Cellular Pharmacodynamics of Small Molecules in Lysosomal Storage Disorders

Cellular Pharmacodynamics of Small Molecules in Sanfilippo Disease(s) (MPS3) and Other Lysosomal Storage Disorders

The purpose of this study is to evaluate the effect of small molecule therapy in primary cells derived from patients with lysosomal storage disease. The study will focus on activity of small molecules, in terms of measurements enzymes activity and level of substrates accumulations. Also, the effects of small molecules on cell function, including autophagy-lysosomal pathways, metabolism, mitochondrial function and immune reaction will be investigated.

Lysosomal storage diseases (LSD) often cause severe disability and have a devastating effect on quality of life. The current standard of care of a majority of LSD is enzyme replacement therapy (ERT). ERT, however, becomes less effective during the advanced stages of a disease. Another therapy is substrate reduction therapy (SRT). For example, SRT therapy for Gaucher disease with small molecules acts on ceramide synthesis pathway by decreasing production of the substrate. But, none of the above therapies are effective for treatment of a neuropathic form of LSD. Neurodegenerative changes in the central nervous system are a major problem in Sanfilippo disease. They cause severe disability and behavioral disturbance. This is the main reason for the absence of therapeutic options for MPS3 (Sanfilippo) patients. The future of neuropathic form of LSD therapy may lie in small molecules acting as agents for enzyme-enhancement therapy (EET). EET is based on the ability of small molecules to fold the misfolded mutant enzyme, activate autophagy-lysosomal pathways or mitochondrial function. This treatment approach has the potential to cross the CNS and carries the potential to treat the neurological symptoms of Sanfilippo disease or other types of LSD.

The purpose of this study will evaluate the effect of small molecule therapy in primary cells derived from patients with lysosomal storage disease. The study will be focused on activity of small molecules, in terms of measurements enzymes activity and level of substrates accumulations. Also, the effects of small molecules on cell function, including autophagy-lysosomal pathways, metabolism, mitochondrial function and immune reaction will be investigated.

Inclusion Criteria:

Subjects with

1. confirmed diagnosis of any lysosomal storage disorder
2. family members with history of lysosomal storage disorders

Exclusion Criteria:

Subjects excluded from the study include those who:

1. present with severe cognitive deficits impairing decision making
2. are unable to or for whom it is medically unsafe to withdraw from their current medications, such as subjects on SSRI s and other psychoactive drugs. The subjects on SSRIs may be included in the study only with an approval from the prescribing physician to discontinue their medications temporarily for the study.
3. are pregnant or nursing. All women of child bearing potential will undergo a pregnancy test.
4. have a history of neurologic conditions such as stroke or any focal brain lesion that may result in parkinonian manifestations. Individuals with such MRI findings will be excluded from the study.