Abstract P091: Transcriptional Profiling of Pluripotent Stem Cell--Derived Neuropilin-1+CD34- Vascular Precursors Reveals Significant Overlap with Ventral Mesoderm and Identifies Signaling Pathways in Differentiation from Vascular Cells
Background: Pluripotent stem cells are a model to understand the mechanisms of vascular differentiation in humans. We previously showed that the onset of Neuropilin-1 (NRP1) expression identifies vascular precursors in mouse and human embryonic stem cells. Our goal was to determine the degree of overlap between NRP1+CD34- cells and embryonic primitive streak, and identify novel growth factor signaling pathways controlling their differentiation.
Methods: Human pluripotent stem cells were differentiated, and NRP1+CD34- cells were isolated. Following RNA extraction, whole genome transcriptional profiling was performed. Microarray data were compared with undifferentiated stem cells and human umbilical vein endothelial cells (HUVECs) using differential gene expression analysis with a false discovery rate of 5%, and greater than two-fold change between groups. We compared significantly enriched transcripts in NRP1+CD34- cells against genes expressed in the primitive streak in Xenopus embryos using hypergeometric testing. Functional annotation-based clustering was used to identify putative cell signaling pathways.
Results: A total of 785 transcripts were significantly enriched in NRP1+CD34- vascular precursors vs. hESCs, and 605 transcripts were unique to NRP1+CD34- vascular precursors. NRP1+CD34- cells shared a significant number of transcripts (46 of 357 human homologs) with ventral mesoderm isolated from Xenopus embryos, (p ≤ 1 x 10-14). We then identified CXCL14, Neuregulin 2, Leptin and Apelin receptors as significantly upregulated in NRP1+CD34- vascular precursors, potentially controlling human ventral mesoderm and new vessel formation.
Conclusions: NRP1+CD34- vascular precursors have significant transcript identity with ventral mesoderm from embryonic primitive streak, and a unique transcriptional profile compared with HUVECs. These findings suggest NRP1+CD34- human vascular precursors significantly resemble ventral mesoderm, and provide a model of human vascular development. The identification of a comprehensive database of cell-surface receptors expressed by the human ventral mesoderm analogs permits future pharmacological approaches to induce vascular differentiation from human pluripotent stem cells.
- © 2011 by American Heart Association, Inc.