Background/Aims: The liver is a vital organ in vertebrates and has a wide range of functions, including glucose absorption, glycogen storage and glucose production. Fibroblast growth factor (FGF)-21 is a metabolic regulator that is primarily produced by the liver. In this paper, we studied the effect of FGF-21 on glucose metabolism in the liver. Methods: The glucose uptake of cells was detected by 2-Deoxy-d-[³H] glucose; the synergy between insulin and FGF-21 was evaluated. The mRNA expression of GLUT1-4, G6Pase and PEPCK was detected by real-time PCR. Glycogen synthesis was examined by the anthrone method. Blood samples to monitor glucose in db/db diabetic mice were obtained by tail snip. Glucose metabolism in the liver and adipose tissues was observed by fluorescence microscopy. Results: In this study, FGF-21 stimulated glucose uptake by liver cells in both a dose and time-dependent manner, and at the same time, FGF-21 specifically stimulated GLUT1 expression in the liver cells. Furthermore, FGF-21 demonstrated a synergistic effect with insulin on glucose absorption, which is in accordance with enhanced GLUT-1 and -4 expression. Treatment with FGF-21 increased glycogen storage in liver cells. Consistent with in vitro results, FGF-21 lowered the plasma glucose level and stimulated GLUT1 expression and glycogen synthesis in db/db diabetic mice. Simultaneously, FGF-21 inhibited the gene expression of G6Pase and PEPCK. Conclusion: Our results suggest that FGF-21 clears up plasma glucose by stimulating glucose absorption in the liver of diabetic animals and decreases glucose release from the liver by inhibiting gluconeogenesis. Overall, these data indicate that the liver is an important target organ of FGF-21 to regulate glucose metabolism.

Macrophages are paramount to the initiation and procession of atherosclerosis, thus targeting macrophages in the progress of atherosclerosis is indispensable. Therefore, we perform in vitro experiments to investigate the effects of FGF-21 on macrophages in the progress of atherosclerosis. First, we use phorbol-12-myristate-13-acetate (PMA), a phorbol ester, to induce THP-1 cells into macrophages as macrophages model. After that we use Ox-LDL to induce macrophages into foam cells and simultaneously administrate with FGF-21 or not to determine whether FGF-21 has effects on foam cells formation and related inflammatory response. Wound healing results show that FGF-21 can inhibit macrophage migration. Oil Red-O stain, immunofluorescence and flow cytometer results show that FGF-21 can repress cholesterol accumulation in macrophages thereby inhibit foam cells formation and these effects can be abolished by FGFR inhibitor. Moreover, real-time PCR results showed that FGF-21 significantly reduces expression of inflammatory factors including IL-1α, IL-6 and TNF-α and this effect can be abolished by FGFR inhibitor. Furthermore, to determine the mechanism of FGF-21 regulates inflammatory response in Ox-LDL-induced THP-1 macrophages, western blotting results show that after treatment of Ox-LDL in macrophages, NF-κB signaling pathway is activated but FGF-21 can significantly inhibit this pathway. In addition, FGF-21 also regulates some regulators of lipid metabolism after treatment of Ox-LDL in macrophages. Above all, our findings demonstrate that FGF-21 can regulate foam cells formation, macrophage migration, inflammatory response and lipid metabolism in Ox-LDL-induced THP-1 macrophages.

Newcastle disease virus (NDV) have shown oncolytic therapeutic efficacy in preclinical study and are currently approved for clinical trials. NDV Anhinga strain which is a mesogenic strain should be classified as lytic strain and has a therapeutic efficacy in hepatocellular cancer. In this study, we evaluated the capacity of NDV Anhinga strain to elicit immune reaction in vivo and the possibility for using as a vaccine vector for expressing tumor therapeutic factors. Interleukin-2 (IL-2) could boost the immune response against the tumor cells. Therefore, we use NDV Anhinga strain as backbone to construct a recombinant virus (NDV/Anh-IL-2) expressing IL-2. The virus growth curve showed that the production of recombinant NDV/Anh-IL-2 was slightly delayed compared to the wild type. The NDV/Anh-IL-2 strain could express soluble IL-2 and effectively inhibit the growth of hepatocellular carcinoma in vivo. 60 days post-treatment, mice which were completely cured by previous treatment were well protected when rechallenged with the same tumor cell. From the H&E-stained sections, intense infiltration of lymphocyte was observed in the NDV Anhinga strain treated group, especially in NDV/Anh-IL-2 group. The NDV Anhinga strain could not only kill the tumor directly, but could also elicit immune reaction and a potent immunological memory when killing tumor in vivo. In conclusion, the Anhinga strain could be an effective vector for tumor therapy; the recombinant NDV/Anh-IL-2 strain expressing soluble IL-2 is a promising candidate for hepatoma therapy.