Biomedical subjects

Yasushi Takii

Publications and source records attributed to Yasushi Takii.

17 recordsLinked to original sources

PubMed2007

Anti-gp210 and anti-centromere antibodies are different risk factors for the progression of primary biliary cirrhosis.

UNLABELLED: The predictive role of antinuclear antibodies (ANAs) remains elusive in the long-term outcome of primary biliary cirrhosis (PBC). The progression of PBC was evaluated in association with ANAs using stepwise Cox proportional hazard regression and an unconditional stepwise logistic regression model based on the data of 276 biopsy-proven, definite PBC patients who have been registered to the National Hospital Organization Study Group for Liver Disease in Japan (NHOSLJ). When death of hepatic failure/liver transplantation (LT) was defined as an end-point, positive anti-gp210 antibodies (Hazard ratio (HR) = 6.742, 95% confidence interval (CI): 2.408, 18.877), the late stage (Scheuer's stage 3, 4) (HR = 4.285, 95% CI:1.682,10.913) and male sex (HR = 3.266, 95% CI: 1.321,8.075) were significant risk factors at the time of initial liver biopsy. When clinical progression to death of hepatic failure/LT (i.e., hepatic failure type progression) or to the development of esophageal varices or hepatocellular carcinoma without developing jaundice (Total bilirubin < 1.5 mg/dL) (i.e., portal hypertension type progression) was defined as an end-point in the early stage (Scheuer's stage 1, 2) PBC patients, positive anti-gp210 antibodies was a significant risk factor for hepatic failure type progression [odds ratio (OR) = 33.777, 95% CI: 5.930, 636.745], whereas positive anti-centromere antibodies was a significant risk factor for portal hypertension type progression (OR = 4.202, 95% CI: 1.307, 14.763). Histologically, positive anti-gp210 antibodies was most significantly associated with more severe interface hepatitis and lobular inflammation, whereas positive anticentromere antibodies was most significantly associated with more severe ductular reaction. CONCLUSION: These results indicate 2 different progression types in PBC, hepatic failure type and portal hypertension type progression, which may be represented by positive-anti-gp210 and positive-anticentromere antibodies, respectively.

Adult↗

PubMed2006

Serum cytokine and soluble cytokine receptor levels in patients with non-alcoholic steatohepatitis.

BACKGROUND: Although the pathogenesis of non-alcoholic steatohepatitis (NASH) remains poorly understood, proinflammatory cytokines seem to play an important role in the process of NASH. We have undertaken this study in order to elucidate the role of proinflammatory cytokines and their soluble receptors in NASH patients. METHODS: Serum cytokines and soluble cytokine receptors levels were determined using an enzyme-linked immunosorbent assay kit in 23 patients with NASH, 21 patients with simple steatosis, and 18 healthy volunteers. RESULTS: Patients with NASH had significantly higher serum tumor necrosis factor-alpha (TNF-alpha) and interleukin-6 (IL-6) levels than did the simple steatosis patients. Similarly, when compared with simple steatosis, NASH was associated with higher soluble TNF receptor 1 (sTNFR1) and soluble IL-6 receptor (sIL-6R) levels, and a significant positive correlation was seen between the levels of sTNFR1 and aminotranferases in NASH patients. CONCLUSIONS: This study shows that circulating TNF-alpha/sTNFR1 and IL-6/sIL-6R levels are significantly increased in NASH patients as compared with simple steatosis patients and healthy volunteers, and that these increased levels may be implicated in the pathogenesis of NASH.

Adult↗

PubMed2006

Human intrahepatic biliary epithelial cells function in innate immunity by producing IL-6 and IL-8 via the TLR4-NF-kappaB and -MAPK signaling pathways.

