Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: EC:2.7.7.49 (reverse transcriptase)
 31,746 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The mesothelium is a flat epithelial lining of serous cavities that could gate the traffic of molecules and cells between the circulation and these body compartments. The present study was designed to elucidate the capacity of mesothelial cells to express adhesion molecules and chemoattractant cytokines, two fundamental mechanisms of regulation of leukocyte recruitment. Cultured human mesothelial cells express appreciable levels of intercellular adhesion molecule 1 (ICAM-1) and vascular cell adhesion molecule 1 (VCAM-1), and these were increased by in vitro exposure to tumor necrosis factor (TNF), interferon gamma (IFN-gamma), or TNF and IFN-gamma. Interleukin 1 (IL-1) was a less consistent stimulus for adhesion molecule expression in vitro. Unlike endothelial cells, used as a reference cell population, resting or stimulated mesothelial cells did not express E-selectin and ICAM-2, as assessed by flow cytometry. Analysis of VCAM-1 mRNA by reverse transcriptase and polymerase chain reaction using appropriate primers revealed that mesothelial cells expressed both the seven- and the six-Ig domain transcripts, with predominance of the longer species. Monocytes bound appreciably to "resting" and, to a greater extent, to stimulated mesothelial cells. Monocytes exposed to IFN-gamma and lipopolysaccharide, used as prototypic activation signals, showed increased capacity to bind mesothelial cells. Anti-CD18 monoclonal antibody significantly inhibited binding of monocytes to mesothelial cells, and this blocking effect was amplified by anti-very late antigen 4. Mesothelial cells were able to express the chemotactic cytokines IL-8 and monocyte chemotactic protein 1 at the mRNA and protein levels. These results indicate that mesothelial cells can express a set of adhesion molecules (ICAM-1 and VCAM-1) overlapping with, but distinct from, that expressed in vascular endothelium (ICAM-1, ICAM-2, VCAM-1, E-selectin), and that these are functionally relevant for interacting with mononuclear phagocytes. The regulated expression of adhesion molecules and chemotactic cytokines by mesothelial cells is probably important in inflammatory and immune reactions that involve serous cavities, such as the long-known macrophage appearance and disappearance reactions.
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PMID:Expression of adhesion molecules and chemotactic cytokines in cultured human mesothelial cells. 138 76

The present study was designed to explore the interaction of interleukin-13 (IL-13) with vascular endothelial cells (EC). In vitro exposure to IL-13 of human umbilical vein EC induced surface expression of vascular cell adhesion molecule-1 (VCAM-1). At optimal concentrations (10 to 50 ng/mL) and exposure times (24 hours), IL-13 was a twofold to threefold less effective inducer of VCAM-1 than IL-1, which was used as reference EC activator. When IL-13 was combined with IL-1, an almost additive induction of VCAM-1 was observed. Induction of VCAM-1 by IL-13 was selective in that E-selectin and intercellular adhesion molecule-1 (ICAM-1) were unaffected. IL-13 caused a modest reduction of IL-1 induction of E-selectin and ICAM-1. Surface expression of VCAM-1 on IL-13-treated cells was associated with mRNA induction (as assessed by Northern analysis and reverse transcriptase-polymerase chain reaction), with predominance of transcripts encoding the 7 Ig domain form of this molecule. In agreement with previous reports, IL-13 inhibited cytokine production in human monocytes. In contrast, IL-13 was a weak inducer and an amplifier (in concert with IL-1) of IL-6 expression in EC. Mesothelial cells, which share properties with EC and regulate the traffic and function of leukocytes in serosal cavities, were stimulated to express VCAM-1 and IL-6 by IL-13. Thus, IL-13 elicits a spectrum of responses in vascular endothelium remarkably similar to that of IL-4 and IL-10. Interaction of these cytokines with vascular endothelium may play an important role in the induction and expression of Th2-dependent responses.
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PMID:Regulation of endothelial and mesothelial cell function by interleukin-13: selective induction of vascular cell adhesion molecule-1 and amplification of interleukin-6 production. 752 94

