Suppression of the Epithelial-Mesenchymal Transition and Maintenance of the Liver Functions in Primary Hepatocytes through Dispersion Culture within a Dome-Shaped Collagen Matrix.

Primary hepatocytes are valuable for studying liver diseases, drug-induced liver injury, and drug metabolism. However, when cultured in a two-dimensional (2D) environment, primary hepatocytes undergo rapid dedifferentiation via an epithelial-mesenchymal transition (EMT) and lose their liver-specific functions. On the other hand, a three-dimensional (3D) culture of primary hepatocyte organoids presents challenges for analyzing cellular functions and molecular behaviors due to strong cell-cell adhesion among heterogeneous cells. In this study, we developed a novel dispersion culture method of hepatocytes within a dome-shaped collagen matrix, overcoming conventional limitations. The expression levels of EMT-related genes were lower in rat primary hepatocytes cultured using this method for 4 d than in cells cultured using the 2D method. Furthermore, albumin production, a marker of liver function, declined sharply in rat primary hepatocytes cultured in two dimensions from 6.40 µg/mL/48 h on day 4 to 1.35 µg/mL/48 h on day 8, and declined gradually from 4.92 µg/mL/48 h on day 8 to 3.89 µg/mL/48 h on day 14 in rat primary hepatocytes cultured using our new method. These findings indicate that the newly developed culture method can suppress EMT and maintain liver functions for 14 d in rat primary hepatocytes, potentially expanding the utility of primary hepatocyte cultured by using conventional 3D methods.

A loss-of-function variant in SUV39H2 identified in autism-spectrum disorder causes altered H3K9 trimethylation and dysregulation of protocadherin ß-cluster genes in the developing brain.

Recent evidence has documented the potential roles of histone-modifying enzymes in autism-spectrum disorder (ASD). Aberrant histone H3 lysine 9 (H3K9) dimethylation resulting from genetic variants in histone methyltransferases is known for neurodevelopmental and behavioral anomalies. However, a systematic examination of H3K9 methylation dynamics in ASD is lacking. Here we resequenced nine genes for histone methyltransferases and demethylases involved in H3K9 methylation in individuals with ASD and healthy controls using targeted next-generation sequencing. We identified a novel rare variant (A211S) in the SUV39H2, which was predicted to be deleterious. The variant showed strongly reduced histone methyltransferase activity in vitro. In silico analysis showed that the variant destabilizes the hydrophobic core and allosterically affects the enzyme activity. The Suv39h2-KO mice displayed hyperactivity and reduced behavioral flexibility in learning the tasks that required complex behavioral adaptation, which is relevant for ASD. The Suv39h2 deficit evoked an elevated expression of a subset of protocadherin ß (Pcdhb) cluster genes in the embryonic brain, which is attributable to the loss of H3K9 trimethylation (me3) at the gene promoters. Reduced H3K9me3 persisted in the cerebellum of Suv39h2-deficient mice to an adult stage. Congruently, reduced expression of SUV39H1 and SUV39H2 in the postmortem brain samples of ASD individuals was observed, underscoring the role of H3K9me3 deficiency in ASD etiology. The present study provides direct evidence for the role of SUV39H2 in ASD and suggests a molecular cascade of SUV39H2 dysfunction leading to H3K9me3 deficiency followed by an untimely, elevated expression of Pcdhb cluster genes during early neurodevelopment.

Key role of soluble epoxide hydrolase in the neurodevelopmental disorders of offspring after maternal immune activation.

