Plasma alanine levels increase in patients with schizophrenia as their clinical symptoms improve-Results from the Juntendo University Schizophrenia Projects (JUSP)

Since oral administration of d-alanine, an agonist that binds to the glycine site of N-methyl-d-aspartate (NMDA) receptors, improves the positive and cognitive symptoms of patients with schizophrenia, measurement of endogenous plasma alanine levels could serve as a clinical marker for schizophrenia severity and improvement. Mean plasma alanine levels were compared in healthy controls and patients with schizophrenia during the clinical course of the disease.

METHODS

eighty-one Japanese patients with schizophrenia and 50 age- and gender-matched healthy controls were studied. Plasma alanine levels were measured twice, during the acute stage and during the remission stage, using high-performance liquid chromatography. On admission, lower plasma alanine levels in patients with schizophrenia were accompanied by more severe schizophrenic symptoms, especially positive symptoms. The plasma alanine levels in patients with schizophrenia increased significantly from the time of admission to discharge, when they were significantly higher than control levels. An increase in plasma alanine levels from the acute stage to the remission stage of schizophrenia was correlated with improvement in symptoms. Drug-naïve patients did not show a significant difference in plasma alanine levels when compared with healthy controls. The measurement of plasma alanine levels may be a therapeutic marker for schizophrenia.

Genetic association analysis between TDP-43 polymorphisms and Alzheimer's disease in a Japanese population

BACKGROUND/AIMS

A recent paper reported that the TAR-DNA binding protein (TDP-43) is the disease protein in amyotrophic lateral sclerosis and frontotemporal lobar dementia with ubiquitin-positive inclusions. In addition, it has been shown that TDP-43 may play a role in the pathogenesis of Alzheimer's disease (AD). This study aims to investigate whether single nucleotide polymorphisms (SNPs) of the TDP-43 gene are associated with AD.

METHODS

Eight SNPs, genotyped using TaqMan technology, were analyzed using a case-control study design including a haplotype analysis. Furthermore, an analysis of the cases divided according to apolipoprotein E (APO E) status was also carried out. Our case-control dataset consists of 181 AD patients and 130 age-matched controls.

RESULTS

Although none of the SNPs showed statistically significant association, we identified an association between a specific haplotype (G-A-A-G) of the TDP-43 gene and risk for AD. We could not confirm any synergetic association between the SNPs and APO E in our AD patients. Despite the relatively small sample size, our results indicate a possible genetic association between TDP- 43 and AD.

CONCLUSION

Further genetic studies are needed to clarify the relationship between the TDP-43 gene and AD.

No genetic association between polymorphisms of heme oxygenase 1 and 2 and Alzheimer's disease in a Japanese population

BACKGROUND/AIMS

Recently, it has been shown that the heme oxygenases HMOX1 and HMOX2 might play a role in the pathogenesis of Alzheimer's disease (AD).

METHODS

To investigate whether there is any association between the HMOX1 and HMOX2 genes and AD, five single nucleotide polymorphisms (SNPs) in each gene were genotyped in 180 AD patients and 132 age-matched controls using TaqMan technology.

RESULTS

Our study failed to detect any association between the SNPs of the HMOX1 and HMOX2 genes and AD. In addition, we did not observe any synergetic association between the SNPs studied and apolipoprotein E in our AD patients.

CONCLUSION

Further genetic studies are needed to clarify the relationship between the two genes and AD.

Association analysis of glycine- and serine-related genes in a Japanese population of patients with schizophrenia

Differences in the levels of the glutamate-related amino acids glycine and serine in brain/plasma between schizophrenic patients and normal subjects and changes in the plasma concentrations of these amino acids according to the clinical course have been reported. It has been hypothesized that glycine and serine metabolism may be altered in schizophrenia. In fact, some genes related to the metabolism of these amino acids have been suggested to be candidate genes for schizophrenia. Thus, we performed a genomic case-control analysis of amino acid metabolism-related genes in Japanese patients with schizophrenia. Case-control genetic association analysis of PHGDH, SHMT1, SRR, and DAO was performed. In addition, the effect of the various genotypes resulting from these four genes on changes in plasma amino acid levels in schizophrenia was assessed. The genetic case-control analysis showed that no individual single-nucleotide polymorphism (SNP) in any of the four genes was associated with schizophrenia; only the two (rs3918347-rs4964770, P=0.0009) and three (rs3825251-rs3918347-rs4964770, P=0.002) SNP-based haplotype analysis of the DAO gene showed an association with schizophrenia even after correction for multiple testing. None of the genotypes studied was associated with changes in the plasma glycine and l- and d-serine levels during the schizophrenic clinical course. The DAO gene may be a susceptibility locus for schizophrenia.

