Gene expression profiling of Jagged1-treated human periodontal ligament cells

A multiscale computational model of arterial growth and remodeling including Notch signaling

Blood vessels grow and remodel in response to mechanical stimuli. Many computational models capture this process phenomenologically, by assuming stress homeostasis, but this approach cannot unravel the underlying cellular mechanisms. Mechano-sensitive Notch signaling is well-known to be key in vascular development and homeostasis. Here, we present a multiscale framework coupling a constrained mixture model, capturing the mechanics and turnover of arterial constituents, to a cell-cell signaling model, describing Notch signaling dynamics among vascular smooth muscle cells (SMCs) as influenced by mechanical stimuli. Tissue turnover was regulated by both Notch activity, informed by in vitro data, and a phenomenological contribution, accounting for mechanisms other than Notch. This novel framework predicted changes in wall thickness and arterial composition in response to hypertension similar to previous in vivo data. The simulations suggested that Notch contributes to arterial growth in hypertension mainly by promoting SMC proliferation, while other mechanisms are needed to fully capture remodeling. The results also indicated that interventions to Notch, such as external Jagged ligands, can alter both the geometry and composition of hypertensive vessels, especially in the short term. Overall, our model enables a deeper analysis of the role of Notch and Notch interventions in arterial growth and remodeling and could be adopted to investigate therapeutic strategies and optimize vascular regeneration protocols.

Effect of Jagged1 on the expression of genes in regulation of osteoblast differentiation and bone mineralization ontology in human dental pulp and periodontal ligament cells

Objective

To define the effect of Jagged1 on the gene expression in osteoblast differentiation, regulation of osteoblast differentiation and regulation of bone mineralization ontology.

Methods

Human dental pulp and periodontal ligament cells were isolated using explant method. Cells were seeded on Jagged1 immobilized surface. The mRNA expression was determined using real-time polymerase chain reaction. Mineral deposition was evaluated using alizarin red s staining. Publicly available database of gene expression profiles (GSE126249 and GSE94989) were downloaded and performed bioinformatic analysis to identify gene expression in osteoblast differentiation and regulation of osteoblast differentiation and mineralization ontology.

Results

Both human dental pulp cells and human periodontal ligament cells expressed higher Notch target gene (HES1 and HEY1) when cells were seeded on Jagged1 immobilization surface. Jagged1 significantly increased an in vitro mineral deposition in both cell types after maintaining in osteogenic induction medium for 14 days. Correspondingly, the significant increase of ALPL mRNA expression was observed, while there was no significant change in ANKH and ENPP1 mRNA expression in Jagged1 treated condition. From bioinformatic analysis of genes in osteoblast differentiation ontology, IARS, COL1A1, ALPL, COL6A1, CREB3L1, and SNAI2 mRNA levels were upregulated while GJA1 mRNA levels were decreased upon Jagged1 exposure. In the regulation of bone mineralization ontology, evidences supported that TFGB1 and TGFB3 were upregulated in Jagged1 treated condition.

Conclusion

Jagged1 promote the mRNA expression of several genes in osteoblast differentiation related gene ontology. This could be further employed to identify the mechanism by which Jagged1 promoted osteogenic differentiation in human dental pulp and periodontal ligament cells.