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Carkaci-Salli N, Bewley MC, Tekin I, Flanagan JM, Vrana KE. The A328 V/E (rs2887147) polymorphisms in human tryptophan hydroxylase 2 compromise enzyme activity. Biochem Biophys Rep 2023; 35:101527. [PMID: 37608910 PMCID: PMC10440358 DOI: 10.1016/j.bbrep.2023.101527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Revised: 08/03/2023] [Accepted: 08/03/2023] [Indexed: 08/24/2023] Open
Abstract
Human tryptophan hydroxylase 2 (hTPH2) is the rate-limiting enzyme for serotonin biosynthesis in the brain. A number of naturally-occurring single nucleotide polymorphisms (SNPs) have been reported for hTPH2. We investigated the activity and kinetic characteristics of the most common missense polymorphism rs2887147 (A328 V/E; 0.92% allelic frequency for the two different reported SNPs at the same site) using bacterially expressed hTPH2. The recombinant full-length enzyme A328E had no measurable enzyme activity, but A328V displayed decreased enzyme activity (Vmax). A328V also displayed substrate inhibition and decreased stability compared to the wild-type enzyme. By contrast, in constructs lacking the N-terminal 150 amino acid regulatory domain, the A328V substitution had no effect; that is, there was no substrate inhibition, enzyme stabilities (for wild-type and A328V) were dramatically increased, and Vmax values were not different (while the A328E variant remained inactive). These findings, in combination with molecular modeling, suggest that substitutions at A328 affect catalytic activity by altering the conformational freedom of the regulatory domain. The reduced activity and substrate inhibition resulting from these polymorphisms may ultimately reduce serotonin synthesis and contribute to behavioral perturbations, emotional stress, and eating disorders.
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Affiliation(s)
- Nurgul Carkaci-Salli
- Departments of Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Maria C. Bewley
- Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Izel Tekin
- Departments of Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - John M. Flanagan
- Biochemistry and Molecular Biology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Kent E. Vrana
- Departments of Pharmacology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
- Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
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Howarth ERI, Szott ID, Witham CL, Wilding CS, Bethell EJ. Genetic polymorphisms in the serotonin, dopamine and opioid pathways influence social attention in rhesus macaques (Macaca mulatta). PLoS One 2023; 18:e0288108. [PMID: 37531334 PMCID: PMC10395878 DOI: 10.1371/journal.pone.0288108] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2023] [Accepted: 06/20/2023] [Indexed: 08/04/2023] Open
Abstract
Behaviour has a significant heritable component; however, unpicking the variants of interest in the neural circuits and molecular pathways that underpin these has proven difficult. Here, we present a comprehensive analysis of the relationship between known and new candidate genes from identified pathways and key behaviours for survival in 109 adult rhesus macaques (Macaca mulatta). Eight genes involved in emotion were analysed for variation at a total of nine loci. Genetic data were then correlated with cognitive and observational measures of behaviour associated with wellbeing and survival using MCMC-based Bayesian GLMM in R, to account for relatedness within the macaque population. For four loci the variants genotyped were length polymorphisms (SLC6A4 5-hydroxytryptamine transporter length-polymorphic repeat (5-HTTLPR), SLC6A4 STin polymorphism, Tryptophan 5-hydroxylase 2 (TPH2) and Monoamine oxidase A (MAOA)) whilst for the other five (5-hydroxytryptamine receptor 2A (HTR2A), Dopamine Receptor D4 (DRD4), Oxytocin receptor (OXTR), Arginine vasopressin receptor 1A (AVPR1a), Opioid receptor mu(μ) 1 (OPRM1)) SNPs were analysed. STin genotype, DRD4 haplotype and OXTR haplotype were significantly associated with the cognitive and observational measures of behaviour associated with wellbeing and survival. Genotype for 5-HTTLPR, STin and AVPR1a, and haplotype for HTR2A, DRD4 and OXTR were significantly associated with the duration of behaviours including fear and anxiety. Understanding the biological underpinnings of individual variation in negative emotion (e.g., fear and anxiety), together with their impact on social behaviour (e.g., social attention including vigilance for threat) has application for managing primate populations in the wild and captivity, as well as potential translational application for understanding of the genetic basis of emotions in humans.
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Affiliation(s)
- Emmeline R. I. Howarth
- Research Centre in Brain and Behaviour, School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, United Kingdom
- Department of Biological Sciences, University of Chester, Chester, United Kingdom
| | - Isabelle D. Szott
- Research Centre in Brain and Behaviour, School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Claire L. Witham
- Centre for Macaques, Harwell Institute, Medical Research Council, Salisbury, United Kingdom
| | - Craig S. Wilding
- Biodiversity and Conservation Group, School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, United Kingdom
| | - Emily J. Bethell
- Research Centre in Brain and Behaviour, School of Biological and Environmental Sciences, Liverpool John Moores University, Liverpool, United Kingdom
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Grant CW, Wilton AR, Kaddurah-Daouk R, Skime M, Biernacka J, Mayes T, Carmody T, Wang L, Lazaridis K, Weinshilboum R, Bobo WV, Trivedi MH, Croarkin PE, Athreya AP. Network science approach elucidates integrative genomic-metabolomic signature of antidepressant response and lifetime history of attempted suicide in adults with major depressive disorder. Front Pharmacol 2022; 13:984383. [PMID: 36263124 PMCID: PMC9573988 DOI: 10.3389/fphar.2022.984383] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 08/15/2022] [Indexed: 11/13/2022] Open
Abstract
Background: Individuals with major depressive disorder (MDD) and a lifetime history of attempted suicide demonstrate lower antidepressant response rates than those without a prior suicide attempt. Identifying biomarkers of antidepressant response and lifetime history of attempted suicide may help augment pharmacotherapy selection and improve the objectivity of suicide risk assessments. Towards this goal, this study sought to use network science approaches to establish a multi-omics (genomic and metabolomic) signature of antidepressant response and lifetime history of attempted suicide in adults with MDD. Methods: Single nucleotide variants (SNVs) which associated with suicide attempt(s) in the literature were identified and then integrated with a) p180-assayed metabolites collected prior to antidepressant pharmacotherapy and b) a binary measure of antidepressant response at 8 weeks of treatment using penalized regression-based networks in 245 'Pharmacogenomics Research Network Antidepressant Medication Study (PGRN-AMPS)' and 103 'Combining Medications to Enhance Depression Outcomes (CO-MED)' patients with major depressive disorder. This approach enabled characterization and comparison of biological profiles and associated antidepressant treatment outcomes of those with (N = 46) and without (N = 302) a self-reported lifetime history of suicide attempt. Results: 351 SNVs were associated with suicide attempt(s) in the literature. Intronic SNVs in the circadian genes CLOCK and ARNTL (encoding the CLOCK:BMAL1 heterodimer) were amongst the top network analysis features to differentiate patients with and without a prior suicide attempt. CLOCK and ARNTL differed in their correlations with plasma phosphatidylcholines, kynurenine, amino acids, and carnitines between groups. CLOCK and ARNTL-associated phosphatidylcholines showed a positive correlation with antidepressant response in individuals without a prior suicide attempt which was not observed in the group with a prior suicide attempt. Conclusion: Results provide evidence for a disturbance between CLOCK:BMAL1 circadian processes and circulating phosphatidylcholines, kynurenine, amino acids, and carnitines in individuals with MDD who have attempted suicide. This disturbance may provide mechanistic insights for differential antidepressant pharmacotherapy outcomes between patients with MDD with versus without a lifetime history of attempted suicide. Future investigations of CLOCK:BMAL1 metabolic regulation in the context of suicide attempts may help move towards biologically-augmented pharmacotherapy selection and stratification of suicide risk for subgroups of patients with MDD and a lifetime history of attempted suicide.
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Affiliation(s)
- Caroline W. Grant
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, United States
| | - Angelina R. Wilton
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, United States
- Department of Molecular and Integrative Physiology, University of Illinois at Urbana-Champaign, Urbana, IL, United States
| | - Rima Kaddurah-Daouk
- Department of Psychiatry and Behavioral Sciences, Department of Medicine, Duke Institute for Brain Sciences, Duke University, Durham, NC, United States
| | - Michelle Skime
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, United States
| | - Joanna Biernacka
- Department of Quantitative Health Sciences, Mayo Clinic, Rochester, MN, United States
| | - Taryn Mayes
- Peter O’Donnell Jr. Brain Institute and the Department of Psychiatry at the University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Thomas Carmody
- Department Population and Data Sciences, University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Liewei Wang
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, United States
| | - Konstantinos Lazaridis
- Department of Internal Medicine, Division of Gastroenterology and Hepatology, Mayo Clinic, Rochester, MN, United States
| | - Richard Weinshilboum
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, United States
| | - William V. Bobo
- Department of Psychiatry and Psychology, Mayo Clinic, Jacksonville, FL, United States
| | - Madhukar H. Trivedi
- Peter O’Donnell Jr. Brain Institute and the Department of Psychiatry at the University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Paul E. Croarkin
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, United States
| | - Arjun P. Athreya
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic, Rochester, MN, United States
- Department of Psychiatry and Psychology, Mayo Clinic, Rochester, MN, United States
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Sundaresan R, Mariyappan V, Chen SM, Keerthi M, Ramachandran R. Electrochemical sensor for detection of tryptophan in the milk sample based on MnWO4 nanoplates encapsulated RGO nanocomposite. Colloids Surf A Physicochem Eng Asp 2021. [DOI: 10.1016/j.colsurfa.2021.126889] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Abstract
Mutations in the genes coding for tryptophan-hydrolase-2 and the scaffold protein FKBP5 are associated with an increased risk of suicide. The mutation in both cases enhances the enzymatic activity of glycogen synthase kinase-3 (GSK3). Conversely, anti-suicidal medications, such as lithium, clozapine, and ketamine, indirectly inhibit the activity of GSK3. When GSK3 is active, it promotes the metabolic removal of the transcription factor NRF2 (nuclear factor erythroid 2-related factor-2), which suppresses the transcription of multiple genes that encode anti-oxidative and anti-inflammatory proteins. Notably, several suicide-biomarkers bear witness to an ongoing inflammatory process. Moreover, alterations in serum lipid levels measured in suicidal individuals are mirrored by data obtained in mice with genetic deletion of the NRF2 gene. Inflammation is presumably causally related to both dysphoria and anger, two factors relevant for suicide ideation and attempt. Preventing the catabolism of NRF2 could be a strategy to obtain novel suicide-prophylactic medications. Possible candidates are minocycline and nicotinic-α7 agonists. The antibiotic minocycline indirectly activates NRF2-transcriptional activity, whereas the activation of nicotinic-α7 receptors indirectly inhibits GSK3.
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Tesoro-Cruz E, Oviedo N, Manuel-Apolinar L, Orozco-Suárez S, Pérez de la Mora M, Martínez-Pérez G, Guerra-Castillo FX, Aguirre-Alvarado C, Bekker-Méndez VC. Ophthalmic Administration of a DNA Plasmid Harboring the Murine Tph2 Gene: Evidence of Recombinant Tph2-FLAG in Brain Structures. Mol Biotechnol 2020; 62:200-209. [PMID: 32030628 DOI: 10.1007/s12033-020-00239-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Tryptophan hydroxylase-type 2 (Tph2) is the first rate-limiting step in the biosynthesis of serotonin (5-HT) in the brain. The ophthalmic administration (Op-Ad) is a non-invasive method that allows delivering genetic vehicles through the eye and reaches the brain. Here, the murine Tph2 gene was cloned in a non-viral vector (pIRES-hrGFP-1a), generating pIRES-hrGFP-1a-Tph2, plus the FLAG-tag. Recombinant Tph2-FLAG was detected and tested in vitro and in vivo, where 25 μg of pIRES-hrGFP-1a-Tph2-FLAG was Op-Ad to mice. The construct was capable of expressing and producing the recombinant Tph2-FLAG in vitro and in vivo. The in vivo assays showed that the construct efficiently crossed the Hemato-Ocular Barrier and the Blood-Brain Barrier, reached brain cells, passed the optical nerves, and transcribed mRNA-Tph2-FLAG in different brain areas. The recombinant Tph2-FLAG was observed in amygdala and brainstem, mainly in raphe dorsal and medial. Relative Tph2 expression of threefold over basal level was recorded three days after Op-Ad. These results demonstrated that pIRES-hrGFP-Tph2-FLAG, administrated through the eyes was capable of reaching the brain, transcribing, and translating Tph2. In conclusion, this study showed the feasibility of delivering therapeutic genes, such as the Tph2, the first enzyme, rate-limiting step in the 5-HT biosynthesis.
