Association of Tag SNPs and Rare CNVs of the MIR155HG/miR-155 Gene with Epilepsy in the Chinese Han Population

The Coordination of mTOR Signaling and Non-Coding RNA in Regulating Epileptic Neuroinflammation

Epilepsy accounts for a significant proportion of the burden of neurological disorders. Neuroinflammation acting as the inflammatory response to epileptic seizures is characterized by aberrant regulation of inflammatory cells and molecules, and has been regarded as a key process in epilepsy where mTOR signaling serves as a pivotal modulator. Meanwhile, accumulating evidence has revealed that non-coding RNAs (ncRNAs) interfering with mTOR signaling are involved in neuroinflammation and therefore articipate in the development and progression of epilepsy. In this review, we highlight recent advances in the regulation of mTOR on neuroinflammatory cells and mediators, and feature the progresses of the interaction between ncRNAs and mTOR in epileptic neuroinflammation.

MicroRNAs in Genetic Etiology of Human Diseases

Since their first discovery more than 20 years ago, miRNAs have been subject to deliberate research and analysis for revealing their physiological or pathological involvement. Regulatory roles of miRNAs in signal transduction, gene expression, and cellular processes in development, differentiation, proliferation, apoptosis, and homeostasis also imply their critical role in disease pathogenesis. Their roles in cancer, neurodegenerative diseases, and other systemic diseases have been studied broadly. In these regulatory pathways, their mutations and target sequence variations play critical roles to determine their functional repertoire. In this chapter, we summarize studies that investigated the role of mutations, polymorphisms, and other variations of miRNAs in respect to pathological processes.

The Role of miR-155 in Nutrition: Modulating Cancer-Associated Inflammation

Nutrition plays an important role in overall human health. Although there is no direct evidence supporting the direct involvement of nutrition in curing disease, for some diseases, good nutrition contributes to disease prevention and our overall well-being, including energy level, optimum internal function, and strength of the immune system. Lately, other major, but more silent players are reported to participate in the body’s response to ingested nutrients, as they are involved in different physiological and pathological processes. Furthermore, the genetic profile of an individual is highly critical in regulating these processes and their interactions. In particular, miR-155, a non-coding microRNA, is reported to be highly correlated with such nutritional processes. In fact, miR-155 is involved in the orchestration of various biological processes such as cellular signaling, immune regulation, metabolism, nutritional responses, inflammation, and carcinogenesis. Thus, this review aims to highlight those critical aspects of the influence of dietary components on gene expression, primarily on miR-155 and its role in modulating cancer-associated processes.

lncRNA MIR155HG Alleviates Depression-Like Behaviors in Mice by Regulating the miR-155/BDNF Axis

Depression is one of most common psychiatric disorders, and the detailed molecular mechanism remains to be fully elucidated. Brain-derived neurotrophic factor (BDNF) is a critical neurotrophic factor that is decreased and closely involved in the development of depression. Noncoding RNAs are central regulators of cellular activities that modulate target genes. However, the roles of long noncoding RNA (lncRNA) MIR155HG and miRNA-155 (miR-155) in the pathophysiology of depression are unclear. In the present study, we aimed to explore the effects of lncRNA MIR155HG and miR-155 on the development of depression and uncover the underlying molecular mechanism. Real-time quantitative polymerase chain reaction was used to examine the expression of MIR155HG and miR-155. Western blotting was applied to measure the expression of BDNF. A luciferase reporter assay was utilized to determine the regulatory relationship between MIR155HG and miR-155. Our current work found that lncRNA MIR155HG and BDNF levels decreased while miR-155 levels increased in the hippocampal region of CUMS (chronic unpredictable mild stress) mice, a well-accepted mouse model of depression. Moreover, MIR155HG rescued while miR-155 exacerbated the depression-like behaviors of CUMS mice. Through bioinformatics analysis and luciferase reporter assays, we found that MIR155HG directly bound to and negatively modulated the expression of miR-155. Moreover, increased miR-155 was found to repress the expression of BDNF, a critical neurotrophic factor that has been reported to alleviate the depression-like behaviors of CUMS mice. Our present study revealed that lncRNA MIR155HG protected CUMS mice by regulating the miR-155/BDNF axis. Our study aimed to understand the pathophysiology of depression and provided potential therapeutic targets to diagnose and treat depression.

