Lithium decreases VEGF mRNA expression in leukocytes of healthy subjects and patients with bipolar disorder

OBJECTIVES

Vascular endothelial growth factor (VEGF) is thought to be involved in the pathophysiology of mood disorders and the target of antidepressants. The aim of this study was to elucidate molecular effects of lithium on VEGF expression by using leukocytes of healthy subjects and patients with bipolar disorder.

METHODS

Eight healthy male subjects participated in the first study. Lithium was prescribed for 2 weeks, enough to reach therapeutic serum concentration. Leukocyte counts and serum lithium concentrations were determined at baseline, at 1- and 2-week medication, and at 2 weeks after stopping medication. VEGF mRNA levels were also examined in nine lithium-treated bipolar patients and healthy controls in the second study.

RESULTS

In the first study, leukocyte counts were significantly increased at 2 weeks compared with those at baseline and were normalized after 2 weeks. VEGF mRNA levels were significantly decreased at 2 weeks and after 2 weeks compared with those at baseline. Consistent with the first study, VEGF mRNA levels were significantly decreased in the lithium-treated bipolar patients compared with healthy controls.

CONCLUSIONS

Our investigation suggests that VEGF mRNA expression may be useful as a peripheral marker of the effects of lithium.

Quality of life and cognitive dysfunction in people with schizophrenia

The main purpose of the present study was to examine the relationship between quality of life (QOL) and cognitive dysfunction in schizophrenia. Subjects were 61 stabilized outpatients. Quality of life and cognitive function were assessed using the Quality of Life Scale (QLS) and the Brief Assessment of Cognition in Schizophrenia (BACS), respectively. Clinical symptoms were evaluated with the Positive and Negative Syndrome Scale (PANSS) and the Calgary Depression Scale for Schizophrenia (CDSS). The BACS composite score and the BACS Verbal memory score were positively correlated with the QLS total score and two subscales. The BACS Attention and speed of information processing score had positive correlation with the QLS total and all the subscales scores. The PANSS Positive and Negative syndrome scores also had significant correlations with the QLS total score and all of the subscales. In addition, the CDSS score was negatively correlated with the QLS total score and some of the subscales. Stepwise regression analysis showed that the BACS Attention and speed of information processing score was an independent predictor of the QLS total score but it was less associated with the QLS than the PANSS Negative syndrome score and the CDSS score. The results suggest that negative and depressive symptoms are important factors on patients' QOL and also support the view that cognitive performance provides a determinant of QOL in patients with schizophrenia.

Gene expression and association analysis of the epithelial membrane protein 1 gene in major depressive disorder in the Japanese population

The epithelial membrane protein 1 (EMP1) plays a role in neuronal differentiation and neurite outgrowth, which are involved in the pathogenesis of major depressive disorder (MDD). We sought to determine whether the EMP1 gene is implicated in MDD. We determined the mRNA expression levels of the EMP1 gene in peripheral-blood leukocytes of patients and control subjects (n=27 each). Next, we performed case-control association analyses (MDD, n=182; controls, n=350) in the Japanese population. The level of expression of the EMP1 mRNA was significantly lower in medication-free patients compared with control subjects (P<0.001). The association analysis revealed an absence of association between the polymorphisms studied and MDD, whereas a gender-specific association was observed between male controls and male patients for marker rs7315725 (permutation P=0.039). Our results suggest that the EMP1 gene may be implicated in the pathophysiology of MDD in the Japanese population.

GABA concentration in schizophrenia patients and the effects of antipsychotic medication: a proton magnetic resonance spectroscopy study

