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Barki M, Xue H. GABRB2, a key player in neuropsychiatric disorders and beyond. Gene 2022; 809:146021. [PMID: 34673206 DOI: 10.1016/j.gene.2021.146021] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/26/2020] [Revised: 08/05/2021] [Accepted: 09/14/2021] [Indexed: 01/11/2023]
Abstract
The GABA receptors represent the main inhibitory system in the central nervous system that ensure synaptogenesis, neurogenesis, and the regulation of neuronal plasticity and learning. GABAA receptors are pentameric in structure and belong to the Cys-loop superfamily. The GABRB2 gene, located on chromosome 5q34, encodes the β2 subunit that combines with the α and γ subunits to form the major subtype of GABAA receptors, which account for 43% of all GABAA receptors in the mammalian brain. Each subunit probably consists of an extracellular N-terminal domain, four membrane-spanning segments, a large intracellular loop between TM3 and TM4, and an extracellular C-terminal domain. Alternative splicing of the RNA transcript of the GABRB2 gene gives rise at least to four long and short isoforms with dissimilar electrophysiological properties. Furthermore, GABRB2 is imprinted and subjected to epigenetic regulation and positive selection. It has been associated with schizophrenia first in Han Chinese, and subsequently validated in other populations. Gabrb2 knockout mice also exhibited schizophrenia-like behavior and neuroinflammation that were ameliorated by the antipsychotic drug risperidone. GABRB2 was also associated with other neuropsychiatric disorders including bipolar disorder, epilepsy, autism spectrum disorder, Alzheimer's disease, frontotemporal dementia, substance dependence, depression, internet gaming disorder, and premenstrual dysphoric disorder. Recently, it has been postulated that GABRB2 might be a potential marker for different cancer types. As GABRB2 has a pivotal role in the central nervous system and is increasingly recognized to contribute to human diseases, further understanding of its structure and function may expedite the generation of new therapeutic approaches.
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Affiliation(s)
- Manel Barki
- Center for Cancer Genomics, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, China
| | - Hong Xue
- Center for Cancer Genomics, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, China; Division of Life Science and Applied Genomics Center, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.
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2
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Long X, Xue H. Genetic-variant hotspots and hotspot clusters in the human genome facilitating adaptation while increasing instability. Hum Genomics 2021; 15:19. [PMID: 33741065 PMCID: PMC7976700 DOI: 10.1186/s40246-021-00318-3] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Accepted: 03/04/2021] [Indexed: 12/25/2022] Open
Abstract
Background Genetic variants, underlining phenotypic diversity, are known to distribute unevenly in the human genome. A comprehensive understanding of the distributions of different genetic variants is important for insights into genetic functions and disorders. Methods Herein, a sliding-window scan of regional densities of eight kinds of germline genetic variants, including single-nucleotide-polymorphisms (SNPs) and four size-classes of copy-number-variations (CNVs) in the human genome has been performed. Results The study has identified 44,379 hotspots with high genetic-variant densities, and 1135 hotspot clusters comprising more than one type of hotspots, accounting for 3.1% and 0.2% of the genome respectively. The hotspots and clusters are found to co-localize with different functional genomic features, as exemplified by the associations of hotspots of middle-size CNVs with histone-modification sites, work with balancing and positive selections to meet the need for diversity in immune proteins, and facilitate the development of sensory-perception and neuroactive ligand-receptor interaction pathways in the function-sparse late-replicating genomic sequences. Genetic variants of different lengths co-localize with retrotransposons of different ages on a “long-with-young” and “short-with-all” basis. Hotspots and clusters are highly associated with tumor suppressor genes and oncogenes (p < 10−10), and enriched with somatic tumor CNVs and the trait- and disease-associated SNPs identified by genome-wise association studies, exceeding tenfold enrichment in clusters comprising SNPs and extra-long CNVs. Conclusions In conclusion, the genetic-variant hotspots and clusters represent two-edged swords that spearhead both positive and negative genomic changes. Their strong associations with complex traits and diseases also open up a potential “Common Disease-Hotspot Variant” approach to the missing heritability problem. Supplementary Information The online version contains supplementary material available at 10.1186/s40246-021-00318-3.
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Affiliation(s)
- Xi Long
- Division of Life Science and Applied Genomics Centre, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China.,HKUST Shenzhen Research Institute, 9 Yuexing First Road, Nanshan, Shenzhen, China
| | - Hong Xue
- Division of Life Science and Applied Genomics Centre, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China. .,HKUST Shenzhen Research Institute, 9 Yuexing First Road, Nanshan, Shenzhen, China. .,Centre for Cancer Genomics, School of Basic Medicine and Clinical Pharmacy, China Pharmaceutical University, Nanjing, Jiangsu, China.
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3
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Heidari Nia M, Sargazi S, Saravani R, Mirinejad S, Jahantigh D, Shakiba M. Relationship between GABRB2 gene polymorphisms and schizophrenia susceptibility: a case-control study and in silico analyses. Int J Neurosci 2020; 132:633-642. [PMID: 32988247 DOI: 10.1080/00207454.2020.1830087] [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: 10/23/2022]
Abstract
PURPOSE Converging evidence has recently established the significance of γ-aminobutyric acid neurotransmitter (GABA) system in the development of schizophrenia (SCZ). We aimed to determine the association of two markers of the GABAA receptor β2 subunit gene (GABRB2), rs12187676 G/C and rs1816072 T/C, with the risk of SCZ in Iranian population. MATERIALS AND METHODS In this case-control study, 190 patients with SCZ and 200 healthy controls were recruited from December 2018 to February 2020. Genotyping was done using the Tetra-ARMS-PCR technique. In silico analyses were performed to determine the potential effects of the variants. RESULTS The C allele and genotypes of codominant CC vs.TT and CT vs.TT, dominant TT vs. TC + CC, recessive TT + TC vs. CC of rs1816072 polymorphism, as well as codominant CC vs. GG and recessive GG + GC vs. CC genetic models of rs12187676 polymorphism were significantly associated with SCZ susceptibility. Compared to the TC/GC model, we have found that the TC/CC combination significantly increased the risk of SCZ by 4.32 fold while the TT/GG combination conferred a protective role against SCZ. Haplotypes analysis indicated that GABRB2 polymorphisms are in weak linkage disequilibrium with each other (LD = 0.1). However, bioinformatics analyses predicted that these polymorphisms do not have significant effects on the secondary structure and the splicing of GABRB2-mRNA. CONCLUSIONS We found that intronic GABRB2 polymorphisms were associated with SCZ risk in a sample of the Iranian population. These findings provided proof of concept for the involvement of the GABAergic neurotransmission system in SCZ development. These observations should be validated across other ethnicities and clinical subtypes.
