Duloxetine improves chronic orofacial pain and comorbid depressive symptoms in association with reduction of serotonin transporter protein through upregulation of ubiquitinated serotonin transporter protein

ABSTRACT

Chronic orofacial pain (COP) is relieved by duloxetine (DLX) and frequently causes depressive symptoms. The aim of this study was to confirm effects of DLX on pain and depressive symptoms, and to associate with their effectiveness in platelet serotonin transporter (SERT) expression, which is a target molecule of DLX and plasma serotonin concentration in COP patients with depressive symptoms. We assessed for the severity of pain and depressive symptoms using the Visual Analog Scale (VAS) and 17-item Hamilton Depression Rating Scale (HDRS), respectively. Chronic orofacial pain patients were classified into 2 groups based on their HDRS before DLX-treatment: COP patients with (COP-D) and without (COP-ND) depressive symptoms. We found that the VAS and HDRS scores of both groups were significantly decreased after DLX treatment compared with those before DLX treatment. Upregulation of total SERT and downregulation of ubiquitinated SERT were observed before DLX treatment in both groups compared with healthy controls. After DLX treatment, there were no differences in total SERT of both groups and in ubiquitinated SERT of COP-D patients compared with healthy controls; whereas, ubiquitinated SERT of COP-ND patients remained downregulated. There were positive correlations between changes of serotonin concentrations and of VAS or HDRS scores in only COP-D patients. Our findings indicate that DLX improves not only pain but also comorbid depressive symptoms of COP-D patients. Duloxetine also reduces platelet SERT through upregulation of ubiquitinated SERT. As the result, decrease of plasma serotonin concentrations may be related to the efficacy of DLX in relieving pain and depression in COP patients.

Functional analysis of basidiomycete specific chitin synthase genes in the agaricomycete fungus Pleurotus ostreatus

Chitin is an essential structural component of fungal cell walls composed of transmembrane proteins called chitin synthases (CHSs), which have a large range of reported effects in ascomycetes; however, are poorly understood in agaricomycetes. In this study, evolutionary and molecular genetic analyses of chs genes were conducted using genomic information from nine ascomycete and six basidiomycete species. The results support the existence of seven previously classified chs clades and the discovery of three novel basidiomycete-specific clades (BI-BIII). The agaricomycete fungus Pleurotus ostreatus was observed to have nine putative chs genes, four of which were basidiomycete-specific. Three of these basidiomycete specific genes were disrupted in the P. ostreatus 20b strain (ku80 disruptant) through homologous recombination and transformants were obtained (Δchsb2, Δchsb3, and Δchsb4). Despite numerous transformations Δchsb1 was unobtainable, suggesting disruption of this gene causes a crucial negative effect in P. ostreatus. Disruption of these chsb2-4 genes caused sparser mycelia with rougher surfaces and shorter aerial hyphae. They also caused increased sensitivity to cell wall and membrane stress, thinner cell walls, and overexpression of other chitin and glucan synthases. These genes have distinct roles in the structural formation of aerial hyphae and cell walls, which are important for understanding basidiomycete evolution in filamentous fungi.

Inhalation adherence for asthma and COPD improved during the COVID-19 pandemic: a questionnaire survey at a university hospital in Japan

Background: Good adherence to an inhaled medication protocol is necessary for the management of asthma and chronic obstructive pulmonary disease (COPD), and several interventions to improve adherence have been reported. However, the impact of patient life changes and psychological aspects on treatment motivation is obscure. Here, we investigated changes in inhaler adherence during the COVID-19 pandemic and how lifestyle and psychological changes affected it.Methods: Seven-hundred sixteen adult patients with asthma and COPD who had visited Nagoya University Hospital between 2015 and 2020 were selected. Among them, 311 patients had received instruction at a pharmacist-managed clinic (PMC). We distributed one-time cross-sectional questionnaires from January 12 to March 31, 2021. The questionnaire covered the status of hospital visits, inhalation adherence before and during the COVID-19 pandemic, lifestyles, medical conditions, and psychological stress. The Adherence Starts with Knowledge-12 (ASK-12) was used to assess adherence barriers.Results: Four-hundred thirty-three patients answered the questionnaire. Inhalation adherence was significantly improved in both diseases during the COVID-19 pandemic. The most common reason for improved adherence was fear of infection. Patients with improved adherence were more likely to believe that controller inhalers could prevent COVID-19 from becoming more severe. Improved adherence was more common in patients with asthma, those not receiving counseling at PMC, and those with poor baseline adherence.Conclusions: Inhalation adherence for asthma and COPD improved in the COVID-19 pandemic. The patients seemed to realize the necessity and benefits of the medication more strongly than before the pandemic, which motivated them to improve adherence.

Involvement of ionic interactions in self-assembly and resultant rodlet formation of class I hydrophobin RolA from Aspergillus oryzae

Hydrophobins are small amphiphilic proteins that are conserved in filamentous fungi. They localized on the conidial surface to make it hydrophobic, which contributes to conidial dispersal in air, and help fungi to infect plants and mammals and to degrade polymers. Hydrophobins self-assemble and undergo structural transition from the amorphous state to the rodlet (rod-like multimeric structure) state. However, it remains unclear whether the amorphous or rodlet state is biologically functional and what external factors regulate state transition. In this study, we analyzed the self-assembly of hydrophobin RolA of Aspergillus oryzae in detail and identified factors regulating this process. Using atomic force microscopy, we observed RolA rodlet formation over time, and determined "rodlet elongation rate" and "rodlet formation frequency." Changes in these kinetic parameters in response to pH and salt concentration suggest that RolA rodlet formation is regulated by the strength of ionic interactions between RolA molecules.

Clinical characterization of patients with schizophrenia and 16p13.11 duplication: A case series

BACKGROUND

Chromosome 16p13.11 duplication is a well-known genetic risk factor for schizophrenia (SCZ) (odds ratio = 1.84). However, no case reports focusing on patients with SCZ and 16p13.11 duplication have been published. Therefore, here, we report the detailed clinical cases of four patients with SCZ and 16p13.11 duplication who were identified in our previous whole-genome copy number variant (CNV) study.

CASE PRESENTATION

In the four patients with SCZ and 16p13.11 duplication detected by array comparative genomic hybridization, one patient was found to have treatment-resistant SCZ and an additional pathogenic rare CNV. Two of the four patients in this study had environmental risk factors that may have been involved in the development of SCZ.

CONCLUSIONS

The results of this case series suggest that a genetic cohort study would be useful for evaluating which genetic and environmental risk factors could better explain the variable expressivity of 16p13.11 duplication. Furthermore, this work could be useful for elucidating the pathophysiology of SCZ.

