title: PDL Progenitor-Mediated PDL Recovery Contributes to Orthodontic Relapse.
abstract: Periodontal ligament (PDL) is subjected to mechanical force during physiologic activities. PDL stem /: progenitor cells are the main mesenchymal stem cells in PDL. However, how PDL progenitors participate in PDL homeostasis upon and after mechanical force is largely unknown. In this study, force-triggered orthodontic tooth movement and the following relapse were used as models to demonstrate the response of PDL progenitors and their role in PDL remodeling upon and after mechanical force. Upon orthodontic force, PDL collagen on the compression side significantly degraded, showing a broken and disorganized pattern. After force withdrawal, the degraded PDL collagen recovered during the early stage of relapse. Correspondingly, increased CD90(+) PDL progenitors with suppressed expression of type I collagen (Col-I) were observed upon orthodontic force, whereas these cells accumulated at the degradation regions and regained Col-I expression after force withdrawal during early relapse. Our results further showed that compressive force altered cell morphology and repressed collagen expression in cultured PDL progenitors, which both recovered after force withdrawal. Force withdrawal-induced recovery of collagen expression in cultured PDL progenitors could be regulated by transforming growth factor-β (TGF-β), a key molecule for tissue homeostasis and extracellular matrix remodeling. More interesting, inhibiting the regained Col-I expression in CD90(+) PDL progenitors by blocking TGF-β interrupted PDL collagen recovery and partially inhibited the early relapse. These data suggest that PDL progenitors can respond to mechanical force and may process intrinsic stability to recover to original status after force withdrawal. PDL progenitors with intrinsic stability are required for PDL recovery and consequently contribute to early orthodontic relapse, which can be regulated by TGF-β signaling.
authors.affiliation: Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: L
authors.initials: L
authors.lastname: Feng
authors.affiliation: Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: R
authors.initials: R
authors.lastname: Yang
authors.affiliation: Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: D
authors.initials: D
authors.lastname: Liu
authors.affiliation: Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: X
authors.initials: X
authors.lastname: Wang
authors.affiliation: Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Song
authors.affiliation: Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: H
authors.initials: H
authors.lastname: Cao
authors.affiliation: Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: D
authors.initials: D
authors.lastname: He
authors.affiliation: Center for Temporomandibular Disorders and Orofacial Pain, Peking University School and Hospital of Stomatology, Beijing, China Center Laboratory, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: Y
authors.initials: Y
authors.lastname: Gan
authors.affiliation: Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, Beijing, China.
authors.forename: X
authors.initials: X
authors.lastname: Kou
authors.affiliation: Department of Orthodontics, Peking University School and Hospital of Stomatology, Beijing, China Center for Craniofacial Stem Cell Research and Regeneration, Peking University School and Hospital of Stomatology, Beijing, China yanhengzhou@vip.163.com.
authors.forename: Y
authors.initials: Y
authors.lastname: Zhou
mesh_terms: D000818:Animals; D001549:Benzamides / Q000494:pharmacology; D003094:Collagen / Q000502:physiology; D004149:Dioxoles / Q000494:pharmacology; D008297:Male; D010513:Periodontal Ligament / Q000166:cytology / Q000502:physiology*; D017207:Rats, Sprague-Dawley; D018125:Receptors, Transforming Growth Factor beta / Q000037:antagonists & inhibitors; D012008:Recurrence; D013234:Stem Cells / Q000187:drug effects / Q000502:physiology*; D013314:Stress, Mechanical; D014087:Tooth Movement Techniques / Q000009:adverse effects
chemical_list: C459179:4-(5-benzo(1,3)dioxol-5-yl-4-pyridin-2-yl-1H-imidazol-2-yl)benzamide; D001549:Benzamides; D004149:Dioxoles; D018125:Receptors, Transforming Growth Factor beta; D003094:Collagen
keywords: collagen; growth factor; orthodontic tooth movement; periodontal ligament; stem cells; stress