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Kazumoto Murata,
Masaya Sugiyama,
Tatsuji Kimura,
Sachiyo Yoshio,
Tatsuya Kanto,
Ikue Kirikae,
Hiroaki Saito,
Yoshihiko Aoki,
Satoshi Hiramine,
Teppei Matsui,
Kiyoaki Ito, Masaaki Korenaga,
Masatoshi Imamura,
Naohiko Masaki,
Masashi Mizokami
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ABSTRACT: BACKGROUND: Genetic variation around interleukin-28B (IL28B), encoding IFN-λ3, predict non-responders to pegylated interferon-α/ribavirin (Peg-IFN/RBV) therapy in chronic hepatitis C (CHC). However, it remains unclear the expression and the role of IL28B itself. The aim of this study is to develop easy and useful methods for the prediction of treatment outcomes. METHODS: The mRNA and protein levels of IFN-λ3 induced by ex vivo stimulation of peripheral blood mononuclear cells (PBMC) or magnetically selected dendritic cells (DCs) with toll-like receptor agonists (TLR3; poly I:C, TLR7; R-837) were measured by the quantitative real-time polymerase chain reaction and our newly developed chemiluminescence enzyme immunoassays, respectively, and compared with the clinical data. RESULTS: We found that BDCA-4(+) plasmacytoid and BDCA-3(+) myeloid DCs were the main producers of IFN-λs when stimulated with R-837 and poly I:C, respectively. Detectable levels of IFN-λs were inducible even in a small amount of PBMC, and IFN-λ3 was more robustly up-regulated by R-837 in PBMC of CHC patients with favorable genotype for the response to Peg-IFN/RBV (TT in rs8099917) than those with TG/GG. Importantly, the protein levels of IFN-λ3 induced by R-837 clearly differentiated the response to Peg-IFN/RBV treatment (p = 1.0 × 10(-10)), including cases that IL28B genotyping failed to predict the treatment response. The measurement of IFN-λ3 protein more accurately predicted treatment efficacies (95.7 %) than that of IL28B genotyping (65.2 %). CONCLUSIONS: Genetic variations around IL28B basically affect IFN-λ3 production, but different amounts of IFN-λ3 protein determines the outcomes of Peg-IFN/RBV treatment. This study, for the first time, presents compelling evidence that IL28B confer a functional phenotype.
Journal of Gastroenterology 04/2013; · 4.16 Impact Factor
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Keiko Korenaga, Masaaki Korenaga,
Fusako Teramoto,
Toshiko Suzuki,
Sohji Nishina,
Kyo Sasaki,
Yoshihiro Nakashima,
Yasuyuki Tomiyama,
Naoko Yoshioka,
Yuichi Hara,
Takuya Moriya,
Keisuke Hino
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ABSTRACT: AIM: Little is known about the effects of non-alcoholic fatty liver disease (NAFLD) on energy metabolism, although this disease is associated with metabolic syndrome. We measured non-protein respiratory quotient (npRQ) using indirect calorimetry, which reflects glucose oxidation, and compared this value with histological disease severity in NAFLD patients. METHODS: Subjects were 32 patients who were diagnosed with NAFLD histopathologically. Subjects underwent body composition analysis and indirect calorimetry, and npRQ was calculated. An oral glucose tolerance test was performed, and plasma glucose area under the curve (AUC glucose) was calculated. RESULTS: There were no differences in body mass index, body fat percentage or visceral fat area among fibrosis stage groups. As fibrosis progressed, npRQ significantly decreased (stage 0, 0.895 ± 0.068; stage 1, 0.869 ± 0.067; stage 2, 0.808 ± 0.046; stage 3, 0.798 ± 0.026; P < 0.005). Glucose intolerance worsened and insulin resistance increased with fibrosis stage. npRQ was negatively correlated with AUC glucose (R = -0.6308, P < 0.001), Homeostasis Model of Assessment - Insulin Resistance (R = -0.5045, P < 0.005), fasting glucose (R = -0.4585, P < 0.01) and insulin levels (R = -0.4431, P < 0.05), suggesting that decreased npRQ may reflect impaired glucose tolerance due to insulin resistance, which was associated with fibrosis progression. Estimation of fibrosis stage using npRQ was as accurate as several previously established scoring systems using receiver-operator curve analysis. CONCLUSION: npRQ was significantly decreased in patients with advanced NAFLD. Our data suggest that measurement of npRQ is useful for the estimation of disease severity in NAFLD patients.
