno R, Gora S, Zylbergold P, Laverdure JP, Labbé JC, Miller GJ, Hébert TE. The expanding roles of Gβγ subunits in G protein-coupled receptor signaling and drug action. Pharmacol Rev 2013; 65:545-77. [PMID: 23406670 DOI: 10.1124/pr.111.005603] [Citation(s) in RCA: 172] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
Gβγ subunits from heterotrimeric G proteins perform a vast array of functions in cells with respect to signaling, often independently as well as in concert with Gα subunits. However, the eponymous term "Gβγ" does not do justice to the fact that 5 Gβ and 12 Gγ isoforms have evolved in mammals to serve much broader roles beyond their canonical roles in cellular signaling. We explore the phylogenetic diversity of Gβγ subunits with a view toward understanding these expanded roles in different cellular organelles. We suggest that the particular content of distinct Gβγ subunits regulates cellular activity, and that the granularity of individual Gβ and Gγ action is only beginning to be understood. Given the therapeutic potential of targeting Gβγ action, this larger view serves as a prelude to more specific development of drugs aimed at individual isoforms.
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Affiliation(s)
- Shahriar M Khan
- Department of Pharmacology and Therapeutics, McGill University, 3655 Promenade Sir-William-Osler, Room 1303, Montréal, Québec H3G 1Y6, Canada
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12
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Sun Z, Runne C, Tang X, Lin F, Chen S. The Gβ3 splice variant associated with the C825T gene polymorphism is an unstable and functionally inactive protein. Cell Signal 2012; 24:2349-59. [PMID: 22940628 DOI: 10.1016/j.cellsig.2012.08.011] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 08/27/2012] [Indexed: 12/13/2022]
Abstract
A splice variant of Gβ3, termed Gβ3s, has been associated with the C825T polymorphism in the Gβ3 gene and linked with many human disorders. However, the biochemical properties and functionality of Gβ3s remain controversial. Here, using multidisciplinary approaches including co-immunoprecipitation analysis and bioluminescence resonance energy transfer (BRET) measurements, we showed that unlike Gβ3, Gβ3s failed to form complexes with either Gγ or Gα subunits. Moreover, using a mutant Gγ2 deficient in lipid modification to purify Gβ3s from Sf9 cells without the use of detergents, we further showed that the failure of Gβ3s to form dimers with Gγ was not due to the instability of the dimers in detergents, but rather, reflected the intrinsic properties of Gβ3s. Additional studies indicated that Gβ3s is unstable, and unable to localize properly to the plasma membrane and to activate diverse Gβγ effectors including PLCβ2/3, PI3Kγ, ERKs and the Rho guanine exchange factor (RhoGEF) PLEKHG2. Thus, these data suggest that the pathological effects of Gβ3 C825T polymorphism may result from the downregulation of Gβ3 function. However, we found that the chemokine SDF1α transmits signals primarily through Gβ1 and Gβ2, but not Gβ3, to regulate chemotaxis of several human lymphocytic cell lines, indicating the effects of Gβ3 C825T polymorphism are likely to be tissue and/or stimuli specific and its association with various disorders in different tissues should be interpreted with great caution.
