A novel heterozygous missense variant of the ARID4A gene identified in Han Chinese families with schizophrenia-diagnosed siblings that interferes with DNA-binding activity.

ARID4A plays an important role in regulating gene expression and cell proliferation. ARID4A belongs to the AT-rich interaction domain (ARID)-containing family, and a PWWP domain immediately precedes its ARID region. The molecular mechanism and structural basis of ARID4A are largely unknown. Whole-exome sequencing (WES) revealed that a novel heterozygous missense variant, ARID4A c.1231 C > G (p.His411Asp), was associated with schizophrenia (SCZ) in this study. We determined the crystal structure of the PWWP-ARID tandem at 2.05 Å, revealing an unexpected mode in which ARID4A assembles with its PWWP and ARID from a structural and functional supramodule. Our results further showed that compared with the wild type, the p.His411Asp ARID mutant protein adopts a less compact conformation and exhibits a weaker dsDNA-binding ability. The p.His411Asp mutation decreased the number of cells that were arrested in the G0-G1 phase and caused more cells to progress to the G2-M phase. In addition, the missense mutation promoted the proliferation of HEK293T cells. In conclusion, our data provide evidence that ARID4A p.His411Asp could cause a conformational change in the ARID4A ARID domain, influence the DNA binding function, and subsequently disturb the cell cycle arrest in the G1 phase. ARID4A is likely a susceptibility gene for SCZ; thus, these findings provide new insight into the role of ARID4A in psychiatric disorders.

RGCC balances self-renewal and neuronal differentiation of neural stem cells in the developing mammalian neocortex.

During neocortical development, neural stem cells (NSCs) divide symmetrically to self-renew at the early stage and then divide asymmetrically to generate post-mitotic neurons. The molecular mechanisms regulating the balance between NSC self-renewal and neurogenesis are not fully understood. Using mouse in utero electroporation (IUE) technique and in vitro human NSC differentiation models including cerebral organoids (hCOs), we show here that regulator of cell cycle (RGCC) modulates NSC self-renewal and neuronal differentiation by affecting cell cycle regulation and spindle orientation. RGCC deficiency hampers normal cell cycle process and dysregulates the mitotic spindle, thus driving more cells to divide asymmetrically. These modulations diminish the NSC population and cause NSC pre-differentiation that eventually leads to brain developmental malformation in hCOs. We further show that RGCC might regulate NSC spindle orientation by affecting the organization of centrosome and microtubules. Our results demonstrate that RGCC is essential to maintain the NSC pool during cortical development and suggest that RGCC defects could have etiological roles in human brain malformations.

A Case-Control Study of ABCB1, ABCB6, and ABCG1 Polymorphisms and Schizophrenia in a Han Chinese Population.

BACKGROUND: Schizophrenia (SCZ) is a complex, heritable, and devastating psychiatric disorder. Mutations in the members of ABC transporters have been associated with psychiatric illnesses. AIMS: In this study, we investigated whether 9 SNPs in ABCB1 (rs6946119, rs28401781, rs4148739, and rs3747802), ABCB6 (rs1109866, rs1109867, rs3731885, and rs3755047), and ABCG1 (rs182694) contribute to the risk of SCZ in a Han Chinese population. METHODS: We conducted a case-control study in a Han Chinese population, involving 1,034 SCZ patients and 1,034 unrelated healthy controls to genotype 9 SNPs. RESULTS: The analysis demonstrated that rs182694 of ABCG1 was significantly different between SCZ patients and controls as to allele (rs182694: p = 0.0070, χ2 = 7.27) and genotype frequencies (rs182694: p = 0.0013, χ2 = 13.35). CONCLUSIONS: Our findings support an association between ABCG1 polymorphism and SCZ in a Han Chinese population.

Metabolomic profiling on rat brain of prenatal malnutrition: implicated for oxidative stress and schizophrenia.

