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Query: UNIPROT:P43026 (lipopolysaccharide)
 62,215 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Chemotactic peptides in the circulation stimulate neutrophils to become sequestered in the pulmonary vasculature, and low concentrations of bacterial lipopolysaccharide (LPS) enhance and prolong this effect. This interaction of neutrophils with the vascular endothelium is thought to involve, in part, the increase in adhesiveness induced in neutrophils by such stimuli. In this study, the binding of albumin-coated latex beads to neutrophils was used to determine whether the enhancement seen with LPS results from an increase in the number of adhesive cells, from the enhancement of the adhesiveness of individual neutrophils, or both. Chemotactic peptides alone and LPS alone induced an increase both in the adhesive population and in the number of beads bound per individual neutrophil. The number of beads bound per cell increased over a very wide range of stimulus concentrations, showing that the degree of adhesiveness of an individual cell in the population varies over a considerable range. Trace concentrations of LPS (10 ng/ml or less), i.e., levels close to those measurable in vivo, had little effect on the proportion of neutrophils that were stimulated by chemotactic factor to become adhesive but did significantly enhance the number of beads bound to each individual neutrophil. The enhancement may require the presence of the CD11/18 glycoprotein complex, but was not further upregulated by LPS. No evidence could be obtained to suggest that the effect of LPS involved release of tumor necrosis factor (TNF) from the numbers of monocytes in the preparation, and the observations are consistent with a direct effect of LPS on the neutrophils. It is suggested that this increase in adhesive sites on the cell could explain the persistence of the sequestration of neutrophils in the microvasculature seen in the presence of both chemoattractants and LPS by enhancing the "strength" of the adhesion to endothelial cells. The increased adhesion may also set the stage for enhanced endothelial injury.
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PMID:Interaction between chemoattractants and bacterial lipopolysaccharide in the induction and enhancement of neutrophil adhesion. 218 56

When the endotoxin-lipopolysaccharide (LPS) derived from the cell wall of gram-negative bacteria is given to the rat in vivo, there are prompt, marked decreases in glomerular filtration rate (GFR), renal blood flow (RBF) and % Na+ reabsorption (%T-Na+). However, it has not been determined whether the endotoxin itself has a direct effect on these renal functions. To test whether endotoxin has a direct renal effect, isolated rat kidneys (N = 8) were perfused for 160 minutes with a Krebs-Ringer-HCO3- solution containing substrate-free albumin (40 g/liter), glucose (5 mM) and L(+) lactate (7.5 mM). After control observations (20 to 80 min) were made, purified LPS from E. coli was added (N = 4) to the perfusate to achieve [endotoxin] of 0.01 micrograms/ml (80 to 120 min) and 0.1 micrograms/ml (120 to 160 min). Endotoxin had no effect on GFR, Na+ reabsorption or tissue K+ content when compared to timed-control perfusions (N = 4). There was a small (approximately 10%) but significant decrease in mean perfusion flow rate (PFR) at the highest [endotoxin] when compared to the low [endotoxin]p but no change in GFR occurred. When the same LPS was given to four rats in vivo at a dose which achieved an [endotoxin] of approximately 0.08 micrograms/ml plasma, there were prompt decreases in GFR and %T-Na+ and an increase in body temperature when compared with timed-controls; there also was a large loss of K+ from the kidney tissue.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Direct effects of endotoxin on the function of the isolated perfused rat kidney. 234 20