Single-Nucleotide Variants in microRNAs Sequences or in their Target Genes Might Influence the Risk of Epilepsy: A Review

Single-nucleotide variant (SNV) is a single base mutation at a specific location in the genome and may play an import role in epilepsy pathophysiology. The aim of this study was to review case-control studies that have investigated the relationship between SNVs within microRNAs (miRs) sequences or in their target genes and epilepsy susceptibility from January 1, 2010 to October 31, 2020. Nine case-control studies were included in the present review. The mainly observed SNVs associated with drug-resistant epilepsy (DRE) risk were SNVs n.60G > C (rs2910164) and n.-411A > G (rs57095329), both located at miR-146a mature sequence and promoter region, respectively. In addition, the CC haplotype (rs987195-rs969885) and the AA genotype at rs4817027 in the MIR155HG/miR-155 tagSNV were also genetic susceptibility markers for early-onset epilepsy. MiR-146a has been observed as upregulated in human astrocytes in epileptogenesis and it regulates inflammatory process through NF-κB signaling by targeting tumor necrosis factor-associated factor 6 (TRAF6) gene. The SNVs rs2910164 and rs57095329 may modify the expression level of mature miR-146a and the risk for epilepsy and SNVs located at rs987195-rs969885 haplotype and at rs4817027 in the MIR155HG/miR-155 tagSNV could interfere in the miR-155 expression modulating inflammatory pathway genes involved in the development of early-onset epilepsy. In addition, SNVs rs662702, rs3208684, and rs35163679 at 3'untranslated region impairs the ability of miR-328, let-7b, and miR-200c binding affinity with paired box protein PAX-6 (PAX6), BCL2 like 1 (BCL2L1), and DNA methyltransferase 3 alpha (DNMT3A) target genes. The SNV rs57095329 might be correlated with DRE when a larger number of patients are evaluated. Thus, we concluded that the main drawback of most of studies is the small number of individuals enrolled, which lacks sample power.

MiRNA155HG polymorphisms influenced the risk of liver cancer among the Han Chinese population

Background

Liver cancer is one of the most common cancers in the world. The primary aim of this research was to discover the correlation between single nucleotide polymorphisms (SNPs) of the MIR155HG and liver cancer risk.

Methods

The selected SNPs in MIR155HG were genotyped utilizing the Agena MassARRAY platform. We evaluated the correlation between MIR155HG polymorphisms and Liver cancer by genetic model analysis, stratification analysis and haplotype analysis. Relative risk of Liver cancer was shown based on odds ratios (ORs) and 95% confidence intervals (95% CIs).

Results

Our results uncovered that rs12482371 and rs1893650 in the MIR155HG were associated with protection against Liver cancer. And the rs928883 was related to increase risk of Liver cancer. Furthermore, apart from rs77218221, other selected SNPs formed two LD blocks, and haplotype “GATAG” in block 2 elevated individual liver cancer risk.

Conclusions

MIR155HG gene polymorphism may be correlated to Liver cancer susceptibility in Han Chinese population, particularly in males and aged ≤55 years.

Analysis of the relationship between MIR155HG variants and gastric Cancer susceptibility

Background

Gastric cancer is one of the most common cancers in the world and a major cause of cancer-related death. This study aims to determine whether genetic variations in MIR155HG could be associated with gastric cancer risk.

Materials & methods

A total of 506 gastric cancer patients and 500 healthy controls were enrolled in this study. Genotypes were examined with the MassARRAY platform and data management and analysis were conducted with the Typer Software. Odds ratios (OR) and 95% confidence intervals (CIs) were calculated with logistic regression adjusting for age and gender to evaluate the associations between SNPs with gastric cancer in genetic model analysis.