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Affiliation(s)
- Milad Heidari Nia
- Cellular and Molecular Research Center, Resistant Tuberculosis Institute, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Saman Sargazi
- Cellular and Molecular Research Center, Resistant Tuberculosis Institute, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Ramin Saravani
- Cellular and Molecular Research Center, Resistant Tuberculosis Institute, Zahedan University of Medical Sciences, Zahedan, Iran.,Department of Clinical Biochemistry, School of Medicine, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Shekoufeh Mirinejad
- Cellular and Molecular Research Center, Resistant Tuberculosis Institute, Zahedan University of Medical Sciences, Zahedan, Iran
| | - Danial Jahantigh
- Department of Biology, Faculty of Science, University of Sistan and Baluchestan, Zahedan, Iran
| | - Mansoor Shakiba
- Department of Psychiatry, Zahedan University of Medical Sciences, Zahedan, Iran
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The association of GABRB2 SNPs with cognitive function in schizophrenia. Eur Arch Psychiatry Clin Neurosci 2020; 270:443-449. [PMID: 30706170 DOI: 10.1007/s00406-019-00985-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 01/09/2019] [Indexed: 12/21/2022]
Abstract
Cognitive impairment is one of the core symptoms of schizophrenia. Multiple domains of cognition are affected in patients with schizophrenia, which has a major effect on the functional outcome. Recent studies indicate that SNPs in the gamma-aminobutyric acid type A receptor beta 2 subunit (GABRB2) gene are associated with the risk of schizophrenia, however, the effect of these SNPs on cognitive function in patients with schizophrenia has not been explored. In this study, we first performed a case-control analysis of three SNPs (rs187269 allele A vs. G, rs252944 allele C vs. G, and rs194072 allele A vs. G) in 100 patients and 90 controls, then conducted a meta-analysis and found the SNP rs194072 was associated with schizophrenia (OR = 0.86, P = 0.0119), and survived after Bonferroni correction. The haplotype analysis suggested that the haplotype ACA, comprising the three SNPs (rs187269, rs252944 and rs194072) was also significantly associated with schizophrenia (P = 0.049).Then, we performed an association analysis of three SNPs (rs187269, rs252944 and rs194072) in GABRB2 gene with cognitive performance in patients with first episode schizophrenia. We found that the allele G of rs187269 in the GABRB2 gene was significantly associated with better cognitive flexibility (P = 0.005), a major aspect of executive function, in patients with first episode schizophrenia. The haplotype ACA was significantly associated with cognitive flexibility in patients with schizophrenia (P = 0.023). Our study showed that SNPs in GABRB2 may have a significant effect on cognitive function in patients with schizophrenia, suggesting that modulating GABRB2 may have therapeutic potential to improve cognitive function of patients with schizophrenia.
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Zong L, Zhou L, Hou Y, Zhang L, Jiang W, Zhang W, Wang L, Luo X, Wang S, Deng C, Peng Z, Li S, Hu J, Zhao H, Zhao C. Genetic and epigenetic regulation on the transcription of GABRB2: Genotype-dependent hydroxymethylation and methylation alterations in schizophrenia. J Psychiatr Res 2017; 88:9-17. [PMID: 28063323 DOI: 10.1016/j.jpsychires.2016.12.019] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2016] [Revised: 11/30/2016] [Accepted: 12/19/2016] [Indexed: 12/17/2022]
Abstract
To improve our understanding of the abnormalities and non-Mendelian inheritance characteristics of schizophrenia, this study examined DNA methylation (5mC) and hydroxymethylation (5hmC) in the schizophrenia-associated GABRB2 gene encoding the type A γ-aminobutyric acid receptor β2 subunit. DNAs from the peripheral white blood cells of 279 schizophrenic patients and 256 controls from the Chinese Han population were examined to reveal that the GABRB2 promoter P1-5mC level which was correlated with olanzapine administration, P2-5mC/5hmC level, and Alu-5mC level which was correlated with administration of ziprasidone or oxcarbazepine, were increased in schizophrenic patients. Significant correlations of the promoter 5mC/5hmC levels with the genotypes of single nucleotide polymorphisms (SNPs) were observed with SNPs rs72815526 (C/A) and rs3811997 (C/T). In schizophrenics, the heterozygous genotypes of rs72815526 (C/A) were correlated with increased 5hmC levels whereas the heterozygous genotypes of rs3811997 (C/T) were correlated with decreased 5mC levels. Moreover, the GABRB2 promoter with rs3811997(C/T) minor allele T or the methylation-disrupted type AG at -254 and -231 CCGG sites was observed to enhance the promoter activity in the luciferase reporter-transfected human embryonic kidney 293 cells. An elevated GABRB2 mRNA transcriptional level in human neuroblastoma IMR32 cells were accompanied by the decreased promoter 5hmC/5mC levels induced by 5-azacytidine or by increased histone H4 acetylation levels of the Alu-Yi6 region induced by valproic acid. These results reveal alterations in GABRB2 genotype-dependent methylation and hydroxymethylation in schizophrenia, which yielded transcriptional and translational alterations in the cultured cells, and help elucidate the genetic-epigenetic interactions influencing schizophrenia.
