Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To elucidate the function of the reticuloendothelial system of liver in hepatic injury, we investigated the effect of endotoxins on superoxide anion (O-2) generating capacity and lysosomal enzyme activities of Kupffer cells isolated from rats treated with galactosamine (Gal N), with Gal N supplemented with polymyxin B (Polymyxin B-Gal N), with lipopolysaccharide (LPS) and from control rats. After collagenase digestion of the liver and centrifugation over metrizamide gradient, Kupffer cells were prepared by the dish adherence procedure. O-2 production by the cells was examined as chemiluminescence during phagocytosis of latex particles and beta-glucuronidase activities were analyzed. High titers of endotoxemia were detected in LPS and Gal N rats by limulus test, while a low endotoxemia titer was found in Polymyxin B-Gal N rats. Hepatocyte damage was found in Gal N rats, but little was recognized in LPS and Polymyxin B-Gal N rats. In the latter groups, Kupffer cells, activated by endotoxins, showed the enhancement of chemiluminescence and a release of lysosomal enzyme. Though lysosomal enzyme was released from Kupffer cells in Gal N rats, chemiluminescence was slightly suppressed in spite of the high titer of endotoxemia. These results appear to be related to the consumption of O-2 during liver injury. The functional state of Kupffer cells was thus changed by the grade of endotoxemia and hepatic injury.
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PMID:Superoxide anion generating capacity and lysosomal enzyme activities of Kupffer cells in galactosamine induced hepatitis. 301 77

Macrophages, which produce the collagenolytic enzyme collagenase, are commonly found at sites of connective tissue destruction in chronic inflammatory lesions. Since tissue macrophages are derived from circulating peripheral blood monocytes, we used these less-differentiated, more readily available cells to examine the production and regulation of collagenase. Human monocytes, isolated in large quantities by counterflow centrifugal elutriation, were shown to produce substantial amounts of collagenase when stimulated by concanavalin A (Con A) and to a lesser extent with lipopolysaccharide, while unstimulated monocyte cultures produced negligible collagenase. Collagenase was detected in the culture media within the first 24 hr of culture after activation with peak production at 48 hr. Analysis of the intracellular regulation of collagenase revealed that synthesis of this enzyme required a prostaglandin (PGE2)-dependent step since indomethacin-inhibited enzyme synthesis was reversed by PGE2. Additionally, dibutyryladenosine cyclic monophosphate (dBcAMP) restored collagenase synthesis in indomethacin-blocked cultures, indicating a PGE2-dependent generation of cAMP requirement for collagenase production similar to that demonstrated in experimental animals systems. In additional studies, anti-inflammatory drugs which are known to modulate connective tissue destruction were analyzed for their influence on monocyte-derived collagenase. Dexamethasone, colchicine or retinoic acid all inhibited collagenase synthesis by monocytes in a dose-dependent manner although the effect of these drugs on monocyte PGE2 synthesis differed. Dexamethasone inhibited PGE2 synthesis, which resulted in the suppression of collagenase. However, PGE2 production was unaffected by colchicine whereas retinoic acid caused a significant increase in PGE2 levels. Inhibition of collagenase synthesis by dexamethasone, but not colchicine or retinoic acid, could be reversed by PGE2 or phospholipase A2. These findings provide insight into the intracellular events regulating monocyte collagenase synthesis and also implicate monocytes as a target of anti-inflammatory agents which ameliorate connective tissue degradation associated with chronic inflammatory lesions.
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PMID:Regulation of human peripheral blood monocyte collagenase by prostaglandins and anti-inflammatory drugs. 303 63

