Cyclooxygenase products formed by primary cultures of cells from human chorion laeve: influence of steroids

1988 ◽  
Vol 66 (6) ◽  
pp. 788-793 ◽  
Author(s):  
W. Gibb ◽  
L. Riopel ◽  
R. Collu ◽  
J. R. Ducharme ◽  
M. D. Mitchell ◽  
...  

Cells were isolated from human chorion laeve obtained at term (38–40 weeks gestation) by elective caesarean section and were maintained in primary culture for 1 week in defined media supplemented with 10% fetal calf serum. The production of various cyclooxygenase products by the cultures was examined. Little or no prostaglandin (PG) F2α, 6-keto-PGF1α, thromboxane B2, or 13,14-dihydro-15-keto-PGF2α was found. In contrast, the cells produced PGE2 which was low on day 0, increased during culture to a maximum on day 1 or 2, then declined to low levels. When cells were grown in the presence of media containing cortisol, dexamethasone, progesterone, and estradiol (at 10−7 or 10−9 M), the glucocorticoids (at 10−7 and 10−9 M), but not estrogen or progesterone, markedly inhibited the increase in PGE2 output. There was no difference in the protein content and thymidine incorporation of cells grown in the presence of glucocorticoids when compared with controls. This inhibitory effect was not sensitive to cycloheximide (1 μg/mL) indicating protein synthesis may not be involved in the process. These studies indicate that PGE2 is the major prostaglandin formed by primary cultures of chorion laeve and that prostaglandin metabolism in the chorion is sensitive to glucocorticoid inhibition.

1997 ◽  
Vol 272 (4) ◽  
pp. H1996-H2003 ◽  
Author(s):  
R. C. Bhalla ◽  
K. F. Toth ◽  
R. A. Bhatty ◽  
L. P. Thompson ◽  
R. V. Sharma

Epidemiological evidence and estrogen replacement studies suggest that estrogen has a protective effect on the cardiovascular system against coronary artery disease. Vascular smooth muscle (VSM) cell replication has been shown to play a causative role in the pathogenesis of atherosclerosis. Therefore, in this study, we investigated the effect of chronic treatment of cultured guinea pig coronary artery VSM cells with physiological concentrations of 17beta-estradiol (E2) on thymidine incorporation, cell proliferation, and bradykinin-stimulated cytosolic calcium concentration ([Ca2+]i). Bradykinin at physiological concentrations causes contraction of endothelium-denuded guinea pig coronary artery rings in a concentration-dependent manner. VSM cells were first treated with low doses of E2 (10 pg/ml) for 1-2 days followed by treatment for 4-6 days with 50 pg/ml of E2, a concentration similar to that found in pregnancy. Using these protocols, we consistently observed the presence of E2-receptor mRNA in VSM cells by a ribonuclease protection assay. Fetal calf serum-stimulated [3H]thymidine incorporation was significantly reduced (P < 0.05) in E2-treated cells compared with untreated control cells. Similarly, E2 treatment significantly inhibited fetal calf serum-stimulated VSM cell proliferation compared with untreated control cells (P < 0.05). We also tested the hypothesis that E2 treatment attenuates agonist-stimulated [Ca2+]i in VSM cells because acute E2 treatment has been shown to produce relaxation of precontracted isolated coronary artery preparations. E2 treatment of VSM cells resulted in a significant decrease in bradykinin-stimulated [Ca2+]i compared with untreated cells (P < 0.05). In conclusion, our data demonstrate that estrogen at physiological concentrations directly regulates coronary VSM cell function.


1996 ◽  
Vol 17 (2) ◽  
pp. 131-138 ◽  
Author(s):  
C Svensson

ABSTRACT This study was undertaken to investigate the effects of growth hormone (GH) on the in vitro maturation of the metabolism of fetal rat islets. For this purpose fetal islets were obtained from 21-day-old fetuses by mild collagenase digestion of the pancreas and cultured in RPMI 1640 supplemented with 10% fetal calf serum. After one day the medium was changed and supplemented with 1% fetal calf serum with or without GH (1 μg/ml, human recombinant) and the islets cultured for another two days. Islets were then studied with regard to insulin secretion, (pro)insulin and total protein biosynthesis, glucose utilization and oxidation, thymidine incorporation, insulin and DNA contents and the contents of mRNAs for either insulin, adenine nucleotide translocator or cytochrome b. In addition, the activities of glucose phosphorylating enzymes and succinate-cytochrome c reductase were measured. Islets treated with GH showed increased insulin secretion in response to glucose, increased rates of glucose oxidation and utilization, increased thymidine incorporation and increased activities of succinate cytochrome c reductase and glucose phosphorylation at high glucose concentrations. There were, however, no changes in (pro)insulin and total protein biosynthesis, contents of insulin and DNA or the contents of any of the mRNAs. These combined data show that fetal β-cells are sensitive to growth hormone with respect to glucose metabolism, insulin release and DNA replication. The increased rates of islet glucose phosphorylation may reflect glucokinase activity and explain part of the increased insulin responsiveness to glucose of the fetal rat β-cell. These observations suggest that GH is of physiological significance for the maturation of the fetal β-cell.