Schizophrenia is a kind of neurodevelopmental disease. Epidemiological data associates schizophrenia with prenatal exposure to famine. Relevant prenatal protein deprivation (PPD) rodent models support this result by observing decreasing prepulse inhibition, altered hippocampal morphology and impaired memory in offspring. All these abnormalities are highly consistent with the pathophysiology of schizophrenia. We developed a prenatal famine rat model by restricting daily diet of the pregnant rat to 50% of low protein diet. A metabolomics study of prefrontal cortex was performed to integrate GC-TOFMS and UPLC-QTOFMS. Thirteen controls and thirteen famine offspring were used to differentiate in PLS-DA (partial least squares-discriminate analysis) model. Furthermore, metabolic pathways and diseases were enriched via KEGG and HMDB databases, respectively. A total of 67 important metabolites were screened out according to the multivariate analysis. Schizophrenia was the most statistical significant disease (P = 0.0016) in our famine model. These metabolites were enriched in key metabolic pathways related to energy metabolism and glutamate metabolism. Based on these important metabolites, further discussion speculated famine group was characterized by higher level of oxidized damage compared to control group. We proposed that oxidative stress might be the pathogenesis of prenatal undernutrition which is induced schizophrenia.

Deficiency of VCP-Interacting Membrane Selenoprotein (VIMP) Leads to G1 Cell Cycle Arrest and Cell Death in MIN6 Insulinoma Cells.

BACKGROUND/AIMS: VCP-interacting membrane selenoprotein (VIMP), an ER resident selenoprotein, is highly expressed in ß-cells, however, the role of VIMP in ß-cells has not been characterized. In this study, we studied the relationship between VIMP deficiency and ß-cell survival in MIN6 insulinoma cells. METHODS: To determine the role of VIMP in ß-cells, lentiviral VIMP shRNAs were used to knock down (KD) expression of VIMP in MIN6 cells. Cell death was quantified by propidium iodide (PI) staining followed by flow cytometric analyses using a FACS Caliber and FlowJo software. Cell apoptosis and proliferation were determined by TUNEL assay and Ki67 staining, respectively. Cell cycle was analyzed after PI staining. RESULTS: The results show that 1) VIMP suppression induces ß-cell apoptosis, which is associated with a decrease in Bcl-xL, and the ß-cell apoptosis induced by VIMP suppression can be inhibited by overexpression of Bcl-xL; 2) VIMP knockdown (KD) decreases cell proliferation and G1 cell cycle arrest by accumulating p27 and decreasing E2F1; 3) VIMP KD suppresses unfolded protein response (UPR) activation by regulating the IRE1α and PERK pathways; 4) VIMP KD increases insulin secretion. CONCLUSION: These results suggest that VIMP may function as a novel regulator to modulate ß-cell survival, proliferation, cell cycle, UPR and insulin secretion in MIN6 cells.

Selenoprotein S protects against adipocyte death through mediation of the IRE1α-sXBP1 pathway.

As the most conserved branch of the unfolded protein response (UPR), the inositol-requiring enzyme 1a (IRE1a)/X-box binding protein 1 (XBP1) pathway plays crucial roles in cell survival and cell death by upregulating UPR-associated genes involved in protein entry into the endoplasmic reticulum (ER) and ER-associated degradation (ERAD). Selenoprotein S (SelS) is localized to the ER membrane and involved in ERAD. Although SelS plays an important role in restoring ER stress, the SelS-dependent protective mechanisms against cell death remain unclear. Here, using an inducible SelS knockdown (KD) 3T3-L1 cell model, we showed that SelS KD resulted adipocyte death, which was associated with imbalance of the Bcl-2 family members. Furthermore, SelS KD decreased spliced XBP1 (sXBP1), increased IRE1α and p-JNK, suggesting a role of SelS in the modulation of the IRE1α-sXBP1 pathway. Moreover, adipocyte death induced by SelS suppression can be inhibited by overexpression of sXBP1. Thus, it is proposed that SelS promotes cell survival through the IRE1α-XBP1 signaling pathway.

Pancreatic ß-Cell Death due to Pdx-1 Deficiency Requires Multi-BH Domain Protein Bax but Not Bak.

Diabetes develops in Pdx1-haploinsufficient mice due to an increase in ß-cell death leading to reduced ß-cell mass and decreased insulin secretion. Knockdown of Pdx1 gene expression in mouse MIN6 insulinoma cells induced apoptotic cell death with an increase in Bax activation and knockdown of Bax reduced apoptotic ß-cell death. In Pdx1 haploinsufficient mice, Bax ablation in ß-cells increased ß-cell mass, decreased the number of TUNEL positive cells and improved glucose tolerance after glucose challenge. These changes were not observed with Bak ablation in Pdx1-haploinsufficient mice. These results suggest that Bax mediates ß-cell apoptosis in Pdx1-deficient diabetes.

