CRISPR activation reveals SOX5/6/9 as key transcriptional regulators directing iPSC-derived cells toward a notochordal lineage

Emerging therapies increasingly focus on NCs, which are rare but therapeutically relevant cells for regenerating degenerated IVDs. In this study, we used CRISPR-based transactivation (CRISPRa) to direct the differentiation of human induced pluripotent stem cells (iPSCs) into NC lineage.

We tested CRISPRa-mediated activation of NOTO, TBXT, FOXA2, SOX5, SOX6, and SOX9, coupled with single-cell sequencing of Aggrecan-2A-mScarlet reporter iPSCs. This approach identified the SOX5/6/9 combination (SOX-trio) as critical for promoting NC lineage commitment. The SOX-trio yielded the largest cell population expressing a range of genes previously associated with NC identity, including SHH, FOXA1, FOXA2, FOXJ1, FN1, ALCAM, KRT8, and KRT18.