Maternal infection during pregnancy increases risk of neurodevelopmental disorders such as schizophrenia and autism spectrum disorder (ASD) in offspring. In rodents, maternal immune activation (MIA) yields offspring with schizophrenia- and ASD-like behavioral abnormalities. Soluble epoxide hydrolase (sEH) plays a key role in inflammation associated with neurodevelopmental disorders. Here we found higher levels of sEH in the prefrontal cortex (PFC) of juvenile offspring after MIA. Oxylipin analysis showed decreased levels of epoxy fatty acids in the PFC of juvenile offspring after MIA, supporting increased activity of sEH in the PFC of juvenile offspring. Furthermore, expression of sEH (or EPHX2) mRNA in induced pluripotent stem cell-derived neurospheres from schizophrenia patients with the 22q11.2 deletion was higher than that of healthy controls. Moreover, the expression of EPHX2 mRNA in postmortem brain samples (Brodmann area 9 and 40) from ASD patients was higher than that of controls. Treatment with 1-trifluoromethoxyphenyl-3-(1-propionylpiperidin-4-yl)urea (TPPU), a potent sEH inhibitor, in juvenile offspring from prenatal day (P) 28 to P56 could prevent cognitive deficits and loss of parvalbumin (PV) immunoreactivity in the medial PFC of adult offspring after MIA. In addition, dosing of TPPU to pregnant mothers from E5 to P21 could prevent cognitive deficits, and social interaction deficits and PV immunoreactivity in the medial prefrontal cortex of juvenile offspring after MIA. These findings suggest that increased activity of sEH in the PFC plays a key role in the etiology of neurodevelopmental disorders in offspring after MIA. Therefore, sEH represents a promising prophylactic or therapeutic target for neurodevelopmental disorders in offspring after MIA.

Differences in detected safety signals between benzodiazepines and non-benzodiazepine hypnotics: pharmacovigilance study using a spontaneous reporting system.

Introduction: In recent years, there has been an increasing number of people who feel sleep-deprived owing to sudden changes in the social environment. Patients prescribed benzodiazepine-based hypnotics (BZ drugs) also develop movement disorder action and memory disorders as adverse events (AEs), and they have further problems such as dependency and tolerance because of long-term use. Therefore, the use of non-benzodiazepine-based hypnotics (Z-drugs) is recommended for patients with insomnia. However, as AEs have also been reported for Z-drugs, it is important to identify these when switching hypnotics. Methods: To understand AEs to be noted when switching from BZ drugs to Z-drugs, we evaluated the differences in AEs developed by both these drugs using volcano plots and safety signals. For this, data registered in the Japanese Adverse Drug Event Report database were used. Results: The volcano plot and safety signals revealed six characteristic Z-drug-induced AEs. Parasomnias (ln odds ratio [OR]: 3.28, -log P: 4.34, proportional reporting ratio [PRR]: 23.47, χ 2: 309.27), Cortical dysfunction NEC (ln OR: 2.76, -log P: 4.34, PRR: 3.62, χ 2: 16.14), and Psychiatric symptoms NEC (ln OR: 2.66, -log P: 2.18, PRR: 2.51, χ 2: 6.63) were detected only in Z-drugs, and safety signals of Suicidal and self-injurious behaviour, Deliria, and Overdoses NEC were also detected with BZ drugs. However, the strength of safety signals was much higher with the Z-drugs. Conclusion: AEs related to falls and bone fractures are expected to be more strongly onset in BZ drugs than in Z-drugs, which are said to have less muscle relaxant action. However, there was no particularly significant difference in this parameter between the two drug classes. Understanding the difference between these AEs of Z-drugs and BZ drugs is important for the proper use of hypnotics.

The association between polypharmacy and the efficiency of the functional independence measure in an acute-stage hospital: a retrospective cohort study.

BACKGROUND: The Functional Independence Measure (FIM) evaluates the activities of daily living (ADL), and FIM efficiency represents daily improvement in FIM. Polypharmacy affects both ADL and FIM; however, few studies have evaluated its relationship with FIM efficiency. AIM: This retrospective study investigated the effect of polypharmacy on FIM efficiency in patients undergoing rehabilitation at our acute care hospital in 2014. METHODS: We collected data on the patients' age, sex, diagnosis, length of hospital stay, type and duration of rehabilitation, indications for rehabilitation, FIM score before and after rehabilitation, and number of pharmaceuticals being used. Polypharmacy was defined as the administration of five or more pharmaceuticals. Using propensity score matching, we compared the FIM efficiency between the polypharmacy and non-polypharmacy groups (sub-scales and totals). RESULTS: A total of 2455 patients were included. The analytical population included 2168 patients. The analytical population used for propensity score matching included 727 patients in each group (total: 1454 patients). The following FIM sub-scale items were found to be associated with significantly low FIM efficiency in the polypharmacy group: self-care (polypharmacy group FIM efficiency: 0.43 points/day, non-polypharmacy group FIM efficiency: 0.54 points/day) and sphincter control (0.11 points/day and 0.18 points/day, respectively). No significant differences in the FIM efficiency were observed either for any other sub-scales or for totals. DISCUSSION: In the polypharmacy group, self-care and sphincter control, in particular, were associated with inhibited improvement in ADL and FIM. CONCLUSIONS: Reducing polypharmacy among acute-phase patients would allow an earlier return to their normal daily lives.

