Genome-wide study of key genes and scoring system as potential noninvasive biomarkers for detection of suicide behavior in major depression disorder

Identification of blood transcriptome modules associated with suicidal ideation in patients with major depressive disorder

The risk of suicide in patients with major depressive disorder (MDD) poses a major concern, with studies suggesting that genetics may be a contributing factor. Although there are many transcriptomic studies on postmortem brain tissue related to suicidal behavior, the blood transcriptional mechanisms of suicidal ideation (SI) remain unknown. This study utilized a weighted gene coexpression network analysis (WGCNA) approach to investigate the associations between gene coexpression modules and SI in individuals with MDD using peripheral blood RNA-seq data from 75 MDD patients with SI (MDD_SI), 82 MDD patients without SI (MDD_nSI), and 149 healthy controls (HC). An ANCOVA was conducted to assess differences in gene coexpression modules among groups, with age and sex included as covariates. The gene ontology (GO) and Kyoto encyclopedia of genes and genomes (KEGG) databases were used to annotate module functions. Results indicated that the magenta module (associated with RNA splicing processes) differentiated MDD_SI from MDD_nSI (p = 0.021), while the green module (related to immune and inflammatory responses) distinguished MDD_SI from HC (p = 0.004). Additionally, three modules showed differences between MDD_nSI and HC: magenta (p = 0.009), brown (related to innate immunity and mitochondrial metabolism; p = 0.001), and turquoise (associated with energy metabolism and neurodegeneration; p = 0.005). Our findings highlight that gene expression regulation, immune response, and inflammation may be linked to SI in patients with MDD, while pathways associated with innate immunity, energy metabolism, mitochondrial function, and neurodegeneration appear to be more broadly related to MDD.

A human-specific insertion promotes cell proliferation and migration by enhancing TBC1D8B expression

Human-specific insertions play important roles in human phenotypes and diseases. Here we reported a 446-bp insertion (Insert-446) in intron 11 of the TBC1D8B gene, located on chromosome X, and traced its origin to a portion of intron 6 of the EBF1 gene on chromosome 5. Interestingly, Insert-446 was present in the human Neanderthal and Denisovans genomes, and was fixed in humans after human-chimpanzee divergence. We have demonstrated that Insert-446 acts as an enhancer through binding transcript factors that promotes a higher expression of human TBC1D8B gene as compared with orthologs in macaques. In addition, over-expression TBC1D8B promoted cell proliferation and migration through "a dual finger" catalytic mechanism (Arg538 and Gln573) in the TBC domain in vitro and knockdown of TBC1D8B attenuated tumorigenesis in vivo. Knockout of Insert-446 prevented cell proliferation and migration in cancer and normal cells. Our results reveal that the human-specific Insert-446 promotes cell proliferation and migration by upregulating the expression of TBC1D8B gene. These findings provide a significant insight into the effects of human-specific insertions on evolution.

Dysconnectivity of the brain functional network and abnormally expressed peripheral transcriptional profiles in patients with anxious depression

BACKGROUND

Major depressive disorder (MDD) is a heterogeneous mental disorder, and accompanying anxiety symptoms, known as anxious depression (AD), are the most common subtype. However, the pathophysiology of AD may be distinct in depressed patients without anxiety (NAD) and remains unknown. This study aimed to investigate the relationship between functional connectivity and peripheral transcriptional profiles in patients with AD and NAD.

METHODS

Functional imaging data were collected to identify differences in functional networks among patients with AD (n = 66), patients with NAD (n = 115), and healthy controls (HC, n = 200). The peripheral transcriptional data were clustered as co-expression modules, and their associations with AD, AND, and HC were analyzed. The gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) functional enrichment analyses of the genes in the significant module were performed. Correlation analysis was performed to identify functional network-associated gene co-expression modules.

RESULTS

A network was identified which consisted of 23 nodes and 28 edges that were significantly different among three sample groups. The regions of the network were located in temporal and occipital lobe. Two gene co-expression modules were shown to be associated with NAD, and one of which was correlated with the disrupted network in the AD group. The biological function of this module was enriched in immune regulation pathways.

CONCLUSION

The results suggested that immune-related mechanisms were associated with functional networks in AD.

