title: Semaphorin 4D Enhances Angiogenic Potential and Suppresses Osteo-/Odontogenic Differentiation of Human Dental Pulp Stem Cells.
abstract: BACKGROUND
  To investigate the roles of semaphorin 4D (Sema4D)/plexin-B1 signaling on the angiogenic potential and osteo-/odontogenic differentiation of human dental pulp stem cells (DPSCs) and to uncover the corresponding molecular mechanisms.
  
  
  METHODS
  DPSCs were treated with Sema4D (10 μg/mL) for different time durations. Osteo-/odontogenic differentiation was assessed by quantifying alkaline phosphatase activity, mineralized nodule formation, and osteo-/odontogenic gene (ALP, Col1A1, BSP, RUNX2, and DSPP) and protein (Col1A1 and DSPP) expression. Involvement of the Sema4D/plexin-B1 signaling pathway was analyzed by Western blot analysis. Additionally, angiogenic gene and protein expression was assessed by reverse-transcription polymerase chain reaction and enzyme-linked immunosorbent assay. In vitro endothelial tube formation assay on Matrigel (BD Biosciences, San Jose, CA) was performed to evaluate the angiogenic inductive potential of the Sema4D-treated DPSCs conditioned medium. Results were analyzed using 1-way analysis of variance and the Student t test.
  
  
  RESULTS
  Sema4D significantly inhibited ALP activity and mineralized nodule formation of DPSCs. Furthermore, Sema4D-treated DPSCs displayed marked down-regulation in the expression of osteo-/odontogenic genes (ALP, Col1A1, BSP, RUNX2, and DSPP) as well as proteins (Col1A1 and DSPP). Elevated levels of plexin-B1 and downstream RhoA protein expression together with phosphorylated plexin-B1 confirmed the involvement of Sema4D/plexin-B1 signaling. Protein expression of ErbB2 was up-regulated, and Met was slightly down-regulated. Furthermore, Sema4D-treated DPSCs exhibited enhanced expression of vascular endothelial growth factor at both the messenger RNA and protein level. Accordingly, the conditioned medium of Sema4D-treated DPSCs promoted the formation of vessel-like structures as shown by the Matrigel assay.
  
  
  CONCLUSIONS
  Sema4D markedly enhances the angiogenic potential but suppresses osteo-/odontogenic differentiation of DPSCs. Sema4D/plexin-B signaling was activated via the RhoA-mediated pathway.
authors.affiliation: Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
authors.forename: Ting
authors.initials: T
authors.lastname: Zou
authors.affiliation: Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
authors.forename: Waruna Lakmal
authors.initials: WL
authors.lastname: Dissanayaka
authors.affiliation: Department of Endodontics and Operative Dentistry, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, Fujian, China.
authors.forename: Shan
authors.initials: S
authors.lastname: Jiang
authors.affiliation: Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
authors.forename: Shuai
authors.initials: S
authors.lastname: Wang
authors.affiliation: Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China.
authors.forename: Boon Chin
authors.initials: BC
authors.lastname: Heng
authors.affiliation: Department of Endodontics and Operative Dentistry, School and Hospital of Stomatology, Fujian Medical University, Fuzhou, Fujian, China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Huang
authors.affiliation: Endodontology, Faculty of Dentistry, The University of Hong Kong, Hong Kong, China. Electronic address: zhangcf@hku.hk.
authors.forename: Chengfei
authors.initials: C
authors.lastname: Zhang
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D015703:Antigens, CD / Q000494:pharmacology*; D015153:Blotting, Western; D002454:Cell Differentiation / Q000187:drug effects; D049109:Cell Proliferation / Q000187:drug effects; D002478:Cells, Cultured; D003782:Dental Pulp / Q000166:cytology / Q000187:drug effects* / Q000254:growth & development; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D018919:Neovascularization, Physiologic / Q000187:drug effects; D060888:Real-Time Polymerase Chain Reaction; D039961:Semaphorins / Q000494:pharmacology*; D013234:Stem Cells / Q000187:drug effects* / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism
chemical_list: D015703:Antigens, CD; C093224:CD100 antigen; D039961:Semaphorins; D042461:Vascular Endothelial Growth Factor A; D000469:Alkaline Phosphatase
keywords: Alkaline phosphatase activity; angiogenic potential; dental pulp stem cells; osteo-/odontogenic differentiation; semaphorin 4D/plexin-B1