Indirect immobilized Jagged1 suppresses cell cycle progression and induces odonto/osteogenic differentiation in human dental pulp cells

Abstract

Notch signaling regulates diverse biological processes in dental pulp tissue. The present study investigated the response of human dental pulp cells (hDPs) to the indirect immobilized Notch ligand Jagged1 in vitro. The indirect immobilized Jagged1 effectively activated Notch signaling in hDPs as confirmed by the upregulation of HES1 and HEY1 expression. Differential gene expression profiling using an RNA sequencing technique revealed that the indirect immobilized Jagged1 upregulated genes were mainly involved in extracellular matrix organization, disease, and signal transduction. Downregulated genes predominantly participated in the cell cycle, DNA replication, and DNA repair. Indirect immobilized Jagged1 significantly reduced cell proliferation, colony forming unit ability, and the number of cells in S phase. Jagged1 treated hDPs exhibited significantly higher ALP enzymatic activity, osteogenic marker gene expression, and mineralization compared with control. Pretreatment with a γ-secretase inhibitor attenuated the Jagged1-induced ALP activity and mineral deposition. NOTCH2 shRNA reduced the Jagged1-induced osteogenic marker gene expression, ALP enzymatic activity, and mineral deposition. In conclusion, indirect immobilized Jagged1 suppresses cell cycle progression and induces the odonto/osteogenic differentiation of hDPs via the canonical Notch signaling pathway.

A non-canonical JAGGED1 signal to JAK2 mediates osteoblast commitment in cranial neural crest cells

“…JAG1 is a definitive NOTCH1 ligand and induces the NOTCH1 canonical pathway, which others and we have demonstrated by examining JAG1-induced expression of classic NOTCH1 target, Hes1 and Hey1 ( Figure 1B & 1C) (33). We and others have also demonstrated, as in Figure 2B & 2C, that JAG1 induces early and late osteoblast markers, Runx2 and Ocn, respectively, along with inducing ALP activity, in vitro, in O9-1 cells, independent of BMP2 ( Figure: 2A, 2B & 2C) suggesting that the JAG1-NOTCH1 axis is essential during commitment of neural crest cells into the osteoblast lineage (33,34).…”

Gene expression profiling of Jagged1‐treated human periodontal ligament cells

“…The biological effect of Jagged1 on hPDLs cell cycle regulation was also indicated by cell proliferation, colony formation, and cell cycle analyses. Previous study in human dental pulp cells demonstrated that Jagged1‐treated cells exhibited lower cell number in S phase, suggesting the G0/G1 arrest (Manokawinchoke, Nattasit et al, ).Similar to the results of the present study, Jagged1‐treated hPDLs exhibited the increased cell population in G0/G1 phase and the decreased S and G2/M population, suggesting G0/G1 cell cycle arrest. Similar observation was noted in pericytes that Jagged1 induced G0/G1 population but reduced S and G2/M population {Ji, 2016 #42}.…”

“…Further, the decrease expression of mRNA related to cell cycle was observed in Jagged1‐treated hPDLs compared with the control. Similarly, Jagged1‐treated human dental pulp cells (hDPs) also enhanced genes related to extracellular matrix pathway and attenuated genes involving in cell cycle regulation (Manokawinchoke, Nattasit et al, ; Manokawinchoke et al, ). The present study demonstrated that CDK1 and PLK1 were downregulated in Jagged1‐treated hPDLs.…”

“…Briefly, tissue culture surfaces were incubated with recombinant protein G at a concentration of 50 μg/ml for 16 hr. After washing, surfaces were then incubated with bovine serum albumin (10 mg/ml) for 2 hr and Jagged1/Fc (10 nM) for 2 hr, respectively (Beckstead et al, ; Manokawinchoke, Nattasit et al, ; Manokawinchoke et al, ; Osathanon, Ritprajak et al, ). Human IgG Fc fragment (hFc) was employed in the control condition.…”

Amelogenesis imperfecta: A novel FAM83H mutation and characteristics of periodontal ligament cells

“…Cell proliferation was determined using 3‐(4,5‐dimethylthiazol‐2‐yl)‐2,5‐diphenyltetrazolium bromide (MTT) assay (Manokawinchoke et al, ; Sukarawan, Nowwarote, Kerdpon, Pavasant, & Osathanon, ). A total of 12,500 cells per well were seeded and maintained in growth medium.…”