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Affiliation(s)
- Emiliano Tesoro-Cruz
- Unidad de Investigación Biomédica en Infectología e Inmunología, Hospital de Infectología, Centro Médico Nacional "La Raza", IMSS, Paseo de las Jacarandas s/n esquina Calzada Vallejo, Col. La Raza, C.P. 02990, Mexico City, Mexico.
| | - Norma Oviedo
- Unidad de Investigación Biomédica en Infectología e Inmunología, Hospital de Infectología, Centro Médico Nacional "La Raza", IMSS, Paseo de las Jacarandas s/n esquina Calzada Vallejo, Col. La Raza, C.P. 02990, Mexico City, Mexico.
| | - Leticia Manuel-Apolinar
- Unidad de Investigación Médica en Enfermedades Endocrinas, UMAE, Hospital de Especialidades, Centro Médico Nacional "Siglo XXI", IMSS, Mexico City, Mexico
| | - Sandra Orozco-Suárez
- Unidad de Investigación Médica en Enfermedades Neurológicas, UMAE, Hospital de Especialidades, Centro Médico Nacional "Siglo XXI", IMSS, Mexico City, Mexico
| | - Miguel Pérez de la Mora
- Division of Neuroscience, Instituto de Fisiología Celular, Universidad Nacional Autónoma de México, UNAM, Mexico City, Mexico
| | - Gloria Martínez-Pérez
- Unidad de Investigación Biomédica en Infectología e Inmunología, Hospital de Infectología, Centro Médico Nacional "La Raza", IMSS, Paseo de las Jacarandas s/n esquina Calzada Vallejo, Col. La Raza, C.P. 02990, Mexico City, Mexico
| | - Francisco Xavier Guerra-Castillo
- Unidad de Investigación Biomédica en Infectología e Inmunología, Hospital de Infectología, Centro Médico Nacional "La Raza", IMSS, Paseo de las Jacarandas s/n esquina Calzada Vallejo, Col. La Raza, C.P. 02990, Mexico City, Mexico
| | - Charmina Aguirre-Alvarado
- Unidad de Investigación Biomédica en Infectología e Inmunología, Hospital de Infectología, Centro Médico Nacional "La Raza", IMSS, Paseo de las Jacarandas s/n esquina Calzada Vallejo, Col. La Raza, C.P. 02990, Mexico City, Mexico
| | - Vilma Carolina Bekker-Méndez
- Unidad de Investigación Biomédica en Infectología e Inmunología, Hospital de Infectología, Centro Médico Nacional "La Raza", IMSS, Paseo de las Jacarandas s/n esquina Calzada Vallejo, Col. La Raza, C.P. 02990, Mexico City, Mexico
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Rao S, Shi M, Han X, Lam MHB, Chien WT, Zhou K, Liu G, Wing YK, So HC, Waye MMY. Genome-wide copy number variation-, validation- and screening study implicates a new copy number polymorphism associated with suicide attempts in major depressive disorder. Gene 2020; 755:144901. [PMID: 32554045 DOI: 10.1016/j.gene.2020.144901] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2019] [Revised: 05/08/2020] [Accepted: 06/10/2020] [Indexed: 12/22/2022]
Abstract
BACKGROUND The genetic basis of suicide attempts (SA) remains unclear. Especially the role of copy number variations (CNVs) remains to be elucidated. The present study aimed to identify susceptibility variants associated with SA among Chinese with major depressive disorder (MDD), covering both CNVs and single-nucleotide polymorphisms (SNPs). METHODS We conducted a genome-wide association study (GWAS) on MDD patients with and without SA and top results were tested in a replication study. A genome-wide CNV study was also performed. Subsequently, a validation assay using qRT-PCR technology was performed to confirm any associated CNVs and then applied to the entire cohort to examine the association. RESULTS Although GWAS did not identify any SNPs reaching genome-wide significance, we identified TPH2 as the top susceptibility gene (p-value = 2.75e-05) in gene-based analysis, which is a strong biological candidate for its role in the serotonergic system. As for CNV analysis, we found that the global rate of CNV was higher in SA than that in non-SA subjects (p-value = 0.023). Genome-wide CNV study revealed an SA-associated CNV region that achieved genome-wide significance (corrected p-value = 0.014). The associated CNV was successfully validated with a more rigorous qRT-PCR assay and identified to be a common variant in this cohort. Its deletion rate was higher in SA subjects [OR = 2.05 (1.02-4.12), adjusted p-value = 0.045]. Based on the GTEx database, genetic variants that probed this CNV were significantly associated with the expression level of ZNF33B in two brain regions (p-value < 4.2e-05). In stratified analysis, the CNV showed a significant effect [OR = 2.58 (1.06-6.27), p-value = 0.039] in those with high neuroticism but not in those with average or low neuroticism. CONCLUSIONS We identified a new common CNV likely involved in the etiology of SA. This finding sheds light on an important role of common CNVs in the pathophysiology of SA, suggesting a new promising avenue for investigating its genetic architecture.
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Affiliation(s)
- Shitao Rao
- The Nethersole School of Nursing, The Croucher Laboratory for Human Genomics, China; Department of Psychiatry, N.T, Hong Kong Special Administrative Region; School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, N.T, Hong Kong Special Administrative Region
| | - Mai Shi
- School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, N.T, Hong Kong Special Administrative Region
| | - Xinyu Han
- College of Food and Biological Engineering, Jimei University, Xiamen, Fujian, China
| | - Marco Ho Bun Lam
- Department of Psychiatry, N.T, Hong Kong Special Administrative Region
| | - Wai Tong Chien
- The Nethersole School of Nursing, The Croucher Laboratory for Human Genomics, China
| | - Keying Zhou
- Shenzhen People's Hospital, The 2nd Clinical Medical College of Jinan University, The 1st Affiliated Hospital of Southern University of Science and Technology, Shenzhen, China
| | - Guangming Liu
- College of Food and Biological Engineering, Jimei University, Xiamen, Fujian, China
| | - Yun Kwok Wing
- Department of Psychiatry, N.T, Hong Kong Special Administrative Region
| | - Hon-Cheong So
- Department of Psychiatry, N.T, Hong Kong Special Administrative Region; School of Biomedical Sciences, Faculty of Medicine, The Chinese University of Hong Kong, N.T, Hong Kong Special Administrative Region; KIZ-CUHK Joint Laboratory of Bioresources and Molecular Research of Common Diseases, Kunming Institute of Zoology and The Chinese University of Hong Kong, China; CUHK Shenzhen Research Institute, Shenzhen, China; Brain and Mind Institute, The Chinese University of Hong Kong, Hong Kong Special Administrative Region.
| | - Mary Miu Yee Waye
- The Nethersole School of Nursing, The Croucher Laboratory for Human Genomics, China.
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Plans L, Barrot C, Nieto E, Rios J, Schulze TG, Papiol S, Mitjans M, Vieta E, Benabarre A. Association between completed suicide and bipolar disorder: A systematic review of the literature. J Affect Disord 2019; 242:111-122. [PMID: 30173059 DOI: 10.1016/j.jad.2018.08.054] [Citation(s) in RCA: 125] [Impact Index Per Article: 25.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 07/25/2018] [Accepted: 08/12/2018] [Indexed: 02/06/2023]
Abstract
BACKGROUND Completed suicide is a major cause of death in bipolar disorder (BD) patients. OBJECTIVE The aim of this paper is to provide an overall review of the existing literature of completed suicide in BD patients, including clinical and genetic data DATA SOURCES: We performed a systematic review of English and non-English articles published on MEDLINE/PubMed, PsycInfo and Cochrane database (1970-2017). Additional studies were identified by contacting clinical experts, searching bibliographies, major textbooks and website of World Health Organization. Initially we did a broad search for the association of bipolar disorder and suicide and we were narrowing the search in terms included "bipolar disorder" and "completed suicide". STUDY SELECTION Inclusion criteria were articles about completed suicide in patients with BD. Articles exclusively focusing on suicide attempts and suicidal behaviour have been excluded. We used PRISMA (Preferred Reporting Items for Systematic reviews and Meta-Analyses) consensus for drafting this systematic review. RESULTS The initial search generated 2806 articles and a total of 61 meeting our inclusion criteria. We reviewed epidemiological data, genetic factors, risk factors and treatment of completed suicide in BD. Suicide rates in BD vary between studies but our analyses show that they are approximately 20-30-fold greater than in general population. The highest risk of successful suicide was observed in BD-II subjects. The heritability of completed suicide is about 40% and some genes related to major neurotransmitter systems have been associated with suicide. Lithium is the only treatment that has shown anti-suicide potential. LIMITATIONS The most important limitation of the present review is the limited existing literature on completed suicide in BD. CONCLUSIONS BD patients are at high risk for suicide. It is possible to identify some factors related to completed suicide, such as early onset, family history of suicide among first-degree relatives, previous attempted suicides, comorbidities and treatment. However it is necessary to promote research on this serious health problem.
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Affiliation(s)
- L Plans
- Mental Health Division of Althaia, Xarxa Assistencial Universitària de Manresa, Catalonia, Spain
| | - C Barrot
- Forensic Genetic Laboratori, University of Barcelona, Catalonia, Spain
| | - E Nieto
- Mental Health Division of Althaia, Xarxa Assistencial Universitària de Manresa, Catalonia, Spain
| | - J Rios
- Universitat Autònoma de Barcelona, Laboratório de Bioestatística e Epidemiologia, Barcelona, Spain; Hospital Clínic, IDIBAPS, Bioestadística y Plataforma de Gestión de Datos, Barcelona, Spain
| | - T G Schulze
- Institute of Psychiatric Phenomics and Genomics (IPPG), University Hospital, Ludwig Maximilian University, Munich, Germany
| | - S Papiol
- Institute of Psychiatric Phenomics and Genomics (IPPG), University Hospital, Ludwig Maximilian University, Munich, Germany; Department of Psychiatry and Psychotherapy, University Hospital, Ludwig Maximilian University, Munich, Germany
| | - M Mitjans
- Clinical Neuroscience, Max Planck Institute of Experimental Medicine, Göttingen, Germany
| | - E Vieta
- Bipolar Disorder Program, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, Barcelona, Catalonia, Spain.
| | - A Benabarre
- Bipolar Disorder Program, Hospital Clinic, University of Barcelona, IDIBAPS, CIBERSAM, Barcelona, Catalonia, Spain
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TPH2 polymorphisms across the spectrum of psychiatric morbidity: A systematic review and meta-analysis. Neurosci Biobehav Rev 2018; 92:29-42. [PMID: 29775696 DOI: 10.1016/j.neubiorev.2018.05.018] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/11/2018] [Accepted: 05/14/2018] [Indexed: 12/19/2022]
Abstract
Tryptophan hydroxylase 2 (TPH2) is the rate-limiting enzyme in brain serotonin synthesis. The TPH2 gene has frequently been investigated in relation to psychiatric morbidity. The aim of the present review is to integrate results from association studies between TPH2 single nucleotide polymorphisms (SNPs) and various psychiatric disorders, which we furthermore quantified with meta-analysis. We reviewed 166 studies investigating 69 TPH2 SNPs in a broad range of psychiatric disorders, including over 30,000 patients. According to our meta-analysis, TPH2 polymorphisms show strongest associations with mood disorders, suicide (attempt) and schizophrenia. Despite small effect sizes, we conclude that TPH2 SNPs in the coding and non-coding areas (rs4570625, rs11178997, rs11178998, rs10748185, rs1843809, rs4290270, rs17110747) are each associated with one or more psychopathological conditions. Our findings highlight the possible common serotonergic mechanisms of the investigated psychiatric disorders. Yet, the functional relevance of most TPH2 polymorphisms is unclear. Characterizing how exactly the different TPH2 variants influence the serotonergic neurotransmission is a next necessary step in understanding the psychiatric disorders where serotonin is implicated.
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Tondo L, Pompili M, Forte A, Baldessarini RJ. Suicide attempts in bipolar disorders: comprehensive review of 101 reports. Acta Psychiatr Scand 2016; 133:174-86. [PMID: 26555604 DOI: 10.1111/acps.12517] [Citation(s) in RCA: 83] [Impact Index Per Article: 10.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/29/2015] [Indexed: 12/24/2022]
Abstract
OBJECTIVE Assess reported risk of suicide attempts by patients with bipolar disorder (BD). METHOD Systematic searching yielded 101 reports from 22 countries (79 937 subjects). We analyzed for risk (%) and incidence rates (%/year) of attempts, comparing sex and diagnostic types, including by meta-analysis. RESULTS Attempt risk averaged 31.1% [CI: 27.9-34.3] of subjects, or 4.24 [3.78-4.70]%/year. In BD-I (43 studies) and BD-II subjects (30 studies), risks (29.9%, 31.4%) and incidence rates (4.01, 4.11%/year) were similar and not different by meta-analysis. Among women vs. men, risks (33.7% vs. 25.5%) and incidence (4.50 vs. 3.21%/year) were greater (also supported by meta-analysis: RR = 1.35 [CI: 1.25-1.45], P < 0.0001). Neither measure was related to reporting year, % women/study, or to onset or current age. Risks were greater with longer exposure, whereas incidence rates decreased with longer time at risk, possibly through 'dilution' by longer exposure. CONCLUSION This systematic update of international experience underscores high risks of suicide attempts among patients with BD (BD-I = BD-II; women > men). Future studies should routinely include exposure times and incidence rates by diagnostic type and sex for those who attempt suicide or not.
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Affiliation(s)
- L Tondo
- International Consortium for Bipolar & Psychotic Disorder Research, McLean Hospital, Belmont, MA, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA, USA.,Lucio Bini Mood Disorder Centers, Cagliari and, Rome, Italy
| | - M Pompili
- International Consortium for Bipolar & Psychotic Disorder Research, McLean Hospital, Belmont, MA, USA.,NESMOS, Sant'Andrea Medical Center, La Sapienza University of Rome, Rome, Italy
| | - A Forte
- International Consortium for Bipolar & Psychotic Disorder Research, McLean Hospital, Belmont, MA, USA.,NESMOS, Sant'Andrea Medical Center, La Sapienza University of Rome, Rome, Italy
| | - R J Baldessarini
- International Consortium for Bipolar & Psychotic Disorder Research, McLean Hospital, Belmont, MA, USA.,Department of Psychiatry, Harvard Medical School, Boston, MA, USA
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Mirkovic B, Laurent C, Podlipski MA, Frebourg T, Cohen D, Gerardin P. Genetic Association Studies of Suicidal Behavior: A Review of the Past 10 Years, Progress, Limitations, and Future Directions. Front Psychiatry 2016; 7:158. [PMID: 27721799 PMCID: PMC5034008 DOI: 10.3389/fpsyt.2016.00158] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/21/2016] [Accepted: 08/31/2016] [Indexed: 12/21/2022] Open
Abstract
Suicidal behaviors (SBs), which range from suicidal ideation to suicide attempts and completed suicide, represent a fatal dimension of mental ill-health. The involvement of genetic risk factors in SB is supported by family, twin, and adoption studies. The aim of this paper is to review recent genetic association studies in SBs including (i) case-control studies, (ii) family-based association studies, and (iii) genome-wide association studies (GWAS). Various studies on genetic associations have tended to suggest that a number of genes [e.g., tryptophan hydroxylase, serotonin receptors and transporters, or brain-derived neurotrophic factors (BDNFs)] are linked to SBs, but these findings are not consistently supported by the results obtained. Although the candidate-gene approach is useful, it is hampered by the present state of knowledge concerning the pathophysiology of diseases. Interpretations of GWAS results are mostly hindered by a lack of annotation describing the functions of most variation throughout the genome. Association studies have addressed a wide range of single-nucleotide polymorphisms in numerous genes. We have included 104 such studies, of which 10 are family-based association studies and 11 are GWAS. Numerous meta-analyses of case-control studies have shown significant associations of SB with variants in the serotonin transporter gene (5-HTT or SLC6A4) and the tryptophan hydroxylase 1 gene (TPH1), but others report contradictory results. The gene encoding BDNF and its receptor (NTRK2) are also promising candidates. Only two of the GWAS showed any significant associations. Several pathways are mentioned in an attempt to understand the lack of reproducibility and the disappointing results. Consequently, we review and discuss here the following aspects: (i) sample characteristics and confounding factors; (ii) statistical limits; (iii) gene-gene interactions; (iv) gene, environment, and by time interactions; and (v) technological and theoretical limits.