Gamma-amino butyric acid (GABA) is thought to play a role in the pathophysiology of schizophrenia. High magnetic field proton magnetic resonance spectroscopy ((1)H-MRS) provides a reliable measurement of GABA in specific regions of the brain. This study measured GABA concentration in the anterior cingulate cortex (ACC) and in the left basal ganglia (ltBG) in 38 patients with chronic schizophrenia and 29 healthy control subjects. There was no significant difference in GABA concentration between the schizophrenia patients and the healthy controls in either the ACC (1.36+/-0.45 mmol/l in schizophrenia patients and 1.52+/-0.54 mmol/l in control subjects) or the ltBG (1.13+/-0.26 mmol/l in schizophrenia patients and 1.18+/-0.20 mmol/l in control subjects). Among the right handed schizophrenia patients, the GABA concentration in the ltBG was significantly higher in patients taking typical antipsychotics (1.25+/-0.24 mmol/l) than in those taking atypical antipsychotics (1.03+/-0.24 mmol/l, p=0.026). In the ACC, the GABA concentration was negatively correlated with the dose of the antipsychotics (rs=-0.347, p=0.035). In the ltBG, the GABA concentration was positively correlated with the dose of the anticholinergics (rs=0.403, p=0.015). To the best of our knowledge, this is the first study to have directly measured GABA concentrations in schizophrenia patients using (1)H-MRS. Our results suggest that there are no differences in GABA concentrations in the ACC or the ltBG of schizophrenia patients compared to healthy controls. Antipsychotic medication may cause changes in GABA concentration, and atypical and typical antipsychotics may have differing effects. It is possible that medication effects conceal inherent differences in GABA concentrations between schizophrenia patients and healthy controls.

The chitinase 3-like 1 gene and schizophrenia: evidence from a multi-center case-control study and meta-analysis

The chitinase 3-like 1 (CHI3L1) gene acts as a cellular survival factor in response to several environmental and psychosocial stresses. The expression level of CHI3L1 was increased in the hippocampus and prefrontal cortex regions of patients with schizophrenia. Genetic variants of the CHI3L1 gene have been significantly associated with schizophrenia in two distinct ethnic groups, the Chinese and Irish populations. The aims of this study are to confirm the association between the CHI3L1 gene and schizophrenia in a Japanese population using the largest sample size to date (1463 cases and 1795 controls) and perform a meta-analysis of the combined samples (3005 cases, 3825 controls and 601 trios). We found significant associations between single nucleotide polymorphism (SNP) 4/rs4950928 (p=0.009), which is located in the promoter region of the CHI3L1 gene, and haplotypes including this SNP and schizophrenia (the most significant global p<0.001). As the meta-analysis of the combined samples showed significant heterogeneity among studies of SNP3/rs10399805 (p=0.026) and SNP4 (p<0.001), we performed meta-analyses separately in the Japanese (2033 cases and 2365 controls) and Chinese populations (412 cases, 464 controls and 601 trios), the major groups analyzed in association studies of the CHI3L1 gene. The meta-analysis in Japanese populations showed stronger evidence for the association of schizophrenia with SNP4 (p=0.003), while the meta-analysis in Chinese populations showed an association with a different variant (SNP3) (p=0.003). We conclude that the genetic variants in the CHI3L1 gene have ethnic heterogeneity and confer a susceptibility to schizophrenia in Asian populations.

Gene expression and association analyses of the phosphodiesterase 4B (PDE4B) gene in major depressive disorder in the Japanese population

The phosphodiesterase 4B (PDE4B) interacts with disrupted-in-schizophrenia 1 (DISC1), which is a known genetic risk factor for schizophrenia, bipolar disorder and major depressive disorder (MDD). PDE4B is also important in the regulation of cAMP signaling, a second messenger implicated in learning, memory, and mood. In this study, we determined mRNA expression levels of the PDE4B gene in the peripheral blood leukocytes of patients with MDD and control subjects (n = 33, each). Next we performed two-stage case-controlled association analyses (first set; case = 174, controls = 348; second set; case = 481, controls = 812) in the Japanese population to determine if the PDE4B gene is implicated in MDD. In the leukocytes, a significantly higher expression of the PDE4B mRNA was observed in the drug-naïve MDD patients compared with control subjects (P < 0.0001) and the expression of the MDD patients significantly decreased after antidepressant treatment (P = 0.030). In the association analysis, we observed significant allelic associations of four SNPs (the most significant, rs472952; P = 0.002) and a significant haplotypic association (permutation P = 0.019) between the PDE4B gene and MDD in the first-set samples. However, we could not confirm these significant associations in the following independent second-set of samples. Our results suggest that the PDE4B gene itself does not link to MDD but the elevated mRNA levels of PDE4B might be implicated in the pathophysiology of MDD.

