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.

Microglia-derived neuregulin expression in psychiatric disorders.

Several studies have revealed that neuregulins (NRGs) are involved in brain function and psychiatric disorders. While NRGs have been regarded as neuron- or astrocyte-derived molecules, our research has revealed that microglia also express NRGs, levels of which are markedly increased in activated microglia. Previous studies have indicated that microglia are activated in the brains of individuals with autism spectrum disorder (ASD). Therefore, we investigated microglial NRG mRNA expression in multiple lines of mice considered models of ASD. Intriguingly, microglial NRG expression significantly increased in BTBR and socially-isolated mice, while maternal immune activation (MIA) mice exhibited identical NRG expression to controls. Furthermore, we observed a positive correlation between NRG expression in microglia and peripheral blood mononuclear cells (PBMCs) in mice, suggesting that NRG expression in human PBMCs may mirror microglia-derived NRG expression in the human brain. To translate these findings for application in clinical psychiatry, we measured levels of NRG1 splice-variant expression in clinically available PBMCs of patients with ASD. Levels of NRG1 type III expression in PBMCs were positively correlated with impairments in social interaction in children with ASD (as assessed using the Autistic Diagnostic Interview-Revised test: ADI-R). These findings suggest that immune cell-derived NRGs may be implicated in the pathobiology of psychiatric disorders such as ASD.

Characteristics of communication among Japanese children with autism spectrum disorder: A cluster analysis using the Children's Communication Checklist-2.

Some overlap has been suggested among the subtypes of autism spectrum disorder (ASD) in children. The Japanese version of the Children's Communication Checklist-2 (CCC-2) is a useful measure for identifying profiles in relation to communication impairments in children with ASD. The aim of this study was to investigate whether the CCC-2 could identify subtypes in relation to communication impairments in Japanese children with ASD. The study participants were 113 children with ASD but without intellectual disabilities aged 3-12 years. Parents were given the Japanese version of the CCC-2 and asked to rate their children, who were then classified into two groups based on statistical analysis. Significant differences were found between clusters in mean CCC-2 subscales. These results suggest that one subtype was associated with low language competence and strong characteristics of autism, while the other was associated with relatively high language competence and milder characteristics of autism.

Zinc finger protein 804A (ZNF804A) and verbal deficits in individuals with autism.

BACKGROUND: In a genome-wide association study of autism, zinc finger protein 804A (ZNF804A) single nucleotide polymorphisms (SNPs) were found to be nominally associated in verbally deficient individuals with autism. Zinc finger protein 804A copy number variations (CNVs) have also been observed in individuals with autism. In addition, ZNF804A is known to be involved in theory of mind (ToM) tasks, and ToM deficits are deemed responsible for the communication and social challenges faced by individuals with autism. We hypothesized that ZNF804A could be a risk gene for autism. METHODS: We examined the genetic association and CNVs of ZNF804A in 841 families in which 1 or more members had autism. We compared the expression of ZNF804A in the postmortem brains of individuals with autism (n = 8) and controls (n = 13). We also assessed in vitro the effect of ZNF804A silencing on the expression of several genes known to be involved in verbal efficiency and social cognition. RESULTS: We found that rs7603001 was nominally associated with autism (p = 0.018). The association was stronger (p = 0.008) in the families of individuals with autism who were verbally deficient (n = 761 families). We observed ZNF804A CNVs in 7 verbally deficient boys with autism. In ZNF804A knockdown cells, the expression of synaptosomal-associated protein, 25kDa (SNAP25) was reduced compared with controls (p = 0.009). The expression of ZNF804A (p = 0.009) and SNAP25 (p = 0.009) were reduced in the anterior cingulate gyrus (ACG) of individuals with autism. There was a strong positive correlation between the expression of ZNF804A and SNAP25 in the ACG (p < 0.001). LIMITATIONS: Study limitations include our small sample size of postmortem brains. CONCLUSION: Our results suggest that ZNF804A could be a potential candidate gene mediating the intermediate phenotypes associated with verbal traits in individuals with autism.

[Psychometric properties of the Japanese version of the Autism Spectrum Screening Questionnaire (ASSQ): development of a short form].

