Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Depression and anxiety disorders often coexist clinically and both are known to have a genetic basis, but the mode of inheritance is too complicated to be determined so far. Serotonin is the biogenic amine neurotransmitter most commonly associated with depression and anxiety. Since tryptophan hydroxylase (TPH1) is the rate-limiting enzyme in serotonin biosynthesis, its role in the pathophysiology of these psychiatric diseases has been intensively studied. In this study, we examined whether polymorphism of the TPH1 gene is related to the etiology of major depression, anxiety and comorbid depression and anxiety. Five single nucleoside polymorphisms of the TPH1 gene were studied in a population-based sample of postpartum Taiwanese women consisting of 120 subjects with depression or/and anxiety and 86 matched normal controls. A significant difference (P = 0.0107) in genotype frequency for the T27224C polymorphism was found between the comorbid and normal groups, and risk analysis showed that the C allele conferred a strong protective effect (odds ratio = 0.27; 95% confident interval = 0.11-0.7). Three-allele haplotypes involving T27224C polymorphism were constructed and haplotype associations between particular haplotype combinations and various diseases identified. However, the associations were weak and the overall haplotype frequency profiles in all groups were similar. The results suggest that depression, anxiety, and comorbid depression and anxiety disorders may have related etiologies. In addition, this study suggests that the TPH1 gene might play a role in the pathogenesis of these closely related disorders.
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PMID:Association of tryptophan hydroxylase gene polymorphism with depression, anxiety and comorbid depression and anxiety in a population-based sample of postpartum Taiwanese women. 1554 76

Evidence indicates the genetic susceptibility to depression and anxiety is both overlapping and dimensional. In the current study, a quantitative phenotype had been created from several depression and anxiety-related measures in order to index this common genetic susceptibility (G). This has been studied in 119 sibships comprising 312 individuals, selected for extreme scores on G, from a community-based sample of 34,371 individuals. In a pathway based candidate gene study, we examined five microsatellite markers located within or nearby to five serotonin system genes (5HT2C, 5HT1D, 5HT1B, TPH1, and MAOB). Statistical analysis, carried out using QTDT, gave a significant association with a microsatellite downstream of TPH1. Further analysis included a life-events composite as a co-variable, this lead to a stronger association of TPH1. To our knowledge, this is the first study to report an association of the 3' end of TPH1 with continuous measures of depression and anxiety.
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PMID:Association analysis of monoamine genes with measures of depression and anxiety in a selected community sample of siblings. 1572 45

Serotonin [5-hydroxytryptamine (5-HT)] is a major therapeutic target of psychiatric disorders. Tryptophan hydroxylase (TPH) catalyzes the rate-limiting reaction in the biosynthesis of 5-HT. Two isoforms (TPH1 and TPH2) having tryptophan hydroxylating activity were identified. Association studies have revealed possible TPH1 involvement in psychiatric conditions and behavioral traits. However, TPH1 mRNA was reported to be mainly expressed in the pineal gland and the periphery and to be barely detected in the brain. Therefore, contribution of TPH1 to brain 5-HT levels is not known, and the mechanisms how TPH1 possibly contributes to the pathogenesis of psychiatric disorders are not understood. Here, we show an unexpected role of TPH1 in the developing brain. We found that TPH1 is expressed preferentially during the late developmental stage in the mouse brain. TPH1 showed higher affinity to tryptophan and stronger enzyme activity than TPH2 in a condition reflecting that of the developing brainstem. Low 5-HT contents in the raphe nucleus were seen during development in New Zealand white (NZW) and SWR mice having common functional polymorphisms in the TPH1 gene. However, the 5-HT contents in these mice were not reduced in adulthood. In adult NZW and SWR mice, depression-related behavior was observed. Considering an involvement of developmental brain disturbance in psychiatric disorders, TPH1 may act specifically on development of 5-HT neurons, and thereby influence behavior later in life.
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PMID:Late developmental stage-specific role of tryptophan hydroxylase 1 in brain serotonin levels. 1640 50

