In vitro accumulation of glucocerebroside in neuroblastoma cells: a model for study of Gaucher disease pathobiology.

Abstract

Gaucher disease is the most common lysosomal glycosphingolipid storage disease; decreased activity of glucosylceramide beta-glucosidase (GCase) results in the accumulation of glucocerebroside (GlcCer) in macrophage-derived cells. The most devastating types of Gaucher disease also involve neuronopathology, thought to be mediated by intracellular GlcCer accumulation in the brain. In this study, we developed an in vitro neuronal cell model for accumulation of endogenous GlcCer to enable studies on the cellular basis for the neuronopathology of this disease. A human neuroblastoma cell line (SH-SY5Y) was selected because it produced appreciable GCase. When these cells were treated with conduritol B epoxide (CBE), a competitive, irreversible inhibitor of this enzyme, GCase levels fell precipitously, while other lysosomal hydrolase levels were unaffected. Relative to untreated control cells, the CBE-treated cells accumulated higher levels of GlcCer, but not other related glycolipids, over time. Thus, this in vitro system displayed many essential biological parameters relevant for studies on cellular events responsible for the neurologic damage that occurs in some types of Gaucher disease. This model should also be useful in investigations of the normal role of sphingolipids in neuronal cell function.