Relationship between Single Nucleotide Polymorphisms of GRHL3 and Schizophrenia Susceptibility: A Preliminary Case-Control Study and Bioinformatics 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.

Evaluation of gene-gene interaction between the interleukin (IL)-2 and IL-2RA gene polymorphisms in schizophrenia patients in the Turkish Population

OBJECTIVES

To evaluate the genetic polymorphisms in IL-2 and IL-2RA genes in schizophrenia (SCZ) patients by comparing them with healthy controls.

METHODS

A sample of 127 patients with SCZ and 100 healthy volunteers were included in the case-control study. These individuals were consecutively selected from the Malazgirt State Hospital Psychiatry Outpatient Clinic in Mus, Turkey, over the three months from October 2020 to December 2020. The Structured Clinical Interview for DSM-5 Disorders, Clinician Version (SCID-5-CV) was used to confirm the diagnosis according to the DSM-5 criteria. In addition, polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine gene polymorphisms from DNA material.

RESULTS

Our findings indicated significant differences in the IL-2 genotype and allele frequencies between SCZ patients and the healthy control group. Specifically, the frequency of the homozygous GG genotype was notably higher in SCZ patients compared to the control group. Conversely, when comparing the IL-2RA genotype and allele frequencies of SCZ patients with the control group, no statistically significant differences were observed between the 2 groups. When compared to individuals with other genotypes, interaction analysis indicated that carriers of the GG/AG (IL-2/IL-2RA) genotype demonstrated a significantly increased risk of SCZ.

CONCLUSION

In light of the analyses, our study indicates that while the IL-2 genotype polymorphism may be considered a risk factor for developing SCZ, the IL-2RA variant was not associated with SCZ among Turkish patients.

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.