Interleukin-1β contributes to dopaminergic neuronal death induced by lipopolysaccharide-stimulated rat glia in vitro

Inflammation is involved in the pathology of Parkinson's disease, a disorder characterised by degeneration of dopaminergic neurons. This study demonstrates that conditioned medium (CM) from lipopolysaccharide (LPS)-treated rat glial-enriched cortical cultures induced death of embryonic rat dopaminergic neurons in vitro, an effect which was additive to the toxicity of the neurotoxin 6-hydroxydopamine. Interleukin-1β (IL-1β) in the CM may mediate this neuronal death. IL-1R1 was found to be expressed on dopaminergic neurons. Blockade of IL-1R1 prevented CM-induced dopaminergic neuronal death. This study suggests that IL-1β in CM from LPS-stimulated glia contributes to dopaminergic neuronal death induced by glia-conditioned medium.