PCGF6 controls neuroectoderm specification of human pluripotent stem cells by activating SOX2 expression

Area of Science:

• Developmental Biology
• Stem Cell Biology
• Epigenetics

Background:

• Polycomb group (PcG) proteins regulate gene expression crucial for embryonic development.
• PCGF6's role in human pluripotent stem cell (PSC) differentiation remains incompletely understood.

Purpose of the Study:

• To elucidate the function of PCGF6 in human PSC neuroectoderm specification.
• To investigate the molecular mechanisms underlying PCGF6-mediated lineage determination.

Main Methods:

• PCGF6 depletion in human PSCs.
• Transcriptome analysis (RNA-seq).
• SOX2 regulatory element analysis and manipulation.
• Overexpression studies.

Main Results:

• PCGF6 depletion impairs neuroectoderm differentiation and enhances mesendoderm formation.
• PCGF6 activates SOX2 expression via interaction with MYC at a distal regulatory element.
• Disruption of the SOX2 regulatory element phenocopies PCGF6 depletion effects.
• SOX2 overexpression rescues neuroectoderm differentiation defects.

Conclusions:

• PCGF6 acts as a lineage switcher in human PSCs, promoting neuroectoderm fate.
• PCGF6 utilizes both gene activation (SOX2) and repression mechanisms.
• WNT/β-catenin signaling de-repression contributes to mesendoderm bias upon PCGF6 loss.