Modulation of Hepatocyte Protein Synthesis by Endotoxin- activated Kupffer Cells II. Mediation by Soluble Transferrable Factors (original) (raw)
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The Journal of Trauma: Injury, Infection, and Critical Care, 1985
The etiology of hepatic insufficiency associated with the multiple systems organ failure (MSOF) syndrome is unclear. The authors have investigated the possibility that a macrophage/ Kupffer cell mediated modulation of hepatocyte function may play a role in this phenomenon. Isolated rat hepatocytes were cultured, and their rate of protein synthesis was measured by cpm of 3H leucine incorporation into protein. Nonparenchymal rat liver cells (NPC) comprised of 35-40% Kupffer cells were added to hepatocytes to establish a co-culture with or without endotoxin. Neither NPC alone nor endotoxin alone affected hepatocyte protein synthesis. However, in the presence of endotoxin, NPC caused a marked diminution of hepatocyte protein synthesis (4,396 ± 449 cpm) compared with control hepatocytes (10,943 ± 623 cpm). No change in microscopic morphology or ability to exclude typan blue occurred. This modulation of hepatocyte function by an endotoxin stimulated Kupffer cell preparation may, in part, represent the mechanism of hepatic insufficiency associated with the MSOF syndrome.
Hepatology, 1991
Communication circuits operating between activated monocytes/macrophages and adjacent hepatocytes in the liver effect important alterations in hepatocyte function. We demonstrate here that primary human hepatocytes and hepatoma cells are able to function as effector cells in the recruitment of inflammatory cells in hepatic disease and inflammatory states by synthesizing a neutrophilflymphocyte chemotactic factor, interleukin-8. We have further investigated the possibility that endogenous factors elaborated by activated peripheral blood monocytes and Kupffer cells in the liver are mediators of hepatocytederived interleukin-8 expression. Twenty-four-hour conditioned medium from lipopolysaccharidestimulated peripheral blood monocytes and nonparenchymal human liver cells enriched for Kupffer cells induced a time-dependent increase in interleukin-8 messenger RNA levels in SK-hepatoma cells over a 24-hr period, similar to that seen for tumor necrosis factor-a or interleukin-16 induction of interleukin-8 in primary hepatocytes. Exogenously added lipopolysaccharide or recombinant interleukin-6 had no effect. Cell-associated interleukin-8 antigen was present in SK-hepatoma and primary hepatocytes that had been incubated with macrophage-conditioned medium, tumor necrosis factor or interleukin-16. Similarly, neutrophil chemotactic activity was secreted by SKhepatoma cells, a significant proportion of which could be blocked with interleukin-8-speciiic antiserum. Preincubation of macrophage-conditioned medium with neutralizing antibodies to tumor necrosis factor-a or interleukin-16 reduced its interleukin-8 messenger RNA-inducing capacity. Exposure of SK-hepatoma to conditioned medium followed by removal of the stimulus resulted in a rapid down-regulation of interleukin-8 messenger RNA to 50% of the maximum level within the first hour. These data suggest that products derived from activated Kupffer cells can modulate hepatoma cells and primary hepatocyte interleukin-8 gene expression. In addition,
Role of Kupffer cells in the pathogenesis of liver disease
World journal of gastroenterology : WJG, 2006
Kupffer cells, the resident liver macrophages have long been considered as mostly scavenger cells responsible for removing particulate material from the portal circulation. However, evidence derived mostly from animal models, indicates that Kupffer cells may be implicated in the pathogenesis of various liver diseases including viral hepatitis, steatohepatitis, alcoholic liver disease, intrahepatic cholostasis, activation or rejection of the liver during liver transplantation and liver fibrosis. There is accumulating evidence, reviewed in this paper, suggesting that Kupffer cells may act both as effector cells in the destruction of hepatocytes by producing harmful soluble mediators as well as antigen presenting cells during viral infections of the liver. Moreover they may represent a significant source of chemoattractant molecules for cytotoxic CD8 and regulatory T cells. Their role in fibrosis is well established as they are one of the main sources of TGFbeta1 production, which lead...
