microRNAs在肝脏中的作用

Construction of a eukaryotic vector expressing human miR-155 and inhibitory effect of miR-155 on HBeAg in HepG2.2.15 cells

AIM: To construct an eukaryotic vector carrying human microRNA-155 (miR-155) and to analyze the inhibitory effect of miR-155 on HBeAg in HepG2.2.15 cells.

METHODS: The pre-miR-155 was amplified from total DNA of human hepatoma cell line HepG2.2.15 by PCR. The target gene fragment was digested with EcoRⅠ and BamHⅠ, and cloned into the pmR-mCherry plasmid. Restriction digestion and DNA sequencing were performed to evaluate the recombinant vector. miR-155 was transfected into HepG2.2.15 cells by liposome-mediated method. The cells transfected with empty plasmid and untransfected cells were used as controls. The expression of cherry was detected by fluorescence microscopy after 24 h. The intracellular expression of miR-155 was detected by RT-PCR. ELISA was carried out to analyze the levels of HBeAg.

RESULTS: The pmiR-155 eukaryotic expression vector was successfully constructed. Fluorescence microscopy showed that the cherry protein was expressed in the HepG2.2.15 cells. miR-155 level in HepG2.2.15 cells transfected with the recombinant plasmid was significantly higher than those in controls. Compared with cells transfected with empty plasmid and untransfected cells, specific miR-155 could significantly decrease HBeAg gene expression in HepG2.2.15 cells.

CONCLUSION: A recombinant plasmid expressing miR-155 has been successfully constructed, and miR-155 is expressed stably in HepG2.2.15 cells. miR-155 can inhibit the expression of HBeAg in HepG2.2.15 cells.

MicroRNAs and biological functions of hepatic stellate cells

MicroRNAs (miRNAs) are single-stranded, 18-24 nucleotide long, non-coding RNA molecules which are involved in virtually every cellular process including proliferation, differentiation and apoptosis by specifically interacting with the mRNA and regulating the expression of genes. Recently it has been found that miRNAs cooperate with transforming growth factor (TGF-β), nuclear factor kappa B (NF-κB), tumor necrosis factor α (TNF-α) and other cytokines, and form complex "network" signaling pathways to influence the activation, proliferation, migration and apoptosis of hepatic stellate cells (HSCs), suggesting that miRNAs may regulate biological behaviors of HSCs via various signal transduction pathways, and have a great influence on the development of hepatic fibrosis. This article will review the impact of miRNAs on the biological functions of HSCs via different signal transduction pathways.