Features of disruption mutants of genes encoding for hydrophobin Vmh2 and Vmh3 in mycelial formation and resistance to environmental stress in Pleurotus ostreatus

Hydrophobins, which are small-secreted proteins with both hydrophobic and hydrophilic parts, can self-assemble into an amphiphilic film at the air-water interface, helping the fungus to form aerial hyphae. In the agaricomycete Pleurotus ostreatus, more than 20 putative hydrophobin genes have been predicted. Of these, two hydrophobin genes, vmh2 and vmh3, are predominantly expressed in the vegetative mycelium. In this study, we focused on the functions of Vmh2 and Vmh3 in vegetative mycelia. Based on the observation of the mycelial cross-section by transmission electron microscopy and the disappearance time of water droplets on the mycelial surface, Vmh2 and Vmh3 were considered essential for the maintenance of the surface hydrophobicity of the mycelium. The Δvmh3 and Δvmh2Δvmh3 strains exhibited relatively slower aerial mycelia formation on a liquid medium, and no significant alteration was observed in Δvmh2 strains. Only the Δvmh3 and Δvmh2Δvmh3 strains grew slower than the wild-type strain under stress conditions involving SDS and H2O2 on agar plates. This study revealed possible distinct roles for these hydrophobins in stress resistance. These results suggest that Agaricomycetes, including P. ostreatus, have evolved to possess multiple different hydrophobins as a means of adapting to various environments.

Physiological function of hydrophobin Vmh3 in lignin degradation by white-rot fungus Pleurotus ostreatus

Hydrophobins are small-secreted proteins comprising both hydrophobic and hydrophilic parts, that can self-assemble into an amphiphilic film at the air-liquid interface. More than 20 hydrophobin genes have been estimated in the white-rot fungus Pleurotus ostreatus. In our previous studies, three hydrophobin genes were shown to be predominantly expressed under ligninolytic conditions, and only vmh3 was downregulated in both the delignification-deficient mutant Δgat1 and Δhir1 strains. Here, we focused on the function of the hydrophobin Vmh3 to clarify its physiological role in lignin degradation. When the hyphae were observed by transmission electron microscopy, deletion of vmh3 resulted in the disappearance of black aggregates at the interface between the cell wall and outer environment. Deletion of vmh3 resulted in reduced hydrophobicity when 0.2% sodium dodecyl sulfate was dropped onto the mycelial surface. These results suggest that Vmh3 functions on the cell surface and plays a major role in mycelial hydrophobization. Furthermore, the Δvmh3 strain showed a marked delay in lignin degradation on beech wood sawdust medium, while the production of lignin-modifying enzymes was not reduced. This study demonstrated, for the first time, the possible effect of hydrophobin on lignin degradation by a white-rot fungus.

Astrotactin 2 (ASTN2) regulates emotional and cognitive functions by affecting neuronal morphogenesis and monoaminergic systems

Astrotactin2 (ASTN2) regulates neuronal migration and synaptic strength through the trafficking and degradation of surface proteins. Deletion of ASTN2 in copy number variants has been identified in patients with schizophrenia, bipolar disorder, and autism spectrum disorder in copy number variant (CNV) analysis. Disruption of ASTN2 is a risk factor for these neurodevelopmental disorders, including schizophrenia, bipolar disorder, autism spectrum disorder, and attention deficit hyperactivity disorder. However, the importance of ASTN2 in physiological functions remains poorly understood. To elucidate the physiological functions of ASTN2, we investigated whether deficiency of ASTN2 affects cognitive and/or emotional behaviors and neurotransmissions using ASTN2-deficient mice. Astn2 knockout (KO) mice produced by CRISPR/Cas9 technique showed no obvious differences in physical characteristics and circadian rhythm. Astn2 KO mice showed increased exploratory activity in a novel environment, social behavior and impulsivity, or decreased despair-, anxiety-like behaviors and exploratory preference for the novel object. Some behavioral abnormalities, such as increased exploratory activity and impulsivity, or decreased exploratory preference were specifically attenuated by risperidone, but not by haloperidol. While, the both drugs did not affect any emotion-related behavioral abnormalities in Astn2 KO mice. Dopamine contents were decreased in the striatum, and serotonin or dopamine turnover were increased in the striatum, nucleus accumbens, and amygdala of Astn2 KO mice. In morphological analyses, thinning of neural cell layers in the hippocampus, reduction of neural cell bodies in the prefrontal cortex, and decrease in spine density and PSD95 protein in both tissues were observed in Astn2 KO mice. The present findings suggest that ASTN2 deficiency develops some emotional or cognitive impairments related to monoaminergic dysfunctions and abnormal neuronal morphogenesis with shrinkage of neuronal soma. ASTN2 protein may contribute to the pathogenic mechanism and symptom onset of mental disorders.

Discovery of a gene cluster for the biosynthesis of novel cyclic peptide compound, KK-1, in Curvularia clavata

KK-1, a cyclic depsipeptide with 10 residues produced by a filamentous fungus Curvularia clavata BAUA-2787, is a promising pesticide active compound with high activity against many plant pathogens, especially Botrytis cinerea. As a first step toward the future mass production of KK-1 through synthetic biological approaches, we aimed to identify the genes responsible for the KK-1 biosynthesis. To achieve this, we conducted whole genome sequencing and transcriptome analysis of C. clavata BAUA-2787 to predict the KK-1 biosynthetic gene cluster. We then generated the overexpression and deletion mutants for each cluster gene using our originally developed transformation system for this fungus, and analyzed the KK-1 production and the cluster gene expression levels to confirm their involvement in KK-1 biosynthesis. As a result of these, a region of approximately 71 kb was found, containing 10 open reading frames, which were co-induced during KK-1 production, as a biosynthetic gene cluster. These include kk1B, which encodes nonribosomal peptide synthetase with a domain structure that is consistent with the structural features of KK-1, and kk1F, which encodes a transcription factor. The overexpression of kk1F increased the expression of the entire cluster genes and, consequently, improved KK-1 production, whereas its deletion decreased the expression of the entire cluster genes and almost eliminated KK-1 production, demonstrating that the protein encoded by kk1F regulates the expressions of the other nine cluster genes cooperatively as the pathway-specific transcription factor. Furthermore, the deletion of each cluster gene caused a reduction in KK-1 productivity, indicating that each gene is involved in KK-1 production. The genes kk1A, kk1D, kk1H, and kk1I, which showed a significant decrease in KK-1 productivity due to deletion, were presumed to be directly involved in KK-1 structure formation, including the biosynthesis of the constituent residues. kk1C, kk1E, kk1G, and kk1J, which maintained a certain level of KK-1 productivity despite deletion, were possibly involved in promoting or assisting KK-1 production, such as extracellular transportation and the removal of aberrant units incorporated into the peptide chain.

