Identification of New Markers of Angiogenic Sprouting Using Transcriptomics: New Role for RND3

Area of Science:

• Molecular Biology
• Cell Biology
• Angiogenesis Research

Background:

• New blood vessel formation (angiogenesis) requires endothelial cells to become invasive.
• Transcriptional changes are crucial for this endothelial cell phenotype switch.
• A comprehensive genome-wide analysis of endothelial cell sprout initiation was lacking.

Purpose of the Study:

• To identify genome-wide transcriptional changes during endothelial cell sprout initiation.
• To characterize the molecular mechanisms underlying endothelial cell invasion.
• To discover novel genes involved in angiogenesis.

Main Methods:

• Developed a protocol to isolate invading endothelial cells from non-invading cells.
• Performed transcriptomic analyses (single-cell and bulk RNA sequencing) on isolated cells.
• Utilized gene silencing and in vivo mouse models to validate gene function.

Main Results:

• Identified common transcriptomic changes in invading endothelial cells.
• Discovered that collagenase digestion upregulates Fos proto-oncogene.
• Validated the role of SNAI1, JUNB, and RND3 (rounding 3) in endothelial cell invasion and filopodia formation.

Conclusions:

• Gene signatures identified are functionally relevant early in the angiogenic process.
• This study expands the known gene list associated with tip cell phenotype acquisition.
• RND3 has a novel role in regulating filopodial extensions during angiogenesis.