Publications (40)163.23 Total impact
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Article: Experimental Evidence for the Involvement of PDLIM5 in Mood Disorders in Hetero Knockout Mice.
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ABSTRACT: Reports indicate that PDLIM5 is involved in mood disorders. The PDLIM5 (PDZ and LIM domain 5) gene has been genetically associated with mood disorders; it's expression is upregulated in the postmortem brains of patients with bipolar disorder and downregulated in the peripheral lymphocytes of patients with major depression. Acute and chronic methamphetamine (METH) administration may model mania and the evolution of mania into psychotic mania or schizophrenia-like behavioral changes, respectively. To address whether the downregulation of PDLIM5 protects against manic symptoms and cause susceptibility to depressive symptoms, we evaluated the effects of reduced Pdlim5 levels on acute and chronic METH-induced locomotor hyperactivity, prepulse inhibition, and forced swimming by using Pdlim5 hetero knockout (KO) mice. The homozygous KO of Pdlim5 is embryonic lethal. The effects of METH administration on locomotor hyperactivity and the impairment of prepulse inhibition were lower in Pdlim5 hetero KO mice than in wild-type mice. The transient inhibition of PDLIM5 (achieved by blocking the translocation of protein kinase C epsilon before the METH challenge) had a similar effect on behavior. Pdlim5 hetero KO mice showed increased immobility time in the forced swimming test, which was diminished after the chronic administration of imipramine. Chronic METH treatment increased, whereas chronic haloperidol treatment decreased, Pdlim5 mRNA levels in the prefrontal cortex. Imipramine increased Pdlim5 mRNA levels in the hippocampus. These findings are partially compatible with reported observations in humans, indicating that PDLIM5 is involved in psychiatric disorders, including mood disorders.PLoS ONE 01/2013; 8(4):e59320. · 4.09 Impact Factor -
Article: NrCAM-regulating neural systems and addiction-related behaviors.
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ABSTRACT: We have previously shown that a haplotype associated with decreased NrCAM expression in brain is protective against addiction vulnerability for polysubstance abuse in humans and that Nrcam knockout mice do not develop conditioned place preferences for morphine, cocaine or amphetamine. In order to gain insight into NrCAM involvement in addiction vulnerability, which may involve specific neural circuits underlying behavioral characteristics relevant to addiction, we evaluated several behavioral phenotypes in Nrcam knockout mice. Consistent with a potential general reduction in motivational function, Nrcam knockout mice demonstrated less curiosity for novel objects and for an unfamiliar conspecific, showed also less anxiety in the zero maze. Nrcam heterozygote knockout mice reduced alcohol preference and buried fewer marbles in home cage. These observations provide further support for a role of NrCAM in substance abuse including alcoholism vulnerability, possibly through its effects on behavioral traits that may affect addiction vulnerability, including novelty seeking, obsessive compulsion and responses to aversive or anxiety-provoking stimuli. Additionally, in order to prove glutamate homeostasis hypothesis of addiction, we analyzed glutamatergic molecules regulated by NRCAM expression. Glutaminase appears to be involved in NrCAM-related molecular pathway in two different tissues from human and mouse. An inhibitor of the enzyme, prolyl-leucyl-glycinamide, treatment produced, at least, some of the phenotypes of mice shown in alcohol preference and in anxiety-like behavior. Thus, NrCAM could affect addiction-related behaviors via at least partially modulation of some glutamatergic pathways and neural function in brain.Addiction Biology 07/2012; · 4.83 Impact Factor -
Article: Association of SNPs linked to increased expression of SLC1A1 with schizophrenia.