Stepwise activation of BAX and BAK by tBID, BIM, and PUMA initiates mitochondrial apoptosis.

While activation of BAX/BAK by BH3-only molecules (BH3s) is essential for mitochondrial apoptosis, the underlying mechanisms remain unsettled. Here we demonstrate that BAX undergoes stepwise structural reorganization leading to mitochondrial targeting and homo-oligomerization. The alpha1 helix of BAX keeps the alpha9 helix engaged in the dimerization pocket, rendering BAX as a monomer in cytosol. The activator BH3s, tBID/BIM/PUMA, attack and expose the alpha1 helix of BAX, resulting in secondary disengagement of the alpha9 helix and thereby mitochondrial insertion. Activator BH3s remain associated with the N-terminally exposed BAX through the BH1 domain to drive homo-oligomerization. BAK, an integral mitochondrial membrane protein, has bypassed the first activation step, explaining why its killing kinetics are faster than those of BAX. Furthermore, death signals initiated at ER induce BIM and PUMA to activate mitochondrial apoptosis. Accordingly, deficiency of Bim/Puma impedes ER stress-induced BAX/BAK activation and apoptosis. Our study provides mechanistic insights regarding the spatiotemporal execution of BAX/BAK-governed cell death.

One-pot synthesis and antifungal activity against plant pathogens of quinazolinone derivatives containing an amide moiety.

An efficient one-pot, three-component synthesis of quinazolinone derivatives containing 3-acrylamino motif was carried out using CeO2 nanoparticles as catalyst. Thirty-nine synthesized compounds were obtained with satisfied yield and elucidated by spectroscopic analysis. Four phytopathogenic fungi were chosen to test the antifungal activities by minimum inhibitory concentration (MIC) method. Compounds 4ag, 4bb, 4bc showed broad antifungal activities against at least three fungi, and dramatic effects of substituents on the activities were observed. Docking studies were established to explore the potential antifungal mechanism of quinazolinone derivatives as the chitinase inhibitors, and also verified the importance of the amide moiety.

Synthesis of Indolyldiketopiperazines with NBS.

Two series of indolyldiketopiperazines were synthesized starting from methyl 1-substituted-1,2,3,4-tetrahydro-ß-carboline-3-carboxylate hydrochlorides via N-bromo-succinimide (NBS) as an important reagent. All eight compounds were characterized by nuclear magnetic resonance (NMR) and elemental analysis. Furthermore, the mechanisms of NBS-reacted rearrangements are also discussed.

Reduction of mRNA m6A associates with glucose metabolism via YTHDC1 in human and mice.

AIMS: N6-methyladenosine (m6A) in mRNA is involved in glucose metabolism. Our goal is to investigate the relationship of glucose metabolism, m6A and YTH domain-containing protein 1 (YTHDC1), a binding protein to m6A, in the development of type 2 diabetes (T2D). METHODS: HPLC-MS/MS and qRT-PCR were used to quantify m6A and YTHDC1 levels in white blood cells from patients with T2D and healthy individuals. MIP-CreERT and tamoxifen treatment were used to create ß-cell Ythdc1 knockout mice (ßKO). m6A sequencing and RNA sequencing were performed in wildtype/ßKO islets and MIN6 cells to identify the differential genes. RESULTS: In T2D patients, both of m6A and YTHDC1 levels were reduced and associated with fasting glucose. Deletion of Ythdc1 resulted in glucose intolerance and diabetes due to decreased insulin secretion, even though ß-cell mass in ßKO mice was comparable to wildtype mice. Moreover, Ythdc1 was shown to bind to SRSF3 (serine/arginine-rich splicing factor 3) and CPSF6 (cleavage and polyadenylation specific factor 6) in ß-cells. CONCLUSIONS: Our data suggested that YTHDC1 may regulate mRNA splicing and export by interacting with SRSF3 and CPSF6 to modulate glucose metabolism via regulating insulin secretion, implying YTHDC1 might be a novel potential target for lowing glucose.

