Showing papers by "Masashi Mizokami published in 2016"

Long noncoding RNA #32 contributes to antiviral responses by controlling interferon-stimulated gene expression

Abstract: Despite the breadth of knowledge that exists regarding the function of long noncoding RNAs (lncRNAs) in biological phenomena, the role of lncRNAs in host antiviral responses is poorly understood. Here, we report that lncRNA#32 is associated with type I IFN signaling. The silencing of lncRNA#32 dramatically reduced the level of IFN-stimulated gene (ISG) expression, resulting in sensitivity to encephalomyocarditis virus (EMCV) infection. In contrast, the ectopic expression of lncRNA#32 significantly suppressed EMCV replication, suggesting that lncRNA#32 positively regulates the host antiviral response. We further demonstrated the suppressive function of lncRNA#32 in hepatitis B virus and hepatitis C virus infection. lncRNA#32 bound to activating transcription factor 2 (ATF2) and regulated ISG expression. Our results reveal a role for lncRNA#32 in host antiviral responses.

The cyclic GMP‐AMP synthetase–STING signaling pathway is required for both the innate immune response against HBV and the suppression of HBV assembly

Abstract: During viral replication, the innate immune response is induced through the recognition of viral replication intermediates by host factor(s). One of these host factors, cyclic GMP-AMP synthetase (cGAS), was recently reported to be involved in the recognition of viral DNA derived from DNA viruses. However, it is uncertain whether cGAS is involved in the recognition of hepatitis B virus (HBV), which is a hepatotropic DNA virus. In the present study, we demonstrated that HBV genome-derived dsDNA induced the innate immune response through cGAS and its adaptor protein, STING, in human hepatoma Li23 cells expressing high levels of cGAS. In addition, we demonstrated that HBV infection induced ISG56 through the cGAS-STING signaling pathway. This signaling pathway also showed an antiviral response towards HBV through the suppression of viral assembly. From these results, we conclude that the cGAS-STING signaling pathway is required for not only the innate immune response against HBV but also the suppression of HBV assembly. The cGAS-STING signaling pathway may thus be a novel target for anti-HBV strategies.

Serum YKL-40 as a marker of liver fibrosis in patients with non-alcoholic fatty liver disease.

Abstract: Non-alcoholic fatty liver disease (NAFLD) is a common cause of chronic non-viral liver disease. YKL-40, chitinase-like protein expressed in multiple tissues including liver, is involved in cell proliferation, inflammation and remodeling of the extracellular matrix. The aim of this study was to assess whether serum YKL-40 levels are associated with liver fibrosis in NAFLD patients. Serum YKL-40 levels were quantified in 111 NAFLD patients and 23 HCC patients with NAFLD. To identify the source of YKL-40, immunofluorescence staining of liver specimens from NAFLD patients was performed. Serum YKL-40 levels in NAFLD patients increased in accordance with the progression of liver fibrosis. Multivariate analysis revealed that YKL-40 was one of the independent factors significantly associated with severe fibrosis (F3-4). We established a new predictive model for fibrosis of NAFLD, using logistic regression analysis: YKL-40 based fibrosis score = −0.0545 + type IV collagen 7s * 0.3456 + YKL-40 * 0.0024. Serum YKL-40 levels of HCC patients with non-cirrhotic NAFLD were significantly higher than those without HCC. Immunofluorescence staining showed that YKL-40 was expressed by macrophages in liver tissue of NAFLD patients. In conclusion, macrophage-derived YKL-40 is a feasible biomarker of liver fibrosis in NAFLD patients.

The impact of PNPLA3 and JAZF1 on hepatocellular carcinoma in non-viral hepatitis patients with type 2 diabetes mellitus

