Functional Variants of miR-143 Are Associated with Schizophrenia Susceptibility: A Preliminary Population-Based Study and Bioinformatics Analysis

Characterization of RNA cargo from extracellular vesicles obtained from cerebrospinal fluid and plasma samples in schizophrenia participants and healthy volunteers

Biomarkers that are clinically useful for the diagnosis and treatment of schizophrenia are lacking. Biomarkers are critical tools that reduce the incidence of misdiagnosis, identify subgroups of patients, assist in the proper characterization of patient phenotypes, predict response to treatment or the development of side effects, and can serve as targets for novel therapeutic interventions. In this study, we evaluated small (< 200 nucleotide) and long (> 200 nucleotide) RNAs found in extracellular vesicles (EVs) isolated from the cerebrospinal fluid (CSF) and plasma of individuals with schizophrenia spectrum disorders (SSD) and healthy volunteers (HV). As EVs carry cargo from all tissues in the body, they act as a potential proxy for the tissue of origin, including cells from the brain. We compared the transcriptomic features of EVs from these two biofluids and examined their ability to discriminate between SSD and HV participants, identifying a total of 141 differentially expressed genes, some of which have been previously associated with SSD. Next, we evaluated the potential cell-types that give rise to the SSD-associated CSF RNA cargo, and found the majority were predominantly expressed in excitatory neurons. Our results highlight the potential of EVs as both a source of schizophrenia relevant biomarkers, and molecular insight into disease mechanisms.

Role of miRNA Gene Variants (miR-22 and miR-155) as the Factors Affecting Susceptibility to Panic Disorder

Objective

Variants within genes encoding microRNAs (miRNAs) may alter the expression of both miRNAs and their target genes, thus contributing to the etiology of psychiatric disorders. The involvement of miRNAs in neuronal differentiation and synaptic plasticity supported this hypothesis. We aimed to investigate the links between miR-155 rs767649/miR-22 rs8076112 and the risk of panic disorder (PD) in a sample of Turkish population.

Methods

In this experimental study, 134 PD patients and 140 healthy controls were recruited. Genotyping was carried out using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) method. To evaluate PD phenotypes, Panic Disorder Severity Scale (PDSS) was also administered to patients to clarify possible associations between the scale and risk variants analyzed.

Results

The genotype analysis of miR-155 rs767649 did not show an association with PD risk and it was not related to the disease severity. For miR-22 rs8076112 variant, a statistically significant association was determined; CC genotypes were lower in patients compared to controls. Logistic regression analysis proved the highly protective effect (80.4%) of CC genotype against PD (p = 0.041; OR = 0.196, 95% CI = 0.041-0.934). Though its significance in disease liability, miR-22 rs8076112 was not associated with the disease severity.

Conclusion

Our findings firstly report the combined analysis of miR-155 rs767649 and miR-22 rs8076112 in PD in terms of both disease susceptibility and severity. These findings await replication in independent cohorts with enrichment of other miRNA gene variants. Thus, certain miRNAs and their target genes involved in the etiology and phenotypes of PD could be enlightened.

'Whole-Body' Perspectives of Schizophrenia and Related Psychotic Illness: miRNA-143 as an Exemplary Molecule Implicated across Multi-System Dysfunctions

A wide array of biological abnormalities in psychotic illness appear to reflect non-cerebral involvement. This review first outlines the evidence for such a whole-body concept of schizophrenia pathobiology, focusing particularly on cardiovascular disease, metabolic syndrome and diabetes, immunity and inflammation, cancer, and the gut-brain axis. It then considers the roles of miRNAs in general and of miRNA-143 in particular as they relate to the epidemiology, pathobiology, and treatment of schizophrenia. This is followed by notable evidence that miRNA-143 is also implicated in each of these domains of cardiovascular disease, metabolic syndrome and diabetes, immunity and inflammation, cancer, and the gut-brain axis. Thus, miRNA-143 is an exemplar of what may be a class of molecules that play a role across the multiple domains of bodily dysfunction that appear to characterize a whole-body perspective of illness in schizophrenia. Importantly, the existence of such an exemplary molecule across these multiple domains implies a coordinated rather than stochastic basis. One candidate process would be a pleiotropic effect of genetic risk for schizophrenia across the whole body.