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Affiliation(s)
- Lu Zong
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China; Guangdong Technology and Engineering Research Center for Molecular Diagnostics of Human Genetic Diseases, Guangzhou, Guangdong, China
| | - Lin Zhou
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China; Guangdong Technology and Engineering Research Center for Molecular Diagnostics of Human Genetic Diseases, Guangzhou, Guangdong, China; Key Laboratory of Genetics and Birth Health of Hunan Province, Family Planning Institute of Hunan Province, Changsha, China
| | - Yu Hou
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China; Guangdong Technology and Engineering Research Center for Molecular Diagnostics of Human Genetic Diseases, Guangzhou, Guangdong, China
| | - Lulu Zhang
- Department of Psychiatry, Guangzhou First People's Hospital, Guangzhou, Guangdong, China
| | - Wei Jiang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China; Guangdong Technology and Engineering Research Center for Molecular Diagnostics of Human Genetic Diseases, Guangzhou, Guangdong, China
| | - Wenwei Zhang
- The Third People's Hospital of Zhongshan, Zhongshan, Guangdong, China
| | - Lijuan Wang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China; Guangdong Technology and Engineering Research Center for Molecular Diagnostics of Human Genetic Diseases, Guangzhou, Guangdong, China
| | - Xia Luo
- Department of Psychiatry, Shenzhen Kangning Hospital & Shenzhen Mental Health Center, Shenzhen, China
| | - Shiqing Wang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China; Guangdong Technology and Engineering Research Center for Molecular Diagnostics of Human Genetic Diseases, Guangzhou, Guangdong, China
| | - Cong Deng
- The Second Affiliated Hospital of Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Zhizhen Peng
- The Third People's Hospital of Zhongshan, Zhongshan, Guangdong, China
| | - Shufen Li
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China; Guangdong Technology and Engineering Research Center for Molecular Diagnostics of Human Genetic Diseases, Guangzhou, Guangdong, China
| | - Jiming Hu
- The Third People's Hospital of Zhongshan, Zhongshan, Guangdong, China
| | - Hu Zhao
- Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, Guangdong, China
| | - Cunyou Zhao
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guangdong, China; Guangdong Technology and Engineering Research Center for Molecular Diagnostics of Human Genetic Diseases, Guangzhou, Guangdong, China.
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Chekouo T, Stingo FC, Guindani M, Do KA. A Bayesian predictive model for imaging genetics with application to schizophrenia. Ann Appl Stat 2016. [DOI: 10.1214/16-aoas948] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022]
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Bristow GC, Bostrom JA, Haroutunian V, Sodhi MS. Sex differences in GABAergic gene expression occur in the anterior cingulate cortex in schizophrenia. Schizophr Res 2015; 167:57-63. [PMID: 25660468 PMCID: PMC4524801 DOI: 10.1016/j.schres.2015.01.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 01/15/2015] [Accepted: 01/17/2015] [Indexed: 01/30/2023]
Abstract
GABAergic dysfunction has been strongly implicated in the pathophysiology of schizophrenia. In this study, we analyzed the expression levels of several GABAergic genes in the anterior cingulate cortex (ACC) of postmortem subjects with schizophrenia (n=21) and a comparison group of individuals without a history of psychiatric illness (n=18). Our analyses revealed a significant sex by diagnosis effect, along with significant differences in GABAergic gene expression based on medication status. Analyses revealed that in male groups, the expression of GABAergic genes was generally lower in schizophrenia cases compared to the controls, with significantly lower expression levels of GABA-Aα5, GABA-Aβ1, and GABA-Aε. In females, the expression of GABAergic genes was higher in the schizophrenia cases, with significantly higher expression of the GABA-Aβ1 and GAD67 genes. Analysis of the effect of medication in the schizophrenia subjects revealed significantly higher expression of GABA-Aα1-3, GABA-Aβ2, GABA-Aγ2, and GAD67 in the medicated group compared to the unmedicated group. These data show that sex differences in the expression of GABAergic genes occur in the ACC in schizophrenia. Therefore, our data support previous findings of GABAergic dysfunction in schizophrenia and emphasize the importance of considering sex in analyses of the pathophysiology of schizophrenia. Sex differences in the GABAergic regulation of ACC function may contribute to the differences observed in the symptoms of male and female patients with schizophrenia. In addition, our findings indicate that antipsychotic medications may alter GABAergic signaling in the ACC, supporting the potential of GABAergic targets for the development of novel antipsychotic medication.
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Affiliation(s)
- Greg C. Bristow
- Department of Pharmacy Practice and Center for Pharmaceutical Biotechnology, College of Pharmacy, University of Illinois at Chicago, Chicago IL 60607, USA.,Corresponding author: Dr. Greg Bristow, Department of Pharmacy Practice, University of Illinois at Chicago, 900 S. Ashland Ave., MC870, Chicago IL 60607-4067, USA. Tel: +1-312-996-1413, Fax: +1-312-413-9303,
| | - John A. Bostrom
- Department of Pharmacy Practice and Center for Pharmaceutical Biotechnology, College of Pharmacy, University of Illinois at Chicago, Chicago IL 60607, USA
| | - Vahram Haroutunian
- Department of Psychiatry, Mount Sinai School of Medicine, New York, NY, USA
| | - Monsheel S. Sodhi
- Department of Pharmacy Practice and Center for Pharmaceutical Biotechnology, College of Pharmacy, University of Illinois at Chicago, Chicago IL 60607, USA.,Department of Psychiatry, University of Illinois at Chicago, Chicago, IL 60612, USA
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Li S, Wang Z, Zhou L, Luo F, Zhao C. Fluorescence polarization-based method with bisulfite conversion-specific one-label extension for quantification of single CpG dinucleotide methylation. Genome 2015; 58:357-63. [DOI: 10.1139/gen-2014-0185] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
To quantify the methylation at individual CpG dinucleotide sites in large biological or clinical samples, we developed a bisulfite conversion-specific one-label extension (BS-OLE) method using visualization by fluorescence polarization (FP) measurement of methylation at single CpG sites in small amounts of genomic DNA. Genomic DNA was treated with sodium bisulfite to convert unmethylated cytosine to uracil leaving 5-methylcytosine unaltered, and BS-PCR was used to generate DNA template containing target CpG sites. BS-OLE uses a BS-primer hybridized immediately upstream of the target CpG site being examined and then fluorescent dCTP or dUTP is incorporated into the methylated (CpG) or unmethylated (TpG) form of the target site through single-nucleotide chain extension, yielding an FP ratio between the fluorescent dCTP- and dUTP-incorporated products as a measure of methylation. This provides stable estimates of the methylation level of human genomic DNA and of a 250-bp plasmid DNA segment containing a single TCGA TaqI cleavage site, in accordance with the results of a combined bisulfite restriction analysis method. We used BS-OLE to measure dose-dependent DNA hypomethylation in human embryonic kidney 293T cells treated with the DNA methyltransferase inhibitor 5-aza-dC. BS-OLE is well suited to high-throughput multi-sample applications in biological and medical studies.