Abstract: Type 2 diabetes mellitus (T2DM) is an established independent risk factor for hepatocellular carcinoma (HCC). T2DM is associated with non-alcoholic steatohepatitis (NASH), which is a major cause of non-HBV and non-HCV-related HCC; nevertheless, it has been difficult to identify those patients with T2DM who have a high risk of developing HCC. The aim of this study was to identify genetic determinants that predispose T2DM patients to HCC by genotyping T2DM susceptibility loci and PNPLA3. We recruited 389 patients with T2DM who satisfied the following three criteria: negative for HBs-Ag and anti-HCV Ab, alcohol intake 10 years. These patients were divided into two groups: T2DM patients with HCC (DM–HCC, n = 59) or those without HCC (DM–non-HCC, n = 330). We genotyped 51 single-nucleotide polymorphisms (SNPs) previously reported as T2DM or NASH susceptibility loci (PNPLA3) compared between the DM-HCC and DM-non-HCC groups with regard to allele frequencies at each SNP. The SNP rs738409 located in PNPLA3 was the greatest risk factor associated with HCC. The frequency of the PNPLA3 G allele was significantly higher among DM–HCC individuals than DM–non-HCC individuals (OR 2.53, p = 1.05 × 10−5). Among individuals homozygous for the PNPLA3 G allele (n = 115), the frequency of the JAZF1 rs864745 G allele was significantly higher among DM–HCC individuals than DM–non-HCC individuals (OR 3.44, p = 0.0002). PNPLA3 and JAZF1 were associated with non-HBV and non-HCV-related HCC development among Japanese patients with T2DM.

Interleukin-34 as a fibroblast-derived marker of liver fibrosis in patients with non-alcoholic fatty liver disease

Abstract: Non-alcoholic fatty liver disease (NAFLD) is a common cause of chronic non-viral liver disease. Activation of macrophages and hepatic stellate cells is a critical step that promotes liver fibrosis. We aimed to explore the feasibility of interleukin-34 (IL-34), a key regulator of macrophages, as a fibrosis marker in patients with NAFLD. We enrolled 197 liver biopsy-proven NAFLD patients. We evaluated the serum levels of IL-34, macrophage-colony stimulating factor (M-CSF), soluble CD163 (sCD163), 40 cytokines/chemokines, hyaluronic acid, type IV collagen 7s, and clinically-approved fibrosis scores. IL-34 increased with the progression of fibrosis and was an independent marker for liver fibrosis. Immunostaining experiments, using resected liver specimens from NAFLD patients, revealed that IL-34 was mainly expressed on liver fibroblasts. IL-34 based fibrosis score (0.0387*IL-34 (pg/ml) + 0.3623*type IV collagen 7s (ng/ml) + 0.0184*age (year)–1.1850) was a practical predictive model of liver fibrosis. Using receiver-operating characteristic analyses, the area under the curve, sensitivity, and specificity of IL-34 based fibrosis score were superior or comparable to the other fibrosis biomarkers and scores. In conclusion, the IL-34 based fibrosis score, including serum IL-34, type IV collagen 7s and age, is a feasible diagnostic marker of liver fibrosis in NAFLD patients.

Chronic Hepatitis B Virus Infection: Disease Revisit and Management Recommendations

Abstract: Chronic hepatitis B virus (HBV) infection evolves from immune-tolerance phase, through immune clearance phase to a quiescent phase or reactivation as hepatitis B e antigen-negative hepatitis. Persistent infection may result in the development of cirrhosis and hepatocellular carcinoma (HCC). Host factors including gender, age, family history, HLA-DP, and viral factors including HBV DNA, genotypes, precore mutations, pre-S deletions, and hepatitis B surface antigen (HBsAg) level are associated with the development of these complications. Risk scores for the development of HCC have been derived. Patients with persistently elevated alanine aminotransferase levels (>30 for males; >19 U/L for females) and HBV DNA levels >2000 IU/mL should be treated. Patients with established cirrhosis with detectable HBV DNA should also be treated. The recommended first-line agents include pegylated interferon and 2 nucleos(t)ide analogs, entecavir and tenofovir. NAs require long-term treatment to maintain suppression of HBV DNA. They have been shown to decrease hepatic fibrosis, or reverse cirrhosis and to reduce the development of HCC. They have very low rates (0% to 1.2%) of resistance. HBsAg seroclearance, although the ideal endpoint, is only achievable in 10% to 12% of patients by multicenter trials usually studying relatively young patients. Patients on long-term treatment should be monitored for viral breakthrough that may be due to noncompliance or the development of resistance. Newer agents are under trials to enhance the rate of HBsAg seroclearance. However, even with the current NAs, long-term treatment of >6 years can markedly reduce the covalently closed circular DNA, the viral component responsible for initiation of viral replication.

