Early changes in extracellular matrix in Alzheimer's disease

Area of Science:

• Neuroscience
• Biochemistry
• Pathology

Background:

• Extracellular matrix (ECM) composition changes in Alzheimer's disease (AD) are known, but perivascular ECM alterations across disease stages remain unclear.
• Investigating basement membrane-associated ECM molecules is crucial for understanding AD pathogenesis.

Purpose of the Study:

• To investigate changes in perivascular ECM components in relation to increasing Braak stages in Alzheimer's disease.
• To correlate ECM alterations with amyloid plaque deposition and microvessel density.

Main Methods:

• Quantification of collagen IV, perlecan, fibronectin, and human platelet endothelial cell adhesion molecule (hPECAM) via immunohistochemistry in control, subclinical AD, and AD patient groups.
• Assessment of vessel density using Von Willebrand factor staining.
• Correlation analysis with Braak stages and amyloid deposition.

Main Results:

• Increased expression of collagen IV, perlecan, and fibronectin in the frontal and temporal cortex of subclinical AD and AD patients compared to controls.
• No further increase in ECM components between subclinical and clinical AD.
• Decreased vessel density in the temporal cortex of AD patients, with no change in hPECAM levels.
• ECM component changes correlated significantly with amyloid deposition across Braak stages.

Conclusions:

• Significant extracellular matrix alterations occur in the early stages of Alzheimer's disease.
• These ECM changes may influence brain microvascular function and disease progression.
• Perivascular ECM components show potential as early diagnostic biomarkers for AD.