Takao Watanabe

Protein Kinase R Modulates c-Fos and c-Jun Signaling to Promote Proliferation of Hepatocellular Carcinoma with Hepatitis C Virus Infection

Double-stranded RNA-activated protein kinase R (PKR) is known to be upregulated by hepatitis C virus (HCV) and overexpressed in hepatocellular carcinoma (HCC). However, the precise roles of PKR in HCC with HCV infection remain unclear. Two HCV replicating cell lines (JFH-1 and H77s), generated by transfection of Huh7.5.1 cells, were used for experiments reported here. PKR expression was modulated with siRNA and a PKR expression plasmid, and cancer-related genes were assessed by real-time PCR and Western blotting; cell lines were further analyzed using a proliferation assay. Modulation of genes by PKR was also assessed in 34 human HCC specimens. Parallel changes in c-Fos and c-Jun gene expression with PKR were observed. Levels of phosphorylated c-Fos and c-Jun were upregulated by an increase of PKR, and were related to levels of phosphorylated JNK1 and Erk1/2. DNA binding activities of c-Fos and c-Jun also correlated with PKR expression, and cell proliferation was dependent on PKR-modulated c-Fos and c-Jun expression. Coordinate expression of c-Jun and PKR was confirmed in human HCC specimens with HCV infection. PKR upregulated c-Fos and c-Jun activities through activation of Erk1/2 and JNK1, respectively. These modulations resulted in HCC cell proliferation with HCV infection. These findings suggest that PKR-related proliferation pathways could be an attractive therapeutic target.

Ribavirin Regulates Hepatitis C Virus Replication Through Enhancing Interferon-Stimulated Genes and Interleukin 8

BACKGROUND The manner in which ribavirin (RBV) enhances the antiviral effects of interferon (IFN) against hepatitis C virus (HCV) remains unknown. We investigated whether RBV modifies IFN-stimulated genes (ISGs) in vivo and in vitro. METHODS We measured the messenger RNA (mRNA) levels of ISGs in T lymphocytes from patients with HCV infection who were receiving IFN-α therapy with or without RBV. We added RBV and/or IFN-α to a plasmid-based HCV replication system containing a full-length HCV genotype 1a sequence in HepG2 and Huh7 cell lines and the JFH-1 HCV genotype 2a sequence in Huh7 cell lines and measured levels of ISGs and autocrine IFN-β. RESULTS The expression of protein kinase R and myxovirus resistance A mRNA was enhanced more with IFN-α and RBV than by IFN-α alone in assays in vivo and in vitro. Such enhancement depended on autocrine IFN-β being enhanced by RBV. RBV upregulated interleukin 8 (IL-8) in the absence of IFN-α. The IL-8 upregulation induced by RBV was responsible for the activation of activator protein 1 (AP-1). CONCLUSIONS Ribavirin augments the anti-HCV effects of IFN-α induced by ISGs through enhancing autocrine IFN-β. Moreover, RBV can enhance IL-8 through activating AP-1. Improved understanding of ISG modulation by RBV would help to establish a means of eliminating HCV.

Predictors of treatment efficacy and ALT non‐normalization with sofosbuvir/ribavirin therapy for patients with hepatitis C virus genotype 2

The tolerability and efficacy of sofosbuvir and ribavirin in patients infected with hepatitis C virus (HCV) genotype 2 were investigated under actual clinical conditions. A total of 208 patients with chronic HCV genotype 2 infection were treated with sofosbuvir 400 mg and ribavirin (weight‐based dosing) for 12 weeks. Treatment discontinuation and sustained virological response 12 (SVR12) were evaluated. Moreover, factors associated with SVR12, hemoglobin decreasing to less than 10 g/dL during treatment, and alanine aminotransferase (ALT) non‐normalization after treatment were evaluated. In all patients, SVR12 responses were 96.1% (200/208). About 6 of 8 patients (3.8%) who did not achieve SVR12 were re‐treatment patients, and eight patients who did not achieve SVR all had liver cirrhosis. Multivariate analysis also identified body mass index (OR = 0.79; P < 0.001), platelet count (OR = 0.88; P = 0.003), and estimated glomerular filtration rate (eGFR) (OR = 0.96; P = 0.007) as independent contributing factors associated with hemoglobin decreasing to less than 10 g/dL during treatment, and only Mac‐2 Binding Protein Glycosylation isomer (M2BpGi) (OR = 2.46; P = 0.017) as an independent contributing factor associated with ALT non‐normalization after treatment. Cirrhotic patients may have a relatively high rate of treatment failure. In patients whose M2BpGi levels are elevated, their ALT tended to not normalize after treatment completion. These patients who did not achieve normalization of ALT after sofosbuvir plus RBV treatment need more careful observation for emergence of hepatocellular carcinoma even after achievement of SVR.

