Notch Signaling Participates in TGF‐β‐Induced SOST Expression Under Intermittent Compressive Stress

Abstract

Notch signaling is regulated by mechanical stimuli in various cell types. It has previously been reported that intermittent compressive stimuli enhanced sclerostin (SOST) expression in human periodontal ligament cells (hPDLs) by regulating transforming growth factor-β (TGF-β) expression. The aim of the present study was to determine the involvement of Notch signaling in the TGF-β-induced SOST expression in hPDLs. Cells were treated with intermittent compressive stress in a computer-controlled apparatus for 24 h. The mRNA and protein expression of the cells were determined by real-time polymerase chain reaction and Western blot analysis, respectively. In some experiments, the target signaling pathway was impeded by the addition of a TGF-β receptor kinase inhibitor (SB431542) or a γ-secretase inhibitor (DAPT). The results demonstrated that hPDLs under intermittent compressive stress exhibited significantly higher NOTCH2, NOTCH3, HES1, and HEY1 mRNA expression compared with control, indicating that mechanical stress induced Notch signaling. DAPT pretreatment markedly reduced the intermittent stress-induced SOST expression. The expression of NOTCH2, NOTCH3, HES1, and HEY1 mRNA under compressive stress was significantly reduced after pretreatment with SB431542, coinciding with a reduction in SOST expression. Recombinant human TGF-β1 enhanced SOST, Notch receptor, and target gene expression in hPDLs. Further, DAPT treatment attenuated rhTGF-β1-induced SOST expression. In summary, intermittent compressive stress regulates Notch receptor and target gene expression via the TGF-β signaling pathway. In addition, Notch signaling participates in TGF-β-induced SOST expression in hPDLs. J. Cell. Physiol. 232: 2221-2230, 2017. © 2016 Wiley Periodicals, Inc.

Gene expression profiling of Jagged1‐treated human periodontal ligament cells

“…TGF‐β1 has been shown to regulate differentiation of periodontal ligament cells toward tenocytes, myocytes, and osteoblasts (Hyun, Lee, Kang, & Jang, ; Li & Zhang, ; Xu et al, ). Previous study illustrated that intermittent compressive stress mimicking chewing cycle supregulated sclerostin expression in hPDLs mediated by TGF‐β1 (Manokawinchoke, Sumrejkanchanakij et al, ). Further, it was shown that Notch signaling was involved in TGF‐β1‐induced sclerostin expression (Manokawinchoke, Sumrejkanchanakij et al, ).…”

“…Previous study illustrated that intermittent compressive stress mimicking chewing cycle supregulated sclerostin expression in hPDLs mediated by TGF‐β1 (Manokawinchoke, Sumrejkanchanakij et al, ). Further, it was shown that Notch signaling was involved in TGF‐β1‐induced sclerostin expression (Manokawinchoke, Sumrejkanchanakij et al, ). Hence, Jagged1‐induced TGF‐β1 mRNA expression may participate in the regulation of periodontal homeostasis in normal condition exposing to chewing force.…”

“…Teeth were extracted according to patient's treatment plan. Teeth were cleaned in sterile phosphate‐buffered saline, and periodontal ligament was gently removed from the middle third of the roots (Manokawinchoke, Sumrejkanchanakij, Pavasant, & Osathanon, ). Cell explant was performed to isolate hPDLs.…”

Intermittent compressive force promotes osteogenic differentiation in human periodontal ligament cells by regulating the transforming growth factor-β pathway

“…Many publications demonstrate that mechanical force controls the biological activities and responses of cells isolated from human PDL tissue [9][10][11] . Cyclic stretch exposure results in differential expression of genes related to the ECM, cell adhesion, and ECM proteases in human PDL cells (hPDLs) 9 .…”

“…Hence, these results indicate the influence of different force types on hPDL behavior. Studies illustrate that CCF and intermittent compressive force (ICF) differentially regulate hPDL behavior 11,12 . CCF and ICF both significantly increased SOST, TGFB1, and HEY1 mRNA expression in hPDLs 11 .…”