The Candidate Schizophrenia Risk Gene Tmem108 Regulates Glucose Metabolism Homeostasis

Multiscale Synergy Networks Offer Insights into Disease and Comorbidity Mechanisms

Complex diseases involve extensive metabolic interactions within intricate biological networks. Consequently, it is advantageous to analyze metabolic phenotype data through metabolite interactions rather than focus on individual metabolites in isolation. In this article, we propose a novel analysis strategy called SynNet, which constructs multiscale synergy networks associated with specific metabolic phenotypes, offering new perspectives on the metabolic response mechanisms of diseases, including the mechanisms underlying disease comorbidity. The SynNet strategy begins with the construction of a metabolite-level synergy network (m-SynNet). This network is based on the definition and identification of significant metabolite pair interactions that distinguish disease phenotypes. Subsequently, a pathway synergy effect is defined by mapping these synergistic metabolite pairs onto the predefined metabolic pathways and performing a hypergeometric test to assess the probability of these pairs affecting a given pathway pair. The resulting significant pathway pairs identified form a pathway-level synergy network (p-SynNet). Both m-SynNet and p-SynNet offer complementary insights into disease mechanisms that go beyond conventional metabolomics analysis. For example, nodes with high connectivity in m-/p-SynNet suggest a strong correlation with the phenotype, while shared pathways across different phenotypes offer clues about the mechanisms of disease comorbidity. We applied the SynNet strategy to two real-world metabolomic data sets of disease comorbidity and identified key pathways associated with disease comorbidity from the p-SynNet. The candidate pathways are supported by the existing literature. Thus, the SynNet strategy may represent an alternative approach for metabolomic data analysis, providing novel insights into disease mechanisms and comorbidity.

Impact of age of onset on the course of chronic schizophrenia: factors associated with first hospitalization in a large-scale cross-sectional study

This study aims to identify the factors influencing the age of first hospitalization in patients with chronic schizophrenia, focusing on clinical features and blood parameters. A total of 1271 patients diagnosed with chronic schizophrenia were recruited from 17 psychiatric hospitals across China. Demographic and clinical data, including age of first hospitalization, were collected. The study also included assessments of psychiatric symptoms, duration of untreated psychosis (DUP), and various blood parameters. Statistical analyses were conducted to examine the relationships between these factors and the age of first hospitalization. The average age of first hospitalization was 28.07 ± 9.993 years. Single patients and those with a family history of mental illness were hospitalized at a younger age. Patients with suicidal ideation or behavior also had an earlier hospitalization age compared to those without such history. Regression analysis revealed that marital status (single), family history of mental illness, and suicide ideation or behavior were significant risk factors for earlier hospitalization age. Conversely, DUP, total protein (TP), and low-density lipoprotein (LDL) levels were positively correlated with the age of first hospitalization, while antipsychotic medication dosage and albumin (ALB) levels were negatively correlated. The study identifies significant demographic, clinical, and biochemical factors associated with the age of first hospitalization in chronic schizophrenia patients in China. These findings underscore the importance of early intervention and targeted support for high-risk groups to improve treatment outcomes.

Causes and countermeasures for the increased infection and COVID-19 mortality rates in patients with schizophrenia

Schizophrenia (SCZ) is a common psychiatric disorder that has a complex pathological mechanism. During the Coronavirus disease 2019 (COVID-19) epidemic, patients with SCZ had substantially higher rates of infection with SARS-CoV-2, the virus that causes COVID-19, as well as higher COVID-19 mortality relative to patients with other mental disorders. However, the reasons for these increased rates in patients with SCZ remain unknown. In this review, we hypothesize that certain molecular pathways exhibit abnormal function in both COVID-19 and SCZ, with a focus on those related to energy metabolism dysregulation, immune system disruption, and abnormalities of the central nervous system. We review that dysregulation of energy metabolism can result in disruptions to the immune system and abnormalities within the central nervous system (CNS). Furthermore, immune system disturbances may also contribute to CNS abnormalities in both SCZ and COVID-19. We also discuss macro-factors associated with the high infection and mortality rates of COVID-19 in patients with SCZ, including sociodemographic factors, reduced access to psychiatric healthcare, structural barriers to COVID-19 vaccination, and proposed approaches to mitigate these macro-factors.

Links between the genetic determinants of morning plasma cortisol and body shape: a two-sample Mendelian randomisation study

High cortisol production in Cushing's syndrome leads to fat centralisation. The influence of modest cortisol variations on body shape, however, is less clear. We examined potentially causal associations between morning plasma cortisol and body shape and obesity with inverse-variance weighted random-effects models in a two-sample Mendelian randomisation analysis. We used publicly available summary statistics from the CORtisol NETwork (CORNET) consortium, UK Biobank, and the Genetic Investigation of Anthropometric Traits (GIANT) consortium. Only in women, morning plasma cortisol (proxied by ten genetic polymorphisms) was associated positively with waist size reflected in waist-to-hip index (WHI, 0.035 standard deviation (SD) units change per one SD cortisol increase; 95% confidence interval (0.002-0.067); p = 0.036) and "a body shape index" (ABSI; 0.039 (0.006-0.071); p = 0.021). There was no evidence for associations with hip index (HI) or body mass index (BMI). Among individual polymorphisms, rs7450600 stood out (chromosome 6; Long Intergenic Non-Protein-Coding RNA 473 gene, LINC00473). Morning plasma cortisol proxied by rs7450600 was associated positively with WHI and inversely with HI and BMI in women and men. Our findings support a causal association of higher morning plasma cortisol with larger waist size in women and highlight LINC00473 as a genetic link between morning plasma cortisol and body shape.

