Hepatitis: Nakamura T

Mizuno S, Nakamura T. · Division of Molecular Regenerative Medicine, Department of Biochemistry and Molecular Biology, Osaka University Graduate School of Medicine, Yamadaoka, Suita, Osaka, Japan. · Regen Med. · Pubmed #17465748 No free full text.

Abstract: Liver cirrhosis is a major cause of morbidity worldwide and is characterized by the loss of hepatocytes with interstitial fibrosis. In this review, we discuss the potential uses of hepatocyte growth factor for treating hepatic diseases, focusing on the molecular mechanisms whereby hepatocyte growth factor reverses liver cirrhosis. Hepatic myofibroblasts play a central role in the development of liver cirrhosis, while myofibroblasts acquire c-Met. Using a rat model of liver cirrhosis, we recently delineated the direct effect of hepatocyte growth factor toward myofibroblasts: the induction of apoptotic cell death associated with matrix degradation, the inhibition of overproliferation and the suppression of transforming growth factor-beta1 production in myofibroblasts. Hepatocyte growth factor elicits mitogenic, anti-apoptotic and anti-inflammatory functions in hepatocytes, therefore contributing to reversing liver dysfunction. Considering the insufficient production of hepatocyte growth factor is responsible for the manifestation of chronic hepatitis, supplementation with or reinduction of hepatocyte growth factor represents a new strategy for attenuating intractable liver diseases.

Nakamura T, Tomoda K, Yamamura Y, Tsukano M, Honda I, Iyama K. · Section of Internal Medicine and Rheumatology, Kumamoto Center for Arthritis and Rheumatology, 1-15-7 Kuhonji, Kumamoto 862-0976, Japan. · Clin Rheumatol. · Pubmed #12740683 No free full text.

Abstract: We describe an unusual case of a 38-year-old woman with a localised form of polyarteritis nodosa (PAN) manifested by acute onset of severe calf pain. Magnetic resonance imaging of the lower legs showed abnormal signal intensity of the outer calves muscle. Biopsies of the gastrocnemius revealed an acute necrotising arteritis with marked non-specific fasciitis. The diseased muscle improved with corticosteroid administration alone. The fascial involvement likely contributed to the severity of the clinical features of PAN, which may be related to a previous hepatitis B virus infection.

Kato J, Kobune M, Nakamura T, Kuroiwa G, Takada K, Takimoto R, Sato Y, Fujikawa K, Takahashi M, Takayama T, Ikeda T, Niitsu Y. · Fourth Department of Internal Medicine, Sapporo Medical University School of Medicine, Sapporo 060-8543, Japan. · Cancer Res. · Pubmed #11751387 links to  free full text

Abstract: Accumulation of 8-hydroxy-2'-deoxyguanosine (8-OHdG) in DNA, which may result from the continuous reactive oxygen species (ROS) generation associated with chronic inflammation, has been reported in various human preneoplastic lesions and in cancerous tissues. However, no direct causative relationship between the 8-OHdG formation and carcinogenesis has been thus far demonstrated in humans. Directly proving the causality requires showing that depletion of 8-OHdG levels in tissue by interfering with ROS generation results in a reduction in cancer. Chronic hepatitis C virus (HCV) infection is associated with a high risk of hepatocellular carcinoma (HCC). Several studies on patients with chronic HCV have shown that hepatic iron overload is attributable to liver injury and that iron depletion improved serum aminotransferase levels. Excess iron is known to generate ROS within cells, which causes mutagenic lesions, such as 8-OHdG. In this study, therefore, we have evaluated whether therapeutic iron reduction (phlebotomy and low iron diet) with a long-term follow-up (6 years) would decrease the hepatic 8-OHdG levels and the risk of HCC development in patients with chronic HCV. Patients (34) enrolled were those who had undergone standard IFN therapy but had no sustained response. Quantitative immunohistochemistry using the KS-400 image analyzing system and electrochemical detection was used for 8-OHdG detection. With this treatment, elevated hepatic 8-OHdG levels in patients with chronic hepatitis C (8.3 +/- 4.6/10(5) dG) significantly decreased to almost normal levels (2.2 +/- 0.9/10(5) dG; P < 0.001) with concomitant improvement of hepatitis severity, including fibrosis, whereas HCV titers were unaffected. None of these patients developed HCC. Thus, long-term iron reduction therapy in patients with chronic hepatitis C may potentially lower the risk of progression to HCC.

Yamane A, Nakamura T, Suzuki H, Ito M, Ohnishi Y, Ikeda Y, Miyakawa Y. · Division of Hematology, Department of Internal Medicine, Keio University School of Medicine, Tokyo, Japan. · Blood. · Pubmed #18523149 links to  free full text

Abstract: Human interferon (IFN)-alpha is the standard therapy for chronic hepatitis C to prevent its progression to liver cirrhosis and hepatocellular carcinoma. Thrombocytopenia is one of the major adverse effects of IFN-alpha and often leads to dose reduction or treatment discontinuation. However, there is little information on how IFN-alpha inhibits human megakaryopoiesis. In this study, we demonstrated that IFN-alpha did not inhibit colony formation of megakaryocytes from human CD34(+) hematopoietic stem cells. IFN-alpha did not inhibit endomitosis but did inhibit cytoplasmic maturation of megakaryocytes and platelet production in vitro. IFN-alpha suppressed the expression of transcription factors regulating late-stage megakaryopoiesis, such as GATA-1, p45(NF-E2), MafG. IFN-alpha also significantly reduced the number of human platelets but not megakaryocytes, and did not inhibit endomitosis of human megakaryocytes in immunodeficient NOD/Shi-scid/IL-2R gamma(null) (NOG) mice transplanted with human CD34(+) cells (hu-NOG). We also demonstrated that a novel thrombopoietin mimetic, NIP-004, was effective for treating IFN-alpha-induced thrombocytopenia in hu-NOG mice. From ultrastructural study, IFN-alpha inhibited the maturation of demarcation membranes in megakaryocytes, although NIP-004 prevented the inhibitory effects of IFN-alpha. These results defined the pathogenesis of IFN-alpha-induced thrombocytopenia and suggested possible future clinical applications for thrombopoietin mimetics.

