Mass isolation and culture of rat kupffer cells.

Collagenase perfusion of the liver followed by pronase treatment of the cell suspension thus obtained gave a quantitative recovery of viable nonparenchymal liver cells (NPC). From these NPC, Kupffer (K) cells can be purified by attachment to tissue culture dishes. Tail vein injection of carbon 1-2 h before liver perfusion permitted stepwise calculation as well as visualization of carbon-containing K cells. When these K cells have been put into tissue culture medium with serum and incubated overnight, they exhibit typical macrophage characteristics. Phase-contrast and transmission electron microscopy showed typical macrophage morphology and scanning electron microscopy revealed well-spread cells with cytoplasmic projections and ruffled membranes. Endocytosis studies using radioactive colloidal gold and inert latex particles also indicated that these cells are highly active in pinocytosis and phagocytosis. Further characterization of K cells is the identification of Fc receptor on their membranes. Studies on lysosomal enzymes showed that purified K cells possess higher specific activities in beta-glucuronidase, acid DNase, and cathepsin D than in purified parenchymal cells.

Modulation of a glycoprotein recognition system on rat hepatic endothelial cells by glucose and diabetes mellitus.

The cellular location and carbohydrate specificities of a glycoprotein recognition system on rat hepatic sinusoidal cells have been determined. Purified preparations of endothelial, Kupffer, and parenchymal cells were prepared by collagenase liver perfusion, centrifugation on Percoll gradients, and centrifugal elutriation. (125)I-labeled agalactoorosomucoid, an N-acetylglucosamine-terminated glycoprotein, was selectively taken up in vitro by endothelial cells. Uptake was shown to be protein dependent, calcium ion dependent, and saturable, and could be described by Michaelis-Menten kinetics (apparent K(m) 0.29 muM; apparent maximum velocity 4.8 pmol/h per 5 x 10(6) cells). Uptake was inhibited not only by N-acetylglucosamine, mannose, and mannan but also by glucose, fructose, and a glucose-albumin conjugate. Inhibition by glucose was competitive over a wide range of concentrations and was almost 100% at a glucose concentration of 56 mM. Fasting and the induction of diabetes mellitus prior to isolation of cells was associated with 60% reductions in the recovery of endothelial cells. Uptake by cells isolated from fasted rats was enhanced (apparent maximum velocity 14.3 pmol/h per 5 x 10(6) cells without change in the apparent K(m)). These observations suggest that fasting is associated with a marked increase in the mean number of glycoprotein receptors per endothelial cell isolated from normal rats. This effect of fasting could be due to upregulation of glycoprotein receptors on endothelial cells or to the selective isolation of a subpopulation of endothelial cells from fasted animals that bears more glycoprotein receptors per cell than does another subpopulation of these cells. In addition, in vivo studies of the fate of intravenously administered (125)I-agalactoorosomucoid indicated that its rate of disappearance from plasma, hepatic accumulation, and catabolism were slower in diabetic than in normal rats. The results suggest that modulation of a carbohydrate-mediated glycoprotein recognition system located on hepatic endothelial cells can be induced by glucose and glucose-conjugated proteins and by fasting and diabetes mellitus. The findings in this study suggest a mechanism for abnormal glycoprotein metabolism in diabetes mellitus.

Identification of prostaglandin D2 as the major eicosanoid from liver endothelial and Kupffer cells.

The capacity of freshly isolated endothelial, Kupffer and parenchymal rat liver cells to produce eicosanoids from [1-14C]arachidonic acid was investigated in order to determine the relative importance of these cells to total liver eicosanoid production. Based upon the total formation of [1-14C]arachidonate metabolites in the liver, it can be calculated that Kupffer and endothelial cells are responsible for 65 and 23%, respectively, of the total amount of eicosanoids produced by the liver. Consequently, parenchymal liver cells, representing 92.5% of the total liver mass, contribute only 12% to the total liver production of eicosanoids. The main product of Kupffer cells was prostaglandin D2 (PGD2), representing 55% of the total amount of eicosanoids produced. Liver endothelial cells produced about 4-times less eicosanoids (per mg cell protein) than Kupffer cells, and PGD2 was also the main product of these cells (44%). The production of eicosanoids by parenchymal cells was lower by a factor of 180 (per mg cell protein) than that in Kupffer cells. Besides the ability to form eicosanoids from added 14C-labeled arachidonic acid, Kupffer and endothelial liver cells were also able to produce significant amounts of PGD2 (the main liver prostaglandin) from endogenous arachidonic acid, as determined by a radioimmunoassay. It is concluded that inside the liver, Kupffer cells together with endothelial cells are of major importance in the production of eicosanoids, while the parenchymal cells may be considered metabolic target cells for these products, as indicated by the finding that the major liver prostaglandin, PGD2, could stimulate the glucose output in isolated parenchymal cells.

