Study On The Expression Difference Of Polycomb Complex In Mouse Embryonic Stem Cells In 2iL And PKCi Systems

Polycomb group(Pc G)is an important transcription repressor in epigenetics.It plays an important role in early embryonic development and is closely related to the pluripotency of embryonic stem cells(Embryonic stem cells,ESC)..In mammals,Polycomb mediates gene silencing through two different protein complexes,PRC1 and PRC2.PRC1 includes Ring1 A,Ring1B,CBX7,RYBP,Pcgf2/3/5,YAF and PHC1 components.The core subunit Ring1A/B has E3 ubiquitin ligase activity and mediates the monoubiquitin of lysine 119 of histone H2A(H2AK119ub1),PRC2 is composed of EZH2,EED,SUZ12,RBBP4,RBBP7,JARID2,and EZH1/2 has histone methyltransferase activity,which mediates the trimethylation of the 27 th lysine of histone(H3K27me3).PRC1 is subdivided into canonical PRC1(c PRC1)and atypical PRC1(nc PRC1)according to the different subunits it contains.c PRC1 contains CBX protein,and nc PRC1 contains RYBP protein,which are combined with PRC2 in different recruitment modes to exert inhibitory function.Recent studies have shown that in the process of self-renewal and differentiation of ESC,the dynamic regulation of epigenetic modification plays an important role.Polycomb catalyzes H2AK119 ubl and H3K27me3 to inhibit differentiation-related gene expression in ES cells.At the same time,the self-renewal and pluripotency of ES involve many complex signaling pathways.The inhibition of ERK/GSK and PKC signaling pathways has been proven to play an important role in the maintenance of stem cell pluripotency.The self-renewal and differentiation of ESC are performed through epigenetic regulation,but how different signaling pathways regulate the epiregulatory factors in ESC is currently unclear.Therefore,this study aims to explore the relationship between the ERK/GSK and PKC signaling pathways and the epigenetic component Polycomb complex in ESC self-renewal and maintenance of pluripotency.In order to explore the differences in the expression of Polycomb under different signaling pathways that maintain the pluripotency of mouse embryonic stem cells(m ESC),we selected two culture systems that maintain the pluripotency of m ESC via signaling pathways: 2i/LIF(ERK inhibitor CHIR99021,GSK3 inhibitor PD0325901 and LIF,2i L for short),PKCi(PKC inhibitor: G?6983,selectively inhibits PKC subtypes(?,?,?,?,? and ?)to cultivate m ESC in Na?ve state.We The fluorescence quantitative PCR method was used to analyze the PRC2 subunits expressed in two m ES:EZH2,EED,SUZ12,RBBP4,RBBP7,JARID2,and PRC1 subunits: Ring1 A,Ring1B,CBX7,RYBP,Pcgf2/3/5,YAF,The RNA level of PHC1 gene was quantitatively detected and analyzed.The study found that under the two different m ESC systems of 2i L and PKCi,Polycomb gene expression showed significant differences;2i L-m ESC highly expressed the functional auxiliary subunit EED of PRC2 And RBBP7 gene,while PKCi-m ESC highly expresses PRC1 functional subunit Ring1 B,nc PRC1 specific component RYBP and PRC2 functional subunit EZH2 gene.Therefore,we speculate that when the PKC signaling pathway is inhibited,Polycomb in PKCi-m ESC mediates the silencing of differentiated genes through the main mode of action of nc PRC1-PRC2,thereby maintaining its pluripotency.In addition,PKCi promotes the activation and function of PRC2 and nc PRC1 related subunits.This study provides a theoretical basis for further understanding of the mutual regulation between the PKC signaling pathway and epigenetics among the many molecular mechanisms of ES cell self-renewal and maintenance of pluripotency.