Proteomic Analysis of Demyelinated and Remyelinating Brain Tissue following Dietary Cuprizone Administration

Abstract

Cuprizone intoxication is a commonly used model of demyelination that allows the temporal separation of demyelination and remyelination. The underlying biochemical alterations leading to demyelination, using this model, remain unclear and may be multifold. Analysis of proteomic changes within the brains of cuprizone-exposed animals may help elucidate key cellular processes. In the current study, we report the results of the liquid chromatography tandem mass spectrometry analysis of total protein from the brain hemispheres of control and toxin-exposed mice at 6 weeks of exposure and after 3 and 6 weeks of recovery to identify protein changes during the remyelination phase. We found that at 6 weeks of cuprizone exposure, myelin proteins were reduced compared to controls and increased throughout the course of recovery, as expected. In contrast, other protein groups, such as proteins related to mitochondrial function, were increased at 6 weeks of treatment compared to untreated controls and returned toward control levels following withdrawal of toxin. These results suggest that a global proteomic analysis of the brain tissue of cuprizone-treated mice can identify changes related to the demyelination/remyelination process.

An initial top-down proteomic analysis of the standard cuprizone mouse model of multiple sclerosis

“…As such, we identified only the protein species that were 100 % altered in abundance between the cuprizone treatment and the control (Table 2); these correspond to the most dramatic alterations and as such are a rational starting point for analysis. While some of these pronounced alterations in abundance correspond to proteins also identified in a previous study [21], overall, the majority of proteins identified in the earlier study do not overlap with the current findings. Notably, eight cortex protein species identified as being altered in the cuprizone model in our study were not identified in the previous study.…”

“…To our knowledge, only one previous proteomic analysis has been carried out on the cuprizone model; this 'shotgun' study (i.e. as opposed to a top-down approach used here) identified protein changes of ≥1.5-fold Figures given are mean±SEM All identified proteins were from Mus musculus + Detectable in cuprizone treatment − Not detectable in cuprizone treatment MP membrane protein fraction, SP soluble protein fraction, T total protein fraction, MW molecular weight and only in the mouse brain [21]. However, here, we only examined protein species that met the criterion of all-or-none change.…”

Recovery of Behavioral Changes and Compromised White Matter in C57BL/6 Mice Exposed to Cuprizone: Effects of Antipsychotic Drugs

“…Therefore, a correlation between white matter damage and certain behavioral abnormalities in the CPZ-treated mice is suggested. Moreover, this animal model allowed us to correlate the behavioral dynamics in CPZ-withdrawn mice with the status of white matter anomalies during a recovery period, since remyelination happens automatically following CPZ withdrawal (Matsushima and Morell, 2001; Skripuletz et al, 2008; Makinodan et al, 2009; Werner et al, 2010). …”

Mitochondria as Crucial Players in Demyelinated Axons: Lessons from Neuropathology and Experimental Demyelination

“…Post-translational modification of mitochondrial respiratory chain subunits as well as transcriptionally regulated changes in mitochondrial function have been observed in animal models of MS [24–27]. Moreover, the addition of reactive oxygen species scavengers resulting in decreased optic nerve degeneration suggests a role for mitochondrial injury via oxidative stress and identifies mitochondrially targeted agents as potential therapy in MS [28].…”