Figure 4.
Reduction in lysosomal storage material following intranasal administration of AAV9-IDUA. Animals were sacrificed 5 months after intranasal instillation, and histopathological analysis of tissue sections for storage material was carried out using toluidine blue staining, as described in the Materials and Methods. Arrows indicate cytoplasmic vacuolization. Extensive vacuolization was seen in all tissues in MPS I animals, while AAV9-IDUA-treated animals show mixed results. Animal 1 exhibited no storage-related pathology in the olfactory bulb and had reduced storage material in all other parts of the brain compared to untreated controls. Animal 2 had no observable storage-related pathology in any part of the brain (n = 2, all groups).