BACKGROUND: Human intrahepatic biliary epithelial cells (HIBECs) may play active roles in both the innate and adaptive immune responses. Little is known, however, about the role of toll-like receptors (TLRs) on HIBECs in inflammatory cholangiopathies. METHODS: The expression of TLR1-9 and the biological responses to their ligands, lipopolysaccharide (LPS) or lipoteichoic acid (LTA), were studied in cultured HIBECs by reverse transcription-polymerase chain reaction, immunoblotting, and enzyme-linked immunosorbent assay. RESULTS: HIBECs constitutively expressed transcripts encoding TLR1-6 and 9, as well as myeloid differentiation factor 88 (MyD88), MD2, and CD14. Stimulation of HIBECs with LPS resulted in translocation of NF-kappaB subunits from the cytoplasmic to the nuclear fraction, followed by increased secretion of a variety of chemokines/cytokines, including interleukin-8 (IL-8), monocyte chemotactic protein-1 (MCP-1), and IL-6. Treatment with BAY11-7082 efficiently inhibited the LPS-induced transcription and secretion of these chemokines/cytokines. In HIBECs, the mitogen-activated protein kinases (MAPKs) were also activated by LPS stimulation. These results indicated that LPS activates HIBECs via a TLR4-MyD88-dependent pathway. Stimulation of HIBECs with LTA induced the secretion of a similar profile of cytokines/chemokines via a TLR2-MyD88-dependent pathway. CONCLUSIONS: In HIBECs, at least TLR2 and 4 are capable of mediating innate immune system function in vitro. This result, in conjunction with our recent finding that TLR4 expression is increased in biliary epithelial cells in primary biliary cirrhosis, suggests the involvement of TLRs in the development of chronic inflammatory cholangiopathies.

Bile Duct Diseases↗

PubMed2005

Increased expression of nuclear envelope gp210 antigen in small bile ducts in primary biliary cirrhosis.

The sustained antibody response to nuclear envelope gp210 antigen indicates a group of primary biliary cirrhosis (PBC) patients at high risk for the progression to end-stage hepatic failure. To address this issue, we immunohistochemically studied the expression of gp210 antigen in needle liver biopsy specimens from PBC patients using a monoclonal antibody specific for gp210 antigen. The specimens from autoimmune hepatitis (AIH), chronic viral hepatitis B (CHB) and C (CHC) patients served as disease controls. The expression of gp210 antigen was apparently increased on the nuclear envelope of biliary epithelial cells (BECs) of small bile ducts in almost all specimens from PBC. In contrast, the expression of gp210 antigen was negative in BECs of small bile ducts in normal liver, while relatively weak anti-gp210 immunostaining was observed in AIH, CHC and CHB. In addition, the degree of gp210 expression in BECs of small bile ducts was positively correlated to that of portal inflammation, interface hepatitis and lobular inflammation in PBC. These results indicate that the increased expression of gp210 in small bile ducts, which is probably associated with damage to BECs by inflammation, is possibly involved in autoimmune response to gp210 leading to the progression to end-stage hepatic failure in PBC.

Adult↗

PubMed2005

Immunosuppressant FK506 inhibits matrix metalloproteinase-9 induction in TNF-alpha-stimulated human hepatic stellate cells.

Activated hepatic stellate cells (HSCs) play a key role in the pathogenesis of hepatic inflammation and fibrosis through the production of matrix metalloproteinases (MMPs). Cytokines and growth factors are thought to activate HSCs. TNF-alpha has pleiotropic functions in hepatitis, but its role in liver fibrosis remains elusive. In this study we investigated the regulation of tumor necrosis factor-alpha (TNF-alpha) in the expression of MMPs by HSCs. We also examined whether the immunosuppressant FK506 influences the MMPs expression in human HSCs. Human HSCs, LI90, were treated with TNF-alpha in the presence of FK506. Release of MMPs into culture media, levels of MMP-9 mRNA and activation of NF-kappaB were compared between the cells cultured with or without FK506. Stimulation of human HSCs, LI90 cells, with TNF-alpha caused the induction of pro-MMP-9. Further, TNF-alpha stimulation induced the degradation of IkappaB-alpha and resulted in the transcriptional activation of NF-kappaB. FK506 suppressed this TNF-alpha-induced NK-kappaB activation, alone with pro-MMP-9 mRNA and protein induction, in HSC. TNF-alpha contributes to the perpetuation of liver fibrosis through MMP-9 production from HSCs and that FK506 inhibits the induction of MMP-9 through NF-kappaB pathway suggesting the anti-inflammatory properties of FK506.