Considerable attention has focused on regulation of central tryptophan hydroxylase (TPH) activity and protein expression. At the time of these earlier studies, it was thought that there was a single central TPH isoform. However, with the recent identification of TPH2, it becomes important to distinguish between regulatory effects on the protein expression and activity of the two isoforms. We have generated a TPH2-specific polyclonal antiserum (TPH2-6361) to study regulation of TPH2 at the protein level and to examine the distribution of TPH2 expression in rodent and human brain. TPH2 immunoreactivity (IR) was detected throughout the raphe nuclei, in lateral hypothalamic nuclei and in the pineal body of rodent and human brain. In addition, a prominent TPH2-IR fiber network was found in the human median eminence. We recently reported that glucocorticoid treatment of C57/Bl6 mice for 4 days markedly decreased TPH2 messenger RNA levels in the raphe nuclei, whereas TPH1 mRNA was unaffected. The glucocorticoid-elicited inhibition of TPH2 gene expression was blocked by co-administration of the glucocorticoid receptor antagonist mifepristone (RU-486). Using TPH2-6361, we have extended these findings to show a dose-dependent decrease in raphe TPH2 protein levels in response to 4 days of treatment with dexamethasone; this effect was blocked by co-administration of mifepristone. Moreover, the glucocorticoid-elicited inhibition of TPH2 was functionally significant: serotonin synthesis was significantly reduced in the frontal cortex of glucocorticoid-treated mice, an effect that was blocked by mifepristone co-administration. This study provides further evidence for the glucocorticoid regulation of serotonin biosynthesis via inhibition of TPH2 expression, and suggest that elevated glucocorticoid levels may be relevant to the etiology of psychiatric diseases, such as depression, where hypothalamic-pituitary-adrenal axis dysregulation has been documented.
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PMID:Glucocorticoid modulation of tryptophan hydroxylase-2 protein in raphe nuclei and 5-hydroxytryptophan concentrations in frontal cortex of C57/Bl6 mice. 1762 21

The serotonin system is strongly implicated in the pathophysiology and therapeutic alleviation of stress-related disorders such as anxiety and depression. Serotonergic modulation of the acute response to stress and the adaptation to chronic stress is mediated by a myriad of molecules controlling serotonin neuron development (Pet-1), synthesis (tryptophan hydroxylase 1 and 2 isozymes), packaging (vesicular monoamine transporter 2), actions at presynaptic and postsynaptic receptors (5-HT1A, 5-HT1B, 5-HT2A, 5-HT2C, 5-HT3A, 5-HT4, 5-HT5A, 5-HT6, 5-HT7), reuptake (serotonin transporter), and degradation (monoamine oxidase A). A growing body of evidence from preclinical rodents models, and especially genetically modified mice and inbred mouse strains, has provided significant insight into how genetic variation in these molecules can affect the development and function of a key neural circuit between the dorsal raphe nucleus, medial prefrontal cortex and amygdala. By extension, such variation is hypothesized to have a major influence on individual differences in the stress response and risk for stress-related disease in humans. The current article provides an update on this rapidly evolving field of research.
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PMID:Genetic variation in cortico-amygdala serotonin function and risk for stress-related disease. 1843 76

Biosynthesis and metabolism of serotonin and catecholamines involve at least eight individual enzymes that are mainly expressed in tissues derived from the neuroectoderm, e.g., the central nervous system (CNS), pineal gland, adrenal medulla, enterochromaffin tissue, sympathetic nerves, and ganglia. Some of the enzymes appear to have additional biological functions and are also expressed in the heart and various other internal organs. The biosynthetic enzymes are tyrosine hydroxylase (TH), tryptophan hydroxylases type 1 and 2 (TPH1, TPH2), aromatic amino acid decarboxylase (AADC), dopamine beta-hydroxylase (DbetaH), and phenylethanolamine N-methyltransferase (PNMT), and the specific catabolic enzymes are monoamine oxidase A (MAO-A) and catechol O-methyltransferase (COMT). For the TH, DDC, DBH, and MAOA genes, many single nucleotide polymorphisms (SNPs) with unknown function, and small but increasing numbers of cases with autosomal recessive mutations have been recognized. For the remaining genes (TPH1, TPH2, PNMT, and COMT) several different genetic markers have been suggested to be associated with regulation of mood, pain perception, and aggression, as well as psychiatric disturbances such as schizophrenia, depression, suicidality, and attention deficit/hyperactivity disorder. The genetic markers may either have a functional role of their own, or be closely linked to other unknown functional variants. In the future, molecular testing may become important for the diagnosis of such conditions. Here we present an overview on mutations and polymorphisms in the group of genes encoding monoamine neurotransmitter metabolizing enzymes. At the same time we propose a unified nomenclature for the nucleic acid aberrations in these genes. New variations or details on mutations will be updated in the Pediatric Neurotransmitter Disorder Data Base (PNDDB) database (www.bioPKU.org).
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PMID:Mutations in human monoamine-related neurotransmitter pathway genes. 1844 57

Several reports have been published investigating the relationship between common variants in serotonin-related candidate genes and antidepressant response, and most of the results have been equivocal. We previously reported a significant association between variants in serotonin-related genes and response to the selective serotonin reuptake inhibitor fluoxetine. Here, we attempt to expand upon and replicate these results by (i) resequencing the exonic and putatively regulatory regions of five serotonin-related candidate genes (HTR1A, HTR2A, TPH1, TPH2, and MAOA) in our fluoxetine-treated sample to uncover novel variants; (ii) selecting tagging single nucleotide polymorphisms (SNPs) for these genes from the resequencing data; and (iii) evaluating these tagging SNPs for association with response to the selective serotonin reuptake inhibitor citalopram in an independent sample of participants who are enrolled in the Sequenced Treatment Alternatives to Relieve Depression (STAR*D) clinical study (N=1953). None of the variants associated previously with fluoxetine response were found to be associated with citalopram response in the STAR*D sample set. Nor were any of the additional tagging SNPs found to be associated with citalopram response. An additional SNP in HTR2A (rs7997012), previously reported to be associated with outcome of citalopram treatment in this sample, but not well tagged by any of the other SNPs we studied, was also genotyped, and was associated with citalopram response (P=0.0002), strongly supporting the previous observation in the same STAR*D sample. Our results suggest that resequencing the serotonin-related genes did not identify any additional common SNPs that have not been identified previously. It appears that genetic variation in these five genes has a marginal effect on response to citalopram, although a previously observed association was supported and awaits replication in an independent sample.
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PMID:Resequencing of serotonin-related genes and association of tagging SNPs to citalopram response. 1907 64

