Fecal Bacteria Contamination of Floodwaters and a Coastal Waterway From Tidally-Driven Stormwater Network Inundation

Inundation of coastal stormwater networks by tides is widespread due to sea-level rise (SLR). The water quality risks posed by tidal water rising up through stormwater infrastructure (pipes and catch basins), out onto roadways, and back out to receiving water bodies is poorly understood but may be substantial given that stormwater networks are a known source of fecal contamination. In this study, we (a) documented temporal variation in concentrations of Enterococcus spp. (ENT), the fecal indicator bacteria standard for marine waters, in a coastal waterway over a 2-month period and more intensively during two perigean spring tide periods, (b) measured ENT concentrations in roadway floodwaters during tidal floods, and (c) explained variation in ENT concentrations as a function of tidal inundation, antecedent rainfall, and stormwater infrastructure using a pipe network inundation model and robust linear mixed effect models. We find that ENT concentrations in the receiving waterway vary as a function of tidal stage and antecedent rainfall, but also site-specific characteristics of the stormwater network that drains to the waterway. Tidal variables significantly explain measured ENT variance in the waterway, however, runoff drove higher ENT concentrations in the receiving waterway. Samples of floodwaters on roadways during both perigean spring tide events were limited, but all samples exceeded the threshold for safe public use of recreational waters. These results indicate that inundation of stormwater networks by tides could pose public health hazards in receiving water bodies and on roadways, which will likely be exacerbated in the future due to continued SLR.

Availability of individual proteins for quantitative analysis in postmortem brains preserved in two different brain banks

AIM

Postmortem brain research is necessary for elucidating the pathology of schizophrenia; an increasing number of studies require a combination of suitable tissue samples preserved at multiple brain banks. In this study, we examined whether a comparative study of protein expression levels can be conducted using postmortem brain samples preserved in different facilities.

METHODS

We compared the demographic factors of postmortem brain samples preserved in two institutions and measured and compared the expression levels of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) and glial fibrillary acidic protein (GFAP) in the prefrontal cortex and superior temporal gyrus. GAPDH is generally used as a loading control for western blotting, and GFAP is considered as an astrocyte marker in the brain.

RESULTS

We found significant differences between the two institutions in postmortem interval, age at death, and preservation time. To reduce the effects of these differences on our measurements, the parameters were set as covariates in our analyses of covariance. Subsequently, no differences in GAPDH and GFAP expression were found between institutions.

CONCLUSIONS

When studies are conducted using brain samples preserved in different brain banks, differences in demographic factors should be carefully considered and taken into account by statistical methods to minimize their impact as much as possible. Since there was no significant difference in the protein expression levels of GAPDH and GFAP in either region between the two institutions that preserved the postmortem brains, we concluded that it is possible to perform protein quantitative analysis assuming that there is no effect of difference between two institutions.

Marked alteration of phosphoinositide signaling-associated molecules in postmortem prefrontal cortex with bipolar disorder

AIM

The etiology of bipolar disorder (BD) remains unknown; however, lipid abnormalities in BD have received increasing attention in recent years. In this study, we examined the expression levels of enzyme proteins associated with the metabolic pathway of phosphoinositides (PIs) and their downstream effectors, protein kinase B (Akt1) and glycogen synthase kinase 3β (GSK3β), which have been assumed to be the targets of mood stabilizers such as lithium, in the postmortem brains of patients with BD.

METHODS

The protein expression levels of phosphatidylinositol 4-phosphate 5-kinase type-1 gamma (PIP5K1C), phosphatidylinositol 4-kinase alpha (PIK4CA), phosphatase and tensin homolog deleted from chromosome 10 (PTEN), Akt1, and GSK3β were measured using enzyme-linked immunosorbent assays and multiplex fluorescent bead-based immunoassays in the prefrontal cortex (PFC). Specifically, PTEN, Akt1, GSK3β, and PIP5K1C were measured in seven BD patients and 48 controls. Additionally, PIK4CA was analyzed in 10 cases and 34 controls.

RESULTS

PTEN expression levels were markedly decreased in the PFCs of patients with BD, whereas those of Akt and GSK3β were prominently elevated. Moreover, patients medicated with lithium exhibited higher Akt1 expression levels and lower PTEN expression levels in comparison with the untreated group.

CONCLUSION

Our results suggest that the expression levels of Akt1/GSK3β and its upstream regulator PTEN are considerably altered.

Ethnicity-dependent effect of rs1799971 polymorphism on OPRM1 expression in the postmortem brain and responsiveness to antipsychotics

Schizophrenia is associated with aberration of inhibitory neurons. Although the mu-opioid receptor (MOR) is an essential modulator of inhibitory neurons, the effect of rs1799971 polymorphism in the MOR gene on risk of schizophrenia is controversial. Moreover, the disturbance of opioids systems in patients with schizophrenia has not been fully examined. We firstly conducted preliminary meta-analyses integrating Asian and European populations separately over 12,000 subjects to assess the effect of rs1799971 on risk of schizophrenia. Based on the above result, we also investigated the effect on the expression levels of MOR mRNA in the prefrontal cortex (PFC) and caudate nucleus of 41 postmortem brains. In addition, we determined whether these levels were related to antemortem schizophrenia symptoms and pharmacotherapeutic effects. The rs1799971 G-allele reduced the risk of schizophrenia in Asian populations (OR: 0.56, 95%CI: 0.32-0.98, p = 0.042) but increased it in European populations (OR: 1.66, 95%CI: 1.08-2.56, p = 0.022). It decreased MOR mRNA levels in PFC in the Japanese population (p = 0.031). Increased MOR mRNA level in PFC correlated with higher total score of antemortem schizophrenia symptoms (p = 0.017). Furthermore, the pharmacotherapeutic effect of first-generation antipsychotics was higher for genotype AA than AG/GG of rs1799971 (p = 0.036). The rs1799971 affects risk of schizophrenia and MOR mRNA expression and the effect varies according to ethnicity. Overexpression of MOR might induce severe schizophrenia symptoms. Therefore, MOR modulation may be the key clue for treating antipsychotics-resistant schizophrenia, and genotyping rs1799971 may provide a better pharmacotherapeutic strategy.

Lipid-correlated alterations in the transcriptome are enriched in several specific pathways in the postmortem prefrontal cortex of Japanese patients with schizophrenia

AIMS

Schizophrenia is a chronic relapsing psychiatric disorder that is characterized by many symptoms and has a high heritability. There were studies showing that the phospholipid abnormalities in subjects with schizophrenia (Front Biosci, S3, 2011, 153; Schizophr Bull, 48, 2022, 1125; Sci Rep, 7, 2017, 6; Anal Bioanal Chem, 400, 2011, 1933). Disturbances in prefrontal cortex phospholipid and fatty acid composition have been reported in subjects with schizophrenia (Sci Rep, 7, 2017, 6; Anal Bioanal Chem, 400, 2011, 1933; Schizophr Res, 215, 2020, 493; J Psychiatr Res, 47, 2013, 636; Int J Mol Sci, 22, 2021). For exploring the signaling pathways contributing to the lipid changes in previous study (Sci Rep, 7, 2017, 6), we performed two types of transcriptome analyses in subjects with schizophrenia: an unbiased transcriptome analysis solely based on RNA-seq data and a correlation analysis between levels of gene expression and lipids.