We examined the psychometric properties of the Japanese version of the Autism Spectrum Screening Questionnaire (ASSQ) and developed a short-form. This study included 157 children with autism spectrum disorders (ASD, ages 7-18, 128 boys) and 4,101 healthy controls (ages 7-15, 3,344 boys) from a general population with a controlled male-female ratio. Four factors (Unusual Interests, Sociality, Peer Relations, and Repetitive Behaviors) were extracted by exploratory factor analysis of control group data. Confirmatory factor analysis revealed that the 4-factor model fit well with data for another sample of the control and ASD groups. Logistic analysis showed that the former 3 factors could significantly predict ASD diagnosis. Thus, a short form of the ASSQ was developed, consisting of 11 items for these 3 factors. This short form showed sufficient internal consistency and high discrimination power for ASD diagnosis that was comparable to that of the 22-item version. Receiver operating characteristic analysis indicated an optimal cut-off of 7 for the 22-item version (sensitivity .949, specificity .801) and 5 for the short-form (sensitivity .936, specificity .818).

Longitudinal associations between response-style strategies and abnormal eating behaviors/attitudes in adolescents: a cross-lagged panel model.

BACKGROUND: Previous studies have suggested that response-style strategies (rumination, problem-solving, and distraction) can be risk or protective factors for the development of abnormal eating behaviors/attitudes (AEB) during adolescence. However, due to limited empirical data regarding the prospective effects of these strategies on AEB, further research is needed to clarify their role in developing AEB in adolescence. METHODS: This study investigated the one-year lagged effects of response-style strategies on AEB in 24,883 fourth- to eighth-grade students in Japan between 2015 and 2019 using a cross-lagged panel model. Depressive symptoms and body mass index (BMI), which are reported to relate to AEB, were also included in the analytic model. The students self-reported their levels of response-style strategies, AEB, and depressive symptoms. We also evaluated BMI based on teachers' reports. RESULTS: We found that greater rumination significantly predicted more severe AEB in the following year among students from all grades, with small to moderate effect sizes. In addition, distraction significantly predicted more severe binge eating/purging behaviors, but with very weak small effect sizes. Problem-solving did not predict any level of AEB. Furthermore, we observed significant reciprocal relationships between response-style strategies, AEB, and depressive symptoms. Positive reciprocal associations between BMI and AEB were also found except for some intervals. CONCLUSIONS: We concluded that a decrease in rumination is critical to alleviating mental health problems, such as AEB and depressive symptoms, during adolescence. This suggests that interventions to reduce the level of rumination should be conducted in the early stages of adolescence. TRIAL REGISTRATION NUMBER: Not Applicable.

This study examines the effects of three response styles when faced with distress­rumination, problem-solving, and distraction­on unhealthy eating behaviors. In this study, we looked at how these coping strategies are linked to unhealthy eating behaviors in 24,883 students in grades four to eight in Japan between 2015 and 2019. We checked again at year-long intervals to see if the coping strategies had any effect on the students' unhealthy eating behaviors. In addition, we considered depressive symptoms and body mass index in our analysis because these variables might also be related to unhealthy eating behaviors. We found that more rumination (i.e., a repetitive negative thinking pattern) predicted the severity of unhealthy eating behaviors and depressive symptoms in the following year across all the grades. In addition, greater depressive symptoms also contributed to an increase in unhealthy eating behaviors in the following year. Therefore, we suggest that rumination is a key factor that influences mental health during adolescence.

Protocadherin α (PCDHA) as a novel susceptibility gene for autism.

BACKGROUND: Synaptic dysfunction has been shown to be involved in the pathogenesis of autism. We hypothesized that the protocadherin α gene cluster (PCDHA), which is involved in synaptic specificity and in serotonergic innervation of the brain, could be a suitable candidate gene for autism. METHODS: We examined 14 PCDHA single nucleotide polymorphisms (SNPs) for genetic association with autism in DNA samples of 3211 individuals (841 families, including 574 multiplex families) obtained from the Autism Genetic Resource Exchange. RESULTS: Five SNPs (rs251379, rs1119032, rs17119271, rs155806 and rs17119346) showed significant associations with autism. The strongest association (p < 0.001) was observed for rs1119032 (z score of risk allele G = 3.415) in multiplex families; SNP associations withstand multiple testing correction in multiplex families (p = 0.041). Haplotypes involving rs1119032 showed very strong associations with autism, withstanding multiple testing corrections. In quantitative transmission disequilibrium testing of multiplex fam - ilies, the G allele of rs1119032 showed a significant association (p = 0.033) with scores on the Autism Diagnostic Interview-Revised (ADI-R)_D (early developmental abnormalities). We also found a significant difference in the distribution of ADI-R_A (social interaction) scores between the A/A, A/G and G/G genotypes of rs17119346 (p = 0.002). LIMITATIONS: Our results should be replicated in an independent population and/or in samples of different racial backgrounds. CONCLUSION: Our study provides strong genetic evidence of PCDHA as a potential candidate gene for autism.

