Genetic basis of psychopathological dimensions shared between schizophrenia and bipolar disorder

Abelson Helper Integration Site 1 haplotypes and peripheral blood expression associates with lithium response and immunomodulation in bipolar patients

RATIONALE

In bipolar disorder (BD), immunological factors play a role in the pathogenesis and treatment of the illness. Studies showed the potential link between Abelson Helper Integration Site 1 (AHI1) protein, behavioural changes and innate immunity regulation. An immunomodulatory effect was suggested for lithium, a mood stabilizer used in BD treatment.

OBJECTIVES

We hypothesized that AHI1 may be an important mediator of lithium treatment response. Our study aimed to investigate whether the AHI1 haplotypes and expression associates with lithium treatment response in BD patients. We also examined whether AHI1 expression and lithium treatment correlate with innate inflammatory response genes.

RESULTS

We genotyped seven AHI1 single nucleotide polymorphisms in 97 euthymic BD patients and found that TG haplotype (rs7739635, rs9494332) was significantly associated with lithium response. We also showed significantly increased AHI1 expression in the blood of lithium responders compared to non-responders and BD patients compared to healthy controls (HC). We analyzed the expression of genes involved in the innate immune response and inflammatory response regulation (TLR4, CASP4, CASP5, NLRP3, IL1A, IL1B, IL6, IL10, IL18) in 21 lithium-treated BD patients, 20 BD patients treated with other mood stabilizer and 19 HC. We found significantly altered expression between BD patients and HC, but not between BD patients treated with different mood stabilizers.

CONCLUSIONS

Our study suggests the involvement of AHI1 in the lithium mode of action. Moreover, mood-stabilizing treatment associated with the innate immunity-related gene expression in BD patients and only the lithium-treated BD patients showed significantly elevated expression of anti-inflammatory IL10, suggesting lithium's immunomodulatory potential.

Association between 14 candidate genes, PM2.5, and affective disorders: a study of the Taiwan Biobank

BACKGROUND

Most studies have focused on the risk factors, treatment, and care of affective psychosis, and several have reported a relationship between ambient air quality and this psychosis. Although an association has been reported between psychosis and genes, studies mainly explored the associations between one type of psychosis and one gene; few have identified genes related to affective psychosis. This study investigates the genetic and environmental factors of affective psychosis.

METHODS

In this retrospective longitudinal study, 27 604 participants aged 30-70 were selected from Taiwan Biobank. The participants' propensity scores were calculated based on their demographic information, and propensity score matching was performed to divide the participants into an experimental (i.e., affective psychosis) and control group at a 1:5 ratio. Plink was used to analyze the major and minor types of gene expression related to affective psychosis, and PM2.5 exposure was incorporated into the analyses.

RESULTS

According to the generalized estimating equation analysis results, 8 single nucleotide polymorphisms (SNPs) belonging to the ANK3, BDNF, CACNA1C, and GRID1 genotypes were significantly correlated with depressive disorder (P < .001), with the majority belonging to the ANK3 and CACNA1C. A total of 5 SNPs belonging to the CACNA1C, GRID1, and SIRT1 genotypes were significantly correlated with bipolar disorder (P < .001), with the majority belonging to the CACNA1C. No significant correlation was identified between ambient air pollution and affective psychosis.

CONCLUSIONS

CACNA1C and GRID1 are common SNP genotypes for depressive disorder and bipolar disorder and should be considered associated with affective psychosis.

The role of EndophilinA1 in chronic unpredicted mild stress-induced depression model mice

BACKGROUND

Depression is a common mental disease, accompanied by anxiety and persistent depression. Endophilin A1 (EPA1) is a brain-specific protein enriched in synaptic terminals that is primarily expressed in the central nervous system. It has been reported that EPA1 is involved in neurotransmitter release, which indicates that the protein may be involved in depression. However, it is unclear whether EPA1 is implicated in the development of depression.