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Affiliation(s)
- Shufen Li
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, No. 1023 Shatai Road, Baiyun District, Guangzhou City, Guangdong Province 510515, China
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, No. 1023 Shatai Road, Baiyun District, Guangzhou City, Guangdong Province 510515, China
| | - Zhongju Wang
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, No. 1023 Shatai Road, Baiyun District, Guangzhou City, Guangdong Province 510515, China
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, No. 1023 Shatai Road, Baiyun District, Guangzhou City, Guangdong Province 510515, China
| | - Lin Zhou
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, No. 1023 Shatai Road, Baiyun District, Guangzhou City, Guangdong Province 510515, China
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, No. 1023 Shatai Road, Baiyun District, Guangzhou City, Guangdong Province 510515, China
| | - Fu Luo
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, No. 1023 Shatai Road, Baiyun District, Guangzhou City, Guangdong Province 510515, China
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, No. 1023 Shatai Road, Baiyun District, Guangzhou City, Guangdong Province 510515, China
| | - Cunyou Zhao
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, No. 1023 Shatai Road, Baiyun District, Guangzhou City, Guangdong Province 510515, China
- Department of Medical Genetics, School of Basic Medical Sciences, Southern Medical University, No. 1023 Shatai Road, Baiyun District, Guangzhou City, Guangdong Province 510515, China
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Zhao C, Xue H. A simple method for high-throughput quantification of genome-wide DNA methylation by fluorescence polarization. Epigenetics 2014; 7:335-9. [DOI: 10.4161/epi.19376] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
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10
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A rapid fluorescence polarization-based method for genotypic detection of drug resistance in Mycobacterium tuberculosis. Appl Microbiol Biotechnol 2014; 98:4095-105. [DOI: 10.1007/s00253-013-5356-1] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2013] [Revised: 10/21/2013] [Accepted: 10/22/2013] [Indexed: 11/24/2022]
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Genetic association of lipid metabolism related SNPs with myocardial infarction in the Pakistani population. Mol Biol Rep 2014; 41:1545-52. [PMID: 24402875 DOI: 10.1007/s11033-013-3000-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2013] [Accepted: 12/28/2013] [Indexed: 12/27/2022]
Abstract
Myocardial infarction (MI) is the major cardiovascular disease. This can be caused by mutual interaction of environmental and genetic factors. The current study was designed to investigate the role of lipid metabolism related genetic polymorphisms with the onset of MI in Punjabi population of Pakistan. A total of 384 subjects was studied from April 2011 to July 2012. To determine the genetic associations with MI, the single nucleotide polymorphisms (SNPs) were genotyped by sequencing, as well as one label extension method. Out of eight SNPs in four candidate genes, seven genetic variants were significantly (P < 0.05) associated with elevated risk of MI. In current study two SNPs rs662799 risk allele G (P = 0.03) and rs3135506 risk allele C (P = 0.05) of APOA5 were found to be associated with significant higher risk of triglyceride levels, irrespective of age, sex, obesity, diabetes, hypertension and smoking. Gene variants (rs1558861, rs662799 and rs10750097) in APOA5 showed almost complete linkage disequilibrium and their minor allele frequencies (0.34, 0.28, and 0.41 respectively) were more prevalent (P < 0.05) in cases than controls. We further revealed risk haplotypes (C-T-G-A, G-C-A-G; P = 0.001) and protective haplotypes (G-T-A-G, C-C-G-A; P = 0.005) between these four SNPs for the progression of MI. Current study confirms the correlation between lipid metabolism related SNPs with MI and supports the role of APOA5 in raising plasma triglyceride levels in Pakistanis. However further studies are needed for delineating the role of these SNPs.
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Tsang SY, Zhong S, Mei L, Chen J, Ng SK, Pun FW, Zhao C, Jing B, Chark R, Guo J, Tan Y, Li L, Wang C, Chew SH, Xue H. Social cognitive role of schizophrenia candidate gene GABRB2. PLoS One 2013; 8:e62322. [PMID: 23638040 PMCID: PMC3634734 DOI: 10.1371/journal.pone.0062322] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 03/20/2013] [Indexed: 11/18/2022] Open
Abstract
The occurrence of positive selection in schizophrenia-associated GABRB2 suggests a broader impact of the gene product on population fitness. The present study considered the possibility of cognition-related GABRB2 involvement by examining the association of GABRB2 with psychosis and altruism, respectively representing psychiatric and psychological facets of social cognition. Four single nucleotide polymorphisms (SNPs) were genotyped for quantitative trait analyses and population-based association studies. Psychosis was measured by either the Positive and Negative Syndrome Scale (PANSS) or antipsychotics dosage, and altruism was based on a self-report altruism scale. The minor alleles of SNPs rs6556547, rs1816071 and rs187269 in GABRB2 were correlated with high PANSS score for positive symptoms in a Han Chinese schizophrenic cohort, whereas those of rs1816071 and rs1816072 were associated with high antipsychotics dosage in a US Caucasian schizophrenic cohort. Moreover, strongly significant GABRB2-disease associations were found among schizophrenics with severe psychosis based on high PANSS positive score, but no significant association was observed for schizophrenics with only mild psychosis. Interestingly, in addition to association with psychosis in schizophrenics, rs187269 was also associated with altruism in healthy Han Chinese. Furthermore, parallel to correlation with severe psychosis, its minor allele was correlated with high altruism scores. These findings revealed that GABRB2 is associated with psychosis, the core symptom and an endophenotype of schizophrenia. Importantly, the association was found across the breadth of the psychiatric (psychosis) to psychological (altruism) spectrum of social cognition suggesting GABRB2 involvement in human cognition.