Identification of erythropoietin producing cells in fetal mouse liver cultures.

Fetal mouse liver explants were cultured and the culture media shown to possess an erythropoietically active substance neutralizable by antiserum to sheep plasma erythropoietin, suggesting that the media contain erythropoietin. Immunofluorescent and carbon particle ingestion techniques suggest that the erythropoietin was elaborated by macrophages or Kupffer cells of the hepatic reticuloendothelial system.

Induction of rat alpha 2-macroglobulin in vivo and in hepatocyte primary cultures: synergistic action of glucocorticoids and a Kupffer cell-derived factor.

Turpentine injection into rats elicits enhanced secretion of acute phase proteins including alpha 2-macroglobulin (alpha 2M). Hypophysectomized rats, however, do not respond in this way unless dexamethasone is given together with turpentine. On the other hand, dexamethasone injection alone did not result in an induction of alpha 2M synthesis. When a medium of Kupffer cell cultures was added to hepatocytes, a dose-dependent stimulation of alpha 2M synthesis of up to 4-fold after 10-12 h was observed. However, the presence of low concentrations (10(-9)M) of dexamethasone was essential for the stimulatory effect. We conclude that the acute phase induction of alpha 2M in hepatocytes requires the synergistic action of glucocorticoids and a non-dialysable factor secreted by Kupffer cells.

Isolation and characterization of hepatocytes and Kupffer cells.

Simplified isolation procedures are described for the parenchymal cell of the liver and the major non-parenchymal cell, the Kupffer cell. Hepatocytes are obtained in a purity of approximately 100%; a yield 10 X 10(6) cells/g liver tissue and the viability is greater than 85%. The recovery of Kupffer cells is 82%, viability 87% and purity 67%. Characterization of Kupffer cells is by the peroxidatic reaction, of hepatocytes by gluconeogenesis and also culture on collagen plates in a non-protein medium yielding albumin.

Kupffer cells in hepatocellular adenomas.

Hepatocellular adenomas are usually visualized as defects on technetium-99m-sulfur colloid liver scans, a fact which has been attributed to the absence of phagocytic Kupffer cells in the tumors. To determine whether this is true, seven hepatocellular adenomas were subjected to immunoperoxidase staining for lysozyme, a marker of mononuclear phagocytes. The Kupffer cells were counted in the tumors and surrounding non-neoplastic liver. All hepatocellular adenomas studied were found to contain Kupffer cells. Three tumors had fewer Kupffer cells than the surrounding liver. Three had about the same number as the surrounding liver, and one had more Kupffer cells than the non-neoplastic liver. Thus, the lack of phagocytosis of colloid in liver scans is probably due to something other than a deficiency of Kupffer cells in the hepatocellular adenomas.

Extra-neural glial fibrillary acidic protein (GFAP) immunoreactivity in perisinusoidal stellate cells of rat liver.

The dendritic processes and perinuclear cytoplasm of stellate-shaped perisinusoidal cells in frozen sections of rat liver were specifically labeled with antisera raised independently to glial fibrillary acidic protein (GFAP), the major component of intermediate filaments in astrocytes. A liver protein co-migrating with authentic GFAP and immunoreactive with GFAP antisera was demonstrated with immunoblots of brain and liver extracts enriched in intermediate filament proteins separated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This study presents yet another example of immunoreactivity to GFAP, or a highly similar protein localized outside the CNS, in cells of mesenchymal origin exhibiting some morphological features common to astroglia.

Characterization of interstitial dendritic cells in human liver.

