Zfp260 Choreographs The Osteolineage Commitment Of Skeletal Stem Cells

This study investigates the mechanisms preceding progenitor commitment in bone regeneration, focusing on the transcription factor Zfp260’s role in bridging stem cell activation with osteogenic fate determination. By integrative analysis of single-cell RNA sequencing (scRNA-seq) and time-series transcriptome sequencing data from fracture and maxillary sinus floor lifting (MSFL) bone regeneration models, we screened for transcription factors significantly upregulated during the stem-to-progenitor transition. Using Ctsk-creER;Zfp260fl/fl conditional knockout mice, we investigated the functional impact of Zfp260 deficiency on both intramembranous and endochondral ossification. Through CUT&Tag, ChIP-seq, and ATAC-seq assays, we elucidated the regulatory mechanisms of Zfp260. GST pull-down coupled with mass spectrometry was employed to identify post-translational modification sites and regulatory patterns of Zfp260. Finally, adeno-associated virus AAV9 targeting periosteal stem cells was utilized to assess the effects of Zfp260 modification defects on bone regeneration in vivo. Zfp260 expression surged during stem-to-progenitor transition, and its loss caused progenitor arrest and impaired bone repair. Zfp260 maintained chromatin accessibility and formed super-enhancers to activate Runx2. PKCα phosphorylated Zfp260 at Y173/S182/S197, with mutations at these sites abolishing its osteogenic activity. Zfp260 is a critical bridge between stem cell activation and osteogenic commitment, integrating epigenetic regulation (via chromatin remodeling and Runx2 activation) and PKCα-dependent phosphorylation. Targeting the PKCα-Zfp260-Runx2 axis may offer therapeutic strategies for bone regeneration.