Assays

Parental and ITCH KO HeLa cells were cultured in lysine- and arginine-free DMEM supplemented with dialyzed FBS, 2 mM L-glutamine, 1 mM sodium pyruvate, penicillin/streptomycin and light (K0) lysine (38 μg/mL) and arginine (66 μg/ml). Heavy medium was the same except the light lysine was replaced with K8-lysine (L-Lysine, 2HCl U-13C U-15N, Cambridge Isotope Laboratories Inc). All cells were treated for 1 h with 1mM LLOMe (Sigma). Subsequently, cells were processed as described before (Fiskin et ...

Dissection of ventral pial cerebral vessels: Mice were anesthetized with Ketamine (100 mg/kg) and Xylazine (10 mg/kg) and transcardially perfused with 20 ml PBS, followed by 2 ml of 2% Evan’s blue (w/v) prepared in PBS. After brain harvest, pial vessels were collected from the ventral face of the brain with micro forceps under a M205 A dissection microscope (Leica) and snap frozen on dry ice. Lysis of cerebral vessels. Vessels were mixed with 4% (w/v) SDS, 100 mM dithiothreitol, 100 mM Tris–HCl, ...

Cells were collected and lysed in urea buffer (9 M Urea, 50 mM Tris pH 8, 150 mM NaCl, 1x Roche protease inhibitor cocktail) followed by short sonification. Samples were cleared by centrifugation and protein amounts were adapted. Protein reduction was performed with dithiothreitol (DTT; 5 mM final) for 25 min at 56°C and protein alkylation by the addition of iodoacetamide (14 mM final) for 30 min at room temperature. Protein mixtures were quenched with DTT and diluted 1:5 with 1 M Tris-Hcl, pH ...

Blood samples (20 ml) from clinically affected homozygous Npc1 mutation carriers and healthy donors were collected. Negative selection of peripheral blood monocyte-derived macrophages was performed by incubating full blood for 20 min at RT with RosetteSep Human Monocyte Enrichment Cocktail (StemCell Technologies). An equal volume of washing buffer (D-PBS/2% FBS/1 mM EDTA) was added to each sample and layer of macrophages was separated from red blood cells and plasma by centrifugation on a Ficoll ...