Sensitive immunofluorescence and immunoperoxidase techniques were used to test an extensive range of monoclonal antibodies for reactivity with Kupffer cells and interstitial dendritic cells (DCs) in cryostat-cut sections of human liver. Leucocytes with a dendritic cell morphology were identified with CD45 (antileucocyte common) reagents in portal tracts, predominantly around bile ducts, and these cells stained strongly for the HLA-DP, DQ, and DR antigens. Kupffer cells stained less intensely with anti-class-II reagents, particularly anti-HLA-DQ. The interstitial DCs expressed the LFA-1 antigen but failed to stain with CD11b, CD11c, and the defined T and B cell CD antibodies; nor did they stain with antibodies to FcR1, FcR11, FcRIII, or the C3b receptor. Of the myeloid monoclonal antibodies available from the 3rd Leucocyte Differentiation Antigen Workshop, only Y2/131, Ki-M7, Ki-M8, and a minority of CD14 antibodies stained DCs, whereas Kupffer cells showed a wider reactivity with antimacrophage antibodies including those of workshop groups 11, 15, 16, and other unique antibodies. A 2nd probable DC population was identified in the liver capsule that had a similar phenotype to portal interstitial DCs. Although some minor phenotypic differences between liver portal DCs and the phenotypes of Langerhans cells and isolated tonsil DCs were noted, our results support the view that there is a unique hemopoietic lineage of DCs. The presence of DCs, which stimulate strong allogeneic T cell responses, in the portal triads is consistent with the fact that the histologic changes of graft-versus-host disease seen in bone marrow transplantation and the lymphocytic infiltrate in a rejecting liver allograft occur predominantly in the periportal region.

Glucagon receptors in endothelial and Kupffer cells of mouse liver.

To determine whether hepatic sinusoidal cells contain glucagon receptors and, if so, to study the significance of the receptors in the cells, binding of [125I]-glucagon to nonparenchymal cells (mainly endothelial cells and Kupffer cells) isolated from mouse liver was examined by quantitative autoradiography and biochemical methods. Furthermore, the pathway of intracellular transport of colloidal gold-labeled glucagon (AuG) was examined in vivo. Autoradiographic and biochemical results demonstrated many glucagon receptors in both endothelial cells and Kupffer cells, and more receptors being present in endothelial cells than in Kupffer cells. In vivo, endothelial cells internalized AuG particles into coated vesicles via coated pits and transported the particles to endosomes, lysosomes, and abluminal plasma membrane. Therefore, receptor-mediated transcytosis of AuG occurs in endothelial cells. The number of particles present on the abluminal plasma membrane was constant if the amount of injected AuG increased. Therefore, the magnitude of receptor-mediated transcytosis of AuG appears to be regulated by endothelial cells. Kupffer cells internalized the ligand into cytoplasmic tubular structures via plasma membrane invaginations and transported the ligand exclusively to endosomes and lysosomes, suggesting that the ligand is degraded by Kupffer cells.

Talc in liver tissue of intravenous drug abusers with chronic hepatitis. A comparative study.

To determine the frequency of talc microcrystals in liver tissue of intravenous (IV) drug abusers and the significance of this finding, the authors reviewed, with light and polarizing microscopy, sections of liver tissue from 70 patients with chronic hepatitis and a history of active (45) or past (25) IV drug abuse. Birefringent crystalline particles consistent with talc were found in 44 cases (63%), 31 associated with active and 13 with past drug abuse. The microcrystals were situated predominantly in hypertrophied portal macrophages; there were no well-formed granulomas. Scanning electron microscopic and energy-dispersive spectrophotometry performed on eight of the positive cases showed the characteristic "flake-pastry" appearance and chemical composition (silicon and magnesium) of talc. For comparison, the authors similarly examined 70 cases of posttransfusion chronic hepatitis, all of which had negative findings for talc, and 70 cases of chronic hepatitis with no documented risk factors for viral hepatitis, of which two had positive findings for talc, even though IV drug abuse was denied by the two patients. The authors conclude that talc is frequently present in the liver of IV drug abusers and whenever encountered it strongly suggests IV drug abuse. Only two patients (1.4%) with a negative history also had talc.

Liver parenchymal cells differ from the fat-storing cells in their lipid composition.

