Physiologic Levels of Endogenous Hydrogen Sulfide Maintain the Proliferation and Differentiation Capacity of Periodontal Ligament Stem Cells.
BACKGROUND
Many invading oral bacteria are known to produce considerable amounts of hydrogen sulfide (H2S). The toxic activity of exogenous H2S in periodontal tissue has been demonstrated, but the role of endogenous H2S in the physiologic function of periodontal tissue remains poorly understood. The purpose of the present study is to investigate the biologic functions of H2S in the proliferation and differentiation of human periodontal ligament stem cells (PDLSCs).


METHODS
PDLSCs were isolated from periodontal ligament tissues of periodontally healthy volunteers or patients with periodontitis. Immunocytochemical staining, flow cytometry, and Western blot analysis were used to examine the expression of H2S-synthesizing enzymes cystathionine-β-synthase (CBS) and cystathionine-γ-lyase (CSE). The proliferation capacity of PDLSCs was determined by cell counting kit-8 assay, carboxyfluorescein succinimidyl ester analysis, and 5-ethynyl-2'-deoxyuridine assay. The osteogenic potential of PDLSCs was tested using alkaline phosphatase staining, Alizarin Red staining, and in vivo transplantation experiments. Oil Red O staining was used to analyze adipogenic ability.


RESULTS
The results show that human PDLSCs express both CBS and CSE and produce H2S. Blocking the generation of endogenous H2S with CBS inhibitor hydroxylamine significantly attenuated PDLSC proliferation and reduced the osteogenic and adipogenic differentiation capacity of PDLSCs. In contrast, CSE inhibitor DL-propargylglycine had no effect on PDLSC function. Exogenous H2S could inhibit the production of endogenous H2S and impair PDLSC function in a dose-dependent manner.


CONCLUSIONS
Physiologic levels of endogenous H2S maintain the proliferation and differentiation capacity of PDLSCs, and CBS may be the main source of endogenous H2S in PDLSCs.
Molecular Laboratory for Gene Therapy and Tooth Regeneration, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing, China.
Yingying
Y
Su
Molecular Laboratory for Gene Therapy and Tooth Regeneration, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing, China.
Dayong
D
Liu
Laboratory of Tissue Regeneration and Immunology and Department of Periodontics, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology.
Yi
Y
Liu
Molecular Laboratory for Gene Therapy and Tooth Regeneration, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing, China.
Chunmei
C
Zhang
Molecular Laboratory for Gene Therapy and Tooth Regeneration, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing, China.|Department of Biochemistry and Molecular Biology, Capital Medical University School of Basic Medical Sciences, Beijing, China.
Jinsong
J
Wang
Molecular Laboratory for Gene Therapy and Tooth Regeneration, Beijing Key Laboratory of Tooth Regeneration and Function Reconstruction, Capital Medical University School of Stomatology, Beijing, China.|Department of Biochemistry and Molecular Biology, Capital Medical University School of Basic Medical Sciences, Beijing, China.
Songlin
S
Wang
D002454:Cell Differentiation; D049109:Cell Proliferation; D006801:Humans; D006862:Hydrogen Sulfide / Q000378:metabolism*; D010513:Periodontal Ligament / Q000166:cytology*; D013234:Stem Cells
D006862:Hydrogen Sulfide
Adipogenesis; cell proliferation; hydrogen sulfide; osteogenesis; periodontal disease; stem cells