Cleavage of α-1,4-glycosidic linkages by the glycosylphosphatidylinositol-anchored α-amylase AgtA decreases the molecular weight of cell wall α-1,3-glucan in Aspergillus oryzae

Aspergillus fungi contain α-1,3-glucan with a low proportion of α-1,4-glucan as a major cell wall polysaccharide. Glycosylphosphatidylinositol (GPI)-anchored α-amylases are conserved in Aspergillus fungi. The GPI-anchored α-amylase AmyD in Aspergillus nidulans has been reported to directly suppress the biosynthesis of cell wall α-1,3-glucan but not to degrade it in vivo. However, the detailed mechanism of cell wall α-1,3-glucan biosynthesis regulation by AmyD remains unclear. Here we focused on AoAgtA, which is encoded by the Aspergillus oryzae agtA gene, an ortholog of the A. nidulans amyD gene. Similar to findings in A. nidulans, agtA overexpression in A. oryzae grown in submerged culture decreased the amount of cell wall α-1,3-glucan and led to the formation of smaller hyphal pellets in comparison with the wild-type strain. We analyzed the enzymatic properties of recombinant (r)AoAgtA produced in Pichia pastoris and found that it degraded soluble starch, but not linear bacterial α-1,3-glucan. Furthermore, rAoAgtA cleaved 3-α-maltotetraosylglucose with a structure similar to the predicted boundary structure between the α-1,3-glucan main chain and a short spacer composed of α-1,4-linked glucose residues in cell wall α-1,3-glucan. Interestingly, rAoAgtA randomly cleaved only the α-1,4-glycosidic bonds of 3-α-maltotetraosylglucose, indicating that AoAgtA may cleave the spacer in cell wall α-1,3-glucan. Consistent with this hypothesis, heterologous overexpression of agtA in A. nidulans decreased the molecular weight of cell wall α-1,3-glucan. These in vitro and in vivo properties of AoAgtA suggest that GPI-anchored α-amylases can degrade the spacer α-1,4-glycosidic linkages in cell wall α-1,3-glucan before its insolubilization, and this spacer cleavage decreases the molecular weight of cell wall α-1,3-glucan in vivo.

Memantine ameliorates the impairment of social behaviors induced by a single social defeat stress as juveniles

Clinically, juveniles are more sensitive to stress than adults, and exposure to stress as juveniles prolongs psychiatric symptoms and causes treatment resistance. However, the efficacy of antidepressants for juveniles with psychiatric disorders is unknown. In the present study, we investigated whether the expression or development of impaired social behavior was attenuated by memantine, a NMDA receptor antagonist. In addition, we clarified the molecular mechanisms related to intracellular signal transduction through NMDA receptors and the ameliorating effect of memantine in mice with impaired social behavior. Acute administration of memantine before the social interaction test, but not before exposure to social defeat stress, attenuated social behavioral impairment. A single social defeat stress increased the phosphorylation of NMDA receptor subunit GluN2A and extracellular-signal-related kinase 1/2 (ERK1/2). Memantine inhibited the increase of phosphorylated GluN2A and ERK1/2 resulting from social interaction behavior. In both GluN2A deficient and pharmacological blockaded mice, social behavioral impairment was not observed in the social interaction test through regulation of ERK1/2 phosphorylation. These findings suggest that memantine ameliorates social behavioral impairment in mice exposed to a single social defeat stress as juveniles by regulating the NMDA receptor and subsequent ERK1/2 signaling activation. Memantine may constitute a novel therapeutic drug for stress-related psychiatric disorders in juveniles with adverse juvenile experiences.

Oligomeric state of the aspartate:alanine transporter (AspT) from Tetragenococcus halophilus

The aspartate:alanine exchanger family of membrane transporters includes industrially important transporters such as succinate exporter and glutamate exporter. No high-resolution structure is available from this family so far, and the transport mechanism of these transporters also remains unclear. In the present study, we focus on the oligomeric status of the aspartate:alanine antiporter (AspT) of Tetragenococcus halophilus, which is the prototype of this family. To investigate the oligomeric structure of AspT, we established a system that produces high yields of highly purified AspT and determined the oligomeric structure of AspT by analysis with size exclusion chromatography coupled with multi-angle light scattering and blue native PAGE and by comparison of the wild-type AspT with a single-cysteine mutant that forms spontaneous inter-molecular thiol crosslinking. All the results consistently support the notion that AspT is a homodimer in solutions and in membranes.

Meiotic Silencing in Dothideomycetous Bipolaris maydis

The filamentous ascomycete Bipolaris maydis is a plant pathogen that causes corn leaf blight and has been used in cytological studies of sexual reproduction. In this fungus, when null mutants of each septin are crossed with the wild-type strain, all ascospores derived from the same asci show abnormal morphology. The phenomenon was remarkably similar to the event known as "ascus dominance" in Neurospora crassa, which is known to be caused by MSUD (meiotic silencing by unpaired DNA). However, it is not clear whether B. maydis possesses functional MSUD. The object of this study is to elucidate whether this fungus carries a functional MSUD system that causes ascus dominance in the crosses of septin mutants and the wild-type strain. The results of homozygous and heterozygous crossing tests with mutants, having the insertional CDC10-septin gene sequence into the genome, suggested that the ascus dominance in B. maydis is triggered by the unpaired DNA as in N. crassa. To investigate whether MSUD is caused by the same mechanism as in N. crassa, an RNA-dependent RNA polymerase, one of the essential factors in MSUD, was identified and disrupted (Δrdr1) in B. maydis. When the Δrdr1 strain was crossed with each mutant of the septins, ascus dominance did not occur in all crosses. These results suggest that this ascus dominance is caused by RNA silencing triggered by an unpaired gene, as in N. crassa, and septin genes were affected by this silencing. To date, although MSUD has been found only in Fusarium graminearum and N. crassa, which are classified as Sordariomycetes, this study showed that MSUD is also functional in B. maydis, which is classified as a Dothideomycete. These results showed the possibility that this posttranscriptional regulation is extensively conserved among filamentous ascomycetes.

Cell Wall Integrity and Its Industrial Applications in Filamentous Fungi

Signal transduction pathways regulating cell wall integrity (CWI) in filamentous fungi have been studied taking into account findings in budding yeast, and much knowledge has been accumulated in recent years. Given that the cell wall is essential for viability in fungi, its architecture has been analyzed in relation to virulence, especially in filamentous fungal pathogens of plants and humans. Although research on CWI signaling in individual fungal species has progressed, an integrated understanding of CWI signaling in diverse fungi has not yet been achieved. For example, the variety of sensor proteins and their functional differences among different fungal species have been described, but the understanding of their general and species-specific biological functions is limited. Our long-term research interest is CWI signaling in filamentous fungi. Here, we outline CWI signaling in these fungi, from sensor proteins required for the recognition of environmental changes to the regulation of cell wall polysaccharide synthesis genes. We discuss the similarities and differences between the functions of CWI signaling factors in filamentous fungi and in budding yeast. We also describe the latest findings on industrial applications, including those derived from studies on CWI signaling: the development of antifungal agents and the development of highly productive strains of filamentous fungi with modified cell surface characteristics by controlling cell wall biogenesis.

Corrigendum: A Glycosylphosphatidylinositol-Anchored α-Amylase Encoded by amyD Contributes to a Decrease in the Molecular Mass of Cell Wall α-1,3-Glucan in Aspergillus nidulans

[This corrects the article DOI: 10.3389/ffunb.2021.821946.].

Duloxetine attenuates pain in association with downregulation of platelet serotonin transporter in patients with burning mouth syndrome and atypical odontalgia

OBJECTIVE

The aim of this study was evaluation of the association between severity of pain and expression of total or ubiquitinated serotonin transporter (SERT) protein in patients with burning mouth syndrome and atypical odontalgia (BMS/AO), who were treated by duloxetine.

METHODS

Patients with BMS/AO were assessed for severity of pain using the visual analog scale (VAS), and expression of total and ubiquitinated SERT protein in platelets before (baseline) and 12 weeks after duloxetine-treatment.

