Reciprocal control of excitatory synapse numbers by Wnt and Wnt inhibitor PRR7 secreted on exosomes. Nat Commun 2018 Aug 24;9(1):3434
Date
08/26/2018Pubmed ID
30143647Pubmed Central ID
PMC6109165DOI
10.1038/s41467-018-05858-2Scopus ID
2-s2.0-85052238097 (requires institutional sign-in at Scopus site) 37 CitationsAbstract
Secreted Wnts play crucial roles in synaptogenesis and synapse maintenance, but endogenous factors promoting synapse elimination in central neurons remain unknown. Here we show that proline-rich 7 (PRR7) induces specific removal of excitatory synapses and acts as a Wnt inhibitor. Remarkably, transmembrane protein PRR7 is activity-dependently released by neurons via exosomes. Exosomal PRR7 is uptaken by neurons through membrane fusion and eliminates excitatory synapses in neighboring neurons. Conversely, PRR7 knockdown in sparse neurons greatly increases excitatory synapse numbers in all surrounding neurons. These non-cell autonomous effects of PRR7 are effectively negated by augmentation or blockade of Wnt signaling. PRR7 exerts its effect by blocking the exosomal secretion of Wnts, activation of GSK3β, and promoting proteasomal degradation of PSD proteins. These data uncover a proximity-dependent, reciprocal mechanism for the regulation of excitatory synapse numbers in local neurons and demonstrate the significance of exosomes in inter-neuronal signaling in the vertebrate brain.
Author List
Lee SH, Shin SM, Zhong P, Kim HT, Kim DI, Kim JM, Heo WD, Kim DW, Yeo CY, Kim CH, Liu QSAuthors
Sang H. Lee PhD Professor in the Pharmacology and Toxicology department at Medical College of WisconsinQing-song Liu PhD Professor in the Pharmacology and Toxicology department at Medical College of Wisconsin
MESH terms used to index this publication - Major topics in bold
AnimalsCells, Cultured
Exosomes
Female
HEK293 Cells
Hippocampus
Humans
Immunohistochemistry
Membrane Proteins
Mice
Mice, Knockout
Nerve Tissue Proteins
Neurogenesis
Neurons
Rats
Signal Transduction
Synapses
Wnt Proteins
