Neuronal Activity Induces Glucosylceramide That Is Secreted via Exosomes for Lysosomal Degradation in Glia

Authors

Liping Wang
Guang Lin
Zhongyuan Zuo
Yarong Li
Seul Kee Byeon
Akhilesh Pandey
Hugo J Bellen

Publication Date

7-15-2022

Journal

Science Advances

DOI

10.1126/sciadv.abn3326

PMID

35857503

PMCID

PMC9278864

PubMedCentral® Posted Date

7-13-2022

PubMedCentral® Full Text Version

Post-print

Published Open-Access

yes

Keywords

Animals, Drosophila, Exosomes, Glucosylceramidase, Glucosylceramides, Humans, Lysosomes, Neuroglia, Neurons

Abstract

Recessive variants in GBA1 cause Gaucher disease, a prevalent form of lysosome storage disease. GBA1 encodes a lysosomal enzyme that hydrolyzes glucosylceramide (GlcCer) into glucose and ceramide. Its loss causes lysosomal dysfunction and increased levels of GlcCer. We generated a null allele of the Drosophila ortholog Gba1b by inserting the Gal4 using CRISPR-Cas9. Here, we show that Gba1b is expressed in glia but not in neurons. Glial-specific knockdown recapitulates the defects found in Gba1b mutants, and these can be rescued by glial expression of human GBA1. We show that GlcCer is synthesized upon neuronal activity, and it is transported from neurons to glia through exosomes. Furthermore, we found that glial TGF-β/BMP induces the transfer of GlcCer from neurons to glia and that the White protein, an ABCG transporter, promotes GlcCer trafficking to glial lysosomes for degradation.