CLN8p is involved in spatial distribution of lysosomes

REMEDI, MÓNICA; QUASSOLLO, GONZALO; BISBAL, MARIANO; PESAOLA, FAVIO; NOHER DE HALAC, RITA INÉS

Roma

Simposio; SSIEM Annual Symposium; 2016

Society for the Study of Inborn Errors of Metabolism

Background: CLN8 (one of 13 diseases grouped as Neuronal Ceroid Lipofuscinosis, NCL) is caused by mutations in CLN8, which encodes for a putative 286 aa, transmembrane protein CLN8p. This protein shuttles between Endoplasmic Reticulum (ER) and the ER-Golgi Intermediate Compartment (ERGIC). As in all NCL, its malfunction causes aggregates of lipofuscin-like compounds into lysosomes of all cell types, affecting in most extent neurons, causing neurodegeneration. CLN8p role as well as how mutations trigger lysosomal storage disorder, is still unknown. Here, we evaluate how CLN8 expression is involved in the spatial pattern of lysosomes. Methods: HeLa cells were transfected with one of four constructs: soluble GFP (control), GFP-CLN8wt or shCLN8. Lysosomes were marked with anti-LAMP1 antibody by immunofluorescence. Images were taken with a Disk Scanning Unit (DSU) microscope and analyzed using ImageJ-Fiji and SpatTrack softwares. Results: Four indexes related to spatial pattern of lysosomes were determined. Nearest Neighborhood (NN) and Clark?s Aggregate Index (CAI) refer to distances between particles. Both indexes showed a significant difference (p