Submitted on April 6, 2005
Revised on August 10, 2005
Accepted on August 24, 2005
A novel sphingomyelin analogue that inhibits sphingomyelin hydrolysis and synthesis, increases cellular ceramide, and leads to cell death
Peter I. Darroch, Arie Dagan, Tami Granot, Xingxuan He, Shimon Gatt, and Edward H. Schuchman
Department of Human Genetics, Mount Sinai School of Medicine, New York, NY 10029
Corresponding Author: edward.schuchman{at}mssm.edu
Herein we report the synthesis and characterization of a novel thiourea derivative of sphingomyelin (AD2765). In vitro assays using pure enzyme and/or cell extracts revealed that this compound inhibited the hydrolysis of BODIPY-conjugated or [14C]-labeled sphingomyelin by acid sphingomyelinase (ASM) and Mg+2-dependent neutral sphingomyelinase. Studies in normal human skin fibroblasts further revealed that AD2765 was taken up by cells and inhibited the hydrolysis of BODIPY-conjugated sphingomyelin in situ. In situ and in vitro studies also showed that this compound inhibited the synthesis of sphingomyelin from BODIPY-conjugated ceramide. The specificity of AD2765 for enzymes involved in sphingomyelin metabolism was demonstrated by the fact that it had no effect on the hydrolysis of BODIPY-conjugated ceramide by acid ceramidase, nor the synthesis of BODIPY-conjugated glucosylceramide from BODIPY-conjugated ceramide. The overall effect of AD2765 on sphingomyelin metabolism was concentration dependent, and treatment of normal human skin fibroblasts or cancer cells with this compound at concentrations >10 
M led to an increase in cellular ceramide and cell death. Thus, AD2765 might be used to manipulate sphingomyelin metabolism in various ways, potentially to reduce substrate accumulation in cells from Types A and B Niemann-Pick disease patients, and/or to affect the growth of human cancer cells.
CiteULike 
Complore 
Connotea 
Del.icio.us 
Digg 
Reddit 
Technorati What's this?
