Description
The role of Striatin Interacting Protein 2 (Strip2) in differentiation of embryonic stem cells (ESCs) is still under debate. Strip2 silenced (KD) ESCs were differentiated for 4, 8, 12, and 16 days. We show that Strip2 is distributed in the perinucleus or nuclei of wild type (WT) undifferentiated ESCs, but is localized in high-density nuclear bodies in differentiated cells. CellNet analysis of microarray gene expression data for KD and scrambled control (SCR) embryoid bodies (EBs), as well as immunostainings of key pluripotent factors, demonstrated that KD ESCs remain undifferentiated. This occurs even in 16-day old EBs, which possessed a high tumorigenic potential. Correlated with very high expression levels of epigenetic regulator genes, Hat1 and Dnmt3, enzymatic activities of the histone acetyltransferase type B (HAT1) and DNA (cytosine-5)-methyltransferase 3 beta (DNMT3b) were higher in differentiated 16-day old KD EBs than in SCR or WT EBs. The expression levels of let-7, 290 and 302 microRNA families were opposed in KD ESCs, while KD EBs had levels comparable to WT and SCR ESCs during differentiation. This demonstrates that Strip2 is critical to the onset of differentiation, regulating expression of epigenetic regulators, HAT1 and DNMT3b, as well as microRNAs involved in pluripotency.