Potential Early Effect Biomarkers for Ambient Air Pollution Related Mental Disorders

Air pollution is one of the greatest environmental risks to health, with 99% of the world's population living where the World Health Organization's air quality guidelines were not met. In addition to the respiratory and cardiovascular systems, the brain is another potential target of air pollution. Population- and experiment-based studies have shown that air pollution may affect mental health through direct or indirect biological pathways. The evidence for mental hazards associated with air pollution has been well documented. However, previous reviews mainly focused on epidemiological associations of air pollution with some specific mental disorders or possible biological mechanisms. A systematic review is absent for early effect biomarkers for characterizing mental health hazards associated with ambient air pollution, which can be used for early warning of related mental disorders and identifying susceptible populations at high risk. This review summarizes possible biomarkers involved in oxidative stress, inflammation, and epigenetic changes linking air pollution and mental disorders, as well as genetic susceptibility biomarkers. These biomarkers may provide a better understanding of air pollution's adverse effects on mental disorders and provide future research direction in this arena.

Regulation of Zbp1 by miR-99b-5p in microglia controls the development of schizophrenia-like symptoms in mice

Current approaches to the treatment of schizophrenia have mainly focused on the protein-coding part of the genome; in this context, the roles of microRNAs have received less attention. In the present study, we analyze the microRNAome in the blood and postmortem brains of schizophrenia patients, showing that the expression of miR-99b-5p is downregulated in both the prefrontal cortex and blood of patients. Lowering the amount of miR-99b-5p in mice leads to both schizophrenia-like phenotypes and inflammatory processes that are linked to synaptic pruning in microglia. The microglial miR-99b-5p-supressed inflammatory response requires Z-DNA binding protein 1 (Zbp1), which we identify as a novel miR-99b-5p target. Antisense oligonucleotides against Zbp1 ameliorate the pathological effects of miR-99b-5p inhibition. Our findings indicate that a novel miR-99b-5p-Zbp1 pathway in microglia might contribute to the pathogenesis of schizophrenia.

Genetic polymorphism of IL-17F rs763780 contributes to the susceptibility to bipolar disorder but not to schizophrenia in the Turkish population

This study aims to investigate the genetic polymorphism in the interleukin-17F (IL-17F) (rs763780, 7488 A/G) gene in bipolar disorder (BD) and schizophrenia (SCZ) patients by comparing it with healthy controls considering clinical parameters. A sample of 107 patients with BD, 129 patients with SCZ, and 100 healthy volunteers were included. SCID-I was used to confirm the diagnosis according to DSM-IV-TR criteria. The Young Mania Rating Scale (YMRS) and the Hamilton Depression Rating Scale (HAM-D) were administered to BD patients. The Positive and Negative Symptoms Scale (PANSS) was applied to the patients with SCZ. PCR-RFLP was used to determine IL-17F gene polymorphism. Our results demonstrated that the distributions of the IL-17F genotype and the allele frequencies of BD patients were statistically significantly different from the control group. The AA genotype (OR: 0.283; 95% Cl: 0.140-0.573; p<.001) and A allele (OR: 0.333; 95% Cl: 0.171-0.646; p=.001) frequencies were significantly higher in the control group than in the BD group. The IL-17F genotype and the allele frequency distributions of SCZ patients were not statistically significantly different from the control group. When comparing scale scores due to the IL-17F genotype distributions in patients with BD or SCZ, there was no statistically significant difference between the groups of IL-17F genotypes. In summary, whereas the IL-17F polymorphism may be associated with BD, this polymorphism was not related to SCZ.

Association of CTNND2 gene polymorphism with schizophrenia: Two-sample case-control study in Chinese Han population

OBJECTIVES

Genetic factors play an important role in the etiology of schizophrenia (SZ). Catenin Delta 2 (CTNND2) is one of the genes regulating neuronal development in the brain. It is unclear whether CTNND2 is involved in SZ. With the hypothesis that CTNND2 may be a risk gene for SZ, we performed a case-control association analysis to investigate if CTNND2 gene single nucleotide polymorphisms (SNPs) are implicated in SZ in a Han Chinese northern population.

MATERIALS AND METHODS

We recruited subjects from 2010 to 2022 from the Han population of northern Henan and divided them into two case-control samples, including a discovery sample (SZ = 528 and control = 528) and replication sample (SZ = 2458 and control = 6914). Twenty-one SNPs were genotyped on the Illumina BeadStation 500G platform using GoldenGate technology and analyzed by PLINK. Positive and Negative Syndrome Scale (PANSS) was used to assess clinical symptoms.

RESULTS

Rs16901943, rs7733427, and rs2168878 SNPs were associated with SZ (Chi² = 7.484, 11.576, and 5.391, respectively, df = 1; p = 0.006, 0.00067, and 0.02, respectively) in two samples. Rs10058868 was associated with SZ in male patients in the discovery sample (Chi² = 6.264, df = 1, p = .044). Only rs7733427 survived Bonferroni correction. Linkage disequilibrium block three haplotypes were associated with SZ in the discovery and total sample. PANSS analysis of the four SNPs implicated rs10058868 and rs2168878 with symptoms of depression and excitement, respectively, in the SZ patients.

