title: Calcium hydroxide promotes cementogenesis and induces cementoblastic differentiation of mesenchymal periodontal ligament cells in a CEMP1- and ERK-dependent manner.
abstract: Periodontal tissue engineering is a complex process requiring the regeneration of bone, cementum, and periodontal ligament (PDL). Since cementum regeneration is poorly understood, we used a dog model of dental pulpal necrosis and in vitro cellular wounding and mineralization assays to determine the mechanism of action of calcium hydroxide, Ca(OH)(2), in cementogenesis. Laser capture microdissection (LCM) followed by qRT-PCR were used to assay responses of periapical tissues to Ca(OH)(2) treatment. Additionally, viability, proliferation, migration, and mineralization responses of human mesenchymal PDL cells to Ca(OH)(2) were assayed. Finally, biochemical inhibitors and siRNA were used to investigate Ca(OH)(2)-mediated signaling in PDL cell differentiation. In vivo, Ca(OH)(2)-treated teeth formed a neocementum in a STRO-1- and cementum protein-1 (CEMP1)-positive cellular environment. LCM-harvested tissues adjacent to the neocementum exhibited higher mRNA levels for CEMP1, integrin-binding sialoprotein, and Runx2 than central PDL cells. In vitro, Ca(OH)(2) and CEMP1 promoted STRO-1-positive cell proliferation, migration, and wound closure. Ca(OH)(2) stimulated expression of the cementum-specific proteins CEMP1 and PTPLA/CAP in an ERK-dependent manner. Lastly, Ca(OH)(2) stimulated mineralization by CEMP1-positive cells. Blocking CEMP1 and ERK function abolished Ca(OH)(2)-induced mineralization, confirming a role for CEMP1 and ERK in the process. Ca(OH)(2) promotes cementogenesis and recruits STRO-1-positive mesenchymal PDL cells to undergo cementoblastic differentiation and mineralization via a CEMP1- and ERK-dependent pathway.
authors.affiliation: Department of Periodontics and Oral Medicine, School of Dentistry, University of Michigan, 1011 N. University Ave., Ann Arbor, MI 48109-1078, USA.
authors.forename: Francisco Wanderley Garcia
authors.initials: FW
authors.lastname: Paula-Silva
authors.forename: Abhijit
authors.initials: A
authors.lastname: Ghosh
authors.forename: Higinio
authors.initials: H
authors.lastname: Arzate
authors.forename: Sunil
authors.initials: S
authors.lastname: Kapila
authors.forename: Léa Assed Bezerra
authors.initials: LA
authors.lastname: da Silva
authors.forename: Yvonne Lorraine
authors.initials: YL
authors.lastname: Kapila
mesh_terms: D000818:Animals; D002126:Calcium Hydroxide / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects; D002478:Cells, Cultured; D025021:Cementogenesis / Q000187:drug effects* / Q000502:physiology; D050659:Core Binding Factor Alpha 1 Subunit / Q000235:genetics / Q000378:metabolism; D003739:Dental Cementum / Q000166:cytology / Q000502:physiology*; D004285:Dogs; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism*; D006801:Humans; D058574:Integrin-Binding Sialoprotein / Q000235:genetics / Q000378:metabolism; D008648:Mesoderm / Q000166:cytology / Q000187:drug effects; D023421:Models, Animal; D010513:Periodontal Ligament / Q000166:cytology* / Q000378:metabolism / Q000502:physiology; D011506:Proteins / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D012038:Regeneration
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D058574:Integrin-Binding Sialoprotein; D011506:Proteins; D012333:RNA, Messenger; D048049:Extracellular Signal-Regulated MAP Kinases; D002126:Calcium Hydroxide