Mechanism of prostaglandin (PG)E2-induced prolactin expression in human T cells: cooperation of two PGE2 receptor subtypes, E-prostanoid (EP) 3 and EP4, via calcium- and cyclic adenosine 5'-monophosphate-mediated signaling pathways.
We previously reported that prolactin gene expression in the T-leukemic cell line Jurkat is stimulated by PGE(2) and that cAMP acts synergistically with Ca(2+) or protein kinase C on the activation of the upstream prolactin promoter. Using the transcription inhibitor actinomycin D, we now show that PGE(2)-induced prolactin expression requires de novo prolactin mRNA synthesis and that PGE(2) does not influence prolactin mRNA stability. Furthermore, PGE(2)-induced prolactin expression was inhibited by protein kinase inhibitor fragment 14-22 and BAPTA-AM, which respectively, inhibit protein kinase A- and Ca(2+)-mediated signaling cascades. Using specific PGE(2) receptor agonists and antagonists, we show that PGE(2) induces prolactin expression through engagement of E-prostanoid (EP) 3 and EP4 receptors. We also found that PGE(2) induces an increase in intracellular cAMP concentration as well as intracellular calcium concentration via EP4 and EP3 receptors, respectively. In transient transfections, 3000 bp flanking the leukocyte prolactin promoter conferred a weak induction of the luciferase reporter gene by PGE(2) and cAMP, whereas cAMP in synergy with ionomycin strongly activated the promoter. Mutation of a C/EBP responsive element at -214 partially abolished the response of the leukocyte prolactin promoter to PGE(2), cAMP, and ionomycin plus cAMP.
Gerlo
Sarah
S
Laboratory of Neuroendocrine Immunology, Department of Pharmacology, Free University of Brussels, Laarbeeklaan 103, B-1090 Brussels, Belgium. Sarah.gerlo@vub.ac.be
Verdood
Peggy
P
Gellersen
Birgit
B
Hooghe-Peters
Elisabeth L
EL
Kooijman
Ron
R
D000276:Adjuvants, Immunologic / Q000502:physiology; D022762:CCAAT-Enhancer-Binding Proteins / Q000235:genetics / Q000378:metabolism; D002118:Calcium / Q000502:physiology*; D000242:Cyclic AMP / Q000096:biosynthesis / Q000235:genetics / Q000502:physiology*; D017868:Cyclic AMP-Dependent Protein Kinases / Q000502:physiology; D015232:Dinoprostone / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D019169:Jurkat Cells; D011388:Prolactin / Q000096:biosynthesis* / Q000235:genetics; D011401:Promoter Regions, Genetic / Q000276:immunology; D011485:Protein Binding / Q000235:genetics / Q000276:immunology; D020871:RNA Stability / Q000276:immunology; D012333:RNA, Messenger / Q000378:metabolism; D018078:Receptors, Prostaglandin E / Q000378:metabolism / Q000502:physiology*; D058307:Receptors, Prostaglandin E, EP2 Subtype; D058308:Receptors, Prostaglandin E, EP3 Subtype; D058309:Receptors, Prostaglandin E, EP4 Subtype; D020218:Response Elements / Q000276:immunology; D015290:Second Messenger Systems / Q000276:immunology; D015398:Signal Transduction / Q000276:immunology*; D013601:T-Lymphocytes / Q000378:metabolism*; D015534:Trans-Activators / Q000502:physiology; D015854:Up-Regulation / Q000276:immunology
D000276:Adjuvants, Immunologic; D022762:CCAAT-Enhancer-Binding Proteins; C545644:PTGER2 protein, human; C545647:PTGER3 protein, human; C545650:PTGER4 protein, human; D012333:RNA, Messenger; D018078:Receptors, Prostaglandin E; D058307:Receptors, Prostaglandin E, EP2 Subtype; D058308:Receptors, Prostaglandin E, EP3 Subtype; D058309:Receptors, Prostaglandin E, EP4 Subtype; D015534:Trans-Activators; D011388:Prolactin; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases; D015232:Dinoprostone; D002118:Calcium