Matrix metalloproteinases-2 and -3 are reduced in cerebrospinal fluid with low beta-amyloid1–42 levels

Matrix metalloproteinases (MMPs), a family of extracellular soluble or membrane bound endopeptidases, are implicated in many physiological and pathophysiological functions—based on their capability to cleave all protein components of the extracellular matrix. Recent studies have implicated several forms of MMPs in chronic neurodegenerative diseases like Alzheimer's disease (AD), vascular dementia (VD), and Parkinson's disease (PD). The aim of the present study was to analyse eight MMPs (MMP-1, -2, -3, -7, -8, -9, -10, -13) in the human cerebrospinal fluid (CSF) and to correlate with the well established biomarkers beta-amyloid1–42 (Aβ), total-tau and phospho-tau-181. Our data show a significant decrease of MMP-2 and MMP-3 levels in the CSF in samples with significantly reduced Aβ levels. It is concluded that MMP-2 and MMP-3 are directly linked to Aβ in the brain and a dysfunction may influence the processing of Aβ.