METHODS

RNA-Seq analysis was performed in the postmortem prefrontal cortex from 10 subjects with schizophrenia and 5 controls. Correlation analysis between the transcriptome and lipidome from 9 subjects, which are the same samples in the previous lipidomics study (Sci Rep, 7, 2017, 6).

RESULTS

Extraction of differentially expressed genes (DEGs) and further sequence and functional group analysis revealed changes in gene expression levels in phosphoinositide 3-kinase (PI3K)-Akt signaling and the complement system. In addition, a correlation analysis clarified alterations in ether lipid metabolism pathway, which is not found as DEGs in transcriptome analysis alone.

CONCLUSIONS

This study provided results of the integrated analysis of the schizophrenia-associated transcriptome and lipidome within the PFC and revealed that lipid-correlated alterations in the transcriptome are enriched in specific pathways including ether lipid metabolism pathway.

Evidence for increased DNA damage repair in the postmortem brain of the high stress-response group of schizophrenia

Background

Schizophrenia (SZ) is a disorder diagnosed by specific symptoms and duration and is highly heterogeneous, clinically and pathologically. Although there are an increasing number of studies on the association between genetic and environmental factors in the development of SZ, the actual distribution of the population with different levels of influence of these factors has not yet been fully elucidated. In this study, we focused on stress as an environmental factor and stratified SZ based on the expression levels of stress-responsive molecules in the postmortem prefrontal cortex.

Methods

We selected the following stress-responsive molecules: interleukin (IL) -1β, IL-6, IL-10, tumor necrosis factor-α, interferon-γ, glucocorticoid receptor, brain-derived neurotrophic factor, synaptophysin, S100 calcium-binding protein B, superoxide dismutase, postsynaptic density protein 95, synuclein, apolipoprotein A1 (ApoA1), ApoA2, and solute carrier family 6 member 4. We performed RNA sequencing in the prefrontal gray matter of 25 SZ cases and 21 healthy controls and conducted a hierarchical cluster analysis of SZ based on the gene expression levels of stress-responsive molecules, which yielded two clusters. After assessing the validity of the clusters, they were designated as the high stress-response SZ group and the low stress-response SZ group, respectively. Ingenuity Pathway Analysis of differentially expressed genes (DEGs) between clusters was performed, and Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) staining was conducted on four cases each in the high and low stress-response SZ groups to validate DNA damage.

Results

We found higher prevalence of family history of SZ in the low stress-response SZ group (0/3 vs. 5/4, p = 0.04). Pathway analysis of DEGs between clusters showed the highest enrichment for DNA double-strand break repair. TUNEL staining showed a trend toward a lower percentage of TUNEL-positive cells in the high stress-response SZ group.

Conclusion

Our results suggest that there are subgroups of SZ with different degrees of stress impact. Furthermore, the pathophysiology of these subgroups may be associated with DNA damage repair. These results provide new insights into the interactions and heterogeneity between genetic and environmental factors.

The influence of tissue pH and RNA integrity number on gene expression of human postmortem brain

Background

Evaluating and controlling confounders are necessary when investigating molecular pathogenesis using human postmortem brain tissue. Particularly, tissue pH and RNA integrity number (RIN) are valuable indicators for controlling confounders. However, the influences of these indicators on the expression of each gene in postmortem brain have not been fully investigated. Therefore, we aimed to assess these effects on gene expressions of human brain samples.

Methods

We isolated total RNA from occipital lobes of 13 patients with schizophrenia and measured the RIN and tissue pH. Gene expression was analyzed and gene sets affected by tissue pH and RIN were identified. Moreover, we examined the functions of these genes by enrichment analysis and upstream regulator analysis.

Results

We identified 2,043 genes (24.7%) whose expressions were highly correlated with pH; 3,004 genes (36.3%) whose expressions were highly correlated with RIN; and 1,293 genes (15.6%) whose expressions were highly correlated with both pH and RIN. Genes commonly affected by tissue pH and RIN were highly associated with energy production and the immune system. In addition, genes uniquely affected by tissue pH were highly associated with the cell cycle, whereas those uniquely affected by RIN were highly associated with RNA processing.

Conclusion

The current study elucidated the influence of pH and RIN on gene expression profiling and identified gene sets whose expressions were affected by tissue pH or RIN. These findings would be helpful in the control of confounders for future postmortem brain studies.

Disease specific brain capillary angiopathy in schizophrenia, bipolar disorder, and Alzheimer's disease

Schizophrenia (SZ) and bipolar disorder (BD), which are both psychiatric disorders, share some common clinical evidence. We recently discovered that brain capillary angiopathy is another common feature of these psychiatric disorders using fibrin accumulation in vascular endothelial cells as an indicator. This study aimed to characterize the similarities and differences in cerebral capillary injuries in various brain diseases to provide new diagnostic methods for SZ and BD and to develop new therapeutic strategies. We evaluated whether discrepancies exist in the degree of vascular damage among SZ and BD and other brain disorders (amyotrophic lateral sclerosis (ALS), Parkinson's disease (PD), and Alzheimer's disease (AD)) using postmortem brains. Our results demonstrate that fibrin was strongly accumulated in the capillaries of the grey matter (GM) of brains of patients with SZ and AD and in the capillaries of the white matter (WM) in those of patients with SZ, BD, and AD when compared with control subjects without any psychiatric or neurological disease history. However, ALS and PD brains did not present a significant increase in the amount of accumulated fibrin, either in the capillaries of WM or GM. Furthermore, significant leakage of fibrin into the brain parenchyma, indicating a vascular physical disruption, was observed in the brains of patients with AD but not in the brains of other patients compared with control subjects. In conclusion, our work reveals that Fibrin-accumulation in the brain capillaries are observed in psychiatric disorders, such as SZ, BD, and AD. Furthermore, fibrin-accumulating, nonbreaking type angiopathy is characteristic of SZ and BD, even though there are regional differences between these diseases.

Comprehensive evaluation of machine learning algorithms for predicting sleep-wake conditions and differentiating between the wake conditions before and after sleep during pregnancy based on heart rate variability

Introduction

Perinatal women tend to have difficulties with sleep along with autonomic characteristics. This study aimed to identify a machine learning algorithm capable of achieving high accuracy in predicting sleep-wake conditions and differentiating between the wake conditions before and after sleep during pregnancy based on heart rate variability (HRV).

