Cocaine activates redox-regulated transcription factors and induces TNF-α expression in human brain endothelial cells

Abstract

Cocaine abuse is frequently associated with cerebrovascular pathology. Although the cellular and molecular mechanisms of these alterations are not fully understood, they may involve oxidative injury or dysfunction of brain microvascular endothelial cells. To test this hypothesis, total glutathione levels, activation of nuclear factor-κB (NF-κB) and activator protein-1 (AP-1), as well as induction of the TNF-α gene expression were determined in human brain microvascular endothelial cells (HBMEC) exposed to cocaine. Exposure of HBMEC to cocaine resulted in a dose-dependent depletion of total glutathione levels. In addition, cocaine markedly activated redox-regulated transcription factors, NF-κB and AP-1. Activation of these transcription factors was accompanied by induction of AP-1- or NF-κB-dependent transcription, as measured by dual luciferase assay in HBMEC transfected with the AP-1- or NF-κB-responsive reporter constructs. Furthermore, HBMEC treatment with cocaine induced a dose-dependent expression of the tumor necrosis factor-α (TNF-α) gene. These results indicate that exposure to cocaine can trigger inflammatory pathways via activation of redox-sensitive transcription factors and induction of expression of the inflammatory genes in HBMEC. These events may contribute to the cerebrovascular insults observed in cocaine-abused patients.