[Relationship among inattentive and hyperactive-impulsive behavior, aggression, and depression in Japanese elementary and junior high school students].

The present study examines the relationship among inattentive, and hyperactive-impulsive behavior, aggression, and depression in elementary school and junior high school students. The participants were 3,885 children and their teachers and caregivers. Children's inattentive and hyperactive-impulsive behavior was rated by their teachers and caregivers (ADHD-RS). Children rated aggression (HAQ-C) and depression (DSRS-C) themselves. Inattentive and hyperactive-impulsive behavior rated by teachers and caregivers were positively related to aggression and depression. Inattention predicted higher levels of aggression and depression. Inattentive and hyperactive-impulsive behavior as rated by teachers was more highly related to depression than those behaviors as rated by caregivers. The relationships among inattentive, and hyperactive-impulsive behavior, aggression, and depression were almost the same for both elementary school and junior high school students. This study suggests the importance of assessing inattentive and hyperactive-impulsive behavior from multiple views to examine the relationship between inattentive and hyperactive-impulsive behavior and mental health problems.

[Development of a Japanese version of Child Social Preference Scale].

This study developed a Japanese version of the Child Social Preference Scale, which measures children's social withdrawal. In addition, we examined developmental changes of children's withdrawal and the relationships between withdrawal and problematic behaviors. The participants were 7 012 mothers of preschool, elementary school, and middle school children. A factor analysis revealed a two-factor solution of shyness and social disinterest, which is consistent with previous studies. Shyness decreased as children's grade level increased. Social disinterest changed in a quadratic manner. The shyness score was lowest in the lower grades of elementary school. Shyness was related to more emotional symptoms, more peer relationship problems, and less prosocial behavior. Social disinterest was related to peer relationship problems. The importance of the distinction between shyness and social disinterest is discussed.

Examining simultaneous associations of four emotion regulation strategies with abnormal eating behaviors/attitudes in early adolescents.

Previous research has suggested that emotion regulation strategies (ERSs) are associated with abnormal eating behaviors and attitudes (AEBs). Available data have demonstrated that frequent rumination, a major maladaptive ERS, is associated with elevated AEBs, whereas adaptive ERSs, such as problem-solving and cognitive reappraisal, showed negative associations with AEBs. Most previous studies examined the association of a single ERS with AEBs. Therefore, any significant associations between an individual ERS and AEB reported in previous research might stem from spurious correlations. The current cross-sectional study sought to examine simultaneous associations of four ERSs (rumination, problem-solving, distraction, and cognitive reappraisal) with two categories of ED symptoms (i.e., drive for thinness and bulimic symptoms) in early adolescents in Japan (ages 10-15, N = 5301). Participants self-reported their use of the different ERSs and the ED symptoms. We found certain ERSs were uniquely associated with levels of drive for thinness and bulimic symptoms even after controlling for body mass index, depression, and socioeconomic status. Particularly, frequent rumination in both boys and girls was associated with a severe drive for thinness and bulimic symptoms. Regarding adaptive strategies, frequent uses of problem-solving was associated with decreased bulimic symptoms only in girls, with the effect size being small. In addition, contrary to our expectation, greater use of distraction was associated with elevated AEBs, except the association with drive for thinness in boys. Although this study extended findings of previous research, prospective studies are required to clarify the causal relationship between ERSs and eating pathology.

Fine and gross motor skills predict later psychosocial maladaptation and academic achievement.

BACKGROUND: Difficulties in fine and gross motor skills are often overlooked as developmental problems, although approximately 6-13% of all school-age children have poor motor coordination. Understanding motor coordination is important from the perspective of school adaptation. This longitudinal cohort study aimed to determine whether fine and gross motor skills in preschool children predict later academic achievement and psychosocial maladaptation. METHODS & PROCEDURES: Participants were 2,501 children from nursery and elementary schools (5-13 years old). The motor skills of preschool children were assessed by their nursery teacher immediately before entering elementary school. The Strengths and Difficulties Questionnaire and a standardized Japanese test were administered annually throughout elementary school. RESULTS: Early motor difficulties in preschool children had significant effects on their academic achievement and psychosocial maladaptation up until the sixth grade. Gross motor difficulties in preschool were associated with the later peer problems and worsened emotional symptoms. CONCLUSIONS: Motor skills in preschool children are useful as a predictor of later psychosocial maladaptation and academic achievement.

Polymorphism screening of brain-expressed FABP7, 5 and 3 genes and association studies in autism and schizophrenia in Japanese subjects.

