Published papers

Most of experiments for HCV infection have been done using lytic infection systems, in which HCV-infected cells inevitably die. Here, to elucidate metabolic alteration in HCV-infected cells in a more stable condition, we established an HCV-persistently-infected cell line, designated as HPI cells. This cell line has displayed prominent steatosis and supported HCV infection for more than 2 years, which is the longest ever reported. It enabled us to analyze metabolism in the HCV-infected cells integrally combining metabolomics and expression arrays. It revealed that rate-limiting enzymes for biosynthesis of cholesterol and fatty acids were up-regulated with actual increase in cholesterol, desmosterol (cholesterol precursor) and pool of fatty acids. Notably, the pentose phosphate pathway was facilitated with marked up-regulation of glucose-6-phosphate dehydrogenase, a rete-limiting enzyme, with actual increase in NADPH. In its downstream, enzymes for purine synthesis were also up-regulated resulting in increase of purine. Contrary to common cancers, the TCA cycle was preferentially facilitated comparing to glycolysis pathway with a marked increase of most of amino acids. Interestingly, some genes controlled by nuclear factor (erythroid-derived 2)-like 2 (Nrf2), a master regulator of antioxidation and metabolism, were constitutively up-regulated in HPI cells. Knockdown of Nrf2 markedly reduced steatosis and HCV infection, indicating that Nrf2 and its target genes play important roles in metabolic alteration and HCV infection. In conclusion, HPI cell is a bona fide HCV-persistently-infected cell line supporting HCV infection for years. This cell line sustained prominent steatosis in a hypermetabolic status producing various metabolites. Therefore, HPI cell is a potent research tool not only for persistent HCV infection but also for liver metabolism, overcoming drawbacks of the lytic infection systems.

AIM: Simeprevir (SMV) is a protease inhibitor which demonstrates good tolerability and high antiviral response in patients with hepatitis C. The clinical outcomes of triple therapy using simeprevir, pegylated interferon and ribavirin (SMV/PEG IFN/RBV) for recurrent hepatitis C after living donor liver transplantation (LDLT) have not been well reported. In this study, we assessed the outcomes of patients with recurrent hepatitis C (genotype 1) after LDLT who received triple therapy at our hospital. METHODS: SMV/PEG IFN/RBV was administrated for 12 weeks (triple therapy), followed by another 12 weeks or extended period of PEG IFN/RBV (dual therapy). Virological response, interaction with calcineurin inhibitors and adverse events were retrospectively analyzed. RESULTS: Ten patients with recurrent hepatitis C after LDLT completed 12 weeks of triple therapy. Nine patients achieved rapid or early virological response, and one patient was a non-responder. The nine responders received subsequent dual therapy, and the duration of dual therapy was extended (24 to 36 weeks) in five cases. Although one patient was in relapse 8 weeks after completing the standard duration (12 weeks) of dual therapy, eight patients achieved sustained virological response for 12 weeks (SVR12). The SVR12 rate was 80%. Trough levels of calcineurin inhibitor did not show marked changes after introduction of SMV in all cases. There were no major adverse events associated with SMV. CONCLUSION: SMV treatment may be a safe and effective option for recurrent hepatitis C after LDLT.

BACKGROUND: Prognostic value or clinical implications of fluid status monitoring in liver cirrhosis are not fully elucidated. Tolvaptan, an orally available, selective vasopressin V2-receptor antagonist approved for hyponatremia in the United States and European Union. It is also used for cirrhotic ascites at a relatively low dose (3.75 mg to 7.5 mg) in Japan, exerts its diuretic function by excreting electrolyte-free water. We hypothesized that bioimpedance-defined dynamic changes in fluid status allow prediction of response of V2 antagonism and survival in cirrhotic patients. METHODS: In this prospective observational study, 30 patients with decompensated liver cirrhosis who were unresponsive to conventional diuretics were enrolled. Detailed serial changes of body composition that were assessed by using non-invasive bioimpedance analysis (BIA) devices, along with biochemical studies, were monitored at 5 time points. RESULTS: Sixteen patients were classified as short-term responders (53%). Rapid and early decrease of BIA-defined intracellular water, as soon as 6 h after the first dose (DeltaICWBIA%-6 h), significantly discriminated responders from non-responders (AUC = 0.97, P < 0.0001). DeltaICWBIA%-6 h was highly correlated with the change of BIA-derived phase angle of trunk, e.g. reduced body reactance operated at 50 kHz after 24 h of the first dose of tolvaptan. Lower baseline blood urea nitrogen and lower serum aldosterone were predictive of a rapid and early decrease of ICWBIA. A rapid and early decrease of ICWBIA in response to tolvaptan was also predictive of a better transplant-free survival. CONCLUSIONS: BIA-defined water compartment monitoring may help predict short-term efficacy and survival in decompensated cirrhotic patients treated with tolvaptan.

Recent epidemiological studies showed that alcoholic liver cirrhosis (ALC) and alcohol-related hepatocellular carcinoma (HCC) continue to increase despite a gradual decrease in alcohol intake, indicating that there are other risk factors for the development of ALC and alcohol-related HCC. A nationwide survey of liver cirrhosis (LC) was undertaken by asking major hospitals in Japan to provide information on the number of patients with LC admitted in 2012 along with information related to etiology including alcohol history and other relevant demographics. Among the 1,478 ALC patients, total alcohol intake was lower in women than in men, and mean age was also lower in women. Mean age was older in the present study in 2012 compared with the data in 2008. Compared to patients without diabetes mellitus (DM), patients with DM had lower daily alcohol intake and higher mean age. The prevalence of HCC was much higher in male elderly ALC patients and also in DM patients among the younger ALC patients (65 years). DM, female sex, and age were identified as risk factors for development of ALC, and DM, male sex, and age were identified as significant risk factors for HCC in ALC.

