The TRF1 Telomere Protein Is Essential for the Generation and Maintenance of Induced Pluripotent Stem Cells and Marks Both Pluripotent and Adult Stem Cells

The study demonstrated that the telomere repeat binding factor 1 (TRF1) was crucial for the generation and maintenance of induced pluripotent stem (iPS) cells and marked both pluripotent and adult stem cells. TRF1 was found to be essential for maintaining small intestine homeostasis and hair follicle stem cell functionality. The research involved creating a reporter mouse model with TRF1 fused to eGFP, revealing that TRF1 expression was highest in adult stem cell compartments, such as hair follicle niches and intestinal crypts, and was independent of telomere length. High levels of TRF1 in iPS cells correlated with increased pluripotency, and TRF1 was identified as a direct target of the transcription factor Oct3/4, linking it to pluripotency. These findings positioned TRF1 as a novel marker for stem cells and a key factor in pluripotency, although it could not serve as an in vivo telomere length indicator.