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 expression of the cytokine and IFN-related genes was studied in mouse embryo using RT-PCR method capable of detecting low levels of mRNA. Total RNA was prepared from the days 7 embryos by acid guanidinium thiocyanate-phenol-chloroform (AGPC) method. cDNA was synthesized by M-MLV reverse transcriptase, and amplified using the specific oligonucleotide primers for IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, TNF-alpha, IFN-alpha, IFN-beta, IFN-gamma, IFN-alpha/beta receptor (IFN-alpha/beta R), IFN-gamma receptor (IFN-gamma R), interferon reguratory factor (IRF)-1, IRF-2 and 2'-5' oligoadenylate synthetase (2-5AS) by PCR method. Although the expressions of IL-1 beta, IL-4, IL-5, IL-6, TNF-alpha and IFN-gamma mRNA were detected in all the embryos tested, the expressions of IL-2, IL-3, IFN-alpha and IFN-beta mRNA were not detected at all. On the other hand, the expressions of IFN-related genes such as IFN-alpha/beta R, IFN-gamma R, IRF-1, IRF-2 and 2-5AS mRNA, were also detected. These results suggest that these cytokine may play an important role in early embryonic development.
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PMID:[Expression of cytokines and interferon-related genes in the mouse embryo]. 754 Jan 2

We have used a reverse transcriptase-polymerase chain reaction (RT-PCR) protocol to examine the expression of cytokines in the pancreases and islets of patients with type I diabetes. We detect a significant increase in the level of expression of interferon (IFN)-alpha in the pancreases of the diabetic patients as compared with the control pancreases. In contrast, IFN-beta was detected at comparable levels in both groups, while IFN-gamma was detected in three of four control pancreases and one of four pancreases from the diabetic individuals. The IFN-alpha cDNAs generated by the RT-PCR were cloned and sequenced to determine which alpha-subtypes were being expressed. We found that the repertoire of subtypes was quite limited in any one individual (diabetic or not), although each individual was different with respect to the pattern of subtypes expressed. We also examined these pancreases for the expression of tumor necrosis factor (TNF)-alpha, interleukin (IL)-1 beta, IL-2, IL-4, and IL-6. We found no detectable expression of TNF-alpha or IL-2 in any pancreases, and the expression of the other cytokines was variable, with no pattern emerging from the comparison of the diabetic and nondiabetic individuals. We conclude that, of the cytokines examined, only IFN-alpha was significantly increased in the diabetic patients, a result that is consistent with the possibility that this cytokine is directly involved in the development of type I diabetes.
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PMID:Interferon expression in the pancreases of patients with type I diabetes. 754 May 71

Acute inflammation is characterized by increased production of acute phase proteins in the liver. The induction of the hepatocytic response is primarily mediated through soluble cytokines such as IL-1, IL-6, TNF-alpha, and transforming growth factor beta, which bind to specific cell surface receptors and regulate gene expression of acute-phase proteins. Hepatoma cell lines, such as HepG2, represent a model system for studying acute-phase protein synthesis. HepG2 is induced to produce a variety of acute-phase proteins, including alpha 1-antitrypsin, alpha 1-antichymotrypsin, fibrinogen, alpha 1-acid glycoprotein, and haptoglobin, upon stimulation with cytokines. Analysis of HepG2 by reverse transcriptase PCR indicated that this cell line synthesized mRNA specific for the human C5a receptor (CD88). Flow cytometric analysis of HepG2 cells indicated that these cells bound anti-CD88 Ab, thus confirming our RT-PCR data by demonstrating that these cells also express the C5a receptor. Because C5a has been shown to be a potent mediator of inflammation and HepG2 cells express CD88, we assessed the possibility that C5a was capable of stimulating acute-phase protein synthesis by HepG2 cells. The results indicate that binding of human C5a to CD88 on HepG2 cells resulted in an increased production of alpha 1-antitrypsin- and alpha 1-antichymotrypsin-specific mRNA as assayed by RT-PCR. Analysis of culture supernatants derived from C5a-stimulated HepG2 cells showed an increased production of alpha 1-antitrypsin as measured by solid-phase ELISA. alpha 1-antitrypsin production by HepG2 cells was a direct result of C5a stimulation as evidenced by the fact that anti-C5a receptor Ab inhibited the response. These results suggest that C5a may be an important mediator of APP production in the regulation of the inflammatory response.
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PMID:Expression of functional receptors for human C5a anaphylatoxin (CD88) on the human hepatocellular carcinoma cell line HepG2. Stimulation of acute-phase protein-specific mRNA and protein synthesis by human C5a anaphylatoxin. 754 17

