Song Pang, Frank M. J. Jacobs, Michael E. Coulter, Raphael Gaudin, C. Shan Xu, Gerrald A Lodewijk, Ganeshwaran H. Mochida, Sarah Cianférani, Harald F. Hess, Wei-Chung Allen Lee, Christopher A. Walsh, Tomas Kirchhausen, Dilenny M. Gonzalez, Monica L. Calicchio, François Delalande, Edward Yang, Cristina M. Dorobantu, Richard S. Smith, Hart G.W. Lidov, David Haussler, Eric T. Wong, Vijay S. Ganesh, Maria K. Lehtinen, Elaine T. Lim, Thorsten M. Schlaeger, Molecular Neuroscience (SILS, FNWI), Equipe Direction scientifique, Sciences et Technologies de la Musique et du Son (STMS), Institut de Recherche et Coordination Acoustique/Musique (IRCAM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche et Coordination Acoustique/Musique (IRCAM)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Centre National de la Recherche Scientifique (CNRS), Département Sciences Analytiques et Interactions Ioniques et Biomoléculaires (DSA-IPHC), Institut Pluridisciplinaire Hubert Curien (IPHC), Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS)-Université de Strasbourg (UNISTRA)-Institut National de Physique Nucléaire et de Physique des Particules du CNRS (IN2P3)-Centre National de la Recherche Scientifique (CNRS), Computer Science and Artificial Intelligence Laboratory [Cambridge] (CSAIL), Massachusetts Institute of Technology (MIT), McMaster Univ, Med Phys & Appl Radiat Sci Dept, Hamilton, ON L8S 4K1, Canada, Analytic and Translational Genetics Unit, Department of Medicine, Massachusetts General Hospital and Harvard Medical School, Harvard Medical School [Boston] (HMS), Center for Biomolecular Science and Engineering, University of California [Santa Cruz] (UCSC), and University of California-University of California
SUMMARY Endosomal sorting complex required for transport (ESCRT) complex proteins regulate biogenesis and release of extracellular vesicles (EVs), which enable cell-to-cell communication in the nervous system essential for development and adult function. We recently showed human loss-of-function (LOF) mutations in ESCRT-III member CHMP1A cause autosomal recessive microcephaly with pontocerebellar hypoplasia, but its mechanism was unclear. Here, we show Chmp1a is required for progenitor proliferation in mouse cortex and cerebellum and progenitor maintenance in human cerebral organoids. In Chmp1a null mice, this defect is associated with impaired sonic hedgehog (Shh) secretion and intraluminal vesicle (ILV) formation in multivesicular bodies (MVBs). Furthermore, we show CHMP1A is important for release of an EV subtype that contains AXL, RAB18, and TMED10 (ART) and SHH. Our findings show CHMP1A loss impairs secretion of SHH on ART-EVs, providing molecular mechanistic insights into the role of ESCRT proteins and EVs in the brain., Graphical Abstract, In Brief Extracellular vesicles (EVs) are essential for cell-to-cell communication in developing brain. Coulter et al. show that the human microcephaly gene CHMP1A is required for neuroprogenitor proliferation through regulation of vesicular secretion of the growth factor sonic hedgehog (SHH). CHMP1A specifically impairs SHH secretion on a distinctive EV subtype, ART-EV.