BACKGROUND
The Notch signaling pathway is essential in embryogenesis of heart and postnatal functioning and remodeling of vascular network. In addition to canonical Notch signaling, there is non-canonical signaling pathway including interactions with elements of extracellular matrix. Multifactorial nature of Notch signaling pathway supposes that its exact mechanism is unclear.
OBJECTIVE
To study the role of Notch signaling pathway in communication of endothelial and mesenchymal stromal cells (MSCs) in angiogenesis before extracellular matrix assembly (19 hours) to exclude the influence of non-canonical signaling system.
MATERIAL AND METHODS
We used a model of capillary-like network formation by human umbilical vein endothelial cells (HUVECs) on Matrigel. Analysis of gene expression during co-culture of MSCs and HUVECs was performed using real-time PCR.
RESULTS
Γ-Secretase inhibitor, which blocks Notch activation, suppressed capillary-like HUVECs network formation on Matrigel by more than 2.5 fold and blocked expression of some Notch-dependent genes in the 2D model of capillary-like network formation in the co-culture of MSCs and HUVECs. In MSCs, the Notch signaling pathway is essential in regulation of expression of genes JAG1, Notch1, Notch3, HES1, HEY1, EFNB2, ANGPT2, TGFB3, ITGB3, SDC2, in endothelial cells — Notch4, HES2. Changes in expression of Notch-dependent genes HES and HEY in MSCs during co-culture were significantly higher than in HUVECs.
CONCLUSION
HUVECs drive the switch of MSCs to a pro-angiogenic phenotype through Notch signaling pathway. Our findings indicate the prospect of a method for modulating angiogenesis processes using cellular therapeutics based on MSCs with constitutively active Notch signaling.