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Buckland P. Michael Gwynne Douglas Davys. West J Med 2002. [DOI: 10.1136/bmj.325.7370.972/a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Austin J, Buckland P, Cardno AG, Williams N, Spurlock G, Hoogendoorn B, Zammit S, Jones G, Sanders R, Jones L, McCarthy G, Jones S, Bray NJ, McGuffin P, Owen MJ, O'Donovan MC. The high affinity neurotensin receptor gene (NTSR1): comparative sequencing and association studies in schizophrenia. Mol Psychiatry 2000; 5:552-7. [PMID: 11032391 DOI: 10.1038/sj.mp.4000761] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Neurotensin and its high affinity receptor (NTSR1) localise within dopaminergic neurones in the mesocortical, mesolimbic and nigrostriatal systems and it is now clear that neurotensin can selectively modulate dopaminergic neurotransmission. This has led to the hypothesis that altered neurotensin function contributes to the pathogenesis of schizophrenia and other psychoses. This hypothesis has been supported circumstantially by a number of lines of evidence. (1) Central administration of neurotensin produces effects similar to those produced by the peripheral administration of atypical antipsychotics. (2) Observations of low levels of neurotensin in the CSF of schizophrenics. (3) Reduced numbers of neurotensin receptors in the brains of schizophrenics. Given the above link between neurotensin and dopamine, and the evidence implicating altered neurotensin function in psychosis, we have postulated that DNA sequence variation in neurotensin or its receptors might be associated with schizophrenia. In keeping with this hypothesis, an association has recently been reported between schizophrenia and the gene encoding the neurotensin high affinity receptor (NTSR1). However, caution is required because the associated marker, a tetranucleotide repeat, is located 3 kb away from the 3' end of the gene and there is no evidence that it is functional. Therefore, as a follow-up to our earlier work on neurotensin, we have now sought to test the hypothesis that DNA sequence variants that alter the structure or expression of the NTSR1 gene (VAPSEs) are associated with schizophrenia. However, while we found 14 novel sequence variants in 28 probands with psychosis, none resulted in an amino acid change, and neither direct nor indirect association studies suggested these are involved in susceptibility to schizophrenia.
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Affiliation(s)
- J Austin
- Division of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff, UK
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Speight G, Turic D, Austin J, Hoogendoorn B, Cardno AG, Jones L, Murphy KC, Sanders R, McCarthy G, Jones I, McCandless F, McGuffin P, Craddock N, Owen MJ, Buckland P, O'Donovan MC. Comparative sequencing and association studies of aromatic L-amino acid decarboxylase in schizophrenia and bipolar disorder. Mol Psychiatry 2000; 5:327-31. [PMID: 10889538 DOI: 10.1038/sj.mp.4000717] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Aromatic L-amino acid decarboxylase (AADC) is a relatively non specific enzyme involved in the biosynthesis of several classical neurotransmitters including dopamine and 5-hydroxytryptamine (5HT; serotonin). AADC does not catalyse the rate limiting step in either pathway, but is rate limiting in the synthesis of 2-phenylethylamine (2PE) which is a positive modulator of dopaminergic transmission and a candidate natural psychotogenic compound.1 We and others have proposed that polymorphism in AADC resulting in altered 2PE activity might contribute to the pathogenesis of psychosis. In order to test this hypothesis, we have used denaturing high performance liquid chromatography (DHPLC)3 to screen 3943 bases of the AADC gene and its promoter regions for variants that might affect protein structure or expression in 15 unrelated people with schizophrenia, and 15 unrelated people with bipolar disorder. Three polymorphisms were identified by DHPLC: a insertion/deletion polymorphism in the 5' UTR of the neuronal specific mRNA (g.-33-30delAGAG, bases 586-589 of GenBank M77828), a T>A variant in the non-neuronal exon 1 (g. -67T>A, GenBank M88070), and a G>A polymorphism within intron 8 (g. IVS8 +75G>A, GenBank M84598). Case-control analysis did not suggest that genetic polymorphism in the AADC gene is associated with liability for developing schizophrenia or bipolar disorder.
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Affiliation(s)
- G Speight
- Division of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff, CF14 4XN, UK
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Austin J, Hoogendoorn B, Buckland P, Jones I, McCandless F, Williams N, Middle F, Owen MJ, Craddock N, O'Donovan MC. Association analysis of the proneurotensin gene and bipolar disorder. Psychiatr Genet 2000; 10:51-4. [PMID: 10909129 DOI: 10.1097/00041444-200010010-00009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Neurotensin (NT) localizes within dopaminergic neurones in the mesocortical, mesolimbic and nigrostriatal systems, and it is now clear that NT can selectively modulate dopaminergic neurotransmission. It has therefore been proposed that altered NT function might contribute to the pathogenesis of neuropsychiatric disorders in which disordered dopaminergic neurotransmission is suspected. We have previously screened the gene encoding NT in a sample of schizophrenic and bipolar subjects, and identified three sequence variants. These have now been tested for association with bipolar disorder using a case-control sample of unrelated bipolar subjects and matched controls. No evidence for association was found, and our data therefore suggest that sequence variation in this gene does not make an important contribution to susceptibility to bipolar disorder.
