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)

Sodding of vascular grafts involves coating the biomaterial with cells prepared from collagenase-digested fat tissue after removal of the adipocytes by centrifugation. The goal of this study was to investigate the staining characteristics of the sodding cells as well as their ability to express the procoagulant protein tissue factor, and to compare these findings to those found with extensively purified microvascular endothelial cells (MEC) prepared from similar tissue. Sodding cells and MEC, isolated using immunomagnetic separation with anti-PECAM antibodies, were prepared from liposuction material and endothelial-specific staining was compared. The expression of tissue factor on these cells was examined using both an ELISA and a chromogenic assay to assess the rate of generation of factor Xa. Sodding cells expressed significantly more tissue factor than the unstimulated MEC in which the expression was undetectable (sodding cells 2466 +/- 830 pg/mL, P < 0.05). There was no further increase in tissue factor expression in the sodding cells with stimulation with lipopolysaccharide (LPS); however, purified MEC expressed significantly more tissue factor after exposure to LPS (1247 +/- 356 pg/mL, P < 0.05). These results were confirmed by the determination of procoagulant activity of the cells whereby the procoagulant activity on unstimulated MEC was significantly less than that found after stimulation of these cells, and it was also less than stimulated and unstimulated sodding cells (absorbance at 405 nm: 0.423 +/- 0.125, unstimulated MEC; 1.000 +/- 0.438, stimulated MEC; 1.129 +/- 0.396, unstimulated sodding cells; 1.171 +/- 0.254, stimulated sodding cells, P < 0.05). Staining of these two cells types also demonstrated significant uptake of acetylated LDL (Ac-LDL) in the purified MEC which was essentially absent in the sodding cells. Further, vWf staining was found to a greater degree in the purified MEC than in the sodding cells. These experiments demonstrated that the cells prepared for cell sodding express large amounts of tissue factor. The sodding cells do not stain for antigens known to be specific for endothelial cells, whereas MEC do and therefore the concentration of endothelial cells in the sodding cells is small. The significance of the tissue factor expression on the surface of sodded grafts is not yet known.
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PMID:Tissue factor expression by cells used for sodding of prosthetic vascular grafts. 934 10

Activated hepatic stellate cells (HSC) participate in matrix remodeling and deposition in liver fibrosis. The present study demonstrates that interleukin (IL)-10 is expressed by HSC upon activation in vitro or in vivo and that autocrine effects of this cytokine include inhibition of collagen production. Culture activation of HSC caused a distinct increase in IL-10 mRNA level compared with freshly isolated quiescent HSC. Treatment of cultured HSC with tumor necrosis factor-alpha, transforming growth factor-beta, or lipopolysaccharide further increased IL-10 mRNA by 2-fold and resulted in the release of IL-10 protein into the medium. HSC isolated from rats after bile duct ligation (BDL) showed prominent increases in IL-10 mRNA (x 100) and protein (x 30) levels at 7 days after BDL, but such induction disappeared in advanced liver fibrosis (19 days after BDL). IL-10 expression correlated positively with mRNA expression of interstitial collagenase and inversely with that of alpha1(I) collagen. Addition of anti-IL-10 IgG to cultured HSC caused enhanced collagen production under a basal or stimulated condition with TGF-beta, tumor necrosis factor-alpha, or lipopolysaccharide. These effects were associated with increased alpha1(I) collagen mRNA and reciprocally reduced collagenase mRNA levels. Co-transfection of HSC with an IL-10 expression vector and collagen reporter genes showed a 40% inhibition of alpha1(I) collagen promoter activity. These results demonstrate that activation of HSC causes enhanced autocrine expression of IL-10 which possesses a negative autoregulatory effect on HSC collagen production mediated at least in part by alpha1(I) collagen transcriptional inhibition and stimulation of collagenase expression. These findings, along with the demonstrated early induction of HSC IL-10 expression and its late disappearance during biliary liver fibrosis, suggest its in vivo role in matrix remodeling and a possibility that failure for HSC to sustain IL-10 expression underlies pathologic progression to liver cirrhosis.
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PMID:Expression of interleukin-10 by in vitro and in vivo activated hepatic stellate cells. 941 80