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ABSTRACT: Glutamate is one of the key molecules involved in signal transduction in the brain, and dysfunction of glutamate signaling could be linked to schizophrenia. The SLC1A1 gene located at 9p24 encodes the glutamate transporter EAAT3/EAAC1. To investigate the association between the SLC1A1 gene and schizophrenia in the Japanese population, we genotyped 19 tagging single nucleotide polymorphisms (tagSNPs) in the SLC1A1 gene in 576 unrelated individuals with schizophrenia and 576 control subjects followed by replication in an independent case-control study of 1,344 individuals with schizophrenia and 1,344 control subjects. In addition, we determined the boundaries of the copy number variation (CNV) region in the first intron (Database of Genomic Variants, chr9:4516796-4520549) and directly genotyped the CNV because of significant deviation from the Hardy-Weinberg equilibrium. The CNV was not associated with schizophrenia. Four SNPs showed a possible association with schizophrenia in the screening subjects and the associations were replicated in the same direction (nominal allelic P < 0.05), and, among them, an association with rs7022369 was replicated even after Bonferroni correction (allelic nominal P = 5 × 10(-5) , allelic corrected P = 2.5 × 10(-4) , allelic odds ratio, 1.30; 95% CI: 1.14-1.47 in the combined subjects). Expression analysis quantified by the real-time quantitative polymerase chain reaction in the postmortem prefrontal cortex of 43 Japanese individuals with schizophrenia and 11 Japanese control subjects revealed increased SLC1A1 expression levels in individuals homozygous for the rs7022369 risk allele (P = 0.003). Our findings suggest the involvement of SLC1A1 in the pathogenesis of schizophrenia.American Journal of Medical Genetics Part B Neuropsychiatric Genetics 11/2011; 159B(1):30-7. · 3.70 Impact Factor -
Article: CNS effects of CB2 cannabinoid receptors: beyond neuro-immuno-cannabinoid activity.
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ABSTRACT: There are two well characterized cannabinoid receptors (CBRs), CB1-Rs and CB2-Rs, with other candidates, such as GPR55, PPARs and vanilloid TRPV1 (VR1) receptors, which are either activated by cannabinoids and/or endocannabinoids (eCBs). The neuronal and functional expression of CB2-Rs in the brain has been much less well characterized in comparison with the expression of the ubiquitous CB1-Rs. CB2-Rs were previously thought to be predominantly expressed in immune cells in the periphery and were traditionally referred to as peripheral CB2-Rs. We and others have now demonstrated the expression of CB2-Rs in neuronal, glial and endothelial cells in the brain, and this warrants a re-evaluation of the CNS effects of CB2-Rs. In the present review we summarize our current understanding of CNR2 genomic structure, its polymorphic nature, subtype specificity, from mice to human subjects, and its variants that confer vulnerabilities to neuropsychiatric disorders beyond neuro-immuno-cannabinoid activity.Journal of Psychopharmacology 03/2011; 26(1):92-103. · 3.04 Impact Factor -
Article: Methylenetetrahydrofolate reductase (MTHFR) C677T and A1298C polymorphisms and age of onset in schizophrenia: a combined analysis of independent samples.
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ABSTRACT: Methylenetetrahydrofolate reductase (MTHFR) is involved in the one-carbon cycle, which is of importance for nucleotide synthesis and methylation of DNA, membranes, proteins and lipids. The MTHFR gene includes two common polymorphisms (rs1801133 or C677T; rs1801131 or A1298C) which both alter enzyme activity. The T-allele of the C677T polymorphism has recently been associated with earlier age at onset of schizophrenia. In the present study we examined the association between the MTHFR C677T and A1298C polymorphisms and age at onset of schizophrenia in twelve samples consisting of 3,213 unrelated schizophrenia patients, including the original Scandinavian sample. There was no consistent relationship between MTHFR C677T, A1298C or combined 677T/1298C carriers and age of onset in schizophrenia when the results of each study were combined using meta-analysis. The present results suggest that the investigated MTHFR polymorphisms do not influence age of onset in schizophrenia.American Journal of Medical Genetics Part B Neuropsychiatric Genetics 03/2011; 156(2):215-24. · 3.70 Impact Factor -
Article: Functional polymorphism in the GPR55 gene is associated with anorexia nervosa.
