Sharma N, Rao SP, Kalivendi SV. The deglycase activity of DJ-1 mitigates α-synuclein glycation and aggregation in dopaminergic cells: Role of oxidative stress mediated downregulation of DJ-1 in Parkinson's disease.
Free Radic Biol Med 2019;
135:28-37. [PMID:
30796974 DOI:
10.1016/j.freeradbiomed.2019.02.014]
[Citation(s) in RCA: 53] [Impact Index Per Article: 10.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/27/2018] [Revised: 02/13/2019] [Accepted: 02/13/2019] [Indexed: 12/20/2022]
Abstract
Parkinson's disease (PD) is a progressive neurodegenerative disorder associated with the degeneration of dopamine neurons of the substantia nigra pars compacta (SNpc) and the presence of intra-neuronal aggregates of α-synuclein and its post-translational products. Based on emerging reports on the association between glycated α-synuclein and PD; and the newly identified deglycase activity of DJ-1, we sought to find the relevance of deglycase activity of DJ-1 on glycation of α-synuclein and its plausible role in PD. Our results demonstrate that DJ-1 has a higher affinity towards the substrate methylglyoxal (MGO) (Km = 900 mM) as compared to its familial mutant, L166P (Km = 1900 mM). Also, CML α-synuclein (CML-syn) served as a substrate for the deglycase activity of DJ-1. Treatment of cells with Parkinsonian mimetic, 1-methyl-4-phenylpyridinium ion (MPP+); oxidants, such as H2O2 and methylglyoxal (MGO) lead to a dose-dependent decrease in the levels of DJ-1 with a concomitant increase in CML-syn. Also, MGO induced cytosolic α-synuclein aggregates in cells which stained positive with the anti-CML antibody. Further, unilateral stereotaxic administration of MGO into the SNpc of mice induced α-synuclein aggregates and CML-syn with a concomitant reduction in the number of TH positive neurons, protein levels of TH and DJ-1 at the site of injection. Interestingly, overexpression of DJ-1 enhanced the clearance of preformed CML-syn in cells, mitigated MGO induced CML-syn and intracellular α-synuclein aggregates. Overall, the findings of our present study demonstrate that DJ-1 plays a pivotal role in the glycation and aggregation of α-synuclein. Reduced DJ-1 activity due to mutations or oxidative stress may lead to the accumulation of glycated α-synuclein and its aggregates.
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