Oxidized lipoproteins increase reactive oxygen species formation in microglia and astrocyte cell lines

Lipoproteins exist in the central nervous system and surrounding vasculature possibly mediating effects upon cells in the brain during times of oxidative stress or compromised blood-brain barrier. The focus of the present study was to determine the effect of unmodified and oxidatively modified lipoproteins on astrocytes and microglia. Application of oxidized low-density lipoprotein resulted in an increase in DCF fluorescence, which was inhibited by pretreatment with antioxidants, consistent with the formation of reactive oxygen species (ROS). Low-density at concentrations below 20 mu g/ml likewise increased ROS formation. Because ROS are associated with numerous astrocyte and microglia activities including proliferation, activation, and cytokine production it is possible that lipoproteins may mediate such effects on glial cells in the central nervous system. (C) 1999 Elsevier Science B.V. All rights reserved.