NOS3 regulates angiogenic potential of human induced pluripotent stem cell-derived endothelial cells

Incorporation of blood capillaries in engineered tissues and their functional connection to host blood vessels is essential for success in engineering vascularized tissues, a process which involves spatial patterning of endothelial cells (ECs) to form functional and integrated vascular networks. Different types of ECs have been employed for vascular network formation and each source offers advantages and disadvantages. While ECs derived from induced pluripotent stem cells (iPSC-ECs) offer advantages over primary ECs in that they can be generated in large quantities for autologous applications, their suitability for disease modelling and cell replacement therapies is not well-explored. The present study compares the angiogenic capacity of iPSC-ECs and primary ECs (cardiac microvascular ECs and lymphatic microvascular ECs) using an in vitro tubulogenesis assay, revealing comparable performance in forming a pseudo-capillary network on Matrigel. Analysis of genes encoding angiogenic factors (VEGFA, VEGFC, VEGFD and ANG), endothelial cell markers (PECAM1, PCDH12 and NOS3) and proliferation markers (AURKB and MKI67) indicates a significant positive correlation between NOS3 mRNA expression levels and various tubulogenic parameters. Further experimentation using a CRISPR activation system demonstrates a positive impact of NOS3 on tubulogenic activity of ECs, suggesting that iPSC-ECs can be enhanced with endogenous NOS3 activation. Collectively, these findings highlight the potential of iPSC-ECs in generating vascularized tissues and advancing therapeutic vascularization.