Methods

Nine HRV indicators (features) and sleep-wake conditions of 154 pregnant women were measured for 1 week, from the 23rd to the 32nd weeks of pregnancy. Ten machine learning and three deep learning methods were applied to predict three types of sleep-wake conditions (wake, shallow sleep, and deep sleep). In addition, the prediction of four conditions, in which the wake conditions before and after sleep were differentiated-shallow sleep, deep sleep, and the two types of wake conditions-was also tested.

Results and Discussion

In the test for predicting three types of sleep-wake conditions, most of the algorithms, except for Naïve Bayes, showed higher areas under the curve (AUCs; 0.82-0.88) and accuracy (0.78-0.81). The test using four types of sleep-wake conditions with differentiation between the wake conditions before and after sleep also resulted in successful prediction by the gated recurrent unit with the highest AUC (0.86) and accuracy (0.79). Among the nine features, seven made major contributions to predicting sleep-wake conditions. Among the seven features, "the number of interval differences of successive RR intervals greater than 50 ms (NN50)" and "the proportion dividing NN50 by the total number of RR intervals (pNN50)" were useful to predict sleep-wake conditions unique to pregnancy. These findings suggest alterations in the vagal tone system specific to pregnancy.

Identification of schizophrenia symptom-related gene modules by postmortem brain transcriptome analysis

Schizophrenia is a multifactorial disorder, the genetic architecture of which remains unclear. Although many studies have examined the etiology of schizophrenia, the gene sets that contribute to its symptoms have not been fully investigated. In this study, we aimed to identify each gene set associated with corresponding symptoms of schizophrenia using the postmortem brains of 26 patients with schizophrenia and 51 controls. We classified genes expressed in the prefrontal cortex (analyzed by RNA-seq) into several modules by weighted gene co-expression network analysis (WGCNA) and examined the correlation between module expression and clinical characteristics. In addition, we calculated the polygenic risk score (PRS) for schizophrenia from Japanese genome-wide association studies, and investigated the association between the identified gene modules and PRS to evaluate whether genetic background affected gene expression. Finally, we conducted pathway analysis and upstream analysis using Ingenuity Pathway Analysis to clarify the functions and upstream regulators of symptom-related gene modules. As a result, three gene modules generated by WGCNA were significantly correlated with clinical characteristics, and one of these showed a significant association with PRS. Genes belonging to the transcriptional module associated with PRS significantly overlapped with signaling pathways of multiple sclerosis, neuroinflammation, and opioid use, suggesting that these pathways may also be profoundly implicated in schizophrenia. Upstream analysis indicated that genes in the detected module were profoundly regulated by lipopolysaccharides and CREB. This study identified schizophrenia symptom-related gene sets and their upstream regulators, revealing aspects of the pathophysiology of schizophrenia and identifying potential therapeutic targets.

Real-Time Prediction of Medical Demand and Mental Health Status in Ukraine under Russian Invasion Using Tweet Analysis

Russia's invasion of Ukraine (February 24, 2022) has begun and there are concerns about the impact on health care supply and mental health. This study analyzed tweets in the Ukrainian language to capture the medical needs and mental health conditions in wartime Ukraine by focusing on ostensibly relevant words. The number of tweets containing the keywords and their overall proportion was compared before and after the Russian invasion of Ukraine. The survey period was divided into four phases-the pre-2022 Russian invasion, acute phase (4 weeks), subacute phase (12 weeks), and the chronic phase (8 weeks) up to August 10, 2022. The analysis targeted tweets sent in Ukrainian. The tweets were screened using a set of six classes with 75 key groups and 303 Ukrainian (204 original Japanese) keywords. Overall, 98,526,440 tweets were analyzed, with a pre-invasion and post-onset average of 1,096,976 and 3,328,243 tweets/week (a 3.0-fold increase), respectively. Of these, 3,197,443 tweets contained the keywords, with a pre-invasion and invasion average of 26,241 and 114,640 tweets/week (a 4.4-fold increase), respectively. The post-onset phase witnessed a considerable increase in all classes-medical services, treatment, medical resources, medical situations, and special situations-but not in the symptom class. Keywords related to psychological distress and anxiety immediately increased during the acute phase; those related to depression and post-traumatic stress reactions continued increasing as the invasion persisted, which may have reflected the mental state of those impacted. Analyzing tweets is useful for predicting people's real-time physical and mental health needs during wartime.

Elevation of EGR1/zif268, a Neural Activity Marker, in the Auditory Cortex of Patients with Schizophrenia and its Animal Model

The family of epidermal growth factor (EGF) including neuregulin-1 are implicated in the neuropathology of schizophrenia. We established a rat model of schizophrenia by exposing perinatal rats to EGF and reported that the auditory pathophysiological traits of this model such as prepulse inhibition, auditory steady-state response, and mismatch negativity are relevant to those of schizophrenia. We assessed the activation status of the auditory cortex in this model, as well as that in patients with schizophrenia, by monitoring the three neural activity-induced proteins: EGR1 (zif268), c-fos, and Arc. Among the activity markers, protein levels of EGR1 were significantly higher at the adult stage in EGF model rats than those in control rats. The group difference was observed despite an EGF model rat and a control rat being housed together, ruling out the contribution of rat vocalization effects. These changes in EGR1 levels were seen to be specific to the auditory cortex of this model. The increase in EGR1 levels were detectable at the juvenile stage and continued until old ages but displayed a peak immediately after puberty, whereas c-fos and Arc levels were nearly indistinguishable between groups at all ages with an exception of Arc decrease at the juvenile stage. A similar increase in EGR1 levels was observed in the postmortem superior temporal cortex of patients with schizophrenia. The commonality of the EGR1 increase indicates that the EGR1 elevation in the auditory cortex might be one of the molecular signatures of this animal model and schizophrenia associating with hallucination.

Tubulin/microtubules as novel clozapine targets

Aim

Clozapine is currently the only effective drug for treatment‐resistant schizophrenia; nonetheless, its pharmacological mechanism remains unclear, and its administration is limited because of severe adverse effects. By comparing the binding proteins of clozapine and its derivative olanzapine, which is safer but less effective than clozapine, we attempted to clarify the mechanism of action specific to clozapine.

Methods

First, using the polyproline rod conjugates attached with clozapine or olanzapine, clozapine‐binding proteins in extracts from the cerebra of 7‐week‐old ICR mice were isolated and separated by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis (SDS‐PAGE) and analyzed by liquid chromatography‐tandem mass spectrometry (LC‐MS/MS) to identify proteins. Second, the effect of clozapine on tubulin polymerization was determined turbidimetrically. Finally, the cellular effects of clozapine were observed in HeLa cells by immunofluorescence microscopy.

Results

Alpha and β tubulins were the most abundant clozapine‐binding proteins. We also found that clozapine directly binds with α and β tubulin heterodimers to inhibit their polymerization to form microtubules and disturbs the microtubule network, causing mitotic arrest in HeLa cells.