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ABSTRACT: Endocannabinoids, anandamide, and 2-arachidonoyl glycerol are involved in food intake and appetite. Although anandamide is now thought to be a ligand for vanilloid receptor, receptors that are targets of anandamide could play a similar role in eating behaviors and related disorders. This study therefore focused on the receptor, which is called G-protein-coupled receptor 55 (GPR55) that had recently been reported to have binding affinity for endocannabinoids. Functional analysis of the sole missense polymorphism, rs3749073 (Gly195Val) in the GPR55 gene was performed by detecting the phosphorylation level of extracellular signal-regulated kinase (ERK) in Chinese-Hamster-Ovary (CHO) cells engineered to express human GPR55. Val195 type GPR55 appeared to induce less phosphorylated ERK than Gly195 type GPR55 when CHO cells were treated with anandamide and lysophosphatidylinositol (LPI). An association between the functional Gly195Val polymorphism and anorexia nervosa was tested in a female Japanese population comprising 235 patients and 1244 controls. The Val195 allele and homozygote of the Val195 allele were more abundant in the group of patients diagnosed with anorexia nervosa (P = 0.023, Odds ratio = 1.31 (95% Cl = 1.03-1.37), P = 0.0048, OR = 2.41 (95% Cl = 1.34-4.34), respectively). In conclusion, the low-functioning Val195 allele of GPR55 appears to be a risk factor for anorexia nervosa.Synapse 02/2011; 65(2):103-8. · 2.94 Impact Factor -
Article: An association study between the dymeclin gene and schizophrenia in the Japanese population.
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ABSTRACT: Many gene variants are involved in the susceptibility to schizophrenia and some of them are expected to be associated with other human characters. Recently reported meta-analysis of genetic associations revealed nucleotide variants in synaptic vesicular transport/Golgi apparatus genes with schizophrenia. In this study, we selected the dymeclin gene (DYM) as a candidate gene for schizophrenia. The DYM gene encodes dymeclin that has been identified to be associated with the Golgi apparatus and with transitional vesicles of the reticulum-Golgi interface. A three-step case-control study of total of 2105 Japanese cases of schizophrenia and 2087 Japanese control subjects was carried out for tag single-nucleotide polymorphisms (SNPs) in the DYM gene and an association between an SNP, rs833497, and schizophrenia was identified (allelic P=2 × 10(-5), in the total sample). DYM is the causal gene for Dyggve-Melchior-Clausen syndrome and this study shows the second neuropsychiatric disorder in which the DYM gene is involved. The present data support the involvement of Golgi function and vesicular transport in the presynapse in schizophrenia.Journal of Human Genetics 09/2010; 55(9):631-4. · 2.57 Impact Factor -
Article: Replication study of association between ADCYAP1 gene polymorphisms and schizophrenia.
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ABSTRACT: The adenylate cyclase-activating polypeptide 1 (ADCYAP1) gene encodes a neuropeptide with neurotransmission activity, which is known as the pituitary adenylate cyclase-activating polypeptide. Associations of two polymorphisms, rs1893154 and rs2856966 (Asp54Gly), in the ADCYAP1 gene with schizophrenia were reported earlier by a Japanese case-control study. In this study, we tried to confirm the association in 2027 Japanese patients with schizophrenia and 2058 controls. The power to detect an association was more than 0.9. However, we did not detect allelic associations of rs1893154 with schizophrenia (P=0.36). Although rs2856966 was nominally significant (P=0.045), the association was in the opposite direction from that reported earlier. Combined data and meta-analysis of the two studies comprising nearly 6000 Japanese case-control patients did not show significant associations (P=0.53-0.86). It is concluded that single-nucleotide polymorphisms, including Asp54Gly, of the ADCYAP1 gene are unlikely to play a sizeable role in the genetic susceptibility to schizophrenia.Psychiatric genetics 04/2010; 20(3):123-5. · 2.33 Impact Factor -
Article: Association of the HSPG2 gene with neuroleptic-induced tardive dyskinesia.