Development of Pancreatic Cancer, Disease-specific Mortality, and All-Cause Mortality in Patients with Nonresected IPMNs: A Long-term Cohort Study

Abstract: Patients with main duct (MD) intraductal papillary mucinous neoplasms (IPMNs) have a greater risk of developing pancreatic cancer and consequent death than patients without MD-IPMNs; however, cyst size was not associated with these outcomes.

Understanding of HLA-conferred susceptibility to chronic hepatitis B infection requires HLA genotyping-based association analysis

Abstract: Associations of variants located in the HLA class II region with chronic hepatitis B (CHB) infection have been identified in Asian populations. Here, HLA imputation method was applied to determine HLA alleles using genome-wide SNP typing data of 1,975 Japanese individuals (1,033 HBV patients and 942 healthy controls). Together with data of an additional 1,481 Japanese healthy controls, association tests of six HLA loci including HLA-A, C, B, DRB1, DQB1, and DPB1, were performed. Although the strongest association was detected at a SNP located in the HLA-DP locus in a SNP-based GWAS using data from the 1,975 Japanese individuals, HLA genotyping-based analysis identified DQB1*06:01 as having the strongest association, showing a greater association with CHB susceptibility (OR = 1.76, P = 6.57 × 10−18) than any one of five HLA-DPB1 alleles that were previously reported as CHB susceptibility alleles. Moreover, HLA haplotype analysis showed that, among the five previously reported HLA-DPB1 susceptibility and protective alleles, the association of two DPB1 alleles (DPB1*09:01, and *04:01) had come from linkage disequilibrium with HLA-DR-DQ haplotypes, DRB1*15:02-DQB1*06:01 and DRB1*13:02-DQB1*06:04, respectively. The present study showed an example that SNP-based GWAS does not necessarily detect the primary susceptibility locus in the HLA region.

Geographic distribution and characteristics of genotype A hepatitis B virus infection in acute and chronic hepatitis B patients in Japan

Abstract: Background and Aims The prevalence of sexually transmitted acute infections of the genotype A hepatitis B virus (HBV) has been increasing in Japan. Genotype A HBV is associated with an increased risk of HBV progression to chronic infection after acute hepatitis B (AHB) in adults. A nationwide survey was conducted to evaluate the geographic distribution, clinical, and virologic characteristics of genotype A AHB and chronic hepatitis B (CHB) in Japan. Methods Five hundred seventy AHB patients were recruited between 2005 and 2010, and 3682 CHB patients were recruited between 2010 and 2011. HBV genotypes were determined for 552 and 3619 AHB and CHB patients, respectively. Clinical characteristics were compared among different genotypes in AHB and CHB patients. Genomic characteristics of HBV genotype A were examined by molecular evolutionary analysis. Results Hepatitis B virus genotype A was the predominant genotype for AHB between 2005 and 2010. Phylogenetic analysis showed that all strains in the AHB patients with genotype A were classified into subtype Ae. Among CHB patients, the occurrence of genotype A was 4.1%, and genotype A was spreading in young adults. In genotype A CHB patients, early stage liver diseases were predominant, although liver diseases progressed to cirrhosis or hepatocellular carcinoma in some patients. Conclusions The distribution of HBV genotypes is quite different between AHB and CHB in Japanese patients. Genotype A infection is spreading in young adults of Japanese CHB patients. Sequences derived from Japanese AHB patients were identical to or closely resembled the sequences derived from other Japanese AHB patients.

Serum WFA+ -M2BP levels as a prognostic factor in patients with early hepatocellular carcinoma undergoing curative resection.

Abstract: BACKGROUND & AIMS Serum tumour markers for hepatocellular carcinoma (HCC) have less prognostic significance in early stage. Serum Wisteria floribunda agglutinin-positive Mac-2-binding protein (WFA(+) -M2BP) levels are reportedly associated with hepatocarcinogenic potential in patients with chronic liver diseases. We investigated the prognostic significance of pretreatment serum WFA(+) -M2BP levels in patients with early-stage HCC. METHODS A total of 240 patients who underwent hepatic resection for naive Barcelona Clinic Liver Cancer (BCLC) class 0 or A HCC were analysed. WFA(+) -M2BP and tumour markers for HCC were measured from serum obtained just prior to treatment. Post-operative recurrence and survival rates were compared according to these serum markers, tumour stage and Child-Pugh class. RESULTS There was an association between serum WFA(+) -M2BP levels and the fibrosis grade of resected noncancerous liver tissue, whereas no association was found between WFA(+) -M2BP levels and tumour progression or liver function. In a multivariate analysis, pretreatment serum WFA(+) -M2BP level was associated with recurrence and survival, respectively, independent of HCC progression or fibrosis grade of resected noncancerous liver tissue. Recurrence rates after hepatic resection were significantly higher in patients with a pretreatment serum WFA(+) -M2BP ≥ 3.00 than those with a pretreatment serum WFA(+) -M2BP < 3.00 (P = 0.0038). Survival rates were lower in patients with a pretreatment serum WFA(+) -M2BP ≥ 3.00 than those with a pretreatment serum WFA(+) -M2BP < 3.00 (P = 0.0187). CONCLUSIONS Serum WFA(+) -M2BP level is a prognostic factor for recurrence and survival, in addition to tumour progression and liver function, in patients with early-stage HCC treated with curative hepatic resection.

