Cell surface proteoglycan-mediated uptake and accumulation of the Alzheimer's disease peptide Aβ(1–42)
Journal article, 2018

Proteoglycans (PGs) have been found in Alzheimer's disease amyloid-β(Aβ) plaques and their glycosaminoglycan chains reportedly influence Aβ aggregation, neurotoxicity and intracellular accumulation in cell and animal models, but their exact pathophysiological role(s) remain unclear. We have studied the cellular uptake of fluorescently labelled Aβ(1–42) and Aβ(1–40) peptides in normal CHO cells (K1) and the mutant cell line (pgsA-745) which lacks all protein-attached heparan and chondroitin sulfate chains. After 24 h of incubation, CHO-K1 accumulates more Aβ(1–42) and Aβ(1–40) compared with CHO-pgsA-745, consistent with the suggested role of PGs in Aβ uptake. However, after short incubation times (≤3 h) there was no difference; moreover, the time evolution of Aβ(1–42) accumulation in CHO-K1 followed an unusual sigmoidal-like trend, indicating a possible involvement of PG-mediated peptide aggregation in Aβ endocytosis. Neither Aβ(1–42) nor Aβ(1–40) could stimulate uptake of a 10 kDa dextran (a general endocytosis marker) suggesting that Aβ-induced upregulation of endocytosis does not occur. CHO-K1 cells contained a higher number of Aβ(1–42)-positive vesicles, but the intensity difference per vesicle was only marginal suggesting that the superior accumulation of Aβ(1–42) stems from a higher number of endocytic events. FRET imaging support that intracellular Aβ(1–42) is aggregated in both cell types. We also report that CHO-pgsA-745 cells perform less endocytosis than CHO-K1 and, albeit this does not explain their difference in Aβ internalisation, we discuss a general method for data compensation. Altogether, this study contributes new insights into the mechanisms of PG-mediated Aβ uptake that may be relevant for our understanding of their role in AD pathology.

Alzheimer's disease

chinese hamster ovary cells

cell surface proteoglycan

protein aggregation

endocytosis

amyloid-β

Author

Emelie Vilhelmsson Wesén

Chalmers, Biology and Biological Engineering, Chemical Biology

Audrey Gallud

Chalmers, Biology and Biological Engineering, Chemical Biology

Alexandra Paul

Chalmers, Biology and Biological Engineering, Chemical Biology

David Lindberg

Chalmers, Biology and Biological Engineering, Chemical Biology

Per Malmberg

Chalmers, Chemistry and Chemical Engineering, Chemistry and Biochemistry

Elin Esbjörner Winters

Chalmers, Biology and Biological Engineering, Chemical Biology

Biochimica et Biophysica Acta - Biomembranes

0005-2736 (ISSN)

Vol. 1860 11 2204-2214

Subject Categories

Cell Biology

Cell and Molecular Biology

Biophysics

Medical Biotechnology (with a focus on Cell Biology (including Stem Cell Biology), Molecular Biology, Microbiology, Biochemistry or Biopharmacy)

Roots

Basic sciences

Areas of Advance

Life Science Engineering (2010-2018)

DOI

10.1016/j.bbamem.2018.08.010

More information

Latest update

12/10/2018