Our previous studies have shown that the degree of damage to a liposome corresponds to the variability of the animal species from which the serum comes, and that a complement activating factor (CAF) plays an important role in inducing the activation of the complement system, ultimately leading to the lysis of the liposomes. In this study, our attention focused on the characterization of the bovine serum factor (bCAF) that is involved in complement-mediated immune lysis of the liposome. The active fraction containing CAF partially purified with PEG and ammonium sulfate results in marked activation of the complement system via the alternative pathway when interacted with CAF-depleted serum, whereas the active fraction or CAF-depleted serum alone does not activate the complement. The interaction between lipopolysaccharide (LPS), heparin, zymosan or their mixture in place of CAF and CAF-depleted serum does not result in any significant activation of the complement system. Results from pretreatment with rabbit anti-bovine IgM IgG and rabbit anti-bovine IgG IgG indicate that activation of the complement system is not attributable to the antibody which is generally involved in activation of complement via the classical pathway. The results have further been proven by pretreatment with Concanavalin A (Con A) sepharose and protein G sepharose ruling out the possibility of antibody-mediated activation of complement. Our studies on collagenase and trypsin digestion demonstrate that the relative activity of CAF does not diminish with increase in collagenase concentration, and decreases with increase in trypsin concentration, strongly indicating that CAF does not have a collagen-like domain in its structure. The relative activity of CAF is dramatically inhibited after reduction with 2-mercaptoethanol (2-ME), clearly demonstrating that CAF is sensitive to reduction with 2-ME and confirming a sulhydryl-dependent protein. The optimal activity of CAF is observed in the range of 35-45 degrees C and its half-life at 37 degrees C is about 105 h. Furthermore, the relative activity of CAF increases and gradually approaches a plateau level with the increase of Mg2+ concentration. Obviously, complement activation induced by CAF depends on adequate Mg2+ concentration, confirming that this dependence is characteristic of the alternative pathway.
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PMID:Characterization of bovine serum factor triggering the lysis of liposomes via complement activation. 958 79

Macrophages play an important role in the intestinal mucosal immune system. However, they are a poorly defined cell population. We therefore determined their phenotype in normal colonic mucosa. Macrophages were isolated from colonic biopsies and surgical specimens by collagenase digestion. Colonic macrophages were positively sorted by anti-CD33 magnetic beads. Flow cytometric triple fluorescence analysis was applied to study CD14, CD16, CD33, CD44, CD11b, CD11c, CD64, HLA-DR, CD80, CD86 and CD3/CD19 expression. CD33 was evaluated as a positive marker for intestinal macrophages. CD33+ cells isolated from normal colonic mucosa showed co-expression of the established intracellular macrophage marker CD68 in FACS analysis. CD33+ cells were capable of phagocytosis. Isolation of this cell population by magnetic anti-CD33 beads and culture resulted in a 4.2-40-fold increase in IL-1beta and 4.5-44-fold increase in tumour necrosis factor-alpha (TNF-alpha) secretion compared with unsorted lamina propria mononuclear cells (LPMC). Of the CD33+ cells, 90.9 +/- 6.9% (mean +/- s.d.) were CD44+. However, macrophages from colonic mucosa showed only a low expression of CD14 (10.5 +/- 3.8%), CD16 (10.1 +/- 3.9%), HLA-DR (27.3 +/- 9.2%), CD11b (17.4 +/- 6.8%), CD11c (17.8 +/- 10.4%). Furthermore, expression of CD80 (9.2 +/- 4.2%) and CD86 (15.1 +/- 7.3%) was low, suggesting a low ability of normal intestinal macrophages to activate T cells and T cell-mediated immune responses. We conclude that CD33 is useful for the isolation and flow cytometric characterization of colonic macrophages. These cells exhibit a single phenotype in normal mucosa (CD33++, CD44++, CD14-, CD16-, CD11b-, CD11c-, HLA-DRlow, CD80-, CD86-) lacking lipopolysaccharide (LPS) receptor and costimulatory molecules.
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PMID:Isolation and phenotypic characterization of colonic macrophages. 964 82

