The interaction of NOS1AP, DISC1, DAOA, and GSK3B confers susceptibility of early-onset schizophrenia in Chinese Han population

Schizophrenia in the genetic era: a review from development history, clinical features and genomic research approaches to insights of susceptibility genes

Schizophrenia is a devastating neuropsychiatric disorder affecting 1% of the world population and ranks as one of the disorders providing the most severe burden for society. Schizophrenia etiology remains obscure involving multi-risk factors, such as genetic, environmental, nutritional, and developmental factors. Complex interactions of genetic and environmental factors have been implicated in the etiology of schizophrenia. This review provides an overview of the historical origins, pathophysiological mechanisms, diagnosis, clinical symptoms and corresponding treatment of schizophrenia. In addition, as schizophrenia is a polygenic, genetic disorder caused by the combined action of multiple micro-effective genes, we further detail several approaches, such as candidate gene association study (CGAS) and genome-wide association study (GWAS), which are commonly used in schizophrenia genomics studies. A number of GWASs about schizophrenia have been performed with the hope to identify novel, consistent and influential risk genetic factors. Finally, some schizophrenia susceptibility genes have been identified and reported in recent years and their biological functions are also listed. This review may serve as a summary of past research on schizophrenia genomics and susceptibility genes (NRG1, DISC1, RELN, BDNF, MSI2), which may point the way to future schizophrenia genetics research. In addition, depending on the above discovery of susceptibility genes and their exact function, the development and application of antipsychotic drugs will be promoted in the future.

Effects of Glycogen Synthase Kinase-3 Beta Gene Polymorphisms on the Plasma Concentration of Aripiprazole in Chinese Patients with Schizophrenia: A Preliminary Study

This study explored the differences in glycogen synthase kinase-3 beta (GSK3β) gene polymorphisms between patients with schizophrenia and healthy controls and investigated the association between gene polymorphisms and plasma concentration of aripiprazole. We enrolled 127 patients with schizophrenia and 125 healthy controls from southern Fujian. The genotypes of the rs6438552, rs12630592, and rs3732361 loci of GSK3β were evaluated by sequencing with amplified polymerase chain reaction, and the plasma concentration of aripiprazole was determined by high-performance liquid chromatography-tandem mass spectrometry. All three loci of GSK3β had three genotypes each. The genotype distribution in each locus was not significantly different, but there was a significant difference in the allele frequency between the schizophrenia and control groups within each locus. Linkage disequilibrium analyses of the three single-nucleotide polymorphisms (SNPs) revealed strong linkage. The haplotype analysis results showed two haplotypes in the three SNPs of GSK3β. The plasma concentrations, dose-corrected concentrations, and normalized concentrations of aripiprazole were significantly different among the different genotypes of the three SNPs. In conclusion, the rs6438552, rs12630592, and rs3732361 loci of GSK3β may be involved in schizophrenia, and GSK3β gene polymorphism may be correlated with the plasma concentration of aripiprazole.

DISC1 inhibits GSK3β activity to prevent tau hyperphosphorylation under diabetic encephalopathy

Diabetic encephalopathy (DE) is a common complication of type 2 diabetes (T2D), especially in those patients with long T2D history. Persistent high glucose (HG) stimulation leads to neuron damage and manifests like Alzheimer's disease's pathological features such as neurofilament tangle. However, the precise mechanism of high-glucose-induced tau hyperphosphorylation is not fully revealed. We here gave evidence that Disrupted in schizophrenia 1 protein (DISC1) could interact with glycogen synthase kinase 3β (GSK3β) and inhibit its activity to prevent tau hyperphosphorylation. By using DB/DB mice as animal model and HG-treated N2a cell as cell model, we found that DISC1 was downregulated both in vivo and in vitro, complicated with Tau hyperphosphorylation and GSK3β activation. Further, we identified DISC1 interacted with GSK3β by its 198th-237th amino acid residues. Overexpression of full length DISC1 but not mutated DISC1 lacking this domain could prevent HG induced tau hyperphosphorylation. Taken together, our work revealed DISC1 could be an important negative modulators of tau phosphorylation, and suggested that preservation of DISC1 could prevent HG induced neuron damage.

The influence of NOS1AP gene polymorphisms and childhood abuse on antisocial personality disorder in Chinese male violent inmates

Antisocial personality disorder (ASPD) is a common behavioral pattern that causes sufferers to ignore or violate the rights of others. Though its cause is still unclear, previous studies have shown that childhood maltreatment is closely related to ASPD. The NOS1AP gene is associated with various neuropsychiatric diseases, but a linkage between it and ASPD has not yet been discovered. This study recruited ASPD and non-ASPD male subjects who had committed violent crimes from a prison in Nanjing, China. By comparing the two groups' genotypes, allele frequencies, and histories of childhood abuse, we explored the interaction between the NOS1AP gene and childhood maltreatment on the pathogenesis of ASPD. The results showed that polymorphism rs945713 in the NOS1AP gene was associated with ASPD and furthermore that this SNP may be involved in regulating the effect of childhood abuse on ASPD. This study found that childhood trauma increases the risk of ASPD in violent adult male inmates; for prisoners with ASPD, it is critical to pay attention to their childhood trauma and take early psychological intervention.