The fundamental mechanism how heterogeneous hepatic macrophage (Mphi) subsets fulfill diverse functions in health and disease has not been elucidated. We recently reported that CCR9+ inflammatory Mphis play a critical role in the course of acute liver injury. To clarify the origin and differentiation of CCR9+Mphis, we used a unique partial bone marrow (BM) chimera model with liver shielding for maintaining hepatic resident Mphis. First, irradiated mice developed less liver injury with less Mphis accumulation by Concanavalin A (Con A) regardless of liver shielding. In mice receiving further BM transplantation, CD11blowF4/80high hepatic-resident Mphis were not replaced by transplanted donors under steady state, while under inflammatory state by Con A, CCR9+Mphis were firmly replaced by donors, indicating that CCR9+Mphis originate from BM, but not from hepatic-resident cells. Regarding the mechanism of differentiation and proliferation, EdU+CCR9+Mphis with a proliferative potential were detected specifically in the inflamed liver, and in vitro study revealed that BM-derived CD11b+ cells co-cultured with hepatic stellate cells (HSCs) or stimulated with retinoic acids could acquire CCR9 with antigen-presenting ability. Collectively, our study demonstrates that inflammatory Mphis originate from BM and became locally differentiated and proliferated by interaction with HSCs via CCR9 axis during acute liver injury.

Controversies and debates remain regarding the best management of severe acute-onset autoimmune hepatitis (SA-AIH) due to the lack of useful outcome or complication prediction systems. We conducted this clinical practice-based observational study to clarify whether Chronic Liver Failure Consortium Organ Failure scores (CLIF-C OFs) and the computed tomography-derived liver volume to standard liver volume (CTLV/SLV) ratio at admission to a tertiary transplant center can predict outcomes and complications due to infection. Thirty-four consecutive corticosteroid-treated patients with SA-AIH from 2007 to 2018 were included. Severe hepatitis was defined as an international normalized ratio (of prothrombin time) over 1.3 any time before admission. Of the 34 corticosteroid-treated patients with SA-AIH inclusive of 25 (73.5%) acute liver failure cases, transplant-free survival was observed in 24 patients (70.6%). Any infection was noticed in 10 patients (29.4%). CLIF-C OFs, at the cutoff of 9, significantly predicted survival (P = 0.0002, log-rank test), outperformed the Model for End-stage Liver Disease system in predicting outcome (P = 0.0325), and significantly discriminated between liver transplant and death in a competing risk analysis. SA-AIH was characterized as having decreased CTLV/SLV, which was also predictive of survival (P < 0.0001). Interestingly, CLIF-C OFs, especially the subscores for respiratory dysfunction, also predicted infection (P = 0.007). Conclusion: In corticosteroid-treated patients with SA-AIH, CLIF-C OFs and CTLV/SLV ratios predicted both survival outcome and complications due to infection. Further investigation is warranted to determine whether making decisions based on CLIF-C OFs or CTLV/SLV ratios is useful.

Gut-derived microbial antigens trigger the innate immune system during acute liver injury. During recovery, regulatory immunity plays a role in suppressing inflammation; however, the precise mechanism underlying this process remains obscure. Here, we find that recruitment of immune-regulatory classical dendritic cells (cDCs) is crucial for liver tolerance in concanavalin A-induced acute liver injury. Acute liver injury resulted in enrichment of commensal Lactobacillus in the gut. Notably, Lactobacillus activated IL-22 production by gut innate lymphoid cells and raised systemic IL-22 levels. Gut-derived IL-22 enhanced mucosal barrier function and promoted the recruitment of regulatory cDCs to the liver. These cDCs produced IL-10 and TGF-beta through TLR9 activation, preventing further liver inflammation. Collectively, our results indicate that beneficial gut microbes influence tolerogenic immune responses in the liver. Therefore, modulation of the gut microbiota might be a potential option to regulate liver tolerance.

© 2020 The Japan Society of Hepatology. An 87-year-old man with an enlarged hepatic tumor was referred to our institute by a medical examination center. He had been diagnosed with a malignant liver tumor through several contrast imaging studies. Because of the patient’s age, the underlying disease, and the absence of bile duct invasion on imaging, radiofrequency ablation (RFA) was selected as a treatment option. A histological examination during the RFA procedure revealed the tumor to be a cholangiocellular carcinoma. In addition, the deposition of Thorotrast, a contrast agent used in the 1930s to 1950s, was suspected in the background liver collected simultaneously. Radiofrequency ablation was performed twice for recurrent lesions, and the tumor was controlled for roughly 3 years following the initial treatment. A case of intrahepatic cholangiocellular carcinoma due to Thorotrast deposition was observed and successfully controlled by RFA. Since intrahepatic cholangiocellular carcinoma from Thorotrast deposition occurs multicentrically and intrahepatically, RFA and other local therapies may present effective options for older patients with cholangiocarcinoma who are at a higher risk of surgical resection intolerance.