Conclusion

These results suggest that α and β tubulin heterodimers are targeted by the clozapine and the microtubules are involved in the etiology of schizophrenia.

Clozapine‐binding proteins were investigated in mouse brain by using the polyproline rod method. The most abundant clozapine‐binding proteins were α and β tubulins. This figure shows immunofluorescence staining of HeLa cells treated without or with indicated doses of clozapine for 3 hours with anti‐tubulin antibody, indicating that clozapine disrupts the microtubule network in the cell. Scale bar, 20 μm.

High-sucrose diets contribute to brain angiopathy with impaired glucose uptake and psychosis-related higher brain dysfunctions in mice

Metabolic dysfunction is thought to contribute to the severity of psychiatric disorders; however, it has been unclear whether current high–simple sugar diets contribute to pathogenesis of these diseases. Here, we demonstrate that a high-sucrose diet during adolescence induces psychosis-related behavioral endophenotypes, including hyperactivity, poor working memory, impaired sensory gating, and disrupted interneuron function in mice deficient for glyoxalase-1 (GLO1), an enzyme involved in detoxification of sucrose metabolites. Furthermore, the high-sucrose diet induced microcapillary impairments and reduced brain glucose uptake in brains of Glo1-deficient mice. Aspirin protected against this angiopathy, enhancing brain glucose uptake and preventing abnormal behavioral phenotypes. Similar vascular damage to our model mice was found in the brains of randomly collected schizophrenia and bipolar disorder patients, suggesting that psychiatric disorders are associated with angiopathy in the brain caused by various environmental stresses, including metabolic stress.

Dysregulation of DPYSL2 expression by mTOR signaling in schizophrenia: Multi-level study of postmortem brain

The mechanistic target of rapamycin (mTOR)-signaling and dihydropyrimidinase-like 2 (DPYSL2), which are increasingly gaining attention as potential therapeutic targets for schizophrenia, are connected via Cap-dependent translation of the 5'TOP motif. We quantified the expression of molecules constituting the mTOR-signaling and DPYSL2 in the prefrontal cortex (PFC) and superior temporal gyrus (STG) of postmortem brain tissue samples from 24 patients with schizophrenia and 32 control individuals and conducted association analysis to examine abnormal regulation of DPYSL2 expression by the mTOR-signaling in schizophrenia. The average ribosomal protein S6 (S6) levels in the PFC and STG were lower in patients with schizophrenia (p < 0.01). DPYSL2 expression showed a significant positive correlation with phospho-S6 expression levels, which were effectors of mTOR translational regulation, and the correlation slope between phospho-S6 and DPYSL2 expressions differed between cases and controls. Association analyses of these mTOR-signaling and DPYSL2 alterations with genetic polymorphisms and the clinical profile suggested that certain genetic variants of DPYSL2 require high mTOR-signaling activity. Thus, the findings confirmed decreased S6 expression levels in schizophrenia and supported the relationship between the mTOR-signaling and DPYSL2 via 5'TOP Cap-dependent translation, thus providing insights connecting the two major schizophrenia treatment strategies associated with the mTOR-signaling and DPYSL2.

Evidence for Altered Phosphoinositide Signaling-Associated Molecules in the Postmortem Prefrontal Cortex of Patients with Schizophrenia

Phosphoinositides (PIs) play important roles in the structure and function of the brain. Associations between PIs and the pathophysiology of schizophrenia have been studied. However, the significance of the PI metabolic pathway in the pathology of schizophrenia is unknown. We examined the expression of PI signaling-associated proteins in the postmortem brain of schizophrenia patients. Protein expression levels of phosphatidylinositol 4-phosphate 5-kinase type-1 gamma (PIP5K1C), phosphatidylinositol 4-kinase alpha (PIK4CA, also known as PIK4A), phosphatase and tensin homolog deleted from chromosome 10 (PTEN), protein kinase B (Akt), and glycogen synthase kinase 3β (GSK3β) were measured using enzyme-linked immunosorbent assays and multiplex fluorescent bead-based immunoassays of the prefrontal cortex (PFC) of postmortem samples from 23 schizophrenia patients and 47 normal controls. We also examined the association between PIK4CA expression and its genetic variants in the same brain samples. PIK4CA expression was lower, whereas Akt expression was higher, in the PFC of schizophrenia patients than in that of controls; PIP5K1C, PTEN, and GSK3β expression was not different. No single-nucleotide polymorphism significantly affected protein expression. We identified molecules involved in the pathology of schizophrenia via this lipid metabolic pathway. These results suggest that PIK4CA is involved in the mechanism underlying the pathogenesis of schizophrenia and is a potential novel therapeutic target.

Detailed Postmortem Profiling of Inflammatory Mediators Expression Revealed Post-inflammatory Alternation in the Superior Temporal Gyrus of Schizophrenia

Recent studies have lent support to the possibility that inflammation is associated with the pathology of schizophrenia. In the study of measurement of inflammatory mediators, which are markers of inflammation, elevated inflammatory cytokine levels in the brain and blood have been reported in patients with schizophrenia. Several postmortem brain studies have also reported changes in the expression of inflammatory cytokines. However, it is not clear how these elevated inflammatory cytokines interact with other inflammatory mediators, and their association with the pathology of schizophrenia. We comprehensively investigated the expression of 30 inflammatory mediators in the superior temporal gyrus (STG) of 24 patients with schizophrenia and 26 controls using a multiplex method. Overall, inflammatory mediator expression in the STG was mostly unchanged. However, the expression of interleukin (IL)1-α and interferon-gamma-inducible protein (IP)-10 was decreased [IL-1α, median (IQR), 0.51 (0.37-0.70) vs. 0.87 (0.47-1.23), p = 0.01; IP-10, 13.99 (8.00-36.64) vs. 30.29 (10.23-134.73), p = 0.05], whereas that of IFN-α was increased [2.34 (1.84-4.48) vs. 1.94 (1.39-2.36), p = 0.04] in schizophrenia, although these alterations did not remain significant after multiple testing. Clustering based on inflammatory mediator expression pattern and analysis of upstream transcription factors using pathway analysis revealed that the suppression of IL-1α and IP-10 protein expression may be induced by regulation of a common upstream pathway. Neuroinflammation is important in understanding the biology of schizophrenia. While neuroimaging has been previously used, direct observation to determine the expression of inflammatory mediators is necessary. In this study, we identified protein changes, previously unreported, using comprehensive protein analysis in STG. These results provide insight into post-inflammatory alternation in chronic schizophrenia.

