Funded Studies
Objective/Rationale:
Mutations in the DJ-1 gene are associated with an early-onset familial form of PD and DJ-1 protein has been shown to be decreased in the CSF of sporadic PD compared to controls. DJ-1 protects nerve cells against oxidative stress. Oxidative stress has been implicated in the pathogenesis of PD. Oxidized DJ-1 may be a more sensitive biomarker for oxidative stress associated with the development and progression of PD. The goals of this study are: 1) To develop new methods for routine detection of the oxidized forms of DJ-1; and 2) To test preliminary feasibility of whether oxidized DJ-1 can be used as a biomarker for PD onset and progression.
Project Description:
We will take several parallel approaches. First, we will determine if a newly identified chemical modification strategy can be used to detect the mildest oxidation form of DJ-1. Secondly, we will adapt a well characterized protein carbonyl detection system for detection of the other forms of DJ-1 oxidation. Third, in conjunction with colleagues at Covance, we will develop polyclonal antibodies for the specific detection of the highest oxidation form of DJ-1.
Relevance to Diagnosis/Treatment of Parkinson’s Disease:
The identification of these biomarkers for PD has the potential to monitor PD progression, which will improve patient care by providing a metric for treatment efficacy. In addition, PD biomarkers facilitate the drug discovery process and aid in the recruitment and performance of clinical trials.
Anticipated Outcome:
Successful completion of the goals of this project will result in the development of new tools for detection of oxidized DJ-1 and the application of these tools to determine if oxidized DJ-1 is a biomarker for PD. As DJ-1 may play an important role in PD pathogenesis, new tools for detecting oxidized DJ-1 may also contribute to an improved understanding of PD.
Final Outcome
Mutations in the DJ-1 gene are causal for an early-onset form of PD. DJ-1 protects nerve cells against oxidative stress. Oxidization of the cysteine residues in DJ-1 occurs as a consequence oxidative stress, but is also necessary to fully activate DJ-1 function.
Oxidized DJ-1, or the ratio of oxidized to total DJ-1, may be a sensitive biomarker for oxidative stressassociated with the onset and progression of PD and other neurological diseases.
Currently, the extent of DJ-1 oxidation is determined by physiochemical means which poses a practical limitation for routine analysis in blood and CSF. In these studies we developed polyclonal antibodies that detect the highest oxidized form of DJ-1. We have established that the antibodies are specific and sensitive tools for the detection of oxidized DJ-1. We have applied these tools to the detection of oxidized DJ-1 in RBC lysates from PD patients and control subjects. We have established the presence of oxidized DJ-1 in RBC lysates and determined that oxidized DJ-1 is present in sufficient abundance to warrant further biomarker assay development.