Distinct development and functions of resident and recruited liver Kupffer cells/macrophages
Journal of Leukocyte Biology, 2013
Although mouse liver F4/80 ϩ Kupffer cells consist of cytokine-producing CD11b ϩ cells and phagocytic CD68 ϩ cells, an undefined CD11b Ϫ CD68 Ϫ subset (30%) also exists. We herein demonstrate a more fundamental classification by adding CD32 (Fc␥RII), which covers most liver F4/80 ϩ cells and the distinct functions of them. Among the F4/80 ϩ cells, 50%, 40%, and 30% of cells were CD32 ϩ , CD68 ϩ , and CD11b ϩ , respectively, and one-half of the CD68 ϩ cells coexpressed CD32. CD68 ϩ and CD32 ϩ cells, but not CD11b ϩ cells, expressed a phagocytosis-related CRIg. Gy (6) irradiation depleted liver CD11b ϩ cells and those in the spleen, bone marrow, and peripheral blood but not liver CD32/ CD68 ϩ cells. Transfer of bone marrow cells into the irradiated mice reconstituted liver CD11b ϩ cells. Conversely, clodronate pretreatment depleted only liver CD32/CD68 ϩ cells but not liver CD11b ϩ cells and peripheral blood or spleen CD11b ϩ monocytes/macrophages. Moreover, the CD32 ϩ cells might be precursors of CD68 ϩ cells, as a large proportion of CD32 ϩ cells expressed the c-kit (CD117), and CD34 and CD32 ϩ cells acquired CD68 immediately after bacteria administration. CD32/CD68 ϩ cells, but not CD11b ϩ cells, expressed resident macrophage-specific MerTK and CD64 (Fc␥RI). Challenge with Staphylococcus aureus or liver metastatic EL-4 tumor cells indicated that the CD68 ϩ subset is engaged in systemic bactericidal activity, whereas the CD11b ϩ subset is pivotal for liver antitumor immunity. Human liver CD14 ϩ Kupffer cells could also be classified into three similar subsets. These results suggest that liver CD68 ϩ Kupffer cells and CD11b ϩ Kupffer cells/macrophages are developmentally and functionally distinct subsets.
American journal of physiology. Gastrointestinal and liver physiology, 2001
This study focuses on the importance of direct contact between Kupffer cells (KCs) and hepatocytes (HCs) during the hepatic inflammatory response using an in vitro approach. The lipopolysaccharide (LPS)-induced inflammatory response in monocultures of porcine HCs and KCs were compared with cocultures prepared either with direct contact between KCs and HCs (DC cocultures) or without direct contact using cell culture membrane inserts. Our data show that DC cocultures exhibited the highest production of tumor necrosis factor (TNF)-alpha, interleukin-6, and nitric oxide (NO) compared with the other cultures. Immunohistochemical studies revealed that TNF-alpha was exclusively produced by KCs, whereas HCs were responsible for NO production after LPS stimulation. Biotransformation capacity, as determined by cytochrome P-450 and UDP glucuronosyl transferase enzyme activities, was most significantly decreased in DC cocultures. These results provide evidence that direct contact between KCs an...
Frontiers in Immunology
Macrophages are key regulators of inflammation and repair, but their heterogeneity and multiple roles in the liver are not fully understood. We aimed herein to map the intrahepatic macrophage populations and their function(s) during acute liver injury. We used flow cytometry, gene expression analysis, multiplex-immunofluorescence, 3D-reconstruction, and spatial image analysis to characterize the intrahepatic immune landscape in mice post-CCl4-induced acute liver injury during three distinct phases: necroinflammation, and early and late repair. We observed hepatocellular necrosis and a reduction in liver resident lymphocytes during necroinflammation accompanied by the infiltration of circulating myeloid cells and upregulation of inflammatory cytokines. These parameters returned to baseline levels during the repair phase while pro-repair chemokines were upregulated. We identified resident CLEC4F+ Kupffer cells (KCs) and infiltrating IBA1+CLEC4F- monocyte-derived macrophages (MoMFs) as...