Hepatology Research 02/2013; · 2.20 Impact Factor
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Hiromi Sawai,
Nao Nishida,
Hamdi Mbarek,
Koichi Matsuda,
Yoriko Mawatari,
Megumi Yamaoka,
Shuhei Hige,
Jong-Hon Kang,
Koichi Abe,
Satoshi Mochida, [......],
Kiyoaki Ito,
Masaya Sugiyama,
Sang Hoon Ahn,
Kwang-Hyub Han,
Jun Yong Park,
Man-Fung Yuen,
Yusuke Nakamura,
Yasuhito Tanaka,
Masashi Mizokami,
Katsushi Tokunaga
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ABSTRACT: A recent genome-wide association study (GWAS) using chronic HBV (hepatitis B virus) carriers with and without hepatocellular carcinoma (HCC) in five independent Chinese populations found that one SNP (rs17401966) in KIF1B was associated with susceptibility to HCC. In the present study, a total of 580 HBV-derived HCC cases and 1351 individuals with chronic hepatitis B (CHB) or asymptomatic carrier (ASC) were used for replication studies in order to evaluate the reported association with HBV-derived HCC in other East Asian populations.
We did not detect any associations between rs17401966 and HCC in the Japanese cohorts (replication 1: OR = 1.09, 95 % CI = 0.82-1.43; replication 2: OR = 0.79, 95 % CI = 0.54-1.15), in the Korean cohort (replication 3: OR = 0.95, 95 % CI = 0.66-1.36), or in the Hong Kong Chinese cohort (replication 4: OR = 1.17, 95 % CI = 0.79-1.75). Meta-analysis using these cohorts also did not show any associations with P = 0.97.
None of the replication cohorts showed associations between rs17401966 and HBV-derived HCC. This may be due to differences in the genetic diversity among the Japanese, Korean and Chinese populations. Other reasons could be the high complexity of multivariate interactions between the genomic information and the phenotype that is manifesting. A much wider range of investigations is needed in order to elucidate the differences in HCC susceptibility among these Asian populations.
BMC Medical Genetics 06/2012; 13:47. · 2.33 Impact Factor
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Kiyoaki Ito,
Atsushi Kuno,
Yuzuru Ikehara,
Masaya Sugiyama,
Hiroaki Saito,
Yoshihiko Aoki,
Teppei Matsui,
Masatoshi Imamura, Masaaki Korenaga,
Kazumoto Murata,
Naohiko Masaki,
Yasuhito Tanaka,
Shuhei Hige,
Namiki Izumi,
Masayuki Kurosaki,
Shuhei Nishiguchi,
Michiie Sakamoto,
Masayoshi Kage,
Hisashi Narimatsu,
Masashi Mizokami
[show abstract]
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ABSTRACT: Assessment of liver fibrosis in patients with chronic hepatitis C (CHC) is critical for predicting disease progression and determining future antiviral therapy. LecT-Hepa, a new glyco-marker derived from fibrosis-related glyco-alteration of serum alpha 1-acid glycoprotein, was used to differentiate cirrhosis from chronic hepatitis in a single-center study. Herein, we aimed to validate this new glyco-marker for estimating liver fibrosis in a multicenter study. Overall, 183 CHC patients were recruited from 5 liver centers. The parameters Aspergillus oryzae lectin (AOL) / Dature stramonium lectin (DSA) and Maackia amurensis lectin (MAL)/DSA were measured using a bedside clinical chemistry analyzer in order to calculate LecT-Hepa levels. The data were compared with those of seven other noninvasive biochemical markers and tests (hyaluronic acid, tissue inhibitor of metalloproteases-1, platelet count, aspartate aminotransferase-to-platelet ratio index [APRI], Forns index, Fib-4 index, and Zeng's score) for assessing liver fibrosis using the receiver-operating characteristic curve. LecT-Hepa correlated well with the fibrosis stage as determined by liver biopsy. The area under the curve (AUC), sensitivity, and specificity of LecT-Hepa were 0.802, 59.6%, and 89.9%, respectively, for significant fibrosis; 0.882, 83.3%, and 80.0%, respectively, for severe fibrosis; and 0.929, 84.6%, and 88.5%, respectively, for cirrhosis. AUC scores of LecT-Hepa at each fibrosis stage were greater than those of the seven aforementioned noninvasive tests and markers. Conclusion: The efficacy of LecT-Hepa, a glyco-marker developed using glycoproteomics, for estimating liver fibrosis was demonstrated in a multicenter study. LecT-Hepa given by a combination of the two glyco-parameters is a reliable method for determining the fibrosis stage and is a potential substitute for liver biopsy. (HEPATOLOGY 2012).
