Dataset Information

SIRT1 facilitates amyloid beta peptide degradation by upregulating lysosome number in primary astrocytes.

ABSTRACT: Previous studies have shown that sirtuin 1 (SIRT1) reduces the production of neuronal amyloid beta (A?) and inhibits the inflammatory response of glial cells, thereby generating a neuroprotective effect against A? neurotoxicity in animal models of Alzheimer's disease. However, the protective effect of SIRT1 on astrocytes is still under investigation. This study established a time point model for the clearance of A? in primary astrocytes. Results showed that 12 hours of culture was sufficient for endocytosis of oligomeric A?, and 36 hours sufficient for effective degradation. Immunofluorescence demonstrated that A? degradation in primary astrocytes relies on lysosome function. Enzymatic agonists or SIRT1 inhibitors were used to stimulate cells over a concentration gradient. A? was co-cultured for 36 hours in medium. Western blot assay results under different conditions revealed that SIRT1 relies on its deacetylase activity to promote intracellular A? degradation. The experiment further screened SIRT1 using quantitative proteomics to investigate downstream, differentially expressed proteins in the A? degradation pathway and selected the ones related to enzyme activity of SIRT1. Most of the differentially expressed proteins detected are close to the primary astrocyte lysosomal pathway. Immunofluorescence staining demonstrated that SIRT1 relies on its deacetylase activity to upregulate lysosome number in primary astrocytes. Taken together, these findings confirm that SIRT1 relies on its deacetylase activity to upregulate lysosome number, thereby facilitating oligomeric A? degradation in primary astrocytes.

SUBMITTER: Li MZ

PROVIDER: S-EPMC6183050 | biostudies-literature | 2018 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

SIRT1 facilitates amyloid beta peptide degradation by upregulating lysosome number in primary astrocytes.

Li Min-Zhe MZ Zheng Liang-Jun LJ Shen Jian J Li Xin-Ya XY Zhang Qi Q Bai Xue X Wang Qing-Song QS Ji Jian-Guo JG

Neural regeneration research 20181101 11

Previous studies have shown that sirtuin 1 (SIRT1) reduces the production of neuronal amyloid beta (Aβ) and inhibits the inflammatory response of glial cells, thereby generating a neuroprotective effect against Aβ neurotoxicity in animal models of Alzheimer's disease. However, the protective effect of SIRT1 on astrocytes is still under investigation. This study established a time point model for the clearance of Aβ in primary astrocytes. Results showed that 12 hours of culture was sufficient for ...[more]

PMID: 30233076

Similar Datasets

Project description:BackgroundAlzheimer's disease (AD) and Parkinson's disease (PD) are characterized by brain accumulation of aggregated amyloid-beta (Aβ) and alpha-synuclein (αSYN), respectively. In order to develop effective therapies, it is crucial to understand how the Aβ/αSYN aggregates can be cleared. Compelling data indicate that neuroinflammatory cells, including astrocytes and microglia, play a central role in the pathogenesis of AD and PD. However, how the interplay between the two cell types affects their clearing capacity and consequently the disease progression remains unclear.MethodsThe aim of the present study was to investigate in which way glial crosstalk influences αSYN and Aβ pathology, focusing on accumulation and degradation. For this purpose, human-induced pluripotent cell (hiPSC)-derived astrocytes and microglia were exposed to sonicated fibrils of αSYN or Aβ and analyzed over time. The capacity of the two cell types to clear extracellular and intracellular protein aggregates when either cultured separately or in co-culture was studied using immunocytochemistry and ELISA. Moreover, the capacity of cells to interact with and process protein aggregates was tracked using time-lapse microscopy and a customized "close-culture" chamber, in which the apical surfaces of astrocyte and microglia monocultures were separated by a <1 mm space.ResultsOur data show that intracellular deposits of αSYN and Aβ are significantly reduced in co-cultures of astrocytes and microglia, compared to monocultures of either cell type. Analysis of conditioned medium and imaging data from the "close-culture" chamber experiments indicate that astrocytes secrete a high proportion of their internalized protein aggregates, while microglia do not. Moreover, co-cultured astrocytes and microglia are in constant contact with each other via tunneling nanotubes and other membrane structures. Notably, our live cell imaging data demonstrate that microglia, when attached to the cell membrane of an astrocyte, can attract and clear intracellular protein deposits from the astrocyte.ConclusionsTaken together, our data demonstrate the importance of astrocyte and microglia interactions in Aβ/αSYN clearance, highlighting the relevance of glial cellular crosstalk in the progression of AD- and PD-related brain pathology.

Dataset Information

SIRT1 facilitates amyloid beta peptide degradation by upregulating lysosome number in primary astrocytes.

Publications

SIRT1 facilitates amyloid beta peptide degradation by upregulating lysosome number in primary astrocytes.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure

Tweets