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Affiliation(s)
- Zhizeng Sun
- Department of Pharmacology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, IA 52242, USA
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13
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Mahmoud S, Yun JK, Ruiz-Velasco V. Gβ2 and Gβ4 participate in the opioid and adrenergic receptor-mediated Ca2+ channel modulation in rat sympathetic neurons. J Physiol 2012; 590:4673-89. [PMID: 22711958 DOI: 10.1113/jphysiol.2012.237644] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/17/2023] Open
Abstract
Cardiac function is regulated in part by the sympathetic branch of the autonomic nervous system via the stellate ganglion (SG) neurons. Neurotransmitters, such as noradrenaline (NA), and neuropeptides, including nociceptin (Noc), influence the excit ability of SG neurons by modulating Ca(2+) channel function following activation of the adrenergic and nociceptin/orphanin FQ peptide (NOP) opioid receptors, respectively. The regulation of Ca(2+) channels is mediated by Gβγ, but the specific Gβ subunit that modulates the channels is not known. In the present study, small interference RNA (siRNA) was employed to silence the natively expressed Gβ proteins in rat SG tissue and to examine the coupling specificity of adrenergic and NOP opioid receptors to Ca(2+) channels employing the whole-cell variant of the patch-clamp technique.Western blotting analysis showed that Gβ1, Gβ2 and Gβ4 are natively expressed. The knockdown of Gβ2 or Gβ4 led to a significant decrease of the NA- and Noc-mediated Ca(2+)current inhibition, while Gβ1 silencing was without effect. However, sustaining low levels of Gβ2 resulted in an increased expression of Gβ4 and a concomitant compensation of both adrenergic and opioid signalling pathways modulating Ca(2+) channels. Conversely, Gβ4-directed siRNA was not accompanied with a compensation of the signalling pathway. Finally, the combined silencing of Gβ2 and Gβ4 prevented any additional compensatory mechanisms.Overall, our studies suggest that in SG neurons, Gβ2 and Gβ4 normally maintain the coupling of Ca(2+) channels with the receptors, with the latter subtype responsible for maintaining the integrity of both pathways.
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Affiliation(s)
- Saifeldin Mahmoud
- Department of Anesthesiology, Penn State College of Medicine, Hershey, PA 17033-0850, USA
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14
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Camilleri M, Busciglio I, Carlson P, McKinzie S, Burton D, Baxter K, Ryks M, Zinsmeister AR. Pharmacogenetics of low dose clonidine in irritable bowel syndrome. Neurogastroenterol Motil 2009; 21:399-410. [PMID: 19309415 PMCID: PMC2690641 DOI: 10.1111/j.1365-2982.2009.01263.x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Adrenergic and serotonergic (ADR-SER) mechanisms alter gut (gastrointestinal, GI) sensorimotor functions. We aimed to determine whether candidate ADR-SER genes affect GI responses to low dose clonidine (CLO) in humans. Forty healthy and 120 irritable bowel syndrome (IBS) participants received CLO, 0.1 mg or 0.15 mg b.i.d., for 6 days. At baseline and post-CLO, we measured: gastric volume (GV); satiation volume; rectal compliance, sensation thresholds and ratings with distensions. Genetic variations tested were: alpha2A (C-1291G), alpha2C (Del 322-325), GNbeta3 (C825T) and solute carrier family 6 (neurotransmitter transporter, serotonin), member 4 (SLC6A4) (serotonin transporter linked polymorphic region). CLO reduced volume to satiation (P = 0.002), postprandial GV (P < 0.001), sensation threshold for pain (<0.001); CLO increased rectal compliance (P = 0.024). There were significant associations between post-CLO responses and gene variations for DeltaGV (alpha2A and SLC6A4), rectal sensation of gas (alpha2A, GNbeta3), urgency (alpha2A); and pain (GNbeta3 and SLC6A4); and rectal compliance (SLC6A4). alpha2A, GNbeta3 and SLC6A4 genotypes significantly modify responses to CLO on sensory and motor GI functions in health and IBS.
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Affiliation(s)
- M Camilleri
- Clinical Enteric Neuroscience Translational and Epidemiological Research (CENTER), Mayo Clinic, Rochester, MN 55905, USA.
