title: Leukemia inhibitory factor induces endothelial differentiation in cardiac stem cells.
abstract: The importance of interleukin 6 (IL-6)-related cytokines in cardiac homeostasis has been studied extensively; however, little is known about their biological significance in cardiac stem cells. Here we describe that leukemia inhibitory factor (LIF), a member of IL-6-related cytokines, activated STAT3 and ERK1/2 in cardiac Sca-1+ stem cells. LIF stimulation resulted in the induction of endothelial cell-specific genes, including VE-cadherin, Flk-1, and CD31, whereas neither smooth muscle nor cardiac muscle marker genes such as GATA4, GATA6, Nkx-2.5, and calponin were up-regulated. Immunocytochemical examination showed that about 25% of total cells were positively stained with anti-CD31 antibody 14 days after LIF stimulation. Immunofluorescent microscopic analyses identified the Sca-1+ cells that were also positively stained with anti-von Willebrand factor antibody, indicating the differentiating process of Sca-1+ cells into the endothelial cells. IL-6, which did not activate STAT3 and ERK1/2, failed to induce the differentiation of cardiac stem cells into the endothelial cells. In cardiac stem cells, the transduction with dominant negative STAT3 abrogated the LIF-induced endothelial differentiation. And the inhibition of ERK1/2 with the MEK1/2 inhibitor U0126 also prevented the differentiation of Sca-1+ cells into endothelial cells. Thus, both STAT3 and ERK1/2 are required for LIF-mediated endothelial differentiation in cardiac stem cells. Collectively, it is proposed that LIF regulates the commitment of cardiac stem cells into the endothelial cell lineage, contributing to neovascularization in the process of tissue remodeling and/or regeneration.
authors.affiliation: Department of Clinical Evaluation of Medicines and Therapeutics, Graduate School of Pharmaceutical Sciences, Osaka University, Suita City, Osaka, Japan.
authors.forename: Tomomi
authors.initials: T
authors.lastname: Mohri
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Fujio
authors.forename: Makiko
authors.initials: M
authors.lastname: Maeda
authors.forename: Takashi
authors.initials: T
authors.lastname: Ito
authors.forename: Tomohiko
authors.initials: T
authors.lastname: Iwakura
authors.forename: Yuichi
authors.initials: Y
authors.lastname: Oshima
authors.forename: Yoriko
authors.initials: Y
authors.lastname: Uozumi
authors.forename: Masashi
authors.initials: M
authors.lastname: Segawa
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Tadamitsu
authors.initials: T
authors.lastname: Kishimoto
authors.forename: Junichi
authors.initials: J
authors.lastname: Azuma
mesh_terms: D000818:Animals; D015415:Biomarkers; D002454:Cell Differentiation / Q000502:physiology*; D004699:Endocardium / Q000166:cytology* / Q000201:enzymology / Q000378:metabolism*; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005786:Gene Expression Regulation / Q000502:physiology; D015850:Interleukin-6 / Q000502:physiology*; D053605:Leukemia Inhibitory Factor; D051379:Mice; D008810:Mice, Inbred C57BL; D018919:Neovascularization, Physiologic / Q000502:physiology; D050796:STAT3 Transcription Factor / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology / Q000201:enzymology / Q000378:metabolism*
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D053605:Leukemia Inhibitory Factor; C507838:Lif protein, mouse; D050796:STAT3 Transcription Factor; C494087:Stat3 protein, mouse; D048049:Extracellular Signal-Regulated MAP Kinases