Hepatitis B and C Virus Infection and Risk of Pancreatic Cancer: A Population-Based Cohort Study (JPHC Study Cohort II)

Abstract: Background: The aim of this study was to assess the association between HBV and HCV and the risk of pancreatic cancer among Japanese adults. Methods: 20,360 subjects of the Japan Public Health Center-based prospective Study Cohort II with available data on HBV and HCV infection status from blood samples were followed up until the end of 2010 for an average of 16 years. Cox proportional hazards models were employed to calculate hazard ratios (HRs) and 95% confidence intervals (95%CIs). Results: During 324,394 person-years, 116 newly diagnosed cases of pancreatic cancer were identified. Compared to individuals without a positive infection marker, the multivariate-adjusted hazard ratios were 1.22 (95% CI, 0.81-1.84) for anti-HBc and 0.69 (95% CI, 0.28-1.69) for anti-HCV. There were no pancreatic cancer cases among HBsAg positive participants. Conclusion: In the JPHC Study we did not observe a statistically significant association between Hepatitis B or C and the risk of pancreatic cancer. Impact: Our results do not support an association between Hepatitis B or C and the risk of pancreatic cancer.

Nationwide prospective and retrospective surveys for hepatitis B virus reactivation during immunosuppressive therapies

Abstract: Background The significance of HBV reactivation during immunosuppressive therapy was evaluated in three nationwide cohorts including patients with previously resolved HBV (prHBV) infection.

Hepatocyte Factor JMJD5 Regulates Hepatitis B Virus Replication through Interaction with HBx.

Abstract: Hepatitis B virus (HBV) is a causative agent for chronic liver diseases such as hepatitis, cirrhosis, and hepatocellular carcinoma (HCC). HBx protein encoded by the HBV genome plays crucial roles not only in pathogenesis but also in replication of HBV. Although HBx has been shown to bind to a number of host proteins, the molecular mechanisms by which HBx regulates HBV replication are largely unknown. In this study, we identified jumonji C-domain-containing 5 (JMJD5) as a novel binding partner of HBx interacting in the cytoplasm. DNA microarray analysis revealed that JMJD5-knockout (JMJD5KO) Huh7 cells exhibited a significant reduction in the expression of transcriptional factors involved in hepatocyte differentiation, such as HNF4A, CEBPA, and FOXA3. We found that hydroxylase activity of JMJD5 participates in the regulation of these transcriptional factors. Moreover, JMJD5KO Huh7 cells exhibited a severe reduction in HBV replication, and complementation of HBx expression failed to rescue replication of a mutant HBV deficient in HBx, suggesting that JMJD5 participates in HBV replication through an interaction with HBx. We also found that replacing Gly 135 with Glu in JMJD5 abrogates binding with HBx and replication of HBV. Moreover, the hydroxylase activity of JMJD5 was crucial for HBV replication. Collectively, these results suggest that direct interaction of JMJD5 with HBx facilitates HBV replication through the hydroxylase activity of JMJD5. IMPORTANCE HBx protein encoded by hepatitis B virus (HBV) plays important roles in pathogenesis and replication of HBV. We identified jumonji C-domain-containing 5 (JMJD5) as a novel binding partner to HBx. JMJD5 was shown to regulate several transcriptional factors to maintain hepatocyte function. Although HBx had been shown to support HBV replication, deficiency of JMJD5 abolished contribution of HBx in HBV replication, suggesting that HBx-mediated HBV replication is largely dependent on JMJD5. We showed that hydroxylase activity of JMJD5 in the C terminus region is crucial for expression of HNF4A and replication of HBV. Furthermore, a mutant JMJD5 with Gly 135 replaced by Glu failed to interact with HBx and to rescue the replication of HBV in JMJD5-knockout cells. Taken together, our data suggest that interaction of JMJD5 with HBx facilitates HBV replication through the hydroxylase activity of JMJD5.

