title: Determination of the role of injection site on the efficacy of intra-CSF enzyme replacement therapy in MPS IIIA mice.
abstract: MPS IIIA is an inherited neurodegenerative lysosomal storage disorder characterized by cognitive impairment, sleep-wake cycle disturbance, speech difficulties, eventual mental regression and early death. Neuropathological changes include accumulation of heparan sulfate and glycolipids, neuroinflammation and degeneration. Pre-clinical animal studies indicate that replacement of the deficient enzyme, sulfamidase, via intra-cerebrospinal fluid (CSF) injection is a clinically-relevant treatment approach, reducing neuropathological changes and improving symptoms. Given that there are several routes of administration of enzyme into the CSF (intrathecal lumbar, cisternal and ventricular), determining the effectiveness of each injection strategy is crucial in order to provide the best outcome for patients. We delivered recombinant human sulfamidase (rhSGSH) to a congenic mouse model of MPS IIIA via each of the three routes. Mice were euthanized 24h or one-week post-injection; the distribution of enzyme within the brain and spinal cord parenchyma was investigated, and the impact on primary substrate levels and other pathological lesions determined. Both ventricular and cisternal injection of rhSGSH enable enzyme delivery to brain and spinal cord regions, with the former mediating large, statistically significant decreases in substrate levels and reducing microglial activation. The single lumbar CSF infusion permitted more restricted enzyme delivery, with no reduction in substrate levels and little change in other disease-related lesions in brain tissue. While the ventricular route is the most invasive of the three methods, this strategy may enable the widest distribution of enzyme within the brain, and thus requires further exploration.
authors: Lysosomal Diseases Research Unit, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, South Australia 5001, Australia.
authors: Helen
authors: H
authors: Beard
authors: Lysosomal Diseases Research Unit, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, South Australia 5001, Australia.
authors: Amanda J
authors: AJ
authors: Luck
authors: Lysosomal Diseases Research Unit, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, South Australia 5001, Australia.
authors: Sofia
authors: S
authors: Hassiotis
authors: Lysosomal Diseases Research Unit, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, South Australia 5001, Australia.
authors: Barbara
authors: B
authors: King
authors: Lysosomal Diseases Research Unit, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, South Australia 5001, Australia.
authors: Paul J
authors: PJ
authors: Trim
authors: Lysosomal Diseases Research Unit, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, South Australia 5001, Australia.
authors: Marten F
authors: MF
authors: Snel
authors: Lysosomal Diseases Research Unit, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, South Australia 5001, Australia.
authors: John J
authors: JJ
authors: Hopwood
authors: Lysosomal Diseases Research Unit, South Australian Health and Medical Research Institute, PO Box 11060, Adelaide, South Australia 5001, Australia.
authors: Kim M
authors: KM
authors: Hemsley
mesh_terms: D000818:Animals; D001921:Brain / Q000473:pathology; D002946:Cisterna Magna; D004195:Disease Models, Animal; D004333:Drug Administration Routes; D056947:Enzyme Replacement Therapy / Q000379:methods*; D006497:Heparan Sulfate / Q000134:cerebrospinal fluid; D006801:Humans; D006867:Hydrolases / Q000008:administration & dosage* / Q000134:cerebrospinal fluid*; D057967:Infusions, Intraventricular; D060186:Infusions, Spinal; D007267:Injections; D007276:Injections, Intraventricular; D051379:Mice; D020297:Mice, Congenic; D008810:Mice, Inbred C57BL; D009084:Mucopolysaccharidosis III / Q000188:drug therapy* / Q000235:genetics*; D011994:Recombinant Proteins / Q000008:administration & dosage / Q000134:cerebrospinal fluid
chemical_list: D006497:Heparan Sulfate; D006867:Hydrolases; D011994:Recombinant Proteins; C022708:N-sulfoglucosamine sulfohydrolase
keywords: Cerebrospinal fluid; Enzyme replacement therapy; Lysosomal storage disorder; MPS IIIA; Mouse; Sanfilippo syndrome