» Articles » PMID: 26194181

Evidence That the Rab5 Effector APPL1 Mediates APP-βCTF-induced Dysfunction of Endosomes in Down Syndrome and Alzheimer's Disease

Overview
Journal Mol Psychiatry
Date 2015 Jul 22
PMID 26194181
Citations 115
Authors
Affiliations
Soon will be listed here.
Abstract

β-Amyloid precursor protein (APP) and its cleaved products are strongly implicated in Alzheimer's disease (AD). Endosomes are highly active APP processing sites, and endosome anomalies associated with upregulated expression of early endosomal regulator, rab5, are the earliest known disease-specific neuronal response in AD. Here, we show that the rab5 effector APPL1 (adaptor protein containing pleckstrin homology domain, phosphotyrosine binding domain and leucine zipper motif) mediates rab5 overactivation in Down syndrome (DS) and AD, which is caused by elevated levels of the β-cleaved carboxy-terminal fragment of APP (βCTF). βCTF recruits APPL1 to rab5 endosomes, where it stabilizes active GTP-rab5, leading to pathologically accelerated endocytosis, endosome swelling and selectively impaired axonal transport of rab5 endosomes. In DS fibroblasts, APPL1 knockdown corrects these endosomal anomalies. βCTF levels are also elevated in AD brain, which is accompanied by abnormally high recruitment of APPL1 to rab5 endosomes as seen in DS fibroblasts. These studies indicate that persistent rab5 overactivation through βCTF-APPL1 interactions constitutes a novel APP-dependent pathogenic pathway in AD.

Citing Articles

Maternal choline supplementation rescues early endosome pathology in basal forebrain cholinergic neurons in the Ts65Dn mouse model of Down syndrome and Alzheimer's disease.

Gautier M, Kelley C, Lee S, Mufson E, Ginsberg S Neurobiol Aging. 2024; 144:30-42.

PMID: 39265450 PMC: 11490376. DOI: 10.1016/j.neurobiolaging.2024.09.002.


Accelerated long-term forgetting: A sensitive paradigm for detecting subtle cognitive impairment and evaluating BACE1 inhibitor efficacy in preclinical Alzheimer's disease.

Ohno M Front Dement. 2024; 2:1161875.

PMID: 39081986 PMC: 11285641. DOI: 10.3389/frdem.2023.1161875.


Alzheimer's disease linked Aβ42 exerts product feedback inhibition on γ-secretase impairing downstream cell signaling.

Zoltowska K, Das U, Lismont S, Enzlein T, Maesako M, Houser M Elife. 2024; 12.

PMID: 39027984 PMC: 11259434. DOI: 10.7554/eLife.90690.


Increasing the Survival of a Neuronal Model of Alzheimer's Disease Using Docosahexaenoic Acid, Restoring Endolysosomal Functioning by Modifying the Interactions between the Membrane Proteins C99 and Rab5.

Vigier M, Uriot M, Djelti-Delbarba F, Claudepierre T, El Hajj A, Yen F Int J Mol Sci. 2024; 25(13).

PMID: 38999927 PMC: 11240902. DOI: 10.3390/ijms25136816.


The amyloid precursor protein and its derived fragments concomitantly contribute to the alterations of mitochondrial transport machinery in Alzheimer's disease.

Vaillant-Beuchot L, Eysert F, Duval B, Kinoshita P, Pardossi-Piquard R, Bauer C Cell Death Dis. 2024; 15(5):367.

PMID: 38806484 PMC: 11133367. DOI: 10.1038/s41419-024-06742-2.


References
1.
Young-Pearse T, Bai J, Chang R, Zheng J, LoTurco J, Selkoe D . A critical function for beta-amyloid precursor protein in neuronal migration revealed by in utero RNA interference. J Neurosci. 2007; 27(52):14459-69. PMC: 6673432. DOI: 10.1523/JNEUROSCI.4701-07.2007. View

2.
Cataldo A, Barnett J, Pieroni C, Nixon R . Increased neuronal endocytosis and protease delivery to early endosomes in sporadic Alzheimer's disease: neuropathologic evidence for a mechanism of increased beta-amyloidogenesis. J Neurosci. 1997; 17(16):6142-51. PMC: 6568334. View

3.
Nixon R . Autophagy, amyloidogenesis and Alzheimer disease. J Cell Sci. 2007; 120(Pt 23):4081-91. DOI: 10.1242/jcs.019265. View

4.
Deinhardt K, Salinas S, Verastegui C, Watson R, Worth D, Hanrahan S . Rab5 and Rab7 control endocytic sorting along the axonal retrograde transport pathway. Neuron. 2006; 52(2):293-305. DOI: 10.1016/j.neuron.2006.08.018. View

5.
Cossec J, Lavaur J, Berman D, Rivals I, Hoischen A, Stora S . Trisomy for synaptojanin1 in Down syndrome is functionally linked to the enlargement of early endosomes. Hum Mol Genet. 2012; 21(14):3156-72. PMC: 3384382. DOI: 10.1093/hmg/dds142. View