Hepatology 04/2012; 56(4):1448-56. · 11.66 Impact Factor
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Nao Nishida,
Hiromi Sawai,
Kentaro Matsuura,
Masaya Sugiyama,
Sang Hoon Ahn,
Jun Yong Park,
Shuhei Hige,
Jong-Hon Kang,
Kazuyuki Suzuki,
Masayuki Kurosaki, [......],
Minae Kawashima,
Yoriko Mawatari,
Megumi Sageshima,
Yuko Ogasawara,
Asako Koike,
Namiki Izumi,
Kwang-Hyub Han,
Yasuhito Tanaka,
Katsushi Tokunaga,
Masashi Mizokami
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ABSTRACT: Hepatitis B virus (HBV) infection can lead to serious liver diseases, including liver cirrhosis (LC) and hepatocellular carcinoma (HCC); however, about 85-90% of infected individuals become inactive carriers with sustained biochemical remission and very low risk of LC or HCC. To identify host genetic factors contributing to HBV clearance, we conducted genome-wide association studies (GWAS) and replication analysis using samples from HBV carriers and spontaneously HBV-resolved Japanese and Korean individuals. Association analysis in the Japanese and Korean data identified the HLA-DPA1 and HLA-DPB1 genes with P(meta) = 1.89×10⁻¹² for rs3077 and P(meta) = 9.69×10⁻¹⁰ for rs9277542. We also found that the HLA-DPA1 and HLA-DPB1 genes were significantly associated with protective effects against chronic hepatitis B (CHB) in Japanese, Korean and other Asian populations, including Chinese and Thai individuals (P(meta) = 4.40×10⁻¹⁹ for rs3077 and P(meta) = 1.28×10⁻¹⁵ for rs9277542). These results suggest that the associations between the HLA-DP locus and the protective effects against persistent HBV infection and with clearance of HBV were replicated widely in East Asian populations; however, there are no reports of GWAS in Caucasian or African populations. Based on the GWAS in this study, there were no significant SNPs associated with HCC development. To clarify the pathogenesis of CHB and the mechanisms of HBV clearance, further studies are necessary, including functional analyses of the HLA-DP molecule.
PLoS ONE 01/2012; 7(6):e39175. · 4.09 Impact Factor
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Nippon rinsho. Japanese journal of clinical medicine 05/2011; 69 Suppl 4:149-55.
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ABSTRACT: A European randomized trial showed biochemical effects of 6-month treatment with Stronger Neo-Minophagen C (SNMC), a glycyrrhizin-containing preparation, in patients with chronic hepatitis C, but its underlying mechanisms remain elusive. We reported previously that SNMC exhibits an anti-oxidative effect in hepatitis C virus (HCV) transgenic mice that develop marked hepatic steatosis with mitochondrial injury under iron overloading. Hepatic steatosis and iron overload are oxidative stress-associated pathophysiological features in chronic hepatitis C. The aim of this study was to investigate whether long-term treatment with SNMC could prevent the development of hepatic steatosis in iron-overloaded HCV transgenic mice.
C57BL/6 transgenic mice expressing the HCV polyprotein were fed an excess iron diet concomitantly with intraperitoneal injection of saline, SNMC, or seven-fold-concentrated SNMC thrice weekly for 6 months.
Stronger Neo-Minophagen C inhibited the development of hepatic steatosis in a dose-dependent manner without affecting hepatic iron content, attenuated ultrastructural alterations of mitochondria of the liver, activated mitochondrial β-oxidation with increased expression of carnitine palmitoyl transferase I and decreased the production of reactive oxygen species in the liver in iron-overloaded transgenic mice. However, SNMC hardly affected the unfolded protein response, which post-transcriptionally activates sterol regulatory element-binding protein 1, a transcription factor involved in lipid synthesis, even though we reported previously the activation of the unfolded protein response in the same iron-overloaded transgenic mice.