Blotting, Western↗

PubMed2005

Peroxynitrite-mediated matrix metalloproteinase-2 activation in human hepatic stellate cells.

To investigate whether hepatic stellate cells (HSCs) alter their expression of MMPs after exposure to nitrogen oxide intermediate (NOI), a human hepatic stellate cell line, LI90 cells, was stimulated with an NO donor, SNAP, or a peroxynitrite donor, SIN-1, and the culture supernatants were analyzed by gelatin zymography or anti-MMPs immunoblot. Although SIN-1 did not enhance the secretions of MMP-1 and 13, SIN-1 induced the NF-kappaB activation, MT1-MMP expression and the secretion of activated MMP-2 in LI90 cells. These results suggest that peroxynitrite may contribute to the remodeling of the extracellular matrix in liver by activating pro-MMP-2.

Cell Line↗

PubMed2005

Idiopathic portal hypertension associated with systemic sclerosis and Sjögren's syndrome.

We report a patient with idiopathic portal hypertension (IPH) associated with systemic sclerosis (SSc) and Sjögren's syndrome. A 72-year-old Japanese woman was admitted to our hospital because of Raynaud's phenomenon, sclerodactyly, and dyspnea. The patient had splenomegaly, esophageal varices in the absence of extrahepatic portal obstruction, and cirrhosis of the liver. Immunological studies revealed positive anti-nuclear antibodies and high titers of anti-Scl-70, anti-SS-A, anti-centromere, and anti-mitochondrial M2 antibodies. Histological examinations of the liver biopsy specimen revealed stenosis and loss of small portal veins without findings of primary biliary cirrhosis. The patient was diagnosed as having IPH associated with SSc and Sjögren's syndrome. These observations suggest an immunological role in the pathogenesis of IPH.

Aged↗

PubMed2005

In vitro sequence-dependent interaction between nedaplatin and paclitaxel in human cancer cell lines.

PURPOSE: To define the most effective combination schedule of paclitaxel and nedaplatin, a new platinum derivative, we investigated the in vitro interaction between these drugs in AZ-521 and NUGC-4 gastric adenocarcinoma and KSE-1 esophageal squamous carcinoma cell lines. MATERIALS AND METHODS: Cytotoxic activity was determined by the WST-1 assay. Different treatment schedules of the two drugs were compared and evaluated for synergism, additivity, or antagonism using a quantitative method based on the median-effect principle of Chou and Talalay. Cell-cycle perturbation and apoptosis were evaluated by means of flow cytometry. RESULTS: Upon 24-h sequential exposure, the sequence paclitaxel followed by nedaplatin induced greater than additive effects in all of the cell lines, with synergistic interactions in NUGC-4 and KSE-1 cells. By contrast, antagonistic effects were observed with the reverse sequence. Simultaneous treatment resulted in either a synergistic or antagonistic effect, depending on the cell line. Therefore, the sequence paclitaxel followed by nedaplatin appears most active, at least in these three cell lines. Flow cytometric analyses at IC50 indicated that paclitaxel induced G2/M arrest with subsequent induction of apoptosis (56%) in the sub-G1 phase. When paclitaxel preceded nedaplatin, apoptosis was most prominent (70%) with pronounced G2/M arrest. By contrast, the reverse sequence yielded only 28% induction of apoptotic cells, with almost identical cell-cycle distribution patterns to those observed with nedaplatin alone, indicating that the activity of paclitaxel is abolished by pretreatment with nedaplatin. CONCLUSIONS: Our findings suggest that the interaction of nedaplatin and paclitaxel is highly schedule dependent and that the sequential administration of paclitaxel followed by nedaplatin should be thus incorporated into the design of a clinical trial.