RESULTS

The expression of total and ubiquitinated SERT protein at baseline in all patients (n = 33) were higher and lower, respectively, compared to those in healthy controls. 12 weeks after duloxetine-treatment, there was no difference in the total SERT protein levels between patients (n = 21) and healthy controls. In the 16 patients who could be measured, mean VAS scores and total SERT protein levels were significantly decreased after the treatment, compared to those at baseline. There was tendency for a positive correlation between total SERT protein levels and VAS scores in these patients.

CONCLUSIONS

Our findings indicate that duloxetine relieves pain in association with downregulation of platelet SERT expression in patients with BMS/AO.

A Glycosylphosphatidylinositol-Anchored α-Amylase Encoded by amyD Contributes to a Decrease in the Molecular Mass of Cell Wall α-1,3-Glucan in Aspergillus nidulans

α-1,3-Glucan is one of the main polysaccharides in the cell wall of Aspergillus nidulans. We previously revealed that it plays a role in hyphal aggregation in liquid culture, and that its molecular mass (MM) in an agsA-overexpressing (agsAOE) strain was larger than that in an agsB-overexpressing (agsBOE) strain. The mechanism that regulates its MM is poorly understood. Although the gene amyD, which encodes glycosylphosphatidylinositol (GPI)-anchored α-amylase (AmyD), is involved in the biosynthesis of α-1,3-glucan in A. nidulans, how it regulates this biosynthesis remains unclear. Here we constructed strains with disrupted amyD (ΔamyD) or overexpressed amyD (amyDOE) in the genetic background of the ABPU1 (wild-type), agsAOE, or agsBOE strain, and characterized the chemical structure of α-1,3-glucans in the cell wall of each strain, focusing on their MM. The MM of α-1,3-glucan from the agsBOE amyDOE strain was smaller than that in the parental agsBOE strain. In addition, the MM of α-1,3-glucan from the agsAOE ΔamyD strain was greater than that in the agsAOE strain. These results suggest that AmyD is involved in decreasing the MM of α-1,3-glucan. We also found that the C-terminal GPI-anchoring region is important for these functions.

Plasma MMP-9 Levels as the Future Risk of Conversion to Dementia in ApoE4-Positive MCI Patients: Investigation Based on the Alzheimer's Disease Neuroimaging Initiative Database

BACKGROUND

Matrix metalloproteinase 9 (MMP-9) has been reported to be correlated with declines in hippocampal volume and cognitive function in ApoE4-positive MCI patients.

OBJECTIVES

The present study was aimed to investigate the effects of plasma matrix MMP-9 on the conversion risk between mild cognitive impairment (MCI) patients with and without ApoE4.

DESIGN AND SETTING

Retrospective observational study using the data extracted from the Alzheimer's Disease Neuroimaging Initiative database.

PARTICIPANTS

We included 211 ApoE4-positive MCI subjects (ApoE4+ MCI) and 184 ApoE4-negative MCI subjects (ApoE4- MCI).

MEASUREMENTS

We obtained demographic and data including plasma MMP-9 levels at baseline and longitudinal changes in Clinical Dementia Rating (CDR) up to 15 years. We compared conversion rates between ApoE4+ MCI and ApoE4- MCI by the Log-rank test and calculated the hazard ratio (HR) for covariates including age, sex, educational attainment, drinking and smoking histories, medications, and plasma MMP-9 levels using a multiple Cox regression analysis of ApoE4+ MCI and ApoE4- MCI.

RESULTS

No significant differences were observed in baseline plasma MMP-9 levels between ApoE4+ MCI and ApoE4- MCI. High plasma MMP-9 levels increased the conversion risk significantly more than low plasma MMP-9 levels (HR, 2.46 [95% CI, 1.31-4.48]) and middle plasma MMP-9 levels (HR, 1.67 [95% CI, 1.04-2.65]) in ApoE4+ MCI, but not in ApoE4- MCI.

CONCLUSION

Plasma MMP-9 would be the risk of the future conversion to dementia in ApoE4+ MCI.

Improved recombinant protein production in Aspergillus oryzae lacking both α-1,3-glucan and galactosaminogalactan in batch culture with a lab-scale bioreactor

Filamentous fungi are used as production hosts for various commercially valuable enzymes and chemicals including organic acids and secondary metabolites. We previously revealed that α-1,3-glucan and galactosaminogalactan (GAG) contribute to hyphal aggregation in the industrial fungus Aspergillus oryzae, and that production of recombinant protein in shake-flask culture is higher in a mutant lacking both α-1,3-glucan and GAG (AGΔ-GAGΔ) than in the parental strain. Here, we compared the productivity of the wild type, AGΔ-GAGΔ, and mutants lacking α-1,3-glucan (AGΔ) or GAG (GAGΔ) in batch culture with intermittent addition of glucose in a 5-L lab-scale bioreactor. The hyphae of the wild type and all mutants were dispersed by agitation, although the wild type and AGΔ formed small amounts of aggregates. Although mycelial weight was similar among the strains, the concentration of a secreted recombinant protein (CutL1) was the highest in AGΔ-GAGΔ. Evaluation of fluid properties revealed that the apparent viscosities of mycelial cultures of the wild type and AGΔ-GAGΔ decreased as the agitation speed was increased. The apparent viscosity of the AGΔ-GAGΔ culture tended to be lower than that of the wild-type strain at each agitation speed, and was significantly lower at 600 rpm. Overall, the lack of α-1,3-glucan and GAG in the hyphae improved culture rheology, resulting in an increase in recombinant protein production in AGΔ-GAGΔ. This is the first report of flow behavior improvement by a cell-surface component defect in a filamentous fungus.

Hyperosmotic medium partially restores the growth defect and the impaired production of sterigmatocystin of an Aspergillus nidulans ΔpmtC mutant in a HogA-independent manner

The protein O-mannosyltransferase catalyzes O-mannosylation in the endoplasmic reticulum by transferring mannose to the seryl or threonyl residues of substrate proteins. We previously reported a deletion mutant of O-mannosyltransferase C (ΔpmtC) in Aspergillus nidulans with impaired vegetative growth and sterigmatocystin (ST) production. In this study, we investigated whether osmotic conditions contribute to the developmental processes and ST biosynthesis of the ΔpmtC deletion mutant. We found that hyphal growth and ST production partially improved in the presence of NaCl, KCl or sorbitol as osmotic stabilizers. Conidiation of the ΔpmtC deletion mutant was not restored under osmotic stress conditions when the hogA gene was deleted. The hogA gene encodes a protein required for the cellular response to osmotic pressure. However, the yield of ST and the vegetative growth of the ΔhogA ΔpmtC double deletant was restored by high osmolarity in a HogA-independent manner.

