title: PKC-dependent extracellular signal-regulated kinase 1/2 pathway is involved in the inhibition of Ib on AngiotensinII-induced proliferation of vascular smooth muscle cells.
abstract: AngiotensinII (AngII) induces vascular smooth muscle cell (VSMC) proliferation, which plays an important role in the development and progression of hypertension. AngII-induced cellular events have been implicated, in part, in the activation of protein kinase C (PKC) and extracellular signal-regulated kinases 1/2 (ERK1/2). In the present study, we investigated the effect of Ib, a novel nonpeptide AngII receptor type 1 (AT(1)) antagonist, on the activation of PKC and ERK1/2 in VSMC proliferation induced by AngII. MTT, and [(3)H]thymidine incorporation assay showed that AngII-induced VSMC proliferation was inhibited significantly by Ib. The specific binding of [(125)I]AngII to AT(1) receptors was blocked by Ib in a concentration-dependent manner with IC(50) value of 0.96nM. PKC activity assay and Western blot analysis demonstrated that Ib significantly inhibited the activation of PKC and phosphorylation of ERK1/2 induced by AngII, respectively. Furthermore, AngII-induced ERK1/2 activation was obviously blocked by GF109203X, a PKC inhibitor. These findings suggest that the suppression of Ib on AngII-induced VSMC proliferation may be attributed to its inhibitory effect on PKC-dependent ERK1/2 pathway.
authors.affiliation: Department of Physiology, China Pharmaceutical University, No. 24, Tong Jia Xiang Street, Nanjing 210009, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Wang
authors.forename: Tianhua
authors.initials: T
authors.lastname: Yan
authors.forename: Qiujuan
authors.initials: Q
authors.lastname: Wang
authors.forename: Wei
authors.initials: W
authors.lastname: Wang
authors.forename: Jinyi
authors.initials: J
authors.lastname: Xu
authors.forename: Xiaoming
authors.initials: X
authors.lastname: Wu
authors.forename: Hui
authors.initials: H
authors.lastname: Ji
mesh_terms: D000804:Angiotensin II / Q000037:antagonists & inhibitors / Q000494:pharmacology; D047228:Angiotensin II Type 1 Receptor Blockers / Q000737:chemistry / Q000494:pharmacology*; D000818:Animals; D049109:Cell Proliferation / Q000187:drug effects*; D002478:Cells, Cultured; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D032389:Myocytes, Smooth Muscle / Q000187:drug effects* / Q000201:enzymology; D010766:Phosphorylation / Q000187:drug effects; D011493:Protein Kinase C / Q000378:metabolism; D011817:Rabbits; D013777:Tetrazoles / Q000737:chemistry / Q000494:pharmacology*; D014230:Triazoles / Q000737:chemistry / Q000494:pharmacology*
chemical_list: D047228:Angiotensin II Type 1 Receptor Blockers; D013777:Tetrazoles; D014230:Triazoles; D000804:Angiotensin II; D011493:Protein Kinase C; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3