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Affiliation(s)
- Bojan Mirkovic
- Department of Child and Adolescent Psychiatry, CHU Charles Nicolle, Rouen, France; INSERM Unit U1079, Genetics of Cancer and Neurogenetics, University of Rouen, Rouen, France; Department of Child and Adolescent Psychiatry, Hôpital Pitié-Salpêtrière, Paris, France
| | - Claudine Laurent
- Department of Child and Adolescent Psychiatry, Hôpital Pitié-Salpêtrière, Paris, France; ICM - Brain and Spine Institute, Hôpital Pitié-Salpêtrière - University Pierre and Marie Curie, Paris, France
| | | | - Thierry Frebourg
- INSERM Unit U1079, Genetics of Cancer and Neurogenetics, University of Rouen, Rouen, France; Department of Genetics, CHU Charles Nicolle, Rouen, France
| | - David Cohen
- Department of Child and Adolescent Psychiatry, Hôpital Pitié-Salpêtrière, Paris, France; UMR 7222, Institute for Intelligent Systems and Robotics, University Pierre and Marie Curie, Paris, France
| | - Priscille Gerardin
- Department of Child and Adolescent Psychiatry, CHU Charles Nicolle, Rouen, France; Laboratoire Psy-NCA-EA-4700, University of Rouen, Rouen, France
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Schaffer A, Isometsä ET, Tondo L, Moreno DH, Sinyor M, Kessing LV, Turecki G, Weizman A, Azorin JM, Ha K, Reis C, Cassidy F, Goldstein T, Rihmer Z, Beautrais A, Chou YH, Diazgranados N, Levitt AJ, Zarate CA, Yatham L. Epidemiology, neurobiology and pharmacological interventions related to suicide deaths and suicide attempts in bipolar disorder: Part I of a report of the International Society for Bipolar Disorders Task Force on Suicide in Bipolar Disorder. Aust N Z J Psychiatry 2015; 49:785-802. [PMID: 26185269 PMCID: PMC5116383 DOI: 10.1177/0004867415594427] [Citation(s) in RCA: 81] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
OBJECTIVES Bipolar disorder is associated with elevated risk of suicide attempts and deaths. Key aims of the International Society for Bipolar Disorders Task Force on Suicide included examining the extant literature on epidemiology, neurobiology and pharmacotherapy related to suicide attempts and deaths in bipolar disorder. METHODS Systematic review of studies from 1 January 1980 to 30 May 2014 examining suicide attempts or deaths in bipolar disorder, with a specific focus on the incidence and characterization of suicide attempts and deaths, genetic and non-genetic biological studies and pharmacotherapy studies specific to bipolar disorder. We conducted pooled, weighted analyses of suicide rates. RESULTS The pooled suicide rate in bipolar disorder is 164 per 100,000 person-years (95% confidence interval = [5, 324]). Sex-specific data on suicide rates identified a 1.7:1 ratio in men compared to women. People with bipolar disorder account for 3.4-14% of all suicide deaths, with self-poisoning and hanging being the most common methods. Epidemiological studies report that 23-26% of people with bipolar disorder attempt suicide, with higher rates in clinical samples. There are numerous genetic associations with suicide attempts and deaths in bipolar disorder, but few replication studies. Data on treatment with lithium or anticonvulsants are strongly suggestive for prevention of suicide attempts and deaths, but additional data are required before relative anti-suicide effects can be confirmed. There were limited data on potential anti-suicide effects of treatment with antipsychotics or antidepressants. CONCLUSION This analysis identified a lower estimated suicide rate in bipolar disorder than what was previously published. Understanding the overall risk of suicide deaths and attempts, and the most common methods, are important building blocks to greater awareness and improved interventions for suicide prevention in bipolar disorder. Replication of genetic findings and stronger prospective data on treatment options are required before more decisive conclusions can be made regarding the neurobiology and specific treatment of suicide risk in bipolar disorder.
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Affiliation(s)
- Ayal Schaffer
- Task Force on Suicide, The International Society for Bipolar Disorders (ISBD), Pittsburgh, PA, USA; Mood and Anxiety Disorders Program, Department of Psychiatry, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Erkki T Isometsä
- Department of Psychiatry, Institute of Clinical Medicine, University of Helsinki, Helsinki, Finland
| | - Leonardo Tondo
- Lucio Bini Center, Cagliari, Italy; Harvard Medical School, Boston, MA, USA; McLean Hospital, Belmont, MA, USA
| | - Doris H Moreno
- Section of Psychiatric Epidemiology and Mood Disorders Unit, Department and Institute of Psychiatry, University of São Paulo, São Paulo, Brazil
| | - Mark Sinyor
- Department of Psychiatry, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Lars Vedel Kessing
- Psychiatric Center Copenhagen, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark
| | - Gustavo Turecki
- Research and Academic Affairs, Department of Psychiatry, McGill University, Montréal, QC, Canada; McGill Group for Suicide Studies, Montréal, QC, Canada; Depressive Disorders Program, Douglas Institute, Montréal, QC, Canada; Departments of Psychiatry, Human Genetics, and Neurology and Neurosurgery, McGill University, Montréal, QC, Canada
| | - Abraham Weizman
- Laboratory of Biological Psychiatry, The Felsenstein Medical Research Center, Petah Tikva, Israel; Research Unit, Geha Mental Health Center, Petah Tikva, Israel; Department of Psychiatry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Jean-Michel Azorin
- Department of Adult Psychiatry, Sainte Marguerite Hospital, Marseille, France; University of Aix-Marseille II, Marseille, France
| | - Kyooseob Ha
- Mood Disorders Clinic and Affective Neuroscience Laboratory, Seoul National University Bundang Hospital, Seongnam, Republic of Korea; Korea Association for Suicide Prevention, Seoul, Republic of Korea
| | - Catherine Reis
- Mood and Anxiety Disorders Program, Department of Psychiatry, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
| | - Frederick Cassidy
- Division of Brain Stimulation and Neurophysiology, Department of Psychiatry and Behavioural Sciences, Duke University, Durham, NC, USA
| | - Tina Goldstein
- Department of Child and Adolescent Psychiatry, Western Psychiatric Institute and Clinic, School of Medicine, University of Pittsburgh, Pittsburgh, PA, USA
| | - Zoltán Rihmer
- Department of Clinical and Theoretical Mental Health, and Department of Psychiatry and Psychotherapy, Semmelweis Medical University, Budapest, Hungary
| | - Annette Beautrais
- Department of Emergency Medicine, Yale School of Medicine, Yale University, New Haven, CT, USA
| | - Yuan-Hwa Chou
- Section of Psychosomatic Medicine, Department of Psychiatry, Taipei Veterans General Hospital, National Yang-Ming University, Taipei, Taiwan
| | - Nancy Diazgranados
- Laboratory of Clinical and Translational Studies, National Institute of Alcohol Abuse and Alcoholism, Bethesda, MD, USA
| | - Anthony J Levitt
- Department of Psychiatry, Sunnybrook Health Sciences Centre, Toronto, ON, Canada; Department of Psychiatry, University of Toronto, Toronto, ON, Canada
| | - Carlos A Zarate
- Experimental Therapeutics & Pathophysiology Branch, Division of Intramural Research Programs, National Institute of Mental Health, Bethesda, MD, USA
| | - Lakshmi Yatham
- Department of Psychiatry, University of British Columbia, Vancouver, BC, Canada
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Clements C, Jones S, Morriss R, Peters S, Cooper J, While D, Kapur N. Self-harm in bipolar disorder: findings from a prospective clinical database. J Affect Disord 2015; 173:113-9. [PMID: 25462404 DOI: 10.1016/j.jad.2014.10.012] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/29/2014] [Revised: 10/06/2014] [Accepted: 10/07/2014] [Indexed: 11/30/2022]
Abstract
BACKGROUND People with bipolar disorder may be at increased risk of suicidal behaviour but there are few prospective studies of self-harm in this group. Our aim was to describe the characteristics and outcome (in terms of repetition) for individuals with bipolar disorder who presented to hospital following self-harm. METHOD A nested case-control study was carried out using a large prospective self-harm database (1997-2010) in Manchester, UK. Characteristics of bipolar cases and non-bipolar controls were compared using conditional logistic regression, and outcomes were assessed via survival analyses. RESULTS Bipolar cases (n=103) were more likely to repeat self-harm than controls (n=515): proportion with at least one repeat episode 58% vs. 25%, HR 3.08 (95% CI; 2.2-4.18). Previous self-harm, unemployment, contact with psychiatric services and sleep disturbance were all more common in cases than controls. Even after adjustment for known risk factors, the risk of repetition remained higher in the bipolar group (adjusted HR 1.68; 95% CI; 1.10-2.56). LIMITATIONS The study covers cases from hospital sites in Manchester, UK, and therefore only includes self-harm that was serious enough to present at hospital emergency departments. CONCLUSION People with bipolar disorder who self-harm have a higher risk of repetition than people who self-harm more generally. Adjusting for some known risk factors moderated, but did not abolish, this finding. Other factors, such as impulsivity, may also be important.
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Affiliation(s)
- Caroline Clements
- Centre for Mental Health and Risk, Institute of Brain, Behaviour and Mental Health, The University of Manchester, UK.
| | - Steve Jones
- Spectrum Centre for Mental Health Research, School of Health and Medicine, Lancaster University, UK
| | - Richard Morriss
- Department of Psychiatry and Community Mental Health, The University of Nottingham, UK
| | - Sarah Peters
- School of Psychological Sciences, The University of Manchester, UK
| | - Jayne Cooper
- Centre for Mental Health and Risk, Institute of Brain, Behaviour and Mental Health, The University of Manchester, UK
| | - David While
- Centre for Mental Health and Risk, Institute of Brain, Behaviour and Mental Health, The University of Manchester, UK
| | - Navneet Kapur
- Centre for Mental Health and Risk, Institute of Brain, Behaviour and Mental Health, The University of Manchester, UK
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Patrick RP, Ames BN. Vitamin D and the omega-3 fatty acids control serotonin synthesis and action, part 2: relevance for ADHD, bipolar disorder, schizophrenia, and impulsive behavior. FASEB J 2015; 29:2207-22. [PMID: 25713056 DOI: 10.1096/fj.14-268342] [Citation(s) in RCA: 272] [Impact Index Per Article: 30.2] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2014] [Accepted: 02/04/2015] [Indexed: 01/22/2023]
Abstract
Serotonin regulates a wide variety of brain functions and behaviors. Here, we synthesize previous findings that serotonin regulates executive function, sensory gating, and social behavior and that attention deficit hyperactivity disorder, bipolar disorder, schizophrenia, and impulsive behavior all share in common defects in these functions. It has remained unclear why supplementation with omega-3 fatty acids and vitamin D improve cognitive function and behavior in these brain disorders. Here, we propose mechanisms by which serotonin synthesis, release, and function in the brain are modulated by vitamin D and the 2 marine omega-3 fatty acids, eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA). Brain serotonin is synthesized from tryptophan by tryptophan hydroxylase 2, which is transcriptionally activated by vitamin D hormone. Inadequate levels of vitamin D (∼70% of the population) and omega-3 fatty acids are common, suggesting that brain serotonin synthesis is not optimal. We propose mechanisms by which EPA increases serotonin release from presynaptic neurons by reducing E2 series prostaglandins and DHA influences serotonin receptor action by increasing cell membrane fluidity in postsynaptic neurons. We propose a model whereby insufficient levels of vitamin D, EPA, or DHA, in combination with genetic factors and at key periods during development, would lead to dysfunctional serotonin activation and function and may be one underlying mechanism that contributes to neuropsychiatric disorders and depression. This model suggests that optimizing vitamin D and marine omega-3 fatty acid intake may help prevent and modulate the severity of brain dysfunction.
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Affiliation(s)
- Rhonda P Patrick
- Nutrition and Metabolism Center, Children's Hospital Oakland Research Institute, Oakland, California, USA
| | - Bruce N Ames
- Nutrition and Metabolism Center, Children's Hospital Oakland Research Institute, Oakland, California, USA
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15
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Xiang B, Yang Z, Lin Y, Guan L, Li X, Deng W, Jiang Z, Lao G, Wang Q, Hao X, Liu X, Wang Y, Zhao L, Ma X, Li T, Cao L, Hu X. Genes in the serotonin pathway are associated with bipolar affective disorder in a Han Chinese population. Neurosci Bull 2014; 30:33-42. [PMID: 24136241 PMCID: PMC5562572 DOI: 10.1007/s12264-013-1380-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2013] [Accepted: 02/10/2013] [Indexed: 02/05/2023] Open
Abstract
Serotonin plays an important role in mood regulation, but the involvement of serotonin pathway genes in the development of bipolar I disorder (BP-I), a mood disorder, is not clear. We selected 21 single-nucleotide polymorphisms (SNPs) within the HTR2A gene, 8 within the SLC6A4 gene and 23 within the TPH2 gene for genotyping using the GoldenGate genotyping assay. A total of 375 patients with BP-I and 475 normal controls were recruited. Two out of 21 SNPs (rs1475196 and rs9567747) in the HTR2A gene and 1/23 SNPs (rs17110566) in the TPH2 gene were significantly associated with BP-I, both genotype-wise and allele-wise. Furthermore, a specific haplotype in the HTR2A gene showed a significant association with BP-I. Our results indicate that the HTR2A and TPH2 genes in the serotonin pathway play important roles in susceptibility to BP-I.