Association study of the G72 gene with schizophrenia in a Japanese population: a multicenter study

G72 is one of the most widely tested genes for association with schizophrenia. As G72 activates the D-amino acid oxidase (DAO), G72 is termed D-amino acid oxidase activator (DAOA). The aim of this study is to investigate the association between G72 and schizophrenia in a Japanese population, using the largest sample size to date (1774 patients with schizophrenia and 2092 healthy controls). We examined eight single nucleotide polymorphisms (SNPs), which had been associated with schizophrenia in previous studies. We found nominal evidence for association of alleles, M22/rs778293, M23/rs3918342 and M24/rs1421292, and the genotype of M22/rs778293 with schizophrenia, although there was no association of allele or genotype in the other five SNPs. We also found nominal haplotypic association, including M15/rs2391191 and M19/rs778294 with schizophrenia. However, these associations were no longer positive after correction for multiple testing. We conclude that G72 might not play a major role in the risk for schizophrenia in the Japanese population.

Genetic association between SORL1 polymorphisms and Alzheimer's disease in a Japanese population

BACKGROUND/AIMS

It has recently been shown that the neuronal sortilin-related receptor (SORL1) plays an important role in the pathogenesis of Alzheimer's disease (AD).

METHODS

To investigate whether variations around the SORL1 gene are associated with AD, 7 single-nucleotide polymorphisms (SNPs) were genotyped using TaqMan technology with 180 AD patients and 130 age-matched controls.

RESULTS

Our results confirmed the strong linkage disequilibrium among the 7 SNPs studied. However, our study failed to detect any association between the SNPs and AD. We could not confirm any synergetic interaction between the SNPs and apolipoprotein E in our AD patients either.

CONCLUSION

Further genetic studies are needed to clarify the relationship between the SORL1 gene and AD.

Changes in plasma glycine, L-serine, and D-serine levels in patients with schizophrenia as their clinical symptoms improve: results from the Juntendo University Schizophrenia Projects (JUSP)

OBJECTIVES

Based on the hypothesis of NMDA receptor hypofunction in schizophrenia, plasma glycine, L-serine, and D-serine levels have been studied, since they could serve as biological markers. However, changes over time in the levels of these amino acids in schizophrenic patients have not been investigated. To clarify the mean plasma glycine, L-serine, and D-serine levels in patients with schizophrenia, levels of these amino acids were compared between healthy controls and patients with schizophrenia. The plasma levels of these amino acids during the clinical course of schizophrenia were also compared.

METHODS

Eighty-nine Japanese patients with schizophrenia and 50 age- and gender-matched healthy controls were studied. Plasma glycine, L-serine, and D-serine levels and their ratios were measured twice, during the acute stage and during the remission stage, using high-performance liquid chromatography.

RESULTS

The admission plasma glycine, L-serine, and D-serine levels of schizophrenic patients were higher than those of healthy controls. There were no significant differences between drug-naïve patients and healthy controls in the admission levels of the plasma amino acids, but chronically medicated patients had higher admission plasma glycine and D-serine levels. Only the D-serine level and the D-/L-serine ratio were markedly significantly increased in schizophrenic patients from the time of admission to the time of discharge as their clinical symptoms improved. In addition, the increase in the plasma D-serine levels of drug-naïve patients was correlated with improvements in positive symptoms.

CONCLUSIONS

Plasma amino acid levels, especially D-serine levels, could be useful as a "therapeutic" or "clinical state" marker in patients with acute schizophrenia.