Changes in circulating cytokine levels in midlife women with psychological symptoms with selective serotonin reuptake inhibitor and Japanese traditional medicine

OBJECTIVE

The aim of the present study was to compare the effects on serum cytokine concentrations of paroxetine, a selective serotonin re-uptake inhibitor, and kamishoyosan, a Japanese traditional medicine, in midlife women with psychological symptoms.

METHODS

Seventy-six women with psychological symptoms such as anxiety and mild depression as menopausal symptoms were enrolled in this study. Thirty-eight women received oral administration of 10mg paroxetine every day, and 38 women received oral administration of kamshoyosan every day for 6 months. Overall climacteric symptoms were assessed using Greene's climacteric scale. Serum levels of cytokines were measured using a multiplexed human cytokine assay.

RESULTS

Greene's total scores in both women treated with paroxetine and in women treated with kamishoyosan decreased significantly. Percentage decreases in Greene's total, psychological and vasomotor scores during the 6-month period in the paroxetine group were significantly greater than those in the kamishoyosan group. Serum IL-6 concentration in women treated with paroxetine decreased significantly. Serum concentrations of IL-8, IL-10, macrophage inflammatory protein (MIP)-1beta and monocyte chemoattractant protein-1 in women treated with paroxetine decreased significantly. On the other hand, serum IL-6 concentration in women treated with kamishoyosan decreased significantly, but other serum concentrations did not change significantly.

CONCLUSION

Decrease in IL-6 concentration may be involved in the mechanism of the actions of both paroxetine and kamishoyosan in women with psychological symptoms, and IL-6 may therefore be useful as a marker of treatment. The action of paroxetine may also be associated with decreases in IL-8, IL-10, MIP-1beta.

Positive association of the pericentrin (PCNT) gene with major depressive disorder in the Japanese population

BACKGROUND

Pericentrin (PCNT) interacts with disruption-in-schizophrenia 1 (DISC1), a known genetic risk factor for schizophrenia, bipolar disorder and major depressive disorder (MDD). We sought to determine whether the PCNT gene is implicated in MDD.

METHODS

We performed case-control association analyses in the Japanese population. We analyzed 9 single nucleotide polymorphisms (SNPs) in 173 patients with MDD and 348 healthy controls.

RESULTS

We found a significant allelic association between 3 SNPs (rs3788265, rs2073376 and rs2073380) of the PCNT gene and MDD (p = 0.006, 0.005 and 0.021, respectively). After correction for multiple testing, 2 SNPs (rs3788265 and rs2073376) retained significant allelic associations with MDD. In addition, we found a significant association between the 2 marker haplotypes (r3788265 and rs2073376) and MDD (permutation p = 0.011).

LIMITATIONS

Our sample was small and comprised only Japanese participants. In addition, owing to the late onset of MDD, it is possible that the disorder will develop in at least some participants in our control group. Finally, we did not show how SNPs of the PCNT gene alter its function.

CONCLUSION

Our results suggest that genetic variations in the PCNT gene may play a significant role in the etiology of MDD in the Japanese population.

Genotyping of Strawberry (Fragaria ananassa Duch.) Cultivars by DNA Markers: Interlaboratory Study

Fourteen Japanese laboratories validated the reproducibility of genotyping by 25 cleavage amplified polymorphic sequence (CAPS) markers for discrimination of strawberry (Fragaria ananassa Duch.) cultivars. Both the sensitivity and specificity rate of 12 markers were 100, those of another 12 were &gt;95, and those of 1 were &gt;90. These results indicate that the method of genotyping by the CAPS markers was highly reproducible and could provide a useful basis for practical identification of strawberry cultivars. This is the first report of the statistical validation of crop genotyping by DNA markers.

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.