Soyama A, Eguchi S, Takatsuki M, Ichikawa T, Moriuchi M, Moriuchi H, Nakamura T, Tajima Y, Kanematsu T. · Department of Surgery, Nagasaki University Graduate School of Biomedical Sciences, Nagasaki, Japan. · Liver Transpl. · Pubmed #18433046 links to  free full text

Abstract: This report describes a patient who developed human T-cell leukemia virus type I-associated myelopathy (HAM) following a living-donor liver transplantation (LDLT) for liver cirrhosis due to hepatitis C virus (HCV) infection. Both the recipient and the living donor (his sister) were human T-cell leukemia virus type I (HTLV-I) carriers. Since the LDLT, he had been treated with immunosuppressive drugs such as tacrolimus and steroids as well as interferon-alpha to prevent rejection and a recurrence of the HCV infection, respectively. Even though the HTLV-I proviral load had decreased upon interferon treatment, he developed a slowly progressive gait disturbance with urinary disturbance 2 years after the LDLT and was diagnosed with HAM. This appears to be the first report of HAM development in an HLTV-I-infected LDLT recipient.

Shibata H, Yoshioka Y, Ohkawa A, Minowa K, Mukai Y, Abe Y, Taniai M, Nomura T, Kayamuro H, Nabeshi H, Sugita T, Imai S, Nagano K, Yoshikawa T, Fujita T, Nakagawa S, Yamamoto A, Ohta T, Hayakawa T, Mayumi T, Vandenabeele P, Aggarwal BB, Nakamura T, Yamagata Y, Tsunoda S, Kamada H, Tsutsumi Y. · National Institute of Biomedical Innovation, 7-6-8 Saito-Asagi, Ibaraki, Osaka 567-0085, Japan. · J Biol Chem. · Pubmed #18003610 links to  free full text

Abstract: Tumor necrosis factor-alpha (TNF) induces inflammatory response predominantly through the TNF receptor-1 (TNFR1). Thus, blocking the binding of TNF to TNFR1 is an important strategy for the treatment of many inflammatory diseases, such as hepatitis and rheumatoid arthritis. In this study, we identified a TNFR1-selective antagonistic mutant TNF from a phage library displaying structural human TNF variants in which each one of the six amino acid residues at the receptor-binding site (amino acids at positions 84-89) was replaced with other amino acids. Consequently, a TNFR1-selective antagonistic mutant TNF (R1antTNF), containing mutations A84S, V85T, S86T, Y87H, Q88N, and T89Q, was isolated from the library. The R1antTNF did not activate TNFR1-mediated responses, although its affinity for the TNFR1 was almost similar to that of the human wild-type TNF (wtTNF). Additionally, the R1antTNF neutralized the TNFR1-mediated bioactivity of wtTNF without influencing its TNFR2-mediated bioactivity and inhibited hepatic injury in an experimental hepatitis model. To understand the mechanism underlying the antagonistic activity of R1antTNF, we analyzed this mutant using the surface plasmon resonance spectroscopy and x-ray crystallography. Kinetic association/dissociation parameters of the R1antTNF were higher than those of the wtTNF, indicating very fast bond dissociation. Furthermore, x-ray crystallographic analysis of R1antTNF suggested that the mutation Y87H changed the binding mode from the hydrophobic to the electrostatic interaction, which may be one of the reasons why R1antTNF behaved as an antagonist. Our studies demonstrate the feasibility of generating TNF receptor subtype-specific antagonist by extensive substitution of amino acids of the wild-type ligand protein.

Kato J, Miyanishi K, Kobune M, Nakamura T, Takada K, Takimoto R, Kawano Y, Takahashi S, Takahashi M, Sato Y, Takayama T, Niitsu Y. · Fourth Department of Internal Medicine, Sapporo Medical University School of Medicine, South-1, West-16, Sapporo 060-8543, Japan. · J Gastroenterol. · Pubmed #17940836 No free full text.

Abstract: BACKGROUND: We have previously demonstrated that in patients with chronic hepatitis C (CHC), iron depletion improves serum alanine aminotransferase (ALT) levels as well as hepatic oxidative DNA damage. However, it has not been determined whether continuation of iron depletion therapy for CHC favorably influences its progression to hepatocellular carcinoma (HCC). METHODS: We conducted a cohort study on biopsy-proven CHC patients with moderate or severe liver fibrosis who failed to respond to previous interferon (IFN) therapy or had conditions for which IFN is contradicted. Patients were divided into two groups: subjects in group A (n = 35) underwent weekly phlebotomy (200 g) until they reached a state of mild iron deficiency, followed by monthly maintenance phlebotomy for 44-144 months (median, 107 months), and they were advised to consume a low-iron diet (5-7 mg iron/day); group B (n = 40) comprised CHC patients who declined to receive iron depletion therapy. RESULTS: In group A, during the maintenance phase, serum ALT levels decreased to less than 60 IU/l in all patients and normalized (<40 IU/l) in 24 patients (69%), whereas in group B no spontaneous decrease in serum ALT occurred. Hepatocarcinogenesis rates in groups A and B were 5.7% and 17.5% at the end of the fifth year, and 8.6% and 39% in the tenth year, respectively. Multivariate analysis revealed that iron depletion therapy significantly lowered the risk of HCC (odds ratio, 0.57) compared with that of untreated patients (P = 0.0337). CONCLUSIONS: Long-term iron depletion for CHC patients is a promising modality for lowering the risk of progression to HCC.

