Dataset Information

Tau and other proteins found in Alzheimer's disease spinal fluid are linked to retromer-mediated endosomal traffic in mice and humans.

ABSTRACT: Endosomal trafficking has emerged as a defective biological pathway in Alzheimer's disease (AD), and the pathway is a source of cerebrospinal fluid (CSF) protein accumulation. Nevertheless, the identity of the CSF proteins that accumulate in the setting of defects in AD's endosomal trafficking pathway remains unknown. Here, we performed a CSF proteomic screen in mice with a neuronal-selective knockout of the core of the retromer complex VPS35, a master conductor of endosomal traffic that has been implicated in AD. We then validated three of the most relevant proteomic findings: the amino terminus of the transmembrane proteins APLP1 and CHL1, and the mid-domain of tau, which is known to be unconventionally secreted and elevated in AD. In patients with AD dementia, the concentration of amino-terminal APLP1 and CHL1 in the CSF correlated with tau and phosphorylated tau. Similar results were observed in healthy controls, where both proteins correlated with tau and phosphorylated tau and were elevated in about 70% of patients in the prodromal stages of AD. Collectively, the mouse-to-human studies suggest that retromer-dependent endosomal trafficking can regulate tau, APLP1, and CHL1 CSF concentration, informing on how AD's trafficking pathway might contribute to disease spread and how to identify its trafficking impairments in vivo.

SUBMITTER: Simoes S

PROVIDER: S-EPMC7901670 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

Tau and other proteins found in Alzheimer's disease spinal fluid are linked to retromer-mediated endosomal traffic in mice and humans.

Simoes Sabrina S Neufeld Jessica L JL Triana-Baltzer Gallen G Moughadam Setareh S Chen Emily I EI Kothiya Milankumar M Qureshi Yasir H YH Patel Vivek V Honig Lawrence S LS Kolb Hartmuth H Small Scott A SA

Science translational medicine 20201101 571

Endosomal trafficking has emerged as a defective biological pathway in Alzheimer's disease (AD), and the pathway is a source of cerebrospinal fluid (CSF) protein accumulation. Nevertheless, the identity of the CSF proteins that accumulate in the setting of defects in AD's endosomal trafficking pathway remains unknown. Here, we performed a CSF proteomic screen in mice with a neuronal-selective knockout of the core of the retromer complex VPS35, a master conductor of endosomal traffic that has bee ...[more]

PMID: 33239387

Similar Datasets

Project description:BackgroundLoss of the Sortilin-related receptor 1 (SORL1) gene seems to act as a causal event for Alzheimer's disease (AD). Recent studies have established that loss of SORL1, as well as mutations in autosomal dominant AD genes APP and PSEN1/2, pathogenically converge by swelling early endosomes, AD's cytopathological hallmark. Acting together with the retromer trafficking complex, SORL1 has been shown to regulate the recycling of the amyloid precursor protein (APP) out of the endosome, contributing to endosomal swelling and to APP misprocessing. We hypothesized that SORL1 plays a broader role in neuronal endosomal recycling and used human induced pluripotent stem cell-derived neurons (hiPSC-Ns) to test this hypothesis. We examined endosomal recycling of three transmembrane proteins linked to AD pathophysiology: APP, the BDNF receptor Tropomyosin-related kinase B (TRKB), and the glutamate receptor subunit AMPA1 (GLUA1).MethodsWe used isogenic hiPSCs engineered to have SORL1 depleted or to have enhanced SORL1 expression. We differentiated neurons from these cell lines and mapped the trafficking of APP, TRKB and GLUA1 within the endosomal network using confocal microscopy. We also performed cell surface recycling and lysosomal degradation assays to assess the functionality of the endosomal network in both SORL1-depleted and -overexpressing neurons. The functional impact of GLUA1 recycling was determined by measuring synaptic activity. Finally, we analyzed alterations in gene expression in SORL1-depleted neurons using RNA sequencing.ResultsWe find that as with APP, endosomal trafficking of GLUA1 and TRKB is impaired by loss of SORL1. We show that trafficking of all three cargoes to late endosomes and lysosomes is affected by manipulating SORL1 expression. We also show that depletion of SORL1 significantly impacts the endosomal recycling pathway for APP and GLUA1 at the level of the recycling endosome and trafficking to the cell surface. This has a functional effect on neuronal activity as shown by multi-electrode array (MEA). Conversely, increased SORL1 expression enhances endosomal recycling for APP and GLUA1. Our unbiased transcriptomic data further support SORL1's role in endosomal recycling. We observe altered expression networks that regulate cell surface trafficking and neurotrophic signaling in SORL1-depleted neurons.ConclusionCollectively, and together with other recent observations, these findings suggest that one role for SORL1 is to contribute to endosomal degradation and recycling pathways in neurons, a conclusion that has both pathogenic and therapeutic implications for Alzheimer's disease.

Dataset Information

Tau and other proteins found in Alzheimer's disease spinal fluid are linked to retromer-mediated endosomal traffic in mice and humans.

Publications

Tau and other proteins found in Alzheimer's disease spinal fluid are linked to retromer-mediated endosomal traffic in mice and humans.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets