Cell surface marker mediated purification of iPS cell intermediates from a reprogrammable mouse model

Area of Science:

• Stem cell biology
• Cellular reprogramming
• Regenerative medicine

Background:

• Induced pluripotent stem (iPS) cells hold promise for regenerative medicine due to their ability to differentiate into all cell types.
• Traditional methods for generating iPS cells using viral delivery of transcription factors (Oct-4, Klf-4, Sox-2, and c-Myc [OKSM]) are inefficient, hindering mechanistic studies.
• Studying rare intermediate cells during reprogramming requires effective isolation techniques.

Purpose of the Study:

• To provide a detailed methodology for isolating reprogramming intermediates from mouse embryonic fibroblasts (MEFs).
• To enhance experimental reproducibility in studying the cellular reprogramming process.
• To facilitate deeper understanding of the mechanisms underlying iPS cell generation.

Main Methods:

• Development of a reprogrammable mouse strain with doxycycline-inducible OKSM expression for homogenous reprogramming.
• Derivation of isogenic MEFs from the engineered mouse model.
• Isolation of reprogramming intermediates using fluorescent activated cell sorting (FACS) based on cell surface marker expression (Thy-1.2, Ssea-1, Epcam).

Main Results:

• Successfully identified distinct cell surface marker expression profiles corresponding to early and late reprogramming stages.
• Demonstrated the loss of fibroblast marker Thy-1.2 and upregulation of pluripotency marker Ssea-1 in early reprogramming cells.
• Observed Epcam expression in late-stage cells transitioning towards pluripotency.

Conclusions:

• The described FACS-based methodology enables efficient isolation of reprogramming intermediates.
• This method significantly improves the study of cellular reprogramming dynamics and efficiency.
• The use of a reprogrammable mouse model enhances reproducibility for investigating iPS cell generation.