Metabolite changes and gender differences in schizophrenia using 3-Tesla proton magnetic resonance spectroscopy (1H-MRS)

A change in the glutamatergic system is thought to play an important role in the pathophysiology of schizophrenia. The aim of this study was to investigate the changes in metabolites, including glutamate (Glu), in the anterior cingulate cortex (ACC) and the left basal ganglia (ltBG) of patients with chronic schizophrenia using proton magnetic resonance spectroscopy ((1)H-MRS). In addition, since gender differences in this illness were known, we examined the effects of gender on these metabolites. The (1)H-MRS was performed on the ACC and ltBG of 30 patients with schizophrenia and 25 healthy individuals who acted as the control group. The levels of Glu, glutamine (Gln), creatine plus phosphocreatine (Cre), myo-inositol (mI), N-acetylaspartate (NAA), and choline-containing compounds (Cho) were measured. Two-way analysis of variance revealed that the illness significantly affected the levels of Glu and mI in the ACC; both metabolites were lower in the patients with schizophrenia as compared to the control subjects. The results also revealed that gender significantly affected the level of Gln in the ACC and the levels of Cre and NAA in the ltBG; the level of Gln in the ACC were higher in male subjects versus female subjects, whereas Cre and NAA levels in the ltBG were lower in male subjects as compared to female subjects. These results confirmed a change in the glutamatergic system and suggested an involvement of mI in the pathophysiology of schizophrenia.

Positive association of the PDE4B (phosphodiesterase 4B) gene with schizophrenia in the Japanese population

The phosphodiesterase 4B (PDE4B) gene is located at 1p31, a susceptibility region for schizophrenia (SZ). Moreover, PDE4B interacts with DISC1, which is a known genetic risk factor for SZ. Recently, it was reported that the PDE4B gene is associated with SZ in Caucasian and African American populations. In this study, case-controlled association analyses were performed in the Japanese population to determine if the PDE4B gene is implicated in SZ. Thirteen single nucleotide polymorphisms (SNPs) were analyzed in 444 schizophrenic patients and 452 control subjects. Three SNPs (rs2180335, rs910694 and rs472952) were significantly associated with SZ after applying multiple test correction (p=0.039, 0.004 and 0.028). In addition, a significant association was found between specific haplotypes (rs2180335 and rs910694) and SZ (permutation p=0.001). Our result suggests that variations at the PDE4B locus may play a significant role in the etiology of SZ in the Japanese population.

TGFBR2 gene expression and genetic association with schizophrenia

TGFBR2 gene is a tumor suppressor gene located at chromosome 3p22, and the locus is reported to be linked with schizophrenia susceptibility. According to the previous studies, a reduced incidence of cancer is observed in schizophrenic patients compared with the general population and tumor suppressor genes may be associated with schizophrenia. We measured the mRNA expression of TGFBR2 gene in the peripheral leukocytes from 19 medication-free schizophrenics and 25 medication-free major depressive patients compared with age- and sex-matched control subjects using a quantitative real-time PCR method. We also followed up the TGFBR2 mRNA expression levels from 13 schizophrenics after several weeks - antipsychotic treatments. The TGFBR2 mRNA levels of medication free schizophrenics were significantly higher than those of control subjects and decreased to almost the same level as controls after antipsychotic treatment. On the other hand, the TGFBR2 mRNA levels of medication-free major depressive patients were not significantly different from controls. In genetic studies, we failed to find any association between the TGFBR2 gene and schizophrenia with 10 SNPs of TGFBR2 gene in Japanese subjects (279 subjects each) and there was no significant difference with haplotype analysis, either. Our results suggest that the TGFBR2 gene itself does not link to schizophrenia but that the TGFBR2 mRNA levels in the peripheral leukocytes may be a potential state marker for schizophrenia.

The Val66Met polymorphism of the brain-derived neurotrophic factor gene is associated with psychotic feature and suicidal behavior in Japanese major depressive patients

Recent researches have suggested that brain-derived neurotrophic factor (BDNF) may be implicated in the pathophysiology of mood disorder. This study examined the association between the BDNF Val66Met polymorphism and major depressive disorder (MDD) in a Japanese population. We genotyped the BDNF Val66Met polymorphism in 154 major depressive patients and 154 age- and sex-matched control subjects. The genotypic distributions and allele frequencies were similar among the patients and control subjects. When the relationships of the polymorphism with several clinical variables (i.e., age, sex, age of onset, number of episode, presence of psychotic features, suicidal behavior, and family history) were examined, the dose of Met allele had significant effects on psychotic feature and suicidal behavior and family history. These results suggest that the BDNF Val66Met polymorphism is not related to the development of MDD but related to clinical features of MDD in a Japanese population.

