title: Investigating a clonal human periodontal ligament progenitor/stem cell line in vitro and in vivo.
abstract: The lifespan of the tooth is influenced by the periodontal ligament (PDL), a specialized connective tissue that connects the cementum with the tooth socket bone. Generation of a cell line from PDL progenitor/stem cells would allow development of tissue engineering-based regenerative PDL therapy. However, little is known about the characteristics of PDL progenitor/stem cells because PDL tissue consists of a heterogeneous cell population and there are no pure PDL cell lines. Recently, we succeeded in immortalizing primary human PDL fibroblasts (HPLFs) by transfecting them with SV40 T-antigen and hTERT (Cell Tissue Res 2006; 324: 117-125). In this study, we isolated three clonal cell lines from these immortalized cells (lines 1-4, 1-11, and 1-24) that express RUNX-2, Col I, ALP, OPN, OCN, RANKL, OPG, scleraxis, periostin, Col XII, and alpha-SMA mRNA. Immunocytochemical analysis demonstrated that CD146 was expressed in cell lines 1-4 and 1-11 and that STRO-1 was expressed in lines 1-11 and 1-24. Lines 1-4 and 1-11 differentiated into osteoblastic cells and adipocytes when cultured in lineage-specific differentiation media. Four weeks after transplanting cell line 1-11 into immunodeficient mice with beta-tricalcium phosphate (beta-TCP), the transplant produced cementum/bone-like tissues around the beta-TCP. Eight weeks after transplantation, the 1-11 cell transplant formed PDL-like structures on the surface of the beta-TCP. These data suggest that cell line 1-11 was derived from a progenitor/stem cell present in the PDL and should be very useful for studying the biology and regeneration of human periodontium.
authors.affiliation: Department of Endodontology and Operative Dentistry, Division of Oral Rehabilitation, Faculty of Dental Science, Kyushu University, Fukuoka, Japan.
authors.forename: Shinsuke
authors.initials: S
authors.lastname: Fujii
authors.forename: Hidefumi
authors.initials: H
authors.lastname: Maeda
authors.forename: Naohisa
authors.initials: N
authors.lastname: Wada
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tomokiyo
authors.forename: Masahiro
authors.initials: M
authors.lastname: Saito
authors.forename: Akifumi
authors.initials: A
authors.lastname: Akamine
mesh_terms: D017667:Adipocytes / Q000166:cytology; D000818:Animals; D002454:Cell Differentiation; D002460:Cell Line; D002999:Clone Cells; D003739:Dental Cementum / Q000166:cytology; D006801:Humans; D051379:Mice; D016513:Mice, SCID; D010006:Osteoblasts / Q000166:cytology; D010513:Periodontal Ligament / Q000166:cytology* / Q000637:transplantation; D013234:Stem Cells / Q000166:cytology*