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Affiliation(s)
- Shui Ying Tsang
- Division of Life Science and Applied Genomics Laboratory, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Songfa Zhong
- Department of Economics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- Department of Economics, National University of Singapore, Singapore, Rep. of Singapore
| | - Lingling Mei
- Division of Life Science and Applied Genomics Laboratory, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Jianhuan Chen
- Division of Life Science and Applied Genomics Laboratory, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Siu-Kin Ng
- Division of Life Science and Applied Genomics Laboratory, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Frank W. Pun
- Division of Life Science and Applied Genomics Laboratory, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- Center for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Cunyou Zhao
- Division of Life Science and Applied Genomics Laboratory, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Bingyi Jing
- Center for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- Department of Mathematics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Robin Chark
- Department of Marketing, National University of Singapore, Singapore, Rep. of Singapore
| | - Jianhua Guo
- School of Mathematics and Statistics, Northeast Normal University, Changchun, China
| | - Yunlong Tan
- Beijing Huilongguan Hospital, Beijing, China
| | - Lijun Li
- Beijing Anding Hospital, Capital Medical University, Beijing, China
| | - Chuanyue Wang
- Beijing Anding Hospital, Capital Medical University, Beijing, China
| | - Soo Hong Chew
- Department of Economics, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- Department of Economics, National University of Singapore, Singapore, Rep. of Singapore
| | - Hong Xue
- Division of Life Science and Applied Genomics Laboratory, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- Center for Statistical Science, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- State Key Laboratory of Molecular Neuroscience, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- * E-mail:
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Zhao C, Wang F, Pun FW, Mei L, Ren L, Yu Z, Ng SK, Chen J, Tsang SY, Xue H. Epigenetic regulation on GABRB2 isoforms expression: developmental variations and disruptions in psychotic disorders. Schizophr Res 2012; 134:260-6. [PMID: 22206711 DOI: 10.1016/j.schres.2011.11.029] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2011] [Revised: 11/18/2011] [Accepted: 11/28/2011] [Indexed: 11/28/2022]
Abstract
INTRODUCTION To improve the understanding of psychotic abnormalities and their non-Mendelian inheritance patterns, the epigenetic regulation of the psychotic disorder-associated GABRB2, gene for the type A γ-aminobutyric acid receptor β(2)-subunit, was investigated. METHODS Expression of GABRB2, and the epigenetic regulatory enzymes histone deacetylases (HDACs) and DNA methyltransferases (DNMTs) in mouse and postmortem human brains was analyzed using real-time PCR. RESULTS Results showed that expression of GABRB2 isoforms significantly increased over time in both mouse and human, especially for the long splicing isoform. In the brains of non-psychiatric controls (CON), a significant positive correlation of GABRB2 expression with age was observed in individuals with MM genotypes of the single nucleotide polymorphisms (SNPs) rs187269 and rs1816072. This was reversed to a significant negative correlation in schizophrenics (SCZ). A similar reversal was also displayed by bipolar disorder (BPD) patients. In parallel, a significant co-variation of HDAC1 with GABRB2 expression observed in CON remained significant in BPD but not in SCZ; comparably, a significant co-variation of HDAC2 with GABRB2 expression observed in CON became non-significant in both SCZ and BPD. Moreover, co-variations of DNMT1 and DNMT3B with GABRB2, not observable in CON, became significant in BPD. CONCLUSION These findings demonstrated that GABRB2 expression was under epigenetic regulation that varied with development, genotype and disease status, and these regulatory mechanisms were observably disrupted in SCZ and BPD. This study provided insight into the complex inheritance patterns of psychiatric disorders, and pointed to the involvement of epigenetic dysregulation in the disease process of major psychotic disorders.
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Affiliation(s)
- Cunyou Zhao
- Division of Life Science, Applied Genomics Center and Fok Ying Tung Graduate School, The Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong, China
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14
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Greenwood TA, Lazzeroni LC, Murray SS, Cadenhead KS, Calkins ME, Dobie DJ, Green MF, Gur RE, Gur RC, Hardiman G, Kelsoe JR, Leonard S, Light GA, Nuechterlein KH, Olincy A, Radant AD, Schork NJ, Seidman LJ, Siever LJ, Silverman JM, Stone WS, Swerdlow NR, Tsuang DW, Tsuang MT, Turetsky BI, Freedman R, Braff DL. Analysis of 94 candidate genes and 12 endophenotypes for schizophrenia from the Consortium on the Genetics of Schizophrenia. Am J Psychiatry 2011; 168:930-46. [PMID: 21498463 PMCID: PMC3751972 DOI: 10.1176/appi.ajp.2011.10050723] [Citation(s) in RCA: 204] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/03/2023]
Abstract
OBJECTIVE The authors used a custom array of 1,536 single-nucleotide polymorphisms (SNPs) to interrogate 94 functionally relevant candidate genes for schizophrenia and identify associations with 12 heritable neurophysiological and neurocognitive endophenotypes in data collected by the Consortium on the Genetics of Schizophrenia. METHOD Variance-component association analyses of 534 genotyped subjects from 130 families were conducted by using Merlin software. A novel bootstrap total significance test was also developed to overcome the limitations of existing genomic multiple testing methods and robustly demonstrate significant associations in the context of complex family data and possible population stratification effects. RESULTS Associations with endophenotypes were observed for 46 genes of potential functional significance, with three SNPs at p<10(-4), 27 SNPs at p<10(-3), and 147 SNPs at p<0.01. The bootstrap analyses confirmed that the 47 SNP-endophenotype combinations with the strongest evidence of association significantly exceeded that expected by chance alone, with 93% of these findings expected to be true. Many of the genes interact on a molecular level, and eight genes (e.g., NRG1 and ERBB4) displayed evidence for pleiotropy, revealing associations with four or more endophenotypes. The results collectively support a strong role for genes related to glutamate signaling in mediating schizophrenia susceptibility. CONCLUSIONS This study supports use of relevant endophenotypes and the bootstrap total significance test for identifying genetic variation underlying the etiology of schizophrenia. In addition, the observation of extensive pleiotropy for some genes and singular associations for others suggests alternative, independent pathways mediating pathogenesis in the "group of schizophrenias."
