title: [Effect of endoplasmic reticulum stress on the expression and osteogenic differentiation of periodontal ligament stem cells].
abstract: OBJECTIVE
  To determine the activity of endoplasmic reticulum stress (ERS) and its effect on osteogenic differentiation of periodontal ligament stem cells (PDLSC) in inflammatory microenvironment.
  
  
  METHODS
  PDLSC were obtained from the primary culture of the human tooth and cloned with limited diluted method. Real-time reverse transcription (RT)-PCR was used to examine the different expression of thapsigargin (TG) treated PDLSC and lipopolysaccharide (LPS) treated PDLSC. Real-time RT-PCR, alizarin red staining and cetyl pyridine chloride quantitative analyze were used to examine the osteogenic differentiation of PDLSC, TG + PDLSC, LPS + PDLSC and LPS + PDLSC + 4-PBA.
  
  
  RESULTS
  Protein kinase receptor like endoplasmic reticulum kinase (PERK), glucose regulated protein 78 (GRP78), transcription activation factor 4(ATF4), CCAAT/enhancer-binding protein-homologous protein (CHOP) mRNA expression in group PDLSC + TG in 6 h were respectively 1.49 ± 0.24, 2.77 ± 0.60, 1.75 ± 0.16, 2.16 ± 0.32, which were all greater than that in group PDLSC (P < 0.05). PERK, CHOP mRNA expression reached the peak at 6 h (1.76 ± 0.08, 2.31 ± 0.17) and were greater than group PDLSC (P < 0.05). ERS could suppress osteogenic differentiation of TG + PDLSC and LPS + PDLSC. The runt-related transcription factor-2 (RUNX2), alkaline phosphatase (ALP), osteocalcin (OCN) mRNA expression of group TG + PDLSC was respectively 0.73 ± 0.06, 0.01 ± 0.00, 0.20 ± 0.06 (P < 0.05). The RUNX2, ALP, OCN mRNA expression of group LPS + PDLSC was respectively 0.80 ± 0.06, 0.48 ± 0.05, 0.29 ± 0.04 (P < 0.05). The RUNX2, ALP, OCN mRNA expression of group PDLSC + TG + 4-PBA was respectively 1.10 ± 0.09, 0.74 ± 0.05, 0.67 ± 0.13, which were greater higher than that of group LPS + PDLSC (P < 0.05).
  
  
  CONCLUSIONS
  ERS was activated in PDLSC and suppressed osteogenic differentiation of PDLSC, which can simulate inflammatory microenvironment in vitro. This effect can be recovered by using ERS inhibitor 4-PBA.
authors.affiliation: State Key Laboratory of Military Stomatology, Department of Periodontology, School of Stomatology, The Fourth Military Medical University, Xi'an 710032, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Xue
authors.forename: Bei
authors.initials: B
authors.lastname: Li
authors.forename: Jun
authors.initials: J
authors.lastname: Tan
authors.forename: Ying
authors.initials: Y
authors.lastname: An
authors.forename: Yan
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Email: yznmbk@fmmu.edu.cn.
authors.forename: Qintao
authors.initials: Q
authors.lastname: Wang
mesh_terms: D000469:Alkaline Phosphatase / Q000378:metabolism; D002082:Butylamines / Q000494:pharmacology; D002454:Cell Differentiation; D060833:Cellular Microenvironment; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism; D000091342:Endoplasmic Reticulum Chaperone BiP; D059865:Endoplasmic Reticulum Stress / Q000502:physiology*; D006801:Humans; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis; D010513:Periodontal Ligament / Q000166:cytology* / Q000378:metabolism; D011134:Polysaccharides / Q000494:pharmacology; D012333:RNA, Messenger / Q000378:metabolism; D013234:Stem Cells / Q000187:drug effects / Q000502:physiology*; D019284:Thapsigargin / Q000494:pharmacology
chemical_list: C121358:4-phenylbutylamine; D002082:Butylamines; D050659:Core Binding Factor Alpha 1 Subunit; D000091342:Endoplasmic Reticulum Chaperone BiP; C000717247:HSPA5 protein, human; D011134:Polysaccharides; D012333:RNA, Messenger; C493709:RUNX2 protein, human; D015675:Osteocalcin; D019284:Thapsigargin; D000469:Alkaline Phosphatase