title: Amphiregulin is a potent mitogen for the vascular smooth muscle cell line, A7r5.
abstract: The regulation of amphiregulin, an epidermal growth factor (EGF) family member, and its effect on vascular smooth muscle cells (VSMC) were examined. Amphiregulin mRNA was upregulated by amphiregulin itself as well as alpha-thrombin. Amphiregulin caused an approximate 3-fold increase in DNA synthesis. Its effect on growth was compared with those of other mitogens, and was found to be approximately 3.5-, 2.4-, and 1.0-fold greater than those of endothelin-I (ET-I), alpha-thrombin, and platelet-derived growth factor-AB (PDGF-AB), respectively. As evidenced by Western blot analysis, amphiregulin stimulated the phosphorylation of p42/p44-mitogen-activated protein kinase (MAPK), p38-MAPK, c-Jun NH2-terminal protein kinase (JNK), and Akt/protein kinase B (PKB), respectively. By statistical analysis, the amphiregulin-induced growth effect was significantly decreased by the MAP kinase/ extracellular regulated kinase kinase-1 (MEK-1) inhibitor PD98059, p38-MAPK inhibitor SB203580, and phosphatidylinositol 3-kinase (PI-3 kinase) inhibitor wortmannin, respectively, but was not decreased by JNK inhibitor SP600125. These results suggest that amphiregulin is the most potent mitogen of the mitogens tested, and its growth effect is mediated at least in part through the p42/p44-MAPK, p38-MAPK, and PI-3 kinase-Akt/PKB pathways in VSMC.
authors.affiliation: The Third Department of Internal Medicine, Fukui Medical University, 23-3 Shimoaizuki, Matsuoka, 910-1193, Fukui, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Kato
authors.forename: Tetsuya
authors.initials: T
authors.lastname: Inazu
authors.forename: Yasuyuki
authors.initials: Y
authors.lastname: Kawai
authors.forename: Katsuhiko
authors.initials: K
authors.lastname: Masamura
authors.forename: Masahiro
authors.initials: M
authors.lastname: Yoshida
authors.forename: Nobuyoshi
authors.initials: N
authors.lastname: Tanaka
authors.forename: Kaoru
authors.initials: K
authors.lastname: Miyamoto
authors.forename: Isamu
authors.initials: I
authors.lastname: Miyamori
mesh_terms: D066258:Amphiregulin; D000818:Animals; D001483:Base Sequence; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D004247:DNA / Q000096:biosynthesis; D066255:EGF Family of Proteins; D004789:Enzyme Activation / Q000187:drug effects; D004815:Epidermal Growth Factor / Q000235:genetics; D066246:ErbB Receptors / Q000235:genetics; D006023:Glycoproteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D036341:Intercellular Signaling Peptides and Proteins / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D020935:MAP Kinase Signaling System; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D008934:Mitogens / Q000494:pharmacology*; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D017346:Protein Serine-Threonine Kinases; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D051057:Proto-Oncogene Proteins c-akt; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D013917:Thrombin / Q000494:pharmacology; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D066258:Amphiregulin; C587850:Areg protein, rat; D066255:EGF Family of Proteins; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D008934:Mitogens; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D004815:Epidermal Growth Factor; D004247:DNA; D066246:ErbB Receptors; C494920:Akt1 protein, rat; D017346:Protein Serine-Threonine Kinases; D051057:Proto-Oncogene Proteins c-akt; D020928:Mitogen-Activated Protein Kinases; D013917:Thrombin