Semaphorin 6A regulates angiogenesis by modulating VEGF signaling

Area of Science:

• Molecular Biology
• Developmental Biology
• Angiogenesis Research

Background:

• Angiogenesis, the formation of new blood vessels, is crucial for development and in mature mammals.
• While molecular pathways like VEGFR2 signaling are known to regulate endothelial cell survival, many aspects of angiogenesis remain unclear.
• Transmembrane semaphorin6A (Sema6A) is implicated in nervous system development but its role in vascular biology was unexplored.

Purpose of the Study:

• To investigate the role of transmembrane semaphorin6A (Sema6A) in endothelial cell survival and angiogenesis.
• To elucidate the molecular mechanisms by which Sema6A influences vascular endothelial growth factor receptor 2 (VEGFR2) signaling.
• To assess the impact of Sema6A deficiency on vascular development and angiogenesis in vivo.

Main Methods:

• Silencing of Sema6A in primary endothelial cells.
• Analysis of endothelial cell survival and VEGFR2 signaling.
• Phenotypic analysis of Sema6A-null mice in developmental and adult angiogenesis models (hyaloid, retinal, tumor, matrigel, choroidal).

Main Results:

• Sema6A is expressed in endothelial cells and modulates VEGFR2 expression and signaling.
• Sema6A silencing leads to endothelial cell death, dependent on loss of autocrine VEGF signaling.
• Sema6A-null mice display defective hyaloid and retinal vascular development, and reduced angiogenesis in adult models.

Conclusions:

• Transmembrane semaphorin6A (Sema6A) is a novel regulator of endothelial cell survival and angiogenesis.
• Sema6A functions by modulating VEGFR2 signaling, essential for maintaining endothelial cell viability.
• Sema6A plays critical roles in both embryonic vascular development and adult angiogenesis.