Relationship between P2XR4 Gene Variants and the Risk of Schizophrenia in South-East of Iran: A Preliminary Case-Control Study and in Silico Analysis

Interaction between RNF4 and SART3 is associated with the risk of schizophrenia

The pathogenesis of schizophrenia (SCZ) is heavily influenced by genetic factors. Ring finger protein 4 (RNF4) and squamous cell carcinoma antigen recognized by T cells 3 (SART3) are thought to be involved in nervous system growth and development via oxidative stress pathways. Moreover, they have previously been linked to SCZ. Yet the role of RNF4 and SART3 in SCZ remains unclear. Here, we investigated how these two genes are involved in SCZ by studying their variants observed in patients. We first observed significantly elevated mRNA levels of RNF4 and SART3 in the peripheral blood in both first-episode (n = 30) and chronic (n = 30) SCZ patients compared to controls (n = 60). Next, we targeted-sequenced three single nucleotide polymorphisms (SNPs) in SART3 and six SNPs in RNF4 for association with SCZ using the genomic DNA extracted from peripheral blood leukocytes from SCZ participants (n = 392) and controls (n = 572). We observed a combination of SNPs that included rs1203860, rs2282765 (both in RNF4), and rs2287550 (in SART3) was associated with increased risk of SCZ, suggesting common pathogenic mechanisms between these two genes. We then conducted experiments in HEK293T cells to better understand the interaction between RNF4 and SART3. We observed that SART3 lowered the expression of RNF4 through ubiquitination and downregulated the expression of nuclear factor E2-related factor 2 (NRF2), a downstream factor of RNF4, implicating the existence of a possible shared regulatory mechanism for RNF4 and SART3. In conclusion, our study provides evidence that the interaction between RNF4 and SART3 contributes to the risk of SCZ. The findings shed light on the underlying molecular mechanisms of SCZ and may lead to the development of new therapies and interventions for this disorder.

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.

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.