LRP4 is required for the olfactory association task in the piriform cortex

Background

Low-density lipoprotein receptor-related protein 4 (LRP4) plays a critical role in the central nervous system (CNS), including hippocampal synaptic plasticity, maintenance of excitatory synaptic transmission, fear regulation, as well as long-term potentiation (LTP).

Results

In this study, we found that Lrp4 was highly expressed in layer II of the piriform cortex. Both body weight and brain weight decreased in Lrp4ECD/ECD mice without TMD (Transmembrane domain) and ICD (intracellular domain) of LRP4. However, in the piriform cortical neurons of Lrp4ECD/ECD mice, the spine density increased, and the frequency of both mEPSC (miniature excitatory postsynaptic current) and sEPSC (spontaneous excitatory postsynaptic current) was enhanced. Intriguingly, finding food in the buried food-seeking test was prolonged in both Lrp4ECD/ECD mice and Lrp4 cKO (conditional knockout of Lrp4 in the piriform cortex) mice.

Conclusions

This study indicated that the full length of LRP4 in the piriform cortex was necessary for maintaining synaptic plasticity and the integrity of olfactory function.

Evaluation of mRNA expression level of the ATP synthase membrane subunit c locus 1 (ATP5G1) gene in patients with schizophrenia

Background

Schizophrenia is a serious, complex mental disorder. The impairment of oxidative phosphorylation has a detrimental consequence on CNS function. Different ATP synthase subunits have been involved in the pathological process of various neurodegenerative disorders. Our goal was to evaluate the mRNA expression level of the ATP synthase membrane subunit c locus 1 (ATP5G1, also named ATP5MC1) gene in patients with schizophrenia.

Methods

Determination of the expression levels of ATP5G1 in plasma and peripheral blood mononuclear cells (PBMCs) were performed by real-time PCR in 90 controls and 90 patients with schizophrenia.

Results

Patients had significantly decreased ATP5G1 mRNA expression levels in both plasma and PBMCs compared to controls. The receiver operating characteristic curve was applied to detect a cut-off value of ATP5G1 expression in plasma and PBMCs. The ATP5G1 relative expression in PBMCs had better performance with a cut-off value ≤ 21 (AUC = 0.892, P < 0.001), sensitivity of 94.44%, and specificity of 72.22% in discriminating between schizophrenic patients. ATP5G1 expression in PBMCs was an independent predictor in schizophrenia.

Conclusion

This study revealed a down-regulation of ATP5G1 expression in schizophrenia, precisely expression in PBMCs. That might give insight into the role of ATP5G1 gene in the pathogenesis of schizophrenia.

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This study revealed a down-regulation of ATP5G1 expression in schizophrenia, precisely expression in PBMCs, which was found as an independent risk factor.

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This might give insight into the role of the ATP5G1 gene in the pathogenesis of schizophrenia.

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Further studies are needed to evaluate the role of ATP5G1 in schizophrenia and their impact on ATP production in these patients.

Crosstalk between Schizophrenia and Metabolic Syndrome: The Role of Oxytocinergic Dysfunction

The high prevalence of metabolic syndrome in persons with schizophrenia has spurred investigational efforts to study the mechanism beneath its pathophysiology. Early psychosis dysfunction is present across multiple organ systems. On this account, schizophrenia may be a multisystem disorder in which one organ system is predominantly affected and where other organ systems are also concurrently involved. Growing evidence of the overlapping neurobiological profiles of metabolic risk factors and psychiatric symptoms, such as an association with cognitive dysfunction, altered autonomic nervous system regulation, desynchrony in the resting-state default mode network, and shared genetic liability, suggest that metabolic syndrome and schizophrenia are connected via common pathways that are central to schizophrenia pathogenesis, which may be underpinned by oxytocin system dysfunction. Oxytocin, a hormone that involves in the mechanisms of food intake and metabolic homeostasis, may partly explain this piece of the puzzle in the mechanism underlying this association. Given its prosocial and anorexigenic properties, oxytocin has been administered intranasally to investigate its therapeutic potential in schizophrenia and obesity. Although the pathophysiology and mechanisms of oxytocinergic dysfunction in metabolic syndrome and schizophrenia are both complex and it is still too early to draw a conclusion upon, oxytocinergic dysfunction may yield a new mechanistic insight into schizophrenia pathogenesis and treatment.

Transmembrane protein 108 inhibits the proliferation and myelination of oligodendrocyte lineage cells in the corpus callosum

Background

Abnormal white matter is a common neurobiological change in bipolar disorder, and dysregulation of myelination in oligodendrocytes (OLs) is the cause. Transmembrane protein 108 (Tmem108), as a susceptible gene of bipolar disorder, is expressed higher in OL lineage cells than any other lineage cells in the central nervous system. Moreover, Tmem108 mutant mice exhibit mania-like behaviors, belonging to one of the signs of bipolar disorder. However, it is unknown whether Tmem108 regulates the myelination of the OLs.

Results

Tmem108 expression in the corpus callosum decreased with the development, and OL progenitor cell proliferation and OL myelination were enhanced in the mutant mice. Moreover, the mutant mice exhibited mania-like behavior after acute restraint stress and were susceptible to drug-induced epilepsy.

Conclusions

Tmem108 inhibited OL progenitor cell proliferation and mitigated OL maturation in the corpus callosum, which may also provide a new role of Tmem108 involving bipolar disorder pathogenesis.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13041-022-00918-7.