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Affiliation(s)
- Bo Xiang
- State Key Laboratory of Biotherapy, Laboratory of Psychiatry Research, West China Hospital, Sichuan University, Chengdu, 610041 China
| | - Zhenxing Yang
- State Key Laboratory of Biotherapy, Laboratory of Psychiatry Research, West China Hospital, Sichuan University, Chengdu, 610041 China
| | - Yin Lin
- State Key Laboratory of Biotherapy, Laboratory of Psychiatry Research, West China Hospital, Sichuan University, Chengdu, 610041 China
- Mental Health Center, West China Hospital, Sichuan University, Chengdu, 610041 China
- Guangzhou Brain Hospital, Guangzhou, 510370 China
| | - Lijie Guan
- Guangzhou Brain Hospital, Guangzhou, 510370 China
| | - Xuan Li
- Guangzhou Brain Hospital, Guangzhou, 510370 China
| | - Wei Deng
- State Key Laboratory of Biotherapy, Laboratory of Psychiatry Research, West China Hospital, Sichuan University, Chengdu, 610041 China
- Mental Health Center, West China Hospital, Sichuan University, Chengdu, 610041 China
| | - Zeyu Jiang
- Guangzhou Brain Hospital, Guangzhou, 510370 China
| | - Guohui Lao
- Guangzhou Brain Hospital, Guangzhou, 510370 China
| | - Qiang Wang
- State Key Laboratory of Biotherapy, Laboratory of Psychiatry Research, West China Hospital, Sichuan University, Chengdu, 610041 China
- Mental Health Center, West China Hospital, Sichuan University, Chengdu, 610041 China
| | - Xiaoyu Hao
- Guangzhou Brain Hospital, Guangzhou, 510370 China
| | - Xiang Liu
- Mental Health Center, West China Hospital, Sichuan University, Chengdu, 610041 China
| | - Yingcheng Wang
- Mental Health Center, West China Hospital, Sichuan University, Chengdu, 610041 China
| | - Liansheng Zhao
- State Key Laboratory of Biotherapy, Laboratory of Psychiatry Research, West China Hospital, Sichuan University, Chengdu, 610041 China
| | - Xiaohong Ma
- State Key Laboratory of Biotherapy, Laboratory of Psychiatry Research, West China Hospital, Sichuan University, Chengdu, 610041 China
- Mental Health Center, West China Hospital, Sichuan University, Chengdu, 610041 China
| | - Tao Li
- State Key Laboratory of Biotherapy, Laboratory of Psychiatry Research, West China Hospital, Sichuan University, Chengdu, 610041 China
- Mental Health Center, West China Hospital, Sichuan University, Chengdu, 610041 China
| | - Liping Cao
- Guangzhou Brain Hospital, Guangzhou, 510370 China
| | - Xun Hu
- State Key Laboratory of Biotherapy, Laboratory of Psychiatry Research, West China Hospital, Sichuan University, Chengdu, 610041 China
- Biobank, West China Hospital, Sichuan University, Chengdu, 610041 China
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16
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Lin YL, Wang S. Prenatal lipopolysaccharide exposure increases depression-like behaviors and reduces hippocampal neurogenesis in adult rats. Behav Brain Res 2014; 259:24-34. [DOI: 10.1016/j.bbr.2013.10.034] [Citation(s) in RCA: 85] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 10/18/2013] [Accepted: 10/20/2013] [Indexed: 12/11/2022]
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17
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Serotonergic genes and suicide: a systematic review. Eur Neuropsychopharmacol 2013; 23:1125-42. [PMID: 23742855 DOI: 10.1016/j.euroneuro.2013.03.013] [Citation(s) in RCA: 99] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/25/2012] [Revised: 02/12/2013] [Accepted: 03/24/2013] [Indexed: 12/12/2022]
Abstract
Suicide is one of the leading causes of death in the world. Its aetiology is complex and diverse, however, epidemiological studies show that suicidal behavior is partly heritable. Neurobiological evidence implicates serotonergic dysfunction in suicidality, stimulating genetic research to focus on genes related to the serotonergic system. In this paper, we review evidence from studies examining the association between various serotonergic genes (Tryptophan Hydroxylase genes: TPH1; TPH2, Serotonin Transporter gene: 5-HTTLPR in SLC6A4, Serotonin Receptor genes: HTR1A, HTR2A, HTR1B, HTR2C and Monoamine Oxidase A gene: MAOA) and suicidal behavior. The data show associations between variation on the TPH1 gene and 5-HTTLPR gene and violent suicidal behavior in Caucasian populations, with the least inconsistencies. Results are mixed for the TPH2 gene and serotonin receptor genes, but for some genes, studies that include haplotypic analyses or that examine a larger coding region of the genes tend to provide more reliable results. Findings on endophenotypes of suicidality, such as aggression and impulsivity traits, show positive associations for the TPH1, HTR2A, and MAOA genes, but need further replication, since negative associations are also occasionally reported. Since genes can only partially explain suicidal risk, several studies during the past decade have tried to incorporate environmental factors in the susceptibility model. Studies to date show that variation on the 5-HTTLPR, MAOA and HTR2A gene can interact with stressful life events to increase risk for suicidal behavior. Limitations of case-control studies are discussed and future considerations are put forward with regard to endophenotypic measurements and gene-environment interactions.
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18
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Van Rheenen TE, Rossell SL. Genetic and neurocognitive foundations of emotion abnormalities in bipolar disorder. Cogn Neuropsychiatry 2013; 18:168-207. [PMID: 23088582 DOI: 10.1080/13546805.2012.690938] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
INTRODUCTION Bipolar Disorder (BD) is a serious mood disorder, the aetiology of which is still unclear. The disorder is characterised by extreme mood variability in which patients fluctuate between markedly euphoric, irritable, and elevated states to periods of severe depression. The current research literature shows that BD patients demonstrate compromised neurocognitive ability in addition to these mood symptoms. Viable candidate genes implicated in neurocognitive and socioemotional processes may explain the development of these core emotion abnormalities. Additionally, links between faulty neurocognition and impaired socioemotional ability complement genetic explanations of BD pathogenesis. This review examines associations between cognition indexing prefrontal neural regions and socioemotional impairments including emotion processing and regulation. A review of the effect of COMT and TPH2 on these functions is also explored. METHODS Major computer databases including PsycINFO, Google Scholar, and Medline were consulted in order to conduct a comprehensive review of the genetic and cognitive literature in BD. RESULTS This review determines that COMT and TPH2 genetic variants contribute susceptibility to abnormal prefrontal neurocognitive function which oversees the processing and regulation of emotion. This provides for greater understanding of some of the emotional and cognitive symptoms in BD. CONCLUSIONS Current findings in this direction show promise, although the literature is still in its infancy and further empirical research is required to investigate these links explicitly.
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Affiliation(s)
- Tamsyn E Van Rheenen
- Brain and Psychological Sciences Research Centre, Faculty of Life and Social Sciences, Swinburne University, and Cognitive Neuropsychology Laboratory, Monash Alfred Psychiatry Research Center, The Alfred Hospital, Melbourne, Australia.
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19
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The role of the serotonergic system at the interface of aggression and suicide. Neuroscience 2013; 236:160-85. [PMID: 23333677 DOI: 10.1016/j.neuroscience.2013.01.015] [Citation(s) in RCA: 70] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2012] [Revised: 01/01/2013] [Accepted: 01/05/2013] [Indexed: 02/07/2023]
Abstract
Alterations in serotonin (5-HT) neurochemistry have been implicated in the aetiology of all major neuropsychiatric disorders, ranging from schizophrenia to mood and anxiety-spectrum disorders. This review will focus on the multifaceted implications of 5-HT-ergic dysfunctions in the pathophysiology of aggressive and suicidal behaviours. After a brief overview of the anatomical distribution of the 5-HT-ergic system in the key brain areas that govern aggression and suicidal behaviours, the implication of 5-HT markers (5-HT receptors, transporter as well as synthetic and metabolic enzymes) in these conditions is discussed. In this regard, particular emphasis is placed on the integration of pharmacological and genetic evidence from animal studies with the findings of human experimental and genetic association studies. Traditional views postulated an inverse relationship between 5-HT and aggression and suicidal behaviours; however, ample evidence has shown that this perspective may be overly simplistic, and that such pathological manifestations may reflect alterations in 5-HT homoeostasis due to the interaction of genetic, environmental and gender-related factors, particularly during early critical developmental stages. The development of animal models that may capture the complexity of such interactions promises to afford a powerful tool to elucidate the pathophysiology of impulsive aggression and suicidability, and identify new effective therapies for these conditions.
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20
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Tryptophan hydroxylase 2 gene polymorphisms and poststroke anxiety disorders. J Affect Disord 2013; 144:179-82. [PMID: 22835848 DOI: 10.1016/j.jad.2012.05.017] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/30/2012] [Revised: 05/06/2012] [Accepted: 05/07/2012] [Indexed: 12/27/2022]
Abstract
BACKGROUND Anxiety is common in stroke survivors and may adversely affect recovery. Polymorphisms of tryptophan hydroxylase2 (THP2) gene have been shown to be associated with anxiety disorders and other affective disorders. This study was aimed to investigate the association of two polymorphisms of THP2 gene, rs4570625 and rs4565946, with poststroke anxiety disorders in a Han Chinese population. METHODS This case control study included 112poststroke anxiety patients and 246 non-anxious controls. All participants completed Hamilton Anxiety Rating Scale and DNA was extracted from blood and genotyped for the two polymorphisms of THP2 gene. RESULTS Results revealed that the G allele of rs4570625 was associated with the increased risk of poststroke anxiety. In the female subgroup, both the GG genotype and G allele were observed to be significantly higher in case than in control. No significant difference in genotype and allele frequencies of the rs4565946 was found between case and control. Haplotype analysis identified that patients with the G-C haplotype had significantly increased the risk of poststroke anxiety. LIMITATIONS More than 20 TPH2 polymorphisms have been detected, some of which are tightly-linked and may function together, only two SNPs of TPH2 were investigated in this study. CONCLUSIONS The findings suggest that these polymorphisms in TPH2 gene are involved in development of poststroke anxiety in the Han Chinese population.
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21
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Kennedy AP, Binder EB, Bowman D, Harenski K, Ely T, Cisler JM, Tripathi SP, VanNess S, Kilts CD. A common TPH2 haplotype regulates the neural processing of a cognitive control demand. Am J Med Genet B Neuropsychiatr Genet 2012; 159B:829-40. [PMID: 22915309 DOI: 10.1002/ajmg.b.32090] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2010] [Accepted: 07/11/2012] [Indexed: 11/10/2022]
Abstract
The monoamine neurotransmitter, serotonin, critically regulates the function of the cerebral cortex and is involved in psychiatric disorders. Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in the synthesis of serotonin with the neuron-specific TPH2 isoform present exclusively in the brain and encoded by the TPH2 gene on chromosome 12q21. The haplotype structure of TPH2 was defined for 16 single-nucleotide polymorphisms (SNPs) in a healthy subject population and a haplotype block analysis confirmed the presence of a six SNP haplotype in a yin configuration that has previously been associated with risk for suicidality, depression, and anxiety disorders. Functional magnetic resonance imaging (fMRI) was used to assess the influence of TPH2 variation on brain function related to cognitive control using the Multi-Source Interference Task (MSIT). The MSIT-related blood oxygen level-dependent (BOLD) response was increased with increasing copies of the TPH2 yin haplotype for the dorsal anterior cingulate cortex (dACC), right inferior frontal cortex (IFC), and anterior striatum. A functional connectivity analysis further revealed that increasing numbers of the TPH2 yin haplotype was associated with diminished functional coupling between the dACC and the right IFC, precentral gyrus, parietal cortex and dlPFC. A moderation analysis indicated that the relationship between neural processing networks and cognitive control was significantly modulated by allelic variation for the TPH2 yin haplotype. These findings suggest that the association of risk for psychiatric disorders with a common TPH2 yin haplotype is related to the inefficient functional engagement of cortical areas involved in cognitive control and alterations in the mode of functional connectivity of dACC pathways.
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Affiliation(s)
- Ashley P Kennedy
- Department of Psychiatry and Behavioral Sciences, Emory University, Atlanta, Georgia, USA
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22
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Gentile MT, Nawa Y, Lunardi G, Florio T, Matsui H, Colucci-D'Amato L. Tryptophan hydroxylase 2 (TPH2) in a neuronal cell line: modulation by cell differentiation and NRSF/rest activity. J Neurochem 2012; 123:963-70. [PMID: 22958208 DOI: 10.1111/jnc.12004] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2012] [Revised: 08/29/2012] [Accepted: 09/01/2012] [Indexed: 01/16/2023]
Abstract
Serotonin (5-HT) is a neurotransmitter involved in many aspects of the neuronal function. The synthesis of 5-HT is initiated by the hydroxylation of tryptophan, catalyzed by tryptophan hydroxylase (TPH). Two isoforms of TPH (TPH1 and TPH2) have been identified, with TPH2 almost exclusively expressed in the brain. Following TPH2 discovery, it was reported that polymorphisms of both gene and non-coding regions are associated with a spectrum of psychiatric disorders. Thus, insights into the mechanisms that specifically regulate TPH2 expression and its modulation by exogenous stimuli may represent a new therapeutic approach to modify serotonergic neurotransmission. To this aim, a CNS-originated cell line expressing TPH2 endogenously represents a valid model system. In this study, we report that TPH2 transcript and protein are modulated by neuronal differentiation in the cell line A1 mes-c-myc (A1). Moreover, we show luciferase activity driven by the human TPH2 promoter region and demonstrate that upon mutation of the NRSF/REST responsive element, the promoter activity strongly increases with cell differentiation. Our data suggest that A1 cells could represent a model system, allowing an insight into the mechanisms of regulation of TPH2 and to identify novel therapeutic targets in the development of drugs for the management of psychiatric disorders.