Fatty acid-binding protein (FABP) gene family encode fatty acid-binding proteins and consist of at least 12 members, of which FABP7, 5 and 3 are expressed in the brain. We previously showed that FABP7 is associated with schizophrenia and bipolar disorder. Recently, genetic overlap between autism and schizophrenia has been reported. Therefore, in this study, we set out to examine the possible roles of brain-expressed FABPs in autism, focusing primarily on potentially functional polymorphisms (that is, missense polymorphisms). First, we resequenced the three genes using 285 autism samples. We identified 13 polymorphisms, of which 7 are novel. Of the novel single-nucleotide polymorphisms (SNPs), two are missense mutations, namely, 376G>C (Val126Leu) in FABP7 and 340G>C (Gly114Arg) in FABP5. Second, we tested for the genetic association of four missense SNPs with autism and schizophrenia, but failed to detect significant results. Finally, as a web-based algorithm predicts that the 8A>G (Asp3Gly; rs17848124) in FABP3 is 'probably damaging', we estimated the possible impact of this SNP, and found that the loss of charge and salt bridge, caused by the Asp3-to-Gly3, may affect stability of the FABP3 protein. Future searches for associated phenotypes with missense SNPs using larger samples are highly warranted.

Metabolite alterations in the hippocampus of high-functioning adult subjects with autism.

The aim of the present study was to investigate metabolite alterations in the hippocampal formation as they relate to aggression in high-functioning adults with autism. We measured concentrations of N-acetylaspartate (NAA), choline-containing compounds (Cho), and creatine plus phosphocreatine (Cr+PCr) in the hippocampal formation by proton magnetic resonance spectroscopy in 12 non-medicated male subjects with autism and 12 age- and sex-matched controls. Aggression was scored in the autistic subjects using the Buss-Perry Aggression Questionnaire. The concentrations of Cho and Cr+PCr in the hippocampal formation in autistic subjects were significantly higher than the corresponding values in control subjects, and a significant positive correlation was observed between the concentrations of these metabolites in the hippocampal formation and scores on the Buss-Perry Aggression Questionnaire in autistic subjects. Results suggest that high-functioning adult subjects with autism have abnormal metabolite concentrations in the hippocampal formation, which may in part account for their aggression.

Sensory Processing Patterns and Fusiform Activity During Face Processing in Autism Spectrum Disorder.

A growing body of evidence has indicated that individuals with autism spectrum disorder (ASD) exhibit abnormal reactions to sensory stimuli and impaired face processing. Although behavioral studies have reported that individual differences in sensory processing patterns are correlated with performance in face processing tasks, the neural substrates underlying the association between sensory processing patterns and face processing remain unknown. Using functional magnetic resonance imaging, the present study examined the relationships between sensory processing patterns assessed with the Adolescent/Adult Sensory Profile (AASP) and brain activity during a one-back task with two types of stimuli (face or house pictures). We enrolled 18 Japanese adults with ASD and 19 age- and IQ-matched controls. Sensation Avoiding scores, which were assessed using the AASP, were positively correlated with right fusiform activity during the presentation of pictures of faces in the ASD group, but not in the control group. This suggests that abnormal sensory processing patterns in ASD are associated with abnormal face-related brain activity, possibly resulting in impaired face processing. Autism Res 2020, 13: 741-750. © 2020 International Society for Autism Research, Wiley Periodicals, Inc. LAY SUMMARY: Sensory abnormalities are one of the most common symptoms in people with autism spectrum disorder (ASD). This study shows that individuals with ASD who react abnormally to sensory stimuli also exhibit atypical brain activity when recognizing faces. Abnormal sensory processing may partly explain the difficulty that people diagnosed with ASD have in identifying others' faces.

Simultaneous evaluation of antioxidative serum profiles facilitates the diagnostic screening of autism spectrum disorder in under-6-year-old children.

This case-control study aimed to assess oxidative stress alterations in autism spectrum disorder (ASD). We used the MULTIS method, an electron spin resonance-based technique measuring multiple free radical scavenging activities simultaneously, in combination with conventional oxidative stress markers to investigate the ability of this MULTIS approach as a non-behavioural diagnostic tool for children with ASD. Serum samples of 39 children with ASD and 58 age-matched children with typical development were analysed. The ASD group showed decreased hydroxyl radical (·OH) and singlet oxygen scavenging activity with increased serum coenzyme Q10 oxidation rate, indicating a prooxidative tendency in ASD. By contrast, scavenging activities against superoxide (O2·-) and alkoxyl radical (RO·) were increased in the ASD group suggesting antioxidative shifts. In the subgroup analysis of 6-year-olds or younger, the combination of ·OH, O2·-, and RO· scavenging activities predicted ASD with high odds ratio (50.4), positive likelihood (12.6), and percentage of correct classification (87.0%). Our results indicate that oxidative stress in children with ASD is not simply elevated but rather shows a compensatory shift. MULTIS measurements may serve as a very powerful non-behavioural tool for the diagnosis of ASD in children.