Sex differences in serum trace elements and minerals levels in unmedicated patients with major depressive episode: The role of suicidal ideation

BACKGROUND

We aimed to examine the influence of gender on serum trace elements and minerals levels in depression, as well as the impact of suicidal ideation (SI) on these gender dimorphisms.

METHODS

A total of 260 unmedicated patients with a current major depressive episode were enrolled. The Beck Scale for Suicide Ideation was utilized to evaluate SI. The serum levels of copper, zinc, iron, calcium, phosphorus, and magnesium were quantified.

RESULTS

Within the non-SI (NSI) group, females exhibited higher levels of copper (p = 0.001) and phosphorus (p = 0.008), and lower levels of zinc (p = 0.022) and calcium (p = 0.008) compared to males. Conversely, no discernible gender disparities were observed in the SI group (all p > 0.05). Also, no group differences in these trace elements/minerals were observed between the SI and NSI groups (all p > 0.05). Notably, serum iron levels exhibited a significant group-by-sex interaction effect (p = 0.024). Further analysis revealed that iron levels were higher in the SI group than in the NSI group among females (p = 0.048), but lower in females than in males within the NSI group (p < 0.001). Moreover, a positive association between the fourth quantile of serum iron and SI was detected in females (odds ratio [OR] = 2.88, 95 % confidence interval [CI]: 1.08-8.11).

CONCLUSIONS

Gender effects on serum trace element/mineral levels were different in depressed patients with and without SI. Female patients were susceptible to SI when serum iron was at the upper end of normal.

Integrative transcriptome- and DNA methylation analysis of brain tissue from the temporal pole in suicide decedents and their controls

Suicide rates have increased steadily world-wide over the past two decades, constituting a serious public health crisis that creates a significant burden to affected families and the society as a whole. Suicidal behavior involves a multi-factorial etiology, including psychological, social and biological factors. Since the molecular neural mechanisms of suicide remain vastly uncharacterized, we examined transcriptional- and methylation profiles of postmortem brain tissue from subjects who died from suicide as well as their neurotypical healthy controls. We analyzed temporal pole tissue from 61 subjects, largely free from antidepressant and antipsychotic medication, using RNA-sequencing and DNA-methylation profiling using an array that targets over 850,000 CpG sites. Expression of NPAS4, a key regulator of inflammation and neuroprotection, was significantly downregulated in the suicide decedent group. Moreover, we identified a total of 40 differentially methylated regions in the suicide decedent group, mapping to seven genes with inflammatory function. There was a significant association between NPAS4 DNA methylation and NPAS4 expression in the control group that was absent in the suicide decedent group, confirming its dysregulation. NPAS4 expression was significantly associated with the expression of multiple inflammatory factors in the brain tissue. Overall, gene sets and pathways closely linked to inflammation were significantly upregulated, while specific pathways linked to neuronal development were suppressed in the suicide decedent group. Excitotoxicity as well as suppressed oligodendrocyte function were also implicated in the suicide decedents. In summary, we have identified central nervous system inflammatory mechanisms that may be active during suicidal behavior, along with oligodendrocyte dysfunction and altered glutamate neurotransmission. In these processes, NPAS4 might be a master regulator, warranting further studies to validate its role as a potential biomarker or therapeutic target in suicidality.

Mesenchymal stem cells overexpressing XIST induce macrophage M2 polarization and improve neural stem cell homeostatic microenvironment, alleviating spinal cord injury

Spinal cord injury (SCI) is a significant cause of disability worldwide, with limited treatment options. This study investigated the potential of bone marrow-derived mesenchymal stem cells (BMSCs) modified with XIST lentiviral vector to modulate macrophage polarization and affect neural stem cell (NSC) microenvironment reconstruction following SCI. Bioinformatics analysis revealed that MID1 might be crucial for BMSCs' treatment of SCI. XIST overexpression enriched Zmynd8 to the promoter region of MID1 and inhibited MID1 transcription, which promoted macrophage M2 polarization. In vitro experiments showed that BMSCs-XIST promoted NSC proliferation, migration, differentiation, and axonal growth by inducing macrophage M2 polarization, suppressing inflammation, and accelerating the re-establishment of the homeostatic microenvironment of NSCs. In vivo, animal experiments confirmed that BMSCs-XIST significantly alleviated SCI by promoting NSC differentiation and axon formation in the injured area. The study demonstrated the potential of XIST-overexpressing BMSCs for treating SCI by regulating macrophage polarization and homeostasis of the NSC microenvironment. These findings provide new insights into the development of stem cell-based therapies for SCI.