Mizui M, Tanaka J, Katayama K, Nakanishi T, Obayashi M, Aimitsu S, Yoshida T, Inoue J, Yokoyama T, Tsuji K, Arataki K, Yamaguchi S, Miura T, Kitamoto M, Takezaki E, Orimen S, Sakata T, Kamada K, Maruhashi A, Tamura T, Nakamura T, Ishida K, Teramen K, Miyakawa Y, Yoshizawa H. · Department of Laboratory Medicine, Japanese Red Cross, Hiroshima Blood Center, Hiroshima, Japan. · Hepatol Res. · Pubmed #17627620 No free full text.

Abstract: Aim: To portray liver disease and project outcomes in carriers of hepatitis C virus (HCV) in the general population. Methods: Liver disease was evaluated in 1019 individuals who were found with HCV infection at blood donation, and they were followed for 5-10 years with or without receiving interferon (IFN). Results: At baseline, chronic hepatitis was detected in 529 (51.9%) HCV carriers and more frequently in men than in women (62.6% [299/478]vs 42.5% [230/541], P < 0.01); cirrhosis was diagnosed in five (0.5% [three men included]) and hepatocellular carcinoma (HCC) in one (0.1% [man]). Of the carriers who were followed for 5 years or longer, loss of HCV-RNA from serum was achieved in 61 (31.0%) of the 197 treated with interferon (IFN) and only one of the 211 (0.5%) without IFN (P < 0.0001). HCC developed in 14 carriers including six ofthe 211 (2.8%) without IFN and eight of the 197 (4.1%) with IFN (six non-responders included). Follow ups of the 949 carriers identified age (P < 0.002), male gender (P < 0.01) and cirrhosis at the baseline (P < 0.0001) as factors contributing to the development of HCC. Cumulative incidence rates of HCC during 10 years among carriers found with chronic hepatitis increased in parallel with the age at the baseline. Conclusion: Identification of HCV carriers in the general population and treating those indicated with IFN would help decrease the development of HCC and lift its medical, as well as economic, burdens off society.

Ikeda K, Marusawa H, Osaki Y, Nakamura T, Kitajima N, Yamashita Y, Kudo M, Sato T, Chiba T. · Kyoto University, Kyoto, Japan. · Ann Intern Med. · Pubmed #17470833 links to  free full text

Abstract: BACKGROUND: Previous exposure to hepatitis B virus (HBV) and occult HBV infection may have an important role in the development of hepatocellular carcinoma (HCC) in patients with chronic liver disease related to hepatitis C virus (HCV). OBJECTIVE: To prospectively study the association between antibody to hepatitis B core antigen (anti-HBc) and clinical outcomes in patients with HCV-related chronic liver disease. DESIGN: Prospective observational study. SETTING: Kyoto University Hospital and 14 regional core hospitals in Japan. PARTICIPANTS: 872 patients with chronic HCV infection (597 with chronic hepatitis and 275 with cirrhosis). MEASUREMENTS: Incidence of HCC on follow-up (from 1995 to 2005). RESULTS: Only 846 of the 872 enrolled patients were followed. Hepatocellular carcinoma occurred in 237 of 846 patients (28.0%) during follow-up. Among patients with cirrhosis, HCC was diagnosed in 85 of 141 patients (60.3%) with anti-HBc and 58 of 129 patients (45.0%) without HBV-related serologic markers. Of 224 patients with chronic hepatitis who had interferon monotherapy, 92 (41.1%) had sustained or transient disappearance of HCV RNA. None of the anti-HBc-negative patients who had a virologic response to interferon therapy developed HCC, whereas cancer was diagnosed in 4 of 37 anti-HBc-positive patients (10.8%) with a virologic response to interferon. On multivariate analysis using a Cox proportional hazards model, anti-HBc-positive results on serologic testing was an independent risk factor in patients with cirrhosis (incidence rate ratio, 1.58 [95% CI, 1.12 to 2.22]). LIMITATIONS: The study included only 1 assessment of smoking and alcohol consumption at study entry and did not precisely determine the duration of smoking or alcohol use. CONCLUSIONS: Anti-HBc-positive results on serologic testing are a marker of high risk for HCC among patients with HCV-related cirrhosis. Interferon therapy might be less effective in preventing HCC among patients with chronic hepatitis C who are anti-HBc-positive than in those with chronic hepatitis C who are anti-HBc-negative.

Takahashi H, Yotsuyanagi H, Yasuda K, Koibuchi T, Suzuki M, Kato T, Nakamura T, Iwamoto A, Nishioka K, Iino S, Koike K, Itoh F. · Department of Internal Medicine, Division of Gastroenterology and Hepatology, Institute of Medical Science, St Marianna University, Kawasaki, Japan. · J Gastroenterol. · Pubmed #17096067 No free full text.

