“Pharmacological restoration of ASM to the normal range improves pathology in AD mice The ASM-mediated lysosomal/autophagic dysfunction in AD prompted us to examine possible therapeutic implications of this pathway. To decrease ASM in APP/PS1 mice, we undertook pharmacological inhibition using amitriptyline-hydrochloride (AMI) for 4 mo (Fig. 9 A). AMI is a known inhibitor of ASM that can cross the blood–brain barrier. At 9 mo of age, AMI-treated APP/PS1 mice exhibited decreased ASM activity compared with vehicle-treated mice (Fig. 9 B). Other sphingolipid metabolites were not changed (Fig. 9 C). Aβ levels were decreased in the AMI-treated APP/PS1 mice compared with the nontreated littermates.”

“ASM activity is known to be increased by environmental stress and in various diseases, and is elevated in AD patients (He and Schuchman, 2012). One downstream consequence of increased ASM is elevated ceramide, contributing to cell death, inflammation, and other common disease findings. Although elevated ASM is known to occur in AD, the cellular mechanisms that link ASM and AD have not been fully characterized. The data presented here suggest a previously unknown role of ASM in the down-regulation of lysosomal biogenesis and inhibition of lysosome-dependent autophagic proteolysis. The findings also establish proof of concept for ASM inhibitor therapy in AD.”