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Affiliation(s)
- J Austin
- Division of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff, UK
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Austin J, Hoogendoorn B, Buckland P, Speight G, Cardno A, Bowen T, Williams N, Spurlock G, Sanders R, Jones L, Murphy K, McCarthy G, McGuffin P, Owen MJ, O'Donovan MC. Comparative sequencing of the proneurotensin gene and association studies in schizophrenia. Mol Psychiatry 2000; 5:208-12. [PMID: 10822351 DOI: 10.1038/sj.mp.4000693] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Neurotensin (NT) is an endogenous tridecapetide1 cleaved from a precursor proneurotensin/ proneuromedin protein. NT localises within dopaminergic neurones in the mesocortical, mesolimbic and nigrostriatal systems1-3 and it is now clear that NT can selectively modulate dopaminergic neurotransmission.2-9 These anatomical and functional connections have led to the hypothesis that NT dysfunction might contribute to the pathogenesis of neuropsychiatric disorders in which disordered dopaminergic neurotransmission is suspected, particularly schizophrenia.3 The latter hypothesis has been supported circumstantially by the observation that central administration of NT produces effects similar to those produced by the peripheral administration of atypical antipsychotics,10,11 and more directly by studies showing levels of NT in cerebral spinal fluid (CSF) is lower in schizophrenics than in controls.12,13 To allow such hypotheses to be tested, we used denaturing high performance liquid chromatography (DHPLC)14 to identify three sequence variants in the neurotensin gene (NTS) that might alter NT structure or expression. However, using a case-control study design and a novel genotyping system based upon a primer extension protocol and HPLC detection,15 we found no evidence to support the hypothesis that variation in the proneurotensin gene contributes to susceptibility to schizophrenia.
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Affiliation(s)
- J Austin
- Division of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff CF4 4XN, UK
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Oretti RG, O'Donovan MC, McGUFFIN P, Buckland P. Tryptophan pyrrolase gene expression in an alcohol preferring and non-preferring mouse strain. Addict Biol 1998; 3:71-7. [PMID: 26736082 DOI: 10.1080/13556219872362] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
There is considerable evidence that the level of cerebral serotonin plays a key role in the volitional consumption of ethanol in both man and animals. Naive alcohol-preferring C57BL/6J mice have been shown to have a lower cerebral serotonin content compared to the non-preferring CBA/Ca mouse strain. This has been attributed to the enhancement of hepatic tryptophan pyrrolase activity in C57 mice. Activity and/or expression of tryptophan pyrrolase may be an important biological determinant of alcohol preference. We have investigated the possible mechanism/s underlying this strain difference in tryptophan pyrrolase activity by assaying both mRNA levels encoding for the tryptophan pyrrolase gene and by mutational analysis of tryptophan pyrrolase cDNA. We were unable to demonstrate any difference in tryptophan pyrrolase mRNA levels between naive C57 and CBA mice. Tryptophan pyrrolase mRNA levels were increased following starvation in C57 mice and following glucocorticoid administration in both C57 and CBA mice. Heteroduplex mutational analysis failed to detect any tryptophan pyrrolase cDNA sequence heterogeneity between these mice strains.
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Affiliation(s)
- R G Oretti
- Department of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff, UK
| | - M C O'Donovan
- Department of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff, UK
| | - P McGUFFIN
- Department of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff, UK
| | - P Buckland
- Department of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff, UK
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Oretti R, Bano S, Morgan CJ, Badawy AA, Bonner A, Buckland P, McGuffin P. Prevention by cycloheximide of the audiogenic seizures and tryptophan metabolic disturbances of ethanol withdrawal in rats. Alcohol Alcohol 1996; 31:243-7. [PMID: 8844029 DOI: 10.1093/oxfordjournals.alcalc.a008143] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
Cycloheximide (20 mg/kg body wt, given intraperitoneally at-1 and 3 h after withdrawal of an ethanol-containing liquid diet) prevents the activation of liver tryptophan pyrrolase, the consequent inhibition of synthesis of brain 5-hydroxytryptamine, and the audiogenic seizures observed at 7 h after alcohol withdrawal. We suggest that a rapidly-turning-over protein mediates the alcohol withdrawal syndrome and discuss the possible role of liver tryptophan pyrrolase.
