Increased sensitivity to MPTP in human α-synuclein A30P transgenic mice

In addition to genetic factors, environmental factors have long been suspected to contribute to the pathogenesis of Parkinson's disease (PD). We investigated the possible interaction between genetic factors and neurotoxins by testing whether α-synuclein A30P Tg5093 transgenic mice show increased sensitivity to secondary toxic insults like 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) or rotenone. While sensitivity to chronic treatment with rotenone was not enhanced in the Tg5093 line, chronic treatment with 80 or 150 mg/kg MPTP resulted in increased deterioration of the nigrostriatal dopaminergic system as assessed by quantitation of nigral tyrosine hydroxylase (TH) positive neurons and striatal dopamine (DA) levels in Tg5093 mice when compared to non-transgenic littermate controls. Thus, the results of this study demonstrate a role for the overexpression of mutant human α-synuclein A30P in increased vulneravility of DA neurons to MPTP.