The skeletal site-specific role of connective tissue growth factor in prenatal osteogenesis

Area of Science:

• Skeletal Biology
• Developmental Biology
• Genetics

Background:

• Connective tissue growth factor (CTGF/CCN2) is crucial for bone development.
• Global CTGF knockout (KO) mice display skeletal abnormalities and perinatal lethality.
• Quantitative analysis of the CTGF KO bone phenotype was previously lacking.

Purpose of the Study:

• To conduct a quantitative analysis of the skeletal phenotype in CTGF KO mice.
• To investigate site-specific changes in bone formation and microarchitecture.
• To explore the impact of CTGF ablation on gene expression and skull morphology.

Main Methods:

• Comparative analysis of CTGF KO and wild-type mice.
• Assessment of growth plate organization, bone microarchitecture, and shape.
• Gene expression analysis of osteogenic markers.
• Detailed skull phenotype analysis.

Main Results:

• CTGF KO mice showed altered growth plate organization with reduced proliferation and increased hypertrophic zones.
• Appendicular skeleton exhibited decreased trabecular bone and increased mid-diaphyseal bone with altered gene expression.
• Axial skeleton, including vertebrae and mandible, showed decreased bone mass and osteogenic marker expression.
• Skull analysis revealed significant global and regional shape changes, including increased width and decreased length, potentially linked to TGF-β-CTGF axis dysregulation.

Conclusions:

• CTGF ablation leads to site-specific aberrations in bone formation.
• The study presents novel quantitative data on the CTGF KO skeletal phenotype.
• Findings highlight CTGF's critical role in regulating skeletal development and morphology.