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Wilkie MJV, Smith D, Reid IC, Day RK, Matthews K, Wolf CR, Blackwood D, Smith G. A splice site polymorphism in the G-protein β subunit influences antidepressant efficacy in depression. Pharmacogenet Genomics 2007; 17:207-15. [PMID: 17460549 DOI: 10.1097/fpc.0b013e32801a3be6] [Citation(s) in RCA: 63] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE Recent evidence suggests that signalling cascades located downstream of monoamine receptors are altered following antidepressant treatment. Our objective was to investigate whether genetic polymorphisms in genes involved in these signalling cascades influenced antidepressant efficacy. METHODS Polymorphisms in the G-protein beta subunit GNB3, the cAMP response element binding protein 1 gene (CREB1), the brain derived neurotrophic factor (BDNF) and CREB binding protein (CREBBP) were studied in well characterised unipolar (n=166) and early onset (n=102) depressive populations and correlated with treatment response. RESULTS The GNB3 C825T polymorphism, which results in a 41 amino acid deletion, was significantly associated with lack of remission (OR=0.18, P=0.02) and lack of response (OR=0.26, P=0.03) following 2nd switch treatment. A cytosine deletion 16 base pairs from the start of exon 8 in CREB1 was found more frequently in remitters and responders to 2nd switch antidepressant drug therapy, although these differences failed to reach significance. Polymorphisms detected BDNF (G196A) and CREBBP (T651 C) did not appear to influence antidepressant response. CONCLUSIONS These results suggest that inheritance of the GNB3C825T allele may significantly influence antidepressant response and emphasises the potential importance of polymorphisms in genes in signalling cascades activated by commonly prescribed antidepressants.
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Affiliation(s)
- Murray J V Wilkie
- Biomedical Research Centre, University of Dundee, Ninewells Hospital and Medical School, Dundee, UK
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Grove ML, Morrison A, Folsom AR, Boerwinkle E, Hoelscher DM, Bray MS. Gene-environment interaction and the GNB3 gene in the Atherosclerosis Risk in Communities study. Int J Obes (Lond) 2007; 31:919-26. [PMID: 17299380 DOI: 10.1038/sj.ijo.0803545] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
OBJECTIVE The purpose of this study was to investigate the interaction between the G-protein beta-3 (GNB3) 825C>T polymorphism and physical activity in relation to prevalent obesity and hypertension. RESEARCH METHODS AND PROCEDURES The GNB3 825C>T genotype was measured in a sample of 14,716 African Americans (AAs) and whites from the Atherosclerosis Risk in Communities (ARIC) study, and logistic regression was used to test for genetic effects and gene-environment interactions. RESULTS The GNB3 825C>T variant was not independently associated with prevalent obesity or hypertension in either AA or whites. However, we observed a significant interaction (P<0.001) between this variant and physical activity in predicting obesity status in AAs. In AAs who were active, each 825T allele was associated with a 20% lower prevalence of obesity (odds ratio (OR)=0.80, 95% confidence interval (CI)=0.689-0.937, P=0.005), whereas each 825T allele was associated with a 23% greater prevalence of obesity for low-active individuals (OR=1.23, 95% CI=1.06-1.44, P=0.008). We also found a significant interaction between the GNB3 825C>T polymorphism, obesity status and physical activity in predicting hypertension in the AA subjects. AA homozygotes for the 825T allele who were both obese and had a low activity level were 2.7 times more likely to be hypertensive, compared to non-obese, active 825C homozygotes (OR=2.71, 95% CI=1.19-6.17, P<0.02). DISCUSSION Our findings suggest that the variation within the GNB3 gene may interact with physical activity level to influence obesity status and, together with obesity and physical activity, the GNB3 825C>T variant may influence hypertension prevalence in AAs.
