Cats with genetic Gm2 gangliosidosis will be used to develop enzyme replacement methodologies applicable to the treatment of human lysosomal storage diseases associated with mental retardation. Depression of glycosyl-mediated hepatic clearance and enhancement of charge-dependent cellular uptake of human placental Beta-hexosaminidase will be obtained by modifying its carbohydrate chain composition and its net charge. The cellular distribution of native and modified enzymes in visceral organs will be compared using immunofluorescence microscopy. The catabolic activity of the enzymes will be studied in vitro and in vivo. Reversible blood brain barrier permeability will be obtained by controlled cerebral gas embolism and by hyperosmotic infusions. Delivery of native and modified enzymes to the CNS parenchyma, and their uptake by neural cells will be studied in both cases by immunofluorescence microscopy. Neuronal uptake and catabolic effects of native and modified placental enzyme and of Beta-hexosaminidase from plasma and cell culture fluids will be studied in short-term cultures of isolated cortical neurons. These cells will also be used to study selected aspects of ganglioside metabolism. The appropriate combination of methodologies will be applied in affected kittens; the effects on ganglioside storage, aberrant neuronal morphology, and clinical neurologic manifestations will be assessed.

Agency
National Institute of Health (NIH)
Institute
National Institute of Neurological Disorders and Stroke (NINDS)
Type
Research Project (R01)
Project #
5R01NS021404-02
Application #
3402498
Study Section
Neurological Sciences Subcommittee 1 (NLS)
Project Start
1984-04-01
Project End
1987-06-30
Budget Start
1985-07-01
Budget End
1986-06-30
Support Year
2
Fiscal Year
1985
Total Cost
Indirect Cost
Name
North Shore University Hospital
Department
Type
DUNS #
City
Manhasset
State
NY
Country
United States
Zip Code
11030
Rattazzi, M C; Dobrenis, K (2001) Treatment of GM2 gangliosidosis: past experiences, implications, and future prospects. Adv Genet 44:317-39
Dobrenis, K; Joseph, A; Rattazzi, M C (1992) Neuronal lysosomal enzyme replacement using fragment C of tetanus toxin. Proc Natl Acad Sci U S A 89:2297-301
Walkley, S U; Baker, H J; Rattazzi, M C et al. (1991) Neuroaxonal dystrophy in neuronal storage disorders: evidence for major GABAergic neuron involvement. J Neurol Sci 104:1-8
Lew, D B; Rattazzi, M C (1991) Mitogenic effect of lysosomal hydrolases on bovine tracheal myocytes in culture. J Clin Invest 88:1969-75
Walkley, S U; Wurzelmann, S; Rattazzi, M C et al. (1990) Distribution of ectopic neurite growth and other geometrical distortions of CNS neurons in feline GM2 gangliosidosis. Brain Res 510:63-73
Walkley, S U; Baker, H J; Rattazzi, M C (1990) Initiation and growth of ectopic neurites and meganeurites during postnatal cortical development in ganglioside storage disease. Brain Res Dev Brain Res 51:167-78
Rattazzi, M C; Dobrenis, K; Joseph, A et al. (1987) Modified beta-D-N-acetylhexosaminidase isozymes for enzyme replacement in GM2 gangliosidosis. Isozymes Curr Top Biol Med Res 16:49-65