Increased CSF-decorin predicts brain pathological changes driven by Alzheimer’s Aβ amyloidosis

Richeng Jiang, Una Smailovic, Hazal Haytural, Betty M. Tijms, Hao Li, Robert Mihai Haret, Ganna Shevchenko, Gefei Chen, Axel Abelein, Johan Gobom, Susanne Frykman, Misaki Sekiguchi, Ryo Fujioka, Naoto Watamura, Hiroki Sasaguri, Sofie Nyström, Per Hammarström, Takaomi C. Saido, Vesna Jelic, Stina SyvänenHenrik Zetterberg, Bengt Winblad, Jonas Bergquist, Pieter Jelle Visser, Per Nilsson

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10 Citations (Scopus)

Abstract

Cerebrospinal fluid (CSF) biomarkers play an important role in diagnosing Alzheimer’s disease (AD) which is characterized by amyloid-β (Aβ) amyloidosis. Here, we used two App knock-in mouse models, AppNL-F/NL-F and AppNL-G-F/NL-G-F, exhibiting AD-like Aβ pathology to analyze how the brain pathologies translate to CSF proteomes by label-free mass spectrometry (MS). This identified several extracellular matrix (ECM) proteins as significantly altered in App knock-in mice. Next, we compared mouse CSF proteomes with previously reported human CSF MS results acquired from patients across the AD spectrum. Intriguingly, the ECM protein decorin was similarly and significantly increased in both AppNL-F/NL-F and AppNL-G-F/NL-G-F mice, strikingly already at three months of age in the AppNL-F/NL-F mice and preclinical AD subjects having abnormal CSF-Aβ42 but normal cognition. Notably, in this group of subjects, CSF-decorin levels positively correlated with CSF-Aβ42 levels indicating that the change in CSF-decorin is associated with early Aβ amyloidosis. Importantly, receiver operating characteristic analysis revealed that CSF-decorin can predict a specific AD subtype having innate immune activation and potential choroid plexus dysfunction in the brain. Consistently, in AppNL-F/NL-F mice, increased CSF-decorin correlated with both Aβ plaque load and with decorin levels in choroid plexus. In addition, a low concentration of human Aβ42 induces decorin secretion from mouse primary neurons. Interestingly, we finally identify decorin to activate neuronal autophagy through enhancing lysosomal function. Altogether, the increased CSF-decorin levels occurring at an early stage of Aβ amyloidosis in the brain may reflect pathological changes in choroid plexus, present in a subtype of AD subjects.
Original languageEnglish
Article number96
JournalActa Neuropathologica Communications
Volume10
Issue number1
DOIs
Publication statusPublished - 1 Dec 2022

Keywords

  • Alzheimer’s disease
  • Amyloid-β (Aβ)
  • App knock-in mice
  • Autophagy
  • Cerebrospinal fluid
  • Choroid plexus
  • Decorin
  • Extracellular matrix
  • Mass spectrometry

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