Ethnicity-Dependent Effects of Schizophrenia Risk Variants of the OLIG2 Gene on OLIG2 Transcription and White Matter Integrity

Previous studies have indicated associations between several OLIG2 gene single-nucleotide polymorphisms (SNPs) and susceptibility to schizophrenia among Caucasians. Consistent with these findings, postmortem brain and diffusion tensor imaging studies have indicated that the schizophrenia-risk-associated allele (A) in the OLIG2 SNP rs1059004 predicts lower OLIG2 gene expression in the dorsolateral prefrontal cortex (DLPFC) of schizophrenia patients and reduced white matter (WM) integrity of the corona radiata in normal brains among Caucasians. In an effort to replicate the association between this variant and WM integrity among healthy Japanese, we found that the number of A alleles was positively correlated with WM integrity in some fiber tracts, including the right posterior limb of the internal capsule, and with mean blood flow in a widespread area, including the inferior frontal operculum, orbital area, and triangular gyrus. Because the A allele affected WM integrity in opposite directions in Japanese and Caucasians, we investigated a possible association between the OLIG2 gene SNPs and the expression level of OLIG2 transcripts in postmortem DLPFCs. We evaluated rs1059004 and additional SNPs in the 5' upstream and 3' downstream regions of rs1059004 to cover the broader region of the OLIG2 gene. The 2 SNPs (rs1059004 and rs9653711) had opposite effects on OLIG2 gene expression in the DLPFC in Japanese and Caucasians. These findings suggest ethnicity-dependent opposite effects of OLIG2 gene SNPs on WM integrity and OLIG2 gene expression in the brain, which may partially explain the failures in replicating associations between genetic variants and psychiatric phenotypes among ethnicities.

ALDH4A1 expression levels are elevated in postmortem brains of patients with schizophrenia and are associated with genetic variants in enzymes related to proline metabolism

BACKGROUND

The molecular mechanisms underlying schizophrenia remain largely unclear, and we recently identified multiple proteins significantly altered in the postmortem prefrontal cortex (PFC) of schizophrenia patients amongst which aldehyde dehydrogenase 4 family member A1 (ALDH4A1) was especially elevated. In this study, we aimed to investigate the expression of ALDH4A1 in the PFC and superior temporal gyrus (STG) and to elucidate functional correlations between schizophrenia risk alleles and molecular expression profiles in the postmortem brains of patients with schizophrenia.

METHODS

The levels of ALDH4A1 protein expression in the PFC and STG in postmortem brains from 24 patients with schizophrenia, 8 patients with bipolar disorder, and 32 controls were assessed using enzyme-linked immunosorbent assay. Moreover, we explored the associations between ALDH4A1 expression and genetic variants in enzymes associated with proline metabolism, including ALDH4A1 (schizophrenia [n = 22], bipolar disorder [n = 6], controls [n = 11]).

RESULTS

ALDH4A1 levels were significantly elevated in both the PFC and STG in patients with schizophrenia and tended to elevate in patients with bipolar disorder. Furthermore, ALDH4A1 expression levels in the PFC were significantly associated with the following three single-nucleotide polymorphisms: rs10882639, rs33823, rs153508. We also found partial coexpression of ALDH4A1 in mitochondria in a subset of putative astrocytes of postmortem brain.

LIMITATIONS

Our study population was relatively small, particularly for a genetic study.

CONCLUSION

These findings indicate that altered expression of ALDH4A1 may reflect the potential molecular mechanisms underlying the pathogenesis of schizophrenia and bipolar disorder, and may aid in the development of novel drug therapies.

Final results for the neutron -asymmetry parameter A0 from the UCNA experiment

The UCNA experiment was designed to measure the neutron β-asymmetry parameter A0 using polarized ultracold neutrons (UCN). UCN produced via downscattering in solid deuterium were polarized via transport through a 7 T magnetic field, and then directed to a 1 T solenoidal electron spectrometer, where the decay electrons were detected in electron detector packages located on the two ends of the spectrometer. A value for A0 was then extracted from the asymmetry in the numbers of counts in the two detector packages. We summarize all of the results from the UCNA experiment, obtained during run periods in 2007, 2008–2009, 2010, and 2011–2013, which ultimately culminated in a 0.67% precision result for A0.

Minimal amount of tissue-based pH measurement to improve quality control in neuropsychiatric post-mortem brain studies

AIM

Tissue pH and RNA integrity are crucial quality-control indicators of human post-mortem brain tissues in the identification of the pathogeneses of neuropsychiatric disorders, but pH has not been measured as often due to limitations in the amount of tissue available. This study was designed to develop and validate a protocol for tissue pH evaluation using a minimal amount of human post-mortem tissues.

METHODS

A procedure that included a proper ratio of brain tissue weight to water for homogenization and the duration of homogenization was designed based on preliminary experiments using mouse brain tissues. The minimal (10 mg) and typical (100 mg) amounts of post-mortem brain tissue from 52 subjects were homogenized in 5 volumes (50 μL/10 mg tissue) and 10 volumes (1000 μL/100 mg tissue) of nuclease-free water and subjected to pH measurements using an InLab Ultra micro pH electrode.

RESULTS

The pH values based on the new protocol using a minimal amount of tissue significantly correlated with measurements of the standard protocol (r² = 0.86). The correlation coefficients of the pH values between gray and white matter of the same brain region, and the values between different brain regions were 0.73 and 0.54, respectively.

CONCLUSION

The proposed protocol used one-tenth of the tissue amount of current standard protocol and enabled us to evaluate the exact quality of post-mortem brain tissue subjected to subsequent analyses. The application of this protocol may improve the detection of biological phenomena of interest in post-mortem brain studies by diminishing confounding factors.

Investigation of betaine as a novel psychotherapeutic for schizophrenia

Background

Betaine is known to act against various biological stresses and its levels were reported to be decreased in schizophrenia patients. We aimed to test the role of betaine in schizophrenia pathophysiology, and to evaluate its potential as a novel psychotherapeutic.

Methods

Using Chdh (a gene for betaine synthesis)-deficient mice and betaine-supplemented inbred mice, we assessed the role of betaine in psychiatric pathophysiology, and its potential as a novel psychotherapeutic, by leveraging metabolomics, behavioral-, transcriptomics and DNA methylation analyses.

Findings

The Chdh-deficient mice revealed remnants of psychiatric behaviors along with schizophrenia-related molecular perturbations in the brain. Betaine supplementation elicited genetic background-dependent improvement in cognitive performance, and suppressed methamphetamine (MAP)-induced behavioral sensitization. Furthermore, betaine rectified the altered antioxidative and proinflammatory responses induced by MAP and in vitro phencyclidine (PCP) treatments. Betaine also showed a prophylactic effect on behavioral abnormality induced by PCP. Notably, betaine levels were decreased in the postmortem brains from schizophrenia, and a coexisting elevated carbonyl stress, a form of oxidative stress, demarcated a subset of schizophrenia with “betaine deficit-oxidative stress pathology”. We revealed the decrease of betaine levels in glyoxylase 1 (GLO1)-deficient hiPSCs, which shows elevated carbonyl stress, and the efficacy of betaine in alleviating it, thus supporting a causal link between betaine and oxidative stress conditions. Furthermore, a CHDH variant, rs35518479, was identified as a cis-expression quantitative trait locus (QTL) for CHDH expression in postmortem brains from schizophrenia, allowing genotype-based stratification of schizophrenia patients for betaine efficacy.