The neutral lipid and phospholipid compositions of purified sinusoidal (fat-storing, endothelial and Kupffer) cells, parenchymal cells and liver homogenates were determined by thin layer chromatography. In addition, the retinoid content of the same purified cell populations was determined by high performance liquid chromatography. From each cell type, both a lipid droplet fraction and a pellet fraction (containing the majority of the remaining cell organelles) were prepared by differential centrifugation. Electron microscopic analysis showed that lipid droplets isolated from fat-storing cells were larger (up to 8 microns) than those isolated from parenchymal cells (up to 2.5 microns). Moreover, the parenchymal lipid droplets seemed to be surrounded by a membranous structure, while the fat-storing lipid droplets seemed not to be. Both fat-storing and parenchymal cells contained high concentrations of neutral lipids, 57.9 micrograms and 71.0 micrograms/10(6) cells, respectively, while endothelial and Kupffer cells contained only 8.6 micrograms and 13.8 micrograms/10(6) cells of neutral lipids, respectively. Sixty-five percent of fat-storing cell lipid droplet fractions comprised esters of retinol and cholesterol. This combined ester fraction contained mainly retinyl esters. In addition, considerable quantities (20%) of triglycerides were present. Parenchymal cell lipid droplet fractions comprised triglycerides (62%) and cholesteryl esters (up to 30%). The pellet fractions prepared from all four cell types consisted mainly of cholesterol (41-67%) and free fatty acids (20-28%). The phospholipid content was much higher in parenchymal cells than in the sinusoidal liver cell types. The relative proportions of the four major phospholipid classes were comparable in all liver cell types analyzed.(ABSTRACT TRUNCATED AT 250 WORDS)

Orcein-positive material in Kupffer cells from the liver.

Orcein-positive material in Kupffer cells obtained from 1,377 needle biopsies of the liver was studied for hepatitis B surface antigen (HBsAg). Fifty-five (57%) out of 96 cases with orcein-positive Kupffer cells had acute hepatitis, and 46 (84%) of these 55 were in the late stage of their illness. Orcein-positive material in Kupffer cells was not associated with HBsAg as evaluated by the immune peroxidase method. Orcein-positive material in Kupffer cells appears to consist mainly of lipofuscins developing in the course of acute hepatitis.

Effects of intravenously administered tetra-thiomolybdate on the distribution of copper in the liver and kidney of copper loaded sheep: a histochemical study.

The effects of intravenously administered thiomolybdate on the liver and kidney of copper loaded sheep were studied using 16 ewes in three groups. Copper, iron and molybdenum concentrations were determined by spectrophotometry and the distribution of copper in the liver and kidney was studied histochemically. Following thiomolybdate administration, the concentration of copper in the liver was reduced, that of molybdenum increased and the concentration of copper and molybdenum in the kidney increased. The reduction of copper concentration in the liver was associated with reductions in the number and size of granules in hepatocytes which stained positively for copper and in the number of Kupffer cells containing positively staining granules. The decrease in the amount of copper in hepatocytes appeared to be greater than that in Kupffer cells. This effect was greatest in the centrilobular zones and least in the periportal zones. The increased concentration of copper and molybdenum in kidney was associated with an increase in the number and size of granules staining positively for copper in the epithelial cells of the proximal convoluted tubules which suggested an uptake of copper-molybdenum complexes by the lysosomes of these cells.

Molecular cloning and sequencing of a cDNA for a carbohydrate binding receptor unique to rat Kupffer cells.

cDNA comprising the entire length of the rat Kupffer cell receptor (Mr = 88,000 and 77,000) for carbohydrates with an affinity for fucose and galactose was isolated, and its nucleotide sequence was determined. Receptor cDNA encoded a protein containing 550 amino acid residues with a Mr = 61,104. This Mr was consistent with the size of the deglycosylated receptor which was found to contain two polypeptides by gel electrophoresis with Mr = 58,000 and 52,000, respectively. Edman degradation of the receptor yielded a sequence which corresponded to amino acid residues 83-104 of the sequence derived from the cDNA. This confirmed that the cDNA which had been isolated corresponded to mRNA for the receptor and suggested that the smaller polypeptide in receptor preparations arises by proteolysis of the intact receptor. Amino acid composition of the receptor was nearly identical to that predicted by the cDNA. The Kupffer cell receptor was found to be homologous to other carbohydrate binding proteins including the hepatic receptors with different binding specificities. The Kupffer cell receptor also contained a series of 18 contiguous, homologous sequences with an average length of 14 residues.

Localization of cathepsin D in rat liver. Immunocytochemical study using post-embedding immunoenzyme and protein A-gold techniques.

