Ana Lysis Of Phosphoproteome Of NSCs Differentiation Induced By OEC Conditioned Medium

Neural stem cells(NSCs)play an important role in both the developing embryonic nervous system through to adulthood.The capacity for self-renewal may be important for normal function of the Neural stem cells(NSCs),such as response to injury.There has been many excitement in regard to the possibility of transplantation of NSCs to replace damaged or lost neurones,or by recruiting endogenous precursors.However,before the realization of full potential of NSCs,it is essential to understand the signaling pathways that control their proliferation and differentiation,as well as the effect of extrinsic factors on these processes.To in depth knowledge the mechanism and pathways involved in NSCs differentiation,we explored the phosphoproteome of C17.2 differentiation induced by retinoic acid(RA)or OECs.Part I,we apply dimethyl labeling combined with the TiO2 phosphopeptide enrichment approach to compare the phosphoproteome of the self-renewal and differentiated cells induced by RA and successfully identified 733 and 517 phosphoproteins respectively.A total of 347 proteins were differentially phosphorylated,and most of which were related to transcription and cell cycle.In addition,we found that PAKs play critical roles in C17.2 cell proliferation.PAK1 activate Wnt/B-catenin via phosphorylate B-catenin(p-S654)resulted in expression of c-myc and cyclin Dl.Interestingly,Merlin,a cellular substrate of PAK2,functions as a negative growth regulator.Inactive merlin(p-S518)may promote B-catenin depolymerize from the plasma membrane and localize to cell nucleus.AKT1 can regulate B-catenin through phosphorylate at S552,which may promote activation of Wnt/?-catenin pathway.Overall,Pak/Merlin,Wnt/B-catenin and hsp90/Akt/mTOR pathways may play a significant role in regulation of cell proliferation and differentiation,and protein phosphorylation maybe a key mechanism.Part ?,we apply dimethyl labeling combined with the TiO2 phosphopeptide enrichment approach to analysis the phosphoproteome of C17.2 differentiation induced by OECs.1404 phosphorylation sites on 290 proteins were identified in 12h group,among them,about 42.78%proteins had their phosphorylation levels significantly changed.Correspondingly,we identified 1946 phosphorylation sites localized in 381 proteins in 24h group,and approximately 42.51%proteins with changed phosphorylation levels.With the peptide motif analysis,acid motif and Pro-directed motif were the main motif that we found.Meanwhile,we discovery that CDK1 could regulate proliferation,differentiation and reprogramming via different pathways collaboration.Cdkl-EzH2 pathway may play important role in regulation of NSCs differentiation induced by OECs,and the changed phosphorylation levels maybe the main mechanism.