Appropriate use of virtual touch quantification and FibroScan® M and XL probes according to the skin capsular distance

Abstract: Appropriate utilization of different diagnostic modalities is essential for the accurate liver stiffness measurements (LSM) in patients with chronic liver diseases. The aim of this study was to evaluate the efficacy of Virtual Touch Quantification® (VTQ) and the FibroScan® M and XL probes in term of accurate LSM and to identify factors associated with inadequate measurements in obese and non-obese Japanese patients. A total of 664 consecutive patients with chronic liver disease were prospectively enrolled. LSM were evaluated concurrently with VTQ and the FibroScan M and XL probes. LSM quality was categorized as inadequate (success rate <60 % and/or interquartile range/median value of ≥30 %) or adequate. No significant differences in the rate of inadequate LSM were observed among the three diagnostic modalities. In multivariate analysis, skin capsule distance (SCD) was strongly associated with inadequate rates obtained with VTQ and the M probe [odds ratio (OR) 1.28, P < 0.0001 and OR 1.20, P < 0.0001, respectively]. Inadequate LSM rates with both VTQ and the M probe increased with longer SCD, with a significant difference between subgroups at an SCD of ≥22.5 mm (VTQ 54.0 %; M probe 51.1 %; XL probe 25.2 %; P < 0.0001). The rates of inadequate LSM rates with VTQ were significantly lower than those with the XL probe at an SCD of <17.5 mm. A total of 15 liver biopsy specimens obtained from nonalcoholic fatty liver disease patients confirmed the diagnostic accuracy and high applicability of the XL probe. Long SCD reduced the diagnostic performance of the FibroScan® M probe and VTQ. LSM modalities should be selected according to SCD.

Smoking is a risk factor for development of adult T-cell leukemia/lymphoma in Japanese human T-cell leukemia virus type-1 carriers.

Abstract: Adult T-cell leukemia/lymphoma (ATLL) is an aggressive hematological malignancy caused by human T-cell leukemia virus type-1 (HTLV-1); no effective methods have yet been identified to prevent development of ATLL in carriers of HTLV-1. This study investigated the association between cigarette smoking and the risk of ATLL development among Japanese carriers of HTLV-1. This study examined the association between smoking and development of ATLL in a cohort of 1,332 Japanese HTLV-1 carriers aged 40–69 years free of ATLL at baseline from two different HTLV-1-endemic areas of Japan. Cox proportional hazards models adjusted for sex, geographic area, age at baseline, and alcohol drinking were used to estimate the effect of cigarette smoking on ATLL development. Between 1993 and 2012, 25 new ATLL cases were identified among these subjects. The overall crude incidence rate for ATLL was 1.08 per 1,000 person-years among HTLV-1 carriers and was higher among male carriers than among female carriers (2.21 vs. 0.74). The risk of ATLL development increased significantly with increasing numbers of cigarettes smoked per day (hazard ratio for every increment of 20 cigarettes, 2.03; 95 % confidence interval (CI) 1.13–3.66 overall, 2.07 (95 % CI 1.13–3.73) in male carriers). Cigarette smoking may influence ATLL development among HTLV-1 carriers in Japan.

Hepatitis B Virus Genotypes

Abstract: Hepatitis B virus (HBV) was discovered as the “Australian antigen” by Blumberg et al. in 1965. This achievement, which contributed to the discovery of and prophylaxis of post-transfusion hepatitis, Blumberg was awarded the Nobel Prize for Physiology and Medicine in 1976. Thereafter, in spite of the development of a vaccine for prophylaxis against HBV infection, more than four billion people have been chronically infected with HBV (HBV carriers). It is estimated that at least 500,000 patients with HBV die annually due to HBV-related diseases. In developing countries, such as Asia and Africa, there are more patients with HBV than with hepatitis C virus infection. Therefore, hepatitis B remains an as-yet unsolved major problem in public health [2].