Complement proteins in serum are mainly synthesized by hepatocytes. Recently, many cell types have been reported to synthesize complement in various tissues. In this study, we report the synthesis and secretion of the third component of complement (C3) by cultured glomerular epithelial cells (GEC). Using reverse transcriptase polymerase reaction, we have found that GEC and whole kidney expressed the C3 mRNA for C3. By ELISA, we have found that C3 was secreted in culture supernatants harvested from cultured GEC. The secretion of C3 is regulated by proinflammatory cytokines (IL-1 beta, TNF-alpha and IL-6). IL-1 beta is shown to be the most potent stimulator of C3 secretion from GEC. The exact significance of C3 produced at glomerular site is not clear, but its upregulation by proinflammatory cytokines may suspect a role in local activation of complement which may lead to glomerular injury. We further studied the expression of C3 step regulatory proteins (membrane cofactor protein (MCP), decay-accelerating factor (DAF), CR-1 and CD59 (a terminal step regulatory protein) by cultured GEC. Treatment of GEC by proinflammatory cytokines IL-1 beta, TGF-beta, TNF-alpha and IL-6 did not modify the expression of MCP, DAF and CR-1 whereas an increase in the expression of CD59 could be observed after treatment with IL-1 beta and TGF-beta. These results indicate that the expression of these regulatory proteins is tissue specific and may be implicated in inflammatory processes.
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PMID:Human glomerular epithelial cells synthesize and secrete the third component of complement. 754 67

The effects of cysteamine (2-aminoethanethiol, MEA) and its disulfide, cystamine, on the human immunodeficiency virus (HIV-1) expression in chronically infected promonocytic cells (U1), T cell line (ACH-2), and peripheral blood monocyte-derived macrophages (MDM) were investigated. U1 and ACH-2 cells constitutively express low levels of virus, which is increased by the addition of tumor necrosis factor (TNF-alpha), interleukin 6 (IL-6), granulocyte-macrophage-colony-stimulating factor (GM-CSF), and other inducers. Cystamine, in noncytotoxic doses, suppressed in a concentration-dependent fashion the induction of HIV-1 expression mediated by TNF-alpha, IL-6, GM-CSF, and monokine-enriched monocyte culture supernatants in both U1 and ACH-2 cells as determined by HIV-1 reverse transcriptase (RT) activity. Similarly, HIV-1 expression was substantially reduced in the cystamine-treated primary MDM cultures compared with the untreated control cultures. The addition of cystamine into HIV-1 chronically infected MDM (12 days after infection was established) also suppressed 80-90% of RT activity in comparison to the untreated controls. HIV-1 (Bal) infected MDM cultures (without cystamine treatment) demonstrated giant syncytium formation, whereas cystamine-treated cultures lacked the giant syncytia induced by HIV-1 infection. Cystamine also inhibited LPS-induced TNF production in MDM. In contrast to cystamine, cysteamine showed no significant effects on either the monokine-induced HIV-1 expression in U1 or ACH-2 or acute and chronic HIV-1 infection in MDM.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Cystamine inhibits HIV type 1 replication in cells of monocyte/macrophage and T cell lineages. 763 61

Although many cytokines have been previously implicated in graft-versus-host disease (GVHD), no study to date has comprehensively evaluated their expression over time or in different tissues affected by GVHD. Using a semi-quantitative reverse transcriptase-PCR technique and a murine model of acute GVHD, we have evaluated the expression levels of mRNA for a wide range of cytokines in spleen, gut and liver tissues at weekly intervals after bone marrow transfer. The earliest cytokine responses seen were increases in IL-2, IL-10, IFN-gamma, MIP-1 alpha and TNF-alpha in the spleen, suggesting a primarily Th1 pathway. Other cytokines (IL-1 alpha, IL-10 and MIP-1 alpha) were persistently elevated in GVHD mice, but were variable depending on the tissue. These data demonstrate that a wide range of cytokines are involved in the GVHD response and that their kinetic pattern of expression is different in various affected tissues.
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PMID:Kinetic and organ-specific patterns of cytokine expression in acute graft-versus-host disease. 765 87

Human nasal mucosal samples exposed in vitro to substance P or allergenic Ag were tested for the mRNA of IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, TNF-alpha, and IFN-gamma using specific reverse transcriptase-polymerase chain reaction assays. After the administration of substance P, at dosages ranging from 10(-6) to 10(-9) M, an enhanced expression of the mRNA for IL-1 beta, -3, -5, -6, TNF-alpha, and IFN-gamma was observed in all mucosal samples of allergic subjects and in half of the nonallergic subjects. The expression of IL-2 and IL-4 was low. Mucosal samples of allergic subjects showed an increased expression of mRNA for cytokines after administration of specific Ag, whereas no enhancement was observed in samples from nonallergic subjects. Our data suggest that substance P may regulate allergic reactions via enhanced production of certain regulatory cytokines.
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PMID:Cytokine expression after the topical administration of substance P to human nasal mucosa. The role of substance P in nasal allergy. 769 47

