Untargeted Metabolomic Profiling of Cuprizone-Induced Demyelination in Mouse Corpus Callosum by UPLC-Orbitrap/MS Reveals Potential Metabolic Biomarkers of CNS Demyelination Disorders

Multiple sclerosis (MS) is a neurodegenerative disorder characterized by periodic neuronal demyelination, which leads to a range of symptoms and eventually to disability. The goal of this research was to use UPLC-Orbitrap/MS to identify validated biomarkers and explore the metabolic mechanisms of MS in mice. Thirty-two C57BL/6 male mice were randomized into two groups that were fed either normal food or 0.2% CPZ for 11 weeks. The mouse demyelination model was assessed by LFB and the expression of MBP by immunofluorescence and immunohistochemistry. The metabolites of the corpus callosum were quantified using UPLC-Orbitrap/MS. The mouse pole climbing experiment was used to assess coordination ability. Multivariate statistical analysis was adopted for screening differential metabolites, and the ingenuity pathway analysis (IPA) was used to reveal the metabolite interaction network. We successfully established the demyelination model. The CPZ group slowly lost weight and showed an increased pole climbing time during feeding compared to the CON group. A total of 81 metabolites ( VIP > 1 and P < 0.05 ) were determined to be enriched in 24 metabolic pathways; 41 metabolites were markedly increased, while 40 metabolites were markedly decreased in the CPZ group. The IPA results revealed that these 81 biomarker metabolites were associated with neuregulin signaling, PI3K-AKT signaling, mTOR signaling, and ERK/MAPK signaling. KEGG pathway analysis showed that two significantly different metabolic pathways were enriched, namely, the glycerophospholipid and sphingolipid metabolic pathways, comprising a total of nine biomarkers. Receiver operating characteristic analysis showed that the metabolites (e.g., PE (16 : 0/22 : 6(4Z, 7Z, 10Z, 13Z, 16Z, 19Z)), PC (18 : 0/22 : 4(7Z, 10Z, 13Z, 16Z)), cytidine 5 ′ -diphosphocholine, PS (18 : 0/22 : 6(4Z, 7Z, 10Z, 13Z, 16Z, 19Z)), glycerol 3-phosphate, SM (d18 : 0/16 : 1(9Z)), Cer (d18:1/18 : 0), galabiosylceramide (d18:1/18 : 0), and GlcCer (d18:1/18 : 0)) have good discrimination ability for the CPZ group. In conclusion, the differential metabolites have great potential to serve as biomarkers of demyelinating diseases. In addition, we identified metabolic pathways associated with CPZ-induced demyelination pathogenesis, which provided a new perspective for understanding the relationship between metabolites and CNS demyelination pathogenesis.

Clinical Correlation of Multiple Sclerosis Immunopathologic Subtypes

Objective:To compare clinical characteristics across immunopathological subtypes of patients with multiple sclerosis.Methods:Immunopathological subtyping was performed on specimens from 547 patients with biopsy and/or autopsy confirmed CNS demyelination.Results:The frequency of immunopathological subtypes were pattern I (23%), II (56%), and III (22%). Immunopatterns were similar in terms of age at autopsy/biopsy (median age 41 years, range 4-83 years, p=0.16) and proportion female (54%, p=0.71). Median follow-up after symptom onset was 2.3 years (range 0-38y). In addition to being overrepresented among autopsy cases (45% vs. 19% in biopsy cohort, p<0.001), index attack-related disability was higher in pattern III vs. pattern II (median EDSS 4 vs. 3, p=0.02). Monophasic clinical course was more common in patients with pattern III than pattern I or II (59% vs. 33% vs. 32%, p<0.001). Similarly, patients with pattern III pathology were likely to have progressive disease compared to patients with patterns I or II, when followed for ≥5 years (24% overall, p=0.49), with no differences in long-term survival, despite a more fulminant attack presentation.Conclusion:All three immunopatterns can be detected in active lesions, although they are found less frequently later into the disease due to the lower number of active lesions. Pattern III is associated with a more fulminant initial attack than either pattern I or II. Biopsied patients appear to have similar long-term outcomes irrespective of their immunopatterns. Progressive disease is less associated with the initial immunopattern and suggests convergence into a final common pathway related to the chronically denuded axon.

CNS demyelination associated with immune dysregulation and a novel CTLA-4 variant

Background: The cytotoxic T-lymphocyte antigen-4 (CTLA-4) pathway acts as a negative immune regulator of T-cell activation and promotes self-tolerance. Case: We report the first case of biopsy-proven central nervous system inflammatory demyelination in the context of primary immunodeficiency and a novel CTLA-4 variant. Conclusion: This case has significant implications for the development of novel treatments for autoimmune conditions including multiple sclerosis and further emphasises the need for caution with clinical use of CTLA-4 immune checkpoint inhibitors in those with a history of inflammatory demyelination.

Subacute CNS Demyelination after Treatment with Immune Checkpoint Inhibitors

Immune checkpoints are molecules on the surface of leucocytes which modulate the amplitude of immune responses. Monoclonal antibodies blocking these molecules are known as immune checkpoints inhibitors (ICIs) and have been shown to unleash anti- tumour immunity and mediate durable cancer regressions. ICIs include ipilimumab which blocks the cytotoxic T-lymphocyte antigen-4 (CTLA-4), nivolumab and pembrolizumab which are both against the programmed cell death protein 1 (PD-1)1. The clinical use of these ICIs has led to significantly improved survival in patients with a variety of solid malignancies including melanoma.