KDM6 Inhibition induces DNA Damage Response (DDR) during ESC Differentiation but not during self-renewal.. Mus musculus

The discovery of the first histone demethylase in 2004 (LSD1/KDM1) opened new avenues for the understanding of how histone methylation impacts cellular functions. A great number of histone demethylases have been identified since, which are potentially linked to gene regulation as well as to stem cell self-renewal and differentiation. KDM6A/UTY and KDM6B/JMJD3 are both H3K27me3/2-specific histone demethylases, which are known to play a central role in regulation of posterior development, by regulating HOX gene expression. So far nothing is known about the role of histone lysine demethylases (KDMs) during early hematopoiesis. We are studying the role of KDM6A and KDM6B on self-renewal, global gene expression and on local and global chromatin states in embryonic stem cells (ESCs) and during differentiation. In order to completely abrogate KDM6 demethylase activity in ESCs we employed a specific inhibitor (GSK-J4, Kruidenier et al. 2012). Treatment of ESCs with GSK-J4 had no effect on viability and proliferation . However, ESC differentiation in the presence of GSK-J4 was completely abrogated. In conclusion we show that ESC differentiation is completely blockend in the absence of any H3K27 demethylase activity. We used microarrays to detail the global gene expression program of genes which are differentially expressed during the early differentiation of ESC derived embryoid bodies (EBs) in the presence of GSK-J4 (KDM6 Inhibitor). Overall design: ESCs (R1) have been cultured and differentiated in the presence of GSK-J4 a KDM6 specific inhibitor.