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)

The insulin-like growth factors (IGF-I and IGF-II) participate in the control of cell proliferation in normal and neoplastic lung cells. To examine the role of IGF binding proteins (IGFBPs) in modulating IGF actions in lung, we examined the production and regulation of IGFBPs from A549 cells, a human adenocarcinoma-derived lung cell line. Ligand blot and immunoblot analysis of conditioned media (CM) from A549 cells demonstrated IGFBP bands of relative molecular mass (M(r)) approximately 39-43,000 (IGFBP-3), 34,000 (IGFBP-2), 30,000 (IGFBP-1), and 24,000 (IGFBP-4). IGFBP-3 abundance in A549 cell CM increased following exposure to IGF-I and IGF-II (3.0- and 1.8-fold, respectively) without a change in IGFBP-3 transcript abundance, suggesting IGFBP-3 is post-transcriptionally regulated. Cycloheximide almost completely abrogated the IGF-I-stimulated increase in CM IGFBP-3, suggesting that ongoing protein synthesis is necessary for the IGF-I-stimulated increase in IGFBP-3 abundance. Increases in IGFBP-3 occurred by at least two mechanisms, through activation of the type 1 IGF receptor and by a type 1 IGF receptor independent mechanism. The increase in IGFBP-3 was due, in part, to activation of the type 1 IGF receptor because blocking type 1 IGF receptor activation with an antibody (alpha IR3) diminished the IGF-I-induced increase in IGFBP-3 and insulin, at doses that stimulate the type 1 IGF receptor, increased IGFBP-3 abundance. The increase in IGFBP-3 was partially independent of type 1 IGF receptor activation because [QAYL]-IGF-I, an analog of IGF-I that binds the type 1 IGF receptor but not IGFBP-3, was less potent than IGF-I in stimulating IGFBP-3 abundance, and IGF-II, which binds IGFBP-3 normally, but binds the type 1 IGF receptor with lower affinity than IGF-I, was nearly equipotent to IGF-I in its stimulation of IGFBP-3 accumulation at low concentrations. These results suggest that ligand binding decreases IGFBP-3 clearance or increases IGFBP-3 accumulation in CM. IGF-I decreased IGFBP-4 abundance in A549 cell CM without decreasing IGFBP-4 mRNA transcripts and without increasing the amount of cell-associated IGFBP-4. To determine whether the decrease in IGFBP-4 was due to increased degradation, cell-free CM was incubated with and without IGF-I, and IGFBP-4 abundance measured by ligand and immunoblot analyses.(ABSTRACT TRUNCATED AT 400 WORDS)
Am J Respir Cell Mol Biol 1995 Oct
PMID:Insulin-like growth factor-I (IGF-I) regulates IGFBP-3 and IGFBP-4 by multiple mechanisms in A549 human adenocarcinoma cells. 754 77

This study was designed to evaluate the effects of cycloheximide and puromycin on activation and protein synthesis of porcine oocytes. When matured oocytes were electrostimulated, then cultured in the presence of cycloheximide (5 micrograms/ml) for 6 or 24 hr, 92% of oocytes were activated as indicated by pronuclear formation, vs. 2.8% for untreated oocytes, 5.3% for oocytes not electrostimulated but cultured with cycloheximide, and 60.0% for those only electrostimulated. When cultured with L-[35S]methionine in the presence of cycloheximide, puromycin (100 micrograms/ml), or no protein synthesis inhibitor for 24 hr, oocytes had mean radiolabeled incorporation rates of 36.5, 2.21, and 32.0 fmol/4 hr/oocyte, respectively. Thus, cycloheximide had little effect on protein synthesis after 24 hr of culture. A 1D-SDS PAGE showed that oocytes cultured with puromycin or cycloheximide are not activated, while electrostimulated oocytes are activated, as characterized by the conversion of a 25-kDa polypeptide to a 22-kDa polypeptide. The radiolabeling experiment was repeated, except that oocytes were cultured for 4 or 24 hr. At 4 hr, mean incorporation rates were lower in the cycloheximide group (2.34 fmol/4 hr/oocyte), but similar in the puromycin (15.7 fmol/4 hr/oocyte) and control groups (18.9 fmol/4 hr/oocyte). At 24 hr, the puromycin group 5.73 fmol/4 hr/oocyte) had a lower rate of incorporation, while the cycloheximide (22.6 fmol/4 hr/oocyte) and control (26.0 fmol/4 hr/oocyte) groups were similar. Cycloheximide was more effective earlier during culture, while puromycin was more effective later. When combined with ES, puromycin did have a higher rate (P = 0.10) of activation (87.8%) than with electrostimulation alone (73.0%).(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Reprod Dev 1995 May
PMID:Differential effects of protein synthesis inhibitors on porcine oocyte activation. 761 8

