Differential Gene Expression and Pathway Analysis of Prx1-Expressing Cells in Calvarial Sutures and Long Bone Periosteum

Abstract

The Pair-related homeobox transcription factor (Prx1) is required for normal development of the cranium and axial skeleton. Prx1-expressing cells are found in the suture of the calvaria and periosteum of the long bones, and function postnatally in the maintenance and regeneration of bone. We evaluated the 2 cell populations by RNA sequencing analysis in a comparative study to determine distinct cell surface targets for regenerative bone therapies in the craniofacial region and axial skeleton. Prx1-expressing cells tagged with green florescent protein (eGFP) were isolated by fluorescent-activated cell sorting (FACS) from the calvaria and long bones of neonate transgenic mice. RNA sequencing data was used to calculate differential gene expression levels and functional enrichment values for pathway analysis. The results validate previous findings obtained by conventional methods and provide a molecular map for future studies in Prx1-mediated bone ossification and bone homeostasis. The trends observed suggest that Prx1-expressing cells of the calvaria and long bones regulate cell-cell communication, cell adhesion, cell migration, vascularization and cross-talk between the mesenchymal stem cell microenvironment and hematopoietic stem cell microenvironment in addition to bone forming capabilities. Cell surface targets differentially expressed in Prx1-expressing cells of the calvaria and long bones are identified for future developments and applications in translational medicine.