Increased plasma glutamate by antipsychotic medication and its relationship to glutaminase 1 and 2 genotypes in schizophrenia -- Juntendo University Schizophrenia Projects (JUSP)

Disturbed glutamatergic neurotransmission has become recognized as a key component in the pathophysiology of schizophrenia. The change in serum/plasma glutamate with the use of antipsychotic medication has been studied and may be a possible clinical marker. In the present study, we examined plasma glutamate concentration, including a comprehensive investigation of its involvement with clinical course of schizophrenia and a genomic analysis. We performed a case-control genetic association analysis of the glutaminase 1 (GLS) and 2 (GLS2) genes. In addition, the difference in plasma glutamate concentration between the "acute stage" and "remission stage", and the effect of genotypes of SNPs within the two genes were assessed. The genetic association analysis of the GLS and GLS2 genes showed no association with schizophrenia. Plasma glutamate was increased with antipsychotic medication at "remission stage". Although GLS and GLS2 are not likely genetic risk factors for schizophrenia, changes in plasma glutamate concentration might be connected with clinical course of schizophrenia.

Genetic analysis of the TrkB gene and schizophrenia in the Japanese population: Juntendo University Schizophrenia Projects (JUSP)

The presence of cognitive and social impairments during childhood and adolescence in patients with schizophrenia has lead to the widespread hypothesis that schizophrenia may be a neurodevelopmental disorder, which suggests that risk genes for schizophrenia may act through the disruption of normal neurodevelopmental processes. Moreover, recent studies indicate that TrkB, which is receptor of neurotrophins including BDNF, might be involved in schizophrenia. The aim of this study is to evaluate the role of sequence variation at the TrkB locus on schizophrenia. We genotyped 12 single nucleotide polymorphisms (SNPs) across TrkB in 276 subjects with schizophrenia and 274 control subjects from the Japanese population and assessed whether TrkB SNPs are associated with a diagnosis of schizophrenia. In addition, we also investigated if any association exists between the TrkB SNPs and the premorbid functioning as measured by M-PAS using 62 subjects with schizophrenia. The TrkB SNPs were not significantly associated with a diagnosis of schizophrenia. Although one TrkB SNP (rs920776) showed weak association with premorbid functioning (p=0.025), the significance did not remain after Bonferroni correction. Thus, these results do not support a significant role for TrkB sequence variation in the etiology of schizophrenia.

Genetic association between Notch4 polymorphisms and Alzheimer's disease in the Japanese population

It is shown that Notch 4 plays important roles in the pathogenesis of Alzheimer's disease (AD). To investigate whether three single nucleotide polymorphisms (SNPs) of the Notch4 gene are associated with AD, the three SNPs were genotyped by a polymerase chain reaction-restriction fragment length polymorphism method for 243 AD patients and 130 age-matched controls. We also confirmed the linkage disequilibrium among these three SNPs of the gene using the EH program. The three SNPs did not seem to alter risk for AD. Our study suggests that SNPs studied are not associated with AD. The linkage disequilibrium of this locus indicates that there is genetic heterogeneity in the Notch4 gene. We could not confirm the previous synergetic associations of the 5' untranslated region (rs367398) C/C genotype in apolipoprotein E epsilon4 bearers in AD patients. Potential markers nearby the 5' untranslated region polymorphism might affect risk for AD.

No genetic association between the myeloperoxidase gene -463 polymorphism and estrogen receptor-alpha gene polymorphisms and Japanese sporadic Alzheimer's disease

Myeloperoxidase (MPO) presence has been demonstrated in microglia associated with senile plaques and contributes to Alzheimer's disease (AD) pathology through oxidation-induced damage. MPO activity is normally higher in women than in men. Additionally, a functional biallelic (G/A) polymorphism in the promoter region (-463) of the MPO gene has been associated with a gender-specific risk factor for AD, but reports of this association have been inconsistent. Furthermore, estrogen is known to enhance MPO activity in myeloid cells and increases the amount of MPO in plasma. Recently, estrogen replacement therapy has been reported to reduce the risk of developing AD and to help maintain cognitive function in patients with AD. In the current study, we analyzed the MPO -463 polymorphism and two estrogen receptor-alpha polymorphisms in 205 Japanese sporadic AD patients and 92 controls. The results suggest that there is no significant difference in the genotypic frequencies and allelic frequencies of the MPO -463 polymorphism and the estrogen receptor-alpha polymorphisms between the Japanese sporadic AD group and the control group.