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.

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.

Sensory processing in children with autism spectrum disorder and the mental health of primary caregivers.

BACKGROUND: Sensory processing difficulties, which commonly occur in autism spectrum disorder (ASD), are expected to have negative effects on the primary caregiver's mental health. The aim of this study was to examine the association between sensory processing difficulties in children with ASD and the mental health of primary caregivers. METHODS: A total of 707 primary caregivers (mothers in the present study) and their children with ASD (4-18 years of age) participated in this study. Sensory processing difficulties were indexed using the Short Sensory Profile (SSP). The mental health of primary caregivers was indexed using the General Health Questionnaire (GHQ12). RESULTS: Higher scores on Auditory Filtering as measured with the SSP were associated with poorer mental health of primary caregivers, even after an adjustment for ASD symptom severity. Analyses of two age sub-groups, a young (4-10 years) and an old age group (11-18 years), revealed that higher scores on Tactile Sensitivity and Auditory Filtering were associated with poorer mental health of primary caregivers in younger children, whereas only higher scores on Auditory Filtering were associated with poorer mental health of primary caregivers in older children. CONCLUSIONS: Our findings suggest that practitioners who support primary caregivers of children with ASD need to focus not only on the social and communication-related symptoms of the child but also on their specific sensory processing difficulties.

Anti-inflammatory Effect of Ghrelin in Lymphoblastoid Cell Lines From Children With Autism Spectrum Disorder.

The gut hormone ghrelin has been implicated in a variety of functional roles in the central nervous system through the brain-gut axis, one of which is an anti-inflammatory effect. An aberrant brain-gut axis producing immune dysfunction has been implicated in the pathobiology of autism spectrum disorder (ASD), and elevated expression of inflammatory markers has been shown in blood and brain tissue from subjects with ASD. We hypothesized that ghrelin may mitigate this effect. Lymphoblastoid cell lines from typically developed children (TD-C) (N = 20) and children with ASD (ASD-C) (N = 20) were cultured with PBS or human ghrelin (0.01 µM) for 24 h, and mRNA expression levels of the inflammation-related molecules interleukin-1ß (IL-1ß), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and nuclear factor kappa B (NF-κB) were measured to examine the effects of ghrelin as an anti-inflammatory agent. Expression levels of TNF-α and NF-κB mRNA, but not IL-1ß or IL-6, were significantly elevated in ASD-C compared to TD-C. Ghrelin showed a tendency to reduce the expression of TNF-α and NF-κB, but this was not statistically significant. Considering the heterogenous pathobiology of ASD, we examined the effects of ghrelin on TD-C and ASD-C with expression levels of TNF-α and NF-κB in the highest and lowest quartiles. We found that ghrelin markedly reduced mRNA expression of TNF-α and NF-κB s in ASD-C with highest-quartile expression, but there were no effects in ASD-C with lowest-quartile expression, TD-C with highest quartile expression, or TD-C with lowest quartile expression. Together, these findings suggest that ghrelin has potential as a novel therapeutic agent for ASD with inflammation and/or immune dysfunction.

Paternal age at birth and high-functioning autistic-spectrum disorder in offspring.

BACKGROUND: Previous studies have reported the association between advanced paternal age at birth and the risk of autistic-spectrum disorder in offspring, including offspring with intellectual disability. AIMS: To test whether an association between advanced paternal age at birth is found in offspring with high-functioning autistic-spectrum disorder (i.e. offspring without intellectual disability). METHOD: A case-control study was conducted in Japan. The participants consisted of individuals with full-scale IQ>or=70, with a DSM-IV autistic disorder or related diagnosis. Unrelated healthy volunteers were recruited as controls. Parental ages were divided into tertiles (i.e. three age classes). Odds ratios and 95% confidence intervals were estimated using logistic regression analyses, with an adjustment for age, gender and birth order. RESULTS: Eighty-four individuals with autistic-spectrum disorder but without intellectual disability and 208 healthy controls were enrolled. Increased paternal, but not maternal, age was associated with an elevated risk of high-functioning autistic-spectrum disorder. A one-level advance in paternal age class corresponded to a 1.8-fold increase in risk, after adjustment for covariates. CONCLUSIONS: Advanced paternal age is associated with an increased risk for high-functioning autistic-spectrum disorder.