CONCLUSION

Four SNPs were identified as being correlated with SZ. The CTNND2 gene may be involved in susceptibility to SZ.

Association Between Single Nucleotide Polymorphisms Within lncRNA NONHSAT102891 and Depression Susceptibility in a Chinese Population

BACKGROUND

Depression is among the most common psychiatric disorders, and is a leading cause of the global disease burden. Its pathophysiological mechanism is unclear, which limits the development of therapeutic strategies. Long non-coding RNA (lncRNA) single nucleotide polymorphisms (SNPS) may be related. In this study, we aimed to determine the effects of the rs2242385, rs155979, rs3762983, and rs3762984 polymorphisms in the lncRNA NONHSAT102891 on depression susceptibility in a Chinese population.

METHODS

We conducted a case-control study in a cohort of 480 patients with depression and 329 healthy controls, and performed genotyping by gene sequencing ii.

RESULTS

The rs155979 GC genotype was significantly associated with increased risk of depression compared with healthy controls. Stratified analysis showed a 2.08-fold increased risk of suicide in patients with rs155979 GC or GG genotype. The rs2242385, rs3762983, and rs3762984 polymorphisms were not significantly associated with the risk of depression. Haploid analysis showed linkage disequilibrium between rs155979, rs3762983, and rs3762984, and the CCG haplotype reduced the risk of depression.

LIMITATIONS

The study sample was relatively small, and was restricted to patients from central and southern China. Further, only peripheral blood was used for DNA extraction.

CONCLUSION

The rs155979 polymorphism may be associated with the occurrence of depression in the Chinese population. However, further studies are needed to verify the reliability of our results in large populations and different ethnic groups.

Association of Interleukin-6 Polymorphisms with Schizophrenia and Depression: A Case-Control Study

Objective

Growing evidence suggests a crossover in genetic susceptibility to schizophrenia and depression. We aimed to investigate the association of the rs1800795 and rs1800796 polymorphisms of the IL-6 gene with schizophrenia and depression in the Han Chinese population, combined with IL-6 serum levels.

Methods

Gene sequencing and enzyme-linked immunosorbent assay were performed on 113 subjects with schizophrenia, 114 subjects with depression, and 110 healthy controls.

Results

Our findings showed that IL-6 concentrations in schizophrenia and depression groups were significantly higher than in the control group. The rs1800796 CC genotype and C allele were significantly associated with depression (P = .012 and P &lt; .05, respectively). The rs1800796 CC and CG genotype was significantly associated with chronic schizophrenia (P = .020 and P = .009, respectively). Regarding the rs1800795 polymorphism, only one case of CG genotype was detected. The remainder were of the GG genotype.

Conclusion

The IL-6 rs1800796 might serve as a protective factor for depression and schizophrenia in the Han Chinese population.

Genetic Polymorphisms in miR-137 and Its Target Genes, TCF4 and CACNA1C, Contribute to the Risk of Bipolar Disorder: A Preliminary Case-Control Study and Bioinformatics Analysis

Accumulating evidence has suggested that miR-137 and its target genes, CACNA1C, and TCF4, are amongst the most robustly implicated genes in psychiatric disorders. This preliminary study is aimed at investigating the effects of genetic variations in miR-137 (rs1625579A/C), TCF4 (rs1261084C/T), and CACNA1C (rs10774053A/G and rs10466907G/T) on BD susceptibility. We recruited 252 BD patients and 213 healthy subjects as the control group. Genotyping was performed using PCR-RFLP and ARMS-PCR methods. Enhanced risk of BD was found under the codominant homozygous, dominant, and allelic models of TCF4 rs1261084C/T, codominant homozygous and allelic models of CACNA1C rs10466907G/T polymorphisms, as well as codominant homozygous, dominant, recessive, and allelic models of the CACNA1C rs10774053A/G. Moreover, both TT/AG/GT/AA and TT/GG/GT/AC genotype combinations strongly increased the risk of BD in the participants. The bioinformatics analyses revealed that rs1261084C/T and rs10466907G/T created and disrupted binding sites of some miRNAs in the 3'-untranslated region of TCF4 and CACNA1C genes. In contrast, the rs10774053A/G created a new binding site for a major splicing factor and might have an effective role in the function of the CACNA1C protein. We have found that all the studied SNPs are positively associated with BD susceptibility. Replicated studies on different ethnicities are required to confirm these findings.