scholarly journals Signaling Pathways Involved in Sphingosine Kinase Activation and Sphingosine-1-Phosphate Release in Rat Myometrium in Late Pregnancy: Role in the Induction of Cyclooxygenase 2

Endocrinology ◽  
2008 ◽  
Vol 149 (9) ◽  
pp. 4669-4679 ◽  
Author(s):  
Martin Serrano-Sanchez ◽  
Zahra Tanfin ◽  
Denis Leiber
Keyword(s):  
Primary Cultures ◽  
Sphingosine Kinase ◽  
Late Pregnancy ◽  
Cyclooxygenase 2 ◽  
Late Gestation ◽  
Pregnant Rats ◽  
Prolonged Incubation ◽  
Sphingosine 1 Phosphate ◽  
Gi Protein ◽  
D 12

We investigated the regulation of the sphingosine kinase (SphK)/sphingosine-1-phosphate (S1P) axis and its role during pregnancy in the rat myometrium. SphK1 and SphK2 were coexpressed in myometrium during gestation. The levels and activity of SphK1/2 were modest at midgestation (d 12), increased at d 19 and progressively declined to low at postpartum. Similar patterns were observed for the phosphorylation of ERK and protein kinase C (PKC). Inhibition of PKC and ERK reduced SphK1/2 activity. In late pregnancy, levels of cyclooxygenase 2 (COX2) increased in parallel to SphK levels. Using a pharmacological approach, we demonstrated that in primary cultures of myometrial cells from d-19 pregnant rats, induction of COX2 was mediated by 4β-phorbol 12,13-dibutyrate and IL-1β through sequential activation of PKC, ERK1/2, and SphK1. S1P produced by SphK1 was released in the medium. Addition of S1P, IL-1β or 4β-phorbol 12,13-dibutyrate enhanced COX2 levels via Gi protein. Interestingly, S1P was also released by myometrial tissues at late gestation. This event was dependent on PKC/ERK/SphK1. By contrast, in d-12 myometrial tissues, the release of S1P was markedly reduced in association with low levels of SphK1 and COX2. However, prolonged incubation of myometrium from midgestation led to the induction of COX2. This effect was blocked by SphK inhibitors, providing evidence of the close relationship between SphK activity and COX2 induction in rat myometrium. Overall, our findings provided insight into the physiological relevance of the SphK activation and S1P release in uterine smooth muscle during gestation.

scholarly journals Role of Sphingosine Kinase/S1P Axis in ECM Remodeling of Cardiac Cells Elicited by Relaxin

2015 ◽  
Vol 29 (1) ◽  
pp. 53-67 ◽  
Author(s):  
Alessia Frati ◽  
Barbara Ricci ◽  
Federica Pierucci ◽  
Silvia Nistri ◽  
Daniele Bani ◽  
...  
Keyword(s):  
Primary Cultures ◽  
Sphingosine Kinase ◽  
Peptide Hormone ◽  
Tissue Growth ◽  
Cardiac Cells ◽  
Sphingolipid Metabolism ◽  
Cardiac Muscle Cells ◽  
Ecm Remodeling ◽  
Cell Proliferation And Differentiation ◽  
Sphingosine 1 Phosphate

Abstract The initiation and progression of heart failure is linked to adverse cardiac remodeling of the extracellular matrix (ECM) during disease mainly through the deregulation of myocardial metalloproteinases (MMPs). Relaxin (RLX), a peptide hormone acting as a physiological cardiac effector, is a key regulator of ECM remodeling in reproductive and nonreproductive tissues. Studying primary cultures of mouse cardiac muscle cells and rat H9c2 cardiomyoblasts, we have obtained evidence for a new signaling pathway activated by RLX to induce ECM remodeling that involves the bioactive sphingolipids sphingosine-1-phosphate (S1P) and ceramide. In both cell populations, recombinant human RLX increased sphingosine kinase activity and S1P formation, whereas sphingomyelin and ceramide content were decreased in [3H]serine-labeled cells. According to the literature, RLX promoted MMP-2 and MMP-9 expression/release. Pharmacological inhibition of sphingolipid metabolism and silencing of sphingosine kinase 1, the enzyme responsible for S1P formation, were able to prevent MMP expression/release elicited by the hormone and induce the expression of tissue inhibitor of MMPs. In addition, we found that sphingolipid signaling is required for the regulation of connective tissue growth factor, a member of the CCN 1–3 family of genes that are involved in cell proliferation and differentiation. Finally, the induction of cardiomyoblast maturation induced by RLX was also found to be counteracted by inhibition of S1P formation. In conclusion, these findings provide a novel mechanism by which RLX acts on cardiac ECM remodeling and cardiac cell differentiation and offer interesting therapeutic options to prevent heart fibrosis and to favor myocardial regeneration.

