Figure 7.

Lipid droplets in glia have a protective antioxidant role. (A) Glia–neuron lipid cycle in adult flies. During the day neurons are active and produce ROS that trigger the synthesis of lipids. These become peroxidated by ROS and are exported to glia. In glia, peroxidated lipids are sequestered into LDs (preventing chain reactions and further damage) during the day (when flies are awake) and then are broken down and re-exported at night (when flies sleep). Thus, glia detoxify incoming peroxidated lipids and convert them into energy-producing molecules that are exported back to neurons [67]. (B) Hypothetical glia–NB cycle in wild-type larvae. A metabolic cycle (like the one described above) protects the cells from oxidative stress and sustains their metabolic needs. PER expression in glia is necessary to maintain mitochondrial function and LDs turnover (C) Hypothetical glia–NB interactions in per⁰ larvae. Absence of PER breaks the protective lipid cycle, resulting in high levels of ROS, mitochondrial dysfunction, changes in chromatin structure and chromosome damage.