Differential endothelial transcriptomics identifies semaphorin 3G as a vascular class 3 semaphorin

Area of Science:

• Vascular Biology
• Molecular Biology
• Cell Signaling

Background:

• Semaphorins are known axon guidance molecules.
• Recent studies highlight their role in regulating angiogenesis.
• Class 3 semaphorins (Sema3s) are secreted proteins with diverse biological functions.

Purpose of the Study:

• To investigate the function of vascular-expressed semaphorin 3G (Sema3G).
• To characterize the role of Sema3G in angiogenesis and vascular development.

Main Methods:

• Transcriptomic screening to identify angiogenic endothelial cell molecules.
• Generation and analysis of Sema3G-deficient mice.
• LacZ staining to visualize Sema3G expression patterns.
• Analysis of Sema3G processing and receptor binding (NP1, NP2).
• Expression profiling and cellular experiments to determine autocrine and paracrine effects.

Main Results:

• Sema3G was identified as a molecule expressed by angiogenic endothelial cells.
• Sema3G-deficient mice showed no overt vascular phenotype, suggesting compensatory mechanisms.
• LacZ expression revealed intense arterial vascular staining in developing vasculature, decreasing in adults.
• Full-length and processed Sema3G bind to neuropilin receptors (NP1 and NP2).
• Sema3G exerts autocrine effects on endothelial cells and paracrine effects on smooth muscle cells.

Conclusions:

• Sema3G is an endothelial cell-expressed class 3 semaphorin.
• It controls endothelial cell function via autocrine signaling.
• It influences smooth muscle cell function through paracrine signaling.
• Compensatory mechanisms may mask the full phenotype in Sema3G knockout mice.