The preclinical evaluation of novel remyelinating therapies for diseases such as multiple sclerosis relies on the use of the cuprizone intoxication model. Mice fed the copper chelator, cuprizone, develop focal areas of demyelination accompanied by the loss of mature myelin-producing oligodendrocytes. These lesions have been proposed to mimic plaques found in multiple sclerosis patients, making this animal model a valuable preclinical test for neuroprotective therapies. Despite its widespread use, the mechanism by which cuprizone treatment leads to oligodendrocyte death is still unknown. In addition, the biotransformation and metabolism of cuprizone has not been elucidated. We propose to examine the mechanisms of toxicity and copper binding by using advanced chemical approaches.
The first aim of this proposal evaluates cuprizone-mediated perturbations in cellular physiology by using global metabolomic profiling. We will also determine the metabolism of cuprizone and copper-bound cuprizone in cells by using stable isotope labeling coupled with mass spectrometry and NMR.
Aim 2 will extend the metabolic studies to cuprizone-fed mice. We will examine early time points in order to identify oligodendrocyte-specific pathways important for cell survival and their relationship to copper metabolism. Finally in Aim 3, we will use X-ray crystallography, mass spectrometry, and EPR spectroscopy to determine the structure of copper-bound cuprizone and cuprizone complexed to small molecule mimics of copper binding sites. At the conclusion of this project, we will have better defined the mechanism by which cuprizone exerts its selective toxicity for oligodendrocytes, established a platform for the evaluation of chelating agents and biological systems, and provided undergraduates with training in common techniques used for the preclinical evaluation of new drug compounds.
The neurotoxin and copper chelator, cuprizone, has been used for over fifty years as a preclinical model of multiple sclerosis. Despite its widespread use in the evaluation of new remyelinating therapies, the mechanism of toxicity remains poorly understood. This project uses a multi-dimensional approach that combines global metabolomic profiling with chemical analysis of cuprizone?s structure and copper affinity to investigate how cuprizone induces selective death of mature oligodendrocytes. We hope to establish a high through-put platform to evaluate metal chelators as well as uncover novel aspects of copper metabolism that are important for oligodendrocyte survival.
| Taraboletti, Alexandra; Walker, Tia; Avila, Robin et al. (2017) Cuprizone Intoxication Induces Cell Intrinsic Alterations in Oligodendrocyte Metabolism Independent of Copper Chelation. Biochemistry 56:1518-1528 |
