title: Cyclic tension promotes osteogenic differentiation in human periodontal ligament stem cells.
abstract: Orthodontic forces result in alveolar bone resorption and formation predominantly on the pressure and tension sides of the tooth roots, respectively. Human periodontal ligament stem cells (PDLSCs) have demonstrated the capacity to differentiate into osteoblasts, and they play important roles in maintaining homeostasis and regenerating periodontal tissues. However, little is known about how PDLSCs contribute to osteoblastogenesis during orthodontic tooth movement on the tension side. In this study, we applied a 12% cyclic tension force to PDLSCs cultured in osteoinductive medium. The osteogenic markers Runx2, ALP, and OCN were detected at the mRNA and protein levels at different time points using real-time PCR and western blot analyses. We discovered that the mRNA and protein levels of Runx2, ALP and OCN were significantly up-regulated after 6, 12 and 24 hours of mechanical loading on PDLSCs compared to levels in unstimulated PDLSCs (P < 0.05). This study demonstrates, for the first time, the effects of mechanical tensile strain on the osteogenic differentiation of PDLSCs, as examined with a Flexcell FX-4000T Tension Plus System. Our findings suggested that cyclic tension could promote the osteogenic differentiation of PDLSCs. Furthermore, the effects of orthodontic force on alveolar bone remodeling might be achieved by PDLSCs.
authors.affiliation: Department of Stomatology, Southwest Hospital, Third Military Medical University Chongqing, China ; Department of Stomatology, Out-Patient Department of 61251 PLA Troops Qinhuangdao, China.
authors.forename: Tao
authors.initials: T
authors.lastname: Shen
authors.affiliation: Department of Stomatology, General Hospital of Beijing Military Area Command Beijing, China.
authors.forename: Lin
authors.initials: L
authors.lastname: Qiu
authors.affiliation: Department of Stomatology, Southwest Hospital, Third Military Medical University Chongqing, China ; Department of Stomatology, Out-Patient Department of Sichuan Military Area Command Chengdu, China.
authors.forename: Huijun
authors.initials: H
authors.lastname: Chang
authors.affiliation: Department of Stomatology, Southwest Hospital, Third Military Medical University Chongqing, China.
authors.forename: Yanchun
authors.initials: Y
authors.lastname: Yang
authors.affiliation: Department of Stomatology, Southwest Hospital, Third Military Medical University Chongqing, China.
authors.forename: Congxiang
authors.initials: C
authors.lastname: Jian
authors.affiliation: Department of Stomatology, Southwest Hospital, Third Military Medical University Chongqing, China.
authors.forename: Jian
authors.initials: J
authors.lastname: Xiong
authors.affiliation: Department of Stomatology, Southwest Hospital, Third Military Medical University Chongqing, China.
authors.forename: Jixiang
authors.initials: J
authors.lastname: Zhou
authors.affiliation: Department of Biomedical Materials Science, School of Biomedical Engineering, Third Military Medical University Chongqing, China.
authors.forename: Shiwu
authors.initials: S
authors.lastname: Dong
mesh_terms: D000293:Adolescent; D000469:Alkaline Phosphatase / Q000378:metabolism; D002648:Child; D050659:Core Binding Factor Alpha 1 Subunit / Q000378:metabolism; D006801:Humans; D010006:Osteoblasts / Q000166:cytology* / Q000378:metabolism; D015675:Osteocalcin / Q000378:metabolism; D010012:Osteogenesis / Q000502:physiology*; D010513:Periodontal Ligament / Q000166:cytology* / Q000378:metabolism; D013234:Stem Cells / Q000166:cytology* / Q000378:metabolism; D013314:Stress, Mechanical; D055815:Young Adult
chemical_list: D050659:Core Binding Factor Alpha 1 Subunit; D015675:Osteocalcin; D000469:Alkaline Phosphatase
keywords: Periodontal ligament; biomechanics; cell differentiation; osteoblasts; stem cells; stress