Interpretation

The present study revealed the role of betaine in psychiatric pathophysiology and underscores the potential benefit of betaine in a subset of schizophrenia.

Fund

This study was supported by the Strategic Research Program for Brain Sciences from AMED (Japan Agency for Medical Research and Development) under Grant Numbers JP18dm0107083 and JP19dm0107083 (TY), JP18dm0107129 (MM), JP18dm0107086 (YK), JP18dm0107107 (HY), JP18dm0107104 (AK) and JP19dm0107119 (KH), by the Grant-in-Aid for Scientific Research on Innovative Areas from the MEXT under Grant Numbers JP18H05435 (TY), JP18H05433 (AH.-T), JP18H05428 (AH.-T and TY), and JP16H06277 (HY), and by JSPS KAKENHI under Grant Number JP17H01574 (TY). In addition, this study was supported by the Collaborative Research Project of Brain Research Institute, Niigata University under Grant Numbers 2018–2809 (YK) and RIKEN Epigenetics Presidential Fund (100214–201801063606-340120) (TY).

Pathological alterations of chondroitin sulfate moiety in postmortem hippocampus of patients with schizophrenia

Perineuronal nets comprise chondroitin sulfate moieties and their core proteins, and their neuropathological alterations have been implicated in schizophrenia. To explore the molecular mechanism of the perineuronal net impairments in schizophrenia, we measured the immunoreactivity of chondroitin sulfate moieties, major components of perineuronal nets, in three brain regions (postmortem dorsolateral prefrontal cortex, caudate nucleus, and hippocampus) of schizophrenia patients and control subjects. Immunoblotting for chondroitin 4-sulfate and chondroitin 6-sulfate moieties revealed a significant increase in intensity of a 180 kD band of chondroitin 4-sulfate immunoreactivity in the hippocampus of patients, although we detected no significant alteration in their immunoreactivities with any other molecular sizes or in other brain regions. The levels of immunoreactivity were not correlated with postmortem interval, age, or storage time. We failed to find such an increase in a similar molecular range of the chondroitin 4-sulfate immunoreactivity in the hippocampus of the rats chronically treated with haloperidol. These results suggest that the level alteration of the chondroitin 4-sulfate moiety might contribute to the perineuronal net abnormality found in patients with schizophrenia.

Effects of the -141C insertion/deletion polymorphism in the dopamine D2 receptor gene on the dopamine system in the striatum in patients with schizophrenia

The relationships between -141C insertion/deletion (Ins/Del) polymorphisms in the dopamine D2 receptor gene and the two dopamine system integrators, i.e., dopamine- and cAMP-regulated phosphoprotein of molecular weight 32 kDa (DARPP-32) and calcineurin (CaN), are still unclear. In this study, we assessed the effect of this polymorphism on DARPP-32 and CaN protein expression in the postmortem striatum of patients with schizophrenia and control individuals. The expression levels of truncated DARPP and CaN were lower in Del allele carriers. These findings provide important insights into the mechanism by which this genotype could result in a poor response to antipsychotic drugs.

DNA methylation of ANKK1 and response to aripiprazole in patients with acute schizophrenia: A preliminary study

Epigenetic modification including DNA methylation may affect pathophysiology and the response to antipsychotic drugs in patients with schizophrenia. The objective of the present study was to investigate the effect of the DNA methylation of ANKK1 (ankyrin repeat and kinase domain containing 1) on the response to aripiprazole and plasma levels of monoamine metabolites in antipsychotic-free acute schizophrenia patients. The subjects were 34 Japanese patients with schizophrenia who had been treated with aripiprazole for 6 weeks. Comprehensive DNA methylation of ANKK1 was determined using a next-generation sequencer. DNA methylation levels at CpG site 387 of ANKK1 were higher in responders to treatment with aripiprazole and correlated with the changes in Positive and Negative Syndrome Scale scores, although the associations did not remain significant after Bonferroni correction. In responders, methylation at all CpG sites was significantly correlated with plasma levels of homovanillic acid (r = 0.587, p = 0.035) and 3-methoxy-4hydroxyphenylglycol (r = 0.684, p = 0.010) at baseline. Despite our non-significant results after multiple correction, our preliminary findings suggest that methylation levels at CpG site 387 of ANKK1 may be associated with treatment response to aripiprazole. Furthermore, methylation of ANKK1 may affect dopaminergic neural transmission in the treatment of schizophrenia, and may influence treatment response. Caution is needed in interpreting these findings because of the small sample size, and further studies are needed to confirm and expand our preliminary results.

COMT Val 108/158 Met polymorphism and treatment response to aripiprazole in patients with acute schizophrenia

INTRODUCTION

The COMT Val 108/158 Met polymorphism (rs4680) may affect treatment response to antipsychotics, as well as metabolism and dynamics of neurotransmitters during the treatment of schizophrenia. We investigated the effects of the COMT Val 108/158 Met polymorphism on treatment response to aripiprazole and plasma monoamine metabolite levels in patients with acute schizophrenia.

MATERIALS AND METHODS

Forty patients with schizophrenia were treated with aripiprazole for 6 weeks. We measured Positive and Negative Syndrome Scale (PANSS) and plasma levels of homovanillic acid (HVA) and plasma MHPG (3-methoxy-4-hydroxyphenethyleneglycol) at baseline and endpoint. The COMT Val 108/158 Met polymorphism was genotyped with the polymerase chain reaction and restriction fragment length polymorphism.

RESULTS

There were significant genotype-time interactions on PANSS total and general psychopathology scores, with Met/Met genotype showing greater improvement. The response rate to aripiprazole did not differ between COMT Val 108/158 Met genotype groups. We found a significant time effect on plasma MHPG levels, but no time effect on plasma HVA levels or time-genotype interactions in the plasma levels of HVA and MHPG. Although the responder rate did not differ among the 3 genotype groups.

CONCLUSION

Our results suggest that individuals with the Met/Met genotype had greater improvement in PANSS score after the treatment with aripiprazole. On the other hand, the Val 108/158 Met polymorphism may not induce changes in plasma levels of monoamine metabolites during aripiprazole treatment. Because of the small sample size, further studies are needed to confirm and to extend our results.

