The fumarate ester dimethyl fumarate (DMF) has been introduced recently as a treatment for relapsing remitting multiple sclerosis (RRMS), a chronic inflammatory condition that results in neuronal demyelination and axonal loss. DMF is known to act by depleting intracellular glutathione and modifying thiols on Keap1 protein, resulting in the stabilization of the transcription factor Nrf2, which in turn induces the expression of antioxidant response element genes. We have previously shown that DMF reacts with a wide range of protein thiols, suggesting that the complete mechanisms of action of DMF are unknown. Here, we investigated other intracellular thiol residues that may also be irreversibly modified by DMF in neurons and astrocytes. Using mass spectrometry, we identified 24 novel proteins that were modified by DMF in neurons and astrocytes, including cofilin-1, tubulin and collapsin response mediator protein 2 (CRMP2). Using an in vitro functional assay, we demonstrated that DMF-modified cofilin-1 loses its activity and generates less monomeric actin, potentially inhibiting its cytoskeletal remodeling activity, which could be beneficial in the modulation of myelination during RRMS. DMF modification of tubulin did not significantly impact axonal lysosomal trafficking. We found that the oxygen consumption rate of N1E-115 neurons and the levels of proteins related to mitochondrial energy production were only slightly affected by the highest doses of DMF, confirming that DMF treatment does not impair cellular respiratory function. In summary, our work provides new insights into the mechanisms supporting the neuroprotective and remyelination benefits associated with DMF treatment in addition to the antioxidant response by Nrf2.
|Number of pages||16|
|Journal||Molecular and Cellular Proteomics|
|State||Published - Mar 2019|
Bibliographical noteFunding Information:
* This work was supported by the University of South Carolina Research Foundation ASPIRE-I award and the National Institutes of Health (R01 NS092938, R03 HD077187, R56 DK105087, P20 GM109091, F31 DK108559). □S This article contains supplemental Figures. ‖ To whom correspondence should be addressed: Department of Pharmacology, Physiology & Neuroscience, School of Medicine, University of South Carolina, 6439 Garners Ferry Road, Columbia, SC 29209. Tel.: (803) 216-3521; Fax: (803) 216-3538; E-mail: norma. firstname.lastname@example.org. ** These authors contributed equally to this work.
© 2019 Piroli et al.
ASJC Scopus subject areas
- Analytical Chemistry
- Molecular Biology