Alternative pre-mRNA splicing switch controls hESC pluripotency and differentiation

Area of Science:

• Molecular Biology
• Stem Cell Biology
• Epigenetics

Background:

• Alternative splicing (AS) is crucial for cellular function and is tightly regulated.
• Understanding splicing's role in cell fate decisions, particularly in human embryonic stem cells (hESCs), is incomplete.
• Pluripotency maintenance in hESCs involves complex regulatory networks.

Purpose of the Study:

• To investigate the role and regulation of alternative splicing in maintaining hESC pluripotency.
• To identify specific splicing events and regulatory factors involved in hESC differentiation.
• To elucidate the molecular mechanisms linking splicing to cell fate decisions.

Main Methods:

• Analysis of alternative splicing patterns during hESC differentiation.
• Investigating the function of heterogeneous nuclear ribonucleoproteins H1 and F (hnRNP H/F).
• Studying the regulation of T-cell factor 3 (TCF3) alternative splicing and its downstream effects.

Main Results:

• Alternative splicing of several genes is significantly altered during hESC differentiation.
• hnRNP H/F activity regulates TCF3 splicing, controlling the mutually exclusive expression of E12 and E47 isoforms.
• Reduced hnRNP H/F promotes E47 expression, decreasing E-cadherin and inducing differentiation; high hnRNP H/F favors E12 for pluripotency maintenance.

Conclusions:

• Alternative splicing is a key regulator of human embryonic stem cell pluripotency.
• The hnRNP H/F-TCF3 splicing axis provides a novel mechanism controlling hESC fate.
• This study highlights a broader role for splicing regulation in stem cell biology.