Differential ROS production in non‐neuronal brain cell subsets in response to Methamphetamine

Abstract

The production of Reactive Oxygen Species (ROS) leads to neurodegeneration in Meth abusers. We examined the contribution of ROS from non‐neuronal cells that affect local immunity and neuron survival in the brain. Using astrocyte (C8S), microglia (BV2) and macrophage (THP1) cell lines we show direct and differential effects of Meth on ROS pathways. Basal levels of H2O2 from macrophages and microglia (MM) were higher than those released by astrocytes. Meth reduced H2O2 in MM, but increased it in astrocytes, in a dose‐dependent manner. Rotenone, Superoxide Dysmutase and Antimycin A further reduced ROS in MM but increased it in astrocytes. This indicates that 1) mitochondria are important sources of H2O2 in MM, 2) superoxide is released to the extracellular space by astrocytes and 3) astrocytes have more tightly coupled mitochondria. In the presence of PMA, Meth highly exacerbated H2O2 production in astrocytes (> 400%) in a dose‐dependent manner, but MM cells produced less H2O2 at higher Meth dose. This indicates 4) a role of Meth downstream of the PKC feedback‐activation of NADPH oxidase (NOX) in astrocytes, and not in MM. Our data suggest that Meth directly enhances NOX‐generated ROS in astrocytes and reduces mitochondrial ROS in all cells, in an environment that excludes dopaminergic influence.