Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, PCA331

Poster Communications

The NADPH oxidase Nox4 promotes endothelial differentiation from murine induced-pluripotent stem cells

F. Hahner1, F. Moll1, R. Brandes1, K. Schröder1

1. Vascular Research centre, Goethe University Frankfurt, Frankfurt am Main, Hesse, Germany.

Nox4 is a constitutively active NADPH oxidase that produces H2O2. It is expressed in endothelial cells, and has been shown to contribute to differentiation of mesenchymal cells. Therefore, we hypothesize that Nox4 promotes endothelial differentiation. MEFs from WT and Nox4-/- mice were reprogramed into iPSCs and then differentiated into endothelial cells by VEGF and BMP4 stimulation. In the course of differentiation, Nox4 expression increased in WT cells. Nox4 knockout results in a prolonged expression of pluripotency markers and in a diminished expression of endothelial markers, such as Flk-1 and eNOS. Differentiated iPSC derived endothelial cells of Nox4-/- mice showed lower tube formation and sprouting capacity. A matrigel plug assay revealed lower capacity of Nox4-/- iPSC-ECs to integrate into a newly formed vascular network. As a potential mechanism, we identified an increased K27 triple methylation at histone H3. Demethylation of H3 is mediated by JmjD3 and methylation by Ezh2, both of which were not differentially expressed in Nox4-/- vs. WT cells. Interestingly a BIAM switch assay identified JmjD3 to be less oxidized in Nox4-/- cells. We therefore conclude Nox4 oxidizes and thereby activates JmjD3. This then results in decreased levels of H3K27me3 and promotes endothelial differentiation.

Where applicable, experiments conform with Society ethical requirements