Diseases and losses were registered in dependence on vitamin A supply with 2,035 pigs (6.5-114 kg live weight). The histologic examinations comprised various organs of 72 animals. The content of the main protein fractions as well as antibody titre after supplementing antigenes were determined in the serum of 104 animals. The feeding of a vitamin-A- and carotinefree casein-starch-respectively a Vitamin-A-free cereal-soybeanmeal-diet led to deficiency symptoms after 7-8 respectively 16-19 weeks of experiment particularly in the shape of nervous disturbances and voice affectations. Histologically a hyperplasia and a metaplasia of the epithelium of the big ducts in the salivory gland could be proved. The repletion of a part of the avitaminotic animals by means of oral (500 I.U./kg feed) and parenteral (500,000 to 1,000,000 I.U. i.m.) vitamin A administration is proof of a lack of vitamin A. Vitamin A and provitamin dosage did not influence diseases and losses with the exception of the occurrence of deficiency symptoms. The protein content of the serum as well as that of the globulin fractions alpha, beta, gamma did not change, the albumin content was lower in the groups without vitamin A (p greater than 0.05). Antibody titre against the lipopolysaccharide of salmonella dublin and human gamma globulin were diminished in piglets and fattening pigs fed vitamin A free (p less than 0.05). Taking the criterion of animal health, a vitamin A requirement higher than for growth (250 I.U./kg feed) cannot be derived.
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PMID:[Vitamin A requirements of growing swine. 3. Effect of vitamin A supply on the state of health of piglets and fattening swine]. 240 96

Serum amyloid A (SAA) is a plasma apolipoprotein produced by the liver in response to inflammatory stimuli. The murine SAA gene family is made up of three genes, SAA1, SAA2, and SAA3, plus a pseudogene. The SAA1 and SAA2 genes are highly homologous while the SAA3 gene has diverged substantially from the other two genes. Using small fragments from the cloned genes, we have analyzed the expression of each gene in the SAA family. Within 12 h after endotoxin administration, total liver SAA mRNA increases by 2000-fold, reaching approximately 20,000 transcripts/cell. Each gene accounts for approximately one-third of total SAA mRNA transcripts at this time. The increase is specific, since the levels of the mRNAs encoding albumin and apolipoprotein A-I in liver decrease 2-fold by 24 h. This correlates with a 2-fold decrease of the serum concentrations of these two proteins as well as their in vitro protein synthesis in primary hepatocytes. SAA1+2 mRNAs maintain their maximum levels until 36 h after lipopolysaccharide administration, while SAA3 mRNA is degraded to 20% its maximal level. As assayed by in vitro transcription in isolated hepatocyte nuclei, total SAA gene transcription increases at least 300-fold during the inflammatory response. The transcription rates of the individual SAA genes are similar during the initial stages of this response, reaching peak levels at 3 h. A comparison of the rates of SAA gene transcription and SAA mRNA accumulation suggests that SAA mRNA levels are regulated during the acute phase response by increased transcription and mRNA stabilization.
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PMID:Transcriptional regulation of serum amyloid A gene expression. 242 96

Human hepatoma (HepG2) cells respond to unfractionated conditioned media of human squamous carcinoma (COLO-16) cells and lipopolysaccharide-stimulated human peripheral blood monocytes by increasing the synthesis of alpha 1-acid glycoprotein, haptoglobin, complement C3, alpha 1-antichymotrypsin, alpha 1-antitrypsin, and fibrinogen, while decreasing the synthesis of albumin. The regulation of the acute phase proteins is mediated by hepatocyte-stimulating factors (HSF) and interleukin 1 (IL-1) present in the conditioned medium. Purified HSF-I from COLO-16 cells stimulates preferentially alpha 1-acid glycoprotein synthesis, whereas COLO-HSF-II stimulates preferentially the synthesis of haptoglobin, fibrinogen, and alpha 1-antitrypsin. HSF from monocytes, which has been identified as interferon-beta 2 (B cell stimulating factor-2), displayed the same activity as COLO-HSF-II. Dexamethasone alone had no effect on acute phase plasma protein synthesis but enhanced the response to various HSF severalfold. IL-1 had a relatively low stimulatory activity on the synthesis of alpha 1-acid glycoprotein, haptoglobin, and alpha 1-antichymotrypsin but strongly reduced the basal expression of fibrinogen. The only synergistic action between IL-1 and HSF (or interferon-beta 2) was noted for the synthesis of alpha 1-acid glycoprotein. Tumor necrosis factor active on other hepatic cells failed to modulate significantly the expression of any plasma proteins in HepG2 cells. These studies showed that for an optimal HepG2-cell response a combination of HSF (or interferon-beta 2), IL-1, and dexamethasone is needed. This finding might indicate the identity of some of those hormones involved in regulation of the hepatic acute phase response in vivo.
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PMID:Interaction among hepatocyte-stimulating factors, interleukin 1, and glucocorticoids for regulation of acute phase plasma proteins in human hepatoma (HepG2) cells. 244 59