Our previous work suggests that one mechanism through which connective tissue breakdown might occur in periodontal diseases is the production of metalloproteinases, including collagenase, by gingival fibroblasts. In this study we investigated whether highly purified preparations of lipopolysaccharide (LPS) and lipoteichoic acid (LTA) from a number of putative periodontal pathogens could induce monolayer cultures of human gingival fibroblasts to synthesize collagenase and prostaglandin E2. Using both biochemical assays and immunocytochemical techniques, we found that cells synthesized only very small amounts of collagenase in direct response to LPS or LTA (0.1 to 20.0 micrograms/ml). At the highest dose of both antigens, prostaglandin E2 production was increased. We then studied whether LPS and LTA could signal collagenase production by interacting primarily with a different cell type. Our results show that LPS and LTA were each able to stimulate cultures of human blood mononuclear cells (greater than 95% monocytes) to release collagenase-inducing cytokines. By indirect immunocytochemistry, we found that a large proportion of human gingival fibroblasts was activated to produce collagenase by supernatants from LPS- and LTA-stimulated mononuclear cells, whereas gingival fibroblasts cultured with supernatants from unstimulated mononuclear cells were not. Furthermore, in a population of activated fibroblasts we demonstrated, using a double-labeling technique, that some cells made collagenase and the specific tissue inhibitor of metalloproteinases (TIMP) simultaneously. As yet, the collagenase-inducing signals remain poorly characterized but the interleukins-1 and tumor necrosis factors seem likely candidates.
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PMID:Bacterial antigens induce collagenase and prostaglandin E2 synthesis in human gingival fibroblasts through a primary effect on circulating mononuclear cells. 304 May 90

Long-term (greater than 2 years) topical, conjunctival application of fluoresceinyl ovalbumin (FL-OA) induced allergic conjunctivitis-like lesions and hyperplasia of conjunctival-associated lymphoid tissue (CALT) in guinea pigs. Single-cell suspensions of CALT and spleen were prepared by collagenase digestion and cultured with or without FL-OA or lipopolysaccharide; the culture supernatants were assayed for IgG, IgA, IgM, and IgE antibody. Absolute values (ng Ab protein/ml) of anti-FL-OA IgG subclasses (IgG1 and IgG2) were measured using purified preparations of IgG1 and IgG2 anti-FL-OA antibody standards in an enzyme-linked immunosorbent assay. Immunohistochemical studies were performed using frozen sectioned CALT tissues as well as cultured single cells. IgG1, IgG2, IgA, IgM, but not IgE, anti-FL-OA antibodies were detected in the culture supernatants of both CALT and spleen. IgG- and IgA-secreting plasma cells were demonstrated in immunoperoxidase-stained CALT and single-cell cultures. The ratio of IgG1 to IgG2 isotypes produced by CALT in vitro was significantly higher than that produced by spleen and also that found in serum. These findings indicated that a site-specific regulation of antibody isotypes may exist within the hyperplastic CALT induced by the long-term topical exposure to FL-OA.
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PMID:Experimental allergic conjunctivitis: production of different isotypes of antibody by conjunctival-associated lymphoid tissue in culture. 327 15

Interleukin 1 (IL 1) is a polypeptide hormone produced by activated macrophages that affects many different cell types involved in immune and inflammatory responses. The cloning and expression of a murine IL 1 cDNA in Escherichia coli encoding a polypeptide precursor of 270 amino acids has been reported, and expression of the carboxy-terminal 156 amino acids of this precursor in E. coli yields biologically active IL 1. By using the murine IL 1 cDNA as a probe, we have isolated its human homolog from cDNA generated to lipopolysaccharide-stimulated human leukocyte mRNA. Nucleotide sequence analysis of this cDNA predicts a protein of analysis of this cDNA predicts a protein of 271 amino acids (termed IL 1 alpha) which shows congruent to 61% homology to its murine counterpart but only 27% homology to a recently characterized human IL 1 precursor (IL 1 beta). We have expressed the carboxy-terminal 154 amino acids of IL 1 alpha in E. coli, purified this protein to homogeneity, and have compared it with pure recombinant murine IL 1 in several different IL 1 assays based on murine and human cells. Recombinant IL 1 is capable of stimulating T cell and fibroblast proliferation and inducing fibroblast collagenase and prostaglandin production, thus proving that a single molecule has many of the activities previously ascribed to only partially purified IL 1 preparations. Our results indicate that there exists a family of at least two human IL 1 genes (alpha and beta) whose dissimilar protein products have similar biological activities.
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PMID:Recombinant human interleukin 1 alpha: purification and biological characterization. 348 52