Genes that regulate the serotonin signalling system are potential targets for research in the aetiology of mood disorders and also in the treatment response of serotonin reuptake inhibitors. In this study, we evaluated the association of seven serotonin signal transduction-linked single nucleotide polymorphisms [HTR1A (rs6295), HTR2A (rs6313, rs6311 and rs7997012), HTR6 (rs1805054), TPH1 (rs1800532) and TPH2 (rs1386494)] with major depressive disorder and/or treatment outcome with serotonin reuptake inhibitors. Patients who met the criteria for major depressive disorder were treated for 6 weeks with fluoxetine, paroxetine or citalopram. The treatment response was evaluated with the Montgomery-Asberg Depression Rating Scale, and according to predefined response criteria, the patients were divided into responders, nonresponders, remitters and nonremitters. Altogether, 86 patients completed the entire study according to the study protocol. We had also a control population (N = 395) of healthy blood donors. None of the seven single nucleotide polymorphisms was associated with major depressive disorder or with treatment response in our study population of Finnish individuals.
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PMID:5-HTR1A, 5-HTR2A, 5-HTR6, TPH1 and TPH2 polymorphisms and major depression. 1959 Mar 97

Although effective treatment for mood and anxiety disorders have been available for more than 40 years, 30-50% of depressed patients and 25% of patients with anxiety disorder do not respond sufficiently to first-line treatment with antidepressants. Genetic factors are supposed to play a major role in both variation of treatment response and incidence of adverse effects to medication. So far, candidate genes of pharmacokinetic and pharmacodynamic pathways of antidepressants have been investigated, and associations between several candidate genes and response to antidepressants are reported. Two functional polymorphisms of the serotonin transporter gene, 5-HTTLPR and STin2 have been investigated in a large number of pharmacogenetic studies of depression; other candidate genes include serotonin receptor genes, brain-derived neurotrophic factor, P-glycoprotein (located in the blood-brain barrier), G-proteins, TPH1 and TPH2, MAOA, the noradrenaline transporter gene, FKBP5, or cytochrome P450 (CYP450) genes. CYP450 genes play a major role in the metabolism of a substantial part of psychotropics, including antidepressants, and the first estimates of dosage adjustments for antidepressants have been provided based on metabolizer status. Genome-wide association studies that use large numbers of single-nucleotide polymorphisms to screen the entire genome for alleles that influence a trait are now feasible, and the results of the first genome-wide association studies of antidepressant treatment outcome will soon be available. The current review not only updates pharmacogenetic research in depression but also focuses on antidepressant treatment response in anxiety disorders.
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PMID:The role of pharmacogenetics in the treatment of depression and anxiety disorders. 1973 81

The association between the tryptophan hydroxylase 1 (TPH1) 218A/C polymorphism and (1) severity of major depressive disorder (MDD) and (2) response to treatment was studied. There were three study populations, the first consisting of 119 treatment-resistant MDD inpatients treated with electro-convulsive therapy (ECT), and the second of 98 MDD open care patients treated with selective serotonin reuptake inhibitors (SSRI). In addition, there was a control population of 395 healthy blood donors. The first aim of the study was to compare the genotypes of the patient with those of the healthy controls and between patient populations. The second aim was to compare the genotypes of MDD patients achieving remission with basic SSRI treatment (MADRS<8) with the genotypes of non-responders to ECT (defined as MADRS>15). TPH1 218A/C polymorphism was associated with the risk of MDD. CC genotype was significantly more common in patients (including both ECT and SSRI treated patients) than in controls (38.2% and 26.8% respectively; p=0.008), and its frequency was significantly higher in more severe forms of depression, i.e. in ECT treated patients compared with SSRI treated patients (42.0% and 33.7%, p=0.026). CC genotype was also associated with lower probability of achieving remission. It was significantly more frequent among ECT non-responders than among SSRI remitters (53.1% and 23.3%, p=0.049). In this Finnish population TPH1 218A/C polymorphism was associated with the risk of MDD and treatment response; CC genotype was associated with the increased risk of MDD and lower probability of responding treatment. Further studies with larger samples will be required to confirm the results.
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PMID:TPH1 218A/C polymorphism is associated with major depressive disorder and its treatment response. 1987 68


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