Open AccessGga3 deletion and a GGA3 rare variant associated with late onset Alzheimer’s disease trigger BACE1 accumulation in axonal swellings
Author(s) -
Selene Lomoio,
Rachel Willen,
WonHee Kim,
Kevin Z. Ho,
Edward K. Robinson,
Dmitry Prokopenko,
Matthew Kennedy,
Rudolph E. Tanzi,
Giuseppina Tesco
Publication year - 2020
Publication title -
science translational medicine
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.819
H-Index - 216
eISSN - 1946-6242
pISSN - 1946-6234
DOI - 10.1126/scitranslmed.aba1871
Subject(s) - pathogenesis , in vivo , microbiology and biotechnology , amyloid precursor protein secretase , chemistry , extracellular , in vitro , amyloid precursor protein , alzheimer's disease , cancer research , disease , neuroscience , biology , medicine , pathology , biochemistry , genetics
Axonal dystrophy, indicative of perturbed axonal transport, occurs early during Alzheimer's disease (AD) pathogenesis. Little is known about the mechanisms underlying this initial sign of the pathology. This study proves that Golgi-localized γ-ear-containing ARF binding protein 3 (GGA3) loss of function, due to Gga3 genetic deletion or a GGA3 rare variant that cosegregates with late-onset AD, disrupts the axonal trafficking of the β-site APP-cleaving enzyme 1 (BACE1) resulting in its accumulation in axonal swellings in cultured neurons and in vivo. We show that BACE pharmacological inhibition ameliorates BACE1 axonal trafficking and diminishes axonal dystrophies in Gga3 null neurons in vitro and in vivo. These data indicate that axonal accumulation of BACE1 engendered by GGA3 loss of function results in local toxicity leading to axonopathy. Gga3 deletion exacerbates axonal dystrophies in a mouse model of AD before β-amyloid (Aβ) deposition. Our study strongly supports a role for GGA3 in AD pathogenesis, where GGA3 loss of function triggers BACE1 axonal accumulation independently of extracellular Aβ, and initiates a cascade of events leading to the axonal damage distinctive of the early stage of AD.