The SNP rs1625579 in miR-137 gene and risk of schizophrenia in Chinese population: A meta-analysis

Metabolic syndrome in patients with schizophrenia: Underlying mechanisms and therapeutic approaches (Review)

Schizophrenia (SCZ) represents a considerable health concern, not only due to its impact on cognitive and psychiatric domains, but also because of its association with metabolic abnormalities. Individuals with SCZ face an increased risk of developing metabolic syndrome (MS), which contributes to the increased cardiovascular burden and reduced life expectancy observed in this population. Metabolic alterations are associated with both the SCZ condition itself and extrinsic factors, particularly the use of antipsychotic medications. Additionally, the link between SCZ and MS seems to be guided by distinct genetic parameters. The present narrative review summarizes the relationship between SCZ and MS and emphasizes the various therapeutic approaches for managing its components in patients with these conditions. Recommended therapeutic approaches include lifestyle modifications as the primary strategy, with a focus on behavioral lifestyle programs, addressing dietary patterns and physical activity. Pharmacological interventions include administering common antidiabetic medications and the selection of less metabolically harmful antipsychotics. Alternative interventions with limited clinical application are also discussed. Ultimately, a personalized therapeutic approach encompassing both the psychological and metabolic aspects is essential for the effective management of MS in patients with SCZ.

Schizophrenia plausible protective effect of microRNA-137 is potentially related to estrogen and prolactin in female patients

Background

Schizophrenia (SCZ) is a serious chronic mental disorder. Our previous case-control genetic association study has shown that microRNA-137 (miR-137) may only protect females against SCZ. Since estrogen, an important female sex hormone, exerts neuroprotective effects, the relationship between estrogen and miR-137 in the pathophysiology of SCZ was further studied in this study.

Methods

Genotyping of single-nucleotide polymorphism rs1625579 of miR-137 gene in 1,004 SCZ patients and 896 healthy controls was conducted using the iMLDR assay. The effect of estradiol (E2) on the miR-137 expression was evaluated on the human mammary adenocarcinoma cell line (MCF-7) and the mouse hippocampal neuron cell line (HT22). The relationships between serum E2, prolactin (PRL), and peripheral blood miR-137 were investigated in 41 SCZ patients and 43 healthy controls. The miR-137 and other reference miRNAs were detected by real-time fluorescent quantitative reverse transcription-PCR.

Results

Based on the well-known SNP rs1625579, the distributions of protective genotypes and alleles of the miR-137 gene were not different between patients and healthy controls but were marginally significantly lower in female patients. E2 upregulated the expression of miR-137 to 2.83 and 1.81 times in MCF-7 and HT22 cells, respectively. Both serum E2 and blood miR-137 were significantly decreased or downregulated in SCZ patients, but they lacked expected positive correlations with each other in both patients and controls. When stratified by sex, blood miR-137 was negatively correlated with serum E2 in female patients. On the other hand, serum PRL was significantly increased in SCZ patients, and the female patients had the highest serum PRL level and a negative correlation between serum PRL and blood miR-137.

Conclusion

The plausible SCZ-protective effect of miR-137 may be female specific, of which the underlying mechanism may be that E2 upregulates the expression of miR-137. This protective mechanism may also be abrogated by elevated PRL in female patients. These preliminary findings suggest a new genetic/environmental interaction mechanism for E2/miR-137 to protect normal females against SCZ and a novel E2/PRL/miR-137-related pathophysiology of female SCZ, implying some new antipsychotic ways for female patients in future.

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.

MIR137 polygenic risk is associated with schizophrenia and affects functional connectivity of the dorsolateral prefrontal cortex

BACKGROUND

Genome-wide association studies (GWAS) have consistently revealed that a variant of microRNA 137 (MIR137) shows a quite significant association with schizophrenia. Identifying the network of genes regulated by MIR137 could provide insights into the biological processes underlying schizophrenia. In addition, DLPFC functional connectivity, a robust correlate of MIR137, may provide plausible endophenotypes. However, the regulatory role of the MIR137 gene network in the disrupted functional connectivity remains unclear. Here, we tested the effects of the MIR137 regulated genes on the risk for schizophrenia and DLPFC functional connectivity.

