Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

We previously reported that tumor necrosis factor-alpha (TNF-alpha) increases in vivo hepatocyte mitoses and liver regeneration in rats. In the present studies, we used in vitro hepatocyte cultures to determine whether TNF-alpha itself was mitogenic or whether other cytokines (IL-1 beta and IL-6) that share similar actions with TNF-alpha might be involved. Hepatocytes were cultured with TNF-alpha (4, 40 or 400 U/ml), IL-1 beta (0.1, 1 and 10 ng/ml) or IL-6 (0.2, 2, or 20 ng/ml) for 24 h and 3 d. Incorporation of [3H]thymidine was increased significantly by TNF-alpha (40 and 400 U/ml) at 3 d. Both IL-1 beta and IL-6 at all concentrations significantly decreased [3H]thymidine incorporation at 3 d. These results indicate that TNF-alpha has a direct mitogenic action on hepatocytes. In contrast, IL-1 beta and IL-6 appear to suppress DNA synthesis in hepatocytes.
Biochem Mol Biol Int 1993 Jan
PMID:Tumor necrosis factor-alpha is a direct hepatocyte mitogen in the rat. 849 May 57

The minibody is a designed small beta-protein conceived to enable the construction of large libraries of minimal discontinuous epitopes displayed on the surface of filamentous phage. The 61 residue molecule consists of three strands from each of the two beta-sheets of the variable domain of immunoglobulins packed face to face, along with the exposed H1 and H2 hypervariable regions. We have previously shown that from a minibody repertoire of more than 50 million molecules displayed on phage, we were able to select a minibody with micromolar affinity for human interleukin-6 that behaves as a selective cytokine antagonist. The minibody exposes a surface composed of two constrained loops, which provides the possibility of improving IL-6 binding and specificity by swapping the hypervariable regions, followed by further selection. We established experimental conditions for "stringent" selection such as monovalent phage display, competitive selection and epitope masking. Here, we show that by virtue of the optimization/selection process, we have isolated a minibody with improved antagonistic potency and greater specificity. Furthermore, using hIL-6 mutants carrying amino acid substitutions in distinct surface sites it was possible to carefully define the cytokine region that binds the minibody.
J Mol Biol 1996 Jan 12
PMID:Coupling protein design and in vitro selection strategies: improving specificity and affinity of a designed beta-protein IL-6 antagonist. 856 77

We previously showed that intra-arterial endotoxin infusion (lipopolysaccharide [LPS]: 25 micrograms.kg-1) induced an early (15 min) and sustained (480 min) rise in plasma ACTH associated with delayed (60-120 min) increases in plasma concentrations of TNF alpha, IL-6, and IL-1 beta. In the present study, we followed the post-LPS time-course of immunocytochemical expression of Fos-like activity in CRH41 neurons whose immunolabeling was enhanced by icv colchicine pretreatment 48 h before the LPS, and CRH41 release in the push-pull cannulated median eminence of free-moving rats, in parallel with the ACTH response. The earliest Fos-like activity in IR-CHR41 neurons was detected 30 min post-LPS. Colchicine strongly inhibited the LPS-induced activation of Fos expression in single-labeled paraventricular neurons. CRH41 release in the median eminence displayed a biphasic stimulation pattern, with a first peak (+60%) at 15 min together with the ACTH surge, followed by a second rise beginning at 45 min and lasting more than 2 h. Thus, the early stage of the ACTH surge following a nonlethal endotoxin challenge (< 60 min) already involves the activation of CRH41-producing neurons.
Mol Chem Neuropathol 1995 Oct
PMID:Early hypothalamic activation of combined Fos and CRH41 immunoreactivity and of CRH41 release in push-pull cannulated rats after systemic endotoxin challenge. 857 42