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ABSTRACT: Tardive dyskinesia (TD) is characterized by repetitive, involuntary, and purposeless movements that develop in patients treated with long-term dopaminergic antagonists, usually antipsychotics. By a genome-wide association screening of TD in 50 Japanese schizophrenia patients with treatment-resistant TD and 50 Japanese schizophrenia patients without TD (non-TD group) and subsequent confirmation in independent samples of 36 treatment-resistant TD and 136 non-TD subjects, we identified association of a single nucleotide polymorphism, rs2445142, (allelic p=2 x 10(-5)) in the HSPG2 (heparan sulfate proteoglycan 2, perlecan) gene with TD. The risk allele was significantly associated with higher expression of HSPG2 in postmortem human prefrontal brain (p<0.01). Administration of daily injection of haloperidol (HDL) for 50 weeks significantly reduced Hspg2 expression in mouse brains (p<0.001). Vacuous chewing movements (VCMs) induced by 7-week injection of haloperidol-reserpine were significantly infrequent in adult Hspg2 hetero-knockout mice compared with wild-type littermates (p<0.001). Treatment by the acetylcholinesterase inhibitor, physostigmine, was significantly effective for reduction of VCMs in wild-type mice but not in Hspg2 hetero-knockout mice. These findings suggest that the HSPG2 gene is involved in neuroleptic-induced TD and higher expression of HSPG2, probably even after antipsychotic treatment, and may be associated with TD susceptibility.Neuropsychopharmacology: official publication of the American College of Neuropsychopharmacology 04/2010; 35(5):1155-64. · 6.99 Impact Factor -
Article: Failure to find an association between myosin heavy chain 9, non-muscle (MYH9) and schizophrenia: a three-stage case-control association study.
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ABSTRACT: Several genome-wide linkage studies have suggested linkage between markers on the long arm of chromosome 22 and schizophrenia. It has also been reported that 22q11.2 deletions increase the risk of schizophrenia. Therefore, 22q is a candidate region for schizophrenia. To search for genetic susceptibility loci for schizophrenia on 22q, we conducted a three-stage case-control association study in Japanese individuals. In the first stage, we examined 13 microsatellite markers on 22q in 766 individuals (340 patients with schizophrenia and 426 control individuals) and found a potential association of AFM262VH5 (D22S283) with schizophrenia. In the second stage, we performed fine mapping of the myosin heavy chain 9, non-muscle (MYH9) gene, where AFM262VH5 is located, using 25 tagging single nucleotide polymorphisms (SNPs). We obtained potential associations between three SNPs in MYH9 and schizophrenia in 1193 individuals (595 patients and 598 controls), which included the individuals analyzed in the first stage. In the third stage, however, we could not replicate these associations in 4694 independent individuals (2288 patients and 2406 controls). Our results suggest that MYH9 does not confer increased susceptibility to schizophrenia in the Japanese population, although we could not exclude possible contributions of other genes on 22q to the pathogenesis of schizophrenia.Biological Psychiatry 02/2010; 118(1-3):106-12. · 8.28 Impact Factor -
Article: Brain cannabinoid CB2 receptor in schizophrenia.
