Lysosomal NEU1 deficiency affects amyloid precursor protein levels and amyloid-β secretion via deregulated lysosomal exocytosis

• Published in: Nature communications Vol. 4; no. 1; p. 2734
• Main Authors: Annunziata, Ida, Patterson, Annette, Helton, Danielle, Hu, Huimin, Moshiach, Simon, Gomero, Elida, Nixon, Ralph, d’Azzo, Alessandra
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 14.11.2013
• Subjects: 692/308; 692/420; 692/699/375/365/1283; Amyloid beta-Peptides - metabolism; Amyloid beta-Protein Precursor - metabolism; Animals; Brain - embryology; Calcimycin - metabolism; Cell Line; Dependovirus - metabolism; Exocytosis - physiology; Hippocampus - embryology; Hippocampus - metabolism; Hippocampus - ultrastructure; Humanities and Social Sciences; Humans; Lysosomes - metabolism; Mice; Mice, Transgenic; Mucolipidoses - genetics; multidisciplinary; Neuraminidase - genetics; Neuraminidase - physiology; Neurons - metabolism; Risk Factors; Science; Science (multidisciplinary)
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/ncomms3734

Alzheimer’s disease (AD) belongs to a category of adult neurodegenerative conditions, which are associated with intracellular and extracellular accumulation of neurotoxic protein aggregates. Understanding how these aggregates are formed, secreted and propagated by neurons has been the subject of intensive research, but so far no preventive or curative therapy for AD is available, and clinical trials have been largely unsuccessful. Here we show that deficiency of the lysosomal sialidase NEU1 leads to the spontaneous occurrence of an AD-like amyloidogenic process in mice. This involves two consecutive events linked to NEU1 loss-of-function—accumulation and amyloidogenic processing of an oversialylated amyloid precursor protein in lysosomes, and extracellular release of Aβ peptides by excessive lysosomal exocytosis. Furthermore, cerebral injection of NEU1 in an established AD mouse model substantially reduces β-amyloid plaques. Our findings identify an additional pathway for the secretion of Aβ and define NEU1 as a potential therapeutic molecule for AD. The enzyme NEU1 negatively regulates lysosomal exocytosis in various cell types. Annunziata et al. show that mice deficient in NEU1 display Alzheimer’s disease-like pathology and that direct brain administration of NEU1 reduces pathology in an Alzheimer’s disease mouse model.