Endothelial Notch1 drives multicellular remodelling during hyaloid vessel regression

Area of Science:

• Developmental Biology
• Ophthalmology
• Vascular Biology

Background:

• Hyaloid vessel regression is vital for clear vision but its mechanisms are poorly understood.
• This transient vascular network's dismantling process requires elucidation.

Purpose of the Study:

• To investigate the molecular mechanisms driving postnatal hyaloid vessel regression in mice.
• To identify key signaling pathways regulating this developmental vascular remodeling process.

Main Methods:

• Utilized mouse models with specific gene deletions (Notch1 in endothelial cells).
• Analyzed cell behavior (delamination, proliferation) and gene expression during regression.
• Investigated the role of Notch1 and Wnt signaling pathways.

Main Results:

• Hyaloid regression is driven by cell delamination and plasticity, not primarily apoptosis.
• Notch1 signaling is essential, as its deletion leads to persistent hyaloid vessels.
• Notch1 loss preserves endothelial identity and suppresses an endothelial-mesenchymal transition-like program.
• Functional convergence between Notch1 and Wnt signaling in vessel involution was observed.

Conclusions:

• Notch1 is identified as a critical regulator of developmental vascular pruning.
• Hyaloid regression is a remodeling process involving cell plasticity, not solely apoptosis.
• Findings offer insights into physiological and pathological vascular remodeling, potentially guiding ocular disorder therapies.