Biomimetic composite hydrogel promotes new bone formation in rat bone defects through regulation of miR-19b-3p/WWP1 axis by loaded extracellular vesicles

OBJECTIVE

This study aims to investigate the mechanism by which biomimetic composite hydrogels loaded with bone marrow mesenchymal stem cells (BMSCs) derived microRNA-19b-3p/WWP1 axis through extracellular vesicles (EVs) affect the new bone formation in rat bone defects.

METHODS

First, synthesize the bionic composite hydrogel Gel-OCS/MBGN. Characterize it through field-emission scanning electron microscopy (FE-SEM), X-ray diffraction (XRD), and FTIR. Then, conduct performance tests such as rheology, dynamic mechanical analysis, in vitro mineralization, and degradation. Rat BMSCs were selected for in vitro cell experiments, and EVs derived from BMSCs were obtained by differential centrifugation. The EVs were loaded onto Gel-OCS/MBGN to obtain Gel-OCS/MBGN@EVs hydrogel. Cell viability and proliferation were detected by live/dead cell staining and CCK-8 assay, respectively. ALP and ARS staining was used to evaluate the osteogenic differentiation of BMSCs. Differential gene expression analysis of osteogenic differentiation was performed using high-throughput sequencing. TargetScan database predicted the binding site between miR-19b-3p and WWP1, and a dual-luciferase reporter assay was performed to confirm the targeting binding site. A rat bone defect model was established, and new bone formation was evaluated by Micro-CT, H&E staining, and Masson's trichrome staining. Immunofluorescence staining and immunohistochemistry were used to detect the expression levels of osteogenic-related factors in rat BMSCs. RT-qPCR and Western blot were used to detect the expression levels of genes and proteins in tissues and cells.

RESULT

Gel-OCS/MBGN was successfully constructed and loaded with EVs, resulting in Gel-OCS/MBGN@EVs. The in vitro drug release experiment results show that Gel-OCS/MBGN could sustainably release EVs. Further experiments have shown that Gel-OCS/MBGN@EVs could significantly promote the differentiation of BMSCs into osteoblasts. Experiments have shown that WWP1 is a key factor in osteogenic differentiation and is regulated by miR-19b-3p. EVs promote osteogenic differentiation by suppressing WWP1 expression through the transmission of miR-19b-3p. In vivo animal experiments have demonstrated that Gel-OCS/MBGN@EVs significantly promote bone repair in rats with bone defects by regulating the miR-19b-3p/WWP1 signaling axis.

CONCLUSION

Functional Gel-OCS/MBGN@EVs were obtained by constructing Gel-OCS/MBGN and loading EVs onto it. EVs could deliver miR-19b-3p to BMSCs, inhibit the expression of WWP1, and promote the osteogenic differentiation of BMSCs, ultimately promoting bone regeneration in rats with bone defects.

The relationship between causes of suicidal attempts in Iran and individual and social variables: a retrospective study

OBJECTIVE

Determine the prevalence of suicide attempts and the relationships between the different causes of attempts with sociodemographic and clinical characteristics among individuals in Iran.

METHODS

A retrospective review of data about suicide attempts from poisoning care centers in Babol city between 2017 and 2021. Multinomial regression analysis (with mental illness being the reference variable) was used to determine the factors associated with the different causes of suicide attempts (addiction, romantic relationship problems, and economic problems).

RESULTS

The overall prevalence of completed suicide in the population sampled was 10.8% (95% confidence interval 9.5-12.1) (244/2,263). Relative to mental disorder, given that other variables in the model are held constant the following were associated with suicide attempts. A previous history of suicide attempts was associated with increasing the relative risk ratio of attempting suicide while having no positive history of smoking was associated with reducing the relative risk ratio of a suicidal attempt. However, the use of multiple drugs to attempt suicide was associated with an increased relative risk ratio of attempting suicide with romantic relationship problems and addiction as causes of suicide attempts. The first year of data collection (2017) and the female gender were both associated with an increased relative risk ratio of having a suicide attempt due to romantic relationships and economic problems. A family history of suicide was associated with an increased relative risk ratio of suicide attempts due to romantic relationship problems. However, using Pesticides-aluminum phosphide and detergent and javel water to attempt reduced the relative risk ratio of attempting due to romantic relationship problems. Age, self-employment, middle income, and married were associated with an increased relative risk ratio of suicide attempts among individuals due to addiction. However, staying longer at the emergency department was associated with a reduced relative risk ratio of having had a suicide attempt due to addiction.