Early postnatal inhibition of GLAST causes abnormalities of psychobehaviors and neuronal morphology in adult mice

The importance of glutamate transporters in learning, memory, and emotion remains poorly understood; hence, in the present study, we investigated whether deficiency of pharmacological GLAST in neurodevelopmental processes affects cognitive and/or emotional behaviors in mice. The mice were injected with a glutamate transporter inhibitor, dl-threo-β-benzyloxyaspartate (dl-TBOA), during the early postnatal period. At 8 weeks of age, they showed impairments in cognitive or emotional behaviors; dysfunction of glutamatergic neurotransmission (increased expressions of GLAST, GLT-1, or GFAP protein, and decreased ability of glutamate release) in the cortex or hippocampus; morphological changes (decreased cell size in the cortex and thickness of the pyramidal neuronal layer of the CA1 area in the hippocampus). Such behavioral and morphological changes were not observed in adult mice injected with dl-TBOA. These results suggest that GLAST plays an important role in the regulation of cognitive and emotional behaviors. Early postnatal glutamatergic facilitation by GLAST dysfunction leads to cognitive and emotional abnormalities due to neurodevelopmental abnormalities such as morphological changes.

Survey of chemotherapy-induced nausea and vomiting in patients with urothelial carcinoma

Chemotherapy-induced nausea and vomiting (CINV) can cause anorexia, weight loss and deterioration of patient quality of life. It is one of the most unpleasant adverse effects of chemotherapy treatment regimens. For the optimal treatment of gastrointestinal symptoms during urothelial carcinoma chemotherapy, the present study investigated the association between gastrointestinal symptoms and therapeutic effects of gemcitabine plus platinum [cisplatin (GC) or carboplatin (GCa)] therapies. The incidence and frequency of nausea/vomiting with GC split therapy (gemcitabine, 1,000 mg/m² on days 1 and 8; split-dose cisplatin, 35 mg/m² on days 1 and 8; 21-day schedule) and GCa therapy [gemcitabine, 750-1,000 mg/m² on days 1, 8 and 15; carboplatin, area under the blood concentration-time curve=5 mg min/ml (Calvert formula) on day 2; 28-day schedule] were lower compared with those of GC therapy (gemcitabine, 1,000 mg/m² on days 1, 8 and 15; single-dose cisplatin 70 mg/m² on day 2; 28-day schedule). However, no differences in therapeutic outcomes were observed among therapies. GCa therapy, regardless of renal function, and GC split therapy demonstrated significant increases compared with GC therapy in alleviating gastrointestinal symptoms associated with cancer chemotherapy in patients with urothelial carcinoma. Overall, these results suggested that split-dose cisplatin administration or the use of carboplatin instead of cisplatin may be useful in patients who experience CINV without compromising treatment effectiveness.

Downregulation of the ypdA Gene Encoding an Intermediate of His-Asp Phosphorelay Signaling in Aspergillus nidulans Induces the Same Cellular Effects as the Phenylpyrrole Fungicide Fludioxonil

Many eukaryotic histidine-to-aspartate (His-Asp) phosphorelay systems consist of three types of signal transducers: a His-kinase (HK), a response regulator (RR), and a histidine-containing phosphotransfer intermediate (HPt). In general, the HPt acts as an intermediate between the HK and the RR and is indispensable for inducing appropriate responses to environmental stresses. In a previous study, we attempted but were unable to obtain deletion mutants of the ypdA gene in order to characterize its function in the filamentous fungus Aspergillus nidulans. In the present study, we constructed the CypdA strain in which ypdA expression is conditionally regulated by the A. nidulans alcA promoter. We constructed CypdA strains with RR gene disruptions (CypdA-sskAΔ, CypdA-srrAΔ, and CypdA-sskAΔsrrAΔ). Suppression of YpdA induced by ypdA downregulation activated the downstream HogA mitogen-activated protein kinase cascade. YpdA suppression caused severe growth defects and abnormal hyphae, with features such as enhanced septation, a decrease in number of nuclei, nuclear fragmentation, and hypertrophy of vacuoles, both regulated in an SskA-dependent manner. Fludioxonil treatment caused the same cellular responses as ypdA suppression. The growth-inhibitory effects of fludioxonil and the lethality caused by ypdA downregulation may be caused by the same or similar mechanisms and to be dependent on both the SskA and SrrA pathways.

Multiple nicotinic acetylcholine receptor subtypes regulate social or cognitive behaviors in mice repeatedly administered phencyclidine

Habitual smoking in patients with schizophrenia (SCZ) is considered to improve their own psychoses or to develop a vulnerability to psychological dependence on (-)-nicotine ([-]-NIC) by stimulating nicotinic acetylcholine receptors (nAChRs) in the central nervous system. In the present study, we investigated whether habitual smoking is due to get therapeutic effect or to psychological dependence and which nAChR subunits are associated with them using mice that were repeatedly administered phencyclidine (PCP: 10 mg/kg/day, s.c. for 14 days) as SCZ-like model mice. Mice that were repeatedly administered PCP showed impairments in social or cognitive behaviors; decreased expression of α7 and/or α4 nAChR subunits in the prefrontal cortex (PFC); and increased expression of α7, α4, and β2 nAChR subunits in the nucleus accumbens (NAc). These changes were attenuated by repeated administration of (-)-NIC. The attenuating effects on behavioral impairments were prevented by a selective α7 nAChR antagonist and a selective α4β2 nAChR antagonist. At non- or weak effective dose by themselves, co-administration of (-)-NIC (0.03 mg/kg) and risperidone (0.03 mg/kg) showed synergistic effects on behavioral impairments in PCP-administered mice. Repeated (-)-NIC administration did not affect the performance of conditioned place preference, while it showed behavioral sensitization to (-)-NIC in the PCP-administered mice. Repeated (-)-NIC administration did not affect the performance of conditioned place preference, while it showed behavioral sensitization to (-)-NIC and attenuating effect on haloperidol-induced catalepsy in the PCP-administered mice. Our findings suggest that habitual smoking in SCZ might be attributed to get therapeutic and reduce side effects mediated by α7 and α4β2 nAChR activation by (-)-NIC.

Involvement of PKCβI-SERT activity in stress vulnerability of mice exposed to twice-swim stress

Stress vulnerability and pathogenic mechanisms in stress-related disorders are strongly associated with the functions of serotonin transporter (SERT). SERT phosphorylation induces a reduction of the serotonin (5-HT, 5-hydroxytryptamine) transport properties, its phosphorylation regulated by protein kinase C (PKC). However, the functional relationship between regulated SERT activity by PKC and stress vulnerability remains unclear. Here, we investigated whether the functional regulation of SERT by PKC was involved in stress vulnerability using mice exposed to twice-swim stress that exhibited the impairment of social behaviors. The mild-swim stress (6 min) given just before the social interaction test did not affect the social behaviors of mice. However, mice exposed to strong-swim stress (15 min) became vulnerable to the mild-swim stress, and subsequent social behaviors were impaired. Chelerythrine, a PKC inhibitor, exacerbated decreased sociality in mice exposed to acute mild-swim stress. Phorbol 12-myristate 13-acetate (PMA), a PKC activator, ameliorated the impairment of social behaviors in mice exposed to twice-swim stress. Phosphorylated PKCβI or SERT and 5-HT levels were decreased in the prefrontal cortex of twice-stressed mice. These decreases were attenuated by PMA. Our findings demonstrate that mice exposed to twice-swim stress developed stress vulnerability, which may be involved in the regulation of SERT phosphorylation and 5-HT levels accompanying PKCβI activity.

