Caprine mucopolysaccharidosis IIID: a preliminary trial of enzyme replacement therapy.
Mucopolysaccharidosis type IIID (MPS IIID) is a lysosomal storage disorder resulting from lack of activity of the lysosomal hydrolase N-acetylglucosamine 6-sulfatase (6S) (EC 3.1.6.14). The syndrome is associated with systemic and central nervous system (CNS) heparan sulfate glycosaminoglycan (HS-GAG) accumulation, secondary storage of lipids, and severe, progressive dementia. In this investigation, caprine MPS IIID, established as a large animal model for the human disease, was used to evaluate the efficacy of enzyme replacement therapy (ERT). Recombinant caprine 6S (rc6S) (1 mg/kg/dose) was administered intravenously to one MPS IIID goat kid at 2, 3, and 4 wks of age. Five days after the last dose, the uronic acid (UA) content and the composition of uncatabolized HS-GAG fractions in the brain of the ERT-treated MPS IIID kid were similar to those from a control, untreated MPS IIID animal. However, hepatic uronic acid levels in the treated MPS IIID kid were approximately 90% lower than those in the untreated MPS IIID control; whereas the composition of the residual hepatic HS-GAG was identical to that in the untreated animal. Marked reduction of lysosomal storage vacuoles in hepatic cells of the treated MPS IIID kid was observed, but ERT had no effect on CNS lesions. No residual 6S activity was detected in brain or liver. This preliminary investigation indicates that other treatment regimens will be necessary to ameliorate MPS III-related CNS lesions.
Downs-Kelly
E
E
Division of Human Pathology, College of Human Medicine and College of Osteopathic Medicine, Michigan State University, East Lansing 48824, USA.
Jones
M Z
MZ
Alroy
J
J
Cavanagh
K T
KT
King
B
B
Lucas
R E
RE
Baker
J C
JC
Kraemer
S A
SA
Hopwood
J J
JJ
D000818:Animals; D001921:Brain / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D004195:Disease Models, Animal; D004591:Electrophoresis, Polyacrylamide Gel; D005260:Female; D006025:Glycosaminoglycans / Q000378:metabolism; D006041:Goats; D006497:Heparan Sulfate / Q000378:metabolism; D022781:Hepatocytes / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D008099:Liver / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D008297:Male; D009084:Mucopolysaccharidosis III / Q000188:drug therapy* / Q000201:enzymology / Q000503:physiopathology; D009474:Neurons / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000235:genetics / Q000494:pharmacology*; D013429:Sulfatases / Q000235:genetics / Q000378:metabolism / Q000494:pharmacology*; D016896:Treatment Outcome; D014574:Uronic Acids / Q000378:metabolism
D006025:Glycosaminoglycans; D006497:Heparan Sulfate; D011994:Recombinant Proteins; D013429:Sulfatases; D014574:Uronic Acids; C018719:N-acetylglucosamine-6-sulfatase