scholarly journals Megakaryocytopoiesis and platelet production are stimulated during late pregnancy and early postpartum in the rat

Blood ◽  
1992 ◽  
Vol 79 (7) ◽  
pp. 1672-1678
Author(s):  
CW Jackson ◽  
SA Steward ◽  
RA Ashmun ◽  
TP McDonald
Keyword(s):  
Platelet Count ◽  
Dna Content ◽  
Late Pregnancy ◽  
Late Gestation ◽  
Platelet Volume ◽  
Pregnant Rats ◽  
Platelet Production ◽  
Platelet Counts ◽  
Platelet Survival ◽  
Early Postpartum

Platelet count during uncomplicated pregnancy shows considerable patient variation. To gain a better understanding of thrombocytopoiesis during pregnancy, megakaryocytes and platelets were examined during gestation and the early postpartum period, using as a model the rat. Platelet counts and megakaryocyte concentrations and DNA content distributions of timed-pregnant rats were examined at intervals from day 10 of gestation through parturition on day 22 and days 1 through 7 postpartum. Platelet survival was studied in late gestation and the early postpartum. Platelet volume was measured on gestation day 21. Platelet counts were moderately increased on gestation days 17 and 19 through 22, and on days 2 to 3 postpartum. However, the actual rate of platelet production was much higher than the platelet count suggests because the blood volume increased in late gestation to 1.5 times the nonpregnant level. Mean platelet volume and platelet volume distribution width of day 21 gestation rats were not significantly altered. Platelet survival in pregnant rats was not significantly different from that in nonpregnant females. In contrast, megakaryocyte concentration was significantly increased on gestation days 12, 17, and 19 through 21, and 2 to 3 days postpartum. In addition, in late gestation, megakaryocyte DNA content distributions displayed a marked increase in the proportion of high ploidy cells, which peaked 1 day before parturition. At that time, the proportions of 32N (43%) and 64N cells (3%) were, respectively, three and four times nonpregnant values. In contrast to megakaryocyte concentration, megakaryocyte DNA content distributions had returned to the nonpregnant pattern by day 1 postpartum. The changes in megakaryocyte DNA content distribution were accompanied by changes in megakaryocyte size. These data indicate that thrombopoiesis is substantially increased during late pregnancy, and that this increase is accomplished through an increase in megakaryocyte DNA content and size, as well as megakaryocyte number. The more rapid return of megakaryocyte DNA content than of megakaryocyte concentration to nonpregnant levels postpartum suggests that pregnancy-associated hormonal changes which produce an increase in megakaryocyte DNA content and size differ from those which cause an increase in megakaryocyte number.

scholarly journals Megakaryocytopoiesis and platelet production are stimulated during late pregnancy and early postpartum in the rat

Blood ◽  
1992 ◽  
Vol 79 (7) ◽  
pp. 1672-1678 ◽  
Author(s):  
CW Jackson ◽  
SA Steward ◽  
RA Ashmun ◽  
TP McDonald
Keyword(s):  
Platelet Count ◽  
Dna Content ◽  
Late Pregnancy ◽  
Late Gestation ◽  
Platelet Volume ◽  
Pregnant Rats ◽  
Platelet Production ◽  
Platelet Counts ◽  
Platelet Survival ◽  
Early Postpartum