1987 ◽  
Vol 72 (1) ◽  
pp. 71-79 ◽  
Author(s):  
V. M. S. Oh ◽  
E. A. Taylor ◽  
J. L. Ding ◽  
N. A. Boon ◽  
J. K. Aronson ◽  
...  

1. We have measured specific [3H]ouabain binding and ouabain sensitive 86rubidium influx in intact human lymphocytes incubated for up to 7 days in media containing different concentrations of fetal calf serum and human serum. 2. Incubation for periods of up to 7 days with fetal calf serum and human serum produced increases in both specific [3H]ouabain binding and ouabain sensitive 86rubidium influx that were dependent on concentration and time. 3. Neither specific [3H]ouabain binding nor ouabain sensitive 86rubidium influx was altered when dialysed serum was used, suggesting that both fetal calf serum and human serum contain a dialysable factor or factors which stimulate specific [3H]ouabain binding and ouabain sensitive 86rubidium influx in intact human lymphocytes. 4. To further elucidate the mechanisms underlying these changes we also measured the activity of two other enzymes of the lymphocyte plasma membrane, 5′-nucleotidase and γ-glutamyltransferase, the uptake of [3H]thymidine by the intact cells, and the effects of cycloheximide, puromycin, and anisomycin, inhibitors of protein synthesis. 5. The activity of 5′-nucleotidase was increased after incubation of the lymphocytes in fetal calf serum for 72 h, but the activity of γ-glutamyltransferase was not changed, suggesting some selectivity of the stimulatory effect. 6. Measurements of [3H]thymidine uptake by the lymphocytes showed that the major part of the observed changes in specific [3H]ouabain binding and ouabain sensitive 86rubidium influx was not attributable to transformation of the lymphocytes to lymphoblasts. 7. All three inhibitors of protein synthesis prevented the increase in specific [3H]ouabain binding due to fetal calf serum.


Blood ◽  
1996 ◽  
Vol 88 (4) ◽  
pp. 1284-1296 ◽  
Author(s):  
N Debili ◽  
L Coulombel ◽  
L Croisille ◽  
A Katz ◽  
J Guichard ◽  
...  

The aim of the present study was to determine if the human erythroid (E) and megakaryocytic (MK) lineages were closely linked to the existence of a bipotent burst-forming unit (BFU) E/MK progenitor. In methylcellulose cultures, BFU-E/MK colonies were observed at day 12 and closely resembled mature BFU-E with the exception that the erythroid component was surrounded by MK. These colonies were quite different from the colony forming unit (CFU)-GEMM-derived colonies, which were composed of a larger number of erythroblasts and which developed later in culture. The existence of these bilineage colonies composed of 100 to 1,000 erythroblasts intermingled with a few MK and without granulocytic cells was confirmed by the plasma clot technique and immunoalkaline phosphatase labeling of the MK. To investigate if this bipotent progenitor belonged to the compartment of primitive progenitors, CD34+ marrow cells were subfractionated according to expression of the CD38 antigen. The bipotent BFU-E/MK progenitor as well as a large fraction of MK progenitors were found in the CD34+ CD38+/- or in the CD34+ CD38- cell fractions. Growth of this bipotent BFU-E/MK progenitor required the combination of stem cell factor (SCF), Interleukin-3 (IL-3), and Epo in serum free conditions. Addition of IL- 6 had only a marginal effect, whereas megakaryocyte growth and development factor (MGDF) was not an absolute requirement, but slightly increased the plating efficiency of CFU-MK and of BFU-E/MK progenitors when combined with SCF, IL-3, and Epo. In contrast, when these cultures were performed in the presence of 30% fetal calf serum, no BFU-E/MK colonies were observed irrespective of the combination of growth factors used, including the presence of MGDF; however, inclusion of the MS-5 cell line restored the growth of this bipotent progenitor. In contrast, in cultures performed in the presence of human normal or aplastic plasma, MS-5 had only a slight effect on the cloning efficiency but improved MK cytoplasmic maturation and MK size, suggesting that the main effect of MS-5 is to diminish the inhibitory effect of the fetal calf serum on the MK differentiation. The clonal origin of bipotent BFU-E/MK colonies was demonstrated in liquid culture of single CD34+ CD38low cells by immunophenotyping individual clones. At day 12, 30% of the clones contained erythroblasts (glycophorin A+) and some MK (CD41+) without granulocytes (G) or macrophages (M) (CD14+ and CD15+). At day 20, clones containing erythroblasts and MK were rare (5%). In contrast multilineage clones could be frequently detected at this time without passage from BFU-E/MK clones at day 12 to GEMM at day 20. These results suggest that a bipotent BFU-E/MK progenitor may be a nonrandom step in the hierarchical development of stem cells.


