PubMed Health⌕ Search

Biomedical subjects

I Pellerin

Publications and source records attributed to I Pellerin.

8 recordsLinked to original sources
PubMed1992

Transfected endometrial cultured cells: a system to study gene-regulation by estrogens.

Glandular epithelial (GE) and stromal cells were isolated from guinea-pig endometrium, cultured and subcultured separately. At the end of subculture, the purity of each cell population was higher than 95% and cells displayed a high level of estrogen receptors. Calcium phosphate transfection conditions were defined using a control plasmid containing the bacterial CAT gene driven by viral promoter and enhancer sequences. Transfection experiments were performed with other plasmids in which CAT gene was linked to different estrogen response elements (EREs) derived from those of vitellogenin genes. CAT activity was significantly increased by estradiol-17 beta treatment only when GE or stromal cells were transfected with plasmids containing EREs previously reported as functional EREs in other cell types. This induction was abolished by ICI 164,384 diethylstilbestrol was as effective as estradiol-17 beta for CAT induction and estradiol-17 alpha was ineffective. Transiently transfected endometrial cells in subculture are a suitable system to study the estrogen effect on gene regulatory elements.

Animals↗
PubMed1992

Superinduction of c-fos gene expression by estrogen in cultured guinea-pig endometrial cells requires priming by a cycloheximide-dependent mechanism.

The c-fos gene expression is rapidly induced by various mitogenic agents and protein synthesis inhibitors in many cell types. Estradiol-17 beta can induce c-fos gene expression in breast cancer cell lines and in the uterus in vivo, but not in cultured guinea-pig endometrial cells. Using this model, we investigated whether a protein synthesis inhibitor, cycloheximide, could induce the c-fos gene and permit a superinduction by estrogens. In the presence of cycloheximide (10 micrograms/ml), protein synthesis was inhibited at 95% within the first hour. From 190 min after the addition of estradiol-17 beta or diethylstilbestrol (10(-8) M) and cycloheximide (10 micrograms/ml), there was a significant increase (ranging from 3- to 5-fold) of the c-fos messenger RNA level (2.2 kilobase in size), compared with the level in cells treated with cycloheximide alone. Nonestrogenic steroid hormones and estradiol-17 alpha were unable to induce c-fos gene expression in the presence of cycloheximide. The effect of estradiol-17 beta observed in the presence of cycloheximide was completely abolished by 4-hydroxy-tamoxifen or by Ly 156758 or by ICI 164384 (10(-6) M). The c-fos mRNAs were rather stable in cells treated with cycloheximide for 2 h (half-life = 51 +/- 6 min) and there was no further increase in the c-fos messenger RNA stability after the addition of cycloheximide plus estradiol-17 beta (half-life = 40 +/- 3 min). The overall results suggest a response at the transcriptional level. In conclusion, cycloheximide transmits activating signals to the c-fos gene which act as priming elements to allow the estrogen action in cultured guinea-pig endometrial cells.

Androstenedione↗
PubMed1991

[Action of estradiol-17 beta on the expression of c-Fos gene in endometrial cells in cultured].

The c-fos expression was investigated in primary culture of guinea-pig endometrial cells. Cells were made quiescent by serum depletion. Stimulation of these cells by estradiol (E2, 10(-8)M) alone or in combination with epidermal growth factor (EGF, 100 ng/ml) or insulin (10 micrograms/ml) failed to induce c-fos gene. The c-fos expression was early and transiently increased by fetal calf serum (15%) or estradiol plus EGF plus insulin. Protein synthesis inhibitors (cycloheximide or anisomycin) in association with E2 induced a superinduction of c-fos gene. In the same conditions puromycin had no effect. It appears that E2 acts in a multiple step process including an initial c-fos gene derepression by either EGF plus insulin or some protein synthesis inhibitors.

Animals↗
PubMed1990

Effects of 17 beta-estradiol and growth factors on c-fos gene expression in endometrial epithelial cells in primary culture.

Primary culture of guinea-pig endometrial cells was made quiescent by serum depletion. When added to quiescent cells, 17 beta-estradiol (E2) alone affected neither c-fos and c-myc gene expression, nor DNA synthesis and cell proliferation. Insulin or epidermal growth factor (EGF) only induced DNA synthesis. An association of both growth factors allowed significant cell proliferation without inducing c-fos or c-myc expression. A response including c-fos induction (maximal expression at 75 min), but not c-myc expression, DNA synthesis and a marked cell proliferation was only obtained when 17 beta-estradiol was associated with insulin plus EGF. In this case, cycloheximide raised the c-fos gene expression. These data suggest that in endometrial epithelial cells, E2 is mitogenic only when it acts in association with EGF plus insulin and the c-fos gene expression may not be correlated with cell proliferation.

Animals↗
PubMed1990

Regulation of c-fos expression in primary culture of guinea pig glandular epithelial cells stimulated by growth factors and estradiol.

The c-fos expression was investigated in primary culture of guinea pig glandular epithelial cells. These cells were made quiescent by serum deprivation and stimulated with fetal calf serum (FCS, 15%), 17 beta-estradiol (E2 10(-8) mol/l) alone or in combination with epidermal growth factor (EGF, 100 ng/ml) and insulin (I, 10 micrograms/ml). Low levels of c-fos mRNA were detectable in quiescent cells and were not increased in cells stimulated with either E2, EGF, I, or EGF plus I. On the contrary, the c-fos mRNA were early and transiently increased by FCS or E2 plus EGF plus I (4.5 and 9.5 fold induction, respectively). This effect was independent of de novo protein synthesis since it was not abolished in the presence of cycloheximide. It appears that E2 acts in a multiple step process including the stimulation by EGF plus insulin.

Animals↗
PubMed1990

Uterine epithelial cells in primary culture: a model system to study cell proliferation.

Guinea-pig uterine glandular epithelial cells were grown in primary culture. During the 4-day initial culture period, a 6.7 fold increase in DNA synthesis and a doubling time of approximately 30 hours were observed. Then the cells were submitted to serum depletion (60 hours) and the quiescent cells were stimulated with 15% fetal calf serum (FCS). The control cells were submitted to 1% heated and dextran-coated charcoal stripped FCS. In stimulated cells, the DNA synthesis increased and peaked between the 12th and 24th hour. In these cells, c-fos mRNAs increased rapidly, within 30 min., peaked at 75 min. (ratio to the control = 2.5), and returned to basal level within 90 min. These results prove that uterine epithelial cells in primary culture are able to respond to unspecific mitogen by both rapid expression of c-fos gene and DNA synthesis, suggesting that this cell culture system will be useful in studying the growth regulation in endometrium.

Animals↗
PubMedDate not supplied

Algodystrophy: treatment.

Treatment of reflex sympathetic dystrophies involves early reduction of the nociceptive input, transient interruption of the sympathetic activity, modulation of central mechanisms of pain control, prevention of neurotrophic changes and treatment of associated behavioural problems. The fundamental steps are early control of pain by means of local anesthetic blocks and antiinflammatory agents followed by sympathetic blocks, physical therapy, transcutaneous electrical stimulation and supportive psychotherapy. The results obtained are not always satisfactory and about 40% of the patients is not susceptible to cure. The best results are obtained when treatment is started early.

Autonomic Nerve Block↗