Requirement of Tryptophan Hydroxylase During Development for Maturation of Sensorimotor Gating

Deficits in sensorimotor gating, a function to focus on the most salient stimulus, could lead to a breakdown of cognitive integrity, and could reflect the "flooding" by sensory overload and cognitive fragmentation seen in schizophrenia. Sensorimotor gating emerges at infancy, and matures during childhood. The mechanisms that underlie its development are largely unclear. Here, we screened the mouse genome, and found that tryptophan hydroxylase (TPH) is implicated in the maturation of sensorimotor gating. TPH, an enzyme involved in the biosynthesis of serotonin, proved to be required only during the weaning period for maturation of sensorimotor gating, but was dispensable for its emergence. Proper serotonin levels during development underlie the mature functional architecture for sensorimotor gating via appropriate actin polymerization. Thus, maintaining proper serotonin levels during childhood may be important for mature sensorimotor gating in adulthood.

Genetic association between USF 1 and USF 2 gene polymorphisms and Japanese Alzheimer's disease

To investigate the effect of single nucleotide polymorphisms (SNPs) of the upstream stimulatory factor (USF) 1 and 2 genes on the onset of Alzheimer's disease (AD), a case-control study was performed. The SNPs were genotyped by a polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 236 AD patients and 120 age-matched controls of Japanese descent. We observed no significant association between the three SNPs of the USF 1 gene and AD in our Japanese participants. In addition, the SNPs studied did not affect plasma cholesterol levels in our AD cases. For the USF 2 gene, the two SNPs did not show significant association with onset of AD. Our study suggests that the three SNPs of the USF 1 gene and two SNPs of the USF 2 gene presented here are not associated with onset of AD.

Phase I study of ON 01910.Na by 3-day continuous infusion (CI) in patients (pts) with advanced cancer

13137

Background: The benzyl styryl sulfone analog ON 01910.Na is a novel anticancer agent that inhibits mitotic progression and induces apoptosis; it has activity against most human cancer cells in vitro and against a broad spectrum of human xenografts in mice. Cell kill effects are exposure time-dependent in vitro. After 3d exposure 200 nM ON 01910.Na killed > 90% of Daudi lymphoma cells, whereas 40-fold higher drug concentration killed only 50% of cells after 24h exposure. Dogs that received CI of 325 mg/kg/d ×3 failed to reach MTD. Methods: Starting dose 50 mg/m2/d as a 72 hr CI was 1/10th MTD of rats’ daily dose given × 28 d. Treatment cycles were repeated every 2 wks until progressive disease, intolerable toxicity, or withdrawal of consent. Dose was escalated by Fibonacci progression in single pts until grade 2 toxicity when cohorts of 3 are to be studied. Volunteers may be retreated at a higher dose if tolerated by a preceding naïve subject. Results: One man and four women (61–77 yrs) have been studied in 21 cycles in 5 mos as of 1/10/06. Doses of 50, 100, 150 and 250 mg/m2/d × 3 have been given for 1 to 10 cycles. Grade 1 granulocytopenia (2/4 pts with carcinoma) indicates biologic activity. Grade 1 fatigue (3/5) was less than in prior chemotherapy regimens. No grade 2 toxicity has yet occurred. Cumulative toxicity has not been seen. Two pts have had stable disease 6+ and 22+ wks. After deproteinization with acetonitrile, plasma or serum samples were measured by mass spectrometry. At 100 mg/m2/d steady state levels were 730 nM after the 1st cycle and 1190 nM after the 4th cycle. Drug levels were maximal at 3 to 6 h despite CI suggesting induction of a metabolizing pathway. Levels fell precipitously at the end of infusion on the 1st cycle but a low level persisted in one pt for 48h after the major drop in the 4th cycle, suggesting drug accumulation. Conclusion: Levels effective in vitro have been obtained in vivo by CI without limiting toxicity. Hints of activity already seen suggest that this compound has clinical promise. This phase I study continues.

[Table: see text]

Case reports and literature review: the association between reactivation of human herpes virus-6 and peripheral white blood cell count in patients with carbamazepine-induced hypersensitivity syndrome

Eruptions induced by anticonvulsants can often be experienced clinically, and the clinical diagnosis of "drug induced hypersensitivity syndrome (HS)" was proposed to characterize these drug eruptions. Reactivation of human herpes virus-6 seems to be an integral component of HS. Previously, we experienced two cases of carbamazepine (an anticonvulsant) induced HS and both cases did not show a reactivation of human herpes virus-6 infection (no elevation of anti-human herpes virus-6 IgG titres). The features of these two cases were compared with other reported cases that presented HS with the reactivation of human herpes virus-6. In the early phase of HS, a change in peripheral white blood cell count seems to be important and could be used as an indicator to predict whether late phase HS with reactivation of human herpes virus-6 will occur, since the increase in white blood cell count is seen before the increase in anti-human herpes virus-6 titres. Reactivation of human herpes virus-6 may cause severe clinical symptoms such as encephalitis. When an increase in white blood cells are observed in HS cases at onset, immediate discontinuation of cause drug and intensive care are necessary to avoid the more severe symptoms of HS.