Human umbilical vein endothelial cells have recently been shown to respond to C5a with increases in intracellular Ca2+, production of D-myo-inositol 1,4,5-triphosphate and superoxide anion generation. In the current studies, C5a had been found to cause in a time- and dose-dependent manner rapid expression of endothelial P-selectin, secretion of von Willebrand factor, and adhesiveness for human neutrophils. The effects of C5a in P-selectin expression and adhesiveness of neutrophils were similar to the effects of histamine and thrombin on endothelial cells. The adhesiveness of C5a-stimulated endothelium for neutrophils was blocked by anti-P-selectin, but not by antibodies to intercellular adhesion molecule 1, E-selectin, or CD18. A cell-based ELISA technique has confirmed upregulation of P-selectin in endothelial cells exposed to C5a. Binding of C5a to endothelial cells has been demonstrated, with molecules bound being approximately 10% of those binding to neutrophils. By a reverse transcriptase-PCR technique, endothelial cells have been shown to contain mRNA for the C5a receptor. These data suggest that C5a may be an important inflammatory mediator for the early adhesive interactions between neutrophils and endothelial cells in the acute inflammatory response.
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PMID:C5a-induced expression of P-selectin in endothelial cells. 752 84

By reverse transcriptase polymerase chain reaction on messenger RNA from human polymorphonuclear cells, we have isolated a sequence identical to the cDNA coding for intracellular interleukin 1 receptor antagonist (icIL-1ra), but containing an additional in-frame 63-bp sequence located three codons downstream of the translation start of icIL-1ra. This additional sequence is inserted between the first and second exon of the intracellular form, the latter of which is colinear with part of the first exon of the secreted form of IL-1ra. The additional sequence is coded by an extra exon located 2 kb downstream the first icIL-1ra-specific exon. The complementary DNA sequence of the alternatively spliced form of icIL-1ra shows that the predicted protein differs from classical icIL-1ra in the NH2 terminus by insertion of a leaderless sequence of 21 amino acids rich in glycine and glutamic acid residues. Transcripts coding for this new form of icIL-1ra were detected in activated fibroblasts, keratinocytes, and at low levels in myelomonocytic cells. The recombinant protein expressed in COS cells had an apparent molecular mass in sodium dodecyl sulfate polyacrylamide gel electrophoresis of 25 kD compared to 22 kD of classical icIL-1ra, and was mostly intracellular. The ability of this new form of icIL-1ra to inhibit IL-1 activity, in terms of induction of E-selectin and human immunodeficiency virus replication, was comparable to that of classical icIL-1ra. We propose to refer to this new form of icIL-1ra as icIL-1ra type II.
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PMID:Cloning and characterization of a new isoform of the interleukin 1 receptor antagonist. 762 20

A circulating form of the membrane-bound ICAM-1 (CD54), a ligand for lymphocyte function-associated antigen-1 (LFA-1), has recently been identified in normal human serum. In this study, serum levels of soluble ICAM-1 (sICAM-1) were determined by sandwich ELISA both in normal healthy individuals of both sexes and in subjects with autoimmune liver diseases. Patients with primary biliary cirrhosis (PBC), primary sclerosing cholangitis and chronic active hepatitis (autoimmune) showed significant elevations in sICAM-1 compared with normal healthy subjects. The median level in PBC was approximately seven-fold above normal. Significant elevations in sICAM-1 were also detected, however, in patients with inactive alcoholic cirrhosis, suggesting that impaired liver clearance might at least in part account for the increased serum levels seen in patients with autoimmune liver disease. In patients with PBC, sICAM-1 levels were related to summary assessment of disease severity (Child-Pugh classification) and correlated significantly with serum biochemical indices of liver function, including measures both of cholestasis and liver cell injury. In contrast, serum levels of E-selectin did not differ significantly from healthy controls. Although it has been suggested that peripheral blood mononuclear cells (PBMC) may be a source of sICAM-1, investigation of ICAM-1 gene expression by reverse transcriptase polymerase chain reaction revealed similar basal levels of ICAM-1 message in PBMC of normal individuals and those with active PBC. This suggests that PBMC may not be a significant source of sICAM-1 in this disease. Similar increases in ICAM-1 mRNA expression were found in cultured, concanavalin A (Con A)-stimulated lymphocytes of both PBC patients and controls. Significantly, stimulation of cultured, normal human hepatocytes with proinflammatory cytokines and endotoxin induced cell surface expression of ICAM-1 and the secretion/shedding of sICAM-1 into the hepatocyte culture medium. This new finding suggests that hepatocytes may be an important source of sICAM-1 in autoimmune and other chronic liver diseases. The possible role of sICAM-1 in inflammatory disorders remains to be determined.
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PMID:Circulating intercellular adhesion molecule-1 (ICAM-1) in autoimmune liver disease and evidence for the production of ICAM-1 by cytokine-stimulated human hepatocytes. 790 46