Primary cultured rat Kupffer cells stimulated with lipopolysaccharide (LPS) produced a hepatocyte stimulating factor (HSF), which enhanced the synthesis of acute phase protein, alpha 2-macroglobulin (alpha 2M), in adult rat hepatocytes. The Kupffer cell derived-HSF (KC-HSF), enhanced the synthesis of alpha 2M over 100 fold by primary cultured adult rat hepatocytes, in the presence of dexamethasone (Dex). The synthesis of albumin was not stimulated by the factor, even in the presence of Dex. The alpha 2M mRNA increased exponentially starting at 3 hr after addition of the factor. Therefore, the synthesis of alpha 2M stimulated by KC-HSF is probably controlled at the pretranslational phase. The LPS stimulated production of the KC-HSF was inhibited by actinomycin D. The HSF was precipitated between 35% and 65% saturation with ammonium sulfate and collected in the over 30,000 daltons fraction, by molecular sieving. Sephacryl S-200 gel chromatography revealed two distinct forms of HSF with apparent molecular weights of approximately 30,000 and 100,000 daltons. The majority of the activity was recovered in the latter fraction. Isoelectric chromatofocusing of the 100,000 daltons form of HSF yielded a single peak of activity with an apparent isoelectric point (pI) of 4.2. Each fraction contained the interleukin-1 (IL-1) activity, determined by thymocyte proliferation assay. These results show that Kupffer cells produce a cytokine, KC-HSF with IL-1 activity but different properties, as seen on the on Sephacryl S-200 gel filtration and isoelectrofocusing from known mouse or human IL-1.
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PMID:Production of hepatocyte stimulating factor of rat Kupffer cells induced by lipopolysaccharide: partial characterization and effects on alpha 2 macroglobulin gene expression in cultured adult rat hepatocytes. 245 91

We defined the acute phase behaviour of a number of rabbit plasma proteins in studies (in vivo) and studied the effects of monokine preparations on their synthesis by rabbit primary hepatocyte cultures. Following turpentine injection, increased serum levels of C-reactive protein, serum amyloid A protein, haptoglobin, ceruloplasmin, and decreased concentrations of albumin were observed. In contrast to what is observed in man, concentrations of alpha 2-macroglobulin and transferrin were increased. Co-culture of primary hepatocyte cultures with lipopolysaccharide-activated human peripheral blood monocytes or incubation with conditioned medium prepared from lipopolysaccharide-activated human or rabbit monocytes resulted in dose-dependent induction of serum amyloid A, haptoglobin, ceruloplasmin and transferrin and depression of albumin synthesis, while C-reactive protein synthesis and mRNA levels remained unchanged. A variety of interleukin-1 preparations induced dose-dependent increases in the synthesis and secretion of serum amyloid A, haptoglobin, ceruloplasmin and transferrin and decreased albumin synthesis. Human recombinant tumour necrosis factor (cachectin) induced a dose-dependent increase in synthesis of haptoglobin and ceruloplasmin. In general, human interleukin-1 was more potent than mouse interleukin-1 and tumour necrosis factor. None of the monokines we studied had an effect on C-reactive protein synthesis or mRNA levels. These data confirm that C-reactive protein, serum amyloid A, haptoglobin and ceruloplasmin display acute phase behaviour in the rabbit, and demonstrate that, in contrast to their behaviour in man, alpha 2M and transferrin are positive acute phase proteins in this species. While both interleukin-1 and tumour necrosis factor regulate biosynthesis of a number of these acute phase proteins in rabbit primary hepatocyte cultures, neither of these monokines induced C-reactive protein synthesis. Comparison of these findings with those in human hepatoma cell lines, in which interleukin-1 does not induce serum amyloid A synthesis, suggests that the effect of interleukin-1 on serum amyloid A synthesis may be indirect.
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PMID:Regulation of rabbit acute phase protein biosynthesis by monokines. 246 85