Results

The “CC” genotype of rs4143370 decreased the risk of gastric cancer in genotype model (p = 0.020) and recessive model (p = 0.018). Inversely, the “CC” genotype of rs1893650 increased the risk of gastric cancer in genotype model (p = 0.023) and recessive model (p = 0.014). Stratified analysis showed that rs11911469 was associated with an increased risk of gastric cancer only among the male group in the dominant model (p = 0.039) and additive model (p = 0.030). The haplotype analysis showed a strong linkage disequilibrium among these six SNPs (rs4143370, rs77699734, rs11911469, rs1893650, rs34904192 and rs928883).

Conclusion

This study confirmed the relationship between SNPs of MIR155HG and the gastric cancer risk among the Chinese Han population. Our data may provide a new perspective to understand the aetiology of gastric cancer.

Analysis of MIR155HG variants and colorectal cancer susceptibility in Han Chinese population

BACKGROUND

MIR155HG plays an important role in malignant tumors, but it is rarely reported in the occurrence and development of colorectal cancer (CRC). This study investigated the effects of MIR155HG polymorphisms on CRC susceptibility from the perspective of molecular genetics.

METHODS

Eight SNPs in MIR155HG were selected and genotyped among 514 CRC cases and 510 healthy controls using the Agena MassARRAY platform. The associations between these SNPs and the CRC risk were evaluated under genetic models using conditional logistic regression analysis. The HaploReg v4.1 database was used for SNPs functional prediction.

RESULTS

The allele "C" of rs12482371 (p = 0.047), allele "C" of rs1893650 (p = 0.025), and the allele "A" of rs928883 (p = 0.037) in MIR155HG were significantly associated with CRC risk. Genetic model analysis revealed that rs12482371 and rs1893650 increased CRC risk; whereas rs928883 was associated with reduced CRC risk. Stratification analysis showed that rs9383938 was a protective factor in CRC patients under 60 years old. Rs12482371 and rs1893650 were associated with the CRC risk in females. Rs11911469 and rs34904192 may affect the clinical stage and lymph node metastasis. Moreover, the haplotypes CTT and GTC of LD block rs4143370|rs77218221|rs12482371, and the haplotypes CATGA and CACGG of LD block rs77699734|rs11911469|rs1893650|rs34904192|rs928883 were significantly associated with CRC risk.

CONCLUSION

This study revealed that MIR155HG SNPs were associated with CRC susceptibility and could be predictive biomarkers for CRC risk.

Role of glyoxalase I gene polymorphisms in late-onset epilepsy and drug-resistant epilepsy

BACKGROUND

Recent studies indicate that increased expression of glyoxalase I (GLO1) could result in epileptic seizures; thus, this study further explored the association of GLO1 with epilepsy from the perspective of molecular genetics.

MATERIAL AND METHODS

GLO1 single nucleotide polymorphisms (SNPs; rs1130534, rs4746 and rs1049346) were investigated in cohort I (the initial samples: 249 cases and 289 controls). A replication study designed to confirm the positive findings in cohort I was performed in cohorts II (the additional samples: 130 cases and 191 controls) and I+II.

RESULTS

In cohorts I, II and I+II, the CC genotype at rs1049346 T>C exerts a protective effect against both late-onset epilepsy (odds ratio [OR]=2.437, p=0.013; OR=2.844, p=0.008; OR=2.645, p=0.000, q=0.003, respectively) and drug-resistant epilepsy (DRE) (OR=2.985, p=0.020; OR=2.943, p=0.014; OR=3.049, p=0.001, q=0.006, respectively). Further analyses in cohort I+II indicate that the presence of the TAC/AAT haplotypes (rs1130534-rs4746-rs1049346) may be used as a marker of predisposition to/protection against DRE (p=0.002, q=0.010; p=0.000, q=0.002, respectively).

CONCLUSIONS

This study is the first to demonstrate that the GLO1 SNPs are significantly associated with epilepsy. In particular, the rs1049346 T>C SNPs are potentially useful for risk assessment of late-onset epilepsy and DRE.