Comparison between real‐time tissue elastography and vibration‐controlled transient elastography for the assessment of liver fibrosis and disease progression in patients with primary biliary cholangitis

Assessing disease progression in patients with primary biliary cholangitis (PBC) is necessary in order to evaluate therapeutic effectiveness. Therefore, the aims of this study were to evaluate both the diagnostic accuracy of both real‐time tissue elastography (RTE) and vibration‐controlled transient elastography (VCTE), and the usefulness of hepatic and splenic elasticity as predictive markers for the progression of symptomatic PBC.

Quantitative imaging of fibrotic and morphological changes in liver of non-alcoholic steatohepatitis (NASH) model mice by second harmonic generation (SHG) and auto-fluorescence (AF) imaging using two-photon excitation microscopy (TPEM)

Non-alcoholic steatohepatitis (NASH) is a common liver disorder caused by fatty liver. Because NASH is associated with fibrotic and morphological changes in liver tissue, a direct imaging technique is required for accurate staging of liver tissue. For this purpose, in this study we took advantage of two label-free optical imaging techniques, second harmonic generation (SHG) and auto-fluorescence (AF), using two-photon excitation microscopy (TPEM). Three-dimensional ex vivo imaging of tissues from NASH model mice, followed by image processing, revealed that SHG and AF are sufficient to quantitatively characterize the hepatic capsule at an early stage and parenchymal morphologies associated with liver disease progression, respectively.

Usefulness of a New Three-Dimensional Simulator System for Radiofrequency Ablation

Multipuncture radiofrequency ablation is expected to produce a large ablated area and reduce intrahepatic recurrence of hepatocellular carcinoma; however, it requires considerable skill. This study evaluated the utility of a new simulator system for multipuncture radiofrequency ablation. To understand positioning of multipuncture electrodes on three-dimensional images, we developed a new technology by expanding real-time virtual ultrasonography. We performed 21 experimental punctures in phantoms. Electrode insertion directions and positions were confirmed on computed tomography, and accuracy and utility of the simulator system were evaluated by measuring angles and intersections for each electrode. Moreover, to appropriately assess placement of the three electrodes, puncture procedures with or without the simulator were performed by experts and non-experts. Technical success was defined as maximum angle and distance ratio, as calculated by maximum and minimum distances between electrodes. In punctures using 2 electrodes, correlations between angles on each imaging modality were strong (ultrasound vs. simulator: r = 0.991, p<0.001, simulator vs. computed tomography: r = 0.991, p<0.001, ultrasound vs. computed tomography: r = 0.999, p<0.001). Correlations between distances in each imaging modality were also strong (ultrasound vs. simulator: r = 0.993, p<0.001; simulator vs. computed tomography: r = 0.994, p<0.001; ultrasound vs. computed tomography: r = 0.994, p<0.001). In cases with 3 electrodes, distances between each electrode correlated strongly (yellow-labeled vs. red-labeled: r = 0.980, p<0.001; red-labeled vs. blue-labeled: r = 0.953, p<0.001; yellow-labeled vs. blue-labeled: r = 0.953, p<0.001). Both angle and distance ratio (expert with simulator vs. without simulator; p = 0.03, p = 0.02) were significantly smaller in procedures performed by experts using the simulator system. The new simulator system appears to accurately guide electrode positioning. This simulator system could allow multipuncture radiofrequency ablation to be performed more effectively and comfortably.

