Immunotherapy targeting plasma ASM is protective in a mouse model of Alzheimer’s disease

Abstract

Acid sphingomyelinase (ASM) has been implicated in neurodegenerative disease pathology, including Alzheimer’s disease (AD). However, the specific role of plasma ASM in promoting these pathologies is poorly understood. Herein, we explore plasma ASM as a circulating factor that accelerates neuropathological features in AD by exposing young APP/PS1 mice to the blood of mice overexpressing ASM, through parabiotic surgery. Elevated plasma ASM was found to enhance several neuropathological features in the young APP/PS1 mice by mediating the differentiation of blood-derived, pathogenic Th17 cells. Antibody-based immunotherapy targeting plasma ASM showed efficient inhibition of ASM activity in the blood of APP/PS1 mice and, interestingly, led to prophylactic effects on neuropathological features by suppressing pathogenic Th17 cells. Our data reveals insights into the potential pathogenic mechanisms underlying AD and highlights ASM-targeting immunotherapy as a potential strategy for further investigation.

Acid sphingomyelinase (ASM) is a sphingolipid metabolizing enzyme that catalyzes the hydrolysis of sphingomyelin to ceramide, and previous work has shown it is upregulated in models of Alzheimer’s disease. Here the authors demonstrate in a mouse model of Alzheimer’s disease that antibody-based immunotherapy targeting plasma ASM resulted in attenuated neuropathological features by suppressing pathogenic Th17 cells.