Association Study of Polymorphisms in Neuronal Nicotinic Acetylcholine Receptor Subunit Genes With Schizophrenia in the Han Chinese Population

OBJECTIVE

To investigate the relation between nicotinic acetylcholine receptor subunit (nAChR) genes and schizophrenia, and the relation between tag single nucleotide polymorphism (rs1317286, rs1044396, rs6494212, rs16969968, and rs684513) and schizophrenia in Han Chinese people.

METHODS

The protein-protein interaction (PPI) network among nAChR protein and 350 proteins encoded by schizophrenia-related susceptibility genes was constructed through the String database to explore whether nAChR genes were associated with schizophrenia in these known databases. Then, five single nucleotide polymorphisms (SNPs) of CHRNA3 (rs1317286), CHRNA4 (rs1044396), CHRNA7 (rs6494212), and CHRNA5 (rs16969968, rs684513) were analyzed in a sample of 1,035 schizophrenic patients and 816 healthy controls. The interaction between the markers was analyzed using multifactor dimensionality reduction (MDR) software. Power analysis was performed using the Quanto program.

RESULTS

There are no significant differences in genotype or allele distribution were identified between the patients and controls (p>0.05). The haplotypes constructed by four markers rs1317286, rs6494212, rs16969968, and rs684513 were not associated with schizophrenia either. However, a significant association between models made of rs1317286, rs1044396, rs6494212, and rs684513 and schizophrenia was revealed in interaction analysis (p<0.05).

CONCLUSION

The nAChR protein may have effects on the development of schizophrenia through the interaction with proteins encoded by schizophrenia-related susceptibility genes, but no relation was found between selected polymorphisms and schizophrenia in the collected Han Chinese people. However, interaction analysis suggested four-SNP model has an important effect on schizophrenia.

Hippocampal overexpression of NOS1AP promotes endophenotypes related to mental disorders

BACKGROUND

Nitric oxide synthase 1 adaptor protein (NOS1AP; previously named CAPON) is linked to the glutamatergic postsynaptic density through interaction with neuronal nitric oxide synthase (nNOS). NOS1AP and its interaction with nNOS have been associated with several mental disorders. Despite the high levels of NOS1AP expression in the hippocampus and the relevance of this brain region in glutamatergic signalling as well as mental disorders, a potential role of hippocampal NOS1AP in the pathophysiology of these disorders has not been investigated yet.

METHODS

To uncover the function of NOS1AP in hippocampus, we made use of recombinant adeno-associated viruses to overexpress murine full-length NOS1AP or the NOS1AP carboxyterminus in the hippocampus of mice. We investigated these mice for changes in gene expression, neuronal morphology, and relevant behavioural phenotypes.

FINDINGS

We found that hippocampal overexpression of NOS1AP markedly increased the interaction of nNOS with PSD-95, reduced dendritic spine density, and changed dendritic spine morphology at CA1 synapses. At the behavioural level, we observed an impairment in social memory and decreased spatial working memory capacity.

INTERPRETATION

Our data provide a mechanistic explanation for a highly selective and specific contribution of hippocampal NOS1AP and its interaction with the glutamatergic postsynaptic density to cross-disorder pathophysiology. Our findings allude to therapeutic relevance due to the druggability of this molecule.

FUNDING

This study was funded in part by the DFG, the BMBF, the Academy of Finland, the NIH, the Japanese Society of Clinical Neuropsychopharmacology, the Ministry of Education of the Russian Federation, and the European Community.

The interaction of ASAH1 and NGF gene involving in neurotrophin signaling pathway contributes to schizophrenia susceptibility and psychopathology

