title: Therapeutic effects of remediating autophagy failure in a mouse model of Alzheimer disease by enhancing lysosomal proteolysis.
abstract: The extensive autophagic-lysosomal pathology in Alzheimer disease (AD) brain has revealed a major defect: in the proteolytic clearance of autophagy substrates. Autophagy failure contributes on several levels to AD pathogenesis and has become an important therapeutic target for AD and other neurodegenerative diseases. We recently observed broad therapeutic effects of stimulating autophagic-lysosomal proteolysis in the TgCRND8 mouse model of AD that exhibits defective proteolytic clearance of autophagic substrates, robust intralysosomal amyloid-β peptide (Aβ) accumulation, extracellular β-amyloid deposition and cognitive deficits. By genetically deleting the lysosomal cysteine protease inhibitor, cystatin B (CstB), to selectively restore depressed cathepsin activities, we substantially cleared Aβ, ubiquitinated proteins and other autophagic substrates from autolysosomes/lysosomes and rescued autophagic-lysosomal pathology, as well as reduced total Aβ40/42 levels and extracellular amyloid deposition, highlighting the underappreciated importance of the lysosomal system for Aβ clearance. Most importantly, lysosomal remediation prevented the marked learning and memory deficits in TgCRND8 mice. Our findings underscore the pathogenic significance of autophagic-lysosomal dysfunction in AD and demonstrate the value of reversing this dysfunction as an innovative therapeautic strategy for AD.
authors.affiliation: Nathan Kline Institute, Orangeburg, NY, USA. dyang@nki.rfmh.org
authors.forename: Dun-Sheng
authors.initials: DS
authors.lastname: Yang
authors.forename: Philip
authors.initials: P
authors.lastname: Stavrides
authors.forename: Panaiyur S
authors.initials: PS
authors.lastname: Mohan
authors.forename: Susmita
authors.initials: S
authors.lastname: Kaushik
authors.forename: Asok
authors.initials: A
authors.lastname: Kumar
authors.forename: Masuo
authors.initials: M
authors.lastname: Ohno
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Schmidt
authors.forename: Daniel W
authors.initials: DW
authors.lastname: Wesson
authors.forename: Urmi
authors.initials: U
authors.lastname: Bandyopadhyay
authors.forename: Ying
authors.initials: Y
authors.lastname: Jiang
authors.forename: Monika
authors.initials: M
authors.lastname: Pawlik
authors.forename: Corrinne M
authors.initials: CM
authors.lastname: Peterhoff
authors.forename: Austin J
authors.initials: AJ
authors.lastname: Yang
authors.forename: Donald A
authors.initials: DA
authors.lastname: Wilson
authors.forename: Peter
authors.initials: P
authors.lastname: St George-Hyslop
authors.forename: David
authors.initials: D
authors.lastname: Westaway
authors.forename: Paul M
authors.initials: PM
authors.lastname: Mathews
authors.forename: Efrat
authors.initials: E
authors.lastname: Levy
authors.forename: Ana M
authors.initials: AM
authors.lastname: Cuervo
authors.forename: Ralph A
authors.initials: RA
authors.lastname: Nixon
mesh_terms: D000544:Alzheimer Disease / Q000473:pathology* / Q000503:physiopathology / Q000628:therapy*; D000682:Amyloid / Q000378:metabolism; D000818:Animals; D001343:Autophagy; D055313:Cystatin B / Q000378:metabolism; D004195:Disease Models, Animal; D017353:Gene Deletion; D008247:Lysosomes / Q000378:metabolism*; D008568:Memory; D051379:Mice; D008822:Mice, Transgenic; D011499:Protein Processing, Post-Translational
chemical_list: D000682:Amyloid; D055313:Cystatin B