Light and electron microscopic localization of cathepsin D in rat liver was investigated by post-embedding immunoenzyme and protein A-gold techniques. By light microscopy, cytoplasmic granules of parenchymal cells and Kupffer cells were stained for cathepsin D. Weak staining was also noted in sinusoidal endothelial cells. In the parenchymal cells many of positive granules located around bile canaliculi. In the Kupffer cells and the endothelial cells, diffuse staining was noted in the cytoplasm in addition to granular staining. By electron microscopy, gold particles representing the antigenic sites for cathepsin D were seen in typical secondary lysosomes and some multivesicular bodies of the parenchymal cells and Kupffer cells. The lysosomes of the endothelial cells and fat-storing cells were weakly labeled. Quantitative analysis of the labeling density in the lysosomes of these three types of cells demonstrated that the lysosomes of parenchymal cells and Kupffer cells are main containers of cathepsin D in rat liver. The results suggest that cathepsin D functions in the intracellular digestive system of parenchymal cells and Kupffer cells but not so much in that of the endothelial cells.

Localization of ferritin in human liver diseases studied by immuno-histochemical and immuno-electron microscopic procedures.

Localization of ferritin using a pre-embedding diffusion technique and an indirect localization sequence has been made in 34 cases of human liver under normal and several pathological conditions. With light microscopic observation, positive immuno-staining for ferritin was demonstrated as diffuse deposits in the hepatocytes and Kupffer cells. Intensity of the positive immuno-staining for ferritin in these cells appeared to roughly coincide with serum ferritin levels of each patient, but showed no disease specificity, although hepatoma cells contained weak deposits or were negative from immuno-staining for ferritin. With electron microscopic studies, intracellular antigen was well preserved in the hepatocytes and Kupffer cells in most cases with the positive immuno-staining for ferritin being observed in cytosol and a few cisternae of rough endoplasmic reticulum. Content of the positive immuno-staining for ferritin differed considerably from one case to another and one cell to another even in the same case. There was no immuno-staining for ferritin in hemosiderin pigment, lysosome, most of rough endoplasmic reticulum, Golgi complexes, and nucleus in both cells.

Low-density-lipoprotein receptors in different rabbit liver cells.

Receptor-dependent uptake mechanisms for low-density lipoprotein (LDL) were studied in rabbit liver parenchymal and non-parenchymal cells. Hybridization studies with a cDNA probe revealed that mRNA for the apo (apolipoprotein) B,E receptor was present in endothelial and Kupffer cells as well as in parenchymal cells. By ligand-blotting experiments we showed that apo B,E-receptor protein was present in both parenchymal and non-parenchymal cells. Studies of binding of homologous LDL in cultured rabbit parenchymal cells suggested that about 63% of the specific LDL binding was mediated via the apo B,E receptor. Approx. 47% of the specific LDL binding was dependent on Ca2+, suggesting that specific Ca2+-dependent as well as Ca2+-independent LDL-binding sites exist in liver parenchymal cells. Methylated LDL bound to the parenchymal cells in a saturable manner. Taken together, our results showed that apo B,E receptors are present in rabbit liver endothelial and Kupffer cells as well as in the parenchymal cells, and that an additional saturable binding activity for LDL may exist on rabbit liver parenchymal cells. This binding activity was not inhibited by EGTA or reductive methylation of lysine residues in apo B. LDL degradation in parenchymal cells was mainly mediated via the apo B,E receptor.

Intracellular distribution of radiogold. Localization to large granule membranes.

The distribution of gold in Kupffer cells and in subcellular fractions of rat liver was studied at intervals following intraperitoneal injection of 195Au sodium thiomalate (Myochrysine). Kupffer cells, isolated by digestion of whole liver with Pronase, had radioactive gold counts per milligram of protein that were twice the counts in the digested liver supernatant. After fractionation of liver cells by differential centrifugation, radiogold was found predominantly in the nuclear, mitochondrial, and lysosomal fractions. When the distribution of isotope was related to the protein content, the highest gold concentration was found in the lysosomal fraction, where it was 28 times that in the soluble fraction. Most radiogold was nondialyzable, probably a result of binding to larger intracellular compounds. Approximately 95% of the nondialyzable gold was in the organelle membrane of attached to membrane-adsorbed material, as determined by treatment of dialyzed mitochondrial and lysosomal fractions with Triton X-100. These data suggest that the intracellular locus of gold action may reside in organelle membranes.