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Affiliation(s)
- M L Grove
- The University of Texas Health Science Center at Houston, School of Public Health, Human Genetics Center, Houston, TX 77030, USA
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Rosskopf D, Schürks M, Rimmbach C, Schäfers R. Genetics of arterial hypertension and hypotension. Naunyn Schmiedebergs Arch Pharmacol 2007; 374:429-69. [PMID: 17262198 DOI: 10.1007/s00210-007-0133-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2006] [Accepted: 12/22/2006] [Indexed: 01/13/2023]
Abstract
Human hypertension affects affects more than 20% of the adult population in industrialized countries, and it is implicated in millions of deaths worldwide each year from stroke, heart failure and ischemic heart disease. Available evidence suggests a major genetic impact on blood pressure regulation. Studies in monogenic hypertension revealed that renal salt and volume regulation systems are predominantly involved in the genesis of these disorders. Mutations here affect the synthesis of mineralocorticoids, the function of the mineralocorticoid receptor, epithelial sodium channels and their regulation by a new class of kinases, termed WNK kinases. It has been learned from monogenic hypotension that almost all ion transporters involved in the renal uptake of Na(+) have a major impact on blood pressure regulation. For essential hypertension as a complex disease, many candidate genes have been analysed. These include components of the renin-angiotensin-aldosterone system, adducin, beta-adrenoceptors, G protein subunits, regulators of G protein signalling (RGS) proteins, Rho kinases and G protein receptor kinases. At present, the individual impact of common polymorphisms in these genes on the observed blood pressure variation, on risk for stroke and as predictors of antihypertensive responses remains small and clinically irrelevant. Nevertheless, these studies have greatly augmented our knowledge on the regulation of renal functions, cellular signal transduction and the integration of both. Together, this provides the basis for the identification of novel drug targets and, hopefully, innovative antihypertensive drugs.
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Affiliation(s)
- Dieter Rosskopf
- Department Pharmacology, Research Center for Pharmacology and Experimental Therapeutics, Ernst-Moritz-Arndt-University Greifswald, Friedrich Loeffler Str. 23d, 17487 Greifswald, Germany.
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Andresen V, Camilleri M, Kim HJ, Stephens DA, Carlson PJ, Talley NJ, Saito YA, Urrutia R, Zinsmeister AR. Is there an association between GNbeta3-C825T genotype and lower functional gastrointestinal disorders? Gastroenterology 2006; 130:1985-94. [PMID: 16762621 DOI: 10.1053/j.gastro.2006.03.017] [Citation(s) in RCA: 52] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2005] [Accepted: 03/09/2006] [Indexed: 12/13/2022]
Abstract
BACKGROUND & AIMS GNbeta3 influences G-protein translation of a majority of ligand-receptor activations. It has been reported that functional dyspepsia (FD) is associated with homozygous genotypes of the C825T polymorphism in the GNbeta3 gene. It is unknown whether the GNbeta3 genotype is associated with lower functional gastrointestinal disorders (FGID). We aimed to compare the prevalence of the different GNbeta3-C825T genotypes in patients with lower FGID and healthy controls and to test the associations of these genetic variations with subgroups of irritable bowel syndrome (IBS), functional abdominal pain (FAP), lower FGID-FD overlap, and high somatic symptom scores. METHODS GNbeta3-C825T polymorphism was analyzed in DNA from blood samples of 233 patients with lower FGID and 152 healthy controls. A validated bowel questionnaire characterized the FGID phenotype: 82 with IBS constipation, 94 with IBS diarrhea, 38 with IBS alternating bowel function, and 19 with FAP. There were 159 patients with lower FGID and overlap FD using Rome II criteria. Regression analyses assessed associations of the GNbeta3 genotypes with lower FGID as a group, and subgroups of FGID and somatic symptom scores. RESULTS GNbeta3-C825T genotype distributions were similar between healthy controls (50.7% CC, 40.8% TC) and patients with lower FGID (8.6% TT, 51.5% CC, 40.8% TC, and 7.7% TT). There were no significant associations of GNbeta3-C825T polymorphism with lower FGID overall or with the separate symptom subgroups including IBS, FAP, lower FGID-FD overlap, or high somatic symptom scores. CONCLUSIONS In contrast to the reported association with FD, GNbeta3-C825T polymorphism is not associated significantly with lower FGID, with different IBS or FAP phenotypes, or lower FGID-FD overlap.