These results suggest that SNMC prevents hepatic steatosis possibly by protecting mitochondria against oxidative stress induced by HCV proteins and iron overload.
Liver international: official journal of the International Association for the Study of the Liver 04/2011; 31(4):552-60. · 3.82 Impact Factor
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Nobuko Doi,
Yasuyuki Tomiyama,
Tomoya Kawase,
Sohji Nishina,
Naoko Yoshioka,
Yuichi Hara,
Koji Yoshida,
Keiko Korenaga, Masaaki Korenaga,
Takuya Moriya,
Atsushi Urakami,
Osamu Nakashima,
Masamichi Kojiro,
Keisuke Hino
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ABSTRACT: We report a patient with alcoholic liver cirrhosis who had a 15 mm focal nodular hyperplasia (FNH)-like nodule in the liver. This FNH-like nodule was diagnosed as hepatocellular carcinoma (HCC) mainly based on hypervascularity during the hepatic arterial phase, washout pattern during the equilibrium phase and low signal intensity during the hepatobiliary phase in gadolinium-ethoxybenzyl-diethylenetriamine pentaacetic acid (Gd-EOB-DTPA)-enhanced MRI; it was surgically resected. Its histology exhibited hepatocyte hyperplasia, fibrous septa containing unpaired small arteries accompanied by reactive bile ductules, remarkable iron deposits and sinusoidal capillarization, and was compatible with the diagnosis of an FNH-like nodule. When we analyzed the images of the present nodule retrospectively, low signal intensity on in-phase and isosignal intensity on opposed-phase T1-weighted MRI may have reflected iron deposits in the FNH-like nodule. In addition, a low signal intensity on T2-weighted MRI and no detection in diffusion-weighted MRI may help in distinguishing FNH-like nodules from HCC, since these image findings are inconsistent with typical HCC. Immunohistochemical analysis revealed a markedly reduced expression of organic anion transporter (OATP) 1B3 in this nodule, which implied decreased Gd-EOB-DTPA uptake by hepatocytes and accounted for the low signal intensity during the hepatobiliary phase on Gd-EOB-DTPA-enhanced MRI. To the best of our knowledge this is the first report in which an FNH-like nodule was assessed for OATP1B3 expression.
Internal Medicine 01/2011; 50(11):1193-9. · 0.94 Impact Factor
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ABSTRACT: Background: Type 1 interferon alpha receptor 2 (IFNAR2) in the liver has been reported to be a predictive factor for the response to intra-arterial 5-fluorouracil (5-FU) + systemic interferon (IFN)-alpha combination therapy in patients with advanced hepatocellular carcinoma. We tested whether IFNAR2 expression in peripheral blood mononuclear cells could predict the response to 5-FU + IFN. Methods: Predictive factors for survival and response to therapy were determined in 30 patients with advanced hepatocellular carcinoma who underwent treatment with 5-FU + IFN. IFNAR2 expression in peripheral blood mononuclear cells was measured in 11 of the 30 patients. Results: With a mean number of 4.2 courses of combination therapy, one patient (3%) showed a complete response, eight (27%) showed partial responses, 13 (43%) had stable disease, and eight (27%) showed progressive disease. The median survival time of responders (complete response/partial response) was 12.7 months and that of nonresponders (stable disease/progressive disease) was 7.5 months. The one-year and two-year cumulative survival rates of responders and nonresponders were 87/69% and 40/11%, respectively (P = 0.019). Multivariate analysis identified response to therapy (P = 0.037) as the sole independent determinant of survival. The expression level of IFNAR2 in peripheral blood mononuclear cells was significantly (P = 0.012) higher in responders (6.5 ± 2.4) than in nonresponders (2.4 ± 0.6), even though no clinical factors were identified as being associated with the response to the combination therapy. Conclusion: IFNAR2 expression in peripheral blood mononuclear cells may predict the response to 5-FU + IFN therapy in patients with advanced hepatocellular carcinoma, although these data are preliminary.
Hepatic Medicine: Evidence and Research 01/2011;
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ABSTRACT: Hepatic iron overload and steatosis play critical roles in the progression of hepatitis C virus (HCV)-associated chronic liver disease. However, how these two pathophysiological features affect each other remains unknown. The aim of this study was to investigate how hepatic iron overload contributes to the development of hepatic steatosis in the presence of HCV proteins.
