Genetic and inflammatory effects on childhood trauma and cognitive functioning in patients with schizophrenia and healthy participants

Cellular and extracellular white matter alterations after childhood trauma experience in individuals with schizophrenia

BACKGROUND

Childhood trauma (CT) is related to altered fractional anisotropy (FA) in individuals with schizophrenia (SZ). However, it remains unclear whether CT may influence specific cellular or extracellular compartments of FA in SZ with CT experience. We extended our previous study on FA in SZ (Costello et al., 2023) and examined the impact of CT on hypothesized lower free water-corrected FA (FAT) and higher extracellular free water (FW).

METHOD

Thirty-seven SZ and 129 healthy controls (HC) were grouped into the 'none/low' or 'high' CT group. All participants underwent diffusion-weighted magnetic resonance imaging. We performed tract-based spatial statistics to study the main effects of diagnostic group and CT, and the interaction between CT and diagnostic group across FAT and FW.

RESULTS

SZ displayed lower FAT within the corpus callosum and corona radiata compared to HC (p < 0.05, Threshold-Free Cluster Enhancement (TFCE)). Independent of diagnosis, we observed lower FAT (p < 0.05, TFCE) and higher FW (p < 0.05, TFCE) in both SZ and HC with high CT levels compared to SZ and HC with none or low CT levels. Furthermore, we did not identify an interaction between CT and diagnostic group (p > 0.05, TFCE).

CONCLUSIONS

These novel findings suggest that the impact of CT on lower FAT may reflect cellular rather than extracellular alterations in established schizophrenia. This highlights the impact of CT on white matter microstructure, regardless of diagnostic status.

Association Between Peptide Antigen-Related Antibody Levels and the Short- and Long-Term Efficacy of Antipsychotic Treatment in Drug-Naïve First-Episode Schizophrenia Patients

OBJECTIVE

This study investigated the relationships between baseline peptide antigen-related IgG levels and 8-week antipsychotic drug (APD) treatment response rates and one-year treatment outcomes, as well as the relationships between changes in peptide antigen-related IgG levels and one-year treatment outcomes, in first-episode schizophrenia (FES) patients.

METHODS

Sixteen peptide antigen-related IgGs from proteins encoded by schizophrenia-related genes were selected on the basis of several selection criteria from a 2022 genome-wide association study. Novel peptide antigen-related IgG levels were measured in drug-naïve FES patients at baseline (n = 155) and in plasma samples from 60 healthy controls (HCs). At the one-year follow-up, 57 patients completed both symptom and autoantibody assessments. Statistical analyses included t tests, Pearson correlation analysis, linear regression analysis, linear mixed-effects models, and simple slope analysis.

RESULTS

Anti-MOB4 IgG and anti-PDIA3 IgG levels were significantly lower in drug-naïve FES patients compared to HCs and showed a negative correlation with baseline excitement factor scores. Baseline anti-EMB IgG levels were associated with the 8-week treatment response, whereas anti-MAD1L1 IgG levels were correlated with one-year outcomes in drug-naïve FES patients. The one-year trajectory of changes in anti-FURIN IgG, anti-MAPK3 IgG, and anti-ACTR1B IgG levels was related to remission.

CONCLUSION

This study revealed that patients with schizophrenia had autoimmune abnormalities, with different peptide antigen-related IgG being associated with short-term or long-term treatment efficacy, and that these antibody levels were regulated by APDs.

Direct targets of MEF2C are enriched for genes associated with schizophrenia and cognitive function and are involved in neuron development and mitochondrial function

Myocyte Enhancer Factor 2C (MEF2C) is a transcription factor that plays a crucial role in neurogenesis and synapse development. Genetic studies have identified MEF2C as a gene that influences cognition and risk for neuropsychiatric disorders, including autism spectrum disorder (ASD) and schizophrenia (SCZ). Here, we investigated the involvement of MEF2C in these phenotypes using human-derived neural stem cells (NSCs) and glutamatergic induced neurons (iNs), which represented early and late neurodevelopmental stages. For these cellular models, MEF2C function had previously been disrupted, either by direct or indirect mutation, and gene expression assayed using RNA-seq. We integrated these RNA-seq data with MEF2C ChIP-seq data to identify dysregulated direct target genes of MEF2C in the NSCs and iNs models. Several MEF2C direct target gene-sets were enriched for SNP-based heritability for intelligence, educational attainment and SCZ, as well as being enriched for genes containing rare de novo mutations reported in ASD and/or developmental disorders. These gene-sets are enriched in both excitatory and inhibitory neurons in the prenatal and adult brain and are involved in a wide range of biological processes including neuron generation, differentiation and development, as well as mitochondrial function and energy production. We observed a trans expression quantitative trait locus (eQTL) effect of a single SNP at MEF2C (rs6893807, which is associated with IQ) on the expression of a target gene, BNIP3L. BNIP3L is a prioritized risk gene from the largest genome-wide association study of SCZ and has a function in mitophagy in mitochondria. Overall, our analysis reveals that either direct or indirect disruption of MEF2C dysregulates sets of genes that contain multiple alleles associated with SCZ risk and cognitive function and implicates neuron development and mitochondrial function in the etiology of these phenotypes.