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Affiliation(s)
- Maria Teresa Gentile
- Department of Environmental, Biological and Pharmaceutical Sciences and Technology, Second University of Naples, Caserta, Italy
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Chistiakov DA, Kekelidze ZI, Chekhonin VP. Endophenotypes as a measure of suicidality. J Appl Genet 2012; 53:389-413. [DOI: 10.1007/s13353-012-0113-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2012] [Revised: 08/13/2012] [Accepted: 08/15/2012] [Indexed: 01/07/2023]
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24
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Berger SM, Weber T, Perreau-Lenz S, Vogt MA, Gartside SE, Maser-Gluth C, Lanfumey L, Gass P, Spanagel R, Bartsch D. A functional Tph2 C1473G polymorphism causes an anxiety phenotype via compensatory changes in the serotonergic system. Neuropsychopharmacology 2012; 37:1986-98. [PMID: 22491354 PMCID: PMC3398728 DOI: 10.1038/npp.2012.46] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The association of single-nucleotide polymorphisms (SNPs) in the human tryptophan hydroxylase 2 (TPH2) gene with anxiety traits and depression has been inconclusive. Observed inconsistencies might result from the fact that TPH2 polymorphisms have been studied in a genetically heterogeneous human population. A defined genetic background, control over environmental factors, and the ability to analyze the molecular and neurochemical consequences of introduced genetic alterations constitute major advantages of investigating SNPs in inbred laboratory mouse strains. To investigate the behavioral and neurochemical consequences of a functional C1473G SNP in the mouse Tph2 gene, we generated congenic C57BL/6N mice homozygous for the Tph2 1473G allele. The Arg(447) substitution in the TPH2 enzyme resulted in a significant reduction of the brain serotonin (5-HT) in vivo synthesis rate. Despite decreased 5-HT synthesis, we could detect neither a reduction of brain region-specific 5-HT concentrations nor changes in baseline and stress-induced 5-HT release using a microdialysis approach. However, using a [(35)S]GTP-γ-S binding assay and 5-HT(1A) receptor autoradiography, a functional desensitization of 5-HT(1A) autoreceptors could be identified. Furthermore, behavioral analysis revealed a distinct anxiety phenotype in homozygous Tph2 1473G mice, which could be reversed with chronic escitalopram treatment. Alterations in depressive-like behavior could not be detected under baseline conditions or after chronic mild stress. These findings provide evidence for an involvement of functional Tph2 polymorphisms in anxiety-related behaviors, which are likely not caused directly by alterations in 5-HT content or release but are rather due to compensatory changes during development involving functional desensitization of 5-HT(1A) autoreceptors.
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Affiliation(s)
- Stefan M Berger
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Tillmann Weber
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany,Department of Addictive Behavior and Addiction Medicine, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany,Department of Psychiatry and Psychotherapy, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Stephanie Perreau-Lenz
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Miriam A Vogt
- Department of Psychiatry and Psychotherapy, Research Group Animal Models in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Sarah E Gartside
- Institute of Neuroscience, The Medical School, Newcastle University, Newcastle upon Tyne, NE2 4HH, UK
| | - Christiane Maser-Gluth
- Steroid Laboratory, Department of Pharmacology, University of Heidelberg, Heidelberg, Germany
| | - Laurence Lanfumey
- INSERM UMRS894, CPN, Université Pierre and Marie Curie, Paris, France
| | - Peter Gass
- Department of Psychiatry and Psychotherapy, Research Group Animal Models in Psychiatry, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Rainer Spanagel
- Institute of Psychopharmacology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany
| | - Dusan Bartsch
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, Mannheim, Germany,Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim/Heidelberg University, J-5, 68159 Mannheim, Germany, Tel: +49 621 1703 6202, Fax: +49 621 1703 6205, E-mail:
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25
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Chen GL, Miller GM. Advances in tryptophan hydroxylase-2 gene expression regulation: new insights into serotonin-stress interaction and clinical implications. Am J Med Genet B Neuropsychiatr Genet 2012; 159B:152-71. [PMID: 22241550 PMCID: PMC3587664 DOI: 10.1002/ajmg.b.32023] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Serotonin (5-HT) modulates the stress response by interacting with the hormonal hypothalamic-pituitary-adrenal (HPA) axis and neuronal sympathetic nervous system (SNS). Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in 5-HT biosynthesis, and the recent identification of a second, neuron-specific TPH isoform (TPH2) opened up a new area of research. While TPH2 genetic variance has been linked to numerous behavioral traits and disorders, findings on TPH2 gene expression have not only reinforced, but also provided new insights into, the long-recognized but not yet fully understood 5-HT-stress interaction. In this review, we summarize advances in TPH2 expression regulation and its relevance to the stress response and clinical implications. Particularly, based on findings on rhesus monkey TPH2 genetics and other relevant literature, we propose that: (i) upon activation of adrenal cortisol secretion, the cortisol surge induces TPH2 expression and de novo 5-HT synthesis; (ii) the induced 5-HT in turn inhibits cortisol secretion by modulating the adrenal sensitivity to ACTH via the suprachiasmatic nuclei (SCN)-SNS-adrenal system, such that it contributes to the feedback inhibition of cortisol production; (iii) basal TPH2 expression or 5-HT synthesis, as well as early-life experience, influence basal cortisol primarily via the hormonal HPA axis; and (iv) 5'- and 3'-regulatory polymorphisms of TPH2 may differentially influence the stress response, presumably due to their differential roles in gene expression regulation. Our increasing knowledge of TPH2 expression regulation not only helps us better understand the 5-HT-stress interaction and the pathophysiology of neuropsychiatric disorders, but also provides new strategies for the treatment of stress-associated diseases.
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Affiliation(s)
- Guo-Lin Chen
- Harvard Medical School, New England Primate Research Center, Division of Neuroscience, Southborough, MA 01772-9102, USA.
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26
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Zhang X, Nicholls PJ, Laje G, Sotnikova TD, Gainetdinov RR, Albert PR, Rajkowska G, Stockmeier CA, Speer MC, Steffens DC, Austin MC, McMahon FJ, Krishnan KRR, Garcia-Blanco MA, Caron MG. A functional alternative splicing mutation in human tryptophan hydroxylase-2. Mol Psychiatry 2011; 16:1169-76. [PMID: 20856248 PMCID: PMC3021090 DOI: 10.1038/mp.2010.99] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The brain serotonergic system has an essential role in the physiological functions of the central nervous system and dysregulation of serotonin (5-HT) homeostasis has been implicated in many neuropsychiatric disorders. The tryptophan hydroxylase-2 (TPH2) gene is the rate-limiting enzyme in brain 5-HT synthesis, and thus is an ideal candidate gene for understanding the role of dysregulation of brain serotonergic homeostasis. Here, we characterized a common, but functional single-nucleotide polymorphism (SNP rs1386493) in the TPH2 gene, which decreases efficiency of normal RNA splicing, resulting in a truncated TPH2 protein (TPH2-TR) by alternative splicing. TPH2-TR, which lacks TPH2 enzyme activity, dominant-negatively affects full-length TPH2 function, causing reduced 5-HT production. The predicted mRNA for TPH2-TR is present in postmortem brain of rs1386493 carriers. The rs13864923 variant does not appear to be overrepresented in either global or multiplex depression cohorts. However, in combination with other gene variants linked to 5-HT homeostasis, this variant may exhibit important epistatic influences.
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Affiliation(s)
- X Zhang
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, USA.
| | - P J Nicholls
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
| | - G Laje
- Unit on Genetic Basis of Mood & Anxiety Disorders, National Institute of Mental Health, NIH, Bethesda, MD, USA
| | - T D Sotnikova
- Department of Cell Biology, Duke University Medical Center, Durham, NC, USA,Department of Neuroscience, Italian Institute of Technology, Genova, Italy
| | - R R Gainetdinov
- Department of Cell Biology, Duke University Medical Center, Durham, NC, USA,Department of Neuroscience, Italian Institute of Technology, Genova, Italy
| | - P R Albert
- OHRI (Neuroscience), University of Ottawa, Ottawa, ON, Canada
| | - G Rajkowska
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, USA
| | - C A Stockmeier
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, USA,Department of Psychiatry, Case Western Reserve University, Cleveland, OH, USA
| | - M C Speer
- Center for Human Genetics, Duke University Medical Center, Durham, NC, USA
| | - D C Steffens
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
| | - M C Austin
- Department of Psychiatry and Human Behavior, University of Mississippi Medical Center, Jackson, MS, USA
| | - F J McMahon
- Unit on Genetic Basis of Mood & Anxiety Disorders, National Institute of Mental Health, NIH, Bethesda, MD, USA
| | - K R R Krishnan
- Department of Psychiatry and Behavioral Sciences, Duke University Medical Center, Durham, NC, USA
| | - M A Garcia-Blanco
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Durham, NC, USA
| | - M G Caron
- Department of Cell Biology, Duke University Medical Center, Durham, NC, USA,Department of Cell Biology, 487 CARL Building, Box 3287, Duke University Medical Center Durham, NC 27710, USA. E-mail:
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Broekman BFP, Chan YH, Goh L, Fung D, Gluckman PD, Saw SM, Meaney MJ. Influence of birth weight on internalizing traits modulated by serotonergic genes. Pediatrics 2011; 128:e1250-8. [PMID: 21969281 DOI: 10.1542/peds.2010-3714] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
OBJECTIVE Fetal growth predicts childhood behavioral problems associated with brain serotonergic systems. We hypothesized that allelic variations in genes involved in serotonergic function would moderate associations between birth weight (BW) and internalizing traits in childhood. METHODS The Child Behavior Checklist was administered to 545 healthy Singaporean children at 8 to 12 years. BW, corrected for gestational age, and candidate single-nucleotide polymorphisms (SNPs) in the TPH2, HTR2A, and SCL6A4 genes were investigated. RESULTS There was no significant main effect of BW on internalizing T scores (F = 1.08; P = .36). After multiple corrections, significant main effects on internalizing T scores were found for HTR2A rs2296972 (adjusted: F = 2.85; P = .019) and HTR2A rs6313 (adjusted: F = 5.91; P = .0002). Significant interactions were found between BW and SNPs for the TPH2 gene (rs2171363: P = .008; rs7305115: P = .007) and the HTR2A gene (rs2770304: P = .001; rs6313: P = .026) for internalizing T scores. The CC genotype of TPH2 rs2171363, GG genotype of TPH2 rs7305115, CC genotype of HTR2A rs2770304, and CC genotype of HTR2A rs6313 were associated with reduced internalizing scores for children born in the quartile above the midpoint. No significant main effects or interactions were found for SCL6A4 SNPs. CONCLUSIONS These findings suggest that sequence variations in genes involved in serotonergic functions modulate relationships between BW and internalizing traits and might be candidates for plasticity mechanisms that determine individual differences in responses to environmental influences over the course of development.
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Affiliation(s)
- Birit F P Broekman
- Department of Psychological Medicine, National University Hospital, National University of Singapore, Singapore.
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Yosifova A, Mushiroda T, Kubo M, Takahashi A, Kamatani Y, Kamatani N, Stoianov D, Vazharova R, Karachanak S, Zaharieva I, Dimova I, Hadjidekova S, Milanova V, Madjirova N, Gerdjikov I, Tolev T, Poryazova N, O'Donovan MC, Owen MJ, Kirov G, Toncheva D, Nakamura Y. Genome-wide association study on bipolar disorder in the Bulgarian population. GENES BRAIN AND BEHAVIOR 2011; 10:789-97. [PMID: 21771265 DOI: 10.1111/j.1601-183x.2011.00721.x] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Bipolar disorder is a severe psychiatric disorder influenced by environmental and genetic factors. Genetic studies have implicated many variants in the disease's etiology but only few have been successfully replicated. We conducted a genome-wide association study (GWAS) on bipolar disorder in the Bulgarian population followed by a replication study of the top 100 single nucleotide polymorphisms (SNPs) showing the smallest P values. The GWAS was performed on 188 bipolar disorder patients and 376 control subjects genotyped on the Illumina 550 platform. The replication study was conducted on 122 patients and 328 controls. Although our study did not show any association P value that achieved genome-wide significance, and none of the top 100 SNPs reached the Bonferroni-corrected P value in the replication study, the plausible involvement of some variants cannot be entirely discarded. Three polymorphisms, rs8099939 [P = 2.12 × 10(-6), odds ratio (OR) = 1.95, 95% confidence interval (CI) = 1.43-2.67] in GRIK5, rs6122972 (P = 3.11 × 10(-6), OR = 2.02, 95% CI = 1.46-2.80) in PARD6B and rs2289700 (P = 9.14 × 10(-6), OR = 2.13, 95% CI = 1.53-2.95) in CTSH remained associated at a similar level after Mantel-Haenszel test for combining the results from the genome-wide and replication studies. A modest association was also detected for SNP rs1012053 (GWAS P = 4.50 × 10(-2)) in DGKH, which has already been reported as the most significant variant in a previous genome-wide scan on bipolar disorder. However, further studies using larger datasets are needed to identify variants with smaller effects that contribute to the risk of bipolar disorder.
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Affiliation(s)
- A Yosifova
- Laboratory for International Alliance, RIKEN Center for Genomic Medicine, Suehiro-cho, Tsurumi-ku, Yokohama, Japan
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29
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Hong KW, Weiss A, Morimura N, Udono T, Hayasaka I, Humle T, Murayama Y, Ito S, Inoue-Murayama M. Polymorphism of the tryptophan hydroxylase 2 (TPH2) gene is associated with chimpanzee neuroticism. PLoS One 2011; 6:e22144. [PMID: 21765945 PMCID: PMC3135609 DOI: 10.1371/journal.pone.0022144] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2011] [Accepted: 06/16/2011] [Indexed: 11/19/2022] Open
Abstract
In the brain, serotonin production is controlled by tryptophan hydroxylase 2 (TPH2), a genotype. Previous studies found that mutations on the TPH2 locus in humans were associated with depression and studies of mice and studies of rhesus macaques have shown that the TPH2 locus was involved with aggressive behavior. We previously reported a functional single nucleotide polymorphism (SNP) in the form of an amino acid substitution, Q468R, in the chimpanzee TPH2 gene coding region. In the present study we tested whether this SNP was associated with neuroticism in captive and wild-born chimpanzees living in Japan and Guinea, respectively. Even after correcting for multiple tests (Bonferroni p = 0.05/6 = 0.008), Q468R was significantly related to higher neuroticism (β = 0.372, p = 0.005). This study is the first to identify a genotype linked to a personality trait in chimpanzees. In light of the prior studies on humans, mice, and rhesus macaques, these findings suggest that the relationship between neuroticism and TPH2 has deep phylogenetic roots.
