The Response of the Glycerophosphocholine Metabolite Lipidome to Experimental Autoimmune Encephalomyelitis and Cycling Female Sex Hormones in the Hippocampus and Temporal-Parietal-Entorhinal Cortex of Female Mice

Abstract

Recently, several glycerophosphocholine biomarkers for multiple sclerosis were discovered in serum, plasma, and cerebrospinal fluid; little is known, however, about brain glycerophosphocholine metabolism during multiple sclerosis despite evidence that lysophosphocholines can elicit demyelination experimentally. Using a lipidomics approach, glycerophosphocholine metabolites in the hippocampus and temporal-parietal-entorhinal cortex of female C57BL/6J mice subjected to experimental autoimmune encephalomyelitis (a mouse model of multiple sclerosis) were quantified and compared to metabolite levels in healthy mice. To control for potential hormonal regulation, glycerophosphocholine metabolites from these same regions were quantified across the estrous cycle in healthy female N5 C57BL/6J x C3h/HeJ mice. I found that several critical glycerophosphocholine metabolites were significantly decreased over the course of experimental autoimmune encephalomyelitis in both brain regions, although the hippocampus was more affected compared to the temporal-parietal-entorhinal cortex. Similarly, hippocampal glycerophosphocholine metabolism was more responsive to fluctuations in female sex hormones than the cortex. Overall, these results suggest that glycerophosphocholine metabolism differs not only between brain regions, but also between conditions, namely experimental autoimmune encephalomyelitis and the estrous cycle.