The PLAGL1-KLF4-IRX5 axis promotes the osteogenesis of periosteal progenitors during mandible regeneration

Transcription factor (TF) networks are pivotal regulators of stem/progenitor cell fate. However, the regulatory mechanisms mediated by key TFs in adult periosteal stem/progenitor cells (PSPCs) remain poorly understood, impeding targeted therapies development for craniofacial bone regeneration. By integrating an analysis of regeneration-related, tissue-specific TF networks with insights from embryonic development, we demonstrate that the imprinted TF PLAGL1 is critical for the osteoblast differentiation of PSPCs and that the loss of Plagl1 compromises mandibular bone regeneration. Mechanistically, PLAGL1 transcriptionally activates TF Irx5 synergistically with TF KLF4, thereby inducing the expression of downstream osteogenic genes. Using the CRISPR-dCas9-Tet1-CD/sgRNA system, we develop a differentially methylated region-targeted therapeutic strategy to reactivate the maternal allele of Plagl1, leveraging its imprinted function to promote mandibular bone regeneration. This study delineates the PLAGL1-KLF4-IRX5 regulatory axis controlling osteoblast differentiation of PSPCs and further proposes an application strategy integrating TF modulation with epigenetic regulation for craniofacial bone regeneration.