Kazuhiro Hayashida

Kupffer Cells May Autoregulate Interleukin 1 Production by Producing Interleukin 1 Inhibitor and Prostaglandin E2

Rat Kupffer cells stimulated with bacterial lipopolysaccharide (LPS) produced high levels of interleukin 1 (IL‐1), as determined by thymocyte proliferation assay. Indomethacin revealed a dose‐dependent augmentation in IL‐l production, in parallel with a dose‐dependent reduction in prostaglandin E2 production by Kupffer cells. The addition of exogenous prostaglandin E2, dibutyryl cAMP, or isoproterenol led to a dose‐dependent suppression of IL‐I production. The supernatant from UPS‐stimulated Kupffer cells also contained factors that Inhibited IL‐1‐induced thymocyte proliferation. Upon gel filtration, two inhibitory peaks, at apparent MW of 27,000 and 6000, were obtained. The latter but not the former fraction also affected Interleukin 2 (IL‐2)‐induced thymocyte proliferation. Increasing amounts of IL‐1 overcame the inhibitory activity derived from the 27,000 MW fraction. These results suggest to us that prostaglandin E2 and IL‐1 inhibitor released by Kupffer cells may be involved in negative self‐control in regulating IL‐1 production and its action.

Rotenone, a mitochondrial NADH dehydrogenase inhibitor, induces cell surface expression of CD 13 and CD38 and apoptosis in HL-60 cells

We previously demonstrated that the mitochondrial NADH dehydrogenase subunit 2 (ND2) gene was overexpressed in human acute myelogenous leukemia (AML) cells. Since this finding suggested that ND2 gene expression was related to myeloid differentiation, we here investigated the effects of rotenone, a specific NADH dehydrogenase inhibitor, on HL-60 cell growth, differentiation and death. Fifty nM rotenone inhibited the growth of HL-60 cells and caused an increase in the cell population in the G(2) +M phase. In the quantitative comparison of myeloid antigen, the expression of CD13 and CD38 were relatively increased in the rotenone-treated cells. These findings suggest that the inhibition of NADH dehydrogenase changes the cell cycle and induces some specific surface antigens of HL-60 cells. On the other hand, the expression of ND2 gene remained unchanged after the rotenone treatment, suggesting the rotenone-mediated mitochondrial inhibition did not affect the mitochondrial gene expression. Five mu M rotenone strongly inhibited the cellular proliferation. Electron microscopy and an electrophoretic analysis of DNA showed that the majority of the HL-60 cells were induced into typical apoptosis within 24-48 hours. On the basis of this and other studies, we believe that mitochondrial function is directly involved in both cellular differentiation and apoptotic cell death.

CD56 DIRECTLY INTERACTS IN THE PROCESS OF NCAM-POSITIVE TARGET CELL-KILLING BY NK CELLS

The role of CD56 in the process of target cell killing by NK cells has been investigated. Addition of NK cells to HuH28 cells, a CD56‐expressing cell line, led to inhibition of the growth of the target cells, which exhibited morphological features of apoptosis. These changes were prevented by the addition of a polyclonal anti‐NCAM to the cultures. Since neither Fas antigen expression nor apoptotic changes were induced by addition to a mixed culture supernatant of NK and target cells, both the Fas‐Fas ligand system and soluble factors do not seem to participate in apoptosis in these circumstances. Increased secretion of interferon‐γ and tumour necrosis factor‐α by NK cells must therefore have been suppressed by the presence of the polyclonal antibody. These results lead us to conclude that CD56, through homophilic binding, plays an important role in the process of target cell killing by an apoptosis mechanism.

Liver lesions of visceral larva migrans due to Ascaris suum infection: CT findings.