The neurodevelopmental hypothesis of schizophrenia has been widely accepted. In light of our previous microarray data, two neurodevelopment-related genes were focused on inclduing the N-acylsphingosine amidohydrolase 1 gene (ASAH1) and the nerve growth factor gene (NGF). The evidence that ASAH1 and NGF are associated with schizophrenia is far from conclusive. Furthermore, their interactions in schizophrenia have not been investigated. Total 413 patients and 578 controls were included. Eleven single-nucleotide polymorphisms (SNPs) in ASAH1 and NGF were selected. A multifactor dimensionality reduction (MDR) was applied to investigate gene-gene interactions in schizophrenia, and the traditional odds ratio methods was applied to validate it. The effects of ASAH1, NGF and their interaction on the severity of the disease were analyzed by 3 × 3 covariance analysis of (ANCOVA). The biological interaction between ASAH1 and NGF was examined. KEGG was used to identify the related signaling pathways. After correction by Bonferroni, there were no differences in the genotypic, allelic, or haplotypic frequencies of 11 SNPs between patients and controls. However, the interaction of certain SNPs had effect on susceptibility to schizophrenia, including two high-risk and one low-risk genotypic combinations (OR = 1.49 [1.11-2.00]; OR = 1.45 [1.09-1.92], and OR = 0.64 [0.41-0.98]). ASAH1-rs7830490 and its interaction with NGF-rs4332358 were associated with the general psychopathological subscale score (F _adjusted = 3.94, p _adjusted = 0.01; F _adjusted = 2.36, p _adjusted = 0.03). We also found that ASAH1 and NGF interacted with CaMK2B involving in the neurotrophin signaling pathway. Our results suggest that the interaction of ASAH1 and NGF with CaMK2B involved in neurotrophin signaling pathway may contribute to schizophrenia susceptibility and psychopathology.

Effects of interaction of NOS1AP gene polymorphisms and childhood abuse on paranoid personality disorder features among male violent offenders in China

BACKGROUND

Paranoid Personality Disorder (PPD) results from a complex synergy between genetic and environmental factors. Childhood abuse is one of risk factors. Nitric Oxide Synthase 1 Adaptor Protein (NOS1AP) is a candidate gene of schizophrenia, which has similar pathophysiology to PPD. This study investigated the role of NOS1AP gene polymorphisms and a history of childhood abuse in predicting PPD features among male violent offenders in the Chinese Han population.

METHOD

Four NOS1AP Single Nucleotide Polymorphisms (SNPs), rs4145621, rs3751284, rs348624 and rs6680461 were genotyped in a sample of 423 male prisoners. Participant evaluations included demographic information, measures of childhood abuse (Child Trauma Questionnaire, CTQ), and PPD features (Personality Diagnostic Questionnaire-4, PDQ-4). Participants were divided into a PPD group and non-PPD group assessed by PDQ-4.

RESULTS

Regression analysis revealed that emotional abuse, NOS1AP SNPs rs348624 and rs4145621 predicted PPD features (P < 0.05) among prison samples. Significant interactions between childhood abuse history and NOS1AP SNPs rs3751284 and rs6680461 were also observed. Individuals carrying the C allele of rs3751284 were susceptible to PPD features when exposed to higher levels of emotional neglect (P < 0.05); Individuals with the G allele of rs6680461 were susceptible to PPD features when exposed to higher levels of emotional, physical and sexual abuse (P < 0.01).

CONCLUSIONS

These results suggest that the interaction between childhood abuse and NOS1AP gene polymorphisms may have an influence on PPD features, at least in male violent offenders.

The interaction of histone modification related H3F3B and NSD2 genes increases the susceptibility to schizophrenia in a Chinese population

The role of histone modifications in the pathogenesis of schizophrenia has been proposed previously. H3F3B is a member of the histone 3. NSD2 is a histone methyltransferase that mediates dimethylation of Histone 3 lysine 36 (H3K36me2). The aim of the current study was to explore the associations between SNPs within H3F3B gene (rs60700976, rs3214028) and NSD2 gene (rs13148597, rs75820801) and the susceptibility to schizophrenia in a Chinese population. A total of 810 patients and 490 healthy controls were recruited and genetic association analyses were performed. The H3F3B gene polymorphisms rs3214028 and rs60700976 were significantly associated with schizophrenia. Rs60700976 was also associated with psychotic symptoms in schizophrenia patients. Furthermore, we found the interaction between NSD2 gene and H3F3B gene was related to the susceptibility to schizophrenia. The corresponding best three-locus model was H3F3B (rs60700976) - NSD2 (rs75820801, rs13148597), and the high-risk genotype combination was rs13148597(CC)- rs60700976(GG)-rs75820801(TT) (OR = 1.388[1.091-1.766], P = .007). The low-risk genotype combination was rs13148597(CC)-rs60700976(GG)-rs75820801(CT) (OR = 0.57 [0.330-0.985], P = .042). Our findings provided the preliminary evidence that the histone modification related H3F3B and NSD2 genes may confer the susceptibility to schizophrenia in a Chinese population.