Male C57BL/6 transgenic mice expressing the HCV polyprotein and nontransgenic littermates were fed an excess-iron diet or a control diet. Mice in each group were assessed for the molecules responsible for fat accumulation in the liver.
Hepatic iron levels were positively correlated with triglyceride concentrations in the liver for all mice. As compared with the livers of nontransgenic mice fed the control diet, the livers of transgenic mice fed the excess-iron diet showed a lower expression of carnitine palmitoyl transferase I, a higher expression of sterol-regulatory element-binding protein 1 and fatty acid synthetase and an activated unfolded protein response indicated by a higher expression of unspliced and spliced X-box DNA-binding protein 1 (XBP-1), phosphorylated eukaryotic initiation factor-2alpha (p-eIF2alpha), CCAAT/enhancer-binding protein homology protein (CHOP) and abundant autophagosomes concomitant with increased production of reactive oxygen species. Six-month treatment with the anti-oxidant N-acetyl cysteine dramatically reduced hepatic steatosis in transgenic mice fed the excess-iron diet through decreased expression of unspliced and spliced XBP-1, p-eIF2alpha, and CHOP.
The iron-induced unfolded protein response appears to be one of the mechanisms responsible for fat accumulation in the liver in transgenic mice expressing the HCV polyprotein.
Liver international: official journal of the International Association for the Study of the Liver 03/2010; 30(5):683-92. · 3.82 Impact Factor
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Yasuhito Tanaka,
Nao Nishida,
Masaya Sugiyama,
Masayuki Kurosaki,
Kentaro Matsuura,
Naoya Sakamoto,
Mina Nakagawa, Masaaki Korenaga,
Keisuke Hino,
Shuhei Hige, [......],
Asako Koike,
Isao Sakaida,
Masatoshi Imamura,
Kiyoaki Ito,
Koji Yano,
Naohiko Masaki,
Fuminaka Sugauchi,
Namiki Izumi,
Katsushi Tokunaga,
Masashi Mizokami
Nature Genetics 09/2009; 41(10):1105-1109. · 35.53 Impact Factor
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Yasuhito Tanaka,
Nao Nishida,
Masaya Sugiyama,
Masayuki Kurosaki,
Kentaro Matsuura,
Naoya Sakamoto,
Mina Nakagawa, Masaaki Korenaga,
Keisuke Hino,
Shuhei Hige, [......],
Asako Koike,
Isao Sakaida,
Masatoshi Imamura,
Kiyoaki Ito,
Koji Yano,
Naohiko Masaki,
Fuminaka Sugauchi,
Namiki Izumi,
Katsushi Tokunaga,
Masashi Mizokami
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ABSTRACT: The recommended treatment for patients with chronic hepatitis C, pegylated interferon-alpha (PEG-IFN-alpha) plus ribavirin (RBV), does not provide sustained virologic response (SVR) in all patients. We report a genome-wide association study (GWAS) to null virological response (NVR) in the treatment of patients with hepatitis C virus (HCV) genotype 1 within a Japanese population. We found two SNPs near the gene IL28B on chromosome 19 to be strongly associated with NVR (rs12980275, P = 1.93 x 10(-13), and rs8099917, 3.11 x 10(-15)). We replicated these associations in an independent cohort (combined P values, 2.84 x 10(-27) (OR = 17.7; 95% CI = 10.0-31.3) and 2.68 x 10(-32) (OR = 27.1; 95% CI = 14.6-50.3), respectively). Compared to NVR, these SNPs were also associated with SVR (rs12980275, P = 3.99 x 10(-24), and rs8099917, P = 1.11 x 10(-27)). In further fine mapping of the region, seven SNPs (rs8105790, rs11881222, rs8103142, rs28416813, rs4803219, rs8099917 and rs7248668) located in the IL28B region showed the most significant associations (P = 5.52 x 10(-28)-2.68 x 10(-32); OR = 22.3-27.1). Real-time quantitative PCR assays in peripheral blood mononuclear cells showed lower IL28B expression levels in individuals carrying the minor alleles (P = 0.015).
Nature Genetics 09/2009; 41(10):1105-9. · 35.53 Impact Factor
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ABSTRACT: We investigated the usefulness of Sonazoid contrast-enhanced ultrasonography (Sonazoid-CEUS) in the diagnosis of hepatocellular carcinoma (HCC). The examination was performed by comparing the images during the Kupffer phase of Sonazoid-CEUS with superparamagnetic iron oxide magnetic resonance (SPIO-MRI).