CONCLUSIONS

This study highlights the interplay between romantic hardships, addiction, economic hardships as reasons for suicide attempts and various sociable variables in a population in Northern Iran. The most associated reason for suicide attempts was romantic relationship hardships. Therefore, interventions such as sessions on conflict resolution, boundary setting, and management of grieving would greatly benefit this society and reduce the rate of suicide, especially among individuals with a history of suicide attempts.

Integrating Metabolomics and Network Analysis for Exploring the Mechanism Underlying the Antidepressant Activity of Paeoniflorin in Rats With CUMS-Induced Depression

Background: Paeoniflorin (PF) represents the major bioactive constituent of the traditional Chinese medicine plant Paeonia suffruticosa (Ranunculaceae), which has a long history as a folk medicine in Asian. Paeoniflorin, a bitter pinene monoterpene glycoside, has antidepressant effects, but its potential therapeutic mechanism has not been thoroughly explored.

Methods: Experimental depression in rats was established by the chronic unpredictable mild stress (CUMS) combined with orphan method, and the efficacy of paeoniflorin on depression was evaluated by the sucrose preference test and open field test. The antidepressant mechanism of paeoniflorin was investigated by metabolomic and network pharmacology. The relevant pathways of biomarkers highlighted in metabolomics were explored, and the possible targets of paeoniflorin in the treatment of depression were further revealed through network analysis. The binding activity of paeoniflorin to key targets was verified by molecular docking.

Results: Metabolomics showed that rats with CUMS-induced depression had urine metabolic disorders, which were reversed by paeoniflorin through the regulation of metabolic pathways. Metabolites that play a key role in the function of paeoniflorin include citric acid, thiamine monophosphate, gluconolactone, 5-hydroxyindoleacetic acid and stachyose. Key predicted targets are SLC6A4, TNF, IL6 and SLC6A3. An important metabolic pathway is the Citrate cycle (TCA cycle).

Conclusion: Network integrative analysis in this study showed that paeoniflorin could improve depressive-like symptoms in model rats with CUMS-induced depression and overall correct the disordered metabolic profile through multiple metabolic pathways.

Identification of Key Modules and Genes Associated with Major Depressive Disorder in Adolescents

Major depressive disorder (MDD) is a leading cause of disability worldwide. Adolescence is a crucial period for the occurrence and development of depression. There are essential distinctions between adolescent and adult depression patients, and the etiology of depressive disorder is unclear. The interactions of multiple genes in a co-expression network are likely to be involved in the physiopathology of MDD. In the present study, RNA-Seq data of mRNA were acquired from the peripheral blood of MDD in adolescents and healthy control (HC) subjects. Co-expression modules were constructed via weighted gene co-expression network analysis (WGCNA) to investigate the relationships between the underlying modules and MDD in adolescents. In the combined MDD and HC groups, the dynamic tree cutting method was utilized to assign genes to modules through hierarchical clustering. Moreover, functional enrichment analysis was conducted on those co-expression genes from interested modules. The results showed that eight modules were constructed by WGCNA. The blue module was significantly associated with MDD after multiple comparison adjustment. Several Gene Ontology (GO) terms and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways associated with stress and inflammation were identified in this module, including histone methylation, apoptosis, NF-kappa β signaling pathway, and TNF signaling pathway. Five genes related to inflammation, immunity, and the nervous system were identified as hub genes: CNTNAP3, IL1RAP, MEGF9, UBE2W, and UBE2D1. All of these findings supported that MDD was associated with stress, inflammation, and immune responses, helping us to obtain a better understanding of the internal molecular mechanism and to explore biomarkers for the diagnosis or treatment of depression in adolescents.