Abstract: BACKGROUND: Transmission routes of hepatitis A virus (HAV) in Japan have changed. The present study investigated changes of transmission routes in relation to genetic drift. METHODS: All 60 patients who were admitted between 1993 and 2003 with a diagnosis of hepatitis A were retrospectively analyzed. Nucleotide sequences of the VP1/2A region of the HAV recovered from their sera were determined. RESULTS: The suspected transmission routes were household contact, 19 (31%); food or waterborne, 16 (27%); homosexual activity, 11 (18%); international travel, 4 (7%); and unknown 10. (17%). The 11 patients presumably infected through homosexual activity were found exclusively in 1998 and 1999. The proportion of patients exposed through homosexual behavior and household contact was higher in those 2 years than in other years. Nucleotide sequences could be determined for 58 patients. Fifty-seven of the 58 sequences belonged to genotype IA HAV, with less than 10% nucleotide diversity. Of the 27 sequences isolated during 1998 and 1999, 25 had an identical nucleotide sequence regardless of the suspected transmission route. In contrast, sequences obtained in the other years differed from one another. A phylogenetic tree constructed from sequences recovered from patients without a history of travel abroad showed several clusters. CONCLUSIONS: Our results suggest that (1) HAV acquired through homosexual activity may be transmitted to nonhomosexual individuals; (2) hepatitis A in metropolitan areas in Japan is caused mainly by sporadic infection with genotype IA HAV; and (3) several subtypes of genotype IA HAV are endemic in Japan.

Li Z, Mizuno S, Nakamura T. · Division of Molecular Regenerative Medicine, Dept of Biochemistry and Molecular Biology, Osaka Univ Graduate School of Medicine, Yamadaoka 2-2-B7, Suita, Osaka, Japan. · Am J Physiol Gastrointest Liver Physiol. · Pubmed #17068118 links to  free full text

Abstract: Cholestasis, an impairment of bile outflux, frequently occurs in liver diseases. In this process, an overaccumulation of bile acids causes hepatocyte necrosis and apoptosis, leading to advanced hepatitis. Hepatocyte growth factor (HGF) is mitogenic toward hepatocytes, but it is still unclear whether HGF has physiological and therapeutic functions during the progression of cholestasis. Using anti-HGF IgG or recombinant HGF in mice that had undergone bile duct ligation (BDL), we investigated the involvement of HGF in cholestasis-induced hepatitis. After the BDL surgery, HGF and c-Met mRNA levels transiently increased in livers during the progression of cholestatic hepatitis. When c-Met tyrosine phosphorylation was blocked in the livers of BDL-treated mice by anti-HGF IgG, hepatic dysfunction became evident, associated with the acceleration of hepatocyte necrosis and apoptosis. Inversely, administration of recombinant HGF into the mice led to the prevention of cholestasis-induced inflammation: HGF suppressed the hepatic expression of intracellular adhesion molecule-1 and neutrophil infiltration in BDL-treated mice. As a result, parenchymal necrosis was suppressed in the HGF-injected BDL mice. In addition, HGF supplement therapy reduced the number of apoptotic hepatocytes in cholestatic mice, associated with the early induction of Bcl-xL. The administration of HGF enhanced hepatic repair, via accelerating G1/S progression in hepatocytes. Our study showed that 1) upregulation of HGF production is required for protective mechanisms against cholestatic hepatitis and 2) enhancement of the intrinsic defense system by adding HGF may be a reasonable strategy to attenuate hepatic inflammation, necrosis, and apoptosis under bile-congestive conditions.

Sasaki H, Yoshida S, Kitahara T, Yoshioka T, Nakagawa H, Nakamura T, Ichikawa N, Nishida K, Nakamura J, Nakashima M. · Department of Hospital Pharmacy, Nagasaki University Hospital of Medicine and Dentistry, 1-7-1 Sakamoto, Nagasaki 852-8501, Japan. · Int J Pharm. · Pubmed #16675174 No free full text.

Abstract: In order to determine the influence of hepatic disease-stage on polyethylenimine-mediated gene delivery, we investigated branched and linear polyethylenimine (B-PEI, L-PEI)-mediated plasmid DNA delivery with time in murine hepatitis induced by a subcutaneous injection of tetrachloro carbon (CCl(4)). Plasmid DNA (pDNA) encoding firefly luciferase was used as the model reporter gene. We determined luciferase activity in various organs of CCl(4)-treated mice and control mice after an intravenous administration of B-PEI and L-PEI/pDNA complexes. Both B-PEI and L-PEI/pDNA complexes showed significantly lower gene expression in the liver, spleen, and lung at the stage of severe hepatitis (18 h after CCl(4) injection), whereas the complexes induced gene expression in the liver at the liver regeneration stage (48 h after CCl(4) injection). Significant differences in gene expressions between CCl(4)-treated mice and control mice vanished in most organs at the hepatitis subsidence stage (168 h after CCl(4) injection), indicating that the influence of hepatitis induced by CCl(4) was reversible with PEI-mediated gene delivery. Our findings demonstrated that murine hepatitis induced by CCl(4) could influence polyethylenimine-mediated plasmid DNA delivery according to the disease stage. These results indicate the necessity of considering the timing and dose of gene therapy according to the disease stage.

Lan RY, Cheng C, Lian ZX, Tsuneyama K, Yang GX, Moritoki Y, Chuang YH, Nakamura T, Saito S, Shimoda S, Tanaka A, Bowlus CL, Takano Y, Ansari AA, Coppel RL, Gershwin ME. · Division of Rheumatology, Allergy, and Clinical Immunology, University of California--Davis, Davis, CA 95616, USA. · Hepatology. · Pubmed #16557534 No free full text.