Abstract Platelet count during uncomplicated pregnancy shows considerable patient variation. To gain a better understanding of thrombocytopoiesis during pregnancy, megakaryocytes and platelets were examined during gestation and the early postpartum period, using as a model the rat. Platelet counts and megakaryocyte concentrations and DNA content distributions of timed-pregnant rats were examined at intervals from day 10 of gestation through parturition on day 22 and days 1 through 7 postpartum. Platelet survival was studied in late gestation and the early postpartum. Platelet volume was measured on gestation day 21. Platelet counts were moderately increased on gestation days 17 and 19 through 22, and on days 2 to 3 postpartum. However, the actual rate of platelet production was much higher than the platelet count suggests because the blood volume increased in late gestation to 1.5 times the nonpregnant level. Mean platelet volume and platelet volume distribution width of day 21 gestation rats were not significantly altered. Platelet survival in pregnant rats was not significantly different from that in nonpregnant females. In contrast, megakaryocyte concentration was significantly increased on gestation days 12, 17, and 19 through 21, and 2 to 3 days postpartum. In addition, in late gestation, megakaryocyte DNA content distributions displayed a marked increase in the proportion of high ploidy cells, which peaked 1 day before parturition. At that time, the proportions of 32N (43%) and 64N cells (3%) were, respectively, three and four times nonpregnant values. In contrast to megakaryocyte concentration, megakaryocyte DNA content distributions had returned to the nonpregnant pattern by day 1 postpartum. The changes in megakaryocyte DNA content distribution were accompanied by changes in megakaryocyte size. These data indicate that thrombopoiesis is substantially increased during late pregnancy, and that this increase is accomplished through an increase in megakaryocyte DNA content and size, as well as megakaryocyte number. The more rapid return of megakaryocyte DNA content than of megakaryocyte concentration to nonpregnant levels postpartum suggests that pregnancy-associated hormonal changes which produce an increase in megakaryocyte DNA content and size differ from those which cause an increase in megakaryocyte number.

scholarly journals Regulation of cyclic AMP synthesis and degradation is modified in rat liver at late gestation

1992 ◽  
Vol 286 (2) ◽  
pp. 419-424 ◽  
Author(s):  
C Martinez ◽  
P Ruiz ◽  
J Satrustegui ◽  
A Andres ◽  
J M Carrascosa
Keyword(s):  
Insulin Resistance ◽  
Cyclic Amp ◽  
Adenylate Cyclase ◽  
Late Pregnancy ◽  
Maximal Activity ◽  
Late Gestation ◽  
Cellular Mechanisms ◽  
Pregnant Rats ◽  
Pregnant Rat ◽  
Insulin Resistant

Cyclic AMP (cAMP) is known to play a key role in regulating insulin action, and it is well documented that in several cases of physiological insulin resistance its concentration is increased. Since late pregnancy in the rat is associated with liver insulin resistance, we have studied possible alterations of some cellular mechanisms regulating the cAMP metabolism. (1) Liver cAMP concentration was shown to be increased by some 30% and 50% at 18 and 22 days of pregnancy respectively, compared with virgins. (2) Basal adenylate cyclase activity was higher only in the 18-days-pregnant rat, and the forskolin-stimulated maximal activity was similar in the three groups of animals. (3) alpha s protein is decreased in term-pregnant rats; however, coupling between Gs and adenylate cyclase is only impaired in the 18-days-pregnant animals, and stimulation by glucagon is impaired in both groups of pregnant animals. (4) Gi-2 protein was shown to be unable to elicit the tonic inhibition of adenylate cyclase in pregnant rats, although it was only decreased at 22 days of gestation. The increased alpha i-2 level detected by immunoblotting at 18 days of gestation did not correlate with its decreased ADP-ribosylation, suggesting that the protein is somehow modified at this stage. (5) Pregnancy is associated with a decrease in membrane phosphodiesterase activity. Our results show that late pregnancy is associated with increases in liver cAMP levels that might be involved in eliciting the characteristic insulin-resistant state, and suggest that mechanisms leading to these increments are changing during this phase of gestation.