Microinjection into bovine zygotes was performed to evaluate the effects of the timing of injection during the phase of DNA replication on the subsequent in vitro development of embryos and expression of injected chicken beta-actin promoter-lac Z gene construct. The period of DNA replication of bovine zygotes, determined by 3H-thymidine incorporation, begins between 12 hr and 13 hr postinsemination (hpi) of in vitro matured oocytes, reaches a maximum from 17 hpi to 19 hpi, and is complete by 21-22 hpi. Aphidicolin, an inhibitor of DNA polymerase alpha, was used to synchronize the pronuclei and the zygote population. Treatment with aphidicolin at 9-18 hpi arrested DNA replication without affecting formation of the pronuclei or embryo development. Cycloheximide, an inhibitor of protein synthesis, was used for nucleocytoplasmic resynchronization of the aphidicolin-treated zygotes. Microinjection was performed at 15 (early), 18 (mid), and 21 (late S phase) hpi. Embryonic development was affected following each of the three microinjection times. The development of zygotes injected at 18 hpi was significantly higher (P < 0.01) after 5 days of culture than those injected at 15 hpi or 21 hpi. Expression of the marker gene was observed in the higher stage of development (> 16 cells) only in the zygotes injected at 18 hpi. At the earlier stages of development, the proportions of embryos showing expression of the foreign gene were the same for all microinjection times. In aphidicolin- and cycloheximide-treated zygotes, expression of the marker gene followed the same curve as development, i.e., expression was low when injected early or late and higher (P < 0.005) when injected in the middle of zygotic S phase. The ability of the embryos to survive microinjection and to express the marker gene as a function of hpi seems to be influenced mostly in the cytoplasm processing stage rather than the pronuclei processing stage.
Mol Reprod Dev 1995 Jun
PMID:Effect of microinjection time during postfertilization S-phase on bovine embryonic development. 765 72

The plant hormone auxin transcriptionally activates early genes. We have isolated a 14-member family of DNA sequences complementary to indoleacetic acid (IAA)-inducible transcripts in Arabidopsis thaliana. The corresponding genes, IAA1 to IAA14, are homologs of PS-IAA4/5 and PS-IAA6 from pea, Aux22 and Aux28 from soybean, ARG3 and ARG4 from mungbean, and AtAux2-11 and AtAux2-27 from Arabidopsis. The members of the family are differentially expressed in mature Arabidopsis plants. Characterization of IAA gene expression in etiolated seedlings demonstrates specificity for auxin inducibility. The response of most family members to IAA is rapid (within 4 to 30 minutes) and insensitive to cycloheximide. Cycloheximide alone induces all the early genes. Auxin-induction of two late genes, IAA7 and IAA8, is inhibited by cycloheximide, indicating requirement of protein synthesis for their activation. All IAA genes display a biphasic dose response that is optimal at 10 microM IAA. However, individual genes respond differentially between 10 nM and 5 microM IAA. Expression of all genes is defective in the Arabidopsis auxin-resistant mutant lines axr1, axr2 and aux1. The encoded polypeptides share four conserved domains, and seven invariant residues in the intervening regions. The spacers vary considerably in length, rendering the calculated molecular mass of IAA proteins to range from 19 kDa to 36 kDa. Overall sequence identity between members of the family is highly variable (36 to 87%). Their most significant structural features are functional nuclear transport signals, and a putative beta alpha alpha-fold whose modeled three dimensional structure appears to be compatible with the prokaryotic beta-ribbon DNA recognition motif. The data suggest that auxin induces in a differential and hierarchical fashion a large family of early genes that encode a structurally diverse class of nuclear proteins. These proteins are proposed to mediate tissue-specific and cell-type restricted responses to the hormone during plant growth and development.
J Mol Biol 1995 Aug 25
PMID:The PS-IAA4/5-like family of early auxin-inducible mRNAs in Arabidopsis thaliana. 765 71

