β-catenin inhibits adipogenic differentiation of hypertrophic chondrocytes and promote osteogenesis

It has been shown that hypertrophic chondrocyte (HC) can become osteoblast, contributing to the formation of trabecular bone and endosteum. However, it is unclear what genes regulate the process of differentiation from chondrocyte to osteoblast. Conditional knock-out of β‑catenin in HCs can reduce the trabecular bone amount and there is also some evidence that ablation of β‑catenin in HCs can promote bone marrow adipogenesis. Conditional stabilization of β‑catenin in HCs results in osteopetrosis. In order to investigate the gene regulatory network with different dosage of β‑catenin in HC descendants (i.e. in Loss-of-Function mutant, Gain-of-Function mutant and Wildtype control), we collected HC descendant cells from proximal tibia of mice at postnatal day 5 and performed bulk RNA seq to profile the gene expression pattern in HC descendants. We sequenced 8 bulk RNAseq samples. Cells were harvested from proximal tibia and only the hypertrophic chondrocyte descendants were collected for RNAseq. Four of them are on Col10a1Cre;Rosa26-Tdtomato;Ctnnb1Δ/Δ (b-cat LoF mutant), two of them are Col10a1Cre;Rosa26-Tdtomato;Ctnnb1-exon3 Δ/+ (b-cat GoF mutant), and the remaining two are Col10a1Cre;Rosa26-Tdtomato (wildtype control). 70 tdTomato-expressing cells were manually picked under fluorescent microscope, pooled and subject to Smart-seq2 protocol.