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Affiliation(s)
- Kyung-Won Hong
- The United Graduate School of Agricultural Science, Gifu University, Gifu, Japan
| | - Alexander Weiss
- Scottish Primate Research Group, Department of Psychology, School of Philosophy, Psychology and Language Sciences, The University of Edinburgh, Edinburgh, United Kingdom
| | | | - Toshifumi Udono
- The Chimpanzee Sanctuary Uto, Sanwa Kagaku Kenkyusho co., Ltd., Uto, Kumamoto, Japan
| | - Ikuo Hayasaka
- The Chimpanzee Sanctuary Uto, Sanwa Kagaku Kenkyusho co., Ltd., Uto, Kumamoto, Japan
| | - Tatyana Humle
- School of Anthropology and Conservation, University of Kent. Canterbury, Kent, United Kingdom
| | | | - Shin'ichi Ito
- Faculty of Applied Biological Sciences, Gifu University, Gifu, Japan
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Archer T, Oscar-Berman M, Blum K. Epigenetics in Developmental Disorder: ADHD and Endophenotypes. JOURNAL OF GENETIC SYNDROMES & GENE THERAPY 2011; 2:1000104. [PMID: 22224195 PMCID: PMC3250517 DOI: 10.4172/2157-7412.1000104] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Heterogeneity in attention-deficit/hyperactivity disorder (ADHD), with complex interactive operations of genetic and environmental factors, is expressed in a variety of disorder manifestations: severity, co-morbidities of symptoms, and the effects of genes on phenotypes. Neurodevelopmental influences of genomic imprinting have set the stage for the structural-physiological variations that modulate the cognitive, affective, and pathophysiological domains of ADHD. The relative contributions of genetic and environmental factors provide rapidly proliferating insights into the developmental trajectory of the condition, both structurally and functionally. Parent-of-origin effects seem to support the notion that genetic risks for disease process debut often interact with the social environment, i.e., the parental environment in infants and young children. The notion of endophenotypes, markers of an underlying liability to the disorder, may facilitate detection of genetic risks relative to a complex clinical disorder. Simple genetic association has proven insufficient to explain the spectrum of ADHD. At a primary level of analysis, the consideration of epigenetic regulation of brain signalling mechanisms, dopamine, serotonin, and noradrenaline is examined. Neurotrophic factors that participate in the neurogenesis, survival, and functional maintenance of brain systems, are involved in neuroplasticity alterations underlying brain disorders, and are implicated in the genetic predisposition to ADHD, but not obviously, nor in a simple or straightforward fashion. In the context of intervention, genetic linkage studies of ADHD pharmacological intervention have demonstrated that associations have fitted the "drug response phenotype," rather than the disorder diagnosis. Despite conflicting evidence for the existence, or not, of genetic associations between disorder diagnosis and genes regulating the structure and function of neurotransmitters and brain-derived neurotrophic factor (BDNF), associations between symptoms-profiles endophenotypes and single nucleotide polymorphisms appear reassuring.
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Affiliation(s)
- Trevor Archer
- Department of Psychology, University of Gothenburg, Box 500, SE-40530 Gothenburg, Sweden
| | - Marlene Oscar-Berman
- Departments of Psychiatry, Neurology, and Anatomy & Neurobiology, Boston University School of Medicine, and Boston VA Healthcare System, Boston, MA, USA
| | - Kenneth Blum
- Department of Psychiatry, University of Florida College of Medicine, and McKnight Brain Institute, Gainesville, FL, USA
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Tsai SJ, Hong CJ, Liou YJ. Recent molecular genetic studies and methodological issues in suicide research. Prog Neuropsychopharmacol Biol Psychiatry 2011; 35:809-17. [PMID: 20977922 DOI: 10.1016/j.pnpbp.2010.10.014] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/23/2010] [Revised: 10/17/2010] [Accepted: 10/17/2010] [Indexed: 12/16/2022]
Abstract
Suicide behavior (SB) spans a spectrum ranging from suicidal ideation to suicide attempts and completed suicide. Strong evidence suggests a genetic susceptibility to SB, including familial heritability and common occurrence in twins. This review addresses recent molecular genetic studies in SB that include case-control association, genome gene-expression microarray, and genome-wide association (GWA). This work also reviews epigenetics in SB and pharmacogenetic studies of antidepressant-induced suicide. SB fulfills criteria for a complex genetic phenotype in which environmental factors interact with multiple genes to influence susceptibility. So far, case-control association approaches are still the mainstream in SB genetic studies, although whole genome gene-expression microarray and GWA studies have begun to emerge in recent years. Genetic association studies have suggested several genes (e.g., serotonin transporter, tryptophan hydroxylase 2, and brain-derived neurotrophic factor) related to SB, but not all reports support these findings. The case-control approach while useful is limited by present knowledge of disease pathophysiology. Genome-wide studies of gene expression and genetic variation are not constrained by our limited knowledge. However, the explanatory power and path to clinical translation of risk estimates for common variants reported in genome-wide association studies remain unclear because of the presence of rare and structural genetic variation. As whole genome sequencing becomes increasingly widespread, available genomic information will no longer be the limiting factor in applying genetics to clinical medicine. These approaches provide exciting new avenues to identify new candidate genes for SB genetic studies. The other limitation of genetic association is the lack of a consistent definition of the SB phenotype among studies, an inconsistency that hampers the comparability of the studies and data pooling. In summary, SB involves multiple genes interacting with non-genetic factors. A better understanding of the SB genes by combining whole genome approaches with case-control association studies, may potentially lead to developing effective screening, prevention, and management of SB.
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Affiliation(s)
- Shih-Jen Tsai
- Department of Psychiatry, Taipei Veterans General Hospital, Taipei, Taiwan.
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32
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Waider J, Araragi N, Gutknecht L, Lesch KP. Tryptophan hydroxylase-2 (TPH2) in disorders of cognitive control and emotion regulation: a perspective. Psychoneuroendocrinology 2011; 36:393-405. [PMID: 21257271 DOI: 10.1016/j.psyneuen.2010.12.012] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/02/2010] [Revised: 12/22/2010] [Accepted: 12/23/2010] [Indexed: 01/24/2023]
Abstract
Based on genetic variation, there is accumulating evidence that altered function of tryptophan hydroxylase-2 (TPH2), the enzyme critical for synthesis of serotonin (5-HT) in the brain, plays a role in anxiety-, aggression- and depression-related personality traits and in the pathogenesis of disorders featuring deficits in cognitive control and emotion regulation. Here, we appraise the genetic and neurobiological evidence to illustrate the critical role of TPH2 in central 5-HT system function and in the pathophysiology of a wide spectrum of disorders of cognitive control and emotion regulation, ranging from depression to attention-deficit/hyperactivity disorder (ADHD), a phenotype commonly associated with difficulties in the control of emotion and with a high co-morbidity of depression. Findings from psychophysiological and functional imaging studies are indicative of various TPH2 polymorphisms directly influencing serotonergic function and thus impacting on mood disorders and on the response to antidepressant treatment. Especially a combination with uncontrollable stress seems to potentiate these effects linking gene-environment interaction directly with behavioral dysfunction in human and animal models. TPH2-deficient mice display alterations in anxiety-like behavior which is accompanied by adaptational changes of 5-HT(1A) receptors and its associated signaling pathway. Mouse models in conjunction with cognitive neuroscience approaches in humans are providing unexpected results and it may well be that future research on TPH2 will provide an entirely new view of 5-HT in brain development and function related to neuropsychiatric disorders.
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Affiliation(s)
- Jonas Waider
- Molecular Psychiatry, Laboratory of Translational Neuroscience, Department of Psychiatry, Psychosomatics, and Psychotherapy, University of Wuerzburg, Fuechsleinstrasse 15, 97080 Wuerzburg, Germany
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Effect of Serotonin-Related Gene Polymorphisms on Pathogenesis and Treatment Response in Korean Schizophrenic Patients. Behav Genet 2011; 41:709-15. [DOI: 10.1007/s10519-011-9460-7] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2010] [Accepted: 02/28/2011] [Indexed: 01/27/2023]
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34
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Zupanc T, Pregelj P, Tomori M, Komel R, Paska AV. TPH2 polymorphisms and alcohol-related suicide. Neurosci Lett 2011; 490:78-81. [PMID: 21182896 DOI: 10.1016/j.neulet.2010.12.030] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2010] [Accepted: 12/11/2010] [Indexed: 10/18/2022]
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Abstract
Major depressive disorder (MDD) is a common psychiatric illness with high levels of morbidity and mortality. Despite intensive research during the past several decades, the neurobiological basis and pathophysiology of depressive disorders remain unknown. Genetic factors play important roles in the development of MDD, as indicated by family, twin, and adoption studies, and may reveal important information about disease mechanisms. This article describes recent developments in the field of psychiatric genetics, with a focus on MDD. Early twin studies, linkage studies, and association studies are discussed. Recent findings from genome-wide association studies are reviewed and future directions discussed. Despite all efforts, thus far, no single genetic variation has been identified to increase the risk of depression substantially. Genetic variants are expected to have only small effects on overall disease risk, and multiple genetic factors in conjunction with environmental factors are likely necessary for the development of MDD. Future large-scale studies are needed to dissect this complex phenotype and to identify pathways involved in the etiology of MDD.
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36
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Popova NK, Kulikov AV. Targeting tryptophan hydroxylase 2 in affective disorder. Expert Opin Ther Targets 2010; 14:1259-71. [DOI: 10.1517/14728222.2010.524208] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
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37
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Variations in tryptophan hydroxylase 2 linked to decreased serotonergic activity are associated with elevated risk for metabolic syndrome in depression. Mol Psychiatry 2010; 15:736-47. [PMID: 19125159 DOI: 10.1038/mp.2008.142] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Major depression and the metabolic syndrome (MetS) are interacting clinical conditions influenced by genetic susceptibility. For both disorders, impaired serotonergic neurotransmission in specific brain areas has been suggested. This led us to investigate whether variants in the gene coding for tryptophan hydroxylase 2 (TPH2), the brain-specific and rate-limiting enzyme for serotonin biosynthesis, might be predictive for an increased liability for the development of MetS in depressed patients. In a case-control study consisting of 988 patients with recurrent unipolar depression (RUD) and 1023 psychiatric healthy controls, MetS components were ascertained according to the International Diabetes Foundation criteria. A total of 41 single nucleotide polymorphisms fully covering the TPH2 gene region were genotyped in stage 1 (300 patients/300 controls), resulting in significant genetic associations of polymorphisms located in exon 7 and intron 8 of TPH2 and the occurrence of MetS in depressed patients after correction for age, gender and multiple testing (51 RUD-MetS/179 RUD-non-MetS). We were able to confirm the significant association of rs17110690 in stage 2 (688 patients/723 controls; 110 RUD-MetS/549 RUD-non-MetS) and to link risk-genotypes and risk-haplotypes for MetS to lower TPH2 mRNA expression and to lower 5-hydroxyindoleacetic acid levels in cerebrospinal fluid previously reported in functional studies. Our findings suggest that TPH2 polymorphisms characterize a subgroup of depressed patients who are especially prone to develop metabolic disorders induced by a genotype-dependent impairment of serotonergic neurotransmission. Identifying depressed patients at high risk for MetS using genetic variants could have direct clinical impact on individualized disease management and prevention strategies.
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Perroud N, Neidhart E, Petit B, Vessaz M, Laforge T, Relecom C, La Harpe R, Malafosse A, Guipponi M. Simultaneous analysis of serotonin transporter, tryptophan hydroxylase 1 and 2 gene expression in the ventral prefrontal cortex of suicide victims. Am J Med Genet B Neuropsychiatr Genet 2010; 153B:909-18. [PMID: 20052688 DOI: 10.1002/ajmg.b.31059] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Serotonergic signaling abnormalities have been implicated in suicide. Tryptophan hydroxylase (TPH), the rate limiting enzyme of serotonin biosynthesis and the serotonin transporter (SLC6A4), involved in the reuptake of serotonin from the synaptic gap, play major role in serotonergic signaling. In this study, we aimed to compare the levels of expression of these serotonin-related genes between suicide completers and controls and to identify genetic loci involved in their regulation. SLC6A4, TPH1, and TPH2 mRNA levels were measured in the ventral prefrontal cortex (VPFC) of 39 suicide completers and 40 matched controls. To identify the molecular basis of gene expression variation, we performed association studies between cis-acting polymorphisms and SLC6A4, TPH1, and TPH2 transcript levels. Finally, association analyses were carried out between suicide and TPH2 cis-single nucleotide polymorphisms (SNPs) in cohorts of 154 suicide completers and 289 control subjects. Whereas SLC6A4 and TPH1 mRNA expression levels did not differ between suicides and controls, TPH2 levels were found significantly increased (P = 0.003) in suicide completers. We observed that SNP rs10748185 located in the promoter region of TPH2 significantly affect levels of TPH2 mRNA expression. However, we did not find positive association between this eQTL (rs10748185) and suicide. Here, we report the simultaneous analysis of the expression of three serotonin-related genes in the VPFC of suicide victims and controls. This study showed that TPH2 expression levels were increased in the VPFC of suicide victims. Although, we identified a genetic variant that explains variance in TPH2 expression, we did not find evidence associating this cis-regulatory SNP with suicidal behavior.
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Affiliation(s)
- Nader Perroud
- Department of Psychiatry, University Hospitals of Geneva, Geneva, Switzerland
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Association of polymorphisms of the tryptophan hydroxylase 2 gene with risk for bipolar disorder or suicidal behavior. J Psychiatr Res 2010; 44:271-4. [PMID: 19800079 DOI: 10.1016/j.jpsychires.2009.09.007] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/19/2009] [Revised: 09/03/2009] [Accepted: 09/08/2009] [Indexed: 11/28/2022]
Abstract
Bipolar disorder (BD) is a severe psychiatric illness characterized by the occurrence of elevated mood alternating with depressive episodes, having a estimated lifetime prevalence of 0.4-1.6% using DSM-IV criteria. Disturbances of the central serotonergic system has been associated with the pathophysiology of affective disorders and suicidal behavior. Tryptophan hydroxylase 2 (TPH2) which is a rate limiting enzyme in the serotonin synthesis is considered an important candidate gene associated with psychiatric disorders. Our sample consisted of 527 subjects (303 diagnosed with bipolar disorder and 224 healthy controls) which were genotyped for eight tagSNPs (rs4448731, rs4565946, rs11179000, rs7955501, rs10506645, rs4760820, rs1487275 and rs10879357) covering the whole gene of the human TPH2. Statistical analyses were performed using UNPHASED version 3.0.12 and Haploview((R)). Single markers, genotype and haplotype association analysis did not show significant genetic association with bipolar disorder or suicidal behavior. Our findings do not support the association between diagnosis of BD or suicidal behavior and TPH2 polymorphisms.