What activities of daily living at discharge affect the discharge destination of patients in an acute-care hospital in Japan: A retrospective factor analysis.

It is important to clarify the influence of activities of daily living (ADL) at discharge on the discharge destination of hospitalised patients. The Functional Independence Measure (FIM) is a widely used ADL assessment scale. In this retrospective study, we aimed to identify what ADL based on FIM at discharge affect the discharge destination of hospitalised patients in an acute-care hospital, in addition to how nutritional status and the number of drugs used, as well as types of disease, affect discharge-to-home. We surveyed age, sex, disease type, length of hospital stay, discharge destination, FIM score at discharge, serum albumin level, and the number of continued drugs in hospitalised patients who underwent rehabilitation in Gifu Municipal Hospital (Gifu, Japan) between January 2014 and December 2014. Multiple logistic regression analysis was performed with discharge to home as a dependent variable and age, sex, disease, FIM score and polypharmacy as independent variables. Multiple logistic regression analysis indicated that a significantly high percentage of discharged-to-home patients were associated with 'self-care' (≥33 points; OR: 2.03), 'sphincter control' (≥14 points; OR: 1.49), 'transfers' (≥13 points; OR: 1.94), and 'locomotion' (≥7 points; OR: 3.55), among others. High FIM sub-scale scores at discharge for self-care, sphincter control, transfers, and locomotion were clarified as factors associated with discharge-to-home. These findings of the association of ADL based on FIM and discharge destination would be useful in deciding discharge destinations for patients in an acute-phase hospital.

Contribution of induced pluripotent stem cell technologies to the understanding of cellular phenotypes in schizophrenia.

Schizophrenia is one of the leading causes of disability among mental disorders, contributing to a substantial socioeconomic burden. Our understanding of the mechanisms of the pathogenesis of the disease has largely been limited by its inherent complexity imparted by the polygenicity and interactions with environmental factors. Since pathobiological events are initiated in the schizophrenic brain long before the onset of the psychotic manifestations, characterizing these processes is limited, mainly due to a lack of access to neuronal tissues. Induced pluripotent stem cell (iPSC) technologies have provided an unprecedented opportunity to establish pluripotent stem cells from patients with schizophrenia and differentiate them into neuronal lineage, enabling an in vitro recapitulation of the pathogenesis of the disease. Despite the inherent challenges, patient-derived iPSC studies of schizophrenia have been instrumental in unraveling the cellular and molecular phenotypes that might be involved in the biological causality. Here we review the literature and focus on studies that have utilized patient-derived iPSCs to model the pathogenesis of schizophrenia. We also discuss the challenges in modeling cellular phenotypes of schizophrenia.

Thiosulfate promotes hair growth in mouse model.

The present study describes the hair growth-promoting effects of sodium thiosulfate (STS), a widely used compound, in mice. STS accelerated hair growth in the "telogen model", suggesting that it stimulates telogen hair follicles to reenter the anagen phase of hair growth. In the same model, STS potentiated hair growth in an additive manner with minoxidil (MXD), a drug used for the treatment of androgenic alopecia. Furthermore, in the "anagen model", STS promoted hair growth, probably by promoting hair follicle proliferation. Since STS elevated the skin surface temperature, its hair growth-promoting activity may be partly due to vasorelaxation, similar to MXD. In addition, STS is known to generate a gaseous mediator, H2S, which has vasorelaxation and anti-inflammatory/anti-oxidative stress activities. Therefore, STS and/or provisionally its metabolite, H2S, may aid the hair growth process. Collectively, these results suggest that salts of thiosulfate may represent a novel and beneficial remedy for hair loss.

