Notch hyper-activation drives trans-differentiation of hESC-derived endothelium.

TitleNotch hyper-activation drives trans-differentiation of hESC-derived endothelium.
Publication TypeJournal Article
Year of Publication2016
AuthorsReichman D, Man L, Park L, Lis R, Gerhardt J, Rosenwaks Z, James D
JournalStem Cell Res
Date Published2016 09
KeywordsBenzamides, Cell Transdifferentiation, Cells, Cultured, Diamines, Dioxoles, Endothelial Cells, Human Embryonic Stem Cells, Humans, Intracellular Signaling Peptides and Proteins, Jagged-1 Protein, Membrane Proteins, Microscopy, Fluorescence, Receptors, Notch, RNA Interference, RNA, Small Interfering, Signal Transduction, Thiazoles, Transcriptional Activation

During development, endothelial cells (EC) display tissue-specific attributes that are unique to each vascular bed, as well as generic signaling mechanisms that are broadly applied to create a patent circulatory system. We have previously utilized human embryonic stem cells (hESC) to generate tissue-specific EC sub-types (Rafii et al., 2013) and identify pathways that govern growth and trans-differentiation potential of hESC-derived ECs (James et al., 2010). Here, we elucidate a novel Notch-dependent mechanism that induces endothelial to mesenchymal transition (EndMT) in confluent monolayer cultures of hESC-derived ECs. We demonstrate density-dependent induction of EndMT that can be rescued by the Notch signaling inhibitor DAPT and identify a positive feedback signaling mechanism in hESC-ECs whereby trans-activation of Notch by DLL4 ligand induces elevated expression and surface presentation of DLL4. Increased Notch activation in confluent hESC-EC monolayer cultures induces areas of EndMT containing transitional cells that are marked by increased Jagged1 expression and reduced Notch signal integration. Jagged1 loss of function in monolayer hESC-ECs induces accelerated feedback stimulation of Notch signaling, increased expression of cell-autonomous, cis-inhibitory DLL4, and EndMT. These data elucidate a novel interplay of Notch ligands in modulating pathway activation during both expansion and EndMT of hESC-derived ECs.

Alternate JournalStem Cell Res
PubMed ID27643563