Cancer is believed to arise primarily through accumulation of genetic mutations. Although induced pluripotent stem cell (iPSC) generation does not require changes in genomic sequence, iPSCs acquire unlimited growth potential, a characteristic shared with cancer cells. Here, we describe a murine system in which reprogramming factor expression in vivo can be controlled temporally with doxycycline (Dox). Notably, transient expression of reprogramming factors in vivo results in tumor development in various tissues consisting of undifferentiated dysplastic cells exhibiting global changes in DNA methylation patterns. The Dox-withdrawn tumors arising in the kidney share a number of characteristics with Wilms tumor, a common pediatric kidney cancer. We also demonstrate that iPSCs derived from Dox-withdrawn kidney tumor cells give rise to nonneoplastic kidney cells in mice, proving that they have not undergone irreversible genetic transformation. These findings suggest that epigenetic regulation associated with iPSC derivation may drive development of particular types of cancer.

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.

Recent schizophrenia (SCZ) studies have reported an increased burden of de novo copy number variants (CNVs) and identified specific high-risk CNVs, although with variable phenotype expressivity. However, the pathogenesis of SCZ has not been fully elucidated. Using array comparative genomic hybridization, we performed a high-resolution genome-wide CNV analysis on a mainly (92%) Japanese population (1699 SCZ cases and 824 controls) and identified 7066 rare CNVs, 70.0% of which were small (<100 kb). Clinically significant CNVs were significantly more frequent in cases than in controls (odds ratio=3.04, P=9.3 × 10, 9.0% of cases). We confirmed a significant association of X-chromosome aneuploidies with SCZ and identified 11 de novo CNVs (e.g., MBD5 deletion) in cases. In patients with clinically significant CNVs, 41.7% had a history of congenital/developmental phenotypes, and the rate of treatment resistance was significantly higher (odds ratio=2.79, P=0.0036). We found more severe clinical manifestations in patients with two clinically significant CNVs. Gene set analysis replicated previous findings (e.g., synapse, calcium signaling) and identified novel biological pathways including oxidative stress response, genomic integrity, kinase and small GTPase signaling. Furthermore, involvement of multiple SCZ candidate genes and biological pathways in the pathogenesis of SCZ was suggested in established SCZ-associated CNV loci. Our study shows the high genetic heterogeneity of SCZ and its clinical features and raises the possibility that genomic instability is involved in its pathogenesis, which may be related to the increased burden of de novo CNVs and variable expressivity of CNVs.

Although small-scale studies have described the effects of oxytocin on social deficits in autism spectrum disorder (ASD), no large-scale study has been conducted. In this randomized, parallel-group, multicenter, placebo-controlled, double-blind trial in Japan, 106 ASD individuals (18-48 y.o.) were enrolled between Jan 2015 and March 2016. Participants were randomly assigned to a 6-week intranasal oxytocin (48IU/day, n = 53) or placebo (n = 53) group. One-hundred-three participants were analyzed. Since oxytocin reduced the primary endpoint, Autism Diagnostic Observation Schedule (ADOS) reciprocity, (from 8.5 to 7.7; P < .001) but placebo also reduced the score (8.3 to 7.2; P < .001), no between-group difference was found (effect size -0.08; 95% CI, -0.46 to 0.31; P = .69); however, plasma oxytocin was only elevated from baseline to endpoint in the oxytocin-group compared with the placebo-group (effect size -1.12; -1.53 to -0.70; P < .0001). Among the secondary endpoints, oxytocin reduced ADOS repetitive behavior (2.0 to 1.5; P < .0001) compared with placebo (2.0 to 1.8; P = .43) (effect size 0.44; 0.05 to 0.83; P = .026). In addition, the duration of gaze fixation on socially relevant regions, another secondary endpoint, was increased by oxytocin (41.2 to 52.3; P = .03) compared with placebo (45.7 to 40.4; P = .25) (effect size 0.55; 0.10 to 1.0; P = .018). No significant effects were observed for the other secondary endpoints. No significant difference in the prevalence of adverse events was observed between groups, although one participant experienced temporary gynecomastia during oxytocin administration. Based on the present findings, we cannot recommend continuous intranasal oxytocin treatment alone at the current dose and duration for treatment of the core social symptoms of high-functioning ASD in adult men, although this large-scale trial suggests oxytocin's possibility to treat ASD repetitive behavior.

Bipolar disorder (BP) and schizophrenia (SCZ) are major psychiatric disorders, but the molecular mechanisms underlying the complicated pathologies of these disorders remain unclear. It is difficult to establish adequate in vitro models for pathological analysis because of the heterogeneity of these disorders. In the present study, to recapitulate the pathologies of these disorders in vitro, we established in vitro models by differentiating mature neurons from human induced pluripotent stem cells (hiPSCs) derived from BP and SCZ patient with contributive copy number variations, as follows: two BP patients with PCDH15 deletion and one SCZ patient with RELN deletion. Glutamatergic neurons and GABAergic neurons were induced from hiPSCs under optimized conditions. Both types of induced neurons from both hiPSCs exhibited similar phenotypes of MAP2 (microtubule-associated protein 2)-positive dendrite shortening and decreasing synapse numbers. Additionally, we analyzed isogenic PCDH15-or RELN-deleted cells. The dendrite and synapse phenotypes of isogenic neurons were partially similar to those of patient-derived neurons. These results suggest that the observed phenotypes are general phenotypes of psychiatric disorders, and our in vitro models using hiPSC-based technology may be suitable for analysis of the pathologies of psychiatric disorders.

Indoleamine 2,3-dioxygenase 1 (IDO1), the L-tryptophan-degrading enzyme, plays a key role in the immunomodulatory effects on several types of immune cells. Originally known for its regulatory function during pregnancy and chronic inflammation in tumorigenesis, the activity of IDO1 seems to modify the inflammatory state of infectious diseases. The pathophysiologic activity of L-tryptophan metabolites, kynurenines, is well recognized. Therefore, an understanding of the regulation of IDO1 and the subsequent biochemical reactions is essential for the design of therapeutic strategies in certain immune diseases. In this paper, current knowledge about the role of IDO1 and its metabolites during various infectious diseases is presented. Particularly, the regulation of type I interferons (IFNs) production via IDO1 in virus infection is discussed. This paper offers insights into new therapeutic strategies in the modulation of viral infection and several immune-related disorders.

PSD-95 associated PSD proteins play a critical role in regulating the density and activity of glutamate receptors. Numerous previous studies have shown an association between the genes that encode these proteins and schizophrenia (SZ) and autism spectrum disorders (ASD), which share a substantial portion of genetic risks. We sequenced the protein-encoding regions of DLG1, DLG2, DLG4, DLGAP1, DLGAP2, and SynGAP in 562 cases (370 SZ and 192 ASD patients) on the Ion PGM platform. We detected 26 rare (minor allele frequency <1%), non-synonymous mutations, and conducted silico functional analysis and pedigree analysis when possible. Three variants, G344R in DLG1, G241S in DLG4, and R604C in DLGAP2, were selected for association analysis in an independent sample set of 1315 SZ patients, 382 ASD patients, and 1793 healthy controls. Neither DLG4-G241S nor DLGAP2-R604C was detected in any samples in case or control sets, whereas one additional SZ patient was found that carried DLG1-G344R. Our results suggest that rare missense mutations in the candidate PSD genes may increase susceptibility to SZ and/or ASD. These findings may strengthen the theory that rare, non-synonymous variants confer substantial genetic risks for these disorders.

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.