Human Periodontal Ligament Stem Cells Co-cultured With Tooth Germ Cells Containing Bone Morphogenetic Protein-2Acquired Cementoblast Feature In Vitro

Cementum is a thin type of mineralized tissue produced bycementoblasts covering on the root surface, which serves as the site foranchoring periodontal ligament fibers between the root surface and alveolarbone to ensure the teeth’s normal function. When the cenmentum isdestroied by periodontal disease, the ability to repair itself is limited,because cementoblasts are scarce in root cementum and not easy to obtain.Thus, mesenchymal stem cells (MSCs)-based therapy for cementumregeneration or periodontal regeneration was focused on with great attentionin the last decade. As we all know that the microenvironment palys animportant role in the tissue regeneration project, so it is necessary toestablish an appropriate microenvironment to favor the differentiation ofcementoblasts and cementogenesis. Otherwise some research think thatBMP-2induces the expression of cementum attachment protein(CAP) inhuman periodontal ligameng clones, which is the specific marker incementoblast and the suggested concentration of BMP-2is50ng/mL. So inthis study we collected the human periodontal ligament stem cells(hPDLSCs) and co-culture with tooth germ cells(TGC) combined with thebone morphogenetic protein-2(BMP-2) in order to create a cementogenicmicroenvironment to induce hPDLSCs differentiating into cementoblast invitro. This strategy may provide a potential stem cells resources for periodontal tissue engineering and a better understanding of regulatorymechanisms for cementogenesis in periodontal development.Methods: After isolation and characterization, hPDLSCs were treatedwith α-MEM medium (control group) or co-culture with apical tooth germcells containing BMP-2(test group). Then RT-PCR and ALP activityanalyses were used to identify the cementoblast markers.Findings: Our findings suggested that when hPDLSCs co-culture withTGC containing BMP-2, they showed a high ALP activity (P<0.001),increased calcified nodules formation (P<0.001) and a significantly increaseof cementum-related genes expression such as CEMP-1,CAP, ALP andOCN (P<0.001).Results: hPDLSCs co-culture with TGC containing BMP-2acquiredcementoblast feature.