title: Direct Gingival Fibroblast/Osteoblast Transdifferentiation via Epigenetics.
abstract: Alveolar bone resorption caused by trauma or periodontal diseases has represented a challenge for both dental clinicians and researchers. In this study, we evaluate the osteogenic potential of human gingival fibroblasts (HGFs) through a direct transdifferentiation from HGFs to functional osteoblasts via epigenetic modification and osteogenic signaling with bone morphogenetic protein 2 (BMP2) in vitro and in vivo. HGF treatment with 5-aza-2'-deoxycytidine (5-aza-dC) induced demethylation in the hypermethylated CpG islands of the osteogenic lineage marker genes RUNX2 and ALP, and subsequent BMP2 treatment successfully drove the fibroblasts to the osteoblasts' lineage. Cell morphological changes viewed under microscopy and alkaline phosphatase (ALP) and alizarin red S (ARS) staining confirmed the osteoblastic change mediated by epigenetic modification as did real-time polymerase chain reaction (PCR), methylation-specific PCR (MSP), and chromatin immunoprecipitation (ChIP) assay, which demonstrated the altered methylation patterns in the RUNX2 and ALP promoter regions and their effect on gene expression. Furthermore, micro-computed tomography (CT) analysis of in vivo mouse cell transplantation experiments showed high-density signal in the epigenetically modified HGF group; in addition, a significant amount of bone formation was observed in the transplanted material using hematoxylin and eosin (H&E) staining as well. Collectively, our results indicate that epigenetic modification permits the direct programming of HGFs into functional osteoblasts, suggesting that this approach might open a novel therapeutic avenue in alveolar bone regeneration.
authors.affiliation: 1 Department of Molecular Genetics, School of Dentistry and Dental Research Institute, BK21 Program, Seoul National University, Seoul, South Korea.|2 Department of Periodontology, School of Dentistry and Dental Research Institute, BK21 Program, Seoul National University, Seoul, South Korea.
authors.forename: Y
authors.initials: Y
authors.lastname: Cho
authors.affiliation: 1 Department of Molecular Genetics, School of Dentistry and Dental Research Institute, BK21 Program, Seoul National University, Seoul, South Korea.
authors.forename: B
authors.initials: B
authors.lastname: Kim
authors.affiliation: 1 Department of Molecular Genetics, School of Dentistry and Dental Research Institute, BK21 Program, Seoul National University, Seoul, South Korea.
authors.forename: H
authors.initials: H
authors.lastname: Bae
authors.affiliation: 1 Department of Molecular Genetics, School of Dentistry and Dental Research Institute, BK21 Program, Seoul National University, Seoul, South Korea.
authors.forename: W
authors.initials: W
authors.lastname: Kim
authors.affiliation: 1 Department of Molecular Genetics, School of Dentistry and Dental Research Institute, BK21 Program, Seoul National University, Seoul, South Korea.
authors.forename: J
authors.initials: J
authors.lastname: Baek
authors.affiliation: 1 Department of Molecular Genetics, School of Dentistry and Dental Research Institute, BK21 Program, Seoul National University, Seoul, South Korea.
authors.forename: K
authors.initials: K
authors.lastname: Woo
authors.affiliation: 1 Department of Molecular Genetics, School of Dentistry and Dental Research Institute, BK21 Program, Seoul National University, Seoul, South Korea.
authors.forename: G
authors.initials: G
authors.lastname: Lee
authors.affiliation: 2 Department of Periodontology, School of Dentistry and Dental Research Institute, BK21 Program, Seoul National University, Seoul, South Korea.
authors.forename: Y
authors.initials: Y
authors.lastname: Seol
authors.affiliation: 2 Department of Periodontology, School of Dentistry and Dental Research Institute, BK21 Program, Seoul National University, Seoul, South Korea.
authors.forename: Y
authors.initials: Y
authors.lastname: Lee
authors.affiliation: 2 Department of Periodontology, School of Dentistry and Dental Research Institute, BK21 Program, Seoul National University, Seoul, South Korea.
authors.forename: Y
authors.initials: Y
authors.lastname: Ku
authors.affiliation: 2 Department of Periodontology, School of Dentistry and Dental Research Institute, BK21 Program, Seoul National University, Seoul, South Korea.
authors.forename: I
authors.initials: I
authors.lastname: Rhyu
authors.affiliation: 1 Department of Molecular Genetics, School of Dentistry and Dental Research Institute, BK21 Program, Seoul National University, Seoul, South Korea.
authors.forename: H
authors.initials: H
authors.lastname: Ryoo
mesh_terms: D000818:Animals; D001374:Azacitidine / Q000031:analogs & derivatives / Q000494:pharmacology; D055396:Bone Morphogenetic Protein 2 / Q000494:pharmacology; D002460:Cell Line; D054338:Cell Transdifferentiation / Q000235:genetics* / Q000502:physiology*; D002478:Cells, Cultured; D047369:Chromatin Immunoprecipitation; D018899:CpG Islands; D019175:DNA Methylation; D000077209:Decitabine; D044127:Epigenesis, Genetic; D005260:Female; D005347:Fibroblasts / Q000166:cytology* / Q000378:metabolism; D005881:Gingiva; D006801:Humans; D008297:Male; D051379:Mice; D008875:Middle Aged; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D010012:Osteogenesis / Q000235:genetics* / Q000502:physiology*; D060888:Real-Time Polymerase Chain Reaction; D015398:Signal Transduction; D023822:Tissue Engineering / Q000379:methods*; D060449:Wnt Signaling Pathway; D055114:X-Ray Microtomography
chemical_list: C525718:BMP2 protein, human; D055396:Bone Morphogenetic Protein 2; D000077209:Decitabine; D001374:Azacitidine
keywords: bone regeneration; cell differentiation; gingiva; periodontal diseases; periodontium; tissue engineering