The role of protein synthesis in sex hormone-binding globulin (SHBG) secretion and gene expression was studied in HepG2 cell cultures. Inhibition of protein synthesis by cycloheximide suppressed SHBG levels. Triiodothyronine and estradiol increased SHBG production, and cycloheximide reduced their effects to an extent which correlated with the degree of suppression obtained with the drug alone. Insulin decreased SHBG production, and the effect of the treatment with insulin and cycloheximide together did not differ from that with cycloheximide alone. Cycloheximide did not, alone or with the hormones, decrease SHBG levels more markedly extra- than intracellularly. Therefore, cycloheximide does not impair the secretion of SHBG which is synthesized in the presence of the drug. In contrast to SHBG protein levels, cycloheximide increased SHBG mRNA levels. When the effect of cycloheximide on the rate of SHBG mRNA decay was tested, the drug was found to extend the half-life of SHBG mRNA. Of the hormones, insulin decreased and triiodothyronine modestly increased SHBG mRNA levels, whereas estradiol had no clear effect. Treatment with cycloheximide together with any of the hormones resulted in an increase in SHBG mRNA levels. We conclude that protein synthesis inhibition does not impair the secretion of SHBG produced under such conditions, but stabilizes SHBG mRNA by removing some hepatic protein species involved in the regulation of its degradation.
J Steroid Biochem Mol Biol 1995 Aug
PMID:Regulation of sex hormone-binding globulin secretion and gene expression by cycloheximide in vitro. 766 87

The growth-regulating actions of IGFs are modulated by their binding proteins (IGFBPs). The serum concentration of IGFBP-1 is down-regulated by insulin, and in-vitro studies have demonstrated that IGFBP-1 secretion from various tissues and cells can be stimulated by theophylline, forskolin, oestrogen and progesterone. We have studied the effects and mechanisms of thyroid hormone action on IGFBP-1 gene expression and secretion by human hepatoma cells in vitro. Tri-iodothyronine dose-dependently enhanced IGFBP-1 secretion in serum-free HepG2 cell cultures after 24-48 h of exposure, as measured by a specific immunofluorometric assay. This was accompanied by an increase (+ 50%) in the amount of IGFBP-1 mRNA, which could be prevented by cycloheximide, a protein synthesis inhibitor. Cycloheximide transiently enhanced (+ 200%) the accumulation of IGFBP-1 mRNA at 3-12 h of incubation, when no effect of tri-iodothyronine was observed. It is concluded that thyroid hormone stimulates IGFBP-1 secretion slowly by enhancing IGFBP-1 gene expression by a protein mediator. The acute stimulation of IGFBP-1 gene transcription by cycloheximide associates this gene with a number of growth-related genes encoding growth- and tumour-associated peptides.
J Mol Endocrinol 1993 Feb
PMID:Tri-iodothyronine and cycloheximide enhance insulin-like growth factor-binding protein-1 gene expression in human hepatoma cells. 768 Aug 63

Endothelin-1 (ET-1) mRNA is expressed by the human placenta in a developmentally regulated manner and has been shown to stimulate the growth of placental mesenchymal cells. The ability of placental fibroblasts to express preproET-1 mRNA was studied to determine if ET-1 could potentially participate via autocrine mechanisms in the proliferation of placental fibroblasts. Fibroblasts were isolated from normal placentae at various gestational ages (7-19 weeks and term) and their abilities to express preproET-1 mRNA in culture evaluated by Northern analysis. Sparse, rapidly growing cultures of placental fibroblasts expressed preproET-1 mRNA at each gestational age in the presence of 10% FBS. The regulation of preproET-1 expression in placental fibroblasts was studied by exposing cells to known mitogenic stimuli. Quiescent, confluent monolayers of placental fibroblasts expressed no detectable levels of preproET-1 mRNA under basal conditions. Epidermal growth factor (EGF, 10 mg/ml), transforming growth factor-beta 1 (TGF-beta 1, 5 ng/ml), or interleukin 1 beta (IL-1 beta) alone, had no significant effect on steady state preproET-1 mRNA levels. Cycloheximide, an inhibitor of protein synthesis, increased the steady state levels of preproET-1 mRNA at a concentration of 10 micrograms/ml. In the presence cycloheximide, IL-1 beta markedly stimulated preproET-1 mRNA expression, whereas EGF was less effective. TGF-beta 1 had no effect in the presence or absence of cycloheximide. In contrast, 12-O-tetradecanoylphorbol 13-acetate (TPA, 20 nM) exerted a small stimulatory effect on preproET-1 mRNA expression which was not influenced by cycloheximide.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Cell Endocrinol 1995 Mar
PMID:Human placental endothelin: expression of endothelin-1 mRNA by human placental fibroblasts in culture. 778 12