The subjects were 48 HCC nodules which were histologically diagnosed (well-differentiated HCC, n=13; moderately differentiated HCC, n=30; poorly differentiated HCC, n=5). We performed Sonazoid-CEUS and SPIO-MRI on all subjects. In the Kupffer phase of Sonazoid-CEUS, the differences in the contrast agent uptake between the tumorous and non-tumorous areas were quantified as the Kupffer phase ratio and compared. In the SPIO-MRI, it was quantified as the SPIO-intensity index. We then compared these results with the histological differentiation of HCCs.
The Kupffer phase ratio decreased as the HCCs became less differentiated (P<0.0001; Kruskal-Wallis test). The SPIO-intensity index also decreased as HCCs became less differentiated (P<0.0001). A positive correlation was found between the Kupffer phase ratio and the SPIO-MRI index (r=0.839). In the Kupffer phase of Sonazoid-CEUS, all of the moderately and poorly differentiated HCCs appeared hypoechoic and were detected as a perfusion defect, whereas the majority (9 of 13 cases, 69.2%) of the well-differentiated HCCs had an isoechoic pattern. The Kupffer phase images of Sonazoid-CEUS and SPIO-MRI matched perfectly (100%) in all of the moderately and poorly differentiated HCCs.
Sonazoid-CEUS is useful for estimating histological grading of HCCs. It is a modality that could potentially replace SPIO-MRI.
Journal of Gastroenterology 05/2009; 44(7):733-41. · 4.16 Impact Factor
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ABSTRACT: Hepatitis C virus (HCV) core protein has been shown to inhibit mitochondrial electron transport and to increase reactive oxygen species (ROS) in vitro and in vivo. The aim of this study was to investigate whether inhibiting HCV replication could restore the mitochondrial redox state and electron transport activity.
We measured ROS, mitochondrial reduced glutathione content, and mitochondrial complex I, II, III and IV activities and protein expression in full genomic HCV replicon cells and cured cells that had been prepared by eliminating HCV RNA from replicon cells by interferon (IFN)-alpha treatment.
Cured cells had significantly lower ROS production and greater mitochondrial glutathione content than replicon cells. Complete inhibition of HCV replication by IFN-alpha restored complex I and IV activities by 20-30% (P<0.01) and complex I expression (P<0.05). Treatment with fluvastatin, one of the 3-hydroxy-3-methylglutaryl co-enzyme A reductase inhibitors, which is known to have anti-HCV activity, partially inhibited core protein expression and restored complex I activity in full genomic HCV replicon cells to a lesser degree (P<0.05).
Our results show that the mitochondrial redox state and electron transport activity can be restored by reducing HCV replication.
Liver international: official journal of the International Association for the Study of the Liver 05/2008; 28(8):1158-66. · 3.82 Impact Factor
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Sohji Nishina,
Keisuke Hino, Masaaki Korenaga,
Chiara Vecchi,
Antonello Pietrangelo,
Yoichi Mizukami,
Takakazu Furutani,
Aya Sakai,
Michiari Okuda,
Isao Hidaka,
Kiwamu Okita,
Isao Sakaida
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ABSTRACT: Despite abundant clinical evidence, the mechanisms by which hepatic iron overload develops in patients with hepatitis C virus (HCV)-associated chronic liver disease remain unknown. The aim of this study was to investigate how hepatic iron overload develops in the presence of HCV proteins.
Male transgenic mice expressing the HCV polyprotein and nontransgenic control mice (C57BL/6) were assessed for iron concentrations in the liver, spleen, and serum and iron regulatory molecules in vivo and ex vivo.
Transgenic mice had increased hepatic and serum iron concentrations, decreased splenic iron concentration, and lower hepcidin expression in the liver accompanied by higher expression of ferroportin in the duodenum, spleen, and liver. In response to hepatocellular iron excess, transferrin receptor 1 expression decreased and ferritin expression increased in the transgenic liver. Transgenic mice showed no inflammation in the liver but preserved the ability to induce hepcidin in response to proinflammatory cytokines induced by lipopolysaccharide. Hepcidin promoter activity and the DNA binding activity of CCAAT/enhancer-binding protein alpha (C/EBP) were down-regulated concomitant with increased expression of C/EBP homology protein, an inhibitor of C/EBP DNA binding activity, and with increased levels of reactive oxygen species in transgenic mice at the ages of 8 and 14 months.