Adenocarcinoma↗

PubMed2005

Acute hepatitis E of a man who consumed wild boar meat prior to the onset of illness in Nagasaki, Japan.

Zoonotic infection of hepatitis E virus (HEV) has been suggested. To date, pigs, deer, and wild boar have been implicated as reservoirs of HEV in Japan. However, it is not known to what extent zoonotic transmission of HEV play roles of causing HEV transmission. In the present report, we describe a case of acute hepatitis E in which a transmission of HEV by a zoonotic transmission is strongly suggested. The patient had eaten grilled wild boar meat 59 days prior to onset of acute hepatitis. Although the meat was not stored, one of the two people who ate boar meat with the patient at the same time showed high levels of HEV-IgM and -IgG and normal levels of liver enzymes, suggesting a subclinical infection of HEV. Accumulating evidence suggests that eating wild boars is associated with a high risk of acquiring hepatitis E infection.

Journal Article↗

PubMed2005

In vitro schedule-dependent interaction between paclitaxel and oxaliplatin in human cancer cell lines.

PURPOSE: In order to define the most effective administration schedule of the combination of paclitaxel and oxaliplatin, we investigated the in vitro interaction between these drugs in a panel of three human cancer cell lines (AZ-521 gastric adenocarcinoma cell line, HST-1 tongue squamous carcinoma cell line, and KSE-1 esophageal squamous carcinoma cell line). MATERIALS AND METHODS: Cytotoxic activity was determined by the WST-1 assay. Different administration schedules of the two drugs were compared and evaluated for synergism, additivity, or antagonism with a quantitative method based on the median-effect principle of Chou and Talalay. Cell cycle perturbation and apoptosis were evaluated by flow cytometry. RESULTS: Simultaneous treatment of cells with paclitaxel and oxaliplatin showed greater than additive effects. Upon 24-h sequential exposure, the sequence of paclitaxel followed by oxaliplatin showed synergistic effects in AZ-521 and HST-1 cells, and greater than additive effects in KSE-1 cells, while the opposite sequence yielded marked antagonistic effects in all three cell lines. Flow cytometric analysis indicated that paclitaxel induced G(2)/M arrest with subsequent induction of apoptosis in the sub-G(1) phase. Apoptosis was most prominent when paclitaxel preceded oxaliplatin, which produced apoptosis in the majority of treated cells (75%). By contrast, the reverse sequence yielded only 39% induction of apoptotic cells, the rate being not different from those induced by each drug singly. CONCLUSIONS: Our findings suggest that the interaction of paclitaxel and oxaliplatin is highly schedule-dependent and that the sequential administration of paclitaxel followed by oxaliplatin should thus be incorporated into the design of a clinical trial.

Apoptosis↗

PubMed2005

Biliary epithelial cells regulate autoreactive T cells: implications for biliary-specific diseases.

The biliary epithelial cell (BEC) is the target for several human immune mediated liver diseases, including primary biliary cirrhosis, but it is not always clear whether the BEC functions as an accessory cell or an antigen presenting cell, although it is well documented that BECs express high levels of human leukocyte antigen Class II, intercellular adhesion molecule-1, and lymphocyte function-associated antigen-3. To examine this issue, we established autoreactive T-cell clones from human leukocyte antigen-DR53 patients with primary biliary cirrhosis and characterized BEC function as a function of the ability of BECs to regulate T-cell activation. We report herein that BEC-mediated T-cell activation occurs partially via programmed death 1 ligands in a cell-contact-dependent manner. Further, such activation occurs via prostaglandin E2 production in a cell-contact-independent fashion. Moreover, the production of prostaglandin E2 was partially controlled by interleukin-1beta and tumor necrosis factor alpha. In conclusion, the regulatory activities of BECs are important for the maintenance of peripheral immune tolerance. Further, modulation of BEC function may be used for therapeutic modulation.

