Extracellular matrix‐mediated endothelial differentiation of human induced pluripotent stem cells (1152.4)

Abstract

Over 8 million Americans are suffering from Peripheral Arterial Disease (PAD), which is due to atherosclerotic occlusion of the peripheral arteries of the limbs. Recent studies suggest that human induced pluripotent stem cell (iPSC)‐derived endothelial cells (iPSC‐ECs) can serve as a promising source for treatment of PAD. However, the low differentiation efficiency of iPSC‐ECs is a major limitation to their clinical use. The purpose of this study was to investigate the role of extracellular matrix (ECM) and cell‐ECM interactions in endothelial differentiation of iPSCs utilizing high throughput ECM microarray technique. We developed a high‐throughput ECM microarray that contains circular printed areas of ECMs on glass slides using a robotic DNA microarrayer. Multi‐component mixtures of purified ECMs components (gelatin, fibronectin, laminin, heparin sulfate proteoglycans, collagen IV, and matrigel) were deposited onto glass slides at fixed distances. A total of 280 spotted matrix features were fabricated with multi‐component mixtures of the ECM components. After dissociating and culturing iPSCs onto ECM microarrays, differentiation was induced by adding VEGF (50ng/ml) for 5 days. EC differentiation was confirmed with CD31 staining, whose expression was scored semi‐quantitatively and averaged among the six replicates on the slide. A greater abundance of CD31 with higher score was observed in ECM features composed of gelatin + laminin + fibronectin tri‐component mixtures comparing to other conditions. Gene expressions of various integrin subunits were compared between iPSCs and iPSC‐ECs to elucidate the role of cell‐ECM interactions. The expression of integrins α1 through α6 and β1 through β4 were elevated in iPSC‐ECs comparing to iPSCs. On the other hand, β5 shows a significant decrease in iPSC‐ECs. In total, this data suggested that ECM differentially promote iPSC differentiation into EC, possibly through binding to various types of integrins. Grant Funding Source : NIH, NSF, Stanford CVI