Wheeler2019.pdf (2.99 MB)
Cytosolic glucosylceramide regulates endolysosomal function in Niemann-Pick type C disease.
journal contributionposted on 2019-04-29, 11:27 authored by S Wheeler, P Haberkant, M Bhardwaj, P Tongue, MJ Ferraz, D Halter, H Sprong, R Schmid, JMFG Aerts, N Sullo, DJ Sillence
Niemann-Pick type C disease (NPCD) is a neurodegenerative disease associated with increases in cellular cholesterol and glycolipids and most commonly caused by defective NPC1, a late endosomal protein. Using ratiometric probes we find that NPCD cells show increased endolysosomal pH. In addition U18666A, an inhibitor of NPC1, was found to increase endolysosomal pH, and the number, size and heterogeneity of endolysosomal vesicles. NPCD fibroblasts and cells treated with U18666A also show disrupted targeting of fluorescent lipid BODIPY-LacCer to high pH vesicles. Inhibiting non-lysosomal glucocerebrosidase (GBA2) reversed increases in endolysosomal pH and restored disrupted BODIPY-LacCer trafficking in NPCD fibroblasts. GBA2 KO cells also show decreased endolysosomal pH. NPCD fibroblasts also show increased expression of a key subunit of the lysosomal proton pump vATPase on GBA2 inhibition. The results are consistent with a model where both endolysosomal pH and Golgi targeting of BODIPY-LacCer are dependent on adequate levels of cytosolic-facing GlcCer, which are reduced in NPC disease.
We thank De Montfort University (to SW/DJS), Beyond Batten Disease Foundation (NS/DJS) the European Council (grant MRTN-CT-2004-5330, to DH/HS) and VKS-GVN (to MF/JA) for financial support. We are grateful to Profs Frances Platt (Oxford University) and Dagmar Wachten (CAESAR, Bonn) for gifts of cells and to Dr. Stephen Muench (Leeds University) for helpful discussions.
CitationNeurobiology of Disease, 2019, 127, pp. 242-252
Author affiliation/Organisation/COLLEGE OF LIFE SCIENCES/Biological Sciences/Molecular & Cell Biology
- AM (Accepted Manuscript)