Involvement of Peroxiredoxin-3, Thioredoxin-2, and Protein Deglycase-1 in Cypermethrin-Induced Parkinsonism.

Owing to its lipophilic nature, cypermethrin makes entry into the brain through the blood-brain barrier and causes severe damage to the nigrostriatal dopaminergic neurons after prolonged exposure. Following substantial accrual in the brain, cypermethrin induces the abnormal expression and accumulation of α-synuclein. Besides, cytochrome P450 2E1 (CYP2E1) causes free radical generation leading to lipid peroxidation in toxicant-induced parkinsonism. Conversely, 4-hydroxynonenal (4-HNE), a byproduct of lipid peroxidation, is known to contribute to neuronal damage. The current investigation aimed to explicate the participation of endogenous redox-sensitive proteins in cypermethrin-induced cellular and animal models of parkinsonism. The qualitative and quantitative expressions of selected redox-sensitive proteins were evaluated employing the standard procedures. Cypermethrin reduced the expression of peroxiredoxin 3 (Prx3), thioredoxin 2 (Trx2), and protein deglycase-1 (DJ-1). Knocking down of Prx3, Trx2, or DJ-1 further reduced the level of expression in the cypermethrin-treated group. Reduction in the expression of Prx3, Trx2, or DJ-1 was found to be associated with overexpression of α-synuclein and 4-HNE modification of proteins. Besides, cypermethrin increased the expression of CYP2E1, which was not altered after Prx3 or Trx2 knockdown. However, knocking down the DJ-1 augmented the level of CYP2E1 both in the cypermethrin-treated group and its respective control. The outcomes of the study demonstrate that cypermethrin reduces the level of Prx3, Trx2, and DJ-1 proteins. While the reduction in the expression of selected redox-sensitive proteins leads to α-synuclein overexpression and 4-HNE modification of proteins, DJ-1 attenuation is also linked with increased CYP2E1 expression, which in turn could lead to oxidative stress-mediated neuronal damage.