Functional polymorphisms in microRNA gene and hepatitis B risk among Asian population: a meta-analysis

Human genetic susceptibility to hepatitis B virus infection

Hepatitis B virus (HBV) infection is still a serious health threat worldwide. The outcomes of HBV infection consist of spontaneous HBV clearance and chronic HBV infection. Multiple factors contribute to the disparity of HBV infection outcomes, including host factors, viral factors and environmental factors. The present review comprehends the current researches mainly focusing on the relationships between genetic determinants, including single nucleotide polymorphisms (SNPs) and haplotypes, and susceptibility of HBV infection, namely chronic (persistent) HBV infection and HBV clearance. A number of determinants in the chromosomes, including mutations in human leukocyte antigens (HLAs), cytokines genes, toll-like receptors (TLRs), and other genes are related to the human susceptibility to HBV infection. Among the above variants, some of those in HLAs have been studied and replicated in multiple-ethnic populations and came to consistent conclusions, while some others are novel and need to be evaluated further.

Host Genetic Determinants of Hepatitis B Virus Infection

Chronic hepatitis B virus (HBV) infection is still a major health problem worldwide. Recently, a great number of genetic studies based on single nucleotide polymorphisms (SNPs) and genome-wide association studies have been performed to search for host determinants of the development of chronic HBV infection, clinical outcomes, therapeutic efficacy, and responses to hepatitis B vaccines, with a focus on human leukocyte antigens (HLA), cytokine genes, and toll-like receptors. In addition to SNPs, gene insertions/deletions and copy number variants are associated with infection. However, conflicting results have been obtained. In the present review, we summarize the current state of research on host genetic factors and chronic HBV infection, its clinical type, therapies, and hepatitis B vaccine responses and classify published results according to their reliability. The potential roles of host genetic determinants of chronic HBV infection identified in these studies and their clinical significance are discussed. In particular, HLAs were relevant for HBV infection and pathogenesis. Finally, we highlight the need for additional studies with large sample sizes, well-matched study designs, appropriate statistical methods, and validation in multiple populations to improve the treatment of HBV infection.

Association between miRNA-146a rs2910164 (G/C) polymorphism with the susceptibility to chronic HBV infection and spontaneous viral clearance in an Iranian population

Hepatitis B virus (HBV) infection is one of the clinical dilemmas in chronic liver diseases. MicroRNAs (miRNAs) are small noncoding RNA molecules that play an important role in the pathogenesis of liver diseases and single nucleotide polymorphisms (SNPs) in miRNA genes affect the clinical course of HBV infection. Previous studies have shown that miRNA-146a rs2910164 polymorphism can be associated with the pathogenesis of liver diseases such as hepatocellular carcinoma. The present study investigated the association between miRNA-146a rs2910164 polymorphism and susceptibility to HBV infection in an Iranian population. The study comprised 266 patients with chronic HBV infection, 172 patients with spontaneous viral clearance (SVC) after acute HBV infection, and 266 healthy control adjusted for sex and age. The genotyping of the miRNA-146a rs2910164 polymorphism was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method. Our data revealed that GG genotype and G allele of miRNA-146a rs2910164 SNP is dominated (P < 0.001) in patients with chronic HBV infection (Odds ratio [OR] = 3.92; 95% confidence interval [CI] = 2.1-7.32). miRNA-146a rs2910164 polymorphism showed a statistically significant association (P < 0.001) between CC genotype and allele C with SVC (OR = 2.92; 95% CI = 1.56-546). Our findings suggest miRNA-146a SNP (C/G) in our population may be associated with the susceptibility to HBV infection and CC genotype is associated with SVC. Also, the GG genotype and G allele at miRNA-146a rs2910164 is associated with chronic HBV infection in our population.

Association of single nucleotide polymorphisms in microRNAs with susceptibility to hepatitis B virus infection and HBV-related liver complications: A study in a Saudi Arabian population

The aim of this study was to evaluate the association of 10 SNPs in different microRNAs (miRNAs) with susceptibility to hepatitis B virus (HBV) infection, HBV clearance, persistence of chronic HBV infection, and progression to liver cirrhosis and hepatocellular carcinoma (HCC). Patients were categorized into the following groups: inactive HBV carrier, active HBV carrier, HBV-cleared subject and cirrhosis+HCC. Samples were analysed for 10 SNPs in microRNAs using either PCR-based genotyping or the TaqMan assay. We found that rs1358379 was associated with susceptibility to HBV infection, HBV clearance, persistent chronic HBV infection and liver cirrhosis+HCC. In addition, we found that rs2292832 and rs11614913 were associated with risk of HBV infection, viral clearance and cirrhosis+HCC, whereas rs2910164 was associated with proneness to HBV infection, and ability to clear the virus. There was evidence of associations between rs6505162 and HBV clearance and the development of liver disease, whereas a single association was found between rs2289030 and HBV clearance. Similarly, rs7372209 and rs4919510 were specifically associated with the development of HBV-induced liver complications. SNPs in miRNAs affect the susceptibility, clearance and progression of HBV infection in Saudi Arabian patients. We found, using Gene Ontology or pathway analyses, that these genes may contribute to the pathophysiology of HBV infection and related liver complications. However, differences in the association of examined SNPs with various clinical stages indicate variations in the respective functional roles of these polymorphisms and their miRNAs, and thus, further investigation to fully explore their therapeutic potential is warranted.

Functional polymorphism rs3783553 in the 3'-untranslated region of IL-1A increased the risk of ischemic stroke: A case-control study

Accumulating evidence indicates interleukin-1 (IL-1) is a critical mediator of inflammatory responses in ischemic stroke (IS). The aim of this study was to investigate whether rs3783553 in the 3'-untranslated region of IL-1A was associated with the risk of IS. In this hospital-based case-control study, we genotyped the rs3783553 using polymerase chain reaction in 316 patients with IS and 332 age, sex, and ethnicity-matched controls. Plasma level of IL-1α was measured by enzyme-linked immunosorbent assay. The relative luciferase activities were measured by the Dual Luciferase assay system. The presence of ins/ins genotype was associated with higher odds ratios (ORs) of IS compared with del/del genotype (ins/ins vs del/del: adjusted OR 1.77, 95% confidence interval [CI] 1.06-2.98; recessive model: adjusted OR 1.69, 95% CI 1.06-2.70). The higher risk of IS was also observed in allele comparison (adjusted OR 1.29, 95% CI 1.00-1.65). Multivariate logistic regression analysis showed that age, hypertension, total cholesterol, triglyceride, low-density lipoprotein, and rs3783553ins/ins genotypes were independent risk factors for IS. Plasma level of IL-1α was higher among IS patients compared with controls (P = .03). Notably, IS patients with the TTCA/TTCA genotype had a higher level of IL-1α compared with those with the del/del genotype (P = .01). Luciferase reporter assay showed that the vector containing the TTCA del allele exhibited a reduced transcriptional activity in the presence of miR-122 and miR-378. These findings indicate that IL-1A rs3783553 ins/ins genotype may increase the susceptibility to IS, possibly by interrupting the binding site of miR-122 and miR-378.