Adipose METTL14-Elicited N6 -Methyladenosine Promotes Obesity, Insulin Resistance, and NAFLD Through Suppressing ß Adrenergic Signaling and Lipolysis.

White adipose tissue (WAT) lipolysis releases free fatty acids as a key energy substance to support metabolism in fasting, cold exposure, and exercise. Atgl, in concert with Cgi-58, catalyzes the first lipolytic reaction. The sympathetic nervous system (SNS) stimulates lipolysis via neurotransmitter norepinephrine that activates adipocyte ß adrenergic receptors (Adrb1-3). In obesity, adipose Adrb signaling and lipolysis are impaired, contributing to pathogenic WAT expansion; however, the underling mechanism remains poorly understood. Recent studies highlight importance of N6 -methyladenosine (m6A)-based RNA modification in health and disease. METTL14 heterodimerizes with METTL3 to form an RNA methyltransferase complex that installs m6A in transcripts. Here, this work shows that adipose Mettl3 and Mettl14 are influenced by fasting, refeeding, and insulin, and are upregulated in high fat diet (HFD) induced obesity. Adipose Adrb2, Adrb3, Atgl, and Cgi-58 transcript m6A contents are elevated in obesity. Mettl14 ablation decreases these transcripts' m6A contents and increases their translations and protein levels in adipocytes, thereby increasing Adrb signaling and lipolysis. Mice with adipocyte-specific deletion of Mettl14 are resistant to HFD-induced obesity, insulin resistance, glucose intolerance, and nonalcoholic fatty liver disease (NAFLD). These results unravel a METTL14/m6A/translation pathway governing Adrb signaling and lipolysis. METTL14/m6A-based epitranscriptomic reprogramming impairs adipose Adrb signaling and lipolysis, promoting obesity, NAFLD, and metabolic disease.

Personality traits as mediators in the association between SIRT1 rs12415800 polymorphism and depressive symptoms among Chinese college students.

Background: Previous research has linked polymorphisms in the SIRT1 gene to depressive symptoms, particularly in Chinese individuals. However, it is not clear how personality traits may contribute to this association. Methods: To explore the potential mediating effect of personality traits, we utilized a mediation model to examine the relationship between the SIRT1 rs12415800 polymorphism and depressive symptoms in 787 Chinese college students. Depressive symptoms were assessed using the Center for Epidemiologic Studies Depression (CES-D) scale, while personality traits were measured using the Big Five Inventory (BFI). Results: Our analysis indicated a significant association between the SIRT1 rs12415800 polymorphism and depressive symptoms, with this relationship partially mediated by the personality traits of neuroticism and conscientiousness. Specifically, individuals who were heterozygous for the rs12415800 polymorphism and had higher levels of conscientiousness were less likely to experience depressive symptoms. Conversely, those who were homozygous for the rs12415800 polymorphism and had higher levels of neuroticism were more likely to experience depressive symptoms. Conclusion: Our results suggest that personality traits, particularly neuroticism and conscientiousness, may play a critical role in the association between the SIRT1 rs12415800 polymorphism and depressive symptoms among Chinese college students. These findings highlight the importance of considering both genetic factors and personality traits when exploring the etiology of depressive symptoms in this population.

TULP4, a novel E3 ligase gene, participates in neuronal migration as a candidate in schizophrenia.

BACKGROUND: TUB-like protein 4 (TULP4) is one of the distant members of tubby family proteins, whose function remains largely unknown. In the present study, we intend to identify the role of TULP4 in schizophrenia from human samples and animal models. METHODS: Whole-exome sequencing was used to detect the four schizophrenia families collected. In different cell lines, the effects of identified variants in TULP4 gene on its expression and localization were analyzed. Knockdown models in utero and adult mice were employed to investigate the role of Tulp4 on neuronal migration and schizophrenia-related behavior. Subsequently, co-IP assays were used to search for proteins that interact with TULP4 and the effects of mutants on the molecular function of TULP4. RESULTS: For the first time, we identified five rare variants in TULP4 from schizophrenia families, of which three significantly reduced TULP4 protein expression. Knockdown the expression of Tulp4 delayed neuronal migration during embryological development and consequently triggered abnormal behaviors in adult mice, including impaired sensorimotor gating and cognitive dysfunction. Furthermore, we confirmed that TULP4 is involved in the formation of a novel E3 ligase through interaction with CUL5-ELOB/C-RNF7 and the three deleterious variants affected the binding amount of TULP4 and CUL5 to a certain extent. CONCLUSIONS: Together, we believe TULP4 plays an important role in neurodevelopment and subsequent schizophrenic-related phenotypes through its E3 ubiquitin ligase function.

