Hemodynamic Forces Regulate Embryonic Stem Cell Commitment to Vascular Progenitors

Pluripotent embryonic stem can (ES) cells can differentiate into all cell lineages. During the process of embryonic development, ES cells are exposed to fluid flow or blood flow generated by the contracting heart. Absence of fluid flow results in the formation of abnormal cardiac chambers and valve formation. Thus, hemodynamic forces and ES cell differentiation to vascular progenitor cells (VPCs) are of emerging interests for restoring endothelial dysfunction, inducing angiogenesis, and forming blood vessel networks. Hemodynamic forces such as fluid shear stress increase the percentage of cells in the S and G(2)-M phases, and induce decondensation of chromatin for gene transcription. Fluid shear stress further accelerates ES commitment to CD31(+) VPC vascular progenitor cells. These ES-derived CD31(+) cells express endothelial nitric oxide synthase (eNOS) and von Willebrand factor (vWF). They are also capable of LDL uptake and tubular network formation. In this context, understanding hemodynamic forces and ES cell kinetics of differentiation towards endothelial lineage has potential therapeutic applications for repairing vascular damage and engineering vascular graft. Multidisciplinary team approach will likely garner momentum and synergize expertise to address the current road blocks in basic stem cell research for engraftable, restorative, low immunogenic, and non-tumorigenic endothelial progenitors in high purity and stability.