title: β-Cyclodextrin-threaded biocleavable polyrotaxanes ameliorate impaired autophagic flux in Niemann-Pick type C disease.
abstract: Niemann-Pick type C (NPC) disease is characterized by the lysosomal accumulation of cholesterols and impaired autophagic flux due to the inhibited fusion of autophagosomes to lysosomes. We have recently developed β-cyclodextrin (β-CD)-threaded biocleavable polyrotaxanes (PRXs), which can release threaded β-CDs in response to intracellular environments as a therapeutic for NPC disease. The biocleavable PRXs exhibited effective cholesterol reduction ability and negligible toxic effect compared with hydroxypropyl-β-CD (HP-β-CD). In this study, we investigated the effect of biocleavable PRX and HP-β-CD on the impaired autophagy in NPC disease. The NPC patient-derived fibroblasts (NPC1 fibroblasts) showed an increase in the number of LC3-positive puncta compared with normal fibroblasts, even in the basal conditions; the HP-β-CD treatment markedly increased the number of LC3-positive puncta and the levels of p62 in NPC1 fibroblasts, indicating that autophagic flux was further perturbed. In sharp contrast, the biocleavable PRX reduced the number of LC3-positive puncta and the levels of p62 in NPC1 fibroblasts through an mTOR-independent mechanism. The mRFP-GFP-LC3 reporter gene expression experiments revealed that the biocleavable PRX facilitated the formation of autolysosomes to allow for autophagic protein degradation. Therefore, the β-CD-threaded biocleavable PRXs may be promising therapeutics for ameliorating not only cholesterol accumulation but also autophagy impairment in NPC disease.
authors.affiliation: From the Department of Organic Biomaterials, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo 101-0062, Japan.
authors.forename: Atsushi
authors.initials: A
authors.lastname: Tamura
authors.affiliation: From the Department of Organic Biomaterials, Institute of Biomaterials and Bioengineering, Tokyo Medical and Dental University, Tokyo 101-0062, Japan yui.org@tmd.ac.jp.
authors.forename: Nobuhiko
authors.initials: N
authors.lastname: Yui
mesh_terms: D000073738:2-Hydroxypropyl-beta-cyclodextrin; D001343:Autophagy / Q000187:drug effects* / Q000235:genetics; D001692:Biological Transport / Q000187:drug effects / Q000235:genetics; D002352:Carrier Proteins / Q000235:genetics / Q000378:metabolism; D002478:Cells, Cultured; D002784:Cholesterol / Q000378:metabolism; D005347:Fibroblasts / Q000187:drug effects* / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D047908:Intracellular Signaling Peptides and Proteins; D008247:Lysosomes / Q000187:drug effects / Q000378:metabolism; D008562:Membrane Glycoproteins / Q000235:genetics / Q000378:metabolism; D018613:Microscopy, Confocal; D009154:Mutation; D000077296:Niemann-Pick C1 Protein; D052556:Niemann-Pick Disease, Type C / Q000235:genetics / Q000378:metabolism / Q000473:pathology; D010588:Phagosomes / Q000187:drug effects / Q000378:metabolism; D043862:Rotaxanes / Q000494:pharmacology*; D047392:beta-Cyclodextrins / Q000494:pharmacology*
chemical_list: D002352:Carrier Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008562:Membrane Glycoproteins; C106881:NPC1 protein, human; D000077296:Niemann-Pick C1 Protein; D043862:Rotaxanes; D047392:beta-Cyclodextrins; D000073738:2-Hydroxypropyl-beta-cyclodextrin; D002784:Cholesterol
keywords: Autophagy; Cholesterol; Cyclodextrin; Drug Delivery System; Lysosomal Storage Disease; Lysosome; Niemann-Pick Type C Disease; Polyrotaxane