No genetic association between postsynaptic density-95 gene polymorphisms and schizophrenia

Disturbed glutamatergic neurotransmission, especially disturbed N-methyl-D-aspartate (NMDA) receptor function, has been hypothesized to be involved in the pathophysiology of schizophrenia. It may also involve abnormalities in the intracellular signaling machineries that are linked to the NMDA receptor. Postsynaptic density-95 is known to bind NMDA receptor subunits and is involved in intracellular signal transduction and synaptic plasticity. Recently, we reported that gene expression of postsynaptic density-95 was altered in schizophrenic brains compared to controls. Therefore, in this study, we examined six polymorphisms in and around the postsynaptic density-95 gene in 259 schizophrenic cases and 188 healthy controls using TaqMan technology. The results suggested that these six polymorphisms did not affect risk for schizophrenia.

Genetic association between Notch4 polymorphisms and Japanese schizophrenics

The objective of this study was to investigate whether three single nucleotide polymorphisms of the Notch4 gene are associated with the onset of schizophrenia. To confirm the linkage disequilibrium among these three single nucleotide polymorphisms of the gene, the three single nucleotide polymorphisms were genotyped by a polymerase chain reaction-restriction-fragment length polymorphism method for all samples. The genotypic frequencies of each single nucleotide polymorphism in the schizophrenic were compared with respective controls using a chi method. To check linkage disequilibrium, the haplotype frequency program was utilized. No statistical association between the two single nucleotide polymorphisms of the Notch4 gene and schizophrenia was observed in our Japanese samples. Although one nonsynonymous single nucleotide polymorphism did show a weakly significant P-value, its allelic frequencies are not positive. Two of the single nucleotide polymorphisms showed strong linkage disequilibrium in our Japanese samples. The single nucleotide polymorphism between the other two single nucleotide polymorphisms showed a weaker linkage disequilibrium with the others. Our study suggests that the three single nucleotide polymorphisms are not associated with the onset of schizophrenia. The linkage disequilibrium of this locus indicates that there is genetic heterogeneity in the Notch4 gene. Linkage disequilibrium may differ among ethnic groups, and so a larger study should be performed in this region.

Genomewide high-density SNP linkage analysis of 236 Japanese families supports the existence of schizophrenia susceptibility loci on chromosomes 1p, 14q, and 20p

The Japanese Schizophrenia Sib-Pair Linkage Group (JSSLG) is a multisite collaborative study group that was organized to create a national resource for affected sib pair (ASP) studies of schizophrenia in Japan. We used a high-density single-nucleotide-polymorphism (SNP) genotyping assay, the Illumina BeadArray linkage mapping panel (version 4) comprising 5,861 SNPs, to perform a genomewide linkage analysis of JSSLG samples comprising 236 Japanese families with 268 nonindependent ASPs with schizophrenia. All subjects were Japanese. Among these families, 122 families comprised the same subjects analyzed with short tandem repeat markers. All the probands and their siblings, with the exception of seven siblings with schizoaffective disorder, had schizophrenia. After excluding SNPs with high linkage disequilibrium, we found significant evidence of linkage of schizophrenia to chromosome 1p21.2-1p13.2 (LOD=3.39) and suggestive evidence of linkage to 14q11.2 (LOD=2.87), 14q11.2-q13.2 (LOD=2.33), and 20p12.1-p11.2 (LOD=2.33). Although linkage to these regions has received little attention, these regions are included in or partially overlap the 10 regions reported by Lewis et al. that passed the two aggregate criteria of a meta-analysis. Results of the present study--which, to our knowledge, is the first genomewide analysis of schizophrenia in ASPs of a single Asian ethnicity that is comparable to the analyses done of ASPs of European descent--indicate the existence of schizophrenia susceptibility loci that are common to different ethnic groups but that likely have different ethnicity-specific effects.