1990 ◽  
Vol 21 (2) ◽  
pp. 223-225 ◽  
Author(s):  
J.L. Jardine ◽  
S.D. Miller ◽  
H.J. Koornhof

Author(s):  
A. B. Taylor ◽  
G. C. Cole ◽  
M. A. Holcomb ◽  
C. A. Baechler

An aliquot from a continuous fermenter culture of baby hamster kidney cells (BHK-21 Clone PD-4) (Wistar) maintained in Ca free Eagle's Basal Medium containing 2% Kaolin adsorbed fetal calf serum was planted in spinner flasks at 300,000 cells per ml, total volume 600 ml. After equilibration for one day at 35°C to insure that cells were in log phase, the culture was infected with the M-33-AGMK25 BHK-219 strain of rubella at an input multiplicity of about 6 TCID50 per cell. The virus was identified with specific rubella antiserum.Preliminary experiments had shown that such cultures would reach a peak or plateau HA titer of approximately 1:64, 24 hrs after inoculation and would continue to yield virus for 6 to 12 days. One hundred ml aliquot harvests were withdrawn daily and the culture was returned to volume with growth medium and incubation continued. The harvested cells were spun down rapidly at 2500 rpm per 15 mins., fixed in 3.7% gluteraldehyde in Ca free phosphate buffer saline, and post fixed in osmium tetraoxide. After dehydration, the cells were embedded in Epon 812 and cured approximately 20 hrs at 60°C.


Author(s):  
Li-Chu Tung ◽  
Yung-Reui Chen ◽  
Shiu-Nan Chen ◽  
Guang-Hsiung Kuo

In the present study, the ultrastructural changes of BPK cells, a fibroblast-like cell line, derived from the kidney of juvenile black porgy Acanthopagrus schlegeli, under heat shock treatment are described.The BPK cells were maintained in L-15 medium supplemented with 10% fetal calf serum and 0.15 M NaCl at 28|C2. The heating was carried out in precalibrated water baths. Monolayers of cells, grown on coverslips in parafilm-sealed petri dishes were submerged under water for 30 min at 40|C treatments. Cells were fixed in 2.5% glutaraldehyde in 0.1 M cacodylate buffer supplemented with 6.6% sucrose, postfixed in 1% OsO4 and flat embedded in Spurr’s resin. Silver section were cut parallel to the substratum, stained with uranyl acetate and Reynold’s lead citrate, and examined in a Hitachi H-600 electron microscope at 75 KV.


Blood ◽  
1990 ◽  
Vol 75 (9) ◽  
pp. 1862-1869 ◽  
Author(s):  
P Constantoulakis ◽  
B Nakamoto ◽  
T Papayannopoulou ◽  
G Stamatoyannopoulos

Abstract Cultures of peripheral blood or bone marrow erythroid progenitors display stimulated production of fetal hemoglobin. We investigated whether this stimulation is due to factors contained in the sera of the culture medium. Comparisons of gamma/gamma + beta biosynthetic ratios in erythroid colonies grown in fetal calf serum (FCS) or in charcoal treated FCS (C-FCS) showed that FCS-grown cells had significantly higher gamma/gamma + beta ratios. This increase in globin chain biosynthesis was reflected by an increase in relative amounts of steady- state gamma-globin mRNA. In contrast to its effect on adult cells, FCS failed to influence gamma-chain synthesis in fetal burst forming units- erythroid (BFU-E) colonies. There was a high correlation of gamma- globin expression in paired cultures done with C-FCS or fetal sheep serum. Dose-response experiments showed that the induction of gamma- globin expression is dependent on the concentration of FCS. These results indicate that FCS contains an activity that induces gamma- globin expression in adult erythroid progenitor cell cultures.


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