Effects of ApoE isoforms on beta-amyloid-induced matrix metalloproteinase-9 in rat astrocytes

Matrix metalloproteinase-9 (MMP-9) may play a role in the inflammatory glial response during Alzheimer's disease (AD). Astrocytes can degrade beta-amyloid (A beta) and extracellular proteolysis via MMP-9 may be involved. Because Apolipoprotein E (APOE) genotype is an important factor for AD, we ask whether various apoE isoforms can influence A beta-induced MMP-9 responses in primary rat astrocytes. Our data show that apoE4 significantly dampens A beta-induced MMP-9 levels, possibly by downregulating the Rho-Rho kinase (ROCK) pathway. Reduction of astrocytic MMP-9 by apoE4 may affect A beta clearance and promote A beta deposition in AD. (c) 2006 Elsevier B.V. All rights reserved.