Abstract The purpose of this study was to analyze computed tomographic (CT) findings of hepatic lesions due to Ascaris suum infection. CT of the liver in three patients, all of whom had immunoserologically confirmed A. suum infection, were retrospectively reviewed. Twenty-five lesions were identified in total. Two radiologists analyzed CT findings in a consensus fashion, with particular interest in the margin, shape, and location of the lesions. Hepatic lesions were ill-defined (22 of 25), small (3–35 mm; average, 11 mm), and nodular (18 of 25) or wedge (three of 25) in shape. Most were located in periportal (16 of 25) or subcapsular (six of 25) regions. Hepatic nodules due to visceral larva migrans of A. suum were located mainly in periportal or subcapsular regions, which may represent periportal eosinophilic granuloma, its pathologic feature. The results were considered to represent the pathophysiology of this entity.

Correlation between histopathological findings of the liver and IgA class antibodies to 2-oxo-acid dehydrogenase complex in primary biliary cirrhosis

Although anti-mitochondrial antibody (AMA) is the characteristic serological feature of primary biliary cirrhosis (PBC), its pathogenetic role remains unclear. We tested sera from 72 Japanese patients with histologically confirmed PBC for AMA by indirect immunofluorescence, anti-pyruvate dehydrogenase complex (PDC) by enzyme inhibition assay, immunoglobulin (Ig) G class anti-PDC by ELISA, and IgG, IgM, and IgA class anti-2-oxo-acid dehydrogenase complex (2-OADC) by immunoblotting. Of the 72 sera, 60 (83%), 50 (69%), 42 (58%), and 71 (99%) were positive for AMA by immunofluorescence, enzyme inhibition assay, ELISA, and immunoblotting, respectively. There was no significant correlation between histological stages and AMA by immunofluorescence, PDC inhibitory antibodies by enzyme inhibition assay, IgG class anti-PDC antibodies by ELISA, or IgG and IgM class anti-2-OADC by immunoblotting. IgA class anti-2-OADC by immunoblotting was more frequent in stages 2–4 than in stage 1 (P = 0.0083). Of the IgA class anti-2-OADC, anti-PDC-E2 (74 kDa) and anti-E3BP (52 kDa) were more frequent in stages 2–4 than in stage 1 (P = 0.0253 and 0.0042, respectively). Further examination of histopathological findings in 53 of 72 liver biopsy specimens showed that IgA class anti-PDC-E2 and IgA class anti-E3BP were associated with bile duct loss, and IgA class anti-PDC-E2 was also associated with interface hepatitis and atypical ductular proliferation. IgA is known to be secreted into the bile through biliary epithelial cells, implying that IgA class anti-PDC-E2 and E3BP may have a specific pathogenetic role during their transport into the bile by binding to their target antigen(s) in biliary epithelial cells, and this may be followed by dysfunction and finally destruction of biliary epithelial cells. Our present results suggest that these autoantibodies against 2-OADC detected by immunoblotting may be associated with the pathogenesis and pathologic progression of PBC.

Human lymphocytes synthesize C-reactive protein

We obtained evidence for the synthesis and secretion of C-reactive protein (CRP) by peripheral mononuclear cells in culture. Human mononuclear cells isolated from peripheral blood, after depletion of platelets, were cultured in giutamine-depleted RPMI 1640 supplemented with [3H]glutamine in the presence of 10-O-tetradecanoyl-phorbol-13-acetate (TPA). Anti-CRP antiserum was added to the culture medium, and the resultant immunoprecipitate was analyzed in SDS-polyacrylamide gel electrophoresis (SDS-PAGE). The immunoprecipitate consisted of CRP, heavy and light chains of IgG, and only the CRP protein band had radioactivity, indicating that CRP was synthesized by mononuclear cells. In the populations of mononuciear cells, T-cell preparations mainly synthesized CRP, under stimulation of a factor derived from activated monocytes. Studies using the inhibitors of phospholipid metabolism suggested that generation of the monocyte factor was relevant to metabolites of an arachidonate cascade.