Pancreatic morphology in pregnant rats exposed to DuP-697 - the irreversible, highly selective cyclooxygenase-2 inhibitor

2008 ◽  
Vol 63 (1) ◽  
pp. 96-101
Author(s):  
Franciszek Burdan ◽  
Justyna Szumiło ◽  
Jarosław Dudka ◽  
Agnieszka Korobowicz ◽  
Agnieszka Fronczek ◽  
...  
Keyword(s):  
Cyclooxygenase 2 ◽  
Pregnant Rats ◽  
Pancreatic Morphology

Apoptotic cell extrusion depends on single-cell synthesis of sphingosine-1-phosphate by sphingosine kinase 2

2021 ◽  
Vol 1866 (4) ◽  
pp. 158888
Author(s):  
Bruno Jaime Santacreu ◽  
Daniela Judith Romero ◽  
Lucila Gisele Pescio ◽  
Estefanía Tarallo ◽  
Norma Beatriz Sterin-Speziale ◽  
...  
Keyword(s):  
Single Cell ◽  
Apoptotic Cell ◽  
Sphingosine Kinase ◽  
Sphingosine Kinase 2 ◽  
Sphingosine 1 Phosphate ◽  
Cell Synthesis ◽  
Cell Extrusion

scholarly journals Cyclooxygenase-2 Glycosylation Is Affected by Peroxynitrite in Endothelial Cells: Impact on Enzyme Activity and Degradation

Antioxidants ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 496
Author(s):  
Sonia Eligini ◽  
Susanna Colli ◽  
Aida Habib ◽  
Giancarlo Aldini ◽  
Alessandra Altomare ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
De Novo ◽  
Cyclooxygenase 2 ◽  
Nitric Oxide Donors ◽  
Metabolic Labeling ◽  
Dependent Manner ◽  
De Novo Synthesis ◽  
Human Endothelial Cells ◽  
Prolonged Incubation ◽  
Cox 2

The exposure of human endothelial cells to 3-morpholinosydnonimine (SIN-1) induced the expression of cyclooxygenase-2 (COX-2) in a dose- and time-dependent manner. Interestingly, after a prolonged incubation (>8 h) several proteoforms were visualized by Western blot, corresponding to different states of glycosylation of the protein. This effect was specific for SIN-1 that generates peroxynitrite and it was not detected with other nitric oxide-donors. Metabolic labeling experiments using 35S or cycloheximide suggested that the formation of hypoglycosylated COX-2 was dependent on de novo synthesis of the protein rather than the deglycosylation of the native protein. Moreover, SIN-1 reduced the activity of the hexokinase, the enzyme responsible for the first step of glycolysis. The hypoglycosylated COX-2 induced by SIN-1 showed a reduced capacity to generate prostaglandins and the activity was only partially recovered after immunoprecipitation. Finally, hypoglycosylated COX-2 showed a more rapid rate of degradation compared to COX-2 induced by IL-1α and an alteration in the localization with an accumulation mainly detected in the nuclear membrane. Our results have important implication to understand the effect of peroxynitrite on COX-2 expression and activity, and they may help to identify new pharmacological tools direct to increase COX-2 degradation or to inhibit its activity.

Human endometrial epithelial cells grown on collagen in serum-free medium. Estrogen responsiveness and morphology

1991 ◽  
Vol 125 (1) ◽  
pp. 101-108 ◽  
Author(s):  
Bertil G. Casslén ◽  
Michael J. K. Harper
Keyword(s):  
Epithelial Cells ◽  
Primary Cultures ◽  
Collagen Matrix ◽  
Human Endometrium ◽  
Serum Free Medium ◽  
Free Medium ◽  
Endometrial Stromal Cells ◽  
Prolonged Incubation ◽  
Serum Free ◽  
Endometrial Epithelial Cells

Abstract. The aim of the study was to explore the possibility of using human endometrial epithelial cells in serum-free culture as a sensitive assay for hormonal effects on the human endometrium. Glands were isolated following enzymatic digestion of the endometrial tissue and plated on a collagen matrix. The epithelial cells were grown in either medium containing serum or in supplemented serum-free medium. No morphologic difference was found between cells grown in these two media for up to 5 days, using either light or scanning electron microscopy. Secretion of prostaglandin F2α (PGF2α) in response to estradiol was not lower in serum-free medium than in medium containing serum for the first 2 days of culture, whereas secretion declined after prolonged incubation in the serum-free medium. This response to estradiol was clearly dose-dependent, and it was further enhanced by addition of arachidonic acid, the precursor for prostaglandin synthesis, to the medium. Co-culture of endometrial stromal cells did not influence the secretion of PGF2α by epithelial cells. We conclude that the secretion of PGF2α from primary cultures of human endometrial epithelial cells grown on collagen in serum-free medium can be used for a limited period as an assay of estrogenic effects on the human endometrium.

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