The purpose of this study was to examine the effect of lithium chloride (LiCl) on human monocytes. Patients undergoing lithium therapy have elevated white blood cell counts. Since both tumor necrosis factor alpha (TNF alpha) and interleukin 1 (IL-1), which are secreted by monocytes, can stimulate endothelial cells to produce granulocyte-macrophage colony-stimulating factor (GM-CSF), we determined whether lithium-stimulated monocytes produced TNF alpha and/or IL-1. Normal human monocytes were incubated for 24 h with medium (negative control), lipopolysaccharide (positive control), or LiCl (0.05-50 mM). The supernatants were removed and assayed for IL-1 and TNF alpha secretion using the D10.G4.01 and L929 assays, respectively. Lithium did not stimulate IL-1 secretion but did stimulate TNF alpha secretion (5-10 U/ml of TNF alpha per 2 x 10(5) monocytes). The increased secretion of TNF alpha was associated with a fourfold increase in TNF alpha mRNA. TNF alpha activity in the supernatants was neutralized by a monoclonal antibody against human TNF alpha but not by antibody against human albumin. Other alkali metals such as rubidium and cesium did not stimulate monocytes to secrete TNF alpha. These data indicate that one mechanism by which Li may cause granulocytosis is through a transcriptional enhancement of TNF production and subsequent secretion by monocytes.
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PMID:Lithium chloride stimulates human monocytes to secrete tumor necrosis factor/cachectin. 255 37

Cytokines released from monocytes upon stimulation by lipopolysaccharide cause a number of cells to undergo proliferative and synthetic changes. At least one of these cytokines affects hepatocytes in vivo causing increased synthesis of a series of acute-phase proteins. We have established an in vitro micro-assay for hepatocyte stimulating factor (HSF) using primary cultures of normal rat hepatocytes. Measurement of increased synthesis of alpha 2-macroglobulin and decreased synthesis of albumin caused by exogenously added factor constitute a sensitive parameter for quantifying HSF. For comparing various cytokines preparations, we have defined a unit of HSF activity in terms of a stimulation index. We have used this assay to follow some preliminary attempts to isolate the factors responsible for stimulation of synthesis of acute-phase reactant by the liver.
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PMID:A simple bioassay for monocyte-derived hepatocyte stimulating factor: increased synthesis of alpha 2-macroglobulin and reduced synthesis of albumin by cultured rat hepatocytes. 257 59

Production of fibronectin (Fn) and prostaglandin E2 (PGE2) by human alveolar macrophages (AM) which were obtained by bronchoalveolar lavage was studied in vitro. AM obtained from patients with idiopathic interstitial pneumonia (IIP) produced much more Fn than those from normal volunteers but produced less amounts of PGE2. We also tested the effect of lipopolysaccharide (LPS), phorbol 12-myristate 13-acetate (PMA), zymosan and albumin-anti albumin complex (alb-anti alb) on production of Fn and PGE2 from AM. LPS, PMA and zymosan suppressed Fn production but stimulated PGE2 production by AM from patients with IIP but indomethacin reversed the suppressive effect of LPS, PMA and zymosan on Fn production. On the contrary, alb-anti alb stimulated Fn production by AM. Furthermore, exogenous PGE2 suppressed Fn production by AM from patients with IIP in a dose-dependent manner. These data suggest that Fn production by AM may be changed by different stimuli or different states of disease, and there is close relationship between the production of Fn and PGE2 by AM.
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PMID:[Production of fibronectin and PGE2 by cultured human alveolar macrophages]. 262 10


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