Rare genetic variants in the gene encoding histone lysine demethylase 4C (KDM4C) and their contributions to susceptibility to schizophrenia and autism spectrum disorder

Dysregulation of epigenetic processes involving histone methylation induces neurodevelopmental impairments and has been implicated in schizophrenia (SCZ) and autism spectrum disorder (ASD). Variants in the gene encoding lysine demethylase 4C (KDM4C) have been suggested to confer a risk for such disorders. However, rare genetic variants in KDM4C have not been fully evaluated, and the functional impact of the variants has not been studied using patient-derived cells. In this study, we conducted copy number variant (CNV) analysis in a Japanese sample set (2605 SCZ and 1141 ASD cases, and 2310 controls). We found evidence for significant associations between CNVs in KDM4C and SCZ (p = 0.003) and ASD (p = 0.04). We also observed a significant association between deletions in KDM4C and SCZ (corrected p = 0.04). Next, to explore the contribution of single nucleotide variants in KDM4C, we sequenced the coding exons in a second sample set (370 SCZ and 192 ASD cases) and detected 18 rare missense variants, including p.D160N within the JmjC domain of KDM4C. We, then, performed association analysis for p.D160N in a third sample set (1751 SCZ and 377 ASD cases, and 2276 controls), but did not find a statistical association with these disorders. Immunoblotting analysis using lymphoblastoid cell lines from a case with KDM4C deletion revealed reduced KDM4C protein expression and altered histone methylation patterns. In conclusion, this study strengthens the evidence for associations between KDM4C CNVs and these two disorders and for their potential functional effect on histone methylation patterns.

Involvement of nicotinic acetylcholine receptors in behavioral abnormalities and psychological dependence in schizophrenia-like model mice

The smoking incentive in patients with schizophrenia (SCZ) depends on stimulation of nicotinic acetylcholine receptors (nAChRs) in the central nervous system. To detect potential predictor genes for nicotine responses in SCZ, we explored common factor using research data in human and animal samples. In lymphoblastoid cell lines from SCZ, the mRNA expression level of α7 nAChR subunit was decreased. In SCZ-like model mice of phencyclidine (PCP; 10 mg/kg/day, subcutaneously for 14 days)-administered mice, the mRNA expression level of α7 nAChR subunit and protein expression level of α7 or α4 nAChR subunit were significantly decreased in the prefrontal cortex during PCP withdrawal. Protein, but not mRNA, expression levels of α7, α4, and β2 nAChR subunits were significantly increased in the nucleus accumbens. Acute (-)-nicotine [(-)-NIC: 0.3 mg/kg, s.c.] treatment attenuated impairments of social behaviors and visual recognition memory. These effects of (-)-NIC were completely blocked by both methyllycaconitine, a selective α7 nAChR antagonist, and dihydro-β-erythroidine (DHβE), a selective α4β2 nAChR antagonist. (-)-NIC did not induce conditioned place preference, but enhanced sensitivity to methamphetamine-induced hyperactivity. These findings suggest that α7 nAChR is associated with development of disease and is implicated in the therapeutic effect of nicotine in SCZ. The smoking incentive in SCZ might be attributed to treat their own symptoms, rather than a result of (-)-NIC dependence, by stimulating α7 and/or α4β2 nAChRs.

ARHGAP10, which encodes Rho GTPase-activating protein 10, is a novel gene for schizophrenia risk

Schizophrenia (SCZ) is known to be a heritable disorder; however, its multifactorial nature has significantly hampered attempts to establish its pathogenesis. Therefore, in this study, we performed genome-wide copy-number variation (CNV) analysis of 2940 patients with SCZ and 2402 control subjects and identified a statistically significant association between SCZ and exonic CNVs in the ARHGAP10 gene. ARHGAP10 encodes a member of the RhoGAP superfamily of proteins that is involved in small GTPase signaling. This signaling pathway is one of the SCZ-associated pathways and may contribute to neural development and function. However, the ARHGAP10 gene is often confused with ARHGAP21, thus, the significance of ARHGAP10 in the molecular pathology of SCZ, including the expression profile of the ARHGAP10 protein, remains poorly understood. To address this issue, we focused on one patient identified to have both an exonic deletion and a missense variant (p.S490P) in ARHGAP10. The missense variant was found to be located in the RhoGAP domain and was determined to be relevant to the association between ARHGAP10 and the active form of RhoA. We evaluated ARHGAP10 protein expression in the brains of reporter mice and generated a mouse model to mimic the patient case. The model exhibited abnormal emotional behaviors, along with reduced spine density in the medial prefrontal cortex (mPFC). In addition, primary cultured neurons prepared from the mouse model brain exhibited immature neurites in vitro. Furthermore, we established induced pluripotent stem cells (iPSCs) from this patient, and differentiated them into tyrosine hydroxylase (TH)-positive neurons in order to analyze their morphological phenotypes. TH-positive neurons differentiated from the patient-derived iPSCs exhibited severe defects in both neurite length and branch number; these defects were restored by the addition of the Rho-kinase inhibitor, Y-27632. Collectively, our findings suggest that rare ARHGAP10 variants may be genetically and biologically associated with SCZ and indicate that Rho signaling represents a promising drug discovery target for SCZ treatment.

The mechanisms of hyphal pellet formation mediated by polysaccharides, α-1,3-glucan and galactosaminogalactan, in Aspergillus species

Filamentous fungi are widely used for production of enzymes and chemicals, and are industrially cultivated both in liquid and solid cultures. Submerged culture is often used as liquid culture for filamentous fungi. In submerged culture, filamentous fungi show diverse macromorphology such as hyphal pellets and dispersed hyphae depending on culture conditions and genetic backgrounds of fungal strains. Although the macromorphology greatly affects the productivity of submerged cultures, the specific cellular components needed for hyphal aggregation after conidial germination have not been characterized. Recently we reported that the primary cell wall polysaccharide α-1,3-glucan and the extracellular polysaccharide galactosaminogalactan (GAG) contribute to hyphal aggregation in Aspergillus oryzae, and that a strain deficient in both α-1,3-glucan and GAG shows dispersed hyphae in liquid culture. In this review, we summarize our current understanding of the contribution of chemical properties of α-1,3-glucan and GAG to hyphal aggregation. Various ascomycetes and basidiomycetes have α-1,3-glucan synthase gene(s). In addition, some Pezizomycotina fungi, including species used in the fermentation industry, also have GAG biosynthetic genes. We also review here the known mechanisms of biosynthesis of α-1,3-glucan and GAG. Regulation of the biosynthesis of the two polysaccharides could be a potential way of controlling formation of hyphal pellets.

Analysis of the self-assembly process of Aspergillus oryzae hydrophobin RolA by Langmuir-Blodgett method

Hydrophobins are small, amphipathic proteins secreted by filamentous fungi. Hydrophobin RolA, which is produced by Aspergillus oryzae, attaches to solid surfaces, recruits the polyesterase CutL1, and consequently promotes hydrolysis of polyesters. Because this interaction requires the N-terminal, positively charged residue of RolA to be exposed on the solid surface, the orientation of RolA on the solid surface is important for recruitment. However, the process by which RolA forms the self-assembled structure at the interface remains unclear. Using the Langmuir-Blodgett technique, we analyzed the process by which RolA forms a self-assembled structure at the air-water interface and observed the structures on the hydrophobic or hydrophilic SiO₂ substrates via atomic force microscopy. We found that RolA formed self-assembled films in two steps during phase transitions. We observed different assembled structures of RolA on hydrophilic and hydrophobic SiO₂ substrates.

