No abstract

Nonalcoholic fatty liver disease (NAFLD) is associated with obesity, insulin resistance, and type 2 diabetes. The hyperinsulinemia that occurs as a consequence of insulin resistance is thought to be an important contributor to the development of fatty liver. We have shown that the iminosugar N-(5'-adamantane-1'-yl-methoxy)-pentyl-1-deoxynojirimycin (AMP-DNM), an inhibitor of the enzyme glucosylceramide synthase, is a potent enhancer of insulin signaling in rodent models for insulin resistance and type 2 diabetes. The present study was designed to assess the impact of AMP-DNM on insulin levels, liver triglyceride synthesis, and gene expression profile. Treatment of ob/ob mice with AMP-DNM restored insulin signaling in the liver, corrected blood glucose values to levels found in lean mice, and decreased insulin concentration. The expression of sterol regulatory element-binding protein 1c target genes involved in fatty acid synthesis normalized. AMP-DNM treatment significantly reduced liver to body weight ratio and reversed hepatic steatosis, comprising fat as well as inflammatory markers. In addition, AMP-DNM treatment corrected to a large extent the gene expression profile of ob/ob mice livers toward the profile of lean mice. Conclusion: Pharmacological lowering of glycosphingolipids with the iminosugar AMP-DNM is a promising approach to restore insulin signaling and improve glucose homeostasis as well as hepatic steatosis.

Enzyme replacement therapy (ERT) with recombinant α‐galactosidase A (r‐αGAL A) for the treatment of Fabry disease has been available for over 15 years. Long‐term treatment may slow down disease progression, but cardiac, renal, and cerebral complications still develop in most patients. In addition, lifelong intravenous treatment is burdensome. Therefore, several new treatment approaches have been explored over the past decade. Chaperone therapy (Migalastat; 1‐deoxygalactonojirimycin) is the only other currently approved therapy for Fabry disease. This oral small molecule aims to improve enzyme activity of mutated α‐galactosidase A and can only be used in patients with specific mutations. Treatments currently under evaluation in (pre)clinical trials are second generation enzyme replacement therapies (Pegunigalsidase‐alfa, Moss‐aGal), substrate reduction therapies (Venglustat and Lucerastat), mRNA‐ and gene‐based therapy. This review summarises the knowledge on currently available and potential future options for the treatment of Fabry disease.