Glycated serum albumin-induced vascular smooth muscle cell proliferation through activation of the mitogen-activated protein kinase/extracellular signal-regulated kinase pathway by protein kinase C.
Proliferation of vascular smooth muscle cells (VSMC) contributes to the pathogenesis of atherosclerosis, and glycated serum albumin (GSA, Amadori adduct of albumin) might be a mitogen for VSMC proliferation, which may further be associated with diabetic vascular complications. In this study, we investigated the involvement of mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK), and protein kinase C (PKC), in GSA-stimulated mitogenesis, as well as the functional relationship between these factors. VSMC stimulation with GSA resulted in a marked activation of ERK. The MAPK kinase (MEK) inhibitor, PD98059, blocked GSA-stimulated MAPK activation and resulted in an inhibition of GSA-stimulated VSMC proliferation. GSA also increased PKC activity in VSMC in a dose-dependent manner. The inhibition of PKC by the PKC inhibitors, GF109203X and Rottlerin (PKCdelta specific inhibitor), as well as PKC downregulation by phorbol 12-myristate 13-acetate (PMA), inhibited GSA-induced cell proliferation and blocked ERK activation. This indicates that phorbol ester-sensitive PKC isoforms including PKCdelta are involved in MAPK activation. Thus, we show that the MAPK cascade is required for GSA-induced proliferation, and that phorbol ester-sensitive PKC isoforms contribute to cell activation and proliferation in GSA-stimulated VSMC.
Hattori
Y
Y
Department of Endocrinology and Metabolism, Dokkyo University School of Medicine, Mibu, Tochigi, Japan. yhattori@dokkyomed.ac.jp
Kakishita
H
H
Akimoto
K
K
Matsumura
M
M
Kasai
K
K
D000818:Animals; D002455:Cell Division / Q000187:drug effects*; D002460:Cell Line; D004247:DNA / Q000096:biosynthesis / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004789:Enzyme Activation / Q000187:drug effects; D004791:Enzyme Inhibitors / Q000494:pharmacology; D005419:Flavonoids / Q000494:pharmacology; D017127:Glycation End Products, Advanced; D006801:Humans; D007211:Indoles / Q000494:pharmacology; D007527:Isoenzymes / Q000037:antagonists & inhibitors / Q000378:metabolism; D008156:Luciferases / Q000235:genetics / Q000378:metabolism; D020935:MAP Kinase Signaling System / Q000187:drug effects; D008301:Maleimides / Q000494:pharmacology; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000201:enzymology; D011493:Protein Kinase C / Q000037:antagonists & inhibitors / Q000378:metabolism*; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D012709:Serum Albumin / Q000494:pharmacology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D015533:Transcriptional Activation / Q000187:drug effects; D000093423:Glycated Serum Albumin
D004791:Enzyme Inhibitors; D005419:Flavonoids; D017127:Glycation End Products, Advanced; D007211:Indoles; D007527:Isoenzymes; D008301:Maleimides; D011993:Recombinant Fusion Proteins; D012709:Serum Albumin; D004247:DNA; D008156:Luciferases; D011493:Protein Kinase C; D020928:Mitogen-Activated Protein Kinases; C070515:bisindolylmaleimide I; D013755:Tetradecanoylphorbol Acetate; C093973:2-(2-amino-3-methoxyphenyl)-4H-1-benzopyran-4-one; D000093423:Glycated Serum Albumin