An Unbiased Approach to Identifying Cellular Reprogramming-Inducible Enhancers

Area of Science:

• Stem Cell Biology
• Epigenetics
• Genomics

Background:

• Cellular reprogramming to induced pluripotency relies on transcription factors Oct4, Sox2, Klf4, and c-Myc (OSKM).
• OSKM factors induce significant epigenetic and transcriptional alterations during this complex process.
• Understanding the dynamic binding patterns of OSKM is crucial for optimizing reprogramming efficiency.

Purpose of the Study:

• To analyze the spatiotemporal dynamics of OSKM transcription factor binding during cellular reprogramming.
• To develop an unbiased method for identifying and isolating cells undergoing efficient reprogramming in real time.
• To characterize the molecular signatures and developmental capacities of isolated reprogrammable cells.

Main Methods:

• Large-scale integration of ChIP-seq, ATAC-seq, and RNA-seq data to map OSKM binding.
• Development of an unbiased approach using Reprogramming-Inducible Enhancers (RIEs) and enhancer-traps.
• Isolation and characterization of cells at different reprogramming time-points using a RIE-GFP reporter system.

Main Results:

• OSKM transcription factors exhibit highly dynamic and temporally distinct binding patterns to pluripotency-related enhancers.
• Coordinated enhancer activity, sequentially bound by OSKM, governs the transcriptional control of reprogramming genes.
• A novel method successfully identified and isolated reprogrammable cells in real time, demonstrating unique molecular signatures and high reprogramming efficiency.

Conclusions:

• The functional dynamics of OSKM binding provide a basis for identifying and isolating reprogrammable cells.
• The developed unbiased method enables real-time isolation of cells with enhanced reprogramming potential.
• These findings offer new biomarkers for efficient cellular reprogramming.