In vitro, expression of E-selectin is largely restricted to endothelial cells activated by inflammatory cytokines. Under activated conditions, cytokines such as interleukin (IL) 10, released by keratinocytes in large quantities, may also increase the expression of E-selectin on the dermal microvasculature. The aim of the present study was to investigate the expression of E-selectin on cultured human dermal microvascular endothelial cells (HDMEC) isolated from neonatal foreskins when exposed to IL-10. Expression of E-selectin was determined by immunofluorescence microscopy, FACS analysis, an HL-60 cell-binding assay, and quantitative polymerase chain reaction (PCR) analysis. For comparison with large blood vessel cells, the expression of E-selectin on human umbilical vein endothelial cells (HUVEC) was also determined in parallel by FACS and reverse transcriptase-PCR analysis under identical conditions. These studies demonstrate that IL-10 induces the expression of E-selectin on both HDMEC and HUVEC and that the level of expression of HDMEC is comparable with that induced by IL-1 beta and tumor necrosis factor-alpha. When HL-60 cells are incubated with HDMEC pretreated with IL-10, a consistent increase in adherence of HL-60 to endothelial cells is observed. This adherence was found to be mediated by L-selectin. PCR analysis and the quantification of E-selectin cDNA by a novel, highly sensitive and specific PCR-immunoassay demonstrate the induction of E-selectin mRNA at the transcriptional level. The induction of the expression of E-selectin by IL-10 on HDMEC may provide additional insights into the pathogenic mechanism of neutrophil accumulation at the site of inflammation in inflammatory skin diseases.
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PMID:Interleukin-10 induces E-selectin on small and large blood vessel endothelial cells. 906 42

The initial (0-24 hr), early (3-5 days), and late (7-14 days) events occurring in LBNF1 renal allografts transplanted into Lew recipients were examined to define precisely the sequential cellular and molecular kinetics during acute rejection. Grafts and spleens were harvested at 3, 6, 12, and 24 hr, and at 3, 5, 7, and 14 days and processed for morphology, immunohistology, and reverse transcriptase-polymerase chain reaction. Various factors (mRNA) were up-regulated sequentially in the allografts over time. In the initial phase, E-selectin and complement (C1 and C3) expression was noted within 6 hr, peaking by 24 hr. RANTES (regulated upon activation, normal T cell expressed and secreted) increased within 6 hr, and then again between 3 and 6 days. By immunohistology, MHC class II was up-regulated consistently after day 1. Intercellular adhesion molecule-1 expression increased after day 3; lymphocyte function-associated antigen-1+ infiltrating leukocytes peaked at day 5. Infiltrating CD8+ T lymphocytes increased strikingly between days 1 and 3, peaking at day 5; CD4+ cells infiltrated more slowly until day 5. The kinetics of ED1+ macrophages were similar to those of lymphocyte function-associated antigen-1+ cells. The CD4+ T cell-derived product, interleukin (IL)-2, peaked at 7 days. Interferon-gamma increased progressively up to 14 days. By 3 days, the macrophage-associated factor, transforming growth factor-beta, peaked; this was followed by increased IL-6 expression by day 5. IL-1, tumor necrosis factor-alpha, and inducible nitric oxide synthase increased slowly until day 7, declining thereafter. Endothelin increased progressively over the 14-day follow-up period. Cytokine dynamics occurring in host spleen were similar to those noted in the allografts. Although acute rejection is primarily T cell mediated, adhesion molecules, macrophages, and their associated products may influence initial and later changes. The brisk expression of complement, E-selectin, and RANTES within the first few hours after engraftment may occur secondary to ischemic injury and trigger subsequent immunological events. Macrophages and their products may play a larger role in the process than hitherto appreciated.
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PMID:Sequential cellular and molecular kinetics in acutely rejecting renal allografts in rats. 913 71

