The Experts below are selected from a list of 252 Experts worldwide ranked by ideXlab platform
Rena Lecanidou - One of the best experts on this subject based on the ideXlab platform.
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a novel role for the bombyx slbo homologue bmc ebp in insect choriogenesis
Biochemical and Biophysical Research Communications, 2005Co-Authors: S. Sourmeli, Argyris Papantonis, Rena LecanidouAbstract:One previously unidentified cDNA clone coding for a C/EBP factor, BmC/EBP, was isolated from Bombyx mori follicular cells. This is the first time that a C/EBP factor has been isolated and characterized in Lepidoptera. We provide information concerning structural features and developmental specificity, as well as in vitro interaction properties with Chorion gene promoter modules. BmC/EBP was capable of effectively recognizing homologous binding sites from Chorion gene promoters derived from flies and other moths, despite significant diversity of Chorion structure, gene organization, and gene expression profiles. We propose that the relative concentration of BmC/EBP, in relation to its differential binding affinity for promoter cis-elements, results in activation or repression of silkmoth Chorion gene expression.
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A novel role for the Bombyx Slbo homologue, BmC/EBP, in insect choriogenesis.
Biochemical and Biophysical Research Communications, 2005Co-Authors: S. Sourmeli, Argyris Papantonis, Rena LecanidouAbstract:One previously unidentified cDNA clone coding for a C/EBP factor, BmC/EBP, was isolated from Bombyx mori follicular cells. This is the first time that a C/EBP factor has been isolated and characterized in Lepidoptera. We provide information concerning structural features and developmental specificity, as well as in vitro interaction properties with Chorion gene promoter modules. BmC/EBP was capable of effectively recognizing homologous binding sites from Chorion gene promoters derived from flies and other moths, despite significant diversity of Chorion structure, gene organization, and gene expression profiles. We propose that the relative concentration of BmC/EBP, in relation to its differential binding affinity for promoter cis-elements, results in activation or repression of silkmoth Chorion gene expression.
S. Sourmeli - One of the best experts on this subject based on the ideXlab platform.
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a novel role for the bombyx slbo homologue bmc ebp in insect choriogenesis
Biochemical and Biophysical Research Communications, 2005Co-Authors: S. Sourmeli, Argyris Papantonis, Rena LecanidouAbstract:One previously unidentified cDNA clone coding for a C/EBP factor, BmC/EBP, was isolated from Bombyx mori follicular cells. This is the first time that a C/EBP factor has been isolated and characterized in Lepidoptera. We provide information concerning structural features and developmental specificity, as well as in vitro interaction properties with Chorion gene promoter modules. BmC/EBP was capable of effectively recognizing homologous binding sites from Chorion gene promoters derived from flies and other moths, despite significant diversity of Chorion structure, gene organization, and gene expression profiles. We propose that the relative concentration of BmC/EBP, in relation to its differential binding affinity for promoter cis-elements, results in activation or repression of silkmoth Chorion gene expression.
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A novel role for the Bombyx Slbo homologue, BmC/EBP, in insect choriogenesis.
Biochemical and Biophysical Research Communications, 2005Co-Authors: S. Sourmeli, Argyris Papantonis, Rena LecanidouAbstract:One previously unidentified cDNA clone coding for a C/EBP factor, BmC/EBP, was isolated from Bombyx mori follicular cells. This is the first time that a C/EBP factor has been isolated and characterized in Lepidoptera. We provide information concerning structural features and developmental specificity, as well as in vitro interaction properties with Chorion gene promoter modules. BmC/EBP was capable of effectively recognizing homologous binding sites from Chorion gene promoters derived from flies and other moths, despite significant diversity of Chorion structure, gene organization, and gene expression profiles. We propose that the relative concentration of BmC/EBP, in relation to its differential binding affinity for promoter cis-elements, results in activation or repression of silkmoth Chorion gene expression.
James C Cross - One of the best experts on this subject based on the ideXlab platform.
