title: In vivo identification of periodontal progenitor cells.
abstract: The periodontal ligament contains progenitor cells; however, their identity and differentiation potential in vivo remain poorly characterized. Previous results have suggested that periodontal tissue progenitors reside in perivascular areas. Therefore, we utilized a lineage-tracing approach to identify and track periodontal progenitor cells from the perivascular region in vivo. We used an alpha-smooth muscle actin (αSMA) promoter-driven and tamoxifen-inducible Cre system (αSMACreERT2) that, in combination with a reporter mouse line (Ai9), permanently labels a cell population, termed 'SMA9'. To trace the differentiation of SMA9-labeled cells into osteoblasts/cementoblasts, we utilized a Col2.3GFP transgene, while expression of Scleraxis-GFP was used to follow differentiation into periodontal ligament fibroblasts during normal tissue formation and remodeling following injury. In uninjured three-week-old SMA9 mice, tamoxifen labeled a small population of cells in the periodontal ligament that expanded over time, particularly in the apical region of the root. By 17 days and 7 weeks after labeling, some SMA9-labeled cells expressed markers indicating differentiation into mature lineages, including cementocytes. Following injury, SMA9 cells expanded, and differentiated into cementoblasts, osteoblasts, and periodontal ligament fibroblasts. SMA9-labeled cells represent a source of progenitors that can give rise to mature osteoblasts, cementoblasts, and fibroblasts within the periodontium.
authors.affiliation: Department of Reconstructive Sciences, University of Connecticut Health Center, Farmington, CT, USA.
authors.forename: H
authors.initials: H
authors.lastname: Roguljic
authors.forename: B G
authors.initials: BG
authors.lastname: Matthews
authors.forename: W
authors.initials: W
authors.lastname: Yang
authors.forename: H
authors.initials: H
authors.lastname: Cvija
authors.forename: M
authors.initials: M
authors.lastname: Mina
authors.forename: I
authors.initials: I
authors.lastname: Kalajzic
mesh_terms: D000199:Actins / Q000235:genetics; D000818:Animals; D051792:Basic Helix-Loop-Helix Proteins / Q000235:genetics; D002454:Cell Differentiation / Q000235:genetics; D019070:Cell Lineage / Q000235:genetics; D024042:Collagen Type I / Q000235:genetics; D004396:Coloring Agents; D003739:Dental Cementum / Q000502:physiology; D005347:Fibroblasts / Q000502:physiology; D017930:Genes, Reporter / Q000235:genetics; D019426:Integrases / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D055806:Microvessels / Q000166:cytology; D010006:Osteoblasts / Q000502:physiology; D020286:Pericytes / Q000502:physiology; D010513:Periodontal Ligament / Q000098:blood supply / Q000166:cytology* / Q000293:injuries; D011401:Promoter Regions, Genetic / Q000235:genetics; D020797:Receptor, Platelet-Derived Growth Factor beta / Q000032:analysis; D013234:Stem Cells / Q000145:classification*; D013629:Tamoxifen; D019227:Tooth Apex / Q000166:cytology; D019237:Tooth Cervix / Q000166:cytology; D019076:Transgenes / Q000235:genetics; D014945:Wound Healing / Q000502:physiology
chemical_list: D000199:Actins; D051792:Basic Helix-Loop-Helix Proteins; D024042:Collagen Type I; D004396:Coloring Agents; D019426:Integrases; D020797:Receptor, Platelet-Derived Growth Factor beta; D013629:Tamoxifen; C558396:Acta2 protein, mouse; C503815:Scx protein, mouse; C045073:Cre recombinase
keywords: Cre recombinase; GFP; cementoblasts; periodontal ligament; scleraxis; α-smooth muscle actin