Although the severity of periodontal disease is known to be affected by age, functional changes of periodontal tissue cells during the aging process are not well characterized. It is important to define how cellular aging affects the progression of periodontal diseases associated with the aging process. In vitro aging of human gingival fibroblast (HGF) and periodontal ligament fibroblast (HPLF) cells was prepared by sequential subcultivations (5 to 6 passages as young, 18 to 20 passages as old). GFs were also prepared from gingiva of Down's syndrome patients and 60-week-old rats. Fetal rat calvarial osteoblasts were prepared by sequential digestion with collagenase. HGF and HPLF cells were treated with lipopolysaccharide (LPS) and cyclic tension force, respectively. Amounts of PGE2, interleukin (IL)-1 beta, IL-6, and plasminogen activator (PA) in conditioned media were measured. Total RNA was extracted, and mRNA expression was analyzed by reverse transcription polymerase chain reaction (RT-PCR). LPS-stimulated PGE2, IL-1 beta, IL-6, and PA production was increased in "old" HGF compared to younger cells. According to RT-PCR analysis, gene expression of COX-2, IL-1 beta, IL-6, and tissue type (t) PA was higher in old cells than in young cells. Cyclic tension force to HPLF also stimulated phenotypic and gene expression of IL-1 beta, PGE2 (COX-2 gene) and tPA. These findings suggest that aging in both HGF and HPLF may be an important factor in the severity of periodontal disease through higher production of inflammatory mediators in response to both LPS and mechanical stress. In addition, oxygen radical-treated fibronectin (FN) as substratum diminished bone nodule formation by osteoblasts when compared with intact FN. This finding suggests that FN plays an important role in Osteoblast activity and that FN damaged by oxygen radicals during the aging process may be related to less bone formation.
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PMID:Effect of aging on functional changes of periodontal tissue cells. 972 19

The activation of the gene for interstitial collagenase in myometrial smooth muscle cells is absolutely dependent upon the presence of serotonin. Our previous studies investigating the mechanisms of this induction demonstrated that the mRNAs of both interleukin-1 (IL-1) isoforms, IL-1alpha and IL-1beta, are induced by serotonin and that the induction of IL-1 is required for the subsequent induction of collagenase. These data provided compelling evidence that serotonin-induced IL-1 acts via an autocrine loop in activating the collagenase gene. The experiments described here were designed to examine the potential role of each IL-1 isoform in collagenase production by using neutralizing antisera specific to each isoform of the cytokine. The antisera were examined for their ability to inhibit the serotonin-dependent production of the mRNA for collagenase and of the cytokines themselves. Neutralizing antiserum against IL-1alpha, but not against IL-1beta, inhibited the induction of the mRNA for collagenase and of the mRNAs for both IL-1alpha and IL-1beta. Western analysis indicated that detectable levels of IL-1alpha protein, but not that of IL-1beta, are produced at the time of serotonin-dependent collagenase induction. In contrast, significant levels of IL-1beta protein are detected only when bacterial lipopolysaccharide is added to the cells. Taken together, the results of our study indicate that IL-1alpha, but not IL-1beta, plays an obligatory role in multiple serotonin-mediated gene regulations in the myometrial smooth muscle cell. In addition, the data suggest that IL-1beta production has the potential for modifying myometrial function in pathological settings, particularly that of uterine infection.
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PMID:Serotonin-mediated production of interstitial collagenase by uterine smooth muscle cells requires interleukin-1alpha, but not interleukin-1beta. 973 19

The traditional two-step EGTA/collagenase method is widely used in studying nitric oxide (NO) production in hepatocytes. The present study first revealed that hepatocytes isolated by this method spontaneously express an iNOS mRNA. Thereafter, based on this novel finding, we characterized the expression and regulation of the gene in primary cultured hepatocytes. Using Northern blot analysis, the iNOS mRNA was observed 4 h after isolation, reached peak at 8 h, and declined to an undetectable level after 24 h. iNOS gene expression was shown to be serum-independent and not due to lipopolysaccharide contamination. Time-course analysis of the effects of actinomycin D demonstrated that the increase in iNOS transcripts is the result of an accompanying great increase in iNOS gene transcription and lower iNOS mRNA stability; also blockage by cycloheximide suggests that it is dependent on de novo protein synthesis. Inhibition by pyrrolidine dithiocarbamate, a NF-kappaB/c-rel inhibitor, further implies the involvement of NF-kappaB/c-rel. To clarify reason(s) for the induction, hepatocytes were isolated with the collagenase buffer perfusion step omitted. As a consequence, iNOS mRNA was undetectable in the hepatocytes. These findings show that the traditional hepatocyte-isolation culture does indeed transiently express a serum-independent but de novo protein synthesis-dependent iNOS mRNA due to collagenase (type IV) buffer perfusion.
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PMID:Post-isolation inducible nitric oxide synthase gene expression due to collagenase buffer perfusion and characterization of the gene regulation in primary cultured murine hepatocytes. 979 10

