| Summary: | Mucopolysaccharidosis type IIIB (MPS IIIB), or Sanfilippo Syndrome type B, is a lysosomal storage disorder caused by mutations in the NAGLU gene, which encodes the enzyme alpha-N-acetylglucosaminidase, responsible for the degradation of heparan sulfate. Progressive accumulation of undegraded glycosaminoglycans primarily affects the central nervous system, resulting in severe neurodegeneration. Cellular findings reveal impaired intracellular trafficking, especially within the Golgi apparatus, linked to GM130 depletion and accumulation of GM2 and GM3 gangliosides. Endocytic vesicles fail to properly fuse with lysosomes due to genetic defects, disrupting lysosomal degradation. This contributes to oxidative stress, mitochondrial dysfunction, and mitophagy failure, which collectively drive neuronal apoptosis. MPS IIIB shares pathways with Alzheimer’s and Parkinson’s, suggesting cellular aging processes. Given the lack of specific treatment, modulation of inflammatory pathways such as TLR4 emerges as a potential therapeutic strategy.
|