Comparative Analyses of Copy-Number Variation in Autism Spectrum Disorder and Schizophrenia Reveal Etiological Overlap and Biological Insights

Compelling evidence in Caucasian populations suggests a role for copy-number variations (CNVs) in autism spectrum disorder (ASD) and schizophrenia (SCZ). We analyzed 1,108 ASD cases, 2,458 SCZ cases, and 2,095 controls in a Japanese population and confirmed an increased burden of rare exonic CNVs in both disorders. Clinically significant (or pathogenic) CNVs, including those at 29 loci common to both disorders, were found in about 8% of ASD and SCZ cases, which was significantly higher than in controls. Phenotypic analysis revealed an association between clinically significant CNVs and intellectual disability. Gene set analysis showed significant overlap of biological pathways in both disorders including oxidative stress response, lipid metabolism/modification, and genomic integrity. Finally, based on bioinformatics analysis, we identified multiple disease-relevant genes in eight well-known ASD/SCZ-associated CNV loci (e.g., 22q11.2, 3q29). Our findings suggest an etiological overlap of ASD and SCZ and provide biological insights into these disorders.

Both Galactosaminogalactan and α-1,3-Glucan Contribute to Aggregation of Aspergillus oryzae Hyphae in Liquid Culture

Filamentous fungi generally form aggregated hyphal pellets in liquid culture. We previously reported that α-1,3-glucan-deficient mutants of Aspergillus nidulans did not form hyphal pellets and their hyphae were fully dispersed, and we suggested that α-1,3-glucan functions in hyphal aggregation. However, Aspergillus oryzae α-1,3-glucan-deficient (AGΔ) mutants still form small pellets; therefore, we hypothesized that another factor responsible for forming hyphal pellets remains in these mutants. Here, we identified an extracellular matrix polysaccharide galactosaminogalactan (GAG) as such a factor. To produce a double mutant of A. oryzae (AG-GAGΔ), we disrupted the genes required for GAG biosynthesis in an AGΔ mutant. Hyphae of the double mutant were fully dispersed in liquid culture, suggesting that GAG is involved in hyphal aggregation in A. oryzae. Addition of partially purified GAG fraction to the hyphae of the AG-GAGΔ strain resulted in formation of mycelial pellets. Acetylation of the amino group in galactosamine of GAG weakened GAG aggregation, suggesting that hydrogen bond formation by this group is important for aggregation. Genome sequences suggest that α-1,3-glucan, GAG, or both are present in many filamentous fungi and thus may function in hyphal aggregation in these fungi. We also demonstrated that production of a recombinant polyesterase, CutL1, was higher in the AG-GAGΔ strain than in the wild-type and AGΔ strains. Thus, controlling hyphal aggregation factors of filamentous fungi may increase productivity in the fermentation industry.

Functional roles of the glial glutamate transporter (GLAST) in emotional and cognitive abnormalities of mice after repeated phencyclidine administration

Alterations of the glutamatergic system components, including N-methyl-d-aspartate (NMDA) receptors are relevant to the pathophysiology of schizophrenia. Repeated phencyclidine (PCP) administration induces several schizophrenia-like psychobehavioral abnormalities and decreases extracellular glutamate levels, which are associated with increased levels of glial glutamate and aspartate transporter (GLAST) in the prefrontal cortex (PFC) of mice. In the present study, we investigated the functional roles of GLAST in the emotional and cognitive abnormalities in mice following repeated PCP administration by using GLAST heterozygous (+/-) mice, since GLAST mutant mice are a useful tool for elucidating the contribution of glutamate dysfunction to the pathophysiology of schizophrenia. PCP-administered GLAST wild-type (+/+) mice showed enhancement of immobility in a forced swimming test, impairments of visual recognition memory in a novel object recognition test, decrease in high potassium (K⁺)-induced extracellular glutamate release, and overexpression of GLAST and S100 proteins in the PFC, compared to saline-administered GLAST^+/+ mice. Such behavioral and neurochemical abnormalities were not observed in PCP-administered GLAST^+/- mice. In conclusion, these results clearly suggest that genetic GLAST dysfunction and glial activation play important roles in the development of emotional and cognitive abnormalities in PCP-administered GLAST^+/+ mice.

Methylation analysis for postpartum depression: a case control study

BACKGROUND

Postpartum depression (PPD) is a major depressive disorder that occurs after childbirth. Objective diagnostic and predictive methods for PPD are important for early detection and appropriate intervention. DNA methylation has been recognized as a potential biomarker for major depressive disorder. In this study, we used methylation analysis and peripheral blood to search for biomarkers that could to lead to the development a predictive method for PPD.

METHODS

Study participants included 36 pregnant women (18 cases and 18 controls determined after childbirth). Genome-wide DNA methylation profiles were obtained by analysis with an Infinium Human Methylation 450BeadChip. The association of DNA methylation status at each DNA methylation site with PPD was assessed using linear regression analysis. We also conducted functional enrichment analysis of PPD using The Database for Annotation, Visualization and Integrated Discovery 6.8 to explore enriched functional-related gene groups for PPD.

RESULTS

In the analysis with postpartum depressed state as an independent variable, the difference in methylation frequency between the postpartum non-depressed group and the postpartum depressed group was small, and sites with genome-wide significant differences were not confirmed. After analysis by The Database for Annotation, Visualization and Integrated Discovery 6.8, we revealed four gene ontology terms, including axon guidance, related to postpartum depression.

CONCLUSIONS

These findings may help with the development of an objective predictive method for PPD.

Author Correction: Proteomic analysis of lymphoblastoid cell lines from schizophrenic patients

The original Article required a few updates; one co-author name, which was given as Hiroki Kiumura, has been updated to Hiroki Kimura. Furthermore, supplementary information has been updated, and grant numbers have been added. These updates have been made to both the PDF and HTML versions of this Article.