Abstract: CD4+CD25high regulatory T cells (Tregs) play a critical role in self-tolerance, as seen in murine autoimmunity. Studies on Tregs in human autoimmunity have focused primarily on peripheral blood samples. A study targeting diseased tissue should identify direct relationships between Tregs and autoimmunity. Peripheral blood samples were collected from 91 patients with primary biliary cirrhosis (PBC), 28 immediate relatives, and 41 healthy controls, and Treg frequencies were determined as a percentage of CD4+CD25high T cells in CD4+TCR-alphabeta+ T cells. A tissue-targeted determination of frequency and distribution of FoxP3+ Tregs was also performed on 90 different liver tissue specimens exhibiting PBC (n = 52), chronic hepatitis C (CHC) (n = 30), and autoimmune hepatitis (AIH) (n = 8). Treg suppression studies were performed on 50 PBC patients and 27 controls. Patients with PBC demonstrated a relative reduction of Tregs compared with controls (P < .0002). Interestingly, a deficiency in CD4+CD25+ Tregs was also found in the daughters and sisters of PBC patients compared with controls (P < .0007). However, functional studies did not reveal a global PBC Treg defect. The level of FoxP3-expressing Tregs was markedly lower in affected PBC portal tracts compared with CHC and AIH (P < .001). In addition, the CD8+T cell/FoxP3+ Treg ratio was significantly higher in livers of late-stage PBC compared with those of CHC (P < .001) and early-stage AIH (P < .001). In conclusion, these data provide support for a genetic modulation of Treg frequency and illustrate the role Tregs play in the loss of tolerance in PBC.

Nakamura T, Takahashi H, Koike N, Mitsutaka M, Soda M, Kimu M. · Department of Ophthalmology, Showa University Northern Yokohama Hospital. 3 5 1 Chigasakichuo, Tsuzuki-ku, Yokohama 224 8503, Japan. · Nippon Ganka Gakkai Zasshi. · Pubmed #16363669 No free full text.

Abstract: PURPOSE: To observe the retinopathy of the patients who received interferon/ribavirin for treatment of chronic hepatitis C. METHODS: We observed 6 patients(5 males and 1 female) who received interferon/ribavirin for treatment of chronic hepatitis C. Visual acuity tests and detailed fundus examinations were performed monthly during 6 months of interferon/ribavirin therapy. RESULTS: All patients developed soft retinal exudate and 5 developed retinal blot hemorrhage. None of the patients exhibited visual impairment or subjective symptoms during the treatment period, and the retinopathy disappeared or decreased in all patients. All of the patients in this study developed interferon retinopathy while undergoing interferon/ribavirin combination therapy. CONCLUSION: Because the combination of ribavirin with interferon may increase the incidence of interferon retinopathy, and cases of severe retinal complications have also been reported, careful fundus examinations should be performed during combination therapy, just as they are performed during conventional interferon therapy.

Toda K, Miwa Y, Kuriyama S, Fukushima H, Shiraki M, Murakami N, Shimazaki M, Ito Y, Nakamura T, Sugihara J, Tomita E, Nagata C, Suzuki K, Moriwaki H. · Department of Internal Medicine, Gifu University School of Medicine, 1-1 Yanagido, Gifu 501-1194, Japan. · J Gastroenterol. · Pubmed #16211346 No free full text.

Abstract: BACKGROUND: In patients with chronic liver disease (CLD), quality of life is generally accepted as poor, especially for physical function. However, sufficient data regarding erectile function has not been shown in patients with CLD. The international index of erectile function (IIEF) is widely used to assess erectile function, and a short form of the IIEF was recently developed (IIEF-5). Using this questionnaire, we evaluated erectile dysfunction (ED) in patients with CLD. METHODS: A total of 117 Japanese patients (64 with chronic hepatitis [CH] and 53 with liver cirrhosis [LC]) were analyzed. The etiologies were hepatitis B virus (HBV) in 21, HCV in 94, and non-B non-C in 2. The IIEF-5 and Medical Outcomes Study Short Form 36 (SF-36) were administered to the patients, and biochemical analyses for items serum albumin, prothrombin time, bilirubin, and ammonia were also performed. RESULTS: The incidence of ED was 85% in the total cohort with CLD, 78% in those with CH, and 92% in those with LC (P < 0.05 between CH and LC). ED was found in 50% of CLD patients under age 50 years, in 79% aged 50-59, and in 100% aged over 60 (P, overall <0.001). The scores for ED severity correlated with increasing grades of a modified Child-Pugh classification (P < 0.05). Simple regression analysis showed age (P < 0.01), physical function (P < 0.001), role physical (P < 0.001), and social functioning (P < 0.05) on the SF-36, and serum albumin (P < 0.001) as significant determinants of ED. Multiple regression analysis identified age (P < 0.001) and serum albumin (P < 0.001) as independent significant factors that determined ED. CONCLUSIONS: These data clearly demonstrate that liver disease is the cause of ED in patients with CLD, and serum protein status could be relevant to this condition in these patients.

Yuge K, Takahashi T, Nagano S, Terazaki Y, Murofushi Y, Ushikoshi H, Kawai T, Khai NC, Nakamura T, Fujiwara H, Kosai K. · Department of Gene Therapy and Regenerative Medicine, Gifu University School of Medicine, Japan. · Int J Oncol. · Pubmed #15942646 No free full text.

