酵母双杂交技术对人胰腺cDNA文库中HBcAg结合蛋白基因的筛选

Influence of HBV on the interleukin-17 receptor signaling pathway in HepG2 cells

AIM: To investigate whether hepatitis B virus influences the expression of interleukin-17 (IL-17) receptor and the adaptor Act1 in HepG2 cells.

METHODS: The mRNA and protein expression of IL-17 receptor and the adaptor Act1 was determined by real-time PCR and Western blot, respectively. NF-kappa B nuclear translocation was detected by immunofluorescence. The content of IL-17 in cell supernatants was measured by ELISA.

RESULTS: IL-17 was not detected in the culture supernatants of HepG2 cells, and IL-17 mRNA expression was not detected in HepG2 cells. The mRNA and protein expression of IL-17 receptor was significantly lower in HepG2 cells infected with HBV recombinant adenovirus than in cells infected with corresponding concentration of wild adenovirus (mRNA: 0.68±0.02 0.89±0.03, 0.33±0.06 vs 0.81±0.01, 0.12±0.01 vs 0.86±0.05, all P < 0.05; protein: 0.84±0.12 vs 1.01±0.13, 0.56±0.09 vs 1.01±0.08, 0.24±0.08 vs 0.98±0.05, all P < 0.05), and the impact of HBV on the IL-17 receptor expression was dose- and time-dependent. However, HBV had no significant impact on the expression of adaptor Act1. Furthermore, HBV recombinant adenovirus inhibited NF-κB activation induced by IL-17 receptor.

CONCLUSION: Our results indicate that HBV recombinant adenovirus can down-regulate the mRNA and protein expression of IL-17 receptor, inhibit NF-κB activation induced by IL-17R, and thereby prevent the IL-17 receptor signaling pathway in HepG2 cells.

Differential gene expression profiling of HepG2 cells transfected with a hepatitis B virus replicon

AIM: To investigate the changes in gene expression profile of HepG2 cells transfected with HBV replicon pHY106-BHBV by cDNA microarray, and to identify differential genes involved in cholesterol metabolism.

METHODS: A cDNA microarray (Affymetrix) that contains 20 000 gene sequences was used to examine gene expression between HepG2 cells transfected with HBV replicon pHY106-BHBV and control plasmid. Differentially expressed genes that may contribute to cholesterol metabolism were subjected to real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis.

RESULTS: The differentially expressed genes identified mostly encode transcription factors, cytokines, and molecules that are involved in signal transduction, glucose metabolism and lipid metabolism. Real-time RT-PCR results indicated that cholesterol metabolism-related genes 7-dehydrocholesterol reductase (dhcr7) and NADH-cytochrome b5 reductase (cyb5r) were down-regulated in HepG2 cells transfected with HBV replicon pHY106-BHBV.

CONCLUSION: Differential gene expression profile is detected between HepG2 cells transfected with HBV replicon pHY106-BHBV and control plasmid. The expression of cholesterol metabolism-related genes dhcr7 and cyb5r may be suppressed by HBV infection.