Functional characterization of FABP3, 5 and 7 gene variants identified in schizophrenia and autism spectrum disorder and mouse behavioral studies.

Disturbances of lipid metabolism have been implicated in psychiatric illnesses. We previously reported an association between the gene for fatty acid binding protein 7 (FABP7) and schizophrenia. Furthermore, we identified and reported several rare non-synonymous polymorphisms of the brain-expressed genes FABP3, FABP5 and FABP7 from schizophrenia and autism spectrum disorder (ASD), diseases known to part share genetic architecture. Here, we conducted further studies to better understand the contribution these genes make to the pathogenesis of schizophrenia and ASD. In postmortem brains, we detected altered mRNA expression levels of FABP5 in schizophrenia, and of FABP7 in ASD and altered FABP5 in peripheral lymphocytes. Using a patient cohort, comprehensive mutation screening identified six missense and two frameshift variants from the three FABP genes. The two frameshift proteins, FABP3 E132fs and FABP7 N80fs, formed cellular aggregates and were unstable when expressed in cultured cells. The four missense mutants with predicted possible damaging outcomes showed no changes in intracellular localization. Examining ligand binding properties, FABP7 S86G and FABP7 V126L lost their preference for docosahexaenoic acid to linoleic acid. Finally, mice deficient in Fabp3, Fabp5 and Fabp7 were evaluated in a systematic behavioral test battery. The Fabp3 knockout (KO) mice showed decreased social memory and novelty seeking, and Fabp7 KO mice displayed hyperactive and anxiety-related phenotypes, while Fabp5 KO mice showed no apparent phenotypes. In conclusion, disturbances in brain-expressed FABPs could represent an underlying disease mechanism in a proportion of schizophrenia and ASD sufferers.

Sequencing and expression analyses of the synaptic lipid raft adapter gene PAG1 in schizophrenia.

Disruption of synaptic networks has been advocated in the pathogenesis of psychiatric diseases like schizophrenia. The majority of synaptic proteins involved in neuronal communications are localized in lipid rafts. These rafts form the platform for coordinating neuronal signal transduction, by clustering interacting partners. The PAG1 protein is a transmembrane adaptor protein in the lipid raft signaling cluster that regulates Src family kinases (SFKs), a convergent point for multiple pathways regulating N-methyl-D-aspartate (NMDA) receptors. Reports of de novo missense mutations in PAG1 and SFK mediated reductions in tyrosine phosphorylation of NMDA receptor subunit proteins in schizophrenia patients, point to a putative role in schizophrenia pathogenesis. To evaluate this, we resequenced the entire coding region of PAG1 in Japanese schizophrenia patients (n = 1,140) and controls (n = 1,140). We identified eight missense variants, of which four were previously unreported. Case-control genetic association analysis of these variants in a larger cohort (n = 4,182) showed neither a statistically significant association of the individual variants with schizophrenia, nor any increased burden of the rare alleles in the patient group. Expression levels of PAG1 in post-mortem brain samples from schizophrenia patients and controls also showed no significant differences. To assess the precise role of PAG1 in schizophrenia, future studies with larger sample sizes are needed.

Glyoxalase I disruption and external carbonyl stress impair mitochondrial function in human induced pluripotent stem cells and derived neurons.

