Signalling pathway crosstalk stimulated by L-proline drives mouse embryonic stem cells to primitive-ectoderm-like...

Area of Science:

• Developmental Biology
• Stem Cell Biology
• Cell Signaling

Background:

• L-proline demonstrates growth factor-like properties, influencing embryonic development and neurogenesis.
• Naïve mouse embryonic stem cells (ESCs) can be directed towards a distinct pluripotent state, early primitive ectoderm-like (EPL) cells.
• The transition from ESCs to EPL cells involves complex signaling networks, including MAPK, FGFR, PI3K, and mTOR pathways.

Purpose of the Study:

• To elucidate the specific signaling pathways governing the transition of ESCs to EPL cells.
• To understand how these pathways regulate morphological changes, cell number, apoptosis, proliferation, and gene expression.
• To investigate the synergistic and antagonistic interactions between signaling pathways during this pluripotent state transition.

Main Methods:

• Utilized a factorial experimental design to systematically investigate signaling pathways.
• Employed statistical modeling to analyze the impact of pathway modulation on cellular properties.
• Applied inhibitors to key signaling pathways (MAPK, FGFR, PI3K, mTOR) to dissect their roles.

Main Results:

• Identified key signaling pathways (MAPK, FGFR, PI3K, mTOR) crucial for the ESC to EPL cell transition.
• Demonstrated that L-proline addition induces EPL cell formation with altered morphology, increased cell number, and specific gene expression changes.
• Revealed that multiple inhibitors affected various aspects of the transition, with each inhibitor blocking distinct features of the naïve-to-primed state change.

Conclusions:

• The transition between pluripotent states is regulated by a complex interplay of signaling pathways.
• These findings provide insights into the mechanisms governing stem cell progression along the in vitro pluripotency continuum.
• The study offers a model for understanding pre-, peri-, and post-implantation embryogenesis.