METHODS

The mice depression model was established by chronic unpredicted mild stress (CUMS). Depression-like behaviors were detected by sucrose preference test (SPT), forced swim test (FST), tail-suspension test (TST) and open-field test (OFT). Neuronal histopathology was applied by hematoxylin and eosin stain (H&E), and Nissl stain. EPA1, NLRP1 inflammatory complexes, NADPH oxidase2 (NOX2), synaptic-related protein expression of the mice were tested by western blot. Immunofluorescence was applied to detect the expression of EPA1 and ROS in mice hippocampus. EPA1 knockdown was performed by an adeno-associated virus (AAV) vector containing EPA1-shRNA-EGFP infusion.

RESULT

CUMS exposure induced depressive-like behaviors and increased the expression of EPA1 in the hippocampus. Knockdown hippocampal EPA1 ameliorated CUMS-induced depressive-like behaviors, decreased calcium (Ca2+) overload, decreased ROS generation and NOX2 expression, inhibited NLRP1 inflammasome-driven neuroinflammation, and restored the levels of BDNF, PSD95, GAP-43, SYN, and MAP-2 in the hippocampus.

CONCLUSION

EPA1 contributes to CUMS induced depressive-like behaviors and the mechanism may be related to NLRP1 inflammasome-driven inflammatory response, regulating calcium ion homeostasis and ROS generation, and alleviating synaptic function damage. This indicated that EPA1 may participate in the occurrence and development of depression.

Synaptotagmin-11 Inhibits Synaptic Vesicle Endocytosis via Endophilin A1

Synaptic vesicle (SV) endocytosis is a critical and well-regulated process for the maintenance of neurotransmission. We previously reported that synaptotagmin-11 (Syt11), an essential non-Ca2+-binding Syt associated with brain diseases, inhibits neuronal endocytosis (Wang et al., 2016). Here, we found that Syt11 deficiency caused accelerated SV endocytosis and vesicle recycling under sustained stimulation and led to the abnormal membrane partition of synaptic proteins in mouse hippocampal boutons of either sex. Furthermore, our study revealed that Syt11 has direct but Ca2+-independent binding with endophilin A1 (EndoA1), a membrane curvature sensor and endocytic protein recruiter, with high affinity. EndoA1-knockdown significantly reversed Syt11-KO phenotype, identifying EndoA1 as a main inhibitory target of Syt11 during SV endocytosis. The N-terminus of EndoA1 and the C2B domain of Syt11 were responsible for this interaction. A peptide (amino acids 314-336) derived from the Syt11 C2B efficiently blocked Syt11-EndoA1 binding both in vitro and in vivo Application of this peptide inhibited SV endocytosis in WT hippocampal neurons but not in EndoA1-knockdown neurons. Moreover, intracellular application of this peptide in mouse calyx of Held terminals of either sex effectively hampered both fast and slow SV endocytosis at physiological temperature. We thus propose that Syt11 ensures the precision of protein retrieval during SV endocytosis by inhibiting EndoA1 function at neuronal terminals.SIGNIFICANCE STATEMENT Endocytosis is a key stage of synaptic vesicle (SV) recycling. SV endocytosis retrieves vesicular membrane and protein components precisely to support sustained neurotransmission. However, the molecular mechanisms underlying the regulation of SV endocytosis remain elusive. Here, we reported that Syt11-KO accelerated SV endocytosis and impaired membrane partition of synaptic proteins. EndoA1 was identified as a main inhibitory target of Syt11 during SV endocytosis. Our study reveals a novel inhibitory mechanism of SV endocytosis in preventing hyperactivation of endocytosis, potentially safeguarding the recycling of synaptic proteins during sustained neurotransmission.

The Role of Endophilin A1 in Lipopolysaccharide-Induced Parkinson's Disease Model Mice

BACKGROUND

Endophilin A1 (EPA1) is encoded by the SH3GL2 gene, and SH3GL2 was designated as a Parkinson's disease (PD) risk locus by genome-wide association analysis, suggesting that EPA1 may be involved in the occurrence and development of PD.

OBJECTIVE

To investigate the role of EPA1 in lipopolysaccharide (LPS)-induced PD model mice.

METHODS

The mice PD model was prepared by injecting LPS into the substantia nigra (SN), and the changes in the behavioral data of mice in each group were observed. The damage of dopaminergic neurons, activation of microglia, and reactive oxygen species (ROS) generation were detected by immunofluorescence method; calcium ion concentration was detected by calcium content detection kit; EPA1 and inflammation and its related indicators were detected by western blot method. EPA1 knockdown was performed by an adeno-associated virus vector containing EPA1-shRNA-eGFP infusion.

