Norepinephrine stimulates protein synthesis in astrocytes

Norepinephrine is a neuromodulator that can activate multiple subcellular signalling pathways to regulate various physiological responses in different cell types. In astrocytes, it is known to have a wide range of metabolic effects, including regulation of glucose uptake and glycolysis, glycogen breakdown and lactate production. Here we report that norepinephrine stimulates protein synthesis in rat primary cortical astrocytes and the C6 glioma cell line. The mTOR-pS6K pathway is engaged during the norepinephrine-mediated induction of protein synthesis, which is abolished by mTOR inhibition and appears to be mediated mainly by β-adrenergic receptors. We show that blocking glycolysis with 2-deoxy-D-glucose inhibits both basal and norepinephrine-induced translation in astrocytes. Finally, we demonstrate that the norepinephrine-mediated increase in protein synthesis is preceded by a decrease in astrocytic ATP levels. Our results reveal a novel regulatory role for norepinephrine in the central nervous system, tightly controlling protein synthesis in astrocytes.