Erschienen in:
27.04.2017 | Original Article
A novel conditional Sgsh knockout mouse model recapitulates phenotypic and neuropathic deficits of Sanfilippo syndrome
verfasst von:
Adeline A. Lau, Barbara M. King, Carly L. Thorsen, Sofia Hassiotis, Helen Beard, Paul J. Trim, Lauren S. Whyte, Sarah J. Tamang, Stephen K. Duplock, Marten F. Snel, John J. Hopwood, Kim M. Hemsley
Erschienen in:
Journal of Inherited Metabolic Disease
|
Ausgabe 5/2017
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Abstract
Mucopolysaccharidosis (MPS) type IIIA, or Sanfilippo syndrome, is a neurodegenerative lysosomal storage disorder caused by a deficiency of the lysosomal enzyme N-sulfoglucosamine sulfohydrolase (SGSH), involved in the catabolism of heparan sulfate. The clinical spectrum is broad and the age of symptom onset and the degree of preservation of cognitive and motor functions appears greatly influenced by genotype. To explore this further, we generated a conditional knockout (Sgsh
KO
) mouse model with ubiquitous Sgsh deletion, and compared the clinical and pathological phenotype with that of the spontaneous Sgsh
D31N
MPS-IIIA mouse model. Phenotypic deficits were noted in Sgsh
KO
mice prior to Sgsh
D31N
mice, however these outcomes did not correlate with any shift in the time of appearance nor rate of accumulation of primary (heparan sulfate) or secondary substrates (GM2/GM3 gangliosides). Other disease lesions (elevations in lysosomal integral membrane protein-II expression, reactive astrocytosis and appearance of ubiquitin-positive inclusions) were also comparable between affected mouse strains. This suggests that gross substrate storage and these neuropathological markers are neither primary determinants, nor good biomarkers/indicators of symptom generation, confirming similar observations made recently in MPS-IIIA patients. The Sgsh
KO
mouse will be a useful tool for elucidation of the neurological basis of disease and assessment of the clinical efficacy of new treatments for Sanfilippo syndrome.