title: Sphingosine-1-phosphate-induced Flk-1 transactivation stimulates mouse embryonic stem cell proliferation through S1P1/S1P3-dependent β-arrestin/c-Src pathways.
abstract: Although recent findings showed that the bioactive lipid metabolites can regulate the ES cell functions, the physiological relevance of interaction between sphingosine-1-phosphate (S1P) and Flk-1 and its related signaling molecules are not yet clear in ES cell proliferation. In the present study, S1P1-5 receptors were expressed in mouse ES cells and S1P increased S1P1-3 receptor expression level. S1P treatment stimulated the cellular proliferation in S1P1/3-dependent manner, located in lipid rafts. In response to S1P, β-arrestin was recruited to S1P1/3 receptor and c-Src was activated. S1P also increased the binding of S1P1/3 receptor with Flk-1. Similar to responses for VEGF, S1P increased Flk-1 phosphorylation, which was blocked by β-arrestin siRNA, and PP2, but not by VEGF-A164 antibody or VEGF siRNA. In addition, S1P induced VEGF expression and VEGFR2 kinase inhibitor (SU1498) blocked the S1P-induced cellular proliferation. However, VEGF-A164 antibody or VEGF siRNA partially blocked S1P-induced cellular proliferation, suggesting that both VEGF-dependent Flk-1 activation and VEGF-independent Flk-1 activation are involved in S1P-induced ES cell proliferation. S1P and VEGF-induced phosphorylation of ERK and JNK were blocked by pretreatment with SU1498. Moreover, inhibition of ERK and JNK blocked S1P-induced cellular proliferation. In conclusion, S1P-elicited transactivation of Flk-1 mediated by S1P1/3-dependent β-arrestin/c-Src pathways stimulated mouse ES cell proliferation.
authors.affiliation: Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, Republic of Korea; Department of Veterinary Physiology, College of Veterinary Medicine, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Jung Min
authors.initials: JM
authors.lastname: Ryu
authors.affiliation: Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, Republic of Korea.
authors.forename: Young Bin
authors.initials: YB
authors.lastname: Baek
authors.affiliation: Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, Republic of Korea.
authors.forename: Myung Sun
authors.initials: MS
authors.lastname: Shin
authors.affiliation: Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, Republic of Korea.
authors.forename: Ji Hoon
authors.initials: JH
authors.lastname: Park
authors.affiliation: Department of Veterinary Physiology, College of Veterinary Medicine, Chonnam National University, Gwangju 500-757, Republic of Korea.
authors.forename: Soo Hyun
authors.initials: SH
authors.lastname: Park
authors.affiliation: Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, Republic of Korea.
authors.forename: Jang Hern
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Veterinary Physiology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 151-741, Republic of Korea. Electronic address: hjhan@snu.ac.kr.
authors.forename: Ho Jae
authors.initials: HJ
authors.lastname: Han
mesh_terms: D000818:Animals; D000906:Antibodies / Q000276:immunology; D019390:Arrestins / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*; D000081247:CSK Tyrosine-Protein Kinase; D002460:Cell Line; D049109:Cell Proliferation; D053595:Embryonic Stem Cells / Q000166:cytology* / Q000378:metabolism; D048049:Extracellular Signal-Regulated MAP Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D048031:JNK Mitogen-Activated Protein Kinases / Q000037:antagonists & inhibitors / Q000378:metabolism; D008246:Lysophospholipids / Q000235:genetics / Q000378:metabolism*; D051379:Mice; D010766:Phosphorylation; D011485:Protein Binding; D034622:RNA Interference; D049349:Receptors, Lysosphingolipid / Q000235:genetics / Q000378:metabolism*; D013110:Sphingosine / Q000031:analogs & derivatives* / Q000235:genetics / Q000378:metabolism; D000081025:Sphingosine-1-Phosphate Receptors; D015533:Transcriptional Activation / Q000235:genetics; D042461:Vascular Endothelial Growth Factor A / Q000037:antagonists & inhibitors / Q000276:immunology / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000235:genetics / Q000378:metabolism*; D000071557:beta-Arrestins; D019061:src-Family Kinases / Q000378:metabolism*
chemical_list: D000906:Antibodies; D019390:Arrestins; D008246:Lysophospholipids; D049349:Receptors, Lysosphingolipid; C501285:S1pr3 protein, mouse; D000081025:Sphingosine-1-Phosphate Receptors; D042461:Vascular Endothelial Growth Factor A; D000071557:beta-Arrestins; C060506:sphingosine 1-phosphate; D040301:Vascular Endothelial Growth Factor Receptor-2; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; D048049:Extracellular Signal-Regulated MAP Kinases; D048031:JNK Mitogen-Activated Protein Kinases; D013110:Sphingosine
keywords: CDK; CLM; Cholesterol-loaded MβCD.; Cyclin dependent kinase; ERK; ESC; Embryonic stem cell; Extracellular signal-regulated kinases; Fetal Liver Kinase 1; Flk-1; JNK; Methyl-β-cyclodextrin; MβCD; RTK; Receptor tyrosine kinase; S1P; Sphingosine-1-phosphate; VEGF; Vascular endothelial growth factor; c-Jun N-terminal kinases