Interferon-alpha-induced mTOR activation is an anti-hepatitis C virus signal via the phosphatidylinositol 3-kinase-Akt-independent pathway.

OBJECT: The interferon-induced Jak-STAT signal alone is not sufficient to explain all the biological effects of IFN. The PI3-K pathways have emerged as a critical additional component of IFN-induced signaling. This study attempted to clarify that relationship between IFN-induced PI3-K-Akt-mTOR activity and anti-viral action. RESULT: When the human normal hepatocyte derived cell line was treated with rapamycin (rapa) before accretion of IFN-alpha, tyrosine phosphorylation of STAT-1 was diminished. Pretreatment of rapa had an inhibitory effect on the IFN-alpha-induced expression of PKR and p48 in a dose dependent manner. Rapa inhibited the IFN-alpha inducible IFN-stimulated regulatory element luciferase activity in a dose-dependent manner. However, wortmannin, LY294002 and Akt inhibitor did not influence IFN-alpha inducible luciferase activity. To examine the effect of PI3-K-Akt-mTOR on the anti-HCV action of IFN-alpha, the full-length HCV replication system, OR6 cells were used. The pretreatment of rapa attenuated its anti-HCV replication effect in comparison to IFN-alpha alone, whereas the pretreatment with PI3-K inhibitors, wortmannin and LY294002 and Akt inhibitor did not influence IFN-induced anti-HCV replication. CONCLUSION: IFN-induced mTOR activity, independent of PI3K and Akt, is the critical factor for its anti-HCV activity. Jak independent mTOR activity involved STAT-1 phosphorylation and nuclear location, and then PKR is expressed in hepatocytes

A high glucose condition sensitizes human hepatocytes to hydrogen peroxide-induced cell death

Oxidative stress is known to play a key role in the progression of liver disease, including non-alcoholic steatohepatitis (NASH), which is often accompanied by hyperglycemia. This study examined the influence of high glucose on oxidative stress-induced hepatic cell death. Hc cells, a normal human hepatocyte-derived cell line, were cultured in normal-to-high glucose (5.5-22 mM)-containing medium with varying concentrations (0.01-1 mM) of hydrogen peroxide. In certain experiments, cyclosporine A (CyA), which inhibits the mitochondrial permeability transition (MPT) pore, or Z-VAD-FMK (z-VAD), a pan-caspase inhibitor, were added to the medium. Cell viability was evaluated using a colorimetric assay. The mode of cell death was determined by nuclear staining methods using Hoechst 33258 and Sytox green. Neither high glucose (22 mM) nor 0.05-0.5 mM of hydrogen peroxide alone killed Hc cells. However, a combination of the two induced cell death, causing the nuclei of Hc cells to become expanded rather than condensed, and the nuclear membrane to become weak. CyA, but not z-VAD, blocked cell death. These results suggest that a high glucose condition may cause human hepatocytes to undergo hydrogen peroxide-induced necrotic cell death

The level of fasting serum insulin, but not adiponectin, is associated with the prognosis of early stage hepatocellular carcinoma.

Impaired glucose tolerance influences the prognosis of hepatocellular carcinoma (HCC), but this mechanism is still not fully understood. We investigated the impact of the fasting serum levels of insulin and adiponectin on the prognosis of HCC and its recurrence. One hundred and forty patients with newly diagnosed HCC were enrolled in the prognosis study. Their fasting serum levels of insulin and adiponectin were determined. Of 140 patients, 59 patients who underwent curative treatment were subjected to analysis of the recurrence-free survival. The 140 patients were divided into two groups by the 50th percentile value of insulin (7.73 microIU/ ml) or total adiponectin (6.95 microg/ml). Kaplan-Meier analysis indicated that high insulin group (>7.73 microIU/ml) exhibited a significantly poorer prognosis than low insulin group (<7.73 microIU/ml) in early stage HCC (P=0.018). In contrast, the level of total adiponectin had no impact on the prognosis of HCC. Multivariate analysis indicated that fasting hyper-insulinemia was an independent risk factor for a poorer prognosis in early stage HCC (P=0.044). Likewise, Kaplan-Meier analysis indicated that the recurrence-free survival of high insulin group was significantly lower than that of low insulin group (P=0.017). The level of total adiponectin had no impact on the recurrence-free survival of HCC. Multivariate analysis indicated that fasting hyperinsulinemia was an independent risk factor for the lower recurrence-free survival of HCC (P=0.049). In conclusion, our study suggests that the fasting insulin level affects the clinical course of early stage HCC

Association of serum levels of fibrosis-related biomarkers with disease activity in patients with IgG4-related disease

Background: The aim of this study was to identify fibrosis-related serological surrogate outcome measures in patients with immunoglobulin G4-related disease (IgG4-RD). Methods: This was a clinical observational study of 72 patients with untreated IgG4-RD from four institutions in Japan.The serum concentrations of growth differentiation factor 15 (GDF-15), CCL2, hyaluronic acid (HA), amino-terminal propeptide of type III procollagen (PIIINP), and tissue inhibitor of metalloproteinases 1 (TIMP-1) were measured by enzyme-linked immunosorbent assays. The enhanced liver fibrosis (ELF) score was calculated from the TIMP-1, PIIINP, and HA values. We evaluated associations between the values of these biomarkers and laboratory data, the IgG4-RD responder index (IgG4-RD RI) score, and organ involvements. Results: Compared with the 44 healthy controls, the patients with IgG4-RD showed significantly elevated serum concentrations of GDF-15, MCP-1, HA, PIIINP, and TIMP-1 and ELF scores. The patients\u27 serum concentrations of GDF-15, CCL2, HA, and TIMP-1 (but not PIIINP) were positively correlated with each other. Among them, serum GDF-15 most efficiently distinguished patients with IgG4-RD from healthy controls. Serum GDF-15 was not associated with the IgG4-RD RI score or the number of organ involvements but was independently associated with the presence of retroperitoneal fibrosis and with parotid gland involvement. Conclusions: We observed increased serological surrogate outcome measures of fibrosis in IgG4-RD. GDF-15 may precisely reflect the fibrotic degree in patients with IgG4-RD