title: Combined effects of proinflammatory cytokines and intermittent cyclic mechanical strain in inhibiting osteogenicity in human periodontal ligament cells.
abstract: Mechanical strain plays an important role in bone formation and resorption during orthodontic tooth movement. The mechanism has not been fully studied, and the process becomes complex with increased amounts of periodontal patients seeking orthodontic care. Our aims were to elucidate the combined effects of proinflammatory cytokines and intermittent cyclic strain (ICS) on the osteogenic capacity of human periodontal ligament cells. Cultured human periodontal ligament cells were exposed to proinflammatory cytokines (interleukin-1β 5 ng/mL and tumor necrosis factor-α 10 ng/mL) for 1 and 5 days, and ICS (0.5 Hz, 12% elongation) was applied for 4 h per day. The autocrine of inflammatory cytokines was measured by enzyme-linked immunosorbent assay. The expression of osteoblast markers runt-related transcription factor 2 and rabbit collagen type I was determined using real-time polymerase chain reaction and Western blot. The osteogenic capacity was also detected by alkaline phosphatase (ALP) staining, ALP activity, and alizarin red staining. We demonstrated that ICS impaired the osteogenic capacity of human periodontal ligament cells when incubated with proinflammatory cytokines, as evidenced by the low expression of ALP staining, low ALP activity, reduced alizarin red staining, and reduced osteoblast markers. These data, for the first time, suggest that ICS has a negative effect on the inductive inhibition of osteogenicity in human PDL cells mediated by proinflammatory cytokines.
authors.affiliation: Department of Orthodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China.
authors.forename: Chaofan
authors.initials: C
authors.lastname: Sun
authors.affiliation: Department of Orthodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China.
authors.forename: Lijiao
authors.initials: L
authors.lastname: Chen
authors.affiliation: Department of Periodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China.
authors.forename: Xinlian
authors.initials: X
authors.lastname: Shi
authors.affiliation: Department of Orthodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China.
authors.forename: Zhensheng
authors.initials: Z
authors.lastname: Cao
authors.affiliation: Department of Orthodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China.
authors.forename: Bibo
authors.initials: B
authors.lastname: Hu
authors.affiliation: Department of Orthodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China.
authors.forename: Wenbin
authors.initials: W
authors.lastname: Yu
authors.affiliation: Department of Periodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China.
authors.forename: Manman
authors.initials: M
authors.lastname: Ren
authors.affiliation: Department of Orthodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China.
authors.forename: Rongdang
authors.initials: R
authors.lastname: Hu
authors.affiliation: Department of Periodontics, School of Stomatology, Wenzhou Medical University, Wenzhou, 325027, Zhejiang, China.
authors.forename: Hui
authors.initials: H
authors.lastname: Deng
mesh_terms: D000293:Adolescent; D000328:Adult; D002454:Cell Differentiation / Q000502:physiology; D002478:Cells, Cultured; D016207:Cytokines / Q000276:immunology / Q000378:metabolism*; D005260:Female; D006801:Humans; D007249:Inflammation / Q000378:metabolism; D008297:Male; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism; D010012:Osteogenesis / Q000502:physiology*; D010513:Periodontal Ligament / Q000166:cytology / Q000276:immunology / Q000378:metabolism*; D010518:Periodontitis / Q000378:metabolism / Q000473:pathology; D013314:Stress, Mechanical; D014086:Tooth Mobility / Q000276:immunology / Q000378:metabolism*; D055815:Young Adult
chemical_list: D016207:Cytokines
keywords: ICS; IL-1β; TNF-α; human periodontal ligament cells; osteogenicity; proinflammatory cytokines