Functional characterization of two different Kupffer cell populations of normal rat liver
Journal of Hepatology, 1996
Background: Kupffer cells of the liver represent the largest population of tissue macrophages. Small and large Kupffer cells were distinguished in normal liver, leading to the suggestion that they have different functions. This study intends to further characterize small and large Kupffer cells of normal rat liver in vivo and in vitro. Methods: Sections of rat liver were investigated by double-staining immunofluorescence with the monoclonal antibodies ED1 and ED2. Isolated nonparenchymal liver cells were separated according to size to obtain small and large Kupffer cells. In culture, phagocytosis was studied by zymosan ingestion and cell proliferation by incorporation of 3H-thymidine. Synthesis of the proteins Cl-inhibitor, apolipoprotein E and interleukin-1 was studied by endogenous labeling of newly synthesized proteins, immunoprecipitation and sodium dodecylsulfate-polyacrylamide gel electrophoresis. Results: ED1 ÷ ED2 + Kupffer cells were located in the liver along the sinusoids. ED1 + ED2-cells were found mainly located around the central vein and portal vessels. By counterflow elution, small ED1 ÷ ED2-cells were separated from larger ED1 ÷ ED2 ÷ cells and cultured. The larger cells abundantly synthesized Cl-inhibitor and apolipoprotein E, while the small cells synthesized only trace amounts of these proteins. Interferon-T increased Cl-inhibitor synthesis in small (5-fold) and large cells (1.5-fold). 3H-thymidine incorporation was ll-foid higher in small than in large cells. However, lipopolysaccharide-induced pro-interleukin-lcx and pro-interleukin-l[3 synthesis and phagocytic activity were similar in both populations. Conclusions: The data demonstrate two different populations of mononuclear phagocytes in normal rat liver well distinguished by immunocytochemical and functional markers.
The International Journal of Biochemistry & Cell Biology, 2004
Background and aims: Recent evidence suggests that inflammatory cytokines may mediate reduced hepatic glucose production and reduced blood glucose concentrations in sepsis. Therefore the aim of this study is to provide direct evidence of a cytokine-mediated interaction between Kupffer cells and hepatocytes by characterising the effects of lipopolysaccharidestimulated Kupffer cells on hepatocyte gluconeogenesis, and the activity of key regulatory enzymes of this pathway. Methods and results: Primary isolates of hepatocytes co-cultured with lipopolysaccharide-stimulated Kupffer cells in Transwell inserts showed a 48% inhibition of gluconeogenesis (P < 0.001). RNase protection assay and ELISA of Kupffer cells and the culture media following exposure to lipopolysaccharide showed increased levels of interleukin-1 alpha and beta, tumour necrosis factor alpha and IL-10. The addition of IL-1 and IL-10 to hepatocyte cultures inhibited gluconeogenesis by 52% (P < 0.001), whereas each cytokine alone was ineffective. To determine whether altered production or activity of phosphoenolpyruvate carboxykinase or pyruvate kinase was responsible for the reduced glucose synthesis, their mRNA, protein levels and enzyme activities were measured. Primary hepatocytes co-cultured with lipopolysaccharide-stimulated Kupffer cells or cultured with a combination of IL-1 and IL-10 displayed reduced levels of phosphoenolpyruvate carboxykinase mRNA, protein and enzyme activity. In contrast the mRNA, protein levels and enzyme activity of pyruvate kinase were not altered; suggesting that gluconeogenesis was suppressed by downregulation of phosphoenolpyruvate carboxykinase. Conclusions: Therefore, hypoglycaemia, which is often observed in sepsis, may be mediated by Kupffer cell-derived IL-1 and IL-10. In addition this study suggests these cytokines inhibit phosphoenolpyruvate carboxykinase production and thereby hepatic gluconeogenesis.