Tumor necrosis factor-alpha (TNF-alpha) is a multifunctional, proinflammatory cytokine that is capable of activating a diverse number of target genes within multiple cell types. Little information is known regarding the role of TNF-alpha in the regulation of human airway mucin hypersecretion and MUC-2 gene expression. To assess the effect of TNF-alpha exposure on mucin secretion, human airway organ cultures and primary cultures of human airway epithelial cells were stimulated with 20 ng/ml of recombinant human TNF-alpha and mucin secretion quantitated by an enzyme-linked immunosorbent assay using a specific monoclonal antibody directed against human airway mucin. Significant increases in mucin secretion from human airway organ cultures were initially detected at 1 h, peaked at 8 h, and persisted for 24 h. The TNF-alpha-mediated mucin hypersecretion at 8 h was concentration dependent. Significant increases in mucin secretion from primary cultures of human airway epithelial cells were initially detected at 4 h, peaked at 48 h, and persisted for 72 h after stimulation with 20 ng/ml of recombinant human TNF-alpha. The TNF-alpha-mediated mucin hypersecretion at 48 h from primary cultures of human airway epithelial cells was inhibited by coincubation with soluble 55 kD, type I TNF receptors. Using reverse transcription-polymerase chain reaction and a human pulmonary mucoepidermoid carcinoma cell line (NCI-H292), increases in MUC-2 steady-state mRNA levels were first detectable after 30 min of TNF-alpha stimulation and persisted for 24 h. Cycloheximide did not inhibit TNF-alpha-mediated MUC-2 mRNA expression at 1 h, suggesting that new protein translation was not required.(ABSTRACT TRUNCATED AT 250 WORDS)
Am J Respir Cell Mol Biol 1995 Feb
PMID:Tumor necrosis factor-alpha induces mucin hypersecretion and MUC-2 gene expression by human airway epithelial cells. 786 17

We have previously shown that both forskolin (F) and phorbol ester (P) induce neuropeptide Y (NPY) production by aggregate cultures formed from dissociated fetal rat brains. In this study, we addressed the question: Do F/P induce NPY-mRNA in aggregate cultures and if so, does induction require active protein kinases and on-going protein synthesis? On Northern blots, the NPY cDNA hybridized to a single species of about 0.8 kb. F and P each induced a time-dependent increase in NPY-mRNA relative abundance, and this was inhibited by staurosporine, an inhibitor of both protein kinase A and C. Cycloheximide (CHX) inhibited F/P induction of mRNA in a time-dependent manner. When aggregates were incubated with F+P for a total 12 h period, CHX added along with F+P (0 h) completely inhibited, CHX added 1.5 h after F+P partially inhibited, and CHX added 6 h after F+P did not inhibit the increase in NPY-mRNA. To rule out the possibility that this inhibitory profile reflects toxicity of CHX, blots were re-hybridized with a SRIF cRNA probe and, as expected for SRIF gene, a 12 h exposure to CHX did not inhibit F+P induction of SRIF-mRNA. Close inspection of the blots (derived from 1.5% agarose gels) suggested the presence in F/P-treated aggregates of 2 species NPY-mRNA [approximately 0.75 and approximately 0.85 kb, most likely differing in the length of poly(A) tail (Jamal et al., 1991)]; size-fractionation on a higher resolution gel (3% agarose) resolved the F/P induced mRNA into 2 distinct bands, while mRNA from untreated cultures migrated as a single band--the 0.75 kb.(ABSTRACT TRUNCATED AT 250 WORDS)
Mol Cell Endocrinol 1993 Aug
PMID:An early and transient period of protein synthesis is required for induction of neuropeptide Y-mRNA by phorbol ester and forskolin in aggregate cultures of fetal brain cells. 790 Nov 1

Alveolar macrophages (AM) play a regulatory role in asthma. AM from asthmatics are activated, release increased amounts of cytokines, and express higher levels of the low affinity receptor for IgE (Fc epsilon RIIb/CD23b) and receptors for adhesion molecules. The bronchial microenvironment may modulate the phenotypic and functional characteristics of AM. On AM from normal subjects, the effects of histamine were studied on the expression of adhesion molecules (LFA-1, ICAM-1) and CD23b as well as on the release of fibronectin. The expression of LFA-1, ICAM-1, and CD23b was examined by immunocytochemistry using the alkaline phosphatase-anti-alkaline phosphatase technique. The expression of CD23b mRNA was studied by in situ hybridization. The release of fibronectin was measured by enzyme immunoassay. We found that histamine induced in a dose- and time-dependent fashion a significant increase of AM expressing the three membrane markers and a significant increase in the release of fibronectin. The maximum effect of histamine was observed after an incubation of 12 to 24 h and a dose of 1 microM. The histamine effects were specific, since they were significantly inhibited by an H1-blocker, pyrilamine, used at a concentration of 10 microM. The effect of an H2-blocker (ranitidine, concentration of 10 microM) was inconstant. Cycloheximide blocked the histamine effects, suggesting that it requires protein synthesis for its action. This study provides an in vitro model of cellular interaction between mast cells and AM, which might be relevant in the airway inflammation in asthma.
Am J Respir Cell Mol Biol 1994 Oct
PMID:Phenotypic and functional modulation of normal human alveolar macrophages by histamine. 791 13


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