Quantitative proteomics analysis of parthenogenetically induced pluripotent stem cells

Area of Science:

• Reproductive biology
• Stem cell research
• Proteomics

Background:

• Parthenogenetic embryonic stem (pES) cells are derived from oocytes and embryos activated without fertilization.
• These cells exhibit pluripotency, demonstrating differentiation potential both in vitro and in vivo.
• Understanding the molecular basis of pES cell pluripotency is crucial for their therapeutic applications.

Purpose of the Study:

• To investigate the molecular mechanisms underlying the developmental pluripotency of pES cells.
• To compare protein expression profiles of pES cells derived from in vitro-matured (IVM) or in vivo-matured ovulated (IVO) oocytes with fertilized embryonic stem (fES) cells.
• To assess the status of genomic imprinting in pES cells.

Main Methods:

• Differential proteomic analysis using differential in-gel electrophoresis (DiGE).
• Isotope-coded affinity tag (ICAT)-based quantitative proteomics.
• Comparison of protein expression between IVM pES cells, IVO pES cells, and fES cells.

Main Results:

• Significant differences in protein expression were observed: 76 proteins upregulated and 16 downregulated in IVM pES cells; 91 proteins upregulated and 9 downregulated in IVO pES cells (≥1.5-fold change).
• Differentially expressed proteins were primarily involved in metabolism and physiological processes, with no distinct pathways identified.
• No differences in imprinted gene expression were found between pES and fES cells, suggesting early passage pES cells can correct genomic imprinting.

Conclusions:

• pES cells possess pluripotency with distinct proteomic profiles compared to fES cells.
• Genomic imprinting appears to be corrected in early passage pES cells.
• Germline-competent IVM pES cells hold potential for germ cell renewal in aging ovaries, particularly if oocytes are sourced from younger individuals.