Endothelium-Derived Semaphorin 3G Regulates Hippocampal Synaptic Structure and Plasticity via Neuropilin-2/PlexinA4

Highlights

• Endothelium-derived Sema3G is necessary for synaptic plasticity in the hippocampus
• Loss of Sema3G in the vascular endothelium results in behavioral and memory deficits
• Sema3G regulates synaptic structure and function via the neuropilin-2/PlexinA4 receptor
• Sema3G functionally links the endothelium to signaling cascades activated in neurons

Summary

The proper interactions between blood vessels and neurons are critical for maintaining the strength of neural circuits and cognitive function. However, the precise molecular events underlying these interactions remain largely unknown. Here, we report that the selective knockout of semaphorin 3G (Sema3G) in endothelial cells impaired hippocampal-dependent memory and reduced dendritic spine density in CA1 neurons in mice; these effects were reversed after restoration of Sema3G levels in the hippocampus by AAV transfection. We further show that Sema3G increased excitatory synapse density via neuropilin-2/PlexinA4 signaling and through activation of Rac1. These results provide the first evidence that, in the central nervous system, endothelial Sema3G serves as a vascular-derived synaptic organizer that regulates synaptic plasticity and hippocampal-dependent memory. Our findings highlight the role of vascular endothelial cells in regulating cognitive function through intercellular communication with neurons in the hippocampus.

 

Link to the publication :

https://www.sciencedirect.com/science/article/pii/S0896627318311565