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Affiliation(s)
- Tiffany A Greenwood
- Department of Psychiatry, University of California at San Diego, La Jolla, CA 92093-0804, USA
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15
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Berretta S. Extracellular matrix abnormalities in schizophrenia. Neuropharmacology 2011; 62:1584-97. [PMID: 21856318 DOI: 10.1016/j.neuropharm.2011.08.010] [Citation(s) in RCA: 129] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2011] [Revised: 08/05/2011] [Accepted: 08/08/2011] [Indexed: 02/06/2023]
Abstract
Emerging evidence points to the involvement of the brain extracellular matrix (ECM) in the pathophysiology of schizophrenia (SZ). Abnormalities affecting several ECM components, including Reelin and chondroitin sulfate proteoglycans (CSPGs), have been described in subjects with this disease. Solid evidence supports the involvement of Reelin, an ECM glycoprotein involved in corticogenesis, synaptic functions and glutamate NMDA receptor regulation, expressed prevalently in distinct populations of GABAergic neurons, which secrete it into the ECM. Marked changes of Reelin expression in SZ have typically been reported in association with GABA-related abnormalities in subjects with SZ and bipolar disorder. Recent findings from our group point to substantial abnormalities affecting CSPGs, a main ECM component, in the amygdala and entorhinal cortex of subjects with schizophrenia, but not bipolar disorder. Striking increases of glial cells expressing CSPGs were accompanied by reductions of perineuronal nets, CSPG- and Reelin-enriched ECM aggregates enveloping distinct neuronal populations. CSPGs developmental and adult functions, including neuronal migration, axon guidance, synaptic and neurotransmission regulation are highly relevant to the pathophysiology of SZ. Together with reports of anomalies affecting several other ECM components, these findings point to the ECM as a key component of the pathology of SZ. We propose that ECM abnormalities may contribute to several aspects of the pathophysiology of this disease, including disrupted connectivity and neuronal migration, synaptic anomalies and altered GABAergic, glutamatergic and dopaminergic neurotransmission.
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Affiliation(s)
- Sabina Berretta
- Translational Neuroscience Laboratory, Mclean Hospital, 115 Mill Street, Belmont, MA 02478, USA.
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A recombination hotspot in a schizophrenia-associated region of GABRB2. PLoS One 2010; 5:e9547. [PMID: 20221451 PMCID: PMC2833194 DOI: 10.1371/journal.pone.0009547] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Accepted: 01/28/2010] [Indexed: 12/01/2022] Open
Abstract
Background Schizophrenia is a major disorder with complex genetic mechanisms. Earlier, population genetic studies revealed the occurrence of strong positive selection in the GABRB2 gene encoding the β2 subunit of GABAA receptors, within a segment of 3,551 bp harboring twenty-nine single nucleotide polymorphisms (SNPs) and containing schizophrenia-associated SNPs and haplotypes. Methodology/Principal Findings In the present study, the possible occurrence of recombination in this ‘S1–S29’ segment was assessed. The occurrence of hotspot recombination was indicated by high resolution recombination rate estimation, haplotype diversity, abundance of rare haplotypes, recurrent mutations and torsos in haplotype networks, and experimental haplotyping of somatic and sperm DNA. The sub-segment distribution of relative recombination strength, measured by the ratio of haplotype diversity (Hd) over mutation rate (θ), was indicative of a human specific Alu-Yi6 insertion serving as a central recombining sequence facilitating homologous recombination. Local anomalous DNA conformation attributable to the Alu-Yi6 element, as suggested by enhanced DNase I sensitivity and obstruction to DNA sequencing, could be a contributing factor of the increased sequence diversity. Linkage disequilibrium (LD) analysis yielded prominent low LD points that supported ongoing recombination. LD contrast revealed significant dissimilarity between control and schizophrenic cohorts. Among the large array of inferred haplotypes, H26 and H73 were identified to be protective, and H19 and H81 risk-conferring, toward the development of schizophrenia. Conclusions/Significance The co-occurrence of hotspot recombination and positive selection in the S1–S29 segment of GABRB2 has provided a plausible contribution to the molecular genetics mechanisms for schizophrenia. The present findings therefore suggest that genome regions characterized by the co-occurrence of positive selection and hotspot recombination, two interacting factors both affecting genetic diversity, merit close scrutiny with respect to the etiology of common complex disorders.
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GABRB2 in schizophrenia and bipolar disorder: disease association, gene expression and clinical correlations. Biochem Soc Trans 2010; 37:1415-8. [PMID: 19909288 DOI: 10.1042/bst0371415] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
The SCZ (schizophrenia)-associated GABA(A) receptor (gamma-aminobutyric acid type A receptor) beta(2) subunit gene GABRB2 was recently associated with BPD (bipolar disorder). Although weaker than its association with SCZ, significant association of GABRB2 with BPD was found in both German and Chinese, especially for the haplotypes rs1816071-rs187269 and rs1816072-rs187269 for which the M-M variants showed higher frequency in disease than the control. Significant genotype-dependent reduction in GABRB2 expression was shown for BPD, but to a lesser extent than that for SCZ. Temporal effects on GABRB2 expression were observed. Moreover, for the homozygous major genotypes of rs1816071, rs1816072 and rs187269, expression increased with time in CON but decreased in SCZ and BPD. The genotypes of these three SNPs (single nucleotide polymorphisms) were further correlated with antipsychotics dosage in SCZ cohorts. The findings highlight the importance of GABRB2 in neuropsychiatric disease aetiology, with respect to haplotype association, as well as reduction of and temporal effects on gene expression in both SCZ and BPD, but to a lesser extent in the latter, supporting the suggestion that functional psychosis can be conceptualized as a continuous spectrum of clinical phenotypes rather than as distinct categories.