Association between PNPO and schizophrenia in the Japanese population

Accumulating evidence suggests that both homocysteine metabolism and monoaminergic neurotransmitter systems are important in schizophrenia pathology. We hypothesized that the gene PNPO (pyridoxine 5'-phosphatase oxidase gene) might be a candidate for susceptibility to schizophrenia because PNPO encodes pyridoxamine 5'-phosphate oxidase (EC 1.4.3.5), a rate-limiting enzyme in pyridoxal 5'-phosphate (PLP, vitamin B(6)) synthesis. PLP is a metabolically-active form of vitamin B(6) and thus, is required as a co-factor for enzymes involved in both homocysteine metabolism and synthesis of neurotransmitters such as catecholamine. We examined 8 single nucleotide polymorphisms (SNPs) in PNPO and its 5'-flanking regions in 359 schizophrenia patients and 582 control subjects. Four marker regions of PNPO showed significant levels of allelic associations with schizophrenia (the highest was rs2325751, P=0.004). In addition, the haplotype case-control study revealed a significant association (permutation P<0.00001) between PNPO and schizophrenia. These findings suggest that variations in PNPO may contribute to overall genetic risk for schizophrenia in the Japanese population.

Brief assessment of cognition in schizophrenia: validation of the Japanese version

This preliminary study was performed to test the reliability and validity of the Brief Assessment of Cognition in Schizophrenia (BACS) as an assessment tool in a Japanese-language version (BACS-J). The subjects for the present study were 30 outpatients with chronic schizophrenia. Each subject gave written informed consent to participate in the research. Cronbach's alpha for the BACS-J was 0.77. The BACS-J composite score was significantly correlated with all primary measures of BACS-J (verbal memory, working memory, motor speed, verbal fluency, attention, and executive function). All BACS-J primary measures and the composite score were significantly correlated between two assessments. The mean score of the Digit Sequencing Task and composite score on the second assessment were significantly larger than those on the first assessment. All BACS-J primary measures except the Symbol Coding Task were significantly correlated with relevant standard neurocognitive tests. Also, the BACS-J composite score was significantly correlated with all standard neurocognitive tests except the Continuous Performance Test. A principal components analysis with varimax rotation resulted in a three-factor solution (executive function and memory; motor speed and general cognitive functions; and working memory). This preliminary study indicates that the BACS-J is a reliable and practical scale to evaluate cognitive function.

Altered HDAC5 and CREB mRNA expressions in the peripheral leukocytes of major depression

BACKGROUND

Gene expressions of the peripheral leukocytes in depressive patients might reflect the systemic dysfunction of major depression. We determined mRNA expression levels of Histone deacetylase 5 (HDAC5) gene and cyclic AMP response element-binding protein 1 (CREB) gene in the leukocyte of depressive patients. HDAC5 and CREB are reported to be important targets of antidepressants, the latter being located in the downstream of the former in lymphocyte calcium signaling.

METHODS

25 patients with major depression and 25 age- and sex-matched healthy controls were included in this study. Twenty patients were able to be followed up until the 8 week-treatment. The mRNA levels were determined by a quantitative RT-PCR method.

RESULT

Levels of HDAC5 and CREB mRNA were significantly higher in drug-free depressive patients than those of controls and the higher mRNA levels decreased to control levels after 8-week paroxetine treatment. There were positive correlation between levels of HDAC5 and CREB.

CONCLUSION

Our results suggest the alteration of HDAC5 and CREB gene expression in the systemic pathophysiology of major depression.