Interleukin-1 (IL-1) is the major immunoregulatory molecule produced by macrophages in response to a variety of environmental insults including chemicals, phagocytosis, bacteria, and bacterial products. Macrophages stimulated by Borrelia burgdorferi produced large quantities of IL-1 when spirochetes were added to macrophages at a ratio of 10 spirochetes per macrophage. The release of IL-1 was dose dependent: a single spirochete per macrophage was sufficient to produce significant quantities of IL-1. Spirochetal lipopolysaccharide was not required for this activity in that polymyxin B in the spirochete-macrophage culture had no effect on IL-1 production. Normal murine fibroblasts cultured with this IL-1 were shown to have an increased rate of DNA synthesis and an increase in secreted collagenase. IL-1 was found in joint fluids from Lyme disease patients. When IL-1 was injected intradermally into the backs of rabbits, the injection sites became indurated, erythematous, and warm to the touch after 4 hrs and annular lesions much like those of erythema chronicum migrans were seen in some animals after 24 hrs. B. burgdorferi is a powerful inducer for IL-1 in vitro, and it is reasonable to presume that it acts similarly in Lyme disease patients. Our results suggest that IL-1 in turn, may play a role in many of the clinical manifestations of Lyme disease.
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PMID:A role for interleukin-1 in the pathogenesis of Lyme disease. 349 83

Hot phenol-water-extracted lipopolysaccharide (LPS) from Bacteroides gingivalis 381 was purified by Sephadex G-100 chromatography with Tris buffer supplemented with sodium deoxycholate and EDTA (B-LPS). In the present study, B-LPS was examined for its ability to induce interleukin 1 (IL-1) production, a mitogenic response, and macrophage activation in LPS high-responder C3H/HeN and low-responder C3H/HeJ mice. A significant increase in IL-1 production was observed in C3H/HeN and C3H/HeJ peritoneal macrophages treated with various doses (1.0 to 50 micrograms/ml) of B-LPS. IL-1 production by C3H/HeN macrophages treated with B-LPS (10 micrograms/ml) was about seven times greater than that by C3H/HeJ macrophages. However, the IL-1 production induced by B-LPS (10 micrograms/ml) in C3H/HeN macrophages was four times lower compared with that induced by Escherichia coli O111 B4 LPS. Also, a significant increase in IL-1 production was found in human monocytes stimulated with B-LPS. That B-LPS-induced IL-1 exhibits some molecular weight heterogeneity was indicated from Sephadex G-75 gel filtration profiles. A significant, high mitogenic response by whole spleen cells with 1 X 10(5) to 5 X 10(4) cells of either mouse strain per well treated with B-LPS (10 to 50 micrograms/ml) was observed. However, the response of C3H/HeJ mice was less than that of the C3H/HeN strain. Also, glucose consumption assays indicated that enhanced macrophage activation occurred in C3H/HeN but not in C3H/HeJ mice treated with B-LPS. In light of recent studies showing that IL-1 stimulates bone resorption in a mouse calvaria system and collagenase production in fibroblasts, we suggest that B-LPS-induced IL-1 may play a significant role in the pathogenesis of adult periodontal disease.
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PMID:Functional role of interleukin 1 in periodontal disease: induction of interleukin 1 production by Bacteroides gingivalis lipopolysaccharide in peritoneal macrophages from C3H/HeN and C3H/HeJ mice. 387 85