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Affiliation(s)
- Viola Andresen
- Clinical Enteric Neuroscience Translational and Epidemiological Research (C.E.N.T.E.R.) Program, Mayo Clinic College of Medicine, Rochester, Minnesota, USA
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Camilleri CE, Carlson PJ, Camilleri M, Castillo EJ, Locke GR, Geno DM, Stephens DA, Zinsmeister AR, Urrutia R. A study of candidate genotypes associated with dyspepsia in a U.S. community. Am J Gastroenterol 2006; 101:581-92. [PMID: 16464220 DOI: 10.1111/j.1572-0241.2006.00481.x] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
BACKGROUND The role of genetic predisposition to the development of dyspepsia is unclear. Recently, a significant association was reported with CC genotype of GNbeta3. AIM To explore the association of candidate genotypes altering adrenergic, serotonergic, CCKergic, and G protein functions, and dyspepsia in a sample from a U.S. community. METHODS Dyspeptics and healthy controls were identified among community respondents who had been randomly selected to complete validated questionnaires. Other diseases were excluded by face-to-face history and physical examination. Polymorphisms of candidate genes for alpha(2A), alpha(2C), 5-HT(1A), 5-HT(2A), 5-HT(2C), CCK-1 receptors and CCK promoter, GNbeta3 protein, and SERT-promoter (SERT-P) were studied. The association between polymorphisms and meal-related or meal-unrelated dyspepsia, high somatic symptom scores, and somatization were evaluated using Fisher's exact test. RESULTS DNA was available from 41 dyspeptics and 47 healthy controls from Olmsted County. Community dyspepsia unrelated to meals was associated with both homozygous GNbeta3 protein 825T and C alleles. There were no significant associations with meal-related dyspepsia. Using Rome II subgroups, the same genotype was associated with dysmotility-like and other dyspepsia. Higher somatization scores were not significantly associated with any of the candidate genes when considered as single factors. CONCLUSION Meal-unrelated dyspepsia in a U.S. community study is associated with the homozygous 825T or C alleles of GNbeta3 protein. Candidate genes controlling adrenergic, serotonergic, and CCKergic functions do not appear to be associated with dyspepsia.
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Affiliation(s)
- Christopher E Camilleri
- Gastroenterology Research Unit, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA
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Sun A, Ge J, Siffert W, Frey UH. Quantification of allele-specific G-protein beta3 subunit mRNA transcripts in different human cells and tissues by Pyrosequencing. Eur J Hum Genet 2005; 13:361-9. [PMID: 15536475 DOI: 10.1038/sj.ejhg.5201334] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Abstract
The G-protein 825T allele is associated with altered drug responses while the underlying mechanism is not fully understood. Differential expression of transcripts from the C and T alleles could contribute to this process. The C825T polymorphism located in exon 10 is in close linkage disequilibrium with the A(-350)G promoter single nucleotide polymorphism (SNP) and the C1429T SNP and could therefore serve as a marker for allele-specific expression resulting from the promoter SNP. However, alternative splicing of exon 10 in 825T allele carriers may result in under-represented mRNA transcripts. We, therefore, established a novel method based on the Pyrosequencing technology to quantify allele-specific transcript expression and quantified the allelic variance of the C1429T polymorphism located in the 3'-untranslated region of GNB3. Validation of the method was performed using linear regression analysis of measured versus expected ratios of DNA mixed at different known concentrations as well as determining allele-specific mRNA expression of the partially imprinted IGF-2 gene. We genotyped the C1429T polymorphism of 83 samples derived from six different human tissues and cell lines and quantified mRNA transcripts from different alleles using heterozygous samples. No significantly different transcript amounts from the two alleles were found. There were also no significantly different transcript amounts associated with different G(-350)A genotypes (P>0.05). As a result, we could show that Pyrosequencing provides a sensitive tool to quantify allele-specific transcript expression. Our data do not support the hypothesis that differential G-protein activity associated with the C825T SNP results from different transcript amounts associated with specific GNB3 genotypes.
