The Role of Gap Junctions in MSC-EA.hy926 (An Endothelial Cell Model) Crosstalk Under Hypoxic Stress: Regulation of the Angiogenic Response.

Effective communication between multipotent mesenchymal stromal cells (MSCs) and endothelial cells (ECs) plays a critical role in the regulation of angiogenesis, especially under conditions of hypoxia. In addition to paracrine stimulation, direct intercellular contacts play an important role in the angiogenic interaction between MSCs and ECs, making them an important target for modulating vascular network restoration under ischemic conditions. The aim of this study was to determine the contribution of gap junctions (GJs) to the angiogenic response of MSCs and the EA.hy926 cell line (an Endothelial Cell Model) under acute hypoxic stress. In a cell co-culture model at 0.1% O2 using a specific GJ inhibitor (carbenoxolone), molecular, cellular, and functional tests were performed: assessment of viability, proliferation, migration, secretion of angiogenic mediators, and expression of crucial genes. GJ blockade was accompanied by decreases in the proliferation and migration activity and angiogenic potential of the conditioned medium in in vitro and in ovo tests. These data highlight the importance of the GJ in coordinating the angiogenic response in conditions of acute hypoxia and can be used to develop protocols for regenerative medicine.