HCV-induced reactive oxygen species may down-regulate hepcidin transcription through inhibition of C/EBPalpha DNA binding activity by C/EBP homology protein, which in turn leads to increased duodenal iron transport and macrophage iron release, causing hepatic iron accumulation.
Gastroenterology 01/2008; 134(1):226-38. · 11.68 Impact Factor
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ABSTRACT: Aim: A late evening snack (LES) is recommended for protein-energy malnutrition in patients with liver cirrhosis. However, many cases of liver cirrhosis have accompanying impaired glucose tolerance and there are concerns that LESs might aggravate glucose intolerance. In this study, we concomitantly used an alpha-glucosidase inhibitor with a LES and examined the effects on glucose tolerance. In addition, we examined whether or not there was an improvement in energy metabolism by slowing glucose absorption with the concomitant use of the alpha-glucosidase inhibitor. Methods: The subjects were 11 patients with liver cirrhosis. From before the study, all the patients had been taking a LES supplementation with a branched-chain amino acid (BCAA)-enriched nutrient mixture. The patients were started on the concomitant use of alpha-glucosidase inhibitor (0.2 mg) taken just prior to the LES. The change of glucose tolerance and energy metabolism were examined using a 75-g oral glucose tolerance test and indirect calorimetry. Results: One week and three months after the start of the concomitant use of the alpha-glucosidase inhibitor, the area under the concentration curve for plasma glucose was significantly decreased. Three months after the concomitant use, the non-protein respiratory quotient was significantly improved. There were no serious side effects during the follow-ups. Conclusion: The concomitant use of the alpha-glucosidase inhibitor use with LES showed the possibility of improving glucose tolerance and energy metabolism. In patients with impaired glucose tolerance, the concomitant use of an alpha-glucosidase inhibitor with LES might be a useful measure for nutritional management.
Hepatology Research 01/2008; 38(11):1087-97. · 2.20 Impact Factor
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ABSTRACT: Stronger Neo-Minophagen C (SNMC), a glycyrrhizin-containing preparation, has been used as a treatment for chronic hepatitis for more than 30 years in Japan, and shown to be effective in preventing the development of hepatocellular carcinoma in chronic hepatitis C patients, but its underlying mechanisms remain elusive. The aim of this study was to investigate if SNMC had an anti-oxidative effect, as oxidative stress has been proposed to be one of the mechanisms of liver injury in hepatitis C virus (HCV)-associated chronic liver diseases.
The protective effect of SNMC against carbon tetrachloride (CCl4)-induced liver injury was examined using transgenic mice expressing the HCV polyprotein.
A small dose of CCl4 (10 microl/kg of body weight) significantly increased the serum alanine aminotransferase (ALT) level and hepatic malondialdehyde content, decreased hepatic reduced glutathione (GSH) content and induced ultrastructural alterations of hepatic mitochondria in transgenic mice, but not in nontransgenic mice. A single SNMC treatment equivalent to a clinical dose significantly restored the serum ALT level and hepatic malondialdehyde and GSH contents, attenuated the ultrastructural alterations of hepatic mitochondria, and increased mRNA expression of gamma-glutamylcysteine synthetase (gamma-GCS).
Transgenic mice expressing the HCV polyprotein are abnormally vulnerable to oxidative stress. SNMC protects hepatocytes against CCl4-induced oxidative stress and mitochondrial injury in the presence of HCV proteins by restoring depleted cellular GSH.
Liver international: official journal of the International Association for the Study of the Liver 09/2007; 27(6):845-53. · 3.82 Impact Factor
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Takakazu Furutani,
Keisuke Hino,
Michiari Okuda,
Toshikazu Gondo,
Sohji Nishina,
Akira Kitase, Masaaki Korenaga,
Shu-Yuan Xiao,
Steven A Weinman,
Stanley M Lemon,
Isao Sakaida,
Kiwamu Okita
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ABSTRACT: Despite the evidence of hepatic iron overload in patients with chronic hepatitis C, it remains unknown if iron overload is related to hepatocarcinogenesis in this condition. The aim of this study was to determine whether iron overload contributes to development of hepatocellular carcinoma (HCC) in transgenic mice expressing the hepatitis C virus (HCV) polyprotein.