RESULTS

LPS-induced PD model mice developed behavioral dysfunction, SN dopaminergic nerve damage, significantly increased calcium ion, calpain 1, and ROS production, activated NLRP1 inflammasome and promoted pro-inflammatory cell release, and SN EPA1 knockdown improves behavioral disorders, alleviates dopaminergic neuron damage, reduces calcium, calpain 1, ROS generation, and blocks NLRP1 inflammasome-driven inflammatory responses.

CONCLUSION

The expression of EPA1 in the SN of LPS-induced PD model mice was increased, and it played a role in promoting the occurrence and development of PD. EPA1 knockdown inhibited the NLRP1 inflammasome activation, decreased the release of inflammatory factors and ROS generation, and alleviated dopaminergic neuron damage. This indicated that EPA1 may participating in the occurrence and development of PD.

Genome-wide association studies-supported rs12966547 variant of the long noncoding RNA LOC105372125 is significantly associated with susceptibility to schizophrenia and bipolar disorder in Han Chinese women

OBJECTIVE

Genome-wide association studies have found that rs12966547 polymorphism was associated with susceptibility to schizophrenia in European populations. Recent studies showed that a genetic overlap may exist in schizophrenia and bipolar disorder. Here, we analyzed the associations between LOC105372125 rs12966547 polymorphism and schizophrenia and bipolar disorder in the Han Chinese population.

METHODS

Our study recruited 548 schizophrenia patients, 512 bipolar disorder patients, and 598 healthy controls. Genotyping of rs12966547 were performed using the Sequenom MassARRAY platform.

RESULTS

A significant association between rs12966547 polymorphism and susceptibility to bipolar disorder was observed after adjusting for sex and age (additive model: Padj = 0.040, recessive model: Padj = 0.044). However, no significant association was found between rs12966547 polymorphism and schizophrenia risk (all P > 0.05). In the analysis of gender, rs12966547 polymorphism was significantly associated with bipolar disorder (additive model: Padj = 0.027) and schizophrenia (dominant model: Padj = 0.039) in women. However, no significant association was found between rs12966547 polymorphism and the risk of bipolar disorder or schizophrenia in men (all Padj > 0.05).

CONCLUSIONS

Polymorphism of rs12966547 on the long noncoding RNA LOC10537215 are a shared genetic variant of schizophrenia and bipolar disorder in Han Chinese women.

A New Prognostic Risk Score: Based on the Analysis of Autophagy-Related Genes and Renal Cell Carcinoma

Introduction: Clear cell renal cell carcinoma (ccRCC) patients suffer from its high recurrence and metastasis rate, and a new prognostic risk score to predict individuals with high possibility of recurrence or metastasis is in urgent need. Autophagy has been found to have a dual influence on tumorigenesis. In this study we aim to analyze autophagy related genes (ATGs) and ccRCC patients and find a new prognostic risk score. Method: Analyzing differential expression genes (DEGs) in TCGA-KIRC dataset, and took intersection with ATGs. Through lasso, univariate, and multivariate cox regression, DEGs were chosen, and the coefficients and expression levels of them were components constructing the formula of risk score. We analyzed mRNA expression of DEGs in tumor and normal tissue in ONCOMINE database and TCGA-KIRC dataset. The Human Protein Atlas (HPA) was used to analyze protein levels of DEGs. The protein-protein interaction (PPI) network was examined in STRING and visualized in cytoscape. Functional enrichment analysis was performed in RStudio. To prove the ability and practicibility of risk score, we analyzed univariate and multivariate cox regression, Kaplan-Meier curve (K-M curve), risk factor association diagram, receiver operating characteristic curve (ROC curve) of survival and nomogram, and the performance of nomogram was evaluated by calibration curve. Then we further explored functional enrichment related to risk groups through Gene Set Enrichment Analysis (GSEA), weighted gene co-expression network analysis (WGCNA), and Metascape database. At last, we investigated immune cell infiltration of DEGs and two risk groups through TIMER database and “Cibersort” algorithm.