METHODS

To evaluate the additive effects of the MIR137 regulated genes (N = 1274), we calculated a MIR137 polygenic risk score (PRS) for schizophrenia and tested its association with the risk for schizophrenia in the genomic data of a Han Chinese population that included schizophrenia patients (N = 589) and normal controls (N = 575). We then investigated the association between MIR137 PRS and DLPFC functional connectivity in two independent young healthy cohorts (N = 356 and N = 314).

RESULTS

We found that the MIR137 PRS successfully captured the differences in genetic structure between the patients and controls, but the single gene MIR137 did not. We then consistently found that a higher MIR137 PRS was correlated with lower functional connectivities between the DLPFC and both the superior parietal cortex and the inferior temporal cortex in two independent cohorts.

CONCLUSION

The findings suggested that these two functional connectivities of the DLPFC could be important endophenotypes linking the MIR137-regulated genetic structure to schizophrenia.

LncRNA GAS5 and miR-137 Polymorphisms and Expression are Associated with Multiple Sclerosis Risk: Mechanistic Insights and Potential Clinical Impact

The pathogenesis of multiple sclerosis (MS) is influenced by the interaction of genetic and epigenetic mechanisms. The long noncoding RNA GAS5 acts as a competing endogenous RNA for microRNA-137 and is involved in demyelination. We investigated the association of GAS5 and miR-137 expression and their polymorphisms with MS susceptibility. One hundred and eight MS patients and 104 healthy controls were included. Expression analysis and genotyping of GAS5-rs2067079 and miR-137-rs1625579 single nucleotide polymorphisms were performed by qPCR. Serum GAS5 was upregulated, while serum miR-137 was downregulated in MS compared with the controls. Serum miR-137 was an excellent discriminator of MS patients from the controls (AUC = 0.97) and a negative independent predictor of MS in multivariate logistic analysis. Serum GAS5 expression was positively correlated with the expanded disability status scale scores in the relapsing-remitting MS patients. The rs2067079TT minor homozygote genotype was associated with an increased MS risk, while the rs1625579G minor allele was protective. rs1625579 showed an age-specific effect, while the rs2067079 affected the MS risk in gender- and age-specific manners. In MS patients, rs2067079TT was associated with a higher serum GAS5 than other genotypes, while serum miR-137 did not differ between rs1625579 genotypes. Our results suggest serum GAS5 and miR-137 as MS biomarkers, with miR-137 as a negative predictor of MS risk and GAS5 as a marker of MS severity. We propose rs2067079 and rs1625579 as novel genetic markers of MS susceptibility, and at least, rs2067079 possibly impacts the crosstalk between GAS5 and miR-137.

The rs1625579 T>G polymorphism in the miRNA-13 gene confers a risk of early- onset Kawasaki disease in a southern Chinese population

BACKGROUND

Kawasaki disease (KD) mainly manifests as excessive inflammation and vascular endothelial cell injury. This disease generally occurs in children younger than 5 years of age and is more severe in children younger than 12 months. KD affects males and females at a ratio of 1.5:1. Polymorphisms of the rs1625579 locus in the miR-13 gene are associated with schizophrenia susceptibility, and high glucose-induced upregulation of miR-137 in vascular endothelial cells promotes monocyte chemotaxis and inflammatory cytokine secretion in gestational diabetes mellitus. However, researchers have not reported whether rs1625579 is associated with KD susceptibility or onset. Therefore, we investigated the relationship between the miRNA-13 rs1625579 T>G polymorphism and KD susceptibility.

