Abstract 18960: Ciliary Neurotrophic Factor Increases the Angiogenic Properties of Human Pluripotent Stem Cell Derived Neuropilin-1+ CD34+ Nascent Endothelial Cells Via a JAK2 Dependent Pathway
Pluripotent stem cells are a model to identify novel regulators of angiogenesis. Previously, we showed that Neuropilin-1 (NRP1) CD34- cells were vascular precursors. Subsequently, genomic analysis revealed that NRP1+ CD34+ cells had transcript content consistent with nascent endothelium, and unique growth factor receptors that may be exploited to modulate their angiogenic properties. The objectives of our study was to verify that NRP1+ CD34+ cells form endothelium, and determine the function of the Ciliary Neurotrophic Factor (CNTF) Receptor and its downstream kinase Jak2 in angiogenesis.
Methods and Results: Human induced pluripotent stem cells (hiPSCs) were differentiated as embyroid bodies and NRP1+ CD34+ nascent endothelial cells were sorted. NRP1+ CD34+ cells readily formed sheets of endothelium expressing VE-Cadherin, CD146, PECAM, and eNOS, absorbed acetylated LDL, and formed tubule networks in Matrigel. These features confirmed their endothelial properties. Here we show that CNTF promotes angiogenic sprouting of NRP1+ CD34+ cells via a Jak2 dependent mechanism. RT-PCR analysis of NRP1+ CD34+ transcripts showed a significant (> 5 fold) increase in the growth factor receptor CNTFR, and the downstream signaling partners Jak2, Stat5A and Stat6 versus undifferentiated hiPSCs. CNTF increased the length of endothelial tubules in Matrigel 44±7.3% vs. no CNTF (p≤0.05), while inhibition of JAK2 in the presence of CNTF blocked the effect of CNTF.
Conclusions: NRP1+ CD34+ cells derived from human pluripotent stem cells readily form endothelium, and their angiogenic properties can be augmented by activation of a novel CNTFR-Jak2 mediated pathway. Collectively, the findings confirm that NRP1+ CD34+ cells are a nascent endothelial cell, and identify a novel growth factor signaling pathway involved in angiogenesis, suggesting a role for CNTF in promotion of angiogenesis in therapy for vascular diseases.
- © 2012 by American Heart Association, Inc.