Serum proteomics in amnestic mild cognitive impairment

Area of Science:

• Biochemistry
• Neuroscience
• Proteomics

Background:

• Mild cognitive impairment (MCI) is a transitional stage between normal aging and dementia.
• Biomarkers for early MCI detection are crucial for timely intervention.
• Serum proteome analysis offers a minimally invasive approach to identify potential biomarkers.

Purpose of the Study:

• To identify differentially expressed proteins in the serum of individuals with amnestic MCI compared to healthy controls.
• To validate potential protein biomarkers for MCI diagnosis using quantitative assays.
• To develop a diagnostic model based on identified protein biomarkers.

Main Methods:

• Serum samples from 35 amnestic MCI patients and 35 healthy controls were analyzed using liquid chromatography-mass spectrometry (LC-MS).
• Differentially expressed proteins were quantified using a multiple reaction monitoring (MRM) assay.
• A diagnostic model was developed using the most significant protein markers.

Main Results:

• 108 differentially expressed peptides, belonging to 39 proteins, were identified between MCI patients and controls.
• Significantly decreased serum levels of carboxypeptidase N subunit 2, complement factor B (CFAB), galectin-3 binding protein (LG3BP), serum amyloid A-4 protein (SAA4), and serum amyloid P-component were observed in MCI patients.
• A model using CFAB, LG3BP, and SAA4 achieved 73% sensitivity and 66% specificity in the initial set, with 77% sensitivity and 75% specificity in an external validation set.

Conclusions:

• Specific serum proteins, notably CFAB, LG3BP, and SAA4, are significantly decreased in amnestic MCI.
• These proteins show promise as potential biomarkers for the early detection of MCI.
• Further validation is warranted to establish their clinical utility in diagnosing MCI.