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Updated: Mar 28, 2026
Isolation of Whole Cell Protein Lysates from Mouse Facial Processes and Cultured Palatal Mesenchyme Cells for Phosphoprotein Analysis
Published on: April 1, 2022
CSF1R+ macrophage and osteoclast depletion impairs neural crest proliferation and craniofacial morphogenesis
Felix Ma1,2, Rose Ru Jing Zhou2,3, Matthew Rosin2,4
1Craniofacial Science Graduate Program, Faculty of Dentistry, The University of British Columbia, Vancouver, BC V6T 1Z3, Canada.
Abstract:
Despite a wealth of knowledge about the mechanisms underlying craniofacial morphogenesis during gestation, the roles of fetal macrophages and osteoclasts during this process remain less well characterized. Here, we used the pharmacological inhibitor PLX5622 to disrupt colony stimulating factor 1 receptor (CSF1R) signaling, which is essential for macrophage and osteoclast proliferation, differentiation and survival. Prenatal PLX5622 exposure in mouse resulted in ∼50% depletion of CSF1R+ macrophages, with complete loss of osteoclasts. While there were no notable changes in craniofacial nerve or muscle development, prenatal exposure to PLX5622 resulted in skull doming and cranial suture impairments, in addition to disruptions to development of the premaxilla, mandible, ear ossicles, palate and cranial base. In response to PLX5622 exposure, cytokine and chemokine signaling was altered and neural crest proliferation was impaired. Our data also highlight sex- and strain-specific differences in PLX5622 phenotypes and together demonstrate that CSF1R+ macrophages and osteoclasts are essential for craniofacial morphogenesis.
Insights
Fetal macrophages and osteoclasts are crucial for craniofacial development. Disrupting colony stimulating factor-1 receptor (CSF1R) signaling impairs skull and facial bone formation, highlighting their essential roles.
Area of Science:
- Developmental Biology
- Immunology
- Craniofacial Biology
Background:
- Craniofacial morphogenesis mechanisms are well-studied, but the roles of fetal macrophages and osteoclasts are less understood.
- Colony stimulating factor-1 receptor (CSF1R) signaling is vital for macrophage and osteoclast functions.
Purpose of the Study:
- To investigate the necessity of CSF1R+ macrophages and osteoclasts in prenatal craniofacial development.
- To characterize the effects of CSF1R signaling disruption on craniofacial structures.
Main Methods:
- Utilized the pharmacological inhibitor PLX5622 to disrupt CSF1R signaling in a prenatal mouse model.
- Quantified macrophage and osteoclast populations and assessed craniofacial morphology.
Main Results:
- Prenatal PLX5622 exposure led to approximately 50% depletion of CSF1R+ macrophages and a complete loss of osteoclasts.
- Observed significant craniofacial abnormalities including skull doming, cranial suture impairments, and malformations of the premaxilla, mandible, ear ossicles, palate, and cranial base.
- Disruption altered cytokine/chemokine signaling and impaired neural crest proliferation, with sex- and strain-specific variations.
Conclusions:
- CSF1R+ macrophages and osteoclasts are essential for normal craniofacial morphogenesis.
- Disruption of CSF1R signaling during gestation severely impacts skeletal development, affecting multiple craniofacial elements.