The cytokine modulating effects of inotropic agents on human umbilical vein endothelial cells (HUVEC) were investigated. Confluent HUVEC in 24-well plates were treated with inotropic agents and then stimulated with 10 ng/ml of human interleukin (IL)-1 beta. After 24 h of incubation, the cytokine levels in the culture supernatants were determined by specific enzyme-linked immunosorbent assay (ELISA) kits. Vesnarinone [OPC-8212; 3,4-dihydro-6-(4-(3,4-dimethoxybenzoil)-1-piperazinyl)-2(1H)- quinolinone] at 26 mumol/l significantly suppressed the production of IL-6, granulocyte macrophage colony stimulating factor (GM-CSF) and granulocyte colony stimulating factor (G-CSF) induced by IL-1 beta. Although 8 bromoadenosine 3'5' cyclic monophosphate (8Br-cAMP) at 100 mumol/l also inhibited the production of these cytokines, the inhibitory effect was less marked than that of vesnarinone. Amrinone at 26 mumol/l and NKH477 at 10 nmol/l also had a less marked inhibitory effect against the production of IL-6. Next, the inhibitory effect of inotropic agents against the expression of the adhesion molecules of HUVEC was measured by a cell ELISA method. Vesnarinone at 26 mumol/l and NKH477 at 10 mumol/l, a water soluble forskolin derivative used as a positive control, both significantly inhibited the expression of E-selectin induced by 10 ng/ml of human tumor necrosis factor (TNF)-alpha. Amrinone at 26 mumol/l did not inhibit the expression of E-selectin. The level of HUVEC cAMP induced by vesnarinone at 26 mumol/l was much lower than that induced by NKH477 at 10 mumol/l. Moreover, according to a 3-(4,5-dimethyl-thiazol-2yl)-2,5-diphenyl tetrazolium bromide (MTT) cell viability assay, vesnarinone did not affect the viability of HUVEC. The immunosuppressive effects of vesnarinone described above are not derived from either a cAMP elevating effect or a cytotoxic effect against HUVEC. Although the cytokine network in heart failure has not yet been elucidated, patients with congestive heart failure might benefit from the immunomodulating effects of inotropic agents.
J Mol Cell Cardiol 1995 Oct
PMID:Inotropic agent vesnarinone inhibits cytokine production and E-selectin expression in human umbilical vein endothelial cells. 857 41

In addition to biophysical properties, pulmonary surfactant has immunomodulatory activity. We previously demonstrated that both synthetic (Exosurf) and modified natural surfactant (Survanta) downregulated endotoxin-stimulated inflammatory c ytokine mRNA levels and protein products (tumor necrosis factor-alpha [TNF], interleukin-1-beta [IL-1], interleukin-6 [IL-6]) in human alveolar macrophages. In this study, we report that both Exosurf and Survanta suppress TNF mRNA and secretion (85 +/- 4% mean percent inhibition +/- SEM by Exosurf; 71 +/- 6% by Survanta) by endotoxin-stimulated THP-1, a human monocytic cell line. Because surfactant downregulated inflammatory cytokine production similarly in both normal human alveolar macrophages and the THP-1 cell line, we used this cell line to investigate whether surfactant affected transcriptional mechanisms. Specifically, we examined nuclear factor-kappa B (NF-kappa B) activation because it is crucial in transcriptional regulation of many inflammatory cytokine genes including TNF, IL-1, and IL-6. Electrophoretic mobility shift assays showed that both surfactants decreased activation of NF-kappa B. The presence of both p65 and p50 NF-kappa B components in LPS-activated THP-1 cells was confirmed by specific antibody induction of supershifts in mobility assays. These results are the first to suggest that surfactant's suppressive effects on inflammatory cytokine production may involve transcriptional regulation through inhibition of NF-kappa B activation.
Am J Respir Cell Mol Biol 1996 Apr
PMID:Surfactant suppresses NF-kappa B activation in human monocytic cells. 860 Sep 42

We explored the effects of cytokines on cytochrome P-450 (CYP) in rat hepatocyte primary cultures. CYP content and several CYP protein levels were assessed in hepatocytes treated with a cytokine combination consisting of tumor necrosis factor-alpha (TNF-alpha), interleukin-1 beta (IL-1 beta), and interferon-gamma (IFN gamma). The combination was found to depress CYP content by 69 +/- 6%. Protein levels of CYP forms 1A2, 2C11, 2B1/2, and 3A2 were assessed with immunoblotting. Treatment with the cytokine combination resulted in a decrease in each CYP enzyme, with CYP2B1/2 exhibiting the greatest loss, to 33 +/- 9% of untreated cells. The addition of inhibitors of nitric oxide synthase (NOS) significantly prevented the cytokine-mediated decrease in each CYP protein, indicating a role for nitric oxide (NO) in the down-regulation. Treatment of hepatocytes with the NO donor 1-hydroxy-2-oxo-3,3-bis(3-aminoethyl)-1-triazene (300 microM) caused a decrease in each CYP apoprotein, with CYP2B1/2 exhibiting the greatest decrease, to 33 +/- 8% of untreated cells. Decreases in CYP protein levels were observed in response to treatment with TNF alpha, IL-1 beta, or IL-6 alone. With IL-1 beta treatment, increased levels of NO production were accompanied by decreased levels of each CYP protein. With TNF alpha treatment, increased levels of NO production were accompanied by decreased levels of CYP2B1/2 and CYP3A2. The effects of IL-1 beta and TNF alpha were blocked by the inclusion of the NOS inhibitors. Conversely, IL-6 caused a decrease in each of the CYP enzymes but did not affect NO production. The results indicate a dissociation in vitro between NOS induction and CYP down-regulation for IL-6 treatment, whereas the down-regulation of CYP by TNF alpha and IL-1 beta in vitro is directly associated with NO production.
Mol Pharmacol 1996 May
PMID:Role of nitric oxide in the cytokine-mediated regulation of cytochrome P-450. 862 28