The p53-cathepsin axis cooperates with ROS to activate programmed necrotic death upon DNA damage.

Three forms of cell death have been described: apoptosis, autophagic cell death, and necrosis. Although genetic and biochemical studies have formulated a detailed blueprint concerning the apoptotic network, necrosis is generally perceived as a passive cellular demise resulted from unmanageable physical damages. Here, we conclude an active de novo genetic program underlying DNA damage-induced necrosis, thus assigning necrotic cell death as a form of "programmed cell death." Cells deficient of the essential mitochondrial apoptotic effectors, BAX and BAK, ultimately succumbed to DNA damage, exhibiting signature necrotic characteristics. Importantly, this genotoxic stress-triggered necrosis was abrogated when either transcription or translation was inhibited. We pinpointed the p53-cathepsin axis as the quintessential framework underlying necrotic cell death. p53 induces cathepsin Q that cooperates with reactive oxygen species (ROS) to execute necrosis. Moreover, we presented the in vivo evidence of p53-activated necrosis in tumor allografts. Current study lays the foundation for future experimental and therapeutic discoveries aimed at "programmed necrotic death."

The association between rs1260326 with the risk of NAFLD and the mediation effect of triglyceride on NAFLD in the elderly Chinese Han population.

BACKGROUND: Accumulated studies have pointed out the striking association between variants in or near APOC3, GCKR, PNPLA3, and nonalcoholic fatty liver disease (NAFLD) at various ages from multiple ethnic groups. This association remained unclear in the Chinese Han elderly population, and whether this relationship correlated to any clinical parameters was also unclear. OBJECTIVES: This study aims to decipher the complex relevance between gene polymorphisms, clinical parameters, and NAFLD by association study and mediation analysis. METHODS: Eight SNPs (rs2854116, rs2854117, rs780093, rs780094, rs1260362, rs738409, rs2294918, and rs2281135) within APOC3, GCKR, and PNPLA3 were genotyped using the MassARRAY® platform in a large Chinese Han sample comprising of 733 elderly NAFLD patients and 824 age- and ethnic-matched controls. Association and mediation analysis were employed by R. RESULTS: The genotypic frequencies of rs1260326 and rs780094 were significantly different between NAFLD and control (rs1260326: P=0.004, Pcorr=0.020, OR [95%CI]= 0.69 [0.54-0.89]; rs780094: P=0.005, Pcorr=0.025, OR [95%CI]= 0.70 [0.55-0.90]). Particularly, an increased triglyceride level was observed in carriers of rs1260326 T allele (1.94±1.19 mmol/L) compared with non-carriers (1.73±1.05 mmol/L).no significant results were observed in rs780094. Notably, triglyceride levels had considerably indirect impacts on association between NAFLD and rs1260326 (ß =0.01, 95% CI: 0.01-0.02), indicating that 12.7% of the association of NAFLD with rs1260326 was mediated by triglyceride levels. CONCLUSIONS: Our results identified a prominent relationship between GCKR rs1260326 and NAFLD, and highlighted the mediated effect of triglyceride levels on the that association in the Chinese Han elderly.

Upregulation of DGCR8, a Candidate Predisposing to Schizophrenia in Han Chinese, Contributes to Phenotypic Deficits and Neuronal Migration Delay.

DiGeorge Syndrome Critical Region Gene 8 (DGCR8) is a key component of the microprocessor complex governing the maturation of most microRNAs, some of which participate in schizophrenia and neural development. Previous studies have found that the 22q11.2 locus, containing DGCR8, confers a risk of schizophrenia. However, the role of DGCR8 in schizophrenia and the early stage of neural development has remained unknown. In the present study, we try to identify the role of DGCR8 in schizophrenia from human samples and animal models. We found that the G allele and GG genotype of rs3757 in DGCR8 conferred a higher risk of schizophrenia, which likely resulted from higher expression of DGCR8 according to our test of dual-luciferase reporter system. Employed overexpression model in utero and adult mice, we also revealed that the aberrant increase of Dgcr8 delayed neuronal migration during embryological development and consequently triggered abnormal behaviors in adult mice. Together, these results demonstrate that DGCR8 may play a role in the etiology of schizophrenia through regulating neural development.

