RT Journal Article
SR Electronic
T1 Fractone bulbs derive from ependymal cells and their laminin composition affects cell proliferation in the subventricular zone
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 093351
DO 10.1101/093351
A1 Marcos Assis Nascimento
A1 Tatiana Coelho-Sampaio
A1 Lydia Sorokin
YR 2016
UL http://biorxiv.org/content/early/2016/12/14/093351.abstract
AB Fractones are extracellular matrix structures in the neural stem cell niche of the subventricular zone (SVZ). Their cellular origin and what determines their localization at this site is poorly studied and it remains unclear whether they influence neural stem and progenitor cells (NSPCs) formation, proliferation and/or maintenance. To address these questions, we analyzed whole mount preparations of the lateral ventricle by confocal microscopy using different extracellular matrix and cell markers, revealing laminin α5 as a major component of fractones, which were profusely distributed throughout the SVZ and appeared at the center of pinwheels, a critical site for adult neurogenesis. We demonstrate that fractones appear at the apical membrane of ependymal cells at the end of the first week after birth, and the use of transgenic mice lacking laminin α5 gene expression (Lama5) in endothelium and in FoxJ1-expressing ependymal cells, revealed ependymal cells as the source of laminin α5-containing fractones. Loss of laminin α5 from fractone bulbs correlated with an aberrant upregulation of laminin α2 and a two-fold increase in the proliferation of NSPCs, as determined by PH3 staining. These results indicate that fractones are a key component of the SVZ and that the laminin isoform composition at this site affects NSPC numbers.