Gene expression and association analysis of vascular endothelial growth factor in major depressive disorder

Vascular endothelial growth factor (VEGF) has been implicated in neuronal survival, neuroprotection, regeneration, growth, differentiation, and axonal outgrowth, which are known to be involved in the pathophysiology of major depressive disorder (MDD). Recently, the VEGF mRNA expression in the peripheral leukocytes from Alzheimer's disease or cardiovascular disease was reported to be changed. We hypothesized that the expression of the VEGF mRNA in the peripheral leukocytes may be a good candidate for the biological marker for MDD. Thirty two patients with MDD and age- and sex-matched control subjects were included in this expression study. The VEGF mRNA levels in the peripheral leukocytes from drug-naive MDD patients were significantly higher than those from the control subjects and the magnitude of the decrease of VEGF mRNA after 8-week treatment significantly correlated with clinical improvement. Then, we genotyped two single nucleotide polymorphic markers of VEGF gene, which were reported to be associated with amyotrophic lateral sclerosis and Alzheimer's disease, in patients with MDD and control subjects (n=154, each). We did not find any significant association between these markers and MDD or its clinical subtypes. Our investigation indicates that the higher expression levels of VEGF mRNA in the peripheral leukocytes are associated with the depressive state and their recovery after treatment may be associated with the clinical improvement.

Association of serum cytokine concentrations with psychological symptoms in midlife women

OBJECTIVE

The purpose of the present study was to clarify the association of serum cytokine concentrations, determined using a multiplexed cytokine assay, with psychological symptoms in midlife women.

METHODS

Fifty-three peri- and post-menopausal women with and without psychological symptoms in Greene's climacteric scale were enrolled in this study. Levels of 17 cytokines in serum samples were measured simultaneously using a multiplexed human cytokine assay.

RESULTS

Serum interleukin (IL)-6 concentration in women with psychological symptoms (2.71+/-047 pg/ml) was significantly (p=0.009) higher than that in women without psychological symptoms (0.98+/-0.18 pg/ml). Serum IL-8 concentration in women with psychological symptoms (33.4+/-8.17 pg/ml) was also significantly (p=0.022) higher than that in women without psychological symptoms (7.87+/-1.64 pg/ml). In addition, serum IL-10 concentration in women with psychological symptoms (0.74+/-0.26 pg/ml) was significantly (p=0.048) higher than that in women without psychological symptoms (0.07+/-0.04 pg/ml). Tumor necrosis factor (TNF)-alpha in serum was detected only in women with psychological symptoms. Serum IL-2 concentration in women with psychological symptoms tended (p=0.066) to be higher than that in women without psychological symptoms. No significant differences were found between levels of other cytokines in women with and without psychological symptoms.

CONCLUSION

Psychological stress manifested as climacteric symptoms in midlife women may be associated with increases in serum concentrations of IL-6, IL-8, IL-10, and TNF-alpha.

Gene expression in the peripheral leukocytes and association analysis of PDLIM5 gene in schizophrenia

PDLIM5 modulates neuronal calcium signaling, co-localizes with synaptic vesicles of neurotransmitters and positive association between its gene and schizophrenia was reported but its relation is still ambiguous. The differential expression of the PDLIM5 gene both in the brain and in the lymphoblasts has been found in schizophrenia compared to control subjects. In this study, we measured the expression level of the PDLIM5 gene transcripts in the peripheral leukocytes from 19 medication-free and 21 chronically medicated schizophrenic patients as well as age- and sex-matched control subjects using a quantitative real-time PCR method. The mRNA levels of the PDLIM5 gene in the leukocytes of medication-free schizophrenic patients were significantly higher than those of control subjects. On the other hand, our group has previously shown that its mRNA expression in the leukocytes of medication-free major depressive patients was significantly lower compared with controls. There was no difference in the PDLIM5 mRNA levels between chronic schizophrenic patients with antipsychotic medication and their controls. Further, we failed to find any genetic association between the PDLIM5 gene and schizophrenia with six single nucleotide polymorphics (SNPs) of the PDLIM5 gene in Japanese subjects (279 subjects each) and there was no significant relation between PDLIM5 gene and schizophrenia with the haplotype analysis (P=0.48), either. We suggest that the higher expression levels of the PDLIM5 mRNA in the peripheral leukocytes may be a candidate marker for medication-free schizophrenic patients.