Recent evidence implicates Actinobacillus actinomycetemcomitans in the etiology of localized juvenile periodontitis. This paper reviews the morphological, biochemical and serological charcteristics of A. actinomycetemcomitans, evidence incriminating it as a periodontopathogen, its importance in human nonoral infections, and virulence factors which may be involved in the pathogenesis of A. actinomycetemcomitans infections. A. actinomycetemcomitans is a non-motile, gram-negative, capnophilic, fermentative coccobacillus which closely resembles several Haemophilus species but which does not require X or V growth factors. The organism has been categorized into 10 biotypes based on the variable fermentation of dextrin, maltose, mannitol, and xylose and into 3 serotypes on the basis of heat stable, cell surface antigens. A. actinomycetemcomitans' primary human ecologic niche is the oral cavity. It is found in dental plaque, in periodontal pockets, and buccal mucosa in up to 36% of the normal population. The organism can apparently seed from these sites to cause severe infections throughout the human body such as brain abscesses and endocarditis. There is a large body of evidence which implicates A. actinomycetemcomitans as an important micro-organism in the etiology of localized juvenile periodontitis including: (1) an increased prevalence of the organism in almost all localized juvenile periodontitis patients and their families compared to other patient groups; (2) the observation that localized juvenile periodontitis patients exhibit elevated antibody levels to A. actinomycetemcomitans in serum, saliva and gingival crevicular fluid; (3) the finding that localized juvenile periodontitis can be successfully treated by eliminating A. actinomycetemcomitans from periodontal pockets; (4) histopathologic investigations showing that A. actinomycetemcomitans invades the gingival connective tissue in localized juvenile periodontitis lesions; (5) the demonstration of several pathogenic products from A. actinomycetemcomitans including factors which may: (a) facilitate its adherence to mucosal surfaces such as capsular polysaccharides; (b) inhibit host defense mechanisms including leukotoxin, a polymorphonuclear leukocyte chemotaxis inhibiting factor, and a lymphocyte suppressing factor (c) cause tissue destruction such as lipopolysaccharide endotoxin, a bone resorption-inducing toxin, acid and alkaline phosphatases, collagenase, a fibroblast inhibiting factor and an epitheliotoxin.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Actinobacillus actinomycetemcomitans in human periodontal disease. 388 66

Although some data suggest that macrophages in the reticuloendothelial system (RES) are important sources of thromboxane A2 (TxA2) and prostacyclin (PGI2) during endotoxic shock, we are unaware of data documenting the ability of hepatic macrophages (Kupffer cells) to release either TxA2 or PGI2 when exposed to lipopolysaccharide (endotoxin, LPS). In this study, Kupffer cells were examined for their ability to release prostaglandin E2 (PGE2), TxA2, and PGI2 following stimulation with 0, 1.0, 50.0, and 100.0 micrograms/ml of Escherichia coli LPS. Kupffer cells were obtained from rat livers by enzymatic digestion with 0.05% collagenase followed by enrichment of the macrophage population on the basis of differences in density and adherence among the various cell populations isolated. Based on several criteria (phagocytosis of opsonized sheep erythrocytes, positive staining for esterase and peroxidase, failure to replicate), 95% of adherent cells were Kupffer cells. After 4 days of incubation, cells were stimulated with various doses of LPS for 4 and 8 hr. Prostanoid concentrations in culture supernatants were determined by radioimmunoassay. Increasing doses of LPS significantly (P less than 0.001) increased the concentration of immunoreactive PGE2 (iPGE2) and iTxB2 (the stable metabolite of TxA2). The concentration of i6-keto-PFG1 alpha (stable metabolite of PGI2) increased following stimulation with 1.0 microgram/ml of LPS, but declined as the dose of LPS was increased. The results provide evidence that endotoxin-activated Kupffer cells, like other macrophage populations, release several metabolites of arachidonic acid. Kupffer cell-derived prostanoids, particularly TxA2, may be important mediators of some of the pathophysiologic manifestations of acute endotoxemia.
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PMID:Prostanoid production by lipopolysaccharide-stimulated Kupffer cells. 388 37

Peritoneal exudate macrophages, when exposed to bacterial lipopolysaccharide in culture, were found to produce collagenase (EC 3.4.24.3). This enzyme was not detected in extracts of the macrophages or in media from nonstimulated macrophage cultures. Lipidcontaining fractions of the lipopolysaccharide, including a glycolipid from the rough mutant of Salmonella minnesota (R595) and lipid A, were potent stimulators of collagenase production. The lipid-free polysaccharide fraction had no effect. Cycloheximide prevented the production of collagenase by endotoxin-treated macrophages, suggesting that it was newly synthesized.
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PMID:Collagenase production by endotoxin-activated macrophages. 437 28


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