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Juhasz G, Downey D, Hinvest N, Thomas E, Chase D, Toth ZG, Lloyd-Williams K, Mekli K, Platt H, Payton A, Bagdy G, Elliott R, Deakin JFW, Anderson IM. Risk-taking behavior in a gambling task associated with variations in the tryptophan hydroxylase 2 gene: relevance to psychiatric disorders. Neuropsychopharmacology 2010; 35:1109-19. [PMID: 20043001 PMCID: PMC3055398 DOI: 10.1038/npp.2009.216] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Decision making, choosing the best option from the possible outcomes, is impaired in many psychiatric conditions including affective disorders. We tested the hypothesis that variations in serotonergic genes (TPH2, TPH1, SLC6A4, HTR1A), which influence serotonin availability, affect choice behavior in a probabilistic gambling task. A population cohort (N=1035) completed a paper-and-pencil gambling task, filled out personality and symptom questionnaires and gave consent for the use of their DNA in a genetic association study. A subgroup of subjects (N=69) also completed a computer version of the task. The gambling task was designed to estimate an individual's tendency to take a risk when choosing between a smaller but more certain 'win' and a larger, less probable one. We genotyped seven haplotype tagging SNPs in the TPH2 gene, and previously reported functional polymorphisms from the other genes (rs1800532, 5HTTLPR, and rs6295). Carriers of the more prevalent TPH2 haplotype, which was previously associated with less active enzyme variant, showed reduced risk taking on both tasks compared with subjects not carrying the common haplotype. The effect of TPH2 haplotypes on risk-taking was independent of current depression and anxiety symptoms, neuroticism and impulsiveness scores. We did not find an association between functional polymorphisms in the TPH1, SLC6A4, HTR1A genes and risk-taking behavior. In conclusion, our study demonstrates the role of the TPH2 gene and the serotonin system in risk taking and suggests that TPH2 gene may contribute to the expression of psychiatric phenotypes through altered decision making.
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Affiliation(s)
- Gabriella Juhasz
- Neuroscience and Psychiatry Unit, School of Community Based Medicine, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK.
| | - Darragh Downey
- Neuroscience and Psychiatry Unit, School of Community Based Medicine, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
| | - Neal Hinvest
- Neuroscience and Psychiatry Unit, School of Community Based Medicine, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
| | - Emma Thomas
- Neuroscience and Psychiatry Unit, School of Community Based Medicine, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
| | - Diana Chase
- Neuroscience and Psychiatry Unit, School of Community Based Medicine, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
| | - Zoltan G Toth
- Faculty of Life Sciences, The University of Manchester, Manchester, UK
| | - Kathryn Lloyd-Williams
- Neuroscience and Psychiatry Unit, School of Community Based Medicine, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
| | - Krisztina Mekli
- Neuroscience and Psychiatry Unit, School of Community Based Medicine, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK,Centre for Integrated Genomic Medical Research, School of Translational Medicine, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK,Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Budapest, Hungary
| | - Hazel Platt
- Centre for Integrated Genomic Medical Research, School of Translational Medicine, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
| | - Antony Payton
- Centre for Integrated Genomic Medical Research, School of Translational Medicine, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
| | - Gyorgy Bagdy
- Department of Pharmacology and Pharmacotherapy, Faculty of Medicine, Semmelweis University, Budapest, Hungary,Department of Pharmacodynamics, and Group of Neurochemistry, Hungarian Academy of Sciences and Semmelweis University, Budapest, Hungary
| | - Rebecca Elliott
- Neuroscience and Psychiatry Unit, School of Community Based Medicine, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
| | - J F William Deakin
- Neuroscience and Psychiatry Unit, School of Community Based Medicine, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
| | - Ian M Anderson
- Neuroscience and Psychiatry Unit, School of Community Based Medicine, Faculty of Medical and Human Sciences, The University of Manchester, Manchester, UK
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Chen GL, Novak MA, Meyer JS, Kelly BJ, Vallender EJ, Miller GM. TPH2 5'- and 3'-regulatory polymorphisms are differentially associated with HPA axis function and self-injurious behavior in rhesus monkeys. GENES, BRAIN, AND BEHAVIOR 2010; 9:335-47. [PMID: 20059554 PMCID: PMC2990963 DOI: 10.1111/j.1601-183x.2010.00564.x] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Tryptophan hydroxylase-2 (TPH2) synthesizes neuronal serotonin and is linked to numerous behavioral traits. We have previously characterized the functionality of polymorphisms (especially 2051A>C) in 3'-untranslated region (3'-UTR) of rhesus monkey TPH2 (rhTPH2). This study further assessed the functionality of additional polymorphisms (-1605T>C, -1491Tn, -1485(AT)n, -1454A>G, -1325In>Del and -363T>G) in rhTPH2 5'-flanking region (5'-FR), and evaluated the effects of rhTPH2 5' and 3' genotypes on central serotonin turnover, hypothalamic-pituitary-adrenal (HPA) axis function and self-injurious behavior (SIB) in 32 unrelated adult male monkeys of Indian origin. Haplotypes of the rhTPH2 5'-FR polymorphisms exert a significant, cell-dependent effect on reporter gene expression, primarily conferred by -1485(AT)n. The -1485(AT)n and 2051A>C polymorphisms interact to influence cerebrospinal fluid (CSF) 5-HIAA and plasma adrenocorticotropic hormone (ACTH) in the afternoon. While -1485(AT)n exerts significant main effects on the afternoon cortisol level and nocturnal HPA negative feedback, 2051A>C has significant main effects on the morning cortisol level and cortisol response to ACTH challenge, as well as marginally significant main effects on the daytime HPA negative feedback and self-biting rate. In addition, the genotype/allele frequency of the 5'-FR -1325Ins>Del differed significantly between the self-wounders and non-wounders, whereas 3'-UTR 2128S>L polymorphism differed significantly in genotype/allele frequency between the high- and low-frequency biters. This study shows the functionality of rhTPH2 5'-FR polymorphisms, and provides evidence for the differential association of rhTPH2 5'-FR and 3'-UTR polymorphisms with HPA axis function and SIB. Our findings shed light on the role of TPH2 gene variance in physiology and behavioral traits, and also contribute to the understanding of the pathophysiology and genetics of SIB.
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Affiliation(s)
- Guo-Lin Chen
- Harvard Medical School, New England Primate Research Center, Division of Neurochemistry, One Pine Hill Drive, Southborough, MA 01772–9102, USA
| | - Melinda A. Novak
- Harvard Medical School, New England Primate Research Center, Division of Neurochemistry, One Pine Hill Drive, Southborough, MA 01772–9102, USA
- Department of Psychology, University of Massachusetts at Amherst, Amherst, MA, USA
| | - Jerrold S. Meyer
- Department of Psychology, University of Massachusetts at Amherst, Amherst, MA, USA
| | - Brian J. Kelly
- Harvard Medical School, New England Primate Research Center, Division of Neurochemistry, One Pine Hill Drive, Southborough, MA 01772–9102, USA
| | - Eric J. Vallender
- Harvard Medical School, New England Primate Research Center, Division of Neurochemistry, One Pine Hill Drive, Southborough, MA 01772–9102, USA
| | - Gregory M. Miller
- Harvard Medical School, New England Primate Research Center, Division of Neurochemistry, One Pine Hill Drive, Southborough, MA 01772–9102, USA
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Inoue H, Yamasue H, Tochigi M, Takei K, Suga M, Abe O, Yamada H, Rogers MA, Aoki S, Sasaki T, Kasai K. Effect of tryptophan hydroxylase-2 gene variants on amygdalar and hippocampal volumes. Brain Res 2010; 1331:51-7. [PMID: 20331984 DOI: 10.1016/j.brainres.2010.03.057] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2009] [Revised: 03/14/2010] [Accepted: 03/15/2010] [Indexed: 02/06/2023]
Abstract
Tryptophan hydroxylase (TPH) is the rate-limiting enzyme in the synthesis of serotonin (5-HT). Genetic variations in human TPH2, a newly identified isoform of TPH, have been shown to impact on enzymatic activity of TPH and to be associated with emotion-related personality traits and mood/anxiety disorders. Identification of an intermediate phenotype that bridges the relationship between genes and behavior may be of great importance in the further clarification of how hTPH2 contributes to emotional regulation. Previous studies have shown that a polymorphism in the upstream regulatory region of hTPH2 (SNP G-703T, rs4570625) correlates functional MRI response of the amygdala. In this study, we examined the effect of this genotype on amygdalar and hippocampal volumes in 208 mentally healthy individuals. To measure volumes of amygdala and hippocampus, gray matter regions of interest were outlined manually on three-dimensional MRI data obtained using a 1.5-T scanner. Additionally, personality traits were evaluated using the Temperament and Character Inventory (TCI). Those subjects with T allele carriers were associated with significantly smaller volumes in bilateral amygdala and hippocampus and higher reward dependence than those with G allele homozygotes. These results suggest that amygdalar and hippocampal volumes assessed using MRI may be a useful intermediate phenotype that will uncover the biological pathway linking 5-HT synthesis and emotional behaviors and affective disorders.
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Affiliation(s)
- Hideyuki Inoue
- Department of Neuropsychiatry, Graduate School of Medicine, University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan.
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Utge S, Soronen P, Partonen T, Loukola A, Kronholm E, Pirkola S, Nyman E, Porkka-Heiskanen T, Paunio T. A population-based association study of candidate genes for depression and sleep disturbance. Am J Med Genet B Neuropsychiatr Genet 2010; 153B:468-476. [PMID: 19548263 DOI: 10.1002/ajmg.b.31002] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The clinical manifestation of depression comprises a variety of symptoms, including early morning awakenings and fatigue, features also indicating disturbed sleep. The presence or absence of these symptoms may reflect differences in neurobiological processes leading to prolonged depression. Several neurobiological mechanisms have been indicated in the induction of depression, including disturbances in serotonergic and glutamatergic neurotransmission and in the action of the hypothalamic-pituitary-adrenal (HPA) axis. The same transmitters have also been linked to sleep regulation. We hypothesized that depression without simultaneous symptoms of disturbed sleep would partly have a different genetic background than depression with symptoms of disturbed sleep. We tested this hypothesis using a systematic population-based association study of 14 candidate genes related to depression and disturbed sleep. Association of genetic variants with either depression alone, depression with early morning awakenings, or depression with fatigue was investigated using permutation-based allelic association analysis of a sample of 1,654 adults recruited from Finland's population-based program. The major findings were associations of TPH2 (rs12229394) with depression accompanied by fatigue in women and CREB1 (rs11904814) with depression alone in men. We also found suggestive associations in women for GAD1, GRIA3, and BDNF with depression accompanied by fatigue, and for CRHR1 with depression accompanied by early morning awakenings. The results indicate sex-dependent and symptom-specific differences in the genetic background of depression. These differences may partially explain the broad spectrum of depressive symptoms, and their systematic monitoring could potentially be used for diagnostic purposes.
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Affiliation(s)
- Siddheshwar Utge
- Public Health Genomics Unit, National Institute for Health and Welfare, Helsinki, Finland.,Department of Physiology, University of Helsinki, Helsinki, Finland.,Department of Psychiatry, Helsinki University Central Hospital, Helsinki, Finland
| | - Pia Soronen
- Public Health Genomics Unit, National Institute for Health and Welfare, Helsinki, Finland.,Department of Psychiatry, Helsinki University Central Hospital, Helsinki, Finland
| | - Timo Partonen
- Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland
| | - Anu Loukola
- Public Health Genomics Unit, National Institute for Health and Welfare, Helsinki, Finland
| | - Erkki Kronholm
- Department of Health and Functional Capacity, Laboratory for Population Research, National Institute for Health and Welfare, Turku, Finland
| | - Sami Pirkola
- Department of Psychiatry, Helsinki University Central Hospital, Helsinki, Finland.,Department of Mental Health and Substance Abuse Services, National Institute for Health and Welfare, Helsinki, Finland
| | - Emma Nyman
- Public Health Genomics Unit, National Institute for Health and Welfare, Helsinki, Finland
| | | | - Tiina Paunio
- Public Health Genomics Unit, National Institute for Health and Welfare, Helsinki, Finland.,Department of Psychiatry, Helsinki University Central Hospital, Helsinki, Finland
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Choi KY, Yoon HK, Kim YK. Association between Serotonin-Related Polymorphisms in 5HT2A, TPH1, TPH2 Genes and Bipolar Disorder in Korean Population. Psychiatry Investig 2010; 7:60-7. [PMID: 20396435 PMCID: PMC2848767 DOI: 10.4306/pi.2010.7.1.60] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/05/2009] [Revised: 01/26/2010] [Accepted: 01/30/2010] [Indexed: 12/01/2022] Open
Abstract
OBJECTIVE The aim of the present study was to examine the association between serotonin-related gene polymorphisms and bipolar disorder in the Korean population. In addition, we sought to explore the relationship between the clinical characteristics of bipolar patients and serotonin-related gene polymorphisms. METHODS Inpatients with bipolar disorder (n=103) and control subjects (n=86) were genotyped for 5HT2A 1438A/G, tryptophan hydroxylase 1 (TPH1) 218 A/C, and TPH2 703G/T. We divided patients with bipolar disorder into two groups according to the presence of psychotic symptoms. The severity of their symptoms was measured using the Young Mania Rating Scale (YMRS) and the Brief Psychiatric Rating Scale (BPRS). RESULTS There were no significant differences in the genotype distributions or allelic frequencies in the three serotonergic polymorphisms between patients with bipolar disorder and normal controls. There were significant differences in genotype distributions and allele frequencies of the 5-HT2A -1438A/G polymorphism between the psychotic mania group and the non-psychotic mania group (genotype: chi(2)=7.50, p=0.024; allele: chi(2)=5.92, p=0.015). However, after Bonferroni correction this signifact difference disappeared. We did not find significant differences in the genotype distributions or allelic frequencies in the TPH1 218 A/C and TPH2 703G/T polymorphisms between the psychotic mania group and non-psychotic mania group. CONCLUSION We failed to found the statistically significant association between three polymorphisms and bipolar disorder. However, there was a trend towards association between 5-HT2A -1438A/G polymorphism and psychotic symptom in bipolar disorder. Future research should seek to clarify this association.