Pretreatment Prediction of Interferon-Alfa Efficacy in Chronic Hepatitis C Patients

BACKGROUND & AIMS Interferon has been used widely to treat patients with chronic hepatitis C infections. Prediction of interferon efficacy before treatment has been performed mainly by using viral information, such as viral load and genotype. This information has allowed the successful prediction of sustained responders (SR) and non-SRs, which includes transient responders (TR) and nonresponders (NR). In the current study we examined whether liver messenger RNA expression profiles also can be used to predict interferon efficacy. METHODS RNA was isolated from 69 liver biopsy samples from patients receiving interferon monotherapy and was analyzed on a complementary DNA microarray. Of these 69 samples, 31 were used to develop an algorithm for predicting interferon efficacy, and 38 were used to validate the precision of the algorithm. We also applied our methodology to the prediction of the efficacy of interferon/ribavirin combination therapy using an additional 56 biopsy samples. RESULTS Our microarray analysis combined with the algorithm was 94% successful at predicting SR/TR and NR patients. A validation study confirmed that this algorithm can predict interferon efficacy with 95% accuracy and a P value of less than .00001. Similarly, we obtained a 93% prediction efficacy and a P value of less than .0001 for patients receiving combination therapy. CONCLUSIONS By using only host data from the complementary DNA microarray we are able to successfully predict SR/TR and NR patients for interferon therapy. Therefore, this technique can help determine the appropriate treatment for hepatitis C patients.

α2-Macroglobulin secretion enhanced in rat hepatocytes by partially characterized factor from Kupffer cells

Isolated rat Kupffer cells produced a factor which stimulated the synthesis ofα2-macroglobulin (α2M) in primary cultured rat hepatocytes. Although Kupffer cells placed in culture produced the factor without stimulation by lipopolysaccharide (LPS), the LPS-stimulated cells produced larger amounts of the factor. On the other hand, the production of the factor was inhibited by addition of actinomycin D. The induction ofα2M synthesis by cultured hepatocytes was enhanced in the presence of dexamethasone (Dex), in that hepatic synthesis ofα2M increased by addition of the factor alone and with Dex 1.5 and three- to four-fold, respectively. The factor was nondialyzable and stable at 60°C for 30 min. When the factor was fractionated using the molecular sieve method, the activity recovered in the fraction had a molecular weight of over 30,000.

Autoimmune hepatitis with membranous glomerulonephritis

Abstract We report on a case of autoimmune hepatitis (AIH) associated with membranous glomerulonephritis. A 61‐year‐old woman was admitted because of peripheral edema, proteinuria and abnormal liver function test findings. A diagnosis of AIH was made on the basis of an elevation of aminotransferase and serum IgG levels, the presence of positive antinuclear antibody and the characteristic histological features of chronic active hepatitis. Histological examination of a renal biopsy specimen disclosed membranous glomerulonephritis with granular deposits of IgG, IgM, C3 and C1q along the capillary walls. This condition is rare in AIH and should be carefully distinguished from systemic lupus erythematosus.

Peripheral B lymphocyte repertoire to mitochondrial antigen in primary biliary cirrhosis-positive correlation between the disease activity and the frequency of circulating B lymphocytes specific for pyruvate dehydroge nase complex

B lymphocytes committed to the production of IgG antibodies (Abs) to mitochondrial antigen such as pyruvate dehydrogenase complex(PDC) were quantitated in the peripheral blood of patients with primary biliary cirrhosis(PBC) using Epstein-Barr virus as a polyclonal activator of human B lymphocytes. B lymphocytes committed to the production of IgG Abs to PDC were found in high frequency in patients with PBC(0.54 +/- 0.16%, mean value +/- SE, of total IgG-producing B lymphocytes) in contrast to type C chronic hepatitis and healthy subjects in which they were less than 0.01%. The frequency of these B lymphocytes specific for PDC increased in parallel to the progression of the Scheuers stage from I to II (stage I: 0.35 +/- 0.23%, stage II: 1.04 +/- 0.32%), but decreased with further progression to stage IV (stage III: 0.39 +/- 0.21%, stage IV: 0.07 +/- 0.06%). In addition, B lymphocytes specific for PDC decreased in the peripheral blood during the administration of cyclosporin A; this was accompanied by an improvement of lymphocyte infiltration severity in the liver. These data indicate that B lymphocytes specific for PDC are present in the peripheral blood of patients with PBC and their frequency reflects the degree of the lymphocyte infiltration in the liver.