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cell cell adhesion defects in mrj mutant trophoblast cells are associated with failure to pattern the Chorion during early placental development
Developmental Dynamics, 2011Co-Authors: Erica D Watson, Martha Hughes, David G Simmons, David R C Natale, Ann Sutherland, James C CrossAbstract:Early placental development in mice involves patterning of the Chorion into distinct layers, though little is understood regarding the interactions that regulate its organization. Here we demonstrate that keratin aggregates found in Mrj(-/-) Chorionic trophoblast cells are associated with abnormal cell morphology, collapse of the actin cytoskeleton, E-cadherin and beta-catenin misexpression and extracellular matrix (ECM) disorganization. Accordingly, Mrj(-/-) trophoblast cells in vitro are nonadherent and display erratic migratory behavior. These cells also fail to differentiate into syncytiotrophoblast cells since Rhox4b expression, a marker of syncytiotrophoblast progenitors, was maintained and Gcm1, Synb, and Syna expression failed to increase. This differentiation defect was not solely attributable to E-cadherin misexpression or ECM disorganization. However, plating Mrj-deficient cells on exogenous laminin-511 normalized their cell behavior. Lastly, we show that Mrj(-/-) Chorions at embryonic day 8.5 have expanded Rhox4b expression domains and do not form normal layers of gene expression suggesting that Chorion patterning requires Mrj. Developmental Dynamics 240: 2505-2519, 2011. (C) 2011 Wiley Periodicals, Inc.
Murray D. Mitchell - One of the best experts on this subject based on the ideXlab platform.
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regulation of cultured human Chorion cell chemokine production by group b streptococci and purified bacterial products
American Journal of Reproductive Immunology, 1996Co-Authors: Donald J Dudley, Albina Dangerfield, Jennifer Van Waggoner, Samuel S. Edwin, Murray D. MitchellAbstract:PROBLEM : To determine if different strains of group B streptococci (GBS) and purified bacterial products regulate chemokine production by cultured human Chorion cells. METHOD OF STUDY : Primary cultures of human Chorion cells were established from placentae isolated from normal women at term gestation having repeat cesarean section. Five different strains of heat-killed GBS were incubated with confluent Chorion cells at 10 7 bacteria/ml for 16 hours at 37°C. In separate experiments, lipoteichoic acid and sialic acid at various concentrations were incubated with Chorion cells for 16 hours at 37°C. Culture supernatants were collected and then assayed to determine concentrations of interleukin-8 (IL-8) and macrophage inflammatory protein-1α (MIP-1α) by ELISA. RESULTS : We found that GBS stimulated Chorion cell production of MIP-1α in a strain-specific fashion. We also found that both lipoteichoic acid and sialic acid stimulated concentration-dependent increases in Chorion cell IL-8 production. Chorion cells, however, did not increase MIP-1α production in response to either lipoteichoic acid or sialic acid. Two strains of GBS tested induced concentration-dependent increases in both IL-8 and MIP-1α, but both stimulated IL-8 production to a greater extent. Similarly, IL-1β also caused Chorion cells to produce more IL-8 than MIP-1α. CONCLUSIONS : Our data are the first to show that GBS and purified bacterial products can stimulate chemokine production by fetal gestational tissues. We suggest that Chorion cells may produce specific types of chemokines to attract different types of inflammatory cells and thus may participate in the pathophysiology of infection-mediated preterm labor by directing specific inflammatory responses.
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Regulation of prostaglandin H synthase-2 in Chorion and decidual cells
Prostaglandins Leukotrienes and Essential Fatty Acids, 1996Co-Authors: Samuel S. Edwin, Michael S. Trautman, Murray D. MitchellAbstract:The regulation of chorio-decidual prostaglandin biosynthesis has important implications for our understanding of the mechanisms of human parturition. It has been known for many years that prostaglandin H synthase (PGHS) is a key enzyme in prostaglandin biosynthesis but recently an inducible form (PGHS-2) has been identified that is separate from the constitutive form (PGHS-1). We have evaluated whether substances known to stimulate prostaglandin biosynthesis in chorio-decidua act via PGHS-2. Human Chorion and decidual cells were grown to confluence and treated for up to 16 h with interleukin 1β 10 ng/ml), epidermal growth factor (EGF) (10 ng/ml) or phorbol 12-myristate 13-acetate (PMA) (10−7 M). Microsomal protein was isolated, separated by gel electrophoresis and PGHS-2 amounts determined using an antibody specific for PGHS-2. All three test agents caused an increase in PGHS-2 levels in Chorion cells (189%–288%) and decidual cells (153%–541%). Hence, induction of PGHS-2 is one of the mechanisms by which several substances can elevate the rate of prostaglandin biosynthesis.
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Biosynthesis of interleukin-6 by cultured human Chorion laeve cells: regulation by cytokines.