Result: We identified 7 DEGs (BIRC5, CAPS, CLDN7, CLVS1, GMIP, IFI16, and TCIRG1) as components of construction of risk score. All 7 DEGs were differently expressed in ccRCC and normal tissue according to ONCOMINE database and TCGA-KIRC dataset. Functional enrichment analysis indicated DEGs, and their most associated genes were shown to be abundant in autophagy-related pathways and played roles in tumorigenesis and progression processes. A serious analysis proved that this risk score is independent from the risk signature of ccRCC patients.

Conclusion: The risk score constructed by 7 DEGs had the ability of predicting prognosis of ccRCC patients and was conducive to the identification of novel prognostic molecular markers. However, further experiment is still needed to verify its ability and practicability.

Endophilin A1 drives acute structural plasticity of dendritic spines in response to Ca2+/calmodulin

Induction of long-term potentiation (LTP) in excitatory neurons triggers a large transient increase in the volume of dendritic spines followed by decays to sustained size expansion, a process termed structural LTP (sLTP) that contributes to the cellular basis of learning and memory. Although mechanisms regulating the early and sustained phases of sLTP have been studied intensively, how the acute spine enlargement immediately after LTP stimulation is achieved remains elusive. Here, we report that endophilin A1 orchestrates membrane dynamics with actin polymerization to initiate spine enlargement in NMDAR-mediated LTP. Upon LTP induction, Ca²⁺/calmodulin enhances binding of endophilin A1 to both membrane and p140Cap, a cytoskeletal regulator. Consequently, endophilin A1 rapidly localizes to the plasma membrane and recruits p140Cap to promote local actin polymerization, leading to spine head expansion. Moreover, its molecular functions in activity-induced rapid spine growth are required for LTP and long-term memory. Thus, endophilin A1 serves as a calmodulin effector to drive acute structural plasticity necessary for learning and memory.

Genome-wide association study of psychiatric and substance use comorbidity in Mexican individuals

The combination of substance use and psychiatric disorders is one of the most common comorbidities. The objective of this study was to perform a genome-wide association study of this comorbidity (Com), substance use alone (Subs), and psychiatric symptomatology alone (Psych) in the Mexican population. The study included 3914 individuals of Mexican descent. Genotyping was carried out using the PsychArray microarray and genome-wide correlations were calculated. Genome-wide associations were analyzed using multiple logistic models, polygenic risk scores (PRSs) were evaluated using multinomial models, and vertical pleiotropy was evaluated by generalized summary-data-based Mendelian randomization. Brain DNA methylation quantitative loci (brain meQTL) were also evaluated in the prefrontal cortex. Genome-wide correlation and vertical pleiotropy were found between all traits. No genome-wide association signals were found, but 64 single-nucleotide polymorphism (SNPs) reached nominal associations (p < 5.00e-05). The SNPs associated with each trait were independent, and the individuals with high PRSs had a higher prevalence of tobacco and alcohol use. In the multinomial models all of the PRSs (Subs-PRS, Com-PRS, and Psych-PRS) were associated with all of the traits. Brain meQTL of the Subs-associated SNPs had an effect on the genes enriched in insulin signaling pathway, and that of the Psych-associated SNPs had an effect on the Fc gamma receptor phagocytosis pathway.

Shared Genetics of Psychiatric Disorders

Until recently, advances in understanding the genetic architecture of psychiatric disorders have been impeded by a historic, and often mandated, commitment to the use of traditional, and unvalidated, categorical diagnoses in isolation as the relevant phenotype. Such studies typically required lengthy structured interviews to delineate differences in the character and duration of behavioral symptomatology amongst disorders that were thought to be etiologic, and they were often underpowered as a result. Increasing acceptance of the fact that co-morbidity in psychiatric disorders is the rule rather than the exception has led to alternative designs in which shared dimensional symptomatology is analyzed as a quantitative trait and to association analyses in which combined polygenic risk scores are computationally compared across multiple traditional categorical diagnoses to identify both distinct and unique genetic and environmental elements. Increasing evidence that most mental disorders share many common genetic risk variants and environmental risk modifiers suggests that the broad spectrum of psychiatric pathology represents the pleiotropic display of a more limited series of pathologic events in neuronal development than was originally believed, regulated by many common risk variants and a smaller number of rare ones.