PKA activation and endothelial claudin-5 breakdown in the schizophrenic prefrontal cortex

Schizophrenia is thought to be caused by a combination of genetic and environmental factors; however, its pathogenesis remains largely unknown. Here, we focus on the endothelial tight-junction protein claudin-5 (CLDN5), because the CLDN5 gene is mapped to the schizophrenia-associated 22q11.2 deletion region, and a single nucleotide polymorphism in the CLDN5 locus is also linked to schizophrenia. We show, by RT-qPCR and immunohistochemistry, that the expressions of CLDN5 mRNA and protein are significantly increased and decreased, respectively, in the schizophrenic prefrontal cortex (PFC) compared with control PFC. These changes were not observed in the schizophrenic visual cortex (VC), and neither the density nor diameter of the CD34-positive microvessels was altered in the schizophrenic PFC or VC. Interestingly, protein kinase A (PKA) was activated in the microvascular and perivascular regions of the schizophrenic PFC, and the pPKA-positive microvascular endothelial cells occasionally exhibited focal loss of CLND5. Since we previously demonstrated that cAMP induced CLDN5 mRNA expression and size-selective loosening of the endothelial barrier in PKA-independent and -dependent manners, respectively, a similar mechanism could contribute to the discrepancy between mRNA and protein expression of CLDN5 in the schizophrenic PFC. Taken collectively, these findings provide novel insights into the pathophysiology of schizophrenia.

Decreased 16:0/20:4-phosphatidylinositol level in the post-mortem prefrontal cortex of elderly patients with schizophrenia

The etiology of schizophrenia includes phospholipid abnormalities. Phospholipids are bioactive substances essential for brain function. To analyze differences in the quantity and types of phospholipids present in the brain tissue of patients with schizophrenia, we performed a global analysis of phospholipids in multiple brain samples using liquid chromatography electrospray ionization mass/mass spectrometry (LC-ESI/MS/MS) and imaging mass spectrometry (IMS). We found significantly decreased 16:0/20:4-phosphatidylinositol (PI) levels in the prefrontal cortex (PFC) in the brains from patients with schizophrenia in the LC-ESI/MS/MS, and that the 16:0/20:4-PI in grey matter was most prominently diminished according to the IMS experiments. Previous reports investigating PI pathology of schizophrenia did not identify differences in the sn-1 and sn-2 fatty acyl chains. This study is the first to clear the fatty acid composition of PI in brains from patients with schizophrenia. Alteration in the characteristic fatty acid composition of PI may also affect neuronal function, and could play a role in the etiology of schizophrenia. Although further studies are necessary to understand the role of reduced 16:0/20:4-PI levels within the prefrontal cortex in the etiology of schizophrenia, our results provide insight into the development of a novel therapy for the clinical treatment of schizophrenia.

Prominent increased calcineurin immunoreactivity in the superior temporal gyrus in schizophrenia: A postmortem study

Many neuroimaging studies have demonstrated structural changes in the superior temporal gyrus (STG) in patients with schizophrenia. Several postmortem studies have reported on the pathogenesis of schizophrenia, but few reports have investigated alterations in molecules in the STG. In addition, several studies have suggested that calcineurin (CaN) inadequacy may be a risk factor for schizophrenia, but no reports about CaN expression in the STG in schizophrenia have been published. We compared the density of CaN-immunoreactive (CaN-IR) neurons in the STG from 11 patients with schizophrenia with that of 11 sex- and age-matched controls. We used immunohistochemical analysis with rabbit polyclonal antibodies against human CaN. In the STG, the density of CaN-IR neurons in layers II - VI in the group with schizophrenia was significantly higher than that in the control group. Our results confirmed pathological changes in the STG in patients with schizophrenia, suggesting that alterations in the CaN pathway play a role in the pathogenesis of schizophrenia.

Decreased VEGFR2 expression and increased phosphorylated Akt1 in the prefrontal cortex of individuals with schizophrenia

The Akt signaling pathway involves various cellular processes and depends on extracellular stimuli. Since Akt signaling participates in cytoprotection, synapse plasticity, axon extension, and neurotransmission in the nervous system, alteration in Akt signaling might be a potential cause of schizophrenia. In this study, we performed multiplex fluorescent bead based immunoassays for members of the Akt signaling pathway in postmortem brains of controls and patients with schizophrenia. Vascular endothelial growth factor receptor 2 (VEGFR2/KDR) was significantly decreased in the prefrontal cortex (PFC) of patients with schizophrenia, and the expression level of VEGFR2 was inversely correlated with the positive symptom subscale of the Diagnostic Instrument for Brain Studies (DIBS) in patients with schizophrenia. There was also an increase in phosphorylated Akt1 in the PFC in the patients, though the ratio of phospho/total Akt1 is not significantly different. In the nucleus accumbens (NAcc) there was no significant difference in expression and phosphorylation levels of Akt signaling proteins. Genetic analysis revealed a significant correlation of a SNP of KDR (rs7692791) with ERK1/2 and Akt1 phospho/total rates. Since VEGFR2 participates in angiogenesis and neurotrophic activation, either or both functions might be responsible for onset of schizophrenia.

Pulsed neutron time-dependent intensity modulation for quasi-elastic neutron scattering spectroscopy

We propose a basic formula and demonstration for a high-resolution quasi-elastic neutron scattering (QENS) by combining the time-of-flight (TOF) method with Modulation of Intensity by Zero Effort (MIEZE) type neutron spin echo spectroscopy. The MIEZE technique has the potential to develop a unique approach to study on slow dynamics of condensed matter; however, the energy resolution is limited owing to the hypersensitivity of the MIEZE signal contrast to the echo condition, which is strongly affected by the alignment of the instruments and the sample. The narrow allowance of the optimal alignment is a major obstacle to the wide use of this technique. Combining the TOF method with MIEZE (TOF-MIEZE), the hypersensitivity of MIEZE signals is significantly alleviated with a short pulsed beam. This robustness is very useful to optimize experimental alignments and enables accurate measurements of QENS. The experimental results demonstrate the characteristic of the TOF-MIEZE technique and are well described by the formula presented in this study.

Decreased calcineurin immunoreactivity in the postmortem brain of a patient with schizophrenia who had been prescribed the calcineurin inhibitor, tacrolimus, for leukemia

BACKGROUND

The calcineurin (CaN) inhibitor, tacrolimus, is widely used in patients undergoing allogeneic organ transplantation and in those with certain allergic diseases. Recently, several reports have suggested that CaN is also associated with schizophrenia. However, little data are currently available on the direct effect of tacrolimus on the human brain.

CASE

A 23-year-old Japanese female experienced severe delusion of persecution, delusional mood, suspiciousness, aggression, and excitement. She visited our hospital and was diagnosed with schizophrenia. When she was 27 years old, she had severe general fatigue, persistent fever, systemic joint pain, gingival bleeding, and breathlessness and was diagnosed with acute myelomonocytic leukemia. Later she underwent bone marrow transplantation (BMT), she was administered methotrexate and cyclosporin A to prevent graft versus host disease (GVHD). Three weeks after BMT, she showed initial symptoms of GVHD and was prescribed tacrolimus instead of cyclosporin A. Seven months after BMT at the age of 31 years, she died of progression of GVHD. Pathological anatomy was examined after her death, including immunohistochemical analysis of her brain using anti-CaN antibodies. For comparison, we used our previous data from both a schizophrenia group and a healthy control group. No significant differences were observed in the percentage of CaN-immunoreactive neurons among the schizophrenia group, healthy control group, and the tacrolimus case (all P>0.5, analysis of covariance). Compared with the healthy control group and schizophrenia group, the percentages of CaN-immunoreactive neurons in layers III-VI of the BA46 and the putamen tended to be lower in the tacrolimus case.

