Inflammatory
demyelination and axonal injury in the central nervous system (CNS) are cardinal features of progressive
multiple sclerosis (MS), and linked to activated brain macrophage-like cells (BMCs) including resident microglia and trafficking macrophages. Caspase-1 is a pivotal mediator of
inflammation and cell death in the CNS. We investigated the effects of caspase-1 activation and its regulation in models of MS. Brains from progressive MS and non-MS patients, as well as cultured human oligodendrocytes were examined by transcriptomic and morphological methods. Next generation transcriptional sequencing of progressive MS compared to non-MS patients' normal appearing white matter (NAWM) showed induction of caspase-1 as well as other
inflammasome-associated genes with concurrent suppression of neuron-specific genes. Oligodendrocytes exposed to TNFα exhibited upregulation of caspase-1 with myelin gene suppression in a cell differentiation state-dependent manner. Brains from
cuprizone-exposed mice treated by intranasal delivery of the
caspase-1 inhibitor,
VX-765 or its vehicle, were investigated in morphological and molecular studies, as well as by fluorodeoxyglucose-positron emission tomography (FDG-PET) imaging.
Cuprizone exposure resulted in BMC and caspase-1 activation accompanied by
demyelination and axonal injury, which was abrogated by intranasal
VX-765 treatment. FDG-PET imaging revealed suppressed
glucose metabolism in the thalamus, hippocampus and cortex of
cuprizone-exposed mice that was restored with
VX-765 treatment. These studies highlight the caspase-1 dependent interactions between
inflammation,
demyelination, and
glucose metabolism in progressive MS and associated models. Intranasal delivery of an anti-caspase-1
therapy represents a promising therapeutic approach for progressive MS and other neuro-inflammatory diseases.