Airway inflammation is characterized by leukocyte extravasation around the peribronchial mucosa and into the airway of the lung. In the present study we utilized a model of airway inflammation induced by intratracheal challenge with soluble parasite (Schistosoma mansoni) egg Ag (SEA) in presensitized mice. The subsequent inflammatory response and leukocyte recruitment consists of early neutrophil (8 to 24 h) and later eosinophil (48 to 72 h) infiltration into the interstitium and airway. Little neutrophil and no eosinophil recruitment was observed in presensitized control mice challenged with vehicle. Multiple studies have demonstrated a crucial role for TNF-alpha during inflammatory responses. In these experiments we investigated the role of TNF-alpha in Ag-specific eosinophilic airway inflammation. Measurement of TNF-alpha expression by reverse transcriptase-PCR and ELISA in whole lung homogenates of SEA-challenged mice demonstrated an early increase in TNF-alpha levels (1 to 8 h). To determine the specific role of TNF-alpha in leukocyte recruitment during airway inflammation, mice were treated with soluble TNF-alpha receptor linked to an Fc Ab molecule (sTNFr-:Fc). This treatment has previously been used to effectively neutralize TNF in vivo. Intratracheal SEA-challenged mice treated with sTNFr-FC demonstrated significantly decreased leukocyte recruitment into the lung and airway. The inflammatory response in the lungs in sTNFr-Fc-treated mice was significantly decreased throughout the study period, as compared with control mice. An approximate decrease in early neutrophil infiltration into the airway was observed when sTNFr-Fc was administered 2 h before the Ag challenge. Eosinophil infiltration was also diminished when sTNFr-Fc was administered before Ag challenge. Interestingly, when sTNFr-Fc was administered therapeutically 24 h after Ag challenge, the eosinophil response was nearly abrogated at 48 h after challenge. These studies indicate that TNF-alpha acts as an initial inflammatory cytokine that subsequently regulates both early neutrophil infiltration and eosinophil recruitment into the lung and airspace.
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PMID:TNF-alpha mediates recruitment of neutrophils and eosinophils during airway inflammation. 773 Jun 42

The inflammatory cytokines IFN-gamma and TNF-alpha have been demonstrated in various autoimmune diseases, and are thought to participate in the induction and pathogenesis of disease. TFN-alpha is a cytopathic cytokine that is cytotoxic for oligodendrocytes in vitro and has been implicated in the pathology of multiple sclerosis and its animal model experimental allergic encephalomyelitis (EAE). We used reverse transcriptase (RT)-PCR to study the kinetics, cellular source, and regulation of cytokine gene expression in the central nervous system (CNS) of SJL/J mice with myelin basic protein-induced EAE at different stages of the disease. The expression of CD3, IL-2, IFN-gamma, and TNF-alpha mRNA was barely detectable in the CNS of unmanipulated mice or mice that were immunized with adjuvant but showed no symptoms. These mRNAs were readily detectable in the CNS of mice during peak disease, then coordinately dropped to background levels during remission. Analysis of cells isolated from the CNS of mice with acute EAE showed that the Th1 cytokines, IL-2 and IFN-gamma, were produced by infiltrating CD4+ T cells. In contrast, TNF-alpha was predominantly transcribed by non-T mononuclear CNS cells, the majority of which were identified as microglia and macrophages by their Mac-1 phenotype. Microglia could be discriminated by their low expression of CD45. Incubation of freshly derived, adult microglia from normal, uninfiltrated, CNS with activated Th1 supernatant induced the production of TNF-alpha mRNA. Therefore, TNF-alpha is made by both CNS-resident microglia and infiltrating macrophages during EAE, and this production is tightly controlled by cytokines secreted by infiltrating CD4+ T cells.
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PMID:TNF-alpha expression by resident microglia and infiltrating leukocytes in the central nervous system of mice with experimental allergic encephalomyelitis. Regulation by Th1 cytokines. 781 94

The expression of the cytokine genes in normal placenta was studied using RT-PCR method capable of detecting low levels of mRNA. Total RNA was prepared from placenta of specific pathogen-free BALB/c mice at the 16th day of gestation by acid guanidinium thiocyanate-phenol-chloroform (AGPC) method. cDNA was synthesized by M-MLV reverse transcriptase, and amplified using the specific oligonucleotide primers for IL-1, IL-2, IL-3, IL-4, IL-5, IL-6, TNF-alpha, IFN-alpha, IFN-beta and IFN-gamma by PCR method. IL-1 beta, IL-6, TNF-alpha, IFN-alpha, IFN-beta and IFN-gamma mRNA were detected in all the placentas tested. On the other hand, the expressions of IL-2, IL-3, IL-4, and IL-5 mRNA were not detected at all. These results suggest that these cytokines may play a role in the evolution of pregnancy.
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PMID:[Expression of cytokine messenger RNA in murine placenta]. 783 98


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