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)

Collagenase was identified within naturally occurring rat chronic otitis media by the use of an immunohistochemical technique with peroxidase-antiperoxidase to stain the paraffin. Collagenase was found in fibroblasts, mononuclear cells, and osteoclast cells in the bone-resorbing area. Collagenase was found only in fibroblasts in contact with epithelial basal cells. Macrophages from rat peritoneum were cultured with different concentrations of a lipopolysaccharide. The prostaglandin E2 level reached a maximum during the 12- to 24-hour period in the presence of endotoxin. This prostaglandin E2 was confirmed by immunofluorescent staining. The endotoxin-activated macrophage produced an insignificant amount of collagenase. These findings suggest that activated macrophages may be able to stimulate fibroblast collagenase production through the chemical mediator prostaglandin E2. Also, the interaction between fibroblasts and epidermal cells appears to encourage and enhance the biochemical events resulting in bone resorption in chronic otitis media.
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PMID:Bone resorption factors in chronic otitis media. 608 44

The production of collagenase by lipopolysaccharide-(LPS) activated guinea pig macrophages is mediated by prostaglandins (PG) of the E series. After stimulation of guinea pig macrophages with LPS, extracellular PGE levels and cellular cAMP levels are elevated. Indomethacin inhibits not only PG synthesis, but also cAMP and collagenase production in LPS-stimulated macrophage cultures. In these indomethacin-inhibited cultures containing LPS, dibutyryl (dB) cAMP, or cholera toxin can restore macrophage collagenase production but not PG synthesis. Moreover, dBcAMP and cholera toxin enhance collagenase production in LPS-activated cultures. Initial activation of the macrophages by an agent such as LPS is a prerequisite for synthesis of collagenase, since in the absence of LPS, dBcAMP or cholera toxin alone are ineffective stimuli. These findings clearly demonstrate a role for PG-induced elevations of cAMP in the production of collagenase by LPS-activated macrophages.
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PMID:Mediation of macrophage collagenase production by 3'-5' cyclic adenosine monophosphate. 624 42

Kupffer cells exposed to bacterial lipopolysaccharide in vitro synthesized collagenase and released the major portion of it into the extracellular space while the intracellular level of enzyme was not altered significantly. Cycloheximide prevented the appearance of collagenase in the medium indicating de novo synthesis. Indomethacin, an inhibitor of cyclooxygenase, also blocked collagenase synthesis. In line with this observation. Kupffer cells were found to synthesize substantial amounts of prostaglandin E2 when exposed to lipopolysaccharide; concomitantly, cellular cAMP levels were increased. Indomethacin was shown to abolish the stimulated cAMP formation. Addition to the culture medium of cAMP or dibutyryladenosine 3', 5'-monophosphate as well as of prostaglandin E2 or, to a lesser extent, prostaglandin E1 allowed indomethacin-inhibited cells to resume the production of collagenase. It is proposed that in rat Kupffer cells lipopolysaccharide-elicited collagenase synthesis and excretion is mediated sequentially by stimulated production of prostaglandin E2, enhanced adenylate cyclase activity and increased intracellular cAMP levels.
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PMID:Involvement of prostaglandin E and adenosine 3', 5'-monophosphate in lipopolysaccharide-stimulated collagenase release by rat Kupffer cells. 628 7

We have compared two components of bacterial cell walls, muramyl dipeptide (MDP) and lipopolysaccharide (LPS), for their effects on bone resorption as measured by the release of previously incorporated 45Ca. MDP is the smallest active component of peptidoglycan, whereas LPS is the active component of endotoxin. Fetal rat long bones were cultured for 5 days in a chemically defined medium supplemented with bovine serum albumin (BSA) or serum. LPS increased 45Ca release at concentrations of 0.03-1.0 microgram/ml. LPS further purified by electrolytic dialysis (ED-LPS) was active at 0.01 microgram/ml. ED-LPS was ineffective at such low concentrations in the presence of serum. The response to MDP was more variable than that to LPS, but bone resorption was stimulated at concentrations of 10(-7)-10(-5) M. MDP was less effective or inactive in medium supplemented with serum. Stereoisomers of MDP that do not have adjuvant activity caused minimal stimulation of bone resorption, whereas 6-0-steroyl MDP stimulated resorption at 10(-8) M. The stimulation of bone resorption by LPS and MDP was not inhibited by indomethacin. Both LPS and MDP increased lysosomal enzyme release in proportion to their effects on 45Ca release. LPS also markedly increased collagenase activity in the medium, but MDP did not. These results indicate that chemically different products of bacterial cell walls can stimulate bone resorption in vitro. These products may be distinguished by differences in dose response curve, serum inhibition, and collagenase release.
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PMID:Effects of two bacterial products, muramyl dipeptide and endotoxin, on bone resorption in organ culture. 629 30