A frequent side effect of cyclosporin A (CsA) administration is gingival overgrowth. Although the molecular mechanisms of CsA-induced gingival overgrowth are still unknown, it has been postulated that CsA acts on lipopolysaccharide (LPS) to induce fibroblastic activity, which results in an increase of the extracellular matrix. Here we provide evidence that CsA is able to affect signal transduction of LPS-induced collagenase expression in fibroblasts. Treatment of fibroblasts with LPS caused activation of collagenase gene, activator protein-1 (AP-1) and c-Jun N-terminal kinase (JNK). These activations were blocked by CsA. We suggest that inhibitory effects of CsA on LPS-induced signal transduction may contribute to the mechanism of CsA-induced gingival overgrowth.
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PMID:Cyclosporin A inhibits collagenase gene expression via AP-1 and JNK suppression in human gingival fibroblasts. 987 17

The primary objective of this investigation was to determine the effect of endotoxin on islet xenograft survival within the first three days after transplantation. Pancreatic islets from Lewis rats were prepared under endotoxin-free conditions with Liberase (Boehringer) and purified by centrifugation on endotoxin-free Ficoll/Histopaque. After overnight incubation, with or without 10 microg/ml endotoxin, the islets were transplanted beneath the kidney capsule of normoglycemic C57Bl/6-mice. Three days later, kidneys were removed and their insulin content were measured. We could demonstrate significant differences (P<0.01) in insulin recovery between lipopolysaccharide-free and lipopolysaccharide-containing grafts. In case of endotoxin contaminated islets, we found only 13+/-2% (n=9) of the original insulin content, in contrast to 53+/-7% (n=9) when endotoxin-free islets where grafted. In experiments with islets isolated by use of conventional (lipopolysaccharide-containing) collagenase, and then cultured in endotoxin-free medium, insulin recovery three days after transplantation was 36+/-1% (n=13).
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PMID:Endotoxin impairs the engraftment of rat islets transplanted beneath the kidney capsule of C57BL/6-mice. 993 Sep 45

The purpose of this study was to determine if exacerbation of apoptosis precedes liver injury during chronic exposure of rats to alcohol. After 7 weeks of feeding an alcohol- or dextrin-containing liquid diet, the animals were treated with gram-negative bacterial lipopolysaccharide (1 mg x kg(-1) body weight, intravenously) or sterile saline and sacrificed 3 hr after the treatment. Alanine:2-oxoglutarate aminotransferase (ALT) and lactate:NAD oxidoreductase [lactate dehydrogenase (LDH)] were measured in plasma. The caudate lobe of the liver was resected for histology, while the rest of the organ was perfused with collagenase to isolate hepatocytes, Kupffer cells (KCs), and sinusoidal endothelial cells (SECs) by centrifugal elutriation. Hepatocyte mitochondria were isolated by differential centrifugation of the cell homogenate. Reduced and oxidized glutathione (GSH and GSSG) in isolated hepatocytes and hepatocyte mitochondria, and malondialdehyde in hepatocytes were assayed. Caspase-3 activity and Fas ligand mRNA expression were determined in hepatocytes, KCs, and SECs. Plasma ALT and LDH activity, liver histology, GSH, GSSG and their ratio, and malondialdehyde content were not affected by alcohol treatment Caspase-3 activity was significantly increased in alcohol-treated rats in all three cell types, with the lowest response observed in hepatocytes and the highest in KCs. Fas ligand mRNA expression, which had the highest level in SECs, followed by KCs and hepatocytes, was not affected by alcohol administration. Lipopolysaccharide had the following effects: an increase in ALT in both pair- and alcohol-fed rats, and LDH only in alcohol-fed rats, a decrease in GSH + GSSG levels in both mitochondria and hepatocytes, an elevation of malondialdehyde content in hepatocytes, a raise in caspase-3 activity in all groups and cell types, and an augmentation of Fas ligand expression in hepatocytes and KCs, but not in SECs. These data suggest that, during chronic alcohol consumption, an exacerbated apoptosis precedes alcohol-induced liver injury.
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PMID:Modulation of caspase-3 activity and Fas ligand mRNA expression in rat liver cells in vivo by alcohol and lipopolysaccharide. 1006 67


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