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Affiliation(s)
- Kwang-Yeon Choi
- Department of Psychiatry, College of Medicine, Korea University, Ansan Hospital, Ansan, Korea
| | - Ho-Kyoung Yoon
- Department of Psychiatry, College of Medicine, Korea University, Ansan Hospital, Ansan, Korea
| | - Yong-Ku Kim
- Department of Psychiatry, College of Medicine, Korea University, Ansan Hospital, Ansan, Korea
- Division of Brain Korea 21 Biomedical Science, Korea University, Seoul, Korea
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Novick DM, Swartz HA, Frank E. Suicide attempts in bipolar I and bipolar II disorder: a review and meta-analysis of the evidence. Bipolar Disord 2010; 12:1-9. [PMID: 20148862 PMCID: PMC4536929 DOI: 10.1111/j.1399-5618.2009.00786.x] [Citation(s) in RCA: 208] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE The prevalence of suicide attempts (SA) in bipolar II disorder (BPII), particularly in comparison to the prevalence in bipolar I disorder (BPI), is an understudied and controversial issue with mixed results. To date, there has been no comprehensive review of the published prevalence data for attempted suicide in BPII. METHODS We conducted a literature review and meta-analysis of published reports that specified the proportion of individuals with BPII in their presentation of SA data. Systematic searching yielded 24 reports providing rates of SA in BPII and 21 reports including rates of SA in both BPI and BPII. We estimated the prevalence of SA in BPII by combining data across reports of similar designs. To compare rates of SA in BPII and BPI, we calculated a pooled odds ratio (OR) and 95% confidence interval (CI) with random-effect meta-analytic techniques with retrospective data from 15 reports that detailed rates of SA in both BPI and BPII. RESULTS Among the 24 reports with any BPII data, 32.4% (356/1099) of individuals retrospectively reported a lifetime history of SA, 19.8% (93/469) prospectively reported attempted suicide, and 20.5% (55/268) of index attempters were diagnosed with BPII. In 15 retrospective studies suitable for meta-analysis, the prevalence of attempted suicide in BPII and BPI was not significantly different: 32.4% and 36.3%, respectively (OR = 1.21, 95% CI: 0.98-1.48, p = 0.07). CONCLUSION The contribution of BPII to suicidal behavior is considerable. Our findings suggest that there is no significant effect of bipolar subtype on rate of SA. Our findings are particularly alarming in concert with other evidence, including (i) the well-documented predictive role of SA for completed suicide and (ii) the evidence suggesting that individuals with BPII use significantly more violent and lethal methods than do individuals with BPI. To reduce suicide-related morbidity and mortality, routine clinical care for BPII must include ongoing risk assessment and interventions targeted at risk factors.
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Affiliation(s)
- Danielle M Novick
- Department of Psychiatry, Western Psychiatric Institute and Clinic, University of Pittsburgh, Pittsburgh, PA 15213, USA.
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46
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Chen GL, Novak MA, Meyer JS, Kelly BJ, Vallender EJ, Miller GM. The effect of rearing experience and TPH2 genotype on HPA axis function and aggression in rhesus monkeys: a retrospective analysis. Horm Behav 2010; 57:184-91. [PMID: 19900455 PMCID: PMC2815197 DOI: 10.1016/j.yhbeh.2009.10.012] [Citation(s) in RCA: 20] [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] [Received: 08/25/2009] [Revised: 10/28/2009] [Accepted: 10/29/2009] [Indexed: 01/14/2023]
Abstract
Gene-environment (GxE) interactions contribute to the development of many neuropsychiatric disorders. Tryptophan hydroxylase-2 (TPH2) synthesizes neuronal serotonin and is closely related to the hypothalamic-pituitary-adrenal (HPA) axis, while early life experience is a critical environmental factor programming the HPA axis response to stress. This retrospective study investigated GxE interaction at the TPH2 locus in rhesus monkeys. Twenty-eight adult, male rhesus monkeys of Indian origin, either mother-reared or peer-reared as infants, were involved in this study. These monkeys have been previously genotyped for the functional A2051C polymorphism in rhTPH2, and had been physiologically and behaviorally characterized. rhTPH2 A2051C exerted a significant main effect (CC>AA&AC) on the cerebrospinal fluid (CSF) level of 5-hydroxyindole-3-acetic acid (5-HIAA; F((1,14))=6.42, p=0.024), plasma cortisol level in the morning (F((1,18))=14.63, p=0.002) and cortisol response to ACTH challenge (F((1,17))=6.87, p=0.018), while the rearing experience showed a significant main effect (PR>MR) on CSF CRH (F((1,20))=11.66, p=0.003) and cage shaking behavior (F((1,27))=4.45, p=0.045). The effects of rhTPH2 A2051C on the afternoon cortisol level, plasma ACTH level, dexamethasone suppression of urinary cortisol excretion, and aggression were dependent upon the rearing experience. These results were not confounded by the functional C77G polymorphism in the mu-opioid receptor (MOR). The present study supports the hypothesis that rearing experience and rhTPH2 A2051C interact to influence central 5-HT metabolism, HPA axis function, and aggressive behaviors. Our findings strengthen the involvement of G x E interactions at the loci of serotonergic genes and the utility of the nonhuman primate to model G x E interactions in the development of human neuropsychiatric diseases.
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Affiliation(s)
- Guo-Lin Chen
- Harvard Medical School, New England Primate Research Center, Division of Neurochemistry, One Pine Hill Drive, Southborough, MA 01772, USA
| | - Melinda A. Novak
- Harvard Medical School, New England Primate Research Center, Division of Neurochemistry, One Pine Hill Drive, Southborough, MA 01772, USA
- Department of Psychology, University of Massachusetts at Amherst, Amherst, MA 01003, USA
| | - Jerrold S. Meyer
- Department of Psychology, University of Massachusetts at Amherst, Amherst, MA 01003, USA
| | - Brian J. Kelly
- Harvard Medical School, New England Primate Research Center, Division of Neurochemistry, One Pine Hill Drive, Southborough, MA 01772, USA
- Department of Psychology, University of Massachusetts at Amherst, Amherst, MA 01003, USA
| | - Eric J. Vallender
- Harvard Medical School, New England Primate Research Center, Division of Neurochemistry, One Pine Hill Drive, Southborough, MA 01772, USA
| | - Gregory M. Miller
- Harvard Medical School, New England Primate Research Center, Division of Neurochemistry, One Pine Hill Drive, Southborough, MA 01772, USA
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Neuronal tryptophan hydroxylase (TPH2) in suicidal behaviour. Transl Neurosci 2010. [DOI: 10.2478/v10134-010-0031-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AbstractSerotonin (5-hydroxytryptamine, 5-HT) is a signalling molecule involved in many brain functions as well as in a variety of psychiatric conditions, including suicidal behaviour. Tryptophan hydroxylase (TPH), the rate-limiting enzyme of 5-HT biosynthesis, plays a critical role in 5-HT metabolism and thus in the regulation of 5-HT neurotransmission. There are two isoforms of TPH, so-called peripheral (TPH1) and neuronal (TPH2), encoded by the two distinct genes. TPH1 is abundant in the peripheral tissues, while TPH2 was detected exclusively within the nervous system. Since its discovery in 2003, TPH2 gene has attracted great interest as a potential factor contributing to diathesis of suicidal behaviour. However, initial positive findings indicating an association of TPH2 genetic variants with suicide have not been replicated consistently. Here we provide an overview of published studies to date, that have evaluated the contribution of TPH2 gene to the etiopathogenesis of suicidal behaviour.
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Mouri K, Hishimoto A, Fukutake M, Shiroiwa K, Asano M, Nagasaki Y, Ueno Y, Shirakawa O, Nishiguchi N, Maeda K. TPH2 is not a susceptibility gene for suicide in Japanese population. Prog Neuropsychopharmacol Biol Psychiatry 2009; 33:1546-50. [PMID: 19748542 DOI: 10.1016/j.pnpbp.2009.09.002] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/05/2009] [Revised: 08/31/2009] [Accepted: 09/01/2009] [Indexed: 11/15/2022]
Abstract
BACKGROUND Serotonergic systems mediate a control of aggression and/or impulsivity in human and are suggested to be involved in suicidal behavior. The newly identified neuronal tryptophan hydroxylase isoform 2 (TPH2), the rate-limiting enzyme in serotonin synthesis, represents a prime candidate in numerous genetic association analyses of suicidal behavior; however, the results are still inconclusive. The discrepancy may result from the heterogeneity of pathogenesis of suicidal behavior and/or methodological mismatches. We, therefore, attempted to replicate the association of TPH2 gene with suicide using a case-control study of 234 completed suicides and 260 control subjects in Japanese population. METHODS We genotyped 15 tagging-single nucleotide polymorphisms (SNPs) including 4 SNPs, which were previously reported to be associated with suicidal behavior, using the TaqMan probe assays and the polymerase chain reaction and restriction fragment length polymorphism (PCR-RFLP) method. RESULTS We found no significant differences in genotypic distributions (uncorrected p=0.06-0.98) or allelic frequencies (uncorrected p=0.09-0.95) of the fifteen SNPs between the completed suicides and control groups. Haplotypes constructed with these SNPs were also not associated with suicide (uncorrected p=0.03-0.96 and corrected p=0.20-1.00). Even when we took sex and suicidal methods (violent or non-violent) into account for the analyses, no significant differences in genotypic distributions, allelic/haplotypic frequencies were found in the two groups. CONCLUSION Our results suggest that the common SNPs and haplotypes of the TPH2 gene are unlikely to contribute to the genetic susceptibility to suicidal behavior in Japanese population.
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Affiliation(s)
- Kentaro Mouri
- Department of Psychiatry, Kobe University Graduate School of Medicine, Kobe, Japan
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Abstract
Depression is one of the leading causes of morbidity worldwide and represents a huge burden to society. As with many other psychiatric disorders, a genetic basis for depression has been identified. Evidence for the role of circadian genes in depression is particularly compelling. Circadian gene mutations are also associated with circadian rhythm disorders such as familial advanced sleep phase syndrome, delayed sleep phase syndrome, and non-24-hour sleep-wake syndrome. Such disorders, plus the other manifestations of a disrupted circadian system such as hormone dysregulation, are often observed among those with depression. This suggests a shared aetiology between circadian disruption and depression, although the exact mechanisms underlying the association are unclear. This paper reviews the molecular mechanisms involved in depression, with an emphasis on circadian genes. Twin studies in depression have reported probandwise concordance rates of 40% and 70% using narrow and broad diagnostic criteria, respectively, and heritability of over 85% for bipolar disorder. In association studies, increased susceptibility to depression has been noted in those with polymorphisms in the following: D-amino-acid-oxidase activator/G30 gene complex, glucocorticoid receptor gene, serotonin transporter gene, tryptophan hydroxylase 2 gene, dopamine transporter gene and G protein-coupled receptor 50 gene. Polymorphisms in these genes have also been linked to a better or worse response to antidepressant therapy, an increased likelihood of responding poorly to adversity and increased suicide ideation. Polymorphisms in the CLOCK, BMAL1, Per3 and TIMELESS genes have been associated with susceptibility to mood disorder, and single nucleotide polymorphisms and haplotypes in several circadian genes have been observed among those displaying certain circadian phenotypes, including worse mood in the evening, insomnia in mania and early, middle or late insomnia in depression. Manipulation of the circadian timing system via sleep deprivation, bright light or pharmacological therapy has also been shown to alleviate depressive symptoms, providing further evidence for the role of circadian dysfunction in depression pathophysiology. The new antidepressant agomelatine is the first melatonergic antidepressant with an innovative mode of action: it is a melatonergic MT(1), MT(2) receptor agonist and 5-HT(2c) antagonist, and is able to restore the internal clock, which is profoundly disturbed in depression, thus being efficacious in major depressive disorders. In conclusion, a wealth of evidence is now available supporting a genetic basis for depression. The apparent importance of mutations in the circadian genes in determining disease susceptibility, disease recurrence and response to treatment suggests that the circadian pathway represents an attractive target for pharmacological manipulation to improve management of this debilitating disorder.
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Affiliation(s)
- Julien Mendlewicz
- Department of Psychiatry, Free University of Brussels, Brussels, Belgium
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Yosifova A, Mushiroda T, Stoianov D, Vazharova R, Dimova I, Karachanak S, Zaharieva I, Milanova V, Madjirova N, Gerdjikov I, Tolev T, Velkova S, Kirov G, Owen MJ, O'Donovan MC, Toncheva D, Nakamura Y. Case-control association study of 65 candidate genes revealed a possible association of a SNP of HTR5A to be a factor susceptible to bipolar disease in Bulgarian population. J Affect Disord 2009; 117:87-97. [PMID: 19328558 DOI: 10.1016/j.jad.2008.12.021] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/19/2008] [Revised: 12/24/2008] [Accepted: 12/24/2008] [Indexed: 11/15/2022]
Abstract
BACKGROUND Bipolar affective disorder (BAD) is a psychiatric illness characterized by episodes of mania and depression. Although the etiology is not clear, epidemiological studies suggest it is a result of an interaction of genetic and environmental factors. Despite of enormous efforts and abundant studies conducted, none has yet been identified definitively a gene susceptible to bipolar disorder. METHODS Ninety-four Bulgarian patients diagnosed with bipolar disorder and 184 Bulgarian healthy individuals, were used for genotyping of 191 single nucleotide polymorphisms (SNPs) by TaqMan and/or Invader assays. Seventeen SNPs that revealed P value less than 0.05 in the first screening were genotyped using an additional independent set of samples, consisting of 78 BAD cases and 372 controls. RESULTS After applying the Bonferonni correction on genotyping results of 172 cases and 556 controls, only one SNP, rs1800883, in the HTR5A gene revealed a significant level of P value (P=0.000097; odds ratio=1.80 (95%CI, 1.27-2.54); corrected P=0.017). CONCLUSIONS Our findings suggest that HTR5A gene could play an important role in the pathogenesis of bipolar disorder in our population. However these findings should be viewed with caution and replication studies in other populations are necessary in support of these findings.
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Affiliation(s)
- Adelina Yosifova
- Laboratory for International Alliance, RIKEN Center for Genomic Medicine, Tsurumi-ku, Yokohama, Japan
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