The binding of prostaglandin E2 (PGE2) to bone cells was studied to provide direct evidence for the existence of specific receptors in bone. Bone cells were isolated by collagenase digestion of fetal and newborn rat calvaria. Isolated cells were incubated with 3H-PGE2 and collected on Millipore filters. Specific binding was determined by subtracting the binding that occurred with 10(-6) M non-radioactive PGE2 and 3H-PGE2 from that with 3H-PGE2 alone. With heterogeneous cell preparations and at PGE2 concentrations from 10(-9) - 1.7 X 10(-8) M at 37 degrees C, specific binding reached steady state within 10 min. Bound 3H-PGE2 was displaced by the addition of increasing amounts of unlabeled PGE2. Inhibition of PGE2 binding was observed with PGE1 and the endoperoxide analog, U44069, but not with PGF2 alpha, a lipopolysaccharide, or 13,14-dihydro 15-keto PGE2. Studies with bone cell populations, obtained by sequential digestions, indicated that an osteoclastic population binds 30-fold more PGE2 than osteoblastic cells. Scatchard analyses revealed that the osteoclastic cells have an affinity constant for PGE2 binding similar to that obtained with heterogeneous populations. However, the PGE2 binding capacity in this osteoclastic population was fivefold greater than in the heterogeneous population. The osteoclastic population responded with an increase in cyclic AMP to lower concentrations of PGE2 than the osteoblastic populations. These studies suggest that differences in the binding capacity of PGE2 receptors exist among bone cell-types and that these differences are reflected in the cellular cyclic AMP response.
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PMID:Prostaglandin E2 binding and cyclic AMP production in isolated bone cells. 630 30

Previous studies have demonstrated that exposure of guinea pig macrophages to a primary signal, such as lipopolysaccharide (LPS), stimulates the synthesis of prostaglandin E2 (PGE2) which, in turn, elevates cAMP levels resulting in the production of the enzyme, collagenase. The potential of regulating the biochemical events in this activation sequence was examined with the anti-inflammatory agents dexamethasone and colchicine, which suppress the destructive sequelae in chronic inflammatory lesions associated with the degradation of connective tissue. The addition of dexamethasone with LPS to macrophage cultures resulted in a dose-dependent inhibition of PGE2 and collagenase production, which was reversed by the exogenous addition of phospholipase A2. Collagenase production was also restored in dexamethasone-treated cultures by the addition of products normally produced as a result of phospholipase action, such as arachidonic acid, PGE2 or dibutyryl-cAMP. Since the effect of dexamethasone was thus linked to phospholipase A2 inhibition, mepacrine, a phospholipase inhibitor, was also tested. Mepacrine, like dexamethasone, caused a dose-dependent inhibition of PGE2 and collagenase. In addition to corticosteroid inhibition, colchicine was also found to block collagenase production. However, this anti-inflammatory agent had no effect on PGE2 synthesis. Colchicine was effective only when added at the onset of culture and not 24 h later, implicating a role for microtubules in the transmission of the activation signal rather than enzyme secretion. The failure of lumicolchicine to inhibit collagenase activity provided additional evidence that microtubules are involved in the activation of macrophages. These findings demonstrate that dexamethasone and colchicine act at specific steps in the activation sequence of guinea pig macrophages to regulate collagenase production.
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PMID:Regulation of guinea pig macrophage collagenase production by dexamethasone and colchicine. 632 92

Surface markers of human gingival fibroblasts in vitro were investigated using monoclonal and heterologous antisera against a range of cell surface antigens, together with rosetting techniques to characterize surface receptors for IgG and C3. WI-38 fibroblasts and human peripheral blood monocytes were used as control cells. Human gingival fibroblasts exhibited complement receptors and beta2-microglobulin, as did WI-38 cells. Ten per cent of the human gingival fibroblasts were positive for HLA-DR antigens and additionally exhibited a granulocyte antigen not apparent on WI-38 cells. Monolayers of the gingival fibroblasts were further exposed for short periods to varying concentrations of enzymes (trypsin, collagenase and neuraminidase), bacterial extracts (lipopolysaccharide and lipoteichoic acid) and crude supra- and subgingival plaque sonicates. Surface-marker analysis was then carried out. The most noticeable effects were obtained with Vibrio cholerae neuraminidase which enhanced C3 receptor and surface antigen expression, and supragingival plaque sonicate which depressed the expression of HLA-DR and granulocyte antigens while not affecting beta2-microglobulin expression. Trypsin reduced antigen expression to a degree, but its effects were mainly on cell adherence.
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PMID:Surface markers of human gingival fibroblasts in vitro. Characterization and modulation by enzymes and bacterial products. 633 Mar 32