Carbonyl stress, a specific form of oxidative stress, is reported to be involved in the pathophysiology of schizophrenia; however, little is known regarding the underlying mechanism. Here, we found that disruption of GLO1, the gene encoding a major catabolic enzyme scavenging the carbonyl group, increases vulnerability to external carbonyl stress, leading to abnormal phenotypes in human induced pluripotent stem cells (hiPSCs). The viability of GLO1 knockout (KO)-hiPSCs decreased and activity of caspase-3 was increased upon addition of methylglyoxal (MGO), a reactive carbonyl compound. In the GLO1 KO-hiPSC-derived neurons, MGO administration impaired neurite extension and cell migration. Further, accumulation of methylglyoxal-derived hydroimidazolone (MG-H1; a derivative of MGO)-modified proteins was detected in isolated mitochondria. Mitochondrial dysfunction, including diminished membrane potential and dampened respiratory function, was observed in the GLO1 KO-hiPSCs and derived neurons after addition of MGO and hence might be the mechanism underlying the effects of carbonyl stress. The susceptibility to MGO was partially rescued by the administration of pyridoxamine, a carbonyl scavenger. Our observations can be used for designing an intervention strategy for diseases, particularly those induced by enhanced carbonyl stress or oxidative stress.

Betaine ameliorates schizophrenic traits by functionally compensating for KIF3-based CRMP2 transport.

In schizophrenia (SCZ), neurons in the brain tend to undergo gross morphological changes, but the related molecular mechanism remains largely elusive. Using Kif3b+/- mice as a model with SCZ-like behaviors, we found that a high-betaine diet can significantly alleviate schizophrenic traits related to neuronal morphogenesis and behaviors. According to a deficiency in the transport of collapsin response mediator protein 2 (CRMP2) by the KIF3 motor, we identified a significant reduction in lamellipodial dynamics in developing Kif3b+/- neurons as a cause of neurite hyperbranching. Betaine administration significantly decreases CRMP2 carbonylation, which enhances the F-actin bundling needed for proper lamellipodial dynamics and microtubule exclusion and may thus functionally compensate for KIF3 deficiency. Because the KIF3 expression levels tend to be downregulated in the human prefrontal cortex of the postmortem brains of SCZ patients, this mechanism may partly participate in human SCZ pathogenesis, which we hypothesize could be alleviated by betaine administration.

Role of an Atypical Cadherin Gene, Cdh23 in Prepulse Inhibition, and Implication of CDH23 in Schizophrenia.

We previously identified quantitative trait loci (QTL) for prepulse inhibition (PPI), an endophenotype of schizophrenia, on mouse chromosome 10 and reported Fabp7 as a candidate gene from an analysis of F2 mice from inbred strains with high (C57BL/6N; B6) and low (C3H/HeN; C3H) PPI levels. Here, we reanalyzed the previously reported QTLs with increased marker density. The highest logarithm of odds score (26.66) peaked at a synonymous coding and splice-site variant, c.753G>A (rs257098870), in the Cdh23 gene on chromosome 10; the c.753G (C3H) allele showed a PPI-lowering effect. Bayesian multiple QTL mapping also supported the same variant with a posterior probability of 1. Thus, we engineered the c.753G (C3H) allele into the B6 genetic background, which led to dampened PPI. We also revealed an e-QTL (expression QTL) effect imparted by the c.753G>A variant for the Cdh23 expression in the brain. In a human study, a homologous variant (c.753G>A; rs769896655) in CDH23 showed a nominally significant enrichment in individuals with schizophrenia. We also identified multiple potentially deleterious CDH23 variants in individuals with schizophrenia. Collectively, the present study reveals a PPI-regulating Cdh23 variant and a possible contribution of CDH23 to schizophrenia susceptibility.

Cooperation of LIM domain-binding 2 (LDB2) with EGR in the pathogenesis of schizophrenia.

Genomic defects with large effect size can help elucidate unknown pathologic architecture of mental disorders. We previously reported on a patient with schizophrenia and a balanced translocation between chromosomes 4 and 13 and found that the breakpoint within chromosome 4 is located near the LDB2 gene. We show here that Ldb2 knockout (KO) mice displayed multiple deficits relevant to mental disorders. In particular, Ldb2 KO mice exhibited deficits in the fear-conditioning paradigm. Analysis of the amygdala suggested that dysregulation of synaptic activities controlled by the immediate early gene Arc is involved in the phenotypes. We show that LDB2 forms protein complexes with known transcription factors. Consistently, ChIP-seq analyses indicated that LDB2 binds to > 10,000 genomic sites in human neurospheres. We found that many of those sites, including the promoter region of ARC, are occupied by EGR transcription factors. Our previous study showed an association of the EGR family genes with schizophrenia. Collectively, the findings suggest that dysregulation in the gene expression controlled by the LDB2-EGR axis underlies a pathogenesis of subset of mental disorders.

