Proteome Analysis of Ground State Pluripotency

Area of Science:

• Stem Cell Biology
• Proteomics
• Cellular Metabolism

Background:

• Embryonic stem cells (ESCs) can be directed towards differentiation or maintained in a naïve pluripotent state.
• The naïve ground state of ESCs is achieved using specific culture conditions, including two inhibitors (2i) targeting mitogen-activated protein kinase (MAPK) and glycogen synthase kinase-3 (Gsk3).

Purpose of the Study:

• To investigate differential protein expression between mouse ESCs (mESCs) cultured in 2i versus serum-containing medium.
• To identify key protein pathways associated with maintaining the naïve ground state versus a metastable state in mESCs.

Main Methods:

• Shotgun proteomics approach was employed to compare protein expression profiles.
• Quantitative analysis of upregulated and downregulated proteins in 2i-treated mESCs compared to serum-treated mESCs.

Main Results:

• 164 proteins were upregulated and 107 downregulated in 2i-grown mESCs compared to serum-grown cells.
• 2i-grown cells showed enriched pathways in glycolysis and gluconeogenesis, while organ development pathways were downregulated.
• Serum-grown ESCs exhibited enriched pathways related to integrin, focal adhesion, and actin cytoskeleton regulation; nuclear proteins involved in self-renewal were higher in 2i-grown cells.

Conclusions:

• The study elucidates distinct proteomic landscapes correlating with ESC states maintained by 2i (naïve) or serum (metastable) conditions.
• Key metabolic and nuclear protein differences highlight mechanisms underlying ESC self-renewal maintenance and pluripotency regulation.