CRISPR Activation of Yamanaka Factors in Human Cells

The Journal Club returns on February 22nd at 12 PM Eastern time / 5 PM UK and will be broadcast live to our Facebook page. This month Dr. Oliver Medvedik will be taking a look at a new method of partial cellular reprogramming using the gene editing tool CRISPR. This is a particularly exciting development as it demonstrates an alternative way of activating the Yamanaka factors to reverse cellular aging and an approach that does not suffer from the potential off-target problems small molecules present.

Abstract

Conventional reprogramming methods rely on the ectopic expression of transcription factors to reprogram somatic cells into induced pluripotent stem cells (iPSCs). The forced expression of transcription factors may lead to off-target gene activation and heterogeneous reprogramming, resulting in the emergence of alternative cell types and aberrant iPSCs. Activation of endogenous pluripotency factors by CRISPR activation (CRISPRa) can reduce this heterogeneity. Here, we describe a high-efficiency reprogramming of human somatic cells into iPSCs using optimized CRISPRa. Efficient reprogramming was dependent on the additional targeting of the embryo genome activation-enriched Alu-motif and the miR-302/367 locus. Single-cell transcriptome analysis revealed that the optimized CRISPRa reprogrammed cells more directly and specifically into the pluripotent state when compared to the conventional reprogramming method. These findings support the use of CRISPRa for high-quality pluripotent reprogramming of human cells.