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Affiliation(s)
- Aijun Sun
- Institute of Cardiovascular Disease, Zhongshan Hospital, Fudan University, P.R. China
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Schreieck J, Dostal S, von Beckerath N, Wacker A, Flory M, Weyerbrock S, Koch W, Schömig A, Schmitt C. C825T polymorphism of the G-protein beta3 subunit gene and atrial fibrillation: association of the TT genotype with a reduced risk for atrial fibrillation. Am Heart J 2004; 148:545-50. [PMID: 15389246 DOI: 10.1016/j.ahj.2004.03.024] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND A polymorphism consisting of a C825T substitution in the G-protein beta(3) subunit gene (GNB3) has been associated with enhanced human atrial inward rectifier potassium currents regarding the TT genotype. Therefore, we investigated a possible impact of the GNB3 C825T polymorphism on atrial fibrillation in an association study. METHODS Two hundred ninety-one consecutive patients admitted to our center with atrial fibrillation (age, 58 +/- 10 years) and 292 consecutive control patients without atrial tachyarrhythmias (59 +/- 11 years) were genotyped for the C825T polymorphism. Patients with coronary heart disease, valvular heart disease, or cardiomyopathy were excluded from the study. Both patient groups had a similar incidence of cardiovascular risk factors (hypertension, hypercholesterolemia, body mass index). RESULTS The prevalence of the GNB3 TT genotype was significantly lower in patients with atrial fibrillation (5.8%) than in the control group (12.0%); however, no significant differences in the frequencies of the CT and CC genotypes were found. The TT genotype was associated with a 54% decrease in the adjusted risk (OR from a multivariant model, 0.46; 95% CI, 0.24 to 0.87; P =.02) for the occurrence of atrial fibrillation. CONCLUSIONS The current study suggests an association between the GNB3 TT genotype and a reduced risk for the occurrence of atrial fibrillation.
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Affiliation(s)
- Juergen Schreieck
- Deutsches Herzzentrum München and 1. Medizinische Klinik, Klinikum rechts der Isar, Technische Universität München, Munich, Germany.
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Sahelijo L, Katz DA, Spear BB. Prediction of successful weight reduction under sibutramine therapy. ACTA ACUST UNITED AC 2004; 14:387; author reply 387-9. [PMID: 15247631 DOI: 10.1097/00008571-200406000-00008] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Abstract
The extent of blood pressure lowering by anti-hypertensive agents is difficult to predict for individual patients, even when evaluated in the context of biochemical or demographic information. Genetic predictors (mainly single nucleotide polymorphisms, SNPs) have been the focus of several recent studies and are gaining much attention. We have conducted a literature search for studies in which the lowering of ambient blood pressure by specific drugs or drug classes in humans was related to specific genotypes. Twenty-eight studies were identified, of which six had a single-dose design, and the remaining 22 studied drug effects after more than 4 weeks of drug administration. Virtually all were association studies. Prospective trials that compared the prognostic value of genetic methods to routine clinical practice were not identified. Almost all studies used a candidate-gene design, usually with a very small number of SNPs (typically one). Gene-gene and gene-environment interactions were studied only rarely. Only one study targeted genes involved in drug metabolism. Most candidate-genes were part of the renin-angiotensin system. By far the most extensively studied has been the angiotensin-converting enzyme insertion/deletion polymorphism (15 studies) but, to date, no clear picture has emerged for this or other genetic variants. Thus, the potential for utility of genetic characterization of individual patients as a predictor of anti-hypertensive response has yet to be realized.
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Affiliation(s)
- Richard P Koopmans
- Department of Pharmacology, Academic Medical Center, University of Amsterdam, Amsterdam, The Netherlands.
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Siffert W. Effects of the G protein beta 3-subunit gene C825T polymorphism: should hypotheses regarding the molecular mechanisms underlying enhanced G protein activation be revised? Focus on "A splice variant of the G protein beta 3-subunit implicated in disease states does not modulate ion channels". Physiol Genomics 2003; 13:81-4. [PMID: 12700359 DOI: 10.1152/physiolgenomics.00031.2003] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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