Overexpression of ephrinB2 in stem cells from apical papilla accelerates angiogenesis

We aimed to accelerate angiogenesis in pulp regeneration by modulating ephrinB2 expression in stem cells from apical papilla (SCAPs).

Stem cells from apical papilla were transducted with ephrinB2-lentiviral expression vector (ephrinB2-SCAPs) in experimental group and green fluorescent protein (GFP-SCAPs) in control group. The transduction efficiency was confirmed by real-time PCR and Western blot assays. MTT assay was performed to detect the proliferative capacity of SCAPs after transduction. In vitro Matrigel assay and in vivo Matrigel plug assay were carried out to evaluate the angiogenic capacity.

Results showed that ephrinB2-SCAPs had significantly higher ephrinB2 expression than GFP-SCAPs. EphrinB2-SCAPs upregulated vascular endothelial growth factor (VEGF) secretion under hypoxia. In vitro Matrigel assay demonstrated that human umbilical vein endothelial cells (HUVECs) cocultured with ephrinB2-SCAPs under hypoxia formed vascular-like structures earlier than GFP-SCAPs. Animal experiments confirmed that SCAPs co-transplanted with HUVECs enabled to generate greater amount of blood vessels than SCAPs alone. EphrinB2-SCAPs produced increased number of blood vessels with references to GFP-SCAPs, and those co-transplanted with HUVECs generated vessels with larger and functional tubule volumes.

Regulating ephrinB2 expression in SCAPs may act as a new avenue for enhancing angiogenesis in dental pulp regeneration.