Dynamic changes of intestinal flora in patients with irritable bowel syndrome combined with anxiety and depression after oral administration of enterobacteria capsules

This study investigated the clinical characteristics and dynamic changes of intestinal bacterial community to evaluate the curative effect of fecal microbiota transplantation (FMT) on irritable bowel syndrome with predominant diarrhea (IBS-D) comorbid with anxiety and depression. Total two treatments were designed in randomize-controlled trial includes oral FMT capsules with 1 week (A1), 8 weeks (A2), and 12 weeks (A3), as well as oral empty capsules with 1 week (B1), 8 weeks (B2), and 12 weeks (B3) as control for comparison. The positive therapeutic effects occurred in FMT colonized patient with IBS-D comorbid psychological disorder, demonstrated at alleviated IBS-D severity (IBS-SSS score from 291.11 reduced to 144.44), altered stool type (from 6 changed to 4), reduced anxiety and depression scores (from 18.33 to 8.39 and from 22.33 to 17.78) after FMT-treated 12 weeks. The FMT therapy improved bacterial alpha diversity and the majority bacterial community predominant by Bacteroidetes and Firmicutes, and the relative abundance (RA) was higher after FMT-treated 12 weeks (50.61% and 45.52%) than control (47.62% and 38.96%). In short, FMT therapy has great potential for IBS-D patients combined with anxiety and depression by alleviated clinical symptoms and restore the intestinal micro-ecology.

Expression and role of microRNA-212/nuclear factor I-A in depressive mice

Depression is characterized by persistent depressed mood and cognitive dysfunction, severely impacting human health. In the present study, we aimed to explore the role and mechanism of microRNA (miR)-212 in depression in vivo. Chronic unpredictable mild stress (CUMS) mice were established, and depression-like behaviors were confirmed using the forced swimming test (FST), sucrose preference test (SPT), and the tail suspension test (TST). Next, the expression of miR-212 and its potential target, i.e., nuclear factor I-A (NFIA), was verified using quantitative reverse transcription (qRT)-PCR analysis and Western blotting in CUMS mice. The effects of miR-212 and NFIA on depression-like behaviors, inflammatory response, and neuronal apoptosis were examined using FST, TST, SPT, enzyme-linked immunosorbent assay (ELISA) assay, and flow cytometry analysis. Finally, the relationship between miR-212 and NFIA was examined using a dual-luciferase reporter assay. Based on our findings, miR-212 was significantly upregulated, while NFIA was downregulated in CUMS mice. miR-212 overexpression could suppress the CUMS-induced weight loss, immobility time in FST and TST, and increased hippocampal neuronal apoptosis and pro-inflammatory cytokines levels. In addition, NFIA upregulation could partially reverse the effects of miR-212 mimic in CUMS mice. Accordingly, miR-212 could ameliorate CUMS-induced depression-like behavior in mice by targeting NFIA, indicating its protective role in depression.

Identification of a prognostic chemoresistance-related gene signature associated with immune microenvironment in breast cancer

Breast cancer is the most common form of cancer among women globally, and chemoresistance is a major challenge to disease treatment that is associated with a poor prognosis. This study was formulated to identify a reliable prognostic biosignature capable of predicting the survival of patients with chemoresistant breast cancer (CRBC) and evaluating the associated tumor immune microenvironment. Through a series of protein-protein interaction and weighted correlation network analyses, genes that were significantly associated with breast cancer chemoresistance were identified. Moreover, univariate Cox regression and lasso-penalized Cox regression analyses were employed to generate a prognostic model, and the prognostic utility of this model was then assessed using time-dependent receiver operating characteristic (ROC) and Kaplan-Meier survival curves. Finally, The CIBERSORT and ESTIMATE algorithms were additionally leveraged to assess relationships between the tumor immune microenvironment and patient prognostic signatures. Overall, a multigenic prognostic biosignature capable of predicting CRBC patient risk was successfully developed based on bioinformatics analysis and in vitro experiments. This biosignature was able to stratify CRBC patients into high- and low-risk subgroups. ROC curves also revealed that this biosignature achieved high diagnostic efficiency, and multivariate regression analyses indicated that this risk signature was an independent risk factor linked to CRBC patient outcomes. In addition, this signature was associated with the infiltration of the tumor microenvironment by multiple immune cell types. In conclusion, the chemoresistance-associated prognostic gene signature developed herein was able to effectively evaluate the prognosis of CRBC patients and to reflect the overall composition of the tumor immune microenvironment.