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Haplotype-based case–control study between human apurinic/apyrimidinic endonuclease 1/redox effector factor-1 gene and cerebral infarction. Clin Biochem 2009; 42:1493-9. [DOI: 10.1016/j.clinbiochem.2009.07.016] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2009] [Revised: 07/04/2009] [Accepted: 07/14/2009] [Indexed: 11/19/2022]
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Charych EI, Liu F, Moss SJ, Brandon NJ. GABA(A) receptors and their associated proteins: implications in the etiology and treatment of schizophrenia and related disorders. Neuropharmacology 2009; 57:481-95. [PMID: 19631671 DOI: 10.1016/j.neuropharm.2009.07.027] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Revised: 07/02/2009] [Accepted: 07/13/2009] [Indexed: 02/05/2023]
Abstract
Gamma-aminobutyric acid type A (GABA(A)) receptors play an important role in mediating fast synaptic inhibition in the brain. They are ubiquitously expressed in the CNS and also represent a major site of action for clinically relevant drugs. Recent technological advances have greatly clarified the molecular and cellular roles played by distinct GABA(A) receptor subunit classes and isoforms in normal brain function. At the same time, postmortem and genetic studies have linked neuropsychiatric disorders including schizophrenia and bipolar disorder with GABAergic neurotransmission and various specific GABA(A) receptor subunits, while evidence implicating GABA(A)R-associated proteins is beginning to emerge. In this review we discuss the mounting genetic, molecular, and cellular evidence pointing toward a role for GABA(A) receptor heterogeneity in both schizophrenia etiology and therapeutic development. Finally, we speculate on the relationship between schizophrenia-related disorders and selected GABA(A) receptor associated proteins, key regulators of GABA(A) receptor trafficking, targeting, clustering, and anchoring that often carry out these functions in a subtype-specific manner.
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Affiliation(s)
- Erik I Charych
- Wyeth Research, Neuroscience Discovery, Princeton NJ 08852, USA.
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Windemuth A, Calhoun VD, Pearlson GD, Kocherla M, Jagannathan K, Ruaño G. Physiogenomic analysis of localized FMRI brain activity in schizophrenia. Ann Biomed Eng 2008; 36:877-88. [PMID: 18330705 DOI: 10.1007/s10439-008-9475-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2007] [Accepted: 02/15/2008] [Indexed: 11/29/2022]
Abstract
The search for genetic factors associated with disease is complicated by the complexity of the biological pathways linking genotype and phenotype. This analytical complexity is particularly concerning in diseases historically lacking reliable diagnostic biological markers, such as schizophrenia and other mental disorders. We investigate the use of functional magnetic resonance imaging (fMRI) as an intermediate phenotype (endophenotype) to identify physiogenomic associations to schizophrenia. We screened 99 subjects, 30 subjects diagnosed with schizophrenia, 13 unaffected relatives of schizophrenia patients, and 56 unrelated controls, for gene polymorphisms associated with fMRI activation patterns at two locations in temporal and frontal lobes previously implied in schizophrenia. A total of 22 single nucleotide polymorphisms (SNPs) in 15 genes from the dopamine and serotonin neurotransmission pathways were genotyped in all subjects. We identified three SNPs in genes that are significantly associated with fMRI activity. SNPs of the dopamine beta-hydroxylase (DBH) gene and of the dopamine receptor D4 (DRD4) were associated with activity in the temporal and frontal lobes, respectively. One SNP of serotonin-3A receptor (HTR3A) was associated with temporal lobe activity. The results of this study support the physiogenomic analysis of neuroimaging data to discover associations between genotype and disease-related phenotypes.
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Lo WS, Xu Z, Yu Z, Pun FW, Ng SK, Chen J, Tong KL, Zhao C, Xu X, Tsang SY, Harano M, Stöber G, Nimgaonkar VL, Xue H. Positive selection within the Schizophrenia-associated GABA(A) receptor beta(2) gene. PLoS One 2007; 2:e462. [PMID: 17520021 PMCID: PMC1866178 DOI: 10.1371/journal.pone.0000462] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2007] [Accepted: 04/24/2007] [Indexed: 01/08/2023] Open
Abstract
The gamma-aminobutyric acid type-A (GABAA) receptor plays a major role in inhibitory neurotransmissions. Intronic SNPs and haplotypes in GABRB2, the gene for GABAA receptor β2 subunit, are associated with schizophrenia and correlated with the expression of two alternatively spliced β2 isoforms. In the present study, using chimpanzee as an ancestral reference, high frequencies were observed for the derived (D) alleles of the four SNPs rs6556547, rs187269, rs1816071 and rs1816072 in GABRB2, suggesting the occurrence of positive selection for these derived alleles. Coalescence-based simulation showed that the population frequency spectra and the frequencies of H56, the haplotype having all four D alleles, significantly deviated from neutral-evolution expectation in various demographic models. Haplotypes containing the derived allele of rs1816072 displayed significantly less diversity compared to haplotypes containing its ancestral allele, further supporting positive selection. The variations in DD-genotype frequencies in five human populations provided a snapshot of the evolutionary history, which suggested that the positive selections of the D alleles are recent and likely ongoing. The divergence between the DD-genotype profiles of schizophrenic and control samples pointed to the schizophrenia-relevance of positive selections, with the schizophrenic samples showing weakened selections compared to the controls. These DD-genotypes were previously found to increase the expression of β2, especially its long isoform. Electrophysiological analysis showed that this long β2 isoform favored by the positive selections is more sensitive than the short isoform to the inhibition of GABAA receptor function by energy depletion. These findings represent the first demonstration of positive selection in a schizophrenia-associated gene.