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ABSTRACT: Neural endocannabinoid function appears to be involved in schizophrenia. Two endocannabinoid receptors, CB1 and CB2, are found in the brain and elsewhere in the body. We investigated roles of CB2 in schizophrenia. An association study was performed between tag single nucleotide polymorphisms (SNPs) in the CNR2 gene encoding the CB2 receptor and schizophrenia in two independent case-control populations. Allelic differences of associated SNPs were analyzed in human postmortem brain tissues and in cultured cells. Prepulse inhibition and locomotor activity in C57BL/6JJmsSlc mice with CB2 receptor antagonist AM630 administration was examined. The analysis in the first population revealed nominally significant associations between schizophrenia and two SNPs, and the associations were replicated in the second population. The R63 allele of rs2501432 (R63Q) (p = .001), the C allele of rs12744386 (p = .005) and the haplotype of the R63-C allele (p = 5 x 10(-6)) were significantly increased among 1920 patients with schizophrenia compared with 1920 control subjects in the combined population. A significantly lower response to CB2 ligands in cultured CHO cells transfected with the R63 allele compared with those with Q63, and significantly lower CB2 receptor mRNA and protein levels found in human brain with the CC and CT genotypes of rs12744386 compared with TT genotype were observed. AM630 exacerbated MK-801- or methamphetamine-induced disturbance of prepulse inhibition and hyperactivity in C57BL/6JJmsSlc mice. These findings indicate an increased risk of schizophrenia for people with low CB2 receptor function.Biological psychiatry 11/2009; 67(10):974-82. · 8.93 Impact Factor -
Article: Involvement of SMARCA2/BRM in the SWI/SNF chromatin-remodeling complex in schizophrenia.
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ABSTRACT: Chromatin remodeling may play a role in the neurobiology of schizophrenia and the process, therefore, may be considered as a therapeutic target. The SMARCA2 gene encodes BRM in the SWI/SNF chromatin-remodeling complex, and associations of single nucleotide polymorphisms (SNPs) to schizophrenia were found in two linkage disequilibrium blocks in the SMARCA2 gene after screening of 11 883 SNPs (rs2296212; overall allelic P = 5.8 x 10(-5)) and subsequent screening of 22 genes involved in chromatin remodeling (rs3793490; overall allelic P = 2.0 x 10(-6)) in a Japanese population. A risk allele of a missense polymorphism (rs2296212) induced a lower nuclear localization efficiency of BRM, and risk alleles of intronic polymorphisms (rs3763627 and rs3793490) were associated with low SMARCA2 expression levels in the postmortem prefrontal cortex. A significant correlation in the fold changes of gene expression from schizophrenic prefrontal cortex (from the Stanley Medical Research Institute online genomics database) was seen with suppression of SMARCA2 in transfected human cells by specific siRNA, and of orthologous genes in the prefrontal cortex of Smarca2 knockout mice. Smarca2 knockout mice showed impaired social interaction and prepulse inhibition. Psychotogenic drugs lowered Smarca2 expression while antipsychotic drugs increased it in the mouse brain. These findings support the existence of a role for BRM in the pathophysiology of schizophrenia.Human Molecular Genetics 05/2009; 18(13):2483-94. · 7.64 Impact Factor -
Article: Supportive evidence for reduced expression of GNB1L in schizophrenia.
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ABSTRACT: Chromosome 22q11 deletion syndrome (22q11DS) increases the risk of development of schizophrenia more than 10 times compared with that of the general population, indicating that haploinsufficiency of a subset of the more than 20 genes contained in the 22q11DS region could increase the risk of schizophrenia. In the present study, we screened for genes located in the 22q11DS region that are expressed at lower levels in postmortem prefrontal cortex of patients with schizophrenia than in those of controls. Gene expression was screened by Illumina Human-6 Expression BeadChip arrays and confirmed by real-time reverse transcription-polymerase chain reaction assays and Western blot analysis. Expression of GNB1L was lower in patients with schizophrenia than in control subjects in both Australian (10 schizophrenia cases and 10 controls) and Japanese (43 schizophrenia cases and 11 controls) brain samples. TBX1 could not be evaluated due to its low expression levels. Expression levels of the other genes were not significantly lower in patients with schizophrenia than in control subjects. Association analysis of tag single-nucleotide polymorphisms in the GNB1L gene region did not confirm excess homozygosity in 1918 Japanese schizophrenia cases and 1909 Japanese controls. Haloperidol treatment for 50 weeks increased Gnb1l gene expression in prefrontal cortex of mice. Taken together with the impaired prepulse inhibition observed in heterozygous Gnb1l knockout mice reported by the previous study, the present findings support assertions that GNB1L is one of the genes in the 22q11DS region responsible for increasing the risk of schizophrenia.Schizophrenia Bulletin 12/2008; 36(4):756-65. · 8.80 Impact Factor -
Article: Functional expression of brain neuronal CB2 cannabinoid receptors are involved in the effects of drugs of abuse and in depression.