Understanding complex functional wiring patterns in major depressive disorder through brain functional connectome

Brain function relies on efficient communications between distinct brain systems. The pathology of major depressive disorder (MDD) damages functional brain networks, resulting in cognitive impairment. Here, we reviewed the associations between brain functional connectome changes and MDD pathogenesis. We also highlighted the utility of brain functional connectome for differentiating MDD from other similar psychiatric disorders, predicting recurrence and suicide attempts in MDD, and evaluating treatment responses. Converging evidence has now linked aberrant brain functional network organization in MDD to the dysregulation of neurotransmitter signaling and neuroplasticity, providing insights into the neurobiological mechanisms of the disease and antidepressant efficacy. Widespread connectome dysfunctions in MDD patients include multiple, large-scale brain networks as well as local disturbances in brain circuits associated with negative and positive valence systems and cognitive functions. Although the clinical utility of the brain functional connectome remains to be realized, recent findings provide further promise that research in this area may lead to improved diagnosis, treatments, and clinical outcomes of MDD.

Identification of the Real Hub Gene and Construction of a Novel Prognostic Signature for Pancreatic Adenocarcinoma Based on the Weighted Gene Co-expression Network Analysis and Least Absolute Shrinkage and Selection Operator Algorithms

Background: Pancreatic adenocarcinoma (PAAD) has a considerably bad prognosis, and its pathophysiologic mechanism remains unclear. Thus, we aimed to identify real hub genes to better explore the pathophysiology of PAAD and construct a prognostic panel to better predict the prognosis of PAAD using the weighted gene co-expression network analysis (WGCNA) and the least absolute shrinkage and selection operator (LASSO) algorithms. Methods: WGCNA identified the modules most closely related to the PAAD stage and grade based on the Gene Expression Omnibus. The module genes significantly associated with PAAD progression and prognosis were considered as the real hub genes. Eligible genes in the most significant module were selected for construction and validation of a multigene prognostic signature based on the LASSO-Cox regression analysis in The Cancer Genome Atlas and the International Cancer Genome Consortium databases, respectively. Results: The brown module identified by WGCNA was most closely associated with the clinical characteristics of PAAD. Scaffold attachment factor B (SAFB) was significantly associated with PAAD progression and prognosis, and was identified as the real hub gene of PAAD. Moreover, both transcriptional and translational levels of SAFB were significantly lower in PAAD tissues compared with normal pancreatic tissues. In addition, a novel multigene-independent prognostic signature consisting of SAFB, SP1, and SERTAD3 was identified and verified. The predictive accuracy of our signature was superior to that of previous studies, especially for predicting 3- and 5-year survival probabilities. Furthermore, a prognostic nomogram based on independent prognostic variables was developed and validated using calibration curves. The predictive ability of this nomogram was also superior to the well-established AJCC stage and histological grade. The potential mechanisms of different prognoses between the high- and low-risk subgroups were also investigated using functional enrichment analysis, GSEA, ssGSEA, immune checkpoint analysis, and mutation profile analysis. Conclusion: SAFB was identified as the real hub gene of PAAD. A novel multigene-independent prognostic signature was successfully identified and validated to better predict PAAD prognosis. An accurate nomogram was also developed and verified to aid in the accurate treatment of tumors, as well as in early intervention.

Potential biomarkers: differentially expressed proteins of the extrinsic coagulation pathway in plasma samples from patients with depression

Depression is a severe disabling psychiatric illness and the pathophysiological mechanisms remain unknown. In previous work, we found the changes in extrinsic coagulation (EC) pathway proteins in depressed patients compared with healthy subjects were significant. In this study, we screened differentially expressed proteins (DEPs) in the EC pathway, and explored the molecular mechanism by constructing a protein-protein interaction (PPI) network. The DEPs of the EC pathwaywere initially screened by isobaric tags for relative and absolute quantification (iTRAQ) in plasma samples obtained from 20 depression patients and 20 healthy controls, and were then identified by Enzyme-linked immunosorbent assays (ELISAs). Ingenuity Pathway Analysis (IPA) software was used to analyse pathway. The differentially expressed genes (DEGs) were identified by analyzing the GSE98793 microarray data from the Gene Expression Omnibus database using the Significance Analysis for Microarrays (SAM, version 4.1) statistical method. Cytoscape version 3.4.0 software was used to construct and visualize PPI networks. The results show that Fibrinogen alpha chain (FGA), Fibrinogen beta chain (FGB), Fibrinogen gamma chain (FGG) and Coagulation factor VII (FVII) were screened in the EC pathway from depression patient samples. FGA, FGB, and FGG were significantly up-regulated, and FVII was down-regulated. Thirteen DEGs related to depression and EC pathways were identified from the microarray database. Among them NF-κB Inhibitor Beta (NFKBIB) and Heat shock protein family B (small) member 1 (HSPB1) were highly correlated with EC pathway. We conclude that EC pathway is associated with depression, which provided clues for the biomarker development and the pathogenesis of depression.

