title: Nicotine deteriorates the osteogenic differentiation of periodontal ligament stem cells through α7 nicotinic acetylcholine receptor regulating Wnt pathway.
abstract: OBJECTIVE
  Cigarette smoking is one of the high risk factors of adult chronic periodontitis and nicotine is the well established toxic substance in cigarette. However, the mechanism of nicotine induced periodontitis is still unknown. Here we studied whether nicotine impaired the osteogenic differentiation of human periodontal ligament stem cells (hPDLSCs) through activating α7 nicotinic acetylcholine receptor (α7 nAChR).
  
  
  METHODS
  hPDLSCs with multi differentiation potential and surface makers for mesenchymal stem cells were harvested by limiting dilution technique. The level of mineralized nodule formation was assessed by alizarin red S staining. Expression level of ostegenic related genes and proteins were detected by real-time PCR and western blot analysis. The expression of α7 nAChR and its downstream signaling pathway were examined by western blot. The role of the receptor and related signaling pathway in nicotine impairing the osteogenic potential of hPDLSCs were also studied in different levels.
  
  
  RESULTS
  Nicotine deteriorated the ostegenic differentiation of hPDLSCs in a dose dependent manner. Activation of α7 nAChR by nicotine treatment activated wnt/β-catenin signaling pathway, leading to osteogenic deficiency of hPDLSCs. Blockage of α7 nAChR and wnt pathway inhibitor treatment rescued nicotine induced osteogenic differentiation deficiency.
  
  
  CONCLUSIONS
  These data suggested that nicotine activated α7 nAChR expressed on PDLSCs and further activated wnt signaling downstream, thus deteriorating the osteogenic potential of PDLSCs. The impairment of osteogenic differentiation of PDLSCs by nicotine might lead to cigarette smoking related periodontitis.
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, China ; Research and Development Center for Tissue Engineering, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Zhifei
authors.initials: Z
authors.lastname: Zhou
authors.affiliation: Research and Development Center for Tissue Engineering, Fourth Military Medical University, Xi'an, Shaanxi, China ; Department of Oral Histology and Pathology, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Bei
authors.initials: B
authors.lastname: Li
authors.affiliation: Department of Oral and Maxillofacial Surgery, General Hospital of Shenyang Military Area Command, Shenyang, Liaoning, China.
authors.forename: Zhiwei
authors.initials: Z
authors.lastname: Dong
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, China ; Department of Oral Medicine, Maternal and Child Care Hospital, Xi'an, Shaanxi, China.
authors.forename: Fen
authors.initials: F
authors.lastname: Liu
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, China ; Research and Development Center for Tissue Engineering, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Zhang
authors.affiliation: Research and Development Center for Tissue Engineering, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Research and Development Center for Tissue Engineering, Fourth Military Medical University, Xi'an, Shaanxi, China ; Department of Orthodontic, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Fengqing
authors.initials: F
authors.lastname: Shang
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Lizheng
authors.initials: L
authors.lastname: Wu
authors.affiliation: Department of Pediatric Dentistry, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Xiaojing
authors.initials: X
authors.lastname: Wang
authors.affiliation: Research and Development Center for Tissue Engineering, Fourth Military Medical University, Xi'an, Shaanxi, China ; Department of Oral Histology and Pathology, School of Stomatology, Fourth Military Medical University, Xi'an, Shaanxi, China.
authors.forename: Yan
authors.initials: Y
authors.lastname: Jin
mesh_terms: D000293:Adolescent; D002454:Cell Differentiation / Q000187:drug effects; D002648:Child; D004305:Dose-Response Relationship, Drug; D005786:Gene Expression Regulation; D006801:Humans; D009538:Nicotine / Q000494:pharmacology*; D010012:Osteogenesis / Q000187:drug effects*; D010513:Periodontal Ligament / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D061251:Primary Cell Culture; D015398:Signal Transduction; D013234:Stem Cells / Q000166:cytology / Q000187:drug effects* / Q000378:metabolism; D051153:Wnt Proteins / Q000819:agonists / Q000235:genetics* / Q000378:metabolism; D055815:Young Adult; D064569:alpha7 Nicotinic Acetylcholine Receptor / Q000819:agonists / Q000235:genetics* / Q000378:metabolism; D051176:beta Catenin / Q000235:genetics / Q000378:metabolism
chemical_list: C495270:CTNNB1 protein, human; D051153:Wnt Proteins; D064569:alpha7 Nicotinic Acetylcholine Receptor; D051176:beta Catenin; D009538:Nicotine