Loss of collagen X facilitates hypertrophic differentiation and endochondral ossification of human iPSC-derived chondrocytes

To investigate the role of collagen X in human chondrocytes, we established human induced pluripotent stem cells (hiPSC) with heterozygous (COL10A1+/-) or homozygous (COL10A1-/-) deletions of COL10A1 gene using dual guide RNAs and CRISPR/Cas9 system. Several mutant clones were established from each of two standard hiPSCs and differentiated into hypertrophic chondrocytes by the previously reported 3D induction method. Transcriptome analyses of chondrocyte pellets at the hypertrophic phase showed lower expression of proliferating-phase genes and higher expression of calcification-phase genes in COL10A1-/- pellets than in parental cell pellets. Overall design: Comparative gene expression profiling analysis of RNA-seq data for hiPSC-derived chondrocyte pellets and COL10A1 KO derivatives.