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Affiliation(s)
- R Oretti
- Department of Psychological Medicine, University of Wales College of Medicine, Health Park, Cardiff, UK
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Morgan JC, Bano S, Buckland P, McGuffin P. Mechanism of enhancement of rat brain serotonin synthesis by acute fluoxetine administration. J Neurochem 1996; 66:436-7. [PMID: 8522987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023]
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Spurlock G, Buckland P, O'Donovan M, McGuffin P. Lack of effect of antidepressant drugs on the levels of mRNAs encoding serotonergic receptors, synthetic enzymes and 5HT transporter. Neuropharmacology 1994; 33:433-40. [PMID: 7984281 DOI: 10.1016/0028-3908(94)90073-6] [Citation(s) in RCA: 57] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/28/2023]
Abstract
Serotonergic transmission is thought to be central to the aetiology of depression and the therapeutic actions of antidepressant drugs, and the latters' delayed effect has given rise to the hypothesis that an adaptive change may be involved, possibly at the level of gene expression. We have examined this hypothesis by treating rats over a time course of up to 32 days with either imipramine, mianserin, fluvoxamine, citalopram, amoxapine or saline and measuring the levels of mRNAs encoding the 5HT1A, 5HT1B, 5HT1C and 5HT2 receptors, the enzymes tryptophan hydroxylase and aromatic amino acid decarboxylase, and the 5HT transporter. None of the treatments gave rise to significant changes in any of the mRNA levels at any time point. These results suggest that the reported changes in 5HT receptor numbers do not occur as a result of changes in the abundance of their encoding mRNAs, and that changes to the latter is not central to the therapeutic effects of antidepressant drugs.
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Affiliation(s)
- G Spurlock
- Department of Psychological Medicine, University of Wales College of Medicine, Heath Park, Cardiff, U.K
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Buckland P, Tidmarsh S, Spurlock G, Kaiser F, Yates M, O'Mahony G, McGuffin P. Amyloid precursor protein mRNA levels in the mononuclear blood cells of Alzheimer's and Down's patients. Brain Res Mol Brain Res 1993; 18:316-20. [PMID: 8326826 DOI: 10.1016/0169-328x(93)90095-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Amyloid precursor protein (APP) is expressed by many non-neural tissues and it is possible that over-expression of the APP gene in non-neural tissue is responsible for the deposition of amyloid beta-protein in the brain and elsewhere. One possible source of beta-protein is circulating mononuclear blood cells which have previously been shown to express APP. To test this hypothesis, RNA was isolated from the mononuclear blood cells of patients suffering from Alzheimer's disease (n = 27), Down's syndrome (n = 13), senile dementia non-Alzheimer type (n = 14) and from normal individuals (n = 48). The relative abundance of mRNA coding for different splicing variants of the amyloid precursor protein (APP) mRNA was measured using multiprobe oligonucleotide solution hybridisation (MOSH). There was no significant difference in APP mRNA levels between any of the groups. This indicates that Alzheimer's disease is not characterised by an increase in production of APP in circulating mononuclear blood cells.
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Affiliation(s)
- P Buckland
- Department of Psychiatry, University of Wales College of Medicine, Cardiff UK
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Asherson P, Parfitt E, Sargeant M, Tidmarsh S, Buckland P, Taylor C, Clements A, Gill M, McGuffin P, Owen M. No evidence for a pseudoautosomal locus for schizophrenia. Linkage analysis of multiply affected families. Br J Psychiatry 1992; 161:63-8. [PMID: 1638331 DOI: 10.1192/bjp.161.1.63] [Citation(s) in RCA: 37] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Evidence for a pseudoautosomal locus for a schizophrenia susceptibility gene was sought by two forms of analysis of 25 multiply affected families. Firstly, in the sample as a whole there was an excess of same-sex over mixed-sex siblings compared with that expected. Secondly, linkage analysis was performed in six of the families. The genotypes were studied for DXYS14, a highly polymorphic marker in the telomeric pseudoautosomal region. No evidence for positive linkage was found with two-point analysis under eight different genetic models for the mode of transmission. A non-parametric, sibling-pair analysis also failed to detect linkage. Our findings provide no evidence for linkage within the pseudoautosomal region; same-sex concordance must arise from some other mechanism.
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Affiliation(s)
- P Asherson
- Department of Psychological Medicine, University of Wales College of Medicine, Cardiff
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McGuffin P, Buckland P. Major genes, minor genes and molecular neurobiology of mental illness: a comment on 'Quantitative trait loci and psychopharmacology' by Plomin, McClearn and Gora-Maslak. J Psychopharmacol 1991; 5:18-22. [PMID: 22282117 DOI: 10.1177/026988119100500105] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- P McGuffin
- University of Wales College of Medicine, Heath Park, Cardiff, UK
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Buckland P. Drug information centres: an industry view. Proc R Soc Med 1977; 70:253-5. [PMID: 866327 PMCID: PMC1543048] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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