title: Endogenous hydrogen sulfide is involved in osteogenic differentiation in human periodontal ligament cells.
abstract: OBJECTIVE
  Endogenous hydrogen sulfide (H2S) has recently emerged as an important intracellular gaseous signaling molecule within cellular systems. Endogenous H2S is synthesized from l-cysteine via cystathionine β-synthase and cystathionine γ-lyase and it regulates multiple signaling pathways in mammalian cells. Indeed, aberrant H2S levels have been linked to defects in bone formation in experimental mice. The aim of this study was to examine the potential production mechanism and function of endogenous H2S within primary human periodontal ligament cells (PDLCs).
  
  
  METHODS
  Primary human PDLCs were obtained from donor molars with volunteer permission. Immunofluorescent labeling determined expression of the H2S synthetase enzymes. These enzymes were inhibited with D,L-propargylglycine or hydroxylamine to examine the effects of H2S signaling upon the osteogenic differentiation of PDLCs. Gene and protein expression levels of osteogenic markers in conjunction with ALP staining and activity and alizarin red S staining of calcium deposition were used to assay the progression of osteogenesis under different treatment conditions. Cultures were exposed to Wnt3a treatment to assess downstream signaling mechanisms.
  
  
  RESULTS
  In this study, we show that H2S is produced by human PDLCs via the cystathionine β-synthase/cystathionine γ-lyase pathway to promote their osteogenic differentiation. These levels must be carefully maintained as excessive or deficient H2S levels temper the observed osteogenic effect by inhibiting Wnt/β-catenin signaling.
  
  
  CONCLUSIONS
  These results demonstrate that optimal concentrations of endogenous H2S must be maintained within PDLCs to promote osteogenic differentiation by activating the Wnt/β-catenin signaling cascade.
authors.affiliation: Department of Periodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Sheng-Dan
authors.initials: SD
authors.lastname: Cen
authors.affiliation: Department of Orthodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Wen-Bin
authors.initials: WB
authors.lastname: Yu
authors.affiliation: Department of Periodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Man-Man
authors.initials: MM
authors.lastname: Ren
authors.affiliation: Department of Orthodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Li-Jiao
authors.initials: LJ
authors.lastname: Chen
authors.affiliation: Department of Orthodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Chao-Fan
authors.initials: CF
authors.lastname: Sun
authors.affiliation: Department of Periodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang, China.
authors.forename: Zhi-Li
authors.initials: ZL
authors.lastname: Ye
authors.affiliation: Department of Periodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang, China. Electronic address: dh0726@gmail.com.
authors.forename: Hui
authors.initials: H
authors.lastname: Deng
authors.affiliation: Department of Orthodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, Zhejiang, China. Electronic address: hurongdang@hotmail.com.
authors.forename: Rong-Dang
authors.initials: RD
authors.lastname: Hu
mesh_terms: D000293:Adolescent; D000328:Adult; D000480:Alkynes / Q000037:antagonists & inhibitors; D015153:Blotting, Western; D002454:Cell Differentiation / Q000502:physiology; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003541:Cystathionine beta-Synthase / Q000378:metabolism; D003542:Cystathionine gamma-Lyase / Q000378:metabolism; D003545:Cysteine / Q000378:metabolism; D005260:Female; D015870:Gene Expression; D005998:Glycine / Q000031:analogs & derivatives / Q000037:antagonists & inhibitors; D006801:Humans; D006862:Hydrogen Sulfide / Q000378:metabolism*; D019811:Hydroxylamine / Q000037:antagonists & inhibitors; D008297:Male; D008963:Molar; D010012:Osteogenesis / Q000235:genetics / Q000502:physiology*; D010513:Periodontal Ligament / Q000166:cytology / Q000378:metabolism*; D060449:Wnt Signaling Pathway; D055815:Young Adult
chemical_list: D000480:Alkynes; D019811:Hydroxylamine; C009055:propargylglycine; D003541:Cystathionine beta-Synthase; D003542:Cystathionine gamma-Lyase; D003545:Cysteine; D005998:Glycine; D006862:Hydrogen Sulfide
keywords: Hydrogen sulfide; Osteogenic differentiation; Periodontal ligament cells; Wnt/β-catenin signaling