Abstract: Hepatocyte growth factor (HGF) gene therapy may have potential for treating chronic hepatitis (CH) and liver cirrhosis (LC). However, the lack of an HGF gene therapy study on hepatomas that are often associated with CH or LC, together with the stimulatory effects of HGF on many types of cancer, may hamper its application. This study explored the effects of adenoviral HGF gene transduction and their mechanisms on two types of hepatoma cells (hepatoblastoma and hepatocellular carcinoma) in in vitro experiments. Both types of hepatomas were revealed to have higher adenoviral gene transduction efficiencies and more efficient expressions of the HGF transgene, which successfully activated the HGF receptor/c-Met in an autocrine fashion, than those of other types of cancer. Notably, not only HGF, but also adenoviral infection, inhibited DNA synthesis, whereas only HGF but not adenoviral infection exerted a potent apoptotic effect. Moreover, adenoviral HGF gene transduction additively exerted inhibitory effects on cisplatin-treated hepatomas. In conclusion, inhibitory and apoptotic effects of adenoviral HGF gene transduction in hepatomas in contrast to potent mitogenic and antiapoptotic effects of HGF for hepatocytes are not only of biological interest, but also pose clinical benefits for adenoviral HGF gene therapy for CH and LC.

Ikeda M, Abe K, Dansako H, Nakamura T, Naka K, Kato N. · Department of Molecular Biology, Okayama University Graduate School of Medicine and Dentistry, Okayama, Japan. · Biochem Biophys Res Commun. · Pubmed #15766575 No free full text.

Abstract: Recently we reported a subgenomic hepatitis C virus (HCV) replicon derived from HCV (HCV-O strain) infected in non-neoplastic human hepatocyte PH5CH8. In this study, we developed a genome-length dicistronic HCV RNA from HCV-O. A cured HuH-7 cell line (sOc) was obtained from a cloned subgenomic replicon cell line (sO) by interferon (IFN) treatment and used for transfection with genome-length HCV RNA. One cloned cell line, O, was successfully selected by G418 treatment following the introduction of genome-length HCV RNA into sOc cells, and the robust expression of HCV RNA and proteins was confirmed. Oc, a cured cell line, was also obtained from the cloned cell line (O) by IFN treatment. The number of colonies increased drastically when genome-length HCV RNA was introduced into Oc cells. However, the cloned cured cell lines, sOc and Oc, differed in their colony formation efficiency despite their common origin. This result suggests that even a cloned cell line can change its characteristics during cell culture. Sequence analysis of HCV RNA from the O cells revealed an amino acid substitution in the NS3 helicase region (K1609E). This substitution worked as an adaptive mutation in transient reporter and colony formation assays. Using the advantages of this adaptive mutation and of Oc cells in colony formation, we established the first cell line in which genome-length dicistronic HCV RNA encoding a luciferase gene replicated efficiently. This culture system is useful tool for the study of HCV replication and mass screening for anti-HCV reagents.

Kato N, Nakamura T, Dansako H, Namba K, Abe K, Nozaki A, Naka K, Ikeda M, Shimotohno K. · Department of Molecular Biology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama 700-8558, Japan. · J Gen Virol. · Pubmed #15722525 links to  free full text

Abstract: Hepatitis C virus (HCV) genomic sequences are known to vary widely among HCV strains, but to date there have been few reports on the genetic variations and dynamics of HCV in an experimental system of HCV replication. In this study, a genetic analysis of HCV replicons obtained in long-term culture of two HCV replicon cells (50-1 and 1B-2R1), which were established from two HCV strains, 1B-1 and 1B-2, respectively, was performed. One person cultured 50-1 cells for 18 months, and two people independently cultured 50-1 cells for 12 months. 1B-2R1 cells were also cultured for 12 months. The whole nucleotide sequences of the three independent replicon RNA clones obtained at several time points were determined. It was observed that genetic mutations in both replicons accumulated in a time-dependent manner, and that the mutation rates of both replicons were approximately 3.0 x 10(-3) base substitutions/site/year. The genetic diversity of both replicons was also enlarged in a time-dependent manner. The colony formation assay by transfection of total RNAs isolated from both replicon cells at different time points into naive HuH-7 cells revealed that the genetic mutations accumulating with time in both replicons apparently improved colony formation efficiency. Taken together, these results suggest that the HCV replicon system is useful for the analysis of evolutionary dynamics and variations of HCV. Using this replicon cell culture system, it was demonstrated further that neither ribavirin nor its derivative mizoribine accelerated the mutation rate or the increase in the genetic diversity of HCV replicon.

Miyata M, Tozawa A, Otsuka H, Nakamura T, Nagata K, Gonzalez FJ, Yamazoe Y. · Division of Drug Metabolism and Molecular Toxicology, Graduate School of Pharmaceutical Sciences, Tohoku University, Aramaki, Aoba-ku, Sendai, 980-8578, Japan. · J Pharmacol Exp Ther. · Pubmed #15466244 links to  free full text

Abstract: Mice lacking the farnesoid X receptor (FXR) involved in the maintenance of hepatic bile acid levels are highly sensitive to cholic acid-induced liver toxicity. Serum aspartate aminotransferase (AST) activity was elevated 15.7-fold after feeding a 0.25% cholic acid diet, whereas only slight increases in serum AST (1.7- and 2.5-fold) were observed in wild-type mice fed 0.25 and 1% cholic acid diet, respectively. Bile salt export pump mRNA and protein levels were increased in wild-type mice fed 1% cholic acid diet (2.1- and 3.0-fold) but were decreased in FXR-null mice fed 0.25% cholic acid diet. The bile acid output rate was 2.0- and 3.7-fold higher after feeding of 0.25 and 1.0% cholic acid diet in wild-type mice, respectively. On the other hand, no significant increase in bile acid output rate was observed in FXR-null mice fed 0.25% cholic acid diet in contrast to a significant decrease observed in mice fed a 1.0% cholic acid diet in spite of the markedly higher levels of hepatic tauro-conjugated bile acids. Unconjugated cholic acid was not detected in the bile of wild-type mice fed a control diet, but it was readily detected in wild-type mice fed 1% cholic acid diet. The ratio of biliary unconjugated cholic acid to total cholic acid (unconjugated cholic acid and tauro-conjugated cholic acid) reached 30% under conditions of hepatic taurine depletion. These results suggest that the cholic acid-induced enhancement of canalicular bile acid output rates and excretion of unconjugated bile acids are involved in adaptive responses for prevention of cholic acid-induced toxicity.

