title: Hemin promotes proliferation and differentiation of endothelial progenitor cells via activation of AKT and ERK.
abstract: Increased neovascularization is commonly observed in hemorrhagic plaques and associated with rupture of atherosclerotic lesions. This study aims to investigate whether hemin accumulated at the site of hematoma promotes neovascularization through affecting the growth and function of endothelial progenitor cells (EPCs) and the possible mechanism involved. Here we demonstrated that hemin promoted a significant increase in neovessel formation in matrigel plugs embedded in vivo and enhanced the proliferation and endothelial gene expression in EPCs in vitro. VEGF-induced migration response and the capability to incorporate into the vascular networks were markedly enhanced in hemin-treated EPCs. Hemin induced the phosphorylation of ERK and AKT but not p38 or JNK. The inhibition of AKT or ERK activation significantly attenuated the effect of hemin on cell proliferation. However, the enhanced migration response induced by hemin was significantly suppressed by the inhibition of AKT but not ERK. Hemin induced significant increase in reactive oxygen species (ROS) production and hemin-induced angiogenic response of EPCs was substantially reduced by treatment with N-acetylcysteine. Collectively, these data support that hemin-induced ROS mediates the activation of AKT and ERK signaling pathways, which in turn promotes the cell proliferation and function of EPCs. J. Cell. Physiol. 219: 617-625, 2009. (c) 2009 Wiley-Liss, Inc.
authors.affiliation: Institute of Biomedical Sciences, Academia Sinica, Taipei, Taiwan, ROC.
authors.forename: Jir-You
authors.initials: JY
authors.lastname: Wang
authors.forename: Yi-Tsun
authors.initials: YT
authors.lastname: Lee
authors.forename: Pi-Fei
authors.initials: PF
authors.lastname: Chang
authors.forename: Lee-Young
authors.initials: LY
authors.lastname: Chau
mesh_terms: D000818:Animals; D002454:Cell Differentiation / Q000187:drug effects / Q000502:physiology; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology* / Q000187:drug effects* / Q000201:enzymology; D004789:Enzyme Activation / Q000187:drug effects; D006412:Hematopoietic Stem Cells / Q000166:cytology* / Q000187:drug effects* / Q000201:enzymology; D051547:Heme Oxygenase-1 / Q000172:deficiency / Q000235:genetics / Q000378:metabolism; D006427:Hemin / Q000494:pharmacology*; D020935:MAP Kinase Signaling System / Q000187:drug effects; D051379:Mice; D008810:Mice, Inbred C57BL; D018345:Mice, Knockout; D008822:Mice, Transgenic; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism*; D018919:Neovascularization, Physiologic / Q000187:drug effects / Q000235:genetics; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D015854:Up-Regulation / Q000187:drug effects
chemical_list: D017382:Reactive Oxygen Species; D006427:Hemin; D051547:Heme Oxygenase-1; D051057:Proto-Oncogene Proteins c-akt; D020929:Mitogen-Activated Protein Kinase Kinases