Mucopolysaccharidoses (MPSs) are inherited
metabolic diseases caused by the deficiency of lysosomal
enzymes needed to catabolize
glycosaminoglycans (GAGs). Four therapeutic options are currently considered:
enzyme replacement therapy, substrate reduction therapy, gene
therapy, and
hematopoietic stem cell transplantation. However, while some of them exhibit limited clinical efficacy and require high costs, others are still in development. Therefore, alternative treatments for MPSs need to be explored. Here we describe an innovative therapeutic approach based on the use of a
recombinant protein that is able to bind the excess of extracellular accumulated
heparan sulfate (HS). We demonstrate that this
protein is able to reduce lysosomal defects in primary fibroblasts from MPS I and
MPS IIIB patients. We also show that, by masking the excess of extracellular accumulated HS in MPS fibroblasts,
fibroblast growth factor (FGF) signal transduction can be positively modulated. We, therefore, suggest the use of a competitive binding molecule for HS in MPSs as an alternative strategy to prevent the detrimental extracellular substrate storage.