Sustained virological response of patients with hepatitis C virus genotype 2 depends on pegylated interferon compliance

Aim:  Patients infected with hepatitis C virus (HCV) genotype 2 are more sensitive to interferon (IFN) therapy than those infected with genotype 1, but 10–20% of patients do not achieve a sustained viral response (SVR) to combination therapy with pegylated (PEG) IFN and ribavirin (RBV). This study examines the prognostic factors associated with SVR in patients infected with HCV genotype 2 treated with PEG IFN and RBV.

Usefulness of laparoscopy and intraductal ultrasonography in a patient with isolated immunoglobulin G4-related sclerosing cholangitis

Immunoglobulin G4-related sclerosing cholangitis (IgG4-SC) is often associated with type 1 autoimmune pancreatitis, and the frequency of isolated IgG4-SC seems to be quite low, making the diagnosis of isolated IgG4-SC challenging. A 63-year-old male was admitted to our hospital for frequent fever. Abdominal magnetic resonance cholangiopancreatography showed diffuse narrowing of the common bile duct and post-stenotic dilatation of the right posterior bile duct. Laboratory tests showed abnormalities in the levels of hepatobiliary enzymes and serum IgG4 levels. Endoscopic retrograde cholangiopancreatography showed diffuse narrowing of intrahepatic bile ducts and post-stenotic dilatation of the right posterior bile duct but no abnormalities in the pancreas. Intraductal ultrasonography showed symmetric circumferentially thickened walls of both narrowed and non-narrowed common bile ducts. Histologic examination of the common bile duct mucosa showed infiltration of IgG4-positive plasma cells. Laparoscopic observations showed discoloration with red lobular markings and multiple small depressed lesions. Liver histology showed mild cholangitis with infiltration of IgG4-positive plasma cells around the bile ducts. From these findings, the patient was diagnosed with isolated IgG4-SC. After treatment with a steroid, bile duct dilatations improved. Laparoscopy and intraductal ultrasonography were useful to diagnose isolated IgG4-SC.

A case of hepatocellular carcinoma treated by radiofrequency ablation confirming the adjacent major bile duct under hybrid contrast mode through a biliary drainage catheter.

Bile duct injury is a potential complication of radiofrequency ablation (RFA). Bipolar RFA devices have recently become available. Because visibility of the bipolar RFA electrodes is not good on ultrasonography, more careful usage of the electrodes to avoid bile ducts is needed. We present a case with hepatocellular carcinoma (HCC) located near the B5 intrahepatic bile duct. To view the bile duct, we used contrast medium for ultrasonography, administered through a biliary drainage catheter for endoscopic nasobiliary drainage (ENBD). Infusing the contrast medium allowed clear visualization of the HCC adjacent to the major bile duct during RFA. We also used a navigation system for bipolar RFA to confirm positions of the electrodes and HCC. We confirmed complete ablation of the HCC while avoiding bile duct injury and late bile duct stenosis. Administration of contrast medium for ultrasonography through an ENBD tube appears useful to avoid bile duct injury during RFA.

High Serum Palmitic Acid is Associated with Low Antiviral Effects of Interferon-Based Therapy for Hepatitis C Virus

Hepatitis C virus (HCV) infection alters fatty acid synthesis and metabolism in association with HCV replication. The present study examined the effect of serum fatty acid composition on interferon (IFN)-based therapy. Fifty-five patients with HCV were enrolled and received IFN-based therapy. Patient characteristics, laboratory data (including fatty acids), and viral factors that could be associated with the anti-HCV effects of IFN-based therapy were evaluated. The effects of individual fatty acids on viral replication and IFN-based therapy were also examined in an in-vitro system. Multivariate logistic regression analysis showed that the level of serum palmitic acid before treatment and HCV genotype were significant predictors for rapid virological response (RVR), early virological response (EVR), and sustained virological response (SVR). High levels of palmitic acid inhibited the anti-HCV effects of IFN-based therapy. HCV replication assays confirmed the inhibitory effects of palmitic acid on anti-HCV therapy. The concentration of serum palmitic acid is an independent predictive factor for RVR, EVR, and SVR in IFN-based antiviral therapy. These results suggest that the effect of IFN-based antiviral therapy in patients with HCV infection might be enhanced by treatment that modulates palmitic acid levels.