Attenuating iPSC reprogramming stress with dominant-negative BET peptides

Area of Science:

• Stem cell biology
• Molecular biology
• Epigenetics

Background:

• Induced pluripotent stem cell (iPSC) generation remains inefficient and unpredictable.
• The specific molecular mechanisms causing reprogramming deficiencies are not fully understood.

Purpose of the Study:

• To investigate the causes of iPSC generation inefficiency.
• To identify strategies for improving iPSC reprogramming efficiency and mitigating associated cellular stresses.

Main Methods:

• Utilized reprogramming factors OCT4, SOX2, and KLF4 (OSK) to induce pluripotency.
• Introduced conserved dominant-negative (DN) peptides of human bromodomain and extraterminal (BET) proteins.
• Analyzed transcriptional turbulence, stress-response gene deregulation, cell cycle, mitotic gene expression, and cytotoxicity.

Main Results:

• The OSK reprogramming factors induced significant "reprogramming stress" including transcriptional chaos, stress gene deregulation, cell cycle arrest, and cytotoxicity.
• DN BET peptides effectively enhanced iPSC reprogramming efficiency.
• DN BET peptides mitigated the observed reprogramming stresses, improving cell survival and reprogramming fidelity.
• DN BET fragments targeted genes similarly to BET chemical inhibitors, suggesting a novel therapeutic strategy.

Conclusions:

• Reprogramming stress is a major barrier to efficient iPSC generation.
• DN BET peptides represent a promising approach to overcome reprogramming stress and improve iPSC technology.
• Targeting BET proteins via DN fragments offers a distinct strategy for enhancing stem cell reprogramming.