title: Involvement of reactive oxygen species in cardiotrophin-1-induced proliferation of cardiomyocytes differentiated from murine embryonic stem cells.
abstract: Cardiotrophin-1 (CT-1) is a cytokine that is involved in the growth and survival of cardiac cells. In the present study, we demonstrate that treatment of embryoid bodies grown from pluripotent murine embryonic stem (ES) cells with CT-1 significantly stimulated cardiomyogenesis and increased nuclear expression of the proliferation marker Ki-67. The increase in Ki-67 expression was inhibited upon pretreatment with the free radical scavenger vitamin E, indicating a role for reactive oxygen species (ROS) in the signaling cascade. CT-1 treatment of cardiac cells raised intracellular ROS in ES cell-derived cardiomyocytes. ROS were presumably generated by an NADPH-oxidase since ROS generation was down-regulated upon preincubation with the NADPH-oxidase inhibitor diphenylen iodonium chloride (DPI) and LY294002, which inhibits phosphatidylinositol 3 kinase (PI3-kinase). CT-1 activated nuclear factor-kappaB (NF-kappaB) and induced phosphorylation of the Janus kinase signal transducer-2 (Jak-2), the signal transducer and activator of transcription-3 (STAT-3) as well as the extracellular signal-regulated kinase 1,2 (ERK1/2). STAT-3 and ERK1/2 phosphorylation as well as NF-kappaB activation were inhibited by pretreatment with the Jak-2 antagonist AG490, the ERK1/2 inhibitor PD98059, the free radical scavenger vitamin E, the NADPH-oxidase inhibitor DPI, as well as by LY294002. PD98059 failed to inhibit Jak-2 phosphorylation, indicating that the ERK and the Jak/STAT signaling cascade interact on a level downstream of Jak-2. It is concluded that CT-1 stimulates the proliferation of ES cell-derived cardiomyocytes by signaling pathways that involve ROS as signaling molecules in the signal transduction cascade.
authors.affiliation: Department of Neurophysiology, University of Cologne, D-50931 Cologne, Germany.
authors.forename: Heinrich
authors.initials: H
authors.lastname: Sauer
authors.forename: Wolfgang
authors.initials: W
authors.lastname: Neukirchen
authors.forename: Gohar
authors.initials: G
authors.lastname: Rahimi
authors.forename: Frank
authors.initials: F
authors.lastname: Grünheck
authors.forename: Jürgen
authors.initials: J
authors.lastname: Hescheler
authors.forename: Maria
authors.initials: M
authors.lastname: Wartenberg
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology*; D002455:Cell Division / Q000187:drug effects / Q000502:physiology; D002478:Cells, Cultured; D016207:Cytokines / Q000378:metabolism* / Q000494:pharmacology; D004268:DNA-Binding Proteins / Q000037:antagonists & inhibitors / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D053614:Janus Kinase 2; D019394:Ki-67 Antigen / Q000378:metabolism; D051379:Mice; D020928:Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors / Q000378:metabolism; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism; D039904:Pluripotent Stem Cells / Q000187:drug effects / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D011518:Proto-Oncogene Proteins; D017382:Reactive Oxygen Species / Q000378:metabolism*; D050796:STAT3 Transcription Factor; D015398:Signal Transduction / Q000187:drug effects / Q000502:physiology; D015534:Trans-Activators / Q000037:antagonists & inhibitors / Q000378:metabolism; D015854:Up-Regulation / Q000187:drug effects / Q000502:physiology; D014810:Vitamin E / Q000494:pharmacology
chemical_list: D016207:Cytokines; D004268:DNA-Binding Proteins; D004791:Enzyme Inhibitors; D019394:Ki-67 Antigen; D016328:NF-kappa B; D011518:Proto-Oncogene Proteins; D017382:Reactive Oxygen Species; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse; D015534:Trans-Activators; D014810:Vitamin E; C092073:cardiotrophin 1; D019255:NADPH Oxidases; D011505:Protein-Tyrosine Kinases; C507926:Jak2 protein, mouse; D053614:Janus Kinase 2; D020928:Mitogen-Activated Protein Kinases