Temporal modulation of collective cell behavior controls vascular network topology

Area of Science:

• Developmental biology
• Vascular biology
• Systems biology

Background:

• Vascular network density is crucial for oxygen and nutrient delivery.
• The generation of diverse vascular densities remains poorly understood.
• Endothelial tip-cell selection, sprout extension, and anastomosis form vascular networks, regulated by the VEGF/Notch feedback loop.

Purpose of the Study:

• To investigate the role of temporal regulation in vascular network formation.
• To identify mechanisms controlling vascular density.
• To explore the impact of tip-cell selection rate on network topology.

Main Methods:

• Combined computational modeling with in vivo live imaging.
• Investigated the temporal dynamics of the VEGF/Notch feedback loop.
• Identified and tested host tissue-derived signals influencing tip-cell selection.

Main Results:

• Temporal regulation of the VEGF/Notch feedback loop is a key determinant of vascular density.
• The rate of tip-cell selection directly influences sprout extension versus branching.
• Semaphorin3E-Plexin-D1 accelerates tip-cell selection, resulting in denser vascular networks.

Conclusions:

• The timing of endothelial tip-cell selection is a critical mechanism for controlling vascular network density.
• Temporal regulation of iterative network formation processes may be a general principle in biology.
• Further research may uncover additional temporal regulators shaping vascular topology.