We have used a semi-quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) assay to detect the expression of mRNA for inflammatory cytokines, integrins and selectins in murine lung tissue, and T cells and eosinophils isolated from lung and bronchoalveolar lavage (BAL) fluid in an in vivo model of ovalbumin (OA)-induced airway inflammation. RNA was isolated from whole lung tissue at 1, 6, 24, 48, 72 h, and 7 days after OA inhalation. mRNA for the Th2 cytokines, IL-4, -5, -6, -10 and -13 in OA-sensitized mice were significantly elevated compared with non-sensitized mice. IL-2, TNF-beta, and eotaxin mRNA were also increased, but IFN-gamma mRNA was not. P- and E-selectin mRNA levels were also enhanced in lung tissue between 6 and 72 h after challenge. Lung T cells were isolated by cell sorting with a flow cytometer at 3, 12, 24, 48 and 72 h after challenge. mRNA levels for IL-5 and -10 were greater in T cells from OA-sensitized and -challenged mice than controls at 24 h. BAL fluid from OA-sensitized and -challenged mice also had significantly higher IL-5 levels than controls. BAL fluid T cells and eosinophils were obtained at 48 and 72 h after aerosol challenge and were purified by cell sorting. Messenger RNA for IL-1 alpha, -2, -4, -5, -10, IFN-gamma, and beta 1 were detected in T cells at both time points. Transcripts for IL-1 alpha, -4, -5, -13, TNF-alpha and beta, and alpha 4, beta 1 and beta 7 were also identified in BAL eosinophils. These data show that in addition to murine lung T cells, airway eosinophils may also contribute to the inflammatory response by their ability to express mRNA for cytokines and integrins.
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PMID:Identification of cytokine and adhesion molecule mRNA in murine lung tissue and isolated T cells and eosinophils by semi-quantitative reverse transcriptase-polymerase chain reaction. 919 71

The selectins and beta2 integrins participate in the recruitment of neutrophils in acute pulmonary inflammation. However, the cell adhesion receptors that mediate lymphocyte trafficking into the lung have not been defined. This study examined the relationship between cell adhesion molecules on the pulmonary vasculature and on lymphocytes recovered from the lung during a pulmonary immune response to intratracheal (I.T.) sheep red blood cells (SRBCs) in sensitized C57BL/6J mice. Silver-enhanced immunogold staining and reverse transcriptase polymerase chain reaction of lung tissues revealed sustained induction of VCAM-1, E-selectin, and P-selectin on the pulmonary vasculature for up to 7 days after I.T.-SRBC challenge. Neither the MECA 79 nor MECA 367 antigens were induced on the pulmonary vasculature during this period. In the peripheral blood, both CD4 and CD8 T-cell subsets showed an initial increase in P-selectin ligand expression after I.T.-SRBC challenge. The number of P-selectin ligand-positive T cells in the peripheral blood fell as T cells with both P-selectin and, to a lesser extent, E-selectin ligands accumulated in the bronchoalveolar lavage fluid. We conclude that I.T.-SRBC challenge in sensitized mice elicits prolonged synthesis of P-selectin, E-selectin, and VCAM-1 by the lung vasculature as well as selectin ligand synthesis by responding T cells. Furthermore, the entry of selectin-ligand-positive T cells into the circulation and their accumulation in the bronchoalveolar lavage fluid indicates that these receptors may contribute to T cell recruitment. Finally, VCAM-1 on the vasculature may also participate; however, the vascular addressins, required for homing to peripheral and mucosal lymphoid organs, are not essential for T-cell entry into the lung following I.T.-SRBC challenge.
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PMID:Lymphocyte recruitment and the kinetics of adhesion receptor expression during the pulmonary immune response to particulate antigen. 940 22

There is increasing evidence that the inflammatory response plays an important role in CNS ischemia. The murine model of focal ischemia, however, remains incompletely characterized. In this study we examined expression of several cytokines and the vascular adhesion molecule E-selectin, in order to characterize the molecular events following stroke in the C57BL/6J mouse. Using a multi-probe RNAse protection assay (RPA), mRNA for 19 cytokines was analyzed following permanent and transient occlusion of the middle cerebral artery in mice. In addition, samples from the same mice were analyzed by reverse transcriptase-polymerase chain reaction (RT-PCR) to evaluate E-selectin mRNA expression levels. Several cytokine mRNAs showed a similar expression pattern in both permanent and transient CNS ischemia while others showed a temporal expression pattern that was dependent on the type of stroke. For both models, mRNA levels of TNFalpha rose early (4 h) followed by IL-6 (10-18 h) and a comparatively late increase (96 h) in TGFbeta1. IL-1alpha, IL-1beta and IL-1ra levels showed a model dependent shift in temporal expression. Reperfusion appeared to delay the induction of these cytokines. Temporal changes in cytokine mRNA expression in the mouse CNS occur following ischemic damage. Our findings demonstrate the utility and power of multi-probe RPA for evaluation of changes in cytokine mRNA levels. Moreover, this study is, to our knowledge the first to show temporal changes in cytokine mRNA in mouse cerebral ischemia, forming a basis for further exploration of the roles of these cytokines in modulating ischemic neuronal damage in this model.
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PMID:Temporal modulation of cytokine expression following focal cerebral ischemia in mice. 1002 29


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