Circulating MicroRNAs in Plasma of Hepatitis B e Antigen Positive Children Reveal Liver-Specific Target Genes

Abstract

Background and Aim. Hepatitis B e antigen positive (HBeAg-positive) children are at high risk of severe complications such as hepatocellular carcinoma and cirrhosis. Liver damage is caused by the host immune response to infected hepatocytes, and we hypothesise that specific microRNAs play a role in this complex interaction between virus and host. The study aimed to identify microRNAs with aberrant plasma expressions in HBeAg-positive children and with liver-specific target genes. Methods. By revisiting our previous screen of microRNA plasma levels in HBeAg-positive and HBeAg-negative children with chronic hepatitis B (CHB) and in healthy controls, candidate microRNAs with aberrant plasma expressions in HBeAg-positive children were identified. MicroRNAs targeting liver-specific genes were selected based on bioinformatics analysis and validated by qRT-PCR using plasma samples from 34 HBeAg-positive, 26 HBeAg-negative, and 60 healthy control children. Results. Thirteen microRNAs showed aberrant plasma expressions in HBeAg-positive children and targeted liver-specific genes. In particular, three microRNAs were upregulated and one was downregulated in HBeAg-positive children compared to HBeAg-negative and healthy control children, which showed equal levels. Conclusion. The identified microRNAs might impact the progression of CHB in children. Functional studies are warranted, however, to elucidate the microRNAs' role in the immunopathogenesis of childhood CHB.

Figure 1

MicroRNA plasma levels in HBeAg-positive, HBeAg-negative, and healthy children. qRT-PCR-data on 34 HBeAg-positive, 25 HBeAg-negative, and 57 healthy control children. The P values shown above the individual figures are results of statistical analyses on HBeAg-positive, HBeAg-negative, and healthy children, and P values shown below left are results on HBeAg-positive versus HBeAg-negative, below centred HBeAg-positive versus healthy controls, and below right HBeAg-negative versus healthy controls. The bars represent geometric means −ΔC _T ± SEM. Due to multiple testing only P < 0.0028 was considered significant.

Figure 2

MicroRNA plasma levels and HBsAg quantity. qRT-PCR and HBsAg data on 34 HBeAg-positive and 25 HBeAg-negative children. P values are based on multivariate analyses. Due to multiple testing only P < 0.0028 was considered significant.