Table 3.
Epigenetic proteins regulating osteoblast differentiation.
| Enzyme | Name | Function | Reference |
|---|---|---|---|
| Histone methylases | EZH2 | Catalyzes the trimethylation of H3K27 and inhibits Runx2 and OCN expression. | 392 |
| Kmt1e/Setdb1/ESET complex | Mediates H3K9 trimethylation. | 394 | |
| Set1a/b-COMPASS | Transits H3K4me1 to H3K4me3. | 400 | |
| Histone demethylases | KDM6B | Removes H3K9me3 and H3K27me3 methyl group. | 390,391 |
| KDM4B | Removes H3K9me3 and H3K27me3 methyl group. | 390,391 | |
| Jarid/Kdm5 | Converts H3K4me3 and H3K4me2 to H3K4me1. | 390 | |
| Histone acetylases | GCN5 | Regulates acetylation of histones at residues K9 and K14. | 410 |
| KAT6A | Responsible for H3K9 and H3K14 acetylation. | 411 | |
| CBP/P300 | Mediates H3K27 acetylation and the activation of Foxo1. | 412 | |
| Histone deacetylases | SIRT1 | Enhances Runx2 trans-activation activity. | 301 |
| HDAC1 | Negatively regulates osteoblast generation by reducing Osx and OCN gene promoters’ H3 and H4 acetyl labeling. | 403 | |
| HDAC2 | Expressed in bone tissue and activates Akt expression, which inhibits FoxO1 transcription and leads to RANKL-induced osteoblast generation. | 403 | |
| HDAC5 | Binds with MEF2C to inhibit SOST expression and reduce H3K27 acetylation levels at the SOST gene site to promote Wnt/β-catenin signaling. | 408 | |
| DNA methylases | Dnmt3a | Inhibits osteoblast differentiation via regulating Wnt/β-catenin signaling and Runx2, Ocn activity. | 422 |
| DNA demethylases | TET1/2 | Converts 5mCpG to 5hmCpG. | 423–425 |
| Chromatin remodeling | Baf45a/ Baf45d | Promote the activation of genes crucial for osteoblast maturation and mineralization | 415,419,420 |