Exposure of animals to adenoviral gene transfer vectors has been associated with respiratory tract inflammation. The pathogenesis of this inflammation is unclear. One hypothesis is that viral vectors directly induce production of inflammatory cytokines by host cells in the airways. We exposed cultured human lung cells to an adenovirus-5--based vector containing the cytomegalovirus promoter and lacZ reporter gene (Ad.CMV.lacZ) and to wild-type adenovirus 5 (wtAd5) and measured subsequent release of cytokines into cell culture supernatants. Inoculation of human bronchial epithelial (HBE) cells with Ad.CMV. lacZ at 10(1) to 10(4) plaque-forming units (pfu)/cell resulted in dose-related expression of lacZ by both X-gal staining and immunohistochemistry but did not increase release of interleukin (IL)-8 or IL-6 at 24, 48, or 96 h after inoculation. In the same cultures, tumor necrosis factor-alpha induced marked increases in release of both IL-8 and IL-6 at 24 and 48 h after stimulation. Similar data were observed in the BEAS-2B HBE cell line. HBE cells incubated with wtAd5 at doses of 10(1) to 10(3) pfu/cell did not release increased amounts of IL-6 or IL-8 up to 48 h after inoculation, though wild-type respiratory syncytial virus (3 pfu/HBE cell) infection resulted in increases in both cytokines. Human alveolar macrophages obtained by bronchoalveolar lavage also showed no increases in cytokine release after incubation with Ad.CMV.lacZ, though relatively little gene transfer occurred in macrophages. These data do not support a role for direct induction of airway epithelial or alveolar macrophage inflammatory cytokines in the pathogenesis of inflammation associated with exposure of airways to adenovirus or to adenoviral gene transfer vectors.
Am J Respir Cell Mol Biol 1996 May
PMID:Cytokine production by cultured human bronchial epithelial cells infected with a replication-deficient adenoviral gene transfer vector or wild-type adenovirus type 5. 862 46

Binding of many cytokines to their cognate receptors immediately activates Jak tyrosine kinases and their substrates, STAT (signal transducers and activators of transcription) DNA-binding proteins. The DNA binding targets of STATs are sequence elements related to the archetypal gamma interferon activation site, GAS. However, association of interleukin 1 (IL-1) with Jak-STAT signaling has remained unresolved. We now report an element termed LILRE (lipopolysaccharide [LPS] and IL-1-responsive element) in the human prointerleukin 1beta gene (IL1B) which can be immediately induced by either lipopolysaccharide (LPS) or IL-1 protein to bind a tyrosine-phosphorylated protein. This LPS- and IL-1-induced factor (LIL factor) is recognized by an antibody raised against the N terminus of Stat1, but not by those specific for either the C terminus of Stat1 or any other GAS-binding STAT. Phosphotyrosine (P-Tyr) specifically inhibits formation of the LIL factor-DNA complex, suggesting the importance of P-Tyr for the DNA-binding activity, as has been found for all STAT dimers. Analysis of DNA-binding specificity demonstrates that the LIL factor possesses a novel GAS-like binding activity that contrasts with those of other STATs in a requirement for a G residue at position 8 (TTCCTGAGA). Further investigation has revealed that IL-6, but neither IL-4 nor gamma interferon, activates the LIL factor. Thus, the existence of such a STAT-like factor (LIL-Stat) relates the LPS and IL-1 signaling pathway to other cytokine receptor signaling pathways via the activation of STATs. Moreover, the unique DNA-binding specificity and antigenicity of this factor suggest that LPS, IL-1, and IL-6 may use a common signaling pathway.
Mol Cell Biol 1996 May
PMID:A novel STAT-like factor mediates lipopolysaccharide, interleukin 1 (IL-1), and IL-6 signaling and recognizes a gamma interferon activation site-like element in the IL1B gene. 862 85