METHODS

TaqMan real-time polymerase chain reaction was applied to determine the genotypes of 532 patients with KD (365 males and 167 females) and 623 control subjects (402 males and 221 females).

RESULTS

Comparison of all cases with all controls revealed that the rs1625579 T>G polymorphism was not associated with KD susceptibility. However, a subgroup analysis revealed that subjects with the rs1625579 TG/GG genotypes exhibited a significantly higher onset risk for KD before 12 months of age than carriers of the TT genotype (adjusted age and gender odds ratio=1.99, 95% CI=1.04-3.83; P=0.039).

CONCLUSION

Our results indicate that the rs1625579 T>G polymorphism confers a risk of early-onset KD in southern Chinese children.

Non-Coding RNA as Novel Players in the Pathophysiology of Schizophrenia

Schizophrenia is associated with diverse changes in the brain's transcriptome and proteome. Underlying these changes is the complex dysregulation of gene expression and protein production that varies both spatially across brain regions and temporally with the progression of the illness. The growing body of literature showing changes in non-coding RNA in individuals with schizophrenia offers new insights into the mechanisms causing this dysregulation. A large number of studies have reported that the expression of microRNA (miRNA) is altered in the brains of individuals with schizophrenia. This evidence is complemented by findings that single nucleotide polymorphisms (SNPs) in miRNA host gene sequences can confer an increased risk of developing the disorder. Additionally, recent evidence suggests the expression of other non-coding RNAs, such as small nucleolar RNA and long non-coding RNA, may also be affected in schizophrenia. Understanding how these changes in non-coding RNAs contribute to the development and progression of schizophrenia offers potential avenues for the better treatment and diagnosis of the disorder. This review will focus on the evidence supporting the involvement of non-coding RNA in schizophrenia and its therapeutic potential.

Polymorphism in schizophrenia risk gene MIR137 is associated with the posterior cingulate Cortex's activation and functional and structural connectivity in healthy controls

MIR137 gene has been repeatedly reported as a schizophrenia risk gene in genome-wide association studies (GWAS). A polymorphism (rs1625579) at the MIR137 gene has been associated with both neural activation and behavioral performance during a working memory task. This study examined MIR137's associations with task-related (N-back working memory) fMRI, resting state fMRI, and diffusion tensor images (DTI) data in 177 healthy adults. We found less deactivation of the PCC in risk allele homozygotes (TT) as compared to the GT heterozygotes (cluster size = 630 voxels, cluster level P_FWE < 0.001) during the N-back task, which replicated previous findings. Using the identified cluster within the PCC as the seed, we further found decreased functional connectivity between the PCC and the anterior cingulate cortex and its adjacent medial prefrontal cortex (ACC/MPFC) in risk allele homozygotes during both resting state (cluster size = 427 voxels, cluster level P_FWE = 0.001) and the N-back task (cluster size = 73 voxels, cluster level P_FWE = 0.05). Finally, an analysis of our DTI data showed decreased white matter integrity of the posterior cingulum in risk allele homozygotes (cluster size = 214 voxels, cluster level P_FWE = 0.03). Taken together, rs1625579 seems to play an important role in both functional and structural connectivity between the PCC and the ACC/MPFC, which may serve as the brain mechanisms for the link between rs1625579 and schizophrenia.

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This study replicated the association between the risk allele of rs1625579 and altered activations at the PCC.

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This study found decreased functional connectivity between the PCC and the ACC/MPFC in the risk allele homozygotes.

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This study found decreased FA value in the posterior cingulum in the risk allele homozygotes.