NGFR Gene and Single Nucleotide Polymorphisms, rs2072446 and rs11466162, Playing Roles in Psychiatric Disorders.

Psychiatric disorders are a class of complex disorders characterized by brain dysfunction with varying degrees of impairment in cognition, emotion, consciousness and behavior, which has become a serious public health issue. The NGFR gene encodes the p75 neurotrophin receptor, which regulates neuronal growth, survival and plasticity, and was reported to be associated with depression, schizophrenia and antidepressant efficacy in human patient and animal studies. In this study, we investigated its association with schizophrenia and major depression and its role in the behavioral phenotype of adult mice. Four NGFR SNPs were detected based on a study among 1010 schizophrenia patients, 610 patients with major depressive disorders (MDD) and 1034 normal controls, respectively. We then knocked down the expression of NGFR protein in the hippocampal dentate gyrus of the mouse brain by injection of shRNA lentivirus to further investigate its behavioral effect in mice. We found significant associations of s2072446 and rs11466162 for schizophrenia. Ngfr knockdown mice showed social and behavioral abnormalities, suggesting that it is linked to the etiology of neuropsychiatric disorders. We found significant associations between NGFR and schizophrenia and that Ngfr may contribute to the social behavior of adult mice in the functional study, which provided meaningful clues to the pathogenesis of psychiatric disorders.

College students' screening early warning factors in identification of suicide risk.

This study aimed to explore the main influencing factors of suicide risk among Chinese students and establish an early warning model to provide interventions for high-risk students. We conducted surveys of students in their first and third years from a cohort study at Jining Medical College. Logistic regression models were used to screen the early warning factors, and four machine learning models were used to establish early warning models. There were 8 factors related to suicide risk that were eventually obtained through screening, including age, having a rough father, and CES-D, OHQ, ASLEC-4, BFI-Neuroticism, BFI-Openness, and MMC-AF-C scores. A random forest model with SMOTE was adopted, and it verified that these 8 early warning signs, for suicide risk can effectively predict suicide risk within 2 years with an AUC score of 0.947. Among the factors, we constructed a model that indicated that different personality traits affected suicide risk by different paths. Moreover, the factors obtained by screening can be used to identify college students in the same year with a high risk of suicide, with an AUC score that reached 0.953. Based on this study, we suggested some interventions to prevent students going high suicide risk.

Structure and Membrane Targeting of the PDZD7 Harmonin Homology Domain (HHD) Associated With Hearing Loss.

Usher syndrome (USH) is the leading cause of hereditary hearing-vision loss in humans. PDZ domain-containing 7 (PDZD7) has been reported to be a modifier of and contributor to USH. PDZD7 co-localizes with USH2 proteins in the inner ear hair cells and is essential for ankle-link formation and stereocilia development. PDZD7 contains three PDZ domains and a low-complexity region between the last two PDZ domains, which has been overlooked in the previous studies. Here we characterized a well-folded harmonin homology domain (HHD) from the middle region and solved the PDZD7 HHD structure at the resolution of 1.49 Å. PDZD7 HHD adopts the same five-helix fold as other HHDs found in Harmonin and Whirlin; however, in PDZD7 HHD, a unique α1N helix occupies the canonical binding pocket, suggesting a distinct binding mode. Moreover, we found that the PDZD7 HHD domain can bind lipid and mediate the localization of PDZD7 to the plasma membrane in HEK293T cells. Intriguingly, a hearing-loss mutation at the N-terminal extension region of the HHD can disrupt the lipid-binding ability of PDZD7 HHD, suggesting that HHD-mediated membrane targeting is required for the hearing process. This structural and biochemical characterization of the PDZD7 HHD region provides mechanistic explanations for human deafness-causing mutations in PDZD7. Furthermore, this structure will also facilitate biochemical and functional studies of other HHDs.