Wntless is required for peripheral lung differentiation and pulmonary vascular development

Area of Science:

• Developmental Biology
• Molecular Biology
• Genetics

Background:

• Wntless (Wls) is a conserved protein essential for Wnt ligand secretion.
• Wnt signaling is vital for lung development and pulmonary morphogenesis.
• The specific role of Wls in lung development is not fully understood.

Purpose of the Study:

• To investigate the role of Wls in embryonic lung development.
• To determine the impact of Wls deletion in respiratory epithelium and mesenchyme on lung morphogenesis and vascularization.
• To elucidate the molecular mechanisms by which Wls influences pulmonary development.

Main Methods:

• Generation of conditional Wls mutant mice using Shh-Cre and Dermo1-Cre drivers.
• Analysis of lung branching morphogenesis, peripheral lung development, and endothelial differentiation in mutant mice.
• In vitro assays to study Wls interaction with Wnt5a.

Main Results:

• Epithelial Wls deletion disrupted lung branching, peripheral development, and endothelial differentiation, leading to neonatal respiratory failure.
• Mesenchymal Wls deletion did not affect lung development.
• Downregulation of VEGF and Tie2-angiopoietin signaling pathways observed in epithelial Wls mutants.
• In vitro studies suggested Wls acts partly via Wnt5a in regulating pulmonary vascular development.

Conclusions:

• Epithelial Wls is critical for pulmonary vascular differentiation and peripheral lung morphogenesis.
• Wls modulates Wnt ligand activity essential for normal lung development.
• These findings offer insights into congenital lung diseases with dysmorphic pulmonary vasculature.