GSE122429
bulk RNA-seq of human nucleusus pulposus cell differentiations from embryonic stem cells and iPSCs
Progressive loss of nucleus pulposus cells (NPCs) is associated with the onset of intervertebral disc degeneration (IDD). Transplantation of NPCs, derived from human pluripotent stem cells including hESC/iPSCs, may offer a novel therapy for IDD. To date, effective in vitro differentiations of notochordal and NP cells remained to be demonstrated. Towards this end, we developed a three-step protocol to directly differentiate hESC/iPSC towards mesodermal, then notochordal and finally NPCs. Our results showed that notochordal-like cells (NCCs) were successfully derived from the first two-steps of the protocol. Furthermore, these cells could be differentiated into NPCs. These NPCs expressed the tyrosine kinase receptor Tie2 (Tie2), disialoganglioside 2 (GD2), collagen II and aggrecan. Genome-wide transcriptomic analyses by sequencing (RNA-seq) revealed the expression of a wide array of known NP markers, extracellular matrix (ECM) genes, up-stream regulators and pathways. Cross-comparison of in vitro RNA-seq profiles with in vivo human NP data confirmed the in vitro NPCs are significantly more similar to in vivo NP than hESC/iPSCs. Transplantation of NPCs effectively attenuated disc injury in a rat model of IDD. We utilized CRISPR/Cas9 to seamlessly knock in an enhanced green fluorescent protein (eGFP) to the loci of the Noto gene in ESCs for NCC generation. Our study achieved effective notochordal differentiation and provided transcriptomic insights into the use of human ESC/iPSCs. Overall design: We sequenced three lines of stem cells, and their respective differentiation products (each has four replicates)