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ABSTRACT: Major depression and addiction are mental health problems associated with stressful events in life with high relapse and recurrence even after treatment. Many laboratories were not able to detect the presence of CB2 cannabinoid receptors (CB2-Rs) in healthy brains, but CB2-R expression has been demonstrated in rat microglial cells and other brain-associated cells during inflammation. Thus, neuronal expression of CB2-Rs has been ambiguous and controversial, and its role in depression and substance abuse is unknown. In this study we tested the hypothesis that genetic variants of the CB2 gene might be associated with depression in a human population and that alteration in CB2 gene expression may be involved in the effects of abused substances, including opiates, cocaine, and ethanol, in rodents. Here we demonstrate that a high incidence of Q63R but not H316Y polymorphism in the CB2 gene was found in Japanese depressed subjects. CB2-Rs and their gene transcripts are expressed in the brains of naïve mice and are modulated after exposure to stressors and administration of abused drugs. Mice that developed an alcohol preference had reduced CB2 gene expression, and chronic treatment with JWH015 a putative CB2-R agonist, enhanced alcohol consumption in stressed but not in control mice. The direct intracerebroventricular microinjection of CB2 antisense oligonucleotide into the mouse brain reduced mouse aversions in the plus-maze test, indicating the functional presence of CB2-Rs in the brain that modifies behavior. Using electron microscopy we report the subcellular localization of CB2-Rs that are mainly on postsynaptic elements in rodent brain. Our data demonstrate the functional expression of CB2-Rs in the brain that may provide novel targets for the effects of cannabinoids in depression and substance abuse disorders beyond neuroimmunocannabinoid activity.Annals of the New York Academy of Sciences 11/2008; 1139:434-49. · 3.15 Impact Factor -
Article: Replication study for associations between polymorphisms in the CLDN5 and DGCR2 genes in the 22q11 deletion syndrome region and schizophrenia.
Psychiatric genetics 11/2008; 18(5):255-6. · 2.33 Impact Factor -
Article: A polymorphism of the metabotropic glutamate receptor mGluR7 (GRM7) gene is associated with schizophrenia.
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ABSTRACT: Glutamate dysfunction has been implicated in the pathophysiology of schizophrenia. The metabotropic glutamate receptors (mGluRs) are G-protein-coupled receptors. GRM7, the gene that encodes mGluR7, is expressed in many regions of the human central nervous system. The GRM7 gene is located on human chromosome 3p26, which has been suggested by linkage analysis to contain a susceptibility locus for schizophrenia. We screened for mutations in all exons, exon/intron junctions, and promoter regions of the GRM7 gene in Japanese patients with schizophrenia and evaluated associations between the detected polymorphisms and schizophrenia. We examined the influence of one polymorphism associated with schizophrenia on the expression of GRM7 by dual-luciferase assay in transfected cells. Twenty-five polymorphisms/mutations were detected in GRM7. Case-control analysis revealed a potential association of a synonymous polymorphism (371T/C, rs3749380) in exon 1 with schizophrenia in our case-control study of 2293 Japanese patients with schizophrenia and 2382 Japanese control subjects (allelic p=0.009). Dual-luciferase assay revealed suppression of transcription activity by exon 1 containing this polymorphism and a statistically significant difference in the promoter activity between the T and C alleles. Our results support the possible association of a GRM7 gene polymorphism with genetic susceptibility to schizophrenia.Schizophrenia Research 05/2008; 101(1-3):9-16. · 4.75 Impact Factor -
Article: Pathway-based association analysis of genome-wide screening data suggest that genes associated with the gamma-aminobutyric acid receptor signaling pathway are involved in neuroleptic-induced, treatment-resistant tardive dyskinesia.
