title: Proliferation of the human urothelium is induced by atypical β1 -adrenoceptors.
abstract: We wanted to assess whether β-adrenoceptors mediate proliferation in the normal and malignant urothelial cell lines UROtsa and T24, respectively. Urothelial cells were cultured for 24 h in the presence of the β-adrenoceptor agonists isoprenaline (β1/2/3 ), dobutamine (β1 ), salbutamol (β2 ), BRL 37344 (β3 ), CGP 12177 (a partial β-agonist) or β-adrenoceptor antagonists (metoprolol; β1 , propranolol; β1/2 ). Phosphorylation of kinases was screened with a Human Phospho-Kinase Array Kit (R&D systems). Intracellular pathways activated by proliferation of urothelial cells were characterized by incubating cells with the MEK1/2 inhibitor PD 98,059, the p38 kinase inhibitor losmapimod or with the Akt 1/2 kinase inhibitor. Proliferation was assessed with the MTT proliferation assay (ATCC). Western blot and immunocytochemistry were used for detection of the β1 -adrenoceptor. Isoprenaline and dobutamine induced proliferation, while salbutamol and BRL 37344 did not. Dobutamine-induced proliferation was not affected by metoprolol or propranolol but was instead antagonized by CGP 12177 in T24 but not in UROtsa. In response to stimulation with dobutamine, Akt1/2/3 was phosphorylated in UROtsa, while ERK1/2 and p38 were phosphorylated in T24. MEK1/2 inhibition blocked basal and dobutamine-induced proliferation in T24 but only basal proliferation in UROtsa. Losmapimod slightly inhibited basal proliferation in T24 but not dobutamine-induced proliferation. Akt 1/2 inhibitor blocked basal and dobutamine-induced proliferation in UROtsa. Immunocytochemistry and Western blot revealed expression of β1 -adrenoceptors in both urothelial cell lines. The present data show that the urothelium expresses atypical β1-adrenoceptors that activate intracellular kinases inducing urothelial proliferation.
authors.affiliation: Department of Pharmacology, University of Gothenburg, Medicinaregatan 13, 405 30, Gothenburg, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Winder
authors.affiliation: Department of Rheumatology and Inflammation Research, University of Gothenburg, Guldhedsgatan 10 A, 405 30, Gothenburg, Sweden.
authors.forename: C
authors.initials: C
authors.lastname: Wasén
authors.affiliation: Department of Pharmacology, University of Gothenburg, Medicinaregatan 13, 405 30, Gothenburg, Sweden.
authors.forename: P
authors.initials: P
authors.lastname: Aronsson
authors.affiliation: Department of Pharmacology, University of Gothenburg, Medicinaregatan 13, 405 30, Gothenburg, Sweden.
authors.forename: D
authors.initials: D
authors.lastname: Giglio
mesh_terms: D000318:Adrenergic beta-Agonists / Q000494:pharmacology; D000319:Adrenergic beta-Antagonists / Q000494:pharmacology; D049109:Cell Proliferation / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D006801:Humans; D018342:Receptors, Adrenergic, beta-1 / Q000378:metabolism*; D019459:Urothelium / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*
chemical_list: D000318:Adrenergic beta-Agonists; D000319:Adrenergic beta-Antagonists; D018342:Receptors, Adrenergic, beta-1
keywords: Akt1/2/3; ERK1/2; proliferation; urothelium; β1-adrenoceptor