Neopterin and cytokines in hereditary dystonia and Parkinson's disease

Abstract

Both neopterin and biopterin concentrations in cerebrospinal fluid from patients with Parkinson's disease, in which the nigrostriatal dopamine neurons degenerate, were lower than those from age-matched older control subjects. However, the decrease in biopterin was more marked than that in neopterin, resulting in the increase in the neopterin/biopterin ratio in Parkinson's disease. These results suggests that neopterin in cerebrospinal fluid in Parkinson's disease may partly be derived from immunoactivated glial cells, besides catecholaminc or serotonin neurons including nigrostriatal dopamine neurons. In accordance to this hypothesis, cytokines (TNF-α, IL- 1β, IL-2, IL-6, EGF, TGF-α, TGF-β1) were found to be increased in the striatum and/or in cerebrospinal fluid. The increment of cytokines in the brain in Parkinson's disease may be related to the mechanism of neurodegeneration of dopaminergic neurons in Parkinson's disease. In contrast to Parkinson's disease, in hereditary progressive dystonia/dopa-responsive dystonia, which is a dopamine deficiency caused by mutations in GTP cyclohydrolase I without neuronal cell death (Segawa's disease), neopterin and biopterin in cerebrospinal fluid decreases in parallel owing to the decreased activity in GTP cyclohydrolase I.