Hdac3 deletion in myeloid progenitor cells enhances bone healing in females and limits osteoclast fusion via Pmepa1

• Published in: Scientific reports 2020-12, Vol.10 (1), p.21804-15, Article 21804
• Main Authors: Molstad, David H. H., Zars, Elizabeth, Norton, Andrew, Mansky, Kim C., Westendorf, Jennifer J., Bradley, Elizabeth W.
• Format: Article
• Language: English
• Subjects: 631/80; 692/308; 692/699; Animals; Bone growth; Bone healing; Bone marrow; Bone Regeneration; Bone resorption; Bone surgery; Cell Fusion; Clonal deletion; Cortical bone; Cortical Bone - injuries; Cortical Bone - metabolism; Cortical Bone - pathology; Defects; Female; Females; Gene Deletion; Gene expression; Histone deacetylase; Histone Deacetylases - deficiency; Histone Deacetylases - metabolism; Humanities and Social Sciences; Inflammation; Kinases; Membrane Proteins - genetics; Membrane Proteins - metabolism; Mice; Mice, Knockout; multidisciplinary; Myeloid cells; Myeloid Progenitor Cells - metabolism; Myeloid Progenitor Cells - pathology; Osteoclastogenesis; Osteoclasts - metabolism; Osteoclasts - pathology; Osteogenesis; Osteoprogenitor cells; Progenitor cells; Proteins; Regeneration; Ribonucleic acid; RNA; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-020-78364-5

Previous studies examining the role of the histone deacetylase Hdac3 within myeloid cells demonstrated that Hdac3 promotes M2 activation and tissue healing in inflammatory conditions. Since myeloid lineage cells are required for proper bone formation and regeneration, in this study we examined the functions of Hdac3 during bone healing. Conditional deletion of Hdac3 within myeloid progenitors accelerates healing of cortical bone defects. Moreover, reduced osteoclast numbers within the defect site are correlated with Hdac3 suppression. Ex vivo osteoclastogenesis assays further demonstrate that Hdac3 deficiency limits osteoclastogenesis, the number of nuclei per cell and bone resorption, suggesting a defect in cell fusion. High throughput RNA sequencing identified the transmembrane protein Pmepa1 as a differentially expressed gene within osteoclast progenitor cells. Knockdown of Pmepa1 partially restores defects in osteoclastogenesis induced by Hdac3 deficiency. These results show that Hdac3 is required for optimal bone healing and osteoclast fusion, potentially via its regulation of Pmepa1 expression.