The Journal of Clinical Endocrinology and Metabolism, 1992Co-Authors: Donald J Dudley, Michael S. Trautman, Samuel S. Edwin, S. Lundin-schiller, Murray D. MitchellAbstract:Intrauterine infection is an important cause of preterm labor and delivery and is characterized by increased production of inflammatory cytokines by gestational tissues. We evaluated the biosynthesis of the inflammatory cytokine interleukin-6 (IL-6) by human Chorion laeve cells and its regulation by other cytokines essential to the inflammatory process. We found that cultured Chorion cells secrete IL-6 in the presence of growth medium supplemented only with 10% fetal calf serum. IL-1β, tumor necrosis factor, and lipopolysaccharide all induced a significant concentration-dependent stimulation of IL-6 production by Chorion cells. The concentration range of each cytokine tested (0.1-10 ng/mL) is within the range of values found in the amniotic fluid of women destined to deliver preterm due to infection of gestational tissues. Additionally, treatment of Chorion cells with IL-1β in combination with actinomycin-D or cycloheximide attenuated the stimulatory action of IL-1β on IL-6 production. Northern blot analysis of total RNA from cultured Chorion cells stimulated with IL-1β demonstrated that IL-6 mRNA increases over time. Our data suggest that IL-6 is produced by human fetal Chorion in response to infection of maternal gestational tissues. In conjunction with other inflammatory mediators, fetally derived IL-6 may play a role in the pathophysiology of preterm labor due to infection.
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Prostaglandin production by human Chorion laeve cells in response to inflammatory mediators
Placenta, 1991Co-Authors: S. Lundin-schiller, Murray D. MitchellAbstract:Abstract Cytokines produced during an intrauterine infection may cause increased prostaglandin production and thus preterm labor. Previously, we have shown that cytokines increase prostaglandin production by human amnion and decidual cells. In the present study we examined the effect ofinterleukin-1β (IL-1β), tumor necrosis factor (TNF), and endotoxin on prostaglandin production by Chorion laeve cells. Upon reaching confluence at day 3 and after 10 days in culture, human Chorion laeve cells in primary culture were incubated with each substance. On day 3 of culture the Chorion cells demonstrated limited responsiveness to the test agents with a maximum response of less than two times basal production. However, after 10 days the cultures were highly responsive to the test agents with maximum responses of greater than ten times basal production. We conclude that early in culture Chorion cells may express fewer functional receptors for the test agents. Alternatively, a subpopulation of Chorion cells responsive to cytokines and endotoxin may predominate by day 10 of culture. Chorion laeve, therefore, could contribute to the increased intrauterine prostaglandin production associated with infection-driven preterm labor.
Samuel S. Edwin - One of the best experts on this subject based on the ideXlab platform.
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regulation of decidual cell and Chorion cell production of interleukin 10 by purified bacterial products
American Journal of Reproductive Immunology, 1997Co-Authors: Donald J Dudley, Albina Dangerfield, Kirsten Jackson, Samuel S. Edwin, Michael S. TrautmanAbstract:PROBLEM: To determine whether cultured human decidual cells and Chorion cells produce interleukin-10 (IL-10) after incubation with purified bacterial products. METHOD OF STUDY: Decidual cell cultures and Chorion cell cultures were established by standard techniques. With confluence, monolayers of each culture were incubated with purified bacterial products, including various concentrations of lipopolysaccharide (LPS), lipid A, and lipoteichoic acid (LTA) for 16 hr in quadruplicate. Culture supernatants were collected and assayed for immunodetectable IL-10 by enzyme-linked immunoadsorbent assay (ELISA). RESULTS: Both decidual cell cultures and Chorion cell cultures produced significant quantities of IL-10 after stimulation with LPS, lipid A, and LTA. Cultures of decidual cells produced more IL-10 than did Chorion cell cultures. CONCLUSIONS: Our data indicate that both maternal decidual cells and fetally derived Chorion cells can produce IL-10 after incubation with bacterial virulence factors. This finding contrasts with our previous findings in which Chorion cells did not produce IL-10 after stimulation with IL-1β, suggesting that Chorion cell production after incubation with bacterial products is independent of IL-1β. We speculate that the contribution of anti-inflammatory IL-10 production by human gestational tissues to the inflammatory process in these tissues may be overcome or abrogated by the pro-inflammatory process.
