Selective distribution of matrix metalloproteinase-3 (MMP-3) in Alzheimer's disease brain

A growing amount of evidence indicates that matrix metalloproteinases (MMPs ) may play an important role in the pathogenesis of Alzheimer's disease (AD ). Stromelysin-1 (MMP-3) plays a central role in activating latent-type MMP s, which are originally secreted as preen zymes. We examined MMP-3 immunore activity in the brains of patients who had suffered from Alzheimer's diseas e and in those of neurologically normal persons. The interstitium between m yelinated axons and astrocytes in the white matter of all brain tissues, an d senile plaques in the gray matter of the patients with AD were stained wi th a monoclonal antibody to MMP-3. Comparison of the number of senile plaqu es stained with the antibody against MMP-3 in the parietal cortex with that in the hippocampus showed that fewer plaques were stained in the hippocamp us. The selective distribution of MMP-3 in the human brain suggests that MM P-3 might play an important role in the pathogenesis of AD, especially in t he degradation of beta-amyloid protein.