Rapamycin Alters Oxidative Stress and Tumor-Associated Protein Profiles in Chicken Embryonic Stem Cells

Embryonic stem cells (ESCs) of chicken undergo a process of controlled autophagy to maintain their stemness during in vitro culture.This controlled autophagy may contribute to differentiation of ESCs to primordial germ cells (PGCs).Our previous study elucidated the role of rapamycin in activating autophagy in chicken ESCs.Treatment of ESCs with rapamycin resulted in the upregulation of autophagyrelated proteins, including MAPLC3A and MAPLC3B.In the present study, an extensive proteomic analysis of chicken embryonic stem cells (ESCs) following treatment with rapamycin was conducted.Liquid chromatography mass spectrometry analysis was performed on three biological replicates of both rapamycin-treated (ESC-Rapa) and untreated ESCs (ESC-Blank), identifying 4,495 proteins.Of these, 126 were found to be upregulated, and 325 downregulated based on log2FC (FC≥1.5).Furthermore, a total of 4,044 proteins exhibited nonsignificant (P>0.05)regulation in both the ESC-Blank and ESC-Rapa groups.The downregulated proteins were predominantly associated with the activation of tumors in various organs throughout the body as determined in several studies.Several tumor-promoting proteins were found to be significantly (P<0.05)downregulated, including HDAC2, YWHAG, HMGB3, PDCD10, POFUT1, VDAC2, and ovoinhibitor.These results suggest that rapamycin may promote autophagy, which could be attributed to the downregulation of tumor-activating genes and proteins.However, further research is needed to determine the role of rapamycin in tumor suppression and the development of chicken embryonic stem cells.