Gene expression associated with morphological changes in osteoblasts.

In the field of bone-tissue engineering, bone morphogenetic protein (BMP)-2 plays a central role because of its potent bone-induction ability. However, the widespread use of BMP-2 is prevented by its dose-dependent inflammation-related side effects. One reason why optimising BMP-induced bone formation is challenging is that this induction process in vivo remains poorly elucidated. Here, RNA-sequencing was performed to identify changes in gene expression in OBs. Out of 23,284 genes, 182 genes showed an adjusted fold-change of >2.0 and an FPKM >0.1 from Day 10 to Day 14. Among the 182 genes, 32 genes associated with 'organisation of cytoskeleton' were upregulated on Day 14. Overall design: We examined the differences in gene expression in osteoblasts between Day 10 and Day 14, a period during which active morphological change and mineralisation were observed. Fluorescence-activated cell sorting was used to isolate ECFP+ osteoblasts in the lesions where ectopic bone formation was occurring, and transcriptome profiling through RNA-sequencing was performed to identify changes in gene expression in osteoblasts.