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B and Protein Kinase C Signaling in the Expression of the Kinin B1 Receptor in Human Vascular Smooth Muscle CellsFaculté de Pharmacie, Université de Montréal, Montréal, Québec, Canada (M.E.M., A.A.); and Centre de Recherche en Rhumatologie et Immunologie, Centre Hospitalier Universitaire de Québec, Ville de Québec, Québec, Canada (M.-T.B., G.M., F.M.).
Kinin B1 receptor expression was characterized in human umbilical artery smooth muscle cells to further elucidate the function and specificity of three previously proposed pathways [nuclear factor-
B (NF-
B), protein kinase C, and agonist autoregulation] that regulate this inducible G protein-coupled receptor. Radioligand binding assays, real-time reverser transcription/polymerase chain reaction with an optional actinomycin D treatment period, and NF-
B immunofluorescence were primarily employed in these primary cell cultures. Various stimulatory compounds that increase receptor mRNA stability only (human and bovine sera, cycloheximide) or that stimulate NF-
B nuclear translocation and both mRNA concentration and stability [interleukin (IL)-1
, phorbol 12-myristate 13-acetate (PMA)] all increased the density of binding sites for the tritiated B1 receptor agonist [3H]Lys-des-Arg9-bradykinin (without change in receptor affinity) in cell-based assays. Small interfering RNA assays indicated that NF-
B p65 is necessary for the effective expression of the cell surface B1 receptor under basal or IL-1
, fetal bovine serum (FBS), or PMA stimulation conditions. Dexamethasone cotreatment reproduced these effects. IL-1
-, FBS-, or PMA-induced stabilization of B1 receptor mRNA was inhibited by the addition of the protein kinase C inhibitor 3-[1-[3-(dimethylamino)propyl]-1H-indol-3-yl]-4-(1H-indol-3-yl)-1H-pyrrole-2,5-dione monohydrochloride (GF-109203x), which also diminished the Bmax under FBS or PMA treatment. Lys-des-Arg9-bradykinin had little effect on NF-
B activation, the Bmax, or receptor mRNA abundance or stability. Both NF-
B and protein kinase C signaling are required for the effective expression of the kinin B1 receptor in human umbilical artery smooth muscle cells.
Address correspondence to: Dr. François Marceau, Centre Hospitalier Universitaire de Québec, Centre de recherche en rhumatologie et immunology, 2705 Laurier Blvd, Ville de Québec (Québec), Canada G1V 4G2. E-mail: francois.marceau{at}crchul.ulaval.ca