Abstract
Despite holding great therapeutic potential, existing protocols for in vitro chondrogenesis and hyaline cartilage production from human induced pluripotent stem cells (hiPSC) are laborious and complex with unclear long-term consequences. Here, we developed a simple xeno- and feeder-free protocol for human hyaline cartilage production in vitro using hydrogel-cultured multi-tissue organoids (MTOs). We investigate gene regulatory networks during spontaneous hiPSC-MTO differentiation using RNA sequencing and bioinformatic analyses. We find the interplays between BMPs and neural FGF pathways are associated with the phenotype transition of MTOs. We recognize TGF-beta/BMP and Wnt signaling likely contribute to the long-term maintenance of MTO cartilage growth and further adoption of articular cartilage development. By comparing the MTO transcriptome with human lower limb chondrocytes, we observe that the expression of chondrocyte-specific genes in MTO shows a strong correlation with fetal lower limb chondrocytes. Collectively, our findings describe the self-organized emergence of hyaline cartilage in MTO, its associated molecular pathways, and its spontaneous adoption of articular cartilage development trajectory.
Competing Interest Statement
Timothy D. O'Brien, Beth Lindborg, Amanda Vegoe are officers of and hold equity in, Ferenc Toth is a consultant for, and Yi Wen Chai is an employee of, Sarcio Inc., which has an option from the University of Minnesota to commercialize the organoid technology described herein. These interests have been reviewed and managed by the University of Minnesota in accordance with its Conflict of Interest policies. Manci Li and Peter A. Larsen declare no competing interests.
Footnotes
↵* Co-senior author
