Alzheimer’s
disease (AD) is associated with a progressive accumulation of senile plaques
(containing β-amyloid (Aβ)) and neurofibrillary tangles, but the underlying
pathology is still, to a large extent, a mystery. Nevertheless, there is growing
evidence that matrix metalloproteinases (MMPs), molecules produced by neurons and glial
cells, may play an important, but complex, role. 

In an article
published last week in Alzheimer’s
Research & Therapy, Stomrud and colleagues examined MMP, tissue inhibitor of
metalloproteinase-1 (TIMP-1), Aβ and
tau protein levels in the cerebrospinal fluid (CSF) of Alzheimer’s patients and
found that compared to individuals with no cognitive dysfunction, AD patients
had higher CSF levels of certain MMPs. Interestingly, cognitively healthy
individuals with risk markers for the future, such as the presence of the APOE-ε4 allele,
also had higher MMP levels when compared to healthy individuals with no risk
markers.

The
results indicate that MMPs could be associated with neuronal degeneration, even
in individuals who are yet to develop any evident cognitive dysfunction.