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ABSTRACT: Neuroleptic-induced tardive dyskinesia (TD) is an involuntary movement disorder that develops in patients who have undergone long-term treatment with antipsychotic medications, and its etiology is unclear. In this study, a genome-wide association screening was done to identify the pathway(s) in which genetic variations influence susceptibility to neuroleptic-induced TD. Screening with Sentrix Human-1 Genotyping BeadChip (Illumina, San Diego, California, USA) was done for 50 Japanese schizophrenia patients with treatment-resistant TD and 50 Japanese schizophrenia patients without TD. A total of 40 573 single nucleotide polymorphisms that were not in linkage disequilibrium with each other and were located in the exonic and intronic regions of 13 307 genes were analyzed. After gene-based corrections, P values for allelic associations were subjected to canonical pathway-based analyses with Ingenuity Pathway Analysis software (Ingenuity Systems, Inc., Redwood City, California, USA). Eight genes (ABAT, ALDH9A1, GABRA3, GABRA4, GABRB2, GABRAG3, GPHN, and SLC6A11) contained polymorphisms with gene-based corrected allelic P values of less than 0.05. They were aggregated significantly in 33 genes belonging to the gamma-aminobutyric acid (GABA) receptor signaling pathway (P=0.00007, corrected P=0.01). Associations were replicated in an independent sample of 36 patients with TD and 136 patients without TD for polymorphisms in SLC6A11 (GABA transporter 3) (P=0.0004 in the total sample), GABRB2 (beta-2 subunit of GABA-A receptor) (P=0.00007 in the total sample), and GABRG3 (gamma-3 subunit of GABA-A receptor) (P=0.0006 in the total sample). The results suggest that the GABA receptor signaling pathway may be involved in genetic susceptibility to treatment-resistant TD, at least in a subgroup of Japanese patients with schizophrenia. The present results suggest that benzodiazepines may be considered as possible treatment option for TD.Pharmacogenetics and Genomics 05/2008; 18(4):317-23. · 3.48 Impact Factor -
Article: Replication study and meta-analysis of the genetic association of GRM3 gene polymorphisms with schizophrenia in a large Japanese case-control population.
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ABSTRACT: The GRM3 gene, which encodes a metabotropic glutamate receptor, is an important candidate gene for susceptibility to schizophrenia. Two single nucleotide polymorphisms (SNPs), rs1468412 and rs2299225 in intron 3, were reported to be associated with schizophrenia in Japanese and Chinese populations, respectively. Haplotypes with these SNPs were also reported to be associated with schizophrenia. In the present study, we attempted to replicate these single marker and haplotype associations in a case-control study of 1,916 Japanese patients with schizophrenia and 1,915 Japanese control subjects. In addition to these two SNPs, we genotyped rs274622 in the promoter region of GRM3. In the present study, none of these polymorphisms were associated with schizophrenia (rs274622, allelic P = 0.68; rs1468412, allelic P = 0.74; rs2299225, allelic P = 0.20). Haplotypes constructed with these SNPs also were not associated with schizophrenia (P = 0.18-0.84). Meta-analysis of five case-control studies of more than 3,000 patients with schizophrenia and more than 3,000 control subjects did not support the associations of rs1468412 and rs2299225 with schizophrenia. Our data indicate that SNPs previously reported to be associated with schizophrenia do not contribute to genetic susceptibility to schizophrenia.American Journal of Medical Genetics Part B Neuropsychiatric Genetics 05/2008; 147(3):392-6. · 3.70 Impact Factor -
Article: Association of PTPRB gene polymorphism with drug addiction.