Deficiency of neural recognition molecule NB-2 affects the development of glutamatergic auditory pathways from the ventral cochlear nucleus to the superior olivary complex in mouse.

Neural recognition molecule NB-2/contactin 5 is expressed transiently during the first postnatal week in glutamatergic neurons of the central auditory system. Here, we investigated the effect of NB-2 deficiency on the auditory brainstem in mouse. While almost all principal neurons are wrapped with the calyces of Held in the medial nucleus of the trapezoid body (MNTB) in wild type, 8% of principal neurons in NB-2 knockout (KO) mice lack the calyces of Held at postnatal day (P) 6. At P10 and P15, apoptotic principal neurons were detected in NB-2 KO mice, but not in wild type. Apoptotic cells were also increased in the ventral cochlear nucleus (VCN) of NB-2 KO mice, which contains bushy neurons projecting to the MNTB and the lateral superior olive (LSO). At the age of 1 month, the number of principal neurons in the MNTB and of glutamatergic synapses in the LSO was reduced in NB-2 KO mice. Finally, interpeak latencies for auditory brainstem response waves II-III and III-IV were significantly increased in NB-2 KO mice. Together, these findings suggest that NB-2 deficiency causes a deficit in synapse formation and then induces apoptosis in MNTB and VCN neurons, affecting auditory brainstem function.

Excessive ingestion of long-chain polyunsaturated fatty acids during developmental stage causes strain- and sex-dependent eye abnormalities in mice.

The eyes are rich in long-chain polyunsaturated fatty acids (LC-PUFAs) such as arachidonic acid [ARA; 20:4 (n-6)] and docosahexaenoic acid [DHA; 22:6 (n-3)]. Despite their abundance in the eyes, ARA and DHA cannot be sufficiently synthesized de novo in mammals. During gestation, eye development is exceptionally rapid, and substantial amounts of LC-PUFAs are needed to ensure proper eye development. Here, we studied the influences of dietary LC-PUFAs in dams (C57BL/6 and C3H/He) on the eye morphogenesis and organogenesis of their pups. Intriguingly, fetuses and newborn mice from C57BL/6 dams fed an LC-PUFA (particularly ARA)-enriched diet displayed a much higher incidence of eye abnormalities such as microphthalmia (small eye) and corneal opacity than those from dams fed an LC-PUFA-poor diet. The effects of LC-PUFAs on eye anomalies were evident only in the female pups of C57BL/6 inbred mice, not in those of C3H/He mice or male C57BL/6 mice. These results demonstrate a gene-by-environment (GxE) interaction in eye development in mice. Furthermore, our molecular analysis suggested the potential roles of Pitx3 and Pax6 in the above interaction involving ARA.

A potential role of fatty acid binding protein 4 in the pathophysiology of autism spectrum disorder.

