ABSTRACT
Abstract Mucopolysaccharidosis type IIIA (MPS IIIA) is a lysosomal storage disorder due to the deficient activity of sulfamidase (SGSH). Traditionally, measurement of this enzymatic activity has been performed using a fluorescently (4-MU) labeled glycoside substrate. While this substrate is inexpensive and readily available, the current method requires a 2-step procedure that is performed over 2 days. Here we report a new and simplified procedure using the 4-MU substrate. Major advantages of this assay method over the existing fluorescent method include a single step vs. 2-step procedure, an incubation time of 1 hour, and high sensitivity. The reaction is also run on UPLC equipment, which is available in most research labs and permits separation of the endogenous, autofluorescent material from the 4-MU signal. This assay method was developed using the MPS IIIA mouse model, and was validated using mouse plasma, liver and brain extracts, and dried blood spots. Human MPS IIIA skin fibroblasts and dried blood spots also were used to validate the method.
ABSTRACT
Abstract Lysosomes were originally described in the early 1950s by de Duve who was also the first to recognize the importance of these organelles in human disease. We know now that lysosomes are involved in numerous biological processes, and abnormalities in lysosomal function may result in a broad range of diseases. This review will briefly discuss the role of lysosomes in inflammation and how disruption of normal lysosomal function in the lysosomal storage diseases (LSDs) leads to abnormalities in inflammation and immunity.