Alteration in Redox Homeostasis in Early-Onset Tay-Sachs Disease Mouse Model

Abstract

Tay-Sachs disease is an autosomal recessively inherited lysosomal disorder. It is caused by mutations on the HEXA gene encoding α-subunit of β-Hexosaminidase A enzyme. The enzyme normally catalyzes GM2 to GM3 conversion but when it is absent or dysfunctional the GM2 degradation is interrupted. The undegraded GM2 ganglioside is progressively accumulated especially in neurons and causes neurodegenaration at the end. The Hexa−/− mice generated as Tay-Sachs model was nearly normal and a bypass mechanism mediated by a sialidase was suggested. Recently we determined that Neu3 sialidase involves in ganglioside degradation in the Tay-Sachs disease pathology and the Hexa−/-Neu3−/− mice mimic the neuropathologic and clinical phenotype of the disease. It was reported that oxidative stress is triggered in neurodegenerative diseases and several lysosomal disorders. It is caused by the imbalance between antioxidant defence mechanism and production of reactive oxygen species (ROS). ROS have high chemical reactivity which react and damage DNA, protein, carbohydrates and lipids.