Proteomic analysis of lymphoblastoid cell lines from schizophrenic patients

Although a number of studies have identified several convincing candidate genes or molecules, the pathophysiology of schizophrenia (SCZ) has not been completely elucidated. Therapeutic optimization based on pathophysiology should be performed as early as possible to improve functional outcomes and prognosis; to detect useful biomarkers for SCZ, which reflect pathophysiology and can be utilized for timely diagnosis and effective therapy. To explore biomarkers for SCZ, we employed fluorescence two-dimensional differential gel electrophoresis (2D-DIGE) of lymphoblastoid cell lines (LCLs) (1st sample set: 30 SCZ and 30 CON). Differentially expressed proteins were sequenced by liquid chromatography tandem-mass spectrometry (LC-MS/MS) and identified proteins were confirmed by western blotting (WB) (1st and 2nd sample set: 60 SCZ and 60 CON). Multivariate logistic regression analysis was performed to identify an optimal combination of biomarkers to create a prediction model for SCZ. Twenty protein spots were differentially expressed between SCZ and CON in 2D-DIGE analysis and 22 unique proteins were identified by LC-MS/MS. Differential expression of eight of 22 proteins was confirmed by WB. Among the eight candidate proteins (HSPA4L, MX1, GLRX3, UROD, MAPRE1, TBCB, IGHM, and GART), we successfully constructed logistic regression models comprised of 4- and 6-markers with good discriminative ability between SCZ and CON. In both WB and gene expression analysis of LCL, MX1 showed reproducibly significant associations. Moreover, Mx1 and its related proinflamatory genes (Mx2, Il1b, and Tnf) were also up-regulated in poly I:C-treated mice. Differentially expressed proteins might be associated with molecular pathophysiology of SCZ, including dysregulation of immunological reactions and potentially provide diagnostic and prognostic biomarkers.

Blonanserin ameliorates social deficit through dopamine-D3 receptor antagonism in mice administered phencyclidine as an animal model of schizophrenia

Blonanserin differs from other antipsychotic drugs, such as risperidone and olanzapine, and exhibits a higher affinity for dopamine-D_2/3 receptors than for serotonin 5-HT_2A receptors. We investigated the involvement of dopamine-D₃ receptors in the effect of blonanserin on the social deficit observed in an animal model of schizophrenia and sought to elucidate the molecular mechanism underlying its action. Mice received phencyclidine (PCP: 10 mg/kg/day, s.c.), a non-competitive N-methyl-d-aspartate (NMDA) receptor antagonist, once a day for 14 consecutive days. We then evaluated the sociability, using a social interaction test, and the expression of GluN1 subunit, an essential subunit of the NMDA receptors, in these mice. Blonanserin significantly ameliorated the PCP-induced social deficit, whereas olanzapine and haloperidol did not. This effect of blonanserin was antagonized by 7-OH-DPAT, a dopamine-D₃ receptor agonist, and SCH23390, a dopamine-D₁ receptor antagonist. However, the ameliorating effect of blonanserin was not inhibited by DOI, a serotonin 5-HT_2A receptor agonist. The PCP-induced social deficit was also ameliorated by U99194, a dopamine-D₃ receptor antagonist and SKF38393, a dopamine-D₁ receptor agonist, being effects antagonized by 7-OH-DPAT or SCH23390. Blonanserin significantly inhibited the decrease in the phosphorylation levels of GluN1 at Ser⁸⁹⁷ by protein kinase A (PKA) in the prefrontal cortex (PFC) in PCPadministered mice. These results suggest that activation of NMDA receptors due to Ser⁸⁹⁷-phosphorylation of GluN1 subunit, which is a step linked to dopamine-D₁ receptor-PKA signaling through dopamine-D₃ receptor antagonism in the PFC, is required for the ameliorating effect of blonanserin on the PCP-induced social deficit. These findings also provide in vivo evidence that blonanserin antagonism of the dopamine-D₃ receptors may be useful as a novel treatment strategy and that the dopamine-D₃ receptors can be a novel therapeutic target molecule for the social deficit observed in schizophrenia.

Molecular Mass and Localization of α-1,3-Glucan in Cell Wall Control the Degree of Hyphal Aggregation in Liquid Culture of Aspergillus nidulans

α-1,3-Glucan is one of the main polysaccharides in the cell wall of filamentous fungi. Aspergillus nidulans has two α-1,3-glucan synthase genes, agsA and agsB. We previously revealed that AgsB is a major α-1,3-glucan synthase in vegetative hyphae, but the function of AgsA remained unknown because of its low expression level and lack of phenotypic alteration upon gene disruption. To clarify the role of α-1,3-glucan in hyphal aggregation, we constructed strains overexpressing agsA (agsA^OE) or agsB (agsB^OE), in which the other α-1,3-glucan synthase gene was disrupted. In liquid culture, the wild-type and agsB^OE strains formed tightly aggregated hyphal pellets, whereas agsA^OE hyphae aggregated weakly. We analyzed the chemical properties of cell wall α-1,3-glucan from the agsA^OE and agsB^OE strains. The peak molecular mass of α-1,3-glucan from the agsA^OE strain (1,480 ± 80 kDa) was much larger than that from the wild type (147 ± 52 kDa) and agsB^OE (372 ± 47 kDa); however, the peak molecular mass of repeating subunits in α-1,3-glucan was almost the same (after Smith degradation: agsA^OE, 41.6 ± 5.8 kDa; agsB^OE, 38.3 ± 3.0 kDa). We also analyzed localization of α-1,3-glucan in the cell wall of the two strains by fluorescent labeling with α-1,3-glucan-binding domain–fused GFP (AGBD-GFP). α-1,3-Glucan of the agsB^OE cells was clearly located in the outermost layer, whereas weak labeling was detected in the agsA^OE cells. However, the agsA^OE cells treated with β-1,3-glucanase were clearly labeled with AGBD-GFP. These observations suggest that β-1,3-glucan covered most of α-1,3-glucan synthesized by AgsA, although a small amount of α-1,3-glucan was still present in the outer layer. We also constructed a strain with disruption of the amyG gene, which encodes an intracellular α-amylase that synthesizes α-1,4-glucooligosaccharide as a primer for α-1,3-glucan biosynthesis. In this strain, the hyphal pellets and peak molecular mass of α-1,3-glucan (94.5 ± 1.4 kDa) were smaller than in the wild-type strain, and α-1,3-glucan was still labeled with AGBD-GFP in the outermost layer. Overall, these results suggest that hyphal pellet formation depends on the molecular mass and spatial localization of α-1,3-glucan as well as the amount of α-1,3-glucan in the cell wall of A. nidulans.

[Effect of Non-alcoholic Beverage Intake in Children on Alcoholic Beverage Drinking and Smoking]

　The early intake of alcohol and/or nicotine in childhood or adolescence is one of risk factors for alcohol and/or nicotine dependence in adult. Recently, non-alcoholic beverages with less than 0.00% alcohol are on sale for adults as substitutes for alcoholic beverages without strict legal limitations. However, it is unclear whether non-alcoholic beverages could be a risk factor in drinking and smoking in childhood or adolescence. The purpose of the present survey is to clarify the effect of non-alcoholic beverage intake in children on alcoholic beverage drinking and smoking. We examined as follows: the experience of alcoholic or non-alcoholic beverage intake, and of smoking in elementary school pupils and/or their family members, and interest in or motivation for drinking and smoking in the pupils. As a result, the percentage of alcoholic or non-alcoholic beverage intake, and of smoking in the pupils were 16.8% or 21.9%, and 0.3%, respectively. The number of family members took the alcoholic or non-alcoholic beverage was larger in the pupils took it compared to the pupils did not take it. In the pupils who experienced the non-alcoholic beverage intake, interest in or motivation for drinking alcoholic beverages and/or smoking is higher than in those who did not. These findings indicate that non-alcoholic beverage intake is related to drinking and smoking. We will introduce drug abuse prevention education on the risk of drug dependence among childhood or adolescents based on the findings of this survey.