Lipidomic Evaluation of Feline Neurologic Disease after AAV Gene Therapy

摘要

{GM1} gangliosidosis is a fatal lysosomal disorder, for which there is no effective treatment. Adeno-associated virus (AAV) gene therapy in {GM1} cats has resulted in a greater than 6-fold increase in lifespan, with many cats remaining alive at 5.7 years of age, with minimal clinical signs. Glycolipids are the principal storage product in {GM1} gangliosidosis whose pathogenic mechanism is not completely understood. Targeted lipidomics analysis was performed to better define disease mechanisms and identify markers of disease progression for upcoming clinical trials in humans. 36 sphingolipids and subspecies associated with ganglioside biosynthesis were tested in the cerebrospinal fluid of untreated {GM1} cats at a humane endpoint (～8?months), AAV-treated {GM1} cats (～5 years old), and normal adult controls. In untreated {GM1} cats, significant alterations were noted in 16?sphingolipid species, including gangliosides (GM1 and GM3), lactosylceramides, ceramides, sphingomyelins, monohexosylceramides, and sulfatides. Variable degrees of correction in many lipid metabolites reflected the efficacy of {AAV} gene therapy. Sphingolipid levels were highly predictive of neurologic disease progression, with 11 metabolites having a coefficient of determination (R2) 0.75. Also, a specific detergent additive significantly increased the recovery of certain lipid species in cerebrospinal fluid samples. This report demonstrates the methodology and utility of targeted lipidomics to examine the pathophysiology of lipid storage disorders.