Int Endod J. 2021 Aug 29. doi: 10.1111/iej.13620. Online ahead of print.
ABSTRACT
AIM: To investigate whether TGF-β/BMP signaling participates in Jagged1-induced osteogenic differentiation in human dental pulp cells (hDPs).
METHODOLOGY: Bioinformatic analysis of publicly available RNA sequencing data of Jagged1 treated hDPs was performed using NetworkAnalyst. The mRNA expression was validated using real-time polymerase chain reaction. hDPs were seeded on Jagged1 immobilized surface in the presence or absence of TGF-β or BMP inhibitor. Osteogenic differentiation was evaluated using alkaline phosphatase staining, osteogenic marker gene expression, and mineralization assay. Statistical analyses were performed using a Kruskal Wallis test, followed by a pairwise comparison for more than three group comparison. Mann Whitney U test was employed for two group comparison. The statistical significance was considered at p< 0.05.
RESULTS: Jagged1 treatment in growth medium significantly promoted TGFB1, TGFB2, and TGFB3 while significantly inhibited BMP2, BMP4, and BMP6 mRNA expression (p<0.05). In osteogenic induction medium, Jagged1 significantly upregulated TGFB1, TGFB2, and TGFB3 at day 1 and 3 (p<0.05). Pretreatment with TGF-β1, TGF-β2, or TGF-β3 prior to osteogenic induction resulted in the significant increase of osteogenic marker gene expression, collagen type 1 protein expression, alkaline phosphatase enzymatic activity, and mineral deposition (p<0.05). However, TGF-β signaling inhibition with SB431542 (4 μM) or SB505124 (47 and 129 nM) failed to attenuate the effect of Jagged1-induced osteogenic differentiation in hDPs. Dorsomorphin (4 and 8 μM) treatment significantly abolished the effect of Jagged1 on mineralization by hDPs (p<0.05).
CONCLUSION: Notch signaling activation by Jagged1 modulated TGF-β and BMP ligand expression. Dorsomorphin, but not TGF-β receptor inhibitor, attenuated Jagged1-induced osteogenic differentiation in hDPs.
PMID:34455605 | DOI:10.1111/iej.13620
