title: The expression of periostin in dental pulp cells.
abstract: OBJECTIVE
  Dental pulp repair is a common process triggered by microbial and mechanical challenges. Matricellular modulators, such as periostin, are key for extracellular matrix stability and tissue healing. In the scope of the dental pulp, periostin expression has been reported during development and active dentinogenesis. However, the specific dental pulp cell population capable of expressing periostin in response to known regulators has not been clearly defined. Among the different relevant cell populations (i.e., stem cells, fibroblasts and pre-odontoblasts) potentially responsible for periostin expression in the dental pulp, this study aimed to determine which is the primary responder to periostin regulators.
  
  
  METHODS
  Human dental pulp stem cells (DPSCs), human dental pulp fibroblasts (DPFs), and rat odontoblast-like cells (MDPC-23) were treated with different concentrations of TGF-β1 or different regimens of biomechanical stimulation to evaluate periostin expression by qRT-PCR, Western blot and ELISA. Statistical analyses were performed by Student's t-test and ANOVA with Fisher's LSD post hoc tests (p ≤ 0.05).
  
  
  RESULTS
  DPSC and MDPC-23 showed a statistically significant increase in periostin mRNA expression after exposure to TGF-β1 for 48 h. TGF-β1 also up-regulated periostin protein levels in DPSC. However, periostin significantly down-regulated protein expression in DPF. Different regimens of biomechanical stimulation showed different patterns in protein and mRNA periostin expression.
  
  
  CONCLUSIONS
  Expression of periostin was identified in each of the analysed dental pulp cell lines, which can be regulated by TGF-β1 and biomechanical stimulation. Overall, DPSCs are the most responsive cells to stimulation.
authors.affiliation: Resident of Endodontics, University of Michigan School of Dentistry, Ann Arbor, MI, USA. Electronic address: rwiesen@umich.edu.
authors.forename: Robert M
authors.initials: RM
authors.lastname: Wiesen
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA; Department of Oral Surgery and Implant Dentistry, School of Dentistry, University of Granada, Granada, Spain. Electronic address: mipadial@ugr.es.
authors.forename: Miguel
authors.initials: M
authors.lastname: Padial-Molina
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA. Electronic address: stomanic@umich.edu.
authors.forename: Sarah L
authors.initials: SL
authors.lastname: Volk
authors.affiliation: Department of Cariology, Restorative Sciences, and Endodontics, University of Michigan School of Dentistry, Ann Arbor, MI, USA. Electronic address: somerled@umich.edu.
authors.forename: Neville
authors.initials: N
authors.lastname: McDonald
authors.affiliation: Department of Cariology, Restorative Sciences, and Endodontics, University of Michigan School of Dentistry, Ann Arbor, MI, USA. Electronic address: djchiego@umich.edu.
authors.forename: Daniel
authors.initials: D
authors.lastname: Chiego
authors.affiliation: Department of Cariology, Restorative Sciences, and Endodontics, University of Michigan School of Dentistry, Ann Arbor, MI, USA. Electronic address: tbotero@umich.edu.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Botero
authors.affiliation: Department of Periodontics and Oral Medicine, University of Michigan School of Dentistry, Ann Arbor, MI, USA. Electronic address: hrios@umich.edu.
authors.forename: Hector F
authors.initials: HF
authors.lastname: Rios
mesh_terms: D000818:Animals; D001696:Biomechanical Phenomena; D015153:Blotting, Western; D015815:Cell Adhesion Molecules / Q000378:metabolism*; D003782:Dental Pulp / Q000166:cytology / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D005347:Fibroblasts / Q000378:metabolism; D006801:Humans; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D060888:Real-Time Polymerase Chain Reaction; D013234:Stem Cells / Q000378:metabolism; D053773:Transforming Growth Factor beta1 / Q000494:pharmacology
chemical_list: D015815:Cell Adhesion Molecules; C512835:POSTN protein, human; C512836:Postn protein, rat; D012333:RNA, Messenger; D053773:Transforming Growth Factor beta1
keywords: Biomechanical stimulation; Dental pulp; Matricellular proteins; Periodontal ligament; Periostin; TGF-β1