Antigen-Presenting Cells↗

PubMed2005

Hepatic expression of toll-like receptor 4 in primary biliary cirrhosis.

Toll-like receptor 4 (TLR4) is a receptor for bacterial lipopolysaccharide, which is suggested to be involved in the pathogenesis of disease of hepatobiliary tracts. To explore a possible role for this receptor in primary biliary cirrhosis (PBC), we investigated the expression of TLR4 in liver tissues from PBC patients. We studied liver biopsy sections from 62 PBC patients and 41 patients with chronic hepatitis C (CHC). Expression of TLR4 in paraffin-embedded sections was analyzed by immunohistochemistry. The bile duct epithelial cells (BECs) of PBC liver tissues markedly expressed TLR4, whereas BECs of CHC liver tissues barely expressed TLR4. The TLR4 expression was also observed in periportal hepatocytes of PBC liver tissues and its expression was extended to interlobular hepatocytes in advanced stage PBC. Although periportal hepatocytes of CHC liver tissues expressed TLR4, its expression levels were not correlated with the fibrosis stage. Our data demonstrated that TLR4 was expressed in BECs and periportal hepatocytes in PBC livers, suggesting the possible involvement of bacterial pathogens and TLR4 in the inflammatory processes of PBC.

Bile Ducts↗

PubMed2005

Antibody titer to gp210-C terminal peptide as a clinical parameter for monitoring primary biliary cirrhosis.

BACKGROUND/AIMS: The presence of antibodies to the 210-kDa glycoprotein of the nuclear pore complex (gp210) is highly indicative of primary biliary cirrhosis (PBC). However, the significance of anti-gp210 antibody titers for monitoring PBC remains unresolved. METHODS: We used an ELISA with a gp210 C-terminal peptide as an antigen to assess serum antibody titers in 71 patients with PBC. RESULTS: Patients were classified into three groups: Group A in whom anti-gp210 titers were sustained at a high level, Group B in whom anti-gp210 status changed from positive to negative under ursodeoxycholic acid (UDCA) therapy, Group C in whom anti-gp210 antibodies were negative at the time of diagnosis. The rate of progression to end-stage hepatic failure was significantly higher in group A (60%) as compared to groups B (0%) and C (4.2%). The sustained antibody response to gp210 was closely associated with the severity of interface hepatitis. The significance of anti-gp210 antibody was confirmed by National Hospital Organization Study Group for Liver Disease in Japan. CONCLUSIONS: The serial quantitation of serum anti-gp210-C-terminal peptide antibodies is useful for monitoring the effect of UDCA and for the early identification of patients at high risk for end-stage hepatic failure.

Antibodies↗

PubMed2005

Enhanced expression of type I interferon and toll-like receptor-3 in primary biliary cirrhosis.

The pathogenesis of primary biliary cirrhosis (PBC) remains enigmatic. In order to address this issue, we analyzed by laser capture microdissection and real-time reverse transcription-polymerase chain reaction the site-specific expression of messenger RNA (mRNA) for cytokines (interferon (IFN)-alpha, -beta, -gamma, interleukin (IL)-1beta, -4, -6, -10, -12p40, -18, tumor necrosis factor-alpha) and toll-like receptors (TLRs) (TLR-2, -3, -4, -7, -9) in portal tract and liver parenchyma from patients with early-stage PBC. Expression of IFN-alpha, -beta and TLR-3 proteins was also studied by immunohistochemistry. Autoimmune hepatitis (AIH) and chronic hepatitis C (CHC) served as disease controls. The expression levels of type I IFN (IFN-alpha, -beta) and TLR-3 mRNAs, which are known to induce type I IFN, were significantly higher in portal tract and liver parenchyma as compared to AIH and CHC. A strong positive correlation between the mRNA levels of type I IFN and TLR-3 was also seen in both areas. Immunohistologically, IFN-alpha is present in the mononuclear cells in portal tract and sinusoidal cells. Macrophages in portal tract and hepatocytes expressed IFN-beta and TLR-3. Furthermore, the level of IFN-alpha mRNA in the portal tract was positively correlated with serum alkaline phosphatase. In conclusion, these data indicate that TLR-3 and type I IFN signaling pathways are active in both the portal tract and liver parenchyma of early-stage PBC, and form the basis for our hypothesis that these signaling pathways are involved in the pathophysiology of PBC.