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Affiliation(s)
- Wing-Sze Lo
- Department of Biochemistry, Applied Genomics Laboratory and HKH Bioinformatics Center, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Zhiwen Xu
- Department of Biochemistry, Applied Genomics Laboratory and HKH Bioinformatics Center, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Zhiliang Yu
- Graduate program of Atmospheric, Marine, and Coastal Environment, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Frank W. Pun
- Department of Biochemistry, Applied Genomics Laboratory and HKH Bioinformatics Center, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Siu-Kin Ng
- Graduate Program of Bioengineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Jianhuan Chen
- Department of Biochemistry, Applied Genomics Laboratory and HKH Bioinformatics Center, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Ka-Lok Tong
- Department of Biochemistry, Applied Genomics Laboratory and HKH Bioinformatics Center, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Cunyou Zhao
- Graduate Program of Bioengineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Xiaojing Xu
- Graduate Program of Bioengineering, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Shui-Ying Tsang
- Department of Biochemistry, Applied Genomics Laboratory and HKH Bioinformatics Center, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
| | - Mutsuo Harano
- Department of Neuropsychiatry, Kurume University School of Medicine, Fukuka, Japan
| | - Gerald Stöber
- Department of Psychiatry and Psychotherapy, University of Würzburg, Würzburg, Germany
| | - Vishwajit L. Nimgaonkar
- Departments of Psychiatry and Human Genetics, University of Pittsburgh School of Medicine, and Graduate School of Public Health, Pittsburgh, Pennsylvania, United States of America
| | - Hong Xue
- Department of Biochemistry, Applied Genomics Laboratory and HKH Bioinformatics Center, Hong Kong University of Science and Technology, Clear Water Bay, Hong Kong, China
- * To whom correspondence should be addressed. E-mail:
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Lo WS, Harano M, Gawlik M, Yu Z, Chen J, Pun FW, Tong KL, Zhao C, Ng SK, Tsang SY, Uchimura N, Stober G, Xue H. GABRB2 association with schizophrenia: commonalities and differences between ethnic groups and clinical subtypes. Biol Psychiatry 2007; 61:653-60. [PMID: 16950232 DOI: 10.1016/j.biopsych.2006.05.003] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/21/2006] [Revised: 05/03/2006] [Accepted: 05/09/2006] [Indexed: 11/29/2022]
Abstract
BACKGROUND Single nucleotide polymorphisms (SNPs) and haplotypes in intron 8 of type A gamma-aminobutyric acid (GABA(A)) receptor beta2 subunit gene (GABRB2) were initially found to be associated with schizophrenia in Chinese. This finding was subjected to cross-validation in this study with Japanese (JP) and German Caucasian (GE) subjects. METHODS Single nucleotide polymorphisms discovery and genotyping were carried out through resequencing of a 1839 base pair (bp) region in GABRB2. Tagging SNPs (tSNPs) were selected based on linkage disequilibrium (LD), combinations of which were analyzed with Bonferroni correction and permutation for disease association. Random resampling was applied to generate size- and gender-balanced cases and control subjects. RESULTS Out of the 17 SNPs (9.2/kilobase [kb]) revealed, 6 were population-specific. Population variations in LD were observable, and at least two low LD points were identified in both populations. Although disease association at single SNP level was only shown in GE, strong association was demonstrated in both JP (p = .0002 - .0191) and GE (p = .0033 - .0410) subjects, centering on haplotypes containing rs1816072 and rs1816071. Among different clinical subtypes, the most significant association was exhibited by systematic schizophrenia. CONCLUSIONS Cross-population validation of GABRB2 association with schizophrenia has been obtained with JP and GE subjects, with the genotype-disease correlations being strongest in systematic schizophrenia, the most severe subtype of the disease.
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Affiliation(s)
- Wing-Sze Lo
- Department of Biochemistry and Applied Genomics Laboratory, Hong Kong University of Science and Technology, Hong Kong, China
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Zhao C, Xu Z, Chen J, Yu Z, Tong KL, Lo WS, Pun FW, Ng SK, Tsang SY, Xue H. Two isoforms of GABA(A) receptor beta2 subunit with different electrophysiological properties: Differential expression and genotypical correlations in schizophrenia. Mol Psychiatry 2006; 11:1092-105. [PMID: 16983389 DOI: 10.1038/sj.mp.4001899] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
Single nucleotide polymorphisms in type A gamma-aminobutyric acid (GABA(A)) receptor beta2 subunit gene (GABRB2) were found to be associated with schizophrenia in Chinese, German, Japanese and Portuguese. To explore potential functional consequences of these DNA sequence polymorphisms, this study examined the expression and electrophysiological properties of two alternatively spliced products of GABRB2 along with genotypical disease association analysis. Real-time quantitative polymerase chain reaction, performed with a cohort of 31 schizophrenics and 31 controls of US population, showed 21.7% reduction in the expression of the long isoform beta(2L), 13.4% in the short isoform beta(2S) and 15.8% in the sum of the two isoforms beta(2T) in postmortem schizophrenic brain. Furthermore, two independent mRNA quantitation methods showed that the relative expression of the long over the short isoforms was significantly decreased, suggesting the occurrence of altered splicing, in schizophrenia. In male schizophrenics, the heterozygous genotypes of rs1876071 (T/C) and rs1876072 (A/G) were correlated with reduced expression of beta(2L), beta(2S) and beta(2T), and the heterozygous of rs2546620 (A/G) and homozygous-minor of rs1876071 (C/C) and rs1876072 (G/G) were correlated with reduced expression of beta(2T). Significant correlations of expression levels with different alleles and haplotypes were also indicated by quantitative trait analysis. Recombinant GABA(A) receptors expressed in HEK293 human cells containing beta(2L) underwent a steeper current rundown upon repetitive GABA activation than receptors containing beta(2S). The results thus revealed genotype-dependent expression of the alternatively spliced isoforms of GABA(A) receptor beta2 subunit, giving rise to electrophysiological consequences that could play an important role in the pathogenesis mechanism of schizophrenia.
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Affiliation(s)
- C Zhao
- Bioengineering Graduate Program, Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong, China
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