Cortical expression of the RAPGEF1 gene in schizophrenia: investigating regional differences and suicide

Rap guanine nucleotide exchange factor 1 (RAPGEF1) is involved in cell adhesion and neuronal migration. Previously we found lower RAPGEF1 mRNA levels in Brodmann's area (BA) 9 in subjects with schizophrenia compared to controls. This study aimed to determine whether RAPGEF1 expression was altered in other brain regions implicated in schizophrenia and whether this was associated with suicide. Using qPCR, we measured the levels of RAPGEF1 in post-mortem BA 8 and 44 from 27 subjects with schizophrenia and 26 non-psychiatric control subjects. To address the effect of antipsychotic treatments, Rapgef1 mRNA levels were measured in the cortex from rats treated with typical antipsychotic drugs. There was no difference in RAPGEF1 normalised relative expression levels in BA 8 or 44. However, in BA 8, schizophrenia subjects had higher raw Ct RAPGEF1 levels compared to controls. There were higher RAPGEF1 levels in suicide completers compared to non-suicide schizophrenia subjects in BA 8. Rapgef1 expression levels in the rat cortex did not vary with antipsychotic treatment. Our findings suggest changes in RAPGEF1 expression may be limited to the dorsolateral prefrontal cortex from subjects with schizophrenia. Further investigation of the function of RAPGEF1 may lead to a greater understanding of the pathophysiology of schizophrenia.

Temporal patterns of suicide and circulatory system disease-related mortality are inversely correlated in several countries

BACKGROUND

Nearly 800,000 suicides occur worldwide annually and suicide rates are increasing faster than population growth. Unfortunately, the pathophysiology of suicide remains poorly understood, which has hindered suicide prevention efforts. However, mechanistic clues may be found by studying effects of seasonality on suicide and other mortality causes. Suicides tend to peak in spring-summer periods and nadir in fall-winter periods while circulatory system disease-related mortality tends to exhibit the opposite temporal trends. This study aimed to determine for the first time whether monthly temporal cross-correlations exist between suicide and circulatory system disease-related mortality at the population level. If so and if common biological factors moderate risks for both mortality types, such factors may be discoverable and utilized to improve suicide prevention.

METHODS

We conducted time series analyses of monthly mortality data from northern (England and Wales, South Korea, United States) and southern (Australia, Brazil) hemisphere countries during the period 2009-2018 (N = 41.8 million all-cause mortality cases). We used a Poisson regression variant of the standard cosinor model to determine peak months of mortality. We also estimated cross-correlations between monthly mortality counts from suicide and from circulatory system diseases.

RESULTS

Suicide and circulatory disease-related mortality temporal patterns were negatively correlated in Australia (- 0.32), Brazil (- 0.57), South Korea (- 0.32), and in the United States (- 0.66), but no temporal correlation was discernable in England and Wales.

CONCLUSIONS

The negative temporal cross-correlations between these mortality types we found in 4 of 5 countries studied suggest that seasonal factors broadly and inversely moderate risks for circulatory disease-related mortality and suicide, but not in all regions, indicating that the effect is not uniform. Since the seasonal factors of temperature and light exert opposite effects on suicide and circulatory disease-related mortality in several countries, we propose that physiologically-adaptive circulatory system responses to heat and light may increase risk for suicide and should be studied to determine whether they affect suicide risk. For example, heat and light increase production and release of the bioactive gas nitric oxide and reduce circulatory system disease by relaxing blood vessel tone, while elevated nitric oxide levels are associated with suicidal behavior, inverse effects that parallel the inverse temporal mortality patterns we detected.