Oxidative Stress Modulates Apoptotic Substrate Phagocytosis by Primary Rat Astrocytes

Abstract

Brain astrocytes are commonly believed to be relatively tolerant to oxidative stress. In this work, we studied the effect of oxidative stress on the ability of rat brain astrocytes in primary culture to clean apoptotic substrates. Using fluorescent microscopy, we demonstrated that the ingestion of rat retinal rod outer segments (ROS), used here as a phagocytic substrate, dramatically decreased in astrocytes preincubated with various hydroperoxides. The ability of primary astrocytes to ingest ROS also depended on the substrate oxidative status. The ingestion of “oxidized” ROS preparations preincubated with hydrogen peroxide was sharply reduced compared to “non-oxidized” ROS. We also showed that natural and synthetic antioxidants (α-tocopherol, Trolox) efficiently protected the phagocytic function of astrocytes from oxidative damage. These data suggest that the phagocytic function of rat brain primary astrocytes is extremely vulnerable to oxidative stress, while oxidative stress tolerance characterizes not all functions of these glial cells.