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regulation of cultured human Chorion cell chemokine production by group b streptococci and purified bacterial products
American Journal of Reproductive Immunology, 1996Co-Authors: Donald J Dudley, Albina Dangerfield, Jennifer Van Waggoner, Samuel S. Edwin, Murray D. MitchellAbstract:PROBLEM : To determine if different strains of group B streptococci (GBS) and purified bacterial products regulate chemokine production by cultured human Chorion cells. METHOD OF STUDY : Primary cultures of human Chorion cells were established from placentae isolated from normal women at term gestation having repeat cesarean section. Five different strains of heat-killed GBS were incubated with confluent Chorion cells at 10 7 bacteria/ml for 16 hours at 37°C. In separate experiments, lipoteichoic acid and sialic acid at various concentrations were incubated with Chorion cells for 16 hours at 37°C. Culture supernatants were collected and then assayed to determine concentrations of interleukin-8 (IL-8) and macrophage inflammatory protein-1α (MIP-1α) by ELISA. RESULTS : We found that GBS stimulated Chorion cell production of MIP-1α in a strain-specific fashion. We also found that both lipoteichoic acid and sialic acid stimulated concentration-dependent increases in Chorion cell IL-8 production. Chorion cells, however, did not increase MIP-1α production in response to either lipoteichoic acid or sialic acid. Two strains of GBS tested induced concentration-dependent increases in both IL-8 and MIP-1α, but both stimulated IL-8 production to a greater extent. Similarly, IL-1β also caused Chorion cells to produce more IL-8 than MIP-1α. CONCLUSIONS : Our data are the first to show that GBS and purified bacterial products can stimulate chemokine production by fetal gestational tissues. We suggest that Chorion cells may produce specific types of chemokines to attract different types of inflammatory cells and thus may participate in the pathophysiology of infection-mediated preterm labor by directing specific inflammatory responses.
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Regulation of prostaglandin H synthase-2 in Chorion and decidual cells
Prostaglandins Leukotrienes and Essential Fatty Acids, 1996Co-Authors: Samuel S. Edwin, Michael S. Trautman, Murray D. MitchellAbstract:The regulation of chorio-decidual prostaglandin biosynthesis has important implications for our understanding of the mechanisms of human parturition. It has been known for many years that prostaglandin H synthase (PGHS) is a key enzyme in prostaglandin biosynthesis but recently an inducible form (PGHS-2) has been identified that is separate from the constitutive form (PGHS-1). We have evaluated whether substances known to stimulate prostaglandin biosynthesis in chorio-decidua act via PGHS-2. Human Chorion and decidual cells were grown to confluence and treated for up to 16 h with interleukin 1β 10 ng/ml), epidermal growth factor (EGF) (10 ng/ml) or phorbol 12-myristate 13-acetate (PMA) (10−7 M). Microsomal protein was isolated, separated by gel electrophoresis and PGHS-2 amounts determined using an antibody specific for PGHS-2. All three test agents caused an increase in PGHS-2 levels in Chorion cells (189%–288%) and decidual cells (153%–541%). Hence, induction of PGHS-2 is one of the mechanisms by which several substances can elevate the rate of prostaglandin biosynthesis.
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Biosynthesis of interleukin-6 by cultured human Chorion laeve cells: regulation by cytokines.
The Journal of Clinical Endocrinology and Metabolism, 1992Co-Authors: Donald J Dudley, Michael S. Trautman, Samuel S. Edwin, S. Lundin-schiller, Murray D. MitchellAbstract:Intrauterine infection is an important cause of preterm labor and delivery and is characterized by increased production of inflammatory cytokines by gestational tissues. We evaluated the biosynthesis of the inflammatory cytokine interleukin-6 (IL-6) by human Chorion laeve cells and its regulation by other cytokines essential to the inflammatory process. We found that cultured Chorion cells secrete IL-6 in the presence of growth medium supplemented only with 10% fetal calf serum. IL-1β, tumor necrosis factor, and lipopolysaccharide all induced a significant concentration-dependent stimulation of IL-6 production by Chorion cells. The concentration range of each cytokine tested (0.1-10 ng/mL) is within the range of values found in the amniotic fluid of women destined to deliver preterm due to infection of gestational tissues. Additionally, treatment of Chorion cells with IL-1β in combination with actinomycin-D or cycloheximide attenuated the stimulatory action of IL-1β on IL-6 production. Northern blot analysis of total RNA from cultured Chorion cells stimulated with IL-1β demonstrated that IL-6 mRNA increases over time. Our data suggest that IL-6 is produced by human fetal Chorion in response to infection of maternal gestational tissues. In conjunction with other inflammatory mediators, fetally derived IL-6 may play a role in the pathophysiology of preterm labor due to infection.