CONCLUSION

Tacrolimus may decrease CaN immunoreactivity in some regions of the human brain. Thus, tacrolimus may introduce side effects such as cognitive dysfunction and extrapyramidal symptoms. In addition, we also found that the effect of tacrolimus on CaN immunore-activity in human brain was stronger than the effect of schizophrenia.

Effectiveness of antibacterial prophylaxis with non-absorbable polymyxin B compared to levofloxacin after allogeneic hematopoietic stem cell transplantation

BACKGROUND

Fluoroquinolones are widely used for antibacterial prophylaxis during neutropenia following hematopoietic stem cell transplantation (HSCT). Nevertheless, data are inadequate as to whether fluoroquinolones decrease mortality rate compared with other antibiotics.

METHODS

We retrospectively compared the efficacy of antibacterial prophylaxis using non-absorbable polymyxin B (PB) (n = 106) or systemic levofloxacin (LVFX) (n = 140) after allogeneic SCT at our institute between 2004 and 2013.

RESULTS

No significant difference was observed between the 2 groups in the cumulative incidences of failure of prophylaxis (P = 0.21), clinically documented infections (P = 0.70), or non-relapse mortality within the first 100 days after transplantation (P = 0.42). With bacteremia, the rate of resistance to LVFX was 82% in the PB group and 100% in the LVFX group (P = 0.41). Also, no significant difference was found in overall survival between the 2 groups (P = 0.78).

CONCLUSION

Our results indicate no difference in the effectiveness of antibacterial prophylaxis between systemic antibiotic LVFX and non-absorbable antibiotic PB.

Assessment of copy number variations in the brain genome of schizophrenia patients

Background

Cytogenomic mutations and chromosomal abnormality are implicated in the neuropathology of several brain diseases. Cell heterogeneity of brain tissues makes their detection and validation difficult, however. In the present study, we analyzed gene dosage alterations in brain DNA of schizophrenia patients and compared those with the copy number variations (CNVs) identified in schizophrenia patients as well as with those in Asian lymphocyte DNA and attempted to obtain hints at the pathological contribution of cytogenomic instability to schizophrenia.

Results

Brain DNA was extracted from postmortem striatum of schizophrenia patients and control subjects (n = 48 each) and subjected to the direct two color microarray analysis that limits technical data variations. Disease-associated biases of relative DNA doses were statistically analyzed with Bonferroni’s compensation on the premise of brain cell mosaicism. We found that the relative gene dosage of 85 regions significantly varied among a million of probe sites. In the candidate CNV regions, 26 regions had no overlaps with the common CNVs found in Asian populations and included the genes (i.e., ANTXRL, CHST9, DNM3, NDST3, SDK1, STRC, SKY) that are associated with schizophrenia and/or other psychiatric diseases. The majority of these candidate CNVs exhibited high statistical probabilities but their signal differences in gene dosage were less than 1.5-fold. For test evaluation, we rather selected the 10 candidate CNV regions that exhibited higher aberration scores or larger global effects and were thus confirmable by PCR. Quantitative PCR verified the loss of gene dosage at two loci (1p36.21 and 1p13.3) and confirmed the global variation of the copy number distributions at two loci (11p15.4 and 13q21.1), both indicating the utility of the present strategy. These test loci, however, exhibited the same somatic CNV patterns in the other brain region.

Conclusions

The present study lists the candidate regions potentially representing cytogenomic CNVs in the brain of schizophrenia patients, although the significant but modest alterations in their brain genome doses largely remain to be characterized further.

Electronic supplementary material

The online version of this article (doi:10.1186/s13039-015-0144-5) contains supplementary material, which is available to authorized users.

Elevated postmortem striatal t-DARPP expression in schizophrenia and associations with DRD2/ANKK1 polymorphism

BACKGROUND

Dopamine- and cAMP-regulated phosphoprotein of molecular weight 32 kDa (DARPP-32) and calcineurin (CaN) have been implicated in the pathogenesis of schizophrenia because they function as molecular integrators of dopamine and glutamate signaling. DARPP-32 and CaN are mainly expressed in the caudate nucleus and putamen; however, a few postmortem brain studies have focused on DARPP-32 expression in striatum from patients with schizophrenia.

METHODS

We used immunoblotting techniques and postmortem tissue samples from patients with schizophrenia and from normal control individuals to examine the expression of two major DARPP-32 isoforms, full-length (FL-DARPP) and truncated (t-DARPP), and of CaN in the striatum. We also assessed whether there was any significant correlation between the expression levels of either protein and the A1 allele of Taq1A genotype in the dopamine D2 receptor (DRD2) gene/ankyrin-repeat containing kinase 1 (ANKK1) gene.

RESULTS

We found that the mean t-DARPP expression level in the caudate was higher in patients with schizophrenia than in control individuals (P<0.05) and the A1 allele of Taq1A genotype in DRD2/ANKK1 was significantly associated with elevated expression of t-DARPP in the caudate. Also, the A1 allele was significantly correlated with the total score of antemortem psychiatric symptoms.

CONCLUSION

These results may reflect potential molecular mechanisms important to the pathogenesis of schizophrenia.

Characterization of putative toxin/antitoxin systems in Vibrio parahaemolyticus

AIM

To obtain more information about the toxin/antitoxin (TA) systems in the Vibrio genus and also to examine their involvement in the induction of a viable but nonculturable (VBNC) state, we searched homologues of the Escherichia coli TA systems in the Vibrio parahaemolyticus genome.

METHODS AND RESULTS

We found that a gene cluster, vp1842/vp1843, in the V. parahaemolyticus genome database has homology to that encoding the E. coli TA proteins, DinJ/YafQ. Expression of the putative toxin gene vp1843 in E. coli cells strongly inhibited the cell growth, while coexpression with the putative antitoxin gene vp1842 neutralized this effect. Mutational analysis identified Lys37 and Pro45 in the gene product VP1843 of vp1843 as crucial residues for the growth retardation of E. coli cells. VP1843, unlike the E. coli toxin YafQ, has no protein synthesis inhibitory activity, and that instead the expression of vp1843 in E. coli caused morphological change of the cells.

CONCLUSIONS

The gene cluster vp1842/vp1843 encodes the V. parahaemolyticus TA system; VP1843 inhibits cell growth, whereas VP1842 serves as an antitoxin by forming a stable complex with VP1843.

SIGNIFICANCE AND IMPACT OF THE STUDY

The putative toxin, VP1843, may be involved in the induction of the VBNC state in V. parahaemolyticus by inhibiting cell division.