Background: Acute liver failure (ALF), known as a rapid and severe clinical syndrome, can induce multiple organ dysfunction and failure. It was noticed that Kupffer cells activation at the initial phase was involved in some intense inflammatory responses in the pathogenesis of ALF. However, detailed regulation mechanism of Kupffer cells activation during ALF is still obscured. Present study aimed to discover the potential regulator and explore deeper information of Kupffer cells activation at the early stage of ALF. Methods: The mouse model of ALF was established by Concanavalin A injection. Dynamic immunological statuses of Kupffer cells at the early stage of ALF were exhibited by detecting typical cytokines. The expression of inflammasome AIM2 was measured in both RNA and protein level. Its role of affecting Kupffer cells activation during ALF by inducing IL-1β production was identified by RNA interference in vitro. Moreover, the expression of miR-223 in vivo was measured by q-PCR and its role in regulating Kupffer cells activation during Con A induced ALF was determined by RNAs transfection. Results: Present study showed that mass production of IL-1β from isolated Kupffer cells in Con A treated mice might be the main driving force of Kupffer cells pro-inflammatory activation during ALF. The role of AIM2 in affecting pro-inflammatory activation of Kupffer cells by inducing IL-1β production was crucial to ALF. Further study found that miR-223 acted as a regulator in Kupffer cells activation at the early stage of ALF by influencing IL-1β production via AIM2 pathway. Conclusion: For the first time, this paper demonstrated that miR-223 acted to inhibit IL-1β production via AIM2 pathway, suppressing Kupffer cells pro-inflammatory activation at the early stage of ALF. Thus, it played an important role in the pathogenesis of ALF.

Background/Aims: Patients with hepatitis B virus (HBV) infection are at a high risk of developing hepatocellular carcinoma (HCC). In this study, we aim to investigate the roles of HBV on angiogenin (ANG), as well as the effects on cell proliferation in presence of ANG down-regulation. Methods: Serum ANG was determined by ELISA. The expression of ANG mRNA and protein in HCC cell lines with or without HBV/HBx were determined. Western blot and ELISA were conducted to determine the effects of HBV/HBx on IL-6 expression. The role of IL-6 on ANG was evaluated by IL-6 recombinant protein or IL-6 neutralizing antibody. Immunofluorescence staining was used to detect the nuclear translocation of ANG. MTT was performed to evaluate the relative inhibition ratio. Result: In vivo experiments showed elevation of serum ANG in patients infected with HBV. In vitro experiments showed HBV and HBx contributed to the transcription and translation of ANG. ANG expression showed increase after IL-6 stimulation, and ANG protein decreased in the presence of IL-6 blocking with its antibody. HBV promoted nuclear translocation of ANG. Inhibiting ANG expression or blocking of nuclear transfer of ANG attenuated the 45S rRNA synthesis and cell proliferation. Conclusion: HBV and HBx protein can increase the level of ANG through IL-6. HBV and HBx contributed to the nuclear translocation of ANG. Cell proliferation was inhibited after inhibiting the expression or nuclear transfer of ANG.

Background: Lipocalin 2 (LCN2), a protein primarily produced by hepatocytes, is highly upregulated under various conditions that induce cellular stress, such as intoxication, infection or inflammation. However, the precise biological functions and underlying mechanisms of LCN2 in hepatocytes remains unknown. Methods: Hepatocyte stress was successfully induced by treating Huh7 cells with interleukin-1β (IL-1β). Interleukin-6 (IL-6), Tumor Necrosis Factor-α (TNF-α) and LCN2 levels were measured in IL-1β treated Huh7 cells and supernatant. Additionally, microarray analysis was conducted to identify genes differentially expressed in LCN2-silenced and control Huh7 cells. Results: TNF-α, IL-6 and LCN2 were significantly elevated in Huh7 cells after IL-1β) treatment. In LCN2-silenced Huh7 cells, expression of IL-6 and TNF-α was significantly increased when compared with the expression levels of control Huh7 cells. Furthermore, differentially expressed genes were observed between the LCN2-silenced and control cells. Microarray analysis indicated that LCN2 acted by influencing genes involved in protein metabolism, stress response, cell cycle and proliferation. Conclusions: Our results suggest that LCN2 upregulation protects hepatocytes from IL-1β-induced stress. Additionally, our microarray analysis of LCN2-silenced and control cells provides a better understanding of the mechanisms that may be influenced by LCN2 induction.

MEAN (6‐methoxyethylamino‐numonafide) is a small molecule compound, and here, we report that it effectively inhibits hepatitis C virus (HCV) infection in an HCV cell culture system using a JC1‐Luc chimeric virus, with a 50% effective concentration (EC50) of 2.36 ± 0.29 μM. Drug combination usage analyses demonstrated that MEAN was synergistic with interferon α, ITX5061 and ribavirin. In addition, MEAN effectively inhibits N415D mutant virus and G451R mutant viral infections. Mechanistic studies show that the treatment of HCV‐infected hepatocytes with MEAN inhibits HCV replication but not translation. Furthermore, treatment with MEAN significantly reduces polypyrimidine tract‐binding protein (PTB) levels and blocks the cytoplasmic redistribution of PTB upon infection. In the host cytoplasm, PTB is directly associated with HCV replication, and the inhibition of HCV replication by MEAN can result in the sequestration of PTB in treated nuclei. Taken together, these results indicate that MEAN is a potential therapeutic candidate for HCV infection, and the targeting of the nucleo‐cytoplasmic translocation of the host PTB protein could be a novel strategy to interrupt HCV replication.