title: How to reduce the accumulation of autophagic vacuoles in NPC1-deficient neurons: a comparison of two pharmacological strategies.
abstract: A disturbed autophagic pathway leads to chronically increased levels of autophagic vacuoles in Niemann Pick Type-C 1 (NPC1) deficient neurons. Since these accumulations potentially contribute to neuronal cell death associated with the disease, we investigated two pharmacological strategies which potentially reduce the number of autophagic structures under following aspects: efficiency, sustainability and effect on neuronal cell viability. The strategies comprised (i) an interruption of the autophagic flux by the class III PI3K inhibitor 3-methyladenine (3-MA) and (ii) an acceleration of the autophagic execution by 2-hydroxypropyl-β-cyclodextrin (pCD). Our data show that the inhibition of autophagy with 3-MA only initially reduced the number of autophagic vacuoles in cultured neurons. Prolonged treatments with the PI3K-inhibitor reversed this lowering effect. The re-increase in the number of autophagic vacuoles was combined with a defect in the integrity of lysosomes which endangered further survival of cells. The treatment with pCD evoked a slow but sustained reduction of autophagic structures and had no negative effects on neuronal survival.
authors.affiliation: Center of Anatomy, Institute of Integrative Neuroanatomy, Department of Clinical Cell and Neurobiology, Charite, Charite-Platz 1, 10098 Berlin, Germany.volker.meske@charite.de
authors.forename: Volker
authors.initials: V
authors.lastname: Meske
authors.forename: Timm
authors.initials: T
authors.lastname: Priesnitz
authors.forename: Frank
authors.initials: F
authors.lastname: Albert
authors.forename: Thomas Georg
authors.initials: TG
authors.lastname: Ohm
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D000225:Adenine / Q000031:analogs & derivatives* / Q000494:pharmacology; D000818:Animals; D001343:Autophagy / Q000187:drug effects*; D002478:Cells, Cultured; D002540:Cerebral Cortex / Q000166:cytology; D002784:Cholesterol / Q000378:metabolism; D004622:Embryo, Mammalian; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects / Q000235:genetics; D047908:Intracellular Signaling Peptides and Proteins; D052119:Lysosomal-Associated Membrane Protein 2 / Q000378:metabolism; D008247:Lysosomes / Q000187:drug effects; D051379:Mice; D008807:Mice, Inbred BALB C; D008822:Mice, Transgenic; D008869:Microtubule-Associated Proteins / Q000378:metabolism; D009474:Neurons / Q000166:cytology* / Q000187:drug effects / Q000378:metabolism; D000077296:Niemann-Pick C1 Protein; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D013997:Time Factors; D014617:Vacuoles / Q000187:drug effects* / Q000378:metabolism; D047392:beta-Cyclodextrins / Q000494:pharmacology*
chemical_list: D004791:Enzyme Inhibitors; D047908:Intracellular Signaling Peptides and Proteins; D052119:Lysosomal-Associated Membrane Protein 2; C480860:Map1lc3b protein, mouse; D008869:Microtubule-Associated Proteins; D000077296:Niemann-Pick C1 Protein; C106831:Npc1 protein, mouse; D011506:Proteins; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin; C025946:3-methyladenine; D002784:Cholesterol; D000225:Adenine