The etiologies of aging, inflammation and neurodegenerative diseases, have all (with varying degrees of certitude) been associated with increased exposure to reactive oxygen species (ROS) and/or reactive nitrogen species (RNS). We have developed a cell-based model of nitrosative stress and showed that protein disulfide isomerase (PDI) is negatively regulated by S-glutathionylation. PDI is the most abundant protein in the endoplasmic reticulum (ER) and facilitates the protein folding process. Three signaling pathways collectively referred to as the unfolded protein response (UPR) have evolved to ensure that misfolded or unfolded proteins do not accumulate in the ER. Excess or prolonged ER stress leads to apoptosis. As such, ER stress and activation of the UPR are associated with a wide variety of disease pathologies. Our current understanding of the UPR begins with sensing the accumulation of misfolded proteins. The cellular malfunction that directly leads to impairment of the protein folding capacity of the cell is not yet fully defined. The central hypothesis is that Sglutathionylation of PDI contributes to, and may even be sufficient for, the induction of ER stress and may concomitantly lead to apoptosis.
Four aims are proposed to 1) Identify target cysteine residues in PDI that are S-glutathionylated following oxidative and nitrosative stress; 2) Determine the consequence of S-glutathionylation on PDI structure/function; 3) Elucidate the role of Sglutathionylation of PDI in the UPR; and 4) To determine the inherent changes in PDI and progressive loss of dopamine neurons in drug-induced and genetic models of PD and evaluate the therapeutic efficacy of NOV-002, a glutathione disulfide mimetic. The connection between S-glutathionylation of PDI and initiation of this cascade is important. There is compelling evidence suggesting that ER-stress contributes to neuronal cell death and ultimately the clinical manifestations of neurodegenerative diseases. Neuronal cells have an enriched ER and will provide an excellent model to study both ER stress and to define molecular targets of ROS/RNS.
Reactive oxygen and nitrogen species (ROS and RNS) are frequently present as environmental toxicants and contribute to human disease states as divergent as neurodegenerative diseases, inflammation and cancer. Protein disulfide isomerase (PDI) is important in facilitating accurate folding of proteins and is a molecular target of RNS. We have generated an exciting link between RNS associated stress, PDI and the unfolded protein response (UPR) that will provide innovative contributions at the interface of human diseases the etiologies of which are associated with aberrant protein folding.
| Pulkoski-Gross, Michael J; Uys, Joachim D; Orr-Gandy, K Alexa et al. (2017) Novel sphingosine kinase-1 inhibitor, LCL351, reduces immune responses in murine DSS-induced colitis. Prostaglandins Other Lipid Mediat 130:47-56 |
| Manuel, Allison M; Walla, Michael D; Faccenda, Adam et al. (2017) Succination of Protein Disulfide Isomerase Links Mitochondrial Stress and Endoplasmic Reticulum Stress in the Adipocyte During Diabetes. Antioxid Redox Signal 27:1281-1296 |
| Qanungo, Suparna; Uys, Joachim D; Manevich, Yefim et al. (2014) N-acetyl-L-cysteine sensitizes pancreatic cancers to gemcitabine by targeting the NF?B pathway. Biomed Pharmacother 68:855-64 |
| Townsend, Danyelle M; Lushchak, Volodymyr I; Cooper, Arthur J L (2014) A comparison of reversible versus irreversible protein glutathionylation. Adv Cancer Res 122:177-98 |
| Zhang, Jie; Grek, Christina; Ye, Zhi-Wei et al. (2014) Pleiotropic functions of glutathione S-transferase P. Adv Cancer Res 122:143-75 |
| Uys, Joachim D; Mulholland, Patrick J; Townsend, Danyelle M (2014) Glutathione and redox signaling in substance abuse. Biomed Pharmacother 68:799-807 |
| Grek, C; Townsend, D M (2014) Protein Disulfide Isomerase Superfamily in Disease and the Regulation of Apoptosis. Endoplasmic Reticulum Stress Dis 1:4-17 |
| Tew, Kenneth D; Townsend, Danyelle M (2011) Regulatory functions of glutathione S-transferase P1-1 unrelated to detoxification. Drug Metab Rev 43:179-93 |
| Uys, Joachim D; Xiong, Ying; Townsend, Danyelle M (2011) Nitrosative stress-induced S-glutathionylation of protein disulfide isomerase. Methods Enzymol 490:321-32 |
| Goetzl, Laura; Manevich, Yefim; Roedner, Chantel et al. (2010) Maternal and fetal oxidative stress and intrapartum term fever. Am J Obstet Gynecol 202:363.e1-5 |
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