Male C57BL/6 transgenic mice expressing the HCV polyprotein and nontransgenic littermates were fed an excess-iron diet or control diet. Mice in each group were assessed for altered liver morphology and function and the development of liver tumors.
Hepatic iron concentrations in mice fed the excess-iron diet were comparable to those of patients with chronic hepatitis C. There was no inflammation in transgenic and nontransgenic livers. Compared with mice in 3 other groups, transgenic mice fed the excess-iron diet showed marked hepatic steatosis including the centrilobular microvesicular type, ultrastructural alterations of the mitochondria and decreased degradation activity of fatty acid at 6 months, and greater hepatic content of lipid peroxidation products and 8-hydroxy-2'-deoxyguanosine at 12 months after initiation of feeding. The number of proliferating hepatocytes was significantly increased in mice fed the excess-iron diet but was not different between transgenic and nontransgenic mice. Hepatic tumors including HCC developed in 5 of 11 (45%) transgenic mice fed the excess-iron diet but not in mice in other groups at 12 months after initiation of feeding.
Iron overload induces mitochondrial injury and increases the risk of HCC development in transgenic mice expressing the HCV polyprotein.
Gastroenterology 07/2006; 130(7):2087-98. · 11.68 Impact Factor
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ABSTRACT: Nonalcoholic steatohepatitis (NASH), which is considered the hepatic manifestation of the metabolic syndrome is an increasingly cause of chronic liver disease in Japan. NASH is finally lead to liver cirrhosis and hepatocellular carcinoma as viral hepatitis, therefore, medical treatment should be considered, when NASH occurs. Treatment of patients with metabolic syndrome has been focused on the management of associated conditions such as obesity, hyperlipidemia, hypertension and hyperinsulinemia. Insulin resistance, that could accelerate liver inflammation and fibrosis by up-regulation of TNFa seems to be most important factor in many cases of NASH. The insulin-sensitizing drugs, which were biguanides (metformin) and thiazolidinediones (pioglitazone) have been shown to correct not only insulin resistance but also steatosis and inflammation in the liver. Metformin and pioglitazone might be useful drugs against NASH, however further investigations were needed.
Nippon rinsho. Japanese journal of clinical medicine 07/2006; 64(6):1157-64.
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Yuichi Hara,
Keisuke Hino,
Michiari Okuda,
Takakazu Furutani,
Isao Hidaka,
Yuhki Yamaguchi, Masaaki Korenaga,
Kui Li,
Steven A Weinman,
Stanley M Lemon,
Kiwamu Okita
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ABSTRACT: Hepatitis C virus (HCV) core protein is known to cause oxidative stress and alter apoptosis pathways. However, the apoptosis results are inconsistent, and the real significance of oxidative stress is not well known. The aim of this study was twofold. First, we wanted to confirm whether core-induced oxidative stress was really significant enough to cause DNA damage, and whether it induced cellular antioxidant responses. Second, we wanted to evaluate whether this core-induced oxidative stress and the antioxidant response to it was responsible for apoptosis changes.
HCV core protein was expressed under control of the Tet-Off promoter in Huh-7 cells and HeLa cells. We chose to use deoxycholic acid (DCA) as a model because it is known to produce both reactive oxygen species (ROS) and apoptosis.
Core expression uniformly increased ROS and 8-hydroxy-2'-deoxyguanosine (8-OHdG) under basal and DCA-stimulated conditions. Core protein expression also increased manganese superoxide dismutase levels. Core protein inhibited DCA-mediated mitochondrial membrane depolarization and DCA-mediated activation of caspase-9 and caspase-3, despite the increase in ROS by DCA. Core protein inhibited DCA-mediated apoptosis by increasing Bcl-x(L) protein and decreasing Bax protein, without affecting the proportion of Bax between mitochondria and cytosol, resulting in suppression of cytochrome c release from mitochondria into cytoplasm.
HCV core protein induces oxidative DNA damage, whereas it inhibits apoptosis that is accompanied by enhancement of ROS production. Thus, oxidative stress and apoptosis modulation by core protein are independent of each other.
Journal of Gastroenterology 04/2006; 41(3):257-68. · 4.16 Impact Factor