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ABSTRACT: Several lines of evidence support the involvement of protein tyrosine phosphatase receptor type beta (PTPRB) in addiction. Generally, PTPs interact with both neuronal receptors and cell adhesion molecules, and appear to play roles in neurite growth and neuronal differentiation. We previously identified a role of the cell adhesion molecule NrCAM in polysubstance abuse vulnerability in humans, as well as in the rewarding effects of abused drugs in animals. Furthermore, we have identified genomic regions containing several cell adhesion molecules as polysubstance abuse vulnerability loci by whole-genome association study. The present study of human chromosome 12 loci revealed that the Ser127Gly polymorphism in PTPRB is associated with substance abuse vulnerability in three independent case-control samples (European-American from COGA families, USA, n = 177, P = 0.047; European-American from Maryland, USA, n = 650, P = 0.018; and African-American from Maryland, USA, n = 331, P = 0.009). However, this polymorphism was not associated with alcoholism in Japanese subjects (n = 1,599, P = 0.37). To confirm the importance of PTPRB in responses to drugs of abuse the expression of Ptprb in mouse brain was examined after chronic morphine treatment and found to be up-regulated in some brain regions. Thus, PTPRB is an addiction-associated and drug-regulated gene whose variants may affect substance abuse vulnerability.American Journal of Medical Genetics Part B Neuropsychiatric Genetics 04/2008; 147B(7):1167-72. · 3.70 Impact Factor -
Chapter: Methods to Study the Behavioral Effects and Expression of CB2 Cannabinoid Receptors and Its Gene Transcripts in Chronic Mild Stress Model of Depression
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ABSTRACT: Behavioral and molecular methods were used to study and determine whether there is a link between depression that may be a factor in drug/alcohol addiction, and the endocannabinoid hypothesis of substance abuse. Depression is a lack of interest in the pleasurable things of life (termed anhedonia) and depressed mood. It is unknown whether CB2 cannabinoid receptors are expressed in the brain and whether they are involved in depression and substance abuse. Therefore, mice were subjected daily for 4 wk to chronic mild stress (CMS), and anhedonia was measured by the consumption of 2% sucrose solution. Behavioral and rewarding effects of abused substances were determined in the CMS and control animals. The expression of CB2 receptors and their gene transcripts was compared in the brains of CMS and control animals by Western blotting using CB2 receptor antibody and reverse transcriptase-polymerase chain reaction (RT-PCR). Furthermore, the expression and immunocytochemical identification of CB2 cannabinoid receptor in the rat brain were determined. CMS induced gender-specific aversions, which were blocked by WIN55,212-2, a nonspecific CB1 and CB2 cannabinoid receptor agonist. Direct CB2 antisense oligonucleotide microinjection into the mouse brain induced anxiolysis, indicating that CB2 or CB2like receptors are present in the brain and may influence behavior. The major finding from these studies was the expression of CB2 receptor and its gene transcript in the mouse brain, which was enhanced by CMS. These preliminary results, if confirmed, suggest that the CB2 receptors are expressed in the mammalian brain and may be nvolved in depression and substance abuse. Key WordsAntisense oligonucleotide–chronic mild stress–neuroinflammation–neuroimmunocannabinoid–depression–CB2 cannabinoid receptor–immunoblots02/2008: pages 291-298;
Top co-authors
Top Journals
Institutions
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2000–2013
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University of Tsukuba
- • School of Medical Sciences
- • Department of Immunology and Medical Genetics
- • Institute of Basic Medical Sciences
Tsukuba, Ibaraki-ken, Japan
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2011
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Yamanashi University
- Department of Psychiatry
Kōfu-shi, Yamanashi-ken, Japan
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2008
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National Institute on Drug Abuse
- Research Branch Molecular Neurobiology
Bethesda, MD, USA
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2002–2008
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William Paterson University
- Department of Biology
Wayne, NJ, USA
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2006
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National Institutes of Health
- Molecular Neurobiology Research Branch
Bethesda, MD, USA
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1998
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Tokyo Medical and Dental University
- Department of Neuropsychiatry
Tokyo, Tokyo-to, Japan
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