Elevated interleukin-1β induced by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine aggravating dopaminergic neurodegeneration in old male mice

IL-1β is a potent pro-inflammatory cytokine that regulates neuroinflammation during brain damage. The expression of IL-1β has been reported to be elevated in the striatum and substantia nigra of patients with Parkinson's disease (PD). Moreover, greater prevalence of PD in men than in women is described previously. Here, by using a sensitive mice model in which the expression of luciferase reporter gene is under the control of human IL-1β gene promoter, we examined IL-1β gene expression pattern in vivo after subacute MPTP toxication in old male and female mice and found that MPTP elicited greater dopaminergic toxicity in old male than in female mice. Old male mice showed dramatically elevated luciferase signals in a flexuous manner at early period of time, meanwhile, the changes in female were more moderate. However, no significant difference in astroglial reaction was observed at later time point between sexes. In conclusion, the present study demonstrated that elevated IL-1β gene expression at early period of time may be in part responsible for the DA neuron susceptibility to MPTP in old male mice.