Aged↗

PubMed2005

Synergistic interaction between oxaliplatin and SN-38 in human gastric cancer cell lines in vitro.

The interaction between CPT-11 and oxaliplatin, a new platinum derivative that has a great antitumor activity against colon cancer, has not been determined in gastric cancer cells. In this study, we investigated in vitro cytotoxic activity of oxaliplatin alone or in combination with SN-38, an active metabolite of CPT-11, using different exposure schedules in three human gastric cancer cell lines (AZ-521, MKN-45, and NUGC-4). Cytotoxicity was determined by WST-1 assay. Different treatment schedules of the two drugs were compared and evaluated for synergism, additivity, or antagonism with a quantitative method based on the median-effect principle of Chou and Talalay. Cell cycle perturbation was evaluated by flow cytometry. In 24-h exposure, simultaneous administration of oxaliplatin and SN-38 showed a synergistic effect in AZ-521 and NUGC-4 cells, and an additive effect in MKN-45 cells. Greater than additive effects were observed in all of the cell lines when cells were treated with oxaliplatin followed by SN-38, whereas such effects were observed only in NUGC-4 cells in the reverse sequence. Flow cytometric analyses at IC(50) indicated that apoptosis was most prominent in simultaneous exposures with accumulation of cells in both G(0)/G(1) and S phases. These results suggest that SN-38 may kill the cells recovering from the G(1) block produced by oxaliplatin as they progress into the S phase. Simultaneous administration appears most active in gastric cancer cell lines. These results may provide important information for a clinical trial of oxaliplatin and CPT-11 combination for patients with gastric cancer.

Antineoplastic Agents↗

PubMed2004

Lipopolysaccharide signaling induces serum amyloid A (SAA) synthesis in human hepatocytes in vitro.

To investigate the role of lipopolysaccharide (LPS) in hepatocyte activation, we examined the expression of Toll-like receptor 4 (TLR4), the putative receptor for LPS in human hepatocytes. TLR4 mRNA and protein expression was confirmed in human hepatocytes. Stimulation of human hepatocytes with LPS results in rapid degradation of IkappaB-alpha and mitogen activated protein kinase activation. Human hepatocytes stimulated by LPS produced serum amyloid A protein. Our data suggest that human hepatocytes utilize components of TLR4 signal transduction pathways in response to LPS and these direct LPS-mediated effects on hepatocytes may contribute to liver inflammation and injury.

Cells, Cultured↗

PubMed2003

Systemic vasculitis associated with alphal-antitrypsin deficiency.

We describe a rare case of systemic vasculitis associated with alpha1-antitrypsin (alpha1-AT) deficiency. Mutational analysis of the alpha1-AT gene in this patient revealed a homozygous alpha1-AT Mnichinan variant. Alpha1-AT possesses broad-spectrum inhibitory activity against many serine proteases, including human neutrophil elastase, to help maintaining the crucial balance between proteases and protease inhibitors. The increase in free protease activity in the context of alpha1-AT deficiency may induce exacerbation of the vasculitis. This serious genetic defect severely affects the balance between a protease and a protease inhibitor at the pathological site.

Female↗