Zfp462, as a novel stimulating factor of osteoblast differentiation, is associated with the development of age-related bone formation alteration.

Zinc finger protein 462 (Zfp462) is a major chromatin regulator containing multiple Cys2His2-type zinc finger motifs and is known to play an important role in embryonic development and neural cell differentiation. Zfp462 can act as a transcription regulator that controls chromatin structure and modification during the aging process. However, the role of Zfp462's transcription regulator remains unclear. Here we demonstrated that Zfp462 directly binds to Runx2 and enhances the DNA binding and transcriptional activity of Runx2. Zfp462 recruits the histone acetyltransferase MOZ to acetylate histone H3 lysines 9, 14, and 23, and thereby promotes osteoblast differentiation and bone formation. Zfp462-deficient mice in osteoblast-lineage cells has an osteopenia phenotype due to impaired osteoblast differentiation. Zfp462/ZNF462 expression were significantly reduced due to a decrease in histone variant H2A.Z and histone H3 lysine 4 tri-methylation occupancies at the Zfp462/ZNF462 loci in aged mice and human. Together, our data reveal a novel role of Zfp462/ZNF462 as a transcription regulator that increases the expression of bone formation-related genes and suggest its potential as a therapeutic target to treat age-related bone loss. Overall design: Primary calvarial osteoblast precursors were isolated from the newborn calvariae of Zfp462-/- mice and WT littermates. The isolated calvarial osteoblast precursors were differentiated into osteoblasts by treating with 50?µg/mL ascorbic acid and 10?mM ß-glycerophosphate in culture medium for 6 days. Total RNA was isolated from the differentiated osteoblasts using the TRIzol reagent. The gene expression regulated in Zfp462 knockout osteoblasts was obtained through RNA-seq analysis.