Prostaglandin F2alpha amplifies tumor necrosis factor-alpha promoter activity by the FPB prostanoid receptor.
This study examines the regulation of tumor necrosis factor-alpha (TNF-alpha) promoter activity by prostaglandin F2alpha ( PGF2alpha ) in HEK cells stably expressing either the FPA or FPB prostanoid receptors. Cells were transiently transfected with a luciferase reporter plasmid under the control of a TNF-alpha promoter and luciferase activity was measured. In the absence of PGF2alpha basal TNF-alpha reporter gene activity is elevated in FPB cells as compared with FPA cells. This elevated basal activity is blocked by pretreatment with a Rho inhibitor, but not by pretreatment with an inhibitor of protein kinase C (PKC). TNF-alpha reporter activity in FPB cells is stimulated by PGF2alpha and this is decreased by pretreatment with a chelator of intracellular calcium or by a gap junction inhibitor. In FPB cells pretreatment with a Rho inhibitor combined with either a calcium chelator or a gap junction inhibitor decreases both basal and PGF2alpha stimulated TNF-alpha reporter activity. Interestingly post-treatment of FPB cells with an inhibitor of PKC decreased PGF2alpha stimulated TNF-alpha reporter gene activity even though pretreatment did not. It, therefore, appears that PGF2alpha stimulated TNF-alpha reporter activity in FPB cells is amplified by a Rho-dependent mechanism involving calcium, gap junctions, and PKC. These findings may help in understanding the function of the FPB isoform in the corpus luteum.
Fujino
Hiromichi
H
Department of Pharmacology and Toxicology, College of Pharmacy, The University of Arizona, Tucson, AZ 85721-0207, USA.
Regan
John W
JW
D000818:Animals; D002460:Cell Line; D015237:Dinoprost / Q000502:physiology*; D004357:Drug Synergism; D004533:Egtazic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D004768:Enterotoxins / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D017930:Genes, Reporter; D006034:Glycyrrhetinic Acid / Q000031:analogs & derivatives* / Q000494:pharmacology; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D008156:Luciferases / Q000378:metabolism; D008301:Maleimides / Q000494:pharmacology; D011401:Promoter Regions, Genetic; D020033:Protein Isoforms; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D011982:Receptors, Prostaglandin / Q000235:genetics / Q000378:metabolism*; D012756:Sheep; D014162:Transfection; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis / Q000235:genetics*; D020741:rho GTP-Binding Proteins / Q000502:physiology
D004768:Enterotoxins; D004791:Enzyme Inhibitors; D007211:Indoles; D008301:Maleimides; D020033:Protein Isoforms; D011982:Receptors, Prostaglandin; D014409:Tumor Necrosis Factor-alpha; C034671:prostaglandin F2alpha receptor; C070379:1,2-bis(2-aminophenoxy)ethane N,N,N',N'-tetraacetic acid acetoxymethyl ester; C119129:18alpha-glycyrrhetinic acid; D004533:Egtazic Acid; D015237:Dinoprost; D008156:Luciferases; D011493:Protein Kinase C; D020741:rho GTP-Binding Proteins; C088060:bisindolylmaleimide; D006034:Glycyrrhetinic Acid