title: Betacellulin and amphiregulin induce upregulation of cyclin D1 and DNA synthesis activity through differential signaling pathways in vascular smooth muscle cells.
abstract: Activation of EGF receptors is closely involved in vascular proliferative diseases. The signaling mechanisms of EGF ligands, including betacellulin (BTC) and amphiregulin (AR), are poorly understood. We examined how BTC and AR induced DNA synthesis activity in primary cultures of human thoracic aortic smooth muscle cells (HTASMCs). BTC induced phosphorylation of all four EGF receptors present on HTASMCs: ErbB1, ErbB2, ErbB3, and ErbB4. BTC rapidly induced the phosphorylation of Akt, GSK3alpha/beta, and two FoxO factors, FKHR and AFX, in a dose- and time-dependent manner. BTC increased nuclear beta-catenin accumulation. BTC increased cyclin D1 mRNA, cyclin D1 protein, and DNA synthesis activity. Pretreatment with the phosphatidylinositol 3'-kinase (PI 3'-kinase) inhibitor wortmannin suppressed BTC-induced cyclin D1 mRNA and protein and DNA synthesis activity. In contrast, AR, a specific ErbB1 ligand, induced sustained ERK1/2 and Elk1 phosphorylation, increased cyclin D1 mRNA and protein, and increased DNA synthesis activity. AR did not produce any changes in Akt phosphorylation. Pretreatment with PD98059 suppressed AR-induced cyclin D1 mRNA and protein. Thus, the PI 3'-kinase/Akt/GSK/FoxO/beta-catenin pathway could be the major signaling cascade for BTC-induced upregulation of cyclin D1 protein, whereas a sustained ERK/Elk1 activation could be the major signaling cascade for AR-induced upregulation of cyclin D1 protein in HTASMCs. Moreover, immunohistochemical staining revealed that that BTC, ErbB1, and ErbB4 are upregulated in the plaques of human atherosclerotic coronary arteries. Taken together, BTC and AR could be potent growth factors in proliferative vascular diseases.
authors.affiliation: National Creative Research Initiatives Center for Endothelial Cells, Division of Molecular and Life Sciences, Pohang University of Science and Technology, Hyoja-Dong, Pohang, Republic of Korea
authors.forename: Hyoung Seek
authors.initials: HS
authors.lastname: Shin
authors.forename: Hyo Jeong
authors.initials: HJ
authors.lastname: Lee
authors.forename: Makoto
authors.initials: M
authors.lastname: Nishida
authors.forename: Mi-Sook
authors.initials: MS
authors.lastname: Lee
authors.forename: Ritsu
authors.initials: R
authors.lastname: Tamura
authors.forename: Shizuya
authors.initials: S
authors.lastname: Yamashita
authors.forename: Yuji
authors.initials: Y
authors.lastname: Matsuzawa
authors.forename: In-Kyu
authors.initials: IK
authors.lastname: Lee
authors.forename: Gou Young
authors.initials: GY
authors.lastname: Koh
mesh_terms: D000077329:Agammaglobulinaemia Tyrosine Kinase; D066258:Amphiregulin; D001161:Arteriosclerosis / Q000378:metabolism / Q000473:pathology; D066259:Betacellulin; D002453:Cell Cycle / Q000187:drug effects; D018797:Cell Cycle Proteins; D002467:Cell Nucleus / Q000187:drug effects / Q000378:metabolism; D002478:Cells, Cultured; D019938:Cyclin D1 / Q000235:genetics / Q000378:metabolism*; D003598:Cytoskeletal Proteins / Q000378:metabolism; D004247:DNA / Q000096:biosynthesis*; D004268:DNA-Binding Proteins / Q000378:metabolism; D066255:EGF Family of Proteins; D004815:Epidermal Growth Factor / Q000494:pharmacology; D066246:ErbB Receptors / Q000378:metabolism; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors; D038362:Glycogen Synthase Kinase 3 / Q000378:metabolism; D000071679:Glycogen Synthase Kinase 3 beta; D006023:Glycoproteins / Q000494:pharmacology*; D006801:Humans; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism / Q000494:pharmacology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D010766:Phosphorylation / Q000187:drug effects; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D011518:Proto-Oncogene Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000187:drug effects / Q000235:genetics / Q000378:metabolism; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D020893:Receptor, ErbB-3 / Q000378:metabolism; D066247:Receptor, ErbB-4; D015398:Signal Transduction / Q000502:physiology; D015534:Trans-Activators / Q000378:metabolism; D014157:Transcription Factors / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects; D051176:beta Catenin; D050807:ets-Domain Protein Elk-1
chemical_list: D000077329:Agammaglobulinaemia Tyrosine Kinase; D066258:Amphiregulin; D066259:Betacellulin; D018797:Cell Cycle Proteins; D019938:Cyclin D1; D003598:Cytoskeletal Proteins; D004247:DNA; D004268:DNA-Binding Proteins; D066255:EGF Family of Proteins; D004815:Epidermal Growth Factor; D066246:ErbB Receptors; D000071161:Forkhead Box Protein O1; D051858:Forkhead Transcription Factors; D038362:Glycogen Synthase Kinase 3; D000071679:Glycogen Synthase Kinase 3 beta; D006023:Glycoproteins; D036341:Intercellular Signaling Peptides and Proteins; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases; D011505:Protein-Tyrosine Kinases; D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D018719:Erb-b2 Receptor Tyrosine Kinases; D020893:Receptor, ErbB-3; D066247:Receptor, ErbB-4; D015534:Trans-Activators; D014157:Transcription Factors; D051176:beta Catenin; D050807:ets-Domain Protein Elk-1; C587848:AREG protein, human; C587851:BTC protein, human; C495270:CTNNB1 protein, human; C494112:ELK1 protein, human; C085126:FOXO1 protein, human; C108803:FOXO4 protein, human; C587689:ERBB4 protein, human; C448021:glycogen synthase kinase 3 alpha