Kanazawa N, Kurosaki M, Sakamoto N, Enomoto N, Itsui Y, Yamashiro T, Tanabe Y, Maekawa S, Nakagawa M, Chen CH, Kakinuma S, Oshima S, Nakamura T, Kato T, Wakita T, Watanabe M. · Department of Gastroenterology and Hepatology, Tokyo Medical and Dental University, 1-5-45 Yushima, Bunkyo-ku, Tokyo 113-8519, Japan. · J Virol. · Pubmed #15331704 links to  free full text

Abstract: Cellular antiviral responses are mediated partly by the expression of interferon-stimulated genes, triggered by viral genomes, their transcripts and replicative intermediates. Persistent replication of a hepatitis C virus (HCV) replicon suggests that the replicon does not elicit cellular innate antiviral responses. In the present study, we investigated regulatory factors of the interferon-mediated antiviral system in cells expressing an HCV replicon. Luciferase reporter assays revealed that the baseline activity of the interferon-stimulated response element (ISRE) was significantly lower in cells harboring the replicon than in naive cells. Among the proteins involved in the IFN/Jak/STAT pathway and in ISRE activity, the expression level of interferon regulatory factor 1 (IRF-1) was found to be significantly lower in cells harboring the replicon. Transfection of an IRF-1 expression construct into cells harboring the replicon caused an increase of ISRE activity, accompanied by suppression of expression of the HCV replicon. Moreover, in cured Huh7 cells from which the HCV replicon had been eliminated, the expression levels of IRF-1 and ISRE activity also were suppressed, demonstrating that the decrease of IRF-1 is attributable, not to active suppression by the viral proteins, but to adaptation of cells that enables replication of the HCV subgenome. The high permissiveness of the cured cells for the replicon was abolished by transgenic supplementation of IRF-1 expression. Taken together, IRF-1 is one of the key host factors that regulate intracellular HCV replication through modulation of interferon-stimulated-gene-mediated antiviral responses.

Hisaeda K, Inokuchi A, Nakamura T, Iwamoto Y, Kohno K, Kuwano M, Uchiumi T. · Department of Medical Biochemistry, Graduate School of Medical Sciences, Kyushu University, Fukuoka, Japan. · Hepatology. · Pubmed #15185298 No free full text.

Abstract: The human multidrug resistance protein 2 (MRP2/ABCC2), expressed on the bile canalicular membrane, mediates the multispecific efflux of several organic anions, including conjugates of glucuronate, sulfate, and glutathione. Expression of MRP2 can be altered in response to environmental stimuli such as cholestasis and jaundice. We previously reported that MRP2 mRNA expression levels are decreased in the nontumorous part of hepatitis C virus-infected human liver tissues, and that inflammatory cytokines inhibit MRP2 expression in human hepatic (HepG2) cells. We investigated the molecular mechanisms by which inflammatory cytokines modulate MRP2 gene expression in hepatic cells. Treatment of human hepatic cells with interleukin-1beta (IL-1beta) or tumor necrosis factor alpha resulted in a decrease in the protein and mRNA levels of MRP2. IL-1beta inhibited the transcriptional activity of MRP2 promoter constructs by 40%, and this inhibition of MRP2 promoter activity was mediated through the interferon stimulatory response element (ISRE). Electrophoretic mobility shift assays with IL-1beta-treated nuclear extracts showed a decrease in the formation of DNA protein complexes, specifically those including interferon regulatory factor 3 (IRF3). Expression of recombinant human IRF3 increased MRP2 promoter activity. Treatment with a specific extracellular signal-regulated kinase inhibitor relieved IL-1beta-induced MRP2 mRNA downregulation and abrogated the binding of IRF3 to the ISRE element. In conclusion, IL-1beta induces downregulation of the MRP2 gene by inactivating IRF3 binding to ISRE on the MRP2 promoter in human hepatic cells; this inactivation is accomplished via interference with the extracellular signal-regulated kinase pathway.

Naganuma A, Dansako H, Nakamura T, Nozaki A, Kato N. · Department of Molecular Biology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama 700-8558, Japan. · Cancer Res. · Pubmed #14973066 links to  free full text

Abstract: Hepatitis C virus proteins exert an effect on a variety of cellular functions, including gene expression, signal transduction, and apoptosis, and because they possess oncogenic potentials, they have also been suggested to play an important role in hepatocarcinogenesis. Although the mechanisms of hepatocarcinogenesis remain poorly understood, we hypothesized that the disease may arise because of a disturbance of the DNA repair system by hepatitis C virus proteins. To test this hypothesis, we developed a reproducible microsatellite instability assay system for mismatch-repair using human-cultured cells transducted with pCXpur retrovirus expression vector, in which the puromycin resistance gene was rendered out-of-frame by insertion of a (CA)(17) dinucleotide repeat tract immediately following the ATG start codon. Using several human cancer cell lines known to be replication error positive or negative, we demonstrated that this assay system was useful for monitoring the propensity for mismatch-repair in the cells. This assay system was applicable to non-neoplastic human PH5CH8 hepatocytes, which could support hepatitis C virus replication. Using PH5CH8 cells, in which hepatitis C virus proteins were stably expressed by the retrovirus-mediated gene transfer, we found that the core protein promoted microsatellite instability in PH5CH8 cells. Interestingly, such promotion by the core protein only occurred in cells having the core protein belonging to genotype 1b or 2a and did not occur in cells having the core protein belonging to genotype 1a, 2b, or 3a. This is the first report to demonstrate that the core protein may disturb the DNA repair system.