A comprehensive analysis of GSK3B variation for schizophrenia in Han Chinese individuals

Glycogen synthase kinase-3B (GSK-3B) is thought to be involved in numerous neuronal functions and is implicated in the pathophysiology of schizophrenia. Interestingly, a functional polymorphism, rs3755557, in the GSK3B promoter region has been consistently reported to be a risk factor for schizophrenia in southwestern and northwestern Han Chinese individuals. In this study, we carried out a comprehensive analysis of the association of the rs3755557 polymorphism within GSK3B and schizophrenia in Han Chinese individuals. We recruited 782 patients with schizophrenia and 807 healthy controls from eastern China. In total, 143 drug-naïve patients with first-episode schizophrenia were enrolled for the evaluation of clinical features. We did not observe significant differences in genotype or allele distribution of the rs3755557 polymorphism between the schizophrenia and control groups in eastern Chinese individuals. After pooling these data of 2188 subjects with schizophrenia and 2885 healthy controls, we observed a significant difference in the A allele distribution of the rs3755557 polymorphism between schizophrenia patients and controls (Z = 4.13 P < 0.01). We further examined the relationship between the rs3755557 polymorphism and the clinical features of schizophrenia by comparing scores of the The Positive and Negative Syndrome Scale (PANSS) and The Repeatable Battery for the Assessment of Neuropsychological Status (RBANS) with the genotypes of the rs3755557 polymorphism. There were significant differences in the scores of RBANS attention, delayed memory and total scores between the patients with the A allele and those without the A allele (P = 0.03, 0.01 and 0.01 after Bonferroni correction, respectively). Our eQTL analysis showed a significant association between the rs3755557 polymorphism and GSK3B expression in the hippocampus (P = 0.027). Our findings indicated that the rs3755557 polymorphism may confer susceptibility to schizophrenia and cognitive dysfunction in Han Chinese individuals.

VRK2, a Candidate Gene for Psychiatric and Neurological Disorders

Recent large-scale genetic approaches, such as genome-wide association studies, have identified multiple genetic variations that contribute to the risk of mental illnesses, among which single nucleotide polymorphisms (SNPs) within or near the vaccinia related kinase 2 (VRK2) gene have gained consistent support for their correlations with multiple psychiatric and neurological disorders including schizophrenia (SCZ), major depressive disorder (MDD), and genetic generalized epilepsy. For instance, the genetic variant rs1518395 in VRK2 showed genome-wide significant associations with SCZ (35,476 cases and 46,839 controls, p = 3.43 × 10-8) and MDD (130,620 cases and 347,620 controls, p = 4.32 × 10-12) in European populations. This SNP was also genome-wide significantly associated with SCZ in Han Chinese population (12,083 cases and 24,097 controls, p = 3.78 × 10-13), and all associations were in the same direction of allelic effects. These studies highlight the potential roles of VRK2 in the central nervous system, and this gene therefore might be a good candidate to investigate the shared genetic and molecular basis between SCZ and MDD, as it is one of the few genes known to show genome-wide significant associations with both illnesses. Furthermore, the VRK2 gene was found to be involved in multiple other congenital deficits related to the malfunction of neurodevelopment, adding further support for the involvement of this gene in the pathogenesis of these neurological and psychiatric illnesses. While the precise function of VRK2 in these conditions remains unclear, preliminary evidence suggests that it may affect neuronal proliferation and migration via interacting with multiple essential signaling pathways involving other susceptibility genes/proteins for psychiatric disorders. Here, we have reviewed the recent progress of genetic and molecular studies of VRK2, with an emphasis on its role in psychiatric illnesses and neurological functions. We believe that attention to this important gene is necessary, and further investigations of VRK2 may provide hints into the underlying mechanisms of SCZ and MDD.

The TRAX, DISC1, and GSK3 complex in mental disorders and therapeutic interventions

Psychiatric disorders (such as bipolar disorder, depression, and schizophrenia) affect the lives of millions of individuals worldwide. Despite the tremendous efforts devoted to various types of psychiatric studies and rapidly accumulating genetic information, the molecular mechanisms underlying psychiatric disorder development remain elusive. Among the genes that have been implicated in schizophrenia and other mental disorders, disrupted in schizophrenia 1 (DISC1) and glycogen synthase kinase 3 (GSK3) have been intensively investigated. DISC1 binds directly to GSK3 and modulates many cellular functions by negatively inhibiting GSK3 activity. The human DISC1 gene is located on chromosome 1 and is highly associated with schizophrenia and other mental disorders. A recent study demonstrated that a neighboring gene of DISC1, translin-associated factor X (TRAX), binds to the DISC1/GSK3β complex and at least partly mediates the actions of the DISC1/GSK3β complex. Previous studies also demonstrate that TRAX and most of its interacting proteins that have been identified so far are risk genes and/or markers of mental disorders. In the present review, we will focus on the emerging roles of TRAX and its interacting proteins (including DISC1 and GSK3β) in psychiatric disorders and the potential implications for developing therapeutic interventions.