Association of MIR137 With Symptom Severity and Cognitive Functioning in Belarusian Schizophrenia Patients

MicroRNA-137 (miRNA-137; miR-137) is one of the important post-transcriptional regulators of the nervous system development, and its MIR137 gene rs1625579 polymorphism was reported to be a potential regulator for schizophrenia susceptibility. However, schizophrenia characteristics controlled by MIR137 rs1625579 polymorphism are still insufficiently understood. There were 3 groups included in the study: (a) subjects with diagnosis of schizophrenia (n = 150; 81-females, 69-males), (b) mentally healthy people (control group; n = 102; 66-females, 36-males) and (c) Belarusian indigenous male group (n = 295). Associations of rs1625579 with schizophrenia, symptom's severity and cognitive performance [by using Positive and Negative Syndrome Scale (PANSS) and Wisconsin Card Sorting Test (WCST), respectively] were studied, when compared to controls. Allele and genotype frequencies were investigated in Belarusian indigenous males. Rs1625579 displayed no association with schizophrenia in Belarusian population. Significant "symptom severity-genotype" interactions were revealed for schizophrenia patients. Patients with T/G genotype displayed lower severity of positive symptoms and general psychopathology compared to homozygous subjects. T/T genotype was associated with the highest symptom's severity. The negative symptom scores and the total PANSS-score were significantly higher in females carrying genotype T/T vs. T/G+G/G; no significant gene-phenotype associations were found in males. WCST parameters did not show any association with rs1625579 polymorphism. MIR137 rs1625579 polymorphism might be an important sex-dependent factor influencing severity of schizophrenia psychopathological manifestations. These findings also contribute to the knowledge on candidate gene effects on characteristics related to schizophrenia phenotype. As miR 137 is considered to be cancer therapeutic target, miR-137 may also explain the lower incidence of cancer in schizophrenia patients. Further studies with larger sample size are needed to confirm these novel findings.

Structural Analysis of G1691S Variant in the Human Filamin B Gene Responsible for Larsen Syndrome: A Comparative Computational Approach

Larsen syndrome (LRS) is a rare genetic disease associated with variable manifestations including skeletal malformations, dislocations of the large joints, and notable changes in facial and limb features. Genetic variants in the Filamin B (FLNB) gene are associated with the development of LRS. We searched two literature databases (OMIM and PubMed) and three gene variant databases (HGMD, UniProt, & dbSNP) to capture all the possible variants associated with LRS phenotype, which may have an impact on the FLNB function. Our search yielded 77 variants that might impact the FLNB protein function in patients with LRS. We performed rigorous computational analysis such as conservational, biochemical, pathogenicity, and structural computational analyses to understand the deleterious effect of the G1691S variant. Further, the structural changes of the G1691S variant was compared with a null variant (G1691A) and the native protein through a molecular dynamic simulation study of 50 ns. We found that the variant G1691S was highly deleterious and destabilize the protein when compared to the native and variant G1691A. This might be due to the physicochemical changes in the variant G1691S when compared to the native and variant G1691A. The destabilization was further supported by transformation of bend to coil in variant G1691S whereas bend was retained in native and variant G1691A through molecular dynamics analysis. Our study shed light on the importance of computational methods to understand the molecular nature of genetic variants and structural insights on the function of the FLNB protein. J. Cell. Biochem. 118: 1900-1910, 2017. © 2017 Wiley Periodicals, Inc.

Associations of microRNA single nucleotide polymorphisms and disease risk and pathophysiology

Single nucleotide polymorphisms (SNPs) are genetic variations that contribute to human phenotypes associated with various diseases. SNPs are involved in the regulation of a broad range of physiological and pathological processes, such as cellular senescence, apoptosis, inflammation, and immune response, by upregulating the expression of classical inflammation markers. Recent studies have suggested that SNPs located in gene-encoding microRNAs (miRNAs) affect various aspects of diseases by regulating the expression or activity of miRNAs. In the last few years, miRNA polymorphisms that increase and/or reduce the risk of developing many diseases, such as cancers, autoimmune diseases, and cardiovascular diseases, have attracted increasing attention not only because of their involvement in the pathophysiology of diseases but also because they can be used as prognostic biomarkers for a variety of diseases. In this review, we summarize the relationships between miRNA SNPs and the pathophysiology and risk of diseases.