title: [Extracellular signal-regulated kinase signaling pathway regulates the endothelial differentiation of periodontal ligament stem cells].
abstract: OBJECTIVE
  To investigate the effect of extracellular signal-regulated kinase (ERK) signaling pathway on the endothelial differentiation of periodontal ligament stem cells (PDLSC).
  
  
  METHODS
  Human PDLSC was cultured in the medium with vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (b-FGF) to induce endothelial differentiation. Endothelial inducing cells was incubated with U0126, a specific p-ERK1/2 inhibitor. PDLSC from one person were randomly divided into four groups: control group, endothelial induced group, endothelial induced+DMSO group and endothelial induced+U0126 group. The protein expression of the p-EKR1/2 was analyzed by Western blotting at 0, 1, 3, 6 and 12 hours during endonthelial induction. The mRNA expressions of CD31, VE-cadherin, and VEGF were detected by quantitative real-time reverse transcriptase polymerase chain reaction (qRT-PCR) after a 7-day induction. The proportion of CD31(+) to VE-cadherin(+) cells was identified by flow cytometry, and the ability of capillary-like tubes formation was detected by Matrigel assay after a 14-day induction. The measurement data were statistically analyzed.
  
  
  RESULTS
  Phosphorylated ERK1/2 protein level in PDLSC was increased to 1.24±0.12 and 1.03±0.24 at 1 h and 3 h respectively, during the endothelial induction (P<0.01). The mRNA expressions of CD31 and VEGF in induced+U0126 group were decreased to 0.09±0.18 and 0.49±0.17, which were both significantly different with those in induced group (P<0.05). The proportion of CD31(+) to VE-cadherin(+) cells of induced+U0126 group were decreased to 5.22±0.85 and 3.56±0.87, which were both significantly different with those in induced group (P<0.05). In Matrigel assay, the branching points, tube number and tube length were decreased to 7.0±2.7, 33.5±6.4, and (15 951.0±758.1) pixels, which were all significantly different with those in induced group (P<0.05).
  
  
  CONCLUSIONS
  The endothelial differentiation of PDLSC is positively regulated by ERK signaling pathway. Inhibition of ERK1/2 phosphorylation could suppress endothelial differentiation of PDLSC.
authors.affiliation: State Key Laboratory of Military Stomatology, Departerment of Periodontology, School of Stomatology, The Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Hong
authors.initials: H
authors.lastname: Zhu
authors.forename: Lankun
authors.initials: L
authors.lastname: Luo
authors.forename: Ying
authors.initials: Y
authors.lastname: Wang
authors.forename: Jun
authors.initials: J
authors.lastname: Tan
authors.forename: Peng
authors.initials: P
authors.lastname: Xue
authors.forename: Qintao
authors.initials: Q
authors.lastname: Wang
mesh_terms: D015703:Antigens, CD / Q000235:genetics / Q000378:metabolism; D002070:Butadienes / Q000494:pharmacology; D015820:Cadherins / Q000235:genetics / Q000378:metabolism; D002454:Cell Differentiation; D042783:Endothelial Cells / Q000166:cytology* / Q000502:physiology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D048049:Extracellular Signal-Regulated MAP Kinases / Q000502:physiology*; D016222:Fibroblast Growth Factor 2 / Q000494:pharmacology; D006801:Humans; D048052:Mitogen-Activated Protein Kinase 3 / Q000037:antagonists & inhibitors / Q000378:metabolism*; D009570:Nitriles / Q000494:pharmacology; D010513:Periodontal Ligament / Q000166:cytology* / Q000378:metabolism; D010766:Phosphorylation; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011897:Random Allocation; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology* / Q000502:physiology; D013997:Time Factors; D042461:Vascular Endothelial Growth Factor A / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology; D000099152:Cadherin 5
chemical_list: D015703:Antigens, CD; D002070:Butadienes; D015820:Cadherins; D004791:Enzyme Inhibitors; D048049:Extracellular Signal-Regulated MAP Kinases; D016222:Fibroblast Growth Factor 2; D048052:Mitogen-Activated Protein Kinase 3; D009570:Nitriles; D019408:Platelet Endothelial Cell Adhesion Molecule-1; D012333:RNA, Messenger; D042461:Vascular Endothelial Growth Factor A; D000099152:Cadherin 5; C113580:U 0126