We have previously described the characterization of genomic clones encoding the entire translated sequence of human pulmonary surfactant protein D (SP-D). We now describe the characterization of a genomic fragment (H5E7) that encodes the entirety of the first translated exon (Exon 2), Intron 1, a short transcribed untranslated sequence (Exon 1; 39 bp), and approximately 4 kb of sequence upstream from the transcription initiation site. The start site was identified by 5'-RACE-PCR cloning and primer extension. A putative TATA box (CATAAATA) was identified approximately 30 bp upstream of the start site. Complete sequencing of a HindIII/SacI fragment (HS-1674) encoding approximately 1.7 kb of sequence 5' to the TATA demonstrated multiple potential cis-regulatory elements including half-site glucocorticoid response elements (GRE), a canonical AP-1 consensus, several AP-1 like sequences, E-box sequences, NF-IL-6 and PEA3 motifs, and putative interferon response elements. H441 lung adenocarcinoma cells, which express low levels of SP-D mRNA, and liver HepG2 cells, were transiently co-transfected with chloramphenicol acetyl transferase (CAT) reporter constructs containing up to 3,000 base pairs of upstream sequence, and with constructs encoding beta-gal. H441 cells transfected with constructs containing at least 161 bp of upstream sequence gave normalized levels of CAT activity greater than or equal to that obtained for parallel positive control transfections using pTK-CAT. Treatment of the cells for 48 h with 50 nM dexamethasone (Dex) gave a 2- to 5-fold increase in CAT activity. Interestingly, a 5'-deletion construct containing 161 bp of upstream sequence (pFS161-CAT) conferred both cell type-restricted and dexamethasone-responsive expression. These studies emphasize the potential complexity of SP-D gene regulation, and further support the hypothesis that the effects of glucocorticoids on SP-D production in vivo are regulated at the level of transcription.
Am J Respir Cell Mol Biol 1996 Feb
PMID:Characterization of the human surfactant protein D promoter: transcriptional regulation of SP-D gene expression by glucocorticoids. 863 Feb 61

Acute-phase reactants (APRs) are proteins synthesized in the liver following induction by interleukin-1 (IL-1), IL-6, and glucocorticoids, involving transcriptional gene activation. Lipopolysaccharide-binding protein (LBP) is a recently identified hepatic secretory protein potentially involved in the pathogenesis of sepsis, capable of binding the bacterial cell wall product endotoxin and directing it to its cellular receptor, CD14. In order to examine the transcriptional induction mechanisms by which the LBP gene is activated, we have investigated the regulation of expression of its mRNA in vitro and in vivo as well as the organization of 5' upstream regulatory DNA sequences. We show that induction of LBP expression is transcriptionally regulated and is dependent on stimulation with IL-1beta, IL-6, and dexamethasone. By definition, LBP thus has to be viewed as a class 1 acute-phase protein and represents the first APR identified which is capable of detecting pathogenic bacteria. Furthermore, cloning of the LBP promoter revealed the presence of regulatory elements, including the common APR promoter motif APRE/STAT-3 (acute-phase response element/signal transducer and activator of transcription 3). Luciferase reporter gene assays utilizing LBP promoter truncation and point mutation variants indicated that transcriptional activation of the LBP gene required a functional APRE/STAT-3 binding site downstream of the transcription start site, as well as an AP-1 and a C/EBP (CCAAT enhancer-binding protein) binding site. Gel retardation and supershift assays confirmed that upon cytokine stimulation APRF/STAT-3 binds to its recognition site, leading to strong activation of the LBP gene. Unraveling of the mechanism of transcriptional activation of the LBP gene, involving three known transcription factors, may contribute to our understanding of the acute-phase response and the pathophysiology of sepsis and septic shock.
Mol Cell Biol 1996 Jul
PMID:The lipopolysaccharide-binding protein is a secretory class 1 acute-phase protein whose gene is transcriptionally activated by APRF/STAT/3 and other cytokine-inducible nuclear proteins. 866 65


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