Interaction and regulatory expression of Polycomb and NuRD complexes in mouse embryonic stem cell under PKC inhibition.

Polycomb repressive complexes (PRC) and nucleosome remodeling and deacetylase (NuRD) complex are crucial for regulating the expression of pluripotent and developmental genes and maintaining the characteristics of mouse embryonic stem cells (mESCs). However, the interplay between the Polycomb and NuRD complexes in mESCs, particularly under protein kinase C (PKC) inhibition, remains to be elucidated. We knocked down Polycomb complexes components Ezh2, Ring1b, and Cbx7 via short hairpin RNA interference and observed significant reductions in most NuRD complex components, especially Mbd3, Mta1, Rbbp4, and Rbbp7. Similarly, Ezh2 overexpression increased the levels of these major NuRD complex components. Further, Mbd3 knockdown significantly reduced the expression of PRC1 major components Ring1b, Rybp, and Cbx7 and PRC2 major components Ezh2, Suz12, and Eed, but its overexpression had no significant effect on their levels. These results indicate that PKC inhibition provides a suitable environment for the expression of PRC components. Altogether, our study demonstrates that mESCs exhibit mutual gene regulation of Polycomb and NuRD complexes under PKC inhibition that maintains pluripotency and self-renewal abilities and regulates the plasticity of mESCs to balance between pluripotency and cell fate determination.