Chung H, Kudo M, Kumada T, Katsushima S, Okano A, Nakamura T, Osaki Y, Kohigashi K, Yamashita Y, Komori H, Nishiuma S. · Department of Gastroenterology and Hepatology, Kinki University School of Medicine, 377-2 Ohno-Higashi, Osaka-Sayama 589-8511, Japan. · J Gastroenterol. · Pubmed #14569445 No free full text.

Abstract: BACKGROUND: We carried out this study to assess the risk of hepatitis C virus (HCV) transmission after needlestick injuries in medical personnel, and to evaluate the efficacy of short-duration interferon administration to prevent HCV transmission. METHODS: A total of 684 personnel who had been occupationally exposed to an anti-HCV-positive source and followed for more than 3 months were retrospectively examined. RESULTS: Of the 684 subjects, 279 (41%) were treated with 1 to 3 days of interferon either just after or 1 to 12 days after the injury. One case of HCV infection was found in each of the treated (1/279; 0.4%) and nontreated (1/405; 0.2%) groups. There was no significant difference in the transmission of HCV between the two groups. Both infected patients were treated with interferon after developing acute hepatitis, and HCV was subsequently cleared. CONCLUSIONS: There is a lower risk of HCV transmission after needlestick accident than previously reported, and short-duration interferon administration at an early stage after the needlestick injury, to prevent HCV transmission, is unnecessary.

Dansako H, Naganuma A, Nakamura T, Ikeda F, Nozaki A, Kato N. · Department of Molecular Biology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, Okayama 700-8558, Japan. · Virus Res. · Pubmed #14550584 No free full text.

Abstract: We previously found that hepatitis C virus (HCV) core protein, which possesses the consensus sequence of genotype 1b, transcriptionally activates the interferon (IFN)-inducible 2'-5'-oligoadenylate synthetase (2'-5'-OAS) gene in human hepatocyte cells. To clarify the mechanism of this activation, we further characterized the core protein as an activator of the 2'-5'-OAS gene. We demonstrated that the activation of the 2'-5'-OAS gene by the core protein is a general phenomenon, regardless of HCV genotype and strain. We showed that the 20 N-terminal amino acids (aa) of the core protein were important to the activation of the 2'-5'-OAS gene, although this N-terminal region did not have any effect on the subcellular localization of the core protein. We demonstrated that the core protein was able to activate all promoters possessing the IFN-stimulated response element (ISRE) examined. However, we found that the level of activation of the 2'-5'-OAS gene promoter possessing a particular variant type of ISRE was significantly higher than that of other IFN-inducible gene promoters. This phenomenon was confirmed using synthetic promoters possessing five repeats of the consensus or a 2'-5'-OAS-type ISRE. In addition, we showed that gene activation induced by the core protein is mediated by the ISRE. These results imply that the core protein prefers a subclass of IFN-inducible genes, the promoters of which possess the 2'-5'-OAS-type ISRE. Accordingly, we found that the IFN-inducible double-stranded RNA-specific adenosine deaminase gene promoter, possessing a 2'-5'-OAS-type ISRE sequence, was also efficiently activated by the core protein. The exact mechanism by which the core protein enhances gene expression was not determined, but we could find no effects of core protein on gene expression and phosphorylation status of the components of the JAK-STAT signaling transduction pathway.

Kato N, Sugiyama K, Namba K, Dansako H, Nakamura T, Takami M, Naka K, Nozaki A, Shimotohno K. · Department of Molecular Biology, Okayama University Graduate School of Medicine and Dentistry, 2-5-1 Shikata-cho, 700-8558, Okayama, Japan. · Biochem Biophys Res Commun. · Pubmed #12810084 No free full text.

Abstract: The hepatitis C virus (HCV) replicon system is a potent tool for understanding the mechanisms of HCV replication and proliferation, and for the development of treatments for patients with HCV. Recently, we established an HCV subgenomic replicon (50-1) using HCV genome RNA obtained from the cultured human T cell line MT-2C infected with HCV (isolate 1B-1) in vitro. In order to further obtain other HCV replicons without difficulty, we generated a replicon RNA library derived from human non-neoplastic hepatocytes infected with HCV (isolate 1B-2) in vitro. Upon transfection of the generated RNA library to "cured cells," from which the 50-1 subgenomic replicon was eliminated by prolonged treatment with interferon-alpha, we successfully established a new HCV subgenomic replicon, 1B-2R1. We characterized 1B-2R1 replicon in terms of efficiency of replication, HCV sequence, and sensitivity to interferons. The results revealed that the replication level of the 1B-2R1 replicon was comparable to that of the 50-1 replicon. We also found that the 1B-2R1 replicon possessed an HCV sequence distinct from those of other replicons established to date, and that the 1B-2R1 replicon was sensitive to interferon-alpha, interferon-beta, and interferon-gamma. Taken together, present results indicate that the replicon RNA library generated using an in vitro HCV infection system is useful for the establishment of an HCV subgenomic replicon.