Dataset Information

Increased Serum Beta-Secretase 1 Activity is an Early Marker of Alzheimer's Disease.

ABSTRACT:

Background

Beta-site APP cleaving enzyme 1 (BACE1) is the rate-limiting enzyme in amyloid-β (Aβ) plaques formation. BACE1 activity is increased in brains of patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) and plasma levels of BACE1 appears to reflect those in the brains.

Objective

In this work, we investigated the role of serum BACE1 activity as biomarker for AD, estimating the diagnostic accuracy of the assay and assessing the correlation of BACE1 activity with levels of Aβ1 - 40, Aβ1 - 42, and Aβ40/42 ratio in serum, known biomarkers of brain amyloidosis.

Methods

Serum BACE1 activity and levels of Aβ1 - 40, Aβ1 - 42, were assessed in 31 AD, 28 MCI, diagnosed as AD at follow-up (MCI-AD), and 30 controls. The BACE1 analysis was performed with a luciferase assay, where interpolation of relative fluorescence units with a standard curve of concentration reveals BACE1 activity. Serum levels of Aβ1 - 40, Aβ1 - 42 were measured with the ultrasensitive Single Molecule Array technology.

Results

BACE1 was increased (higher than 60%) in AD and MCI-AD: a cut-off of 11.04 kU/L discriminated patients with high sensitivity (98.31%) and specificity (100%). Diagnostic accuracy was higher for BACE1 than Aβ40/42 ratio. High BACE1 levels were associated with worse cognitive performance and earlier disease onset, which was anticipated by 8 years in patients with BACE1 values above the median value (> 16.67 kU/L).

Conclusion

Our results provide new evidence supporting serum/plasma BACE1 activity as an early biomarker of AD.

SUBMITTER: Nicsanu R

PROVIDER: S-EPMC9198762 | biostudies-literature | 2022

REPOSITORIES: biostudies-literature

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Publications

Increased Serum Beta-Secretase 1 Activity is an Early Marker of Alzheimer's Disease.

Nicsanu Roland R Cervellati Carlo C Benussi Luisa L Squitti Rosanna R Zanardini Roberta R Rosta Valentina V Trentini Alessandro A Ferrari Clarissa C Saraceno Claudia C Longobardi Antonio A Bellini Sonia S Binetti Giuliano G Zanetti Orazio O Zuliani Giovanni G Ghidoni Roberta R

Journal of Alzheimer's disease : JAD 20220101 1

<h4>Background</h4>Beta-site APP cleaving enzyme 1 (BACE1) is the rate-limiting enzyme in amyloid-β (Aβ) plaques formation. BACE1 activity is increased in brains of patients with Alzheimer's disease (AD) and mild cognitive impairment (MCI) and plasma levels of BACE1 appears to reflect those in the brains.<h4>Objective</h4>In this work, we investigated the role of serum BACE1 activity as biomarker for AD, estimating the diagnostic accuracy of the assay and assessing the correlation of BACE1 activ ...[more]

PMID: 35275540

Similar Datasets

Project description:BackgroundPolymorphisms in the gene for phosphatidylinositol binding clathrin assembly protein (PICALM), an endocytic-related protein, are associated with a small, increased risk of developing Alzheimer's disease (AD), strongly suggesting that changes in endocytosis are involved in the aetiology of the disease. We have investigated the involvement of PICALM in the processing of amyloid precursor protein (APP) to understand how PICALM could be linked to the development of AD. We used siRNA to deplete levels of PICALM, its isoforms and clathrin heavy chain in the human brain-derived H4 neuroglioma cell line that expresses endogenous levels of APP. We then used Western blotting, ELISA and immunohistochemistry to detect intra- and extracellular protein levels of endocytic-related proteins, APP and APP metabolites including β-amyloid (Aβ). Levels of functional endocytosis were quantified using ALEXA 488-conjugated transferrin and flow cytometry as a marker of clathrin-mediated endocytosis (CME).ResultsFollowing depletion of all the isoforms of PICALM by siRNA in H4 cells, levels of intracellular APP, intracellular β-C-terminal fragment (β-CTF) and secreted sAPPβ (APP fragments produced by β-secretase cleavage) were significantly reduced but Aβ40 was not affected. Functional endocytosis was significantly reduced after both PICALM and clathrin depletion, highlighting the importance of PICALM in this process. However, depletion of clathrin did not affect APP but did reduce β-CTF levels. PICALM depletion altered the intracellular distribution of clathrin while clathrin reduction affected the subcellular pattern of PICALM labelling. Both PICALM and clathrin depletion reduced the expression of BACE1 mRNA and PICALM siRNA reduced protein levels. Individual depletion of PICALM isoforms 1 and 2 did not affect APP levels while clathrin depletion had a differential effect on the isoforms, increasing isoform 1 while decreasing isoform 2 expression.ConclusionsThe depletion of PICALM in brain-derived cells has significant effects on the processing of APP, probably by reducing CME. In particular, it affects the production of β-CTF which is increasingly considered to be an important mediator in AD independent of Aβ. Thus a decrease in PICALM expression in the brain could be beneficial to slow or prevent the development of AD.

Dataset Information

Increased Serum Beta-Secretase 1 Activity is an Early Marker of Alzheimer's Disease.

Background

Objective

Methods

Results

Conclusion

Publications

Increased Serum Beta-Secretase 1 Activity is an Early Marker of Alzheimer's Disease.

Similar Datasets

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