Autism spectrum disorder is a neurodevelopmental disorder characterized by difficulties in social communication and interaction, as well as repetitive and characteristic patterns of behaviour. Although the pathogenesis of autism spectrum disorder is unknown, being overweight or obesity during infancy and low weight at birth are known as risks, suggesting a metabolic aspect. In this study, we investigated adipose tissue development as a pathophysiological factor of autism spectrum disorder by examining the serum levels of adipokines and other metabolic markers in autism spectrum disorder children (n = 123) and typically developing children (n = 92) at 4-12 years of age. Among multiple measures exhibiting age-dependent trajectories, the leptin levels displayed different trajectory patterns between autism spectrum disorder and typically developing children, supporting an adipose tissue-dependent mechanism of autism spectrum disorder. Of particular interest, the levels of fatty acid binding protein 4 (FABP4) were significantly lower in autism spectrum disorder children than in typically developing subjects, at preschool age (4-6 years old: n = 21 for autism spectrum disorder and n = 26 for typically developing). The receiver operating characteristic curve analysis discriminated autism spectrum disorder children from typically developing children with a sensitivity of 94.4% and a specificity of 75.0%. We re-sequenced the exons of the FABP4 gene in a Japanese cohort comprising 659 autism spectrum disorder and 1000 control samples, and identified two rare functional variants in the autism spectrum disorder group. The Trp98Stop, one of the two variants, was transmitted to the proband from his mother with a history of depression. The disruption of the Fabp4 gene in mice evoked autism spectrum disorder-like behavioural phenotypes and increased spine density on apical dendrites of pyramidal neurons, which has been observed in the postmortem brains of autism spectrum disorder subjects. The Fabp4 knockout mice had an altered fatty acid composition in the cortex. Collectively, these results suggest that an 'adipo-brain axis' may underlie the pathophysiology of autism spectrum disorder, with FABP4 as a potential molecule for use as a biomarker.

VLDL-specific increases of fatty acids in autism spectrum disorder correlate with social interaction.

BACKGROUND: Abnormalities of lipid metabolism contributing to the autism spectrum disorder (ASD) pathogenesis have been suggested, but the mechanisms are not fully understood. We aimed to characterize the lipid metabolism in ASD and to explore a biomarker for clinical evaluation. METHODS: An age-matched case-control study was designed. Lipidomics was conducted using the plasma samples from 30 children with ASD compared to 30 typical developmental control (TD) children. Large-scale lipoprotein analyses were also conducted using the serum samples from 152 children with ASD compared to 122 TD children. Data comparing ASD to TD subjects were evaluated using univariate (Mann-Whitney test) and multivariate analyses (conditional logistic regression analysis) for main analyses using cofounders (diagnosis, sex, age, height, weight, and BMI), Spearman rank correlation coefficient, and discriminant analyses. FINDINGS: Forty-eight significant metabolites involved in lipid biosynthesis and metabolism, oxidative stress, and synaptic function were identified in the plasma of ASD children by lipidomics. Among these, increased fatty acids (FAs), such as omega-3 (n-3) and omega-6 (n-6), showed correlations with clinical social interaction score and ASD diagnosis. Specific reductions of very-low-density lipoprotein (VLDL) and apoprotein B (APOB) in serum of ASD children also were found by large-scale lipoprotein analysis. VLDL-specific reduction in ASD was correlated with APOB, indicating VLDL-specific dyslipidaemia associated with APOB in ASD children. INTERPRETATION: Our results demonstrated that the increases in FAs correlated positively with social interaction are due to VLDL-specific degradation, providing novel insights into the lipid metabolism underlying ASD pathophysiology. FUNDING: This study was supported mainly by MEXT, Japan.

Enhanced carbonyl stress induces irreversible multimerization of CRMP2 in schizophrenia pathogenesis.

Enhanced carbonyl stress underlies a subset of schizophrenia, but its causal effects remain elusive. Here, we elucidated the molecular mechanism underlying the effects of carbonyl stress in iPS cells in which the gene encoding zinc metalloenzyme glyoxalase I (GLO1), a crucial enzyme for the clearance of carbonyl stress, was disrupted. The iPS cells exhibited significant cellular and developmental deficits, and hyper-carbonylation of collapsing response mediator protein 2 (CRMP2). Structural and biochemical analyses revealed an array of multiple carbonylation sites in the functional motifs of CRMP2, particularly D-hook (for dimerization) and T-site (for tetramerization), which are critical for the activity of the CRMP2 tetramer. Interestingly, carbonylated CRMP2 was stacked in the multimer conformation by irreversible cross-linking, resulting in loss of its unique function to bundle microtubules. Thus, the present study revealed that the enhanced carbonyl stress stemmed from the genetic aberrations results in neurodevelopmental deficits through the formation of irreversible dysfunctional multimer of carbonylated CRMP2.