Prevention of Neurocognitive Deficiency in Mucopolysaccharidosis Type II Mice by Central Nervous System-Directed, AAV9-Mediated Iduronate Sulfatase Gene Transfer.

Abstract

Mucopolysaccharidosis type II (MPS II; Hunter syndrome) is a rare X-linked recessive lysosomal disorder caused by defective iduronate-2-sulfatase (IDS), resulting in accumulation of heparan sulfate and dermatan sulfate glycosaminoglycans (GAGs). Enzyme replacement is the only Food and Drug Administration-approved therapy available for MPS II, but it is expensive and does not improve neurologic outcomes in MPS II patients. This study evaluated the effectiveness of adeno-associated virus (AAV) vector encoding human IDS delivered intracerebroventricularly in a murine model of MPS II. Supraphysiological levels of IDS were observed in the circulation (160-fold higher than wild type) for at least 28 weeks post injection and in most tested peripheral organs (up to 270-fold) at 10 months post injection. In contrast, only low levels of IDS were observed (7-40% of wild type) in all areas of the brain. Sustained IDS expression had a profound effect on normalization of GAG in all tested tissues and on prevention of hepatomegaly. Additionally, sustained IDS expression in the central nervous system (CNS) had a prominent effect in preventing neurocognitive deficit in MPS II mice treated at 2 months of age. This study demonstrates that CNS-directed, AAV9 mediated gene transfer is a potentially effective treatment for Hunter syndrome, as well as other monogenic disorders with neurologic involvement.

• Authors: Kanut Laoharawee, Kelly M Podetz-Pedersen, Tam T Nguyen, Laura B Evenstar, Kelley F Kitto, Zhenhong Nan, Carolyn A Fairbanks, Walter C Low, Karen F Kozarsky, R Scott McIvor
• Journal: Human gene therapy (Hum Gene Ther) Vol. 28 Issue 8 Pg. 626-638 (08 2017) ISSN: 1557-7422 [Electronic] United States
• PMID: 28478695 (Publication Type: Journal Article, Research Support, Non-U.S. Gov't)

Chemical References

• Glycosaminoglycans
• Iduronate Sulfatase

Topics

• Animals
• Central Nervous System (metabolism)
• Cognition
• Dependovirus (genetics)
• Disease Models, Animal
• Enzyme Activation
• Female
• Gene Expression
• Gene Order
• Gene Transfer Techniques
• Genetic Therapy
• Genetic Vectors (administration & dosage, genetics)
• Glycosaminoglycans (metabolism)
• Humans
• Iduronate Sulfatase (blood, genetics, metabolism)
• Male
• Mice
• Mucopolysaccharidosis II (blood, genetics, psychology, therapy)
• Neuropsychological Tests
• Pilot Projects
• Time Factors
• Tissue Distribution
• Transduction, Genetic