The cellular localization of indoleamine 2,3-dioxygenase was studied in the mouse lung after induction by lipopolysaccharide treatment. No significant indoleamine 2,3-dioxygenase activity was detected in alveolar macrophages and type II epithelial cells, which were recovered by alveolar lavages and trypsin-treatment, respectively. To determine this enzyme activity in other types of lung cells, we prepared monodispersed lung cells (6.5 X 10(7) cells/lung) by incubation with 0.1% collagenase and 0.1% trypsin. In a Percoll isopycnic gradient, the dispersed cells were distributed with two peaks at the densities of 1.040 and 1.080 g/ml. The enzyme activity was recovered exclusively in the lighter fractions. As examined by electron microscopy or more quantitatively by using various marker enzyme activities, endothelial cells (angiotensin-converting enzyme as a marker enzyme of these cells), alveolar interstitial cells (prostaglandin dehydrogenase), type I epithelial cells, type II epithelial cells, alveolar macrophages (beta-glucuronidase), Clara cells (coumarin hydroxylase), and polymorphonuclear leucocytes (arylsulfatase) were distributed with peaks at the densities of 1.033, 1.040, 1.042, 1.045, 1.070, 1.082, and 1.093 g/ml, respectively. The distribution pattern of the indoleamine 2,3-dioxygenase activity exactly coincided with that of alveolar interstitial cells. The localization of this enzyme in alveolar interstitial cells was immunohistochemically confirmed with the anti-indoleamine 2,3-dioxygenase antibody.
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PMID:Induction of indoleamine 2,3-dioxygenase in alveolar interstitial cells of mouse lung by bacterial lipopolysaccharide. 634 79

We investigated whether stromelysin activity in the medium of canine articular cartilage explants is associated with proteoglycan degradation in these explants. Cartilage explants were treated with recombinant human interleukin 1 alpha (rh-IL-1 alpha), lipopolysaccharide, or canine monocyte-conditioned medium. Proteoglycan synthesis and degradation were measured. Metalloproteinase activity (inhibitable by tissue inhibitor of metalloproteinase 2) in the culture medium was measured by use of fluorimetry with a quenched fluorescent substrate. Western blots of the medium were probed with polyclonal antibodies to human stromelysin, collagenase, and gelatinase. Neither metalloproteinase activity nor proteoglycan degradation were inducible in canine cartilage explants treated with rh-IL-1 alpha. However, proteoglycan synthesis was significantly (P < 0.05) decreased by concentrations of 10 and 100 ng of rh-IL-1 alpha/ml. Metalloproteinase activity in the medium accompanied proteoglycan degradation of cartilage treated with lipopolysaccharide and monocyte-conditioned medium. The metalloproteinase released into the medium was identified as prostromelysin by results of western blotting.
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PMID:Effects of stromelysin activity on proteoglycan degradation of canine articular cartilage explants. 748 6

Nitric oxide (NO) is a messenger molecule that is produced from L-arginine by NO synthase (NOS). Some NOS isoforms are present in cells constitutively, whereas others can be induced by cytokines. Recent evidence suggests that NO inhibits intracellular pH regulation by the vacuolar H(+)-adenosinetriphosphatase (ATPase) in macrophages, which contain an inducible form of NOS. The vacuolar H(+)-ATPase is involved in proton secretion in intercalated cells in the collecting duct. We have therefore examined the effect of NO on bafilomycin-sensitive H(+)-ATPase activity in individual cortical collecting ducts (CCD) microdissected from collagenase-treated kidneys of normal rats using a fluorometric microassay. Incubation of CCD with the NO donors, sodium nitroprusside (0.1 and 1 mM) or 3-morpholino-sydnonimine hydrochloride (SIN-1, 30 microM), caused a dose-dependent decrease in H(+)-ATPase activity. Incubation of CCD with lipopolysaccharide (LPS) and interferon-gamma, which induces NOS in macrophages, decreased H(+)-ATPase activity by 85%. This effect was prevented by simultaneous incubation with N omega-nitro-L-arginine, a competitive inhibitor of NOS, indicating that the decrease in H(+)-ATPase activity was caused by NO production. Incubation with 8-bromo-guanosine 3',5'-cyclic monophosphate (cGMP) also inhibited H(+)-ATPase activity, suggesting that NO may exert its effect in the CCD via activation of guanylyl cyclase and production of cGMP. Immunohistochemistry using antibodies to the macrophage-type NOS revealed strong labeling of intercalated cells in the CCD, confirming the presence of NOS in these cells.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Nitric oxide inhibits bafilomycin-sensitive H(+)-ATPase activity in rat cortical collecting duct. 752 55


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